diff --git a/src/bench/block_assemble.cpp b/src/bench/block_assemble.cpp
index a1defe85a..70ccbed13 100644
--- a/src/bench/block_assemble.cpp
+++ b/src/bench/block_assemble.cpp
@@ -1,67 +1,65 @@
 // Copyright (c) 2011-2017 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <bench/bench.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <script/standard.h>
 #include <test/util/mining.h>
 #include <test/util/setup_common.h>
 #include <test/util/wallet.h>
 #include <txmempool.h>
 #include <validation.h>
 
 #include <vector>
 
 static void AssembleBlock(benchmark::Bench &bench) {
     const Config &config = GetConfig();
     TestingSetup test_setup{
         CBaseChainParams::REGTEST,
         /* extra_args */
         {
             "-nodebuglogfile",
             "-nodebug",
         },
     };
 
     const CScript redeemScript = CScript() << OP_DROP << OP_TRUE;
     const CScript SCRIPT_PUB =
         CScript() << OP_HASH160 << ToByteVector(CScriptID(redeemScript))
                   << OP_EQUAL;
 
     const CScript scriptSig = CScript() << std::vector<uint8_t>(100, 0xff)
                                         << ToByteVector(redeemScript);
 
     // Collect some loose transactions that spend the coinbases of our mined
     // blocks
     constexpr size_t NUM_BLOCKS{200};
     std::array<CTransactionRef, NUM_BLOCKS - COINBASE_MATURITY + 1> txs;
     for (size_t b = 0; b < NUM_BLOCKS; ++b) {
         CMutableTransaction tx;
         tx.vin.push_back(MineBlock(config, test_setup.m_node, SCRIPT_PUB));
         tx.vin.back().scriptSig = scriptSig;
         tx.vout.emplace_back(1337 * SATOSHI, SCRIPT_PUB);
         if (NUM_BLOCKS - b >= COINBASE_MATURITY) {
             txs.at(b) = MakeTransactionRef(tx);
         }
     }
 
     {
         // Required for ::AcceptToMemoryPool.
         LOCK(::cs_main);
 
         for (const auto &txr : txs) {
-            TxValidationState vstate;
-            bool ret{::AcceptToMemoryPool(
+            const MempoolAcceptResult res = ::AcceptToMemoryPool(
                 test_setup.m_node.chainman->ActiveChainstate(), config,
-                *test_setup.m_node.mempool, vstate, txr,
-                false /* bypass_limits */)};
-            assert(ret);
+                *test_setup.m_node.mempool, txr, false /* bypass_limits */);
+            assert(res.m_result_type == MempoolAcceptResult::ResultType::VALID);
         }
     }
 
     bench.run([&] { PrepareBlock(config, test_setup.m_node, SCRIPT_PUB); });
 }
 
 BENCHMARK(AssembleBlock);
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 59d892c07..8c6d27ba1 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1,7126 +1,7129 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <net_processing.h>
 
 #include <addrman.h>
 #include <avalanche/avalanche.h>
 #include <avalanche/compactproofs.h>
 #include <avalanche/peermanager.h>
 #include <avalanche/processor.h>
 #include <avalanche/proof.h>
 #include <avalanche/validation.h>
 #include <banman.h>
 #include <blockdb.h>
 #include <blockencodings.h>
 #include <blockfilter.h>
 #include <blockvalidity.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
 #include <invrequest.h>
 #include <merkleblock.h>
 #include <netbase.h>
 #include <netmessagemaker.h>
 #include <node/blockstorage.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <reverse_iterator.h>
 #include <scheduler.h>
 #include <streams.h>
 #include <tinyformat.h>
 #include <txmempool.h>
 #include <txorphanage.h>
 #include <util/check.h> // For NDEBUG compile time check
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validation.h>
 
 #include <algorithm>
 #include <functional>
 #include <memory>
 #include <typeinfo>
 
 /** How long to cache transactions in mapRelay for normal relay */
 static constexpr auto RELAY_TX_CACHE_TIME = 15min;
 /**
  * How long a transaction has to be in the mempool before it can
  * unconditionally be relayed (even when not in mapRelay).
  */
 static constexpr auto UNCONDITIONAL_RELAY_DELAY = 2min;
 /**
  * Headers download timeout.
  * Timeout = base + per_header * (expected number of headers)
  */
 static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_BASE = 15min;
 static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER = 1ms;
 /**
  * Protect at least this many outbound peers from disconnection due to
  * slow/behind headers chain.
  */
 static constexpr int32_t MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT = 4;
 /**
  * Timeout for (unprotected) outbound peers to sync to our chainwork, in
  * seconds.
  */
 // 20 minutes
 static constexpr int64_t CHAIN_SYNC_TIMEOUT = 20 * 60;
 /** How frequently to check for stale tips, in seconds */
 // 10 minutes
 static constexpr int64_t STALE_CHECK_INTERVAL = 10 * 60;
 /**
  * How frequently to check for extra outbound peers and disconnect, in seconds.
  */
 static constexpr int64_t EXTRA_PEER_CHECK_INTERVAL = 45;
 /**
  * Minimum time an outbound-peer-eviction candidate must be connected for, in
  * order to evict, in seconds.
  */
 static constexpr std::chrono::seconds MINIMUM_CONNECT_TIME{30};
 /** SHA256("main address relay")[0:8] */
 static constexpr uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL;
 /// Age after which a stale block will no longer be served if requested as
 /// protection against fingerprinting. Set to one month, denominated in seconds.
 static constexpr int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60;
 /// Age after which a block is considered historical for purposes of rate
 /// limiting block relay. Set to one week, denominated in seconds.
 static constexpr int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60;
 /**
  * Time between pings automatically sent out for latency probing and keepalive.
  */
 static constexpr std::chrono::minutes PING_INTERVAL{2};
 /** The maximum number of entries in a locator */
 static const unsigned int MAX_LOCATOR_SZ = 101;
 /** The maximum number of entries in an 'inv' protocol message */
 static const unsigned int MAX_INV_SZ = 50000;
 static_assert(MAX_PROTOCOL_MESSAGE_LENGTH > MAX_INV_SZ * sizeof(CInv),
               "Max protocol message length must be greater than largest "
               "possible INV message");
 
 /** Minimum time between 2 successives getavaaddr messages from the same peer */
 static constexpr std::chrono::minutes GETAVAADDR_INTERVAL{2};
 
 /**
  * If no proof was requested from a compact proof message after this timeout
  * expired, the proof radix tree can be cleaned up.
  */
 static constexpr std::chrono::minutes AVALANCHE_AVAPROOFS_TIMEOUT{2};
 
 struct DataRequestParameters {
     /**
      * Maximum number of in-flight data requests from a peer. It is not a hard
      * limit, but the threshold at which point the overloaded_peer_delay kicks
      * in.
      */
     const size_t max_peer_request_in_flight;
 
     /**
      * Maximum number of inventories to consider for requesting, per peer. It
      * provides a reasonable DoS limit to per-peer memory usage spent on
      * announcements, while covering peers continuously sending INVs at the
      * maximum rate (by our own policy, see INVENTORY_BROADCAST_PER_SECOND) for
      * several minutes, while not receiving the actual data (from any peer) in
      * response to requests for them.
      */
     const size_t max_peer_announcements;
 
     /** How long to delay requesting data from non-preferred peers */
     const std::chrono::seconds nonpref_peer_delay;
 
     /**
      * How long to delay requesting data from overloaded peers (see
      * max_peer_request_in_flight).
      */
     const std::chrono::seconds overloaded_peer_delay;
 
     /**
      * How long to wait (in microseconds) before a data request from an
      * additional peer.
      */
     const std::chrono::microseconds getdata_interval;
 
     /**
      * Permission flags a peer requires to bypass the request limits tracking
      * limits and delay penalty.
      */
     const NetPermissionFlags bypass_request_limits_permissions;
 };
 
 static constexpr DataRequestParameters TX_REQUEST_PARAMS{
     100,                      // max_peer_request_in_flight
     5000,                     // max_peer_announcements
     std::chrono::seconds(2),  // nonpref_peer_delay
     std::chrono::seconds(2),  // overloaded_peer_delay
     std::chrono::seconds(60), // getdata_interval
     PF_RELAY,                 // bypass_request_limits_permissions
 };
 
 static constexpr DataRequestParameters PROOF_REQUEST_PARAMS{
     100,                            // max_peer_request_in_flight
     5000,                           // max_peer_announcements
     std::chrono::seconds(2),        // nonpref_peer_delay
     std::chrono::seconds(2),        // overloaded_peer_delay
     std::chrono::seconds(60),       // getdata_interval
     PF_BYPASS_PROOF_REQUEST_LIMITS, // bypass_request_limits_permissions
 };
 
 /**
  * Limit to avoid sending big packets. Not used in processing incoming GETDATA
  * for compatibility.
  */
 static const unsigned int MAX_GETDATA_SZ = 1000;
 /**
  * Number of blocks that can be requested at any given time from a single peer.
  */
 static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16;
 /**
  * Time during which a peer must stall block download progress before being
  * disconnected.
  */
 static constexpr auto BLOCK_STALLING_TIMEOUT = 2s;
 /**
  * Number of headers sent in one getheaders result. We rely on the assumption
  * that if a peer sends
  *  less than this number, we reached its tip. Changing this value is a protocol
  * upgrade.
  */
 static const unsigned int MAX_HEADERS_RESULTS = 2000;
 /**
  * Maximum depth of blocks we're willing to serve as compact blocks to peers
  *  when requested. For older blocks, a regular BLOCK response will be sent.
  */
 static const int MAX_CMPCTBLOCK_DEPTH = 5;
 /**
  * Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests
  * for.
  */
 static const int MAX_BLOCKTXN_DEPTH = 10;
 /**
  * Size of the "block download window": how far ahead of our current height do
  * we fetch? Larger windows tolerate larger download speed differences between
  * peer, but increase the potential degree of disordering of blocks on disk
  * (which make reindexing and pruning harder). We'll probably
  *  want to make this a per-peer adaptive value at some point.
  */
 static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024;
 /**
  * Block download timeout base, expressed in multiples of the block interval
  * (i.e. 10 min)
  */
 static constexpr double BLOCK_DOWNLOAD_TIMEOUT_BASE = 1;
 /**
  * Additional block download timeout per parallel downloading peer (i.e. 5 min)
  */
 static constexpr double BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 0.5;
 /**
  * Maximum number of headers to announce when relaying blocks with headers
  * message.
  */
 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8;
 /** Maximum number of unconnecting headers announcements before DoS score */
 static const int MAX_UNCONNECTING_HEADERS = 10;
 /** Minimum blocks required to signal NODE_NETWORK_LIMITED */
 static const unsigned int NODE_NETWORK_LIMITED_MIN_BLOCKS = 288;
 /**
  * Average delay between local address broadcasts.
  */
 static constexpr auto AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24h;
 /**
  * Average delay between peer address broadcasts.
  */
 static constexpr auto AVG_ADDRESS_BROADCAST_INTERVAL = 30s;
 /**
  * Average delay between trickled inventory transmissions for inbound peers.
  * Blocks and peers with noban permission bypass this.
  */
 static constexpr auto INBOUND_INVENTORY_BROADCAST_INTERVAL = 5s;
 /**
  * Maximum rate of inventory items to send per second.
  * Limits the impact of low-fee transaction floods.
  */
 static constexpr unsigned int INVENTORY_BROADCAST_PER_SECOND = 7;
 /** Maximum number of inventory items to send per transmission. */
 static constexpr unsigned int INVENTORY_BROADCAST_MAX_PER_MB =
     INVENTORY_BROADCAST_PER_SECOND *
     count_seconds(INBOUND_INVENTORY_BROADCAST_INTERVAL);
 /** The number of most recently announced transactions a peer can request. */
 static constexpr unsigned int INVENTORY_MAX_RECENT_RELAY = 3500;
 /**
  * Verify that INVENTORY_MAX_RECENT_RELAY is enough to cache everything
  * typically relayed before unconditional relay from the mempool kicks in. This
  * is only a lower bound, and it should be larger to account for higher inv rate
  * to outbound peers, and random variations in the broadcast mechanism.
  */
 static_assert(INVENTORY_MAX_RECENT_RELAY >= INVENTORY_BROADCAST_PER_SECOND *
                                                 UNCONDITIONAL_RELAY_DELAY /
                                                 std::chrono::seconds{1},
               "INVENTORY_RELAY_MAX too low");
 
 /**
  * Average delay between feefilter broadcasts in seconds.
  */
 static constexpr auto AVG_FEEFILTER_BROADCAST_INTERVAL = 10min;
 /**
  * Maximum feefilter broadcast delay after significant change.
  */
 static constexpr auto MAX_FEEFILTER_CHANGE_DELAY = 5min;
 /**
  * Maximum number of compact filters that may be requested with one
  * getcfilters. See BIP 157.
  */
 static constexpr uint32_t MAX_GETCFILTERS_SIZE = 1000;
 /**
  * Maximum number of cf hashes that may be requested with one getcfheaders. See
  * BIP 157.
  */
 static constexpr uint32_t MAX_GETCFHEADERS_SIZE = 2000;
 /**
  * the maximum percentage of addresses from our addrman to return in response
  * to a getaddr message.
  */
 static constexpr size_t MAX_PCT_ADDR_TO_SEND = 23;
 /** The maximum number of address records permitted in an ADDR message. */
 static constexpr size_t MAX_ADDR_TO_SEND{1000};
 /**
  * The maximum rate of address records we're willing to process on average. Can
  * be bypassed using the NetPermissionFlags::Addr permission.
  */
 static constexpr double MAX_ADDR_RATE_PER_SECOND{0.1};
 /**
  * The soft limit of the address processing token bucket (the regular
  * MAX_ADDR_RATE_PER_SECOND based increments won't go above this, but the
  * MAX_ADDR_TO_SEND increment following GETADDR is exempt from this limit).
  */
 static constexpr size_t MAX_ADDR_PROCESSING_TOKEN_BUCKET{MAX_ADDR_TO_SEND};
 
 inline size_t GetMaxAddrToSend() {
     return gArgs.GetArg("-maxaddrtosend", MAX_ADDR_TO_SEND);
 }
 
 // Internal stuff
 namespace {
 /**
  * Blocks that are in flight, and that are in the queue to be downloaded.
  */
 struct QueuedBlock {
     BlockHash hash;
     //! Optional.
     const CBlockIndex *pindex;
     //! Whether this block has validated headers at the time of request.
     bool fValidatedHeaders;
     //! Optional, used for CMPCTBLOCK downloads
     std::unique_ptr<PartiallyDownloadedBlock> partialBlock;
 };
 
 /**
  * Data structure for an individual peer. This struct is not protected by
  * cs_main since it does not contain validation-critical data.
  *
  * Memory is owned by shared pointers and this object is destructed when
  * the refcount drops to zero.
  *
  * Mutexes inside this struct must not be held when locking m_peer_mutex.
  *
  * TODO: move most members from CNodeState to this structure.
  * TODO: move remaining application-layer data members from CNode to this
  * structure.
  */
 struct Peer {
     /** Same id as the CNode object for this peer */
     const NodeId m_id{0};
 
     /** Protects misbehavior data members */
     Mutex m_misbehavior_mutex;
     /** Accumulated misbehavior score for this peer */
     int m_misbehavior_score GUARDED_BY(m_misbehavior_mutex){0};
     /** Whether this peer should be disconnected and marked as discouraged
      * (unless it has the noban permission). */
     bool m_should_discourage GUARDED_BY(m_misbehavior_mutex){false};
 
     /** Protects block inventory data members */
     Mutex m_block_inv_mutex;
     /**
      * List of blocks that we'll anounce via an `inv` message.
      * There is no final sorting before sending, as they are always sent
      * immediately and in the order requested.
      */
     std::vector<BlockHash> m_blocks_for_inv_relay GUARDED_BY(m_block_inv_mutex);
     /**
      * Unfiltered list of blocks that we'd like to announce via a `headers`
      * message. If we can't announce via a `headers` message, we'll fall back to
      * announcing via `inv`.
      */
     std::vector<BlockHash>
         m_blocks_for_headers_relay GUARDED_BY(m_block_inv_mutex);
 
     /**
      * The final block hash that we sent in an `inv` message to this peer.
      * When the peer requests this block, we send an `inv` message to trigger
      * the peer to request the next sequence of block hashes.
      * Most peers use headers-first syncing, which doesn't use this mechanism
      */
     BlockHash m_continuation_block GUARDED_BY(m_block_inv_mutex){};
 
     /** This peer's reported block height when we connected */
     std::atomic<int> m_starting_height{-1};
 
     /** The pong reply we're expecting, or 0 if no pong expected. */
     std::atomic<uint64_t> m_ping_nonce_sent{0};
     /** When the last ping was sent, or 0 if no ping was ever sent */
     std::atomic<std::chrono::microseconds> m_ping_start{0us};
     /** Whether a ping has been requested by the user */
     std::atomic<bool> m_ping_queued{false};
 
     /**
      * A vector of addresses to send to the peer, limited to MAX_ADDR_TO_SEND.
      */
     std::vector<CAddress> m_addrs_to_send;
     /**
      * Probabilistic filter to track recent addr messages relayed with this
      * peer. Used to avoid relaying redundant addresses to this peer.
      *
      *  We initialize this filter for outbound peers (other than
      *  block-relay-only connections) or when an inbound peer sends us an
      *  address related message (ADDR, ADDRV2, GETADDR).
      *
      *  Presence of this filter must correlate with m_addr_relay_enabled.
      **/
     std::unique_ptr<CRollingBloomFilter> m_addr_known;
     /**
      * Whether we are participating in address relay with this connection.
      *
      * We set this bool to true for outbound peers (other than
      * block-relay-only connections), or when an inbound peer sends us an
      * address related message (ADDR, ADDRV2, GETADDR).
      *
      * We use this bool to decide whether a peer is eligible for gossiping
      * addr messages. This avoids relaying to peers that are unlikely to
      * forward them, effectively blackholing self announcements. Reasons
      * peers might support addr relay on the link include that they connected
      * to us as a block-relay-only peer or they are a light client.
      *
      * This field must correlate with whether m_addr_known has been
      * initialized.
      */
     std::atomic_bool m_addr_relay_enabled{false};
     /** Whether a getaddr request to this peer is outstanding. */
     bool m_getaddr_sent{false};
     /** Guards address sending timers. */
     mutable Mutex m_addr_send_times_mutex;
     /** Time point to send the next ADDR message to this peer. */
     std::chrono::microseconds
         m_next_addr_send GUARDED_BY(m_addr_send_times_mutex){0};
     /** Time point to possibly re-announce our local address to this peer. */
     std::chrono::microseconds
         m_next_local_addr_send GUARDED_BY(m_addr_send_times_mutex){0};
     /**
      * Whether the peer has signaled support for receiving ADDRv2 (BIP155)
      * messages, indicating a preference to receive ADDRv2 instead of ADDR ones.
      */
     std::atomic_bool m_wants_addrv2{false};
     /** Whether this peer has already sent us a getaddr message. */
     bool m_getaddr_recvd{false};
     /** Guards m_addr_token_bucket */
     mutable Mutex m_addr_token_bucket_mutex;
     /**
      * Number of addresses that can be processed from this peer. Start at 1
      * to permit self-announcement.
      */
     double m_addr_token_bucket GUARDED_BY(m_addr_token_bucket_mutex){1.0};
     /** When m_addr_token_bucket was last updated */
     std::chrono::microseconds m_addr_token_timestamp{
         GetTime<std::chrono::microseconds>()};
     /** Total number of addresses that were dropped due to rate limiting. */
     std::atomic<uint64_t> m_addr_rate_limited{0};
     /**
      * Total number of addresses that were processed (excludes rate-limited
      * ones).
      */
     std::atomic<uint64_t> m_addr_processed{0};
 
     /**
      * Set of txids to reconsider once their parent transactions have been
      * accepted
      */
     std::set<TxId> m_orphan_work_set GUARDED_BY(g_cs_orphans);
 
     /** Protects m_getdata_requests **/
     Mutex m_getdata_requests_mutex;
     /** Work queue of items requested by this peer **/
     std::deque<CInv> m_getdata_requests GUARDED_BY(m_getdata_requests_mutex);
 
     explicit Peer(NodeId id) : m_id(id) {}
 };
 
 using PeerRef = std::shared_ptr<Peer>;
 
 class PeerManagerImpl final : public PeerManager {
 public:
     PeerManagerImpl(const CChainParams &chainparams, CConnman &connman,
                     BanMan *banman, CScheduler &scheduler,
                     ChainstateManager &chainman, CTxMemPool &pool,
                     bool ignore_incoming_txs);
 
     /** Overridden from CValidationInterface. */
     void BlockConnected(const std::shared_ptr<const CBlock> &pblock,
                         const CBlockIndex *pindexConnected) override;
     void BlockDisconnected(const std::shared_ptr<const CBlock> &block,
                            const CBlockIndex *pindex) override;
     void UpdatedBlockTip(const CBlockIndex *pindexNew,
                          const CBlockIndex *pindexFork,
                          bool fInitialDownload) override;
     void BlockChecked(const CBlock &block,
                       const BlockValidationState &state) override;
     void NewPoWValidBlock(const CBlockIndex *pindex,
                           const std::shared_ptr<const CBlock> &pblock) override;
 
     /** Implement NetEventsInterface */
     void InitializeNode(const Config &config, CNode *pnode) override;
     void FinalizeNode(const Config &config, const CNode &node,
                       bool &fUpdateConnectionTime) override;
     bool ProcessMessages(const Config &config, CNode *pfrom,
                          std::atomic<bool> &interrupt) override;
     bool SendMessages(const Config &config, CNode *pto) override
         EXCLUSIVE_LOCKS_REQUIRED(pto->cs_sendProcessing);
 
     /** Implement PeerManager */
     void CheckForStaleTipAndEvictPeers() override;
     bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) override;
     bool IgnoresIncomingTxs() override { return m_ignore_incoming_txs; }
     void SendPings() override;
     void SetBestHeight(int height) override { m_best_height = height; };
     void Misbehaving(const NodeId pnode, const int howmuch,
                      const std::string &message) override;
     void ProcessMessage(const Config &config, CNode &pfrom,
                         const std::string &msg_type, CDataStream &vRecv,
                         const std::chrono::microseconds time_received,
                         const std::atomic<bool> &interruptMsgProc) override;
 
 private:
     /**
      * Consider evicting an outbound peer based on the amount of time they've
      * been behind our tip.
      */
     void ConsiderEviction(CNode &pto, int64_t time_in_seconds)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /**
      * If we have extra outbound peers, try to disconnect the one with the
      * oldest block announcement.
      */
     void EvictExtraOutboundPeers(std::chrono::seconds now)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Retrieve unbroadcast transactions from the mempool and reattempt
      * sending to peers
      */
     void ReattemptInitialBroadcast(CScheduler &scheduler) const;
 
     /**
      * Update the avalanche statistics for all the nodes
      */
     void UpdateAvalancheStatistics() const;
 
     /**
      * Process periodic avalanche network messaging and cleanups.
      */
     void AvalanchePeriodicNetworking(CScheduler &scheduler) const;
 
     /**
      * Get a shared pointer to the Peer object.
      * May return an empty shared_ptr if the Peer object can't be found.
      */
     PeerRef GetPeerRef(NodeId id) const;
 
     /**
      * Get a shared pointer to the Peer object and remove it from m_peer_map.
      * May return an empty shared_ptr if the Peer object can't be found.
      */
     PeerRef RemovePeer(NodeId id);
 
     // overloaded variant of above to operate on CNode*s
     void Misbehaving(const CNode &node, int howmuch,
                      const std::string &message) {
         Misbehaving(node.GetId(), howmuch, message);
     }
 
     /**
      * Potentially mark a node discouraged based on the contents of a
      * BlockValidationState object
      *
      * @param[in] via_compact_block this bool is passed in because
      * net_processing should punish peers differently depending on whether the
      * data was provided in a compact block message or not. If the compact block
      * had a valid header, but contained invalid txs, the peer should not be
      * punished. See BIP 152.
      *
      * @return Returns true if the peer was punished (probably disconnected)
      */
     bool MaybePunishNodeForBlock(NodeId nodeid,
                                  const BlockValidationState &state,
                                  bool via_compact_block,
                                  const std::string &message = "");
 
     /**
      * Potentially disconnect and discourage a node based on the contents of a
      * TxValidationState object
      *
      * @return Returns true if the peer was punished (probably disconnected)
      */
     bool MaybePunishNodeForTx(NodeId nodeid, const TxValidationState &state,
                               const std::string &message = "");
 
     /**
      * Maybe disconnect a peer and discourage future connections from its
      * address.
      *
      * @param[in]   pnode     The node to check.
      * @param[in]   peer      The peer object to check.
      * @return                True if the peer was marked for disconnection in
      * this function
      */
     bool MaybeDiscourageAndDisconnect(CNode &pnode, Peer &peer);
 
     void ProcessOrphanTx(const Config &config, std::set<TxId> &orphan_work_set)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_cs_orphans);
     /** Process a single headers message from a peer. */
     void ProcessHeadersMessage(const Config &config, CNode &pfrom,
                                const Peer &peer,
                                const std::vector<CBlockHeader> &headers,
                                bool via_compact_block);
 
     void SendBlockTransactions(CNode &pfrom, const CBlock &block,
                                const BlockTransactionsRequest &req);
 
     /**
      * Register with InvRequestTracker that a TX INV has been received from a
      * peer. The announcement parameters are decided in PeerManager and then
      * passed to InvRequestTracker.
      */
     void AddTxAnnouncement(const CNode &node, const TxId &txid,
                            std::chrono::microseconds current_time)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /**
      * Register with InvRequestTracker that a PROOF INV has been received from a
      * peer. The announcement parameters are decided in PeerManager and then
      * passed to InvRequestTracker.
      */
     void
     AddProofAnnouncement(const CNode &node, const avalanche::ProofId &proofid,
                          std::chrono::microseconds current_time, bool preferred)
         EXCLUSIVE_LOCKS_REQUIRED(cs_proofrequest);
 
     /** Send a version message to a peer */
     void PushNodeVersion(const Config &config, CNode &pnode, int64_t nTime);
 
     /**
      * Send a ping message every PING_INTERVAL or if requested via RPC. May mark
      * the peer to be disconnected if a ping has timed out.
      * We use mockable time for ping timeouts, so setmocktime may cause pings
      * to time out.
      */
     void MaybeSendPing(CNode &node_to, Peer &peer,
                        std::chrono::microseconds now);
 
     /** Send `addr` messages on a regular schedule. */
     void MaybeSendAddr(CNode &node, Peer &peer,
                        std::chrono::microseconds current_time);
 
     /**
      * Relay (gossip) an address to a few randomly chosen nodes.
      *
      * @param[in] originator   The id of the peer that sent us the address. We
      *                         don't want to relay it back.
      * @param[in] addr         Address to relay.
      * @param[in] fReachable   Whether the address' network is reachable. We
      *                         relay unreachable addresses less.
      */
     void RelayAddress(NodeId originator, const CAddress &addr, bool fReachable);
 
     const CChainParams &m_chainparams;
     CConnman &m_connman;
     /**
      * Pointer to this node's banman. May be nullptr - check existence before
      * dereferencing.
      */
     BanMan *const m_banman;
     ChainstateManager &m_chainman;
     CTxMemPool &m_mempool;
     InvRequestTracker<TxId> m_txrequest GUARDED_BY(::cs_main);
 
     Mutex cs_proofrequest;
     InvRequestTracker<avalanche::ProofId>
         m_proofrequest GUARDED_BY(cs_proofrequest);
 
     /** The height of the best chain */
     std::atomic<int> m_best_height{-1};
 
     //! Next time to check for stale tip
     int64_t m_stale_tip_check_time;
 
     /** Whether this node is running in blocks only mode */
     const bool m_ignore_incoming_txs;
 
     /**
      * Whether we've completed initial sync yet, for determining when to turn
      * on extra block-relay-only peers.
      */
     bool m_initial_sync_finished{false};
 
     /**
      * Protects m_peer_map. This mutex must not be locked while holding a lock
      * on any of the mutexes inside a Peer object.
      */
     mutable Mutex m_peer_mutex;
     /**
      * Map of all Peer objects, keyed by peer id. This map is protected
      * by the m_peer_mutex. Once a shared pointer reference is
      * taken, the lock may be released. Individual fields are protected by
      * their own locks.
      */
     std::map<NodeId, PeerRef> m_peer_map GUARDED_BY(m_peer_mutex);
 
     /** Number of nodes with fSyncStarted. */
     int nSyncStarted GUARDED_BY(cs_main) = 0;
 
     /**
      * Sources of received blocks, saved to be able to punish them when
      * processing happens afterwards.
      * Set mapBlockSource[hash].second to false if the node should not be
      * punished if the block is invalid.
      */
     std::map<BlockHash, std::pair<NodeId, bool>>
         mapBlockSource GUARDED_BY(cs_main);
 
     /** Number of outbound peers with m_chain_sync.m_protect. */
     int m_outbound_peers_with_protect_from_disconnect GUARDED_BY(cs_main) = 0;
 
     bool AlreadyHaveTx(const TxId &txid) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Filter for transactions that were recently rejected by
      * AcceptToMemoryPool. These are not rerequested until the chain tip
      * changes, at which point the entire filter is reset.
      *
      * Without this filter we'd be re-requesting txs from each of our peers,
      * increasing bandwidth consumption considerably. For instance, with 100
      * peers, half of which relay a tx we don't accept, that might be a 50x
      * bandwidth increase. A flooding attacker attempting to roll-over the
      * filter using minimum-sized, 60byte, transactions might manage to send
      * 1000/sec if we have fast peers, so we pick 120,000 to give our peers a
      * two minute window to send invs to us.
      *
      * Decreasing the false positive rate is fairly cheap, so we pick one in a
      * million to make it highly unlikely for users to have issues with this
      * filter.
      *
      * Memory used: 1.3 MB
      */
     std::unique_ptr<CRollingBloomFilter> recentRejects GUARDED_BY(cs_main);
     uint256 hashRecentRejectsChainTip GUARDED_BY(cs_main);
 
     /**
      * Filter for transactions that have been recently confirmed.
      * We use this to avoid requesting transactions that have already been
      * confirmed.
      */
     Mutex m_recent_confirmed_transactions_mutex;
     std::unique_ptr<CRollingBloomFilter> m_recent_confirmed_transactions
         GUARDED_BY(m_recent_confirmed_transactions_mutex);
 
     /**
      * Returns a bool indicating whether we requested this block.
      * Also used if a block was /not/ received and timed out or started with
      * another peer
      */
     bool MarkBlockAsReceived(const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Mark a block as in flight
      * Returns false, still setting pit, if the block was already in flight from
      * the same peer pit will only be valid as long as the same cs_main lock is
      * being held
      */
     bool MarkBlockAsInFlight(const Config &config, NodeId nodeid,
                              const BlockHash &hash,
                              const CBlockIndex *pindex = nullptr,
                              std::list<QueuedBlock>::iterator **pit = nullptr)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool TipMayBeStale() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Update pindexLastCommonBlock and add not-in-flight missing successors to
      * vBlocks, until it has at most count entries.
      */
     void FindNextBlocksToDownload(NodeId nodeid, unsigned int count,
                                   std::vector<const CBlockIndex *> &vBlocks,
                                   NodeId &nodeStaller)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     std::map<BlockHash, std::pair<NodeId, std::list<QueuedBlock>::iterator>>
         mapBlocksInFlight GUARDED_BY(cs_main);
 
     /** When our tip was last updated. */
     std::atomic<int64_t> m_last_tip_update{0};
 
     /**
      * Determine whether or not a peer can request a transaction, and return it
      * (or nullptr if not found or not allowed).
      */
     CTransactionRef FindTxForGetData(const CNode &peer, const TxId &txid,
                                      const std::chrono::seconds mempool_req,
                                      const std::chrono::seconds now)
         LOCKS_EXCLUDED(cs_main);
 
     void ProcessGetData(const Config &config, CNode &pfrom, Peer &peer,
                         const std::atomic<bool> &interruptMsgProc)
         EXCLUSIVE_LOCKS_REQUIRED(peer.m_getdata_requests_mutex)
             LOCKS_EXCLUDED(cs_main);
 
     /** Relay map. */
     typedef std::map<TxId, CTransactionRef> MapRelay;
     MapRelay mapRelay GUARDED_BY(cs_main);
 
     /**
      * Expiration-time ordered list of (expire time, relay map entry) pairs,
      * protected by cs_main).
      */
     std::deque<std::pair<std::chrono::microseconds, MapRelay::iterator>>
         g_relay_expiration GUARDED_BY(cs_main);
 
     /**
      * When a peer sends us a valid block, instruct it to announce blocks to us
      * using CMPCTBLOCK if possible by adding its nodeid to the end of
      * lNodesAnnouncingHeaderAndIDs, and keeping that list under a certain size
      * by removing the first element if necessary.
      */
     void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Stack of nodes which we have set to announce using compact blocks */
     std::list<NodeId> lNodesAnnouncingHeaderAndIDs GUARDED_BY(cs_main);
 
     /** Number of peers from which we're downloading blocks. */
     int nPeersWithValidatedDownloads GUARDED_BY(cs_main) = 0;
 
     /** Storage for orphan information */
     TxOrphanage m_orphanage;
 
     void AddToCompactExtraTransactions(const CTransactionRef &tx)
         EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 
     /**
      * Orphan/conflicted/etc transactions that are kept for compact block
      * reconstruction.
      * The last
      * -blockreconstructionextratxn/DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN of
      * these are kept in a ring buffer
      */
     std::vector<std::pair<TxHash, CTransactionRef>>
         vExtraTxnForCompact GUARDED_BY(g_cs_orphans);
     /** Offset into vExtraTxnForCompact to insert the next tx */
     size_t vExtraTxnForCompactIt GUARDED_BY(g_cs_orphans) = 0;
 
     /**
      * Check whether the last unknown block a peer advertised is not yet known.
      */
     void ProcessBlockAvailability(NodeId nodeid)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /**
      * Update tracking information about which blocks a peer is assumed to have.
      */
     void UpdateBlockAvailability(NodeId nodeid, const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool CanDirectFetch(const Consensus::Params &consensusParams)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * To prevent fingerprinting attacks, only send blocks/headers outside of
      * the active chain if they are no more than a month older (both in time,
      * and in best equivalent proof of work) than the best header chain we know
      * about and we fully-validated them at some point.
      */
     bool BlockRequestAllowed(const CBlockIndex *pindex,
                              const Consensus::Params &consensusParams)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool AlreadyHaveBlock(const BlockHash &block_hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool AlreadyHaveProof(const avalanche::ProofId &proofid);
     void ProcessGetBlockData(const Config &config, CNode &pfrom, Peer &peer,
                              const CInv &inv, CConnman &connman);
 
     /**
      * Validation logic for compact filters request handling.
      *
      * May disconnect from the peer in the case of a bad request.
      *
      * @param[in]   peer            The peer that we received the request from
      * @param[in]   chain_params    Chain parameters
      * @param[in]   filter_type     The filter type the request is for. Must be
      *                              basic filters.
      * @param[in]   start_height    The start height for the request
      * @param[in]   stop_hash       The stop_hash for the request
      * @param[in]   max_height_diff The maximum number of items permitted to
      *                              request, as specified in BIP 157
      * @param[out]  stop_index      The CBlockIndex for the stop_hash block, if
      *                              the request can be serviced.
      * @param[out]  filter_index    The filter index, if the request can be
      *                              serviced.
      * @return                      True if the request can be serviced.
      */
     bool PrepareBlockFilterRequest(
         CNode &peer, const CChainParams &chain_params,
         BlockFilterType filter_type, uint32_t start_height,
         const BlockHash &stop_hash, uint32_t max_height_diff,
         const CBlockIndex *&stop_index, BlockFilterIndex *&filter_index);
 
     /**
      * Handle a cfilters request.
      *
      * May disconnect from the peer in the case of a bad request.
      *
      * @param[in]   peer            The peer that we received the request from
      * @param[in]   vRecv           The raw message received
      * @param[in]   chain_params    Chain parameters
      * @param[in]   connman         Pointer to the connection manager
      */
     void ProcessGetCFilters(CNode &peer, CDataStream &vRecv,
                             const CChainParams &chain_params,
                             CConnman &connman);
     /**
      * Handle a cfheaders request.
      *
      * May disconnect from the peer in the case of a bad request.
      *
      * @param[in]   peer            The peer that we received the request from
      * @param[in]   vRecv           The raw message received
      * @param[in]   chain_params    Chain parameters
      * @param[in]   connman         Pointer to the connection manager
      */
     void ProcessGetCFHeaders(CNode &peer, CDataStream &vRecv,
                              const CChainParams &chain_params,
                              CConnman &connman);
 
     /**
      * Handle a getcfcheckpt request.
      *
      * May disconnect from the peer in the case of a bad request.
      *
      * @param[in]   peer            The peer that we received the request from
      * @param[in]   vRecv           The raw message received
      * @param[in]   chain_params    Chain parameters
      * @param[in]   connman         Pointer to the connection manager
      */
     void ProcessGetCFCheckPt(CNode &peer, CDataStream &vRecv,
                              const CChainParams &chain_params,
                              CConnman &connman);
 
     /**
      * Decide a response for an Avalanche poll about the given block.
      *
      * @param[in]   hash            The hash of the block being polled for
      * @return                      Our current vote for the block
      */
     uint32_t GetAvalancheVoteForBlock(const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Checks if address relay is permitted with peer. If needed, initializes
      * the m_addr_known bloom filter and sets m_addr_relay_enabled to true.
      *
      *  @return   True if address relay is enabled with peer
      *            False if address relay is disallowed
      */
     bool SetupAddressRelay(CNode &node, Peer &peer);
 
     /**
      * Manage reception of an avalanche proof.
      *
      * @return   False if the peer is misbehaving, true otherwise
      */
     bool ReceivedAvalancheProof(CNode &peer, const avalanche::ProofRef &proof);
 };
 } // namespace
 
 namespace {
 /**
  * Filter for proofs that were recently rejected but not orphaned.
  * These are not rerequested until they are rolled out of the filter.
  *
  * Without this filter we'd be re-requesting proofs from each of our peers,
  * increasing bandwidth consumption considerably.
  *
  * Decreasing the false positive rate is fairly cheap, so we pick one in a
  * million to make it highly unlikely for users to have issues with this filter.
  */
 Mutex cs_rejectedProofs;
 std::unique_ptr<CRollingBloomFilter>
     rejectedProofs GUARDED_BY(cs_rejectedProofs);
 
 /** Number of preferable block download peers. */
 int nPreferredDownload GUARDED_BY(cs_main) = 0;
 } // namespace
 
 namespace {
 /**
  * Maintain validation-specific state about nodes, protected by cs_main, instead
  * by CNode's own locks. This simplifies asynchronous operation, where
  * processing of incoming data is done after the ProcessMessage call returns,
  * and we're no longer holding the node's locks.
  */
 struct CNodeState {
     //! The peer's address
     const CService address;
     //! The best known block we know this peer has announced.
     const CBlockIndex *pindexBestKnownBlock;
     //! The hash of the last unknown block this peer has announced.
     BlockHash hashLastUnknownBlock;
     //! The last full block we both have.
     const CBlockIndex *pindexLastCommonBlock;
     //! The best header we have sent our peer.
     const CBlockIndex *pindexBestHeaderSent;
     //! Length of current-streak of unconnecting headers announcements
     int nUnconnectingHeaders;
     //! Whether we've started headers synchronization with this peer.
     bool fSyncStarted;
     //! When to potentially disconnect peer for stalling headers download
     std::chrono::microseconds m_headers_sync_timeout{0us};
     //! Since when we're stalling block download progress (in microseconds), or
     //! 0.
     std::chrono::microseconds m_stalling_since{0us};
     std::list<QueuedBlock> vBlocksInFlight;
     //! When the first entry in vBlocksInFlight started downloading. Don't care
     //! when vBlocksInFlight is empty.
     std::chrono::microseconds m_downloading_since{0us};
     int nBlocksInFlight;
     int nBlocksInFlightValidHeaders;
     //! Whether we consider this a preferred download peer.
     bool fPreferredDownload;
     //! Whether this peer wants invs or headers (when possible) for block
     //! announcements.
     bool fPreferHeaders;
     //! Whether this peer wants invs or cmpctblocks (when possible) for block
     //! announcements.
     bool fPreferHeaderAndIDs;
     /**
      * Whether this peer will send us cmpctblocks if we request them.
      * This is not used to gate request logic, as we really only care about
      * fSupportsDesiredCmpctVersion, but is used as a flag to "lock in" the
      * version of compact blocks we send.
      */
     bool fProvidesHeaderAndIDs;
     /**
      * If we've announced NODE_WITNESS to this peer: whether the peer sends
      * witnesses in cmpctblocks/blocktxns, otherwise: whether this peer sends
      * non-witnesses in cmpctblocks/blocktxns.
      */
     bool fSupportsDesiredCmpctVersion;
 
     /**
      * State used to enforce CHAIN_SYNC_TIMEOUT and EXTRA_PEER_CHECK_INTERVAL
      * logic.
      *
      * Both are only in effect for outbound, non-manual, non-protected
      * connections. Any peer protected (m_protect = true) is not chosen for
      * eviction. A peer is marked as protected if all of these are true:
      *   - its connection type is IsBlockOnlyConn() == false
      *   - it gave us a valid connecting header
      *   - we haven't reached MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT yet
      *   - it has a better chain than we have
      *
      * CHAIN_SYNC_TIMEOUT:  if a peer's best known block has less work than our
      * tip, set a timeout CHAIN_SYNC_TIMEOUT seconds in the future:
      *   - If at timeout their best known block now has more work than our tip
      * when the timeout was set, then either reset the timeout or clear it
      * (after comparing against our current tip's work)
      *   - If at timeout their best known block still has less work than our tip
      * did when the timeout was set, then send a getheaders message, and set a
      * shorter timeout, HEADERS_RESPONSE_TIME seconds in future. If their best
      * known block is still behind when that new timeout is reached, disconnect.
      *
      * EXTRA_PEER_CHECK_INTERVAL: after each interval, if we have too many
      * outbound peers, drop the outbound one that least recently announced us a
      * new block.
      */
     struct ChainSyncTimeoutState {
         //! A timeout used for checking whether our peer has sufficiently
         //! synced.
         int64_t m_timeout;
         //! A header with the work we require on our peer's chain.
         const CBlockIndex *m_work_header;
         //! After timeout is reached, set to true after sending getheaders.
         bool m_sent_getheaders;
         //! Whether this peer is protected from disconnection due to a bad/slow
         //! chain.
         bool m_protect;
     };
 
     ChainSyncTimeoutState m_chain_sync;
 
     //! Time of last new block announcement
     int64_t m_last_block_announcement;
 
     struct AvalancheState {
         std::chrono::time_point<std::chrono::steady_clock> last_poll;
     };
 
     AvalancheState m_avalanche_state;
 
     //! Whether this peer is an inbound connection
     bool m_is_inbound;
 
     //! A rolling bloom filter of all announced tx CInvs to this peer.
     CRollingBloomFilter m_recently_announced_invs =
         CRollingBloomFilter{INVENTORY_MAX_RECENT_RELAY, 0.000001};
 
     //! A rolling bloom filter of all announced Proofs CInvs to this peer.
     CRollingBloomFilter m_recently_announced_proofs =
         CRollingBloomFilter{INVENTORY_MAX_RECENT_RELAY, 0.000001};
 
     CNodeState(CAddress addrIn, bool is_inbound)
         : address(addrIn), m_is_inbound(is_inbound) {
         pindexBestKnownBlock = nullptr;
         hashLastUnknownBlock = BlockHash();
         pindexLastCommonBlock = nullptr;
         pindexBestHeaderSent = nullptr;
         nUnconnectingHeaders = 0;
         fSyncStarted = false;
         nBlocksInFlight = 0;
         nBlocksInFlightValidHeaders = 0;
         fPreferredDownload = false;
         fPreferHeaders = false;
         fPreferHeaderAndIDs = false;
         fProvidesHeaderAndIDs = false;
         fSupportsDesiredCmpctVersion = false;
         m_chain_sync = {0, nullptr, false, false};
         m_last_block_announcement = 0;
         m_recently_announced_invs.reset();
         m_recently_announced_proofs.reset();
     }
 };
 
 /** Map maintaining per-node state. */
 static std::map<NodeId, CNodeState> mapNodeState GUARDED_BY(cs_main);
 
 static CNodeState *State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     std::map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
     if (it == mapNodeState.end()) {
         return nullptr;
     }
 
     return &it->second;
 }
 
 /**
  * Whether the peer supports the address. For example, a peer that does not
  * implement BIP155 cannot receive Tor v3 addresses because it requires
  * ADDRv2 (BIP155) encoding.
  */
 static bool IsAddrCompatible(const Peer &peer, const CAddress &addr) {
     return peer.m_wants_addrv2 || addr.IsAddrV1Compatible();
 }
 
 static void AddAddressKnown(Peer &peer, const CAddress &addr) {
     assert(peer.m_addr_known);
     peer.m_addr_known->insert(addr.GetKey());
 }
 
 static void PushAddress(Peer &peer, const CAddress &addr,
                         FastRandomContext &insecure_rand) {
     // Known checking here is only to save space from duplicates.
     // Before sending, we'll filter it again for known addresses that were
     // added after addresses were pushed.
     assert(peer.m_addr_known);
     if (addr.IsValid() && !peer.m_addr_known->contains(addr.GetKey()) &&
         IsAddrCompatible(peer, addr)) {
         if (peer.m_addrs_to_send.size() >= GetMaxAddrToSend()) {
             peer.m_addrs_to_send[insecure_rand.randrange(
                 peer.m_addrs_to_send.size())] = addr;
         } else {
             peer.m_addrs_to_send.push_back(addr);
         }
     }
 }
 
 static bool isPreferredDownloadPeer(const CNode &pfrom) {
     LOCK(cs_main);
     const CNodeState *state = State(pfrom.GetId());
     return state && state->fPreferredDownload;
 }
 
 static void UpdatePreferredDownload(const CNode &node, CNodeState *state)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     nPreferredDownload -= state->fPreferredDownload;
 
     // Whether this node should be marked as a preferred download node.
     state->fPreferredDownload =
         (!node.IsInboundConn() || node.HasPermission(PF_NOBAN)) &&
         !node.IsAddrFetchConn() && !node.fClient;
 
     nPreferredDownload += state->fPreferredDownload;
 }
 
 bool PeerManagerImpl::MarkBlockAsReceived(const BlockHash &hash) {
     std::map<BlockHash,
              std::pair<NodeId, std::list<QueuedBlock>::iterator>>::iterator
         itInFlight = mapBlocksInFlight.find(hash);
     if (itInFlight != mapBlocksInFlight.end()) {
         CNodeState *state = State(itInFlight->second.first);
         assert(state != nullptr);
         state->nBlocksInFlightValidHeaders -=
             itInFlight->second.second->fValidatedHeaders;
         if (state->nBlocksInFlightValidHeaders == 0 &&
             itInFlight->second.second->fValidatedHeaders) {
             // Last validated block on the queue was received.
             nPeersWithValidatedDownloads--;
         }
         if (state->vBlocksInFlight.begin() == itInFlight->second.second) {
             // First block on the queue was received, update the start download
             // time for the next one
             state->m_downloading_since =
                 std::max(state->m_downloading_since,
                          GetTime<std::chrono::microseconds>());
         }
         state->vBlocksInFlight.erase(itInFlight->second.second);
         state->nBlocksInFlight--;
         state->m_stalling_since = 0us;
         mapBlocksInFlight.erase(itInFlight);
         return true;
     }
 
     return false;
 }
 
 bool PeerManagerImpl::MarkBlockAsInFlight(
     const Config &config, NodeId nodeid, const BlockHash &hash,
     const CBlockIndex *pindex, std::list<QueuedBlock>::iterator **pit) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     // Short-circuit most stuff in case it is from the same node.
     std::map<BlockHash,
              std::pair<NodeId, std::list<QueuedBlock>::iterator>>::iterator
         itInFlight = mapBlocksInFlight.find(hash);
     if (itInFlight != mapBlocksInFlight.end() &&
         itInFlight->second.first == nodeid) {
         if (pit) {
             *pit = &itInFlight->second.second;
         }
         return false;
     }
 
     // Make sure it's not listed somewhere already.
     MarkBlockAsReceived(hash);
 
     std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(
         state->vBlocksInFlight.end(),
         {hash, pindex, pindex != nullptr,
          std::unique_ptr<PartiallyDownloadedBlock>(
              pit ? new PartiallyDownloadedBlock(config, &m_mempool)
                  : nullptr)});
     state->nBlocksInFlight++;
     state->nBlocksInFlightValidHeaders += it->fValidatedHeaders;
     if (state->nBlocksInFlight == 1) {
         // We're starting a block download (batch) from this peer.
         state->m_downloading_since = GetTime<std::chrono::microseconds>();
     }
 
     if (state->nBlocksInFlightValidHeaders == 1 && pindex != nullptr) {
         nPeersWithValidatedDownloads++;
     }
 
     itInFlight = mapBlocksInFlight
                      .insert(std::make_pair(hash, std::make_pair(nodeid, it)))
                      .first;
 
     if (pit) {
         *pit = &itInFlight->second.second;
     }
 
     return true;
 }
 
 void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid) {
     AssertLockHeld(cs_main);
     CNodeState *nodestate = State(nodeid);
     if (!nodestate) {
         LogPrint(BCLog::NET, "node state unavailable: peer=%d\n", nodeid);
         return;
     }
     if (!nodestate->fProvidesHeaderAndIDs) {
         return;
     }
     for (std::list<NodeId>::iterator it = lNodesAnnouncingHeaderAndIDs.begin();
          it != lNodesAnnouncingHeaderAndIDs.end(); it++) {
         if (*it == nodeid) {
             lNodesAnnouncingHeaderAndIDs.erase(it);
             lNodesAnnouncingHeaderAndIDs.push_back(nodeid);
             return;
         }
     }
     m_connman.ForNode(nodeid, [this](CNode *pfrom) EXCLUSIVE_LOCKS_REQUIRED(
                                   ::cs_main) {
         AssertLockHeld(::cs_main);
         uint64_t nCMPCTBLOCKVersion = 1;
         if (lNodesAnnouncingHeaderAndIDs.size() >= 3) {
             // As per BIP152, we only get 3 of our peers to announce
             // blocks using compact encodings.
             m_connman.ForNode(
                 lNodesAnnouncingHeaderAndIDs.front(),
                 [this, nCMPCTBLOCKVersion](CNode *pnodeStop) {
                     m_connman.PushMessage(
                         pnodeStop, CNetMsgMaker(pnodeStop->GetCommonVersion())
                                        .Make(NetMsgType::SENDCMPCT,
                                              /*fAnnounceUsingCMPCTBLOCK=*/false,
                                              nCMPCTBLOCKVersion));
                     // save BIP152 bandwidth state: we select peer to be
                     // low-bandwidth
                     pnodeStop->m_bip152_highbandwidth_to = false;
                     return true;
                 });
             lNodesAnnouncingHeaderAndIDs.pop_front();
         }
         m_connman.PushMessage(pfrom,
                               CNetMsgMaker(pfrom->GetCommonVersion())
                                   .Make(NetMsgType::SENDCMPCT,
                                         /*fAnnounceUsingCMPCTBLOCK=*/true,
                                         nCMPCTBLOCKVersion));
         // save BIP152 bandwidth state: we select peer to be high-bandwidth
         pfrom->m_bip152_highbandwidth_to = true;
         lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
         return true;
     });
 }
 
 bool PeerManagerImpl::TipMayBeStale() {
     AssertLockHeld(cs_main);
     const Consensus::Params &consensusParams = m_chainparams.GetConsensus();
     if (m_last_tip_update == 0) {
         m_last_tip_update = GetTime();
     }
     return m_last_tip_update <
                GetTime() - consensusParams.nPowTargetSpacing * 3 &&
            mapBlocksInFlight.empty();
 }
 
 bool PeerManagerImpl::CanDirectFetch(const Consensus::Params &consensusParams) {
     return m_chainman.ActiveChain().Tip()->GetBlockTime() >
            GetAdjustedTime() - consensusParams.nPowTargetSpacing * 20;
 }
 
 static bool PeerHasHeader(CNodeState *state, const CBlockIndex *pindex)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     if (state->pindexBestKnownBlock &&
         pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight)) {
         return true;
     }
     if (state->pindexBestHeaderSent &&
         pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight)) {
         return true;
     }
     return false;
 }
 
 void PeerManagerImpl::ProcessBlockAvailability(NodeId nodeid) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     if (!state->hashLastUnknownBlock.IsNull()) {
         const CBlockIndex *pindex =
             m_chainman.m_blockman.LookupBlockIndex(state->hashLastUnknownBlock);
         if (pindex && pindex->nChainWork > 0) {
             if (state->pindexBestKnownBlock == nullptr ||
                 pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
                 state->pindexBestKnownBlock = pindex;
             }
             state->hashLastUnknownBlock.SetNull();
         }
     }
 }
 
 void PeerManagerImpl::UpdateBlockAvailability(NodeId nodeid,
                                               const BlockHash &hash) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     ProcessBlockAvailability(nodeid);
 
     const CBlockIndex *pindex = m_chainman.m_blockman.LookupBlockIndex(hash);
     if (pindex && pindex->nChainWork > 0) {
         // An actually better block was announced.
         if (state->pindexBestKnownBlock == nullptr ||
             pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
             state->pindexBestKnownBlock = pindex;
         }
     } else {
         // An unknown block was announced; just assume that the latest one is
         // the best one.
         state->hashLastUnknownBlock = hash;
     }
 }
 
 void PeerManagerImpl::FindNextBlocksToDownload(
     NodeId nodeid, unsigned int count,
     std::vector<const CBlockIndex *> &vBlocks, NodeId &nodeStaller) {
     if (count == 0) {
         return;
     }
 
     vBlocks.reserve(vBlocks.size() + count);
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     // Make sure pindexBestKnownBlock is up to date, we'll need it.
     ProcessBlockAvailability(nodeid);
 
     if (state->pindexBestKnownBlock == nullptr ||
         state->pindexBestKnownBlock->nChainWork <
             m_chainman.ActiveChain().Tip()->nChainWork ||
         state->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
         // This peer has nothing interesting.
         return;
     }
 
     if (state->pindexLastCommonBlock == nullptr) {
         // Bootstrap quickly by guessing a parent of our best tip is the forking
         // point. Guessing wrong in either direction is not a problem.
         state->pindexLastCommonBlock =
             m_chainman
                 .ActiveChain()[std::min(state->pindexBestKnownBlock->nHeight,
                                         m_chainman.ActiveChain().Height())];
     }
 
     // If the peer reorganized, our previous pindexLastCommonBlock may not be an
     // ancestor of its current tip anymore. Go back enough to fix that.
     state->pindexLastCommonBlock = LastCommonAncestor(
         state->pindexLastCommonBlock, state->pindexBestKnownBlock);
     if (state->pindexLastCommonBlock == state->pindexBestKnownBlock) {
         return;
     }
 
     std::vector<const CBlockIndex *> vToFetch;
     const CBlockIndex *pindexWalk = state->pindexLastCommonBlock;
     // Never fetch further than the best block we know the peer has, or more
     // than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last linked block we have in
     // common with this peer. The +1 is so we can detect stalling, namely if we
     // would be able to download that next block if the window were 1 larger.
     int nWindowEnd =
         state->pindexLastCommonBlock->nHeight + BLOCK_DOWNLOAD_WINDOW;
     int nMaxHeight =
         std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1);
     NodeId waitingfor = -1;
     while (pindexWalk->nHeight < nMaxHeight) {
         // Read up to 128 (or more, if more blocks than that are needed)
         // successors of pindexWalk (towards pindexBestKnownBlock) into
         // vToFetch. We fetch 128, because CBlockIndex::GetAncestor may be as
         // expensive as iterating over ~100 CBlockIndex* entries anyway.
         int nToFetch = std::min(nMaxHeight - pindexWalk->nHeight,
                                 std::max<int>(count - vBlocks.size(), 128));
         vToFetch.resize(nToFetch);
         pindexWalk = state->pindexBestKnownBlock->GetAncestor(
             pindexWalk->nHeight + nToFetch);
         vToFetch[nToFetch - 1] = pindexWalk;
         for (unsigned int i = nToFetch - 1; i > 0; i--) {
             vToFetch[i - 1] = vToFetch[i]->pprev;
         }
 
         // Iterate over those blocks in vToFetch (in forward direction), adding
         // the ones that are not yet downloaded and not in flight to vBlocks. In
         // the meantime, update pindexLastCommonBlock as long as all ancestors
         // are already downloaded, or if it's already part of our chain (and
         // therefore don't need it even if pruned).
         for (const CBlockIndex *pindex : vToFetch) {
             if (!pindex->IsValid(BlockValidity::TREE)) {
                 // We consider the chain that this peer is on invalid.
                 return;
             }
             if (pindex->nStatus.hasData() ||
                 m_chainman.ActiveChain().Contains(pindex)) {
                 if (pindex->HaveTxsDownloaded()) {
                     state->pindexLastCommonBlock = pindex;
                 }
             } else if (mapBlocksInFlight.count(pindex->GetBlockHash()) == 0) {
                 // The block is not already downloaded, and not yet in flight.
                 if (pindex->nHeight > nWindowEnd) {
                     // We reached the end of the window.
                     if (vBlocks.size() == 0 && waitingfor != nodeid) {
                         // We aren't able to fetch anything, but we would be if
                         // the download window was one larger.
                         nodeStaller = waitingfor;
                     }
                     return;
                 }
                 vBlocks.push_back(pindex);
                 if (vBlocks.size() == count) {
                     return;
                 }
             } else if (waitingfor == -1) {
                 // This is the first already-in-flight block.
                 waitingfor = mapBlocksInFlight[pindex->GetBlockHash()].first;
             }
         }
     }
 }
 
 } // namespace
 
 template <class InvId>
 static bool TooManyAnnouncements(const CNode &node,
                                  const InvRequestTracker<InvId> &requestTracker,
                                  const DataRequestParameters &requestParams) {
     return !node.HasPermission(
                requestParams.bypass_request_limits_permissions) &&
            requestTracker.Count(node.GetId()) >=
                requestParams.max_peer_announcements;
 }
 
 /**
  * Compute the request time for this announcement, current time plus delays for:
  *   - nonpref_peer_delay for announcements from non-preferred connections
  *   - overloaded_peer_delay for announcements from peers which have at least
  *     max_peer_request_in_flight requests in flight (and don't have PF_RELAY).
  */
 template <class InvId>
 static std::chrono::microseconds
 ComputeRequestTime(const CNode &node,
                    const InvRequestTracker<InvId> &requestTracker,
                    const DataRequestParameters &requestParams,
                    std::chrono::microseconds current_time, bool preferred) {
     auto delay = std::chrono::microseconds{0};
 
     if (!preferred) {
         delay += requestParams.nonpref_peer_delay;
     }
 
     if (!node.HasPermission(requestParams.bypass_request_limits_permissions) &&
         requestTracker.CountInFlight(node.GetId()) >=
             requestParams.max_peer_request_in_flight) {
         delay += requestParams.overloaded_peer_delay;
     }
 
     return current_time + delay;
 }
 
 void PeerManagerImpl::PushNodeVersion(const Config &config, CNode &pnode,
                                       int64_t nTime) {
     // Note that pnode.GetLocalServices() is a reflection of the local
     // services we were offering when the CNode object was created for this
     // peer.
     ServiceFlags nLocalNodeServices = pnode.GetLocalServices();
     uint64_t nonce = pnode.GetLocalNonce();
     const int nNodeStartingHeight{m_best_height};
     NodeId nodeid = pnode.GetId();
     CAddress addr = pnode.addr;
     uint64_t extraEntropy = pnode.GetLocalExtraEntropy();
 
     CAddress addrYou =
         addr.IsRoutable() && !IsProxy(addr) && addr.IsAddrV1Compatible()
             ? addr
             : CAddress(CService(), addr.nServices);
     CAddress addrMe = CAddress(CService(), nLocalNodeServices);
 
     const bool tx_relay = !m_ignore_incoming_txs &&
                           pnode.m_tx_relay != nullptr && !pnode.IsFeelerConn();
     m_connman.PushMessage(
         &pnode, CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::VERSION, PROTOCOL_VERSION,
                           uint64_t(nLocalNodeServices), nTime, addrYou, addrMe,
                           nonce, userAgent(config), nNodeStartingHeight,
                           tx_relay, extraEntropy));
 
     if (fLogIPs) {
         LogPrint(BCLog::NET,
                  "send version message: version %d, blocks=%d, us=%s, them=%s, "
                  "txrelay=%d, peer=%d\n",
                  PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(),
                  addrYou.ToString(), tx_relay, nodeid);
     } else {
         LogPrint(BCLog::NET,
                  "send version message: version %d, blocks=%d, us=%s, "
                  "txrelay=%d, peer=%d\n",
                  PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(),
                  tx_relay, nodeid);
     }
 }
 
 void PeerManagerImpl::AddTxAnnouncement(
     const CNode &node, const TxId &txid,
     std::chrono::microseconds current_time) {
     // For m_txrequest and state
     AssertLockHeld(::cs_main);
 
     if (TooManyAnnouncements(node, m_txrequest, TX_REQUEST_PARAMS)) {
         return;
     }
 
     const bool preferred = isPreferredDownloadPeer(node);
     auto reqtime = ComputeRequestTime(node, m_txrequest, TX_REQUEST_PARAMS,
                                       current_time, preferred);
 
     m_txrequest.ReceivedInv(node.GetId(), txid, preferred, reqtime);
 }
 
 void PeerManagerImpl::AddProofAnnouncement(
     const CNode &node, const avalanche::ProofId &proofid,
     std::chrono::microseconds current_time, bool preferred) {
     // For m_proofrequest
     AssertLockHeld(cs_proofrequest);
 
     if (TooManyAnnouncements(node, m_proofrequest, PROOF_REQUEST_PARAMS)) {
         return;
     }
 
     auto reqtime = ComputeRequestTime(
         node, m_proofrequest, PROOF_REQUEST_PARAMS, current_time, preferred);
 
     m_proofrequest.ReceivedInv(node.GetId(), proofid, preferred, reqtime);
 }
 
 // This function is used for testing the stale tip eviction logic, see
 // denialofservice_tests.cpp
 void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) {
     LOCK(cs_main);
     CNodeState *state = State(node);
     if (state) {
         state->m_last_block_announcement = time_in_seconds;
     }
 }
 
 void PeerManagerImpl::InitializeNode(const Config &config, CNode *pnode) {
     CAddress addr = pnode->addr;
     std::string addrName = pnode->GetAddrName();
     NodeId nodeid = pnode->GetId();
     {
         LOCK(cs_main);
         mapNodeState.emplace_hint(
             mapNodeState.end(), std::piecewise_construct,
             std::forward_as_tuple(nodeid),
             std::forward_as_tuple(addr, pnode->IsInboundConn()));
         assert(m_txrequest.Count(nodeid) == 0);
     }
     {
         PeerRef peer = std::make_shared<Peer>(nodeid);
         LOCK(m_peer_mutex);
         m_peer_map.emplace_hint(m_peer_map.end(), nodeid, std::move(peer));
     }
     if (!pnode->IsInboundConn()) {
         PushNodeVersion(config, *pnode, GetTime());
     }
 }
 
 void PeerManagerImpl::ReattemptInitialBroadcast(CScheduler &scheduler) const {
     std::set<TxId> unbroadcast_txids = m_mempool.GetUnbroadcastTxs();
 
     for (const TxId &txid : unbroadcast_txids) {
         // Sanity check: all unbroadcast txns should exist in the mempool
         if (m_mempool.exists(txid)) {
             RelayTransaction(txid, m_connman);
         } else {
             m_mempool.RemoveUnbroadcastTx(txid, true);
         }
     }
 
     if (g_avalanche && isAvalancheEnabled(gArgs)) {
         // Get and sanitize the list of proofids to broadcast. The RelayProof
         // call is done in a second loop to avoid locking cs_vNodes while
         // cs_peerManager is locked which would cause a potential deadlock due
         // to reversed lock order.
         auto unbroadcasted_proofids =
             g_avalanche->withPeerManager([&](avalanche::PeerManager &pm) {
                 auto unbroadcasted_proofids = pm.getUnbroadcastProofs();
 
                 auto it = unbroadcasted_proofids.begin();
                 while (it != unbroadcasted_proofids.end()) {
                     // Sanity check: all unbroadcast proofs should be bound to a
                     // peer in the peermanager
                     if (!pm.isBoundToPeer(*it)) {
                         pm.removeUnbroadcastProof(*it);
                         it = unbroadcasted_proofids.erase(it);
                         continue;
                     }
 
                     ++it;
                 }
 
                 return unbroadcasted_proofids;
             });
 
         // Remaining proofids are the ones to broadcast
         for (const auto &proofid : unbroadcasted_proofids) {
             RelayProof(proofid, m_connman);
         }
     }
 
     // Schedule next run for 10-15 minutes in the future.
     // We add randomness on every cycle to avoid the possibility of P2P
     // fingerprinting.
     const auto reattemptBroadcastInterval = 10min + GetRandMillis(5min);
     scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); },
                               reattemptBroadcastInterval);
 }
 
 void PeerManagerImpl::UpdateAvalancheStatistics() const {
     m_connman.ForEachNode([](CNode *pnode) {
         if (pnode->m_avalanche_state) {
             pnode->m_avalanche_state->updateAvailabilityScore();
         }
     });
 }
 
 void PeerManagerImpl::AvalanchePeriodicNetworking(CScheduler &scheduler) const {
     const auto now = GetTime<std::chrono::seconds>();
     std::vector<NodeId> avanode_ids;
 
     const bool fQuorumEstablished =
         g_avalanche && g_avalanche->isQuorumEstablished();
 
     if (!g_avalanche) {
         // Not enabled or not ready yet, retry later
         goto scheduleLater;
     }
 
     m_connman.ForEachNode([&](CNode *pnode) {
         // Build a list of the avalanche peers nodeids
         if (pnode->m_avalanche_state &&
             (!fQuorumEstablished || !pnode->IsInboundConn())) {
             avanode_ids.push_back(pnode->GetId());
         }
 
         // If a proof radix tree timed out, cleanup
         if (pnode->m_proof_relay &&
             now > (pnode->m_proof_relay->lastSharedProofsUpdate.load() +
                    AVALANCHE_AVAPROOFS_TIMEOUT)) {
             pnode->m_proof_relay->sharedProofs = {};
         }
     });
 
     if (avanode_ids.empty()) {
         // No node is available for messaging, retry later
         goto scheduleLater;
     }
 
     Shuffle(avanode_ids.begin(), avanode_ids.end(), FastRandomContext());
 
     if (!fQuorumEstablished ||
         g_avalanche->withPeerManager([&](avalanche::PeerManager &pm) {
             return pm.shouldRequestMoreNodes();
         })) {
         // Randomly select an avalanche peer to send the getavaaddr message to
         const NodeId avanodeId = avanode_ids.front();
 
         m_connman.ForNode(avanodeId, [&](CNode *pavanode) {
             LogPrint(BCLog::AVALANCHE,
                      "Requesting more avalanche addresses from peer %d\n",
                      avanodeId);
             m_connman.PushMessage(pavanode,
                                   CNetMsgMaker(pavanode->GetCommonVersion())
                                       .Make(NetMsgType::GETAVAADDR));
             PeerRef peer = GetPeerRef(avanodeId);
             WITH_LOCK(peer->m_addr_token_bucket_mutex,
                       peer->m_addr_token_bucket += GetMaxAddrToSend());
             return true;
         });
     }
 
     if (m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
         // Don't request proofs while in IBD. We're likely to orphan them
         // because we don't have the UTXOs.
         goto scheduleLater;
     }
 
     // If we never had an avaproofs message yet, be kind and only request to a
     // subset of our peers as we expect a ton of avaproofs message in the
     // process.
     if (g_avalanche->getAvaproofsNodeCounter() == 0) {
         avanode_ids.resize(std::min<size_t>(avanode_ids.size(), 3));
     }
 
     for (NodeId nodeid : avanode_ids) {
         // Send a getavaproofs to one of our peers
         m_connman.ForNode(nodeid, [&](CNode *pavanode) {
             LogPrint(BCLog::AVALANCHE,
                      "Requesting compact proofs from peer %d\n",
                      pavanode->GetId());
             if (pavanode->m_proof_relay) {
                 m_connman.PushMessage(pavanode,
                                       CNetMsgMaker(pavanode->GetCommonVersion())
                                           .Make(NetMsgType::GETAVAPROOFS));
 
                 pavanode->m_proof_relay->compactproofs_requested = true;
             }
             return true;
         });
     }
 
 scheduleLater:
     // Schedule next run for 2-5 minutes in the future.
     // We add randomness on every cycle to avoid the possibility of P2P
     // fingerprinting.
     const auto avalanchePeriodicNetworkingInterval = 2min + GetRandMillis(3min);
     scheduler.scheduleFromNow([&] { AvalanchePeriodicNetworking(scheduler); },
                               avalanchePeriodicNetworkingInterval);
 }
 
 void PeerManagerImpl::FinalizeNode(const Config &config, const CNode &node,
                                    bool &fUpdateConnectionTime) {
     NodeId nodeid = node.GetId();
     fUpdateConnectionTime = false;
     {
         LOCK(cs_main);
         int misbehavior{0};
         {
             // We remove the PeerRef from g_peer_map here, but we don't always
             // destruct the Peer. Sometimes another thread is still holding a
             // PeerRef, so the refcount is >= 1. Be careful not to do any
             // processing here that assumes Peer won't be changed before it's
             // destructed.
             PeerRef peer = RemovePeer(nodeid);
             assert(peer != nullptr);
             misbehavior = WITH_LOCK(peer->m_misbehavior_mutex,
                                     return peer->m_misbehavior_score);
             LOCK(m_peer_mutex);
             m_peer_map.erase(nodeid);
         }
         CNodeState *state = State(nodeid);
         assert(state != nullptr);
 
         if (state->fSyncStarted) {
             nSyncStarted--;
         }
 
         if (node.fSuccessfullyConnected && misbehavior == 0 &&
             !node.IsBlockOnlyConn() && !node.IsInboundConn()) {
             // Only change visible addrman state for outbound, full-relay peers
             fUpdateConnectionTime = true;
         }
 
         for (const QueuedBlock &entry : state->vBlocksInFlight) {
             mapBlocksInFlight.erase(entry.hash);
         }
         WITH_LOCK(g_cs_orphans, m_orphanage.EraseForPeer(nodeid));
         m_txrequest.DisconnectedPeer(nodeid);
         nPreferredDownload -= state->fPreferredDownload;
         nPeersWithValidatedDownloads -=
             (state->nBlocksInFlightValidHeaders != 0);
         assert(nPeersWithValidatedDownloads >= 0);
         m_outbound_peers_with_protect_from_disconnect -=
             state->m_chain_sync.m_protect;
         assert(m_outbound_peers_with_protect_from_disconnect >= 0);
 
         mapNodeState.erase(nodeid);
 
         if (mapNodeState.empty()) {
             // Do a consistency check after the last peer is removed.
             assert(mapBlocksInFlight.empty());
             assert(nPreferredDownload == 0);
             assert(nPeersWithValidatedDownloads == 0);
             assert(m_outbound_peers_with_protect_from_disconnect == 0);
             assert(m_txrequest.Size() == 0);
         }
     }
 
     WITH_LOCK(cs_proofrequest, m_proofrequest.DisconnectedPeer(nodeid));
 
     LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid);
 }
 
 PeerRef PeerManagerImpl::GetPeerRef(NodeId id) const {
     LOCK(m_peer_mutex);
     auto it = m_peer_map.find(id);
     return it != m_peer_map.end() ? it->second : nullptr;
 }
 
 PeerRef PeerManagerImpl::RemovePeer(NodeId id) {
     PeerRef ret;
     LOCK(m_peer_mutex);
     auto it = m_peer_map.find(id);
     if (it != m_peer_map.end()) {
         ret = std::move(it->second);
         m_peer_map.erase(it);
     }
     return ret;
 }
 
 bool PeerManagerImpl::GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
     {
         LOCK(cs_main);
         CNodeState *state = State(nodeid);
         if (state == nullptr) {
             return false;
         }
         stats.nSyncHeight = state->pindexBestKnownBlock
                                 ? state->pindexBestKnownBlock->nHeight
                                 : -1;
         stats.nCommonHeight = state->pindexLastCommonBlock
                                   ? state->pindexLastCommonBlock->nHeight
                                   : -1;
         for (const QueuedBlock &queue : state->vBlocksInFlight) {
             if (queue.pindex) {
                 stats.vHeightInFlight.push_back(queue.pindex->nHeight);
             }
         }
     }
 
     PeerRef peer = GetPeerRef(nodeid);
     if (peer == nullptr) {
         return false;
     }
     stats.m_starting_height = peer->m_starting_height;
     // It is common for nodes with good ping times to suddenly become lagged,
     // due to a new block arriving or other large transfer.
     // Merely reporting pingtime might fool the caller into thinking the node
     // was still responsive, since pingtime does not update until the ping is
     // complete, which might take a while. So, if a ping is taking an unusually
     // long time in flight, the caller can immediately detect that this is
     // happening.
     std::chrono::microseconds ping_wait{0};
     if ((0 != peer->m_ping_nonce_sent) &&
         (0 != peer->m_ping_start.load().count())) {
         ping_wait =
             GetTime<std::chrono::microseconds>() - peer->m_ping_start.load();
     }
 
     stats.m_ping_wait = ping_wait;
     stats.m_addr_processed = peer->m_addr_processed.load();
     stats.m_addr_rate_limited = peer->m_addr_rate_limited.load();
     stats.m_addr_relay_enabled = peer->m_addr_relay_enabled.load();
 
     return true;
 }
 
 void PeerManagerImpl::AddToCompactExtraTransactions(const CTransactionRef &tx) {
     size_t max_extra_txn = gArgs.GetArg("-blockreconstructionextratxn",
                                         DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN);
     if (max_extra_txn <= 0) {
         return;
     }
 
     if (!vExtraTxnForCompact.size()) {
         vExtraTxnForCompact.resize(max_extra_txn);
     }
 
     vExtraTxnForCompact[vExtraTxnForCompactIt] =
         std::make_pair(tx->GetHash(), tx);
     vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn;
 }
 
 void PeerManagerImpl::Misbehaving(const NodeId pnode, const int howmuch,
                                   const std::string &message) {
     assert(howmuch > 0);
 
     PeerRef peer = GetPeerRef(pnode);
     if (peer == nullptr) {
         return;
     }
 
     LOCK(peer->m_misbehavior_mutex);
 
     peer->m_misbehavior_score += howmuch;
     const std::string message_prefixed =
         message.empty() ? "" : (": " + message);
     if (peer->m_misbehavior_score >= DISCOURAGEMENT_THRESHOLD &&
         peer->m_misbehavior_score - howmuch < DISCOURAGEMENT_THRESHOLD) {
         LogPrint(BCLog::NET,
                  "Misbehaving: peer=%d (%d -> %d) BAN THRESHOLD EXCEEDED%s\n",
                  pnode, peer->m_misbehavior_score - howmuch,
                  peer->m_misbehavior_score, message_prefixed);
         peer->m_should_discourage = true;
     } else {
         LogPrint(BCLog::NET, "Misbehaving: peer=%d (%d -> %d)%s\n", pnode,
                  peer->m_misbehavior_score - howmuch, peer->m_misbehavior_score,
                  message_prefixed);
     }
 }
 
 bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid,
                                               const BlockValidationState &state,
                                               bool via_compact_block,
                                               const std::string &message) {
     switch (state.GetResult()) {
         case BlockValidationResult::BLOCK_RESULT_UNSET:
             break;
         // The node is providing invalid data:
         case BlockValidationResult::BLOCK_CONSENSUS:
         case BlockValidationResult::BLOCK_MUTATED:
             if (!via_compact_block) {
                 Misbehaving(nodeid, 100, message);
                 return true;
             }
             break;
         case BlockValidationResult::BLOCK_CACHED_INVALID: {
             LOCK(cs_main);
             CNodeState *node_state = State(nodeid);
             if (node_state == nullptr) {
                 break;
             }
 
             // Ban outbound (but not inbound) peers if on an invalid chain.
             // Exempt HB compact block peers. Manual connections are always
             // protected from discouragement.
             if (!via_compact_block && !node_state->m_is_inbound) {
                 Misbehaving(nodeid, 100, message);
                 return true;
             }
             break;
         }
         case BlockValidationResult::BLOCK_INVALID_HEADER:
         case BlockValidationResult::BLOCK_CHECKPOINT:
         case BlockValidationResult::BLOCK_INVALID_PREV:
             Misbehaving(nodeid, 100, message);
             return true;
         case BlockValidationResult::BLOCK_FINALIZATION:
             // TODO: Use the state object to report this is probably not the
             // best idea. This is effectively unreachable, unless there is a bug
             // somewhere.
             Misbehaving(nodeid, 20, message);
             return true;
         // Conflicting (but not necessarily invalid) data or different policy:
         case BlockValidationResult::BLOCK_MISSING_PREV:
             // TODO: Handle this much more gracefully (10 DoS points is super
             // arbitrary)
             Misbehaving(nodeid, 10, message);
             return true;
         case BlockValidationResult::BLOCK_RECENT_CONSENSUS_CHANGE:
         case BlockValidationResult::BLOCK_TIME_FUTURE:
             break;
     }
     if (message != "") {
         LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message);
     }
     return false;
 }
 
 bool PeerManagerImpl::MaybePunishNodeForTx(NodeId nodeid,
                                            const TxValidationState &state,
                                            const std::string &message) {
     switch (state.GetResult()) {
         case TxValidationResult::TX_RESULT_UNSET:
             break;
         // The node is providing invalid data:
         case TxValidationResult::TX_CONSENSUS:
             Misbehaving(nodeid, 100, message);
             return true;
         // Conflicting (but not necessarily invalid) data or different policy:
         case TxValidationResult::TX_RECENT_CONSENSUS_CHANGE:
         case TxValidationResult::TX_INPUTS_NOT_STANDARD:
         case TxValidationResult::TX_NOT_STANDARD:
         case TxValidationResult::TX_MISSING_INPUTS:
         case TxValidationResult::TX_PREMATURE_SPEND:
         case TxValidationResult::TX_CONFLICT:
         case TxValidationResult::TX_MEMPOOL_POLICY:
             break;
     }
     if (message != "") {
         LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message);
     }
     return false;
 }
 
 bool PeerManagerImpl::BlockRequestAllowed(
     const CBlockIndex *pindex, const Consensus::Params &consensusParams) {
     AssertLockHeld(cs_main);
     if (m_chainman.ActiveChain().Contains(pindex)) {
         return true;
     }
     return pindex->IsValid(BlockValidity::SCRIPTS) &&
            (pindexBestHeader != nullptr) &&
            (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() <
             STALE_RELAY_AGE_LIMIT) &&
            (GetBlockProofEquivalentTime(*pindexBestHeader, *pindex,
                                         *pindexBestHeader, consensusParams) <
             STALE_RELAY_AGE_LIMIT);
 }
 
 std::unique_ptr<PeerManager>
 PeerManager::make(const CChainParams &chainparams, CConnman &connman,
                   BanMan *banman, CScheduler &scheduler,
                   ChainstateManager &chainman, CTxMemPool &pool,
                   bool ignore_incoming_txs) {
     return std::make_unique<PeerManagerImpl>(chainparams, connman, banman,
                                              scheduler, chainman, pool,
                                              ignore_incoming_txs);
 }
 
 PeerManagerImpl::PeerManagerImpl(const CChainParams &chainparams,
                                  CConnman &connman, BanMan *banman,
                                  CScheduler &scheduler,
                                  ChainstateManager &chainman, CTxMemPool &pool,
                                  bool ignore_incoming_txs)
     : m_chainparams(chainparams), m_connman(connman), m_banman(banman),
       m_chainman(chainman), m_mempool(pool), m_stale_tip_check_time(0),
       m_ignore_incoming_txs(ignore_incoming_txs) {
     // Initialize global variables that cannot be constructed at startup.
     recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
 
     {
         LOCK(cs_rejectedProofs);
         rejectedProofs =
             std::make_unique<CRollingBloomFilter>(100000, 0.000001);
     }
 
     // Blocks don't typically have more than 4000 transactions, so this should
     // be at least six blocks (~1 hr) worth of transactions that we can store.
     // If the number of transactions appearing in a block goes up, or if we are
     // seeing getdata requests more than an hour after initial announcement, we
     // can increase this number.
     // The false positive rate of 1/1M should come out to less than 1
     // transaction per day that would be inadvertently ignored (which is the
     // same probability that we have in the reject filter).
     m_recent_confirmed_transactions.reset(
         new CRollingBloomFilter(24000, 0.000001));
 
     // Stale tip checking and peer eviction are on two different timers, but we
     // don't want them to get out of sync due to drift in the scheduler, so we
     // combine them in one function and schedule at the quicker (peer-eviction)
     // timer.
     static_assert(
         EXTRA_PEER_CHECK_INTERVAL < STALE_CHECK_INTERVAL,
         "peer eviction timer should be less than stale tip check timer");
     scheduler.scheduleEvery(
         [this]() {
             this->CheckForStaleTipAndEvictPeers();
             return true;
         },
         std::chrono::seconds{EXTRA_PEER_CHECK_INTERVAL});
 
     // schedule next run for 10-15 minutes in the future
     const auto reattemptBroadcastInterval = 10min + GetRandMillis(5min);
     scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); },
                               reattemptBroadcastInterval);
 
     // Update the avalanche statistics on a schedule
     scheduler.scheduleEvery(
         [this]() {
             UpdateAvalancheStatistics();
             return true;
         },
         AVALANCHE_STATISTICS_REFRESH_PERIOD);
 
     // schedule next run for 2-5 minutes in the future
     const auto avalanchePeriodicNetworkingInterval = 2min + GetRandMillis(3min);
     scheduler.scheduleFromNow([&] { AvalanchePeriodicNetworking(scheduler); },
                               avalanchePeriodicNetworkingInterval);
 }
 
 /**
  * Evict orphan txn pool entries based on a newly connected
  * block, remember the recently confirmed transactions, and delete tracked
  * announcements for them. Also save the time of the last tip update.
  */
 void PeerManagerImpl::BlockConnected(
     const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex) {
     m_orphanage.EraseForBlock(*pblock);
     m_last_tip_update = GetTime();
 
     {
         LOCK(m_recent_confirmed_transactions_mutex);
         for (const CTransactionRef &ptx : pblock->vtx) {
             m_recent_confirmed_transactions->insert(ptx->GetId());
         }
     }
     {
         LOCK(cs_main);
         for (const auto &ptx : pblock->vtx) {
             m_txrequest.ForgetInvId(ptx->GetId());
         }
     }
 }
 
 void PeerManagerImpl::BlockDisconnected(
     const std::shared_ptr<const CBlock> &block, const CBlockIndex *pindex) {
     // To avoid relay problems with transactions that were previously
     // confirmed, clear our filter of recently confirmed transactions whenever
     // there's a reorg.
     // This means that in a 1-block reorg (where 1 block is disconnected and
     // then another block reconnected), our filter will drop to having only one
     // block's worth of transactions in it, but that should be fine, since
     // presumably the most common case of relaying a confirmed transaction
     // should be just after a new block containing it is found.
     LOCK(m_recent_confirmed_transactions_mutex);
     m_recent_confirmed_transactions->reset();
 }
 
 // All of the following cache a recent block, and are protected by
 // cs_most_recent_block
 static RecursiveMutex cs_most_recent_block;
 static std::shared_ptr<const CBlock>
     most_recent_block GUARDED_BY(cs_most_recent_block);
 static std::shared_ptr<const CBlockHeaderAndShortTxIDs>
     most_recent_compact_block GUARDED_BY(cs_most_recent_block);
 static uint256 most_recent_block_hash GUARDED_BY(cs_most_recent_block);
 
 /**
  * Maintain state about the best-seen block and fast-announce a compact block
  * to compatible peers.
  */
 void PeerManagerImpl::NewPoWValidBlock(
     const CBlockIndex *pindex, const std::shared_ptr<const CBlock> &pblock) {
     std::shared_ptr<const CBlockHeaderAndShortTxIDs> pcmpctblock =
         std::make_shared<const CBlockHeaderAndShortTxIDs>(*pblock);
     const CNetMsgMaker msgMaker(PROTOCOL_VERSION);
 
     LOCK(cs_main);
 
     static int nHighestFastAnnounce = 0;
     if (pindex->nHeight <= nHighestFastAnnounce) {
         return;
     }
     nHighestFastAnnounce = pindex->nHeight;
 
     uint256 hashBlock(pblock->GetHash());
 
     {
         LOCK(cs_most_recent_block);
         most_recent_block_hash = hashBlock;
         most_recent_block = pblock;
         most_recent_compact_block = pcmpctblock;
     }
 
     m_connman.ForEachNode(
         [this, &pcmpctblock, pindex, &msgMaker,
          &hashBlock](CNode *pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
             AssertLockHeld(::cs_main);
 
             // TODO: Avoid the repeated-serialization here
             if (pnode->GetCommonVersion() < INVALID_CB_NO_BAN_VERSION ||
                 pnode->fDisconnect) {
                 return;
             }
             ProcessBlockAvailability(pnode->GetId());
             CNodeState &state = *State(pnode->GetId());
             // If the peer has, or we announced to them the previous block
             // already, but we don't think they have this one, go ahead and
             // announce it.
             if (state.fPreferHeaderAndIDs && !PeerHasHeader(&state, pindex) &&
                 PeerHasHeader(&state, pindex->pprev)) {
                 LogPrint(BCLog::NET,
                          "%s sending header-and-ids %s to peer=%d\n",
                          "PeerManager::NewPoWValidBlock", hashBlock.ToString(),
                          pnode->GetId());
                 m_connman.PushMessage(
                     pnode, msgMaker.Make(NetMsgType::CMPCTBLOCK, *pcmpctblock));
                 state.pindexBestHeaderSent = pindex;
             }
         });
 }
 
 /**
  * Update our best height and announce any block hashes which weren't previously
  * in m_chainman.ActiveChain() to our peers.
  */
 void PeerManagerImpl::UpdatedBlockTip(const CBlockIndex *pindexNew,
                                       const CBlockIndex *pindexFork,
                                       bool fInitialDownload) {
     SetBestHeight(pindexNew->nHeight);
     SetServiceFlagsIBDCache(!fInitialDownload);
 
     // Don't relay inventory during initial block download.
     if (fInitialDownload) {
         return;
     }
 
     // Find the hashes of all blocks that weren't previously in the best chain.
     std::vector<BlockHash> vHashes;
     const CBlockIndex *pindexToAnnounce = pindexNew;
     while (pindexToAnnounce != pindexFork) {
         vHashes.push_back(pindexToAnnounce->GetBlockHash());
         pindexToAnnounce = pindexToAnnounce->pprev;
         if (vHashes.size() == MAX_BLOCKS_TO_ANNOUNCE) {
             // Limit announcements in case of a huge reorganization. Rely on the
             // peer's synchronization mechanism in that case.
             break;
         }
     }
 
     {
         LOCK(m_peer_mutex);
         for (auto &it : m_peer_map) {
             Peer &peer = *it.second;
             LOCK(peer.m_block_inv_mutex);
             for (const BlockHash &hash : reverse_iterate(vHashes)) {
                 peer.m_blocks_for_headers_relay.push_back(hash);
             }
         }
     }
 
     m_connman.WakeMessageHandler();
 }
 
 /**
  * Handle invalid block rejection and consequent peer banning, maintain which
  * peers announce compact blocks.
  */
 void PeerManagerImpl::BlockChecked(const CBlock &block,
                                    const BlockValidationState &state) {
     LOCK(cs_main);
 
     const BlockHash hash = block.GetHash();
     std::map<BlockHash, std::pair<NodeId, bool>>::iterator it =
         mapBlockSource.find(hash);
 
     // If the block failed validation, we know where it came from and we're
     // still connected to that peer, maybe punish.
     if (state.IsInvalid() && it != mapBlockSource.end() &&
         State(it->second.first)) {
         MaybePunishNodeForBlock(/*nodeid=*/it->second.first, state,
                                 /*via_compact_block=*/!it->second.second);
     }
     // Check that:
     // 1. The block is valid
     // 2. We're not in initial block download
     // 3. This is currently the best block we're aware of. We haven't updated
     //    the tip yet so we have no way to check this directly here. Instead we
     //    just check that there are currently no other blocks in flight.
     else if (state.IsValid() &&
              !m_chainman.ActiveChainstate().IsInitialBlockDownload() &&
              mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) {
         if (it != mapBlockSource.end()) {
             MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first);
         }
     }
 
     if (it != mapBlockSource.end()) {
         mapBlockSource.erase(it);
     }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // Messages
 //
 
 bool PeerManagerImpl::AlreadyHaveTx(const TxId &txid) {
     assert(recentRejects);
     if (m_chainman.ActiveChain().Tip()->GetBlockHash() !=
         hashRecentRejectsChainTip) {
         // If the chain tip has changed previously rejected transactions
         // might be now valid, e.g. due to a nLockTime'd tx becoming
         // valid, or a double-spend. Reset the rejects filter and give
         // those txs a second chance.
         hashRecentRejectsChainTip =
             m_chainman.ActiveChain().Tip()->GetBlockHash();
         recentRejects->reset();
     }
 
     if (m_orphanage.HaveTx(txid)) {
         return true;
     }
 
     {
         LOCK(m_recent_confirmed_transactions_mutex);
         if (m_recent_confirmed_transactions->contains(txid)) {
             return true;
         }
     }
 
     return recentRejects->contains(txid) || m_mempool.exists(txid);
 }
 
 bool PeerManagerImpl::AlreadyHaveBlock(const BlockHash &block_hash) {
     return m_chainman.m_blockman.LookupBlockIndex(block_hash) != nullptr;
 }
 
 bool PeerManagerImpl::AlreadyHaveProof(const avalanche::ProofId &proofid) {
     assert(g_avalanche);
 
     const bool hasProof = g_avalanche->withPeerManager(
         [&proofid](avalanche::PeerManager &pm) { return pm.exists(proofid); });
 
     LOCK(cs_rejectedProofs);
     return hasProof || rejectedProofs->contains(proofid);
 }
 
 void PeerManagerImpl::SendPings() {
     LOCK(m_peer_mutex);
     for (auto &it : m_peer_map) {
         it.second->m_ping_queued = true;
     }
 }
 
 void RelayTransaction(const TxId &txid, const CConnman &connman) {
     connman.ForEachNode(
         [&txid](CNode *pnode) { pnode->PushTxInventory(txid); });
 }
 
 void RelayProof(const avalanche::ProofId &proofid, const CConnman &connman) {
     connman.ForEachNode(
         [&proofid](CNode *pnode) { pnode->PushProofInventory(proofid); });
 }
 
 void PeerManagerImpl::RelayAddress(NodeId originator, const CAddress &addr,
                                    bool fReachable) {
     // We choose the same nodes within a given 24h window (if the list of
     // connected nodes does not change) and we don't relay to nodes that already
     // know an address. So within 24h we will likely relay a given address once.
     // This is to prevent a peer from unjustly giving their address better
     // propagation by sending it to us repeatedly.
 
     if (!fReachable && !addr.IsRelayable()) {
         return;
     }
 
     // Relay to a limited number of other nodes
     // Use deterministic randomness to send to the same nodes for 24 hours
     // at a time so the m_addr_knowns of the chosen nodes prevent repeats
     uint64_t hashAddr = addr.GetHash();
     const CSipHasher hasher =
         m_connman.GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY)
             .Write(hashAddr << 32)
             .Write((GetTime() + hashAddr) / (24 * 60 * 60));
     FastRandomContext insecure_rand;
 
     // Relay reachable addresses to 2 peers. Unreachable addresses are relayed
     // randomly to 1 or 2 peers.
     unsigned int nRelayNodes = (fReachable || (hasher.Finalize() & 1)) ? 2 : 1;
     std::array<std::pair<uint64_t, Peer *>, 2> best{
         {{0, nullptr}, {0, nullptr}}};
     assert(nRelayNodes <= best.size());
 
     LOCK(m_peer_mutex);
 
     for (auto &[id, peer] : m_peer_map) {
         if (peer->m_addr_relay_enabled && id != originator &&
             IsAddrCompatible(*peer, addr)) {
             uint64_t hashKey = CSipHasher(hasher).Write(id).Finalize();
             for (unsigned int i = 0; i < nRelayNodes; i++) {
                 if (hashKey > best[i].first) {
                     std::copy(best.begin() + i, best.begin() + nRelayNodes - 1,
                               best.begin() + i + 1);
                     best[i] = std::make_pair(hashKey, peer.get());
                     break;
                 }
             }
         }
     };
 
     for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) {
         PushAddress(*best[i].second, addr, insecure_rand);
     }
 }
 
 void PeerManagerImpl::ProcessGetBlockData(const Config &config, CNode &pfrom,
                                           Peer &peer, const CInv &inv,
                                           CConnman &connman) {
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
 
     const BlockHash hash(inv.hash);
 
     bool send = false;
     std::shared_ptr<const CBlock> a_recent_block;
     std::shared_ptr<const CBlockHeaderAndShortTxIDs> a_recent_compact_block;
     {
         LOCK(cs_most_recent_block);
         a_recent_block = most_recent_block;
         a_recent_compact_block = most_recent_compact_block;
     }
 
     bool need_activate_chain = false;
     {
         LOCK(cs_main);
         const CBlockIndex *pindex =
             m_chainman.m_blockman.LookupBlockIndex(hash);
         if (pindex) {
             if (pindex->HaveTxsDownloaded() &&
                 !pindex->IsValid(BlockValidity::SCRIPTS) &&
                 pindex->IsValid(BlockValidity::TREE)) {
                 // If we have the block and all of its parents, but have not yet
                 // validated it, we might be in the middle of connecting it (ie
                 // in the unlock of cs_main before ActivateBestChain but after
                 // AcceptBlock). In this case, we need to run ActivateBestChain
                 // prior to checking the relay conditions below.
                 need_activate_chain = true;
             }
         }
     } // release cs_main before calling ActivateBestChain
     if (need_activate_chain) {
         BlockValidationState state;
         if (!m_chainman.ActiveChainstate().ActivateBestChain(config, state,
                                                              a_recent_block)) {
             LogPrint(BCLog::NET, "failed to activate chain (%s)\n",
                      state.ToString());
         }
     }
 
     LOCK(cs_main);
     const CBlockIndex *pindex = m_chainman.m_blockman.LookupBlockIndex(hash);
     if (pindex) {
         send = BlockRequestAllowed(pindex, consensusParams);
         if (!send) {
             LogPrint(BCLog::NET,
                      "%s: ignoring request from peer=%i for old "
                      "block that isn't in the main chain\n",
                      __func__, pfrom.GetId());
         }
     }
     const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
     // Disconnect node in case we have reached the outbound limit for serving
     // historical blocks.
     if (send && connman.OutboundTargetReached(true) &&
         (((pindexBestHeader != nullptr) &&
           (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() >
            HISTORICAL_BLOCK_AGE)) ||
          inv.IsMsgFilteredBlk()) &&
         // nodes with the download permission may exceed target
         !pfrom.HasPermission(PF_DOWNLOAD)) {
         LogPrint(BCLog::NET,
                  "historical block serving limit reached, disconnect peer=%d\n",
                  pfrom.GetId());
 
         // disconnect node
         pfrom.fDisconnect = true;
         send = false;
     }
     // Avoid leaking prune-height by never sending blocks below the
     // NODE_NETWORK_LIMITED threshold.
     // Add two blocks buffer extension for possible races
     if (send && !pfrom.HasPermission(PF_NOBAN) &&
         ((((pfrom.GetLocalServices() & NODE_NETWORK_LIMITED) ==
            NODE_NETWORK_LIMITED) &&
           ((pfrom.GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) &&
           (m_chainman.ActiveChain().Tip()->nHeight - pindex->nHeight >
            (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2)))) {
         LogPrint(BCLog::NET,
                  "Ignore block request below NODE_NETWORK_LIMITED "
                  "threshold from peer=%d\n",
                  pfrom.GetId());
 
         // disconnect node and prevent it from stalling (would otherwise wait
         // for the missing block)
         pfrom.fDisconnect = true;
         send = false;
     }
     // Pruned nodes may have deleted the block, so check whether it's available
     // before trying to send.
     if (send && pindex->nStatus.hasData()) {
         std::shared_ptr<const CBlock> pblock;
         if (a_recent_block &&
             a_recent_block->GetHash() == pindex->GetBlockHash()) {
             pblock = a_recent_block;
         } else {
             // Send block from disk
             std::shared_ptr<CBlock> pblockRead = std::make_shared<CBlock>();
             if (!ReadBlockFromDisk(*pblockRead, pindex, consensusParams)) {
                 assert(!"cannot load block from disk");
             }
             pblock = pblockRead;
         }
         if (inv.IsMsgBlk()) {
             connman.PushMessage(&pfrom,
                                 msgMaker.Make(NetMsgType::BLOCK, *pblock));
         } else if (inv.IsMsgFilteredBlk()) {
             bool sendMerkleBlock = false;
             CMerkleBlock merkleBlock;
             if (pfrom.m_tx_relay != nullptr) {
                 LOCK(pfrom.m_tx_relay->cs_filter);
                 if (pfrom.m_tx_relay->pfilter) {
                     sendMerkleBlock = true;
                     merkleBlock =
                         CMerkleBlock(*pblock, *pfrom.m_tx_relay->pfilter);
                 }
             }
             if (sendMerkleBlock) {
                 connman.PushMessage(
                     &pfrom,
                     msgMaker.Make(NetMsgType::MERKLEBLOCK, merkleBlock));
                 // CMerkleBlock just contains hashes, so also push any
                 // transactions in the block the client did not see. This avoids
                 // hurting performance by pointlessly requiring a round-trip.
                 // Note that there is currently no way for a node to request any
                 // single transactions we didn't send here - they must either
                 // disconnect and retry or request the full block. Thus, the
                 // protocol spec specified allows for us to provide duplicate
                 // txn here, however we MUST always provide at least what the
                 // remote peer needs.
                 typedef std::pair<size_t, uint256> PairType;
                 for (PairType &pair : merkleBlock.vMatchedTxn) {
                     connman.PushMessage(
                         &pfrom, msgMaker.Make(NetMsgType::TX,
                                               *pblock->vtx[pair.first]));
                 }
             }
             // else
             // no response
         } else if (inv.IsMsgCmpctBlk()) {
             // If a peer is asking for old blocks, we're almost guaranteed they
             // won't have a useful mempool to match against a compact block, and
             // we don't feel like constructing the object for them, so instead
             // we respond with the full, non-compact block.
             int nSendFlags = 0;
             if (CanDirectFetch(consensusParams) &&
                 pindex->nHeight >=
                     m_chainman.ActiveChain().Height() - MAX_CMPCTBLOCK_DEPTH) {
                 CBlockHeaderAndShortTxIDs cmpctblock(*pblock);
                 connman.PushMessage(
                     &pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK,
                                           cmpctblock));
             } else {
                 connman.PushMessage(
                     &pfrom,
                     msgMaker.Make(nSendFlags, NetMsgType::BLOCK, *pblock));
             }
         }
 
         {
             LOCK(peer.m_block_inv_mutex);
             // Trigger the peer node to send a getblocks request for the next
             // batch of inventory.
             if (hash == peer.m_continuation_block) {
                 // Send immediately. This must send even if redundant, and
                 // we want it right after the last block so they don't wait for
                 // other stuff first.
                 std::vector<CInv> vInv;
                 vInv.push_back(CInv(
                     MSG_BLOCK, m_chainman.ActiveChain().Tip()->GetBlockHash()));
                 connman.PushMessage(&pfrom,
                                     msgMaker.Make(NetMsgType::INV, vInv));
                 peer.m_continuation_block = BlockHash();
             }
         }
     }
 }
 
 CTransactionRef
 PeerManagerImpl::FindTxForGetData(const CNode &peer, const TxId &txid,
                                   const std::chrono::seconds mempool_req,
                                   const std::chrono::seconds now) {
     auto txinfo = m_mempool.info(txid);
     if (txinfo.tx) {
         // If a TX could have been INVed in reply to a MEMPOOL request,
         // or is older than UNCONDITIONAL_RELAY_DELAY, permit the request
         // unconditionally.
         if ((mempool_req.count() && txinfo.m_time <= mempool_req) ||
             txinfo.m_time <= now - UNCONDITIONAL_RELAY_DELAY) {
             return std::move(txinfo.tx);
         }
     }
 
     {
         LOCK(cs_main);
 
         // Otherwise, the transaction must have been announced recently.
         if (State(peer.GetId())->m_recently_announced_invs.contains(txid)) {
             // If it was, it can be relayed from either the mempool...
             if (txinfo.tx) {
                 return std::move(txinfo.tx);
             }
             // ... or the relay pool.
             auto mi = mapRelay.find(txid);
             if (mi != mapRelay.end()) {
                 return mi->second;
             }
         }
     }
 
     return {};
 }
 
 //! Determine whether or not a peer can request a proof, and return it (or
 //! nullptr if not found or not allowed).
 static avalanche::ProofRef
 FindProofForGetData(const CNode &peer, const avalanche::ProofId &proofid,
                     const std::chrono::seconds now) {
     avalanche::ProofRef proof;
 
     bool send_unconditionally =
         g_avalanche->withPeerManager([&](const avalanche::PeerManager &pm) {
             return pm.forPeer(proofid, [&](const avalanche::Peer &peer) {
                 proof = peer.proof;
 
                 // If we know that proof for long enough, allow for requesting
                 // it.
                 return peer.registration_time <=
                        now - UNCONDITIONAL_RELAY_DELAY;
             });
         });
 
     if (!proof) {
         // Always send our local proof if it gets requested, assuming it's
         // valid. This will make it easier to bind with peers upon startup where
         // the status of our proof is unknown pending for a block. Note that it
         // still needs to have been announced first (presumably via an avahello
         // message).
         proof = g_avalanche->getLocalProof();
     }
 
     // We don't have this proof
     if (!proof) {
         return avalanche::ProofRef();
     }
 
     if (send_unconditionally) {
         return proof;
     }
 
     // Otherwise, the proofs must have been announced recently.
     LOCK(cs_main);
     if (State(peer.GetId())->m_recently_announced_proofs.contains(proofid)) {
         return proof;
     }
 
     return avalanche::ProofRef();
 }
 
 void PeerManagerImpl::ProcessGetData(
     const Config &config, CNode &pfrom, Peer &peer,
     const std::atomic<bool> &interruptMsgProc) {
     AssertLockNotHeld(cs_main);
 
     std::deque<CInv>::iterator it = peer.m_getdata_requests.begin();
     std::vector<CInv> vNotFound;
     const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
 
     const std::chrono::seconds now = GetTime<std::chrono::seconds>();
     // Get last mempool request time
     const std::chrono::seconds mempool_req =
         pfrom.m_tx_relay != nullptr
             ? pfrom.m_tx_relay->m_last_mempool_req.load()
             : std::chrono::seconds::min();
 
     // Process as many TX or AVA_PROOF items from the front of the getdata
     // queue as possible, since they're common and it's efficient to batch
     // process them.
     while (it != peer.m_getdata_requests.end()) {
         if (interruptMsgProc) {
             return;
         }
         // The send buffer provides backpressure. If there's no space in
         // the buffer, pause processing until the next call.
         if (pfrom.fPauseSend) {
             break;
         }
 
         const CInv &inv = *it;
 
         if (it->IsMsgProof()) {
             const avalanche::ProofId proofid(inv.hash);
             auto proof = FindProofForGetData(pfrom, proofid, now);
             if (proof) {
                 m_connman.PushMessage(
                     &pfrom, msgMaker.Make(NetMsgType::AVAPROOF, *proof));
                 g_avalanche->withPeerManager([&](avalanche::PeerManager &pm) {
                     pm.removeUnbroadcastProof(proofid);
                 });
             } else {
                 vNotFound.push_back(inv);
             }
 
             ++it;
             continue;
         }
 
         if (it->IsMsgTx()) {
             if (pfrom.m_tx_relay == nullptr) {
                 // Ignore GETDATA requests for transactions from blocks-only
                 // peers.
                 continue;
             }
 
             const TxId txid(inv.hash);
             CTransactionRef tx =
                 FindTxForGetData(pfrom, txid, mempool_req, now);
             if (tx) {
                 int nSendFlags = 0;
                 m_connman.PushMessage(
                     &pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *tx));
                 m_mempool.RemoveUnbroadcastTx(txid);
                 // As we're going to send tx, make sure its unconfirmed parents
                 // are made requestable.
                 std::vector<TxId> parent_ids_to_add;
                 {
                     LOCK(m_mempool.cs);
                     auto txiter = m_mempool.GetIter(tx->GetId());
                     if (txiter) {
                         const CTxMemPoolEntry::Parents &parents =
                             (*txiter)->GetMemPoolParentsConst();
                         parent_ids_to_add.reserve(parents.size());
                         for (const CTxMemPoolEntry &parent : parents) {
                             if (parent.GetTime() >
                                 now - UNCONDITIONAL_RELAY_DELAY) {
                                 parent_ids_to_add.push_back(
                                     parent.GetTx().GetId());
                             }
                         }
                     }
                 }
                 for (const TxId &parent_txid : parent_ids_to_add) {
                     // Relaying a transaction with a recent but unconfirmed
                     // parent.
                     if (WITH_LOCK(pfrom.m_tx_relay->cs_tx_inventory,
                                   return !pfrom.m_tx_relay->filterInventoryKnown
                                               .contains(parent_txid))) {
                         LOCK(cs_main);
                         State(pfrom.GetId())
                             ->m_recently_announced_invs.insert(parent_txid);
                     }
                 }
             } else {
                 vNotFound.push_back(inv);
             }
 
             ++it;
             continue;
         }
 
         // It's neither a proof nor a transaction
         break;
     }
 
     // Only process one BLOCK item per call, since they're uncommon and can be
     // expensive to process.
     if (it != peer.m_getdata_requests.end() && !pfrom.fPauseSend) {
         const CInv &inv = *it++;
         if (inv.IsGenBlkMsg()) {
             ProcessGetBlockData(config, pfrom, peer, inv, m_connman);
         }
         // else: If the first item on the queue is an unknown type, we erase it
         // and continue processing the queue on the next call.
     }
 
     peer.m_getdata_requests.erase(peer.m_getdata_requests.begin(), it);
 
     if (!vNotFound.empty()) {
         // Let the peer know that we didn't find what it asked for, so it
         // doesn't have to wait around forever. SPV clients care about this
         // message: it's needed when they are recursively walking the
         // dependencies of relevant unconfirmed transactions. SPV clients want
         // to do that because they want to know about (and store and rebroadcast
         // and risk analyze) the dependencies of transactions relevant to them,
         // without having to download the entire memory pool. Also, other nodes
         // can use these messages to automatically request a transaction from
         // some other peer that annnounced it, and stop waiting for us to
         // respond. In normal operation, we often send NOTFOUND messages for
         // parents of transactions that we relay; if a peer is missing a parent,
         // they may assume we have them and request the parents from us.
         m_connman.PushMessage(&pfrom,
                               msgMaker.Make(NetMsgType::NOTFOUND, vNotFound));
     }
 }
 
 void PeerManagerImpl::SendBlockTransactions(
     CNode &pfrom, const CBlock &block, const BlockTransactionsRequest &req) {
     BlockTransactions resp(req);
     for (size_t i = 0; i < req.indices.size(); i++) {
         if (req.indices[i] >= block.vtx.size()) {
             Misbehaving(pfrom, 100,
                         "getblocktxn with out-of-bounds tx indices");
             return;
         }
         resp.txn[i] = block.vtx[req.indices[i]];
     }
     LOCK(cs_main);
     const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
     int nSendFlags = 0;
     m_connman.PushMessage(
         &pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp));
 }
 
 void PeerManagerImpl::ProcessHeadersMessage(
     const Config &config, CNode &pfrom, const Peer &peer,
     const std::vector<CBlockHeader> &headers, bool via_compact_block) {
     const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
     size_t nCount = headers.size();
 
     if (nCount == 0) {
         // Nothing interesting. Stop asking this peers for more headers.
         return;
     }
 
     bool received_new_header = false;
     const CBlockIndex *pindexLast = nullptr;
     {
         LOCK(cs_main);
         CNodeState *nodestate = State(pfrom.GetId());
 
         // If this looks like it could be a block announcement (nCount <
         // MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that
         // don't connect:
         // - Send a getheaders message in response to try to connect the chain.
         // - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that
         // don't connect before giving DoS points
         // - Once a headers message is received that is valid and does connect,
         // nUnconnectingHeaders gets reset back to 0.
         if (!m_chainman.m_blockman.LookupBlockIndex(headers[0].hashPrevBlock) &&
             nCount < MAX_BLOCKS_TO_ANNOUNCE) {
             nodestate->nUnconnectingHeaders++;
             m_connman.PushMessage(
                 &pfrom, msgMaker.Make(NetMsgType::GETHEADERS,
                                       m_chainman.ActiveChain().GetLocator(
                                           pindexBestHeader),
                                       uint256()));
             LogPrint(
                 BCLog::NET,
                 "received header %s: missing prev block %s, sending getheaders "
                 "(%d) to end (peer=%d, nUnconnectingHeaders=%d)\n",
                 headers[0].GetHash().ToString(),
                 headers[0].hashPrevBlock.ToString(), pindexBestHeader->nHeight,
                 pfrom.GetId(), nodestate->nUnconnectingHeaders);
             // Set hashLastUnknownBlock for this peer, so that if we eventually
             // get the headers - even from a different peer - we can use this
             // peer to download.
             UpdateBlockAvailability(pfrom.GetId(), headers.back().GetHash());
 
             if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS ==
                 0) {
                 // The peer is sending us many headers we can't connect.
                 Misbehaving(pfrom, 20,
                             strprintf("%d non-connecting headers",
                                       nodestate->nUnconnectingHeaders));
             }
             return;
         }
 
         BlockHash hashLastBlock;
         for (const CBlockHeader &header : headers) {
             if (!hashLastBlock.IsNull() &&
                 header.hashPrevBlock != hashLastBlock) {
                 Misbehaving(pfrom, 20, "non-continuous headers sequence");
                 return;
             }
             hashLastBlock = header.GetHash();
         }
 
         // If we don't have the last header, then they'll have given us
         // something new (if these headers are valid).
         if (!m_chainman.m_blockman.LookupBlockIndex(hashLastBlock)) {
             received_new_header = true;
         }
     }
 
     BlockValidationState state;
     if (!m_chainman.ProcessNewBlockHeaders(config, headers, state,
                                            &pindexLast)) {
         if (state.IsInvalid()) {
             MaybePunishNodeForBlock(pfrom.GetId(), state, via_compact_block,
                                     "invalid header received");
             return;
         }
     }
 
     {
         LOCK(cs_main);
         CNodeState *nodestate = State(pfrom.GetId());
         if (nodestate->nUnconnectingHeaders > 0) {
             LogPrint(BCLog::NET,
                      "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n",
                      pfrom.GetId(), nodestate->nUnconnectingHeaders);
         }
         nodestate->nUnconnectingHeaders = 0;
 
         assert(pindexLast);
         UpdateBlockAvailability(pfrom.GetId(), pindexLast->GetBlockHash());
 
         // From here, pindexBestKnownBlock should be guaranteed to be non-null,
         // because it is set in UpdateBlockAvailability. Some nullptr checks are
         // still present, however, as belt-and-suspenders.
 
         if (received_new_header &&
             pindexLast->nChainWork >
                 m_chainman.ActiveChain().Tip()->nChainWork) {
             nodestate->m_last_block_announcement = GetTime();
         }
 
         if (nCount == MAX_HEADERS_RESULTS) {
             // Headers message had its maximum size; the peer may have more
             // headers.
             // TODO: optimize: if pindexLast is an ancestor of
             // m_chainman.ActiveChain().Tip or pindexBestHeader, continue from
             // there instead.
             LogPrint(
                 BCLog::NET,
                 "more getheaders (%d) to end to peer=%d (startheight:%d)\n",
                 pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height);
             m_connman.PushMessage(
                 &pfrom,
                 msgMaker.Make(NetMsgType::GETHEADERS,
                               m_chainman.ActiveChain().GetLocator(pindexLast),
                               uint256()));
         }
 
         bool fCanDirectFetch = CanDirectFetch(m_chainparams.GetConsensus());
         // If this set of headers is valid and ends in a block with at least as
         // much work as our tip, download as much as possible.
         if (fCanDirectFetch && pindexLast->IsValid(BlockValidity::TREE) &&
             m_chainman.ActiveChain().Tip()->nChainWork <=
                 pindexLast->nChainWork) {
             std::vector<const CBlockIndex *> vToFetch;
             const CBlockIndex *pindexWalk = pindexLast;
             // Calculate all the blocks we'd need to switch to pindexLast, up to
             // a limit.
             while (pindexWalk &&
                    !m_chainman.ActiveChain().Contains(pindexWalk) &&
                    vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
                 if (!pindexWalk->nStatus.hasData() &&
                     !mapBlocksInFlight.count(pindexWalk->GetBlockHash())) {
                     // We don't have this block, and it's not yet in flight.
                     vToFetch.push_back(pindexWalk);
                 }
                 pindexWalk = pindexWalk->pprev;
             }
             // If pindexWalk still isn't on our main chain, we're looking at a
             // very large reorg at a time we think we're close to caught up to
             // the main chain -- this shouldn't really happen. Bail out on the
             // direct fetch and rely on parallel download instead.
             if (!m_chainman.ActiveChain().Contains(pindexWalk)) {
                 LogPrint(
                     BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n",
                     pindexLast->GetBlockHash().ToString(), pindexLast->nHeight);
             } else {
                 std::vector<CInv> vGetData;
                 // Download as much as possible, from earliest to latest.
                 for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) {
                     if (nodestate->nBlocksInFlight >=
                         MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
                         // Can't download any more from this peer
                         break;
                     }
                     vGetData.push_back(CInv(MSG_BLOCK, pindex->GetBlockHash()));
                     MarkBlockAsInFlight(config, pfrom.GetId(),
                                         pindex->GetBlockHash(), pindex);
                     LogPrint(BCLog::NET, "Requesting block %s from  peer=%d\n",
                              pindex->GetBlockHash().ToString(), pfrom.GetId());
                 }
                 if (vGetData.size() > 1) {
                     LogPrint(BCLog::NET,
                              "Downloading blocks toward %s (%d) via headers "
                              "direct fetch\n",
                              pindexLast->GetBlockHash().ToString(),
                              pindexLast->nHeight);
                 }
                 if (vGetData.size() > 0) {
                     if (nodestate->fSupportsDesiredCmpctVersion &&
                         vGetData.size() == 1 && mapBlocksInFlight.size() == 1 &&
                         pindexLast->pprev->IsValid(BlockValidity::CHAIN)) {
                         // In any case, we want to download using a compact
                         // block, not a regular one.
                         vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash);
                     }
                     m_connman.PushMessage(
                         &pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData));
                 }
             }
         }
         // If we're in IBD, we want outbound peers that will serve us a useful
         // chain. Disconnect peers that are on chains with insufficient work.
         if (m_chainman.ActiveChainstate().IsInitialBlockDownload() &&
             nCount != MAX_HEADERS_RESULTS) {
             // When nCount < MAX_HEADERS_RESULTS, we know we have no more
             // headers to fetch from this peer.
             if (nodestate->pindexBestKnownBlock &&
                 nodestate->pindexBestKnownBlock->nChainWork <
                     nMinimumChainWork) {
                 // This peer has too little work on their headers chain to help
                 // us sync -- disconnect if it is an outbound disconnection
                 // candidate.
                 // Note: We compare their tip to nMinimumChainWork (rather than
                 // m_chainman.ActiveChain().Tip()) because we won't start block
                 // download until we have a headers chain that has at least
                 // nMinimumChainWork, even if a peer has a chain past our tip,
                 // as an anti-DoS measure.
                 if (pfrom.IsOutboundOrBlockRelayConn()) {
                     LogPrintf("Disconnecting outbound peer %d -- headers "
                               "chain has insufficient work\n",
                               pfrom.GetId());
                     pfrom.fDisconnect = true;
                 }
             }
         }
 
         // If this is an outbound full-relay peer, check to see if we should
         // protect it from the bad/lagging chain logic.
         // Note that outbound block-relay peers are excluded from this
         // protection, and thus always subject to eviction under the bad/lagging
         // chain logic.
         // See ChainSyncTimeoutState.
         if (!pfrom.fDisconnect && pfrom.IsFullOutboundConn() &&
             nodestate->pindexBestKnownBlock != nullptr) {
             if (m_outbound_peers_with_protect_from_disconnect <
                     MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT &&
                 nodestate->pindexBestKnownBlock->nChainWork >=
                     m_chainman.ActiveChain().Tip()->nChainWork &&
                 !nodestate->m_chain_sync.m_protect) {
                 LogPrint(BCLog::NET,
                          "Protecting outbound peer=%d from eviction\n",
                          pfrom.GetId());
                 nodestate->m_chain_sync.m_protect = true;
                 ++m_outbound_peers_with_protect_from_disconnect;
             }
         }
     }
 }
 
 /**
  * Reconsider orphan transactions after a parent has been accepted to the
  * mempool.
  *
  * @param[in,out]  orphan_work_set  The set of orphan transactions to
  *    reconsider. Generally only one orphan will be reconsidered on each call of
  *    this function. This set may be added to if accepting an orphan causes its
  *    children to be reconsidered.
  */
 void PeerManagerImpl::ProcessOrphanTx(const Config &config,
                                       std::set<TxId> &orphan_work_set) {
     AssertLockHeld(cs_main);
     AssertLockHeld(g_cs_orphans);
     while (!orphan_work_set.empty()) {
         const TxId orphanTxId = *orphan_work_set.begin();
         orphan_work_set.erase(orphan_work_set.begin());
 
         const auto [porphanTx, from_peer] = m_orphanage.GetTx(orphanTxId);
         if (porphanTx == nullptr) {
             continue;
         }
 
-        TxValidationState state;
-        if (AcceptToMemoryPool(m_chainman.ActiveChainstate(), config, m_mempool,
-                               state, porphanTx, false /* bypass_limits */)) {
+        const MempoolAcceptResult result =
+            AcceptToMemoryPool(m_chainman.ActiveChainstate(), config, m_mempool,
+                               porphanTx, false /* bypass_limits */);
+        const TxValidationState &state = result.m_state;
+        if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
             LogPrint(BCLog::MEMPOOL, "   accepted orphan tx %s\n",
                      orphanTxId.ToString());
             RelayTransaction(orphanTxId, m_connman);
             m_orphanage.AddChildrenToWorkSet(*porphanTx, orphan_work_set);
             m_orphanage.EraseTx(orphanTxId);
             break;
         } else if (state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) {
             if (state.IsInvalid()) {
                 LogPrint(BCLog::MEMPOOL,
                          "   invalid orphan tx %s from peer=%d. %s\n",
                          orphanTxId.ToString(), from_peer, state.ToString());
                 // Punish peer that gave us an invalid orphan tx
                 MaybePunishNodeForTx(from_peer, state);
             }
             // Has inputs but not accepted to mempool
             // Probably non-standard or insufficient fee
             LogPrint(BCLog::MEMPOOL, "   removed orphan tx %s\n",
                      orphanTxId.ToString());
 
             assert(recentRejects);
             recentRejects->insert(orphanTxId);
 
             m_orphanage.EraseTx(orphanTxId);
             break;
         }
     }
     m_mempool.check(m_chainman.ActiveChainstate());
 }
 
 bool PeerManagerImpl::PrepareBlockFilterRequest(
     CNode &peer, const CChainParams &chain_params, BlockFilterType filter_type,
     uint32_t start_height, const BlockHash &stop_hash, uint32_t max_height_diff,
     const CBlockIndex *&stop_index, BlockFilterIndex *&filter_index) {
     const bool supported_filter_type =
         (filter_type == BlockFilterType::BASIC &&
          (peer.GetLocalServices() & NODE_COMPACT_FILTERS));
     if (!supported_filter_type) {
         LogPrint(BCLog::NET,
                  "peer %d requested unsupported block filter type: %d\n",
                  peer.GetId(), static_cast<uint8_t>(filter_type));
         peer.fDisconnect = true;
         return false;
     }
 
     {
         LOCK(cs_main);
         stop_index = m_chainman.m_blockman.LookupBlockIndex(stop_hash);
 
         // Check that the stop block exists and the peer would be allowed to
         // fetch it.
         if (!stop_index ||
             !BlockRequestAllowed(stop_index, chain_params.GetConsensus())) {
             LogPrint(BCLog::NET, "peer %d requested invalid block hash: %s\n",
                      peer.GetId(), stop_hash.ToString());
             peer.fDisconnect = true;
             return false;
         }
     }
 
     uint32_t stop_height = stop_index->nHeight;
     if (start_height > stop_height) {
         LogPrint(
             BCLog::NET,
             "peer %d sent invalid getcfilters/getcfheaders with " /* Continued
                                                                    */
             "start height %d and stop height %d\n",
             peer.GetId(), start_height, stop_height);
         peer.fDisconnect = true;
         return false;
     }
     if (stop_height - start_height >= max_height_diff) {
         LogPrint(BCLog::NET,
                  "peer %d requested too many cfilters/cfheaders: %d / %d\n",
                  peer.GetId(), stop_height - start_height + 1, max_height_diff);
         peer.fDisconnect = true;
         return false;
     }
 
     filter_index = GetBlockFilterIndex(filter_type);
     if (!filter_index) {
         LogPrint(BCLog::NET, "Filter index for supported type %s not found\n",
                  BlockFilterTypeName(filter_type));
         return false;
     }
 
     return true;
 }
 
 void PeerManagerImpl::ProcessGetCFilters(CNode &peer, CDataStream &vRecv,
                                          const CChainParams &chain_params,
                                          CConnman &connman) {
     uint8_t filter_type_ser;
     uint32_t start_height;
     BlockHash stop_hash;
 
     vRecv >> filter_type_ser >> start_height >> stop_hash;
 
     const BlockFilterType filter_type =
         static_cast<BlockFilterType>(filter_type_ser);
 
     const CBlockIndex *stop_index;
     BlockFilterIndex *filter_index;
     if (!PrepareBlockFilterRequest(
             peer, chain_params, filter_type, start_height, stop_hash,
             MAX_GETCFILTERS_SIZE, stop_index, filter_index)) {
         return;
     }
 
     std::vector<BlockFilter> filters;
     if (!filter_index->LookupFilterRange(start_height, stop_index, filters)) {
         LogPrint(BCLog::NET,
                  "Failed to find block filter in index: filter_type=%s, "
                  "start_height=%d, stop_hash=%s\n",
                  BlockFilterTypeName(filter_type), start_height,
                  stop_hash.ToString());
         return;
     }
 
     for (const auto &filter : filters) {
         CSerializedNetMsg msg = CNetMsgMaker(peer.GetCommonVersion())
                                     .Make(NetMsgType::CFILTER, filter);
         connman.PushMessage(&peer, std::move(msg));
     }
 }
 
 void PeerManagerImpl::ProcessGetCFHeaders(CNode &peer, CDataStream &vRecv,
                                           const CChainParams &chain_params,
                                           CConnman &connman) {
     uint8_t filter_type_ser;
     uint32_t start_height;
     BlockHash stop_hash;
 
     vRecv >> filter_type_ser >> start_height >> stop_hash;
 
     const BlockFilterType filter_type =
         static_cast<BlockFilterType>(filter_type_ser);
 
     const CBlockIndex *stop_index;
     BlockFilterIndex *filter_index;
     if (!PrepareBlockFilterRequest(
             peer, chain_params, filter_type, start_height, stop_hash,
             MAX_GETCFHEADERS_SIZE, stop_index, filter_index)) {
         return;
     }
 
     uint256 prev_header;
     if (start_height > 0) {
         const CBlockIndex *const prev_block =
             stop_index->GetAncestor(static_cast<int>(start_height - 1));
         if (!filter_index->LookupFilterHeader(prev_block, prev_header)) {
             LogPrint(BCLog::NET,
                      "Failed to find block filter header in index: "
                      "filter_type=%s, block_hash=%s\n",
                      BlockFilterTypeName(filter_type),
                      prev_block->GetBlockHash().ToString());
             return;
         }
     }
 
     std::vector<uint256> filter_hashes;
     if (!filter_index->LookupFilterHashRange(start_height, stop_index,
                                              filter_hashes)) {
         LogPrint(BCLog::NET,
                  "Failed to find block filter hashes in index: filter_type=%s, "
                  "start_height=%d, stop_hash=%s\n",
                  BlockFilterTypeName(filter_type), start_height,
                  stop_hash.ToString());
         return;
     }
 
     CSerializedNetMsg msg =
         CNetMsgMaker(peer.GetCommonVersion())
             .Make(NetMsgType::CFHEADERS, filter_type_ser,
                   stop_index->GetBlockHash(), prev_header, filter_hashes);
     connman.PushMessage(&peer, std::move(msg));
 }
 
 void PeerManagerImpl::ProcessGetCFCheckPt(CNode &peer, CDataStream &vRecv,
                                           const CChainParams &chain_params,
                                           CConnman &connman) {
     uint8_t filter_type_ser;
     BlockHash stop_hash;
 
     vRecv >> filter_type_ser >> stop_hash;
 
     const BlockFilterType filter_type =
         static_cast<BlockFilterType>(filter_type_ser);
 
     const CBlockIndex *stop_index;
     BlockFilterIndex *filter_index;
     if (!PrepareBlockFilterRequest(
             peer, chain_params, filter_type, /*start_height=*/0, stop_hash,
             /*max_height_diff=*/std::numeric_limits<uint32_t>::max(),
             stop_index, filter_index)) {
         return;
     }
 
     std::vector<uint256> headers(stop_index->nHeight / CFCHECKPT_INTERVAL);
 
     // Populate headers.
     const CBlockIndex *block_index = stop_index;
     for (int i = headers.size() - 1; i >= 0; i--) {
         int height = (i + 1) * CFCHECKPT_INTERVAL;
         block_index = block_index->GetAncestor(height);
 
         if (!filter_index->LookupFilterHeader(block_index, headers[i])) {
             LogPrint(BCLog::NET,
                      "Failed to find block filter header in index: "
                      "filter_type=%s, block_hash=%s\n",
                      BlockFilterTypeName(filter_type),
                      block_index->GetBlockHash().ToString());
             return;
         }
     }
 
     CSerializedNetMsg msg = CNetMsgMaker(peer.GetCommonVersion())
                                 .Make(NetMsgType::CFCHECKPT, filter_type_ser,
                                       stop_index->GetBlockHash(), headers);
     connman.PushMessage(&peer, std::move(msg));
 }
 
 bool IsAvalancheMessageType(const std::string &msg_type) {
     return msg_type == NetMsgType::AVAHELLO ||
            msg_type == NetMsgType::AVAPOLL ||
            msg_type == NetMsgType::AVARESPONSE ||
            msg_type == NetMsgType::AVAPROOF ||
            msg_type == NetMsgType::GETAVAADDR ||
            msg_type == NetMsgType::GETAVAPROOFS ||
            msg_type == NetMsgType::AVAPROOFS ||
            msg_type == NetMsgType::AVAPROOFSREQ;
 }
 
 uint32_t PeerManagerImpl::GetAvalancheVoteForBlock(const BlockHash &hash) {
     AssertLockHeld(cs_main);
 
     const CBlockIndex *pindex = m_chainman.m_blockman.LookupBlockIndex(hash);
 
     // Unknown block.
     if (!pindex) {
         return -1;
     }
 
     // Invalid block
     if (pindex->nStatus.isInvalid()) {
         return 1;
     }
 
     // Parked block
     if (pindex->nStatus.isOnParkedChain()) {
         return 2;
     }
 
     const CBlockIndex *pindexTip = m_chainman.ActiveChain().Tip();
     const CBlockIndex *pindexFork = LastCommonAncestor(pindex, pindexTip);
 
     // Active block.
     if (pindex == pindexFork) {
         return 0;
     }
 
     // Fork block.
     if (pindexFork != pindexTip) {
         return 3;
     }
 
     // Missing block data.
     if (!pindex->nStatus.hasData()) {
         return -2;
     }
 
     // This block is built on top of the tip, we have the data, it
     // is pending connection or rejection.
     return -3;
 };
 
 /**
  * Decide a response for an Avalanche poll about the given transaction.
  *
  * FIXME This function should be expanded to return different vote responses
  * based on inspection of mempool.
  *
  * @param[in] mempool  The mempool to base our votes on
  * @param[in] id       The id of the transaction being polled for
  * @return             Our current vote for the proof
  */
 static uint32_t getAvalancheVoteForTx(CTxMemPool &mempool, const TxId &id) {
     return -1;
 };
 
 /**
  * Decide a response for an Avalanche poll about the given proof.
  *
  * @param[in] id   The id of the proof being polled for
  * @return         Our current vote for the proof
  */
 static uint32_t getAvalancheVoteForProof(const avalanche::ProofId &id) {
     assert(g_avalanche);
 
     // Rejected proof
     if (WITH_LOCK(cs_rejectedProofs, return rejectedProofs->contains(id))) {
         return 1;
     }
 
     return g_avalanche->withPeerManager([&id](avalanche::PeerManager &pm) {
         // The proof is actively bound to a peer
         if (pm.isBoundToPeer(id)) {
             return 0;
         }
 
         // Unknown proof
         if (!pm.exists(id)) {
             return -1;
         }
 
         // Orphan proof
         if (pm.isOrphan(id)) {
             return 2;
         }
 
         // Not an orphan, but in conflict with an actively bound proof
         if (pm.isInConflictingPool(id)) {
             return 3;
         }
 
         // The proof is known, not rejected, not an orphan, not a conflict, but
         // for some reason unbound. This should not happen if the above pools
         // are managed correctly, but added for robustness.
         return -2;
     });
 };
 
 void PeerManagerImpl::ProcessMessage(
     const Config &config, CNode &pfrom, const std::string &msg_type,
     CDataStream &vRecv, const std::chrono::microseconds time_received,
     const std::atomic<bool> &interruptMsgProc) {
     LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n",
              SanitizeString(msg_type), vRecv.size(), pfrom.GetId());
 
     PeerRef peer = GetPeerRef(pfrom.GetId());
     if (peer == nullptr) {
         return;
     }
 
     if (IsAvalancheMessageType(msg_type)) {
         if (!g_avalanche) {
             LogPrint(BCLog::AVALANCHE,
                      "Avalanche is not initialized, ignoring %s message\n",
                      msg_type);
             return;
         }
 
         if (!isAvalancheEnabled(gArgs)) {
             // If avalanche is not enabled, ignore avalanche messages
             return;
         }
     }
 
     if (msg_type == NetMsgType::VERSION) {
         // Each connection can only send one version message
         if (pfrom.nVersion != 0) {
             Misbehaving(pfrom, 1, "redundant version message");
             return;
         }
 
         int64_t nTime;
         CAddress addrMe;
         CAddress addrFrom;
         uint64_t nNonce = 1;
         uint64_t nServiceInt;
         ServiceFlags nServices;
         int nVersion;
         std::string cleanSubVer;
         int starting_height = -1;
         bool fRelay = true;
         uint64_t nExtraEntropy = 1;
 
         vRecv >> nVersion >> nServiceInt >> nTime >> addrMe;
         nServices = ServiceFlags(nServiceInt);
         if (!pfrom.IsInboundConn()) {
             m_connman.SetServices(pfrom.addr, nServices);
         }
         if (pfrom.ExpectServicesFromConn() &&
             !HasAllDesirableServiceFlags(nServices)) {
             LogPrint(BCLog::NET,
                      "peer=%d does not offer the expected services "
                      "(%08x offered, %08x expected); disconnecting\n",
                      pfrom.GetId(), nServices,
                      GetDesirableServiceFlags(nServices));
             pfrom.fDisconnect = true;
             return;
         }
 
         if (pfrom.IsAvalancheOutboundConnection() &&
             !(nServices & NODE_AVALANCHE)) {
             LogPrint(
                 BCLog::AVALANCHE,
                 "peer=%d does not offer the avalanche service; disconnecting\n",
                 pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
 
         if (nVersion < MIN_PEER_PROTO_VERSION) {
             // disconnect from peers older than this proto version
             LogPrint(BCLog::NET,
                      "peer=%d using obsolete version %i; disconnecting\n",
                      pfrom.GetId(), nVersion);
             pfrom.fDisconnect = true;
             return;
         }
 
         if (!vRecv.empty()) {
             vRecv >> addrFrom >> nNonce;
         }
         if (!vRecv.empty()) {
             std::string strSubVer;
             vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH);
             cleanSubVer = SanitizeString(strSubVer);
         }
         if (!vRecv.empty()) {
             vRecv >> starting_height;
         }
         if (!vRecv.empty()) {
             vRecv >> fRelay;
         }
         if (!vRecv.empty()) {
             vRecv >> nExtraEntropy;
         }
         // Disconnect if we connected to ourself
         if (pfrom.IsInboundConn() && !m_connman.CheckIncomingNonce(nNonce)) {
             LogPrintf("connected to self at %s, disconnecting\n",
                       pfrom.addr.ToString());
             pfrom.fDisconnect = true;
             return;
         }
 
         if (pfrom.IsInboundConn() && addrMe.IsRoutable()) {
             SeenLocal(addrMe);
         }
 
         // Inbound peers send us their version message when they connect.
         // We send our version message in response.
         if (pfrom.IsInboundConn()) {
             PushNodeVersion(config, pfrom, GetAdjustedTime());
         }
 
         // Change version
         const int greatest_common_version =
             std::min(nVersion, PROTOCOL_VERSION);
         pfrom.SetCommonVersion(greatest_common_version);
         pfrom.nVersion = nVersion;
 
         const CNetMsgMaker msg_maker(greatest_common_version);
 
         m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::VERACK));
 
         // Signal ADDRv2 support (BIP155).
         m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::SENDADDRV2));
 
         pfrom.nServices = nServices;
         pfrom.SetAddrLocal(addrMe);
         {
             LOCK(pfrom.cs_SubVer);
             pfrom.cleanSubVer = cleanSubVer;
         }
         peer->m_starting_height = starting_height;
 
         // set nodes not relaying blocks and tx and not serving (parts) of the
         // historical blockchain as "clients"
         pfrom.fClient = (!(nServices & NODE_NETWORK) &&
                          !(nServices & NODE_NETWORK_LIMITED));
 
         // set nodes not capable of serving the complete blockchain history as
         // "limited nodes"
         pfrom.m_limited_node =
             (!(nServices & NODE_NETWORK) && (nServices & NODE_NETWORK_LIMITED));
 
         if (pfrom.m_tx_relay != nullptr) {
             LOCK(pfrom.m_tx_relay->cs_filter);
             // set to true after we get the first filter* message
             pfrom.m_tx_relay->fRelayTxes = fRelay;
         }
 
         pfrom.nRemoteHostNonce = nNonce;
         pfrom.nRemoteExtraEntropy = nExtraEntropy;
 
         // Potentially mark this peer as a preferred download peer.
         {
             LOCK(cs_main);
             UpdatePreferredDownload(pfrom, State(pfrom.GetId()));
         }
 
         // Self advertisement & GETADDR logic
         if (!pfrom.IsInboundConn() && SetupAddressRelay(pfrom, *peer)) {
             // For outbound peers, we try to relay our address (so that other
             // nodes can try to find us more quickly, as we have no guarantee
             // that an outbound peer is even aware of how to reach us) and do a
             // one-time address fetch (to help populate/update our addrman). If
             // we're starting up for the first time, our addrman may be pretty
             // empty and no one will know who we are, so these mechanisms are
             // important to help us connect to the network.
             //
             // We skip this for block-relay-only peers. We want to avoid
             // potentially leaking addr information and we do not want to
             // indicate to the peer that we will participate in addr relay.
             if (fListen &&
                 !m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
                 CAddress addr =
                     GetLocalAddress(&pfrom.addr, pfrom.GetLocalServices());
                 FastRandomContext insecure_rand;
                 if (addr.IsRoutable()) {
                     LogPrint(BCLog::NET,
                              "ProcessMessages: advertising address %s\n",
                              addr.ToString());
                     PushAddress(*peer, addr, insecure_rand);
                 } else if (IsPeerAddrLocalGood(&pfrom)) {
                     addr.SetIP(addrMe);
                     LogPrint(BCLog::NET,
                              "ProcessMessages: advertising address %s\n",
                              addr.ToString());
                     PushAddress(*peer, addr, insecure_rand);
                 }
             }
 
             // Get recent addresses
             m_connman.PushMessage(&pfrom, CNetMsgMaker(greatest_common_version)
                                               .Make(NetMsgType::GETADDR));
             peer->m_getaddr_sent = true;
             // When requesting a getaddr, accept an additional MAX_ADDR_TO_SEND
             // addresses in response (bypassing the
             // MAX_ADDR_PROCESSING_TOKEN_BUCKET limit).
             WITH_LOCK(peer->m_addr_token_bucket_mutex,
                       peer->m_addr_token_bucket += GetMaxAddrToSend());
         }
 
         if (!pfrom.IsInboundConn()) {
             // For non-inbound connections, we update the addrman to record
             // connection success so that addrman will have an up-to-date
             // notion of which peers are online and available.
             //
             // While we strive to not leak information about block-relay-only
             // connections via the addrman, not moving an address to the tried
             // table is also potentially detrimental because new-table entries
             // are subject to eviction in the event of addrman collisions.  We
             // mitigate the information-leak by never calling
             // CAddrMan::Connected() on block-relay-only peers; see
             // FinalizeNode().
             //
             // This moves an address from New to Tried table in Addrman,
             // resolves tried-table collisions, etc.
             m_connman.MarkAddressGood(pfrom.addr);
         }
 
         std::string remoteAddr;
         if (fLogIPs) {
             remoteAddr = ", peeraddr=" + pfrom.addr.ToString();
         }
 
         LogPrint(BCLog::NET,
                  "receive version message: [%s] %s: version %d, blocks=%d, "
                  "us=%s, txrelay=%d, peer=%d%s\n",
                  pfrom.addr.ToString(), cleanSubVer, pfrom.nVersion,
                  peer->m_starting_height, addrMe.ToString(), fRelay,
                  pfrom.GetId(), remoteAddr);
 
         // Ignore time offsets that are improbable (before the Genesis block)
         // and may underflow the nTimeOffset calculation.
         int64_t currentTime = GetTime();
         if (nTime >= int64_t(m_chainparams.GenesisBlock().nTime)) {
             int64_t nTimeOffset = nTime - currentTime;
             pfrom.nTimeOffset = nTimeOffset;
             AddTimeData(pfrom.addr, nTimeOffset);
         } else {
             Misbehaving(pfrom, 20,
                         "Ignoring invalid timestamp in version message");
         }
 
         // Feeler connections exist only to verify if address is online.
         if (pfrom.IsFeelerConn()) {
             LogPrint(BCLog::NET,
                      "feeler connection completed peer=%d; disconnecting\n",
                      pfrom.GetId());
             pfrom.fDisconnect = true;
         }
         return;
     }
 
     if (pfrom.nVersion == 0) {
         // Must have a version message before anything else
         Misbehaving(pfrom, 10, "non-version message before version handshake");
         return;
     }
 
     // At this point, the outgoing message serialization version can't change.
     const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
 
     if (msg_type == NetMsgType::VERACK) {
         if (pfrom.fSuccessfullyConnected) {
             LogPrint(BCLog::NET,
                      "ignoring redundant verack message from peer=%d\n",
                      pfrom.GetId());
             return;
         }
 
         if (!pfrom.IsInboundConn()) {
             LogPrintf(
                 "New outbound peer connected: version: %d, blocks=%d, "
                 "peer=%d%s (%s)\n",
                 pfrom.nVersion.load(), peer->m_starting_height, pfrom.GetId(),
                 (fLogIPs ? strprintf(", peeraddr=%s", pfrom.addr.ToString())
                          : ""),
                 pfrom.ConnectionTypeAsString());
         }
 
         if (pfrom.GetCommonVersion() >= SENDHEADERS_VERSION) {
             // Tell our peer we prefer to receive headers rather than inv's
             // We send this to non-NODE NETWORK peers as well, because even
             // non-NODE NETWORK peers can announce blocks (such as pruning
             // nodes)
             m_connman.PushMessage(&pfrom,
                                   msgMaker.Make(NetMsgType::SENDHEADERS));
         }
 
         if (pfrom.GetCommonVersion() >= SHORT_IDS_BLOCKS_VERSION) {
             // Tell our peer we are willing to provide version 1 or 2
             // cmpctblocks. However, we do not request new block announcements
             // using cmpctblock messages. We send this to non-NODE NETWORK peers
             // as well, because they may wish to request compact blocks from us.
             bool fAnnounceUsingCMPCTBLOCK = false;
             uint64_t nCMPCTBLOCKVersion = 1;
             m_connman.PushMessage(&pfrom,
                                   msgMaker.Make(NetMsgType::SENDCMPCT,
                                                 fAnnounceUsingCMPCTBLOCK,
                                                 nCMPCTBLOCKVersion));
         }
 
         if (g_avalanche && isAvalancheEnabled(gArgs)) {
             if (g_avalanche->sendHello(&pfrom)) {
                 LogPrint(BCLog::AVALANCHE, "Send avahello to peer %d\n",
                          pfrom.GetId());
 
                 auto localProof = g_avalanche->getLocalProof();
 
                 if (localProof) {
                     // Add our proof id to the list or the recently announced
                     // proof INVs to this peer. This is used for filtering which
                     // INV can be requested for download.
                     LOCK(cs_main);
                     State(pfrom.GetId())
                         ->m_recently_announced_proofs.insert(
                             localProof->getId());
                 }
             }
         }
 
         pfrom.fSuccessfullyConnected = true;
         return;
     }
 
     if (!pfrom.fSuccessfullyConnected) {
         // Must have a verack message before anything else
         Misbehaving(pfrom, 10, "non-verack message before version handshake");
         return;
     }
 
     if (msg_type == NetMsgType::ADDR || msg_type == NetMsgType::ADDRV2) {
         int stream_version = vRecv.GetVersion();
         if (msg_type == NetMsgType::ADDRV2) {
             // Add ADDRV2_FORMAT to the version so that the CNetAddr and
             // CAddress unserialize methods know that an address in v2 format is
             // coming.
             stream_version |= ADDRV2_FORMAT;
         }
 
         OverrideStream<CDataStream> s(&vRecv, vRecv.GetType(), stream_version);
         std::vector<CAddress> vAddr;
 
         s >> vAddr;
 
         if (!SetupAddressRelay(pfrom, *peer)) {
             LogPrint(BCLog::NET, "ignoring %s message from %s peer=%d\n",
                      msg_type, pfrom.ConnectionTypeAsString(), pfrom.GetId());
             return;
         }
 
         if (vAddr.size() > GetMaxAddrToSend()) {
             Misbehaving(
                 pfrom, 20,
                 strprintf("%s message size = %u", msg_type, vAddr.size()));
             return;
         }
 
         // Store the new addresses
         std::vector<CAddress> vAddrOk;
         int64_t nNow = GetAdjustedTime();
         int64_t nSince = nNow - 10 * 60;
 
         // Update/increment addr rate limiting bucket.
         const auto current_time = GetTime<std::chrono::microseconds>();
         {
             LOCK(peer->m_addr_token_bucket_mutex);
             if (peer->m_addr_token_bucket < MAX_ADDR_PROCESSING_TOKEN_BUCKET) {
                 // Don't increment bucket if it's already full
                 const auto time_diff =
                     std::max(current_time - peer->m_addr_token_timestamp, 0us);
                 const double increment =
                     CountSecondsDouble(time_diff) * MAX_ADDR_RATE_PER_SECOND;
                 peer->m_addr_token_bucket =
                     std::min<double>(peer->m_addr_token_bucket + increment,
                                      MAX_ADDR_PROCESSING_TOKEN_BUCKET);
             }
         }
         peer->m_addr_token_timestamp = current_time;
 
         const bool rate_limited =
             !pfrom.HasPermission(NetPermissionFlags::PF_ADDR);
         uint64_t num_proc = 0;
         uint64_t num_rate_limit = 0;
         Shuffle(vAddr.begin(), vAddr.end(), FastRandomContext());
         for (CAddress &addr : vAddr) {
             if (interruptMsgProc) {
                 return;
             }
 
             {
                 LOCK(peer->m_addr_token_bucket_mutex);
                 // Apply rate limiting.
                 if (peer->m_addr_token_bucket < 1.0) {
                     if (rate_limited) {
                         ++num_rate_limit;
                         continue;
                     }
                 } else {
                     peer->m_addr_token_bucket -= 1.0;
                 }
             }
 
             // We only bother storing full nodes, though this may include things
             // which we would not make an outbound connection to, in part
             // because we may make feeler connections to them.
             if (!MayHaveUsefulAddressDB(addr.nServices) &&
                 !HasAllDesirableServiceFlags(addr.nServices)) {
                 continue;
             }
 
             if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60) {
                 addr.nTime = nNow - 5 * 24 * 60 * 60;
             }
             AddAddressKnown(*peer, addr);
             if (m_banman &&
                 (m_banman->IsDiscouraged(addr) || m_banman->IsBanned(addr))) {
                 // Do not process banned/discouraged addresses beyond
                 // remembering we received them
                 continue;
             }
             ++num_proc;
             bool fReachable = IsReachable(addr);
             if (addr.nTime > nSince && !peer->m_getaddr_sent &&
                 vAddr.size() <= 10 && addr.IsRoutable()) {
                 // Relay to a limited number of other nodes
                 RelayAddress(pfrom.GetId(), addr, fReachable);
             }
             // Do not store addresses outside our network
             if (fReachable) {
                 vAddrOk.push_back(addr);
             }
         }
         peer->m_addr_processed += num_proc;
         peer->m_addr_rate_limited += num_rate_limit;
         LogPrint(BCLog::NET,
                  "Received addr: %u addresses (%u processed, %u rate-limited) "
                  "from peer=%d\n",
                  vAddr.size(), num_proc, num_rate_limit, pfrom.GetId());
 
         m_connman.AddNewAddresses(vAddrOk, pfrom.addr, 2 * 60 * 60);
         if (vAddr.size() < 1000) {
             peer->m_getaddr_sent = false;
         }
 
         // AddrFetch: Require multiple addresses to avoid disconnecting on
         // self-announcements
         if (pfrom.IsAddrFetchConn() && vAddr.size() > 1) {
             LogPrint(BCLog::NET,
                      "addrfetch connection completed peer=%d; disconnecting\n",
                      pfrom.GetId());
             pfrom.fDisconnect = true;
         }
         return;
     }
 
     if (msg_type == NetMsgType::SENDADDRV2) {
         peer->m_wants_addrv2 = true;
         return;
     }
 
     if (msg_type == NetMsgType::SENDHEADERS) {
         LOCK(cs_main);
         State(pfrom.GetId())->fPreferHeaders = true;
         return;
     }
 
     if (msg_type == NetMsgType::SENDCMPCT) {
         bool fAnnounceUsingCMPCTBLOCK = false;
         uint64_t nCMPCTBLOCKVersion = 0;
         vRecv >> fAnnounceUsingCMPCTBLOCK >> nCMPCTBLOCKVersion;
         if (nCMPCTBLOCKVersion == 1) {
             LOCK(cs_main);
             // fProvidesHeaderAndIDs is used to "lock in" version of compact
             // blocks we send.
             if (!State(pfrom.GetId())->fProvidesHeaderAndIDs) {
                 State(pfrom.GetId())->fProvidesHeaderAndIDs = true;
             }
 
             State(pfrom.GetId())->fPreferHeaderAndIDs =
                 fAnnounceUsingCMPCTBLOCK;
             // save whether peer selects us as BIP152 high-bandwidth peer
             // (receiving sendcmpct(1) signals high-bandwidth,
             // sendcmpct(0) low-bandwidth)
             pfrom.m_bip152_highbandwidth_from = fAnnounceUsingCMPCTBLOCK;
             if (!State(pfrom.GetId())->fSupportsDesiredCmpctVersion) {
                 State(pfrom.GetId())->fSupportsDesiredCmpctVersion = true;
             }
         }
         return;
     }
 
     if (msg_type == NetMsgType::INV) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ) {
             Misbehaving(pfrom, 20,
                         strprintf("inv message size = %u", vInv.size()));
             return;
         }
 
         // We won't accept tx inv's if we're in blocks-only mode, or this is a
         // block-relay-only peer
         bool fBlocksOnly =
             m_ignore_incoming_txs || (pfrom.m_tx_relay == nullptr);
 
         // Allow peers with relay permission to send data other than blocks
         // in blocks only mode
         if (pfrom.HasPermission(PF_RELAY)) {
             fBlocksOnly = false;
         }
 
         const auto current_time = GetTime<std::chrono::microseconds>();
         std::optional<BlockHash> best_block;
 
         auto logInv = [&](const CInv &inv, bool fAlreadyHave) {
             LogPrint(BCLog::NET, "got inv: %s  %s peer=%d\n", inv.ToString(),
                      fAlreadyHave ? "have" : "new", pfrom.GetId());
         };
 
         for (CInv &inv : vInv) {
             if (interruptMsgProc) {
                 return;
             }
 
             if (inv.IsMsgBlk()) {
                 LOCK(cs_main);
                 const bool fAlreadyHave = AlreadyHaveBlock(BlockHash(inv.hash));
                 logInv(inv, fAlreadyHave);
 
                 const BlockHash hash{inv.hash};
                 UpdateBlockAvailability(pfrom.GetId(), hash);
                 if (!fAlreadyHave && !fImporting && !fReindex &&
                     !mapBlocksInFlight.count(hash)) {
                     // Headers-first is the primary method of announcement on
                     // the network. If a node fell back to sending blocks by
                     // inv, it's probably for a re-org. The final block hash
                     // provided should be the highest, so send a getheaders and
                     // then fetch the blocks we need to catch up.
                     best_block = std::move(hash);
                 }
 
                 continue;
             }
 
             if (inv.IsMsgProof()) {
                 const avalanche::ProofId proofid(inv.hash);
                 const bool fAlreadyHave = AlreadyHaveProof(proofid);
                 logInv(inv, fAlreadyHave);
                 pfrom.AddKnownProof(proofid);
 
                 if (!fAlreadyHave && g_avalanche && isAvalancheEnabled(gArgs)) {
                     const bool preferred = isPreferredDownloadPeer(pfrom);
 
                     LOCK(cs_proofrequest);
                     AddProofAnnouncement(pfrom, proofid, current_time,
                                          preferred);
                 }
                 continue;
             }
 
             if (inv.IsMsgTx()) {
                 LOCK(cs_main);
                 const TxId txid(inv.hash);
                 const bool fAlreadyHave = AlreadyHaveTx(txid);
                 logInv(inv, fAlreadyHave);
 
                 pfrom.AddKnownTx(txid);
                 if (fBlocksOnly) {
                     LogPrint(BCLog::NET,
                              "transaction (%s) inv sent in violation of "
                              "protocol, disconnecting peer=%d\n",
                              txid.ToString(), pfrom.GetId());
                     pfrom.fDisconnect = true;
                     return;
                 } else if (!fAlreadyHave && !m_chainman.ActiveChainstate()
                                                  .IsInitialBlockDownload()) {
                     AddTxAnnouncement(pfrom, txid, current_time);
                 }
 
                 continue;
             }
 
             LogPrint(BCLog::NET,
                      "Unknown inv type \"%s\" received from peer=%d\n",
                      inv.ToString(), pfrom.GetId());
         }
 
         if (best_block) {
             m_connman.PushMessage(
                 &pfrom, msgMaker.Make(NetMsgType::GETHEADERS,
                                       m_chainman.ActiveChain().GetLocator(
                                           pindexBestHeader),
                                       *best_block));
             LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n",
                      pindexBestHeader->nHeight, best_block->ToString(),
                      pfrom.GetId());
         }
 
         return;
     }
 
     if (msg_type == NetMsgType::GETDATA) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ) {
             Misbehaving(pfrom, 20,
                         strprintf("getdata message size = %u", vInv.size()));
             return;
         }
 
         LogPrint(BCLog::NET, "received getdata (%u invsz) peer=%d\n",
                  vInv.size(), pfrom.GetId());
 
         if (vInv.size() > 0) {
             LogPrint(BCLog::NET, "received getdata for: %s peer=%d\n",
                      vInv[0].ToString(), pfrom.GetId());
         }
 
         {
             LOCK(peer->m_getdata_requests_mutex);
             peer->m_getdata_requests.insert(peer->m_getdata_requests.end(),
                                             vInv.begin(), vInv.end());
             ProcessGetData(config, pfrom, *peer, interruptMsgProc);
         }
 
         return;
     }
 
     if (msg_type == NetMsgType::GETBLOCKS) {
         CBlockLocator locator;
         uint256 hashStop;
         vRecv >> locator >> hashStop;
 
         if (locator.vHave.size() > MAX_LOCATOR_SZ) {
             LogPrint(BCLog::NET,
                      "getblocks locator size %lld > %d, disconnect peer=%d\n",
                      locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
 
         // We might have announced the currently-being-connected tip using a
         // compact block, which resulted in the peer sending a getblocks
         // request, which we would otherwise respond to without the new block.
         // To avoid this situation we simply verify that we are on our best
         // known chain now. This is super overkill, but we handle it better
         // for getheaders requests, and there are no known nodes which support
         // compact blocks but still use getblocks to request blocks.
         {
             std::shared_ptr<const CBlock> a_recent_block;
             {
                 LOCK(cs_most_recent_block);
                 a_recent_block = most_recent_block;
             }
             BlockValidationState state;
             if (!m_chainman.ActiveChainstate().ActivateBestChain(
                     config, state, a_recent_block)) {
                 LogPrint(BCLog::NET, "failed to activate chain (%s)\n",
                          state.ToString());
             }
         }
 
         LOCK(cs_main);
 
         // Find the last block the caller has in the main chain
         const CBlockIndex *pindex = m_chainman.m_blockman.FindForkInGlobalIndex(
             m_chainman.ActiveChain(), locator);
 
         // Send the rest of the chain
         if (pindex) {
             pindex = m_chainman.ActiveChain().Next(pindex);
         }
         int nLimit = 500;
         LogPrint(BCLog::NET, "getblocks %d to %s limit %d from peer=%d\n",
                  (pindex ? pindex->nHeight : -1),
                  hashStop.IsNull() ? "end" : hashStop.ToString(), nLimit,
                  pfrom.GetId());
         for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex)) {
             if (pindex->GetBlockHash() == hashStop) {
                 LogPrint(BCLog::NET, "  getblocks stopping at %d %s\n",
                          pindex->nHeight, pindex->GetBlockHash().ToString());
                 break;
             }
             // If pruning, don't inv blocks unless we have on disk and are
             // likely to still have for some reasonable time window (1 hour)
             // that block relay might require.
             const int nPrunedBlocksLikelyToHave =
                 MIN_BLOCKS_TO_KEEP -
                 3600 / m_chainparams.GetConsensus().nPowTargetSpacing;
             if (fPruneMode &&
                 (!pindex->nStatus.hasData() ||
                  pindex->nHeight <= m_chainman.ActiveChain().Tip()->nHeight -
                                         nPrunedBlocksLikelyToHave)) {
                 LogPrint(
                     BCLog::NET,
                     " getblocks stopping, pruned or too old block at %d %s\n",
                     pindex->nHeight, pindex->GetBlockHash().ToString());
                 break;
             }
             WITH_LOCK(
                 peer->m_block_inv_mutex,
                 peer->m_blocks_for_inv_relay.push_back(pindex->GetBlockHash()));
             if (--nLimit <= 0) {
                 // When this block is requested, we'll send an inv that'll
                 // trigger the peer to getblocks the next batch of inventory.
                 LogPrint(BCLog::NET, "  getblocks stopping at limit %d %s\n",
                          pindex->nHeight, pindex->GetBlockHash().ToString());
                 WITH_LOCK(peer->m_block_inv_mutex, {
                     peer->m_continuation_block = pindex->GetBlockHash();
                 });
                 break;
             }
         }
         return;
     }
 
     if (msg_type == NetMsgType::GETBLOCKTXN) {
         BlockTransactionsRequest req;
         vRecv >> req;
 
         std::shared_ptr<const CBlock> recent_block;
         {
             LOCK(cs_most_recent_block);
             if (most_recent_block_hash == req.blockhash) {
                 recent_block = most_recent_block;
             }
             // Unlock cs_most_recent_block to avoid cs_main lock inversion
         }
         if (recent_block) {
             SendBlockTransactions(pfrom, *recent_block, req);
             return;
         }
 
         {
             LOCK(cs_main);
 
             const CBlockIndex *pindex =
                 m_chainman.m_blockman.LookupBlockIndex(req.blockhash);
             if (!pindex || !pindex->nStatus.hasData()) {
                 LogPrint(
                     BCLog::NET,
                     "Peer %d sent us a getblocktxn for a block we don't have\n",
                     pfrom.GetId());
                 return;
             }
 
             if (pindex->nHeight >=
                 m_chainman.ActiveChain().Height() - MAX_BLOCKTXN_DEPTH) {
                 CBlock block;
                 bool ret = ReadBlockFromDisk(block, pindex,
                                              m_chainparams.GetConsensus());
                 assert(ret);
 
                 SendBlockTransactions(pfrom, block, req);
                 return;
             }
         }
 
         // If an older block is requested (should never happen in practice,
         // but can happen in tests) send a block response instead of a
         // blocktxn response. Sending a full block response instead of a
         // small blocktxn response is preferable in the case where a peer
         // might maliciously send lots of getblocktxn requests to trigger
         // expensive disk reads, because it will require the peer to
         // actually receive all the data read from disk over the network.
         LogPrint(BCLog::NET,
                  "Peer %d sent us a getblocktxn for a block > %i deep\n",
                  pfrom.GetId(), MAX_BLOCKTXN_DEPTH);
         CInv inv;
         inv.type = MSG_BLOCK;
         inv.hash = req.blockhash;
         WITH_LOCK(peer->m_getdata_requests_mutex,
                   peer->m_getdata_requests.push_back(inv));
         // The message processing loop will go around again (without pausing)
         // and we'll respond then (without cs_main)
         return;
     }
 
     if (msg_type == NetMsgType::GETHEADERS) {
         CBlockLocator locator;
         BlockHash hashStop;
         vRecv >> locator >> hashStop;
 
         if (locator.vHave.size() > MAX_LOCATOR_SZ) {
             LogPrint(BCLog::NET,
                      "getheaders locator size %lld > %d, disconnect peer=%d\n",
                      locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
 
         LOCK(cs_main);
         if (m_chainman.ActiveChainstate().IsInitialBlockDownload() &&
             !pfrom.HasPermission(PF_DOWNLOAD)) {
             LogPrint(BCLog::NET,
                      "Ignoring getheaders from peer=%d because node is in "
                      "initial block download\n",
                      pfrom.GetId());
             return;
         }
 
         CNodeState *nodestate = State(pfrom.GetId());
         const CBlockIndex *pindex = nullptr;
         if (locator.IsNull()) {
             // If locator is null, return the hashStop block
             pindex = m_chainman.m_blockman.LookupBlockIndex(hashStop);
             if (!pindex) {
                 return;
             }
 
             if (!BlockRequestAllowed(pindex, m_chainparams.GetConsensus())) {
                 LogPrint(BCLog::NET,
                          "%s: ignoring request from peer=%i for old block "
                          "header that isn't in the main chain\n",
                          __func__, pfrom.GetId());
                 return;
             }
         } else {
             // Find the last block the caller has in the main chain
             pindex = m_chainman.m_blockman.FindForkInGlobalIndex(
                 m_chainman.ActiveChain(), locator);
             if (pindex) {
                 pindex = m_chainman.ActiveChain().Next(pindex);
             }
         }
 
         // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx
         // count at the end
         std::vector<CBlock> vHeaders;
         int nLimit = MAX_HEADERS_RESULTS;
         LogPrint(BCLog::NET, "getheaders %d to %s from peer=%d\n",
                  (pindex ? pindex->nHeight : -1),
                  hashStop.IsNull() ? "end" : hashStop.ToString(),
                  pfrom.GetId());
         for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex)) {
             vHeaders.push_back(pindex->GetBlockHeader());
             if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop) {
                 break;
             }
         }
         // pindex can be nullptr either if we sent
         // m_chainman.ActiveChain().Tip() OR if our peer has
         // m_chainman.ActiveChain().Tip() (and thus we are sending an empty
         // headers message). In both cases it's safe to update
         // pindexBestHeaderSent to be our tip.
         //
         // It is important that we simply reset the BestHeaderSent value here,
         // and not max(BestHeaderSent, newHeaderSent). We might have announced
         // the currently-being-connected tip using a compact block, which
         // resulted in the peer sending a headers request, which we respond to
         // without the new block. By resetting the BestHeaderSent, we ensure we
         // will re-announce the new block via headers (or compact blocks again)
         // in the SendMessages logic.
         nodestate->pindexBestHeaderSent =
             pindex ? pindex : m_chainman.ActiveChain().Tip();
         m_connman.PushMessage(&pfrom,
                               msgMaker.Make(NetMsgType::HEADERS, vHeaders));
         return;
     }
 
     if (msg_type == NetMsgType::TX) {
         // Stop processing the transaction early if
         // 1) We are in blocks only mode and peer has no relay permission
         // 2) This peer is a block-relay-only peer
         if ((m_ignore_incoming_txs && !pfrom.HasPermission(PF_RELAY)) ||
             (pfrom.m_tx_relay == nullptr)) {
             LogPrint(BCLog::NET,
                      "transaction sent in violation of protocol peer=%d\n",
                      pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
 
         CTransactionRef ptx;
         vRecv >> ptx;
         const CTransaction &tx = *ptx;
         const TxId &txid = tx.GetId();
         pfrom.AddKnownTx(txid);
 
         LOCK2(cs_main, g_cs_orphans);
 
         m_txrequest.ReceivedResponse(pfrom.GetId(), txid);
 
         if (AlreadyHaveTx(txid)) {
             if (pfrom.HasPermission(PF_FORCERELAY)) {
                 // Always relay transactions received from peers with
                 // forcerelay permission, even if they were already in the
                 // mempool, allowing the node to function as a gateway for
                 // nodes hidden behind it.
                 if (!m_mempool.exists(tx.GetId())) {
                     LogPrintf("Not relaying non-mempool transaction %s from "
                               "forcerelay peer=%d\n",
                               tx.GetId().ToString(), pfrom.GetId());
                 } else {
                     LogPrintf("Force relaying tx %s from peer=%d\n",
                               tx.GetId().ToString(), pfrom.GetId());
                     RelayTransaction(tx.GetId(), m_connman);
                 }
             }
             return;
         }
 
-        TxValidationState state;
-
-        if (AcceptToMemoryPool(m_chainman.ActiveChainstate(), config, m_mempool,
-                               state, ptx, false /* bypass_limits */)) {
+        const MempoolAcceptResult result =
+            AcceptToMemoryPool(m_chainman.ActiveChainstate(), config, m_mempool,
+                               ptx, false /* bypass_limits */);
+        const TxValidationState &state = result.m_state;
+        if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
             m_mempool.check(m_chainman.ActiveChainstate());
             // As this version of the transaction was acceptable, we can forget
             // about any requests for it.
             m_txrequest.ForgetInvId(tx.GetId());
             RelayTransaction(tx.GetId(), m_connman);
             m_orphanage.AddChildrenToWorkSet(tx, peer->m_orphan_work_set);
 
             pfrom.m_last_tx_time = GetTime<std::chrono::seconds>();
 
             LogPrint(BCLog::MEMPOOL,
                      "AcceptToMemoryPool: peer=%d: accepted %s "
                      "(poolsz %u txn, %u kB)\n",
                      pfrom.GetId(), tx.GetId().ToString(), m_mempool.size(),
                      m_mempool.DynamicMemoryUsage() / 1000);
 
             // Recursively process any orphan transactions that depended on this
             // one
             ProcessOrphanTx(config, peer->m_orphan_work_set);
         } else if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) {
             // It may be the case that the orphans parents have all been
             // rejected.
             bool fRejectedParents = false;
 
             // Deduplicate parent txids, so that we don't have to loop over
             // the same parent txid more than once down below.
             std::vector<TxId> unique_parents;
             unique_parents.reserve(tx.vin.size());
             for (const CTxIn &txin : tx.vin) {
                 // We start with all parents, and then remove duplicates below.
                 unique_parents.push_back(txin.prevout.GetTxId());
             }
             std::sort(unique_parents.begin(), unique_parents.end());
             unique_parents.erase(
                 std::unique(unique_parents.begin(), unique_parents.end()),
                 unique_parents.end());
             for (const TxId &parent_txid : unique_parents) {
                 if (recentRejects->contains(parent_txid)) {
                     fRejectedParents = true;
                     break;
                 }
             }
             if (!fRejectedParents) {
                 const auto current_time = GetTime<std::chrono::microseconds>();
 
                 for (const TxId &parent_txid : unique_parents) {
                     // FIXME: MSG_TX should use a TxHash, not a TxId.
                     pfrom.AddKnownTx(parent_txid);
                     if (!AlreadyHaveTx(parent_txid)) {
                         AddTxAnnouncement(pfrom, parent_txid, current_time);
                     }
                 }
 
                 if (m_orphanage.AddTx(ptx, pfrom.GetId())) {
                     AddToCompactExtraTransactions(ptx);
                 }
 
                 // Once added to the orphan pool, a tx is considered
                 // AlreadyHave, and we shouldn't request it anymore.
                 m_txrequest.ForgetInvId(tx.GetId());
 
                 // DoS prevention: do not allow m_orphanage to grow
                 // unbounded (see CVE-2012-3789)
                 unsigned int nMaxOrphanTx = (unsigned int)std::max(
                     int64_t(0), gArgs.GetArg("-maxorphantx",
                                              DEFAULT_MAX_ORPHAN_TRANSACTIONS));
                 unsigned int nEvicted = m_orphanage.LimitOrphans(nMaxOrphanTx);
                 if (nEvicted > 0) {
                     LogPrint(BCLog::MEMPOOL,
                              "orphanage overflow, removed %u tx\n", nEvicted);
                 }
             } else {
                 LogPrint(BCLog::MEMPOOL,
                          "not keeping orphan with rejected parents %s\n",
                          tx.GetId().ToString());
                 // We will continue to reject this tx since it has rejected
                 // parents so avoid re-requesting it from other peers.
                 recentRejects->insert(tx.GetId());
                 m_txrequest.ForgetInvId(tx.GetId());
             }
         } else {
             assert(recentRejects);
             recentRejects->insert(tx.GetId());
             m_txrequest.ForgetInvId(tx.GetId());
 
             if (RecursiveDynamicUsage(*ptx) < 100000) {
                 AddToCompactExtraTransactions(ptx);
             }
         }
 
         // If a tx has been detected by recentRejects, we will have reached
         // this point and the tx will have been ignored. Because we haven't run
         // the tx through AcceptToMemoryPool, we won't have computed a DoS
         // score for it or determined exactly why we consider it invalid.
         //
         // This means we won't penalize any peer subsequently relaying a DoSy
         // tx (even if we penalized the first peer who gave it to us) because
         // we have to account for recentRejects showing false positives. In
         // other words, we shouldn't penalize a peer if we aren't *sure* they
         // submitted a DoSy tx.
         //
         // Note that recentRejects doesn't just record DoSy or invalid
         // transactions, but any tx not accepted by the mempool, which may be
         // due to node policy (vs. consensus). So we can't blanket penalize a
         // peer simply for relaying a tx that our recentRejects has caught,
         // regardless of false positives.
 
         if (state.IsInvalid()) {
             LogPrint(BCLog::MEMPOOLREJ,
                      "%s from peer=%d was not accepted: %s\n",
                      tx.GetHash().ToString(), pfrom.GetId(), state.ToString());
             MaybePunishNodeForTx(pfrom.GetId(), state);
         }
         return;
     }
 
     if (msg_type == NetMsgType::CMPCTBLOCK) {
         // Ignore cmpctblock received while importing
         if (fImporting || fReindex) {
             LogPrint(BCLog::NET,
                      "Unexpected cmpctblock message received from peer %d\n",
                      pfrom.GetId());
             return;
         }
 
         CBlockHeaderAndShortTxIDs cmpctblock;
         try {
             vRecv >> cmpctblock;
         } catch (std::ios_base::failure &e) {
             // This block has non contiguous or overflowing indexes
             Misbehaving(pfrom, 100, "cmpctblock-bad-indexes");
             return;
         }
 
         bool received_new_header = false;
 
         {
             LOCK(cs_main);
 
             if (!m_chainman.m_blockman.LookupBlockIndex(
                     cmpctblock.header.hashPrevBlock)) {
                 // Doesn't connect (or is genesis), instead of DoSing in
                 // AcceptBlockHeader, request deeper headers
                 if (!m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
                     m_connman.PushMessage(
                         &pfrom,
                         msgMaker.Make(NetMsgType::GETHEADERS,
                                       m_chainman.ActiveChain().GetLocator(
                                           pindexBestHeader),
                                       uint256()));
                 }
                 return;
             }
 
             if (!m_chainman.m_blockman.LookupBlockIndex(
                     cmpctblock.header.GetHash())) {
                 received_new_header = true;
             }
         }
 
         const CBlockIndex *pindex = nullptr;
         BlockValidationState state;
         if (!m_chainman.ProcessNewBlockHeaders(config, {cmpctblock.header},
                                                state, &pindex)) {
             if (state.IsInvalid()) {
                 MaybePunishNodeForBlock(pfrom.GetId(), state,
                                         /*via_compact_block*/ true,
                                         "invalid header via cmpctblock");
                 return;
             }
         }
 
         // When we succeed in decoding a block's txids from a cmpctblock
         // message we typically jump to the BLOCKTXN handling code, with a
         // dummy (empty) BLOCKTXN message, to re-use the logic there in
         // completing processing of the putative block (without cs_main).
         bool fProcessBLOCKTXN = false;
         CDataStream blockTxnMsg(SER_NETWORK, PROTOCOL_VERSION);
 
         // If we end up treating this as a plain headers message, call that as
         // well
         // without cs_main.
         bool fRevertToHeaderProcessing = false;
 
         // Keep a CBlock for "optimistic" compactblock reconstructions (see
         // below)
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         bool fBlockReconstructed = false;
 
         {
             LOCK2(cs_main, g_cs_orphans);
             // If AcceptBlockHeader returned true, it set pindex
             assert(pindex);
             UpdateBlockAvailability(pfrom.GetId(), pindex->GetBlockHash());
 
             CNodeState *nodestate = State(pfrom.GetId());
 
             // If this was a new header with more work than our tip, update the
             // peer's last block announcement time
             if (received_new_header &&
                 pindex->nChainWork >
                     m_chainman.ActiveChain().Tip()->nChainWork) {
                 nodestate->m_last_block_announcement = GetTime();
             }
 
             std::map<BlockHash,
                      std::pair<NodeId, std::list<QueuedBlock>::iterator>>::
                 iterator blockInFlightIt =
                     mapBlocksInFlight.find(pindex->GetBlockHash());
             bool fAlreadyInFlight = blockInFlightIt != mapBlocksInFlight.end();
 
             if (pindex->nStatus.hasData()) {
                 // Nothing to do here
                 return;
             }
 
             if (pindex->nChainWork <=
                     m_chainman.ActiveChain()
                         .Tip()
                         ->nChainWork || // We know something better
                 pindex->nTx != 0) {
                 // We had this block at some point, but pruned it
                 if (fAlreadyInFlight) {
                     // We requested this block for some reason, but our mempool
                     // will probably be useless so we just grab the block via
                     // normal getdata.
                     std::vector<CInv> vInv(1);
                     vInv[0] = CInv(MSG_BLOCK, cmpctblock.header.GetHash());
                     m_connman.PushMessage(
                         &pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                 }
                 return;
             }
 
             // If we're not close to tip yet, give up and let parallel block
             // fetch work its magic.
             if (!fAlreadyInFlight &&
                 !CanDirectFetch(m_chainparams.GetConsensus())) {
                 return;
             }
 
             // We want to be a bit conservative just to be extra careful about
             // DoS possibilities in compact block processing...
             if (pindex->nHeight <= m_chainman.ActiveChain().Height() + 2) {
                 if ((!fAlreadyInFlight && nodestate->nBlocksInFlight <
                                               MAX_BLOCKS_IN_TRANSIT_PER_PEER) ||
                     (fAlreadyInFlight &&
                      blockInFlightIt->second.first == pfrom.GetId())) {
                     std::list<QueuedBlock>::iterator *queuedBlockIt = nullptr;
                     if (!MarkBlockAsInFlight(config, pfrom.GetId(),
                                              pindex->GetBlockHash(), pindex,
                                              &queuedBlockIt)) {
                         if (!(*queuedBlockIt)->partialBlock) {
                             (*queuedBlockIt)
                                 ->partialBlock.reset(
                                     new PartiallyDownloadedBlock(config,
                                                                  &m_mempool));
                         } else {
                             // The block was already in flight using compact
                             // blocks from the same peer.
                             LogPrint(BCLog::NET, "Peer sent us compact block "
                                                  "we were already syncing!\n");
                             return;
                         }
                     }
 
                     PartiallyDownloadedBlock &partialBlock =
                         *(*queuedBlockIt)->partialBlock;
                     ReadStatus status =
                         partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
                     if (status == READ_STATUS_INVALID) {
                         // Reset in-flight state in case Misbehaving does not
                         // result in a disconnect
                         MarkBlockAsReceived(pindex->GetBlockHash());
                         Misbehaving(pfrom, 100, "invalid compact block");
                         return;
                     } else if (status == READ_STATUS_FAILED) {
                         // Duplicate txindices, the block is now in-flight, so
                         // just request it.
                         std::vector<CInv> vInv(1);
                         vInv[0] = CInv(MSG_BLOCK, cmpctblock.header.GetHash());
                         m_connman.PushMessage(
                             &pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                         return;
                     }
 
                     BlockTransactionsRequest req;
                     for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) {
                         if (!partialBlock.IsTxAvailable(i)) {
                             req.indices.push_back(i);
                         }
                     }
                     if (req.indices.empty()) {
                         // Dirty hack to jump to BLOCKTXN code (TODO: move
                         // message handling into their own functions)
                         BlockTransactions txn;
                         txn.blockhash = cmpctblock.header.GetHash();
                         blockTxnMsg << txn;
                         fProcessBLOCKTXN = true;
                     } else {
                         req.blockhash = pindex->GetBlockHash();
                         m_connman.PushMessage(
                             &pfrom,
                             msgMaker.Make(NetMsgType::GETBLOCKTXN, req));
                     }
                 } else {
                     // This block is either already in flight from a different
                     // peer, or this peer has too many blocks outstanding to
                     // download from. Optimistically try to reconstruct anyway
                     // since we might be able to without any round trips.
                     PartiallyDownloadedBlock tempBlock(config, &m_mempool);
                     ReadStatus status =
                         tempBlock.InitData(cmpctblock, vExtraTxnForCompact);
                     if (status != READ_STATUS_OK) {
                         // TODO: don't ignore failures
                         return;
                     }
                     std::vector<CTransactionRef> dummy;
                     status = tempBlock.FillBlock(*pblock, dummy);
                     if (status == READ_STATUS_OK) {
                         fBlockReconstructed = true;
                     }
                 }
             } else {
                 if (fAlreadyInFlight) {
                     // We requested this block, but its far into the future, so
                     // our mempool will probably be useless - request the block
                     // normally.
                     std::vector<CInv> vInv(1);
                     vInv[0] = CInv(MSG_BLOCK, cmpctblock.header.GetHash());
                     m_connman.PushMessage(
                         &pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                     return;
                 } else {
                     // If this was an announce-cmpctblock, we want the same
                     // treatment as a header message.
                     fRevertToHeaderProcessing = true;
                 }
             }
         } // cs_main
 
         if (fProcessBLOCKTXN) {
             return ProcessMessage(config, pfrom, NetMsgType::BLOCKTXN,
                                   blockTxnMsg, time_received, interruptMsgProc);
         }
 
         if (fRevertToHeaderProcessing) {
             // Headers received from HB compact block peers are permitted to be
             // relayed before full validation (see BIP 152), so we don't want to
             // disconnect the peer if the header turns out to be for an invalid
             // block. Note that if a peer tries to build on an invalid chain,
             // that will be detected and the peer will be banned.
             return ProcessHeadersMessage(config, pfrom, *peer,
                                          {cmpctblock.header},
                                          /*via_compact_block=*/true);
         }
 
         if (fBlockReconstructed) {
             // If we got here, we were able to optimistically reconstruct a
             // block that is in flight from some other peer.
             {
                 LOCK(cs_main);
                 mapBlockSource.emplace(pblock->GetHash(),
                                        std::make_pair(pfrom.GetId(), false));
             }
             bool fNewBlock = false;
             // Setting fForceProcessing to true means that we bypass some of
             // our anti-DoS protections in AcceptBlock, which filters
             // unrequested blocks that might be trying to waste our resources
             // (eg disk space). Because we only try to reconstruct blocks when
             // we're close to caught up (via the CanDirectFetch() requirement
             // above, combined with the behavior of not requesting blocks until
             // we have a chain with at least nMinimumChainWork), and we ignore
             // compact blocks with less work than our tip, it is safe to treat
             // reconstructed compact blocks as having been requested.
             m_chainman.ProcessNewBlock(config, pblock,
                                        /*fForceProcessing=*/true, &fNewBlock);
             if (fNewBlock) {
                 pfrom.m_last_block_time = GetTime<std::chrono::seconds>();
             } else {
                 LOCK(cs_main);
                 mapBlockSource.erase(pblock->GetHash());
             }
 
             // hold cs_main for CBlockIndex::IsValid()
             LOCK(cs_main);
             if (pindex->IsValid(BlockValidity::TRANSACTIONS)) {
                 // Clear download state for this block, which is in process from
                 // some other peer. We do this after calling. ProcessNewBlock so
                 // that a malleated cmpctblock announcement can't be used to
                 // interfere with block relay.
                 MarkBlockAsReceived(pblock->GetHash());
             }
         }
         return;
     }
 
     if (msg_type == NetMsgType::BLOCKTXN) {
         // Ignore blocktxn received while importing
         if (fImporting || fReindex) {
             LogPrint(BCLog::NET,
                      "Unexpected blocktxn message received from peer %d\n",
                      pfrom.GetId());
             return;
         }
 
         BlockTransactions resp;
         vRecv >> resp;
 
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         bool fBlockRead = false;
         {
             LOCK(cs_main);
 
             std::map<BlockHash,
                      std::pair<NodeId, std::list<QueuedBlock>::iterator>>::
                 iterator it = mapBlocksInFlight.find(resp.blockhash);
             if (it == mapBlocksInFlight.end() ||
                 !it->second.second->partialBlock ||
                 it->second.first != pfrom.GetId()) {
                 LogPrint(BCLog::NET,
                          "Peer %d sent us block transactions for block "
                          "we weren't expecting\n",
                          pfrom.GetId());
                 return;
             }
 
             PartiallyDownloadedBlock &partialBlock =
                 *it->second.second->partialBlock;
             ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn);
             if (status == READ_STATUS_INVALID) {
                 // Reset in-flight state in case of Misbehaving does not
                 // result in a disconnect.
                 MarkBlockAsReceived(resp.blockhash);
                 Misbehaving(
                     pfrom, 100,
                     "invalid compact block/non-matching block transactions");
                 return;
             } else if (status == READ_STATUS_FAILED) {
                 // Might have collided, fall back to getdata now :(
                 std::vector<CInv> invs;
                 invs.push_back(CInv(MSG_BLOCK, resp.blockhash));
                 m_connman.PushMessage(&pfrom,
                                       msgMaker.Make(NetMsgType::GETDATA, invs));
             } else {
                 // Block is either okay, or possibly we received
                 // READ_STATUS_CHECKBLOCK_FAILED.
                 // Note that CheckBlock can only fail for one of a few reasons:
                 // 1. bad-proof-of-work (impossible here, because we've already
                 //    accepted the header)
                 // 2. merkleroot doesn't match the transactions given (already
                 //    caught in FillBlock with READ_STATUS_FAILED, so
                 //    impossible here)
                 // 3. the block is otherwise invalid (eg invalid coinbase,
                 //    block is too big, too many legacy sigops, etc).
                 // So if CheckBlock failed, #3 is the only possibility.
                 // Under BIP 152, we don't DoS-ban unless proof of work is
                 // invalid (we don't require all the stateless checks to have
                 // been run). This is handled below, so just treat this as
                 // though the block was successfully read, and rely on the
                 // handling in ProcessNewBlock to ensure the block index is
                 // updated, etc.
 
                 // it is now an empty pointer
                 MarkBlockAsReceived(resp.blockhash);
                 fBlockRead = true;
                 // mapBlockSource is used for potentially punishing peers and
                 // updating which peers send us compact blocks, so the race
                 // between here and cs_main in ProcessNewBlock is fine.
                 // BIP 152 permits peers to relay compact blocks after
                 // validating the header only; we should not punish peers
                 // if the block turns out to be invalid.
                 mapBlockSource.emplace(resp.blockhash,
                                        std::make_pair(pfrom.GetId(), false));
             }
         } // Don't hold cs_main when we call into ProcessNewBlock
         if (fBlockRead) {
             bool fNewBlock = false;
             // Since we requested this block (it was in mapBlocksInFlight),
             // force it to be processed, even if it would not be a candidate for
             // new tip (missing previous block, chain not long enough, etc)
             // This bypasses some anti-DoS logic in AcceptBlock (eg to prevent
             // disk-space attacks), but this should be safe due to the
             // protections in the compact block handler -- see related comment
             // in compact block optimistic reconstruction handling.
             m_chainman.ProcessNewBlock(config, pblock,
                                        /*fForceProcessing=*/true, &fNewBlock);
             if (fNewBlock) {
                 pfrom.m_last_block_time = GetTime<std::chrono::seconds>();
             } else {
                 LOCK(cs_main);
                 mapBlockSource.erase(pblock->GetHash());
             }
         }
         return;
     }
 
     if (msg_type == NetMsgType::HEADERS) {
         // Ignore headers received while importing
         if (fImporting || fReindex) {
             LogPrint(BCLog::NET,
                      "Unexpected headers message received from peer %d\n",
                      pfrom.GetId());
             return;
         }
 
         std::vector<CBlockHeader> headers;
 
         // Bypass the normal CBlock deserialization, as we don't want to risk
         // deserializing 2000 full blocks.
         unsigned int nCount = ReadCompactSize(vRecv);
         if (nCount > MAX_HEADERS_RESULTS) {
             Misbehaving(pfrom, 20,
                         strprintf("too-many-headers: headers message size = %u",
                                   nCount));
             return;
         }
         headers.resize(nCount);
         for (unsigned int n = 0; n < nCount; n++) {
             vRecv >> headers[n];
             // Ignore tx count; assume it is 0.
             ReadCompactSize(vRecv);
         }
 
         return ProcessHeadersMessage(config, pfrom, *peer, headers,
                                      /*via_compact_block=*/false);
     }
 
     if (msg_type == NetMsgType::BLOCK) {
         // Ignore block received while importing
         if (fImporting || fReindex) {
             LogPrint(BCLog::NET,
                      "Unexpected block message received from peer %d\n",
                      pfrom.GetId());
             return;
         }
 
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         vRecv >> *pblock;
 
         LogPrint(BCLog::NET, "received block %s peer=%d\n",
                  pblock->GetHash().ToString(), pfrom.GetId());
 
         // Process all blocks from whitelisted peers, even if not requested,
         // unless we're still syncing with the network. Such an unrequested
         // block may still be processed, subject to the conditions in
         // AcceptBlock().
         bool forceProcessing =
             pfrom.HasPermission(PF_NOBAN) &&
             !m_chainman.ActiveChainstate().IsInitialBlockDownload();
         const BlockHash hash = pblock->GetHash();
         {
             LOCK(cs_main);
             // Also always process if we requested the block explicitly, as we
             // may need it even though it is not a candidate for a new best tip.
             forceProcessing |= MarkBlockAsReceived(hash);
             // mapBlockSource is only used for punishing peers and setting
             // which peers send us compact blocks, so the race between here and
             // cs_main in ProcessNewBlock is fine.
             mapBlockSource.emplace(hash, std::make_pair(pfrom.GetId(), true));
         }
         bool fNewBlock = false;
         m_chainman.ProcessNewBlock(config, pblock, forceProcessing, &fNewBlock);
         if (fNewBlock) {
             pfrom.m_last_block_time = GetTime<std::chrono::seconds>();
         } else {
             LOCK(cs_main);
             mapBlockSource.erase(hash);
         }
         return;
     }
 
     if (msg_type == NetMsgType::AVAHELLO) {
         if (pfrom.m_avalanche_state) {
             LogPrint(
                 BCLog::AVALANCHE,
                 "Ignoring avahello from peer %d: already in our node set\n",
                 pfrom.GetId());
             return;
         }
 
         pfrom.m_avalanche_state = std::make_unique<CNode::AvalancheState>();
 
         avalanche::Delegation delegation;
         vRecv >> delegation;
 
         // A delegation with an all zero limited id indicates that the peer has
         // no proof, so we're done.
         if (delegation.getLimitedProofId() != uint256::ZERO) {
             avalanche::DelegationState state;
             CPubKey &pubkey = pfrom.m_avalanche_state->pubkey;
             if (!delegation.verify(state, pubkey)) {
                 Misbehaving(pfrom, 100, "invalid-delegation");
                 return;
             }
 
             CHashWriter sighasher(SER_GETHASH, 0);
             sighasher << delegation.getId();
             sighasher << pfrom.nRemoteHostNonce;
             sighasher << pfrom.GetLocalNonce();
             sighasher << pfrom.nRemoteExtraEntropy;
             sighasher << pfrom.GetLocalExtraEntropy();
 
             SchnorrSig sig;
             vRecv >> sig;
             if (!pubkey.VerifySchnorr(sighasher.GetHash(), sig)) {
                 Misbehaving(pfrom, 100, "invalid-avahello-signature");
                 return;
             }
 
             // If we don't know this proof already, add it to the tracker so it
             // can be requested.
             const avalanche::ProofId proofid(delegation.getProofId());
             if (!AlreadyHaveProof(proofid)) {
                 const bool preferred = isPreferredDownloadPeer(pfrom);
                 LOCK(cs_proofrequest);
                 AddProofAnnouncement(pfrom, proofid,
                                      GetTime<std::chrono::microseconds>(),
                                      preferred);
             }
 
             if (gArgs.GetBoolArg("-enableavalanchepeerdiscovery",
                                  AVALANCHE_DEFAULT_PEER_DISCOVERY_ENABLED)) {
                 // Don't check the return value. If it fails we probably don't
                 // know about the proof yet.
                 g_avalanche->withPeerManager([&](avalanche::PeerManager &pm) {
                     return pm.addNode(pfrom.GetId(), proofid);
                 });
             }
         }
 
         // Send getavaaddr and getavaproofs to our avalanche outbound or
         // manual connections
         if (!pfrom.IsInboundConn()) {
             m_connman.PushMessage(&pfrom,
                                   msgMaker.Make(NetMsgType::GETAVAADDR));
             WITH_LOCK(peer->m_addr_token_bucket_mutex,
                       peer->m_addr_token_bucket += GetMaxAddrToSend());
 
             if (pfrom.m_proof_relay &&
                 !m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
                 m_connman.PushMessage(&pfrom,
                                       msgMaker.Make(NetMsgType::GETAVAPROOFS));
                 pfrom.m_proof_relay->compactproofs_requested = true;
             }
         }
 
         return;
     }
 
     if (msg_type == NetMsgType::AVAPOLL) {
         auto now = std::chrono::steady_clock::now();
         int64_t cooldown =
             gArgs.GetArg("-avacooldown", AVALANCHE_DEFAULT_COOLDOWN);
 
         {
             LOCK(cs_main);
             auto &node_state = State(pfrom.GetId())->m_avalanche_state;
 
             if (now <
                 node_state.last_poll + std::chrono::milliseconds(cooldown)) {
                 Misbehaving(pfrom, 20, "avapool-cooldown");
             }
 
             node_state.last_poll = now;
         }
 
         const bool quorum_established =
             g_avalanche && g_avalanche->isQuorumEstablished();
 
         uint64_t round;
         Unserialize(vRecv, round);
 
         unsigned int nCount = ReadCompactSize(vRecv);
         if (nCount > AVALANCHE_MAX_ELEMENT_POLL) {
             Misbehaving(
                 pfrom, 20,
                 strprintf("too-many-ava-poll: poll message size = %u", nCount));
             return;
         }
 
         std::vector<avalanche::Vote> votes;
         votes.reserve(nCount);
 
         LogPrint(BCLog::AVALANCHE, "received avalanche poll from peer=%d\n",
                  pfrom.GetId());
 
         for (unsigned int n = 0; n < nCount; n++) {
             CInv inv;
             vRecv >> inv;
 
             // Default vote for unknown inv type
             uint32_t vote = -1;
 
             // We don't vote definitively until we have an established quorum
             if (!quorum_established) {
                 votes.emplace_back(vote, inv.hash);
                 continue;
             }
 
             // If inv's type is known, get a vote for its hash
             switch (inv.type) {
                 case MSG_TX: {
                     vote = getAvalancheVoteForTx(m_mempool, TxId(inv.hash));
                 } break;
                 case MSG_BLOCK: {
                     vote = WITH_LOCK(cs_main, return GetAvalancheVoteForBlock(
                                                   BlockHash(inv.hash)));
                 } break;
                 case MSG_AVA_PROOF: {
                     vote =
                         getAvalancheVoteForProof(avalanche::ProofId(inv.hash));
                 } break;
                 default: {
                     LogPrint(BCLog::AVALANCHE,
                              "poll inv type unknown from peer=%d\n", inv.type);
                 }
             }
 
             votes.emplace_back(vote, inv.hash);
         }
 
         // Send the query to the node.
         g_avalanche->sendResponse(
             &pfrom, avalanche::Response(round, cooldown, std::move(votes)));
         return;
     }
 
     if (msg_type == NetMsgType::AVARESPONSE) {
         // As long as QUIC is not implemented, we need to sign response and
         // verify response's signatures in order to avoid any manipulation of
         // messages at the transport level.
         CHashVerifier<CDataStream> verifier(&vRecv);
         avalanche::Response response;
         verifier >> response;
 
         SchnorrSig sig;
         vRecv >> sig;
         if (!pfrom.m_avalanche_state ||
             !pfrom.m_avalanche_state->pubkey.VerifySchnorr(verifier.GetHash(),
                                                            sig)) {
             Misbehaving(pfrom, 100, "invalid-ava-response-signature");
             return;
         }
 
         std::vector<avalanche::BlockUpdate> blockUpdates;
         std::vector<avalanche::ProofUpdate> proofUpdates;
         int banscore;
         std::string error;
         if (!g_avalanche->registerVotes(pfrom.GetId(), response, blockUpdates,
                                         proofUpdates, banscore, error)) {
             Misbehaving(pfrom, banscore, error);
             return;
         }
 
         pfrom.m_avalanche_state->invsVoted(response.GetVotes().size());
 
         auto logVoteUpdate = [](const auto &voteUpdate,
                                 const std::string &voteItemTypeStr,
                                 const auto &voteItemId) {
             std::string voteOutcome;
             switch (voteUpdate.getStatus()) {
                 case avalanche::VoteStatus::Invalid:
                     voteOutcome = "invalidated";
                     break;
                 case avalanche::VoteStatus::Rejected:
                     voteOutcome = "rejected";
                     break;
                 case avalanche::VoteStatus::Accepted:
                     voteOutcome = "accepted";
                     break;
                 case avalanche::VoteStatus::Finalized:
                     voteOutcome = "finalized";
                     break;
                 case avalanche::VoteStatus::Stale:
                     voteOutcome = "stalled";
                     break;
 
                     // No default case, so the compiler can warn about missing
                     // cases
             }
 
             LogPrint(BCLog::AVALANCHE, "Avalanche %s %s %s\n", voteOutcome,
                      voteItemTypeStr, voteItemId.ToString());
         };
 
         for (avalanche::ProofUpdate &u : proofUpdates) {
             avalanche::ProofRef proof = u.getVoteItem();
             const avalanche::ProofId &proofid = proof->getId();
 
             logVoteUpdate(u, "proof", proofid);
 
             auto rejectionMode = avalanche::PeerManager::RejectionMode::DEFAULT;
             auto nextCooldownTimePoint = GetTime<std::chrono::seconds>();
             switch (u.getStatus()) {
                 case avalanche::VoteStatus::Invalid:
                     WITH_LOCK(cs_rejectedProofs,
                               rejectedProofs->insert(proofid));
                     // Fallthrough
                 case avalanche::VoteStatus::Stale:
                     // Invalidate mode removes the proof from all proof pools
                     rejectionMode =
                         avalanche::PeerManager::RejectionMode::INVALIDATE;
                     // Fallthrough
                 case avalanche::VoteStatus::Rejected:
                     if (!g_avalanche->withPeerManager(
                             [&](avalanche::PeerManager &pm) {
                                 return pm.rejectProof(proofid, rejectionMode);
                             })) {
                         LogPrint(BCLog::AVALANCHE,
                                  "ERROR: Failed to reject proof: %s\n",
                                  proofid.GetHex());
                     }
                     break;
                 case avalanche::VoteStatus::Finalized:
                     nextCooldownTimePoint += std::chrono::seconds(gArgs.GetArg(
                         "-avalanchepeerreplacementcooldown",
                         AVALANCHE_DEFAULT_PEER_REPLACEMENT_COOLDOWN));
                 case avalanche::VoteStatus::Accepted:
                     if (!g_avalanche->withPeerManager(
                             [&](avalanche::PeerManager &pm) {
                                 pm.registerProof(
                                     proof, avalanche::PeerManager::
                                                RegistrationMode::FORCE_ACCEPT);
                                 return pm.forPeer(
                                     proofid, [&](const avalanche::Peer &peer) {
                                         pm.updateNextPossibleConflictTime(
                                             peer.peerid, nextCooldownTimePoint);
                                         if (u.getStatus() ==
                                             avalanche::VoteStatus::Finalized) {
                                             pm.setFinalized(peer.peerid);
                                         }
                                         // Only fail if the peer was not
                                         // created
                                         return true;
                                     });
                             })) {
                         LogPrint(BCLog::AVALANCHE,
                                  "ERROR: Failed to accept proof: %s\n",
                                  proofid.GetHex());
                     }
                     break;
             }
         }
 
         if (blockUpdates.size()) {
             for (avalanche::BlockUpdate &u : blockUpdates) {
                 CBlockIndex *pindex = u.getVoteItem();
 
                 logVoteUpdate(u, "block", pindex->GetBlockHash());
 
                 switch (u.getStatus()) {
                     case avalanche::VoteStatus::Invalid:
                     case avalanche::VoteStatus::Rejected: {
                         BlockValidationState state;
                         m_chainman.ActiveChainstate().ParkBlock(config, state,
                                                                 pindex);
                         if (!state.IsValid()) {
                             LogPrintf("ERROR: Database error: %s\n",
                                       state.GetRejectReason());
                             return;
                         }
                     } break;
                     case avalanche::VoteStatus::Accepted:
                     case avalanche::VoteStatus::Finalized: {
                         LOCK(cs_main);
                         m_chainman.ActiveChainstate().UnparkBlock(pindex);
                     } break;
                     case avalanche::VoteStatus::Stale:
                         // Fall back on Nakamoto consensus in the absence of
                         // Avalanche votes for other competing or descendant
                         // blocks.
                         break;
                 }
             }
 
             BlockValidationState state;
             if (!m_chainman.ActiveChainstate().ActivateBestChain(config,
                                                                  state)) {
                 LogPrintf("failed to activate chain (%s)\n", state.ToString());
             }
         }
 
         return;
     }
 
     if (msg_type == NetMsgType::AVAPROOF) {
         auto proof = RCUPtr<avalanche::Proof>::make();
         vRecv >> *proof;
 
         ReceivedAvalancheProof(pfrom, proof);
 
         return;
     }
 
     if (msg_type == NetMsgType::GETAVAPROOFS) {
         if (pfrom.m_proof_relay == nullptr) {
             return;
         }
 
         pfrom.m_proof_relay->lastSharedProofsUpdate =
             GetTime<std::chrono::seconds>();
 
         pfrom.m_proof_relay->sharedProofs =
             g_avalanche->withPeerManager([&](const avalanche::PeerManager &pm) {
                 return pm.getShareableProofsSnapshot();
             });
 
         avalanche::CompactProofs compactProofs(
             pfrom.m_proof_relay->sharedProofs);
         m_connman.PushMessage(
             &pfrom, msgMaker.Make(NetMsgType::AVAPROOFS, compactProofs));
 
         return;
     }
 
     if (msg_type == NetMsgType::AVAPROOFS) {
         if (pfrom.m_proof_relay == nullptr) {
             return;
         }
 
         // Only process the compact proofs if we requested them
         if (!pfrom.m_proof_relay->compactproofs_requested) {
             LogPrint(BCLog::AVALANCHE, "Ignoring unsollicited avaproofs\n");
             return;
         }
         pfrom.m_proof_relay->compactproofs_requested = false;
 
         avalanche::CompactProofs compactProofs;
         try {
             vRecv >> compactProofs;
         } catch (std::ios_base::failure &e) {
             // This compact proofs have non contiguous or overflowing indexes
             Misbehaving(pfrom, 100, "avaproofs-bad-indexes");
             return;
         }
 
         // If there are prefilled proofs, process them first
         std::set<uint32_t> prefilledIndexes;
         for (const auto &prefilledProof : compactProofs.getPrefilledProofs()) {
             if (!ReceivedAvalancheProof(pfrom, prefilledProof.proof)) {
                 // If we got an invalid proof, the peer is getting banned and we
                 // can bail out.
                 return;
             }
         }
 
         // If there is no shortid, avoid parsing/responding/accounting for the
         // message.
         if (compactProofs.getShortIDs().size() == 0) {
             LogPrint(BCLog::AVALANCHE,
                      "Got an avaproofs message with no shortid (peer %d)\n",
                      pfrom.GetId());
             return;
         }
 
         // To determine the chance that the number of entries in a bucket
         // exceeds N, we use the fact that the number of elements in a single
         // bucket is binomially distributed (with n = the number of shorttxids
         // S, and p = 1 / the number of buckets), that in the worst case the
         // number of buckets is equal to S (due to std::unordered_map having a
         // default load factor of 1.0), and that the chance for any bucket to
         // exceed N elements is at most buckets * (the chance that any given
         // bucket is above N elements). Thus:
         //   P(max_elements_per_bucket > N) <=
         //     S * (1 - cdf(binomial(n=S,p=1/S), N))
         // If we assume up to 21000000, allowing 15 elements per bucket should
         // only fail once per ~2.5 million avaproofs transfers (per peer and
         // connection).
         // TODO re-evaluate the bucket count to a more realistic value.
         // TODO: In the case of a shortid-collision, we should request all the
         // proofs which collided. For now, we only request one, which is not
         // that bad considering this event is expected to be very rare.
         auto shortIdProcessor =
             avalanche::ProofShortIdProcessor(compactProofs.getPrefilledProofs(),
                                              compactProofs.getShortIDs(), 15);
 
         if (shortIdProcessor.hasOutOfBoundIndex()) {
             // This should be catched by deserialization, but catch it here as
             // well as a good measure.
             Misbehaving(pfrom, 100, "avaproofs-bad-indexes");
             return;
         }
         if (!shortIdProcessor.isEvenlyDistributed()) {
             // This is suspicious, don't ban but bail out
             return;
         }
 
         const auto &proofs =
             g_avalanche->withPeerManager([&](const avalanche::PeerManager &pm) {
                 return pm.getShareableProofsSnapshot();
             });
 
         size_t proofCount = 0;
         proofs.forEachLeaf([&](const avalanche::ProofRef &proof) {
             uint64_t shortid = compactProofs.getShortID(proof->getId());
 
             proofCount += shortIdProcessor.matchKnownItem(shortid, proof);
 
             // Though ideally we'd continue scanning for the
             // two-proofs-match-shortid case, the performance win of an early
             // exit here is too good to pass up and worth the extra risk.
             return proofCount != shortIdProcessor.getShortIdCount();
         });
 
         avalanche::ProofsRequest req;
         for (size_t i = 0; i < compactProofs.size(); i++) {
             if (shortIdProcessor.getItem(i) == nullptr) {
                 req.indices.push_back(i);
             }
         }
 
         m_connman.PushMessage(&pfrom,
                               msgMaker.Make(NetMsgType::AVAPROOFSREQ, req));
 
         // We want to keep a count of how many nodes we successfully requested
         // avaproofs from as this is used to determine when we are confident our
         // quorum is close enough to the other participants.
         g_avalanche->avaproofsSent(pfrom.GetId());
 
         return;
     }
 
     if (msg_type == NetMsgType::AVAPROOFSREQ) {
         if (pfrom.m_proof_relay == nullptr) {
             return;
         }
 
         avalanche::ProofsRequest proofreq;
         vRecv >> proofreq;
 
         auto requestedIndiceIt = proofreq.indices.begin();
         uint32_t treeIndice = 0;
         pfrom.m_proof_relay->sharedProofs.forEachLeaf([&](const auto &proof) {
             if (requestedIndiceIt == proofreq.indices.end()) {
                 // No more indice to process
                 return false;
             }
 
             if (treeIndice++ == *requestedIndiceIt) {
                 m_connman.PushMessage(
                     &pfrom, msgMaker.Make(NetMsgType::AVAPROOF, *proof));
                 requestedIndiceIt++;
             }
 
             return true;
         });
 
         pfrom.m_proof_relay->sharedProofs = {};
         return;
     }
 
     if (msg_type == NetMsgType::GETADDR) {
         // This asymmetric behavior for inbound and outbound connections was
         // introduced to prevent a fingerprinting attack: an attacker can send
         // specific fake addresses to users' AddrMan and later request them by
         // sending getaddr messages. Making nodes which are behind NAT and can
         // only make outgoing connections ignore the getaddr message mitigates
         // the attack.
         if (!pfrom.IsInboundConn()) {
             LogPrint(BCLog::NET,
                      "Ignoring \"getaddr\" from %s connection. peer=%d\n",
                      pfrom.ConnectionTypeAsString(), pfrom.GetId());
             return;
         }
 
         // Since this must be an inbound connection, SetupAddressRelay will
         // never fail.
         Assume(SetupAddressRelay(pfrom, *peer));
 
         // Only send one GetAddr response per connection to reduce resource
         // waste and discourage addr stamping of INV announcements.
         if (peer->m_getaddr_recvd) {
             LogPrint(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n",
                      pfrom.GetId());
             return;
         }
         peer->m_getaddr_recvd = true;
 
         peer->m_addrs_to_send.clear();
         std::vector<CAddress> vAddr;
         const size_t maxAddrToSend = GetMaxAddrToSend();
         if (pfrom.HasPermission(PF_ADDR)) {
             vAddr = m_connman.GetAddresses(maxAddrToSend, MAX_PCT_ADDR_TO_SEND,
                                            /* network */ std::nullopt);
         } else {
             vAddr = m_connman.GetAddresses(pfrom, maxAddrToSend,
                                            MAX_PCT_ADDR_TO_SEND);
         }
         FastRandomContext insecure_rand;
         for (const CAddress &addr : vAddr) {
             PushAddress(*peer, addr, insecure_rand);
         }
         return;
     }
 
     if (msg_type == NetMsgType::GETAVAADDR) {
         auto now = GetTime<std::chrono::seconds>();
         if (now < pfrom.m_nextGetAvaAddr) {
             // Prevent a peer from exhausting our resources by spamming
             // getavaaddr messages.
             LogPrint(BCLog::AVALANCHE,
                      "Ignoring repeated getavaaddr from peer %d\n",
                      pfrom.GetId());
             return;
         }
 
         // Only accept a getavaaddr every GETAVAADDR_INTERVAL at most
         pfrom.m_nextGetAvaAddr = now + GETAVAADDR_INTERVAL;
 
         auto availabilityScoreComparator = [](const CNode *lhs,
                                               const CNode *rhs) {
             double scoreLhs = lhs->m_avalanche_state->getAvailabilityScore();
             double scoreRhs = rhs->m_avalanche_state->getAvailabilityScore();
 
             if (scoreLhs != scoreRhs) {
                 return scoreLhs > scoreRhs;
             }
 
             return lhs < rhs;
         };
 
         // Get up to MAX_ADDR_TO_SEND addresses of the nodes which are the
         // most active in the avalanche network. Account for 0 availability as
         // well so we can send addresses even if we did not start polling yet.
         std::set<const CNode *, decltype(availabilityScoreComparator)> avaNodes(
             availabilityScoreComparator);
         m_connman.ForEachNode([&](const CNode *pnode) {
             if (pnode && pnode->m_avalanche_state &&
                 !(pnode->m_avalanche_state->getAvailabilityScore() < 0.)) {
                 avaNodes.insert(pnode);
                 if (avaNodes.size() > GetMaxAddrToSend()) {
                     avaNodes.erase(std::prev(avaNodes.end()));
                 }
             }
         });
 
         peer->m_addrs_to_send.clear();
         FastRandomContext insecure_rand;
         for (const CNode *pnode : avaNodes) {
             PushAddress(*peer, pnode->addr, insecure_rand);
         }
 
         return;
     }
 
     if (msg_type == NetMsgType::MEMPOOL) {
         if (!(pfrom.GetLocalServices() & NODE_BLOOM) &&
             !pfrom.HasPermission(PF_MEMPOOL)) {
             if (!pfrom.HasPermission(PF_NOBAN)) {
                 LogPrint(BCLog::NET,
                          "mempool request with bloom filters disabled, "
                          "disconnect peer=%d\n",
                          pfrom.GetId());
                 pfrom.fDisconnect = true;
             }
             return;
         }
 
         if (m_connman.OutboundTargetReached(false) &&
             !pfrom.HasPermission(PF_MEMPOOL)) {
             if (!pfrom.HasPermission(PF_NOBAN)) {
                 LogPrint(BCLog::NET,
                          "mempool request with bandwidth limit reached, "
                          "disconnect peer=%d\n",
                          pfrom.GetId());
                 pfrom.fDisconnect = true;
             }
             return;
         }
 
         if (pfrom.m_tx_relay != nullptr) {
             LOCK(pfrom.m_tx_relay->cs_tx_inventory);
             pfrom.m_tx_relay->fSendMempool = true;
         }
         return;
     }
 
     if (msg_type == NetMsgType::PING) {
         if (pfrom.GetCommonVersion() > BIP0031_VERSION) {
             uint64_t nonce = 0;
             vRecv >> nonce;
             // Echo the message back with the nonce. This allows for two useful
             // features:
             //
             // 1) A remote node can quickly check if the connection is
             // operational.
             // 2) Remote nodes can measure the latency of the network thread. If
             // this node is overloaded it won't respond to pings quickly and the
             // remote node can avoid sending us more work, like chain download
             // requests.
             //
             // The nonce stops the remote getting confused between different
             // pings: without it, if the remote node sends a ping once per
             // second and this node takes 5 seconds to respond to each, the 5th
             // ping the remote sends would appear to return very quickly.
             m_connman.PushMessage(&pfrom,
                                   msgMaker.Make(NetMsgType::PONG, nonce));
         }
         return;
     }
 
     if (msg_type == NetMsgType::PONG) {
         const auto ping_end = time_received;
         uint64_t nonce = 0;
         size_t nAvail = vRecv.in_avail();
         bool bPingFinished = false;
         std::string sProblem;
 
         if (nAvail >= sizeof(nonce)) {
             vRecv >> nonce;
 
             // Only process pong message if there is an outstanding ping (old
             // ping without nonce should never pong)
             if (peer->m_ping_nonce_sent != 0) {
                 if (nonce == peer->m_ping_nonce_sent) {
                     // Matching pong received, this ping is no longer
                     // outstanding
                     bPingFinished = true;
                     const auto ping_time = ping_end - peer->m_ping_start.load();
                     if (ping_time.count() >= 0) {
                         // Let connman know about this successful ping-pong
                         pfrom.PongReceived(ping_time);
                     } else {
                         // This should never happen
                         sProblem = "Timing mishap";
                     }
                 } else {
                     // Nonce mismatches are normal when pings are overlapping
                     sProblem = "Nonce mismatch";
                     if (nonce == 0) {
                         // This is most likely a bug in another implementation
                         // somewhere; cancel this ping
                         bPingFinished = true;
                         sProblem = "Nonce zero";
                     }
                 }
             } else {
                 sProblem = "Unsolicited pong without ping";
             }
         } else {
             // This is most likely a bug in another implementation somewhere;
             // cancel this ping
             bPingFinished = true;
             sProblem = "Short payload";
         }
 
         if (!(sProblem.empty())) {
             LogPrint(BCLog::NET,
                      "pong peer=%d: %s, %x expected, %x received, %u bytes\n",
                      pfrom.GetId(), sProblem, peer->m_ping_nonce_sent, nonce,
                      nAvail);
         }
         if (bPingFinished) {
             peer->m_ping_nonce_sent = 0;
         }
         return;
     }
 
     if (msg_type == NetMsgType::FILTERLOAD) {
         if (!(pfrom.GetLocalServices() & NODE_BLOOM)) {
             LogPrint(BCLog::NET,
                      "filterload received despite not offering bloom services "
                      "from peer=%d; disconnecting\n",
                      pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
         CBloomFilter filter;
         vRecv >> filter;
 
         if (!filter.IsWithinSizeConstraints()) {
             // There is no excuse for sending a too-large filter
             Misbehaving(pfrom, 100, "too-large bloom filter");
         } else if (pfrom.m_tx_relay != nullptr) {
             LOCK(pfrom.m_tx_relay->cs_filter);
             pfrom.m_tx_relay->pfilter.reset(new CBloomFilter(filter));
             pfrom.m_tx_relay->fRelayTxes = true;
         }
         return;
     }
 
     if (msg_type == NetMsgType::FILTERADD) {
         if (!(pfrom.GetLocalServices() & NODE_BLOOM)) {
             LogPrint(BCLog::NET,
                      "filteradd received despite not offering bloom services "
                      "from peer=%d; disconnecting\n",
                      pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
         std::vector<uint8_t> vData;
         vRecv >> vData;
 
         // Nodes must NEVER send a data item > 520 bytes (the max size for a
         // script data object, and thus, the maximum size any matched object can
         // have) in a filteradd message.
         bool bad = false;
         if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE) {
             bad = true;
         } else if (pfrom.m_tx_relay != nullptr) {
             LOCK(pfrom.m_tx_relay->cs_filter);
             if (pfrom.m_tx_relay->pfilter) {
                 pfrom.m_tx_relay->pfilter->insert(vData);
             } else {
                 bad = true;
             }
         }
         if (bad) {
             // The structure of this code doesn't really allow for a good error
             // code. We'll go generic.
             Misbehaving(pfrom, 100, "bad filteradd message");
         }
         return;
     }
 
     if (msg_type == NetMsgType::FILTERCLEAR) {
         if (!(pfrom.GetLocalServices() & NODE_BLOOM)) {
             LogPrint(BCLog::NET,
                      "filterclear received despite not offering bloom services "
                      "from peer=%d; disconnecting\n",
                      pfrom.GetId());
             pfrom.fDisconnect = true;
             return;
         }
         if (pfrom.m_tx_relay == nullptr) {
             return;
         }
         LOCK(pfrom.m_tx_relay->cs_filter);
         pfrom.m_tx_relay->pfilter = nullptr;
         pfrom.m_tx_relay->fRelayTxes = true;
         return;
     }
 
     if (msg_type == NetMsgType::FEEFILTER) {
         Amount newFeeFilter = Amount::zero();
         vRecv >> newFeeFilter;
         if (MoneyRange(newFeeFilter)) {
             if (pfrom.m_tx_relay != nullptr) {
                 LOCK(pfrom.m_tx_relay->cs_feeFilter);
                 pfrom.m_tx_relay->minFeeFilter = newFeeFilter;
             }
             LogPrint(BCLog::NET, "received: feefilter of %s from peer=%d\n",
                      CFeeRate(newFeeFilter).ToString(), pfrom.GetId());
         }
         return;
     }
 
     if (msg_type == NetMsgType::GETCFILTERS) {
         ProcessGetCFilters(pfrom, vRecv, m_chainparams, m_connman);
         return;
     }
 
     if (msg_type == NetMsgType::GETCFHEADERS) {
         ProcessGetCFHeaders(pfrom, vRecv, m_chainparams, m_connman);
         return;
     }
 
     if (msg_type == NetMsgType::GETCFCHECKPT) {
         ProcessGetCFCheckPt(pfrom, vRecv, m_chainparams, m_connman);
         return;
     }
 
     if (msg_type == NetMsgType::NOTFOUND) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         // A peer might send up to 1 notfound per getdata request, but no more
         if (vInv.size() <= PROOF_REQUEST_PARAMS.max_peer_announcements +
                                TX_REQUEST_PARAMS.max_peer_announcements +
                                MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
             for (CInv &inv : vInv) {
                 if (inv.IsMsgTx()) {
                     // If we receive a NOTFOUND message for a tx we requested,
                     // mark the announcement for it as completed in
                     // InvRequestTracker.
                     LOCK(::cs_main);
                     m_txrequest.ReceivedResponse(pfrom.GetId(), TxId(inv.hash));
                     continue;
                 }
                 if (inv.IsMsgProof()) {
                     LOCK(cs_proofrequest);
                     m_proofrequest.ReceivedResponse(
                         pfrom.GetId(), avalanche::ProofId(inv.hash));
                 }
             }
         }
         return;
     }
 
     // Ignore unknown commands for extensibility
     LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n",
              SanitizeString(msg_type), pfrom.GetId());
     return;
 }
 
 bool PeerManagerImpl::MaybeDiscourageAndDisconnect(CNode &pnode, Peer &peer) {
     {
         LOCK(peer.m_misbehavior_mutex);
 
         // There's nothing to do if the m_should_discourage flag isn't set
         if (!peer.m_should_discourage) {
             return false;
         }
 
         peer.m_should_discourage = false;
     } // peer.m_misbehavior_mutex
 
     if (pnode.HasPermission(PF_NOBAN)) {
         // We never disconnect or discourage peers for bad behavior if they have
         // the NOBAN permission flag
         LogPrintf("Warning: not punishing noban peer %d!\n", peer.m_id);
         return false;
     }
 
     if (pnode.IsManualConn()) {
         // We never disconnect or discourage manual peers for bad behavior
         LogPrintf("Warning: not punishing manually connected peer %d!\n",
                   peer.m_id);
         return false;
     }
 
     if (pnode.addr.IsLocal()) {
         // We disconnect local peers for bad behavior but don't discourage
         // (since that would discourage all peers on the same local address)
         LogPrintf(
             "Warning: disconnecting but not discouraging local peer %d!\n",
             peer.m_id);
         pnode.fDisconnect = true;
         return true;
     }
 
     // Normal case: Disconnect the peer and discourage all nodes sharing the
     // address
     LogPrintf("Disconnecting and discouraging peer %d!\n", peer.m_id);
     if (m_banman) {
         m_banman->Discourage(pnode.addr);
     }
     m_connman.DisconnectNode(pnode.addr);
     return true;
 }
 
 bool PeerManagerImpl::ProcessMessages(const Config &config, CNode *pfrom,
                                       std::atomic<bool> &interruptMsgProc) {
     //
     // Message format
     //  (4) message start
     //  (12) command
     //  (4) size
     //  (4) checksum
     //  (x) data
     //
     bool fMoreWork = false;
 
     PeerRef peer = GetPeerRef(pfrom->GetId());
     if (peer == nullptr) {
         return false;
     }
 
     {
         LOCK(peer->m_getdata_requests_mutex);
         if (!peer->m_getdata_requests.empty()) {
             ProcessGetData(config, *pfrom, *peer, interruptMsgProc);
         }
     }
 
     {
         LOCK2(cs_main, g_cs_orphans);
         if (!peer->m_orphan_work_set.empty()) {
             ProcessOrphanTx(config, peer->m_orphan_work_set);
         }
     }
 
     if (pfrom->fDisconnect) {
         return false;
     }
 
     // this maintains the order of responses and prevents m_getdata_requests
     // from growing unbounded
     {
         LOCK(peer->m_getdata_requests_mutex);
         if (!peer->m_getdata_requests.empty()) {
             return true;
         }
     }
 
     {
         LOCK(g_cs_orphans);
         if (!peer->m_orphan_work_set.empty()) {
             return true;
         }
     }
 
     // Don't bother if send buffer is too full to respond anyway
     if (pfrom->fPauseSend) {
         return false;
     }
 
     std::list<CNetMessage> msgs;
     {
         LOCK(pfrom->cs_vProcessMsg);
         if (pfrom->vProcessMsg.empty()) {
             return false;
         }
         // Just take one message
         msgs.splice(msgs.begin(), pfrom->vProcessMsg,
                     pfrom->vProcessMsg.begin());
         pfrom->nProcessQueueSize -= msgs.front().m_raw_message_size;
         pfrom->fPauseRecv =
             pfrom->nProcessQueueSize > m_connman.GetReceiveFloodSize();
         fMoreWork = !pfrom->vProcessMsg.empty();
     }
     CNetMessage &msg(msgs.front());
 
     msg.SetVersion(pfrom->GetCommonVersion());
 
     // Check network magic
     if (!msg.m_valid_netmagic) {
         LogPrint(BCLog::NET,
                  "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n",
                  SanitizeString(msg.m_command), pfrom->GetId());
 
         // Make sure we discourage where that come from for some time.
         if (m_banman) {
             m_banman->Discourage(pfrom->addr);
         }
         m_connman.DisconnectNode(pfrom->addr);
 
         pfrom->fDisconnect = true;
         return false;
     }
 
     // Check header
     if (!msg.m_valid_header) {
         LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n",
                  SanitizeString(msg.m_command), pfrom->GetId());
         return fMoreWork;
     }
     const std::string &msg_type = msg.m_command;
 
     // Message size
     unsigned int nMessageSize = msg.m_message_size;
 
     // Checksum
     CDataStream &vRecv = msg.m_recv;
     if (!msg.m_valid_checksum) {
         LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR peer=%d\n",
                  __func__, SanitizeString(msg_type), nMessageSize,
                  pfrom->GetId());
         if (m_banman) {
             m_banman->Discourage(pfrom->addr);
         }
         m_connman.DisconnectNode(pfrom->addr);
         return fMoreWork;
     }
 
     try {
         ProcessMessage(config, *pfrom, msg_type, vRecv, msg.m_time,
                        interruptMsgProc);
         if (interruptMsgProc) {
             return false;
         }
 
         {
             LOCK(peer->m_getdata_requests_mutex);
             if (!peer->m_getdata_requests.empty()) {
                 fMoreWork = true;
             }
         }
     } catch (const std::exception &e) {
         LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' (%s) caught\n",
                  __func__, SanitizeString(msg_type), nMessageSize, e.what(),
                  typeid(e).name());
     } catch (...) {
         LogPrint(BCLog::NET, "%s(%s, %u bytes): Unknown exception caught\n",
                  __func__, SanitizeString(msg_type), nMessageSize);
     }
 
     return fMoreWork;
 }
 
 void PeerManagerImpl::ConsiderEviction(CNode &pto, int64_t time_in_seconds) {
     AssertLockHeld(cs_main);
 
     CNodeState &state = *State(pto.GetId());
     const CNetMsgMaker msgMaker(pto.GetCommonVersion());
 
     if (!state.m_chain_sync.m_protect && pto.IsOutboundOrBlockRelayConn() &&
         state.fSyncStarted) {
         // This is an outbound peer subject to disconnection if they don't
         // announce a block with as much work as the current tip within
         // CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds (note: if their
         // chain has more work than ours, we should sync to it, unless it's
         // invalid, in which case we should find that out and disconnect from
         // them elsewhere).
         if (state.pindexBestKnownBlock != nullptr &&
             state.pindexBestKnownBlock->nChainWork >=
                 m_chainman.ActiveChain().Tip()->nChainWork) {
             if (state.m_chain_sync.m_timeout != 0) {
                 state.m_chain_sync.m_timeout = 0;
                 state.m_chain_sync.m_work_header = nullptr;
                 state.m_chain_sync.m_sent_getheaders = false;
             }
         } else if (state.m_chain_sync.m_timeout == 0 ||
                    (state.m_chain_sync.m_work_header != nullptr &&
                     state.pindexBestKnownBlock != nullptr &&
                     state.pindexBestKnownBlock->nChainWork >=
                         state.m_chain_sync.m_work_header->nChainWork)) {
             // Our best block known by this peer is behind our tip, and we're
             // either noticing that for the first time, OR this peer was able to
             // catch up to some earlier point where we checked against our tip.
             // Either way, set a new timeout based on current tip.
             state.m_chain_sync.m_timeout = time_in_seconds + CHAIN_SYNC_TIMEOUT;
             state.m_chain_sync.m_work_header = m_chainman.ActiveChain().Tip();
             state.m_chain_sync.m_sent_getheaders = false;
         } else if (state.m_chain_sync.m_timeout > 0 &&
                    time_in_seconds > state.m_chain_sync.m_timeout) {
             // No evidence yet that our peer has synced to a chain with work
             // equal to that of our tip, when we first detected it was behind.
             // Send a single getheaders message to give the peer a chance to
             // update us.
             if (state.m_chain_sync.m_sent_getheaders) {
                 // They've run out of time to catch up!
                 LogPrintf(
                     "Disconnecting outbound peer %d for old chain, best known "
                     "block = %s\n",
                     pto.GetId(),
                     state.pindexBestKnownBlock != nullptr
                         ? state.pindexBestKnownBlock->GetBlockHash().ToString()
                         : "<none>");
                 pto.fDisconnect = true;
             } else {
                 assert(state.m_chain_sync.m_work_header);
                 LogPrint(
                     BCLog::NET,
                     "sending getheaders to outbound peer=%d to verify chain "
                     "work (current best known block:%s, benchmark blockhash: "
                     "%s)\n",
                     pto.GetId(),
                     state.pindexBestKnownBlock != nullptr
                         ? state.pindexBestKnownBlock->GetBlockHash().ToString()
                         : "<none>",
                     state.m_chain_sync.m_work_header->GetBlockHash()
                         .ToString());
                 m_connman.PushMessage(
                     &pto,
                     msgMaker.Make(NetMsgType::GETHEADERS,
                                   m_chainman.ActiveChain().GetLocator(
                                       state.m_chain_sync.m_work_header->pprev),
                                   uint256()));
                 state.m_chain_sync.m_sent_getheaders = true;
                 // 2 minutes
                 constexpr int64_t HEADERS_RESPONSE_TIME = 120;
                 // Bump the timeout to allow a response, which could clear the
                 // timeout (if the response shows the peer has synced), reset
                 // the timeout (if the peer syncs to the required work but not
                 // to our tip), or result in disconnect (if we advance to the
                 // timeout and pindexBestKnownBlock has not sufficiently
                 // progressed)
                 state.m_chain_sync.m_timeout =
                     time_in_seconds + HEADERS_RESPONSE_TIME;
             }
         }
     }
 }
 
 void PeerManagerImpl::EvictExtraOutboundPeers(std::chrono::seconds now) {
     // If we have any extra block-relay-only peers, disconnect the youngest
     // unless it's given us a block -- in which case, compare with the
     // second-youngest, and out of those two, disconnect the peer who least
     // recently gave us a block.
     // The youngest block-relay-only peer would be the extra peer we connected
     // to temporarily in order to sync our tip; see net.cpp.
     // Note that we use higher nodeid as a measure for most recent connection.
     if (m_connman.GetExtraBlockRelayCount() > 0) {
         std::pair<NodeId, std::chrono::seconds> youngest_peer{-1, 0},
             next_youngest_peer{-1, 0};
 
         m_connman.ForEachNode([&](CNode *pnode) {
             if (!pnode->IsBlockOnlyConn() || pnode->fDisconnect) {
                 return;
             }
             if (pnode->GetId() > youngest_peer.first) {
                 next_youngest_peer = youngest_peer;
                 youngest_peer.first = pnode->GetId();
                 youngest_peer.second = pnode->m_last_block_time;
             }
         });
 
         NodeId to_disconnect = youngest_peer.first;
         if (youngest_peer.second > next_youngest_peer.second) {
             // Our newest block-relay-only peer gave us a block more recently;
             // disconnect our second youngest.
             to_disconnect = next_youngest_peer.first;
         }
 
         m_connman.ForNode(
             to_disconnect,
             [&](CNode *pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
                 AssertLockHeld(::cs_main);
                 // Make sure we're not getting a block right now, and that we've
                 // been connected long enough for this eviction to happen at
                 // all. Note that we only request blocks from a peer if we learn
                 // of a valid headers chain with at least as much work as our
                 // tip.
                 CNodeState *node_state = State(pnode->GetId());
                 if (node_state == nullptr ||
                     (now - pnode->m_connected >= MINIMUM_CONNECT_TIME &&
                      node_state->nBlocksInFlight == 0)) {
                     pnode->fDisconnect = true;
                     LogPrint(BCLog::NET,
                              "disconnecting extra block-relay-only peer=%d "
                              "(last block received at time %d)\n",
                              pnode->GetId(),
                              count_seconds(pnode->m_last_block_time));
                     return true;
                 } else {
                     LogPrint(
                         BCLog::NET,
                         "keeping block-relay-only peer=%d chosen for eviction "
                         "(connect time: %d, blocks_in_flight: %d)\n",
                         pnode->GetId(), count_seconds(pnode->m_connected),
                         node_state->nBlocksInFlight);
                 }
                 return false;
             });
     }
 
     // Check whether we have too many OUTBOUND_FULL_RELAY peers
     if (m_connman.GetExtraFullOutboundCount() <= 0) {
         return;
     }
 
     // If we have more OUTBOUND_FULL_RELAY peers than we target, disconnect one.
     // Pick the OUTBOUND_FULL_RELAY peer that least recently announced us a new
     // block, with ties broken by choosing the more recent connection (higher
     // node id)
     NodeId worst_peer = -1;
     int64_t oldest_block_announcement = std::numeric_limits<int64_t>::max();
 
     m_connman.ForEachNode([&](CNode *pnode) EXCLUSIVE_LOCKS_REQUIRED(
                               ::cs_main) {
         AssertLockHeld(::cs_main);
 
         // Only consider OUTBOUND_FULL_RELAY peers that are not already marked
         // for disconnection
         if (!pnode->IsFullOutboundConn() || pnode->fDisconnect) {
             return;
         }
         CNodeState *state = State(pnode->GetId());
         if (state == nullptr) {
             // shouldn't be possible, but just in case
             return;
         }
         // Don't evict our protected peers
         if (state->m_chain_sync.m_protect) {
             return;
         }
         if (state->m_last_block_announcement < oldest_block_announcement ||
             (state->m_last_block_announcement == oldest_block_announcement &&
              pnode->GetId() > worst_peer)) {
             worst_peer = pnode->GetId();
             oldest_block_announcement = state->m_last_block_announcement;
         }
     });
 
     if (worst_peer == -1) {
         return;
     }
 
     bool disconnected = m_connman.ForNode(
         worst_peer, [&](CNode *pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
             AssertLockHeld(::cs_main);
 
             // Only disconnect a peer that has been connected to us for some
             // reasonable fraction of our check-frequency, to give it time for
             // new information to have arrived. Also don't disconnect any peer
             // we're trying to download a block from.
             CNodeState &state = *State(pnode->GetId());
             if (now - pnode->m_connected > MINIMUM_CONNECT_TIME &&
                 state.nBlocksInFlight == 0) {
                 LogPrint(BCLog::NET,
                          "disconnecting extra outbound peer=%d (last block "
                          "announcement received at time %d)\n",
                          pnode->GetId(), oldest_block_announcement);
                 pnode->fDisconnect = true;
                 return true;
             } else {
                 LogPrint(BCLog::NET,
                          "keeping outbound peer=%d chosen for eviction "
                          "(connect time: %d, blocks_in_flight: %d)\n",
                          pnode->GetId(), count_seconds(pnode->m_connected),
                          state.nBlocksInFlight);
                 return false;
             }
         });
 
     if (disconnected) {
         // If we disconnected an extra peer, that means we successfully
         // connected to at least one peer after the last time we detected a
         // stale tip. Don't try any more extra peers until we next detect a
         // stale tip, to limit the load we put on the network from these extra
         // connections.
         m_connman.SetTryNewOutboundPeer(false);
     }
 }
 
 void PeerManagerImpl::CheckForStaleTipAndEvictPeers() {
     LOCK(cs_main);
 
     int64_t time_in_seconds = GetTime();
 
     EvictExtraOutboundPeers(std::chrono::seconds{time_in_seconds});
 
     if (time_in_seconds > m_stale_tip_check_time) {
         // Check whether our tip is stale, and if so, allow using an extra
         // outbound peer.
         if (!fImporting && !fReindex && m_connman.GetNetworkActive() &&
             m_connman.GetUseAddrmanOutgoing() && TipMayBeStale()) {
             LogPrintf("Potential stale tip detected, will try using extra "
                       "outbound peer (last tip update: %d seconds ago)\n",
                       time_in_seconds - m_last_tip_update);
             m_connman.SetTryNewOutboundPeer(true);
         } else if (m_connman.GetTryNewOutboundPeer()) {
             m_connman.SetTryNewOutboundPeer(false);
         }
         m_stale_tip_check_time = time_in_seconds + STALE_CHECK_INTERVAL;
     }
 
     if (!m_initial_sync_finished &&
         CanDirectFetch(m_chainparams.GetConsensus())) {
         m_connman.StartExtraBlockRelayPeers();
         m_initial_sync_finished = true;
     }
 }
 
 void PeerManagerImpl::MaybeSendPing(CNode &node_to, Peer &peer,
                                     std::chrono::microseconds now) {
     if (m_connman.ShouldRunInactivityChecks(
             node_to, std::chrono::duration_cast<std::chrono::seconds>(now)) &&
         peer.m_ping_nonce_sent &&
         now > peer.m_ping_start.load() + TIMEOUT_INTERVAL) {
         // The ping timeout is using mocktime. To disable the check during
         // testing, increase -peertimeout.
         LogPrint(BCLog::NET, "ping timeout: %fs peer=%d\n",
                  0.000001 * count_microseconds(now - peer.m_ping_start.load()),
                  peer.m_id);
         node_to.fDisconnect = true;
         return;
     }
 
     const CNetMsgMaker msgMaker(node_to.GetCommonVersion());
     bool pingSend = false;
 
     if (peer.m_ping_queued) {
         // RPC ping request by user
         pingSend = true;
     }
 
     if (peer.m_ping_nonce_sent == 0 &&
         now > peer.m_ping_start.load() + PING_INTERVAL) {
         // Ping automatically sent as a latency probe & keepalive.
         pingSend = true;
     }
 
     if (pingSend) {
         uint64_t nonce = 0;
         while (nonce == 0) {
             GetRandBytes((uint8_t *)&nonce, sizeof(nonce));
         }
         peer.m_ping_queued = false;
         peer.m_ping_start = now;
         if (node_to.GetCommonVersion() > BIP0031_VERSION) {
             peer.m_ping_nonce_sent = nonce;
             m_connman.PushMessage(&node_to,
                                   msgMaker.Make(NetMsgType::PING, nonce));
         } else {
             // Peer is too old to support ping command with nonce, pong will
             // never arrive.
             peer.m_ping_nonce_sent = 0;
             m_connman.PushMessage(&node_to, msgMaker.Make(NetMsgType::PING));
         }
     }
 }
 
 void PeerManagerImpl::MaybeSendAddr(CNode &node, Peer &peer,
                                     std::chrono::microseconds current_time) {
     // Nothing to do for non-address-relay peers
     if (!peer.m_addr_relay_enabled) {
         return;
     }
 
     LOCK(peer.m_addr_send_times_mutex);
     if (fListen && !m_chainman.ActiveChainstate().IsInitialBlockDownload() &&
         peer.m_next_local_addr_send < current_time) {
         // If we've sent before, clear the bloom filter for the peer, so
         // that our self-announcement will actually go out. This might
         // be unnecessary if the bloom filter has already rolled over
         // since our last self-announcement, but there is only a small
         // bandwidth cost that we can incur by doing this (which happens
         // once a day on average).
         if (peer.m_next_local_addr_send != 0us) {
             peer.m_addr_known->reset();
         }
         if (std::optional<CAddress> local_addr = GetLocalAddrForPeer(&node)) {
             FastRandomContext insecure_rand;
             PushAddress(peer, *local_addr, insecure_rand);
         }
         peer.m_next_local_addr_send =
             PoissonNextSend(current_time, AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL);
     }
 
     // We sent an `addr` message to this peer recently. Nothing more to do.
     if (current_time <= peer.m_next_addr_send) {
         return;
     }
 
     peer.m_next_addr_send =
         PoissonNextSend(current_time, AVG_ADDRESS_BROADCAST_INTERVAL);
 
     const size_t max_addr_to_send = GetMaxAddrToSend();
     if (!Assume(peer.m_addrs_to_send.size() <= max_addr_to_send)) {
         // Should be impossible since we always check size before adding to
         // m_addrs_to_send. Recover by trimming the vector.
         peer.m_addrs_to_send.resize(max_addr_to_send);
     }
 
     // Remove addr records that the peer already knows about, and add new
     // addrs to the m_addr_known filter on the same pass.
     auto addr_already_known = [&peer](const CAddress &addr) {
         bool ret = peer.m_addr_known->contains(addr.GetKey());
         if (!ret) {
             peer.m_addr_known->insert(addr.GetKey());
         }
         return ret;
     };
     peer.m_addrs_to_send.erase(std::remove_if(peer.m_addrs_to_send.begin(),
                                               peer.m_addrs_to_send.end(),
                                               addr_already_known),
                                peer.m_addrs_to_send.end());
 
     // No addr messages to send
     if (peer.m_addrs_to_send.empty()) {
         return;
     }
 
     const char *msg_type;
     int make_flags;
     if (peer.m_wants_addrv2) {
         msg_type = NetMsgType::ADDRV2;
         make_flags = ADDRV2_FORMAT;
     } else {
         msg_type = NetMsgType::ADDR;
         make_flags = 0;
     }
     m_connman.PushMessage(
         &node, CNetMsgMaker(node.GetCommonVersion())
                    .Make(make_flags, msg_type, peer.m_addrs_to_send));
     peer.m_addrs_to_send.clear();
 
     // we only send the big addr message once
     if (peer.m_addrs_to_send.capacity() > 40) {
         peer.m_addrs_to_send.shrink_to_fit();
     }
 }
 
 namespace {
 class CompareInvMempoolOrder {
     CTxMemPool *mp;
 
 public:
     explicit CompareInvMempoolOrder(CTxMemPool *_mempool) { mp = _mempool; }
 
     bool operator()(std::set<TxId>::iterator a, std::set<TxId>::iterator b) {
         /**
          * As std::make_heap produces a max-heap, we want the entries with the
          * fewest ancestors/highest fee to sort later.
          */
         return mp->CompareDepthAndScore(*b, *a);
     }
 };
 } // namespace
 
 bool PeerManagerImpl::SetupAddressRelay(CNode &node, Peer &peer) {
     // We don't participate in addr relay with outbound block-relay-only
     // connections to prevent providing adversaries with the additional
     // information of addr traffic to infer the link.
     if (node.IsBlockOnlyConn()) {
         return false;
     }
 
     if (!peer.m_addr_relay_enabled.exchange(true)) {
         // First addr message we have received from the peer, initialize
         // m_addr_known
         peer.m_addr_known = std::make_unique<CRollingBloomFilter>(5000, 0.001);
     }
 
     return true;
 }
 
 bool PeerManagerImpl::SendMessages(const Config &config, CNode *pto) {
     PeerRef peer = GetPeerRef(pto->GetId());
     if (!peer) {
         return false;
     }
     const Consensus::Params &consensusParams = m_chainparams.GetConsensus();
 
     // We must call MaybeDiscourageAndDisconnect first, to ensure that we'll
     // disconnect misbehaving peers even before the version handshake is
     // complete.
     if (MaybeDiscourageAndDisconnect(*pto, *peer)) {
         return true;
     }
 
     // Don't send anything until the version handshake is complete
     if (!pto->fSuccessfullyConnected || pto->fDisconnect) {
         return true;
     }
 
     // If we get here, the outgoing message serialization version is set and
     // can't change.
     const CNetMsgMaker msgMaker(pto->GetCommonVersion());
 
     const auto current_time = GetTime<std::chrono::microseconds>();
 
     if (pto->IsAddrFetchConn() &&
         current_time - pto->m_connected > 10 * AVG_ADDRESS_BROADCAST_INTERVAL) {
         LogPrint(BCLog::NET,
                  "addrfetch connection timeout; disconnecting peer=%d\n",
                  pto->GetId());
         pto->fDisconnect = true;
         return true;
     }
 
     MaybeSendPing(*pto, *peer, current_time);
 
     // MaybeSendPing may have marked peer for disconnection
     if (pto->fDisconnect) {
         return true;
     }
 
     bool fFetch;
 
     MaybeSendAddr(*pto, *peer, current_time);
 
     {
         LOCK(cs_main);
 
         CNodeState &state = *State(pto->GetId());
 
         // Start block sync
         if (pindexBestHeader == nullptr) {
             pindexBestHeader = m_chainman.ActiveChain().Tip();
         }
 
         // Download if this is a nice peer, or we have no nice peers and this
         // one might do.
         fFetch = state.fPreferredDownload ||
                  (nPreferredDownload == 0 && !pto->fClient &&
                   !pto->IsAddrFetchConn());
 
         if (!state.fSyncStarted && !pto->fClient && !fImporting && !fReindex) {
             // Only actively request headers from a single peer, unless we're
             // close to today.
             if ((nSyncStarted == 0 && fFetch) ||
                 pindexBestHeader->GetBlockTime() >
                     GetAdjustedTime() - 24 * 60 * 60) {
                 state.fSyncStarted = true;
                 state.m_headers_sync_timeout =
                     current_time + HEADERS_DOWNLOAD_TIMEOUT_BASE +
                     (
                         // Convert HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER to
                         // microseconds before scaling to maintain precision
                         std::chrono::microseconds{
                             HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER} *
                         (GetAdjustedTime() - pindexBestHeader->GetBlockTime()) /
                         consensusParams.nPowTargetSpacing);
                 nSyncStarted++;
                 const CBlockIndex *pindexStart = pindexBestHeader;
                 /**
                  * If possible, start at the block preceding the currently best
                  * known header. This ensures that we always get a non-empty
                  * list of headers back as long as the peer is up-to-date. With
                  * a non-empty response, we can initialise the peer's known best
                  * block. This wouldn't be possible if we requested starting at
                  * pindexBestHeader and got back an empty response.
                  */
                 if (pindexStart->pprev) {
                     pindexStart = pindexStart->pprev;
                 }
 
                 LogPrint(
                     BCLog::NET,
                     "initial getheaders (%d) to peer=%d (startheight:%d)\n",
                     pindexStart->nHeight, pto->GetId(),
                     peer->m_starting_height);
                 m_connman.PushMessage(
                     pto, msgMaker.Make(
                              NetMsgType::GETHEADERS,
                              m_chainman.ActiveChain().GetLocator(pindexStart),
                              uint256()));
             }
         }
 
         //
         // Try sending block announcements via headers
         //
         {
             // If we have less than MAX_BLOCKS_TO_ANNOUNCE in our list of block
             // hashes we're relaying, and our peer wants headers announcements,
             // then find the first header not yet known to our peer but would
             // connect, and send. If no header would connect, or if we have too
             // many blocks, or if the peer doesn't want headers, just add all to
             // the inv queue.
             LOCK(peer->m_block_inv_mutex);
             std::vector<CBlock> vHeaders;
             bool fRevertToInv =
                 ((!state.fPreferHeaders &&
                   (!state.fPreferHeaderAndIDs ||
                    peer->m_blocks_for_headers_relay.size() > 1)) ||
                  peer->m_blocks_for_headers_relay.size() >
                      MAX_BLOCKS_TO_ANNOUNCE);
             // last header queued for delivery
             const CBlockIndex *pBestIndex = nullptr;
             // ensure pindexBestKnownBlock is up-to-date
             ProcessBlockAvailability(pto->GetId());
 
             if (!fRevertToInv) {
                 bool fFoundStartingHeader = false;
                 // Try to find first header that our peer doesn't have, and then
                 // send all headers past that one. If we come across an headers
                 // that aren't on m_chainman.ActiveChain(), give up.
                 for (const BlockHash &hash : peer->m_blocks_for_headers_relay) {
                     const CBlockIndex *pindex =
                         m_chainman.m_blockman.LookupBlockIndex(hash);
                     assert(pindex);
                     if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) {
                         // Bail out if we reorged away from this block
                         fRevertToInv = true;
                         break;
                     }
                     if (pBestIndex != nullptr && pindex->pprev != pBestIndex) {
                         // This means that the list of blocks to announce don't
                         // connect to each other. This shouldn't really be
                         // possible to hit during regular operation (because
                         // reorgs should take us to a chain that has some block
                         // not on the prior chain, which should be caught by the
                         // prior check), but one way this could happen is by
                         // using invalidateblock / reconsiderblock repeatedly on
                         // the tip, causing it to be added multiple times to
                         // m_blocks_for_headers_relay. Robustly deal with this
                         // rare situation by reverting to an inv.
                         fRevertToInv = true;
                         break;
                     }
                     pBestIndex = pindex;
                     if (fFoundStartingHeader) {
                         // add this to the headers message
                         vHeaders.push_back(pindex->GetBlockHeader());
                     } else if (PeerHasHeader(&state, pindex)) {
                         // Keep looking for the first new block.
                         continue;
                     } else if (pindex->pprev == nullptr ||
                                PeerHasHeader(&state, pindex->pprev)) {
                         // Peer doesn't have this header but they do have the
                         // prior one. Start sending headers.
                         fFoundStartingHeader = true;
                         vHeaders.push_back(pindex->GetBlockHeader());
                     } else {
                         // Peer doesn't have this header or the prior one --
                         // nothing will connect, so bail out.
                         fRevertToInv = true;
                         break;
                     }
                 }
             }
             if (!fRevertToInv && !vHeaders.empty()) {
                 if (vHeaders.size() == 1 && state.fPreferHeaderAndIDs) {
                     // We only send up to 1 block as header-and-ids, as
                     // otherwise probably means we're doing an initial-ish-sync
                     // or they're slow.
                     LogPrint(BCLog::NET,
                              "%s sending header-and-ids %s to peer=%d\n",
                              __func__, vHeaders.front().GetHash().ToString(),
                              pto->GetId());
 
                     int nSendFlags = 0;
 
                     bool fGotBlockFromCache = false;
                     {
                         LOCK(cs_most_recent_block);
                         if (most_recent_block_hash ==
                             pBestIndex->GetBlockHash()) {
                             CBlockHeaderAndShortTxIDs cmpctblock(
                                 *most_recent_block);
                             m_connman.PushMessage(
                                 pto, msgMaker.Make(nSendFlags,
                                                    NetMsgType::CMPCTBLOCK,
                                                    cmpctblock));
                             fGotBlockFromCache = true;
                         }
                     }
                     if (!fGotBlockFromCache) {
                         CBlock block;
                         bool ret = ReadBlockFromDisk(block, pBestIndex,
                                                      consensusParams);
                         assert(ret);
                         CBlockHeaderAndShortTxIDs cmpctblock(block);
                         m_connman.PushMessage(
                             pto,
                             msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK,
                                           cmpctblock));
                     }
                     state.pindexBestHeaderSent = pBestIndex;
                 } else if (state.fPreferHeaders) {
                     if (vHeaders.size() > 1) {
                         LogPrint(BCLog::NET,
                                  "%s: %u headers, range (%s, %s), to peer=%d\n",
                                  __func__, vHeaders.size(),
                                  vHeaders.front().GetHash().ToString(),
                                  vHeaders.back().GetHash().ToString(),
                                  pto->GetId());
                     } else {
                         LogPrint(BCLog::NET,
                                  "%s: sending header %s to peer=%d\n", __func__,
                                  vHeaders.front().GetHash().ToString(),
                                  pto->GetId());
                     }
                     m_connman.PushMessage(
                         pto, msgMaker.Make(NetMsgType::HEADERS, vHeaders));
                     state.pindexBestHeaderSent = pBestIndex;
                 } else {
                     fRevertToInv = true;
                 }
             }
             if (fRevertToInv) {
                 // If falling back to using an inv, just try to inv the tip. The
                 // last entry in m_blocks_for_headers_relay was our tip at some
                 // point in the past.
                 if (!peer->m_blocks_for_headers_relay.empty()) {
                     const BlockHash &hashToAnnounce =
                         peer->m_blocks_for_headers_relay.back();
                     const CBlockIndex *pindex =
                         m_chainman.m_blockman.LookupBlockIndex(hashToAnnounce);
                     assert(pindex);
 
                     // Warn if we're announcing a block that is not on the main
                     // chain. This should be very rare and could be optimized
                     // out. Just log for now.
                     if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) {
                         LogPrint(
                             BCLog::NET,
                             "Announcing block %s not on main chain (tip=%s)\n",
                             hashToAnnounce.ToString(),
                             m_chainman.ActiveChain()
                                 .Tip()
                                 ->GetBlockHash()
                                 .ToString());
                     }
 
                     // If the peer's chain has this block, don't inv it back.
                     if (!PeerHasHeader(&state, pindex)) {
                         peer->m_blocks_for_inv_relay.push_back(hashToAnnounce);
                         LogPrint(BCLog::NET,
                                  "%s: sending inv peer=%d hash=%s\n", __func__,
                                  pto->GetId(), hashToAnnounce.ToString());
                     }
                 }
             }
             peer->m_blocks_for_headers_relay.clear();
         }
     } // release cs_main
 
     //
     // Message: inventory
     //
     std::vector<CInv> vInv;
     auto addInvAndMaybeFlush = [&](uint32_t type, const uint256 &hash) {
         vInv.emplace_back(type, hash);
         if (vInv.size() == MAX_INV_SZ) {
             m_connman.PushMessage(
                 pto, msgMaker.Make(NetMsgType::INV, std::move(vInv)));
             vInv.clear();
         }
     };
 
     {
         LOCK2(cs_main, peer->m_block_inv_mutex);
 
         vInv.reserve(std::max<size_t>(peer->m_blocks_for_inv_relay.size(),
                                       INVENTORY_BROADCAST_MAX_PER_MB *
                                           config.GetMaxBlockSize() / 1000000));
 
         // Add blocks
         for (const BlockHash &hash : peer->m_blocks_for_inv_relay) {
             addInvAndMaybeFlush(MSG_BLOCK, hash);
         }
         peer->m_blocks_for_inv_relay.clear();
 
         auto computeNextInvSendTime =
             [&](std::chrono::microseconds &next) -> bool {
             bool fSendTrickle = pto->HasPermission(PF_NOBAN);
 
             if (next < current_time) {
                 fSendTrickle = true;
                 if (pto->IsInboundConn()) {
                     next = m_connman.PoissonNextSendInbound(
                         current_time, INBOUND_INVENTORY_BROADCAST_INTERVAL);
                 } else {
                     // Skip delay for outbound peers, as there is less privacy
                     // concern for them.
                     next = current_time;
                 }
             }
 
             return fSendTrickle;
         };
 
         // Add proofs to inventory
         if (pto->m_proof_relay != nullptr) {
             LOCK(pto->m_proof_relay->cs_proof_inventory);
 
             if (computeNextInvSendTime(pto->m_proof_relay->nextInvSend)) {
                 auto it = pto->m_proof_relay->setInventoryProofToSend.begin();
                 while (it !=
                        pto->m_proof_relay->setInventoryProofToSend.end()) {
                     const avalanche::ProofId proofid = *it;
 
                     it = pto->m_proof_relay->setInventoryProofToSend.erase(it);
 
                     if (pto->m_proof_relay->filterProofKnown.contains(
                             proofid)) {
                         continue;
                     }
 
                     pto->m_proof_relay->filterProofKnown.insert(proofid);
                     addInvAndMaybeFlush(MSG_AVA_PROOF, proofid);
                     State(pto->GetId())
                         ->m_recently_announced_proofs.insert(proofid);
                 }
             }
         }
 
         if (pto->m_tx_relay != nullptr) {
             LOCK(pto->m_tx_relay->cs_tx_inventory);
             // Check whether periodic sends should happen
             const bool fSendTrickle =
                 computeNextInvSendTime(pto->m_tx_relay->nNextInvSend);
 
             // Time to send but the peer has requested we not relay
             // transactions.
             if (fSendTrickle) {
                 LOCK(pto->m_tx_relay->cs_filter);
                 if (!pto->m_tx_relay->fRelayTxes) {
                     pto->m_tx_relay->setInventoryTxToSend.clear();
                 }
             }
 
             // Respond to BIP35 mempool requests
             if (fSendTrickle && pto->m_tx_relay->fSendMempool) {
                 auto vtxinfo = m_mempool.infoAll();
                 pto->m_tx_relay->fSendMempool = false;
                 CFeeRate filterrate;
                 {
                     LOCK(pto->m_tx_relay->cs_feeFilter);
                     filterrate = CFeeRate(pto->m_tx_relay->minFeeFilter);
                 }
 
                 LOCK(pto->m_tx_relay->cs_filter);
 
                 for (const auto &txinfo : vtxinfo) {
                     const TxId &txid = txinfo.tx->GetId();
                     pto->m_tx_relay->setInventoryTxToSend.erase(txid);
                     // Don't send transactions that peers will not put into
                     // their mempool
                     if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
                         continue;
                     }
                     if (pto->m_tx_relay->pfilter &&
                         !pto->m_tx_relay->pfilter->IsRelevantAndUpdate(
                             *txinfo.tx)) {
                         continue;
                     }
                     pto->m_tx_relay->filterInventoryKnown.insert(txid);
                     // Responses to MEMPOOL requests bypass the
                     // m_recently_announced_invs filter.
                     addInvAndMaybeFlush(MSG_TX, txid);
                 }
                 pto->m_tx_relay->m_last_mempool_req =
                     std::chrono::duration_cast<std::chrono::seconds>(
                         current_time);
             }
 
             // Determine transactions to relay
             if (fSendTrickle) {
                 // Produce a vector with all candidates for sending
                 std::vector<std::set<TxId>::iterator> vInvTx;
                 vInvTx.reserve(pto->m_tx_relay->setInventoryTxToSend.size());
                 for (std::set<TxId>::iterator it =
                          pto->m_tx_relay->setInventoryTxToSend.begin();
                      it != pto->m_tx_relay->setInventoryTxToSend.end(); it++) {
                     vInvTx.push_back(it);
                 }
                 CFeeRate filterrate;
                 {
                     LOCK(pto->m_tx_relay->cs_feeFilter);
                     filterrate = CFeeRate(pto->m_tx_relay->minFeeFilter);
                 }
                 // Topologically and fee-rate sort the inventory we send for
                 // privacy and priority reasons. A heap is used so that not
                 // all items need sorting if only a few are being sent.
                 CompareInvMempoolOrder compareInvMempoolOrder(&m_mempool);
                 std::make_heap(vInvTx.begin(), vInvTx.end(),
                                compareInvMempoolOrder);
                 // No reason to drain out at many times the network's
                 // capacity, especially since we have many peers and some
                 // will draw much shorter delays.
                 unsigned int nRelayedTransactions = 0;
                 LOCK(pto->m_tx_relay->cs_filter);
                 while (!vInvTx.empty() &&
                        nRelayedTransactions < INVENTORY_BROADCAST_MAX_PER_MB *
                                                   config.GetMaxBlockSize() /
                                                   1000000) {
                     // Fetch the top element from the heap
                     std::pop_heap(vInvTx.begin(), vInvTx.end(),
                                   compareInvMempoolOrder);
                     std::set<TxId>::iterator it = vInvTx.back();
                     vInvTx.pop_back();
                     const TxId txid = *it;
                     // Remove it from the to-be-sent set
                     pto->m_tx_relay->setInventoryTxToSend.erase(it);
                     // Check if not in the filter already
                     if (pto->m_tx_relay->filterInventoryKnown.contains(txid)) {
                         continue;
                     }
                     // Not in the mempool anymore? don't bother sending it.
                     auto txinfo = m_mempool.info(txid);
                     if (!txinfo.tx) {
                         continue;
                     }
                     // Peer told you to not send transactions at that
                     // feerate? Don't bother sending it.
                     if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
                         continue;
                     }
                     if (pto->m_tx_relay->pfilter &&
                         !pto->m_tx_relay->pfilter->IsRelevantAndUpdate(
                             *txinfo.tx)) {
                         continue;
                     }
                     // Send
                     State(pto->GetId())->m_recently_announced_invs.insert(txid);
                     addInvAndMaybeFlush(MSG_TX, txid);
                     nRelayedTransactions++;
                     {
                         // Expire old relay messages
                         while (!g_relay_expiration.empty() &&
                                g_relay_expiration.front().first <
                                    current_time) {
                             mapRelay.erase(g_relay_expiration.front().second);
                             g_relay_expiration.pop_front();
                         }
 
                         auto ret = mapRelay.insert(
                             std::make_pair(txid, std::move(txinfo.tx)));
                         if (ret.second) {
                             g_relay_expiration.push_back(std::make_pair(
                                 current_time + RELAY_TX_CACHE_TIME, ret.first));
                         }
                     }
                     pto->m_tx_relay->filterInventoryKnown.insert(txid);
                 }
             }
         }
     } // release cs_main, pto->cs_inventory
 
     if (!vInv.empty()) {
         m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv));
     }
 
     {
         LOCK(cs_main);
 
         CNodeState &state = *State(pto->GetId());
 
         // Detect whether we're stalling
         if (state.m_stalling_since.count() &&
             state.m_stalling_since < current_time - BLOCK_STALLING_TIMEOUT) {
             // Stalling only triggers when the block download window cannot
             // move. During normal steady state, the download window should be
             // much larger than the to-be-downloaded set of blocks, so
             // disconnection should only happen during initial block download.
             LogPrintf("Peer=%d is stalling block download, disconnecting\n",
                       pto->GetId());
             pto->fDisconnect = true;
             return true;
         }
         // In case there is a block that has been in flight from this peer for
         // block_interval * (1 + 0.5 * N) (with N the number of peers from which
         // we're downloading validated blocks), disconnect due to timeout.
         // We compensate for other peers to prevent killing off peers due to our
         // own downstream link being saturated. We only count validated
         // in-flight blocks so peers can't advertise non-existing block hashes
         // to unreasonably increase our timeout.
         if (state.vBlocksInFlight.size() > 0) {
             QueuedBlock &queuedBlock = state.vBlocksInFlight.front();
             int nOtherPeersWithValidatedDownloads =
                 nPeersWithValidatedDownloads -
                 (state.nBlocksInFlightValidHeaders > 0);
             if (current_time >
                 state.m_downloading_since +
                     std::chrono::seconds{consensusParams.nPowTargetSpacing} *
                         (BLOCK_DOWNLOAD_TIMEOUT_BASE +
                          BLOCK_DOWNLOAD_TIMEOUT_PER_PEER *
                              nOtherPeersWithValidatedDownloads)) {
                 LogPrintf("Timeout downloading block %s from peer=%d, "
                           "disconnecting\n",
                           queuedBlock.hash.ToString(), pto->GetId());
                 pto->fDisconnect = true;
                 return true;
             }
         }
 
         // Check for headers sync timeouts
         if (state.fSyncStarted &&
             state.m_headers_sync_timeout < std::chrono::microseconds::max()) {
             // Detect whether this is a stalling initial-headers-sync peer
             if (pindexBestHeader->GetBlockTime() <=
                 GetAdjustedTime() - 24 * 60 * 60) {
                 if (current_time > state.m_headers_sync_timeout &&
                     nSyncStarted == 1 &&
                     (nPreferredDownload - state.fPreferredDownload >= 1)) {
                     // Disconnect a peer (without the noban permission) if it
                     // is our only sync peer, and we have others we could be
                     // using instead.
                     // Note: If all our peers are inbound, then we won't
                     // disconnect our sync peer for stalling; we have bigger
                     // problems if we can't get any outbound peers.
                     if (!pto->HasPermission(PF_NOBAN)) {
                         LogPrintf("Timeout downloading headers from peer=%d, "
                                   "disconnecting\n",
                                   pto->GetId());
                         pto->fDisconnect = true;
                         return true;
                     } else {
                         LogPrintf("Timeout downloading headers from noban "
                                   "peer=%d, not disconnecting\n",
                                   pto->GetId());
                         // Reset the headers sync state so that we have a chance
                         // to try downloading from a different peer. Note: this
                         // will also result in at least one more getheaders
                         // message to be sent to this peer (eventually).
                         state.fSyncStarted = false;
                         nSyncStarted--;
                         state.m_headers_sync_timeout = 0us;
                     }
                 }
             } else {
                 // After we've caught up once, reset the timeout so we can't
                 // trigger disconnect later.
                 state.m_headers_sync_timeout = std::chrono::microseconds::max();
             }
         }
 
         // Check that outbound peers have reasonable chains GetTime() is used by
         // this anti-DoS logic so we can test this using mocktime.
         ConsiderEviction(*pto, GetTime());
     } // release cs_main
 
     std::vector<CInv> vGetData;
 
     //
     // Message: getdata (blocks)
     //
     {
         LOCK(cs_main);
 
         CNodeState &state = *State(pto->GetId());
 
         if (!pto->fClient &&
             ((fFetch && !pto->m_limited_node) ||
              !m_chainman.ActiveChainstate().IsInitialBlockDownload()) &&
             state.nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
             std::vector<const CBlockIndex *> vToDownload;
             NodeId staller = -1;
             FindNextBlocksToDownload(pto->GetId(),
                                      MAX_BLOCKS_IN_TRANSIT_PER_PEER -
                                          state.nBlocksInFlight,
                                      vToDownload, staller);
             for (const CBlockIndex *pindex : vToDownload) {
                 vGetData.push_back(CInv(MSG_BLOCK, pindex->GetBlockHash()));
                 MarkBlockAsInFlight(config, pto->GetId(),
                                     pindex->GetBlockHash(), pindex);
                 LogPrint(BCLog::NET, "Requesting block %s (%d) peer=%d\n",
                          pindex->GetBlockHash().ToString(), pindex->nHeight,
                          pto->GetId());
             }
             if (state.nBlocksInFlight == 0 && staller != -1) {
                 if (State(staller)->m_stalling_since == 0us) {
                     State(staller)->m_stalling_since = current_time;
                     LogPrint(BCLog::NET, "Stall started peer=%d\n", staller);
                 }
             }
         }
     } // release cs_main
 
     auto addGetDataAndMaybeFlush = [&](uint32_t type, const uint256 &hash) {
         CInv inv(type, hash);
         LogPrint(BCLog::NET, "Requesting %s from peer=%d\n", inv.ToString(),
                  pto->GetId());
         vGetData.push_back(std::move(inv));
         if (vGetData.size() >= MAX_GETDATA_SZ) {
             m_connman.PushMessage(
                 pto, msgMaker.Make(NetMsgType::GETDATA, std::move(vGetData)));
             vGetData.clear();
         }
     };
 
     //
     // Message: getdata (proof)
     //
     {
         LOCK(cs_proofrequest);
         std::vector<std::pair<NodeId, avalanche::ProofId>> expired;
         auto requestable =
             m_proofrequest.GetRequestable(pto->GetId(), current_time, &expired);
         for (const auto &entry : expired) {
             LogPrint(BCLog::AVALANCHE,
                      "timeout of inflight proof %s from peer=%d\n",
                      entry.second.ToString(), entry.first);
         }
         for (const auto &proofid : requestable) {
             if (!AlreadyHaveProof(proofid)) {
                 addGetDataAndMaybeFlush(MSG_AVA_PROOF, proofid);
                 m_proofrequest.RequestedData(
                     pto->GetId(), proofid,
                     current_time + PROOF_REQUEST_PARAMS.getdata_interval);
             } else {
                 // We have already seen this proof, no need to download.
                 // This is just a belt-and-suspenders, as this should
                 // already be called whenever a transaction becomes
                 // AlreadyHaveProof().
                 m_proofrequest.ForgetInvId(proofid);
             }
         }
     } // release cs_proofrequest
 
     //
     // Message: getdata (transactions)
     //
     {
         LOCK(cs_main);
         std::vector<std::pair<NodeId, TxId>> expired;
         auto requestable =
             m_txrequest.GetRequestable(pto->GetId(), current_time, &expired);
         for (const auto &entry : expired) {
             LogPrint(BCLog::NET, "timeout of inflight tx %s from peer=%d\n",
                      entry.second.ToString(), entry.first);
         }
         for (const TxId &txid : requestable) {
             if (!AlreadyHaveTx(txid)) {
                 addGetDataAndMaybeFlush(MSG_TX, txid);
                 m_txrequest.RequestedData(
                     pto->GetId(), txid,
                     current_time + TX_REQUEST_PARAMS.getdata_interval);
             } else {
                 // We have already seen this transaction, no need to download.
                 // This is just a belt-and-suspenders, as this should already be
                 // called whenever a transaction becomes AlreadyHaveTx().
                 m_txrequest.ForgetInvId(txid);
             }
         }
 
         if (!vGetData.empty()) {
             m_connman.PushMessage(pto,
                                   msgMaker.Make(NetMsgType::GETDATA, vGetData));
         }
 
         //
         // Message: feefilter
         //
         // peers with the forcerelay permission should not filter txs to us
         if (pto->m_tx_relay != nullptr &&
             pto->GetCommonVersion() >= FEEFILTER_VERSION &&
             gArgs.GetBoolArg("-feefilter", DEFAULT_FEEFILTER) &&
             !pto->HasPermission(PF_FORCERELAY)) {
             Amount currentFilter =
                 m_mempool
                     .GetMinFee(
                         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                         1000000)
                     .GetFeePerK();
             static FeeFilterRounder g_filter_rounder{
                 CFeeRate{DEFAULT_MIN_RELAY_TX_FEE_PER_KB}};
             if (m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
                 // Received tx-inv messages are discarded when the active
                 // chainstate is in IBD, so tell the peer to not send them.
                 currentFilter = MAX_MONEY;
             } else {
                 static const Amount MAX_FILTER{
                     g_filter_rounder.round(MAX_MONEY)};
                 if (pto->m_tx_relay->lastSentFeeFilter == MAX_FILTER) {
                     // Send the current filter if we sent MAX_FILTER previously
                     // and made it out of IBD.
                     pto->m_tx_relay->m_next_send_feefilter = 0us;
                 }
             }
             if (current_time > pto->m_tx_relay->m_next_send_feefilter) {
                 Amount filterToSend = g_filter_rounder.round(currentFilter);
                 filterToSend =
                     std::max(filterToSend, ::minRelayTxFee.GetFeePerK());
 
                 if (filterToSend != pto->m_tx_relay->lastSentFeeFilter) {
                     m_connman.PushMessage(
                         pto,
                         msgMaker.Make(NetMsgType::FEEFILTER, filterToSend));
                     pto->m_tx_relay->lastSentFeeFilter = filterToSend;
                 }
                 pto->m_tx_relay->m_next_send_feefilter = PoissonNextSend(
                     current_time, AVG_FEEFILTER_BROADCAST_INTERVAL);
             }
             // If the fee filter has changed substantially and it's still more
             // than MAX_FEEFILTER_CHANGE_DELAY until scheduled broadcast, then
             // move the broadcast to within MAX_FEEFILTER_CHANGE_DELAY.
             else if (current_time + MAX_FEEFILTER_CHANGE_DELAY <
                          pto->m_tx_relay->m_next_send_feefilter &&
                      (currentFilter <
                           3 * pto->m_tx_relay->lastSentFeeFilter / 4 ||
                       currentFilter >
                           4 * pto->m_tx_relay->lastSentFeeFilter / 3)) {
                 pto->m_tx_relay->m_next_send_feefilter =
                     current_time + GetRandomDuration<std::chrono::microseconds>(
                                        MAX_FEEFILTER_CHANGE_DELAY);
             }
         }
     } // release cs_main
     return true;
 }
 
 bool PeerManagerImpl::ReceivedAvalancheProof(CNode &peer,
                                              const avalanche::ProofRef &proof) {
     assert(proof != nullptr);
 
     const avalanche::ProofId &proofid = proof->getId();
 
     peer.AddKnownProof(proofid);
 
     const NodeId nodeid = peer.GetId();
 
     {
         LOCK(cs_proofrequest);
         m_proofrequest.ReceivedResponse(nodeid, proofid);
 
         if (AlreadyHaveProof(proofid)) {
             m_proofrequest.ForgetInvId(proofid);
             return true;
         }
     }
 
     // registerProof should not be called while cs_proofrequest because it
     // holds cs_main and that creates a potential deadlock during shutdown
 
     avalanche::ProofRegistrationState state;
     if (g_avalanche->withPeerManager([&](avalanche::PeerManager &pm) {
             return pm.registerProof(proof, state);
         })) {
         WITH_LOCK(cs_proofrequest, m_proofrequest.ForgetInvId(proofid));
         RelayProof(proofid, m_connman);
 
         peer.m_last_proof_time = GetTime<std::chrono::seconds>();
 
         LogPrint(BCLog::NET, "New avalanche proof: peer=%d, proofid %s\n",
                  nodeid, proofid.ToString());
     }
 
     if (state.GetResult() == avalanche::ProofRegistrationResult::INVALID) {
         WITH_LOCK(cs_rejectedProofs, rejectedProofs->insert(proofid));
         Misbehaving(nodeid, 100, state.GetRejectReason());
         return false;
     }
 
     if (state.GetResult() ==
         avalanche::ProofRegistrationResult::COOLDOWN_NOT_ELAPSED) {
         // Conflicting proofs are not necessarly adversarial, but if they are
         // repeated within a short time period this is suspicious, so we affect
         // a low ban score to our peer.
         Misbehaving(nodeid, 5, state.GetRejectReason());
         return false;
     }
 
     if (!g_avalanche->addProofToReconcile(proof)) {
         LogPrint(BCLog::AVALANCHE,
                  "Not polling the avalanche proof (%s): peer=%d, proofid %s\n",
                  state.IsValid() ? "not-worth-polling"
                                  : state.GetRejectReason(),
                  nodeid, proofid.ToString());
     }
 
     return true;
 }
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
index 4a8dab601..94a9fbf3b 100644
--- a/src/node/transaction.cpp
+++ b/src/node/transaction.cpp
@@ -1,120 +1,122 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <node/transaction.h>
 
 #include <config.h>
 #include <consensus/validation.h>
 #include <net.h>
 #include <net_processing.h>
 #include <node/context.h>
 #include <primitives/txid.h>
 #include <txmempool.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 #include <future>
 
 static TransactionError HandleATMPError(const TxValidationState &state,
                                         std::string &err_string_out) {
     err_string_out = state.ToString();
     if (state.IsInvalid()) {
         if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) {
             return TransactionError::MISSING_INPUTS;
         }
         return TransactionError::MEMPOOL_REJECTED;
     } else {
         return TransactionError::MEMPOOL_ERROR;
     }
 }
 
 TransactionError BroadcastTransaction(NodeContext &node, const Config &config,
                                       const CTransactionRef tx,
                                       std::string &err_string,
                                       const Amount max_tx_fee, bool relay,
                                       bool wait_callback) {
     // BroadcastTransaction can be called by either sendrawtransaction RPC or
     // wallet RPCs. node.connman is assigned both before chain clients and
     // before RPC server is accepting calls, and reset after chain clients and
     // RPC sever are stopped. node.connman should never be null here.
     assert(node.connman);
     assert(node.mempool);
     std::promise<void> promise;
     TxId txid = tx->GetId();
     bool callback_set = false;
 
     { // cs_main scope
         assert(node.chainman);
         LOCK(cs_main);
         // If the transaction is already confirmed in the chain, don't do
         // anything and return early.
         CCoinsViewCache &view = node.chainman->ActiveChainstate().CoinsTip();
         for (size_t o = 0; o < tx->vout.size(); o++) {
             const Coin &existingCoin = view.AccessCoin(COutPoint(txid, o));
             // IsSpent doesn't mean the coin is spent, it means the output
             // doesn't exist. So if the output does exist, then this transaction
             // exists in the chain.
             if (!existingCoin.IsSpent()) {
                 return TransactionError::ALREADY_IN_CHAIN;
             }
         }
 
         if (!node.mempool->exists(txid)) {
             // Transaction is not already in the mempool.
-            TxValidationState state;
             if (max_tx_fee > Amount::zero()) {
                 // First, call ATMP with test_accept and check the fee. If ATMP
                 // fails here, return error immediately.
-                Amount fee = Amount::zero();
-                if (!AcceptToMemoryPool(node.chainman->ActiveChainstate(),
-                                        config, *node.mempool, state, tx,
-                                        false /* bypass_limits */,
-                                        /* test_accept */ true, &fee)) {
-                    return HandleATMPError(state, err_string);
-                } else if (fee > max_tx_fee) {
+                const MempoolAcceptResult result = AcceptToMemoryPool(
+                    node.chainman->ActiveChainstate(), config, *node.mempool,
+                    tx, false /* bypass_limits */,
+                    /* test_accept */ true);
+                if (result.m_result_type !=
+                    MempoolAcceptResult::ResultType::VALID) {
+                    return HandleATMPError(result.m_state, err_string);
+                } else if (result.m_base_fees.value() > max_tx_fee) {
                     return TransactionError::MAX_FEE_EXCEEDED;
                 }
             }
             // Try to submit the transaction to the mempool.
-            if (!AcceptToMemoryPool(node.chainman->ActiveChainstate(), config,
-                                    *node.mempool, state, tx,
-                                    false /* bypass_limits */)) {
-                return HandleATMPError(state, err_string);
+            const MempoolAcceptResult result = AcceptToMemoryPool(
+                node.chainman->ActiveChainstate(), config, *node.mempool, tx,
+                false /* bypass_limits */);
+            if (result.m_result_type !=
+                MempoolAcceptResult::ResultType::VALID) {
+                return HandleATMPError(result.m_state, err_string);
             }
 
             // Transaction was accepted to the mempool.
 
             if (wait_callback) {
                 // For transactions broadcast from outside the wallet, make sure
                 // that the wallet has been notified of the transaction before
                 // continuing.
                 //
                 // This prevents a race where a user might call
                 // sendrawtransaction with a transaction to/from their wallet,
                 // immediately call some wallet RPC, and get a stale result
                 // because callbacks have not yet been processed.
                 CallFunctionInValidationInterfaceQueue(
                     [&promise] { promise.set_value(); });
                 callback_set = true;
             }
         }
     } // cs_main
 
     if (callback_set) {
         // Wait until Validation Interface clients have been notified of the
         // transaction entering the mempool.
         promise.get_future().wait();
     }
 
     if (relay) {
         // the mempool tracks locally submitted transactions to make a
         // best-effort of initial broadcast
         node.mempool->AddUnbroadcastTx(txid);
 
         RelayTransaction(txid, *node.connman);
     }
 
     return TransactionError::OK;
 }
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 570eb54bd..38c3adef6 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -1,2245 +1,2245 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <blockdb.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <coins.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <index/txindex.h>
 #include <key_io.h>
 #include <merkleblock.h>
 #include <node/blockstorage.h>
 #include <node/coin.h>
 #include <node/context.h>
 #include <node/psbt.h>
 #include <node/transaction.h>
 #include <policy/policy.h>
 #include <primitives/transaction.h>
 #include <psbt.h>
 #include <random.h>
 #include <rpc/blockchain.h>
 #include <rpc/rawtransaction_util.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <script/script.h>
 #include <script/sign.h>
 #include <script/signingprovider.h>
 #include <script/standard.h>
 #include <txmempool.h>
 #include <uint256.h>
 #include <util/bip32.h>
 #include <util/error.h>
 #include <util/moneystr.h>
 #include <util/strencodings.h>
 #include <util/string.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 #include <cstdint>
 #include <numeric>
 
 #include <univalue.h>
 
 static void TxToJSON(const CTransaction &tx, const BlockHash &hashBlock,
                      UniValue &entry, CChainState &active_chainstate) {
     // Call into TxToUniv() in bitcoin-common to decode the transaction hex.
     //
     // Blockchain contextual information (confirmations and blocktime) is not
     // available to code in bitcoin-common, so we query them here and push the
     // data into the returned UniValue.
     TxToUniv(tx, uint256(), entry, true, RPCSerializationFlags());
 
     if (!hashBlock.IsNull()) {
         LOCK(cs_main);
 
         entry.pushKV("blockhash", hashBlock.GetHex());
         CBlockIndex *pindex =
             active_chainstate.m_blockman.LookupBlockIndex(hashBlock);
         if (pindex) {
             if (active_chainstate.m_chain.Contains(pindex)) {
                 entry.pushKV("confirmations",
                              1 + active_chainstate.m_chain.Height() -
                                  pindex->nHeight);
                 entry.pushKV("time", pindex->GetBlockTime());
                 entry.pushKV("blocktime", pindex->GetBlockTime());
             } else {
                 entry.pushKV("confirmations", 0);
             }
         }
     }
 }
 
 static RPCHelpMan getrawtransaction() {
     return RPCHelpMan{
         "getrawtransaction",
         "By default this function only works for mempool transactions. When "
         "called with a blockhash\n"
         "argument, getrawtransaction will return the transaction if the "
         "specified block is available and\n"
         "the transaction is found in that block. When called without a "
         "blockhash argument, getrawtransaction\n"
         "will return the transaction if it is in the mempool, or if -txindex "
         "is enabled and the transaction\n"
         "is in a block in the blockchain.\n"
 
         "\nReturn the raw transaction data.\n"
         "\nIf verbose is 'true', returns an Object with information about "
         "'txid'.\n"
         "If verbose is 'false' or omitted, returns a string that is "
         "serialized, hex-encoded data for 'txid'.\n",
         {
             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "The transaction id"},
             {"verbose", RPCArg::Type::BOOL, /* default */ "false",
              "If false, return a string, otherwise return a json object"},
             {"blockhash", RPCArg::Type::STR_HEX,
              RPCArg::Optional::OMITTED_NAMED_ARG,
              "The block in which to look for the transaction"},
         },
         {
             RPCResult{"if verbose is not set or set to false",
                       RPCResult::Type::STR, "data",
                       "The serialized, hex-encoded data for 'txid'"},
             RPCResult{
                 "if verbose is set to true",
                 RPCResult::Type::OBJ,
                 "",
                 "",
                 {
                     {RPCResult::Type::BOOL, "in_active_chain",
                      "Whether specified block is in the active chain or not "
                      "(only present with explicit \"blockhash\" argument)"},
                     {RPCResult::Type::STR_HEX, "hex",
                      "The serialized, hex-encoded data for 'txid'"},
                     {RPCResult::Type::STR_HEX, "txid",
                      "The transaction id (same as provided)"},
                     {RPCResult::Type::STR_HEX, "hash", "The transaction hash"},
                     {RPCResult::Type::NUM, "size",
                      "The serialized transaction size"},
                     {RPCResult::Type::NUM, "version", "The version"},
                     {RPCResult::Type::NUM_TIME, "locktime", "The lock time"},
                     {RPCResult::Type::ARR,
                      "vin",
                      "",
                      {
                          {RPCResult::Type::OBJ,
                           "",
                           "",
                           {
                               {RPCResult::Type::STR_HEX, "txid",
                                "The transaction id"},
                               {RPCResult::Type::STR, "vout", ""},
                               {RPCResult::Type::OBJ,
                                "scriptSig",
                                "The script",
                                {
                                    {RPCResult::Type::STR, "asm", "asm"},
                                    {RPCResult::Type::STR_HEX, "hex", "hex"},
                                }},
                               {RPCResult::Type::NUM, "sequence",
                                "The script sequence number"},
                           }},
                      }},
                     {RPCResult::Type::ARR,
                      "vout",
                      "",
                      {
                          {RPCResult::Type::OBJ,
                           "",
                           "",
                           {
                               {RPCResult::Type::NUM, "value",
                                "The value in " + Currency::get().ticker},
                               {RPCResult::Type::NUM, "n", "index"},
                               {RPCResult::Type::OBJ,
                                "scriptPubKey",
                                "",
                                {
                                    {RPCResult::Type::STR, "asm", "the asm"},
                                    {RPCResult::Type::STR, "hex", "the hex"},
                                    {RPCResult::Type::NUM, "reqSigs",
                                     "The required sigs"},
                                    {RPCResult::Type::STR, "type",
                                     "The type, eg 'pubkeyhash'"},
                                    {RPCResult::Type::ARR,
                                     "addresses",
                                     "",
                                     {
                                         {RPCResult::Type::STR, "address",
                                          "bitcoin address"},
                                     }},
                                }},
                           }},
                      }},
                     {RPCResult::Type::STR_HEX, "blockhash", "the block hash"},
                     {RPCResult::Type::NUM, "confirmations",
                      "The confirmations"},
                     {RPCResult::Type::NUM_TIME, "blocktime",
                      "The block time expressed in " + UNIX_EPOCH_TIME},
                     {RPCResult::Type::NUM, "time", "Same as \"blocktime\""},
                 }},
         },
         RPCExamples{HelpExampleCli("getrawtransaction", "\"mytxid\"") +
                     HelpExampleCli("getrawtransaction", "\"mytxid\" true") +
                     HelpExampleRpc("getrawtransaction", "\"mytxid\", true") +
                     HelpExampleCli("getrawtransaction",
                                    "\"mytxid\" false \"myblockhash\"") +
                     HelpExampleCli("getrawtransaction",
                                    "\"mytxid\" true \"myblockhash\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             const NodeContext &node = EnsureAnyNodeContext(request.context);
             ChainstateManager &chainman = EnsureChainman(node);
 
             bool in_active_chain = true;
             TxId txid = TxId(ParseHashV(request.params[0], "parameter 1"));
             CBlockIndex *blockindex = nullptr;
 
             const CChainParams &params = config.GetChainParams();
             if (txid == params.GenesisBlock().hashMerkleRoot) {
                 // Special exception for the genesis block coinbase transaction
                 throw JSONRPCError(
                     RPC_INVALID_ADDRESS_OR_KEY,
                     "The genesis block coinbase is not considered an "
                     "ordinary transaction and cannot be retrieved");
             }
 
             // Accept either a bool (true) or a num (>=1) to indicate verbose
             // output.
             bool fVerbose = false;
             if (!request.params[1].isNull()) {
                 fVerbose = request.params[1].isNum()
                                ? (request.params[1].get_int() != 0)
                                : request.params[1].get_bool();
             }
 
             if (!request.params[2].isNull()) {
                 LOCK(cs_main);
 
                 BlockHash blockhash(
                     ParseHashV(request.params[2], "parameter 3"));
                 blockindex = chainman.m_blockman.LookupBlockIndex(blockhash);
                 if (!blockindex) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Block hash not found");
                 }
                 in_active_chain = chainman.ActiveChain().Contains(blockindex);
             }
 
             bool f_txindex_ready = false;
             if (g_txindex && !blockindex) {
                 f_txindex_ready = g_txindex->BlockUntilSyncedToCurrentChain();
             }
 
             BlockHash hash_block;
             const CTransactionRef tx =
                 GetTransaction(blockindex, node.mempool.get(), txid,
                                params.GetConsensus(), hash_block);
             if (!tx) {
                 std::string errmsg;
                 if (blockindex) {
                     if (!blockindex->nStatus.hasData()) {
                         throw JSONRPCError(RPC_MISC_ERROR,
                                            "Block not available");
                     }
                     errmsg = "No such transaction found in the provided block";
                 } else if (!g_txindex) {
                     errmsg =
                         "No such mempool transaction. Use -txindex or provide "
                         "a block hash to enable blockchain transaction queries";
                 } else if (!f_txindex_ready) {
                     errmsg = "No such mempool transaction. Blockchain "
                              "transactions are still in the process of being "
                              "indexed";
                 } else {
                     errmsg = "No such mempool or blockchain transaction";
                 }
                 throw JSONRPCError(
                     RPC_INVALID_ADDRESS_OR_KEY,
                     errmsg + ". Use gettransaction for wallet transactions.");
             }
 
             if (!fVerbose) {
                 return EncodeHexTx(*tx, RPCSerializationFlags());
             }
 
             UniValue result(UniValue::VOBJ);
             if (blockindex) {
                 result.pushKV("in_active_chain", in_active_chain);
             }
             TxToJSON(*tx, hash_block, result, chainman.ActiveChainstate());
             return result;
         },
     };
 }
 
 static RPCHelpMan gettxoutproof() {
     return RPCHelpMan{
         "gettxoutproof",
         "Returns a hex-encoded proof that \"txid\" was included in a block.\n"
         "\nNOTE: By default this function only works sometimes. "
         "This is when there is an\n"
         "unspent output in the utxo for this transaction. To make it always "
         "work,\n"
         "you need to maintain a transaction index, using the -txindex command "
         "line option or\n"
         "specify the block in which the transaction is included manually (by "
         "blockhash).\n",
         {
             {
                 "txids",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The txids to filter",
                 {
                     {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED,
                      "A transaction hash"},
                 },
             },
             {"blockhash", RPCArg::Type::STR_HEX,
              RPCArg::Optional::OMITTED_NAMED_ARG,
              "If specified, looks for txid in the block with this hash"},
         },
         RPCResult{
             RPCResult::Type::STR, "data",
             "A string that is a serialized, hex-encoded data for the proof."},
         RPCExamples{""},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             std::set<TxId> setTxIds;
             TxId oneTxId;
             UniValue txids = request.params[0].get_array();
             for (unsigned int idx = 0; idx < txids.size(); idx++) {
                 const UniValue &utxid = txids[idx];
                 TxId txid(ParseHashV(utxid, "txid"));
                 if (setTxIds.count(txid)) {
                     throw JSONRPCError(
                         RPC_INVALID_PARAMETER,
                         std::string("Invalid parameter, duplicated txid: ") +
                             utxid.get_str());
                 }
 
                 setTxIds.insert(txid);
                 oneTxId = txid;
             }
 
             CBlockIndex *pblockindex = nullptr;
 
             BlockHash hashBlock;
             ChainstateManager &chainman = EnsureAnyChainman(request.context);
             if (!request.params[1].isNull()) {
                 LOCK(cs_main);
                 hashBlock =
                     BlockHash(ParseHashV(request.params[1], "blockhash"));
                 pblockindex = chainman.m_blockman.LookupBlockIndex(hashBlock);
                 if (!pblockindex) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Block not found");
                 }
             } else {
                 LOCK(cs_main);
                 CChainState &active_chainstate = chainman.ActiveChainstate();
                 // Loop through txids and try to find which block they're in.
                 // Exit loop once a block is found.
                 for (const auto &txid : setTxIds) {
                     const Coin &coin =
                         AccessByTxid(active_chainstate.CoinsTip(), txid);
                     if (!coin.IsSpent()) {
                         pblockindex =
                             active_chainstate.m_chain[coin.GetHeight()];
                         break;
                     }
                 }
             }
 
             // Allow txindex to catch up if we need to query it and before we
             // acquire cs_main.
             if (g_txindex && !pblockindex) {
                 g_txindex->BlockUntilSyncedToCurrentChain();
             }
 
             const Consensus::Params &params =
                 config.GetChainParams().GetConsensus();
 
             LOCK(cs_main);
 
             if (pblockindex == nullptr) {
                 const CTransactionRef tx = GetTransaction(
                     /* block_index */ nullptr,
                     /* mempool */ nullptr, oneTxId, Params().GetConsensus(),
                     hashBlock);
                 if (!tx || hashBlock.IsNull()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Transaction not yet in block");
                 }
 
                 pblockindex = chainman.m_blockman.LookupBlockIndex(hashBlock);
                 if (!pblockindex) {
                     throw JSONRPCError(RPC_INTERNAL_ERROR,
                                        "Transaction index corrupt");
                 }
             }
 
             CBlock block;
             if (!ReadBlockFromDisk(block, pblockindex, params)) {
                 throw JSONRPCError(RPC_INTERNAL_ERROR,
                                    "Can't read block from disk");
             }
 
             unsigned int ntxFound = 0;
             for (const auto &tx : block.vtx) {
                 if (setTxIds.count(tx->GetId())) {
                     ntxFound++;
                 }
             }
 
             if (ntxFound != setTxIds.size()) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Not all transactions found in specified or "
                                    "retrieved block");
             }
 
             CDataStream ssMB(SER_NETWORK, PROTOCOL_VERSION);
             CMerkleBlock mb(block, setTxIds);
             ssMB << mb;
             std::string strHex = HexStr(ssMB);
             return strHex;
         },
     };
 }
 
 static RPCHelpMan verifytxoutproof() {
     return RPCHelpMan{
         "verifytxoutproof",
         "Verifies that a proof points to a transaction in a block, returning "
         "the transaction it commits to\n"
         "and throwing an RPC error if the block is not in our best chain\n",
         {
             {"proof", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "The hex-encoded proof generated by gettxoutproof"},
         },
         RPCResult{RPCResult::Type::ARR,
                   "",
                   "",
                   {
                       {RPCResult::Type::STR_HEX, "txid",
                        "The txid(s) which the proof commits to, or empty array "
                        "if the proof can not be validated."},
                   }},
         RPCExamples{""},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             CDataStream ssMB(ParseHexV(request.params[0], "proof"), SER_NETWORK,
                              PROTOCOL_VERSION);
             CMerkleBlock merkleBlock;
             ssMB >> merkleBlock;
 
             UniValue res(UniValue::VARR);
 
             std::vector<uint256> vMatch;
             std::vector<size_t> vIndex;
             if (merkleBlock.txn.ExtractMatches(vMatch, vIndex) !=
                 merkleBlock.header.hashMerkleRoot) {
                 return res;
             }
 
             ChainstateManager &chainman = EnsureAnyChainman(request.context);
             LOCK(cs_main);
 
             const CBlockIndex *pindex = chainman.m_blockman.LookupBlockIndex(
                 merkleBlock.header.GetHash());
             if (!pindex || !chainman.ActiveChain().Contains(pindex) ||
                 pindex->nTx == 0) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Block not found in chain");
             }
 
             // Check if proof is valid, only add results if so
             if (pindex->nTx == merkleBlock.txn.GetNumTransactions()) {
                 for (const uint256 &hash : vMatch) {
                     res.push_back(hash.GetHex());
                 }
             }
 
             return res;
         },
     };
 }
 
 static RPCHelpMan createrawtransaction() {
     return RPCHelpMan{
         "createrawtransaction",
         "Create a transaction spending the given inputs and creating new "
         "outputs.\n"
         "Outputs can be addresses or data.\n"
         "Returns hex-encoded raw transaction.\n"
         "Note that the transaction's inputs are not signed, and\n"
         "it is not stored in the wallet or transmitted to the network.\n",
         {
             {
                 "inputs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The inputs",
                 {
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"txid", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO,
                              "The output number"},
                             {"sequence", RPCArg::Type::NUM, /* default */
                              "depends on the value of the 'locktime' argument",
                              "The sequence number"},
                         },
                     },
                 },
             },
             {
                 "outputs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The outputs (key-value pairs), where none of "
                 "the keys are duplicated.\n"
                 "That is, each address can only appear once and there can only "
                 "be one 'data' object.\n"
                 "For compatibility reasons, a dictionary, which holds the "
                 "key-value pairs directly, is also\n"
                 "                             accepted as second parameter.",
                 {
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"address", RPCArg::Type::AMOUNT,
                              RPCArg::Optional::NO,
                              "A key-value pair. The key (string) is the "
                              "bitcoin address, the value (float or string) is "
                              "the amount in " +
                                  Currency::get().ticker},
                         },
                     },
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"data", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::NO,
                              "A key-value pair. The key must be \"data\", the "
                              "value is hex-encoded data"},
                         },
                     },
                 },
             },
             {"locktime", RPCArg::Type::NUM, /* default */ "0",
              "Raw locktime. Non-0 value also locktime-activates inputs"},
         },
         RPCResult{RPCResult::Type::STR_HEX, "transaction",
                   "hex string of the transaction"},
         RPCExamples{
             HelpExampleCli("createrawtransaction",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]"
                            "\" \"[{\\\"address\\\":10000.00}]\"") +
             HelpExampleCli("createrawtransaction",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]"
                            "\" \"[{\\\"data\\\":\\\"00010203\\\"}]\"") +
             HelpExampleRpc("createrawtransaction",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]"
                            "\", \"[{\\\"address\\\":10000.00}]\"") +
             HelpExampleRpc("createrawtransaction",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]"
                            "\", \"[{\\\"data\\\":\\\"00010203\\\"}]\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params,
                          {UniValue::VARR,
                           UniValueType(), // ARR or OBJ, checked later
                           UniValue::VNUM},
                          true);
 
             CMutableTransaction rawTx =
                 ConstructTransaction(config.GetChainParams(), request.params[0],
                                      request.params[1], request.params[2]);
 
             return EncodeHexTx(CTransaction(rawTx));
         },
     };
 }
 
 static RPCHelpMan decoderawtransaction() {
     return RPCHelpMan{
         "decoderawtransaction",
         "Return a JSON object representing the serialized, hex-encoded "
         "transaction.\n",
         {
             {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "The transaction hex string"},
         },
         RPCResult{
             RPCResult::Type::OBJ,
             "",
             "",
             {
                 {RPCResult::Type::STR_HEX, "txid", "The transaction id"},
                 {RPCResult::Type::STR_HEX, "hash", "The transaction hash"},
                 {RPCResult::Type::NUM, "size", "The transaction size"},
                 {RPCResult::Type::NUM, "version", "The version"},
                 {RPCResult::Type::NUM_TIME, "locktime", "The lock time"},
                 {RPCResult::Type::ARR,
                  "vin",
                  "",
                  {
                      {RPCResult::Type::OBJ,
                       "",
                       "",
                       {
                           {RPCResult::Type::STR_HEX, "txid",
                            "The transaction id"},
                           {RPCResult::Type::NUM, "vout", "The output number"},
                           {RPCResult::Type::OBJ,
                            "scriptSig",
                            "The script",
                            {
                                {RPCResult::Type::STR, "asm", "asm"},
                                {RPCResult::Type::STR_HEX, "hex", "hex"},
                            }},
                           {RPCResult::Type::NUM, "sequence",
                            "The script sequence number"},
                       }},
                  }},
                 {RPCResult::Type::ARR,
                  "vout",
                  "",
                  {
                      {RPCResult::Type::OBJ,
                       "",
                       "",
                       {
                           {RPCResult::Type::NUM, "value",
                            "The value in " + Currency::get().ticker},
                           {RPCResult::Type::NUM, "n", "index"},
                           {RPCResult::Type::OBJ,
                            "scriptPubKey",
                            "",
                            {
                                {RPCResult::Type::STR, "asm", "the asm"},
                                {RPCResult::Type::STR_HEX, "hex", "the hex"},
                                {RPCResult::Type::NUM, "reqSigs",
                                 "The required sigs"},
                                {RPCResult::Type::STR, "type",
                                 "The type, eg 'pubkeyhash'"},
                                {RPCResult::Type::ARR,
                                 "addresses",
                                 "",
                                 {
                                     {RPCResult::Type::STR, "address",
                                      "bitcoin address"},
                                 }},
                            }},
                       }},
                  }},
             }},
         RPCExamples{HelpExampleCli("decoderawtransaction", "\"hexstring\"") +
                     HelpExampleRpc("decoderawtransaction", "\"hexstring\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR});
 
             CMutableTransaction mtx;
 
             if (!DecodeHexTx(mtx, request.params[0].get_str())) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "TX decode failed");
             }
 
             UniValue result(UniValue::VOBJ);
             TxToUniv(CTransaction(std::move(mtx)), uint256(), result, false);
 
             return result;
         },
     };
 }
 
 static RPCHelpMan decodescript() {
     return RPCHelpMan{
         "decodescript",
         "Decode a hex-encoded script.\n",
         {
             {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "the hex-encoded script"},
         },
         RPCResult{
             RPCResult::Type::OBJ,
             "",
             "",
             {
                 {RPCResult::Type::STR, "asm", "Script public key"},
                 {RPCResult::Type::STR, "type",
                  "The output type (e.g. " + GetAllOutputTypes() + ")"},
                 {RPCResult::Type::NUM, "reqSigs", "The required signatures"},
                 {RPCResult::Type::ARR,
                  "addresses",
                  "",
                  {
                      {RPCResult::Type::STR, "address", "bitcoin address"},
                  }},
                 {RPCResult::Type::STR, "p2sh",
                  "address of P2SH script wrapping this redeem script (not "
                  "returned if the script is already a P2SH)"},
             }},
         RPCExamples{HelpExampleCli("decodescript", "\"hexstring\"") +
                     HelpExampleRpc("decodescript", "\"hexstring\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR});
 
             UniValue r(UniValue::VOBJ);
             CScript script;
             if (request.params[0].get_str().size() > 0) {
                 std::vector<uint8_t> scriptData(
                     ParseHexV(request.params[0], "argument"));
                 script = CScript(scriptData.begin(), scriptData.end());
             } else {
                 // Empty scripts are valid.
             }
 
             ScriptPubKeyToUniv(script, r, /* fIncludeHex */ false);
 
             UniValue type;
             type = find_value(r, "type");
 
             if (type.isStr() && type.get_str() != "scripthash") {
                 // P2SH cannot be wrapped in a P2SH. If this script is already a
                 // P2SH, don't return the address for a P2SH of the P2SH.
                 r.pushKV("p2sh", EncodeDestination(ScriptHash(script), config));
             }
 
             return r;
         },
     };
 }
 
 static RPCHelpMan combinerawtransaction() {
     return RPCHelpMan{
         "combinerawtransaction",
         "Combine multiple partially signed transactions into one "
         "transaction.\n"
         "The combined transaction may be another partially signed transaction "
         "or a \n"
         "fully signed transaction.",
         {
             {
                 "txs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The hex strings of partially signed "
                 "transactions",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX,
                      RPCArg::Optional::OMITTED,
                      "A hex-encoded raw transaction"},
                 },
             },
         },
         RPCResult{RPCResult::Type::STR, "",
                   "The hex-encoded raw transaction with signature(s)"},
         RPCExamples{HelpExampleCli("combinerawtransaction",
                                    R"('["myhex1", "myhex2", "myhex3"]')")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             UniValue txs = request.params[0].get_array();
             std::vector<CMutableTransaction> txVariants(txs.size());
 
             for (unsigned int idx = 0; idx < txs.size(); idx++) {
                 if (!DecodeHexTx(txVariants[idx], txs[idx].get_str())) {
                     throw JSONRPCError(
                         RPC_DESERIALIZATION_ERROR,
                         strprintf("TX decode failed for tx %d", idx));
                 }
             }
 
             if (txVariants.empty()) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "Missing transactions");
             }
 
             // mergedTx will end up with all the signatures; it
             // starts as a clone of the rawtx:
             CMutableTransaction mergedTx(txVariants[0]);
 
             // Fetch previous transactions (inputs):
             CCoinsView viewDummy;
             CCoinsViewCache view(&viewDummy);
             {
                 NodeContext &node = EnsureAnyNodeContext(request.context);
                 const CTxMemPool &mempool = EnsureMemPool(node);
                 ChainstateManager &chainman = EnsureChainman(node);
                 LOCK2(cs_main, mempool.cs);
                 CCoinsViewCache &viewChain =
                     chainman.ActiveChainstate().CoinsTip();
                 CCoinsViewMemPool viewMempool(&viewChain, mempool);
                 // temporarily switch cache backend to db+mempool view
                 view.SetBackend(viewMempool);
 
                 for (const CTxIn &txin : mergedTx.vin) {
                     // Load entries from viewChain into view; can fail.
                     view.AccessCoin(txin.prevout);
                 }
 
                 // switch back to avoid locking mempool for too long
                 view.SetBackend(viewDummy);
             }
 
             // Use CTransaction for the constant parts of the
             // transaction to avoid rehashing.
             const CTransaction txConst(mergedTx);
             // Sign what we can:
             for (size_t i = 0; i < mergedTx.vin.size(); i++) {
                 CTxIn &txin = mergedTx.vin[i];
                 const Coin &coin = view.AccessCoin(txin.prevout);
                 if (coin.IsSpent()) {
                     throw JSONRPCError(RPC_VERIFY_ERROR,
                                        "Input not found or already spent");
                 }
                 SignatureData sigdata;
 
                 const CTxOut &txout = coin.GetTxOut();
 
                 // ... and merge in other signatures:
                 for (const CMutableTransaction &txv : txVariants) {
                     if (txv.vin.size() > i) {
                         sigdata.MergeSignatureData(
                             DataFromTransaction(txv, i, txout));
                     }
                 }
                 ProduceSignature(DUMMY_SIGNING_PROVIDER,
                                  MutableTransactionSignatureCreator(
                                      &mergedTx, i, txout.nValue),
                                  txout.scriptPubKey, sigdata);
 
                 UpdateInput(txin, sigdata);
             }
 
             return EncodeHexTx(CTransaction(mergedTx));
         },
     };
 }
 
 static RPCHelpMan signrawtransactionwithkey() {
     return RPCHelpMan{
         "signrawtransactionwithkey",
         "Sign inputs for raw transaction (serialized, hex-encoded).\n"
         "The second argument is an array of base58-encoded private\n"
         "keys that will be the only keys used to sign the transaction.\n"
         "The third optional argument (may be null) is an array of previous "
         "transaction outputs that\n"
         "this transaction depends on but may not yet be in the block chain.\n",
         {
             {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "The transaction hex string"},
             {
                 "privkeys",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The base58-encoded private keys for signing",
                 {
                     {"privatekey", RPCArg::Type::STR, RPCArg::Optional::OMITTED,
                      "private key in base58-encoding"},
                 },
             },
             {
                 "prevtxs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::OMITTED_NAMED_ARG,
                 "The previous dependent transaction outputs",
                 {
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"txid", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO,
                              "The output number"},
                             {"scriptPubKey", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::NO, "script key"},
                             {"redeemScript", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::OMITTED,
                              "(required for P2SH) redeem script"},
                             {"amount", RPCArg::Type::AMOUNT,
                              RPCArg::Optional::NO, "The amount spent"},
                         },
                     },
                 },
             },
             {"sighashtype", RPCArg::Type::STR, /* default */ "ALL|FORKID",
              "The signature hash type. Must be one of:\n"
              "       \"ALL|FORKID\"\n"
              "       \"NONE|FORKID\"\n"
              "       \"SINGLE|FORKID\"\n"
              "       \"ALL|FORKID|ANYONECANPAY\"\n"
              "       \"NONE|FORKID|ANYONECANPAY\"\n"
              "       \"SINGLE|FORKID|ANYONECANPAY\""},
         },
         RPCResult{
             RPCResult::Type::OBJ,
             "",
             "",
             {
                 {RPCResult::Type::STR_HEX, "hex",
                  "The hex-encoded raw transaction with signature(s)"},
                 {RPCResult::Type::BOOL, "complete",
                  "If the transaction has a complete set of signatures"},
                 {RPCResult::Type::ARR,
                  "errors",
                  /* optional */ true,
                  "Script verification errors (if there are any)",
                  {
                      {RPCResult::Type::OBJ,
                       "",
                       "",
                       {
                           {RPCResult::Type::STR_HEX, "txid",
                            "The hash of the referenced, previous transaction"},
                           {RPCResult::Type::NUM, "vout",
                            "The index of the output to spent and used as "
                            "input"},
                           {RPCResult::Type::STR_HEX, "scriptSig",
                            "The hex-encoded signature script"},
                           {RPCResult::Type::NUM, "sequence",
                            "Script sequence number"},
                           {RPCResult::Type::STR, "error",
                            "Verification or signing error related to the "
                            "input"},
                       }},
                  }},
             }},
         RPCExamples{
             HelpExampleCli("signrawtransactionwithkey",
                            "\"myhex\" \"[\\\"key1\\\",\\\"key2\\\"]\"") +
             HelpExampleRpc("signrawtransactionwithkey",
                            "\"myhex\", \"[\\\"key1\\\",\\\"key2\\\"]\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params,
                          {UniValue::VSTR, UniValue::VARR, UniValue::VARR,
                           UniValue::VSTR},
                          true);
 
             CMutableTransaction mtx;
             if (!DecodeHexTx(mtx, request.params[0].get_str())) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "TX decode failed");
             }
 
             FillableSigningProvider keystore;
             const UniValue &keys = request.params[1].get_array();
             for (size_t idx = 0; idx < keys.size(); ++idx) {
                 UniValue k = keys[idx];
                 CKey key = DecodeSecret(k.get_str());
                 if (!key.IsValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Invalid private key");
                 }
                 keystore.AddKey(key);
             }
 
             // Fetch previous transactions (inputs):
             std::map<COutPoint, Coin> coins;
             for (const CTxIn &txin : mtx.vin) {
                 // Create empty map entry keyed by prevout.
                 coins[txin.prevout];
             }
             NodeContext &node = EnsureAnyNodeContext(request.context);
             FindCoins(node, coins);
 
             // Parse the prevtxs array
             ParsePrevouts(request.params[2], &keystore, coins);
 
             UniValue result(UniValue::VOBJ);
             SignTransaction(mtx, &keystore, coins, request.params[3], result);
             return result;
         },
     };
 }
 
 static RPCHelpMan sendrawtransaction() {
     return RPCHelpMan{
         "sendrawtransaction",
         "Submits raw transaction (serialized, hex-encoded) to local node and "
         "network.\n"
         "\nAlso see createrawtransaction and "
         "signrawtransactionwithkey calls.\n",
         {
             {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "The hex string of the raw transaction"},
             {"maxfeerate", RPCArg::Type::AMOUNT,
              /* default */
              FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK()),
              "Reject transactions whose fee rate is higher than the specified "
              "value, expressed in " +
                  Currency::get().ticker +
                  "/kB\nSet to 0 to accept any fee rate.\n"},
         },
         RPCResult{RPCResult::Type::STR_HEX, "", "The transaction hash in hex"},
         RPCExamples{
             "\nCreate a transaction\n" +
             HelpExampleCli(
                 "createrawtransaction",
                 "\"[{\\\"txid\\\" : \\\"mytxid\\\",\\\"vout\\\":0}]\" "
                 "\"{\\\"myaddress\\\":10000}\"") +
             "Sign the transaction, and get back the hex\n" +
             HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"") +
             "\nSend the transaction (signed hex)\n" +
             HelpExampleCli("sendrawtransaction", "\"signedhex\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("sendrawtransaction", "\"signedhex\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params,
                          {
                              UniValue::VSTR,
                              // VNUM or VSTR, checked inside AmountFromValue()
                              UniValueType(),
                          });
 
             // parse hex string from parameter
             CMutableTransaction mtx;
             if (!DecodeHexTx(mtx, request.params[0].get_str())) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "TX decode failed");
             }
 
             CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
 
             const CFeeRate max_raw_tx_fee_rate =
                 request.params[1].isNull()
                     ? DEFAULT_MAX_RAW_TX_FEE_RATE
                     : CFeeRate(AmountFromValue(request.params[1]));
 
             int64_t virtual_size = GetVirtualTransactionSize(*tx);
             Amount max_raw_tx_fee = max_raw_tx_fee_rate.GetFee(virtual_size);
 
             std::string err_string;
             AssertLockNotHeld(cs_main);
             NodeContext &node = EnsureAnyNodeContext(request.context);
             const TransactionError err = BroadcastTransaction(
                 node, config, tx, err_string, max_raw_tx_fee, /*relay*/ true,
                 /*wait_callback*/ true);
             if (err != TransactionError::OK) {
                 throw JSONRPCTransactionError(err, err_string);
             }
 
             return tx->GetHash().GetHex();
         },
     };
 }
 
 static RPCHelpMan testmempoolaccept() {
     return RPCHelpMan{
         "testmempoolaccept",
         "Returns result of mempool acceptance tests indicating if raw"
         " transaction (serialized, hex-encoded) would be accepted"
         " by mempool.\n"
         "\nThis checks if the transaction violates the consensus or policy "
         "rules.\n"
         "\nSee sendrawtransaction call.\n",
         {
             {
                 "rawtxs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "An array of hex strings of raw transactions.\n"
                 "                             Length must be one for now.",
                 {
                     {"rawtx", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED,
                      ""},
                 },
             },
             {"maxfeerate", RPCArg::Type::AMOUNT,
              /* default */
              FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK()),
              "Reject transactions whose fee rate is higher than the specified "
              "value, expressed in " +
                  Currency::get().ticker + "/kB\n"},
         },
         RPCResult{
             RPCResult::Type::ARR,
             "",
             "The result of the mempool acceptance test for each raw "
             "transaction in the input array.\n"
             "Length is exactly one for now.",
             {
                 {RPCResult::Type::OBJ,
                  "",
                  "",
                  {
                      {RPCResult::Type::STR_HEX, "txid",
                       "The transaction hash in hex"},
                      {RPCResult::Type::BOOL, "allowed",
                       "If the mempool allows this tx to be inserted"},
                      {RPCResult::Type::NUM, "size", "The transaction size"},
                      {RPCResult::Type::OBJ,
                       "fees",
                       "Transaction fees (only present if 'allowed' is true)",
                       {
                           {RPCResult::Type::STR_AMOUNT, "base",
                            "transaction fee in " + Currency::get().ticker},
                       }},
                      {RPCResult::Type::STR, "reject-reason",
                       "Rejection string (only present when 'allowed' is "
                       "false)"},
                  }},
             }},
         RPCExamples{
             "\nCreate a transaction\n" +
             HelpExampleCli(
                 "createrawtransaction",
                 "\"[{\\\"txid\\\" : \\\"mytxid\\\",\\\"vout\\\":0}]\" "
                 "\"{\\\"myaddress\\\":10000}\"") +
             "Sign the transaction, and get back the hex\n" +
             HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"") +
             "\nTest acceptance of the transaction (signed hex)\n" +
             HelpExampleCli("testmempoolaccept", R"('["signedhex"]')") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("testmempoolaccept", "[\"signedhex\"]")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params,
                          {
                              UniValue::VARR,
                              // VNUM or VSTR, checked inside AmountFromValue()
                              UniValueType(),
                          });
 
             if (request.params[0].get_array().size() != 1) {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     "Array must contain exactly one raw transaction for now");
             }
 
             CMutableTransaction mtx;
             if (!DecodeHexTx(mtx, request.params[0].get_array()[0].get_str())) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "TX decode failed");
             }
             CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
             const TxId &txid = tx->GetId();
 
             const CFeeRate max_raw_tx_fee_rate =
                 request.params[1].isNull()
                     ? DEFAULT_MAX_RAW_TX_FEE_RATE
                     : CFeeRate(AmountFromValue(request.params[1]));
 
             NodeContext &node = EnsureAnyNodeContext(request.context);
 
             CTxMemPool &mempool = EnsureMemPool(node);
             int64_t virtual_size = GetVirtualTransactionSize(*tx);
             Amount max_raw_tx_fee = max_raw_tx_fee_rate.GetFee(virtual_size);
 
             UniValue result(UniValue::VARR);
             UniValue result_0(UniValue::VOBJ);
             result_0.pushKV("txid", txid.GetHex());
 
-            TxValidationState state;
-            bool test_accept_res;
-            Amount fee = Amount::zero();
             ChainstateManager &chainman = EnsureChainman(node);
 
-            test_accept_res = WITH_LOCK(
-                cs_main, return AcceptToMemoryPool(
-                             chainman.ActiveChainstate(), config, mempool,
-                             state, std::move(tx), false /* bypass_limits */,
-                             true /* test_accept */, &fee));
+            const MempoolAcceptResult accept_result = WITH_LOCK(
+                cs_main,
+                return AcceptToMemoryPool(
+                    chainman.ActiveChainstate(), config, mempool, std::move(tx),
+                    false /* bypass_limits */, true /* test_accept */));
 
             // Only return the fee and size if the transaction would pass ATMP.
             // These can be used to calculate the feerate.
-            if (test_accept_res) {
+            if (accept_result.m_result_type ==
+                MempoolAcceptResult::ResultType::VALID) {
+                const Amount fee = accept_result.m_base_fees.value();
                 // Check that fee does not exceed maximum fee
                 if (max_raw_tx_fee != Amount::zero() && fee > max_raw_tx_fee) {
                     result_0.pushKV("allowed", false);
                     result_0.pushKV("reject-reason", "max-fee-exceeded");
                 } else {
                     result_0.pushKV("allowed", true);
                     result_0.pushKV("size", virtual_size);
                     UniValue fees(UniValue::VOBJ);
                     fees.pushKV("base", fee);
                     result_0.pushKV("fees", fees);
                 }
                 result.push_back(std::move(result_0));
             } else {
                 result_0.pushKV("allowed", false);
+                const TxValidationState state = accept_result.m_state;
                 if (state.GetResult() ==
                     TxValidationResult::TX_MISSING_INPUTS) {
                     result_0.pushKV("reject-reason", "missing-inputs");
                 } else {
                     result_0.pushKV("reject-reason", state.GetRejectReason());
                 }
                 result.push_back(std::move(result_0));
             }
             return result;
         },
     };
 }
 
 static RPCHelpMan decodepsbt() {
     return RPCHelpMan{
         "decodepsbt",
         "Return a JSON object representing the serialized, base64-encoded "
         "partially signed Bitcoin transaction.\n",
         {
             {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO,
              "The PSBT base64 string"},
         },
         RPCResult{
             RPCResult::Type::OBJ,
             "",
             "",
             {
                 {RPCResult::Type::OBJ,
                  "tx",
                  "The decoded network-serialized unsigned transaction.",
                  {
                      {RPCResult::Type::ELISION, "",
                       "The layout is the same as the output of "
                       "decoderawtransaction."},
                  }},
                 {RPCResult::Type::OBJ_DYN,
                  "unknown",
                  "The unknown global fields",
                  {
                      {RPCResult::Type::STR_HEX, "key",
                       "(key-value pair) An unknown key-value pair"},
                  }},
                 {RPCResult::Type::ARR,
                  "inputs",
                  "",
                  {
                      {RPCResult::Type::OBJ,
                       "",
                       "",
                       {
                           {RPCResult::Type::OBJ,
                            "utxo",
                            /* optional */ true,
                            "Transaction output for UTXOs",
                            {
                                {RPCResult::Type::NUM, "amount",
                                 "The value in " + Currency::get().ticker},
                                {RPCResult::Type::OBJ,
                                 "scriptPubKey",
                                 "",
                                 {
                                     {RPCResult::Type::STR, "asm", "The asm"},
                                     {RPCResult::Type::STR_HEX, "hex",
                                      "The hex"},
                                     {RPCResult::Type::STR, "type",
                                      "The type, eg 'pubkeyhash'"},
                                     {RPCResult::Type::STR, "address",
                                      " Bitcoin address if there is one"},
                                 }},
                            }},
                           {RPCResult::Type::OBJ_DYN,
                            "partial_signatures",
                            /* optional */ true,
                            "",
                            {
                                {RPCResult::Type::STR, "pubkey",
                                 "The public key and signature that corresponds "
                                 "to it."},
                            }},
                           {RPCResult::Type::STR, "sighash", /* optional */ true,
                            "The sighash type to be used"},
                           {RPCResult::Type::OBJ,
                            "redeem_script",
                            /* optional */ true,
                            "",
                            {
                                {RPCResult::Type::STR, "asm", "The asm"},
                                {RPCResult::Type::STR_HEX, "hex", "The hex"},
                                {RPCResult::Type::STR, "type",
                                 "The type, eg 'pubkeyhash'"},
                            }},
                           {RPCResult::Type::ARR,
                            "bip32_derivs",
                            /* optional */ true,
                            "",
                            {
                                {RPCResult::Type::OBJ,
                                 "pubkey",
                                 /* optional */ true,
                                 "The public key with the derivation path as "
                                 "the value.",
                                 {
                                     {RPCResult::Type::STR, "master_fingerprint",
                                      "The fingerprint of the master key"},
                                     {RPCResult::Type::STR, "path", "The path"},
                                 }},
                            }},
                           {RPCResult::Type::OBJ,
                            "final_scriptsig",
                            /* optional */ true,
                            "",
                            {
                                {RPCResult::Type::STR, "asm", "The asm"},
                                {RPCResult::Type::STR, "hex", "The hex"},
                            }},
                           {RPCResult::Type::OBJ_DYN,
                            "unknown",
                            "The unknown global fields",
                            {
                                {RPCResult::Type::STR_HEX, "key",
                                 "(key-value pair) An unknown key-value pair"},
                            }},
                       }},
                  }},
                 {RPCResult::Type::ARR,
                  "outputs",
                  "",
                  {
                      {RPCResult::Type::OBJ,
                       "",
                       "",
                       {
                           {RPCResult::Type::OBJ,
                            "redeem_script",
                            /* optional */ true,
                            "",
                            {
                                {RPCResult::Type::STR, "asm", "The asm"},
                                {RPCResult::Type::STR_HEX, "hex", "The hex"},
                                {RPCResult::Type::STR, "type",
                                 "The type, eg 'pubkeyhash'"},
                            }},
                           {RPCResult::Type::ARR,
                            "bip32_derivs",
                            /* optional */ true,
                            "",
                            {
                                {RPCResult::Type::OBJ,
                                 "",
                                 "",
                                 {
                                     {RPCResult::Type::STR, "pubkey",
                                      "The public key this path corresponds to"},
                                     {RPCResult::Type::STR, "master_fingerprint",
                                      "The fingerprint of the master key"},
                                     {RPCResult::Type::STR, "path", "The path"},
                                 }},
                            }},
                           {RPCResult::Type::OBJ_DYN,
                            "unknown",
                            "The unknown global fields",
                            {
                                {RPCResult::Type::STR_HEX, "key",
                                 "(key-value pair) An unknown key-value pair"},
                            }},
                       }},
                  }},
                 {RPCResult::Type::STR_AMOUNT, "fee", /* optional */ true,
                  "The transaction fee paid if all UTXOs slots in the PSBT have "
                  "been filled."},
             }},
         RPCExamples{HelpExampleCli("decodepsbt", "\"psbt\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR});
 
             // Unserialize the transactions
             PartiallySignedTransaction psbtx;
             std::string error;
             if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    strprintf("TX decode failed %s", error));
             }
 
             UniValue result(UniValue::VOBJ);
 
             // Add the decoded tx
             UniValue tx_univ(UniValue::VOBJ);
             TxToUniv(CTransaction(*psbtx.tx), uint256(), tx_univ, false);
             result.pushKV("tx", tx_univ);
 
             // Unknown data
             if (psbtx.unknown.size() > 0) {
                 UniValue unknowns(UniValue::VOBJ);
                 for (auto entry : psbtx.unknown) {
                     unknowns.pushKV(HexStr(entry.first), HexStr(entry.second));
                 }
                 result.pushKV("unknown", unknowns);
             }
 
             // inputs
             Amount total_in = Amount::zero();
             bool have_all_utxos = true;
             UniValue inputs(UniValue::VARR);
             for (size_t i = 0; i < psbtx.inputs.size(); ++i) {
                 const PSBTInput &input = psbtx.inputs[i];
                 UniValue in(UniValue::VOBJ);
                 // UTXOs
                 if (!input.utxo.IsNull()) {
                     const CTxOut &txout = input.utxo;
 
                     UniValue out(UniValue::VOBJ);
 
                     out.pushKV("amount", txout.nValue);
                     if (MoneyRange(txout.nValue) &&
                         MoneyRange(total_in + txout.nValue)) {
                         total_in += txout.nValue;
                     } else {
                         // Hack to just not show fee later
                         have_all_utxos = false;
                     }
 
                     UniValue o(UniValue::VOBJ);
                     ScriptToUniv(txout.scriptPubKey, o, true);
                     out.pushKV("scriptPubKey", o);
                     in.pushKV("utxo", out);
                 } else {
                     have_all_utxos = false;
                 }
 
                 // Partial sigs
                 if (!input.partial_sigs.empty()) {
                     UniValue partial_sigs(UniValue::VOBJ);
                     for (const auto &sig : input.partial_sigs) {
                         partial_sigs.pushKV(HexStr(sig.second.first),
                                             HexStr(sig.second.second));
                     }
                     in.pushKV("partial_signatures", partial_sigs);
                 }
 
                 // Sighash
                 uint8_t sighashbyte =
                     input.sighash_type.getRawSigHashType() & 0xff;
                 if (sighashbyte > 0) {
                     in.pushKV("sighash", SighashToStr(sighashbyte));
                 }
 
                 // Redeem script
                 if (!input.redeem_script.empty()) {
                     UniValue r(UniValue::VOBJ);
                     ScriptToUniv(input.redeem_script, r, false);
                     in.pushKV("redeem_script", r);
                 }
 
                 // keypaths
                 if (!input.hd_keypaths.empty()) {
                     UniValue keypaths(UniValue::VARR);
                     for (auto entry : input.hd_keypaths) {
                         UniValue keypath(UniValue::VOBJ);
                         keypath.pushKV("pubkey", HexStr(entry.first));
 
                         keypath.pushKV(
                             "master_fingerprint",
                             strprintf("%08x",
                                       ReadBE32(entry.second.fingerprint)));
                         keypath.pushKV("path",
                                        WriteHDKeypath(entry.second.path));
                         keypaths.push_back(keypath);
                     }
                     in.pushKV("bip32_derivs", keypaths);
                 }
 
                 // Final scriptSig
                 if (!input.final_script_sig.empty()) {
                     UniValue scriptsig(UniValue::VOBJ);
                     scriptsig.pushKV(
                         "asm", ScriptToAsmStr(input.final_script_sig, true));
                     scriptsig.pushKV("hex", HexStr(input.final_script_sig));
                     in.pushKV("final_scriptSig", scriptsig);
                 }
 
                 // Unknown data
                 if (input.unknown.size() > 0) {
                     UniValue unknowns(UniValue::VOBJ);
                     for (auto entry : input.unknown) {
                         unknowns.pushKV(HexStr(entry.first),
                                         HexStr(entry.second));
                     }
                     in.pushKV("unknown", unknowns);
                 }
 
                 inputs.push_back(in);
             }
             result.pushKV("inputs", inputs);
 
             // outputs
             Amount output_value = Amount::zero();
             UniValue outputs(UniValue::VARR);
             for (size_t i = 0; i < psbtx.outputs.size(); ++i) {
                 const PSBTOutput &output = psbtx.outputs[i];
                 UniValue out(UniValue::VOBJ);
                 // Redeem script
                 if (!output.redeem_script.empty()) {
                     UniValue r(UniValue::VOBJ);
                     ScriptToUniv(output.redeem_script, r, false);
                     out.pushKV("redeem_script", r);
                 }
 
                 // keypaths
                 if (!output.hd_keypaths.empty()) {
                     UniValue keypaths(UniValue::VARR);
                     for (auto entry : output.hd_keypaths) {
                         UniValue keypath(UniValue::VOBJ);
                         keypath.pushKV("pubkey", HexStr(entry.first));
                         keypath.pushKV(
                             "master_fingerprint",
                             strprintf("%08x",
                                       ReadBE32(entry.second.fingerprint)));
                         keypath.pushKV("path",
                                        WriteHDKeypath(entry.second.path));
                         keypaths.push_back(keypath);
                     }
                     out.pushKV("bip32_derivs", keypaths);
                 }
 
                 // Unknown data
                 if (output.unknown.size() > 0) {
                     UniValue unknowns(UniValue::VOBJ);
                     for (auto entry : output.unknown) {
                         unknowns.pushKV(HexStr(entry.first),
                                         HexStr(entry.second));
                     }
                     out.pushKV("unknown", unknowns);
                 }
 
                 outputs.push_back(out);
 
                 // Fee calculation
                 if (MoneyRange(psbtx.tx->vout[i].nValue) &&
                     MoneyRange(output_value + psbtx.tx->vout[i].nValue)) {
                     output_value += psbtx.tx->vout[i].nValue;
                 } else {
                     // Hack to just not show fee later
                     have_all_utxos = false;
                 }
             }
             result.pushKV("outputs", outputs);
             if (have_all_utxos) {
                 result.pushKV("fee", total_in - output_value);
             }
 
             return result;
         },
     };
 }
 
 static RPCHelpMan combinepsbt() {
     return RPCHelpMan{
         "combinepsbt",
         "Combine multiple partially signed Bitcoin transactions into one "
         "transaction.\n"
         "Implements the Combiner role.\n",
         {
             {
                 "txs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The base64 strings of partially signed transactions",
                 {
                     {"psbt", RPCArg::Type::STR, RPCArg::Optional::OMITTED,
                      "A base64 string of a PSBT"},
                 },
             },
         },
         RPCResult{RPCResult::Type::STR, "",
                   "The base64-encoded partially signed transaction"},
         RPCExamples{HelpExampleCli(
             "combinepsbt", R"('["mybase64_1", "mybase64_2", "mybase64_3"]')")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VARR}, true);
 
             // Unserialize the transactions
             std::vector<PartiallySignedTransaction> psbtxs;
             UniValue txs = request.params[0].get_array();
             if (txs.empty()) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "Parameter 'txs' cannot be empty");
             }
             for (size_t i = 0; i < txs.size(); ++i) {
                 PartiallySignedTransaction psbtx;
                 std::string error;
                 if (!DecodeBase64PSBT(psbtx, txs[i].get_str(), error)) {
                     throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                        strprintf("TX decode failed %s", error));
                 }
                 psbtxs.push_back(psbtx);
             }
 
             PartiallySignedTransaction merged_psbt;
             const TransactionError error = CombinePSBTs(merged_psbt, psbtxs);
             if (error != TransactionError::OK) {
                 throw JSONRPCTransactionError(error);
             }
 
             CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
             ssTx << merged_psbt;
             return EncodeBase64(MakeUCharSpan(ssTx));
         },
     };
 }
 
 static RPCHelpMan finalizepsbt() {
     return RPCHelpMan{
         "finalizepsbt",
         "Finalize the inputs of a PSBT. If the transaction is fully signed, it "
         "will produce a\n"
         "network serialized transaction which can be broadcast with "
         "sendrawtransaction. Otherwise a PSBT will be\n"
         "created which has the final_scriptSigfields filled for inputs that "
         "are complete.\n"
         "Implements the Finalizer and Extractor roles.\n",
         {
             {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO,
              "A base64 string of a PSBT"},
             {"extract", RPCArg::Type::BOOL, /* default */ "true",
              "If true and the transaction is complete,\n"
              "                             extract and return the complete "
              "transaction in normal network serialization instead of the "
              "PSBT."},
         },
         RPCResult{RPCResult::Type::OBJ,
                   "",
                   "",
                   {
                       {RPCResult::Type::STR, "psbt",
                        "The base64-encoded partially signed transaction if not "
                        "extracted"},
                       {RPCResult::Type::STR_HEX, "hex",
                        "The hex-encoded network transaction if extracted"},
                       {RPCResult::Type::BOOL, "complete",
                        "If the transaction has a complete set of signatures"},
                   }},
         RPCExamples{HelpExampleCli("finalizepsbt", "\"psbt\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VBOOL},
                          true);
 
             // Unserialize the transactions
             PartiallySignedTransaction psbtx;
             std::string error;
             if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    strprintf("TX decode failed %s", error));
             }
 
             bool extract =
                 request.params[1].isNull() ||
                 (!request.params[1].isNull() && request.params[1].get_bool());
 
             CMutableTransaction mtx;
             bool complete = FinalizeAndExtractPSBT(psbtx, mtx);
 
             UniValue result(UniValue::VOBJ);
             CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
             std::string result_str;
 
             if (complete && extract) {
                 ssTx << mtx;
                 result_str = HexStr(ssTx);
                 result.pushKV("hex", result_str);
             } else {
                 ssTx << psbtx;
                 result_str = EncodeBase64(ssTx.str());
                 result.pushKV("psbt", result_str);
             }
             result.pushKV("complete", complete);
 
             return result;
         },
     };
 }
 
 static RPCHelpMan createpsbt() {
     return RPCHelpMan{
         "createpsbt",
         "Creates a transaction in the Partially Signed Transaction format.\n"
         "Implements the Creator role.\n",
         {
             {
                 "inputs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The json objects",
                 {
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"txid", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO,
                              "The output number"},
                             {"sequence", RPCArg::Type::NUM, /* default */
                              "depends on the value of the 'locktime' argument",
                              "The sequence number"},
                         },
                     },
                 },
             },
             {
                 "outputs",
                 RPCArg::Type::ARR,
                 RPCArg::Optional::NO,
                 "The outputs (key-value pairs), where none of "
                 "the keys are duplicated.\n"
                 "That is, each address can only appear once and there can only "
                 "be one 'data' object.\n"
                 "For compatibility reasons, a dictionary, which holds the "
                 "key-value pairs directly, is also\n"
                 "                             accepted as second parameter.",
                 {
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"address", RPCArg::Type::AMOUNT,
                              RPCArg::Optional::NO,
                              "A key-value pair. The key (string) is the "
                              "bitcoin address, the value (float or string) is "
                              "the amount in " +
                                  Currency::get().ticker},
                         },
                     },
                     {
                         "",
                         RPCArg::Type::OBJ,
                         RPCArg::Optional::OMITTED,
                         "",
                         {
                             {"data", RPCArg::Type::STR_HEX,
                              RPCArg::Optional::NO,
                              "A key-value pair. The key must be \"data\", the "
                              "value is hex-encoded data"},
                         },
                     },
                 },
             },
             {"locktime", RPCArg::Type::NUM, /* default */ "0",
              "Raw locktime. Non-0 value also locktime-activates inputs"},
         },
         RPCResult{RPCResult::Type::STR, "",
                   "The resulting raw transaction (base64-encoded string)"},
         RPCExamples{HelpExampleCli(
             "createpsbt", "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]"
                           "\" \"[{\\\"data\\\":\\\"00010203\\\"}]\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params,
                          {
                              UniValue::VARR,
                              UniValueType(), // ARR or OBJ, checked later
                              UniValue::VNUM,
                          },
                          true);
 
             CMutableTransaction rawTx =
                 ConstructTransaction(config.GetChainParams(), request.params[0],
                                      request.params[1], request.params[2]);
 
             // Make a blank psbt
             PartiallySignedTransaction psbtx;
             psbtx.tx = rawTx;
             for (size_t i = 0; i < rawTx.vin.size(); ++i) {
                 psbtx.inputs.push_back(PSBTInput());
             }
             for (size_t i = 0; i < rawTx.vout.size(); ++i) {
                 psbtx.outputs.push_back(PSBTOutput());
             }
 
             // Serialize the PSBT
             CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
             ssTx << psbtx;
 
             return EncodeBase64(MakeUCharSpan(ssTx));
         },
     };
 }
 
 static RPCHelpMan converttopsbt() {
     return RPCHelpMan{
         "converttopsbt",
         "Converts a network serialized transaction to a PSBT. "
         "This should be used only with createrawtransaction and "
         "fundrawtransaction\n"
         "createpsbt and walletcreatefundedpsbt should be used for new "
         "applications.\n",
         {
             {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
              "The hex string of a raw transaction"},
             {"permitsigdata", RPCArg::Type::BOOL, /* default */ "false",
              "If true, any signatures in the input will be discarded and "
              "conversion.\n"
              "                              will continue. If false, RPC will "
              "fail if any signatures are present."},
         },
         RPCResult{RPCResult::Type::STR, "",
                   "The resulting raw transaction (base64-encoded string)"},
         RPCExamples{
             "\nCreate a transaction\n" +
             HelpExampleCli("createrawtransaction",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]"
                            "\" \"[{\\\"data\\\":\\\"00010203\\\"}]\"") +
             "\nConvert the transaction to a PSBT\n" +
             HelpExampleCli("converttopsbt", "\"rawtransaction\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VBOOL},
                          true);
 
             // parse hex string from parameter
             CMutableTransaction tx;
             bool permitsigdata = request.params[1].isNull()
                                      ? false
                                      : request.params[1].get_bool();
             if (!DecodeHexTx(tx, request.params[0].get_str())) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "TX decode failed");
             }
 
             // Remove all scriptSigs from inputs
             for (CTxIn &input : tx.vin) {
                 if (!input.scriptSig.empty() && !permitsigdata) {
                     throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                        "Inputs must not have scriptSigs");
                 }
                 input.scriptSig.clear();
             }
 
             // Make a blank psbt
             PartiallySignedTransaction psbtx;
             psbtx.tx = tx;
             for (size_t i = 0; i < tx.vin.size(); ++i) {
                 psbtx.inputs.push_back(PSBTInput());
             }
             for (size_t i = 0; i < tx.vout.size(); ++i) {
                 psbtx.outputs.push_back(PSBTOutput());
             }
 
             // Serialize the PSBT
             CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
             ssTx << psbtx;
 
             return EncodeBase64(MakeUCharSpan(ssTx));
         },
     };
 }
 
 RPCHelpMan utxoupdatepsbt() {
     return RPCHelpMan{
         "utxoupdatepsbt",
         "Updates all inputs and outputs in a PSBT with data from output "
         "descriptors, the UTXO set or the mempool.\n",
         {
             {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO,
              "A base64 string of a PSBT"},
             {"descriptors",
              RPCArg::Type::ARR,
              RPCArg::Optional::OMITTED_NAMED_ARG,
              "An array of either strings or objects",
              {
                  {"", RPCArg::Type::STR, RPCArg::Optional::OMITTED,
                   "An output descriptor"},
                  {"",
                   RPCArg::Type::OBJ,
                   RPCArg::Optional::OMITTED,
                   "An object with an output descriptor and extra information",
                   {
                       {"desc", RPCArg::Type::STR, RPCArg::Optional::NO,
                        "An output descriptor"},
                       {"range", RPCArg::Type::RANGE, "1000",
                        "Up to what index HD chains should be explored (either "
                        "end or [begin,end])"},
                   }},
              }},
         },
         RPCResult{RPCResult::Type::STR, "",
                   "The base64-encoded partially signed transaction with inputs "
                   "updated"},
         RPCExamples{HelpExampleCli("utxoupdatepsbt", "\"psbt\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VARR},
                          true);
 
             // Unserialize the transactions
             PartiallySignedTransaction psbtx;
             std::string error;
             if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    strprintf("TX decode failed %s", error));
             }
 
             // Parse descriptors, if any.
             FlatSigningProvider provider;
             if (!request.params[1].isNull()) {
                 auto descs = request.params[1].get_array();
                 for (size_t i = 0; i < descs.size(); ++i) {
                     EvalDescriptorStringOrObject(descs[i], provider);
                 }
             }
             // We don't actually need private keys further on; hide them as a
             // precaution.
             HidingSigningProvider public_provider(&provider, /* nosign */ true,
                                                   /* nobip32derivs */ false);
 
             // Fetch previous transactions (inputs):
             CCoinsView viewDummy;
             CCoinsViewCache view(&viewDummy);
             {
                 NodeContext &node = EnsureAnyNodeContext(request.context);
                 const CTxMemPool &mempool = EnsureMemPool(node);
                 ChainstateManager &chainman = EnsureChainman(node);
                 LOCK2(cs_main, mempool.cs);
                 CCoinsViewCache &viewChain =
                     chainman.ActiveChainstate().CoinsTip();
                 CCoinsViewMemPool viewMempool(&viewChain, mempool);
                 // temporarily switch cache backend to db+mempool view
                 view.SetBackend(viewMempool);
 
                 for (const CTxIn &txin : psbtx.tx->vin) {
                     // Load entries from viewChain into view; can fail.
                     view.AccessCoin(txin.prevout);
                 }
 
                 // switch back to avoid locking mempool for too long
                 view.SetBackend(viewDummy);
             }
 
             // Fill the inputs
             for (size_t i = 0; i < psbtx.tx->vin.size(); ++i) {
                 PSBTInput &input = psbtx.inputs.at(i);
 
                 if (!input.utxo.IsNull()) {
                     continue;
                 }
 
                 // Update script/keypath information using descriptor data.
                 // Note that SignPSBTInput does a lot more than just
                 // constructing ECDSA signatures we don't actually care about
                 // those here, in fact.
                 SignPSBTInput(public_provider, psbtx, i,
                               /* sighash_type */ SigHashType().withForkId());
             }
 
             // Update script/keypath information using descriptor data.
             for (unsigned int i = 0; i < psbtx.tx->vout.size(); ++i) {
                 UpdatePSBTOutput(public_provider, psbtx, i);
             }
 
             CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
             ssTx << psbtx;
             return EncodeBase64(MakeUCharSpan(ssTx));
         },
     };
 }
 
 RPCHelpMan joinpsbts() {
     return RPCHelpMan{
         "joinpsbts",
         "Joins multiple distinct PSBTs with different inputs and outputs "
         "into one PSBT with inputs and outputs from all of the PSBTs\n"
         "No input in any of the PSBTs can be in more than one of the PSBTs.\n",
         {{"txs",
           RPCArg::Type::ARR,
           RPCArg::Optional::NO,
           "The base64 strings of partially signed transactions",
           {{"psbt", RPCArg::Type::STR, RPCArg::Optional::NO,
             "A base64 string of a PSBT"}}}},
         RPCResult{RPCResult::Type::STR, "",
                   "The base64-encoded partially signed transaction"},
         RPCExamples{HelpExampleCli("joinpsbts", "\"psbt\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VARR}, true);
 
             // Unserialize the transactions
             std::vector<PartiallySignedTransaction> psbtxs;
             UniValue txs = request.params[0].get_array();
 
             if (txs.size() <= 1) {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     "At least two PSBTs are required to join PSBTs.");
             }
 
             uint32_t best_version = 1;
             uint32_t best_locktime = 0xffffffff;
             for (size_t i = 0; i < txs.size(); ++i) {
                 PartiallySignedTransaction psbtx;
                 std::string error;
                 if (!DecodeBase64PSBT(psbtx, txs[i].get_str(), error)) {
                     throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                        strprintf("TX decode failed %s", error));
                 }
                 psbtxs.push_back(psbtx);
                 // Choose the highest version number
                 if (static_cast<uint32_t>(psbtx.tx->nVersion) > best_version) {
                     best_version = static_cast<uint32_t>(psbtx.tx->nVersion);
                 }
                 // Choose the lowest lock time
                 if (psbtx.tx->nLockTime < best_locktime) {
                     best_locktime = psbtx.tx->nLockTime;
                 }
             }
 
             // Create a blank psbt where everything will be added
             PartiallySignedTransaction merged_psbt;
             merged_psbt.tx = CMutableTransaction();
             merged_psbt.tx->nVersion = static_cast<int32_t>(best_version);
             merged_psbt.tx->nLockTime = best_locktime;
 
             // Merge
             for (auto &psbt : psbtxs) {
                 for (size_t i = 0; i < psbt.tx->vin.size(); ++i) {
                     if (!merged_psbt.AddInput(psbt.tx->vin[i],
                                               psbt.inputs[i])) {
                         throw JSONRPCError(
                             RPC_INVALID_PARAMETER,
                             strprintf("Input %s:%d exists in multiple PSBTs",
                                       psbt.tx->vin[i]
                                           .prevout.GetTxId()
                                           .ToString()
                                           .c_str(),
                                       psbt.tx->vin[i].prevout.GetN()));
                     }
                 }
                 for (size_t i = 0; i < psbt.tx->vout.size(); ++i) {
                     merged_psbt.AddOutput(psbt.tx->vout[i], psbt.outputs[i]);
                 }
                 merged_psbt.unknown.insert(psbt.unknown.begin(),
                                            psbt.unknown.end());
             }
 
             // Generate list of shuffled indices for shuffling inputs and
             // outputs of the merged PSBT
             std::vector<int> input_indices(merged_psbt.inputs.size());
             std::iota(input_indices.begin(), input_indices.end(), 0);
             std::vector<int> output_indices(merged_psbt.outputs.size());
             std::iota(output_indices.begin(), output_indices.end(), 0);
 
             // Shuffle input and output indices lists
             Shuffle(input_indices.begin(), input_indices.end(),
                     FastRandomContext());
             Shuffle(output_indices.begin(), output_indices.end(),
                     FastRandomContext());
 
             PartiallySignedTransaction shuffled_psbt;
             shuffled_psbt.tx = CMutableTransaction();
             shuffled_psbt.tx->nVersion = merged_psbt.tx->nVersion;
             shuffled_psbt.tx->nLockTime = merged_psbt.tx->nLockTime;
             for (int i : input_indices) {
                 shuffled_psbt.AddInput(merged_psbt.tx->vin[i],
                                        merged_psbt.inputs[i]);
             }
             for (int i : output_indices) {
                 shuffled_psbt.AddOutput(merged_psbt.tx->vout[i],
                                         merged_psbt.outputs[i]);
             }
             shuffled_psbt.unknown.insert(merged_psbt.unknown.begin(),
                                          merged_psbt.unknown.end());
 
             CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
             ssTx << shuffled_psbt;
             return EncodeBase64(MakeUCharSpan(ssTx));
         },
     };
 }
 
 RPCHelpMan analyzepsbt() {
     return RPCHelpMan{
         "analyzepsbt",
         "Analyzes and provides information about the current status of a "
         "PSBT and its inputs\n",
         {{"psbt", RPCArg::Type::STR, RPCArg::Optional::NO,
           "A base64 string of a PSBT"}},
         RPCResult{
             RPCResult::Type::OBJ,
             "",
             "",
             {
                 {RPCResult::Type::ARR,
                  "inputs",
                  "",
                  {
                      {RPCResult::Type::OBJ,
                       "",
                       "",
                       {
                           {RPCResult::Type::BOOL, "has_utxo",
                            "Whether a UTXO is provided"},
                           {RPCResult::Type::BOOL, "is_final",
                            "Whether the input is finalized"},
                           {RPCResult::Type::OBJ,
                            "missing",
                            /* optional */ true,
                            "Things that are missing that are required to "
                            "complete this input",
                            {
                                {RPCResult::Type::ARR,
                                 "pubkeys",
                                 /* optional */ true,
                                 "",
                                 {
                                     {RPCResult::Type::STR_HEX, "keyid",
                                      "Public key ID, hash160 of the public "
                                      "key, of a public key whose BIP 32 "
                                      "derivation path is missing"},
                                 }},
                                {RPCResult::Type::ARR,
                                 "signatures",
                                 /* optional */ true,
                                 "",
                                 {
                                     {RPCResult::Type::STR_HEX, "keyid",
                                      "Public key ID, hash160 of the public "
                                      "key, of a public key whose signature is "
                                      "missing"},
                                 }},
                                {RPCResult::Type::STR_HEX, "redeemscript",
                                 /* optional */ true,
                                 "Hash160 of the redeemScript that is missing"},
                            }},
                           {RPCResult::Type::STR, "next", /* optional */ true,
                            "Role of the next person that this input needs to "
                            "go to"},
                       }},
                  }},
                 {RPCResult::Type::NUM, "estimated_vsize", /* optional */ true,
                  "Estimated vsize of the final signed transaction"},
                 {RPCResult::Type::STR_AMOUNT, "estimated_feerate",
                  /* optional */ true,
                  "Estimated feerate of the final signed transaction in " +
                      Currency::get().ticker +
                      "/kB. Shown only if all UTXO slots in the PSBT have been "
                      "filled"},
                 {RPCResult::Type::STR_AMOUNT, "fee", /* optional */ true,
                  "The transaction fee paid. Shown only if all UTXO slots in "
                  "the PSBT have been filled"},
                 {RPCResult::Type::STR, "next",
                  "Role of the next person that this psbt needs to go to"},
                 {RPCResult::Type::STR, "error", /* optional */ true,
                  "Error message (if there is one)"},
             }},
         RPCExamples{HelpExampleCli("analyzepsbt", "\"psbt\"")},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
             RPCTypeCheck(request.params, {UniValue::VSTR});
 
             // Unserialize the transaction
             PartiallySignedTransaction psbtx;
             std::string error;
             if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    strprintf("TX decode failed %s", error));
             }
 
             PSBTAnalysis psbta = AnalyzePSBT(psbtx);
 
             UniValue result(UniValue::VOBJ);
             UniValue inputs_result(UniValue::VARR);
             for (const auto &input : psbta.inputs) {
                 UniValue input_univ(UniValue::VOBJ);
                 UniValue missing(UniValue::VOBJ);
 
                 input_univ.pushKV("has_utxo", input.has_utxo);
                 input_univ.pushKV("is_final", input.is_final);
                 input_univ.pushKV("next", PSBTRoleName(input.next));
 
                 if (!input.missing_pubkeys.empty()) {
                     UniValue missing_pubkeys_univ(UniValue::VARR);
                     for (const CKeyID &pubkey : input.missing_pubkeys) {
                         missing_pubkeys_univ.push_back(HexStr(pubkey));
                     }
                     missing.pushKV("pubkeys", missing_pubkeys_univ);
                 }
                 if (!input.missing_redeem_script.IsNull()) {
                     missing.pushKV("redeemscript",
                                    HexStr(input.missing_redeem_script));
                 }
                 if (!input.missing_sigs.empty()) {
                     UniValue missing_sigs_univ(UniValue::VARR);
                     for (const CKeyID &pubkey : input.missing_sigs) {
                         missing_sigs_univ.push_back(HexStr(pubkey));
                     }
                     missing.pushKV("signatures", missing_sigs_univ);
                 }
                 if (!missing.getKeys().empty()) {
                     input_univ.pushKV("missing", missing);
                 }
                 inputs_result.push_back(input_univ);
             }
             if (!inputs_result.empty()) {
                 result.pushKV("inputs", inputs_result);
             }
             if (psbta.estimated_vsize != std::nullopt) {
                 result.pushKV("estimated_vsize", (int)*psbta.estimated_vsize);
             }
             if (psbta.estimated_feerate != std::nullopt) {
                 result.pushKV("estimated_feerate",
                               psbta.estimated_feerate->GetFeePerK());
             }
             if (psbta.fee != std::nullopt) {
                 result.pushKV("fee", *psbta.fee);
             }
             result.pushKV("next", PSBTRoleName(psbta.next));
             if (!psbta.error.empty()) {
                 result.pushKV("error", psbta.error);
             }
 
             return result;
         },
     };
 }
 
 void RegisterRawTransactionRPCCommands(CRPCTable &t) {
     // clang-format off
     static const CRPCCommand commands[] = {
         //  category            actor (function)
         //  ------------------  ----------------------
         { "rawtransactions",    getrawtransaction,          },
         { "rawtransactions",    createrawtransaction,       },
         { "rawtransactions",    decoderawtransaction,       },
         { "rawtransactions",    decodescript,               },
         { "rawtransactions",    sendrawtransaction,         },
         { "rawtransactions",    combinerawtransaction,      },
         { "rawtransactions",    signrawtransactionwithkey,  },
         { "rawtransactions",    testmempoolaccept,          },
         { "rawtransactions",    decodepsbt,                 },
         { "rawtransactions",    combinepsbt,                },
         { "rawtransactions",    finalizepsbt,               },
         { "rawtransactions",    createpsbt,                 },
         { "rawtransactions",    converttopsbt,              },
         { "rawtransactions",    utxoupdatepsbt,             },
         { "rawtransactions",    joinpsbts,                  },
         { "rawtransactions",    analyzepsbt,                },
         { "blockchain",         gettxoutproof,              },
         { "blockchain",         verifytxoutproof,           },
     };
     // clang-format on
     for (const auto &c : commands) {
         t.appendCommand(c.name, &c);
     }
 }
diff --git a/src/test/txvalidation_tests.cpp b/src/test/txvalidation_tests.cpp
index bce0b9917..3c5d76b28 100644
--- a/src/test/txvalidation_tests.cpp
+++ b/src/test/txvalidation_tests.cpp
@@ -1,56 +1,54 @@
 // Copyright (c) 2017-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <config.h>
 #include <consensus/validation.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
 #include <txmempool.h>
 #include <validation.h>
 
 #include <test/util/setup_common.h>
 
 #include <boost/test/unit_test.hpp>
 
 BOOST_AUTO_TEST_SUITE(txvalidation_tests)
 
 /**
  * Ensure that the mempool won't accept coinbase transactions.
  */
 BOOST_FIXTURE_TEST_CASE(tx_mempool_reject_coinbase, TestChain100Setup) {
     CScript scriptPubKey = CScript() << ToByteVector(coinbaseKey.GetPubKey())
                                      << OP_CHECKSIG;
     CMutableTransaction coinbaseTx;
 
     coinbaseTx.nVersion = 1;
     coinbaseTx.vin.resize(1);
     coinbaseTx.vout.resize(1);
     coinbaseTx.vin[0].scriptSig = CScript() << OP_11 << OP_EQUAL;
     coinbaseTx.vout[0].nValue = 1 * CENT;
     coinbaseTx.vout[0].scriptPubKey = scriptPubKey;
 
     BOOST_CHECK(CTransaction(coinbaseTx).IsCoinBase());
 
-    TxValidationState state;
-
     LOCK(cs_main);
 
     unsigned int initialPoolSize = m_node.mempool->size();
+    const MempoolAcceptResult result = AcceptToMemoryPool(
+        m_node.chainman->ActiveChainstate(), GetConfig(), *m_node.mempool,
+        MakeTransactionRef(coinbaseTx), true /* bypass_limits */);
 
-    BOOST_CHECK_EQUAL(false,
-                      AcceptToMemoryPool(m_node.chainman->ActiveChainstate(),
-                                         GetConfig(), *m_node.mempool, state,
-                                         MakeTransactionRef(coinbaseTx),
-                                         true /* bypass_limits */));
+    BOOST_CHECK(result.m_result_type ==
+                MempoolAcceptResult::ResultType::INVALID);
 
     // Check that the transaction hasn't been added to mempool.
     BOOST_CHECK_EQUAL(m_node.mempool->size(), initialPoolSize);
 
     // Check that the validation state reflects the unsuccesful attempt.
-    BOOST_CHECK(state.IsInvalid());
-    BOOST_CHECK_EQUAL(state.GetRejectReason(), "bad-tx-coinbase");
-    BOOST_CHECK(state.GetResult() == TxValidationResult::TX_CONSENSUS);
+    BOOST_CHECK(result.m_state.IsInvalid());
+    BOOST_CHECK_EQUAL(result.m_state.GetRejectReason(), "bad-tx-coinbase");
+    BOOST_CHECK(result.m_state.GetResult() == TxValidationResult::TX_CONSENSUS);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index 35c038b45..4f3a170c9 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -1,694 +1,694 @@
 // Copyright (c) 2011-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chain.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <key.h>
 #include <policy/policy.h>
 #include <script/scriptcache.h>
 #include <script/sighashtype.h>
 #include <script/sign.h>
 #include <script/signingprovider.h>
 #include <txmempool.h>
 #include <validation.h>
 
 #include <test/lcg.h>
 #include <test/sigutil.h>
 #include <test/util/setup_common.h>
 
 #include <boost/test/unit_test.hpp>
 
 BOOST_AUTO_TEST_SUITE(txvalidationcache_tests)
 
 BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup) {
     // Make sure skipping validation of transactions that were validated going
     // into the memory pool does not allow double-spends in blocks to pass
     // validation when they should not.
     CScript scriptPubKey = CScript() << ToByteVector(coinbaseKey.GetPubKey())
                                      << OP_CHECKSIG;
 
     const auto ToMemPool = [this](const CMutableTransaction &tx) {
         LOCK(cs_main);
 
-        TxValidationState state;
-        return AcceptToMemoryPool(
+        const MempoolAcceptResult result = AcceptToMemoryPool(
             m_node.chainman->ActiveChainstate(), GetConfig(), *m_node.mempool,
-            state, MakeTransactionRef(tx), true /* bypass_limits */);
+            MakeTransactionRef(tx), true /* bypass_limits */);
+        return result.m_result_type == MempoolAcceptResult::ResultType::VALID;
     };
 
     // Create a double-spend of mature coinbase txn:
     std::vector<CMutableTransaction> spends;
     spends.resize(2);
     for (int i = 0; i < 2; i++) {
         spends[i].nVersion = 1;
         spends[i].vin.resize(1);
         spends[i].vin[0].prevout = COutPoint(m_coinbase_txns[0]->GetId(), 0);
         spends[i].vout.resize(1);
         spends[i].vout[0].nValue = 11 * CENT;
         spends[i].vout[0].scriptPubKey = scriptPubKey;
 
         // Sign:
         std::vector<uint8_t> vchSig;
         uint256 hash = SignatureHash(scriptPubKey, CTransaction(spends[i]), 0,
                                      SigHashType().withForkId(),
                                      m_coinbase_txns[0]->vout[0].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(hash, vchSig));
         vchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         spends[i].vin[0].scriptSig << vchSig;
     }
 
     CBlock block;
 
     // Test 1: block with both of those transactions should be rejected.
     block = CreateAndProcessBlock(spends, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() !=
                     block.GetHash());
     }
 
     // Test 2: ... and should be rejected if spend1 is in the memory pool
     BOOST_CHECK(ToMemPool(spends[0]));
     block = CreateAndProcessBlock(spends, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() !=
                     block.GetHash());
     }
     m_node.mempool->clear();
 
     // Test 3: ... and should be rejected if spend2 is in the memory pool
     BOOST_CHECK(ToMemPool(spends[1]));
     block = CreateAndProcessBlock(spends, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() !=
                     block.GetHash());
     }
     m_node.mempool->clear();
 
     // Final sanity test: first spend in mempool, second in block, that's OK:
     std::vector<CMutableTransaction> oneSpend;
     oneSpend.push_back(spends[0]);
     BOOST_CHECK(ToMemPool(spends[1]));
     block = CreateAndProcessBlock(oneSpend, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() ==
                     block.GetHash());
     }
     // spends[1] should have been removed from the mempool when the block with
     // spends[0] is accepted:
     BOOST_CHECK_EQUAL(m_node.mempool->size(), 0U);
 }
 
 static inline bool
 CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                   const CCoinsViewCache &view, const uint32_t flags,
                   bool sigCacheStore, bool scriptCacheStore,
                   const PrecomputedTransactionData &txdata, int &nSigChecksOut,
                   std::vector<CScriptCheck> *pvChecks,
                   CheckInputsLimiter *pBlockLimitSigChecks = nullptr)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     // nSigChecksTxLimiter need to outlive this function call, because test
     // cases are using pvChecks, so the verification is done asynchronously.
     static TxSigCheckLimiter nSigChecksTxLimiter;
     nSigChecksTxLimiter = TxSigCheckLimiter();
     return CheckInputScripts(
         tx, state, view, flags, sigCacheStore, scriptCacheStore, txdata,
         nSigChecksOut, nSigChecksTxLimiter, pBlockLimitSigChecks, pvChecks);
 }
 
 // Run CheckInputScripts (using CoinsTip()) on the given transaction, for all
 // script flags. Test that CheckInputScripts passes for all flags that don't
 // overlap with the failing_flags argument, but otherwise fails.
 // CHECKLOCKTIMEVERIFY and CHECKSEQUENCEVERIFY (and future NOP codes that may
 // get reassigned) have an interaction with DISCOURAGE_UPGRADABLE_NOPS: if the
 // script flags used contain DISCOURAGE_UPGRADABLE_NOPS but don't contain
 // CHECKLOCKTIMEVERIFY (or CHECKSEQUENCEVERIFY), but the script does contain
 // OP_CHECKLOCKTIMEVERIFY (or OP_CHECKSEQUENCEVERIFY), then script execution
 // should fail.
 // Capture this interaction with the upgraded_nop argument: set it when
 // evaluating any script flag that is implemented as an upgraded NOP code.
 static void ValidateCheckInputsForAllFlags(
     const CTransaction &tx, uint32_t failing_flags, uint32_t required_flags,
     bool add_to_cache, CCoinsViewCache &active_coins_tip,
     int expected_sigchecks) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     PrecomputedTransactionData txdata(tx);
 
     MMIXLinearCongruentialGenerator lcg;
     for (int i = 0; i < 4096; i++) {
         uint32_t test_flags = lcg.next() | required_flags;
         TxValidationState state;
 
         // Filter out incompatible flag choices
         if ((test_flags & SCRIPT_VERIFY_CLEANSTACK)) {
             // CLEANSTACK requires P2SH, see VerifyScript() in
             // script/interpreter.cpp
             test_flags |= SCRIPT_VERIFY_P2SH;
         }
 
         int nSigChecksDirect = 0xf00d;
         bool ret =
             CheckInputScripts(tx, state, &active_coins_tip, test_flags, true,
                               add_to_cache, txdata, nSigChecksDirect);
 
         // CheckInputScripts should succeed iff test_flags doesn't intersect
         // with failing_flags
         bool expected_return_value = !(test_flags & failing_flags);
         BOOST_CHECK_EQUAL(ret, expected_return_value);
 
         if (ret) {
             BOOST_CHECK(nSigChecksDirect == expected_sigchecks);
         }
 
         // Test the caching
         if (ret && add_to_cache) {
             // Check that we get a cache hit if the tx was valid
             std::vector<CScriptCheck> scriptchecks;
             int nSigChecksCached = 0xbeef;
             BOOST_CHECK(CheckInputScripts(
                 tx, state, &active_coins_tip, test_flags, true, add_to_cache,
                 txdata, nSigChecksCached, &scriptchecks));
             BOOST_CHECK(nSigChecksCached == nSigChecksDirect);
             BOOST_CHECK(scriptchecks.empty());
         } else {
             // Check that we get script executions to check, if the transaction
             // was invalid, or we didn't add to cache.
             std::vector<CScriptCheck> scriptchecks;
             int nSigChecksUncached = 0xbabe;
             BOOST_CHECK(CheckInputScripts(
                 tx, state, &active_coins_tip, test_flags, true, add_to_cache,
                 txdata, nSigChecksUncached, &scriptchecks));
             BOOST_CHECK(!ret || nSigChecksUncached == 0);
             BOOST_CHECK_EQUAL(scriptchecks.size(), tx.vin.size());
         }
     }
 }
 
 BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup) {
     // Test that passing CheckInputScripts with one set of script flags doesn't
     // imply that we would pass again with a different set of flags.
     {
         LOCK(cs_main);
         InitScriptExecutionCache();
     }
 
     CScript p2pk_scriptPubKey =
         CScript() << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     CScript p2sh_scriptPubKey =
         GetScriptForDestination(ScriptHash(p2pk_scriptPubKey));
     CScript p2pkh_scriptPubKey =
         GetScriptForDestination(PKHash(coinbaseKey.GetPubKey()));
 
     FillableSigningProvider keystore;
     BOOST_CHECK(keystore.AddKey(coinbaseKey));
     BOOST_CHECK(keystore.AddCScript(p2pk_scriptPubKey));
 
     CMutableTransaction funding_tx;
     // Needed when spending the output of this transaction
     CScript noppyScriptPubKey;
     // Create a transaction output that can fail DISCOURAGE_UPGRADABLE_NOPS
     // checks when spent. This is for testing consensus vs non-standard rules in
     // `checkinputs_test`.
     {
         funding_tx.nVersion = 1;
         funding_tx.vin.resize(1);
         funding_tx.vin[0].prevout = COutPoint(m_coinbase_txns[0]->GetId(), 0);
         funding_tx.vout.resize(1);
         funding_tx.vout[0].nValue = 50 * COIN;
 
         noppyScriptPubKey << OP_IF << OP_NOP10 << OP_ENDIF << OP_1;
         funding_tx.vout[0].scriptPubKey = noppyScriptPubKey;
         std::vector<uint8_t> fundingVchSig;
         uint256 fundingSigHash = SignatureHash(
             p2pk_scriptPubKey, CTransaction(funding_tx), 0,
             SigHashType().withForkId(), m_coinbase_txns[0]->vout[0].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(fundingSigHash, fundingVchSig));
         fundingVchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         funding_tx.vin[0].scriptSig << fundingVchSig;
     }
 
     // Spend the funding transaction by mining it into a block
     {
         CBlock block = CreateAndProcessBlock({funding_tx}, p2pk_scriptPubKey);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() ==
                     block.GetHash());
         LOCK(cs_main);
         BOOST_CHECK(
             m_node.chainman->ActiveChainstate().CoinsTip().GetBestBlock() ==
             block.GetHash());
     }
 
     // flags to test: SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY,
     // SCRIPT_VERIFY_CHECKSEQUENCE_VERIFY,
     // SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS, uncompressed pubkey thing
 
     // Create 2 outputs that match the three scripts above, spending the first
     // coinbase tx.
     CMutableTransaction spend_tx;
     spend_tx.nVersion = 1;
     spend_tx.vin.resize(1);
     spend_tx.vin[0].prevout = COutPoint(funding_tx.GetId(), 0);
     spend_tx.vout.resize(4);
     spend_tx.vout[0].nValue = 11 * CENT;
     spend_tx.vout[0].scriptPubKey = p2sh_scriptPubKey;
     spend_tx.vout[1].nValue = 11 * CENT;
     spend_tx.vout[1].scriptPubKey =
         CScript() << OP_CHECKLOCKTIMEVERIFY << OP_DROP
                   << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     spend_tx.vout[2].nValue = 11 * CENT;
     spend_tx.vout[2].scriptPubKey =
         CScript() << OP_CHECKSEQUENCEVERIFY << OP_DROP
                   << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     spend_tx.vout[3].nValue = 11 * CENT;
     spend_tx.vout[3].scriptPubKey = p2sh_scriptPubKey;
 
     // "Sign" the main transaction that we spend from.
     {
         // This will cause OP_NOP10 to execute.
         spend_tx.vin[0].scriptSig << OP_1;
     }
 
     // Test that invalidity under a set of flags doesn't preclude validity under
     // other (eg consensus) flags.
     // spend_tx is invalid according to DISCOURAGE_UPGRADABLE_NOPS
     {
         const CTransaction tx(spend_tx);
 
         LOCK(cs_main);
 
         TxValidationState state;
         PrecomputedTransactionData ptd_spend_tx(tx);
         int nSigChecksDummy;
 
         BOOST_CHECK(!CheckInputScripts(
             tx, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, ptd_spend_tx,
             nSigChecksDummy, nullptr));
 
         // If we call again asking for scriptchecks (as happens in
         // ConnectBlock), we should add a script check object for this -- we're
         // not caching invalidity (if that changes, delete this test case).
         std::vector<CScriptCheck> scriptchecks;
         BOOST_CHECK(CheckInputScripts(
             tx, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, ptd_spend_tx,
             nSigChecksDummy, &scriptchecks));
         BOOST_CHECK_EQUAL(scriptchecks.size(), 1U);
 
         // Test that CheckInputScripts returns true iff cleanstack-enforcing
         // flags are not present. Don't add these checks to the cache, so that
         // we can test later that block validation works fine in the absence of
         // cached successes.
         ValidateCheckInputsForAllFlags(
             tx, SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS, 0, false,
             m_node.chainman->ActiveChainstate().CoinsTip(), 0);
     }
 
     // And if we produce a block with this tx, it should be valid, even though
     // there's no cache entry.
     CBlock block;
 
     block = CreateAndProcessBlock({spend_tx}, p2pk_scriptPubKey);
     LOCK(cs_main);
     BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() ==
                 block.GetHash());
     BOOST_CHECK(m_node.chainman->ActiveChainstate().CoinsTip().GetBestBlock() ==
                 block.GetHash());
 
     // Test P2SH: construct a transaction that is valid without P2SH, and then
     // test validity with P2SH.
     {
         CMutableTransaction invalid_under_p2sh_tx;
         invalid_under_p2sh_tx.nVersion = 1;
         invalid_under_p2sh_tx.vin.resize(1);
         invalid_under_p2sh_tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 0);
         invalid_under_p2sh_tx.vout.resize(1);
         invalid_under_p2sh_tx.vout[0].nValue = 11 * CENT;
         invalid_under_p2sh_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
         std::vector<uint8_t> vchSig2(p2pk_scriptPubKey.begin(),
                                      p2pk_scriptPubKey.end());
         invalid_under_p2sh_tx.vin[0].scriptSig << vchSig2;
 
         ValidateCheckInputsForAllFlags(
             CTransaction(invalid_under_p2sh_tx), SCRIPT_VERIFY_P2SH, 0, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 0);
     }
 
     // Test CHECKLOCKTIMEVERIFY
     {
         CMutableTransaction invalid_with_cltv_tx;
         invalid_with_cltv_tx.nVersion = 1;
         invalid_with_cltv_tx.nLockTime = 100;
         invalid_with_cltv_tx.vin.resize(1);
         invalid_with_cltv_tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 1);
         invalid_with_cltv_tx.vin[0].nSequence = 0;
         invalid_with_cltv_tx.vout.resize(1);
         invalid_with_cltv_tx.vout[0].nValue = 11 * CENT;
         invalid_with_cltv_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
         std::vector<uint8_t> vchSig;
         uint256 hash = SignatureHash(
             spend_tx.vout[1].scriptPubKey, CTransaction(invalid_with_cltv_tx),
             0, SigHashType().withForkId(), spend_tx.vout[1].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(hash, vchSig));
         vchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 101;
 
         ValidateCheckInputsForAllFlags(
             CTransaction(invalid_with_cltv_tx),
             SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY | SCRIPT_ENABLE_REPLAY_PROTECTION,
             SCRIPT_ENABLE_SIGHASH_FORKID, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 1);
 
         // Make it valid, and check again
         invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         TxValidationState state;
 
         CTransaction transaction(invalid_with_cltv_tx);
         PrecomputedTransactionData txdata(transaction);
 
         int nSigChecksRet;
         BOOST_CHECK(CheckInputScripts(
             transaction, state, m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, txdata, nSigChecksRet,
             nullptr));
         BOOST_CHECK(nSigChecksRet == 1);
     }
 
     // TEST CHECKSEQUENCEVERIFY
     {
         CMutableTransaction invalid_with_csv_tx;
         invalid_with_csv_tx.nVersion = 2;
         invalid_with_csv_tx.vin.resize(1);
         invalid_with_csv_tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 2);
         invalid_with_csv_tx.vin[0].nSequence = 100;
         invalid_with_csv_tx.vout.resize(1);
         invalid_with_csv_tx.vout[0].nValue = 11 * CENT;
         invalid_with_csv_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
         std::vector<uint8_t> vchSig;
         uint256 hash = SignatureHash(
             spend_tx.vout[2].scriptPubKey, CTransaction(invalid_with_csv_tx), 0,
             SigHashType().withForkId(), spend_tx.vout[2].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(hash, vchSig));
         vchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 101;
 
         ValidateCheckInputsForAllFlags(
             CTransaction(invalid_with_csv_tx),
             SCRIPT_VERIFY_CHECKSEQUENCEVERIFY | SCRIPT_ENABLE_REPLAY_PROTECTION,
             SCRIPT_ENABLE_SIGHASH_FORKID, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 1);
 
         // Make it valid, and check again
         invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         TxValidationState state;
 
         CTransaction transaction(invalid_with_csv_tx);
         PrecomputedTransactionData txdata(transaction);
 
         int nSigChecksRet;
         BOOST_CHECK(CheckInputScripts(
             transaction, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, txdata, nSigChecksRet,
             nullptr));
         BOOST_CHECK(nSigChecksRet == 1);
     }
 
     // TODO: add tests for remaining script flags
 
     {
         // Test a transaction with multiple inputs.
         CMutableTransaction tx;
 
         tx.nVersion = 1;
         tx.vin.resize(2);
         tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 0);
         tx.vin[1].prevout = COutPoint(spend_tx.GetId(), 3);
         tx.vout.resize(1);
         tx.vout[0].nValue = 22 * CENT;
         tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
         {
             SignatureData sigdata;
             BOOST_CHECK(ProduceSignature(
                 keystore,
                 MutableTransactionSignatureCreator(&tx, 0, 11 * CENT,
                                                    SigHashType().withForkId()),
                 spend_tx.vout[0].scriptPubKey, sigdata));
             UpdateInput(tx.vin[0], sigdata);
         }
         {
             SignatureData sigdata;
             BOOST_CHECK(ProduceSignature(
                 keystore,
                 MutableTransactionSignatureCreator(&tx, 1, 11 * CENT,
                                                    SigHashType().withForkId()),
                 spend_tx.vout[3].scriptPubKey, sigdata));
             UpdateInput(tx.vin[1], sigdata);
         }
 
         // This should be valid under all script flags that support our sighash
         // convention.
         ValidateCheckInputsForAllFlags(
             CTransaction(tx), SCRIPT_ENABLE_REPLAY_PROTECTION,
             SCRIPT_ENABLE_SIGHASH_FORKID | SCRIPT_VERIFY_P2SH, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 2);
 
         {
             // Try checking this valid transaction with sigchecks limiter
             // supplied. Each input consumes 1 sigcheck.
 
             TxValidationState state;
             CTransaction transaction(tx);
             PrecomputedTransactionData txdata(transaction);
             const uint32_t flags =
                 STANDARD_SCRIPT_VERIFY_FLAGS | SCRIPT_ENFORCE_SIGCHECKS;
             int nSigChecksDummy;
 
             /**
              * Parallel validation initially works (no cached value), but
              * evaluation of the script checks produces a failure.
              */
             std::vector<CScriptCheck> scriptchecks1;
             CheckInputsLimiter sigchecklimiter1(1);
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks1,
                 &sigchecklimiter1));
             // the first check passes but it did consume the limit.
             BOOST_CHECK(scriptchecks1[1]());
             BOOST_CHECK(sigchecklimiter1.check());
             // the second check (the first input) fails due to the limiter.
             BOOST_CHECK(!scriptchecks1[0]());
             BOOST_CHECK_EQUAL(scriptchecks1[0].GetScriptError(),
                               ScriptError::SIGCHECKS_LIMIT_EXCEEDED);
             BOOST_CHECK(!sigchecklimiter1.check());
 
             // Serial validation fails with the limiter.
             CheckInputsLimiter sigchecklimiter2(1);
             TxValidationState state2;
             BOOST_CHECK(!CheckInputScripts(
                 transaction, state2,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, nullptr, &sigchecklimiter2));
             BOOST_CHECK(!sigchecklimiter2.check());
             BOOST_CHECK_EQUAL(state2.GetRejectReason(),
                               "non-mandatory-script-verify-flag (Validation "
                               "resources exceeded (SigChecks))");
 
             /**
              * A slightly more permissive limiter (just enough) passes, and
              * allows caching the result.
              */
             std::vector<CScriptCheck> scriptchecks3;
             CheckInputsLimiter sigchecklimiter3(2);
             // first in parallel
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks3,
                 &sigchecklimiter3));
             BOOST_CHECK(scriptchecks3[1]());
             BOOST_CHECK(scriptchecks3[0]());
             BOOST_CHECK(sigchecklimiter3.check());
             // then in serial, caching the result.
             CheckInputsLimiter sigchecklimiter4(2);
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, nullptr, &sigchecklimiter4));
             BOOST_CHECK(sigchecklimiter4.check());
             // now in parallel again, grabbing the cached result.
             std::vector<CScriptCheck> scriptchecks5;
             CheckInputsLimiter sigchecklimiter5(2);
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks5,
                 &sigchecklimiter5));
             BOOST_CHECK(scriptchecks5.empty());
             BOOST_CHECK(sigchecklimiter5.check());
 
             /**
              * Going back to the lower limit, we now fail immediately due to the
              * caching.
              */
             CheckInputsLimiter sigchecklimiter6(1);
             TxValidationState state6;
             BOOST_CHECK(!CheckInputScripts(
                 transaction, state6,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, nullptr, &sigchecklimiter6));
             BOOST_CHECK_EQUAL(state6.GetRejectReason(), "too-many-sigchecks");
             BOOST_CHECK_EQUAL(state6.GetResult(),
                               TxValidationResult::TX_CONSENSUS);
             BOOST_CHECK(!sigchecklimiter6.check());
             // even in parallel validation, immediate fail from the cache.
             std::vector<CScriptCheck> scriptchecks7;
             CheckInputsLimiter sigchecklimiter7(1);
             TxValidationState state7;
             BOOST_CHECK(!CheckInputScripts(
                 transaction, state7,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks7,
                 &sigchecklimiter7));
             BOOST_CHECK_EQUAL(state7.GetRejectReason(), "too-many-sigchecks");
             BOOST_CHECK_EQUAL(state6.GetResult(),
                               TxValidationResult::TX_CONSENSUS);
             BOOST_CHECK(!sigchecklimiter7.check());
             BOOST_CHECK(scriptchecks7.empty());
         }
 
         // Check that if the second input is invalid, but the first input is
         // valid, the transaction is not cached.
         // Invalidate vin[1]
         tx.vin[1].scriptSig = CScript();
 
         TxValidationState state;
         CTransaction transaction(tx);
         PrecomputedTransactionData txdata(transaction);
 
         // This transaction is now invalid because the second signature is
         // missing.
         int nSigChecksDummy;
         BOOST_CHECK(!CheckInputScripts(
             transaction, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, txdata, nSigChecksDummy,
             nullptr));
 
         // Make sure this transaction was not cached (ie becausethe first input
         // was valid)
         std::vector<CScriptCheck> scriptchecks;
         BOOST_CHECK(CheckInputScripts(
             transaction, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS | SCRIPT_ENFORCE_SIGCHECKS, true, true,
             txdata, nSigChecksDummy, &scriptchecks));
         // Should get 2 script checks back -- caching is on a whole-transaction
         // basis.
         BOOST_CHECK_EQUAL(scriptchecks.size(), 2U);
 
         // Execute the first check, and check its result
         BOOST_CHECK(scriptchecks[0]());
         BOOST_CHECK_EQUAL(scriptchecks[0].GetScriptError(), ScriptError::OK);
         BOOST_CHECK_EQUAL(
             scriptchecks[0].GetScriptExecutionMetrics().nSigChecks, 1);
         // The second check does fail
         BOOST_CHECK(!scriptchecks[1]());
         BOOST_CHECK_EQUAL(scriptchecks[1].GetScriptError(),
                           ScriptError::INVALID_STACK_OPERATION);
     }
 }
 
 BOOST_AUTO_TEST_CASE(scriptcache_values) {
     LOCK(cs_main);
     // Test insertion and querying of keys&values from the script cache.
 
     // Define a couple of macros (handier than functions since errors will print
     // out the correct line number)
 #define CHECK_CACHE_HAS(key, expected_sigchecks)                               \
     {                                                                          \
         int nSigChecksRet(0x12345678 ^ (expected_sigchecks));                  \
         BOOST_CHECK(IsKeyInScriptCache(key, false, nSigChecksRet));            \
         BOOST_CHECK(nSigChecksRet == (expected_sigchecks));                    \
     }
 #define CHECK_CACHE_MISSING(key)                                               \
     {                                                                          \
         int dummy;                                                             \
         BOOST_CHECK(!IsKeyInScriptCache(key, false, dummy));                   \
     }
 
     InitScriptExecutionCache();
 
     // construct four distinct keys from very slightly different data
     CMutableTransaction tx1;
     tx1.nVersion = 1;
     CMutableTransaction tx2;
     tx2.nVersion = 2;
     uint32_t flagsA = 0x7fffffff;
     uint32_t flagsB = 0xffffffff;
     ScriptCacheKey key1A(CTransaction(tx1), flagsA);
     ScriptCacheKey key1B(CTransaction(tx1), flagsB);
     ScriptCacheKey key2A(CTransaction(tx2), flagsA);
     ScriptCacheKey key2B(CTransaction(tx2), flagsB);
 
     BOOST_CHECK(key1A == key1A);
     BOOST_CHECK(!(key1A == key1B));
     BOOST_CHECK(!(key1A == key2A));
     BOOST_CHECK(!(key1A == key2B));
     BOOST_CHECK(key1B == key1B);
     BOOST_CHECK(!(key1B == key2A));
     BOOST_CHECK(!(key1B == key2B));
     BOOST_CHECK(key2A == key2A);
     BOOST_CHECK(!(key2A == key2B));
     BOOST_CHECK(key2B == key2B);
 
     // Key is not yet inserted.
     CHECK_CACHE_MISSING(key1A);
     // Add the key and check it worked
     AddKeyInScriptCache(key1A, 42);
     CHECK_CACHE_HAS(key1A, 42);
 
     CHECK_CACHE_MISSING(key1B);
     CHECK_CACHE_MISSING(key2A);
     CHECK_CACHE_MISSING(key2B);
 
     // 0 may be stored
     AddKeyInScriptCache(key1B, 0);
 
     // Calculate the most possible transaction sigchecks that can occur in a
     // standard transaction, and make sure the cache can hold it.
     //
     // To be pessimistic, use consensus (MAX_TX_SIZE) instead of policy
     // (MAX_STANDARD_TX_SIZE) since that particular policy limit is bypassed on
     // testnet.
     //
     // Assume that a standardness rule limiting density to ~33 bytes/sigcheck is
     // in place.
     const int max_standard_sigchecks = 1 + (MAX_TX_SIZE / 33);
     AddKeyInScriptCache(key2A, max_standard_sigchecks);
 
     // Read out values again.
     CHECK_CACHE_HAS(key1A, 42);
     CHECK_CACHE_HAS(key1B, 0);
     CHECK_CACHE_HAS(key2A, max_standard_sigchecks);
     CHECK_CACHE_MISSING(key2B);
 
     // Try overwriting an existing entry with different value (should never
     // happen in practice but see what happens).
     AddKeyInScriptCache(key1A, 99);
     // This succeeds without error, but (currently) no replacement is done.
     // It would also be acceptable to overwrite, but if we ever come to a
     // situation where this matters then neither alternative is better.
     CHECK_CACHE_HAS(key1A, 42);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/validation_block_tests.cpp b/src/test/validation_block_tests.cpp
index 5bc230c1e..5befd8870 100644
--- a/src/test/validation_block_tests.cpp
+++ b/src/test/validation_block_tests.cpp
@@ -1,390 +1,392 @@
 // Copyright (c) 2018-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <boost/test/unit_test.hpp>
 
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/merkle.h>
 #include <consensus/validation.h>
 #include <miner.h>
 #include <pow/pow.h>
 #include <random.h>
 #include <script/standard.h>
 #include <test/util/setup_common.h>
 #include <util/time.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 #include <thread>
 
 namespace validation_block_tests {
 struct MinerTestingSetup : public RegTestingSetup {
     std::shared_ptr<CBlock> Block(const Config &config,
                                   const BlockHash &prev_hash);
     std::shared_ptr<const CBlock> GoodBlock(const Config &config,
                                             const BlockHash &prev_hash);
     std::shared_ptr<const CBlock> BadBlock(const Config &config,
                                            const BlockHash &prev_hash);
     std::shared_ptr<CBlock> FinalizeBlock(const Consensus::Params &params,
                                           std::shared_ptr<CBlock> pblock);
     void BuildChain(const Config &config, const BlockHash &root, int height,
                     const unsigned int invalid_rate,
                     const unsigned int branch_rate, const unsigned int max_size,
                     std::vector<std::shared_ptr<const CBlock>> &blocks);
 };
 } // namespace validation_block_tests
 
 BOOST_FIXTURE_TEST_SUITE(validation_block_tests, MinerTestingSetup)
 
 struct TestSubscriber final : public CValidationInterface {
     uint256 m_expected_tip;
 
     explicit TestSubscriber(uint256 tip) : m_expected_tip(tip) {}
 
     void UpdatedBlockTip(const CBlockIndex *pindexNew,
                          const CBlockIndex *pindexFork,
                          bool fInitialDownload) override {
         BOOST_CHECK_EQUAL(m_expected_tip, pindexNew->GetBlockHash());
     }
 
     void BlockConnected(const std::shared_ptr<const CBlock> &block,
                         const CBlockIndex *pindex) override {
         BOOST_CHECK_EQUAL(m_expected_tip, block->hashPrevBlock);
         BOOST_CHECK_EQUAL(m_expected_tip, pindex->pprev->GetBlockHash());
 
         m_expected_tip = block->GetHash();
     }
 
     void BlockDisconnected(const std::shared_ptr<const CBlock> &block,
                            const CBlockIndex *pindex) override {
         BOOST_CHECK_EQUAL(m_expected_tip, block->GetHash());
         BOOST_CHECK_EQUAL(m_expected_tip, pindex->GetBlockHash());
 
         m_expected_tip = block->hashPrevBlock;
     }
 };
 
 std::shared_ptr<CBlock> MinerTestingSetup::Block(const Config &config,
                                                  const BlockHash &prev_hash) {
     static int i = 0;
     static uint64_t time = config.GetChainParams().GenesisBlock().nTime;
 
     CScript pubKey;
     pubKey << i++ << OP_TRUE;
 
     auto ptemplate = BlockAssembler(config, m_node.chainman->ActiveChainstate(),
                                     *m_node.mempool)
                          .CreateNewBlock(pubKey);
     auto pblock = std::make_shared<CBlock>(ptemplate->block);
     pblock->hashPrevBlock = prev_hash;
     pblock->nTime = ++time;
 
     pubKey.clear();
     {
         pubKey << OP_HASH160 << ToByteVector(CScriptID(CScript() << OP_TRUE))
                << OP_EQUAL;
     }
     // Make the coinbase transaction with two outputs:
     // One zero-value one that has a unique pubkey to make sure that blocks at
     // the same height can have a different hash. Another one that has the
     // coinbase reward in a P2SH with OP_TRUE as scriptPubKey to make it easy to
     // spend
     CMutableTransaction txCoinbase(*pblock->vtx[0]);
     txCoinbase.vout.resize(2);
     txCoinbase.vout[1].scriptPubKey = pubKey;
     txCoinbase.vout[1].nValue = txCoinbase.vout[0].nValue;
     txCoinbase.vout[0].nValue = Amount::zero();
     pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
 
     return pblock;
 }
 
 std::shared_ptr<CBlock>
 MinerTestingSetup::FinalizeBlock(const Consensus::Params &params,
                                  std::shared_ptr<CBlock> pblock) {
     pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
 
     while (!CheckProofOfWork(pblock->GetHash(), pblock->nBits, params)) {
         ++(pblock->nNonce);
     }
 
     return pblock;
 }
 
 // construct a valid block
 std::shared_ptr<const CBlock>
 MinerTestingSetup::GoodBlock(const Config &config, const BlockHash &prev_hash) {
     return FinalizeBlock(config.GetChainParams().GetConsensus(),
                          Block(config, prev_hash));
 }
 
 // construct an invalid block (but with a valid header)
 std::shared_ptr<const CBlock>
 MinerTestingSetup::BadBlock(const Config &config, const BlockHash &prev_hash) {
     auto pblock = Block(config, prev_hash);
 
     CMutableTransaction coinbase_spend;
     coinbase_spend.vin.push_back(
         CTxIn(COutPoint(pblock->vtx[0]->GetId(), 0), CScript(), 0));
     coinbase_spend.vout.push_back(pblock->vtx[0]->vout[0]);
 
     CTransactionRef tx = MakeTransactionRef(coinbase_spend);
     pblock->vtx.push_back(tx);
 
     auto ret = FinalizeBlock(config.GetChainParams().GetConsensus(), pblock);
     return ret;
 }
 
 void MinerTestingSetup::BuildChain(
     const Config &config, const BlockHash &root, int height,
     const unsigned int invalid_rate, const unsigned int branch_rate,
     const unsigned int max_size,
     std::vector<std::shared_ptr<const CBlock>> &blocks) {
     if (height <= 0 || blocks.size() >= max_size) {
         return;
     }
 
     bool gen_invalid = InsecureRandRange(100) < invalid_rate;
     bool gen_fork = InsecureRandRange(100) < branch_rate;
 
     const std::shared_ptr<const CBlock> pblock =
         gen_invalid ? BadBlock(config, root) : GoodBlock(config, root);
     blocks.push_back(pblock);
     if (!gen_invalid) {
         BuildChain(config, pblock->GetHash(), height - 1, invalid_rate,
                    branch_rate, max_size, blocks);
     }
 
     if (gen_fork) {
         blocks.push_back(GoodBlock(config, root));
         BuildChain(config, blocks.back()->GetHash(), height - 1, invalid_rate,
                    branch_rate, max_size, blocks);
     }
 }
 
 BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering) {
     GlobalConfig config;
     const CChainParams &chainParams = config.GetChainParams();
 
     // build a large-ish chain that's likely to have some forks
     std::vector<std::shared_ptr<const CBlock>> blocks;
     while (blocks.size() < 50) {
         blocks.clear();
         BuildChain(config, chainParams.GenesisBlock().GetHash(), 100, 15, 10,
                    500, blocks);
     }
 
     bool ignored;
     BlockValidationState state;
     std::vector<CBlockHeader> headers;
     std::transform(
         blocks.begin(), blocks.end(), std::back_inserter(headers),
         [](std::shared_ptr<const CBlock> b) { return b->GetBlockHeader(); });
 
     // Process all the headers so we understand the toplogy of the chain
     BOOST_CHECK(Assert(m_node.chainman)
                     ->ProcessNewBlockHeaders(config, headers, state));
 
     // Connect the genesis block and drain any outstanding events
     BOOST_CHECK(Assert(m_node.chainman)
                     ->ProcessNewBlock(
                         config,
                         std::make_shared<CBlock>(chainParams.GenesisBlock()),
                         true, &ignored));
     SyncWithValidationInterfaceQueue();
 
     // subscribe to events (this subscriber will validate event ordering)
     const CBlockIndex *initial_tip = nullptr;
     {
         LOCK(cs_main);
         initial_tip = m_node.chainman->ActiveTip();
     }
     auto sub = std::make_shared<TestSubscriber>(initial_tip->GetBlockHash());
     RegisterSharedValidationInterface(sub);
 
     // create a bunch of threads that repeatedly process a block generated above
     // at random this will create parallelism and randomness inside validation -
     // the ValidationInterface will subscribe to events generated during block
     // validation and assert on ordering invariance
     std::vector<std::thread> threads;
     for (int i = 0; i < 10; i++) {
         threads.emplace_back([&]() {
             bool tlignored;
             FastRandomContext insecure;
             for (int j = 0; j < 1000; j++) {
                 auto block = blocks[insecure.randrange(blocks.size() - 1)];
                 Assert(m_node.chainman)
                     ->ProcessNewBlock(config, block, true, &tlignored);
             }
 
             // to make sure that eventually we process the full chain - do it
             // here
             for (auto block : blocks) {
                 if (block->vtx.size() == 1) {
                     bool processed =
                         Assert(m_node.chainman)
                             ->ProcessNewBlock(config, block, true, &tlignored);
                     assert(processed);
                 }
             }
         });
     }
 
     for (auto &t : threads) {
         t.join();
     }
     SyncWithValidationInterfaceQueue();
 
     UnregisterSharedValidationInterface(sub);
 
     LOCK(cs_main);
     BOOST_CHECK_EQUAL(sub->m_expected_tip,
                       m_node.chainman->ActiveTip()->GetBlockHash());
 }
 
 /**
  * Test that mempool updates happen atomically with reorgs.
  *
  * This prevents RPC clients, among others, from retrieving
  * immediately-out-of-date mempool data during large reorgs.
  *
  * The test verifies this by creating a chain of `num_txs` blocks, matures their
  * coinbases, and then submits txns spending from their coinbase to the mempool.
  * A fork chain is then processed, invalidating the txns and evicting them from
  * the mempool.
  *
  * We verify that the mempool updates atomically by polling it continuously
  * from another thread during the reorg and checking that its size only changes
  * once. The size changing exactly once indicates that the polling thread's
  * view of the mempool is either consistent with the chain state before reorg,
  * or consistent with the chain state after the reorg, and not just consistent
  * with some intermediate state during the reorg.
  */
 BOOST_AUTO_TEST_CASE(mempool_locks_reorg) {
     GlobalConfig config;
     const CChainParams &chainParams = config.GetChainParams();
 
     bool ignored;
     auto ProcessBlock = [&](std::shared_ptr<const CBlock> block) -> bool {
         return Assert(m_node.chainman)
             ->ProcessNewBlock(config, block, /* fForceProcessing */ true,
                               /* fNewBlock */ &ignored);
     };
 
     // Process all mined blocks
     BOOST_REQUIRE(
         ProcessBlock(std::make_shared<CBlock>(chainParams.GenesisBlock())));
     auto last_mined = GoodBlock(config, chainParams.GenesisBlock().GetHash());
     BOOST_REQUIRE(ProcessBlock(last_mined));
 
     // Run the test multiple times
     for (int test_runs = 3; test_runs > 0; --test_runs) {
         BOOST_CHECK_EQUAL(last_mined->GetHash(),
                           m_node.chainman->ActiveTip()->GetBlockHash());
 
         // Later on split from here
         const BlockHash split_hash{last_mined->hashPrevBlock};
 
         // Create a bunch of transactions to spend the miner rewards of the
         // most recent blocks
         std::vector<CTransactionRef> txs;
         for (int num_txs = 22; num_txs > 0; --num_txs) {
             CMutableTransaction mtx;
             mtx.vin.push_back(
                 CTxIn(COutPoint(last_mined->vtx[0]->GetId(), 1),
                       CScript() << ToByteVector(CScript() << OP_TRUE)));
             // Two outputs to make sure the transaction is larger than 100 bytes
             for (int i = 1; i < 3; ++i) {
                 mtx.vout.emplace_back(
                     CTxOut(50000 * SATOSHI,
                            CScript() << OP_DUP << OP_HASH160
                                      << ToByteVector(CScriptID(CScript() << i))
                                      << OP_EQUALVERIFY << OP_CHECKSIG));
             }
             txs.push_back(MakeTransactionRef(mtx));
             last_mined = GoodBlock(config, last_mined->GetHash());
             BOOST_REQUIRE(ProcessBlock(last_mined));
         }
 
         // Mature the inputs of the txs
         for (int j = COINBASE_MATURITY; j > 0; --j) {
             last_mined = GoodBlock(config, last_mined->GetHash());
             BOOST_REQUIRE(ProcessBlock(last_mined));
         }
 
         // Mine a reorg (and hold it back) before adding the txs to the mempool
         const BlockHash tip_init{last_mined->GetHash()};
 
         std::vector<std::shared_ptr<const CBlock>> reorg;
         last_mined = GoodBlock(config, split_hash);
         reorg.push_back(last_mined);
         for (size_t j = COINBASE_MATURITY + txs.size() + 1; j > 0; --j) {
             last_mined = GoodBlock(config, last_mined->GetHash());
             reorg.push_back(last_mined);
         }
 
         // Add the txs to the tx pool
         {
             LOCK(cs_main);
-            TxValidationState state;
             for (const auto &tx : txs) {
-                BOOST_REQUIRE_MESSAGE(
+                const MempoolAcceptResult result =
                     AcceptToMemoryPool(m_node.chainman->ActiveChainstate(),
-                                       config, *m_node.mempool, state, tx,
-                                       /* bypass_limits */ false),
-                    state.GetRejectReason());
+                                       config, *m_node.mempool, tx,
+                                       /* bypass_limits */ false);
+                BOOST_REQUIRE_MESSAGE(
+                    result.m_result_type ==
+                        MempoolAcceptResult::ResultType::VALID,
+                    result.m_state.GetRejectReason());
             }
         }
 
         // Check that all txs are in the pool
         {
             LOCK(m_node.mempool->cs);
             BOOST_CHECK_EQUAL(m_node.mempool->mapTx.size(), txs.size());
         }
 
         // Run a thread that simulates an RPC caller that is polling while
         // validation is doing a reorg
         std::thread rpc_thread{[&]() {
             // This thread is checking that the mempool either contains all of
             // the transactions invalidated by the reorg, or none of them, and
             // not some intermediate amount.
             while (true) {
                 LOCK(m_node.mempool->cs);
                 if (m_node.mempool->mapTx.size() == 0) {
                     // We are done with the reorg
                     break;
                 }
                 // Internally, we might be in the middle of the reorg, but
                 // externally the reorg to the most-proof-of-work chain should
                 // be atomic. So the caller assumes that the returned mempool
                 // is consistent. That is, it has all txs that were there
                 // before the reorg.
                 assert(m_node.mempool->mapTx.size() == txs.size());
                 continue;
             }
             LOCK(cs_main);
             // We are done with the reorg, so the tip must have changed
             assert(tip_init != m_node.chainman->ActiveTip()->GetBlockHash());
         }};
 
         // Make sure we disable reorg protection.
         gArgs.ForceSetArg("-parkdeepreorg", "false");
 
         // Submit the reorg in this thread to invalidate and remove the txs from
         // the tx pool
         for (const auto &b : reorg) {
             ProcessBlock(b);
         }
         // Check that the reorg was eventually successful
         BOOST_CHECK_EQUAL(last_mined->GetHash(),
                           m_node.chainman->ActiveTip()->GetBlockHash());
 
         // We can join the other thread, which returns when the reorg was
         // successful
         rpc_thread.join();
     }
 }
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 4badc0fb6..96b5af021 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -1,1447 +1,1447 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <txmempool.h>
 
 #include <chain.h>
 #include <chainparams.h> // for GetConsensus.
 #include <clientversion.h>
 #include <config.h>
 #include <consensus/consensus.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
 #include <reverse_iterator.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <validation.h>
 #include <validationinterface.h>
 #include <version.h>
 
 #include <algorithm>
 
 CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef &_tx, const Amount _nFee,
                                  int64_t _nTime, unsigned int _entryHeight,
                                  bool _spendsCoinbase, int64_t _sigOpsCount,
                                  LockPoints lp)
     : tx(_tx), nFee(_nFee), nTxSize(tx->GetTotalSize()),
       nUsageSize(RecursiveDynamicUsage(tx)), nTime(_nTime),
       entryHeight(_entryHeight), spendsCoinbase(_spendsCoinbase),
       sigOpCount(_sigOpsCount), lockPoints(lp) {
     nCountWithDescendants = 1;
     nSizeWithDescendants = GetTxSize();
     nSigOpCountWithDescendants = sigOpCount;
     nModFeesWithDescendants = nFee;
 
     feeDelta = Amount::zero();
 
     nCountWithAncestors = 1;
     nSizeWithAncestors = GetTxSize();
     nModFeesWithAncestors = nFee;
     nSigOpCountWithAncestors = sigOpCount;
 }
 
 size_t CTxMemPoolEntry::GetTxVirtualSize() const {
     return GetVirtualTransactionSize(nTxSize, sigOpCount);
 }
 
 uint64_t CTxMemPoolEntry::GetVirtualSizeWithDescendants() const {
     // note this is distinct from the sum of descendants' individual virtual
     // sizes, and may be smaller.
     return GetVirtualTransactionSize(nSizeWithDescendants,
                                      nSigOpCountWithDescendants);
 }
 
 uint64_t CTxMemPoolEntry::GetVirtualSizeWithAncestors() const {
     // note this is distinct from the sum of ancestors' individual virtual
     // sizes, and may be smaller.
     return GetVirtualTransactionSize(nSizeWithAncestors,
                                      nSigOpCountWithAncestors);
 }
 
 void CTxMemPoolEntry::UpdateFeeDelta(Amount newFeeDelta) {
     nModFeesWithDescendants += newFeeDelta - feeDelta;
     nModFeesWithAncestors += newFeeDelta - feeDelta;
     feeDelta = newFeeDelta;
 }
 
 void CTxMemPoolEntry::UpdateLockPoints(const LockPoints &lp) {
     lockPoints = lp;
 }
 
 // Update the given tx for any in-mempool descendants.
 // Assumes that CTxMemPool::m_children is correct for the given tx and all
 // descendants.
 void CTxMemPool::UpdateForDescendants(txiter updateIt,
                                       cacheMap &cachedDescendants,
                                       const std::set<TxId> &setExclude) {
     CTxMemPoolEntry::Children stageEntries, descendants;
     stageEntries = updateIt->GetMemPoolChildrenConst();
 
     while (!stageEntries.empty()) {
         const CTxMemPoolEntry &descendant = *stageEntries.begin();
         descendants.insert(descendant);
         stageEntries.erase(descendant);
         const CTxMemPoolEntry::Children &children =
             descendant.GetMemPoolChildrenConst();
         for (const CTxMemPoolEntry &childEntry : children) {
             cacheMap::iterator cacheIt =
                 cachedDescendants.find(mapTx.iterator_to(childEntry));
             if (cacheIt != cachedDescendants.end()) {
                 // We've already calculated this one, just add the entries for
                 // this set but don't traverse again.
                 for (txiter cacheEntry : cacheIt->second) {
                     descendants.insert(*cacheEntry);
                 }
             } else if (!descendants.count(childEntry)) {
                 // Schedule for later processing
                 stageEntries.insert(childEntry);
             }
         }
     }
     // descendants now contains all in-mempool descendants of updateIt.
     // Update and add to cached descendant map
     int64_t modifySize = 0;
     int64_t modifyCount = 0;
     Amount modifyFee = Amount::zero();
     int64_t modifySigOpCount = 0;
     for (const CTxMemPoolEntry &descendant : descendants) {
         if (!setExclude.count(descendant.GetTx().GetId())) {
             modifySize += descendant.GetTxSize();
             modifyFee += descendant.GetModifiedFee();
             modifyCount++;
             modifySigOpCount += descendant.GetSigOpCount();
             cachedDescendants[updateIt].insert(mapTx.iterator_to(descendant));
             // Update ancestor state for each descendant
             mapTx.modify(mapTx.iterator_to(descendant),
                          update_ancestor_state(updateIt->GetTxSize(),
                                                updateIt->GetModifiedFee(), 1,
                                                updateIt->GetSigOpCount()));
         }
     }
     mapTx.modify(updateIt,
                  update_descendant_state(modifySize, modifyFee, modifyCount,
                                          modifySigOpCount));
 }
 
 // txidsToUpdate is the set of transaction hashes from a disconnected block
 // which has been re-added to the mempool. For each entry, look for descendants
 // that are outside txidsToUpdate, and add fee/size information for such
 // descendants to the parent. For each such descendant, also update the ancestor
 // state to include the parent.
 void CTxMemPool::UpdateTransactionsFromBlock(
     const std::vector<TxId> &txidsToUpdate) {
     AssertLockHeld(cs);
     // For each entry in txidsToUpdate, store the set of in-mempool, but not
     // in-txidsToUpdate transactions, so that we don't have to recalculate
     // descendants when we come across a previously seen entry.
     cacheMap mapMemPoolDescendantsToUpdate;
 
     // Use a set for lookups into txidsToUpdate (these entries are already
     // accounted for in the state of their ancestors)
     std::set<TxId> setAlreadyIncluded(txidsToUpdate.begin(),
                                       txidsToUpdate.end());
 
     // Iterate in reverse, so that whenever we are looking at a transaction
     // we are sure that all in-mempool descendants have already been processed.
     // This maximizes the benefit of the descendant cache and guarantees that
     // CTxMemPool::m_children will be updated, an assumption made in
     // UpdateForDescendants.
     for (const TxId &txid : reverse_iterate(txidsToUpdate)) {
         // calculate children from mapNextTx
         txiter it = mapTx.find(txid);
         if (it == mapTx.end()) {
             continue;
         }
 
         auto iter = mapNextTx.lower_bound(COutPoint(txid, 0));
         // First calculate the children, and update CTxMemPool::m_children to
         // include them, and update their CTxMemPoolEntry::m_parents to include
         // this tx. we cache the in-mempool children to avoid duplicate updates
         {
             WITH_FRESH_EPOCH(m_epoch);
             for (; iter != mapNextTx.end() && iter->first->GetTxId() == txid;
                  ++iter) {
                 const TxId &childTxId = iter->second->GetId();
                 txiter childIter = mapTx.find(childTxId);
                 assert(childIter != mapTx.end());
                 // We can skip updating entries we've encountered before or that
                 // are in the block (which are already accounted for).
                 if (!visited(childIter) &&
                     !setAlreadyIncluded.count(childTxId)) {
                     UpdateChild(it, childIter, true);
                     UpdateParent(childIter, it, true);
                 }
             }
         } // release epoch guard for UpdateForDescendants
         UpdateForDescendants(it, mapMemPoolDescendantsToUpdate,
                              setAlreadyIncluded);
     }
 }
 
 bool CTxMemPool::CalculateMemPoolAncestors(
     const CTxMemPoolEntry &entry, setEntries &setAncestors,
     uint64_t limitAncestorCount, uint64_t limitAncestorSize,
     uint64_t limitDescendantCount, uint64_t limitDescendantSize,
     std::string &errString, bool fSearchForParents /* = true */) const {
     CTxMemPoolEntry::Parents staged_ancestors;
     const CTransaction &tx = entry.GetTx();
 
     if (fSearchForParents) {
         // Get parents of this transaction that are in the mempool
         // GetMemPoolParents() is only valid for entries in the mempool, so we
         // iterate mapTx to find parents.
         for (const CTxIn &in : tx.vin) {
             std::optional<txiter> piter = GetIter(in.prevout.GetTxId());
             if (!piter) {
                 continue;
             }
             staged_ancestors.insert(**piter);
             if (staged_ancestors.size() + 1 > limitAncestorCount) {
                 errString =
                     strprintf("too many unconfirmed parents [limit: %u]",
                               limitAncestorCount);
                 return false;
             }
         }
     } else {
         // If we're not searching for parents, we require this to be an entry in
         // the mempool already.
         txiter it = mapTx.iterator_to(entry);
         staged_ancestors = it->GetMemPoolParentsConst();
     }
 
     size_t totalSizeWithAncestors = entry.GetTxSize();
 
     while (!staged_ancestors.empty()) {
         const CTxMemPoolEntry &stage = staged_ancestors.begin()->get();
         txiter stageit = mapTx.iterator_to(stage);
 
         setAncestors.insert(stageit);
         staged_ancestors.erase(stage);
         totalSizeWithAncestors += stageit->GetTxSize();
 
         if (stageit->GetSizeWithDescendants() + entry.GetTxSize() >
             limitDescendantSize) {
             errString = strprintf(
                 "exceeds descendant size limit for tx %s [limit: %u]",
                 stageit->GetTx().GetId().ToString(), limitDescendantSize);
             return false;
         }
 
         if (stageit->GetCountWithDescendants() + 1 > limitDescendantCount) {
             errString = strprintf("too many descendants for tx %s [limit: %u]",
                                   stageit->GetTx().GetId().ToString(),
                                   limitDescendantCount);
             return false;
         }
 
         if (totalSizeWithAncestors > limitAncestorSize) {
             errString = strprintf("exceeds ancestor size limit [limit: %u]",
                                   limitAncestorSize);
             return false;
         }
 
         const CTxMemPoolEntry::Parents &parents =
             stageit->GetMemPoolParentsConst();
         for (const CTxMemPoolEntry &parent : parents) {
             txiter parent_it = mapTx.iterator_to(parent);
 
             // If this is a new ancestor, add it.
             if (setAncestors.count(parent_it) == 0) {
                 staged_ancestors.insert(parent);
             }
             if (staged_ancestors.size() + setAncestors.size() + 1 >
                 limitAncestorCount) {
                 errString =
                     strprintf("too many unconfirmed ancestors [limit: %u]",
                               limitAncestorCount);
                 return false;
             }
         }
     }
 
     return true;
 }
 
 void CTxMemPool::UpdateAncestorsOf(bool add, txiter it,
                                    setEntries &setAncestors) {
     CTxMemPoolEntry::Parents parents = it->GetMemPoolParents();
     // add or remove this tx as a child of each parent
     for (const CTxMemPoolEntry &parent : parents) {
         UpdateChild(mapTx.iterator_to(parent), it, add);
     }
     const int64_t updateCount = (add ? 1 : -1);
     const int64_t updateSize = updateCount * it->GetTxSize();
     const int64_t updateSigOpCount = updateCount * it->GetSigOpCount();
     const Amount updateFee = updateCount * it->GetModifiedFee();
     for (txiter ancestorIt : setAncestors) {
         mapTx.modify(ancestorIt,
                      update_descendant_state(updateSize, updateFee, updateCount,
                                              updateSigOpCount));
     }
 }
 
 void CTxMemPool::UpdateEntryForAncestors(txiter it,
                                          const setEntries &setAncestors) {
     int64_t updateCount = setAncestors.size();
     int64_t updateSize = 0;
     int64_t updateSigOpsCount = 0;
     Amount updateFee = Amount::zero();
 
     for (txiter ancestorIt : setAncestors) {
         updateSize += ancestorIt->GetTxSize();
         updateFee += ancestorIt->GetModifiedFee();
         updateSigOpsCount += ancestorIt->GetSigOpCount();
     }
     mapTx.modify(it, update_ancestor_state(updateSize, updateFee, updateCount,
                                            updateSigOpsCount));
 }
 
 void CTxMemPool::UpdateChildrenForRemoval(txiter it) {
     const CTxMemPoolEntry::Children &children = it->GetMemPoolChildrenConst();
     for (const CTxMemPoolEntry &updateIt : children) {
         UpdateParent(mapTx.iterator_to(updateIt), it, false);
     }
 }
 
 void CTxMemPool::UpdateForRemoveFromMempool(const setEntries &entriesToRemove,
                                             bool updateDescendants) {
     // For each entry, walk back all ancestors and decrement size associated
     // with this transaction.
     const uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
     if (updateDescendants) {
         // updateDescendants should be true whenever we're not recursively
         // removing a tx and all its descendants, eg when a transaction is
         // confirmed in a block.
         // Here we only update statistics and not data in CTxMemPool::Parents
         // and CTxMemPoolEntry::Children (which we need to preserve until we're
         // finished with all operations that need to traverse the mempool).
         for (txiter removeIt : entriesToRemove) {
             setEntries setDescendants;
             CalculateDescendants(removeIt, setDescendants);
             setDescendants.erase(removeIt); // don't update state for self
             int64_t modifySize = -int64_t(removeIt->GetTxSize());
             Amount modifyFee = -1 * removeIt->GetModifiedFee();
             int modifySigOps = -removeIt->GetSigOpCount();
             for (txiter dit : setDescendants) {
                 mapTx.modify(dit, update_ancestor_state(modifySize, modifyFee,
                                                         -1, modifySigOps));
             }
         }
     }
 
     for (txiter removeIt : entriesToRemove) {
         setEntries setAncestors;
         const CTxMemPoolEntry &entry = *removeIt;
         std::string dummy;
         // Since this is a tx that is already in the mempool, we can call CMPA
         // with fSearchForParents = false.  If the mempool is in a consistent
         // state, then using true or false should both be correct, though false
         // should be a bit faster.
         // However, if we happen to be in the middle of processing a reorg, then
         // the mempool can be in an inconsistent state.  In this case, the set
         // of ancestors reachable via GetMemPoolParents()/GetMemPoolChildren()
         // will be the same as the set of ancestors whose packages include this
         // transaction, because when we add a new transaction to the mempool in
         // addUnchecked(), we assume it has no children, and in the case of a
         // reorg where that assumption is false, the in-mempool children aren't
         // linked to the in-block tx's until UpdateTransactionsFromBlock() is
         // called.
         // So if we're being called during a reorg, ie before
         // UpdateTransactionsFromBlock() has been called, then
         // GetMemPoolParents()/GetMemPoolChildren() will differ from the set of
         // mempool parents we'd calculate by searching, and it's important that
         // we use the cached notion of ancestor transactions as the set of
         // things to update for removal.
         CalculateMemPoolAncestors(entry, setAncestors, nNoLimit, nNoLimit,
                                   nNoLimit, nNoLimit, dummy, false);
         // Note that UpdateAncestorsOf severs the child links that point to
         // removeIt in the entries for the parents of removeIt.
         UpdateAncestorsOf(false, removeIt, setAncestors);
     }
     // After updating all the ancestor sizes, we can now sever the link between
     // each transaction being removed and any mempool children (ie, update
     // CTxMemPoolEntry::m_parents for each direct child of a transaction being
     // removed).
     for (txiter removeIt : entriesToRemove) {
         UpdateChildrenForRemoval(removeIt);
     }
 }
 
 void CTxMemPoolEntry::UpdateDescendantState(int64_t modifySize,
                                             Amount modifyFee,
                                             int64_t modifyCount,
                                             int64_t modifySigOpCount) {
     nSizeWithDescendants += modifySize;
     assert(int64_t(nSizeWithDescendants) > 0);
     nModFeesWithDescendants += modifyFee;
     nCountWithDescendants += modifyCount;
     assert(int64_t(nCountWithDescendants) > 0);
     nSigOpCountWithDescendants += modifySigOpCount;
     assert(int64_t(nSigOpCountWithDescendants) >= 0);
 }
 
 void CTxMemPoolEntry::UpdateAncestorState(int64_t modifySize, Amount modifyFee,
                                           int64_t modifyCount,
                                           int64_t modifySigOps) {
     nSizeWithAncestors += modifySize;
     assert(int64_t(nSizeWithAncestors) > 0);
     nModFeesWithAncestors += modifyFee;
     nCountWithAncestors += modifyCount;
     assert(int64_t(nCountWithAncestors) > 0);
     nSigOpCountWithAncestors += modifySigOps;
     assert(int(nSigOpCountWithAncestors) >= 0);
 }
 
 CTxMemPool::CTxMemPool(int check_ratio) : m_check_ratio(check_ratio) {
     // lock free clear
     _clear();
 }
 
 CTxMemPool::~CTxMemPool() {}
 
 bool CTxMemPool::isSpent(const COutPoint &outpoint) const {
     LOCK(cs);
     return mapNextTx.count(outpoint);
 }
 
 unsigned int CTxMemPool::GetTransactionsUpdated() const {
     return nTransactionsUpdated;
 }
 
 void CTxMemPool::AddTransactionsUpdated(unsigned int n) {
     nTransactionsUpdated += n;
 }
 
 void CTxMemPool::addUnchecked(const CTxMemPoolEntry &entry,
                               setEntries &setAncestors) {
     // Add to memory pool without checking anything.
     // Used by AcceptToMemoryPool(), which DOES do all the appropriate checks.
     indexed_transaction_set::iterator newit = mapTx.insert(entry).first;
 
     // Update transaction for any feeDelta created by PrioritiseTransaction
     // TODO: refactor so that the fee delta is calculated before inserting into
     // mapTx.
     Amount feeDelta = Amount::zero();
     ApplyDelta(entry.GetTx().GetId(), feeDelta);
     if (feeDelta != Amount::zero()) {
         mapTx.modify(newit, update_fee_delta(feeDelta));
     }
 
     // Update cachedInnerUsage to include contained transaction's usage.
     // (When we update the entry for in-mempool parents, memory usage will be
     // further updated.)
     cachedInnerUsage += entry.DynamicMemoryUsage();
 
     const CTransaction &tx = newit->GetTx();
     std::set<TxId> setParentTransactions;
     for (const CTxIn &in : tx.vin) {
         mapNextTx.insert(std::make_pair(&in.prevout, &tx));
         setParentTransactions.insert(in.prevout.GetTxId());
     }
     // Don't bother worrying about child transactions of this one. Normal case
     // of a new transaction arriving is that there can't be any children,
     // because such children would be orphans. An exception to that is if a
     // transaction enters that used to be in a block. In that case, our
     // disconnect block logic will call UpdateTransactionsFromBlock to clean up
     // the mess we're leaving here.
 
     // Update ancestors with information about this tx
     for (const auto &pit : GetIterSet(setParentTransactions)) {
         UpdateParent(newit, pit, true);
     }
     UpdateAncestorsOf(true, newit, setAncestors);
     UpdateEntryForAncestors(newit, setAncestors);
 
     nTransactionsUpdated++;
     totalTxSize += entry.GetTxSize();
 
     vTxHashes.emplace_back(tx.GetHash(), newit);
     newit->vTxHashesIdx = vTxHashes.size() - 1;
 }
 
 void CTxMemPool::removeUnchecked(txiter it, MemPoolRemovalReason reason) {
     // We increment mempool sequence value no matter removal reason
     // even if not directly reported below.
     uint64_t mempool_sequence = GetAndIncrementSequence();
 
     if (reason != MemPoolRemovalReason::BLOCK) {
         // Notify clients that a transaction has been removed from the mempool
         // for any reason except being included in a block. Clients interested
         // in transactions included in blocks can subscribe to the
         // BlockConnected notification.
         GetMainSignals().TransactionRemovedFromMempool(
             it->GetSharedTx(), reason, mempool_sequence);
     }
 
     for (const CTxIn &txin : it->GetTx().vin) {
         mapNextTx.erase(txin.prevout);
     }
 
     /* add logging because unchecked */
     RemoveUnbroadcastTx(it->GetTx().GetId(), true);
 
     if (vTxHashes.size() > 1) {
         vTxHashes[it->vTxHashesIdx] = std::move(vTxHashes.back());
         vTxHashes[it->vTxHashesIdx].second->vTxHashesIdx = it->vTxHashesIdx;
         vTxHashes.pop_back();
         if (vTxHashes.size() * 2 < vTxHashes.capacity()) {
             vTxHashes.shrink_to_fit();
         }
     } else {
         vTxHashes.clear();
     }
 
     totalTxSize -= it->GetTxSize();
     cachedInnerUsage -= it->DynamicMemoryUsage();
     cachedInnerUsage -= memusage::DynamicUsage(it->GetMemPoolParentsConst()) +
                         memusage::DynamicUsage(it->GetMemPoolChildrenConst());
     mapTx.erase(it);
     nTransactionsUpdated++;
 }
 
 // Calculates descendants of entry that are not already in setDescendants, and
 // adds to setDescendants. Assumes entryit is already a tx in the mempool and
 // CTxMemPoolEntry::m_children is correct for tx and all descendants. Also
 // assumes that if an entry is in setDescendants already, then all in-mempool
 // descendants of it are already in setDescendants as well, so that we can save
 // time by not iterating over those entries.
 void CTxMemPool::CalculateDescendants(txiter entryit,
                                       setEntries &setDescendants) const {
     setEntries stage;
     if (setDescendants.count(entryit) == 0) {
         stage.insert(entryit);
     }
     // Traverse down the children of entry, only adding children that are not
     // accounted for in setDescendants already (because those children have
     // either already been walked, or will be walked in this iteration).
     while (!stage.empty()) {
         txiter it = *stage.begin();
         setDescendants.insert(it);
         stage.erase(it);
 
         const CTxMemPoolEntry::Children &children =
             it->GetMemPoolChildrenConst();
         for (const CTxMemPoolEntry &child : children) {
             txiter childiter = mapTx.iterator_to(child);
             if (!setDescendants.count(childiter)) {
                 stage.insert(childiter);
             }
         }
     }
 }
 
 void CTxMemPool::removeRecursive(const CTransaction &origTx,
                                  MemPoolRemovalReason reason) {
     // Remove transaction from memory pool.
     AssertLockHeld(cs);
     setEntries txToRemove;
     txiter origit = mapTx.find(origTx.GetId());
     if (origit != mapTx.end()) {
         txToRemove.insert(origit);
     } else {
         // When recursively removing but origTx isn't in the mempool be sure to
         // remove any children that are in the pool. This can happen during
         // chain re-orgs if origTx isn't re-accepted into the mempool for any
         // reason.
         for (size_t i = 0; i < origTx.vout.size(); i++) {
             auto it = mapNextTx.find(COutPoint(origTx.GetId(), i));
             if (it == mapNextTx.end()) {
                 continue;
             }
 
             txiter nextit = mapTx.find(it->second->GetId());
             assert(nextit != mapTx.end());
             txToRemove.insert(nextit);
         }
     }
 
     setEntries setAllRemoves;
     for (txiter it : txToRemove) {
         CalculateDescendants(it, setAllRemoves);
     }
 
     RemoveStaged(setAllRemoves, false, reason);
 }
 
 void CTxMemPool::removeForReorg(const Config &config,
                                 CChainState &active_chainstate, int flags) {
     // Remove transactions spending a coinbase which are now immature and
     // no-longer-final transactions.
     AssertLockHeld(cs);
     setEntries txToRemove;
     for (indexed_transaction_set::const_iterator it = mapTx.begin();
          it != mapTx.end(); it++) {
         const CTransaction &tx = it->GetTx();
         LockPoints lp = it->GetLockPoints();
         bool validLP = TestLockPointValidity(active_chainstate.m_chain, &lp);
 
         TxValidationState state;
         if (!ContextualCheckTransactionForCurrentBlock(
                 active_chainstate.m_chain.Tip(),
                 config.GetChainParams().GetConsensus(), tx, state, flags) ||
             !CheckSequenceLocks(active_chainstate, *this, tx, flags, &lp,
                                 validLP)) {
             // Note if CheckSequenceLocks fails the LockPoints may still be
             // invalid. So it's critical that we remove the tx and not depend on
             // the LockPoints.
             txToRemove.insert(it);
         } else if (it->GetSpendsCoinbase()) {
             for (const CTxIn &txin : tx.vin) {
                 indexed_transaction_set::const_iterator it2 =
                     mapTx.find(txin.prevout.GetTxId());
                 if (it2 != mapTx.end()) {
                     continue;
                 }
 
                 const Coin &coin =
                     active_chainstate.CoinsTip().AccessCoin(txin.prevout);
                 if (m_check_ratio != 0) {
                     assert(!coin.IsSpent());
                 }
                 unsigned int nMemPoolHeight =
                     active_chainstate.m_chain.Tip()->nHeight + 1;
                 if (coin.IsSpent() ||
                     (coin.IsCoinBase() &&
                      int64_t(nMemPoolHeight) - coin.GetHeight() <
                          COINBASE_MATURITY)) {
                     txToRemove.insert(it);
                     break;
                 }
             }
         }
         if (!validLP) {
             mapTx.modify(it, update_lock_points(lp));
         }
     }
     setEntries setAllRemoves;
     for (txiter it : txToRemove) {
         CalculateDescendants(it, setAllRemoves);
     }
     RemoveStaged(setAllRemoves, false, MemPoolRemovalReason::REORG);
 }
 
 void CTxMemPool::removeConflicts(const CTransaction &tx) {
     // Remove transactions which depend on inputs of tx, recursively
     AssertLockHeld(cs);
     for (const CTxIn &txin : tx.vin) {
         auto it = mapNextTx.find(txin.prevout);
         if (it != mapNextTx.end()) {
             const CTransaction &txConflict = *it->second;
             if (txConflict != tx) {
                 ClearPrioritisation(txConflict.GetId());
                 removeRecursive(txConflict, MemPoolRemovalReason::CONFLICT);
             }
         }
     }
 }
 
 /**
  * Called when a block is connected. Removes from mempool and updates the miner
  * fee estimator.
  */
 void CTxMemPool::removeForBlock(const std::vector<CTransactionRef> &vtx,
                                 unsigned int nBlockHeight) {
     AssertLockHeld(cs);
 
     DisconnectedBlockTransactions disconnectpool;
     disconnectpool.addForBlock(vtx, *this);
 
     std::vector<const CTxMemPoolEntry *> entries;
     for (const CTransactionRef &tx :
          reverse_iterate(disconnectpool.GetQueuedTx().get<insertion_order>())) {
         const TxId &txid = tx->GetId();
 
         indexed_transaction_set::iterator i = mapTx.find(txid);
         if (i != mapTx.end()) {
             entries.push_back(&*i);
         }
     }
 
     for (const CTransactionRef &tx :
          reverse_iterate(disconnectpool.GetQueuedTx().get<insertion_order>())) {
         txiter it = mapTx.find(tx->GetId());
         if (it != mapTx.end()) {
             setEntries stage;
             stage.insert(it);
             RemoveStaged(stage, true, MemPoolRemovalReason::BLOCK);
         }
         removeConflicts(*tx);
         ClearPrioritisation(tx->GetId());
     }
 
     disconnectpool.clear();
 
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = true;
 }
 
 void CTxMemPool::_clear() {
     mapTx.clear();
     mapNextTx.clear();
     vTxHashes.clear();
     totalTxSize = 0;
     cachedInnerUsage = 0;
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = false;
     rollingMinimumFeeRate = 0;
     ++nTransactionsUpdated;
 }
 
 void CTxMemPool::clear() {
     LOCK(cs);
     _clear();
 }
 
 static void CheckInputsAndUpdateCoins(const CTransaction &tx,
                                       CCoinsViewCache &mempoolDuplicate,
                                       const int64_t spendheight) {
     // Not used. CheckTxInputs() should always pass
     TxValidationState dummy_state;
     Amount txfee = Amount::zero();
     bool fCheckResult =
         tx.IsCoinBase() ||
         Consensus::CheckTxInputs(tx, dummy_state, mempoolDuplicate, spendheight,
                                  txfee);
     assert(fCheckResult);
     UpdateCoins(mempoolDuplicate, tx, std::numeric_limits<int>::max());
 }
 
 void CTxMemPool::check(CChainState &active_chainstate) const {
     if (m_check_ratio == 0) {
         return;
     }
 
     if (GetRand(m_check_ratio) >= 1) {
         return;
     }
 
     AssertLockHeld(::cs_main);
     LOCK(cs);
     LogPrint(BCLog::MEMPOOL,
              "Checking mempool with %u transactions and %u inputs\n",
              (unsigned int)mapTx.size(), (unsigned int)mapNextTx.size());
 
     uint64_t checkTotal = 0;
     uint64_t innerUsage = 0;
 
     CCoinsViewCache &active_coins_tip = active_chainstate.CoinsTip();
     CCoinsViewCache mempoolDuplicate(
         const_cast<CCoinsViewCache *>(&active_coins_tip));
     const int64_t spendheight = active_chainstate.m_chain.Height() + 1;
 
     std::list<const CTxMemPoolEntry *> waitingOnDependants;
     for (indexed_transaction_set::const_iterator it = mapTx.begin();
          it != mapTx.end(); it++) {
         unsigned int i = 0;
         checkTotal += it->GetTxSize();
         innerUsage += it->DynamicMemoryUsage();
         const CTransaction &tx = it->GetTx();
         innerUsage += memusage::DynamicUsage(it->GetMemPoolParentsConst()) +
                       memusage::DynamicUsage(it->GetMemPoolChildrenConst());
         bool fDependsWait = false;
         CTxMemPoolEntry::Parents setParentCheck;
         for (const CTxIn &txin : tx.vin) {
             // Check that every mempool transaction's inputs refer to available
             // coins, or other mempool tx's.
             indexed_transaction_set::const_iterator it2 =
                 mapTx.find(txin.prevout.GetTxId());
             if (it2 != mapTx.end()) {
                 const CTransaction &tx2 = it2->GetTx();
                 assert(tx2.vout.size() > txin.prevout.GetN() &&
                        !tx2.vout[txin.prevout.GetN()].IsNull());
                 fDependsWait = true;
                 setParentCheck.insert(*it2);
             } else {
                 assert(active_coins_tip.HaveCoin(txin.prevout));
             }
             // Check whether its inputs are marked in mapNextTx.
             auto it3 = mapNextTx.find(txin.prevout);
             assert(it3 != mapNextTx.end());
             assert(it3->first == &txin.prevout);
             assert(it3->second == &tx);
             i++;
         }
         auto comp = [](const CTxMemPoolEntry &a,
                        const CTxMemPoolEntry &b) -> bool {
             return a.GetTx().GetId() == b.GetTx().GetId();
         };
         assert(setParentCheck.size() == it->GetMemPoolParentsConst().size());
         assert(std::equal(setParentCheck.begin(), setParentCheck.end(),
                           it->GetMemPoolParentsConst().begin(), comp));
         // Verify ancestor state is correct.
         setEntries setAncestors;
         uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
         std::string dummy;
         CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit,
                                   nNoLimit, nNoLimit, dummy);
         uint64_t nCountCheck = setAncestors.size() + 1;
         uint64_t nSizeCheck = it->GetTxSize();
         Amount nFeesCheck = it->GetModifiedFee();
         int64_t nSigOpCheck = it->GetSigOpCount();
 
         for (txiter ancestorIt : setAncestors) {
             nSizeCheck += ancestorIt->GetTxSize();
             nFeesCheck += ancestorIt->GetModifiedFee();
             nSigOpCheck += ancestorIt->GetSigOpCount();
         }
 
         assert(it->GetCountWithAncestors() == nCountCheck);
         assert(it->GetSizeWithAncestors() == nSizeCheck);
         assert(it->GetSigOpCountWithAncestors() == nSigOpCheck);
         assert(it->GetModFeesWithAncestors() == nFeesCheck);
 
         // Check children against mapNextTx
         CTxMemPoolEntry::Children setChildrenCheck;
         auto iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetId(), 0));
         uint64_t child_sizes = 0;
         int64_t child_sigop_counts = 0;
         for (; iter != mapNextTx.end() &&
                iter->first->GetTxId() == it->GetTx().GetId();
              ++iter) {
             txiter childit = mapTx.find(iter->second->GetId());
             // mapNextTx points to in-mempool transactions
             assert(childit != mapTx.end());
             if (setChildrenCheck.insert(*childit).second) {
                 child_sizes += childit->GetTxSize();
                 child_sigop_counts += childit->GetSigOpCount();
             }
         }
         assert(setChildrenCheck.size() == it->GetMemPoolChildrenConst().size());
         assert(std::equal(setChildrenCheck.begin(), setChildrenCheck.end(),
                           it->GetMemPoolChildrenConst().begin(), comp));
         // Also check to make sure size is greater than sum with immediate
         // children. Just a sanity check, not definitive that this calc is
         // correct...
         assert(it->GetSizeWithDescendants() >= child_sizes + it->GetTxSize());
         assert(it->GetSigOpCountWithDescendants() >=
                child_sigop_counts + it->GetSigOpCount());
 
         if (fDependsWait) {
             waitingOnDependants.push_back(&(*it));
         } else {
             CheckInputsAndUpdateCoins(tx, mempoolDuplicate, spendheight);
         }
     }
 
     unsigned int stepsSinceLastRemove = 0;
     while (!waitingOnDependants.empty()) {
         const CTxMemPoolEntry *entry = waitingOnDependants.front();
         waitingOnDependants.pop_front();
         if (!mempoolDuplicate.HaveInputs(entry->GetTx())) {
             waitingOnDependants.push_back(entry);
             stepsSinceLastRemove++;
             assert(stepsSinceLastRemove < waitingOnDependants.size());
         } else {
             CheckInputsAndUpdateCoins(entry->GetTx(), mempoolDuplicate,
                                       spendheight);
             stepsSinceLastRemove = 0;
         }
     }
 
     for (auto it = mapNextTx.cbegin(); it != mapNextTx.cend(); it++) {
         const TxId &txid = it->second->GetId();
         indexed_transaction_set::const_iterator it2 = mapTx.find(txid);
         const CTransaction &tx = it2->GetTx();
         assert(it2 != mapTx.end());
         assert(&tx == it->second);
     }
 
     assert(totalTxSize == checkTotal);
     assert(innerUsage == cachedInnerUsage);
 }
 
 bool CTxMemPool::CompareDepthAndScore(const TxId &txida, const TxId &txidb) {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(txida);
     if (i == mapTx.end()) {
         return false;
     }
     indexed_transaction_set::const_iterator j = mapTx.find(txidb);
     if (j == mapTx.end()) {
         return true;
     }
     uint64_t counta = i->GetCountWithAncestors();
     uint64_t countb = j->GetCountWithAncestors();
     if (counta == countb) {
         return CompareTxMemPoolEntryByScore()(*i, *j);
     }
     return counta < countb;
 }
 
 namespace {
 class DepthAndScoreComparator {
 public:
     bool
     operator()(const CTxMemPool::indexed_transaction_set::const_iterator &a,
                const CTxMemPool::indexed_transaction_set::const_iterator &b) {
         uint64_t counta = a->GetCountWithAncestors();
         uint64_t countb = b->GetCountWithAncestors();
         if (counta == countb) {
             return CompareTxMemPoolEntryByScore()(*a, *b);
         }
         return counta < countb;
     }
 };
 } // namespace
 
 std::vector<CTxMemPool::indexed_transaction_set::const_iterator>
 CTxMemPool::GetSortedDepthAndScore() const {
     std::vector<indexed_transaction_set::const_iterator> iters;
     AssertLockHeld(cs);
 
     iters.reserve(mapTx.size());
     for (indexed_transaction_set::iterator mi = mapTx.begin();
          mi != mapTx.end(); ++mi) {
         iters.push_back(mi);
     }
 
     std::sort(iters.begin(), iters.end(), DepthAndScoreComparator());
     return iters;
 }
 
 void CTxMemPool::queryHashes(std::vector<uint256> &vtxid) const {
     LOCK(cs);
     auto iters = GetSortedDepthAndScore();
 
     vtxid.clear();
     vtxid.reserve(mapTx.size());
 
     for (auto it : iters) {
         vtxid.push_back(it->GetTx().GetId());
     }
 }
 
 static TxMempoolInfo
 GetInfo(CTxMemPool::indexed_transaction_set::const_iterator it) {
     return TxMempoolInfo{it->GetSharedTx(), it->GetTime(), it->GetFee(),
                          it->GetTxSize(), it->GetModifiedFee() - it->GetFee()};
 }
 
 std::vector<TxMempoolInfo> CTxMemPool::infoAll() const {
     LOCK(cs);
     auto iters = GetSortedDepthAndScore();
 
     std::vector<TxMempoolInfo> ret;
     ret.reserve(mapTx.size());
     for (auto it : iters) {
         ret.push_back(GetInfo(it));
     }
 
     return ret;
 }
 
 CTransactionRef CTxMemPool::get(const TxId &txid) const {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(txid);
     if (i == mapTx.end()) {
         return nullptr;
     }
 
     return i->GetSharedTx();
 }
 
 TxMempoolInfo CTxMemPool::info(const TxId &txid) const {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(txid);
     if (i == mapTx.end()) {
         return TxMempoolInfo();
     }
 
     return GetInfo(i);
 }
 
 CFeeRate CTxMemPool::estimateFee() const {
     LOCK(cs);
 
     uint64_t maxMempoolSize =
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
     // minerPolicy uses recent blocks to figure out a reasonable fee.  This
     // may disagree with the rollingMinimumFeerate under certain scenarios
     // where the mempool  increases rapidly, or blocks are being mined which
     // do not contain propagated transactions.
     return std::max(::minRelayTxFee, GetMinFee(maxMempoolSize));
 }
 
 void CTxMemPool::PrioritiseTransaction(const TxId &txid,
                                        const Amount nFeeDelta) {
     {
         LOCK(cs);
         Amount &delta = mapDeltas[txid];
         delta += nFeeDelta;
         txiter it = mapTx.find(txid);
         if (it != mapTx.end()) {
             mapTx.modify(it, update_fee_delta(delta));
             // Now update all ancestors' modified fees with descendants
             setEntries setAncestors;
             uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
             std::string dummy;
             CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit,
                                       nNoLimit, nNoLimit, dummy, false);
             for (txiter ancestorIt : setAncestors) {
                 mapTx.modify(ancestorIt,
                              update_descendant_state(0, nFeeDelta, 0, 0));
             }
 
             // Now update all descendants' modified fees with ancestors
             setEntries setDescendants;
             CalculateDescendants(it, setDescendants);
             setDescendants.erase(it);
             for (txiter descendantIt : setDescendants) {
                 mapTx.modify(descendantIt,
                              update_ancestor_state(0, nFeeDelta, 0, 0));
             }
             ++nTransactionsUpdated;
         }
     }
     LogPrintf("PrioritiseTransaction: %s fee += %s\n", txid.ToString(),
               FormatMoney(nFeeDelta));
 }
 
 void CTxMemPool::ApplyDelta(const TxId &txid, Amount &nFeeDelta) const {
     AssertLockHeld(cs);
     std::map<TxId, Amount>::const_iterator pos = mapDeltas.find(txid);
     if (pos == mapDeltas.end()) {
         return;
     }
 
     nFeeDelta += pos->second;
 }
 
 void CTxMemPool::ClearPrioritisation(const TxId &txid) {
     AssertLockHeld(cs);
     mapDeltas.erase(txid);
 }
 
 const CTransaction *CTxMemPool::GetConflictTx(const COutPoint &prevout) const {
     const auto it = mapNextTx.find(prevout);
     return it == mapNextTx.end() ? nullptr : it->second;
 }
 
 std::optional<CTxMemPool::txiter> CTxMemPool::GetIter(const TxId &txid) const {
     auto it = mapTx.find(txid);
     if (it != mapTx.end()) {
         return it;
     }
     return std::nullopt;
 }
 
 CTxMemPool::setEntries
 CTxMemPool::GetIterSet(const std::set<TxId> &txids) const {
     CTxMemPool::setEntries ret;
     for (const auto &txid : txids) {
         const auto mi = GetIter(txid);
         if (mi) {
             ret.insert(*mi);
         }
     }
     return ret;
 }
 
 bool CTxMemPool::HasNoInputsOf(const CTransaction &tx) const {
     for (const CTxIn &in : tx.vin) {
         if (exists(in.prevout.GetTxId())) {
             return false;
         }
     }
 
     return true;
 }
 
 CCoinsViewMemPool::CCoinsViewMemPool(CCoinsView *baseIn,
                                      const CTxMemPool &mempoolIn)
     : CCoinsViewBacked(baseIn), mempool(mempoolIn) {}
 
 bool CCoinsViewMemPool::GetCoin(const COutPoint &outpoint, Coin &coin) const {
     // If an entry in the mempool exists, always return that one, as it's
     // guaranteed to never conflict with the underlying cache, and it cannot
     // have pruned entries (as it contains full) transactions. First checking
     // the underlying cache risks returning a pruned entry instead.
     CTransactionRef ptx = mempool.get(outpoint.GetTxId());
     if (ptx) {
         if (outpoint.GetN() < ptx->vout.size()) {
             coin = Coin(ptx->vout[outpoint.GetN()], MEMPOOL_HEIGHT, false);
             return true;
         }
         return false;
     }
     return base->GetCoin(outpoint, coin);
 }
 
 size_t CTxMemPool::DynamicMemoryUsage() const {
     LOCK(cs);
     // Estimate the overhead of mapTx to be 12 pointers + an allocation, as no
     // exact formula for boost::multi_index_contained is implemented.
     return memusage::MallocUsage(sizeof(CTxMemPoolEntry) +
                                  12 * sizeof(void *)) *
                mapTx.size() +
            memusage::DynamicUsage(mapNextTx) +
            memusage::DynamicUsage(mapDeltas) +
            memusage::DynamicUsage(vTxHashes) + cachedInnerUsage;
 }
 
 void CTxMemPool::RemoveUnbroadcastTx(const TxId &txid, const bool unchecked) {
     LOCK(cs);
 
     if (m_unbroadcast_txids.erase(txid)) {
         LogPrint(
             BCLog::MEMPOOL, "Removed %i from set of unbroadcast txns%s\n",
             txid.GetHex(),
             (unchecked ? " before confirmation that txn was sent out" : ""));
     }
 }
 
 void CTxMemPool::RemoveStaged(setEntries &stage, bool updateDescendants,
                               MemPoolRemovalReason reason) {
     AssertLockHeld(cs);
     UpdateForRemoveFromMempool(stage, updateDescendants);
     for (txiter it : stage) {
         removeUnchecked(it, reason);
     }
 }
 
 int CTxMemPool::Expire(std::chrono::seconds time) {
     AssertLockHeld(cs);
     indexed_transaction_set::index<entry_time>::type::iterator it =
         mapTx.get<entry_time>().begin();
     setEntries toremove;
     while (it != mapTx.get<entry_time>().end() && it->GetTime() < time) {
         toremove.insert(mapTx.project<0>(it));
         it++;
     }
 
     setEntries stage;
     for (txiter removeit : toremove) {
         CalculateDescendants(removeit, stage);
     }
 
     RemoveStaged(stage, false, MemPoolRemovalReason::EXPIRY);
     return stage.size();
 }
 
 void CTxMemPool::LimitSize(CCoinsViewCache &coins_cache, size_t limit,
                            std::chrono::seconds age) {
     int expired = Expire(GetTime<std::chrono::seconds>() - age);
     if (expired != 0) {
         LogPrint(BCLog::MEMPOOL,
                  "Expired %i transactions from the memory pool\n", expired);
     }
 
     std::vector<COutPoint> vNoSpendsRemaining;
     TrimToSize(limit, &vNoSpendsRemaining);
     for (const COutPoint &removed : vNoSpendsRemaining) {
         coins_cache.Uncache(removed);
     }
 }
 
 void CTxMemPool::addUnchecked(const CTxMemPoolEntry &entry) {
     setEntries setAncestors;
     uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
     std::string dummy;
     CalculateMemPoolAncestors(entry, setAncestors, nNoLimit, nNoLimit, nNoLimit,
                               nNoLimit, dummy);
     return addUnchecked(entry, setAncestors);
 }
 
 void CTxMemPool::UpdateChild(txiter entry, txiter child, bool add) {
     AssertLockHeld(cs);
     CTxMemPoolEntry::Children s;
     if (add && entry->GetMemPoolChildren().insert(*child).second) {
         cachedInnerUsage += memusage::IncrementalDynamicUsage(s);
     } else if (!add && entry->GetMemPoolChildren().erase(*child)) {
         cachedInnerUsage -= memusage::IncrementalDynamicUsage(s);
     }
 }
 
 void CTxMemPool::UpdateParent(txiter entry, txiter parent, bool add) {
     AssertLockHeld(cs);
     CTxMemPoolEntry::Parents s;
     if (add && entry->GetMemPoolParents().insert(*parent).second) {
         cachedInnerUsage += memusage::IncrementalDynamicUsage(s);
     } else if (!add && entry->GetMemPoolParents().erase(*parent)) {
         cachedInnerUsage -= memusage::IncrementalDynamicUsage(s);
     }
 }
 
 CFeeRate CTxMemPool::GetMinFee(size_t sizelimit) const {
     LOCK(cs);
     if (!blockSinceLastRollingFeeBump || rollingMinimumFeeRate == 0) {
         return CFeeRate(int64_t(ceill(rollingMinimumFeeRate)) * SATOSHI);
     }
 
     int64_t time = GetTime();
     if (time > lastRollingFeeUpdate + 10) {
         double halflife = ROLLING_FEE_HALFLIFE;
         if (DynamicMemoryUsage() < sizelimit / 4) {
             halflife /= 4;
         } else if (DynamicMemoryUsage() < sizelimit / 2) {
             halflife /= 2;
         }
 
         rollingMinimumFeeRate =
             rollingMinimumFeeRate /
             pow(2.0, (time - lastRollingFeeUpdate) / halflife);
         lastRollingFeeUpdate = time;
     }
     return CFeeRate(int64_t(ceill(rollingMinimumFeeRate)) * SATOSHI);
 }
 
 void CTxMemPool::trackPackageRemoved(const CFeeRate &rate) {
     AssertLockHeld(cs);
     if ((rate.GetFeePerK() / SATOSHI) > rollingMinimumFeeRate) {
         rollingMinimumFeeRate = rate.GetFeePerK() / SATOSHI;
         blockSinceLastRollingFeeBump = false;
     }
 }
 
 void CTxMemPool::TrimToSize(size_t sizelimit,
                             std::vector<COutPoint> *pvNoSpendsRemaining) {
     AssertLockHeld(cs);
 
     unsigned nTxnRemoved = 0;
     CFeeRate maxFeeRateRemoved(Amount::zero());
     while (!mapTx.empty() && DynamicMemoryUsage() > sizelimit) {
         indexed_transaction_set::index<descendant_score>::type::iterator it =
             mapTx.get<descendant_score>().begin();
 
         // We set the new mempool min fee to the feerate of the removed set,
         // plus the "minimum reasonable fee rate" (ie some value under which we
         // consider txn to have 0 fee). This way, we don't allow txn to enter
         // mempool with feerate equal to txn which were removed with no block in
         // between.
         CFeeRate removed(it->GetModFeesWithDescendants(),
                          it->GetVirtualSizeWithDescendants());
         removed += MEMPOOL_FULL_FEE_INCREMENT;
 
         trackPackageRemoved(removed);
         maxFeeRateRemoved = std::max(maxFeeRateRemoved, removed);
 
         setEntries stage;
         CalculateDescendants(mapTx.project<0>(it), stage);
         nTxnRemoved += stage.size();
 
         std::vector<CTransaction> txn;
         if (pvNoSpendsRemaining) {
             txn.reserve(stage.size());
             for (txiter iter : stage) {
                 txn.push_back(iter->GetTx());
             }
         }
         RemoveStaged(stage, false, MemPoolRemovalReason::SIZELIMIT);
         if (pvNoSpendsRemaining) {
             for (const CTransaction &tx : txn) {
                 for (const CTxIn &txin : tx.vin) {
                     if (exists(txin.prevout.GetTxId())) {
                         continue;
                     }
                     pvNoSpendsRemaining->push_back(txin.prevout);
                 }
             }
         }
     }
 
     if (maxFeeRateRemoved > CFeeRate(Amount::zero())) {
         LogPrint(BCLog::MEMPOOL,
                  "Removed %u txn, rolling minimum fee bumped to %s\n",
                  nTxnRemoved, maxFeeRateRemoved.ToString());
     }
 }
 
 uint64_t CTxMemPool::CalculateDescendantMaximum(txiter entry) const {
     // find parent with highest descendant count
     std::vector<txiter> candidates;
     setEntries counted;
     candidates.push_back(entry);
     uint64_t maximum = 0;
     while (candidates.size()) {
         txiter candidate = candidates.back();
         candidates.pop_back();
         if (!counted.insert(candidate).second) {
             continue;
         }
         const CTxMemPoolEntry::Parents &parents =
             candidate->GetMemPoolParentsConst();
         if (parents.size() == 0) {
             maximum = std::max(maximum, candidate->GetCountWithDescendants());
         } else {
             for (const CTxMemPoolEntry &i : parents) {
                 candidates.push_back(mapTx.iterator_to(i));
             }
         }
     }
     return maximum;
 }
 
 void CTxMemPool::GetTransactionAncestry(const TxId &txid, size_t &ancestors,
                                         size_t &descendants) const {
     LOCK(cs);
     auto it = mapTx.find(txid);
     ancestors = descendants = 0;
     if (it != mapTx.end()) {
         ancestors = it->GetCountWithAncestors();
         descendants = CalculateDescendantMaximum(it);
     }
 }
 
 bool CTxMemPool::IsLoaded() const {
     LOCK(cs);
     return m_is_loaded;
 }
 
 void CTxMemPool::SetIsLoaded(bool loaded) {
     LOCK(cs);
     m_is_loaded = loaded;
 }
 
 /** Maximum bytes for transactions to store for processing during reorg */
 static const size_t MAX_DISCONNECTED_TX_POOL_SIZE = 20 * DEFAULT_MAX_BLOCK_SIZE;
 
 void DisconnectedBlockTransactions::addForBlock(
     const std::vector<CTransactionRef> &vtx, CTxMemPool &pool) {
     AssertLockHeld(pool.cs);
     for (const auto &tx : reverse_iterate(vtx)) {
         // If we already added it, just skip.
         auto it = queuedTx.find(tx->GetId());
         if (it != queuedTx.end()) {
             continue;
         }
 
         // Insert the transaction into the pool.
         addTransaction(tx);
 
         // Fill in the set of parents.
         std::unordered_set<TxId, SaltedTxIdHasher> parents;
         for (const CTxIn &in : tx->vin) {
             parents.insert(in.prevout.GetTxId());
         }
 
         // In order to make sure we keep things in topological order, we check
         // if we already know of the parent of the current transaction. If so,
         // we remove them from the set and then add them back.
         while (parents.size() > 0) {
             std::unordered_set<TxId, SaltedTxIdHasher> worklist(
                 std::move(parents));
             parents.clear();
 
             for (const TxId &txid : worklist) {
                 // If we do not have that txid in the set, nothing needs to be
                 // done.
                 auto pit = queuedTx.find(txid);
                 if (pit == queuedTx.end()) {
                     continue;
                 }
 
                 // We have parent in our set, we reinsert them at the right
                 // position.
                 const CTransactionRef ptx = *pit;
                 queuedTx.erase(pit);
                 queuedTx.insert(ptx);
 
                 // And we make sure ancestors are covered.
                 for (const CTxIn &in : ptx->vin) {
                     parents.insert(in.prevout.GetTxId());
                 }
             }
         }
     }
 
     // Keep the size under control.
     while (DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE) {
         // Drop the earliest entry, and remove its children from the
         // mempool.
         auto it = queuedTx.get<insertion_order>().begin();
         pool.removeRecursive(**it, MemPoolRemovalReason::REORG);
         removeEntry(it);
     }
 }
 
 void DisconnectedBlockTransactions::importMempool(CTxMemPool &pool) {
     AssertLockHeld(pool.cs);
     // addForBlock's algorithm sorts a vector of transactions back into
     // topological order. We use it in a separate object to create a valid
     // ordering of all mempool transactions, which we then splice in front of
     // the current queuedTx. This results in a valid sequence of transactions to
     // be reprocessed in updateMempoolForReorg.
 
     // We create vtx in order of the entry_time index to facilitate for
     // addForBlocks (which iterates in reverse order), as vtx probably end in
     // the correct ordering for queuedTx.
     std::vector<CTransactionRef> vtx;
 
     vtx.reserve(pool.mapTx.size());
     for (const CTxMemPoolEntry &e : pool.mapTx.get<entry_time>()) {
         vtx.push_back(e.GetSharedTx());
     }
     pool.clear();
 
     // Use addForBlocks to sort the transactions and then splice them in front
     // of queuedTx
     DisconnectedBlockTransactions orderedTxnPool;
     orderedTxnPool.addForBlock(vtx, pool);
     cachedInnerUsage += orderedTxnPool.cachedInnerUsage;
     queuedTx.get<insertion_order>().splice(
         queuedTx.get<insertion_order>().begin(),
         orderedTxnPool.queuedTx.get<insertion_order>());
 
     // We limit memory usage because we can't know if more blocks will be
     // disconnected
     while (DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE) {
         // Drop the earliest entry which, by definition, has no children
         removeEntry(queuedTx.get<insertion_order>().begin());
     }
 }
 
 void DisconnectedBlockTransactions::updateMempoolForReorg(
     const Config &config, CChainState &active_chainstate, bool fAddToMempool,
     CTxMemPool &pool) {
     AssertLockHeld(cs_main);
     AssertLockHeld(pool.cs);
     std::vector<TxId> txidsUpdate;
 
     // disconnectpool's insertion_order index sorts the entries from oldest to
     // newest, but the oldest entry will be the last tx from the latest mined
     // block that was disconnected.
     // Iterate disconnectpool in reverse, so that we add transactions back to
     // the mempool starting with the earliest transaction that had been
     // previously seen in a block.
     for (const CTransactionRef &tx :
          reverse_iterate(queuedTx.get<insertion_order>())) {
         // ignore validation errors in resurrected transactions
-        TxValidationState stateDummy;
         if (!fAddToMempool || tx->IsCoinBase() ||
-            !AcceptToMemoryPool(active_chainstate, config, pool, stateDummy, tx,
-                                true /* bypass_limits */)) {
+            AcceptToMemoryPool(active_chainstate, config, pool, tx,
+                               true /* bypass_limits */)
+                    .m_result_type != MempoolAcceptResult::ResultType::VALID) {
             // If the transaction doesn't make it in to the mempool, remove any
             // transactions that depend on it (which would now be orphans).
             pool.removeRecursive(*tx, MemPoolRemovalReason::REORG);
         } else if (pool.exists(tx->GetId())) {
             txidsUpdate.push_back(tx->GetId());
         }
     }
 
     queuedTx.clear();
 
     // AcceptToMemoryPool/addUnchecked all assume that new mempool entries have
     // no in-mempool children, which is generally not true when adding
     // previously-confirmed transactions back to the mempool.
     // UpdateTransactionsFromBlock finds descendants of any transactions in the
     // disconnectpool that were added back and cleans up the mempool state.
     pool.UpdateTransactionsFromBlock(txidsUpdate);
 
     // We also need to remove any now-immature transactions
     pool.removeForReorg(config, active_chainstate,
                         STANDARD_LOCKTIME_VERIFY_FLAGS);
 
     // Re-limit mempool size, in case we added any transactions
     pool.LimitSize(active_chainstate.CoinsTip(),
                    gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                        1000000,
                    std::chrono::hours{
                        gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY)});
 }
diff --git a/src/validation.cpp b/src/validation.cpp
index b8ec65a4e..cbd7c39b1 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1,6322 +1,6320 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Copyright (c) 2017-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <validation.h>
 
 #include <arith_uint256.h>
 #include <avalanche/avalanche.h>
 #include <avalanche/processor.h>
 #include <blockdb.h>
 #include <blockvalidity.h>
 #include <chainparams.h>
 #include <checkpoints.h>
 #include <checkqueue.h>
 #include <config.h>
 #include <consensus/activation.h>
 #include <consensus/merkle.h>
 #include <consensus/tx_check.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
 #include <index/txindex.h>
 #include <logging.h>
 #include <logging/timer.h>
 #include <minerfund.h>
 #include <node/blockstorage.h>
 #include <node/coinstats.h>
 #include <node/ui_interface.h>
 #include <policy/fees.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
 #include <pow/pow.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <reverse_iterator.h>
 #include <script/script.h>
 #include <script/scriptcache.h>
 #include <script/sigcache.h>
 #include <shutdown.h>
 #include <timedata.h>
 #include <tinyformat.h>
 #include <txdb.h>
 #include <txmempool.h>
 #include <undo.h>
 #include <util/check.h> // For NDEBUG compile time check
 #include <util/moneystr.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
 #include <boost/algorithm/string/replace.hpp>
 
 #include <optional>
 #include <string>
 #include <thread>
 
 #define MICRO 0.000001
 #define MILLI 0.001
 
 /** Time to wait between writing blocks/block index to disk. */
 static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1};
 /** Time to wait between flushing chainstate to disk. */
 static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24};
 const std::vector<std::string> CHECKLEVEL_DOC{
     "level 0 reads the blocks from disk",
     "level 1 verifies block validity",
     "level 2 verifies undo data",
     "level 3 checks disconnection of tip blocks",
     "level 4 tries to reconnect the blocks",
     "each level includes the checks of the previous levels",
 };
 
 /**
  * Global state
  *
  * Mutex to guard access to validation specific variables, such as reading
  * or changing the chainstate.
  *
  * This may also need to be locked when updating the transaction pool, e.g. on
  * AcceptToMemoryPool. See CTxMemPool::cs comment for details.
  *
  * The transaction pool has a separate lock to allow reading from it and the
  * chainstate at the same time.
  */
 RecursiveMutex cs_main;
 
 CBlockIndex *pindexBestHeader = nullptr;
 Mutex g_best_block_mutex;
 std::condition_variable g_best_block_cv;
 uint256 g_best_block;
 std::atomic_bool fImporting(false);
 std::atomic_bool fReindex(false);
 bool fHavePruned = false;
 bool fPruneMode = false;
 bool fRequireStandard = true;
 bool fCheckBlockIndex = false;
 bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
 uint64_t nPruneTarget = 0;
 int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
 
 BlockHash hashAssumeValid;
 arith_uint256 nMinimumChainWork;
 
 CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE_PER_KB);
 
 // Internal stuff
 namespace {
 CBlockIndex *pindexBestInvalid = nullptr;
 CBlockIndex *pindexBestParked = nullptr;
 
 RecursiveMutex cs_LastBlockFile;
 std::vector<CBlockFileInfo> vinfoBlockFile;
 int nLastBlockFile = 0;
 /**
  * Global flag to indicate we should check to see if there are block/undo files
  * that should be deleted. Set on startup or if we allocate more file space when
  * we're in prune mode.
  */
 bool fCheckForPruning = false;
 
 /** Dirty block index entries. */
 std::set<const CBlockIndex *> setDirtyBlockIndex;
 
 /** Dirty block file entries. */
 std::set<int> setDirtyFileInfo;
 } // namespace
 
 BlockValidationOptions::BlockValidationOptions(const Config &config)
     : excessiveBlockSize(config.GetMaxBlockSize()), checkPoW(true),
       checkMerkleRoot(true) {}
 
 CBlockIndex *BlockManager::LookupBlockIndex(const BlockHash &hash) const {
     AssertLockHeld(cs_main);
     BlockMap::const_iterator it = m_block_index.find(hash);
     return it == m_block_index.end() ? nullptr : it->second;
 }
 
 CBlockIndex *BlockManager::FindForkInGlobalIndex(const CChain &chain,
                                                  const CBlockLocator &locator) {
     AssertLockHeld(cs_main);
 
     // Find the latest block common to locator and chain - we expect that
     // locator.vHave is sorted descending by height.
     for (const BlockHash &hash : locator.vHave) {
         CBlockIndex *pindex = LookupBlockIndex(hash);
         if (pindex) {
             if (chain.Contains(pindex)) {
                 return pindex;
             }
             if (pindex->GetAncestor(chain.Height()) == chain.Tip()) {
                 return chain.Tip();
             }
         }
     }
     return chain.Genesis();
 }
 
 std::unique_ptr<CBlockTreeDB> pblocktree;
 
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex);
 
 bool TestLockPointValidity(const CChain &active_chain, const LockPoints *lp) {
     AssertLockHeld(cs_main);
     assert(lp);
     // If there are relative lock times then the maxInputBlock will be set
     // If there are no relative lock times, the LockPoints don't depend on the
     // chain
     if (lp->maxInputBlock) {
         // Check whether active_chain is an extension of the block at which
         // the LockPoints calculation was valid. If not LockPoints are no longer
         // valid.
         if (!active_chain.Contains(lp->maxInputBlock)) {
             return false;
         }
     }
 
     // LockPoints still valid
     return true;
 }
 
 bool CheckSequenceLocks(CChainState &active_chainstate, const CTxMemPool &pool,
                         const CTransaction &tx, int flags, LockPoints *lp,
                         bool useExistingLockPoints) {
     AssertLockHeld(cs_main);
     AssertLockHeld(pool.cs);
 
     CBlockIndex *tip = active_chainstate.m_chain.Tip();
     assert(tip != nullptr);
 
     CBlockIndex index;
     index.pprev = tip;
     // CheckSequenceLocks() uses active_chainstate.m_chain.Height()+1 to
     // evaluate height based locks because when SequenceLocks() is called within
     // ConnectBlock(), the height of the block *being* evaluated is what is
     // used. Thus if we want to know if a transaction can be part of the *next*
     // block, we need to use one more than active_chainstate.m_chain.Height()
     index.nHeight = tip->nHeight + 1;
 
     std::pair<int, int64_t> lockPair;
     if (useExistingLockPoints) {
         assert(lp);
         lockPair.first = lp->height;
         lockPair.second = lp->time;
     } else {
         // CoinsTip() contains the UTXO set for active_chainstate.m_chain.Tip()
         CCoinsViewMemPool viewMemPool(&active_chainstate.CoinsTip(), pool);
         std::vector<int> prevheights;
         prevheights.resize(tx.vin.size());
         for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
             const CTxIn &txin = tx.vin[txinIndex];
             Coin coin;
             if (!viewMemPool.GetCoin(txin.prevout, coin)) {
                 return error("%s: Missing input", __func__);
             }
             if (coin.GetHeight() == MEMPOOL_HEIGHT) {
                 // Assume all mempool transaction confirm in the next block
                 prevheights[txinIndex] = tip->nHeight + 1;
             } else {
                 prevheights[txinIndex] = coin.GetHeight();
             }
         }
         lockPair = CalculateSequenceLocks(tx, flags, prevheights, index);
         if (lp) {
             lp->height = lockPair.first;
             lp->time = lockPair.second;
             // Also store the hash of the block with the highest height of all
             // the blocks which have sequence locked prevouts. This hash needs
             // to still be on the chain for these LockPoint calculations to be
             // valid.
             // Note: It is impossible to correctly calculate a maxInputBlock if
             // any of the sequence locked inputs depend on unconfirmed txs,
             // except in the special case where the relative lock time/height is
             // 0, which is equivalent to no sequence lock. Since we assume input
             // height of tip+1 for mempool txs and test the resulting lockPair
             // from CalculateSequenceLocks against tip+1. We know
             // EvaluateSequenceLocks will fail if there was a non-zero sequence
             // lock on a mempool input, so we can use the return value of
             // CheckSequenceLocks to indicate the LockPoints validity.
             int maxInputHeight = 0;
             for (const int height : prevheights) {
                 // Can ignore mempool inputs since we'll fail if they had
                 // non-zero locks.
                 if (height != tip->nHeight + 1) {
                     maxInputHeight = std::max(maxInputHeight, height);
                 }
             }
             lp->maxInputBlock = tip->GetAncestor(maxInputHeight);
         }
     }
     return EvaluateSequenceLocks(index, lockPair);
 }
 
 // Command-line argument "-replayprotectionactivationtime=<timestamp>" will
 // cause the node to switch to replay protected SigHash ForkID value when the
 // median timestamp of the previous 11 blocks is greater than or equal to
 // <timestamp>. Defaults to the pre-defined timestamp when not set.
 static bool IsReplayProtectionEnabled(const Consensus::Params &params,
                                       int64_t nMedianTimePast) {
     return nMedianTimePast >= gArgs.GetArg("-replayprotectionactivationtime",
                                            params.jeffersonActivationTime);
 }
 
 static bool IsReplayProtectionEnabled(const Consensus::Params &params,
                                       const CBlockIndex *pindexPrev) {
     if (pindexPrev == nullptr) {
         return false;
     }
 
     return IsReplayProtectionEnabled(params, pindexPrev->GetMedianTimePast());
 }
 
 /**
  * Checks to avoid mempool polluting consensus critical paths since cached
  * signature and script validity results will be reused if we validate this
  * transaction again during block validation.
  */
 static bool CheckInputsFromMempoolAndCache(
     const CTransaction &tx, TxValidationState &state,
     const CCoinsViewCache &view, const CTxMemPool &pool, const uint32_t flags,
     PrecomputedTransactionData &txdata, int &nSigChecksOut,
     CCoinsViewCache &coins_tip) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) {
     AssertLockHeld(cs_main);
     AssertLockHeld(pool.cs);
 
     assert(!tx.IsCoinBase());
     for (const CTxIn &txin : tx.vin) {
         const Coin &coin = view.AccessCoin(txin.prevout);
 
         // This coin was checked in PreChecks and MemPoolAccept
         // has been holding cs_main since then.
         Assume(!coin.IsSpent());
         if (coin.IsSpent()) {
             return false;
         }
 
         // If the Coin is available, there are 2 possibilities:
         // it is available in our current ChainstateActive UTXO set,
         // or it's a UTXO provided by a transaction in our mempool.
         // Ensure the scriptPubKeys in Coins from CoinsView are correct.
         const CTransactionRef &txFrom = pool.get(txin.prevout.GetTxId());
         if (txFrom) {
             assert(txFrom->GetId() == txin.prevout.GetTxId());
             assert(txFrom->vout.size() > txin.prevout.GetN());
             assert(txFrom->vout[txin.prevout.GetN()] == coin.GetTxOut());
         } else {
             const Coin &coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout);
             assert(!coinFromUTXOSet.IsSpent());
             assert(coinFromUTXOSet.GetTxOut() == coin.GetTxOut());
         }
     }
 
     // Call CheckInputScripts() to cache signature and script validity against
     // current tip consensus rules.
     return CheckInputScripts(tx, state, view, flags, /* cacheSigStore = */ true,
                              /* cacheFullScriptStore = */ true, txdata,
                              nSigChecksOut);
 }
 
 namespace {
 
 class MemPoolAccept {
 public:
     MemPoolAccept(CTxMemPool &mempool, CChainState &active_chainstate)
         : m_pool(mempool), m_view(&m_dummy),
           m_viewmempool(&active_chainstate.CoinsTip(), m_pool),
           m_active_chainstate(active_chainstate),
           m_limit_ancestors(
               gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT)),
           m_limit_ancestor_size(
               gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT) *
               1000),
           m_limit_descendants(
               gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT)),
           m_limit_descendant_size(gArgs.GetArg("-limitdescendantsize",
                                                DEFAULT_DESCENDANT_SIZE_LIMIT) *
                                   1000) {}
 
     // We put the arguments we're handed into a struct, so we can pass them
     // around easier.
     struct ATMPArgs {
         const Config &m_config;
         TxValidationState &m_state;
         const int64_t m_accept_time;
         const bool m_bypass_limits;
         /*
          * Return any outpoints which were not previously present in the coins
          * cache, but were added as a result of validating the tx for mempool
          * acceptance. This allows the caller to optionally remove the cache
          * additions if the associated transaction ends up being rejected by
          * the mempool.
          */
         std::vector<COutPoint> &m_coins_to_uncache;
         const bool m_test_accept;
-        Amount *m_fee_out;
+        Amount m_fee_out;
     };
 
     // Single transaction acceptance
-    bool AcceptSingleTransaction(const CTransactionRef &ptx, ATMPArgs &args)
+    MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef &ptx,
+                                                ATMPArgs &args)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 private:
     // All the intermediate state that gets passed between the various levels
     // of checking a given transaction.
     struct Workspace {
         Workspace(const CTransactionRef &ptx,
                   const uint32_t next_block_script_verify_flags)
             : m_ptx(ptx),
               m_next_block_script_verify_flags(next_block_script_verify_flags) {
         }
         CTxMemPool::setEntries m_ancestors;
         std::unique_ptr<CTxMemPoolEntry> m_entry;
 
         Amount m_modified_fees;
 
         const CTransactionRef &m_ptx;
 
         // ABC specific flags that are used in both PreChecks and
         // ConsensusScriptChecks
         const uint32_t m_next_block_script_verify_flags;
         int m_sig_checks_standard;
     };
 
     // Run the policy checks on a given transaction, excluding any script
     // checks. Looks up inputs, calculates feerate, considers replacement,
     // evaluates package limits, etc. As this function can be invoked for "free"
     // by a peer, only tests that are fast should be done here (to avoid CPU
     // DoS).
     bool PreChecks(ATMPArgs &args, Workspace &ws)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
     // Re-run the script checks, using consensus flags, and try to cache the
     // result in the scriptcache. This should be done after
     // PolicyScriptChecks(). This requires that all inputs either be in our
     // utxo set or in the mempool.
     bool ConsensusScriptChecks(ATMPArgs &args, const Workspace &ws,
                                PrecomputedTransactionData &txdata)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
     // Try to add the transaction to the mempool, removing any conflicts first.
     // Returns true if the transaction is in the mempool after any size
     // limiting is performed, false otherwise.
     bool Finalize(ATMPArgs &args, Workspace &ws)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
 private:
     CTxMemPool &m_pool;
     CCoinsViewCache m_view;
     CCoinsViewMemPool m_viewmempool;
     CCoinsView m_dummy;
 
     CChainState &m_active_chainstate;
 
     // The package limits in effect at the time of invocation.
     const size_t m_limit_ancestors;
     const size_t m_limit_ancestor_size;
     // These may be modified while evaluating a transaction (eg to account for
     // in-mempool conflicts; see below).
     size_t m_limit_descendants;
     size_t m_limit_descendant_size;
 };
 
 bool MemPoolAccept::PreChecks(ATMPArgs &args, Workspace &ws) {
     const CTransactionRef &ptx = ws.m_ptx;
     const CTransaction &tx = *ws.m_ptx;
     const TxId &txid = ws.m_ptx->GetId();
 
     // Copy/alias what we need out of args
     TxValidationState &state = args.m_state;
     const int64_t nAcceptTime = args.m_accept_time;
     const bool bypass_limits = args.m_bypass_limits;
     std::vector<COutPoint> &coins_to_uncache = args.m_coins_to_uncache;
 
     // Alias what we need out of ws
     CTxMemPool::setEntries &setAncestors = ws.m_ancestors;
     std::unique_ptr<CTxMemPoolEntry> &entry = ws.m_entry;
     Amount &nModifiedFees = ws.m_modified_fees;
 
     // Coinbase is only valid in a block, not as a loose transaction.
     if (!CheckRegularTransaction(tx, state)) {
         // state filled in by CheckRegularTransaction.
         return false;
     }
 
     // Rather not work on nonstandard transactions (unless -testnet)
     std::string reason;
     if (fRequireStandard && !IsStandardTx(tx, reason)) {
         return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason);
     }
 
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.
     TxValidationState ctxState;
     if (!ContextualCheckTransactionForCurrentBlock(
             m_active_chainstate.m_chain.Tip(),
             args.m_config.GetChainParams().GetConsensus(), tx, ctxState,
             STANDARD_LOCKTIME_VERIFY_FLAGS)) {
         // We copy the state from a dummy to ensure we don't increase the
         // ban score of peer for transaction that could be valid in the future.
         return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND,
                              ctxState.GetRejectReason(),
                              ctxState.GetDebugMessage());
     }
 
     // Is it already in the memory pool?
     if (m_pool.exists(txid)) {
         return state.Invalid(TxValidationResult::TX_CONFLICT,
                              "txn-already-in-mempool");
     }
 
     // Check for conflicts with in-memory transactions
     for (const CTxIn &txin : tx.vin) {
         auto itConflicting = m_pool.mapNextTx.find(txin.prevout);
         if (itConflicting != m_pool.mapNextTx.end()) {
             // Disable replacement feature for good
             return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                                  "txn-mempool-conflict");
         }
     }
 
     LockPoints lp;
     m_view.SetBackend(m_viewmempool);
 
     const CCoinsViewCache &coins_cache = m_active_chainstate.CoinsTip();
     // Do all inputs exist?
     for (const CTxIn &txin : tx.vin) {
         if (!coins_cache.HaveCoinInCache(txin.prevout)) {
             coins_to_uncache.push_back(txin.prevout);
         }
 
         // Note: this call may add txin.prevout to the coins cache
         // (coins_cache.cacheCoins) by way of FetchCoin(). It should be
         // removed later (via coins_to_uncache) if this tx turns out to be
         // invalid.
         if (!m_view.HaveCoin(txin.prevout)) {
             // Are inputs missing because we already have the tx?
             for (size_t out = 0; out < tx.vout.size(); out++) {
                 // Optimistically just do efficient check of cache for
                 // outputs.
                 if (coins_cache.HaveCoinInCache(COutPoint(txid, out))) {
                     return state.Invalid(TxValidationResult::TX_CONFLICT,
                                          "txn-already-known");
                 }
             }
 
             // Otherwise assume this might be an orphan tx for which we just
             // haven't seen parents yet.
             return state.Invalid(TxValidationResult::TX_MISSING_INPUTS,
                                  "bad-txns-inputs-missingorspent");
         }
     }
 
     // Are the actual inputs available?
     if (!m_view.HaveInputs(tx)) {
         return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                              "bad-txns-inputs-spent");
     }
 
     // Bring the best block into scope.
     m_view.GetBestBlock();
 
     // we have all inputs cached now, so switch back to dummy (to protect
     // against bugs where we pull more inputs from disk that miss being
     // added to coins_to_uncache)
     m_view.SetBackend(m_dummy);
 
     // Only accept BIP68 sequence locked transactions that can be mined in
     // the next block; we don't want our mempool filled up with transactions
     // that can't be mined yet. Must keep pool.cs for this unless we change
     // CheckSequenceLocks to take a CoinsViewCache instead of create its
     // own.
     if (!CheckSequenceLocks(m_active_chainstate, m_pool, tx,
                             STANDARD_LOCKTIME_VERIFY_FLAGS, &lp)) {
         return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND,
                              "non-BIP68-final");
     }
 
     Amount nFees = Amount::zero();
     if (!Consensus::CheckTxInputs(
             tx, state, m_view,
             m_active_chainstate.m_blockman.GetSpendHeight(m_view), nFees)) {
         // state filled in by CheckTxInputs
         return false;
     }
 
-    // If fee_out is passed, return the fee to the caller
-    if (args.m_fee_out) {
-        *args.m_fee_out = nFees;
-    }
+    args.m_fee_out = nFees;
 
     // Check for non-standard pay-to-script-hash in inputs
     if (fRequireStandard &&
         !AreInputsStandard(tx, m_view, ws.m_next_block_script_verify_flags)) {
         return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD,
                              "bad-txns-nonstandard-inputs");
     }
 
     // nModifiedFees includes any fee deltas from PrioritiseTransaction
     nModifiedFees = nFees;
     m_pool.ApplyDelta(txid, nModifiedFees);
 
     // Keep track of transactions that spend a coinbase, which we re-scan
     // during reorgs to ensure COINBASE_MATURITY is still met.
     bool fSpendsCoinbase = false;
     for (const CTxIn &txin : tx.vin) {
         const Coin &coin = m_view.AccessCoin(txin.prevout);
         if (coin.IsCoinBase()) {
             fSpendsCoinbase = true;
             break;
         }
     }
 
     unsigned int nSize = tx.GetTotalSize();
 
     // No transactions are allowed below minRelayTxFee except from disconnected
     // blocks.
     // Do not change this to use virtualsize without coordinating a network
     // policy upgrade.
     if (!bypass_limits && nModifiedFees < minRelayTxFee.GetFee(nSize)) {
         return state.Invalid(
             TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
             strprintf("%d < %d", nModifiedFees, ::minRelayTxFee.GetFee(nSize)));
     }
 
     // Validate input scripts against standard script flags.
     const uint32_t scriptVerifyFlags =
         ws.m_next_block_script_verify_flags | STANDARD_SCRIPT_VERIFY_FLAGS;
     PrecomputedTransactionData txdata(tx);
     if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false,
                            txdata, ws.m_sig_checks_standard)) {
         // State filled in by CheckInputScripts
         return false;
     }
 
     entry.reset(new CTxMemPoolEntry(
         ptx, nFees, nAcceptTime, m_active_chainstate.m_chain.Height(),
         fSpendsCoinbase, ws.m_sig_checks_standard, lp));
 
     unsigned int nVirtualSize = entry->GetTxVirtualSize();
 
     Amount mempoolRejectFee =
         m_pool
             .GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                        1000000)
             .GetFee(nVirtualSize);
     if (!bypass_limits && mempoolRejectFee > Amount::zero() &&
         nModifiedFees < mempoolRejectFee) {
         return state.Invalid(
             TxValidationResult::TX_MEMPOOL_POLICY, "mempool min fee not met",
             strprintf("%d < %d", nModifiedFees, mempoolRejectFee));
     }
 
     // Calculate in-mempool ancestors, up to a limit.
     std::string errString;
     if (!m_pool.CalculateMemPoolAncestors(
             *entry, setAncestors, m_limit_ancestors, m_limit_ancestor_size,
             m_limit_descendants, m_limit_descendant_size, errString)) {
         return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                              "too-long-mempool-chain", errString);
     }
     return true;
 }
 
 bool MemPoolAccept::ConsensusScriptChecks(ATMPArgs &args, const Workspace &ws,
                                           PrecomputedTransactionData &txdata) {
     const CTransaction &tx = *ws.m_ptx;
     const TxId &txid = tx.GetId();
 
     TxValidationState &state = args.m_state;
 
     // Check again against the next block's script verification flags
     // to cache our script execution flags.
     //
     // This is also useful in case of bugs in the standard flags that cause
     // transactions to pass as valid when they're actually invalid. For
     // instance the STRICTENC flag was incorrectly allowing certain CHECKSIG
     // NOT scripts to pass, even though they were invalid.
     //
     // There is a similar check in CreateNewBlock() to prevent creating
     // invalid blocks (using TestBlockValidity), however allowing such
     // transactions into the mempool can be exploited as a DoS attack.
     int nSigChecksConsensus;
     if (!CheckInputsFromMempoolAndCache(
             tx, state, m_view, m_pool, ws.m_next_block_script_verify_flags,
             txdata, nSigChecksConsensus, m_active_chainstate.CoinsTip())) {
         // This can occur under some circumstances, if the node receives an
         // unrequested tx which is invalid due to new consensus rules not
         // being activated yet (during IBD).
         return error("%s: BUG! PLEASE REPORT THIS! CheckInputScripts failed "
                      "against next-block but not STANDARD flags %s, %s",
                      __func__, txid.ToString(), state.ToString());
     }
 
     if (ws.m_sig_checks_standard != nSigChecksConsensus) {
         // We can't accept this transaction as we've used the standard count
         // for the mempool/mining, but the consensus count will be enforced
         // in validation (we don't want to produce bad block templates).
         return error(
             "%s: BUG! PLEASE REPORT THIS! SigChecks count differed between "
             "standard and consensus flags in %s",
             __func__, txid.ToString());
     }
     return true;
 }
 
 bool MemPoolAccept::Finalize(ATMPArgs &args, Workspace &ws) {
     const TxId &txid = ws.m_ptx->GetId();
     TxValidationState &state = args.m_state;
     const bool bypass_limits = args.m_bypass_limits;
 
     CTxMemPool::setEntries &setAncestors = ws.m_ancestors;
     std::unique_ptr<CTxMemPoolEntry> &entry = ws.m_entry;
 
     // Store transaction in memory.
     m_pool.addUnchecked(*entry, setAncestors);
 
     // Trim mempool and check if tx was trimmed.
     if (!bypass_limits) {
         m_pool.LimitSize(
             m_active_chainstate.CoinsTip(),
             gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000,
             std::chrono::hours{
                 gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY)});
         if (!m_pool.exists(txid)) {
             return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                                  "mempool full");
         }
     }
     return true;
 }
 
-bool MemPoolAccept::AcceptSingleTransaction(const CTransactionRef &ptx,
-                                            ATMPArgs &args) {
+MempoolAcceptResult
+MemPoolAccept::AcceptSingleTransaction(const CTransactionRef &ptx,
+                                       ATMPArgs &args) {
     AssertLockHeld(cs_main);
     // mempool "read lock" (held through
     // GetMainSignals().TransactionAddedToMempool())
     LOCK(m_pool.cs);
 
     Workspace workspace(ptx, GetNextBlockScriptFlags(
                                  args.m_config.GetChainParams().GetConsensus(),
                                  m_active_chainstate.m_chain.Tip()));
 
     if (!PreChecks(args, workspace)) {
-        return false;
+        return MempoolAcceptResult(args.m_state);
     }
 
     // Only compute the precomputed transaction data if we need to verify
     // scripts (ie, other policy checks pass). We perform the inexpensive
     // checks first and avoid hashing and signature verification unless those
     // checks pass, to mitigate CPU exhaustion denial-of-service attacks.
     PrecomputedTransactionData txdata(*ptx);
 
     if (!ConsensusScriptChecks(args, workspace, txdata)) {
-        return false;
+        return MempoolAcceptResult(args.m_state);
     }
 
     // Tx was accepted, but not added
     if (args.m_test_accept) {
-        return true;
+        return MempoolAcceptResult(args.m_fee_out);
     }
 
     if (!Finalize(args, workspace)) {
-        return false;
+        return MempoolAcceptResult(args.m_state);
     }
 
     GetMainSignals().TransactionAddedToMempool(
         ptx, m_pool.GetAndIncrementSequence());
 
-    return true;
+    return MempoolAcceptResult(args.m_fee_out);
 }
 
 } // namespace
 
 /**
  * (try to) add transaction to memory pool with a specified acceptance time.
  */
-static bool AcceptToMemoryPoolWithTime(
+static MempoolAcceptResult AcceptToMemoryPoolWithTime(
     const Config &config, CTxMemPool &pool, CChainState &active_chainstate,
-    TxValidationState &state, const CTransactionRef &tx, int64_t nAcceptTime,
-    bool bypass_limits, bool test_accept, Amount *fee_out = nullptr)
-    EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
+    const CTransactionRef &tx, int64_t nAcceptTime, bool bypass_limits,
+    bool test_accept) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
+    TxValidationState state;
     std::vector<COutPoint> coins_to_uncache;
     MemPoolAccept::ATMPArgs args{
         config,           state,       nAcceptTime, bypass_limits,
-        coins_to_uncache, test_accept, fee_out};
-    bool res = MemPoolAccept(pool, active_chainstate)
-                   .AcceptSingleTransaction(tx, args);
-    if (!res) {
+        coins_to_uncache, test_accept, {}};
+    const MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate)
+                                           .AcceptSingleTransaction(tx, args);
+    if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
         // Remove coins that were not present in the coins cache before calling
         // ATMPW; this is to prevent memory DoS in case we receive a large
         // number of invalid transactions that attempt to overrun the in-memory
         // coins cache
         // (`CCoinsViewCache::cacheCoins`).
 
         for (const COutPoint &outpoint : coins_to_uncache) {
             active_chainstate.CoinsTip().Uncache(outpoint);
         }
     }
 
     // After we've (potentially) uncached entries, ensure our coins cache is
     // still within its size limits
     BlockValidationState stateDummy;
     active_chainstate.FlushStateToDisk(config.GetChainParams(), stateDummy,
                                        FlushStateMode::PERIODIC);
-    return res;
+    return result;
 }
 
-bool AcceptToMemoryPool(CChainState &active_chainstate, const Config &config,
-                        CTxMemPool &pool, TxValidationState &state,
-                        const CTransactionRef &tx, bool bypass_limits,
-                        bool test_accept, Amount *fee_out) {
-    return AcceptToMemoryPoolWithTime(config, pool, active_chainstate, state,
-                                      tx, GetTime(), bypass_limits, test_accept,
-                                      fee_out);
+MempoolAcceptResult AcceptToMemoryPool(CChainState &active_chainstate,
+                                       const Config &config, CTxMemPool &pool,
+                                       const CTransactionRef &tx,
+                                       bool bypass_limits, bool test_accept) {
+    return AcceptToMemoryPoolWithTime(config, pool, active_chainstate, tx,
+                                      GetTime(), bypass_limits, test_accept);
 }
 
 CTransactionRef GetTransaction(const CBlockIndex *const block_index,
                                const CTxMemPool *const mempool,
                                const TxId &txid,
                                const Consensus::Params &consensusParams,
                                BlockHash &hashBlock) {
     LOCK(cs_main);
 
     if (block_index) {
         CBlock block;
         if (ReadBlockFromDisk(block, block_index, consensusParams)) {
             for (const auto &tx : block.vtx) {
                 if (tx->GetId() == txid) {
                     hashBlock = block_index->GetBlockHash();
                     return tx;
                 }
             }
         }
         return nullptr;
     }
     if (mempool) {
         CTransactionRef ptx = mempool->get(txid);
         if (ptx) {
             return ptx;
         }
     }
     if (g_txindex) {
         CTransactionRef tx;
         if (g_txindex->FindTx(txid, hashBlock, tx)) {
             return tx;
         }
     }
     return nullptr;
 }
 
 Amount GetBlockSubsidy(int nHeight, const Consensus::Params &consensusParams) {
     int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
     // Force block reward to zero when right shift is undefined.
     if (halvings >= 64) {
         return Amount::zero();
     }
 
     Amount nSubsidy = 50 * COIN;
     // Subsidy is cut in half every 210,000 blocks which will occur
     // approximately every 4 years.
     return ((nSubsidy / SATOSHI) >> halvings) * SATOSHI;
 }
 
 CoinsViews::CoinsViews(std::string ldb_name, size_t cache_size_bytes,
                        bool in_memory, bool should_wipe)
     : m_dbview(GetDataDir() / ldb_name, cache_size_bytes, in_memory,
                should_wipe),
       m_catcherview(&m_dbview) {}
 
 void CoinsViews::InitCache() {
     m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview);
 }
 
 CChainState::CChainState(CTxMemPool &mempool, BlockManager &blockman,
                          std::optional<BlockHash> from_snapshot_blockhash)
     : m_mempool(mempool), m_blockman(blockman),
       m_from_snapshot_blockhash(from_snapshot_blockhash) {}
 
 void CChainState::InitCoinsDB(size_t cache_size_bytes, bool in_memory,
                               bool should_wipe, std::string leveldb_name) {
     if (m_from_snapshot_blockhash) {
         leveldb_name += "_" + m_from_snapshot_blockhash->ToString();
     }
     m_coins_views = std::make_unique<CoinsViews>(leveldb_name, cache_size_bytes,
                                                  in_memory, should_wipe);
 }
 
 void CChainState::InitCoinsCache(size_t cache_size_bytes) {
     assert(m_coins_views != nullptr);
     m_coinstip_cache_size_bytes = cache_size_bytes;
     m_coins_views->InitCache();
 }
 
 // Note that though this is marked const, we may end up modifying
 // `m_cached_finished_ibd`, which is a performance-related implementation
 // detail. This function must be marked `const` so that `CValidationInterface`
 // clients (which are given a `const CChainState*`) can call it.
 //
 bool CChainState::IsInitialBlockDownload() const {
     // Optimization: pre-test latch before taking the lock.
     if (m_cached_finished_ibd.load(std::memory_order_relaxed)) {
         return false;
     }
 
     LOCK(cs_main);
     if (m_cached_finished_ibd.load(std::memory_order_relaxed)) {
         return false;
     }
     if (fImporting || fReindex) {
         return true;
     }
     if (m_chain.Tip() == nullptr) {
         return true;
     }
     if (m_chain.Tip()->nChainWork < nMinimumChainWork) {
         return true;
     }
     if (m_chain.Tip()->GetBlockTime() < (GetTime() - nMaxTipAge)) {
         return true;
     }
     LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
     m_cached_finished_ibd.store(true, std::memory_order_relaxed);
     return false;
 }
 
 static CBlockIndex const *pindexBestForkTip = nullptr;
 static CBlockIndex const *pindexBestForkBase = nullptr;
 
 static void AlertNotify(const std::string &strMessage) {
     uiInterface.NotifyAlertChanged();
 #if defined(HAVE_SYSTEM)
     std::string strCmd = gArgs.GetArg("-alertnotify", "");
     if (strCmd.empty()) {
         return;
     }
 
     // Alert text should be plain ascii coming from a trusted source, but to be
     // safe we first strip anything not in safeChars, then add single quotes
     // around the whole string before passing it to the shell:
     std::string singleQuote("'");
     std::string safeStatus = SanitizeString(strMessage);
     safeStatus = singleQuote + safeStatus + singleQuote;
     boost::replace_all(strCmd, "%s", safeStatus);
 
     std::thread t(runCommand, strCmd);
     // thread runs free
     t.detach();
 #endif
 }
 
 void CChainState::CheckForkWarningConditions() {
     AssertLockHeld(cs_main);
 
     // Before we get past initial download, we cannot reliably alert about forks
     // (we assume we don't get stuck on a fork before finishing our initial
     // sync)
     if (IsInitialBlockDownload()) {
         return;
     }
 
     // If our best fork is no longer within 72 blocks (+/- 12 hours if no one
     // mines it) of our head, drop it
     if (pindexBestForkTip &&
         m_chain.Height() - pindexBestForkTip->nHeight >= 72) {
         pindexBestForkTip = nullptr;
     }
 
     if (pindexBestForkTip ||
         (pindexBestInvalid &&
          pindexBestInvalid->nChainWork >
              m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6))) {
         if (!GetfLargeWorkForkFound() && pindexBestForkBase) {
             std::string warning =
                 std::string("'Warning: Large-work fork detected, forking after "
                             "block ") +
                 pindexBestForkBase->phashBlock->ToString() + std::string("'");
             AlertNotify(warning);
         }
 
         if (pindexBestForkTip && pindexBestForkBase) {
             LogPrintf("%s: Warning: Large fork found\n  forking the "
                       "chain at height %d (%s)\n  lasting to height %d "
                       "(%s).\nChain state database corruption likely.\n",
                       __func__, pindexBestForkBase->nHeight,
                       pindexBestForkBase->phashBlock->ToString(),
                       pindexBestForkTip->nHeight,
                       pindexBestForkTip->phashBlock->ToString());
             SetfLargeWorkForkFound(true);
         } else {
             LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks "
                       "longer than our best chain.\nChain state database "
                       "corruption likely.\n",
                       __func__);
             SetfLargeWorkInvalidChainFound(true);
         }
     } else {
         SetfLargeWorkForkFound(false);
         SetfLargeWorkInvalidChainFound(false);
     }
 }
 
 void CChainState::CheckForkWarningConditionsOnNewFork(
     CBlockIndex *pindexNewForkTip) {
     AssertLockHeld(cs_main);
 
     // If we are on a fork that is sufficiently large, set a warning flag.
     const CBlockIndex *pfork = m_chain.FindFork(pindexNewForkTip);
 
     // We define a condition where we should warn the user about as a fork of at
     // least 7 blocks with a tip within 72 blocks (+/- 12 hours if no one mines
     // it) of ours. We use 7 blocks rather arbitrarily as it represents just
     // under 10% of sustained network hash rate operating on the fork, or a
     // chain that is entirely longer than ours and invalid (note that this
     // should be detected by both). We define it this way because it allows us
     // to only store the highest fork tip (+ base) which meets the 7-block
     // condition and from this always have the most-likely-to-cause-warning fork
     if (pfork &&
         (!pindexBestForkTip ||
          pindexNewForkTip->nHeight > pindexBestForkTip->nHeight) &&
         pindexNewForkTip->nChainWork - pfork->nChainWork >
             (GetBlockProof(*pfork) * 7) &&
         m_chain.Height() - pindexNewForkTip->nHeight < 72) {
         pindexBestForkTip = pindexNewForkTip;
         pindexBestForkBase = pfork;
     }
 
     CheckForkWarningConditions();
 }
 
 // Called both upon regular invalid block discovery *and* InvalidateBlock
 void CChainState::InvalidChainFound(CBlockIndex *pindexNew) {
     AssertLockHeld(cs_main);
     if (!pindexBestInvalid ||
         pindexNew->nChainWork > pindexBestInvalid->nChainWork) {
         pindexBestInvalid = pindexNew;
     }
     if (pindexBestHeader != nullptr &&
         pindexBestHeader->GetAncestor(pindexNew->nHeight) == pindexNew) {
         pindexBestHeader = m_chain.Tip();
     }
 
     // If the invalid chain found is supposed to be finalized, we need to move
     // back the finalization point.
     if (IsBlockFinalized(pindexNew)) {
         m_finalizedBlockIndex = pindexNew->pprev;
     }
 
     LogPrintf("%s: invalid block=%s  height=%d  log2_work=%f  date=%s\n",
               __func__, pindexNew->GetBlockHash().ToString(),
               pindexNew->nHeight,
               log(pindexNew->nChainWork.getdouble()) / log(2.0),
               FormatISO8601DateTime(pindexNew->GetBlockTime()));
     CBlockIndex *tip = m_chain.Tip();
     assert(tip);
     LogPrintf("%s:  current best=%s  height=%d  log2_work=%f  date=%s\n",
               __func__, tip->GetBlockHash().ToString(), m_chain.Height(),
               log(tip->nChainWork.getdouble()) / log(2.0),
               FormatISO8601DateTime(tip->GetBlockTime()));
 }
 
 // Same as InvalidChainFound, above, except not called directly from
 // InvalidateBlock, which does its own setBlockIndexCandidates management.
 void CChainState::InvalidBlockFound(CBlockIndex *pindex,
                                     const BlockValidationState &state) {
     if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
         pindex->nStatus = pindex->nStatus.withFailed();
         m_blockman.m_failed_blocks.insert(pindex);
         setDirtyBlockIndex.insert(pindex);
         InvalidChainFound(pindex);
     }
 }
 
 void SpendCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                 int nHeight) {
     // Mark inputs spent.
     if (tx.IsCoinBase()) {
         return;
     }
 
     txundo.vprevout.reserve(tx.vin.size());
     for (const CTxIn &txin : tx.vin) {
         txundo.vprevout.emplace_back();
         bool is_spent = view.SpendCoin(txin.prevout, &txundo.vprevout.back());
         assert(is_spent);
     }
 }
 
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                  int nHeight) {
     SpendCoins(view, tx, txundo, nHeight);
     AddCoins(view, tx, nHeight);
 }
 
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, int nHeight) {
     // Mark inputs spent.
     if (!tx.IsCoinBase()) {
         for (const CTxIn &txin : tx.vin) {
             bool is_spent = view.SpendCoin(txin.prevout);
             assert(is_spent);
         }
     }
 
     // Add outputs.
     AddCoins(view, tx, nHeight);
 }
 
 bool CScriptCheck::operator()() {
     const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
     if (!VerifyScript(scriptSig, m_tx_out.scriptPubKey, nFlags,
                       CachingTransactionSignatureChecker(
                           ptxTo, nIn, m_tx_out.nValue, cacheStore, txdata),
                       metrics, &error)) {
         return false;
     }
     if ((pTxLimitSigChecks &&
          !pTxLimitSigChecks->consume_and_check(metrics.nSigChecks)) ||
         (pBlockLimitSigChecks &&
          !pBlockLimitSigChecks->consume_and_check(metrics.nSigChecks))) {
         // we can't assign a meaningful script error (since the script
         // succeeded), but remove the ScriptError::OK which could be
         // misinterpreted.
         error = ScriptError::SIGCHECKS_LIMIT_EXCEEDED;
         return false;
     }
     return true;
 }
 
 int BlockManager::GetSpendHeight(const CCoinsViewCache &inputs) {
     AssertLockHeld(cs_main);
     CBlockIndex *pindexPrev = LookupBlockIndex(inputs.GetBestBlock());
     return pindexPrev->nHeight + 1;
 }
 
 bool CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                        const CCoinsViewCache &inputs, const uint32_t flags,
                        bool sigCacheStore, bool scriptCacheStore,
                        const PrecomputedTransactionData &txdata,
                        int &nSigChecksOut, TxSigCheckLimiter &txLimitSigChecks,
                        CheckInputsLimiter *pBlockLimitSigChecks,
                        std::vector<CScriptCheck> *pvChecks) {
     AssertLockHeld(cs_main);
     assert(!tx.IsCoinBase());
 
     if (pvChecks) {
         pvChecks->reserve(tx.vin.size());
     }
 
     // First check if script executions have been cached with the same flags.
     // Note that this assumes that the inputs provided are correct (ie that the
     // transaction hash which is in tx's prevouts properly commits to the
     // scriptPubKey in the inputs view of that transaction).
     ScriptCacheKey hashCacheEntry(tx, flags);
     if (IsKeyInScriptCache(hashCacheEntry, !scriptCacheStore, nSigChecksOut)) {
         if (!txLimitSigChecks.consume_and_check(nSigChecksOut) ||
             (pBlockLimitSigChecks &&
              !pBlockLimitSigChecks->consume_and_check(nSigChecksOut))) {
             return state.Invalid(TxValidationResult::TX_CONSENSUS,
                                  "too-many-sigchecks");
         }
         return true;
     }
 
     int nSigChecksTotal = 0;
 
     for (size_t i = 0; i < tx.vin.size(); i++) {
         const COutPoint &prevout = tx.vin[i].prevout;
         const Coin &coin = inputs.AccessCoin(prevout);
         assert(!coin.IsSpent());
 
         // We very carefully only pass in things to CScriptCheck which are
         // clearly committed to by tx's hash. This provides a sanity
         // check that our caching is not introducing consensus failures through
         // additional data in, eg, the coins being spent being checked as a part
         // of CScriptCheck.
 
         // Verify signature
         CScriptCheck check(coin.GetTxOut(), tx, i, flags, sigCacheStore, txdata,
                            &txLimitSigChecks, pBlockLimitSigChecks);
 
         // If pvChecks is not null, defer the check execution to the caller.
         if (pvChecks) {
             pvChecks->push_back(std::move(check));
             continue;
         }
 
         if (!check()) {
             ScriptError scriptError = check.GetScriptError();
             // Compute flags without the optional standardness flags.
             // This differs from MANDATORY_SCRIPT_VERIFY_FLAGS as it contains
             // additional upgrade flags (see AcceptToMemoryPoolWorker variable
             // extraFlags).
             uint32_t mandatoryFlags =
                 flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS;
             if (flags != mandatoryFlags) {
                 // Check whether the failure was caused by a non-mandatory
                 // script verification check. If so, ensure we return
                 // NOT_STANDARD instead of CONSENSUS to avoid downstream users
                 // splitting the network between upgraded and non-upgraded nodes
                 // by banning CONSENSUS-failing data providers.
                 CScriptCheck check2(coin.GetTxOut(), tx, i, mandatoryFlags,
                                     sigCacheStore, txdata);
                 if (check2()) {
                     return state.Invalid(
                         TxValidationResult::TX_NOT_STANDARD,
                         strprintf("non-mandatory-script-verify-flag (%s)",
                                   ScriptErrorString(scriptError)));
                 }
                 // update the error message to reflect the mandatory violation.
                 scriptError = check2.GetScriptError();
             }
 
             // MANDATORY flag failures correspond to
             // TxValidationResult::TX_CONSENSUS. Because CONSENSUS failures are
             // the most serious case of validation failures, we may need to
             // consider using RECENT_CONSENSUS_CHANGE for any script failure
             // that could be due to non-upgraded nodes which we may want to
             // support, to avoid splitting the network (but this depends on the
             // details of how net_processing handles such errors).
             return state.Invalid(
                 TxValidationResult::TX_CONSENSUS,
                 strprintf("mandatory-script-verify-flag-failed (%s)",
                           ScriptErrorString(scriptError)));
         }
 
         nSigChecksTotal += check.GetScriptExecutionMetrics().nSigChecks;
     }
 
     nSigChecksOut = nSigChecksTotal;
 
     if (scriptCacheStore && !pvChecks) {
         // We executed all of the provided scripts, and were told to cache the
         // result. Do so now.
         AddKeyInScriptCache(hashCacheEntry, nSigChecksTotal);
     }
 
     return true;
 }
 
 static bool UndoWriteToDisk(const CBlockUndo &blockundo, FlatFilePos &pos,
                             const BlockHash &hashBlock,
                             const CMessageHeader::MessageMagic &messageStart) {
     // Open history file to append
     CAutoFile fileout(OpenUndoFile(pos), SER_DISK, CLIENT_VERSION);
     if (fileout.IsNull()) {
         return error("%s: OpenUndoFile failed", __func__);
     }
 
     // Write index header
     unsigned int nSize = GetSerializeSize(blockundo, fileout.GetVersion());
     fileout << messageStart << nSize;
 
     // Write undo data
     long fileOutPos = ftell(fileout.Get());
     if (fileOutPos < 0) {
         return error("%s: ftell failed", __func__);
     }
     pos.nPos = (unsigned int)fileOutPos;
     fileout << blockundo;
 
     // calculate & write checksum
     CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
     hasher << hashBlock;
     hasher << blockundo;
     fileout << hasher.GetHash();
 
     return true;
 }
 
 bool UndoReadFromDisk(CBlockUndo &blockundo, const CBlockIndex *pindex) {
     FlatFilePos pos = pindex->GetUndoPos();
     if (pos.IsNull()) {
         return error("%s: no undo data available", __func__);
     }
 
     // Open history file to read
     CAutoFile filein(OpenUndoFile(pos, true), SER_DISK, CLIENT_VERSION);
     if (filein.IsNull()) {
         return error("%s: OpenUndoFile failed", __func__);
     }
 
     // Read block
     uint256 hashChecksum;
     // We need a CHashVerifier as reserializing may lose data
     CHashVerifier<CAutoFile> verifier(&filein);
     try {
         verifier << pindex->pprev->GetBlockHash();
         verifier >> blockundo;
         filein >> hashChecksum;
     } catch (const std::exception &e) {
         return error("%s: Deserialize or I/O error - %s", __func__, e.what());
     }
 
     // Verify checksum
     if (hashChecksum != verifier.GetHash()) {
         return error("%s: Checksum mismatch", __func__);
     }
 
     return true;
 }
 
 static bool AbortNode(BlockValidationState &state,
                       const std::string &strMessage,
                       const bilingual_str &userMessage = bilingual_str()) {
     AbortNode(strMessage, userMessage);
     return state.Error(strMessage);
 }
 
 /** Restore the UTXO in a Coin at a given COutPoint. */
 DisconnectResult UndoCoinSpend(const Coin &undo, CCoinsViewCache &view,
                                const COutPoint &out) {
     bool fClean = true;
 
     if (view.HaveCoin(out)) {
         // Overwriting transaction output.
         fClean = false;
     }
 
     if (undo.GetHeight() == 0) {
         // Missing undo metadata (height and coinbase). Older versions included
         // this information only in undo records for the last spend of a
         // transactions' outputs. This implies that it must be present for some
         // other output of the same tx.
         const Coin &alternate = AccessByTxid(view, out.GetTxId());
         if (alternate.IsSpent()) {
             // Adding output for transaction without known metadata
             return DisconnectResult::FAILED;
         }
 
         // This is somewhat ugly, but hopefully utility is limited. This is only
         // useful when working from legacy on disck data. In any case, putting
         // the correct information in there doesn't hurt.
         const_cast<Coin &>(undo) = Coin(undo.GetTxOut(), alternate.GetHeight(),
                                         alternate.IsCoinBase());
     }
 
     // If the coin already exists as an unspent coin in the cache, then the
     // possible_overwrite parameter to AddCoin must be set to true. We have
     // already checked whether an unspent coin exists above using HaveCoin, so
     // we don't need to guess. When fClean is false, an unspent coin already
     // existed and it is an overwrite.
     view.AddCoin(out, std::move(undo), !fClean);
 
     return fClean ? DisconnectResult::OK : DisconnectResult::UNCLEAN;
 }
 
 /**
  * Undo the effects of this block (with given index) on the UTXO set represented
  * by coins. When FAILED is returned, view is left in an indeterminate state.
  */
 DisconnectResult CChainState::DisconnectBlock(const CBlock &block,
                                               const CBlockIndex *pindex,
                                               CCoinsViewCache &view) {
     CBlockUndo blockUndo;
     if (!UndoReadFromDisk(blockUndo, pindex)) {
         error("DisconnectBlock(): failure reading undo data");
         return DisconnectResult::FAILED;
     }
 
     return ApplyBlockUndo(blockUndo, block, pindex, view);
 }
 
 DisconnectResult ApplyBlockUndo(const CBlockUndo &blockUndo,
                                 const CBlock &block, const CBlockIndex *pindex,
                                 CCoinsViewCache &view) {
     bool fClean = true;
 
     if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
         error("DisconnectBlock(): block and undo data inconsistent");
         return DisconnectResult::FAILED;
     }
 
     // First, restore inputs.
     for (size_t i = 1; i < block.vtx.size(); i++) {
         const CTransaction &tx = *(block.vtx[i]);
         const CTxUndo &txundo = blockUndo.vtxundo[i - 1];
         if (txundo.vprevout.size() != tx.vin.size()) {
             error("DisconnectBlock(): transaction and undo data inconsistent");
             return DisconnectResult::FAILED;
         }
 
         for (size_t j = 0; j < tx.vin.size(); j++) {
             const COutPoint &out = tx.vin[j].prevout;
             const Coin &undo = txundo.vprevout[j];
             DisconnectResult res = UndoCoinSpend(undo, view, out);
             if (res == DisconnectResult::FAILED) {
                 return DisconnectResult::FAILED;
             }
             fClean = fClean && res != DisconnectResult::UNCLEAN;
         }
     }
 
     // Second, revert created outputs.
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         const TxId &txid = tx.GetId();
         const bool is_coinbase = tx.IsCoinBase();
 
         // Check that all outputs are available and match the outputs in the
         // block itself exactly.
         for (size_t o = 0; o < tx.vout.size(); o++) {
             if (tx.vout[o].scriptPubKey.IsUnspendable()) {
                 continue;
             }
 
             COutPoint out(txid, o);
             Coin coin;
             bool is_spent = view.SpendCoin(out, &coin);
             if (!is_spent || tx.vout[o] != coin.GetTxOut() ||
                 uint32_t(pindex->nHeight) != coin.GetHeight() ||
                 is_coinbase != coin.IsCoinBase()) {
                 // transaction output mismatch
                 fClean = false;
             }
         }
     }
 
     // Move best block pointer to previous block.
     view.SetBestBlock(block.hashPrevBlock);
 
     return fClean ? DisconnectResult::OK : DisconnectResult::UNCLEAN;
 }
 
 static void FlushUndoFile(int block_file, bool finalize = false) {
     FlatFilePos undo_pos_old(block_file, vinfoBlockFile[block_file].nUndoSize);
     if (!UndoFileSeq().Flush(undo_pos_old, finalize)) {
         AbortNode("Flushing undo file to disk failed. This is likely the "
                   "result of an I/O error.");
     }
 }
 
 static void FlushBlockFile(bool fFinalize = false, bool finalize_undo = false) {
     LOCK(cs_LastBlockFile);
     FlatFilePos block_pos_old(nLastBlockFile,
                               vinfoBlockFile[nLastBlockFile].nSize);
     if (!BlockFileSeq().Flush(block_pos_old, fFinalize)) {
         AbortNode("Flushing block file to disk failed. This is likely the "
                   "result of an I/O error.");
     }
     // we do not always flush the undo file, as the chain tip may be lagging
     // behind the incoming blocks,
     // e.g. during IBD or a sync after a node going offline
     if (!fFinalize || finalize_undo) {
         FlushUndoFile(nLastBlockFile, finalize_undo);
     }
 }
 
 static bool FindUndoPos(BlockValidationState &state, int nFile,
                         FlatFilePos &pos, unsigned int nAddSize);
 
 static bool WriteUndoDataForBlock(const CBlockUndo &blockundo,
                                   BlockValidationState &state,
                                   CBlockIndex *pindex,
                                   const CChainParams &chainparams) {
     // Write undo information to disk
     if (pindex->GetUndoPos().IsNull()) {
         FlatFilePos _pos;
         if (!FindUndoPos(state, pindex->nFile, _pos,
                          ::GetSerializeSize(blockundo, CLIENT_VERSION) + 40)) {
             return error("ConnectBlock(): FindUndoPos failed");
         }
         if (!UndoWriteToDisk(blockundo, _pos, pindex->pprev->GetBlockHash(),
                              chainparams.DiskMagic())) {
             return AbortNode(state, "Failed to write undo data");
         }
         // rev files are written in block height order, whereas blk files are
         // written as blocks come in (often out of order) we want to flush the
         // rev (undo) file once we've written the last block, which is indicated
         // by the last height in the block file info as below; note that this
         // does not catch the case where the undo writes are keeping up with the
         // block writes (usually when a synced up node is getting newly mined
         // blocks) -- this case is caught in the FindBlockPos function
         if (_pos.nFile < nLastBlockFile &&
             static_cast<uint32_t>(pindex->nHeight) ==
                 vinfoBlockFile[_pos.nFile].nHeightLast) {
             FlushUndoFile(_pos.nFile, true);
         }
 
         // update nUndoPos in block index
         pindex->nUndoPos = _pos.nPos;
         pindex->nStatus = pindex->nStatus.withUndo();
         setDirtyBlockIndex.insert(pindex);
     }
 
     return true;
 }
 
 static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
 
 void StartScriptCheckWorkerThreads(int threads_num) {
     scriptcheckqueue.StartWorkerThreads(threads_num);
 }
 
 void StopScriptCheckWorkerThreads() {
     scriptcheckqueue.StopWorkerThreads();
 }
 
 VersionBitsCache versionbitscache GUARDED_BY(cs_main);
 
 int32_t ComputeBlockVersion(const CBlockIndex *pindexPrev,
                             const Consensus::Params &params) {
     LOCK(cs_main);
     int32_t nVersion = VERSIONBITS_TOP_BITS;
 
     for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
         ThresholdState state = VersionBitsState(
             pindexPrev, params, static_cast<Consensus::DeploymentPos>(i),
             versionbitscache);
         if (state == ThresholdState::LOCKED_IN ||
             state == ThresholdState::STARTED) {
             nVersion |= VersionBitsMask(
                 params, static_cast<Consensus::DeploymentPos>(i));
         }
     }
 
     // Clear the last 4 bits (miner fund activation).
     return nVersion & ~uint32_t(0x0f);
 }
 
 // Returns the script flags which should be checked for the block after
 // the given block.
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex) {
     uint32_t flags = SCRIPT_VERIFY_NONE;
 
     // Start enforcing P2SH (BIP16)
     if ((pindex->nHeight + 1) >= params.BIP16Height) {
         flags |= SCRIPT_VERIFY_P2SH;
     }
 
     // Start enforcing the DERSIG (BIP66) rule.
     if ((pindex->nHeight + 1) >= params.BIP66Height) {
         flags |= SCRIPT_VERIFY_DERSIG;
     }
 
     // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule.
     if ((pindex->nHeight + 1) >= params.BIP65Height) {
         flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
     }
 
     // Start enforcing CSV (BIP68, BIP112 and BIP113) rule.
     if ((pindex->nHeight + 1) >= params.CSVHeight) {
         flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
     }
 
     // If the UAHF is enabled, we start accepting replay protected txns
     if (IsUAHFenabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_STRICTENC;
         flags |= SCRIPT_ENABLE_SIGHASH_FORKID;
     }
 
     // If the DAA HF is enabled, we start rejecting transaction that use a high
     // s in their signature. We also make sure that signature that are supposed
     // to fail (for instance in multisig or other forms of smart contracts) are
     // null.
     if (IsDAAEnabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_LOW_S;
         flags |= SCRIPT_VERIFY_NULLFAIL;
     }
 
     // When the magnetic anomaly fork is enabled, we start accepting
     // transactions using the OP_CHECKDATASIG opcode and it's verify
     // alternative. We also start enforcing push only signatures and
     // clean stack.
     if (IsMagneticAnomalyEnabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_SIGPUSHONLY;
         flags |= SCRIPT_VERIFY_CLEANSTACK;
     }
 
     if (IsGravitonEnabled(params, pindex)) {
         flags |= SCRIPT_ENABLE_SCHNORR_MULTISIG;
         flags |= SCRIPT_VERIFY_MINIMALDATA;
     }
 
     if (IsPhononEnabled(params, pindex)) {
         flags |= SCRIPT_ENFORCE_SIGCHECKS;
     }
 
     // We make sure this node will have replay protection during the next hard
     // fork.
     if (IsReplayProtectionEnabled(params, pindex)) {
         flags |= SCRIPT_ENABLE_REPLAY_PROTECTION;
     }
 
     return flags;
 }
 
 static int64_t nTimeCheck = 0;
 static int64_t nTimeForks = 0;
 static int64_t nTimeVerify = 0;
 static int64_t nTimeConnect = 0;
 static int64_t nTimeIndex = 0;
 static int64_t nTimeCallbacks = 0;
 static int64_t nTimeTotal = 0;
 static int64_t nBlocksTotal = 0;
 
 /**
  * Apply the effects of this block (with given index) on the UTXO set
  * represented by coins. Validity checks that depend on the UTXO set are also
  * done; ConnectBlock() can fail if those validity checks fail (among other
  * reasons).
  */
 bool CChainState::ConnectBlock(const CBlock &block, BlockValidationState &state,
                                CBlockIndex *pindex, CCoinsViewCache &view,
                                const CChainParams &params,
                                BlockValidationOptions options,
                                bool fJustCheck) {
     AssertLockHeld(cs_main);
     assert(pindex);
     assert(*pindex->phashBlock == block.GetHash());
     int64_t nTimeStart = GetTimeMicros();
 
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     // Check it again in case a previous version let a bad block in
     // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
     // ContextualCheckBlockHeader() here. This means that if we add a new
     // consensus rule that is enforced in one of those two functions, then we
     // may have let in a block that violates the rule prior to updating the
     // software, and we would NOT be enforcing the rule here. Fully solving
     // upgrade from one software version to the next after a consensus rule
     // change is potentially tricky and issue-specific.
     // Also, currently the rule against blocks more than 2 hours in the future
     // is enforced in ContextualCheckBlockHeader(); we wouldn't want to
     // re-enforce that rule here (at least until we make it impossible for
     // GetAdjustedTime() to go backward).
     if (!CheckBlock(block, state, consensusParams,
                     options.withCheckPoW(!fJustCheck)
                         .withCheckMerkleRoot(!fJustCheck))) {
         if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) {
             // We don't write down blocks to disk if they may have been
             // corrupted, so this should be impossible unless we're having
             // hardware problems.
             return AbortNode(state, "Corrupt block found indicating potential "
                                     "hardware failure; shutting down");
         }
         return error("%s: Consensus::CheckBlock: %s", __func__,
                      state.ToString());
     }
 
     // Verify that the view's current state corresponds to the previous block
     BlockHash hashPrevBlock =
         pindex->pprev == nullptr ? BlockHash() : pindex->pprev->GetBlockHash();
     assert(hashPrevBlock == view.GetBestBlock());
 
     nBlocksTotal++;
 
     // Special case for the genesis block, skipping connection of its
     // transactions (its coinbase is unspendable)
     if (block.GetHash() == consensusParams.hashGenesisBlock) {
         if (!fJustCheck) {
             view.SetBestBlock(pindex->GetBlockHash());
         }
 
         return true;
     }
 
     bool fScriptChecks = true;
     if (!hashAssumeValid.IsNull()) {
         // We've been configured with the hash of a block which has been
         // externally verified to have a valid history. A suitable default value
         // is included with the software and updated from time to time. Because
         // validity relative to a piece of software is an objective fact these
         // defaults can be easily reviewed. This setting doesn't force the
         // selection of any particular chain but makes validating some faster by
         // effectively caching the result of part of the verification.
         BlockMap::const_iterator it =
             m_blockman.m_block_index.find(hashAssumeValid);
         if (it != m_blockman.m_block_index.end()) {
             if (it->second->GetAncestor(pindex->nHeight) == pindex &&
                 pindexBestHeader->GetAncestor(pindex->nHeight) == pindex &&
                 pindexBestHeader->nChainWork >= nMinimumChainWork) {
                 // This block is a member of the assumed verified chain and an
                 // ancestor of the best header.
                 // Script verification is skipped when connecting blocks under
                 // the assumevalid block. Assuming the assumevalid block is
                 // valid this is safe because block merkle hashes are still
                 // computed and checked, Of course, if an assumed valid block is
                 // invalid due to false scriptSigs this optimization would allow
                 // an invalid chain to be accepted.
                 // The equivalent time check discourages hash power from
                 // extorting the network via DOS attack into accepting an
                 // invalid block through telling users they must manually set
                 // assumevalid. Requiring a software change or burying the
                 // invalid block, regardless of the setting, makes it hard to
                 // hide the implication of the demand. This also avoids having
                 // release candidates that are hardly doing any signature
                 // verification at all in testing without having to artificially
                 // set the default assumed verified block further back. The test
                 // against nMinimumChainWork prevents the skipping when denied
                 // access to any chain at least as good as the expected chain.
                 fScriptChecks =
                     (GetBlockProofEquivalentTime(
                          *pindexBestHeader, *pindex, *pindexBestHeader,
                          consensusParams) <= 60 * 60 * 24 * 7 * 2);
             }
         }
     }
 
     int64_t nTime1 = GetTimeMicros();
     nTimeCheck += nTime1 - nTimeStart;
     LogPrint(BCLog::BENCH, "    - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime1 - nTimeStart), nTimeCheck * MICRO,
              nTimeCheck * MILLI / nBlocksTotal);
 
     // Do not allow blocks that contain transactions which 'overwrite' older
     // transactions, unless those are already completely spent. If such
     // overwrites are allowed, coinbases and transactions depending upon those
     // can be duplicated to remove the ability to spend the first instance --
     // even after being sent to another address.
     // See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html
     // for more information. This logic is not necessary for memory pool
     // transactions, as AcceptToMemoryPool already refuses previously-known
     // transaction ids entirely. This rule was originally applied to all blocks
     // with a timestamp after March 15, 2012, 0:00 UTC. Now that the whole
     // chain is irreversibly beyond that time it is applied to all blocks
     // except the two in the chain that violate it. This prevents exploiting
     // the issue against nodes during their initial block download.
     bool fEnforceBIP30 = !((pindex->nHeight == 91842 &&
                             pindex->GetBlockHash() ==
                                 uint256S("0x00000000000a4d0a398161ffc163c503763"
                                          "b1f4360639393e0e4c8e300e0caec")) ||
                            (pindex->nHeight == 91880 &&
                             pindex->GetBlockHash() ==
                                 uint256S("0x00000000000743f190a18c5577a3c2d2a1f"
                                          "610ae9601ac046a38084ccb7cd721")));
 
     // Once BIP34 activated it was not possible to create new duplicate
     // coinbases and thus other than starting with the 2 existing duplicate
     // coinbase pairs, not possible to create overwriting txs. But by the time
     // BIP34 activated, in each of the existing pairs the duplicate coinbase had
     // overwritten the first before the first had been spent. Since those
     // coinbases are sufficiently buried it's no longer possible to create
     // further duplicate transactions descending from the known pairs either. If
     // we're on the known chain at height greater than where BIP34 activated, we
     // can save the db accesses needed for the BIP30 check.
 
     // BIP34 requires that a block at height X (block X) has its coinbase
     // scriptSig start with a CScriptNum of X (indicated height X).  The above
     // logic of no longer requiring BIP30 once BIP34 activates is flawed in the
     // case that there is a block X before the BIP34 height of 227,931 which has
     // an indicated height Y where Y is greater than X.  The coinbase for block
     // X would also be a valid coinbase for block Y, which could be a BIP30
     // violation.  An exhaustive search of all mainnet coinbases before the
     // BIP34 height which have an indicated height greater than the block height
     // reveals many occurrences. The 3 lowest indicated heights found are
     // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3
     // heights would be the first opportunity for BIP30 to be violated.
 
     // The search reveals a great many blocks which have an indicated height
     // greater than 1,983,702, so we simply remove the optimization to skip
     // BIP30 checking for blocks at height 1,983,702 or higher.  Before we reach
     // that block in another 25 years or so, we should take advantage of a
     // future consensus change to do a new and improved version of BIP34 that
     // will actually prevent ever creating any duplicate coinbases in the
     // future.
     static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702;
 
     // There is no potential to create a duplicate coinbase at block 209,921
     // because this is still before the BIP34 height and so explicit BIP30
     // checking is still active.
 
     // The final case is block 176,684 which has an indicated height of
     // 490,897. Unfortunately, this issue was not discovered until about 2 weeks
     // before block 490,897 so there was not much opportunity to address this
     // case other than to carefully analyze it and determine it would not be a
     // problem. Block 490,897 was, in fact, mined with a different coinbase than
     // block 176,684, but it is important to note that even if it hadn't been or
     // is remined on an alternate fork with a duplicate coinbase, we would still
     // not run into a BIP30 violation.  This is because the coinbase for 176,684
     // is spent in block 185,956 in transaction
     // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781.  This
     // spending transaction can't be duplicated because it also spends coinbase
     // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29.  This
     // coinbase has an indicated height of over 4.2 billion, and wouldn't be
     // duplicatable until that height, and it's currently impossible to create a
     // chain that long. Nevertheless we may wish to consider a future soft fork
     // which retroactively prevents block 490,897 from creating a duplicate
     // coinbase. The two historical BIP30 violations often provide a confusing
     // edge case when manipulating the UTXO and it would be simpler not to have
     // another edge case to deal with.
 
     // testnet3 has no blocks before the BIP34 height with indicated heights
     // post BIP34 before approximately height 486,000,000 and presumably will
     // be reset before it reaches block 1,983,702 and starts doing unnecessary
     // BIP30 checking again.
     assert(pindex->pprev);
     CBlockIndex *pindexBIP34height =
         pindex->pprev->GetAncestor(consensusParams.BIP34Height);
     // Only continue to enforce if we're below BIP34 activation height or the
     // block hash at that height doesn't correspond.
     fEnforceBIP30 =
         fEnforceBIP30 &&
         (!pindexBIP34height ||
          !(pindexBIP34height->GetBlockHash() == consensusParams.BIP34Hash));
 
     // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have
     // a consensus change that ensures coinbases at those heights can not
     // duplicate earlier coinbases.
     if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) {
         for (const auto &tx : block.vtx) {
             for (size_t o = 0; o < tx->vout.size(); o++) {
                 if (view.HaveCoin(COutPoint(tx->GetId(), o))) {
                     LogPrintf("ERROR: ConnectBlock(): tried to overwrite "
                               "transaction\n");
                     return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                          "bad-txns-BIP30");
                 }
             }
         }
     }
 
     // Start enforcing BIP68 (sequence locks).
     int nLockTimeFlags = 0;
     if (pindex->nHeight >= consensusParams.CSVHeight) {
         nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
     }
 
     const uint32_t flags =
         GetNextBlockScriptFlags(consensusParams, pindex->pprev);
 
     int64_t nTime2 = GetTimeMicros();
     nTimeForks += nTime2 - nTime1;
     LogPrint(BCLog::BENCH, "    - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime2 - nTime1), nTimeForks * MICRO,
              nTimeForks * MILLI / nBlocksTotal);
 
     std::vector<int> prevheights;
     Amount nFees = Amount::zero();
     int nInputs = 0;
 
     // Limit the total executed signature operations in the block, a consensus
     // rule. Tracking during the CPU-consuming part (validation of uncached
     // inputs) is per-input atomic and validation in each thread stops very
     // quickly after the limit is exceeded, so an adversary cannot cause us to
     // exceed the limit by much at all.
     CheckInputsLimiter nSigChecksBlockLimiter(
         GetMaxBlockSigChecksCount(options.getExcessiveBlockSize()));
 
     std::vector<TxSigCheckLimiter> nSigChecksTxLimiters;
     nSigChecksTxLimiters.resize(block.vtx.size() - 1);
 
     CBlockUndo blockundo;
     blockundo.vtxundo.resize(block.vtx.size() - 1);
 
     CCheckQueueControl<CScriptCheck> control(fScriptChecks ? &scriptcheckqueue
                                                            : nullptr);
 
     // Add all outputs
     try {
         for (const auto &ptx : block.vtx) {
             AddCoins(view, *ptx, pindex->nHeight);
         }
     } catch (const std::logic_error &e) {
         // This error will be thrown from AddCoin if we try to connect a block
         // containing duplicate transactions. Such a thing should normally be
         // caught early nowadays (due to ContextualCheckBlock's CTOR
         // enforcement) however some edge cases can escape that:
         // - ContextualCheckBlock does not get re-run after saving the block to
         // disk, and older versions may have saved a weird block.
         // - its checks are not applied to pre-CTOR chains, which we might visit
         // with checkpointing off.
         LogPrintf("ERROR: ConnectBlock(): tried to overwrite transaction\n");
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "tx-duplicate");
     }
 
     size_t txIndex = 0;
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         const bool isCoinBase = tx.IsCoinBase();
         nInputs += tx.vin.size();
 
         {
             Amount txfee = Amount::zero();
             TxValidationState tx_state;
             if (!isCoinBase &&
                 !Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight,
                                           txfee)) {
                 // Any transaction validation failure in ConnectBlock is a block
                 // consensus failure.
                 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                               tx_state.GetRejectReason(),
                               tx_state.GetDebugMessage());
 
                 return error("%s: Consensus::CheckTxInputs: %s, %s", __func__,
                              tx.GetId().ToString(), state.ToString());
             }
             nFees += txfee;
         }
 
         if (!MoneyRange(nFees)) {
             LogPrintf("ERROR: %s: accumulated fee in the block out of range.\n",
                       __func__);
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  "bad-txns-accumulated-fee-outofrange");
         }
 
         // The following checks do not apply to the coinbase.
         if (isCoinBase) {
             continue;
         }
 
         // Check that transaction is BIP68 final BIP68 lock checks (as
         // opposed to nLockTime checks) must be in ConnectBlock because they
         // require the UTXO set.
         prevheights.resize(tx.vin.size());
         for (size_t j = 0; j < tx.vin.size(); j++) {
             prevheights[j] = view.AccessCoin(tx.vin[j].prevout).GetHeight();
         }
 
         if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) {
             LogPrintf("ERROR: %s: contains a non-BIP68-final transaction\n",
                       __func__);
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  "bad-txns-nonfinal");
         }
 
         // Don't cache results if we're actually connecting blocks (still
         // consult the cache, though).
         bool fCacheResults = fJustCheck;
 
         const bool fEnforceSigCheck = flags & SCRIPT_ENFORCE_SIGCHECKS;
         if (!fEnforceSigCheck) {
             // Historically, there has been transactions with a very high
             // sigcheck count, so we need to disable this check for such
             // transactions.
             nSigChecksTxLimiters[txIndex] = TxSigCheckLimiter::getDisabled();
         }
 
         std::vector<CScriptCheck> vChecks;
         // nSigChecksRet may be accurate (found in cache) or 0 (checks were
         // deferred into vChecks).
         int nSigChecksRet;
         TxValidationState tx_state;
         if (fScriptChecks &&
             !CheckInputScripts(tx, tx_state, view, flags, fCacheResults,
                                fCacheResults, PrecomputedTransactionData(tx),
                                nSigChecksRet, nSigChecksTxLimiters[txIndex],
                                &nSigChecksBlockLimiter, &vChecks)) {
             // Any transaction validation failure in ConnectBlock is a block
             // consensus failure
             state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                           tx_state.GetRejectReason(),
                           tx_state.GetDebugMessage());
             return error(
                 "ConnectBlock(): CheckInputScripts on %s failed with %s",
                 tx.GetId().ToString(), state.ToString());
         }
 
         control.Add(vChecks);
 
         // Note: this must execute in the same iteration as CheckTxInputs (not
         // in a separate loop) in order to detect double spends. However,
         // this does not prevent double-spending by duplicated transaction
         // inputs in the same transaction (cf. CVE-2018-17144) -- that check is
         // done in CheckBlock (CheckRegularTransaction).
         SpendCoins(view, tx, blockundo.vtxundo.at(txIndex), pindex->nHeight);
         txIndex++;
     }
 
     int64_t nTime3 = GetTimeMicros();
     nTimeConnect += nTime3 - nTime2;
     LogPrint(BCLog::BENCH,
              "      - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) "
              "[%.2fs (%.2fms/blk)]\n",
              (unsigned)block.vtx.size(), MILLI * (nTime3 - nTime2),
              MILLI * (nTime3 - nTime2) / block.vtx.size(),
              nInputs <= 1 ? 0 : MILLI * (nTime3 - nTime2) / (nInputs - 1),
              nTimeConnect * MICRO, nTimeConnect * MILLI / nBlocksTotal);
 
     Amount blockReward =
         nFees + GetBlockSubsidy(pindex->nHeight, consensusParams);
     if (block.vtx[0]->GetValueOut() > blockReward) {
         LogPrintf("ERROR: ConnectBlock(): coinbase pays too much (actual=%d vs "
                   "limit=%d)\n",
                   block.vtx[0]->GetValueOut(), blockReward);
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-cb-amount");
     }
 
     const std::vector<CTxDestination> whitelist =
         GetMinerFundWhitelist(consensusParams, pindex->pprev);
     if (!whitelist.empty()) {
         const Amount required = GetMinerFundAmount(blockReward);
 
         for (auto &o : block.vtx[0]->vout) {
             if (o.nValue < required) {
                 // This output doesn't qualify because its amount is too low.
                 continue;
             }
 
             CTxDestination address;
             if (!ExtractDestination(o.scriptPubKey, address)) {
                 // Cannot decode address.
                 continue;
             }
 
             if (std::find(whitelist.begin(), whitelist.end(), address) !=
                 whitelist.end()) {
                 goto MinerFundSuccess;
             }
         }
 
         // We did not find an output that match the miner fund requirements.
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-cb-minerfund");
     }
 
 MinerFundSuccess:
 
     if (!control.Wait()) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "blk-bad-inputs", "parallel script check failed");
     }
 
     int64_t nTime4 = GetTimeMicros();
     nTimeVerify += nTime4 - nTime2;
     LogPrint(
         BCLog::BENCH,
         "    - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n",
         nInputs - 1, MILLI * (nTime4 - nTime2),
         nInputs <= 1 ? 0 : MILLI * (nTime4 - nTime2) / (nInputs - 1),
         nTimeVerify * MICRO, nTimeVerify * MILLI / nBlocksTotal);
 
     if (fJustCheck) {
         return true;
     }
 
     if (!WriteUndoDataForBlock(blockundo, state, pindex, params)) {
         return false;
     }
 
     if (!pindex->IsValid(BlockValidity::SCRIPTS)) {
         pindex->RaiseValidity(BlockValidity::SCRIPTS);
         setDirtyBlockIndex.insert(pindex);
     }
 
     assert(pindex->phashBlock);
     // add this block to the view's block chain
     view.SetBestBlock(pindex->GetBlockHash());
 
     int64_t nTime5 = GetTimeMicros();
     nTimeIndex += nTime5 - nTime4;
     LogPrint(BCLog::BENCH, "    - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime5 - nTime4), nTimeIndex * MICRO,
              nTimeIndex * MILLI / nBlocksTotal);
 
     int64_t nTime6 = GetTimeMicros();
     nTimeCallbacks += nTime6 - nTime5;
     LogPrint(BCLog::BENCH, "    - Callbacks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime6 - nTime5), nTimeCallbacks * MICRO,
              nTimeCallbacks * MILLI / nBlocksTotal);
 
     return true;
 }
 
 CoinsCacheSizeState
 CChainState::GetCoinsCacheSizeState(const CTxMemPool *tx_pool) {
     return this->GetCoinsCacheSizeState(
         tx_pool, m_coinstip_cache_size_bytes,
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000);
 }
 
 CoinsCacheSizeState
 CChainState::GetCoinsCacheSizeState(const CTxMemPool *tx_pool,
                                     size_t max_coins_cache_size_bytes,
                                     size_t max_mempool_size_bytes) {
     int64_t nMempoolUsage = tx_pool->DynamicMemoryUsage();
     int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
     int64_t nTotalSpace =
         max_coins_cache_size_bytes +
         std::max<int64_t>(max_mempool_size_bytes - nMempoolUsage, 0);
 
     //! No need to periodic flush if at least this much space still available.
     static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES =
         10 * 1024 * 1024; // 10MB
     int64_t large_threshold = std::max(
         (9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES);
 
     if (cacheSize > nTotalSpace) {
         LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize,
                   nTotalSpace);
         return CoinsCacheSizeState::CRITICAL;
     } else if (cacheSize > large_threshold) {
         return CoinsCacheSizeState::LARGE;
     }
     return CoinsCacheSizeState::OK;
 }
 
 bool CChainState::FlushStateToDisk(const CChainParams &chainparams,
                                    BlockValidationState &state,
                                    FlushStateMode mode,
                                    int nManualPruneHeight) {
     LOCK(cs_main);
     assert(this->CanFlushToDisk());
     static std::chrono::microseconds nLastWrite{0};
     static std::chrono::microseconds nLastFlush{0};
     std::set<int> setFilesToPrune;
     bool full_flush_completed = false;
 
     const size_t coins_count = CoinsTip().GetCacheSize();
     const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage();
 
     try {
         {
             bool fFlushForPrune = false;
             bool fDoFullFlush = false;
 
             CoinsCacheSizeState cache_state =
                 GetCoinsCacheSizeState(&m_mempool);
             LOCK(cs_LastBlockFile);
             if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) &&
                 !fReindex) {
                 // Make sure we don't prune above the blockfilterindexes
                 // bestblocks. Pruning is height-based.
                 int last_prune = m_chain.Height();
                 ForEachBlockFilterIndex([&](BlockFilterIndex &index) {
                     last_prune = std::max(
                         1, std::min(last_prune,
                                     index.GetSummary().best_block_height));
                 });
 
                 if (nManualPruneHeight > 0) {
                     LOG_TIME_MILLIS_WITH_CATEGORY(
                         "find files to prune (manual)", BCLog::BENCH);
                     m_blockman.FindFilesToPruneManual(
                         setFilesToPrune,
                         std::min(last_prune, nManualPruneHeight),
                         m_chain.Height());
                 } else {
                     LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune",
                                                   BCLog::BENCH);
                     m_blockman.FindFilesToPrune(
                         setFilesToPrune, chainparams.PruneAfterHeight(),
                         m_chain.Height(), last_prune, IsInitialBlockDownload());
                     fCheckForPruning = false;
                 }
                 if (!setFilesToPrune.empty()) {
                     fFlushForPrune = true;
                     if (!fHavePruned) {
                         pblocktree->WriteFlag("prunedblockfiles", true);
                         fHavePruned = true;
                     }
                 }
             }
             const auto nNow = GetTime<std::chrono::microseconds>();
             // Avoid writing/flushing immediately after startup.
             if (nLastWrite.count() == 0) {
                 nLastWrite = nNow;
             }
             if (nLastFlush.count() == 0) {
                 nLastFlush = nNow;
             }
             // The cache is large and we're within 10% and 10 MiB of the limit,
             // but we have time now (not in the middle of a block processing).
             bool fCacheLarge = mode == FlushStateMode::PERIODIC &&
                                cache_state >= CoinsCacheSizeState::LARGE;
             // The cache is over the limit, we have to write now.
             bool fCacheCritical = mode == FlushStateMode::IF_NEEDED &&
                                   cache_state >= CoinsCacheSizeState::CRITICAL;
             // It's been a while since we wrote the block index to disk. Do this
             // frequently, so we don't need to redownload after a crash.
             bool fPeriodicWrite = mode == FlushStateMode::PERIODIC &&
                                   nNow > nLastWrite + DATABASE_WRITE_INTERVAL;
             // It's been very long since we flushed the cache. Do this
             // infrequently, to optimize cache usage.
             bool fPeriodicFlush = mode == FlushStateMode::PERIODIC &&
                                   nNow > nLastFlush + DATABASE_FLUSH_INTERVAL;
             // Combine all conditions that result in a full cache flush.
             fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge ||
                            fCacheCritical || fPeriodicFlush || fFlushForPrune;
             // Write blocks and block index to disk.
             if (fDoFullFlush || fPeriodicWrite) {
                 // Depend on nMinDiskSpace to ensure we can write block index
                 if (!CheckDiskSpace(gArgs.GetBlocksDirPath())) {
                     return AbortNode(state, "Disk space is too low!",
                                      _("Disk space is too low!"));
                 }
 
                 {
                     LOG_TIME_MILLIS_WITH_CATEGORY(
                         "write block and undo data to disk", BCLog::BENCH);
 
                     // First make sure all block and undo data is flushed to
                     // disk.
                     FlushBlockFile();
                 }
                 // Then update all block file information (which may refer to
                 // block and undo files).
                 {
                     LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk",
                                                   BCLog::BENCH);
 
                     std::vector<std::pair<int, const CBlockFileInfo *>> vFiles;
                     vFiles.reserve(setDirtyFileInfo.size());
                     for (int i : setDirtyFileInfo) {
                         vFiles.push_back(std::make_pair(i, &vinfoBlockFile[i]));
                     }
 
                     setDirtyFileInfo.clear();
 
                     std::vector<const CBlockIndex *> vBlocks;
                     vBlocks.reserve(setDirtyBlockIndex.size());
                     for (const CBlockIndex *cbi : setDirtyBlockIndex) {
                         vBlocks.push_back(cbi);
                     }
 
                     setDirtyBlockIndex.clear();
 
                     if (!pblocktree->WriteBatchSync(vFiles, nLastBlockFile,
                                                     vBlocks)) {
                         return AbortNode(
                             state, "Failed to write to block index database");
                     }
                 }
 
                 // Finally remove any pruned files
                 if (fFlushForPrune) {
                     LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files",
                                                   BCLog::BENCH);
 
                     UnlinkPrunedFiles(setFilesToPrune);
                 }
                 nLastWrite = nNow;
             }
             // Flush best chain related state. This can only be done if the
             // blocks / block index write was also done.
             if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) {
                 LOG_TIME_SECONDS(
                     strprintf("write coins cache to disk (%d coins, %.2fkB)",
                               coins_count, coins_mem_usage / 1000));
 
                 // Typical Coin structures on disk are around 48 bytes in size.
                 // Pushing a new one to the database can cause it to be written
                 // twice (once in the log, and once in the tables). This is
                 // already an overestimation, as most will delete an existing
                 // entry or overwrite one. Still, use a conservative safety
                 // factor of 2.
                 if (!CheckDiskSpace(GetDataDir(),
                                     48 * 2 * 2 * CoinsTip().GetCacheSize())) {
                     return AbortNode(state, "Disk space is too low!",
                                      _("Disk space is too low!"));
                 }
 
                 // Flush the chainstate (which may refer to block index
                 // entries).
                 if (!CoinsTip().Flush()) {
                     return AbortNode(state, "Failed to write to coin database");
                 }
                 nLastFlush = nNow;
                 full_flush_completed = true;
             }
         }
 
         if (full_flush_completed) {
             // Update best block in wallet (so we can detect restored wallets).
             GetMainSignals().ChainStateFlushed(m_chain.GetLocator());
         }
     } catch (const std::runtime_error &e) {
         return AbortNode(state, std::string("System error while flushing: ") +
                                     e.what());
     }
     return true;
 }
 
 void CChainState::ForceFlushStateToDisk() {
     BlockValidationState state;
     const CChainParams &chainparams = Params();
     if (!this->FlushStateToDisk(chainparams, state, FlushStateMode::ALWAYS)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   state.ToString());
     }
 }
 
 void CChainState::PruneAndFlush() {
     BlockValidationState state;
     fCheckForPruning = true;
     const CChainParams &chainparams = Params();
     if (!this->FlushStateToDisk(chainparams, state, FlushStateMode::NONE)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   state.ToString());
     }
 }
 
 /** Check warning conditions and do some notifications on new chain tip set. */
 static void UpdateTip(CTxMemPool &mempool, CBlockIndex *pindexNew,
                       const CChainParams &params,
                       CChainState &active_chainstate)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
     // New best block
     mempool.AddTransactionsUpdated(1);
 
     {
         LOCK(g_best_block_mutex);
         g_best_block = pindexNew->GetBlockHash();
         g_best_block_cv.notify_all();
     }
 
     LogPrintf(
         "%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%ld "
         "date='%s' progress=%f cache=%.1fMiB(%utxo)\n",
         __func__, pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
         pindexNew->nVersion, log(pindexNew->nChainWork.getdouble()) / log(2.0),
         pindexNew->GetChainTxCount(),
         FormatISO8601DateTime(pindexNew->GetBlockTime()),
         GuessVerificationProgress(params.TxData(), pindexNew),
         active_chainstate.CoinsTip().DynamicMemoryUsage() * (1.0 / (1 << 20)),
         active_chainstate.CoinsTip().GetCacheSize());
 }
 
 /**
  * Disconnect m_chain's tip.
  * After calling, the mempool will be in an inconsistent state, with
  * transactions from disconnected blocks being added to disconnectpool. You
  * should make the mempool consistent again by calling updateMempoolForReorg.
  * with cs_main held.
  *
  * If disconnectpool is nullptr, then no disconnected transactions are added to
  * disconnectpool (note that the caller is responsible for mempool consistency
  * in any case).
  */
 bool CChainState::DisconnectTip(const CChainParams &params,
                                 BlockValidationState &state,
                                 DisconnectedBlockTransactions *disconnectpool) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_mempool.cs);
     CBlockIndex *pindexDelete = m_chain.Tip();
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     assert(pindexDelete);
 
     // Read block from disk.
     std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
     CBlock &block = *pblock;
     if (!ReadBlockFromDisk(block, pindexDelete, consensusParams)) {
         return error("DisconnectTip(): Failed to read block");
     }
 
     // Apply the block atomically to the chain state.
     int64_t nStart = GetTimeMicros();
     {
         CCoinsViewCache view(&CoinsTip());
         assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
         if (DisconnectBlock(block, pindexDelete, view) !=
             DisconnectResult::OK) {
             return error("DisconnectTip(): DisconnectBlock %s failed",
                          pindexDelete->GetBlockHash().ToString());
         }
 
         bool flushed = view.Flush();
         assert(flushed);
     }
 
     LogPrint(BCLog::BENCH, "- Disconnect block: %.2fms\n",
              (GetTimeMicros() - nStart) * MILLI);
 
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(params, state, FlushStateMode::IF_NEEDED)) {
         return false;
     }
 
     // If this block is deactivating a fork, we move all mempool transactions
     // in front of disconnectpool for reprocessing in a future
     // updateMempoolForReorg call
     if (pindexDelete->pprev != nullptr &&
         GetNextBlockScriptFlags(consensusParams, pindexDelete) !=
             GetNextBlockScriptFlags(consensusParams, pindexDelete->pprev)) {
         LogPrint(BCLog::MEMPOOL,
                  "Disconnecting mempool due to rewind of upgrade block\n");
         if (disconnectpool) {
             disconnectpool->importMempool(m_mempool);
         }
         m_mempool.clear();
     }
 
     if (disconnectpool) {
         disconnectpool->addForBlock(block.vtx, m_mempool);
     }
 
     // If the tip is finalized, then undo it.
     if (m_finalizedBlockIndex == pindexDelete) {
         m_finalizedBlockIndex = pindexDelete->pprev;
     }
 
     m_chain.SetTip(pindexDelete->pprev);
 
     UpdateTip(m_mempool, pindexDelete->pprev, params, *this);
     // Let wallets know transactions went from 1-confirmed to
     // 0-confirmed or conflicted:
     GetMainSignals().BlockDisconnected(pblock, pindexDelete);
     return true;
 }
 
 static int64_t nTimeReadFromDisk = 0;
 static int64_t nTimeConnectTotal = 0;
 static int64_t nTimeFlush = 0;
 static int64_t nTimeChainState = 0;
 static int64_t nTimePostConnect = 0;
 
 struct PerBlockConnectTrace {
     CBlockIndex *pindex = nullptr;
     std::shared_ptr<const CBlock> pblock;
     PerBlockConnectTrace() {}
 };
 
 /**
  * Used to track blocks whose transactions were applied to the UTXO state as a
  * part of a single ActivateBestChainStep call.
  *
  * This class is single-use, once you call GetBlocksConnected() you have to
  * throw it away and make a new one.
  */
 class ConnectTrace {
 private:
     std::vector<PerBlockConnectTrace> blocksConnected;
 
 public:
     explicit ConnectTrace() : blocksConnected(1) {}
 
     void BlockConnected(CBlockIndex *pindex,
                         std::shared_ptr<const CBlock> pblock) {
         assert(!blocksConnected.back().pindex);
         assert(pindex);
         assert(pblock);
         blocksConnected.back().pindex = pindex;
         blocksConnected.back().pblock = std::move(pblock);
         blocksConnected.emplace_back();
     }
 
     std::vector<PerBlockConnectTrace> &GetBlocksConnected() {
         // We always keep one extra block at the end of our list because blocks
         // are added after all the conflicted transactions have been filled in.
         // Thus, the last entry should always be an empty one waiting for the
         // transactions from the next block. We pop the last entry here to make
         // sure the list we return is sane.
         assert(!blocksConnected.back().pindex);
         blocksConnected.pop_back();
         return blocksConnected;
     }
 };
 
 bool CChainState::MarkBlockAsFinal(BlockValidationState &state,
                                    const CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
     if (pindex->nStatus.isInvalid()) {
         // We try to finalize an invalid block.
         LogPrintf("ERROR: %s: Trying to finalize invalid block %s\n", __func__,
                   pindex->GetBlockHash().ToString());
         return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID,
                              "finalize-invalid-block");
     }
 
     // Check that the request is consistent with current finalization.
     if (m_finalizedBlockIndex &&
         !AreOnTheSameFork(pindex, m_finalizedBlockIndex)) {
         LogPrintf("ERROR: %s: Trying to finalize block %s which conflicts with "
                   "already finalized block\n",
                   __func__, pindex->GetBlockHash().ToString());
         return state.Invalid(BlockValidationResult::BLOCK_FINALIZATION,
                              "bad-fork-prior-finalized");
     }
 
     if (IsBlockFinalized(pindex)) {
         // The block is already finalized.
         return true;
     }
 
     // We have a new block to finalize.
     m_finalizedBlockIndex = pindex;
     return true;
 }
 
 const CBlockIndex *CChainState::FindBlockToFinalize(CBlockIndex *pindexNew) {
     AssertLockHeld(cs_main);
 
     const int32_t maxreorgdepth =
         gArgs.GetArg("-maxreorgdepth", DEFAULT_MAX_REORG_DEPTH);
 
     const int64_t finalizationdelay =
         gArgs.GetArg("-finalizationdelay", DEFAULT_MIN_FINALIZATION_DELAY);
 
     // Find our candidate.
     // If maxreorgdepth is < 0 pindex will be null and auto finalization
     // disabled
     const CBlockIndex *pindex =
         pindexNew->GetAncestor(pindexNew->nHeight - maxreorgdepth);
 
     int64_t now = GetTime();
 
     // If the finalization delay is not expired since the startup time,
     // finalization should be avoided. Header receive time is not saved to disk
     // and so cannot be anterior to startup time.
     if (now < (GetStartupTime() + finalizationdelay)) {
         return nullptr;
     }
 
     // While our candidate is not eligible (finalization delay not expired), try
     // the previous one.
     while (pindex && (pindex != GetFinalizedBlock())) {
         // Check that the block to finalize is known for a long enough time.
         // This test will ensure that an attacker could not cause a block to
         // finalize by forking the chain with a depth > maxreorgdepth.
         // If the block is loaded from disk, header receive time is 0 and the
         // block will be finalized. This is safe because the delay since the
         // node startup is already expired.
         auto headerReceivedTime = pindex->GetHeaderReceivedTime();
 
         // If finalization delay is <= 0, finalization always occurs immediately
         if (now >= (headerReceivedTime + finalizationdelay)) {
             return pindex;
         }
 
         pindex = pindex->pprev;
     }
 
     return nullptr;
 }
 
 /**
  * Connect a new block to m_chain. pblock is either nullptr or a pointer to
  * a CBlock corresponding to pindexNew, to bypass loading it again from disk.
  *
  * The block is always added to connectTrace (either after loading from disk or
  * by copying pblock) - if that is not intended, care must be taken to remove
  * the last entry in blocksConnected in case of failure.
  */
 bool CChainState::ConnectTip(const Config &config, BlockValidationState &state,
                              CBlockIndex *pindexNew,
                              const std::shared_ptr<const CBlock> &pblock,
                              ConnectTrace &connectTrace,
                              DisconnectedBlockTransactions &disconnectpool) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_mempool.cs);
 
     const CChainParams &params = config.GetChainParams();
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     assert(pindexNew->pprev == m_chain.Tip());
     // Read block from disk.
     int64_t nTime1 = GetTimeMicros();
     std::shared_ptr<const CBlock> pthisBlock;
     if (!pblock) {
         std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
         if (!ReadBlockFromDisk(*pblockNew, pindexNew, consensusParams)) {
             return AbortNode(state, "Failed to read block");
         }
         pthisBlock = pblockNew;
     } else {
         pthisBlock = pblock;
     }
 
     const CBlock &blockConnecting = *pthisBlock;
 
     // Apply the block atomically to the chain state.
     int64_t nTime2 = GetTimeMicros();
     nTimeReadFromDisk += nTime2 - nTime1;
     int64_t nTime3;
     LogPrint(BCLog::BENCH, "  - Load block from disk: %.2fms [%.2fs]\n",
              (nTime2 - nTime1) * MILLI, nTimeReadFromDisk * MICRO);
     {
         CCoinsViewCache view(&CoinsTip());
         bool rv = ConnectBlock(blockConnecting, state, pindexNew, view, params,
                                BlockValidationOptions(config));
         GetMainSignals().BlockChecked(blockConnecting, state);
         if (!rv) {
             if (state.IsInvalid()) {
                 InvalidBlockFound(pindexNew, state);
             }
 
             return error("%s: ConnectBlock %s failed, %s", __func__,
                          pindexNew->GetBlockHash().ToString(),
                          state.ToString());
         }
 
         // Update the finalized block.
         const CBlockIndex *pindexToFinalize = FindBlockToFinalize(pindexNew);
         if (pindexToFinalize && !MarkBlockAsFinal(state, pindexToFinalize)) {
             return error("ConnectTip(): MarkBlockAsFinal %s failed (%s)",
                          pindexNew->GetBlockHash().ToString(),
                          state.ToString());
         }
 
         nTime3 = GetTimeMicros();
         nTimeConnectTotal += nTime3 - nTime2;
         assert(nBlocksTotal > 0);
         LogPrint(BCLog::BENCH,
                  "  - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
                  (nTime3 - nTime2) * MILLI, nTimeConnectTotal * MICRO,
                  nTimeConnectTotal * MILLI / nBlocksTotal);
         bool flushed = view.Flush();
         assert(flushed);
     }
 
     int64_t nTime4 = GetTimeMicros();
     nTimeFlush += nTime4 - nTime3;
     LogPrint(BCLog::BENCH, "  - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime4 - nTime3) * MILLI, nTimeFlush * MICRO,
              nTimeFlush * MILLI / nBlocksTotal);
 
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(config.GetChainParams(), state,
                           FlushStateMode::IF_NEEDED)) {
         return false;
     }
 
     int64_t nTime5 = GetTimeMicros();
     nTimeChainState += nTime5 - nTime4;
     LogPrint(BCLog::BENCH,
              "  - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime5 - nTime4) * MILLI, nTimeChainState * MICRO,
              nTimeChainState * MILLI / nBlocksTotal);
 
     // Remove conflicting transactions from the mempool.;
     m_mempool.removeForBlock(blockConnecting.vtx, pindexNew->nHeight);
     disconnectpool.removeForBlock(blockConnecting.vtx);
 
     // If this block is activating a fork, we move all mempool transactions
     // in front of disconnectpool for reprocessing in a future
     // updateMempoolForReorg call
     if (pindexNew->pprev != nullptr &&
         GetNextBlockScriptFlags(consensusParams, pindexNew) !=
             GetNextBlockScriptFlags(consensusParams, pindexNew->pprev)) {
         LogPrint(BCLog::MEMPOOL,
                  "Disconnecting mempool due to acceptance of upgrade block\n");
         disconnectpool.importMempool(m_mempool);
     }
 
     // Update m_chain & related variables.
     m_chain.SetTip(pindexNew);
     UpdateTip(m_mempool, pindexNew, params, *this);
 
     int64_t nTime6 = GetTimeMicros();
     nTimePostConnect += nTime6 - nTime5;
     nTimeTotal += nTime6 - nTime1;
     LogPrint(BCLog::BENCH,
              "  - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime6 - nTime5) * MILLI, nTimePostConnect * MICRO,
              nTimePostConnect * MILLI / nBlocksTotal);
     LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime6 - nTime1) * MILLI, nTimeTotal * MICRO,
              nTimeTotal * MILLI / nBlocksTotal);
 
     connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
     return true;
 }
 
 /**
  * Return the tip of the chain with the most work in it, that isn't known to be
  * invalid (it's however far from certain to be valid).
  */
 CBlockIndex *CChainState::FindMostWorkChain() {
     AssertLockHeld(cs_main);
     do {
         CBlockIndex *pindexNew = nullptr;
 
         // Find the best candidate header.
         {
             std::set<CBlockIndex *, CBlockIndexWorkComparator>::reverse_iterator
                 it = setBlockIndexCandidates.rbegin();
             if (it == setBlockIndexCandidates.rend()) {
                 return nullptr;
             }
             pindexNew = *it;
         }
 
         // If this block will cause a finalized block to be reorged, then we
         // mark it as invalid.
         if (m_finalizedBlockIndex &&
             !AreOnTheSameFork(pindexNew, m_finalizedBlockIndex)) {
             LogPrintf("Mark block %s invalid because it forks prior to the "
                       "finalization point %d.\n",
                       pindexNew->GetBlockHash().ToString(),
                       m_finalizedBlockIndex->nHeight);
             pindexNew->nStatus = pindexNew->nStatus.withFailed();
             InvalidChainFound(pindexNew);
         }
 
         const bool fAvalancheEnabled = isAvalancheEnabled(gArgs);
         const bool fAutoUnpark =
             gArgs.GetBoolArg("-automaticunparking", !fAvalancheEnabled);
 
         const CBlockIndex *pindexFork = m_chain.FindFork(pindexNew);
 
         // Check whether all blocks on the path between the currently active
         // chain and the candidate are valid. Just going until the active chain
         // is an optimization, as we know all blocks in it are valid already.
         CBlockIndex *pindexTest = pindexNew;
         bool hasValidAncestor = true;
         while (hasValidAncestor && pindexTest && pindexTest != pindexFork) {
             assert(pindexTest->HaveTxsDownloaded() || pindexTest->nHeight == 0);
 
             // If this is a parked chain, but it has enough PoW, clear the park
             // state.
             bool fParkedChain = pindexTest->nStatus.isOnParkedChain();
             if (fAutoUnpark && fParkedChain) {
                 const CBlockIndex *pindexTip = m_chain.Tip();
 
                 // During initialization, pindexTip and/or pindexFork may be
                 // null. In this case, we just ignore the fact that the chain is
                 // parked.
                 if (!pindexTip || !pindexFork) {
                     UnparkBlock(pindexTest);
                     continue;
                 }
 
                 // A parked chain can be unparked if it has twice as much PoW
                 // accumulated as the main chain has since the fork block.
                 CBlockIndex const *pindexExtraPow = pindexTip;
                 arith_uint256 requiredWork = pindexTip->nChainWork;
                 switch (pindexTip->nHeight - pindexFork->nHeight) {
                     // Limit the penality for depth 1, 2 and 3 to half a block
                     // worth of work to ensure we don't fork accidentally.
                     case 3:
                     case 2:
                         pindexExtraPow = pindexExtraPow->pprev;
                     // FALLTHROUGH
                     case 1: {
                         const arith_uint256 deltaWork =
                             pindexExtraPow->nChainWork - pindexFork->nChainWork;
                         requiredWork += (deltaWork >> 1);
                         break;
                     }
                     default:
                         requiredWork +=
                             pindexExtraPow->nChainWork - pindexFork->nChainWork;
                         break;
                 }
 
                 if (pindexNew->nChainWork > requiredWork) {
                     // We have enough, clear the parked state.
                     LogPrintf("Unpark chain up to block %s as it has "
                               "accumulated enough PoW.\n",
                               pindexNew->GetBlockHash().ToString());
                     fParkedChain = false;
                     UnparkBlock(pindexTest);
                 }
             }
 
             // Pruned nodes may have entries in setBlockIndexCandidates for
             // which block files have been deleted. Remove those as candidates
             // for the most work chain if we come across them; we can't switch
             // to a chain unless we have all the non-active-chain parent blocks.
             bool fInvalidChain = pindexTest->nStatus.isInvalid();
             bool fMissingData = !pindexTest->nStatus.hasData();
             if (!(fInvalidChain || fParkedChain || fMissingData)) {
                 // The current block is acceptable, move to the parent, up to
                 // the fork point.
                 pindexTest = pindexTest->pprev;
                 continue;
             }
 
             // Candidate chain is not usable (either invalid or parked or
             // missing data)
             hasValidAncestor = false;
             setBlockIndexCandidates.erase(pindexTest);
 
             if (fInvalidChain &&
                 (pindexBestInvalid == nullptr ||
                  pindexNew->nChainWork > pindexBestInvalid->nChainWork)) {
                 pindexBestInvalid = pindexNew;
             }
 
             if (fParkedChain &&
                 (pindexBestParked == nullptr ||
                  pindexNew->nChainWork > pindexBestParked->nChainWork)) {
                 pindexBestParked = pindexNew;
             }
 
             LogPrintf("Considered switching to better tip %s but that chain "
                       "contains a%s%s%s block.\n",
                       pindexNew->GetBlockHash().ToString(),
                       fInvalidChain ? "n invalid" : "",
                       fParkedChain ? " parked" : "",
                       fMissingData ? " missing-data" : "");
 
             CBlockIndex *pindexFailed = pindexNew;
             // Remove the entire chain from the set.
             while (pindexTest != pindexFailed) {
                 if (fInvalidChain || fParkedChain) {
                     pindexFailed->nStatus =
                         pindexFailed->nStatus.withFailedParent(fInvalidChain)
                             .withParkedParent(fParkedChain);
                 } else if (fMissingData) {
                     // If we're missing data, then add back to
                     // m_blocks_unlinked, so that if the block arrives in the
                     // future we can try adding to setBlockIndexCandidates
                     // again.
                     m_blockman.m_blocks_unlinked.insert(
                         std::make_pair(pindexFailed->pprev, pindexFailed));
                 }
                 setBlockIndexCandidates.erase(pindexFailed);
                 pindexFailed = pindexFailed->pprev;
             }
 
             if (fInvalidChain || fParkedChain) {
                 // We discovered a new chain tip that is either parked or
                 // invalid, we may want to warn.
                 CheckForkWarningConditionsOnNewFork(pindexNew);
             }
         }
 
         if (fAvalancheEnabled && g_avalanche) {
             g_avalanche->addBlockToReconcile(pindexNew);
         }
 
         // We found a candidate that has valid ancestors. This is our guy.
         if (hasValidAncestor) {
             return pindexNew;
         }
     } while (true);
 }
 
 /**
  * Delete all entries in setBlockIndexCandidates that are worse than the current
  * tip.
  */
 void CChainState::PruneBlockIndexCandidates() {
     // Note that we can't delete the current block itself, as we may need to
     // return to it later in case a reorganization to a better block fails.
     auto it = setBlockIndexCandidates.begin();
     while (it != setBlockIndexCandidates.end() &&
            setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) {
         setBlockIndexCandidates.erase(it++);
     }
 
     // Either the current tip or a successor of it we're working towards is left
     // in setBlockIndexCandidates.
     assert(!setBlockIndexCandidates.empty());
 }
 
 /**
  * Try to make some progress towards making pindexMostWork the active block.
  * pblock is either nullptr or a pointer to a CBlock corresponding to
  * pindexMostWork.
  *
  * @returns true unless a system error occurred
  */
 bool CChainState::ActivateBestChainStep(
     const Config &config, BlockValidationState &state,
     CBlockIndex *pindexMostWork, const std::shared_ptr<const CBlock> &pblock,
     bool &fInvalidFound, ConnectTrace &connectTrace) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_mempool.cs);
 
     const CBlockIndex *pindexOldTip = m_chain.Tip();
     const CBlockIndex *pindexFork = m_chain.FindFork(pindexMostWork);
 
     // Disconnect active blocks which are no longer in the best chain.
     bool fBlocksDisconnected = false;
     DisconnectedBlockTransactions disconnectpool;
     while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
         if (!DisconnectTip(config.GetChainParams(), state, &disconnectpool)) {
             // This is likely a fatal error, but keep the mempool consistent,
             // just in case. Only remove from the mempool in this case.
             disconnectpool.updateMempoolForReorg(config, *this, false,
                                                  m_mempool);
 
             // If we're unable to disconnect a block during normal operation,
             // then that is a failure of our local system -- we should abort
             // rather than stay on a less work chain.
             AbortNode(state,
                       "Failed to disconnect block; see debug.log for details");
             return false;
         }
 
         fBlocksDisconnected = true;
     }
 
     // Build list of new blocks to connect.
     std::vector<CBlockIndex *> vpindexToConnect;
     bool fContinue = true;
     int nHeight = pindexFork ? pindexFork->nHeight : -1;
     while (fContinue && nHeight != pindexMostWork->nHeight) {
         // Don't iterate the entire list of potential improvements toward the
         // best tip, as we likely only need a few blocks along the way.
         int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
         vpindexToConnect.clear();
         vpindexToConnect.reserve(nTargetHeight - nHeight);
         CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
         while (pindexIter && pindexIter->nHeight != nHeight) {
             vpindexToConnect.push_back(pindexIter);
             pindexIter = pindexIter->pprev;
         }
 
         nHeight = nTargetHeight;
 
         // Connect new blocks.
         for (CBlockIndex *pindexConnect : reverse_iterate(vpindexToConnect)) {
             if (!ConnectTip(config, state, pindexConnect,
                             pindexConnect == pindexMostWork
                                 ? pblock
                                 : std::shared_ptr<const CBlock>(),
                             connectTrace, disconnectpool)) {
                 if (state.IsInvalid()) {
                     // The block violates a consensus rule.
                     if (state.GetResult() !=
                         BlockValidationResult::BLOCK_MUTATED) {
                         InvalidChainFound(vpindexToConnect.back());
                     }
                     state = BlockValidationState();
                     fInvalidFound = true;
                     fContinue = false;
                     break;
                 }
 
                 // A system error occurred (disk space, database error, ...).
                 // Make the mempool consistent with the current tip, just in
                 // case any observers try to use it before shutdown.
                 disconnectpool.updateMempoolForReorg(config, *this, false,
                                                      m_mempool);
                 return false;
             } else {
                 PruneBlockIndexCandidates();
                 if (!pindexOldTip ||
                     m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) {
                     // We're in a better position than we were. Return
                     // temporarily to release the lock.
                     fContinue = false;
                     break;
                 }
             }
         }
     }
 
     if (fBlocksDisconnected || !disconnectpool.isEmpty()) {
         // If any blocks were disconnected, we need to update the mempool even
         // if disconnectpool is empty. The disconnectpool may also be non-empty
         // if the mempool was imported due to new validation rules being in
         // effect.
         LogPrint(BCLog::MEMPOOL, "Updating mempool due to reorganization or "
                                  "rules upgrade/downgrade\n");
         disconnectpool.updateMempoolForReorg(config, *this, true, m_mempool);
     }
 
     m_mempool.check(*this);
 
     // Callbacks/notifications for a new best chain.
     if (fInvalidFound) {
         CheckForkWarningConditionsOnNewFork(pindexMostWork);
     } else {
         CheckForkWarningConditions();
     }
 
     return true;
 }
 
 static SynchronizationState GetSynchronizationState(bool init) {
     if (!init) {
         return SynchronizationState::POST_INIT;
     }
     if (::fReindex) {
         return SynchronizationState::INIT_REINDEX;
     }
     return SynchronizationState::INIT_DOWNLOAD;
 }
 
 static bool NotifyHeaderTip(CChainState &chainstate) LOCKS_EXCLUDED(cs_main) {
     bool fNotify = false;
     bool fInitialBlockDownload = false;
     static CBlockIndex *pindexHeaderOld = nullptr;
     CBlockIndex *pindexHeader = nullptr;
     {
         LOCK(cs_main);
         pindexHeader = pindexBestHeader;
 
         if (pindexHeader != pindexHeaderOld) {
             fNotify = true;
             fInitialBlockDownload = chainstate.IsInitialBlockDownload();
             pindexHeaderOld = pindexHeader;
         }
     }
 
     // Send block tip changed notifications without cs_main
     if (fNotify) {
         uiInterface.NotifyHeaderTip(
             GetSynchronizationState(fInitialBlockDownload), pindexHeader);
     }
     return fNotify;
 }
 
 static void LimitValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main) {
     AssertLockNotHeld(cs_main);
 
     if (GetMainSignals().CallbacksPending() > 10) {
         SyncWithValidationInterfaceQueue();
     }
 }
 
 bool CChainState::ActivateBestChain(const Config &config,
                                     BlockValidationState &state,
                                     std::shared_ptr<const CBlock> pblock) {
     // Note that while we're often called here from ProcessNewBlock, this is
     // far from a guarantee. Things in the P2P/RPC will often end up calling
     // us in the middle of ProcessNewBlock - do not assume pblock is set
     // sanely for performance or correctness!
     AssertLockNotHeld(cs_main);
 
     const CChainParams &params = config.GetChainParams();
 
     // ABC maintains a fair degree of expensive-to-calculate internal state
     // because this function periodically releases cs_main so that it does not
     // lock up other threads for too long during large connects - and to allow
     // for e.g. the callback queue to drain we use m_cs_chainstate to enforce
     // mutual exclusion so that only one caller may execute this function at a
     // time
     LOCK(m_cs_chainstate);
 
     CBlockIndex *pindexMostWork = nullptr;
     CBlockIndex *pindexNewTip = nullptr;
     int nStopAtHeight = gArgs.GetArg("-stopatheight", DEFAULT_STOPATHEIGHT);
     do {
         // Block until the validation queue drains. This should largely
         // never happen in normal operation, however may happen during
         // reindex, causing memory blowup if we run too far ahead.
         // Note that if a validationinterface callback ends up calling
         // ActivateBestChain this may lead to a deadlock! We should
         // probably have a DEBUG_LOCKORDER test for this in the future.
         LimitValidationInterfaceQueue();
 
         {
             LOCK(cs_main);
             // Lock transaction pool for at least as long as it takes for
             // connectTrace to be consumed
             LOCK(m_mempool.cs);
             CBlockIndex *starting_tip = m_chain.Tip();
             bool blocks_connected = false;
             do {
                 // We absolutely may not unlock cs_main until we've made forward
                 // progress (with the exception of shutdown due to hardware
                 // issues, low disk space, etc).
 
                 // Destructed before cs_main is unlocked
                 ConnectTrace connectTrace;
 
                 if (pindexMostWork == nullptr) {
                     pindexMostWork = FindMostWorkChain();
                 }
 
                 // Whether we have anything to do at all.
                 if (pindexMostWork == nullptr ||
                     pindexMostWork == m_chain.Tip()) {
                     break;
                 }
 
                 bool fInvalidFound = false;
                 std::shared_ptr<const CBlock> nullBlockPtr;
                 if (!ActivateBestChainStep(
                         config, state, pindexMostWork,
                         pblock && pblock->GetHash() ==
                                       pindexMostWork->GetBlockHash()
                             ? pblock
                             : nullBlockPtr,
                         fInvalidFound, connectTrace)) {
                     // A system error occurred
                     return false;
                 }
                 blocks_connected = true;
 
                 if (fInvalidFound) {
                     // Wipe cache, we may need another branch now.
                     pindexMostWork = nullptr;
                 }
 
                 pindexNewTip = m_chain.Tip();
                 for (const PerBlockConnectTrace &trace :
                      connectTrace.GetBlocksConnected()) {
                     assert(trace.pblock && trace.pindex);
                     GetMainSignals().BlockConnected(trace.pblock, trace.pindex);
                 }
             } while (!m_chain.Tip() ||
                      (starting_tip && CBlockIndexWorkComparator()(
                                           m_chain.Tip(), starting_tip)));
 
             // Check the index once we're done with the above loop, since
             // we're going to release cs_main soon. If the index is in a bad
             // state now, then it's better to know immediately rather than
             // randomly have it cause a problem in a race.
             CheckBlockIndex(params.GetConsensus());
 
             if (!blocks_connected) {
                 return true;
             }
 
             const CBlockIndex *pindexFork = m_chain.FindFork(starting_tip);
             bool fInitialDownload = IsInitialBlockDownload();
 
             // Notify external listeners about the new tip.
             // Enqueue while holding cs_main to ensure that UpdatedBlockTip is
             // called in the order in which blocks are connected
             if (pindexFork != pindexNewTip) {
                 // Notify ValidationInterface subscribers
                 GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork,
                                                  fInitialDownload);
 
                 // Always notify the UI if a new block tip was connected
                 uiInterface.NotifyBlockTip(
                     GetSynchronizationState(fInitialDownload), pindexNewTip);
             }
         }
         // When we reach this point, we switched to a new tip (stored in
         // pindexNewTip).
 
         if (nStopAtHeight && pindexNewTip &&
             pindexNewTip->nHeight >= nStopAtHeight) {
             StartShutdown();
         }
 
         // We check shutdown only after giving ActivateBestChainStep a chance to
         // run once so that we never shutdown before connecting the genesis
         // block during LoadChainTip(). Previously this caused an assert()
         // failure during shutdown in such cases as the UTXO DB flushing checks
         // that the best block hash is non-null.
         if (ShutdownRequested()) {
             break;
         }
     } while (pindexNewTip != pindexMostWork);
 
     // Write changes periodically to disk, after relay.
     if (!FlushStateToDisk(params, state, FlushStateMode::PERIODIC)) {
         return false;
     }
 
     return true;
 }
 
 bool CChainState::PreciousBlock(const Config &config,
                                 BlockValidationState &state,
                                 CBlockIndex *pindex) {
     {
         LOCK(cs_main);
         if (pindex->nChainWork < m_chain.Tip()->nChainWork) {
             // Nothing to do, this block is not at the tip.
             return true;
         }
 
         if (m_chain.Tip()->nChainWork > nLastPreciousChainwork) {
             // The chain has been extended since the last call, reset the
             // counter.
             nBlockReverseSequenceId = -1;
         }
 
         nLastPreciousChainwork = m_chain.Tip()->nChainWork;
         setBlockIndexCandidates.erase(pindex);
         pindex->nSequenceId = nBlockReverseSequenceId;
         if (nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
             // We can't keep reducing the counter if somebody really wants to
             // call preciousblock 2**31-1 times on the same set of tips...
             nBlockReverseSequenceId--;
         }
 
         // In case this was parked, unpark it.
         UnparkBlock(pindex);
 
         // Make sure it is added to the candidate list if appropriate.
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
             pindex->HaveTxsDownloaded()) {
             setBlockIndexCandidates.insert(pindex);
             PruneBlockIndexCandidates();
         }
     }
 
     return ActivateBestChain(config, state);
 }
 
 bool CChainState::UnwindBlock(const Config &config, BlockValidationState &state,
                               CBlockIndex *pindex, bool invalidate) {
     CBlockIndex *to_mark_failed_or_parked = pindex;
     bool pindex_was_in_chain = false;
     int disconnected = 0;
     const CChainParams &chainparams = config.GetChainParams();
 
     // We do not allow ActivateBestChain() to run while UnwindBlock() is
     // running, as that could cause the tip to change while we disconnect
     // blocks. (Note for backport of Core PR16849: we acquire
     // LOCK(m_cs_chainstate) in the Park, Invalidate and FinalizeBlock functions
     // due to differences in our code)
     AssertLockHeld(m_cs_chainstate);
 
     // We'll be acquiring and releasing cs_main below, to allow the validation
     // callbacks to run. However, we should keep the block index in a
     // consistent state as we disconnect blocks -- in particular we need to
     // add equal-work blocks to setBlockIndexCandidates as we disconnect.
     // To avoid walking the block index repeatedly in search of candidates,
     // build a map once so that we can look up candidate blocks by chain
     // work as we go.
     std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work;
 
     {
         LOCK(cs_main);
         for (const auto &entry : m_blockman.m_block_index) {
             CBlockIndex *candidate = entry.second;
             // We don't need to put anything in our active chain into the
             // multimap, because those candidates will be found and considered
             // as we disconnect.
             // Instead, consider only non-active-chain blocks that have at
             // least as much work as where we expect the new tip to end up.
             if (!m_chain.Contains(candidate) &&
                 !CBlockIndexWorkComparator()(candidate, pindex->pprev) &&
                 candidate->IsValid(BlockValidity::TRANSACTIONS) &&
                 candidate->HaveTxsDownloaded()) {
                 candidate_blocks_by_work.insert(
                     std::make_pair(candidate->nChainWork, candidate));
             }
         }
     }
 
     // Disconnect (descendants of) pindex, and mark them invalid.
     while (true) {
         if (ShutdownRequested()) {
             break;
         }
 
         // Make sure the queue of validation callbacks doesn't grow unboundedly.
         LimitValidationInterfaceQueue();
 
         LOCK(cs_main);
         // Lock for as long as disconnectpool is in scope to make sure
         // UpdateMempoolForReorg is called after DisconnectTip without unlocking
         // in between
         LOCK(m_mempool.cs);
 
         if (!m_chain.Contains(pindex)) {
             break;
         }
 
         pindex_was_in_chain = true;
         CBlockIndex *invalid_walk_tip = m_chain.Tip();
 
         // ActivateBestChain considers blocks already in m_chain
         // unconditionally valid already, so force disconnect away from it.
 
         DisconnectedBlockTransactions disconnectpool;
 
         bool ret = DisconnectTip(chainparams, state, &disconnectpool);
 
         // DisconnectTip will add transactions to disconnectpool.
         // Adjust the mempool to be consistent with the new tip, adding
         // transactions back to the mempool if disconnecting was successful,
         // and we're not doing a very deep invalidation (in which case
         // keeping the mempool up to date is probably futile anyway).
         disconnectpool.updateMempoolForReorg(
             config, *this,
             /* fAddToMempool = */ (++disconnected <= 10) && ret, m_mempool);
 
         if (!ret) {
             return false;
         }
 
         assert(invalid_walk_tip->pprev == m_chain.Tip());
 
         // We immediately mark the disconnected blocks as invalid.
         // This prevents a case where pruned nodes may fail to invalidateblock
         // and be left unable to start as they have no tip candidates (as there
         // are no blocks that meet the "have data and are not invalid per
         // nStatus" criteria for inclusion in setBlockIndexCandidates).
 
         invalid_walk_tip->nStatus =
             invalidate ? invalid_walk_tip->nStatus.withFailed()
                        : invalid_walk_tip->nStatus.withParked();
 
         setDirtyBlockIndex.insert(invalid_walk_tip);
         setBlockIndexCandidates.insert(invalid_walk_tip->pprev);
 
         if (invalid_walk_tip == to_mark_failed_or_parked->pprev &&
             (invalidate ? to_mark_failed_or_parked->nStatus.hasFailed()
                         : to_mark_failed_or_parked->nStatus.isParked())) {
             // We only want to mark the last disconnected block as
             // Failed (or Parked); its children need to be FailedParent (or
             // ParkedParent) instead.
             to_mark_failed_or_parked->nStatus =
                 (invalidate
                      ? to_mark_failed_or_parked->nStatus.withFailed(false)
                            .withFailedParent()
                      : to_mark_failed_or_parked->nStatus.withParked(false)
                            .withParkedParent());
 
             setDirtyBlockIndex.insert(to_mark_failed_or_parked);
         }
 
         // Add any equal or more work headers to setBlockIndexCandidates
         auto candidate_it = candidate_blocks_by_work.lower_bound(
             invalid_walk_tip->pprev->nChainWork);
         while (candidate_it != candidate_blocks_by_work.end()) {
             if (!CBlockIndexWorkComparator()(candidate_it->second,
                                              invalid_walk_tip->pprev)) {
                 setBlockIndexCandidates.insert(candidate_it->second);
                 candidate_it = candidate_blocks_by_work.erase(candidate_it);
             } else {
                 ++candidate_it;
             }
         }
 
         // Track the last disconnected block, so we can correct its
         // FailedParent (or ParkedParent) status in future iterations, or, if
         // it's the last one, call InvalidChainFound on it.
         to_mark_failed_or_parked = invalid_walk_tip;
     }
 
     CheckBlockIndex(chainparams.GetConsensus());
 
     {
         LOCK(cs_main);
         if (m_chain.Contains(to_mark_failed_or_parked)) {
             // If the to-be-marked invalid block is in the active chain,
             // something is interfering and we can't proceed.
             return false;
         }
 
         // Mark pindex (or the last disconnected block) as invalid (or parked),
         // even when it never was in the main chain.
         to_mark_failed_or_parked->nStatus =
             invalidate ? to_mark_failed_or_parked->nStatus.withFailed()
                        : to_mark_failed_or_parked->nStatus.withParked();
         setDirtyBlockIndex.insert(to_mark_failed_or_parked);
         if (invalidate) {
             m_blockman.m_failed_blocks.insert(to_mark_failed_or_parked);
         }
 
         // If any new blocks somehow arrived while we were disconnecting
         // (above), then the pre-calculation of what should go into
         // setBlockIndexCandidates may have missed entries. This would
         // technically be an inconsistency in the block index, but if we clean
         // it up here, this should be an essentially unobservable error.
         // Loop back over all block index entries and add any missing entries
         // to setBlockIndexCandidates.
         for (const std::pair<const BlockHash, CBlockIndex *> &it :
              m_blockman.m_block_index) {
             CBlockIndex *i = it.second;
             if (i->IsValid(BlockValidity::TRANSACTIONS) &&
                 i->HaveTxsDownloaded() &&
                 !setBlockIndexCandidates.value_comp()(i, m_chain.Tip())) {
                 setBlockIndexCandidates.insert(i);
             }
         }
 
         if (invalidate) {
             InvalidChainFound(to_mark_failed_or_parked);
         }
     }
 
     // Only notify about a new block tip if the active chain was modified.
     if (pindex_was_in_chain) {
         uiInterface.NotifyBlockTip(
             GetSynchronizationState(IsInitialBlockDownload()),
             to_mark_failed_or_parked->pprev);
     }
     return true;
 }
 
 bool CChainState::InvalidateBlock(const Config &config,
                                   BlockValidationState &state,
                                   CBlockIndex *pindex) {
     AssertLockNotHeld(m_cs_chainstate);
     // See 'Note for backport of Core PR16849' in CChainState::UnwindBlock
     LOCK(m_cs_chainstate);
 
     return UnwindBlock(config, state, pindex, true);
 }
 
 bool CChainState::ParkBlock(const Config &config, BlockValidationState &state,
                             CBlockIndex *pindex) {
     AssertLockNotHeld(m_cs_chainstate);
     // See 'Note for backport of Core PR16849' in CChainState::UnwindBlock
     LOCK(m_cs_chainstate);
 
     return UnwindBlock(config, state, pindex, false);
 }
 
 bool CChainState::FinalizeBlock(const Config &config,
                                 BlockValidationState &state,
                                 CBlockIndex *pindex) {
     AssertLockNotHeld(m_cs_chainstate);
     // See 'Note for backport of Core PR16849' in CChainState::UnwindBlock
     LOCK(m_cs_chainstate);
 
     AssertLockNotHeld(cs_main);
     CBlockIndex *pindexToInvalidate = nullptr;
     {
         LOCK(cs_main);
         if (!MarkBlockAsFinal(state, pindex)) {
             // state is set by MarkBlockAsFinal.
             return false;
         }
 
         // We have a valid candidate, make sure it is not parked.
         if (pindex->nStatus.isOnParkedChain()) {
             UnparkBlock(pindex);
         }
 
         // If the finalized block is on the active chain, there is no need to
         // rewind.
         if (m_chain.Contains(pindex)) {
             return true;
         }
 
         // If the finalized block is not on the active chain, that chain is
         // invalid
         // ...
         const CBlockIndex *pindexFork = m_chain.FindFork(pindex);
         pindexToInvalidate = m_chain.Next(pindexFork);
         if (!pindexToInvalidate) {
             return false;
         }
     } // end of locked cs_main scope
 
     // ... therefore, we invalidate the block on the active chain that comes
     // immediately after it
     return UnwindBlock(config, state, pindexToInvalidate,
                        true /* invalidating */);
 }
 
 template <typename F>
 bool CChainState::UpdateFlagsForBlock(CBlockIndex *pindexBase,
                                       CBlockIndex *pindex, F f) {
     BlockStatus newStatus = f(pindex->nStatus);
     if (pindex->nStatus != newStatus &&
         (!pindexBase ||
          pindex->GetAncestor(pindexBase->nHeight) == pindexBase)) {
         pindex->nStatus = newStatus;
         setDirtyBlockIndex.insert(pindex);
         if (newStatus.isValid()) {
             m_blockman.m_failed_blocks.erase(pindex);
         }
 
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
             pindex->HaveTxsDownloaded() &&
             setBlockIndexCandidates.value_comp()(m_chain.Tip(), pindex)) {
             setBlockIndexCandidates.insert(pindex);
         }
         return true;
     }
     return false;
 }
 
 template <typename F, typename C, typename AC>
 void CChainState::UpdateFlags(CBlockIndex *pindex, CBlockIndex *&pindexReset,
                               F f, C fChild, AC fAncestorWasChanged) {
     AssertLockHeld(cs_main);
 
     // Update the current block and ancestors; while we're doing this, identify
     // which was the deepest ancestor we changed.
     CBlockIndex *pindexDeepestChanged = pindex;
     for (auto pindexAncestor = pindex; pindexAncestor != nullptr;
          pindexAncestor = pindexAncestor->pprev) {
         if (UpdateFlagsForBlock(nullptr, pindexAncestor, f)) {
             pindexDeepestChanged = pindexAncestor;
         }
     }
 
     if (pindexReset &&
         pindexReset->GetAncestor(pindexDeepestChanged->nHeight) ==
             pindexDeepestChanged) {
         // reset pindexReset if it had a modified ancestor.
         pindexReset = nullptr;
     }
 
     // Update all blocks under modified blocks.
     BlockMap::iterator it = m_blockman.m_block_index.begin();
     while (it != m_blockman.m_block_index.end()) {
         UpdateFlagsForBlock(pindex, it->second, fChild);
         UpdateFlagsForBlock(pindexDeepestChanged, it->second,
                             fAncestorWasChanged);
         it++;
     }
 }
 
 void CChainState::ResetBlockFailureFlags(CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
 
     // In case we are reconsidering something before the finalization point,
     // move the finalization point to the last common ancestor.
     if (m_finalizedBlockIndex) {
         m_finalizedBlockIndex =
             LastCommonAncestor(pindex, m_finalizedBlockIndex);
     }
 
     UpdateFlags(
         pindex, pindexBestInvalid,
         [](const BlockStatus status) {
             return status.withClearedFailureFlags();
         },
         [](const BlockStatus status) {
             return status.withClearedFailureFlags();
         },
         [](const BlockStatus status) {
             return status.withFailedParent(false);
         });
 }
 
 void CChainState::UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren) {
     AssertLockHeld(cs_main);
 
     UpdateFlags(
         pindex, pindexBestParked,
         [](const BlockStatus status) {
             return status.withClearedParkedFlags();
         },
         [fClearChildren](const BlockStatus status) {
             return fClearChildren ? status.withClearedParkedFlags()
                                   : status.withParkedParent(false);
         },
         [](const BlockStatus status) {
             return status.withParkedParent(false);
         });
 }
 
 void CChainState::UnparkBlockAndChildren(CBlockIndex *pindex) {
     return UnparkBlockImpl(pindex, true);
 }
 
 void CChainState::UnparkBlock(CBlockIndex *pindex) {
     return UnparkBlockImpl(pindex, false);
 }
 
 bool CChainState::IsBlockFinalized(const CBlockIndex *pindex) const {
     AssertLockHeld(cs_main);
     return m_finalizedBlockIndex &&
            m_finalizedBlockIndex->GetAncestor(pindex->nHeight) == pindex;
 }
 
 /** Return the currently finalized block index. */
 const CBlockIndex *CChainState::GetFinalizedBlock() const {
     AssertLockHeld(cs_main);
     return m_finalizedBlockIndex;
 }
 
 CBlockIndex *BlockManager::AddToBlockIndex(const CBlockHeader &block) {
     AssertLockHeld(cs_main);
 
     // Check for duplicate
     BlockHash hash = block.GetHash();
     BlockMap::iterator it = m_block_index.find(hash);
     if (it != m_block_index.end()) {
         return it->second;
     }
 
     // Construct new block index object
     CBlockIndex *pindexNew = new CBlockIndex(block);
     // We assign the sequence id to blocks only when the full data is available,
     // to avoid miners withholding blocks but broadcasting headers, to get a
     // competitive advantage.
     pindexNew->nSequenceId = 0;
     BlockMap::iterator mi =
         m_block_index.insert(std::make_pair(hash, pindexNew)).first;
     pindexNew->phashBlock = &((*mi).first);
     BlockMap::iterator miPrev = m_block_index.find(block.hashPrevBlock);
     if (miPrev != m_block_index.end()) {
         pindexNew->pprev = (*miPrev).second;
         pindexNew->nHeight = pindexNew->pprev->nHeight + 1;
         pindexNew->BuildSkip();
     }
     pindexNew->nTimeReceived = GetTime();
     pindexNew->nTimeMax =
         (pindexNew->pprev
              ? std::max(pindexNew->pprev->nTimeMax, pindexNew->nTime)
              : pindexNew->nTime);
     pindexNew->nChainWork =
         (pindexNew->pprev ? pindexNew->pprev->nChainWork : 0) +
         GetBlockProof(*pindexNew);
     pindexNew->RaiseValidity(BlockValidity::TREE);
     if (pindexBestHeader == nullptr ||
         pindexBestHeader->nChainWork < pindexNew->nChainWork) {
         pindexBestHeader = pindexNew;
     }
 
     setDirtyBlockIndex.insert(pindexNew);
     return pindexNew;
 }
 
 /**
  * Mark a block as having its data received and checked (up to
  * BLOCK_VALID_TRANSACTIONS).
  */
 void CChainState::ReceivedBlockTransactions(const CBlock &block,
                                             CBlockIndex *pindexNew,
                                             const FlatFilePos &pos) {
     pindexNew->nTx = block.vtx.size();
     pindexNew->nSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
     pindexNew->nFile = pos.nFile;
     pindexNew->nDataPos = pos.nPos;
     pindexNew->nUndoPos = 0;
     pindexNew->nStatus = pindexNew->nStatus.withData();
     pindexNew->RaiseValidity(BlockValidity::TRANSACTIONS);
     setDirtyBlockIndex.insert(pindexNew);
 
     if (pindexNew->UpdateChainStats()) {
         // If pindexNew is the genesis block or all parents are
         // BLOCK_VALID_TRANSACTIONS.
         std::deque<CBlockIndex *> queue;
         queue.push_back(pindexNew);
 
         // Recursively process any descendant blocks that now may be eligible to
         // be connected.
         while (!queue.empty()) {
             CBlockIndex *pindex = queue.front();
             queue.pop_front();
             pindex->UpdateChainStats();
             if (pindex->nSequenceId == 0) {
                 // We assign a sequence is when transaction are received to
                 // prevent a miner from being able to broadcast a block but not
                 // its content. However, a sequence id may have been set
                 // manually, for instance via PreciousBlock, in which case, we
                 // don't need to assign one.
                 pindex->nSequenceId = nBlockSequenceId++;
             }
 
             if (m_chain.Tip() == nullptr ||
                 !setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
                 setBlockIndexCandidates.insert(pindex);
             }
 
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 range = m_blockman.m_blocks_unlinked.equal_range(pindex);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator it =
                     range.first;
                 queue.push_back(it->second);
                 range.first++;
                 m_blockman.m_blocks_unlinked.erase(it);
             }
         }
     } else if (pindexNew->pprev &&
                pindexNew->pprev->IsValid(BlockValidity::TREE)) {
         m_blockman.m_blocks_unlinked.insert(
             std::make_pair(pindexNew->pprev, pindexNew));
     }
 }
 
 // TODO move to blockstorage
 bool FindBlockPos(FlatFilePos &pos, unsigned int nAddSize, unsigned int nHeight,
                   CChain &active_chain, uint64_t nTime, bool fKnown = false) {
     LOCK(cs_LastBlockFile);
 
     unsigned int nFile = fKnown ? pos.nFile : nLastBlockFile;
     if (vinfoBlockFile.size() <= nFile) {
         vinfoBlockFile.resize(nFile + 1);
     }
 
     bool finalize_undo = false;
     if (!fKnown) {
         while (vinfoBlockFile[nFile].nSize + nAddSize >=
                (gArgs.GetBoolArg("-fastprune", false) ? 0x10000 /* 64kb */
                                                       : MAX_BLOCKFILE_SIZE)) {
             // when the undo file is keeping up with the block file, we want to
             // flush it explicitly when it is lagging behind (more blocks arrive
             // than are being connected), we let the undo block write case
             // handle it
             finalize_undo = (vinfoBlockFile[nFile].nHeightLast ==
                              (unsigned int)active_chain.Tip()->nHeight);
             nFile++;
             if (vinfoBlockFile.size() <= nFile) {
                 vinfoBlockFile.resize(nFile + 1);
             }
         }
         pos.nFile = nFile;
         pos.nPos = vinfoBlockFile[nFile].nSize;
     }
 
     if ((int)nFile != nLastBlockFile) {
         if (!fKnown) {
             LogPrintf("Leaving block file %i: %s\n", nLastBlockFile,
                       vinfoBlockFile[nLastBlockFile].ToString());
         }
         FlushBlockFile(!fKnown, finalize_undo);
         nLastBlockFile = nFile;
     }
 
     vinfoBlockFile[nFile].AddBlock(nHeight, nTime);
     if (fKnown) {
         vinfoBlockFile[nFile].nSize =
             std::max(pos.nPos + nAddSize, vinfoBlockFile[nFile].nSize);
     } else {
         vinfoBlockFile[nFile].nSize += nAddSize;
     }
 
     if (!fKnown) {
         bool out_of_space;
         size_t bytes_allocated =
             BlockFileSeq().Allocate(pos, nAddSize, out_of_space);
         if (out_of_space) {
             return AbortNode("Disk space is too low!",
                              _("Disk space is too low!"));
         }
         if (bytes_allocated != 0 && fPruneMode) {
             fCheckForPruning = true;
         }
     }
 
     setDirtyFileInfo.insert(nFile);
     return true;
 }
 
 static bool FindUndoPos(BlockValidationState &state, int nFile,
                         FlatFilePos &pos, unsigned int nAddSize) {
     pos.nFile = nFile;
 
     LOCK(cs_LastBlockFile);
 
     pos.nPos = vinfoBlockFile[nFile].nUndoSize;
     vinfoBlockFile[nFile].nUndoSize += nAddSize;
     setDirtyFileInfo.insert(nFile);
 
     bool out_of_space;
     size_t bytes_allocated =
         UndoFileSeq().Allocate(pos, nAddSize, out_of_space);
     if (out_of_space) {
         return AbortNode(state, "Disk space is too low!",
                          _("Disk space is too low!"));
     }
     if (bytes_allocated != 0 && fPruneMode) {
         fCheckForPruning = true;
     }
 
     return true;
 }
 
 /**
  * Return true if the provided block header is valid.
  * Only verify PoW if blockValidationOptions is configured to do so.
  * This allows validation of headers on which the PoW hasn't been done.
  * For example: to validate template handed to mining software.
  * Do not call this for any check that depends on the context.
  * For context-dependent calls, see ContextualCheckBlockHeader.
  */
 static bool CheckBlockHeader(const CBlockHeader &block,
                              BlockValidationState &state,
                              const Consensus::Params &params,
                              BlockValidationOptions validationOptions) {
     // Check proof of work matches claimed amount
     if (validationOptions.shouldValidatePoW() &&
         !CheckProofOfWork(block.GetHash(), block.nBits, params)) {
         return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
                              "high-hash", "proof of work failed");
     }
 
     return true;
 }
 
 bool CheckBlock(const CBlock &block, BlockValidationState &state,
                 const Consensus::Params &params,
                 BlockValidationOptions validationOptions) {
     // These are checks that are independent of context.
     if (block.fChecked) {
         return true;
     }
 
     // Check that the header is valid (particularly PoW).  This is mostly
     // redundant with the call in AcceptBlockHeader.
     if (!CheckBlockHeader(block, state, params, validationOptions)) {
         return false;
     }
 
     // Check the merkle root.
     if (validationOptions.shouldValidateMerkleRoot()) {
         bool mutated;
         uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
         if (block.hashMerkleRoot != hashMerkleRoot2) {
             return state.Invalid(BlockValidationResult::BLOCK_MUTATED,
                                  "bad-txnmrklroot", "hashMerkleRoot mismatch");
         }
 
         // Check for merkle tree malleability (CVE-2012-2459): repeating
         // sequences of transactions in a block without affecting the merkle
         // root of a block, while still invalidating it.
         if (mutated) {
             return state.Invalid(BlockValidationResult::BLOCK_MUTATED,
                                  "bad-txns-duplicate", "duplicate transaction");
         }
     }
 
     // All potential-corruption validation must be done before we do any
     // transaction validation, as otherwise we may mark the header as invalid
     // because we receive the wrong transactions for it.
 
     // First transaction must be coinbase.
     if (block.vtx.empty()) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-cb-missing", "first tx is not coinbase");
     }
 
     // Size limits.
     auto nMaxBlockSize = validationOptions.getExcessiveBlockSize();
 
     // Bail early if there is no way this block is of reasonable size.
     if ((block.vtx.size() * MIN_TRANSACTION_SIZE) > nMaxBlockSize) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-blk-length", "size limits failed");
     }
 
     auto currentBlockSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
     if (currentBlockSize > nMaxBlockSize) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-blk-length", "size limits failed");
     }
 
     // And a valid coinbase.
     TxValidationState tx_state;
     if (!CheckCoinbase(*block.vtx[0], tx_state)) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              tx_state.GetRejectReason(),
                              strprintf("Coinbase check failed (txid %s) %s",
                                        block.vtx[0]->GetId().ToString(),
                                        tx_state.GetDebugMessage()));
     }
 
     // Check transactions for regularity, skipping the first. Note that this
     // is the first time we check that all after the first are !IsCoinBase.
     for (size_t i = 1; i < block.vtx.size(); i++) {
         auto *tx = block.vtx[i].get();
         if (!CheckRegularTransaction(*tx, tx_state)) {
             return state.Invalid(
                 BlockValidationResult::BLOCK_CONSENSUS,
                 tx_state.GetRejectReason(),
                 strprintf("Transaction check failed (txid %s) %s",
                           tx->GetId().ToString(), tx_state.GetDebugMessage()));
         }
     }
 
     if (validationOptions.shouldValidatePoW() &&
         validationOptions.shouldValidateMerkleRoot()) {
         block.fChecked = true;
     }
 
     return true;
 }
 
 CBlockIndex *BlockManager::GetLastCheckpoint(const CCheckpointData &data) {
     const MapCheckpoints &checkpoints = data.mapCheckpoints;
 
     for (const MapCheckpoints::value_type &i : reverse_iterate(checkpoints)) {
         const BlockHash &hash = i.second;
         CBlockIndex *pindex = LookupBlockIndex(hash);
         if (pindex) {
             return pindex;
         }
     }
 
     return nullptr;
 }
 
 /**
  * Context-dependent validity checks.
  * By "context", we mean only the previous block headers, but not the UTXO
  * set; UTXO-related validity checks are done in ConnectBlock().
  * NOTE: This function is not currently invoked by ConnectBlock(), so we
  * should consider upgrade issues if we change which consensus rules are
  * enforced in this function (eg by adding a new consensus rule). See comment
  * in ConnectBlock().
  * Note that -reindex-chainstate skips the validation that happens here!
  */
 static bool
 ContextualCheckBlockHeader(const CChainParams &params,
                            const CBlockHeader &block,
                            BlockValidationState &state, BlockManager &blockman,
                            const CBlockIndex *pindexPrev, int64_t nAdjustedTime)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     assert(pindexPrev != nullptr);
     const int nHeight = pindexPrev->nHeight + 1;
 
     // Check proof of work
     if (block.nBits != GetNextWorkRequired(pindexPrev, &block, params)) {
         LogPrintf("bad bits after height: %d\n", pindexPrev->nHeight);
         return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
                              "bad-diffbits", "incorrect proof of work");
     }
 
     // Check against checkpoints
     if (fCheckpointsEnabled) {
         const CCheckpointData &checkpoints = params.Checkpoints();
 
         // Check that the block chain matches the known block chain up to a
         // checkpoint.
         if (!Checkpoints::CheckBlock(checkpoints, nHeight, block.GetHash())) {
             LogPrintf("ERROR: %s: rejected by checkpoint lock-in at %d\n",
                       __func__, nHeight);
             return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT,
                                  "checkpoint mismatch");
         }
 
         // Don't accept any forks from the main chain prior to last checkpoint.
         // GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's
         // in our BlockIndex().
 
         CBlockIndex *pcheckpoint = blockman.GetLastCheckpoint(checkpoints);
         if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
             LogPrintf("ERROR: %s: forked chain older than last checkpoint "
                       "(height %d)\n",
                       __func__, nHeight);
             return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT,
                                  "bad-fork-prior-to-checkpoint");
         }
     }
 
     // Check timestamp against prev
     if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) {
         return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
                              "time-too-old", "block's timestamp is too early");
     }
 
     // Check timestamp
     if (block.GetBlockTime() > nAdjustedTime + MAX_FUTURE_BLOCK_TIME) {
         return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE,
                              "time-too-new",
                              "block timestamp too far in the future");
     }
 
     // Reject outdated version blocks when 95% (75% on testnet) of the network
     // has upgraded:
     // check for version 2, 3 and 4 upgrades
     const Consensus::Params &consensusParams = params.GetConsensus();
     if ((block.nVersion < 2 && nHeight >= consensusParams.BIP34Height) ||
         (block.nVersion < 3 && nHeight >= consensusParams.BIP66Height) ||
         (block.nVersion < 4 && nHeight >= consensusParams.BIP65Height)) {
         return state.Invalid(
             BlockValidationResult::BLOCK_INVALID_HEADER,
             strprintf("bad-version(0x%08x)", block.nVersion),
             strprintf("rejected nVersion=0x%08x block", block.nVersion));
     }
 
     return true;
 }
 
 bool ContextualCheckTransactionForCurrentBlock(
     const CBlockIndex *active_chain_tip, const Consensus::Params &params,
     const CTransaction &tx, TxValidationState &state, int flags) {
     AssertLockHeld(cs_main);
     // TODO: Make active_chain_tip a reference
     assert(active_chain_tip);
 
     // By convention a negative value for flags indicates that the current
     // network-enforced consensus rules should be used. In a future soft-fork
     // scenario that would mean checking which rules would be enforced for the
     // next block and setting the appropriate flags. At the present time no
     // soft-forks are scheduled, so no flags are set.
     flags = std::max(flags, 0);
 
     // ContextualCheckTransactionForCurrentBlock() uses
     // active_chain_tip.Height()+1 to evaluate nLockTime because when
     // IsFinalTx() is called within CBlock::AcceptBlock(), the height of the
     // block *being* evaluated is what is used. Thus if we want to know if a
     // transaction can be part of the *next* block, we need to call
     // ContextualCheckTransaction() with one more than
     // active_chain_tip.Height().
     const int nBlockHeight = active_chain_tip->nHeight + 1;
 
     // BIP113 will require that time-locked transactions have nLockTime set to
     // less than the median time of the previous block they're contained in.
     // When the next block is created its previous block will be the current
     // chain tip, so we use that to calculate the median time passed to
     // ContextualCheckTransaction() if LOCKTIME_MEDIAN_TIME_PAST is set.
     const int64_t nMedianTimePast = active_chain_tip->GetMedianTimePast();
     const int64_t nLockTimeCutoff = (flags & LOCKTIME_MEDIAN_TIME_PAST)
                                         ? nMedianTimePast
                                         : GetAdjustedTime();
 
     return ContextualCheckTransaction(params, tx, state, nBlockHeight,
                                       nLockTimeCutoff, nMedianTimePast);
 }
 
 /**
  * NOTE: This function is not currently invoked by ConnectBlock(), so we
  * should consider upgrade issues if we change which consensus rules are
  * enforced in this function (eg by adding a new consensus rule). See comment
  * in ConnectBlock().
  * Note that -reindex-chainstate skips the validation that happens here!
  */
 static bool ContextualCheckBlock(const CBlock &block,
                                  BlockValidationState &state,
                                  const Consensus::Params &params,
                                  const CBlockIndex *pindexPrev) {
     const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
 
     // Start enforcing BIP113 (Median Time Past).
     int nLockTimeFlags = 0;
     if (nHeight >= params.CSVHeight) {
         assert(pindexPrev != nullptr);
         nLockTimeFlags |= LOCKTIME_MEDIAN_TIME_PAST;
     }
 
     const int64_t nMedianTimePast =
         pindexPrev == nullptr ? 0 : pindexPrev->GetMedianTimePast();
 
     const int64_t nLockTimeCutoff = (nLockTimeFlags & LOCKTIME_MEDIAN_TIME_PAST)
                                         ? nMedianTimePast
                                         : block.GetBlockTime();
 
     const bool fIsMagneticAnomalyEnabled =
         IsMagneticAnomalyEnabled(params, pindexPrev);
 
     // Check transactions:
     // - canonical ordering
     // - ensure they are finalized
     // - perform a preliminary block-sigops count (they will be recounted more
     // strictly during ConnectBlock).
     // - perform a transaction-sigops check (again, a more strict check will
     // happen in ConnectBlock).
     const CTransaction *prevTx = nullptr;
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         if (fIsMagneticAnomalyEnabled) {
             if (prevTx && (tx.GetId() <= prevTx->GetId())) {
                 if (tx.GetId() == prevTx->GetId()) {
                     return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                          "tx-duplicate",
                                          strprintf("Duplicated transaction %s",
                                                    tx.GetId().ToString()));
                 }
 
                 return state.Invalid(
                     BlockValidationResult::BLOCK_CONSENSUS, "tx-ordering",
                     strprintf("Transaction order is invalid (%s < %s)",
                               tx.GetId().ToString(),
                               prevTx->GetId().ToString()));
             }
 
             if (prevTx || !tx.IsCoinBase()) {
                 prevTx = &tx;
             }
         }
 
         TxValidationState tx_state;
         if (!ContextualCheckTransaction(params, tx, tx_state, nHeight,
                                         nLockTimeCutoff, nMedianTimePast)) {
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  tx_state.GetRejectReason(),
                                  tx_state.GetDebugMessage());
         }
     }
 
     // Enforce rule that the coinbase starts with serialized block height
     if (nHeight >= params.BIP34Height) {
         CScript expect = CScript() << nHeight;
         if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
             !std::equal(expect.begin(), expect.end(),
                         block.vtx[0]->vin[0].scriptSig.begin())) {
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  "bad-cb-height",
                                  "block height mismatch in coinbase");
         }
     }
 
     return true;
 }
 
 /**
  * If the provided block header is valid, add it to the block index.
  *
  * Returns true if the block is successfully added to the block index.
  */
 bool BlockManager::AcceptBlockHeader(const Config &config,
                                      const CBlockHeader &block,
                                      BlockValidationState &state,
                                      CBlockIndex **ppindex) {
     AssertLockHeld(cs_main);
     const CChainParams &chainparams = config.GetChainParams();
 
     // Check for duplicate
     BlockHash hash = block.GetHash();
     BlockMap::iterator miSelf = m_block_index.find(hash);
     if (hash != chainparams.GetConsensus().hashGenesisBlock) {
         if (miSelf != m_block_index.end()) {
             // Block header is already known.
             CBlockIndex *pindex = miSelf->second;
             if (ppindex) {
                 *ppindex = pindex;
             }
 
             if (pindex->nStatus.isInvalid()) {
                 LogPrintf("ERROR: %s: block %s is marked invalid\n", __func__,
                           hash.ToString());
                 return state.Invalid(
                     BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate");
             }
 
             return true;
         }
 
         if (!CheckBlockHeader(block, state, chainparams.GetConsensus(),
                               BlockValidationOptions(config))) {
             LogPrint(BCLog::VALIDATION,
                      "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__,
                      hash.ToString(), state.ToString());
             return false;
         }
 
         // Get prev block index
         BlockMap::iterator mi = m_block_index.find(block.hashPrevBlock);
         if (mi == m_block_index.end()) {
             LogPrintf("ERROR: %s: prev block not found\n", __func__);
             return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV,
                                  "prev-blk-not-found");
         }
 
         CBlockIndex *pindexPrev = (*mi).second;
         assert(pindexPrev);
         if (pindexPrev->nStatus.isInvalid()) {
             LogPrintf("ERROR: %s: prev block invalid\n", __func__);
             return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV,
                                  "bad-prevblk");
         }
 
         if (!ContextualCheckBlockHeader(chainparams, block, state, *this,
                                         pindexPrev, GetAdjustedTime())) {
             return error("%s: Consensus::ContextualCheckBlockHeader: %s, %s",
                          __func__, hash.ToString(), state.ToString());
         }
 
         /* Determine if this block descends from any block which has been found
          * invalid (m_failed_blocks), then mark pindexPrev and any blocks
          * between them as failed. For example:
          *
          *                D3
          *              /
          *      B2 - C2
          *    /         \
          *  A             D2 - E2 - F2
          *    \
          *      B1 - C1 - D1 - E1
          *
          * In the case that we attempted to reorg from E1 to F2, only to find
          * C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD
          * but NOT D3 (it was not in any of our candidate sets at the time).
          *
          * In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart
          * in LoadBlockIndex.
          */
         if (!pindexPrev->IsValid(BlockValidity::SCRIPTS)) {
             // The above does not mean "invalid": it checks if the previous
             // block hasn't been validated up to BlockValidity::SCRIPTS. This is
             // a performance optimization, in the common case of adding a new
             // block to the tip, we don't need to iterate over the failed blocks
             // list.
             for (const CBlockIndex *failedit : m_failed_blocks) {
                 if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) {
                     assert(failedit->nStatus.hasFailed());
                     CBlockIndex *invalid_walk = pindexPrev;
                     while (invalid_walk != failedit) {
                         invalid_walk->nStatus =
                             invalid_walk->nStatus.withFailedParent();
                         setDirtyBlockIndex.insert(invalid_walk);
                         invalid_walk = invalid_walk->pprev;
                     }
                     LogPrintf("ERROR: %s: prev block invalid\n", __func__);
                     return state.Invalid(
                         BlockValidationResult::BLOCK_INVALID_PREV,
                         "bad-prevblk");
                 }
             }
         }
     }
 
     CBlockIndex *pindex = AddToBlockIndex(block);
 
     if (ppindex) {
         *ppindex = pindex;
     }
 
     return true;
 }
 
 // Exposed wrapper for AcceptBlockHeader
 bool ChainstateManager::ProcessNewBlockHeaders(
     const Config &config, const std::vector<CBlockHeader> &headers,
     BlockValidationState &state, const CBlockIndex **ppindex) {
     AssertLockNotHeld(cs_main);
     {
         LOCK(cs_main);
         for (const CBlockHeader &header : headers) {
             // Use a temp pindex instead of ppindex to avoid a const_cast
             CBlockIndex *pindex = nullptr;
             bool accepted =
                 m_blockman.AcceptBlockHeader(config, header, state, &pindex);
             ActiveChainstate().CheckBlockIndex(
                 config.GetChainParams().GetConsensus());
 
             if (!accepted) {
                 return false;
             }
 
             if (ppindex) {
                 *ppindex = pindex;
             }
         }
     }
 
     if (NotifyHeaderTip(ActiveChainstate())) {
         if (ActiveChainstate().IsInitialBlockDownload() && ppindex &&
             *ppindex) {
             LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n",
                       (*ppindex)->nHeight,
                       100.0 /
                           ((*ppindex)->nHeight +
                            (GetAdjustedTime() - (*ppindex)->GetBlockTime()) /
                                Params().GetConsensus().nPowTargetSpacing) *
                           (*ppindex)->nHeight);
         }
     }
     return true;
 }
 
 /**
  * Store a block on disk.
  *
  * @param[in]     config     The global config.
  * @param[in,out] pblock     The block we want to accept.
  * @param[in]     fRequested A boolean to indicate if this block was requested
  *                           from our peers.
  * @param[in]     dbp        If non-null, the disk position of the block.
  * @param[in,out] fNewBlock  True if block was first received via this call.
  * @return True if the block is accepted as a valid block and written to disk.
  */
 bool CChainState::AcceptBlock(const Config &config,
                               const std::shared_ptr<const CBlock> &pblock,
                               BlockValidationState &state, bool fRequested,
                               const FlatFilePos *dbp, bool *fNewBlock) {
     AssertLockHeld(cs_main);
 
     const CBlock &block = *pblock;
     if (fNewBlock) {
         *fNewBlock = false;
     }
 
     CBlockIndex *pindex = nullptr;
 
     bool accepted_header =
         m_blockman.AcceptBlockHeader(config, block, state, &pindex);
     CheckBlockIndex(config.GetChainParams().GetConsensus());
 
     if (!accepted_header) {
         return false;
     }
 
     // Try to process all requested blocks that we don't have, but only
     // process an unrequested block if it's new and has enough work to
     // advance our tip, and isn't too many blocks ahead.
     bool fAlreadyHave = pindex->nStatus.hasData();
 
     // TODO: deal better with return value and error conditions for duplicate
     // and unrequested blocks.
     if (fAlreadyHave) {
         return true;
     }
 
     // Compare block header timestamps and received times of the block and the
     // chaintip.  If they have the same chain height, use these diffs as a
     // tie-breaker, attempting to pick the more honestly-mined block.
     int64_t newBlockTimeDiff = std::llabs(pindex->GetReceivedTimeDiff());
     int64_t chainTipTimeDiff =
         m_chain.Tip() ? std::llabs(m_chain.Tip()->GetReceivedTimeDiff()) : 0;
 
     bool isSameHeight =
         m_chain.Tip() && (pindex->nChainWork == m_chain.Tip()->nChainWork);
     if (isSameHeight) {
         LogPrintf("Chain tip timestamp-to-received-time difference: hash=%s, "
                   "diff=%d\n",
                   m_chain.Tip()->GetBlockHash().ToString(), chainTipTimeDiff);
         LogPrintf("New block timestamp-to-received-time difference: hash=%s, "
                   "diff=%d\n",
                   pindex->GetBlockHash().ToString(), newBlockTimeDiff);
     }
 
     bool fHasMoreOrSameWork =
         (m_chain.Tip() ? pindex->nChainWork >= m_chain.Tip()->nChainWork
                        : true);
 
     // Blocks that are too out-of-order needlessly limit the effectiveness of
     // pruning, because pruning will not delete block files that contain any
     // blocks which are too close in height to the tip.  Apply this test
     // regardless of whether pruning is enabled; it should generally be safe to
     // not process unrequested blocks.
     bool fTooFarAhead =
         (pindex->nHeight > int(m_chain.Height() + MIN_BLOCKS_TO_KEEP));
 
     // TODO: Decouple this function from the block download logic by removing
     // fRequested
     // This requires some new chain data structure to efficiently look up if a
     // block is in a chain leading to a candidate for best tip, despite not
     // being such a candidate itself.
 
     // If we didn't ask for it:
     if (!fRequested) {
         // This is a previously-processed block that was pruned.
         if (pindex->nTx != 0) {
             return true;
         }
 
         // Don't process less-work chains.
         if (!fHasMoreOrSameWork) {
             return true;
         }
 
         // Block height is too high.
         if (fTooFarAhead) {
             return true;
         }
 
         // Protect against DoS attacks from low-work chains.
         // If our tip is behind, a peer could try to send us
         // low-work blocks on a fake chain that we would never
         // request; don't process these.
         if (pindex->nChainWork < nMinimumChainWork) {
             return true;
         }
     }
 
     const CChainParams &chainparams = config.GetChainParams();
     const Consensus::Params &consensusParams = chainparams.GetConsensus();
 
     if (!CheckBlock(block, state, consensusParams,
                     BlockValidationOptions(config)) ||
         !ContextualCheckBlock(block, state, consensusParams, pindex->pprev)) {
         if (state.IsInvalid() &&
             state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
             pindex->nStatus = pindex->nStatus.withFailed();
             setDirtyBlockIndex.insert(pindex);
         }
 
         return error("%s: %s (block %s)", __func__, state.ToString(),
                      block.GetHash().ToString());
     }
 
     // If connecting the new block would require rewinding more than one block
     // from the active chain (i.e., a "deep reorg"), then mark the new block as
     // parked. If it has enough work then it will be automatically unparked
     // later, during FindMostWorkChain. We mark the block as parked at the very
     // last minute so we can make sure everything is ready to be reorged if
     // needed.
     if (gArgs.GetBoolArg("-parkdeepreorg", true)) {
         const CBlockIndex *pindexFork = m_chain.FindFork(pindex);
         if (pindexFork && pindexFork->nHeight + 1 < m_chain.Height()) {
             LogPrintf("Park block %s as it would cause a deep reorg.\n",
                       pindex->GetBlockHash().ToString());
             pindex->nStatus = pindex->nStatus.withParked();
             setDirtyBlockIndex.insert(pindex);
         }
     }
 
     // Header is valid/has work and the merkle tree is good.
     // Relay now, but if it does not build on our best tip, let the
     // SendMessages loop relay it.
     if (!IsInitialBlockDownload() && m_chain.Tip() == pindex->pprev) {
         GetMainSignals().NewPoWValidBlock(pindex, pblock);
     }
 
     // Write block to history file
     if (fNewBlock) {
         *fNewBlock = true;
     }
     try {
         FlatFilePos blockPos =
             SaveBlockToDisk(block, pindex->nHeight, m_chain, chainparams, dbp);
         if (blockPos.IsNull()) {
             state.Error(strprintf(
                 "%s: Failed to find position to write new block to disk",
                 __func__));
             return false;
         }
         ReceivedBlockTransactions(block, pindex, blockPos);
     } catch (const std::runtime_error &e) {
         return AbortNode(state, std::string("System error: ") + e.what());
     }
 
     FlushStateToDisk(chainparams, state, FlushStateMode::NONE);
 
     CheckBlockIndex(consensusParams);
 
     return true;
 }
 
 bool ChainstateManager::ProcessNewBlock(
     const Config &config, const std::shared_ptr<const CBlock> pblock,
     bool fForceProcessing, bool *fNewBlock) {
     AssertLockNotHeld(cs_main);
 
     {
         if (fNewBlock) {
             *fNewBlock = false;
         }
 
         BlockValidationState state;
 
         // CheckBlock() does not support multi-threaded block validation
         // because CBlock::fChecked can cause data race.
         // Therefore, the following critical section must include the
         // CheckBlock() call as well.
         LOCK(cs_main);
 
         // Ensure that CheckBlock() passes before calling AcceptBlock, as
         // belt-and-suspenders.
         bool ret =
             CheckBlock(*pblock, state, config.GetChainParams().GetConsensus(),
                        BlockValidationOptions(config));
         if (ret) {
             // Store to disk
             ret = ActiveChainstate().AcceptBlock(
                 config, pblock, state, fForceProcessing, nullptr, fNewBlock);
         }
 
         if (!ret) {
             GetMainSignals().BlockChecked(*pblock, state);
             return error("%s: AcceptBlock FAILED (%s)", __func__,
                          state.ToString());
         }
     }
 
     NotifyHeaderTip(ActiveChainstate());
 
     // Only used to report errors, not invalidity - ignore it
     BlockValidationState state;
     if (!ActiveChainstate().ActivateBestChain(config, state, pblock)) {
         return error("%s: ActivateBestChain failed (%s)", __func__,
                      state.ToString());
     }
 
     return true;
 }
 
 bool TestBlockValidity(BlockValidationState &state, const CChainParams &params,
                        CChainState &chainstate, const CBlock &block,
                        CBlockIndex *pindexPrev,
                        BlockValidationOptions validationOptions) {
     AssertLockHeld(cs_main);
     assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip());
     CCoinsViewCache viewNew(&chainstate.CoinsTip());
     BlockHash block_hash(block.GetHash());
     CBlockIndex indexDummy(block);
     indexDummy.pprev = pindexPrev;
     indexDummy.nHeight = pindexPrev->nHeight + 1;
     indexDummy.phashBlock = &block_hash;
 
     // NOTE: CheckBlockHeader is called by CheckBlock
     if (!ContextualCheckBlockHeader(params, block, state, chainstate.m_blockman,
                                     pindexPrev, GetAdjustedTime())) {
         return error("%s: Consensus::ContextualCheckBlockHeader: %s", __func__,
                      state.ToString());
     }
 
     if (!CheckBlock(block, state, params.GetConsensus(), validationOptions)) {
         return error("%s: Consensus::CheckBlock: %s", __func__,
                      state.ToString());
     }
 
     if (!ContextualCheckBlock(block, state, params.GetConsensus(),
                               pindexPrev)) {
         return error("%s: Consensus::ContextualCheckBlock: %s", __func__,
                      state.ToString());
     }
 
     if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew, params,
                                  validationOptions, true)) {
         return false;
     }
 
     assert(state.IsValid());
     return true;
 }
 
 /**
  * BLOCK PRUNING CODE
  */
 
 /**
  * Calculate the amount of disk space the block & undo files currently use.
  */
 uint64_t CalculateCurrentUsage() {
     LOCK(cs_LastBlockFile);
 
     uint64_t retval = 0;
     for (const CBlockFileInfo &file : vinfoBlockFile) {
         retval += file.nSize + file.nUndoSize;
     }
 
     return retval;
 }
 
 void BlockManager::PruneOneBlockFile(const int fileNumber) {
     AssertLockHeld(cs_main);
     LOCK(cs_LastBlockFile);
 
     for (const auto &entry : m_block_index) {
         CBlockIndex *pindex = entry.second;
         if (pindex->nFile == fileNumber) {
             pindex->nStatus = pindex->nStatus.withData(false).withUndo(false);
             pindex->nFile = 0;
             pindex->nDataPos = 0;
             pindex->nUndoPos = 0;
             setDirtyBlockIndex.insert(pindex);
 
             // Prune from m_blocks_unlinked -- any block we prune would have
             // to be downloaded again in order to consider its chain, at which
             // point it would be considered as a candidate for
             // m_blocks_unlinked or setBlockIndexCandidates.
             auto range = m_blocks_unlinked.equal_range(pindex->pprev);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator _it =
                     range.first;
                 range.first++;
                 if (_it->second == pindex) {
                     m_blocks_unlinked.erase(_it);
                 }
             }
         }
     }
 
     vinfoBlockFile[fileNumber].SetNull();
     setDirtyFileInfo.insert(fileNumber);
 }
 
 void UnlinkPrunedFiles(const std::set<int> &setFilesToPrune) {
     for (const int i : setFilesToPrune) {
         FlatFilePos pos(i, 0);
         fs::remove(BlockFileSeq().FileName(pos));
         fs::remove(UndoFileSeq().FileName(pos));
         LogPrintf("Prune: %s deleted blk/rev (%05u)\n", __func__, i);
     }
 }
 
 void BlockManager::FindFilesToPruneManual(std::set<int> &setFilesToPrune,
                                           int nManualPruneHeight,
                                           int chain_tip_height) {
     assert(fPruneMode && nManualPruneHeight > 0);
 
     LOCK2(cs_main, cs_LastBlockFile);
     if (chain_tip_height < 0) {
         return;
     }
 
     // last block to prune is the lesser of (user-specified height,
     // MIN_BLOCKS_TO_KEEP from the tip)
     unsigned int nLastBlockWeCanPrune = std::min(
         (unsigned)nManualPruneHeight, chain_tip_height - MIN_BLOCKS_TO_KEEP);
     int count = 0;
     for (int fileNumber = 0; fileNumber < nLastBlockFile; fileNumber++) {
         if (vinfoBlockFile[fileNumber].nSize == 0 ||
             vinfoBlockFile[fileNumber].nHeightLast > nLastBlockWeCanPrune) {
             continue;
         }
         PruneOneBlockFile(fileNumber);
         setFilesToPrune.insert(fileNumber);
         count++;
     }
     LogPrintf("Prune (Manual): prune_height=%d removed %d blk/rev pairs\n",
               nLastBlockWeCanPrune, count);
 }
 
 /* This function is called from the RPC code for pruneblockchain */
 void PruneBlockFilesManual(CChainState &active_chainstate,
                            int nManualPruneHeight) {
     BlockValidationState state;
     const CChainParams &chainparams = Params();
     if (active_chainstate.FlushStateToDisk(
             chainparams, state, FlushStateMode::NONE, nManualPruneHeight)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   state.ToString());
     }
 }
 
 void BlockManager::FindFilesToPrune(std::set<int> &setFilesToPrune,
                                     uint64_t nPruneAfterHeight,
                                     int chain_tip_height, int prune_height,
                                     bool is_ibd) {
     LOCK2(cs_main, cs_LastBlockFile);
     if (chain_tip_height < 0 || nPruneTarget == 0) {
         return;
     }
     if (uint64_t(chain_tip_height) <= nPruneAfterHeight) {
         return;
     }
 
     unsigned int nLastBlockWeCanPrune = std::min(
         prune_height, chain_tip_height - static_cast<int>(MIN_BLOCKS_TO_KEEP));
     uint64_t nCurrentUsage = CalculateCurrentUsage();
     // We don't check to prune until after we've allocated new space for files,
     // so we should leave a buffer under our target to account for another
     // allocation before the next pruning.
     uint64_t nBuffer = BLOCKFILE_CHUNK_SIZE + UNDOFILE_CHUNK_SIZE;
     uint64_t nBytesToPrune;
     int count = 0;
 
     if (nCurrentUsage + nBuffer >= nPruneTarget) {
         // On a prune event, the chainstate DB is flushed.
         // To avoid excessive prune events negating the benefit of high dbcache
         // values, we should not prune too rapidly.
         // So when pruning in IBD, increase the buffer a bit to avoid a re-prune
         // too soon.
         if (is_ibd) {
             // Since this is only relevant during IBD, we use a fixed 10%
             nBuffer += nPruneTarget / 10;
         }
 
         for (int fileNumber = 0; fileNumber < nLastBlockFile; fileNumber++) {
             nBytesToPrune = vinfoBlockFile[fileNumber].nSize +
                             vinfoBlockFile[fileNumber].nUndoSize;
 
             if (vinfoBlockFile[fileNumber].nSize == 0) {
                 continue;
             }
 
             // are we below our target?
             if (nCurrentUsage + nBuffer < nPruneTarget) {
                 break;
             }
 
             // don't prune files that could have a block within
             // MIN_BLOCKS_TO_KEEP of the main chain's tip but keep scanning
             if (vinfoBlockFile[fileNumber].nHeightLast > nLastBlockWeCanPrune) {
                 continue;
             }
 
             PruneOneBlockFile(fileNumber);
             // Queue up the files for removal
             setFilesToPrune.insert(fileNumber);
             nCurrentUsage -= nBytesToPrune;
             count++;
         }
     }
 
     LogPrint(BCLog::PRUNE,
              "Prune: target=%dMiB actual=%dMiB diff=%dMiB "
              "max_prune_height=%d removed %d blk/rev pairs\n",
              nPruneTarget / 1024 / 1024, nCurrentUsage / 1024 / 1024,
              ((int64_t)nPruneTarget - (int64_t)nCurrentUsage) / 1024 / 1024,
              nLastBlockWeCanPrune, count);
 }
 
 CBlockIndex *BlockManager::InsertBlockIndex(const BlockHash &hash) {
     AssertLockHeld(cs_main);
 
     if (hash.IsNull()) {
         return nullptr;
     }
 
     // Return existing
     BlockMap::iterator mi = m_block_index.find(hash);
     if (mi != m_block_index.end()) {
         return (*mi).second;
     }
 
     // Create new
     CBlockIndex *pindexNew = new CBlockIndex();
     mi = m_block_index.insert(std::make_pair(hash, pindexNew)).first;
     pindexNew->phashBlock = &((*mi).first);
 
     return pindexNew;
 }
 
 bool BlockManager::LoadBlockIndex(
     const Consensus::Params &params, CBlockTreeDB &blocktree,
     std::set<CBlockIndex *, CBlockIndexWorkComparator>
         &block_index_candidates) {
     AssertLockHeld(cs_main);
     if (!blocktree.LoadBlockIndexGuts(
             params, [this](const BlockHash &hash) EXCLUSIVE_LOCKS_REQUIRED(
                         cs_main) { return this->InsertBlockIndex(hash); })) {
         return false;
     }
 
     // Calculate nChainWork
     std::vector<std::pair<int, CBlockIndex *>> vSortedByHeight;
     vSortedByHeight.reserve(m_block_index.size());
     for (const std::pair<const BlockHash, CBlockIndex *> &item :
          m_block_index) {
         CBlockIndex *pindex = item.second;
         vSortedByHeight.push_back(std::make_pair(pindex->nHeight, pindex));
     }
 
     sort(vSortedByHeight.begin(), vSortedByHeight.end());
     for (const std::pair<int, CBlockIndex *> &item : vSortedByHeight) {
         if (ShutdownRequested()) {
             return false;
         }
         CBlockIndex *pindex = item.second;
         pindex->nChainWork = (pindex->pprev ? pindex->pprev->nChainWork : 0) +
                              GetBlockProof(*pindex);
         pindex->nTimeMax =
             (pindex->pprev ? std::max(pindex->pprev->nTimeMax, pindex->nTime)
                            : pindex->nTime);
         // We can link the chain of blocks for which we've received transactions
         // at some point. Pruned nodes may have deleted the block.
         if (pindex->nTx > 0) {
             if (!pindex->UpdateChainStats() && pindex->pprev) {
                 m_blocks_unlinked.insert(std::make_pair(pindex->pprev, pindex));
             }
         }
 
         if (!pindex->nStatus.hasFailed() && pindex->pprev &&
             pindex->pprev->nStatus.hasFailed()) {
             pindex->nStatus = pindex->nStatus.withFailedParent();
             setDirtyBlockIndex.insert(pindex);
         }
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
             (pindex->HaveTxsDownloaded() || pindex->pprev == nullptr)) {
             block_index_candidates.insert(pindex);
         }
 
         if (pindex->nStatus.isInvalid() &&
             (!pindexBestInvalid ||
              pindex->nChainWork > pindexBestInvalid->nChainWork)) {
             pindexBestInvalid = pindex;
         }
 
         if (pindex->nStatus.isOnParkedChain() &&
             (!pindexBestParked ||
              pindex->nChainWork > pindexBestParked->nChainWork)) {
             pindexBestParked = pindex;
         }
 
         if (pindex->pprev) {
             pindex->BuildSkip();
         }
 
         if (pindex->IsValid(BlockValidity::TREE) &&
             (pindexBestHeader == nullptr ||
              CBlockIndexWorkComparator()(pindexBestHeader, pindex))) {
             pindexBestHeader = pindex;
         }
     }
 
     return true;
 }
 
 void BlockManager::Unload() {
     m_failed_blocks.clear();
     m_blocks_unlinked.clear();
 
     for (const BlockMap::value_type &entry : m_block_index) {
         delete entry.second;
     }
 
     m_block_index.clear();
 }
 
 bool CChainState::LoadBlockIndexDB(const Consensus::Params &params) {
     if (!m_blockman.LoadBlockIndex(params, *pblocktree,
                                    setBlockIndexCandidates)) {
         return false;
     }
 
     // Load block file info
     pblocktree->ReadLastBlockFile(nLastBlockFile);
     vinfoBlockFile.resize(nLastBlockFile + 1);
     LogPrintf("%s: last block file = %i\n", __func__, nLastBlockFile);
     for (int nFile = 0; nFile <= nLastBlockFile; nFile++) {
         pblocktree->ReadBlockFileInfo(nFile, vinfoBlockFile[nFile]);
     }
     LogPrintf("%s: last block file info: %s\n", __func__,
               vinfoBlockFile[nLastBlockFile].ToString());
     for (int nFile = nLastBlockFile + 1; true; nFile++) {
         CBlockFileInfo info;
         if (pblocktree->ReadBlockFileInfo(nFile, info)) {
             vinfoBlockFile.push_back(info);
         } else {
             break;
         }
     }
 
     // Check presence of blk files
     LogPrintf("Checking all blk files are present...\n");
     std::set<int> setBlkDataFiles;
     for (const std::pair<const BlockHash, CBlockIndex *> &item :
          m_blockman.m_block_index) {
         CBlockIndex *pindex = item.second;
         if (pindex->nStatus.hasData()) {
             setBlkDataFiles.insert(pindex->nFile);
         }
     }
 
     for (const int i : setBlkDataFiles) {
         FlatFilePos pos(i, 0);
         if (CAutoFile(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION)
                 .IsNull()) {
             return false;
         }
     }
 
     // Check whether we have ever pruned block & undo files
     pblocktree->ReadFlag("prunedblockfiles", fHavePruned);
     if (fHavePruned) {
         LogPrintf(
             "LoadBlockIndexDB(): Block files have previously been pruned\n");
     }
 
     // Check whether we need to continue reindexing
     if (pblocktree->IsReindexing()) {
         fReindex = true;
     }
 
     return true;
 }
 
 void CChainState::LoadMempool(const Config &config, const ArgsManager &args) {
     if (args.GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
         ::LoadMempool(config, m_mempool, *this);
     }
     m_mempool.SetIsLoaded(!ShutdownRequested());
 }
 
 bool CChainState::LoadChainTip(const CChainParams &chainparams) {
     AssertLockHeld(cs_main);
     const CCoinsViewCache &coins_cache = CoinsTip();
     // Never called when the coins view is empty
     assert(!coins_cache.GetBestBlock().IsNull());
     const CBlockIndex *tip = m_chain.Tip();
 
     if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
         return true;
     }
 
     // Load pointer to end of best chain
     CBlockIndex *pindex =
         m_blockman.LookupBlockIndex(coins_cache.GetBestBlock());
     if (!pindex) {
         return false;
     }
     m_chain.SetTip(pindex);
     PruneBlockIndexCandidates();
 
     tip = m_chain.Tip();
     LogPrintf(
         "Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
         tip->GetBlockHash().ToString(), m_chain.Height(),
         FormatISO8601DateTime(tip->GetBlockTime()),
         GuessVerificationProgress(chainparams.TxData(), tip));
     return true;
 }
 
 CVerifyDB::CVerifyDB() {
     uiInterface.ShowProgress(_("Verifying blocks...").translated, 0, false);
 }
 
 CVerifyDB::~CVerifyDB() {
     uiInterface.ShowProgress("", 100, false);
 }
 
 bool CVerifyDB::VerifyDB(CChainState &chainstate, const Config &config,
                          CCoinsView &coinsview, int nCheckLevel,
                          int nCheckDepth) {
     AssertLockHeld(cs_main);
 
     const CChainParams &params = config.GetChainParams();
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     if (chainstate.m_chain.Tip() == nullptr ||
         chainstate.m_chain.Tip()->pprev == nullptr) {
         return true;
     }
 
     // Verify blocks in the best chain
     if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) {
         nCheckDepth = chainstate.m_chain.Height();
     }
 
     nCheckLevel = std::max(0, std::min(4, nCheckLevel));
     LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth,
               nCheckLevel);
 
     CCoinsViewCache coins(&coinsview);
     CBlockIndex *pindex;
     CBlockIndex *pindexFailure = nullptr;
     int nGoodTransactions = 0;
     BlockValidationState state;
     int reportDone = 0;
     LogPrintfToBeContinued("[0%%]...");
 
     const bool is_snapshot_cs{!chainstate.m_from_snapshot_blockhash};
 
     for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev;
          pindex = pindex->pprev) {
         const int percentageDone = std::max(
             1, std::min(99, (int)(((double)(chainstate.m_chain.Height() -
                                             pindex->nHeight)) /
                                   (double)nCheckDepth *
                                   (nCheckLevel >= 4 ? 50 : 100))));
         if (reportDone < percentageDone / 10) {
             // report every 10% step
             LogPrintfToBeContinued("[%d%%]...", percentageDone);
             reportDone = percentageDone / 10;
         }
 
         uiInterface.ShowProgress(_("Verifying blocks...").translated,
                                  percentageDone, false);
         if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) {
             break;
         }
 
         if ((fPruneMode || is_snapshot_cs) && !pindex->nStatus.hasData()) {
             // If pruning or running under an assumeutxo snapshot, only go
             // back as far as we have data.
             LogPrintf("VerifyDB(): block verification stopping at height %d "
                       "(pruning, no data)\n",
                       pindex->nHeight);
             break;
         }
 
         CBlock block;
 
         // check level 0: read from disk
         if (!ReadBlockFromDisk(block, pindex, consensusParams)) {
             return error(
                 "VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s",
                 pindex->nHeight, pindex->GetBlockHash().ToString());
         }
 
         // check level 1: verify block validity
         if (nCheckLevel >= 1 && !CheckBlock(block, state, consensusParams,
                                             BlockValidationOptions(config))) {
             return error("%s: *** found bad block at %d, hash=%s (%s)\n",
                          __func__, pindex->nHeight,
                          pindex->GetBlockHash().ToString(), state.ToString());
         }
 
         // check level 2: verify undo validity
         if (nCheckLevel >= 2 && pindex) {
             CBlockUndo undo;
             if (!pindex->GetUndoPos().IsNull()) {
                 if (!UndoReadFromDisk(undo, pindex)) {
                     return error(
                         "VerifyDB(): *** found bad undo data at %d, hash=%s\n",
                         pindex->nHeight, pindex->GetBlockHash().ToString());
                 }
             }
         }
         // check level 3: check for inconsistencies during memory-only
         // disconnect of tip blocks
         size_t curr_coins_usage = coins.DynamicMemoryUsage() +
                                   chainstate.CoinsTip().DynamicMemoryUsage();
 
         if (nCheckLevel >= 3 &&
             curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) {
             assert(coins.GetBestBlock() == pindex->GetBlockHash());
             DisconnectResult res =
                 chainstate.DisconnectBlock(block, pindex, coins);
             if (res == DisconnectResult::FAILED) {
                 return error("VerifyDB(): *** irrecoverable inconsistency in "
                              "block data at %d, hash=%s",
                              pindex->nHeight,
                              pindex->GetBlockHash().ToString());
             }
 
             if (res == DisconnectResult::UNCLEAN) {
                 nGoodTransactions = 0;
                 pindexFailure = pindex;
             } else {
                 nGoodTransactions += block.vtx.size();
             }
         }
 
         if (ShutdownRequested()) {
             return true;
         }
     }
 
     if (pindexFailure) {
         return error("VerifyDB(): *** coin database inconsistencies found "
                      "(last %i blocks, %i good transactions before that)\n",
                      chainstate.m_chain.Height() - pindexFailure->nHeight + 1,
                      nGoodTransactions);
     }
 
     // store block count as we move pindex at check level >= 4
     int block_count = chainstate.m_chain.Height() - pindex->nHeight;
 
     // check level 4: try reconnecting blocks
     if (nCheckLevel >= 4) {
         while (pindex != chainstate.m_chain.Tip()) {
             const int percentageDone = std::max(
                 1, std::min(99, 100 - int(double(chainstate.m_chain.Height() -
                                                  pindex->nHeight) /
                                           double(nCheckDepth) * 50)));
             if (reportDone < percentageDone / 10) {
                 // report every 10% step
                 LogPrintfToBeContinued("[%d%%]...", percentageDone);
                 reportDone = percentageDone / 10;
             }
             uiInterface.ShowProgress(_("Verifying blocks...").translated,
                                      percentageDone, false);
             pindex = chainstate.m_chain.Next(pindex);
             CBlock block;
             if (!ReadBlockFromDisk(block, pindex, consensusParams)) {
                 return error(
                     "VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s",
                     pindex->nHeight, pindex->GetBlockHash().ToString());
             }
             if (!chainstate.ConnectBlock(block, state, pindex, coins, params,
                                          BlockValidationOptions(config))) {
                 return error("VerifyDB(): *** found unconnectable block at %d, "
                              "hash=%s (%s)",
                              pindex->nHeight, pindex->GetBlockHash().ToString(),
                              state.ToString());
             }
             if (ShutdownRequested()) {
                 return true;
             }
         }
     }
 
     LogPrintf("[DONE].\n");
     LogPrintf("No coin database inconsistencies in last %i blocks (%i "
               "transactions)\n",
               block_count, nGoodTransactions);
 
     return true;
 }
 
 /**
  * Apply the effects of a block on the utxo cache, ignoring that it may already
  * have been applied.
  */
 bool CChainState::RollforwardBlock(const CBlockIndex *pindex,
                                    CCoinsViewCache &view,
                                    const Consensus::Params &params) {
     // TODO: merge with ConnectBlock
     CBlock block;
     if (!ReadBlockFromDisk(block, pindex, params)) {
         return error("ReplayBlock(): ReadBlockFromDisk failed at %d, hash=%s",
                      pindex->nHeight, pindex->GetBlockHash().ToString());
     }
 
     for (const CTransactionRef &tx : block.vtx) {
         // Pass check = true as every addition may be an overwrite.
         AddCoins(view, *tx, pindex->nHeight, true);
     }
 
     for (const CTransactionRef &tx : block.vtx) {
         if (tx->IsCoinBase()) {
             continue;
         }
 
         for (const CTxIn &txin : tx->vin) {
             view.SpendCoin(txin.prevout);
         }
     }
 
     return true;
 }
 
 bool CChainState::ReplayBlocks(const Consensus::Params &params) {
     LOCK(cs_main);
 
     CCoinsView &db = this->CoinsDB();
     CCoinsViewCache cache(&db);
 
     std::vector<BlockHash> hashHeads = db.GetHeadBlocks();
     if (hashHeads.empty()) {
         // We're already in a consistent state.
         return true;
     }
     if (hashHeads.size() != 2) {
         return error("ReplayBlocks(): unknown inconsistent state");
     }
 
     uiInterface.ShowProgress(_("Replaying blocks...").translated, 0, false);
     LogPrintf("Replaying blocks\n");
 
     // Old tip during the interrupted flush.
     const CBlockIndex *pindexOld = nullptr;
     // New tip during the interrupted flush.
     const CBlockIndex *pindexNew;
     // Latest block common to both the old and the new tip.
     const CBlockIndex *pindexFork = nullptr;
 
     if (m_blockman.m_block_index.count(hashHeads[0]) == 0) {
         return error(
             "ReplayBlocks(): reorganization to unknown block requested");
     }
 
     pindexNew = m_blockman.m_block_index[hashHeads[0]];
 
     if (!hashHeads[1].IsNull()) {
         // The old tip is allowed to be 0, indicating it's the first flush.
         if (m_blockman.m_block_index.count(hashHeads[1]) == 0) {
             return error(
                 "ReplayBlocks(): reorganization from unknown block requested");
         }
 
         pindexOld = m_blockman.m_block_index[hashHeads[1]];
         pindexFork = LastCommonAncestor(pindexOld, pindexNew);
         assert(pindexFork != nullptr);
     }
 
     // Rollback along the old branch.
     while (pindexOld != pindexFork) {
         if (pindexOld->nHeight > 0) {
             // Never disconnect the genesis block.
             CBlock block;
             if (!ReadBlockFromDisk(block, pindexOld, params)) {
                 return error("RollbackBlock(): ReadBlockFromDisk() failed at "
                              "%d, hash=%s",
                              pindexOld->nHeight,
                              pindexOld->GetBlockHash().ToString());
             }
 
             LogPrintf("Rolling back %s (%i)\n",
                       pindexOld->GetBlockHash().ToString(), pindexOld->nHeight);
             DisconnectResult res = DisconnectBlock(block, pindexOld, cache);
             if (res == DisconnectResult::FAILED) {
                 return error(
                     "RollbackBlock(): DisconnectBlock failed at %d, hash=%s",
                     pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
             }
 
             // If DisconnectResult::UNCLEAN is returned, it means a non-existing
             // UTXO was deleted, or an existing UTXO was overwritten. It
             // corresponds to cases where the block-to-be-disconnect never had
             // all its operations applied to the UTXO set. However, as both
             // writing a UTXO and deleting a UTXO are idempotent operations, the
             // result is still a version of the UTXO set with the effects of
             // that block undone.
         }
         pindexOld = pindexOld->pprev;
     }
 
     // Roll forward from the forking point to the new tip.
     int nForkHeight = pindexFork ? pindexFork->nHeight : 0;
     for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight;
          ++nHeight) {
         const CBlockIndex *pindex = pindexNew->GetAncestor(nHeight);
         LogPrintf("Rolling forward %s (%i)\n",
                   pindex->GetBlockHash().ToString(), nHeight);
         uiInterface.ShowProgress(_("Replaying blocks...").translated,
                                  (int)((nHeight - nForkHeight) * 100.0 /
                                        (pindexNew->nHeight - nForkHeight)),
                                  false);
         if (!RollforwardBlock(pindex, cache, params)) {
             return false;
         }
     }
 
     cache.SetBestBlock(pindexNew->GetBlockHash());
     cache.Flush();
     uiInterface.ShowProgress("", 100, false);
     return true;
 }
 
 // May NOT be used after any connections are up as much of the peer-processing
 // logic assumes a consistent block index state
 void CChainState::UnloadBlockIndex() {
     nBlockSequenceId = 1;
     setBlockIndexCandidates.clear();
 
     // Do not point to CBlockIndex that will be free'd
     m_finalizedBlockIndex = nullptr;
 }
 
 // May NOT be used after any connections are up as much
 // of the peer-processing logic assumes a consistent
 // block index state
 void UnloadBlockIndex(CTxMemPool *mempool, ChainstateManager &chainman) {
     LOCK(cs_main);
     chainman.Unload();
     pindexBestInvalid = nullptr;
     pindexBestParked = nullptr;
     pindexBestHeader = nullptr;
     pindexBestForkTip = nullptr;
     pindexBestForkBase = nullptr;
     if (mempool) {
         mempool->clear();
     }
     vinfoBlockFile.clear();
     nLastBlockFile = 0;
     setDirtyBlockIndex.clear();
     setDirtyFileInfo.clear();
     fHavePruned = false;
 }
 
 bool ChainstateManager::LoadBlockIndex(const Consensus::Params &params) {
     AssertLockHeld(cs_main);
     // Load block index from databases
     bool needs_init = fReindex;
     if (!fReindex) {
         bool ret = ActiveChainstate().LoadBlockIndexDB(params);
         if (!ret) {
             return false;
         }
 
         needs_init = m_blockman.m_block_index.empty();
     }
 
     if (needs_init) {
         // Everything here is for *new* reindex/DBs. Thus, though
         // LoadBlockIndexDB may have set fReindex if we shut down
         // mid-reindex previously, we don't check fReindex and
         // instead only check it prior to LoadBlockIndexDB to set
         // needs_init.
 
         LogPrintf("Initializing databases...\n");
     }
     return true;
 }
 
 bool CChainState::LoadGenesisBlock(const CChainParams &chainparams) {
     LOCK(cs_main);
 
     // Check whether we're already initialized by checking for genesis in
     // m_blockman.m_block_index. Note that we can't use m_chain here, since it
     // is set based on the coins db, not the block index db, which is the only
     // thing loaded at this point.
     if (m_blockman.m_block_index.count(chainparams.GenesisBlock().GetHash())) {
         return true;
     }
 
     try {
         const CBlock &block = chainparams.GenesisBlock();
         FlatFilePos blockPos =
             SaveBlockToDisk(block, 0, m_chain, chainparams, nullptr);
         if (blockPos.IsNull()) {
             return error("%s: writing genesis block to disk failed", __func__);
         }
         CBlockIndex *pindex = m_blockman.AddToBlockIndex(block);
         ReceivedBlockTransactions(block, pindex, blockPos);
     } catch (const std::runtime_error &e) {
         return error("%s: failed to write genesis block: %s", __func__,
                      e.what());
     }
 
     return true;
 }
 
 void CChainState::LoadExternalBlockFile(const Config &config, FILE *fileIn,
                                         FlatFilePos *dbp) {
     // Map of disk positions for blocks with unknown parent (only used for
     // reindex)
     static std::multimap<uint256, FlatFilePos> mapBlocksUnknownParent;
     int64_t nStart = GetTimeMillis();
 
     const CChainParams &chainparams = config.GetChainParams();
 
     int nLoaded = 0;
     try {
         // This takes over fileIn and calls fclose() on it in the CBufferedFile
         // destructor. Make sure we have at least 2*MAX_TX_SIZE space in there
         // so any transaction can fit in the buffer.
         CBufferedFile blkdat(fileIn, 2 * MAX_TX_SIZE, MAX_TX_SIZE + 8, SER_DISK,
                              CLIENT_VERSION);
         uint64_t nRewind = blkdat.GetPos();
         while (!blkdat.eof()) {
             if (ShutdownRequested()) {
                 return;
             }
 
             blkdat.SetPos(nRewind);
             // Start one byte further next time, in case of failure.
             nRewind++;
             // Remove former limit.
             blkdat.SetLimit();
             unsigned int nSize = 0;
             try {
                 // Locate a header.
                 uint8_t buf[CMessageHeader::MESSAGE_START_SIZE];
                 blkdat.FindByte(chainparams.DiskMagic()[0]);
                 nRewind = blkdat.GetPos() + 1;
                 blkdat >> buf;
                 if (memcmp(buf, chainparams.DiskMagic().data(),
                            CMessageHeader::MESSAGE_START_SIZE)) {
                     continue;
                 }
 
                 // Read size.
                 blkdat >> nSize;
                 if (nSize < 80) {
                     continue;
                 }
             } catch (const std::exception &) {
                 // No valid block header found; don't complain.
                 break;
             }
 
             try {
                 // read block
                 uint64_t nBlockPos = blkdat.GetPos();
                 if (dbp) {
                     dbp->nPos = nBlockPos;
                 }
                 blkdat.SetLimit(nBlockPos + nSize);
                 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
                 CBlock &block = *pblock;
                 blkdat >> block;
                 nRewind = blkdat.GetPos();
 
                 const BlockHash hash = block.GetHash();
                 {
                     LOCK(cs_main);
                     // detect out of order blocks, and store them for later
                     if (hash != chainparams.GetConsensus().hashGenesisBlock &&
                         !m_blockman.LookupBlockIndex(block.hashPrevBlock)) {
                         LogPrint(
                             BCLog::REINDEX,
                             "%s: Out of order block %s, parent %s not known\n",
                             __func__, hash.ToString(),
                             block.hashPrevBlock.ToString());
                         if (dbp) {
                             mapBlocksUnknownParent.insert(
                                 std::make_pair(block.hashPrevBlock, *dbp));
                         }
                         continue;
                     }
 
                     // process in case the block isn't known yet
                     CBlockIndex *pindex = m_blockman.LookupBlockIndex(hash);
                     if (!pindex || !pindex->nStatus.hasData()) {
                         BlockValidationState state;
                         if (AcceptBlock(config, pblock, state, true, dbp,
                                         nullptr)) {
                             nLoaded++;
                         }
                         if (state.IsError()) {
                             break;
                         }
                     } else if (hash != chainparams.GetConsensus()
                                            .hashGenesisBlock &&
                                pindex->nHeight % 1000 == 0) {
                         LogPrint(
                             BCLog::REINDEX,
                             "Block Import: already had block %s at height %d\n",
                             hash.ToString(), pindex->nHeight);
                     }
                 }
 
                 // Activate the genesis block so normal node progress can
                 // continue
                 if (hash == chainparams.GetConsensus().hashGenesisBlock) {
                     BlockValidationState state;
                     if (!ActivateBestChain(config, state, nullptr)) {
                         break;
                     }
                 }
 
                 NotifyHeaderTip(*this);
 
                 // Recursively process earlier encountered successors of this
                 // block
                 std::deque<uint256> queue;
                 queue.push_back(hash);
                 while (!queue.empty()) {
                     uint256 head = queue.front();
                     queue.pop_front();
                     std::pair<std::multimap<uint256, FlatFilePos>::iterator,
                               std::multimap<uint256, FlatFilePos>::iterator>
                         range = mapBlocksUnknownParent.equal_range(head);
                     while (range.first != range.second) {
                         std::multimap<uint256, FlatFilePos>::iterator it =
                             range.first;
                         std::shared_ptr<CBlock> pblockrecursive =
                             std::make_shared<CBlock>();
                         if (ReadBlockFromDisk(*pblockrecursive, it->second,
                                               chainparams.GetConsensus())) {
                             LogPrint(
                                 BCLog::REINDEX,
                                 "%s: Processing out of order child %s of %s\n",
                                 __func__, pblockrecursive->GetHash().ToString(),
                                 head.ToString());
                             LOCK(cs_main);
                             BlockValidationState dummy;
                             if (AcceptBlock(config, pblockrecursive, dummy,
                                             true, &it->second, nullptr)) {
                                 nLoaded++;
                                 queue.push_back(pblockrecursive->GetHash());
                             }
                         }
                         range.first++;
                         mapBlocksUnknownParent.erase(it);
                         NotifyHeaderTip(*this);
                     }
                 }
             } catch (const std::exception &e) {
                 LogPrintf("%s: Deserialize or I/O error - %s\n", __func__,
                           e.what());
             }
         }
     } catch (const std::runtime_error &e) {
         AbortNode(std::string("System error: ") + e.what());
     }
 
     LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded,
               GetTimeMillis() - nStart);
 }
 
 void CChainState::CheckBlockIndex(const Consensus::Params &consensusParams) {
     if (!fCheckBlockIndex) {
         return;
     }
 
     LOCK(cs_main);
 
     // During a reindex, we read the genesis block and call CheckBlockIndex
     // before ActivateBestChain, so we have the genesis block in
     // m_blockman.m_block_index but no active chain. (A few of the tests when
     // iterating the block tree require that m_chain has been initialized.)
     if (m_chain.Height() < 0) {
         assert(m_blockman.m_block_index.size() <= 1);
         return;
     }
 
     // Build forward-pointing map of the entire block tree.
     std::multimap<CBlockIndex *, CBlockIndex *> forward;
     for (const auto &entry : m_blockman.m_block_index) {
         forward.emplace(entry.second->pprev, entry.second);
     }
 
     assert(forward.size() == m_blockman.m_block_index.size());
 
     std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
               std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
         rangeGenesis = forward.equal_range(nullptr);
     CBlockIndex *pindex = rangeGenesis.first->second;
     rangeGenesis.first++;
     // There is only one index entry with parent nullptr.
     assert(rangeGenesis.first == rangeGenesis.second);
 
     // Iterate over the entire block tree, using depth-first search.
     // Along the way, remember whether there are blocks on the path from genesis
     // block being explored which are the first to have certain properties.
     size_t nNodes = 0;
     int nHeight = 0;
     // Oldest ancestor of pindex which is invalid.
     CBlockIndex *pindexFirstInvalid = nullptr;
     // Oldest ancestor of pindex which is parked.
     CBlockIndex *pindexFirstParked = nullptr;
     // Oldest ancestor of pindex which does not have data available.
     CBlockIndex *pindexFirstMissing = nullptr;
     // Oldest ancestor of pindex for which nTx == 0.
     CBlockIndex *pindexFirstNeverProcessed = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotTreeValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotTransactionsValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotChainValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotScriptsValid = nullptr;
     while (pindex != nullptr) {
         nNodes++;
         if (pindexFirstInvalid == nullptr && pindex->nStatus.hasFailed()) {
             pindexFirstInvalid = pindex;
         }
         if (pindexFirstParked == nullptr && pindex->nStatus.isParked()) {
             pindexFirstParked = pindex;
         }
         if (pindexFirstMissing == nullptr && !pindex->nStatus.hasData()) {
             pindexFirstMissing = pindex;
         }
         if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) {
             pindexFirstNeverProcessed = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::TREE) {
             pindexFirstNotTreeValid = pindex;
         }
         if (pindex->pprev != nullptr &&
             pindexFirstNotTransactionsValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::TRANSACTIONS) {
             pindexFirstNotTransactionsValid = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotChainValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::CHAIN) {
             pindexFirstNotChainValid = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotScriptsValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::SCRIPTS) {
             pindexFirstNotScriptsValid = pindex;
         }
 
         // Begin: actual consistency checks.
         if (pindex->pprev == nullptr) {
             // Genesis block checks.
             // Genesis block's hash must match.
             assert(pindex->GetBlockHash() == consensusParams.hashGenesisBlock);
             // The current active chain's genesis block must be this block.
             assert(pindex == m_chain.Genesis());
         }
         if (!pindex->HaveTxsDownloaded()) {
             // nSequenceId can't be set positive for blocks that aren't linked
             // (negative is used for preciousblock)
             assert(pindex->nSequenceId <= 0);
         }
         // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or
         // not pruning has occurred). HAVE_DATA is only equivalent to nTx > 0
         // (or VALID_TRANSACTIONS) if no pruning has occurred.
         if (!fHavePruned) {
             // If we've never pruned, then HAVE_DATA should be equivalent to nTx
             // > 0
             assert(pindex->nStatus.hasData() == (pindex->nTx > 0));
             assert(pindexFirstMissing == pindexFirstNeverProcessed);
         } else if (pindex->nStatus.hasData()) {
             // If we have pruned, then we can only say that HAVE_DATA implies
             // nTx > 0
             assert(pindex->nTx > 0);
         }
         if (pindex->nStatus.hasUndo()) {
             assert(pindex->nStatus.hasData());
         }
         // This is pruning-independent.
         assert((pindex->nStatus.getValidity() >= BlockValidity::TRANSACTIONS) ==
                (pindex->nTx > 0));
         // All parents having had data (at some point) is equivalent to all
         // parents being VALID_TRANSACTIONS, which is equivalent to
         // HaveTxsDownloaded(). All parents having had data (at some point) is
         // equivalent to all parents being VALID_TRANSACTIONS, which is
         // equivalent to HaveTxsDownloaded().
         assert((pindexFirstNeverProcessed == nullptr) ==
                (pindex->HaveTxsDownloaded()));
         assert((pindexFirstNotTransactionsValid == nullptr) ==
                (pindex->HaveTxsDownloaded()));
         // nHeight must be consistent.
         assert(pindex->nHeight == nHeight);
         // For every block except the genesis block, the chainwork must be
         // larger than the parent's.
         assert(pindex->pprev == nullptr ||
                pindex->nChainWork >= pindex->pprev->nChainWork);
         // The pskip pointer must point back for all but the first 2 blocks.
         assert(nHeight < 2 ||
                (pindex->pskip && (pindex->pskip->nHeight < nHeight)));
         // All m_blockman.m_block_index entries must at least be TREE valid
         assert(pindexFirstNotTreeValid == nullptr);
         if (pindex->nStatus.getValidity() >= BlockValidity::TREE) {
             // TREE valid implies all parents are TREE valid
             assert(pindexFirstNotTreeValid == nullptr);
         }
         if (pindex->nStatus.getValidity() >= BlockValidity::CHAIN) {
             // CHAIN valid implies all parents are CHAIN valid
             assert(pindexFirstNotChainValid == nullptr);
         }
         if (pindex->nStatus.getValidity() >= BlockValidity::SCRIPTS) {
             // SCRIPTS valid implies all parents are SCRIPTS valid
             assert(pindexFirstNotScriptsValid == nullptr);
         }
         if (pindexFirstInvalid == nullptr) {
             // Checks for not-invalid blocks.
             // The failed mask cannot be set for blocks without invalid parents.
             assert(!pindex->nStatus.isInvalid());
         }
         if (pindexFirstParked == nullptr) {
             // Checks for not-parked blocks.
             // The parked mask cannot be set for blocks without parked parents.
             // (i.e., hasParkedParent only if an ancestor is properly parked).
             assert(!pindex->nStatus.isOnParkedChain());
         }
         if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) &&
             pindexFirstNeverProcessed == nullptr) {
             if (pindexFirstInvalid == nullptr) {
                 // If this block sorts at least as good as the current tip and
                 // is valid and we have all data for its parents, it must be in
                 // setBlockIndexCandidates or be parked.
                 if (pindexFirstMissing == nullptr) {
                     assert(pindex->nStatus.isOnParkedChain() ||
                            setBlockIndexCandidates.count(pindex));
                 }
                 // m_chain.Tip() must also be there even if some data has
                 // been pruned.
                 if (pindex == m_chain.Tip()) {
                     assert(setBlockIndexCandidates.count(pindex));
                 }
                 // If some parent is missing, then it could be that this block
                 // was in setBlockIndexCandidates but had to be removed because
                 // of the missing data. In this case it must be in
                 // m_blocks_unlinked -- see test below.
             }
         } else {
             // If this block sorts worse than the current tip or some ancestor's
             // block has never been seen, it cannot be in
             // setBlockIndexCandidates.
             assert(setBlockIndexCandidates.count(pindex) == 0);
         }
         // Check whether this block is in m_blocks_unlinked.
         std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                   std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
             rangeUnlinked =
                 m_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
         bool foundInUnlinked = false;
         while (rangeUnlinked.first != rangeUnlinked.second) {
             assert(rangeUnlinked.first->first == pindex->pprev);
             if (rangeUnlinked.first->second == pindex) {
                 foundInUnlinked = true;
                 break;
             }
             rangeUnlinked.first++;
         }
         if (pindex->pprev && pindex->nStatus.hasData() &&
             pindexFirstNeverProcessed != nullptr &&
             pindexFirstInvalid == nullptr) {
             // If this block has block data available, some parent was never
             // received, and has no invalid parents, it must be in
             // m_blocks_unlinked.
             assert(foundInUnlinked);
         }
         if (!pindex->nStatus.hasData()) {
             // Can't be in m_blocks_unlinked if we don't HAVE_DATA
             assert(!foundInUnlinked);
         }
         if (pindexFirstMissing == nullptr) {
             // We aren't missing data for any parent -- cannot be in
             // m_blocks_unlinked.
             assert(!foundInUnlinked);
         }
         if (pindex->pprev && pindex->nStatus.hasData() &&
             pindexFirstNeverProcessed == nullptr &&
             pindexFirstMissing != nullptr) {
             // We HAVE_DATA for this block, have received data for all parents
             // at some point, but we're currently missing data for some parent.
             // We must have pruned.
             assert(fHavePruned);
             // This block may have entered m_blocks_unlinked if:
             //  - it has a descendant that at some point had more work than the
             //    tip, and
             //  - we tried switching to that descendant but were missing
             //    data for some intermediate block between m_chain and the
             //    tip.
             // So if this block is itself better than m_chain.Tip() and it
             // wasn't in
             // setBlockIndexCandidates, then it must be in m_blocks_unlinked.
             if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) &&
                 setBlockIndexCandidates.count(pindex) == 0) {
                 if (pindexFirstInvalid == nullptr) {
                     assert(foundInUnlinked);
                 }
             }
         }
         // Perhaps too slow
         // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash());
         // End: actual consistency checks.
 
         // Try descending into the first subnode.
         std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                   std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
             range = forward.equal_range(pindex);
         if (range.first != range.second) {
             // A subnode was found.
             pindex = range.first->second;
             nHeight++;
             continue;
         }
         // This is a leaf node. Move upwards until we reach a node of which we
         // have not yet visited the last child.
         while (pindex) {
             // We are going to either move to a parent or a sibling of pindex.
             // If pindex was the first with a certain property, unset the
             // corresponding variable.
             if (pindex == pindexFirstInvalid) {
                 pindexFirstInvalid = nullptr;
             }
             if (pindex == pindexFirstParked) {
                 pindexFirstParked = nullptr;
             }
             if (pindex == pindexFirstMissing) {
                 pindexFirstMissing = nullptr;
             }
             if (pindex == pindexFirstNeverProcessed) {
                 pindexFirstNeverProcessed = nullptr;
             }
             if (pindex == pindexFirstNotTreeValid) {
                 pindexFirstNotTreeValid = nullptr;
             }
             if (pindex == pindexFirstNotTransactionsValid) {
                 pindexFirstNotTransactionsValid = nullptr;
             }
             if (pindex == pindexFirstNotChainValid) {
                 pindexFirstNotChainValid = nullptr;
             }
             if (pindex == pindexFirstNotScriptsValid) {
                 pindexFirstNotScriptsValid = nullptr;
             }
             // Find our parent.
             CBlockIndex *pindexPar = pindex->pprev;
             // Find which child we just visited.
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 rangePar = forward.equal_range(pindexPar);
             while (rangePar.first->second != pindex) {
                 // Our parent must have at least the node we're coming from as
                 // child.
                 assert(rangePar.first != rangePar.second);
                 rangePar.first++;
             }
             // Proceed to the next one.
             rangePar.first++;
             if (rangePar.first != rangePar.second) {
                 // Move to the sibling.
                 pindex = rangePar.first->second;
                 break;
             } else {
                 // Move up further.
                 pindex = pindexPar;
                 nHeight--;
                 continue;
             }
         }
     }
 
     // Check that we actually traversed the entire map.
     assert(nNodes == forward.size());
 }
 
 std::string CChainState::ToString() {
     CBlockIndex *tip = m_chain.Tip();
     return strprintf("Chainstate [%s] @ height %d (%s)",
                      m_from_snapshot_blockhash ? "snapshot" : "ibd",
                      tip ? tip->nHeight : -1,
                      tip ? tip->GetBlockHash().ToString() : "null");
 }
 
 bool CChainState::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) {
     if (coinstip_size == m_coinstip_cache_size_bytes &&
         coinsdb_size == m_coinsdb_cache_size_bytes) {
         // Cache sizes are unchanged, no need to continue.
         return true;
     }
     size_t old_coinstip_size = m_coinstip_cache_size_bytes;
     m_coinstip_cache_size_bytes = coinstip_size;
     m_coinsdb_cache_size_bytes = coinsdb_size;
     CoinsDB().ResizeCache(coinsdb_size);
 
     LogPrintf("[%s] resized coinsdb cache to %.1f MiB\n", this->ToString(),
               coinsdb_size * (1.0 / 1024 / 1024));
     LogPrintf("[%s] resized coinstip cache to %.1f MiB\n", this->ToString(),
               coinstip_size * (1.0 / 1024 / 1024));
 
     BlockValidationState state;
     const CChainParams &chainparams = Params();
 
     bool ret;
 
     if (coinstip_size > old_coinstip_size) {
         // Likely no need to flush if cache sizes have grown.
         ret = FlushStateToDisk(chainparams, state, FlushStateMode::IF_NEEDED);
     } else {
         // Otherwise, flush state to disk and deallocate the in-memory coins
         // map.
         ret = FlushStateToDisk(chainparams, state, FlushStateMode::ALWAYS);
         CoinsTip().ReallocateCache();
     }
     return ret;
 }
 
 std::string CBlockFileInfo::ToString() const {
     return strprintf(
         "CBlockFileInfo(blocks=%u, size=%u, heights=%u...%u, time=%s...%s)",
         nBlocks, nSize, nHeightFirst, nHeightLast,
         FormatISO8601DateTime(nTimeFirst), FormatISO8601DateTime(nTimeLast));
 }
 
 CBlockFileInfo *GetBlockFileInfo(size_t n) {
     LOCK(cs_LastBlockFile);
 
     return &vinfoBlockFile.at(n);
 }
 
 static const uint64_t MEMPOOL_DUMP_VERSION = 1;
 
 bool LoadMempool(const Config &config, CTxMemPool &pool,
                  CChainState &active_chainstate) {
     int64_t nExpiryTimeout =
         gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60;
     FILE *filestr = fsbridge::fopen(GetDataDir() / "mempool.dat", "rb");
     CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
     if (file.IsNull()) {
         LogPrintf(
             "Failed to open mempool file from disk. Continuing anyway.\n");
         return false;
     }
 
     int64_t count = 0;
     int64_t expired = 0;
     int64_t failed = 0;
     int64_t already_there = 0;
     int64_t unbroadcast = 0;
     int64_t nNow = GetTime();
 
     try {
         uint64_t version;
         file >> version;
         if (version != MEMPOOL_DUMP_VERSION) {
             return false;
         }
 
         uint64_t num;
         file >> num;
         while (num--) {
             CTransactionRef tx;
             int64_t nTime;
             int64_t nFeeDelta;
             file >> tx;
             file >> nTime;
             file >> nFeeDelta;
 
             Amount amountdelta = nFeeDelta * SATOSHI;
             if (amountdelta != Amount::zero()) {
                 pool.PrioritiseTransaction(tx->GetId(), amountdelta);
             }
-            TxValidationState state;
             if (nTime > nNow - nExpiryTimeout) {
                 LOCK(cs_main);
-                AcceptToMemoryPoolWithTime(
-                    config, pool, active_chainstate, state, tx, nTime,
-                    false /* bypass_limits */, false /* test_accept */);
-                if (state.IsValid()) {
+                if (AcceptToMemoryPoolWithTime(
+                        config, pool, active_chainstate, tx, nTime,
+                        false /* bypass_limits */, false /* test_accept */)
+                        .m_result_type ==
+                    MempoolAcceptResult::ResultType::VALID) {
                     ++count;
                 } else {
                     // mempool may contain the transaction already, e.g. from
                     // wallet(s) having loaded it while we were processing
                     // mempool transactions; consider these as valid, instead of
                     // failed, but mark them as 'already there'
                     if (pool.exists(tx->GetId())) {
                         ++already_there;
                     } else {
                         ++failed;
                     }
                 }
             } else {
                 ++expired;
             }
 
             if (ShutdownRequested()) {
                 return false;
             }
         }
         std::map<TxId, Amount> mapDeltas;
         file >> mapDeltas;
 
         for (const auto &i : mapDeltas) {
             pool.PrioritiseTransaction(i.first, i.second);
         }
 
         std::set<TxId> unbroadcast_txids;
         file >> unbroadcast_txids;
         unbroadcast = unbroadcast_txids.size();
         for (const auto &txid : unbroadcast_txids) {
             // Ensure transactions were accepted to mempool then add to
             // unbroadcast set.
             if (pool.get(txid) != nullptr) {
                 pool.AddUnbroadcastTx(txid);
             }
         }
     } catch (const std::exception &e) {
         LogPrintf("Failed to deserialize mempool data on disk: %s. Continuing "
                   "anyway.\n",
                   e.what());
         return false;
     }
 
     LogPrintf("Imported mempool transactions from disk: %i succeeded, %i "
               "failed, %i expired, %i already there, %i waiting for initial "
               "broadcast\n",
               count, failed, expired, already_there, unbroadcast);
     return true;
 }
 
 bool DumpMempool(const CTxMemPool &pool) {
     int64_t start = GetTimeMicros();
 
     std::map<uint256, Amount> mapDeltas;
     std::vector<TxMempoolInfo> vinfo;
     std::set<TxId> unbroadcast_txids;
 
     static Mutex dump_mutex;
     LOCK(dump_mutex);
 
     {
         LOCK(pool.cs);
         for (const auto &i : pool.mapDeltas) {
             mapDeltas[i.first] = i.second;
         }
 
         vinfo = pool.infoAll();
         unbroadcast_txids = pool.GetUnbroadcastTxs();
     }
 
     int64_t mid = GetTimeMicros();
 
     try {
         FILE *filestr = fsbridge::fopen(GetDataDir() / "mempool.dat.new", "wb");
         if (!filestr) {
             return false;
         }
 
         CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
 
         uint64_t version = MEMPOOL_DUMP_VERSION;
         file << version;
 
         file << uint64_t(vinfo.size());
         for (const auto &i : vinfo) {
             file << *(i.tx);
             file << int64_t(count_seconds(i.m_time));
             file << i.nFeeDelta;
             mapDeltas.erase(i.tx->GetId());
         }
 
         file << mapDeltas;
 
         LogPrintf("Writing %d unbroadcast transactions to disk.\n",
                   unbroadcast_txids.size());
         file << unbroadcast_txids;
 
         if (!FileCommit(file.Get())) {
             throw std::runtime_error("FileCommit failed");
         }
         file.fclose();
         if (!RenameOver(GetDataDir() / "mempool.dat.new",
                         GetDataDir() / "mempool.dat")) {
             throw std::runtime_error("Rename failed");
         }
         int64_t last = GetTimeMicros();
         LogPrintf("Dumped mempool: %gs to copy, %gs to dump\n",
                   (mid - start) * MICRO, (last - mid) * MICRO);
     } catch (const std::exception &e) {
         LogPrintf("Failed to dump mempool: %s. Continuing anyway.\n", e.what());
         return false;
     }
     return true;
 }
 
 bool IsBlockPruned(const CBlockIndex *pblockindex) {
     return (fHavePruned && !pblockindex->nStatus.hasData() &&
             pblockindex->nTx > 0);
 }
 
 //! Guess how far we are in the verification process at the given block index
 //! require cs_main if pindex has not been validated yet (because the chain's
 //! transaction count might be unset) This conditional lock requirement might be
 //! confusing, see: https://github.com/bitcoin/bitcoin/issues/15994
 double GuessVerificationProgress(const ChainTxData &data,
                                  const CBlockIndex *pindex) {
     if (pindex == nullptr) {
         return 0.0;
     }
 
     int64_t nNow = time(nullptr);
 
     double fTxTotal;
     if (pindex->GetChainTxCount() <= data.nTxCount) {
         fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate;
     } else {
         fTxTotal = pindex->GetChainTxCount() +
                    (nNow - pindex->GetBlockTime()) * data.dTxRate;
     }
 
     return std::min<double>(pindex->GetChainTxCount() / fTxTotal, 1.0);
 }
 
 std::optional<BlockHash> ChainstateManager::SnapshotBlockhash() const {
     LOCK(::cs_main);
     if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) {
         // If a snapshot chainstate exists, it will always be our active.
         return m_active_chainstate->m_from_snapshot_blockhash;
     }
     return std::nullopt;
 }
 
 std::vector<CChainState *> ChainstateManager::GetAll() {
     LOCK(::cs_main);
     std::vector<CChainState *> out;
 
     if (!IsSnapshotValidated() && m_ibd_chainstate) {
         out.push_back(m_ibd_chainstate.get());
     }
 
     if (m_snapshot_chainstate) {
         out.push_back(m_snapshot_chainstate.get());
     }
 
     return out;
 }
 
 CChainState &ChainstateManager::InitializeChainstate(
     CTxMemPool &mempool, const std::optional<BlockHash> &snapshot_blockhash) {
     bool is_snapshot = snapshot_blockhash.has_value();
     std::unique_ptr<CChainState> &to_modify =
         is_snapshot ? m_snapshot_chainstate : m_ibd_chainstate;
 
     if (to_modify) {
         throw std::logic_error("should not be overwriting a chainstate");
     }
     to_modify.reset(new CChainState(mempool, m_blockman, snapshot_blockhash));
 
     // Snapshot chainstates and initial IBD chaintates always become active.
     if (is_snapshot || (!is_snapshot && !m_active_chainstate)) {
         LogPrintf("Switching active chainstate to %s\n", to_modify->ToString());
         m_active_chainstate = to_modify.get();
     } else {
         throw std::logic_error("unexpected chainstate activation");
     }
 
     return *to_modify;
 }
 
 const AssumeutxoData *ExpectedAssumeutxo(const int height,
                                          const CChainParams &chainparams) {
     const MapAssumeutxo &valid_assumeutxos_map = chainparams.Assumeutxo();
     const auto assumeutxo_found = valid_assumeutxos_map.find(height);
 
     if (assumeutxo_found != valid_assumeutxos_map.end()) {
         return &assumeutxo_found->second;
     }
     return nullptr;
 }
 
 bool ChainstateManager::ActivateSnapshot(CAutoFile &coins_file,
                                          const SnapshotMetadata &metadata,
                                          bool in_memory) {
     BlockHash base_blockhash = metadata.m_base_blockhash;
 
     if (this->SnapshotBlockhash()) {
         LogPrintf("[snapshot] can't activate a snapshot-based chainstate more "
                   "than once\n");
         return false;
     }
 
     int64_t current_coinsdb_cache_size{0};
     int64_t current_coinstip_cache_size{0};
 
     // Cache percentages to allocate to each chainstate.
     //
     // These particular percentages don't matter so much since they will only be
     // relevant during snapshot activation; caches are rebalanced at the
     // conclusion of this function. We want to give (essentially) all available
     // cache capacity to the snapshot to aid the bulk load later in this
     // function.
     static constexpr double IBD_CACHE_PERC = 0.01;
     static constexpr double SNAPSHOT_CACHE_PERC = 0.99;
 
     {
         LOCK(::cs_main);
         // Resize the coins caches to ensure we're not exceeding memory limits.
         //
         // Allocate the majority of the cache to the incoming snapshot
         // chainstate, since (optimistically) getting to its tip will be the top
         // priority. We'll need to call `MaybeRebalanceCaches()` once we're done
         // with this function to ensure the right allocation (including the
         // possibility that no snapshot was activated and that we should restore
         // the active chainstate caches to their original size).
         //
         current_coinsdb_cache_size =
             this->ActiveChainstate().m_coinsdb_cache_size_bytes;
         current_coinstip_cache_size =
             this->ActiveChainstate().m_coinstip_cache_size_bytes;
 
         // Temporarily resize the active coins cache to make room for the
         // newly-created snapshot chain.
         this->ActiveChainstate().ResizeCoinsCaches(
             static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC),
             static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC));
     }
 
     auto snapshot_chainstate = WITH_LOCK(
         ::cs_main,
         return std::make_unique<CChainState>(this->ActiveChainstate().m_mempool,
                                              m_blockman, base_blockhash));
 
     {
         LOCK(::cs_main);
         snapshot_chainstate->InitCoinsDB(
             static_cast<size_t>(current_coinsdb_cache_size *
                                 SNAPSHOT_CACHE_PERC),
             in_memory, false, "chainstate");
         snapshot_chainstate->InitCoinsCache(static_cast<size_t>(
             current_coinstip_cache_size * SNAPSHOT_CACHE_PERC));
     }
 
     const bool snapshot_ok = this->PopulateAndValidateSnapshot(
         *snapshot_chainstate, coins_file, metadata);
 
     if (!snapshot_ok) {
         WITH_LOCK(::cs_main, this->MaybeRebalanceCaches());
         return false;
     }
 
     {
         LOCK(::cs_main);
         assert(!m_snapshot_chainstate);
         m_snapshot_chainstate.swap(snapshot_chainstate);
         const bool chaintip_loaded =
             m_snapshot_chainstate->LoadChainTip(::Params());
         assert(chaintip_loaded);
 
         m_active_chainstate = m_snapshot_chainstate.get();
 
         LogPrintf("[snapshot] successfully activated snapshot %s\n",
                   base_blockhash.ToString());
         LogPrintf("[snapshot] (%.2f MB)\n",
                   m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() /
                       (1000 * 1000));
 
         this->MaybeRebalanceCaches();
     }
     return true;
 }
 
 bool ChainstateManager::PopulateAndValidateSnapshot(
     CChainState &snapshot_chainstate, CAutoFile &coins_file,
     const SnapshotMetadata &metadata) {
     // It's okay to release cs_main before we're done using `coins_cache`
     // because we know that nothing else will be referencing the newly created
     // snapshot_chainstate yet.
     CCoinsViewCache &coins_cache =
         *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip());
 
     BlockHash base_blockhash = metadata.m_base_blockhash;
 
     CBlockIndex *snapshot_start_block = WITH_LOCK(
         ::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
 
     if (!snapshot_start_block) {
         // Needed for GetUTXOStats and ExpectedAssumeutxo to determine the
         // height and to avoid a crash when base_blockhash.IsNull()
         LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n",
                   base_blockhash.ToString());
         return false;
     }
 
     int base_height = snapshot_start_block->nHeight;
     auto maybe_au_data = ExpectedAssumeutxo(base_height, ::Params());
 
     if (!maybe_au_data) {
         LogPrintf("[snapshot] assumeutxo height in snapshot metadata not "
                   "recognized (%d) - refusing to load snapshot\n",
                   base_height);
         return false;
     }
 
     const AssumeutxoData &au_data = *maybe_au_data;
 
     COutPoint outpoint;
     Coin coin;
     const uint64_t coins_count = metadata.m_coins_count;
     uint64_t coins_left = metadata.m_coins_count;
 
     LogPrintf("[snapshot] loading coins from snapshot %s\n",
               base_blockhash.ToString());
     int64_t flush_now{0};
     int64_t coins_processed{0};
 
     while (coins_left > 0) {
         try {
             coins_file >> outpoint;
             coins_file >> coin;
         } catch (const std::ios_base::failure &) {
             LogPrintf("[snapshot] bad snapshot format or truncated snapshot "
                       "after deserializing %d coins\n",
                       coins_count - coins_left);
             return false;
         }
         coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint),
                                               std::move(coin));
 
         --coins_left;
         ++coins_processed;
 
         if (coins_processed % 1000000 == 0) {
             LogPrintf("[snapshot] %d coins loaded (%.2f%%, %.2f MB)\n",
                       coins_processed,
                       static_cast<float>(coins_processed) * 100 /
                           static_cast<float>(coins_count),
                       coins_cache.DynamicMemoryUsage() / (1000 * 1000));
         }
 
         // Batch write and flush (if we need to) every so often.
         //
         // If our average Coin size is roughly 41 bytes, checking every 120,000
         // coins means <5MB of memory imprecision.
         if (coins_processed % 120000 == 0) {
             if (ShutdownRequested()) {
                 return false;
             }
 
             const auto snapshot_cache_state = WITH_LOCK(
                 ::cs_main, return snapshot_chainstate.GetCoinsCacheSizeState(
                                &snapshot_chainstate.m_mempool));
 
             if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) {
                 LogPrintfToBeContinued(
                     "[snapshot] flushing coins cache (%.2f MB)... ",
                     coins_cache.DynamicMemoryUsage() / (1000 * 1000));
                 flush_now = GetTimeMillis();
 
                 // This is a hack - we don't know what the actual best block is,
                 // but that doesn't matter for the purposes of flushing the
                 // cache here. We'll set this to its correct value
                 // (`base_blockhash`) below after the coins are loaded.
                 coins_cache.SetBestBlock(BlockHash{GetRandHash()});
 
                 coins_cache.Flush();
                 LogPrintf("done (%.2fms)\n", GetTimeMillis() - flush_now);
             }
         }
     }
 
     // Important that we set this. This and the coins_cache accesses above are
     // sort of a layer violation, but either we reach into the innards of
     // CCoinsViewCache here or we have to invert some of the CChainState to
     // embed them in a snapshot-activation-specific CCoinsViewCache bulk load
     // method.
     coins_cache.SetBestBlock(base_blockhash);
 
     bool out_of_coins{false};
     try {
         coins_file >> outpoint;
     } catch (const std::ios_base::failure &) {
         // We expect an exception since we should be out of coins.
         out_of_coins = true;
     }
     if (!out_of_coins) {
         LogPrintf("[snapshot] bad snapshot - coins left over after "
                   "deserializing %d coins\n",
                   coins_count);
         return false;
     }
 
     LogPrintf("[snapshot] loaded %d (%.2f MB) coins from snapshot %s\n",
               coins_count, coins_cache.DynamicMemoryUsage() / (1000 * 1000),
               base_blockhash.ToString());
 
     LogPrintf("[snapshot] flushing snapshot chainstate to disk\n");
     // No need to acquire cs_main since this chainstate isn't being used yet.
     // TODO: if #17487 is merged, add erase=false here for better performance.
     coins_cache.Flush();
 
     assert(coins_cache.GetBestBlock() == base_blockhash);
 
     CCoinsStats stats{CoinStatsHashType::HASH_SERIALIZED};
     auto breakpoint_fnc = [] { /* TODO insert breakpoint here? */ };
 
     // As above, okay to immediately release cs_main here since no other context
     // knows about the snapshot_chainstate.
     CCoinsViewDB *snapshot_coinsdb =
         WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB());
 
     if (!GetUTXOStats(snapshot_coinsdb,
                       WITH_LOCK(::cs_main, return std::ref(m_blockman)), stats,
                       breakpoint_fnc)) {
         LogPrintf("[snapshot] failed to generate coins stats\n");
         return false;
     }
 
     // Assert that the deserialized chainstate contents match the expected
     // assumeutxo value.
     if (AssumeutxoHash{stats.hashSerialized} != au_data.hash_serialized) {
         LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n",
                   au_data.hash_serialized.ToString(),
                   stats.hashSerialized.ToString());
         return false;
     }
 
     snapshot_chainstate.m_chain.SetTip(snapshot_start_block);
 
     // The remainder of this function requires modifying data protected by
     // cs_main.
     LOCK(::cs_main);
 
     // Fake various pieces of CBlockIndex state:
     //
     //   - nChainTx: so that we accurately report IBD-to-tip progress
     //   - nTx: so that LoadBlockIndex() loads assumed-valid CBlockIndex entries
     //       (among other things)
     //
     CBlockIndex *index = nullptr;
     for (int i = 0; i <= snapshot_chainstate.m_chain.Height(); ++i) {
         index = snapshot_chainstate.m_chain[i];
 
         if (!index->nTx) {
             index->nTx = 1;
         }
         index->nChainTx =
             index->pprev ? index->pprev->nChainTx + index->nTx : 1;
     }
 
     assert(index);
     index->nChainTx = au_data.nChainTx;
     snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block);
 
     LogPrintf("[snapshot] validated snapshot (%.2f MB)\n",
               coins_cache.DynamicMemoryUsage() / (1000 * 1000));
     return true;
 }
 
 CChainState &ChainstateManager::ActiveChainstate() const {
     LOCK(::cs_main);
     assert(m_active_chainstate);
     return *m_active_chainstate;
 }
 
 bool ChainstateManager::IsSnapshotActive() const {
     LOCK(::cs_main);
     return m_snapshot_chainstate &&
            m_active_chainstate == m_snapshot_chainstate.get();
 }
 
 CChainState &ChainstateManager::ValidatedChainstate() const {
     LOCK(::cs_main);
     if (m_snapshot_chainstate && IsSnapshotValidated()) {
         return *m_snapshot_chainstate.get();
     }
     assert(m_ibd_chainstate);
     return *m_ibd_chainstate.get();
 }
 
 bool ChainstateManager::IsBackgroundIBD(CChainState *chainstate) const {
     LOCK(::cs_main);
     return (m_snapshot_chainstate && chainstate == m_ibd_chainstate.get());
 }
 
 void ChainstateManager::Unload() {
     for (CChainState *chainstate : this->GetAll()) {
         chainstate->m_chain.SetTip(nullptr);
         chainstate->UnloadBlockIndex();
     }
 
     m_blockman.Unload();
 }
 
 void ChainstateManager::Reset() {
     LOCK(::cs_main);
     m_ibd_chainstate.reset();
     m_snapshot_chainstate.reset();
     m_active_chainstate = nullptr;
     m_snapshot_validated = false;
 }
 
 void ChainstateManager::MaybeRebalanceCaches() {
     if (m_ibd_chainstate && !m_snapshot_chainstate) {
         LogPrintf("[snapshot] allocating all cache to the IBD chainstate\n");
         // Allocate everything to the IBD chainstate.
         m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache,
                                             m_total_coinsdb_cache);
     } else if (m_snapshot_chainstate && !m_ibd_chainstate) {
         LogPrintf(
             "[snapshot] allocating all cache to the snapshot chainstate\n");
         // Allocate everything to the snapshot chainstate.
         m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache,
                                                  m_total_coinsdb_cache);
     } else if (m_ibd_chainstate && m_snapshot_chainstate) {
         // If both chainstates exist, determine who needs more cache based on
         // IBD status.
         //
         // Note: shrink caches first so that we don't inadvertently overwhelm
         // available memory.
         if (m_snapshot_chainstate->IsInitialBlockDownload()) {
             m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache * 0.05,
                                                 m_total_coinsdb_cache * 0.05);
             m_snapshot_chainstate->ResizeCoinsCaches(
                 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
         } else {
             m_snapshot_chainstate->ResizeCoinsCaches(
                 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
             m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache * 0.95,
                                                 m_total_coinsdb_cache * 0.95);
         }
     }
 }
diff --git a/src/validation.h b/src/validation.h
index c66500bc6..578f27572 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -1,1328 +1,1368 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2019 The Bitcoin Core developers
 // Copyright (c) 2017-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_VALIDATION_H
 #define BITCOIN_VALIDATION_H
 
 #if defined(HAVE_CONFIG_H)
 #include <config/bitcoin-config.h>
 #endif
 
 #include <amount.h>
 #include <attributes.h>
 #include <blockfileinfo.h>
 #include <blockindexworkcomparator.h>
 #include <coins.h>
 #include <consensus/consensus.h>
+#include <consensus/validation.h>
 #include <disconnectresult.h>
 #include <flatfile.h>
 #include <fs.h>
 #include <node/utxo_snapshot.h>
 #include <protocol.h> // For CMessageHeader::MessageMagic
 #include <script/script_error.h>
 #include <script/script_metrics.h>
 #include <sync.h>
 #include <txdb.h>
 #include <txmempool.h> // For CTxMemPool::cs
+#include <util/check.h>
 #include <versionbits.h>
 
 #include <atomic>
 #include <cstdint>
 #include <map>
 #include <memory>
 #include <optional>
 #include <set>
 #include <string>
 #include <thread>
 #include <utility>
 #include <vector>
 
 class BlockValidationState;
 class CBlockIndex;
 class CBlockTreeDB;
 class CBlockUndo;
 class CChainParams;
 class CChain;
 class CChainState;
 class CConnman;
 class CInv;
 class ChainstateManager;
 class Config;
 class CScriptCheck;
 class CTxMemPool;
 class CTxUndo;
 class DisconnectedBlockTransactions;
-class TxValidationState;
 
 struct CCheckpointData;
 struct ChainTxData;
 struct FlatFilePos;
 struct PrecomputedTransactionData;
 struct LockPoints;
 struct AssumeutxoData;
 
 namespace Consensus {
 struct Params;
 }
 
 #define MIN_TRANSACTION_SIZE                                                   \
     (::GetSerializeSize(CTransaction(), PROTOCOL_VERSION))
 
 /** Default for -minrelaytxfee, minimum relay fee for transactions */
 static const Amount DEFAULT_MIN_RELAY_TX_FEE_PER_KB(1000 * SATOSHI);
 /** Default for -excessutxocharge for transactions transactions */
 static const Amount DEFAULT_UTXO_FEE = Amount::zero();
 /**
  * Default for -mempoolexpiry, expiration time for mempool transactions in
  * hours.
  */
 static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336;
 /** The maximum size of a blk?????.dat file (since 0.8) */
 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
 /** Maximum number of dedicated script-checking threads allowed */
 static const int MAX_SCRIPTCHECK_THREADS = 15;
 /** -par default (number of script-checking threads, 0 = auto) */
 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
 static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
 static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
 static const bool DEFAULT_TXINDEX = false;
 static constexpr bool DEFAULT_COINSTATSINDEX{false};
 static const char *const DEFAULT_BLOCKFILTERINDEX = "0";
 
 /** Default for -persistmempool */
 static const bool DEFAULT_PERSIST_MEMPOOL = true;
 /** Default for using fee filter */
 static const bool DEFAULT_FEEFILTER = true;
 
 static const bool DEFAULT_PEERBLOOMFILTERS = true;
 
 /** Default for -stopatheight */
 static const int DEFAULT_STOPATHEIGHT = 0;
 /** Default for -maxreorgdepth */
 static const int DEFAULT_MAX_REORG_DEPTH = 10;
 /**
  * Default for -finalizationdelay
  * This is the minimum time between a block header reception and the block
  * finalization.
  * This value should be >> block propagation and validation time
  */
 static const int64_t DEFAULT_MIN_FINALIZATION_DELAY = 2 * 60 * 60;
 /**
  * Block files containing a block-height within MIN_BLOCKS_TO_KEEP of
  * ActiveChain().Tip() will not be pruned.
  */
 static const unsigned int MIN_BLOCKS_TO_KEEP = 288;
 static const signed int DEFAULT_CHECKBLOCKS = 6;
 static const unsigned int DEFAULT_CHECKLEVEL = 3;
 /**
  * Require that user allocate at least 550 MiB for block & undo files
  * (blk???.dat and rev???.dat)
  * At 1MB per block, 288 blocks = 288MB.
  * Add 15% for Undo data = 331MB
  * Add 20% for Orphan block rate = 397MB
  * We want the low water mark after pruning to be at least 397 MB and since we
  * prune in full block file chunks, we need the high water mark which triggers
  * the prune to be one 128MB block file + added 15% undo data = 147MB greater
  * for a total of 545MB
  * Setting the target to >= 550 MiB will make it likely we can respect the
  * target.
  */
 static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;
 
 /** Current sync state passed to tip changed callbacks. */
 enum class SynchronizationState { INIT_REINDEX, INIT_DOWNLOAD, POST_INIT };
 
 extern RecursiveMutex cs_main;
 typedef std::unordered_map<BlockHash, CBlockIndex *, BlockHasher> BlockMap;
 extern Mutex g_best_block_mutex;
 extern std::condition_variable g_best_block_cv;
 extern uint256 g_best_block;
 extern std::atomic_bool fImporting;
 extern std::atomic_bool fReindex;
 extern bool fRequireStandard;
 extern bool fCheckBlockIndex;
 extern bool fCheckpointsEnabled;
 
 /**
  * A fee rate smaller than this is considered zero fee (for relaying, mining and
  * transaction creation)
  */
 extern CFeeRate minRelayTxFee;
 /**
  * If the tip is older than this (in seconds), the node is considered to be in
  * initial block download.
  */
 extern int64_t nMaxTipAge;
 
 /**
  * Block hash whose ancestors we will assume to have valid scripts without
  * checking them.
  */
 extern BlockHash hashAssumeValid;
 
 /**
  * Minimum work we will assume exists on some valid chain.
  */
 extern arith_uint256 nMinimumChainWork;
 
 /**
  * Best header we've seen so far (used for getheaders queries' starting points).
  */
 extern CBlockIndex *pindexBestHeader;
 
 /** Pruning-related variables and constants */
 /** True if any block files have ever been pruned. */
 extern bool fHavePruned;
 /** True if we're running in -prune mode. */
 extern bool fPruneMode;
 /** Number of MiB of block files that we're trying to stay below. */
 extern uint64_t nPruneTarget;
 /** Documentation for argument 'checklevel'. */
 extern const std::vector<std::string> CHECKLEVEL_DOC;
 
 class BlockValidationOptions {
 private:
     uint64_t excessiveBlockSize;
     bool checkPoW : 1;
     bool checkMerkleRoot : 1;
 
 public:
     // Do full validation by default
     explicit BlockValidationOptions(const Config &config);
     explicit BlockValidationOptions(uint64_t _excessiveBlockSize,
                                     bool _checkPow = true,
                                     bool _checkMerkleRoot = true)
         : excessiveBlockSize(_excessiveBlockSize), checkPoW(_checkPow),
           checkMerkleRoot(_checkMerkleRoot) {}
 
     BlockValidationOptions withCheckPoW(bool _checkPoW = true) const {
         BlockValidationOptions ret = *this;
         ret.checkPoW = _checkPoW;
         return ret;
     }
 
     BlockValidationOptions
     withCheckMerkleRoot(bool _checkMerkleRoot = true) const {
         BlockValidationOptions ret = *this;
         ret.checkMerkleRoot = _checkMerkleRoot;
         return ret;
     }
 
     bool shouldValidatePoW() const { return checkPoW; }
     bool shouldValidateMerkleRoot() const { return checkMerkleRoot; }
     uint64_t getExcessiveBlockSize() const { return excessiveBlockSize; }
 };
 
 /**
  * Unload database information.
  */
 void UnloadBlockIndex(CTxMemPool *mempool, ChainstateManager &chainman);
 
 /**
  * Run instances of script checking worker threads
  */
 void StartScriptCheckWorkerThreads(int threads_num);
 
 /**
  * Stop all of the script checking worker threads
  */
 void StopScriptCheckWorkerThreads();
 
 /**
  * Return transaction from the block at block_index.
  * If block_index is not provided, fall back to mempool.
  * If mempool is not provided or the tx couldn't be found in mempool, fall back
  * to g_txindex.
  *
  * @param[in]  block_index     The block to read from disk, or nullptr
  * @param[in]  mempool         If block_index is not provided, look in the
  *                             mempool, if provided
  * @param[in]  txid            The txid
  * @param[in]  consensusParams The params
  * @param[out] hashBlock       The hash of block_index, if the tx was found via
  *                             block_index
  * @returns                    The tx if found, otherwise nullptr
  */
 CTransactionRef GetTransaction(const CBlockIndex *const block_index,
                                const CTxMemPool *const mempool,
                                const TxId &txid,
                                const Consensus::Params &consensusParams,
                                BlockHash &hashBlock);
 Amount GetBlockSubsidy(int nHeight, const Consensus::Params &consensusParams);
 
 /**
  * Guess verification progress (as a fraction between 0.0=genesis and
  * 1.0=current tip).
  */
 double GuessVerificationProgress(const ChainTxData &data,
                                  const CBlockIndex *pindex);
 
 /**
  * Calculate the amount of disk space the block & undo files currently use.
  */
 uint64_t CalculateCurrentUsage();
 
 /**
  * Actually unlink the specified files
  */
 void UnlinkPrunedFiles(const std::set<int> &setFilesToPrune);
 
 /** Prune block files up to a given height */
 void PruneBlockFilesManual(CChainState &active_chainstate,
                            int nManualPruneHeight);
 
+/**
+ * Validation result for a single transaction mempool acceptance.
+ */
+struct MempoolAcceptResult {
+    /**
+     * Used to indicate the results of mempool validation,
+     * including the possibility of unfinished validation.
+     */
+    enum class ResultType {
+        //! Fully validated, valid.
+        VALID,
+        //! Invalid.
+        INVALID,
+    };
+    ResultType m_result_type;
+    TxValidationState m_state;
+
+    // The following fields are only present when m_result_type =
+    // ResultType::VALID
+    /** Raw base fees. */
+    std::optional<Amount> m_base_fees;
+
+    /** Constructor for failure case */
+    explicit MempoolAcceptResult(TxValidationState state)
+        : m_result_type(ResultType::INVALID), m_state(state),
+          m_base_fees(std::nullopt) {
+        // Can be invalid or error
+        Assume(!state.IsValid());
+    }
+
+    /** Constructor for success case */
+    explicit MempoolAcceptResult(Amount fees)
+        : m_result_type(ResultType::VALID), m_state(TxValidationState{}),
+          m_base_fees(fees) {}
+};
+
 /**
  * (try to) add transaction to memory pool
- * @param[out] fee_out optional argument to return tx fee to the caller
+ *
+ * @param[in]  bypass_limits   When true, don't enforce mempool fee limits.
+ * @param[in]  test_accept     When true, run validation checks but don't submit
+ * to mempool.
  */
-bool AcceptToMemoryPool(CChainState &active_chainstate, const Config &config,
-                        CTxMemPool &pool, TxValidationState &state,
-                        const CTransactionRef &tx, bool bypass_limits,
-                        bool test_accept = false, Amount *fee_out = nullptr)
+MempoolAcceptResult
+AcceptToMemoryPool(CChainState &active_chainstate, const Config &config,
+                   CTxMemPool &pool, const CTransactionRef &tx,
+                   bool bypass_limits, bool test_accept = false)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Simple class for regulating resource usage during CheckInputScripts (and
  * CScriptCheck), atomic so as to be compatible with parallel validation.
  */
 class CheckInputsLimiter {
 protected:
     std::atomic<int64_t> remaining;
 
 public:
     explicit CheckInputsLimiter(int64_t limit) : remaining(limit) {}
 
     bool consume_and_check(int consumed) {
         auto newvalue = (remaining -= consumed);
         return newvalue >= 0;
     }
 
     bool check() { return remaining >= 0; }
 };
 
 class TxSigCheckLimiter : public CheckInputsLimiter {
 public:
     TxSigCheckLimiter() : CheckInputsLimiter(MAX_TX_SIGCHECKS) {}
 
     // Let's make this bad boy copiable.
     TxSigCheckLimiter(const TxSigCheckLimiter &rhs)
         : CheckInputsLimiter(rhs.remaining.load()) {}
 
     TxSigCheckLimiter &operator=(const TxSigCheckLimiter &rhs) {
         remaining = rhs.remaining.load();
         return *this;
     }
 
     static TxSigCheckLimiter getDisabled() {
         TxSigCheckLimiter txLimiter;
         // Historically, there has not been a transaction with more than 20k sig
         // checks on testnet or mainnet, so this effectively disable sigchecks.
         txLimiter.remaining = 20000;
         return txLimiter;
     }
 };
 
 class ConnectTrace;
 
 /**
  * Check whether all of this transaction's input scripts succeed.
  *
  * This involves ECDSA signature checks so can be computationally intensive.
  * This function should only be called after the cheap sanity checks in
  * CheckTxInputs passed.
  *
  * If pvChecks is not nullptr, script checks are pushed onto it instead of being
  * performed inline. Any script checks which are not necessary (eg due to script
  * execution cache hits) are, obviously, not pushed onto pvChecks/run.
  *
  * Upon success nSigChecksOut will be filled in with either:
  * - correct total for all inputs, or,
  * - 0, in the case when checks were pushed onto pvChecks (i.e., a cache miss
  * with pvChecks non-null), in which case the total can be found by executing
  * pvChecks and adding the results.
  *
  * Setting sigCacheStore/scriptCacheStore to false will remove elements from the
  * corresponding cache which are matched. This is useful for checking blocks
  * where we will likely never need the cache entry again.
  *
  * pLimitSigChecks can be passed to limit the sigchecks count either in parallel
  * or serial validation. With pvChecks null (serial validation), breaking the
  * pLimitSigChecks limit will abort evaluation early and return false. With
  * pvChecks not-null (parallel validation): the cached nSigChecks may itself
  * break the limit in which case false is returned, OR, each entry in the
  * returned pvChecks must be executed exactly once in order to probe the limit
  * accurately.
  */
 bool CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                        const CCoinsViewCache &view, const uint32_t flags,
                        bool sigCacheStore, bool scriptCacheStore,
                        const PrecomputedTransactionData &txdata,
                        int &nSigChecksOut, TxSigCheckLimiter &txLimitSigChecks,
                        CheckInputsLimiter *pBlockLimitSigChecks,
                        std::vector<CScriptCheck> *pvChecks)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Handy shortcut to full fledged CheckInputScripts call.
  */
 static inline bool
 CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                   const CCoinsViewCache &view, const uint32_t flags,
                   bool sigCacheStore, bool scriptCacheStore,
                   const PrecomputedTransactionData &txdata, int &nSigChecksOut)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     TxSigCheckLimiter nSigChecksTxLimiter;
     return CheckInputScripts(tx, state, view, flags, sigCacheStore,
                              scriptCacheStore, txdata, nSigChecksOut,
                              nSigChecksTxLimiter, nullptr, nullptr);
 }
 
 /**
  * Mark all the coins corresponding to a given transaction inputs as spent.
  */
 void SpendCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                 int nHeight);
 
 /**
  * Apply the effects of this transaction on the UTXO set represented by view.
  */
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, int nHeight);
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                  int nHeight);
 
 /**
  * Test whether the LockPoints height and time are still valid on the current
  * chain.
  */
 bool TestLockPointValidity(const CChain &active_chain, const LockPoints *lp)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Check if transaction will be BIP 68 final in the next block to be created.
  *
  * Simulates calling SequenceLocks() with data from the tip of the current
  * active chain. Optionally stores in LockPoints the resulting height and time
  * calculated and the hash of the block needed for calculation or skips the
  * calculation and uses the LockPoints passed in for evaluation. The LockPoints
  * should not be considered valid if CheckSequenceLocks returns false.
  *
  * See consensus/consensus.h for flag definitions.
  */
 bool CheckSequenceLocks(CChainState &active_chainstate, const CTxMemPool &pool,
                         const CTransaction &tx, int flags,
                         LockPoints *lp = nullptr,
                         bool useExistingLockPoints = false)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs);
 
 /**
  * Closure representing one script verification.
  * Note that this stores references to the spending transaction.
  *
  * Note that if pLimitSigChecks is passed, then failure does not imply that
  * scripts have failed.
  */
 class CScriptCheck {
 private:
     CTxOut m_tx_out;
     const CTransaction *ptxTo;
     unsigned int nIn;
     uint32_t nFlags;
     bool cacheStore;
     ScriptError error;
     ScriptExecutionMetrics metrics;
     PrecomputedTransactionData txdata;
     TxSigCheckLimiter *pTxLimitSigChecks;
     CheckInputsLimiter *pBlockLimitSigChecks;
 
 public:
     CScriptCheck()
         : ptxTo(nullptr), nIn(0), nFlags(0), cacheStore(false),
           error(ScriptError::UNKNOWN), txdata(), pTxLimitSigChecks(nullptr),
           pBlockLimitSigChecks(nullptr) {}
 
     CScriptCheck(const CTxOut &outIn, const CTransaction &txToIn,
                  unsigned int nInIn, uint32_t nFlagsIn, bool cacheIn,
                  const PrecomputedTransactionData &txdataIn,
                  TxSigCheckLimiter *pTxLimitSigChecksIn = nullptr,
                  CheckInputsLimiter *pBlockLimitSigChecksIn = nullptr)
         : m_tx_out(outIn), ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn),
           cacheStore(cacheIn), error(ScriptError::UNKNOWN), txdata(txdataIn),
           pTxLimitSigChecks(pTxLimitSigChecksIn),
           pBlockLimitSigChecks(pBlockLimitSigChecksIn) {}
 
     bool operator()();
 
     void swap(CScriptCheck &check) {
         std::swap(ptxTo, check.ptxTo);
         std::swap(m_tx_out, check.m_tx_out);
         std::swap(nIn, check.nIn);
         std::swap(nFlags, check.nFlags);
         std::swap(cacheStore, check.cacheStore);
         std::swap(error, check.error);
         std::swap(metrics, check.metrics);
         std::swap(txdata, check.txdata);
         std::swap(pTxLimitSigChecks, check.pTxLimitSigChecks);
         std::swap(pBlockLimitSigChecks, check.pBlockLimitSigChecks);
     }
 
     ScriptError GetScriptError() const { return error; }
 
     ScriptExecutionMetrics GetScriptExecutionMetrics() const { return metrics; }
 };
 
 /** Functions for validating blocks and updating the block tree */
 
 /**
  * Context-independent validity checks.
  *
  * Returns true if the provided block is valid (has valid header,
  * transactions are valid, block is a valid size, etc.)
  */
 bool CheckBlock(const CBlock &block, BlockValidationState &state,
                 const Consensus::Params &params,
                 BlockValidationOptions validationOptions);
 
 /**
  * This is a variant of ContextualCheckTransaction which computes the contextual
  * check for a transaction based on the chain tip.
  *
  * See consensus/consensus.h for flag definitions.
  */
 bool ContextualCheckTransactionForCurrentBlock(
     const CBlockIndex *active_chain_tip, const Consensus::Params &params,
     const CTransaction &tx, TxValidationState &state, int flags = -1)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Check a block is completely valid from start to finish (only works on top of
  * our current best block)
  */
 bool TestBlockValidity(BlockValidationState &state, const CChainParams &params,
                        CChainState &chainstate, const CBlock &block,
                        CBlockIndex *pindexPrev,
                        BlockValidationOptions validationOptions)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * RAII wrapper for VerifyDB: Verify consistency of the block and coin
  * databases.
  */
 class CVerifyDB {
 public:
     CVerifyDB();
 
     ~CVerifyDB();
 
     bool VerifyDB(CChainState &chainstate, const Config &config,
                   CCoinsView &coinsview, int nCheckLevel, int nCheckDepth)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 };
 
 /** @see CChainState::FlushStateToDisk */
 enum class FlushStateMode { NONE, IF_NEEDED, PERIODIC, ALWAYS };
 
 /** Global variable that points to the active CCoinsView (protected by cs_main)
  */
 extern std::unique_ptr<CCoinsViewCache> pcoinsTip;
 
 /**
  * Maintains a tree of blocks (stored in `m_block_index`) which is consulted
  * to determine where the most-work tip is.
  *
  * This data is used mostly in `CChainState` - information about, e.g.,
  * candidate tips is not maintained here.
  */
 class BlockManager {
     friend CChainState;
 
 private:
     /**
      * Calculate the block/rev files to delete based on height specified
      * by user with RPC command pruneblockchain
      */
     void FindFilesToPruneManual(std::set<int> &setFilesToPrune,
                                 int nManualPruneHeight, int chain_tip_height);
 
     /**
      * Prune block and undo files (blk???.dat and undo???.dat) so that the disk
      * space used is less than a user-defined target. The user sets the target
      * (in MB) on the command line or in config file.  This will be run on
      * startup and whenever new space is allocated in a block or undo file,
      * staying below the target. Changing back to unpruned requires a reindex
      * (which in this case means the blockchain must be re-downloaded.)
      *
      * Pruning functions are called from FlushStateToDisk when the global
      * fCheckForPruning flag has been set. Block and undo files are deleted in
      * lock-step (when blk00003.dat is deleted, so is rev00003.dat.) Pruning
      * cannot take place until the longest chain is at least a certain length
      * (100000 on mainnet, 1000 on testnet, 1000 on regtest). Pruning will never
      * delete a block within a defined distance (currently 288) from the active
      * chain's tip. The block index is updated by unsetting HAVE_DATA and
      * HAVE_UNDO for any blocks that were stored in the deleted files. A db flag
      * records the fact that at least some block files have been pruned.
      *
      * @param[out]   setFilesToPrune   The set of file indices that can be
      *                                 unlinked will be returned
      */
     void FindFilesToPrune(std::set<int> &setFilesToPrune,
                           uint64_t nPruneAfterHeight, int chain_tip_height,
                           int prune_height, bool is_ibd);
 
 public:
     BlockMap m_block_index GUARDED_BY(cs_main);
 
     /**
      * In order to efficiently track invalidity of headers, we keep the set of
      * blocks which we tried to connect and found to be invalid here (ie which
      * were set to BLOCK_FAILED_VALID since the last restart). We can then
      * walk this set and check if a new header is a descendant of something in
      * this set, preventing us from having to walk m_block_index when we try
      * to connect a bad block and fail.
      *
      * While this is more complicated than marking everything which descends
      * from an invalid block as invalid at the time we discover it to be
      * invalid, doing so would require walking all of m_block_index to find all
      * descendants. Since this case should be very rare, keeping track of all
      * BLOCK_FAILED_VALID blocks in a set should be just fine and work just as
      * well.
      *
      * Because we already walk m_block_index in height-order at startup, we go
      * ahead and mark descendants of invalid blocks as FAILED_CHILD at that
      * time, instead of putting things in this set.
      */
     std::set<CBlockIndex *> m_failed_blocks;
 
     /**
      * All pairs A->B, where A (or one of its ancestors) misses transactions,
      * but B has transactions. Pruned nodes may have entries where B is missing
      * data.
      */
     std::multimap<CBlockIndex *, CBlockIndex *> m_blocks_unlinked;
 
     /**
      * Load the blocktree off disk and into memory. Populate certain metadata
      * per index entry (nStatus, nChainWork, nTimeMax, etc.) as well as
      * peripheral collections like setDirtyBlockIndex.
      *
      * @param[out] block_index_candidates  Fill this set with any valid blocks
      * for which we've downloaded all transactions.
      */
     bool LoadBlockIndex(const Consensus::Params &consensus_params,
                         CBlockTreeDB &blocktree,
                         std::set<CBlockIndex *, CBlockIndexWorkComparator>
                             &block_index_candidates)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Clear all data members. */
     void Unload() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     CBlockIndex *AddToBlockIndex(const CBlockHeader &block)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /** Create a new block index entry for a given block hash */
     CBlockIndex *InsertBlockIndex(const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Mark one block file as pruned (modify associated database entries)
     void PruneOneBlockFile(const int fileNumber)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * If a block header hasn't already been seen, call CheckBlockHeader on it,
      * ensure that it doesn't descend from an invalid block, and then add it to
      * m_block_index.
      */
     bool AcceptBlockHeader(const Config &config, const CBlockHeader &block,
                            BlockValidationState &state, CBlockIndex **ppindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     CBlockIndex *LookupBlockIndex(const BlockHash &hash) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Find the last common block between the parameter chain and a locator. */
     CBlockIndex *FindForkInGlobalIndex(const CChain &chain,
                                        const CBlockLocator &locator)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Returns last CBlockIndex* that is a checkpoint
     CBlockIndex *GetLastCheckpoint(const CCheckpointData &data)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Return the spend height, which is one more than the
      * inputs.GetBestBlock(). While checking, GetBestBlock() refers to the
      * parent block. (protected by cs_main)
      * This is also true for mempool checks.
      */
     int GetSpendHeight(const CCoinsViewCache &inputs)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     ~BlockManager() { Unload(); }
 };
 
 /**
  * A convenience class for constructing the CCoinsView* hierarchy used
  * to facilitate access to the UTXO set.
  *
  * This class consists of an arrangement of layered CCoinsView objects,
  * preferring to store and retrieve coins in memory via `m_cacheview` but
  * ultimately falling back on cache misses to the canonical store of UTXOs on
  * disk, `m_dbview`.
  */
 class CoinsViews {
 public:
     //! The lowest level of the CoinsViews cache hierarchy sits in a leveldb
     //! database on disk. All unspent coins reside in this store.
     CCoinsViewDB m_dbview GUARDED_BY(cs_main);
 
     //! This view wraps access to the leveldb instance and handles read errors
     //! gracefully.
     CCoinsViewErrorCatcher m_catcherview GUARDED_BY(cs_main);
 
     //! This is the top layer of the cache hierarchy - it keeps as many coins in
     //! memory as can fit per the dbcache setting.
     std::unique_ptr<CCoinsViewCache> m_cacheview GUARDED_BY(cs_main);
 
     //! This constructor initializes CCoinsViewDB and CCoinsViewErrorCatcher
     //! instances, but it *does not* create a CCoinsViewCache instance by
     //! default. This is done separately because the presence of the cache has
     //! implications on whether or not we're allowed to flush the cache's state
     //! to disk, which should not be done until the health of the database is
     //! verified.
     //!
     //! All arguments forwarded onto CCoinsViewDB.
     CoinsViews(std::string ldb_name, size_t cache_size_bytes, bool in_memory,
                bool should_wipe);
 
     //! Initialize the CCoinsViewCache member.
     void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 };
 
 enum class CoinsCacheSizeState {
     //! The coins cache is in immediate need of a flush.
     CRITICAL = 2,
     //! The cache is at >= 90% capacity.
     LARGE = 1,
     OK = 0
 };
 
 /**
  * CChainState stores and provides an API to update our local knowledge of the
  * current best chain.
  *
  * Eventually, the API here is targeted at being exposed externally as a
  * consumable libconsensus library, so any functions added must only call
  * other class member functions, pure functions in other parts of the consensus
  * library, callbacks via the validation interface, or read/write-to-disk
  * functions (eventually this will also be via callbacks).
  *
  * Anything that is contingent on the current tip of the chain is stored here,
  * whereas block information and metadata independent of the current tip is
  * kept in `BlockMetadataManager`.
  */
 class CChainState {
 private:
     /**
      * the ChainState CriticalSection
      * A lock that must be held when modifying this ChainState - held in
      * ActivateBestChain()
      */
     RecursiveMutex m_cs_chainstate;
 
     /**
      * Every received block is assigned a unique and increasing identifier, so
      * we know which one to give priority in case of a fork.
      * Blocks loaded from disk are assigned id 0, so start the counter at 1.
      */
     std::atomic<int32_t> nBlockSequenceId{1};
     /** Decreasing counter (used by subsequent preciousblock calls). */
     int32_t nBlockReverseSequenceId = -1;
     /** chainwork for the last block that preciousblock has been applied to. */
     arith_uint256 nLastPreciousChainwork = 0;
 
     /**
      * Whether this chainstate is undergoing initial block download.
      *
      * Mutable because we need to be able to mark IsInitialBlockDownload()
      * const, which latches this for caching purposes.
      */
     mutable std::atomic<bool> m_cached_finished_ibd{false};
 
     //! mempool that is kept in sync with the chain
     CTxMemPool &m_mempool;
 
     //! Manages the UTXO set, which is a reflection of the contents of
     //! `m_chain`.
     std::unique_ptr<CoinsViews> m_coins_views;
 
     /**
      * The best finalized block.
      * This block cannot be reorged in any way except by explicit user action.
      */
     const CBlockIndex *m_finalizedBlockIndex GUARDED_BY(cs_main) = nullptr;
 
 public:
     //! Reference to a BlockManager instance which itself is shared across all
     //! CChainState instances.
     BlockManager &m_blockman;
 
     explicit CChainState(
         CTxMemPool &mempool, BlockManager &blockman,
         std::optional<BlockHash> from_snapshot_blockhash = std::nullopt);
 
     /**
      * Initialize the CoinsViews UTXO set database management data structures.
      * The in-memory cache is initialized separately.
      *
      * All parameters forwarded to CoinsViews.
      */
     void InitCoinsDB(size_t cache_size_bytes, bool in_memory, bool should_wipe,
                      std::string leveldb_name = "chainstate");
 
     //! Initialize the in-memory coins cache (to be done after the health of the
     //! on-disk database is verified).
     void InitCoinsCache(size_t cache_size_bytes)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! @returns whether or not the CoinsViews object has been fully initialized
     //! and we can
     //!          safely flush this object to disk.
     bool CanFlushToDisk() const EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         return m_coins_views && m_coins_views->m_cacheview;
     }
 
     //! The current chain of blockheaders we consult and build on.
     //! @see CChain, CBlockIndex.
     CChain m_chain;
 
     /**
      * The blockhash which is the base of the snapshot this chainstate was
      * created from.
      *
      * std::nullopt if this chainstate was not created from a snapshot.
      */
     const std::optional<BlockHash> m_from_snapshot_blockhash{};
 
     /**
      * The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS (for
      * itself and all ancestors) and as good as our current tip or better.
      * Entries may be failed, though, and pruning nodes may be missing the data
      * for the block.
      */
     std::set<CBlockIndex *, CBlockIndexWorkComparator> setBlockIndexCandidates;
 
     //! @returns A reference to the in-memory cache of the UTXO set.
     CCoinsViewCache &CoinsTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         assert(m_coins_views->m_cacheview);
         return *m_coins_views->m_cacheview.get();
     }
 
     //! @returns A reference to the on-disk UTXO set database.
     CCoinsViewDB &CoinsDB() { return m_coins_views->m_dbview; }
 
     //! @returns A reference to a wrapped view of the in-memory UTXO set that
     //!     handles disk read errors gracefully.
     CCoinsViewErrorCatcher &CoinsErrorCatcher()
         EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         return m_coins_views->m_catcherview;
     }
 
     //! Destructs all objects related to accessing the UTXO set.
     void ResetCoinsViews() { m_coins_views.reset(); }
 
     //! The cache size of the on-disk coins view.
     size_t m_coinsdb_cache_size_bytes{0};
 
     //! The cache size of the in-memory coins view.
     size_t m_coinstip_cache_size_bytes{0};
 
     //! Resize the CoinsViews caches dynamically and flush state to disk.
     //! @returns true unless an error occurred during the flush.
     bool ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /** Import blocks from an external file */
     void LoadExternalBlockFile(const Config &config, FILE *fileIn,
                                FlatFilePos *dbp = nullptr);
 
     /**
      * Update the on-disk chain state.
      * The caches and indexes are flushed depending on the mode we're called
      * with if they're too large, if it's been a while since the last write, or
      * always and in all cases if we're in prune mode and are deleting files.
      *
      * If FlushStateMode::NONE is used, then FlushStateToDisk(...) won't do
      * anything besides checking if we need to prune.
      *
      * @returns true unless a system error occurred
      */
     bool FlushStateToDisk(const CChainParams &chainparams,
                           BlockValidationState &state, FlushStateMode mode,
                           int nManualPruneHeight = 0);
 
     //! Unconditionally flush all changes to disk.
     void ForceFlushStateToDisk();
 
     //! Prune blockfiles from the disk if necessary and then flush chainstate
     //! changes if we pruned.
     void PruneAndFlush();
 
     /**
      * Find the best known block, and make it the tip of the block chain. The
      * result is either failure or an activated best chain. pblock is either
      * nullptr or a pointer to a block that is already loaded (to avoid loading
      * it again from disk).
      *
      * ActivateBestChain is split into steps (see ActivateBestChainStep) so that
      * we avoid holding cs_main for an extended period of time; the length of
      * this call may be quite long during reindexing or a substantial reorg.
      *
      * May not be called with cs_main held. May not be called in a
      * validationinterface callback.
      *
      * @returns true unless a system error occurred
      */
     bool ActivateBestChain(const Config &config, BlockValidationState &state,
                            std::shared_ptr<const CBlock> pblock = nullptr)
         LOCKS_EXCLUDED(cs_main);
 
     bool AcceptBlock(const Config &config,
                      const std::shared_ptr<const CBlock> &pblock,
                      BlockValidationState &state, bool fRequested,
                      const FlatFilePos *dbp, bool *fNewBlock)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Block (dis)connection on a given view:
     DisconnectResult DisconnectBlock(const CBlock &block,
                                      const CBlockIndex *pindex,
                                      CCoinsViewCache &view);
     bool ConnectBlock(const CBlock &block, BlockValidationState &state,
                       CBlockIndex *pindex, CCoinsViewCache &view,
                       const CChainParams &params,
                       BlockValidationOptions options, bool fJustCheck = false)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Block disconnection on our pcoinsTip:
     bool DisconnectTip(const CChainParams &params, BlockValidationState &state,
                        DisconnectedBlockTransactions *disconnectpool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool.cs);
 
     // Manual block validity manipulation:
     /**
      * Mark a block as precious and reorganize.
      *
      * May not be called in a validationinterface callback.
      */
     bool PreciousBlock(const Config &config, BlockValidationState &state,
                        CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main);
     /** Mark a block as invalid. */
     bool InvalidateBlock(const Config &config, BlockValidationState &state,
                          CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main)
         EXCLUSIVE_LOCKS_REQUIRED(!m_cs_chainstate);
     /** Park a block. */
     bool ParkBlock(const Config &config, BlockValidationState &state,
                    CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main)
         EXCLUSIVE_LOCKS_REQUIRED(!m_cs_chainstate);
 
     /**
      * Finalize a block.
      * A finalized block can not be reorged in any way.
      */
     bool FinalizeBlock(const Config &config, BlockValidationState &state,
                        CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main)
         EXCLUSIVE_LOCKS_REQUIRED(!m_cs_chainstate);
     /** Return the currently finalized block index. */
     const CBlockIndex *GetFinalizedBlock() const
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /**
      * Checks if a block is finalized.
      */
     bool IsBlockFinalized(const CBlockIndex *pindex) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Remove invalidity status from a block and its descendants. */
     void ResetBlockFailureFlags(CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F>
     bool UpdateFlagsForBlock(CBlockIndex *pindexBase, CBlockIndex *pindex, F f)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F, typename C, typename AC>
     void UpdateFlags(CBlockIndex *pindex, CBlockIndex *&pindexReset, F f,
                      C fChild, AC fAncestorWasChanged)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Remove parked status from a block and its descendants. */
     void UnparkBlockAndChildren(CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Remove parked status from a block. */
     void UnparkBlock(CBlockIndex *pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Replay blocks that aren't fully applied to the database. */
     bool ReplayBlocks(const Consensus::Params &params);
 
     /**
      * Ensures we have a genesis block in the block tree, possibly writing one
      * to disk.
      */
     bool LoadGenesisBlock(const CChainParams &chainparams);
 
     void PruneBlockIndexCandidates();
 
     void UnloadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Check whether we are doing an initial block download (synchronizing from
      * disk or network)
      */
     bool IsInitialBlockDownload() const;
 
     /**
      * Make various assertions about the state of the block index.
      *
      * By default this only executes fully when using the Regtest chain; see:
      * fCheckBlockIndex.
      */
     void CheckBlockIndex(const Consensus::Params &consensusParams);
 
     /** Load the persisted mempool from disk */
     void LoadMempool(const Config &config, const ArgsManager &args);
 
     /** Update the chain tip based on database information, i.e. CoinsTip()'s
      * best block. */
     bool LoadChainTip(const CChainParams &chainparams)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Dictates whether we need to flush the cache to disk or not.
     //!
     //! @return the state of the size of the coins cache.
     CoinsCacheSizeState GetCoinsCacheSizeState(const CTxMemPool *tx_pool)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     CoinsCacheSizeState GetCoinsCacheSizeState(
         const CTxMemPool *tx_pool, size_t max_coins_cache_size_bytes,
         size_t max_mempool_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     std::string ToString() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
 private:
     bool ActivateBestChainStep(const Config &config,
                                BlockValidationState &state,
                                CBlockIndex *pindexMostWork,
                                const std::shared_ptr<const CBlock> &pblock,
                                bool &fInvalidFound, ConnectTrace &connectTrace)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool.cs);
     bool ConnectTip(const Config &config, BlockValidationState &state,
                     CBlockIndex *pindexNew,
                     const std::shared_ptr<const CBlock> &pblock,
                     ConnectTrace &connectTrace,
                     DisconnectedBlockTransactions &disconnectpool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool.cs);
     void InvalidBlockFound(CBlockIndex *pindex,
                            const BlockValidationState &state)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     CBlockIndex *FindMostWorkChain() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool MarkBlockAsFinal(BlockValidationState &state,
                           const CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void ReceivedBlockTransactions(const CBlock &block, CBlockIndex *pindexNew,
                                    const FlatFilePos &pos)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool RollforwardBlock(const CBlockIndex *pindex, CCoinsViewCache &inputs,
                           const Consensus::Params &params)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     void UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool UnwindBlock(const Config &config, BlockValidationState &state,
                      CBlockIndex *pindex, bool invalidate)
         EXCLUSIVE_LOCKS_REQUIRED(m_cs_chainstate);
 
     void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void CheckForkWarningConditionsOnNewFork(CBlockIndex *pindexNewForkTip)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void InvalidChainFound(CBlockIndex *pindexNew)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool LoadBlockIndexDB(const Consensus::Params &params)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     const CBlockIndex *FindBlockToFinalize(CBlockIndex *pindexNew)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     friend ChainstateManager;
 };
 
 /**
  * Provides an interface for creating and interacting with one or two
  * chainstates: an IBD chainstate generated by downloading blocks, and
  * an optional snapshot chainstate loaded from a UTXO snapshot. Managed
  * chainstates can be maintained at different heights simultaneously.
  *
  * This class provides abstractions that allow the retrieval of the current
  * most-work chainstate ("Active") as well as chainstates which may be in
  * background use to validate UTXO snapshots.
  *
  * Definitions:
  *
  * *IBD chainstate*: a chainstate whose current state has been "fully"
  *   validated by the initial block download process.
  *
  * *Snapshot chainstate*: a chainstate populated by loading in an
  *    assumeutxo UTXO snapshot.
  *
  * *Active chainstate*: the chainstate containing the current most-work
  *    chain. Consulted by most parts of the system (net_processing,
  *    wallet) as a reflection of the current chain and UTXO set.
  *    This may either be an IBD chainstate or a snapshot chainstate.
  *
  * *Background IBD chainstate*: an IBD chainstate for which the
  *    IBD process is happening in the background while use of the
  *    active (snapshot) chainstate allows the rest of the system to function.
  *
  * *Validated chainstate*: the most-work chainstate which has been validated
  *   locally via initial block download. This will be the snapshot chainstate
  *   if a snapshot was loaded and all blocks up to the snapshot starting point
  *   have been downloaded and validated (via background validation), otherwise
  *   it will be the IBD chainstate.
  */
 class ChainstateManager {
 private:
     //! The chainstate used under normal operation (i.e. "regular" IBD) or, if
     //! a snapshot is in use, for background validation.
     //!
     //! Its contents (including on-disk data) will be deleted *upon shutdown*
     //! after background validation of the snapshot has completed. We do not
     //! free the chainstate contents immediately after it finishes validation
     //! to cautiously avoid a case where some other part of the system is still
     //! using this pointer (e.g. net_processing).
     //!
     //! Once this pointer is set to a corresponding chainstate, it will not
     //! be reset until init.cpp:Shutdown().
     //!
     //! This is especially important when, e.g., calling ActivateBestChain()
     //! on all chainstates because we are not able to hold ::cs_main going into
     //! that call.
     std::unique_ptr<CChainState> m_ibd_chainstate GUARDED_BY(::cs_main);
 
     //! A chainstate initialized on the basis of a UTXO snapshot. If this is
     //! non-null, it is always our active chainstate.
     //!
     //! Once this pointer is set to a corresponding chainstate, it will not
     //! be reset until init.cpp:Shutdown().
     //!
     //! This is especially important when, e.g., calling ActivateBestChain()
     //! on all chainstates because we are not able to hold ::cs_main going into
     //! that call.
     std::unique_ptr<CChainState> m_snapshot_chainstate GUARDED_BY(::cs_main);
 
     //! Points to either the ibd or snapshot chainstate; indicates our
     //! most-work chain.
     //!
     //! Once this pointer is set to a corresponding chainstate, it will not
     //! be reset until init.cpp:Shutdown().
     //!
     //! This is especially important when, e.g., calling ActivateBestChain()
     //! on all chainstates because we are not able to hold ::cs_main going into
     //! that call.
     CChainState *m_active_chainstate GUARDED_BY(::cs_main){nullptr};
 
     //! If true, the assumed-valid chainstate has been fully validated
     //! by the background validation chainstate.
     bool m_snapshot_validated{false};
 
     //! Internal helper for ActivateSnapshot().
     [[nodiscard]] bool
     PopulateAndValidateSnapshot(CChainState &snapshot_chainstate,
                                 CAutoFile &coins_file,
                                 const SnapshotMetadata &metadata);
 
 public:
     std::thread m_load_block;
     //! A single BlockManager instance is shared across each constructed
     //! chainstate to avoid duplicating block metadata.
     BlockManager m_blockman GUARDED_BY(::cs_main);
 
     //! The total number of bytes available for us to use across all in-memory
     //! coins caches. This will be split somehow across chainstates.
     int64_t m_total_coinstip_cache{0};
     //
     //! The total number of bytes available for us to use across all leveldb
     //! coins databases. This will be split somehow across chainstates.
     int64_t m_total_coinsdb_cache{0};
 
     //! Instantiate a new chainstate and assign it based upon whether it is
     //! from a snapshot.
     //!
     //! @param[in] mempool              The mempool to pass to the chainstate
     //                                  constructor
     //! @param[in] snapshot_blockhash   If given, signify that this chainstate
     //!                                 is based on a snapshot.
     CChainState &InitializeChainstate(
         CTxMemPool &mempool,
         const std::optional<BlockHash> &snapshot_blockhash = std::nullopt)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Get all chainstates currently being used.
     std::vector<CChainState *> GetAll();
 
     //! Construct and activate a Chainstate on the basis of UTXO snapshot data.
     //!
     //! Steps:
     //!
     //! - Initialize an unused CChainState.
     //! - Load its `CoinsViews` contents from `coins_file`.
     //! - Verify that the hash of the resulting coinsdb matches the expected
     //!   hash per assumeutxo chain parameters.
     //! - Wait for our headers chain to include the base block of the snapshot.
     //! - "Fast forward" the tip of the new chainstate to the base of the
     //!   snapshot, faking nTx* block index data along the way.
     //! - Move the new chainstate to `m_snapshot_chainstate` and make it our
     //!   ActiveChainstate().
     [[nodiscard]] bool ActivateSnapshot(CAutoFile &coins_file,
                                         const SnapshotMetadata &metadata,
                                         bool in_memory);
 
     //! The most-work chain.
     CChainState &ActiveChainstate() const;
     CChain &ActiveChain() const { return ActiveChainstate().m_chain; }
     int ActiveHeight() const { return ActiveChain().Height(); }
     CBlockIndex *ActiveTip() const { return ActiveChain().Tip(); }
 
     BlockMap &BlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         return m_blockman.m_block_index;
     }
 
     //! @returns true if a snapshot-based chainstate is in use. Also implies
     //!          that a background validation chainstate is also in use.
     bool IsSnapshotActive() const;
 
     std::optional<BlockHash> SnapshotBlockhash() const;
 
     //! Is there a snapshot in use and has it been fully validated?
     bool IsSnapshotValidated() const { return m_snapshot_validated; }
 
     //! @returns true if this chainstate is being used to validate an active
     //!          snapshot in the background.
     bool IsBackgroundIBD(CChainState *chainstate) const;
 
     //! Return the most-work chainstate that has been fully validated.
     //!
     //! During background validation of a snapshot, this is the IBD chain. After
     //! background validation has completed, this is the snapshot chain.
     CChainState &ValidatedChainstate() const;
 
     CChain &ValidatedChain() const { return ValidatedChainstate().m_chain; }
     CBlockIndex *ValidatedTip() const { return ValidatedChain().Tip(); }
 
     /**
      * Process an incoming block. This only returns after the best known valid
      * block is made active. Note that it does not, however, guarantee that the
      * specific block passed to it has been checked for validity!
      *
      * If you want to *possibly* get feedback on whether pblock is valid, you
      * must install a CValidationInterface (see validationinterface.h) - this
      * will have its BlockChecked method called whenever *any* block completes
      * validation.
      *
      * Note that we guarantee that either the proof-of-work is valid on pblock,
      * or (and possibly also) BlockChecked will have been called.
      *
      * May not be called in a validationinterface callback.
      *
      * @param[in]   config  The global config.
      * @param[in]   pblock  The block we want to process.
      * @param[in]   fForceProcessing Process this block even if unrequested;
      *              used for non-network block sources.
      * @param[out]  fNewBlock A boolean which is set to indicate if the block
      * was first received via this call.
      * @returns     If the block was processed, independently of block validity
      */
     bool ProcessNewBlock(const Config &config,
                          const std::shared_ptr<const CBlock> pblock,
                          bool fForceProcessing, bool *fNewBlock)
         LOCKS_EXCLUDED(cs_main);
 
     /**
      * Process incoming block headers.
      *
      * May not be called in a validationinterface callback.
      *
      * @param[in]  config        The config.
      * @param[in]  block         The block headers themselves.
      * @param[out] state         This may be set to an Error state if any error
      *                           occurred processing them.
      * @param[out] ppindex       If set, the pointer will be set to point to the
      *                           last new block index object for the given
      * headers.
      * @return True if block headers were accepted as valid.
      */
     bool ProcessNewBlockHeaders(const Config &config,
                                 const std::vector<CBlockHeader> &block,
                                 BlockValidationState &state,
                                 const CBlockIndex **ppindex = nullptr)
         LOCKS_EXCLUDED(cs_main);
 
     //! Load the block tree and coins database from disk, initializing state if
     //! we're running with -reindex
     bool LoadBlockIndex(const Consensus::Params &params)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Unload block index and chain data before shutdown.
     void Unload() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Clear (deconstruct) chainstate data.
     void Reset();
 
     //! Check to see if caches are out of balance and if so, call
     //! ResizeCoinsCaches() as needed.
     void MaybeRebalanceCaches() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     ~ChainstateManager() {
         LOCK(::cs_main);
         UnloadBlockIndex(/* mempool */ nullptr, *this);
         Reset();
     }
 };
 
 /**
  * Global variable that points to the active block tree (protected by cs_main)
  */
 extern std::unique_ptr<CBlockTreeDB> pblocktree;
 
 extern VersionBitsCache versionbitscache;
 
 /**
  * Determine what nVersion a new block should use.
  */
 int32_t ComputeBlockVersion(const CBlockIndex *pindexPrev,
                             const Consensus::Params &params);
 
 /** Get block file info entry for one block file */
 CBlockFileInfo *GetBlockFileInfo(size_t n);
 
 /** Dump the mempool to disk. */
 bool DumpMempool(const CTxMemPool &pool);
 
 /** Load the mempool from disk. */
 bool LoadMempool(const Config &config, CTxMemPool &pool,
                  CChainState &active_chainstate);
 
 //! Check whether the block associated with this index entry is pruned or not.
 bool IsBlockPruned(const CBlockIndex *pblockindex);
 
 /**
  * Return the expected assumeutxo value for a given height, if one exists.
  *
  * @param[in] height Get the assumeutxo value for this height.
  *
  * @returns empty if no assumeutxo configuration exists for the given height.
  */
 const AssumeutxoData *ExpectedAssumeutxo(const int height,
                                          const CChainParams &params);
 
 #endif // BITCOIN_VALIDATION_H