diff --git a/src/net.cpp b/src/net.cpp
index d2fd42a8f..b5927de40 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1,3095 +1,3099 @@
 // 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.
 
 #if defined(HAVE_CONFIG_H)
 #include "config/bitcoin-config.h"
 #endif
 
 #include "net.h"
 
 #include "addrman.h"
 #include "chainparams.h"
 #include "clientversion.h"
 #include "config.h"
 #include "consensus/consensus.h"
 #include "crypto/common.h"
 #include "crypto/sha256.h"
 #include "hash.h"
 #include "netbase.h"
 #include "primitives/transaction.h"
 #include "scheduler.h"
 #include "ui_interface.h"
 #include "utilstrencodings.h"
 
 #ifdef WIN32
 #include <string.h>
 #else
 #include <fcntl.h>
 #endif
 
 #ifdef USE_UPNP
 #include <miniupnpc/miniupnpc.h>
 #include <miniupnpc/miniwget.h>
 #include <miniupnpc/upnpcommands.h>
 #include <miniupnpc/upnperrors.h>
 #endif
 
 #include <cmath>
 
 // Dump addresses to peers.dat and banlist.dat every 15 minutes (900s)
 #define DUMP_ADDRESSES_INTERVAL 900
 
 // We add a random period time (0 to 1 seconds) to feeler connections to prevent
 // synchronization.
 #define FEELER_SLEEP_WINDOW 1
 
 // MSG_NOSIGNAL is not available on some platforms, if it doesn't exist define
 // it as 0
 #if !defined(MSG_NOSIGNAL)
 #define MSG_NOSIGNAL 0
 #endif
 
 // MSG_DONTWAIT is not available on some platforms, if it doesn't exist define
 // it as 0
 #if !defined(MSG_DONTWAIT)
 #define MSG_DONTWAIT 0
 #endif
 
 // Fix for ancient MinGW versions, that don't have defined these in ws2tcpip.h.
 // Todo: Can be removed when our pull-tester is upgraded to a modern MinGW
 // version.
 #ifdef WIN32
 #ifndef PROTECTION_LEVEL_UNRESTRICTED
 #define PROTECTION_LEVEL_UNRESTRICTED 10
 #endif
 #ifndef IPV6_PROTECTION_LEVEL
 #define IPV6_PROTECTION_LEVEL 23
 #endif
 #endif
 
 /** Used to pass flags to the Bind() function */
 enum BindFlags {
     BF_NONE = 0,
     BF_EXPLICIT = (1U << 0),
     BF_REPORT_ERROR = (1U << 1),
     BF_WHITELIST = (1U << 2),
 };
 
 const static std::string NET_MESSAGE_COMMAND_OTHER = "*other*";
 
 // SHA256("netgroup")[0:8]
 static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL;
 // SHA256("localhostnonce")[0:8]
 static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL;
 //
 // Global state variables
 //
 bool fDiscover = true;
 bool fListen = true;
 bool fRelayTxes = true;
 CCriticalSection cs_mapLocalHost;
 std::map<CNetAddr, LocalServiceInfo> mapLocalHost;
 static bool vfLimited[NET_MAX] = {};
 
 limitedmap<uint256, int64_t> mapAlreadyAskedFor(MAX_INV_SZ);
 
 void CConnman::AddOneShot(const std::string &strDest) {
     LOCK(cs_vOneShots);
     vOneShots.push_back(strDest);
 }
 
 unsigned short GetListenPort() {
     return (unsigned short)(gArgs.GetArg("-port", Params().GetDefaultPort()));
 }
 
 // find 'best' local address for a particular peer
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer) {
     if (!fListen) {
         return false;
     }
 
     int nBestScore = -1;
     int nBestReachability = -1;
     {
         LOCK(cs_mapLocalHost);
         for (const auto &entry : mapLocalHost) {
             int nScore = entry.second.nScore;
             int nReachability = entry.first.GetReachabilityFrom(paddrPeer);
             if (nReachability > nBestReachability ||
                 (nReachability == nBestReachability && nScore > nBestScore)) {
                 addr = CService(entry.first, entry.second.nPort);
                 nBestReachability = nReachability;
                 nBestScore = nScore;
             }
         }
     }
     return nBestScore >= 0;
 }
 
 //! Convert the pnSeeds6 array into usable address objects.
 static std::vector<CAddress>
 convertSeed6(const std::vector<SeedSpec6> &vSeedsIn) {
     // It'll only connect to one or two seed nodes because once it connects,
     // it'll get a pile of addresses with newer timestamps. Seed nodes are given
     // a random 'last seen time' of between one and two weeks ago.
     const int64_t nOneWeek = 7 * 24 * 60 * 60;
     std::vector<CAddress> vSeedsOut;
     vSeedsOut.reserve(vSeedsIn.size());
     for (const auto &seed_in : vSeedsIn) {
         struct in6_addr ip;
         memcpy(&ip, seed_in.addr, sizeof(ip));
         CAddress addr(CService(ip, seed_in.port),
                       GetDesirableServiceFlags(NODE_NONE));
         addr.nTime = GetTime() - GetRand(nOneWeek) - nOneWeek;
         vSeedsOut.push_back(addr);
     }
     return vSeedsOut;
 }
 
 // Get best local address for a particular peer as a CAddress. Otherwise, return
 // the unroutable 0.0.0.0 but filled in with the normal parameters, since the IP
 // may be changed to a useful one by discovery.
 CAddress GetLocalAddress(const CNetAddr *paddrPeer,
                          ServiceFlags nLocalServices) {
     CAddress ret(CService(CNetAddr(), GetListenPort()), nLocalServices);
     CService addr;
     if (GetLocal(addr, paddrPeer)) {
         ret = CAddress(addr, nLocalServices);
     }
     ret.nTime = GetAdjustedTime();
     return ret;
 }
 
 static int GetnScore(const CService &addr) {
     LOCK(cs_mapLocalHost);
     if (mapLocalHost.count(addr) == LOCAL_NONE) {
         return 0;
     }
     return mapLocalHost[addr].nScore;
 }
 
 // Is our peer's addrLocal potentially useful as an external IP source?
 bool IsPeerAddrLocalGood(CNode *pnode) {
     CService addrLocal = pnode->GetAddrLocal();
     return fDiscover && pnode->addr.IsRoutable() && addrLocal.IsRoutable() &&
            !IsLimited(addrLocal.GetNetwork());
 }
 
 // Pushes our own address to a peer.
 void AdvertiseLocal(CNode *pnode) {
     if (fListen && pnode->fSuccessfullyConnected) {
         CAddress addrLocal =
             GetLocalAddress(&pnode->addr, pnode->GetLocalServices());
         // If discovery is enabled, sometimes give our peer the address it tells
         // us that it sees us as in case it has a better idea of our address
         // than we do.
         if (IsPeerAddrLocalGood(pnode) &&
             (!addrLocal.IsRoutable() ||
              GetRand((GetnScore(addrLocal) > LOCAL_MANUAL) ? 8 : 2) == 0)) {
             addrLocal.SetIP(pnode->GetAddrLocal());
         }
         if (addrLocal.IsRoutable()) {
             LogPrint(BCLog::NET, "AdvertiseLocal: advertising address %s\n",
                      addrLocal.ToString());
             FastRandomContext insecure_rand;
             pnode->PushAddress(addrLocal, insecure_rand);
         }
     }
 }
 
 // Learn a new local address.
 bool AddLocal(const CService &addr, int nScore) {
     if (!addr.IsRoutable()) {
         return false;
     }
 
     if (!fDiscover && nScore < LOCAL_MANUAL) {
         return false;
     }
 
     if (IsLimited(addr)) {
         return false;
     }
 
     LogPrintf("AddLocal(%s,%i)\n", addr.ToString(), nScore);
 
     {
         LOCK(cs_mapLocalHost);
         bool fAlready = mapLocalHost.count(addr) > 0;
         LocalServiceInfo &info = mapLocalHost[addr];
         if (!fAlready || nScore >= info.nScore) {
             info.nScore = nScore + (fAlready ? 1 : 0);
             info.nPort = addr.GetPort();
         }
     }
 
     return true;
 }
 
 bool AddLocal(const CNetAddr &addr, int nScore) {
     return AddLocal(CService(addr, GetListenPort()), nScore);
 }
 
 void RemoveLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     LogPrintf("RemoveLocal(%s)\n", addr.ToString());
     mapLocalHost.erase(addr);
 }
 
 /**
  * Make a particular network entirely off-limits (no automatic connects to it).
  */
 void SetLimited(enum Network net, bool fLimited) {
     if (net == NET_UNROUTABLE || net == NET_INTERNAL) {
         return;
     }
     LOCK(cs_mapLocalHost);
     vfLimited[net] = fLimited;
 }
 
 bool IsLimited(enum Network net) {
     LOCK(cs_mapLocalHost);
     return vfLimited[net];
 }
 
 bool IsLimited(const CNetAddr &addr) {
     return IsLimited(addr.GetNetwork());
 }
 
 /** vote for a local address */
 bool SeenLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     if (mapLocalHost.count(addr) == 0) {
         return false;
     }
     mapLocalHost[addr].nScore++;
     return true;
 }
 
 /** check whether a given address is potentially local */
 bool IsLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     return mapLocalHost.count(addr) > 0;
 }
 
 /** check whether a given network is one we can probably connect to */
 bool IsReachable(enum Network net) {
     LOCK(cs_mapLocalHost);
     return !vfLimited[net];
 }
 
 /** check whether a given address is in a network we can probably connect to */
 bool IsReachable(const CNetAddr &addr) {
     enum Network net = addr.GetNetwork();
     return IsReachable(net);
 }
 
 CNode *CConnman::FindNode(const CNetAddr &ip) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (static_cast<CNetAddr>(pnode->addr) == ip) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 CNode *CConnman::FindNode(const CSubNet &subNet) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (subNet.Match(static_cast<CNetAddr>(pnode->addr))) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 CNode *CConnman::FindNode(const std::string &addrName) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (pnode->GetAddrName() == addrName) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 CNode *CConnman::FindNode(const CService &addr) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (static_cast<CService>(pnode->addr) == addr) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 bool CConnman::CheckIncomingNonce(uint64_t nonce) {
     LOCK(cs_vNodes);
     for (const CNode *pnode : vNodes) {
         if (!pnode->fSuccessfullyConnected && !pnode->fInbound &&
             pnode->GetLocalNonce() == nonce)
             return false;
     }
     return true;
 }
 
 /** Get the bind address for a socket as CAddress */
 static CAddress GetBindAddress(SOCKET sock) {
     CAddress addr_bind;
     struct sockaddr_storage sockaddr_bind;
     socklen_t sockaddr_bind_len = sizeof(sockaddr_bind);
     if (sock != INVALID_SOCKET) {
         if (!getsockname(sock, (struct sockaddr *)&sockaddr_bind,
                          &sockaddr_bind_len)) {
             addr_bind.SetSockAddr((const struct sockaddr *)&sockaddr_bind);
         } else {
             LogPrint(BCLog::NET, "Warning: getsockname failed\n");
         }
     }
     return addr_bind;
 }
 
 CNode *CConnman::ConnectNode(CAddress addrConnect, const char *pszDest,
                              bool fCountFailure) {
     if (pszDest == nullptr) {
         if (IsLocal(addrConnect)) {
             return nullptr;
         }
 
         // Look for an existing connection
         CNode *pnode = FindNode(static_cast<CService>(addrConnect));
         if (pnode) {
             LogPrintf("Failed to open new connection, already connected\n");
             return nullptr;
         }
     }
 
     /// debug print
     LogPrint(BCLog::NET, "trying connection %s lastseen=%.1fhrs\n",
              pszDest ? pszDest : addrConnect.ToString(),
              pszDest
                  ? 0.0
                  : (double)(GetAdjustedTime() - addrConnect.nTime) / 3600.0);
 
     // Resolve
     const int default_port = Params().GetDefaultPort();
     if (pszDest) {
         std::vector<CService> resolved;
         if (Lookup(pszDest, resolved, default_port,
                    fNameLookup && !HaveNameProxy(), 256) &&
             !resolved.empty()) {
             addrConnect =
                 CAddress(resolved[GetRand(resolved.size())], NODE_NONE);
             if (!addrConnect.IsValid()) {
                 LogPrint(BCLog::NET,
                          "Resolver returned invalid address %s for %s\n",
                          addrConnect.ToString(), pszDest);
                 return nullptr;
             }
             // It is possible that we already have a connection to the IP/port
             // pszDest resolved to. In that case, drop the connection that was
             // just created, and return the existing CNode instead. Also store
             // the name we used to connect in that CNode, so that future
             // FindNode() calls to that name catch this early.
             LOCK(cs_vNodes);
             CNode *pnode = FindNode(static_cast<CService>(addrConnect));
             if (pnode) {
                 pnode->MaybeSetAddrName(std::string(pszDest));
                 LogPrintf("Failed to open new connection, already connected\n");
                 return nullptr;
             }
         }
     }
 
     // Connect
     bool connected = false;
     SOCKET hSocket = INVALID_SOCKET;
     proxyType proxy;
     if (addrConnect.IsValid()) {
         bool proxyConnectionFailed = false;
 
         if (GetProxy(addrConnect.GetNetwork(), proxy)) {
             hSocket = CreateSocket(proxy.proxy);
             if (hSocket == INVALID_SOCKET) {
                 return nullptr;
             }
             connected = ConnectThroughProxy(
                 proxy, addrConnect.ToStringIP(), addrConnect.GetPort(), hSocket,
                 nConnectTimeout, &proxyConnectionFailed);
         } else {
             // no proxy needed (none set for target network)
             hSocket = CreateSocket(addrConnect);
             if (hSocket == INVALID_SOCKET) {
                 return nullptr;
             }
             connected =
                 ConnectSocketDirectly(addrConnect, hSocket, nConnectTimeout);
         }
         if (!proxyConnectionFailed) {
             // If a connection to the node was attempted, and failure (if any)
             // is not caused by a problem connecting to the proxy, mark this as
             // an attempt.
             addrman.Attempt(addrConnect, fCountFailure);
         }
     } else if (pszDest && GetNameProxy(proxy)) {
         hSocket = CreateSocket(proxy.proxy);
         if (hSocket == INVALID_SOCKET) {
             return nullptr;
         }
         std::string host;
         int port = default_port;
         SplitHostPort(std::string(pszDest), port, host);
         connected = ConnectThroughProxy(proxy, host, port, hSocket,
                                         nConnectTimeout, nullptr);
     }
     if (!connected) {
         CloseSocket(hSocket);
         return nullptr;
     }
 
     // Add node
     NodeId id = GetNewNodeId();
     uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE)
                          .Write(id)
                          .Finalize();
     CAddress addr_bind = GetBindAddress(hSocket);
     CNode *pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket,
                              addrConnect, CalculateKeyedNetGroup(addrConnect),
                              nonce, addr_bind, pszDest ? pszDest : "", false);
     pnode->AddRef();
 
     return pnode;
 }
 
 void CConnman::DumpBanlist() {
     // Clean unused entries (if bantime has expired)
     SweepBanned();
 
     if (!BannedSetIsDirty()) {
         return;
     }
 
     int64_t nStart = GetTimeMillis();
 
     CBanDB bandb(config->GetChainParams());
     banmap_t banmap;
     GetBanned(banmap);
     if (bandb.Write(banmap)) {
         SetBannedSetDirty(false);
     }
 
     LogPrint(BCLog::NET,
              "Flushed %d banned node ips/subnets to banlist.dat  %dms\n",
              banmap.size(), GetTimeMillis() - nStart);
 }
 
 void CNode::CloseSocketDisconnect() {
     fDisconnect = true;
     LOCK(cs_hSocket);
     if (hSocket != INVALID_SOCKET) {
         LogPrint(BCLog::NET, "disconnecting peer=%d\n", id);
         CloseSocket(hSocket);
     }
 }
 
 void CConnman::ClearBanned() {
     {
         LOCK(cs_setBanned);
         setBanned.clear();
         setBannedIsDirty = true;
     }
 
     // Store banlist to disk.
     DumpBanlist();
     if (clientInterface) {
         clientInterface->BannedListChanged();
     }
 }
 
 bool CConnman::IsBanned(CNetAddr ip) {
     LOCK(cs_setBanned);
     for (const auto &it : setBanned) {
         CSubNet subNet = it.first;
         CBanEntry banEntry = it.second;
 
         if (subNet.Match(ip) && GetTime() < banEntry.nBanUntil) {
             return true;
         }
     }
 
     return false;
 }
 
 bool CConnman::IsBanned(CSubNet subnet) {
     LOCK(cs_setBanned);
 
     banmap_t::iterator i = setBanned.find(subnet);
     if (i != setBanned.end()) {
         CBanEntry banEntry = (*i).second;
         if (GetTime() < banEntry.nBanUntil) {
             return true;
         }
     }
 
     return false;
 }
 
 void CConnman::Ban(const CNetAddr &addr, const BanReason &banReason,
                    int64_t bantimeoffset, bool sinceUnixEpoch) {
     CSubNet subNet(addr);
     Ban(subNet, banReason, bantimeoffset, sinceUnixEpoch);
 }
 
 void CConnman::Ban(const CSubNet &subNet, const BanReason &banReason,
                    int64_t bantimeoffset, bool sinceUnixEpoch) {
     CBanEntry banEntry(GetTime());
     banEntry.banReason = banReason;
     if (bantimeoffset <= 0) {
         bantimeoffset = gArgs.GetArg("-bantime", DEFAULT_MISBEHAVING_BANTIME);
         sinceUnixEpoch = false;
     }
     banEntry.nBanUntil = (sinceUnixEpoch ? 0 : GetTime()) + bantimeoffset;
 
     {
         LOCK(cs_setBanned);
         if (setBanned[subNet].nBanUntil < banEntry.nBanUntil) {
             setBanned[subNet] = banEntry;
             setBannedIsDirty = true;
         } else {
             return;
         }
     }
 
     if (clientInterface) {
         clientInterface->BannedListChanged();
     }
 
     {
         LOCK(cs_vNodes);
         for (CNode *pnode : vNodes) {
             if (subNet.Match(static_cast<CNetAddr>(pnode->addr))) {
                 pnode->fDisconnect = true;
             }
         }
     }
 
     if (banReason == BanReasonManuallyAdded) {
         // Store banlist to disk immediately if user requested ban.
         DumpBanlist();
     }
 }
 
 bool CConnman::Unban(const CNetAddr &addr) {
     CSubNet subNet(addr);
     return Unban(subNet);
 }
 
 bool CConnman::Unban(const CSubNet &subNet) {
     {
         LOCK(cs_setBanned);
         if (!setBanned.erase(subNet)) {
             return false;
         }
         setBannedIsDirty = true;
     }
 
     if (clientInterface) {
         clientInterface->BannedListChanged();
     }
 
     // Store banlist to disk immediately.
     DumpBanlist();
     return true;
 }
 
 void CConnman::GetBanned(banmap_t &banMap) {
     LOCK(cs_setBanned);
     // Sweep the banlist so expired bans are not returned
     SweepBanned();
     // Create a thread safe copy.
     banMap = setBanned;
 }
 
 void CConnman::SetBanned(const banmap_t &banMap) {
     LOCK(cs_setBanned);
     setBanned = banMap;
     setBannedIsDirty = true;
 }
 
 void CConnman::SweepBanned() {
     int64_t now = GetTime();
     bool notifyUI = false;
     {
         LOCK(cs_setBanned);
         banmap_t::iterator it = setBanned.begin();
         while (it != setBanned.end()) {
             CSubNet subNet = (*it).first;
             CBanEntry banEntry = (*it).second;
             if (now > banEntry.nBanUntil) {
                 setBanned.erase(it++);
                 setBannedIsDirty = true;
                 notifyUI = true;
                 LogPrint(
                     BCLog::NET,
                     "%s: Removed banned node ip/subnet from banlist.dat: %s\n",
                     __func__, subNet.ToString());
             } else {
                 ++it;
             }
         }
     }
 
     // update UI
     if (notifyUI && clientInterface) {
         clientInterface->BannedListChanged();
     }
 }
 
 bool CConnman::BannedSetIsDirty() {
     LOCK(cs_setBanned);
     return setBannedIsDirty;
 }
 
 void CConnman::SetBannedSetDirty(bool dirty) {
     // Reuse setBanned lock for the isDirty flag.
     LOCK(cs_setBanned);
     setBannedIsDirty = dirty;
 }
 
 bool CConnman::IsWhitelistedRange(const CNetAddr &addr) {
     for (const CSubNet &subnet : vWhitelistedRange) {
         if (subnet.Match(addr)) {
             return true;
         }
     }
     return false;
 }
 
 std::string CNode::GetAddrName() const {
     LOCK(cs_addrName);
     return addrName;
 }
 
 void CNode::MaybeSetAddrName(const std::string &addrNameIn) {
     LOCK(cs_addrName);
     if (addrName.empty()) {
         addrName = addrNameIn;
     }
 }
 
 CService CNode::GetAddrLocal() const {
     LOCK(cs_addrLocal);
     return addrLocal;
 }
 
 void CNode::SetAddrLocal(const CService &addrLocalIn) {
     LOCK(cs_addrLocal);
     if (addrLocal.IsValid()) {
         error("Addr local already set for node: %i. Refusing to change from %s "
               "to %s",
               id, addrLocal.ToString(), addrLocalIn.ToString());
     } else {
         addrLocal = addrLocalIn;
     }
 }
 
 void CNode::copyStats(CNodeStats &stats) {
     stats.nodeid = this->GetId();
     stats.nServices = nServices;
     stats.addr = addr;
     stats.addrBind = addrBind;
     {
         LOCK(cs_filter);
         stats.fRelayTxes = fRelayTxes;
     }
     stats.nLastSend = nLastSend;
     stats.nLastRecv = nLastRecv;
     stats.nTimeConnected = nTimeConnected;
     stats.nTimeOffset = nTimeOffset;
     stats.addrName = GetAddrName();
     stats.nVersion = nVersion;
     {
         LOCK(cs_SubVer);
         stats.cleanSubVer = cleanSubVer;
     }
     stats.fInbound = fInbound;
     stats.m_manual_connection = m_manual_connection;
     stats.nStartingHeight = nStartingHeight;
     {
         LOCK(cs_vSend);
         stats.mapSendBytesPerMsgCmd = mapSendBytesPerMsgCmd;
         stats.nSendBytes = nSendBytes;
     }
     {
         LOCK(cs_vRecv);
         stats.mapRecvBytesPerMsgCmd = mapRecvBytesPerMsgCmd;
         stats.nRecvBytes = nRecvBytes;
     }
     stats.fWhitelisted = fWhitelisted;
 
     // 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.
     int64_t nPingUsecWait = 0;
     if ((0 != nPingNonceSent) && (0 != nPingUsecStart)) {
         nPingUsecWait = GetTimeMicros() - nPingUsecStart;
     }
 
     // Raw ping time is in microseconds, but show it to user as whole seconds
     // (Bitcoin users should be well used to small numbers with many decimal
     // places by now :)
     stats.dPingTime = ((double(nPingUsecTime)) / 1e6);
     stats.dMinPing = ((double(nMinPingUsecTime)) / 1e6);
     stats.dPingWait = ((double(nPingUsecWait)) / 1e6);
 
     // Leave string empty if addrLocal invalid (not filled in yet)
     CService addrLocalUnlocked = GetAddrLocal();
     stats.addrLocal =
         addrLocalUnlocked.IsValid() ? addrLocalUnlocked.ToString() : "";
 }
 
 static bool IsOversizedMessage(const Config &config, const CNetMessage &msg) {
     if (!msg.in_data) {
         // Header only, cannot be oversized.
         return false;
     }
 
     return msg.hdr.IsOversized(config);
 }
 
 bool CNode::ReceiveMsgBytes(const Config &config, const char *pch,
                             uint32_t nBytes, bool &complete) {
     complete = false;
     int64_t nTimeMicros = GetTimeMicros();
     LOCK(cs_vRecv);
     nLastRecv = nTimeMicros / 1000000;
     nRecvBytes += nBytes;
     while (nBytes > 0) {
         // Get current incomplete message, or create a new one.
         if (vRecvMsg.empty() || vRecvMsg.back().complete()) {
             vRecvMsg.push_back(CNetMessage(config.GetChainParams().NetMagic(),
                                            SER_NETWORK, INIT_PROTO_VERSION));
         }
 
         CNetMessage &msg = vRecvMsg.back();
 
         // Absorb network data.
         int handled;
         if (!msg.in_data) {
             handled = msg.readHeader(config, pch, nBytes);
         } else {
             handled = msg.readData(pch, nBytes);
         }
 
         if (handled < 0) {
             return false;
         }
 
         if (IsOversizedMessage(config, msg)) {
             LogPrint(BCLog::NET,
                      "Oversized message from peer=%i, disconnecting\n",
                      GetId());
             return false;
         }
 
         pch += handled;
         nBytes -= handled;
 
         if (msg.complete()) {
             // Store received bytes per message command to prevent a memory DOS,
             // only allow valid commands.
             mapMsgCmdSize::iterator i =
                 mapRecvBytesPerMsgCmd.find(msg.hdr.pchCommand.data());
             if (i == mapRecvBytesPerMsgCmd.end()) {
                 i = mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER);
             }
 
             assert(i != mapRecvBytesPerMsgCmd.end());
             i->second += msg.hdr.nMessageSize + CMessageHeader::HEADER_SIZE;
 
             msg.nTime = nTimeMicros;
             complete = true;
         }
     }
 
     return true;
 }
 
 void CNode::SetSendVersion(int nVersionIn) {
     // Send version may only be changed in the version message, and only one
     // version message is allowed per session. We can therefore treat this value
     // as const and even atomic as long as it's only used once a version message
     // has been successfully processed. Any attempt to set this twice is an
     // error.
     if (nSendVersion != 0) {
         error("Send version already set for node: %i. Refusing to change from "
               "%i to %i",
               id, nSendVersion, nVersionIn);
     } else {
         nSendVersion = nVersionIn;
     }
 }
 
 int CNode::GetSendVersion() const {
     // The send version should always be explicitly set to INIT_PROTO_VERSION
     // rather than using this value until SetSendVersion has been called.
     if (nSendVersion == 0) {
         error("Requesting unset send version for node: %i. Using %i", id,
               INIT_PROTO_VERSION);
         return INIT_PROTO_VERSION;
     }
     return nSendVersion;
 }
 
 int CNetMessage::readHeader(const Config &config, const char *pch,
                             uint32_t nBytes) {
     // copy data to temporary parsing buffer
     uint32_t nRemaining = 24 - nHdrPos;
     uint32_t nCopy = std::min(nRemaining, nBytes);
 
     memcpy(&hdrbuf[nHdrPos], pch, nCopy);
     nHdrPos += nCopy;
 
     // if header incomplete, exit
     if (nHdrPos < 24) {
         return nCopy;
     }
 
     // deserialize to CMessageHeader
     try {
         hdrbuf >> hdr;
     } catch (const std::exception &) {
         return -1;
     }
 
     // Reject oversized messages
     if (hdr.IsOversized(config)) {
         LogPrint(BCLog::NET, "Oversized header detected\n");
         return -1;
     }
 
     // switch state to reading message data
     in_data = true;
 
     return nCopy;
 }
 
 int CNetMessage::readData(const char *pch, uint32_t nBytes) {
     unsigned int nRemaining = hdr.nMessageSize - nDataPos;
     unsigned int nCopy = std::min(nRemaining, nBytes);
 
     if (vRecv.size() < nDataPos + nCopy) {
         // Allocate up to 256 KiB ahead, but never more than the total message
         // size.
         vRecv.resize(std::min(hdr.nMessageSize, nDataPos + nCopy + 256 * 1024));
     }
 
     hasher.Write((const uint8_t *)pch, nCopy);
     memcpy(&vRecv[nDataPos], pch, nCopy);
     nDataPos += nCopy;
 
     return nCopy;
 }
 
 const uint256 &CNetMessage::GetMessageHash() const {
     assert(complete());
     if (data_hash.IsNull()) {
         hasher.Finalize(data_hash.begin());
     }
     return data_hash;
 }
 
 // requires LOCK(cs_vSend)
 size_t CConnman::SocketSendData(CNode *pnode) const {
     AssertLockHeld(pnode->cs_vSend);
     size_t nSentSize = 0;
     size_t nMsgCount = 0;
 
     for (const auto &data : pnode->vSendMsg) {
         assert(data.size() > pnode->nSendOffset);
         int nBytes = 0;
 
         {
             LOCK(pnode->cs_hSocket);
             if (pnode->hSocket == INVALID_SOCKET) {
                 break;
             }
 
             nBytes = send(pnode->hSocket,
                           reinterpret_cast<const char *>(data.data()) +
                               pnode->nSendOffset,
                           data.size() - pnode->nSendOffset,
                           MSG_NOSIGNAL | MSG_DONTWAIT);
         }
 
         if (nBytes == 0) {
             // couldn't send anything at all
             break;
         }
 
         if (nBytes < 0) {
             // error
             int nErr = WSAGetLastError();
             if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE &&
                 nErr != WSAEINTR && nErr != WSAEINPROGRESS) {
                 LogPrintf("socket send error %s\n", NetworkErrorString(nErr));
                 pnode->CloseSocketDisconnect();
             }
 
             break;
         }
 
         assert(nBytes > 0);
         pnode->nLastSend = GetSystemTimeInSeconds();
         pnode->nSendBytes += nBytes;
         pnode->nSendOffset += nBytes;
         nSentSize += nBytes;
         if (pnode->nSendOffset != data.size()) {
             // could not send full message; stop sending more
             break;
         }
 
         pnode->nSendOffset = 0;
         pnode->nSendSize -= data.size();
         pnode->fPauseSend = pnode->nSendSize > nSendBufferMaxSize;
         nMsgCount++;
     }
 
     pnode->vSendMsg.erase(pnode->vSendMsg.begin(),
                           pnode->vSendMsg.begin() + nMsgCount);
 
     if (pnode->vSendMsg.empty()) {
         assert(pnode->nSendOffset == 0);
         assert(pnode->nSendSize == 0);
     }
 
     return nSentSize;
 }
 
 struct NodeEvictionCandidate {
     NodeId id;
     int64_t nTimeConnected;
     int64_t nMinPingUsecTime;
     int64_t nLastBlockTime;
     int64_t nLastTXTime;
     bool fRelevantServices;
     bool fRelayTxes;
     bool fBloomFilter;
     CAddress addr;
     uint64_t nKeyedNetGroup;
 };
 
 static bool ReverseCompareNodeMinPingTime(const NodeEvictionCandidate &a,
                                           const NodeEvictionCandidate &b) {
     return a.nMinPingUsecTime > b.nMinPingUsecTime;
 }
 
 static bool ReverseCompareNodeTimeConnected(const NodeEvictionCandidate &a,
                                             const NodeEvictionCandidate &b) {
     return a.nTimeConnected > b.nTimeConnected;
 }
 
 static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a,
                                  const NodeEvictionCandidate &b) {
     return a.nKeyedNetGroup < b.nKeyedNetGroup;
 }
 
 static bool CompareNodeBlockTime(const NodeEvictionCandidate &a,
                                  const NodeEvictionCandidate &b) {
     // There is a fall-through here because it is common for a node to have many
     // peers which have not yet relayed a block.
     if (a.nLastBlockTime != b.nLastBlockTime) {
         return a.nLastBlockTime < b.nLastBlockTime;
     }
 
     if (a.fRelevantServices != b.fRelevantServices) {
         return b.fRelevantServices;
     }
 
     return a.nTimeConnected > b.nTimeConnected;
 }
 
 static bool CompareNodeTXTime(const NodeEvictionCandidate &a,
                               const NodeEvictionCandidate &b) {
     // There is a fall-through here because it is common for a node to have more
     // than a few peers that have not yet relayed txn.
     if (a.nLastTXTime != b.nLastTXTime) {
         return a.nLastTXTime < b.nLastTXTime;
     }
 
     if (a.fRelayTxes != b.fRelayTxes) {
         return b.fRelayTxes;
     }
 
     if (a.fBloomFilter != b.fBloomFilter) {
         return a.fBloomFilter;
     }
 
     return a.nTimeConnected > b.nTimeConnected;
 }
 
 //! Sort an array by the specified comparator, then erase the last K elements.
 template <typename T, typename Comparator>
 static void EraseLastKElements(std::vector<T> &elements, Comparator comparator,
                                size_t k) {
     std::sort(elements.begin(), elements.end(), comparator);
     size_t eraseSize = std::min(k, elements.size());
     elements.erase(elements.end() - eraseSize, elements.end());
 }
 
 /**
  * Try to find a connection to evict when the node is full.
  * Extreme care must be taken to avoid opening the node to attacker triggered
  * network partitioning.
  * The strategy used here is to protect a small number of peers for each of
  * several distinct characteristics which are difficult to forge. In order to
  * partition a node the attacker must be simultaneously better at all of them
  * than honest peers.
  */
 bool CConnman::AttemptToEvictConnection() {
     std::vector<NodeEvictionCandidate> vEvictionCandidates;
     {
         LOCK(cs_vNodes);
 
         for (CNode *node : vNodes) {
             if (node->fWhitelisted || !node->fInbound || node->fDisconnect) {
                 continue;
             }
             NodeEvictionCandidate candidate = {
                 node->GetId(),
                 node->nTimeConnected,
                 node->nMinPingUsecTime,
                 node->nLastBlockTime,
                 node->nLastTXTime,
                 HasAllDesirableServiceFlags(node->nServices),
                 node->fRelayTxes,
                 node->pfilter != nullptr,
                 node->addr,
                 node->nKeyedNetGroup};
             vEvictionCandidates.push_back(candidate);
         }
     }
 
     // Protect connections with certain characteristics
 
     // Deterministically select 4 peers to protect by netgroup.
     // An attacker cannot predict which netgroups will be protected
     EraseLastKElements(vEvictionCandidates, CompareNetGroupKeyed, 4);
     // Protect the 8 nodes with the lowest minimum ping time.
     // An attacker cannot manipulate this metric without physically moving nodes
     // closer to the target.
     EraseLastKElements(vEvictionCandidates, ReverseCompareNodeMinPingTime, 8);
     // Protect 4 nodes that most recently sent us transactions.
     // An attacker cannot manipulate this metric without performing useful work.
     EraseLastKElements(vEvictionCandidates, CompareNodeTXTime, 4);
     // Protect 4 nodes that most recently sent us blocks.
     // An attacker cannot manipulate this metric without performing useful work.
     EraseLastKElements(vEvictionCandidates, CompareNodeBlockTime, 4);
     // Protect the half of the remaining nodes which have been connected the
     // longest. This replicates the non-eviction implicit behavior, and
     // precludes attacks that start later.
     EraseLastKElements(vEvictionCandidates, ReverseCompareNodeTimeConnected,
                        vEvictionCandidates.size() / 2);
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Identify the network group with the most connections and youngest member.
     // (vEvictionCandidates is already sorted by reverse connect time)
     uint64_t naMostConnections;
     unsigned int nMostConnections = 0;
     int64_t nMostConnectionsTime = 0;
     std::map<uint64_t, std::vector<NodeEvictionCandidate>> mapNetGroupNodes;
     for (const NodeEvictionCandidate &node : vEvictionCandidates) {
         std::vector<NodeEvictionCandidate> &group =
             mapNetGroupNodes[node.nKeyedNetGroup];
         group.push_back(node);
         int64_t grouptime = group[0].nTimeConnected;
         size_t group_size = group.size();
         if (group_size > nMostConnections ||
             (group_size == nMostConnections &&
              grouptime > nMostConnectionsTime)) {
             nMostConnections = group_size;
             nMostConnectionsTime = grouptime;
             naMostConnections = node.nKeyedNetGroup;
         }
     }
 
     // Reduce to the network group with the most connections
     vEvictionCandidates = std::move(mapNetGroupNodes[naMostConnections]);
 
     // Disconnect from the network group with the most connections
     NodeId evicted = vEvictionCandidates.front().id;
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (pnode->GetId() == evicted) {
             pnode->fDisconnect = true;
             return true;
         }
     }
     return false;
 }
 
 void CConnman::AcceptConnection(const ListenSocket &hListenSocket) {
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
     SOCKET hSocket =
         accept(hListenSocket.socket, (struct sockaddr *)&sockaddr, &len);
     CAddress addr;
     int nInbound = 0;
     int nMaxInbound = nMaxConnections - (nMaxOutbound + nMaxFeeler);
 
     if (hSocket != INVALID_SOCKET) {
         if (!addr.SetSockAddr((const struct sockaddr *)&sockaddr)) {
             LogPrintf("Warning: Unknown socket family\n");
         }
     }
 
     bool whitelisted = hListenSocket.whitelisted || IsWhitelistedRange(addr);
     {
         LOCK(cs_vNodes);
         for (const CNode *pnode : vNodes) {
             if (pnode->fInbound) {
                 nInbound++;
             }
         }
     }
 
     if (hSocket == INVALID_SOCKET) {
         int nErr = WSAGetLastError();
         if (nErr != WSAEWOULDBLOCK) {
             LogPrintf("socket error accept failed: %s\n",
                       NetworkErrorString(nErr));
         }
         return;
     }
 
     if (!fNetworkActive) {
         LogPrintf("connection from %s dropped: not accepting new connections\n",
                   addr.ToString());
         CloseSocket(hSocket);
         return;
     }
 
     if (!IsSelectableSocket(hSocket)) {
         LogPrintf("connection from %s dropped: non-selectable socket\n",
                   addr.ToString());
         CloseSocket(hSocket);
         return;
     }
 
     // According to the internet TCP_NODELAY is not carried into accepted
     // sockets on all platforms.  Set it again here just to be sure.
     SetSocketNoDelay(hSocket);
 
     if (IsBanned(addr) && !whitelisted) {
         LogPrint(BCLog::NET, "connection from %s dropped (banned)\n",
                  addr.ToString());
         CloseSocket(hSocket);
         return;
     }
 
     if (nInbound >= nMaxInbound) {
         if (!AttemptToEvictConnection()) {
             // No connection to evict, disconnect the new connection
             LogPrint(BCLog::NET, "failed to find an eviction candidate - "
                                  "connection dropped (full)\n");
             CloseSocket(hSocket);
             return;
         }
     }
 
     NodeId id = GetNewNodeId();
     uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE)
                          .Write(id)
                          .Finalize();
     CAddress addr_bind = GetBindAddress(hSocket);
 
     CNode *pnode =
         new CNode(id, nLocalServices, GetBestHeight(), hSocket, addr,
                   CalculateKeyedNetGroup(addr), nonce, addr_bind, "", true);
     pnode->AddRef();
     pnode->fWhitelisted = whitelisted;
     m_msgproc->InitializeNode(*config, pnode);
 
     LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToString());
 
     {
         LOCK(cs_vNodes);
         vNodes.push_back(pnode);
     }
 }
 
 void CConnman::ThreadSocketHandler() {
     unsigned int nPrevNodeCount = 0;
     while (!interruptNet) {
         //
         // Disconnect nodes
         //
         {
             LOCK(cs_vNodes);
 
             if (!fNetworkActive) {
                 // Disconnect any connected nodes
                 for (CNode *pnode : vNodes) {
                     if (!pnode->fDisconnect) {
                         LogPrint(BCLog::NET,
                                  "Network not active, dropping peer=%d\n",
                                  pnode->GetId());
                         pnode->fDisconnect = true;
                     }
                 }
             }
 
             // Disconnect unused nodes
             std::vector<CNode *> vNodesCopy = vNodes;
             for (CNode *pnode : vNodesCopy) {
                 if (pnode->fDisconnect) {
                     // remove from vNodes
                     vNodes.erase(remove(vNodes.begin(), vNodes.end(), pnode),
                                  vNodes.end());
 
                     // release outbound grant (if any)
                     pnode->grantOutbound.Release();
 
                     // close socket and cleanup
                     pnode->CloseSocketDisconnect();
 
                     // hold in disconnected pool until all refs are released
                     pnode->Release();
                     vNodesDisconnected.push_back(pnode);
                 }
             }
         }
         {
             // Delete disconnected nodes
             std::list<CNode *> vNodesDisconnectedCopy = vNodesDisconnected;
             for (CNode *pnode : vNodesDisconnectedCopy) {
                 // wait until threads are done using it
                 if (pnode->GetRefCount() <= 0) {
                     bool fDelete = false;
                     {
                         TRY_LOCK(pnode->cs_inventory, lockInv);
                         if (lockInv) {
                             TRY_LOCK(pnode->cs_vSend, lockSend);
                             if (lockSend) {
                                 fDelete = true;
                             }
                         }
                     }
                     if (fDelete) {
                         vNodesDisconnected.remove(pnode);
                         DeleteNode(pnode);
                     }
                 }
             }
         }
         size_t vNodesSize;
         {
             LOCK(cs_vNodes);
             vNodesSize = vNodes.size();
         }
         if (vNodesSize != nPrevNodeCount) {
             nPrevNodeCount = vNodesSize;
             if (clientInterface) {
                 clientInterface->NotifyNumConnectionsChanged(nPrevNodeCount);
             }
         }
 
         //
         // Find which sockets have data to receive
         //
         struct timeval timeout;
         timeout.tv_sec = 0;
         // Frequency to poll pnode->vSend
         timeout.tv_usec = 50000;
 
         fd_set fdsetRecv;
         fd_set fdsetSend;
         fd_set fdsetError;
         FD_ZERO(&fdsetRecv);
         FD_ZERO(&fdsetSend);
         FD_ZERO(&fdsetError);
         SOCKET hSocketMax = 0;
         bool have_fds = false;
 
         for (const ListenSocket &hListenSocket : vhListenSocket) {
             FD_SET(hListenSocket.socket, &fdsetRecv);
             hSocketMax = std::max(hSocketMax, hListenSocket.socket);
             have_fds = true;
         }
 
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodes) {
                 // Implement the following logic:
                 // * If there is data to send, select() for sending data. As
                 // this only happens when optimistic write failed, we choose to
                 // first drain the write buffer in this case before receiving
                 // more. This avoids needlessly queueing received data, if the
                 // remote peer is not themselves receiving data. This means
                 // properly utilizing TCP flow control signalling.
                 // * Otherwise, if there is space left in the receive buffer,
                 // select() for receiving data.
                 // * Hand off all complete messages to the processor, to be
                 // handled without blocking here.
 
                 bool select_recv = !pnode->fPauseRecv;
                 bool select_send;
                 {
                     LOCK(pnode->cs_vSend);
                     select_send = !pnode->vSendMsg.empty();
                 }
 
                 LOCK(pnode->cs_hSocket);
                 if (pnode->hSocket == INVALID_SOCKET) {
                     continue;
                 }
 
                 FD_SET(pnode->hSocket, &fdsetError);
                 hSocketMax = std::max(hSocketMax, pnode->hSocket);
                 have_fds = true;
 
                 if (select_send) {
                     FD_SET(pnode->hSocket, &fdsetSend);
                     continue;
                 }
                 if (select_recv) {
                     FD_SET(pnode->hSocket, &fdsetRecv);
                 }
             }
         }
 
         int nSelect = select(have_fds ? hSocketMax + 1 : 0, &fdsetRecv,
                              &fdsetSend, &fdsetError, &timeout);
         if (interruptNet) {
             return;
         }
 
         if (nSelect == SOCKET_ERROR) {
             if (have_fds) {
                 int nErr = WSAGetLastError();
                 LogPrintf("socket select error %s\n", NetworkErrorString(nErr));
                 for (unsigned int i = 0; i <= hSocketMax; i++) {
                     FD_SET(i, &fdsetRecv);
                 }
             }
             FD_ZERO(&fdsetSend);
             FD_ZERO(&fdsetError);
             if (!interruptNet.sleep_for(
                     std::chrono::milliseconds(timeout.tv_usec / 1000))) {
                 return;
             }
         }
 
         //
         // Accept new connections
         //
         for (const ListenSocket &hListenSocket : vhListenSocket) {
             if (hListenSocket.socket != INVALID_SOCKET &&
                 FD_ISSET(hListenSocket.socket, &fdsetRecv)) {
                 AcceptConnection(hListenSocket);
             }
         }
 
         //
         // Service each socket
         //
         std::vector<CNode *> vNodesCopy;
         {
             LOCK(cs_vNodes);
             vNodesCopy = vNodes;
             for (CNode *pnode : vNodesCopy) {
                 pnode->AddRef();
             }
         }
         for (CNode *pnode : vNodesCopy) {
             if (interruptNet) {
                 return;
             }
 
             //
             // Receive
             //
             bool recvSet = false;
             bool sendSet = false;
             bool errorSet = false;
             {
                 LOCK(pnode->cs_hSocket);
                 if (pnode->hSocket == INVALID_SOCKET) {
                     continue;
                 }
                 recvSet = FD_ISSET(pnode->hSocket, &fdsetRecv);
                 sendSet = FD_ISSET(pnode->hSocket, &fdsetSend);
                 errorSet = FD_ISSET(pnode->hSocket, &fdsetError);
             }
             if (recvSet || errorSet) {
                 // typical socket buffer is 8K-64K
                 char pchBuf[0x10000];
                 int32_t nBytes = 0;
                 {
                     LOCK(pnode->cs_hSocket);
                     if (pnode->hSocket == INVALID_SOCKET) {
                         continue;
                     }
                     nBytes = recv(pnode->hSocket, pchBuf, sizeof(pchBuf),
                                   MSG_DONTWAIT);
                 }
                 if (nBytes > 0) {
                     bool notify = false;
                     if (!pnode->ReceiveMsgBytes(*config, pchBuf, nBytes,
                                                 notify)) {
                         pnode->CloseSocketDisconnect();
                     }
                     RecordBytesRecv(nBytes);
                     if (notify) {
                         size_t nSizeAdded = 0;
                         auto it(pnode->vRecvMsg.begin());
                         for (; it != pnode->vRecvMsg.end(); ++it) {
                             if (!it->complete()) {
                                 break;
                             }
                             nSizeAdded +=
                                 it->vRecv.size() + CMessageHeader::HEADER_SIZE;
                         }
                         {
                             LOCK(pnode->cs_vProcessMsg);
                             pnode->vProcessMsg.splice(
                                 pnode->vProcessMsg.end(), pnode->vRecvMsg,
                                 pnode->vRecvMsg.begin(), it);
                             pnode->nProcessQueueSize += nSizeAdded;
                             pnode->fPauseRecv =
                                 pnode->nProcessQueueSize > nReceiveFloodSize;
                         }
                         WakeMessageHandler();
                     }
                 } else if (nBytes == 0) {
                     // socket closed gracefully
                     if (!pnode->fDisconnect) {
                         LogPrint(BCLog::NET, "socket closed\n");
                     }
                     pnode->CloseSocketDisconnect();
                 } else if (nBytes < 0) {
                     // error
                     int nErr = WSAGetLastError();
                     if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE &&
                         nErr != WSAEINTR && nErr != WSAEINPROGRESS) {
                         if (!pnode->fDisconnect) {
                             LogPrintf("socket recv error %s\n",
                                       NetworkErrorString(nErr));
                         }
                         pnode->CloseSocketDisconnect();
                     }
                 }
             }
 
             //
             // Send
             //
             if (sendSet) {
                 LOCK(pnode->cs_vSend);
                 size_t nBytes = SocketSendData(pnode);
                 if (nBytes) {
                     RecordBytesSent(nBytes);
                 }
             }
 
             //
             // Inactivity checking
             //
             int64_t nTime = GetSystemTimeInSeconds();
             if (nTime - pnode->nTimeConnected > 60) {
                 if (pnode->nLastRecv == 0 || pnode->nLastSend == 0) {
                     LogPrint(BCLog::NET, "socket no message in first 60 "
                                          "seconds, %d %d from %d\n",
                              pnode->nLastRecv != 0, pnode->nLastSend != 0,
                              pnode->GetId());
                     pnode->fDisconnect = true;
                 } else if (nTime - pnode->nLastSend > TIMEOUT_INTERVAL) {
                     LogPrintf("socket sending timeout: %is\n",
                               nTime - pnode->nLastSend);
                     pnode->fDisconnect = true;
                 } else if (nTime - pnode->nLastRecv >
                            (pnode->nVersion > BIP0031_VERSION ? TIMEOUT_INTERVAL
                                                               : 90 * 60)) {
                     LogPrintf("socket receive timeout: %is\n",
                               nTime - pnode->nLastRecv);
                     pnode->fDisconnect = true;
                 } else if (pnode->nPingNonceSent &&
                            pnode->nPingUsecStart + TIMEOUT_INTERVAL * 1000000 <
                                GetTimeMicros()) {
                     LogPrintf("ping timeout: %fs\n",
                               0.000001 *
                                   (GetTimeMicros() - pnode->nPingUsecStart));
                     pnode->fDisconnect = true;
                 } else if (!pnode->fSuccessfullyConnected) {
                     LogPrint(BCLog::NET, "version handshake timeout from %d\n",
                              pnode->GetId());
                     pnode->fDisconnect = true;
                 }
             }
         }
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodesCopy) {
                 pnode->Release();
             }
         }
     }
 }
 
 void CConnman::WakeMessageHandler() {
     {
         std::lock_guard<std::mutex> lock(mutexMsgProc);
         fMsgProcWake = true;
     }
     condMsgProc.notify_one();
 }
 
 #ifdef USE_UPNP
 static CThreadInterrupt g_upnp_interrupt;
 static std::thread g_upnp_thread;
 static void ThreadMapPort() {
     std::string port = strprintf("%u", GetListenPort());
     const char *multicastif = nullptr;
     const char *minissdpdpath = nullptr;
     struct UPNPDev *devlist = nullptr;
     char lanaddr[64];
 
 #ifndef UPNPDISCOVER_SUCCESS
     /* miniupnpc 1.5 */
     devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0);
 #elif MINIUPNPC_API_VERSION < 14
     /* miniupnpc 1.6 */
     int error = 0;
     devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0, 0, &error);
 #else
     /* miniupnpc 1.9.20150730 */
     int error = 0;
     devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0, 0, 2, &error);
 #endif
 
     struct UPNPUrls urls;
     struct IGDdatas data;
     int r;
 
     r = UPNP_GetValidIGD(devlist, &urls, &data, lanaddr, sizeof(lanaddr));
     if (r == 1) {
         if (fDiscover) {
             char externalIPAddress[40];
             r = UPNP_GetExternalIPAddress(
                 urls.controlURL, data.first.servicetype, externalIPAddress);
             if (r != UPNPCOMMAND_SUCCESS) {
                 LogPrintf("UPnP: GetExternalIPAddress() returned %d\n", r);
             } else {
                 if (externalIPAddress[0]) {
                     CNetAddr resolved;
                     if (LookupHost(externalIPAddress, resolved, false)) {
                         LogPrintf("UPnP: ExternalIPAddress = %s\n",
                                   resolved.ToString().c_str());
                         AddLocal(resolved, LOCAL_UPNP);
                     }
                 } else {
                     LogPrintf("UPnP: GetExternalIPAddress failed.\n");
                 }
             }
         }
 
         std::string strDesc = "Bitcoin " + FormatFullVersion();
 
         do {
 #ifndef UPNPDISCOVER_SUCCESS
             /* miniupnpc 1.5 */
             r = UPNP_AddPortMapping(urls.controlURL, data.first.servicetype,
                                     port.c_str(), port.c_str(), lanaddr,
                                     strDesc.c_str(), "TCP", 0);
 #else
             /* miniupnpc 1.6 */
             r = UPNP_AddPortMapping(urls.controlURL, data.first.servicetype,
                                     port.c_str(), port.c_str(), lanaddr,
                                     strDesc.c_str(), "TCP", 0, "0");
 #endif
 
             if (r != UPNPCOMMAND_SUCCESS) {
                 LogPrintf(
                     "AddPortMapping(%s, %s, %s) failed with code %d (%s)\n",
                     port, port, lanaddr, r, strupnperror(r));
             } else {
                 LogPrintf("UPnP Port Mapping successful.\n");
             }
         } while (g_upnp_interrupt.sleep_for(std::chrono::minutes(20)));
 
         r = UPNP_DeletePortMapping(urls.controlURL, data.first.servicetype,
                                    port.c_str(), "TCP", 0);
         LogPrintf("UPNP_DeletePortMapping() returned: %d\n", r);
         freeUPNPDevlist(devlist);
         devlist = nullptr;
         FreeUPNPUrls(&urls);
     } else {
         LogPrintf("No valid UPnP IGDs found\n");
         freeUPNPDevlist(devlist);
         devlist = nullptr;
         if (r != 0) {
             FreeUPNPUrls(&urls);
         }
     }
 }
 
 void StartMapPort() {
     if (!g_upnp_thread.joinable()) {
         assert(!g_upnp_interrupt);
         g_upnp_thread = std::thread(
             (std::bind(&TraceThread<void (*)()>, "upnp", &ThreadMapPort)));
     }
 }
 
 void InterruptMapPort() {
     if (g_upnp_thread.joinable()) {
         g_upnp_interrupt();
     }
 }
 
 void StopMapPort() {
     if (g_upnp_thread.joinable()) {
         g_upnp_thread.join();
         g_upnp_interrupt.reset();
     }
 }
 
 #else
 void StartMapPort() {
     // Intentionally left blank.
 }
 void InterruptMapPort() {
     // Intentionally left blank.
 }
 void StopMapPort() {
     // Intentionally left blank.
 }
 #endif
 
 void CConnman::ThreadDNSAddressSeed() {
     // goal: only query DNS seeds if address need is acute.
     // Avoiding DNS seeds when we don't need them improves user privacy by
     // creating fewer identifying DNS requests, reduces trust by giving seeds
     // less influence on the network topology, and reduces traffic to the seeds.
     if ((addrman.size() > 0) &&
         (!gArgs.GetBoolArg("-forcednsseed", DEFAULT_FORCEDNSSEED))) {
         if (!interruptNet.sleep_for(std::chrono::seconds(11))) {
             return;
         }
 
         LOCK(cs_vNodes);
         int nRelevant = 0;
         for (const CNode *pnode : vNodes) {
             nRelevant += pnode->fSuccessfullyConnected && !pnode->fFeeler &&
                          !pnode->fOneShot && !pnode->m_manual_connection &&
                          !pnode->fInbound;
         }
         if (nRelevant >= 2) {
             LogPrintf("P2P peers available. Skipped DNS seeding.\n");
             return;
         }
     }
 
     const std::vector<std::string> &vSeeds =
         config->GetChainParams().DNSSeeds();
     int found = 0;
 
     LogPrintf("Loading addresses from DNS seeds (could take a while)\n");
 
     for (const std::string &seed : vSeeds) {
         if (interruptNet) {
             return;
         }
         if (HaveNameProxy()) {
             AddOneShot(seed);
         } else {
             std::vector<CNetAddr> vIPs;
             std::vector<CAddress> vAdd;
             ServiceFlags requiredServiceBits =
                 GetDesirableServiceFlags(NODE_NONE);
             std::string host = strprintf("x%x.%s", requiredServiceBits, seed);
             CNetAddr resolveSource;
             if (!resolveSource.SetInternal(host)) {
                 continue;
             }
 
             // Limits number of IPs learned from a DNS seed
             unsigned int nMaxIPs = 256;
             if (LookupHost(host.c_str(), vIPs, nMaxIPs, true)) {
                 for (const CNetAddr &ip : vIPs) {
                     int nOneDay = 24 * 3600;
                     CAddress addr = CAddress(
                         CService(ip, config->GetChainParams().GetDefaultPort()),
                         requiredServiceBits);
                     // Use a random age between 3 and 7 days old.
                     addr.nTime = GetTime() - 3 * nOneDay - GetRand(4 * nOneDay);
                     vAdd.push_back(addr);
                     found++;
                 }
                 addrman.Add(vAdd, resolveSource);
             } else {
                 // We now avoid directly using results from DNS Seeds which do
                 // not support service bit filtering, instead using them as a
                 // oneshot to get nodes with our desired service bits.
                 AddOneShot(seed);
             }
         }
     }
 
     LogPrintf("%d addresses found from DNS seeds\n", found);
 }
 
 void CConnman::DumpAddresses() {
     int64_t nStart = GetTimeMillis();
 
     CAddrDB adb(config->GetChainParams());
     adb.Write(addrman);
 
     LogPrint(BCLog::NET, "Flushed %d addresses to peers.dat  %dms\n",
              addrman.size(), GetTimeMillis() - nStart);
 }
 
 void CConnman::DumpData() {
     DumpAddresses();
     DumpBanlist();
 }
 
 void CConnman::ProcessOneShot() {
     std::string strDest;
     {
         LOCK(cs_vOneShots);
         if (vOneShots.empty()) {
             return;
         }
         strDest = vOneShots.front();
         vOneShots.pop_front();
     }
     CAddress addr;
     CSemaphoreGrant grant(*semOutbound, true);
     if (grant) {
         OpenNetworkConnection(addr, false, &grant, strDest.c_str(), true);
     }
 }
 
 bool CConnman::GetTryNewOutboundPeer() {
     return m_try_another_outbound_peer;
 }
 
 void CConnman::SetTryNewOutboundPeer(bool flag) {
     m_try_another_outbound_peer = flag;
     LogPrint(BCLog::NET, "net: setting try another outbound peer=%s\n",
              flag ? "true" : "false");
 }
 
 // Return the number of peers we have over our outbound connection limit.
 // Exclude peers that are marked for disconnect, or are going to be disconnected
 // soon (eg one-shots and feelers).
 // Also exclude peers that haven't finished initial connection handshake yet (so
 // that we don't decide we're over our desired connection limit, and then evict
 // some peer that has finished the handshake).
 int CConnman::GetExtraOutboundCount() {
     int nOutbound = 0;
     {
         LOCK(cs_vNodes);
         for (const CNode *pnode : vNodes) {
             if (!pnode->fInbound && !pnode->m_manual_connection &&
                 !pnode->fFeeler && !pnode->fDisconnect && !pnode->fOneShot &&
                 pnode->fSuccessfullyConnected) {
                 ++nOutbound;
             }
         }
     }
     return std::max(nOutbound - nMaxOutbound, 0);
 }
 
 void CConnman::ThreadOpenConnections(const std::vector<std::string> connect) {
     // Connect to specific addresses
     if (!connect.empty()) {
         for (int64_t nLoop = 0;; nLoop++) {
             ProcessOneShot();
             for (const std::string &strAddr : connect) {
                 CAddress addr(CService(), NODE_NONE);
                 OpenNetworkConnection(addr, false, nullptr, strAddr.c_str(),
                                       false, false, true);
                 for (int i = 0; i < 10 && i < nLoop; i++) {
                     if (!interruptNet.sleep_for(
                             std::chrono::milliseconds(500))) {
                         return;
                     }
                 }
             }
             if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) {
                 return;
             }
         }
     }
 
     // Initiate network connections
     int64_t nStart = GetTime();
 
     // Minimum time before next feeler connection (in microseconds).
     int64_t nNextFeeler =
         PoissonNextSend(nStart * 1000 * 1000, FEELER_INTERVAL);
     while (!interruptNet) {
         ProcessOneShot();
 
         if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) {
             return;
         }
 
         CSemaphoreGrant grant(*semOutbound);
         if (interruptNet) {
             return;
         }
 
         // Add seed nodes if DNS seeds are all down (an infrastructure attack?).
         if (addrman.size() == 0 && (GetTime() - nStart > 60)) {
             static bool done = false;
             if (!done) {
                 LogPrintf("Adding fixed seed nodes as DNS doesn't seem to be "
                           "available.\n");
                 CNetAddr local;
                 local.SetInternal("fixedseeds");
                 addrman.Add(convertSeed6(config->GetChainParams().FixedSeeds()),
                             local);
                 done = true;
             }
         }
 
         //
         // Choose an address to connect to based on most recently seen
         //
         CAddress addrConnect;
 
         // Only connect out to one peer per network group (/16 for IPv4). Do
         // this here so we don't have to critsect vNodes inside mapAddresses
         // critsect.
         int nOutbound = 0;
         std::set<std::vector<uint8_t>> setConnected;
         {
             LOCK(cs_vNodes);
             for (const CNode *pnode : vNodes) {
                 if (!pnode->fInbound && !pnode->m_manual_connection) {
                     // Netgroups for inbound and addnode peers are not excluded
                     // because our goal here is to not use multiple of our
                     // limited outbound slots on a single netgroup but inbound
                     // and addnode peers do not use our outbound slots. Inbound
                     // peers also have the added issue that they're attacker
                     // controlled and could be used to prevent us from
                     // connecting to particular hosts if we used them here.
                     setConnected.insert(pnode->addr.GetGroup());
                     nOutbound++;
                 }
             }
         }
 
         // Feeler Connections
         //
         // Design goals:
         //  * Increase the number of connectable addresses in the tried table.
         //
         // Method:
         //  * Choose a random address from new and attempt to connect to it if
         //    we can connect successfully it is added to tried.
         //  * Start attempting feeler connections only after node finishes
         //    making outbound connections.
         //  * Only make a feeler connection once every few minutes.
         //
         bool fFeeler = false;
 
         if (nOutbound >= nMaxOutbound && !GetTryNewOutboundPeer()) {
             // The current time right now (in microseconds).
             int64_t nTime = GetTimeMicros();
             if (nTime > nNextFeeler) {
                 nNextFeeler = PoissonNextSend(nTime, FEELER_INTERVAL);
                 fFeeler = true;
             } else {
                 continue;
             }
         }
 
         addrman.ResolveCollisions();
 
         int64_t nANow = GetAdjustedTime();
         int nTries = 0;
         while (!interruptNet) {
             CAddrInfo addr = addrman.SelectTriedCollision();
 
             // SelectTriedCollision returns an invalid address if it is empty.
             if (!fFeeler || !addr.IsValid()) {
                 addr = addrman.Select(fFeeler);
             }
 
             // if we selected an invalid address, restart
             if (!addr.IsValid() || setConnected.count(addr.GetGroup()) ||
                 IsLocal(addr)) {
                 break;
             }
 
             // If we didn't find an appropriate destination after trying 100
             // addresses fetched from addrman, stop this loop, and let the outer
             // loop run again (which sleeps, adds seed nodes, recalculates
             // already-connected network ranges, ...) before trying new addrman
             // addresses.
             nTries++;
             if (nTries > 100) {
                 break;
             }
 
             if (IsLimited(addr)) {
                 continue;
             }
 
             // only consider very recently tried nodes after 30 failed attempts
             if (nANow - addr.nLastTry < 600 && nTries < 30) {
                 continue;
             }
 
             // for non-feelers, require all the services we'll want,
             // for feelers, only require they be a full node (only because most
             // SPV clients don't have a good address DB available)
             if (!fFeeler && !HasAllDesirableServiceFlags(addr.nServices)) {
                 continue;
             }
 
             if (fFeeler && !MayHaveUsefulAddressDB(addr.nServices)) {
                 continue;
             }
 
             // do not allow non-default ports, unless after 50 invalid addresses
             // selected already.
             if (addr.GetPort() != config->GetChainParams().GetDefaultPort() &&
                 nTries < 50) {
                 continue;
             }
 
             addrConnect = addr;
             break;
         }
 
         if (addrConnect.IsValid()) {
 
             if (fFeeler) {
                 // Add small amount of random noise before connection to avoid
                 // synchronization.
                 int randsleep = GetRandInt(FEELER_SLEEP_WINDOW * 1000);
                 if (!interruptNet.sleep_for(
                         std::chrono::milliseconds(randsleep))) {
                     return;
                 }
                 LogPrint(BCLog::NET, "Making feeler connection to %s\n",
                          addrConnect.ToString());
             }
 
             OpenNetworkConnection(addrConnect,
                                   (int)setConnected.size() >=
                                       std::min(nMaxConnections - 1, 2),
                                   &grant, nullptr, false, fFeeler);
         }
     }
 }
 
 std::vector<AddedNodeInfo> CConnman::GetAddedNodeInfo() {
     std::vector<AddedNodeInfo> ret;
 
     std::list<std::string> lAddresses(0);
     {
         LOCK(cs_vAddedNodes);
         ret.reserve(vAddedNodes.size());
         std::copy(vAddedNodes.cbegin(), vAddedNodes.cend(),
                   std::back_inserter(lAddresses));
     }
 
     // Build a map of all already connected addresses (by IP:port and by name)
     // to inbound/outbound and resolved CService
     std::map<CService, bool> mapConnected;
     std::map<std::string, std::pair<bool, CService>> mapConnectedByName;
     {
         LOCK(cs_vNodes);
         for (const CNode *pnode : vNodes) {
             if (pnode->addr.IsValid()) {
                 mapConnected[pnode->addr] = pnode->fInbound;
             }
             std::string addrName = pnode->GetAddrName();
             if (!addrName.empty()) {
                 mapConnectedByName[std::move(addrName)] =
                     std::make_pair(pnode->fInbound,
                                    static_cast<const CService &>(pnode->addr));
             }
         }
     }
 
     for (const std::string &strAddNode : lAddresses) {
         CService service(
             LookupNumeric(strAddNode.c_str(), Params().GetDefaultPort()));
         AddedNodeInfo addedNode{strAddNode, CService(), false, false};
         if (service.IsValid()) {
             // strAddNode is an IP:port
             auto it = mapConnected.find(service);
             if (it != mapConnected.end()) {
                 addedNode.resolvedAddress = service;
                 addedNode.fConnected = true;
                 addedNode.fInbound = it->second;
             }
         } else {
             // strAddNode is a name
             auto it = mapConnectedByName.find(strAddNode);
             if (it != mapConnectedByName.end()) {
                 addedNode.resolvedAddress = it->second.second;
                 addedNode.fConnected = true;
                 addedNode.fInbound = it->second.first;
             }
         }
         ret.emplace_back(std::move(addedNode));
     }
 
     return ret;
 }
 
 void CConnman::ThreadOpenAddedConnections() {
     while (true) {
         CSemaphoreGrant grant(*semAddnode);
         std::vector<AddedNodeInfo> vInfo = GetAddedNodeInfo();
         bool tried = false;
         for (const AddedNodeInfo &info : vInfo) {
             if (!info.fConnected) {
                 if (!grant.TryAcquire()) {
                     // If we've used up our semaphore and need a new one, lets
                     // not wait here since while we are waiting the
                     // addednodeinfo state might change.
                     break;
                 }
                 tried = true;
                 CAddress addr(CService(), NODE_NONE);
                 OpenNetworkConnection(addr, false, &grant,
                                       info.strAddedNode.c_str(), false, false,
                                       true);
                 if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) {
                     return;
                 }
             }
         }
         // Retry every 60 seconds if a connection was attempted, otherwise two
         // seconds.
         if (!interruptNet.sleep_for(std::chrono::seconds(tried ? 60 : 2))) {
             return;
         }
     }
 }
 
 // If successful, this moves the passed grant to the constructed node.
 void CConnman::OpenNetworkConnection(const CAddress &addrConnect,
                                      bool fCountFailure,
                                      CSemaphoreGrant *grantOutbound,
                                      const char *pszDest, bool fOneShot,
                                      bool fFeeler, bool manual_connection) {
     //
     // Initiate outbound network connection
     //
     if (interruptNet) {
         return;
     }
     if (!fNetworkActive) {
         return;
     }
     if (!pszDest) {
         if (IsLocal(addrConnect) || FindNode((CNetAddr)addrConnect) ||
             IsBanned(addrConnect) || FindNode(addrConnect.ToStringIPPort())) {
             return;
         }
     } else if (FindNode(std::string(pszDest))) {
         return;
     }
 
     CNode *pnode = ConnectNode(addrConnect, pszDest, fCountFailure);
 
     if (!pnode) {
         return;
     }
     if (grantOutbound) {
         grantOutbound->MoveTo(pnode->grantOutbound);
     }
     if (fOneShot) {
         pnode->fOneShot = true;
     }
     if (fFeeler) {
         pnode->fFeeler = true;
     }
     if (manual_connection) {
         pnode->m_manual_connection = true;
     }
 
     m_msgproc->InitializeNode(*config, pnode);
     {
         LOCK(cs_vNodes);
         vNodes.push_back(pnode);
     }
 }
 
 void CConnman::ThreadMessageHandler() {
     while (!flagInterruptMsgProc) {
         std::vector<CNode *> vNodesCopy;
         {
             LOCK(cs_vNodes);
             vNodesCopy = vNodes;
             for (CNode *pnode : vNodesCopy) {
                 pnode->AddRef();
             }
         }
 
         bool fMoreWork = false;
 
         for (CNode *pnode : vNodesCopy) {
             if (pnode->fDisconnect) {
                 continue;
             }
 
             // Receive messages
             bool fMoreNodeWork = m_msgproc->ProcessMessages(
                 *config, pnode, flagInterruptMsgProc);
             fMoreWork |= (fMoreNodeWork && !pnode->fPauseSend);
             if (flagInterruptMsgProc) {
                 return;
             }
 
             // Send messages
             {
                 LOCK(pnode->cs_sendProcessing);
                 m_msgproc->SendMessages(*config, pnode, flagInterruptMsgProc);
             }
 
             if (flagInterruptMsgProc) {
                 return;
             }
         }
 
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodesCopy) {
                 pnode->Release();
             }
         }
 
         WAIT_LOCK(mutexMsgProc, lock);
         if (!fMoreWork) {
             condMsgProc.wait_until(lock,
                                    std::chrono::steady_clock::now() +
                                        std::chrono::milliseconds(100),
                                    [this] { return fMsgProcWake; });
         }
         fMsgProcWake = false;
     }
 }
 
 bool CConnman::BindListenPort(const CService &addrBind, std::string &strError,
                               bool fWhitelisted) {
     strError = "";
     int nOne = 1;
 
     // Create socket for listening for incoming connections
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
     if (!addrBind.GetSockAddr((struct sockaddr *)&sockaddr, &len)) {
         strError = strprintf("Error: Bind address family for %s not supported",
                              addrBind.ToString());
         LogPrintf("%s\n", strError);
         return false;
     }
 
     SOCKET hListenSocket = CreateSocket(addrBind);
     if (hListenSocket == INVALID_SOCKET) {
         strError = strprintf("Error: Couldn't open socket for incoming "
                              "connections (socket returned error %s)",
                              NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }
 
     // Allow binding if the port is still in TIME_WAIT state after
     // the program was closed and restarted.
     setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (sockopt_arg_type)&nOne,
                sizeof(int));
 
     // Some systems don't have IPV6_V6ONLY but are always v6only; others do have
     // the option and enable it by default or not. Try to enable it, if
     // possible.
     if (addrBind.IsIPv6()) {
 #ifdef IPV6_V6ONLY
         setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_V6ONLY,
                    (sockopt_arg_type)&nOne, sizeof(int));
 #endif
 #ifdef WIN32
         int nProtLevel = PROTECTION_LEVEL_UNRESTRICTED;
         setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_PROTECTION_LEVEL,
                    (sockopt_arg_type)&nProtLevel, sizeof(int));
 #endif
     }
 
     if (::bind(hListenSocket, (struct sockaddr *)&sockaddr, len) ==
         SOCKET_ERROR) {
         int nErr = WSAGetLastError();
         if (nErr == WSAEADDRINUSE) {
             strError = strprintf(_("Unable to bind to %s on this computer. %s "
                                    "is probably already running."),
                                  addrBind.ToString(), _(PACKAGE_NAME));
         } else {
             strError = strprintf(_("Unable to bind to %s on this computer "
                                    "(bind returned error %s)"),
                                  addrBind.ToString(), NetworkErrorString(nErr));
         }
         LogPrintf("%s\n", strError);
         CloseSocket(hListenSocket);
         return false;
     }
     LogPrintf("Bound to %s\n", addrBind.ToString());
 
     // Listen for incoming connections
     if (listen(hListenSocket, SOMAXCONN) == SOCKET_ERROR) {
         strError = strprintf(_("Error: Listening for incoming connections "
                                "failed (listen returned error %s)"),
                              NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         CloseSocket(hListenSocket);
         return false;
     }
 
     vhListenSocket.push_back(ListenSocket(hListenSocket, fWhitelisted));
 
     if (addrBind.IsRoutable() && fDiscover && !fWhitelisted) {
         AddLocal(addrBind, LOCAL_BIND);
     }
 
     return true;
 }
 
 void Discover() {
     if (!fDiscover) {
         return;
     }
 
 #ifdef WIN32
     // Get local host IP
     char pszHostName[256] = "";
     if (gethostname(pszHostName, sizeof(pszHostName)) != SOCKET_ERROR) {
         std::vector<CNetAddr> vaddr;
         if (LookupHost(pszHostName, vaddr, 0, true)) {
             for (const CNetAddr &addr : vaddr) {
                 if (AddLocal(addr, LOCAL_IF)) {
                     LogPrintf("%s: %s - %s\n", __func__, pszHostName,
                               addr.ToString());
                 }
             }
         }
     }
 #else
     // Get local host ip
     struct ifaddrs *myaddrs;
     if (getifaddrs(&myaddrs) == 0) {
         for (struct ifaddrs *ifa = myaddrs; ifa != nullptr;
              ifa = ifa->ifa_next) {
             if (ifa->ifa_addr == nullptr || (ifa->ifa_flags & IFF_UP) == 0 ||
                 strcmp(ifa->ifa_name, "lo") == 0 ||
                 strcmp(ifa->ifa_name, "lo0") == 0) {
                 continue;
             }
             if (ifa->ifa_addr->sa_family == AF_INET) {
                 struct sockaddr_in *s4 = (struct sockaddr_in *)(ifa->ifa_addr);
                 CNetAddr addr(s4->sin_addr);
                 if (AddLocal(addr, LOCAL_IF)) {
                     LogPrintf("%s: IPv4 %s: %s\n", __func__, ifa->ifa_name,
                               addr.ToString());
                 }
             } else if (ifa->ifa_addr->sa_family == AF_INET6) {
                 struct sockaddr_in6 *s6 =
                     (struct sockaddr_in6 *)(ifa->ifa_addr);
                 CNetAddr addr(s6->sin6_addr);
                 if (AddLocal(addr, LOCAL_IF)) {
                     LogPrintf("%s: IPv6 %s: %s\n", __func__, ifa->ifa_name,
                               addr.ToString());
                 }
             }
         }
         freeifaddrs(myaddrs);
     }
 #endif
 }
 
 void CConnman::SetNetworkActive(bool active) {
     LogPrint(BCLog::NET, "SetNetworkActive: %s\n", active);
 
     if (fNetworkActive == active) {
         return;
     }
 
     fNetworkActive = active;
     uiInterface.NotifyNetworkActiveChanged(fNetworkActive);
 }
 
 CConnman::CConnman(const Config &configIn, uint64_t nSeed0In, uint64_t nSeed1In)
     : config(&configIn), nSeed0(nSeed0In), nSeed1(nSeed1In) {
     fNetworkActive = true;
     setBannedIsDirty = false;
     fAddressesInitialized = false;
     nLastNodeId = 0;
     nSendBufferMaxSize = 0;
     nReceiveFloodSize = 0;
     flagInterruptMsgProc = false;
     SetTryNewOutboundPeer(false);
 
     Options connOptions;
     Init(connOptions);
 }
 
 NodeId CConnman::GetNewNodeId() {
     return nLastNodeId.fetch_add(1, std::memory_order_relaxed);
 }
 
 bool CConnman::Bind(const CService &addr, unsigned int flags) {
     if (!(flags & BF_EXPLICIT) && IsLimited(addr)) {
         return false;
     }
     std::string strError;
     if (!BindListenPort(addr, strError, (flags & BF_WHITELIST) != 0)) {
         if ((flags & BF_REPORT_ERROR) && clientInterface) {
             clientInterface->ThreadSafeMessageBox(
                 strError, "", CClientUIInterface::MSG_ERROR);
         }
         return false;
     }
     return true;
 }
 
 bool CConnman::InitBinds(const std::vector<CService> &binds,
                          const std::vector<CService> &whiteBinds) {
     bool fBound = false;
     for (const auto &addrBind : binds) {
         fBound |= Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR));
     }
     for (const auto &addrBind : whiteBinds) {
         fBound |=
             Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR | BF_WHITELIST));
     }
     if (binds.empty() && whiteBinds.empty()) {
         struct in_addr inaddr_any;
         inaddr_any.s_addr = INADDR_ANY;
         struct in6_addr inaddr6_any = IN6ADDR_ANY_INIT;
         fBound |= Bind(CService(inaddr6_any, GetListenPort()), BF_NONE);
         fBound |= Bind(CService(inaddr_any, GetListenPort()),
                        !fBound ? BF_REPORT_ERROR : BF_NONE);
     }
     return fBound;
 }
 
 bool CConnman::Start(CScheduler &scheduler, const Options &connOptions) {
     Init(connOptions);
 
     nTotalBytesRecv = 0;
     nTotalBytesSent = 0;
     nMaxOutboundTotalBytesSentInCycle = 0;
     nMaxOutboundCycleStartTime = 0;
 
     if (fListen && !InitBinds(connOptions.vBinds, connOptions.vWhiteBinds)) {
         if (clientInterface) {
             clientInterface->ThreadSafeMessageBox(
                 _("Failed to listen on any port. Use -listen=0 if you want "
                   "this."),
                 "", CClientUIInterface::MSG_ERROR);
         }
         return false;
     }
 
     for (const auto &strDest : connOptions.vSeedNodes) {
         AddOneShot(strDest);
     }
 
     if (clientInterface) {
         clientInterface->InitMessage(_("Loading P2P addresses..."));
     }
     // Load addresses from peers.dat
     int64_t nStart = GetTimeMillis();
     {
         CAddrDB adb(config->GetChainParams());
         if (adb.Read(addrman)) {
             LogPrintf("Loaded %i addresses from peers.dat  %dms\n",
                       addrman.size(), GetTimeMillis() - nStart);
         } else {
             // Addrman can be in an inconsistent state after failure, reset it
             addrman.Clear();
             LogPrintf("Invalid or missing peers.dat; recreating\n");
             DumpAddresses();
         }
     }
     if (clientInterface) {
         clientInterface->InitMessage(_("Loading banlist..."));
     }
     // Load addresses from banlist.dat
     nStart = GetTimeMillis();
     CBanDB bandb(config->GetChainParams());
     banmap_t banmap;
     if (bandb.Read(banmap)) {
         // thread save setter
         SetBanned(banmap);
         // no need to write down, just read data
         SetBannedSetDirty(false);
         // sweep out unused entries
         SweepBanned();
 
         LogPrint(BCLog::NET,
                  "Loaded %d banned node ips/subnets from banlist.dat  %dms\n",
                  banmap.size(), GetTimeMillis() - nStart);
     } else {
         LogPrintf("Invalid or missing banlist.dat; recreating\n");
         // force write
         SetBannedSetDirty(true);
         DumpBanlist();
     }
 
     uiInterface.InitMessage(_("Starting network threads..."));
 
     fAddressesInitialized = true;
 
     if (semOutbound == nullptr) {
         // initialize semaphore
         semOutbound = std::unique_ptr<CSemaphore>(new CSemaphore(
             std::min((nMaxOutbound + nMaxFeeler), nMaxConnections)));
     }
     if (semAddnode == nullptr) {
         // initialize semaphore
         semAddnode = std::unique_ptr<CSemaphore>(new CSemaphore(nMaxAddnode));
     }
 
     //
     // Start threads
     //
     assert(m_msgproc);
     InterruptSocks5(false);
     interruptNet.reset();
     flagInterruptMsgProc = false;
 
     {
         LOCK(mutexMsgProc);
         fMsgProcWake = false;
     }
 
     // Send and receive from sockets, accept connections
     threadSocketHandler = std::thread(
         &TraceThread<std::function<void()>>, "net",
         std::function<void()>(std::bind(&CConnman::ThreadSocketHandler, this)));
 
     if (!gArgs.GetBoolArg("-dnsseed", true)) {
         LogPrintf("DNS seeding disabled\n");
     } else {
         threadDNSAddressSeed =
             std::thread(&TraceThread<std::function<void()>>, "dnsseed",
                         std::function<void()>(
                             std::bind(&CConnman::ThreadDNSAddressSeed, this)));
     }
 
     // Initiate outbound connections from -addnode
     threadOpenAddedConnections =
         std::thread(&TraceThread<std::function<void()>>, "addcon",
                     std::function<void()>(std::bind(
                         &CConnman::ThreadOpenAddedConnections, this)));
 
     if (connOptions.m_use_addrman_outgoing &&
         !connOptions.m_specified_outgoing.empty()) {
         if (clientInterface) {
             clientInterface->ThreadSafeMessageBox(
                 _("Cannot provide specific connections and have addrman find "
                   "outgoing connections at the same."),
                 "", CClientUIInterface::MSG_ERROR);
         }
         return false;
     }
     if (connOptions.m_use_addrman_outgoing ||
         !connOptions.m_specified_outgoing.empty()) {
         threadOpenConnections =
             std::thread(&TraceThread<std::function<void()>>, "opencon",
                         std::function<void()>(
                             std::bind(&CConnman::ThreadOpenConnections, this,
                                       connOptions.m_specified_outgoing)));
     }
 
     // Process messages
     threadMessageHandler =
         std::thread(&TraceThread<std::function<void()>>, "msghand",
                     std::function<void()>(
                         std::bind(&CConnman::ThreadMessageHandler, this)));
 
     // Dump network addresses
-    scheduler.scheduleEvery(std::bind(&CConnman::DumpData, this),
-                            DUMP_ADDRESSES_INTERVAL * 1000);
+    scheduler.scheduleEvery(
+        [this]() {
+            this->DumpData();
+            return true;
+        },
+        DUMP_ADDRESSES_INTERVAL * 1000);
 
     return true;
 }
 
 class CNetCleanup {
 public:
     CNetCleanup() {}
 
     ~CNetCleanup() {
 #ifdef WIN32
         // Shutdown Windows Sockets
         WSACleanup();
 #endif
     }
 } instance_of_cnetcleanup;
 
 void CConnman::Interrupt() {
     {
         std::lock_guard<std::mutex> lock(mutexMsgProc);
         flagInterruptMsgProc = true;
     }
     condMsgProc.notify_all();
 
     interruptNet();
     InterruptSocks5(true);
 
     if (semOutbound) {
         for (int i = 0; i < (nMaxOutbound + nMaxFeeler); i++) {
             semOutbound->post();
         }
     }
 
     if (semAddnode) {
         for (int i = 0; i < nMaxAddnode; i++) {
             semAddnode->post();
         }
     }
 }
 
 void CConnman::Stop() {
     if (threadMessageHandler.joinable()) {
         threadMessageHandler.join();
     }
     if (threadOpenConnections.joinable()) {
         threadOpenConnections.join();
     }
     if (threadOpenAddedConnections.joinable()) {
         threadOpenAddedConnections.join();
     }
     if (threadDNSAddressSeed.joinable()) {
         threadDNSAddressSeed.join();
     }
     if (threadSocketHandler.joinable()) {
         threadSocketHandler.join();
     }
 
     if (fAddressesInitialized) {
         DumpData();
         fAddressesInitialized = false;
     }
 
     // Close sockets
     for (CNode *pnode : vNodes) {
         pnode->CloseSocketDisconnect();
     }
     for (ListenSocket &hListenSocket : vhListenSocket) {
         if (hListenSocket.socket != INVALID_SOCKET) {
             if (!CloseSocket(hListenSocket.socket)) {
                 LogPrintf("CloseSocket(hListenSocket) failed with error %s\n",
                           NetworkErrorString(WSAGetLastError()));
             }
         }
     }
 
     // clean up some globals (to help leak detection)
     for (CNode *pnode : vNodes) {
         DeleteNode(pnode);
     }
     for (CNode *pnode : vNodesDisconnected) {
         DeleteNode(pnode);
     }
     vNodes.clear();
     vNodesDisconnected.clear();
     vhListenSocket.clear();
     semOutbound.reset();
     semAddnode.reset();
 }
 
 void CConnman::DeleteNode(CNode *pnode) {
     assert(pnode);
     bool fUpdateConnectionTime = false;
     m_msgproc->FinalizeNode(*config, pnode->GetId(), fUpdateConnectionTime);
     if (fUpdateConnectionTime) {
         addrman.Connected(pnode->addr);
     }
     delete pnode;
 }
 
 CConnman::~CConnman() {
     Interrupt();
     Stop();
 }
 
 size_t CConnman::GetAddressCount() const {
     return addrman.size();
 }
 
 void CConnman::SetServices(const CService &addr, ServiceFlags nServices) {
     addrman.SetServices(addr, nServices);
 }
 
 void CConnman::MarkAddressGood(const CAddress &addr) {
     addrman.Good(addr);
 }
 
 void CConnman::AddNewAddresses(const std::vector<CAddress> &vAddr,
                                const CAddress &addrFrom, int64_t nTimePenalty) {
     addrman.Add(vAddr, addrFrom, nTimePenalty);
 }
 
 std::vector<CAddress> CConnman::GetAddresses() {
     return addrman.GetAddr();
 }
 
 bool CConnman::AddNode(const std::string &strNode) {
     LOCK(cs_vAddedNodes);
     for (const std::string &it : vAddedNodes) {
         if (strNode == it) {
             return false;
         }
     }
 
     vAddedNodes.push_back(strNode);
     return true;
 }
 
 bool CConnman::RemoveAddedNode(const std::string &strNode) {
     LOCK(cs_vAddedNodes);
     for (std::vector<std::string>::iterator it = vAddedNodes.begin();
          it != vAddedNodes.end(); ++it) {
         if (strNode == *it) {
             vAddedNodes.erase(it);
             return true;
         }
     }
     return false;
 }
 
 size_t CConnman::GetNodeCount(NumConnections flags) {
     LOCK(cs_vNodes);
     // Shortcut if we want total
     if (flags == CConnman::CONNECTIONS_ALL) {
         return vNodes.size();
     }
 
     int nNum = 0;
     for (const auto &pnode : vNodes) {
         if (flags & (pnode->fInbound ? CONNECTIONS_IN : CONNECTIONS_OUT)) {
             nNum++;
         }
     }
 
     return nNum;
 }
 
 void CConnman::GetNodeStats(std::vector<CNodeStats> &vstats) {
     vstats.clear();
     LOCK(cs_vNodes);
     vstats.reserve(vNodes.size());
     for (CNode *pnode : vNodes) {
         vstats.emplace_back();
         pnode->copyStats(vstats.back());
     }
 }
 
 bool CConnman::DisconnectNode(const std::string &strNode) {
     LOCK(cs_vNodes);
     if (CNode *pnode = FindNode(strNode)) {
         pnode->fDisconnect = true;
         return true;
     }
     return false;
 }
 bool CConnman::DisconnectNode(NodeId id) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (id == pnode->GetId()) {
             pnode->fDisconnect = true;
             return true;
         }
     }
     return false;
 }
 
 void CConnman::RecordBytesRecv(uint64_t bytes) {
     LOCK(cs_totalBytesRecv);
     nTotalBytesRecv += bytes;
 }
 
 void CConnman::RecordBytesSent(uint64_t bytes) {
     LOCK(cs_totalBytesSent);
     nTotalBytesSent += bytes;
 
     uint64_t now = GetTime();
     if (nMaxOutboundCycleStartTime + nMaxOutboundTimeframe < now) {
         // timeframe expired, reset cycle
         nMaxOutboundCycleStartTime = now;
         nMaxOutboundTotalBytesSentInCycle = 0;
     }
 
     // TODO, exclude whitebind peers
     nMaxOutboundTotalBytesSentInCycle += bytes;
 }
 
 void CConnman::SetMaxOutboundTarget(uint64_t limit) {
     LOCK(cs_totalBytesSent);
     nMaxOutboundLimit = limit;
 }
 
 uint64_t CConnman::GetMaxOutboundTarget() {
     LOCK(cs_totalBytesSent);
     return nMaxOutboundLimit;
 }
 
 uint64_t CConnman::GetMaxOutboundTimeframe() {
     LOCK(cs_totalBytesSent);
     return nMaxOutboundTimeframe;
 }
 
 uint64_t CConnman::GetMaxOutboundTimeLeftInCycle() {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundLimit == 0) {
         return 0;
     }
 
     if (nMaxOutboundCycleStartTime == 0) {
         return nMaxOutboundTimeframe;
     }
 
     uint64_t cycleEndTime = nMaxOutboundCycleStartTime + nMaxOutboundTimeframe;
     uint64_t now = GetTime();
     return (cycleEndTime < now) ? 0 : cycleEndTime - GetTime();
 }
 
 void CConnman::SetMaxOutboundTimeframe(uint64_t timeframe) {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundTimeframe != timeframe) {
         // reset measure-cycle in case of changing the timeframe.
         nMaxOutboundCycleStartTime = GetTime();
     }
     nMaxOutboundTimeframe = timeframe;
 }
 
 bool CConnman::OutboundTargetReached(bool historicalBlockServingLimit) {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundLimit == 0) {
         return false;
     }
 
     if (historicalBlockServingLimit) {
         // keep a large enough buffer to at least relay each block once.
         uint64_t timeLeftInCycle = GetMaxOutboundTimeLeftInCycle();
         uint64_t buffer = timeLeftInCycle / 600 * ONE_MEGABYTE;
         if (buffer >= nMaxOutboundLimit ||
             nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit - buffer) {
             return true;
         }
     } else if (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit) {
         return true;
     }
 
     return false;
 }
 
 uint64_t CConnman::GetOutboundTargetBytesLeft() {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundLimit == 0) {
         return 0;
     }
 
     return (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit)
                ? 0
                : nMaxOutboundLimit - nMaxOutboundTotalBytesSentInCycle;
 }
 
 uint64_t CConnman::GetTotalBytesRecv() {
     LOCK(cs_totalBytesRecv);
     return nTotalBytesRecv;
 }
 
 uint64_t CConnman::GetTotalBytesSent() {
     LOCK(cs_totalBytesSent);
     return nTotalBytesSent;
 }
 
 ServiceFlags CConnman::GetLocalServices() const {
     return nLocalServices;
 }
 
 void CConnman::SetBestHeight(int height) {
     nBestHeight.store(height, std::memory_order_release);
 }
 
 int CConnman::GetBestHeight() const {
     return nBestHeight.load(std::memory_order_acquire);
 }
 
 unsigned int CConnman::GetReceiveFloodSize() const {
     return nReceiveFloodSize;
 }
 
 CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn,
              int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn,
              uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn,
              const CAddress &addrBindIn, const std::string &addrNameIn,
              bool fInboundIn)
     : nTimeConnected(GetSystemTimeInSeconds()), addr(addrIn),
       addrBind(addrBindIn), fInbound(fInboundIn),
       nKeyedNetGroup(nKeyedNetGroupIn), addrKnown(5000, 0.001),
       filterInventoryKnown(50000, 0.000001), id(idIn),
       nLocalHostNonce(nLocalHostNonceIn), nLocalServices(nLocalServicesIn),
       nMyStartingHeight(nMyStartingHeightIn), nSendVersion(0) {
     nServices = NODE_NONE;
     hSocket = hSocketIn;
     nRecvVersion = INIT_PROTO_VERSION;
     nLastSend = 0;
     nLastRecv = 0;
     nSendBytes = 0;
     nRecvBytes = 0;
     nTimeOffset = 0;
     addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
     nVersion = 0;
     strSubVer = "";
     fWhitelisted = false;
     fOneShot = false;
     m_manual_connection = false;
     // set by version message
     fClient = false;
     fFeeler = false;
     fSuccessfullyConnected = false;
     fDisconnect = false;
     nRefCount = 0;
     nSendSize = 0;
     nSendOffset = 0;
     hashContinue = uint256();
     nStartingHeight = -1;
     filterInventoryKnown.reset();
     fSendMempool = false;
     fGetAddr = false;
     nNextLocalAddrSend = 0;
     nNextAddrSend = 0;
     nNextInvSend = 0;
     fRelayTxes = false;
     fSentAddr = false;
     pfilter = std::unique_ptr<CBloomFilter>(new CBloomFilter());
     timeLastMempoolReq = 0;
     nLastBlockTime = 0;
     nLastTXTime = 0;
     nPingNonceSent = 0;
     nPingUsecStart = 0;
     nPingUsecTime = 0;
     fPingQueued = false;
     nMinPingUsecTime = std::numeric_limits<int64_t>::max();
     minFeeFilter = Amount::zero();
     lastSentFeeFilter = Amount::zero();
     nextSendTimeFeeFilter = 0;
     fPauseRecv = false;
     fPauseSend = false;
     nProcessQueueSize = 0;
 
     for (const std::string &msg : getAllNetMessageTypes()) {
         mapRecvBytesPerMsgCmd[msg] = 0;
     }
     mapRecvBytesPerMsgCmd[NET_MESSAGE_COMMAND_OTHER] = 0;
 
     if (fLogIPs) {
         LogPrint(BCLog::NET, "Added connection to %s peer=%d\n", addrName, id);
     } else {
         LogPrint(BCLog::NET, "Added connection peer=%d\n", id);
     }
 }
 
 CNode::~CNode() {
     CloseSocket(hSocket);
 }
 
 void CNode::AskFor(const CInv &inv) {
     if (mapAskFor.size() > MAPASKFOR_MAX_SZ ||
         setAskFor.size() > SETASKFOR_MAX_SZ) {
         return;
     }
 
     // a peer may not have multiple non-responded queue positions for a single
     // inv item.
     if (!setAskFor.insert(inv.hash).second) {
         return;
     }
 
     // We're using mapAskFor as a priority queue, the key is the earliest time
     // the request can be sent.
     int64_t nRequestTime;
     limitedmap<uint256, int64_t>::const_iterator it =
         mapAlreadyAskedFor.find(inv.hash);
     if (it != mapAlreadyAskedFor.end()) {
         nRequestTime = it->second;
     } else {
         nRequestTime = 0;
     }
     LogPrint(BCLog::NET, "askfor %s  %d (%s) peer=%d\n", inv.ToString(),
              nRequestTime,
              DateTimeStrFormat("%H:%M:%S", nRequestTime / 1000000), id);
 
     // Make sure not to reuse time indexes to keep things in the same order
     int64_t nNow = GetTimeMicros() - 1000000;
     static int64_t nLastTime;
     ++nLastTime;
     nNow = std::max(nNow, nLastTime);
     nLastTime = nNow;
 
     // Each retry is 2 minutes after the last
     nRequestTime = std::max(nRequestTime + 2 * 60 * 1000000, nNow);
     if (it != mapAlreadyAskedFor.end()) {
         mapAlreadyAskedFor.update(it, nRequestTime);
     } else {
         mapAlreadyAskedFor.insert(std::make_pair(inv.hash, nRequestTime));
     }
     mapAskFor.insert(std::make_pair(nRequestTime, inv));
 }
 
 bool CConnman::NodeFullyConnected(const CNode *pnode) {
     return pnode && pnode->fSuccessfullyConnected && !pnode->fDisconnect;
 }
 
 void CConnman::PushMessage(CNode *pnode, CSerializedNetMsg &&msg) {
     size_t nMessageSize = msg.data.size();
     size_t nTotalSize = nMessageSize + CMessageHeader::HEADER_SIZE;
     LogPrint(BCLog::NET, "sending %s (%d bytes) peer=%d\n",
              SanitizeString(msg.command.c_str()), nMessageSize, pnode->GetId());
 
     std::vector<uint8_t> serializedHeader;
     serializedHeader.reserve(CMessageHeader::HEADER_SIZE);
     uint256 hash = Hash(msg.data.data(), msg.data.data() + nMessageSize);
     CMessageHeader hdr(config->GetChainParams().NetMagic(), msg.command.c_str(),
                        nMessageSize);
     memcpy(hdr.pchChecksum, hash.begin(), CMessageHeader::CHECKSUM_SIZE);
 
     CVectorWriter{SER_NETWORK, INIT_PROTO_VERSION, serializedHeader, 0, hdr};
 
     size_t nBytesSent = 0;
     {
         LOCK(pnode->cs_vSend);
         bool optimisticSend(pnode->vSendMsg.empty());
 
         // log total amount of bytes per command
         pnode->mapSendBytesPerMsgCmd[msg.command] += nTotalSize;
         pnode->nSendSize += nTotalSize;
 
         if (pnode->nSendSize > nSendBufferMaxSize) {
             pnode->fPauseSend = true;
         }
         pnode->vSendMsg.push_back(std::move(serializedHeader));
         if (nMessageSize) {
             pnode->vSendMsg.push_back(std::move(msg.data));
         }
 
         // If write queue empty, attempt "optimistic write"
         if (optimisticSend == true) {
             nBytesSent = SocketSendData(pnode);
         }
     }
     if (nBytesSent) {
         RecordBytesSent(nBytesSent);
     }
 }
 
 bool CConnman::ForNode(NodeId id, std::function<bool(CNode *pnode)> func) {
     CNode *found = nullptr;
     LOCK(cs_vNodes);
     for (auto &&pnode : vNodes) {
         if (pnode->GetId() == id) {
             found = pnode;
             break;
         }
     }
     return found != nullptr && NodeFullyConnected(found) && func(found);
 }
 
 int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds) {
     return nNow + int64_t(log1p(GetRand(1ULL << 48) *
                                 -0.0000000000000035527136788 /* -1/2^48 */) *
                               average_interval_seconds * -1000000.0 +
                           0.5);
 }
 
 CSipHasher CConnman::GetDeterministicRandomizer(uint64_t id) const {
     return CSipHasher(nSeed0, nSeed1).Write(id);
 }
 
 uint64_t CConnman::CalculateKeyedNetGroup(const CAddress &ad) const {
     std::vector<uint8_t> vchNetGroup(ad.GetGroup());
 
     return GetDeterministicRandomizer(RANDOMIZER_ID_NETGROUP)
         .Write(vchNetGroup.data(), vchNetGroup.size())
         .Finalize();
 }
 
 /**
  * This function convert MaxBlockSize from byte to
  * MB with a decimal precision one digit rounded down
  * E.g.
  * 1660000 -> 1.6
  * 2010000 -> 2.0
  * 1000000 -> 1.0
  * 230000  -> 0.2
  * 50000   -> 0.0
  *
  *  NB behavior for EB<1MB not standardized yet still
  *  the function applies the same algo used for
  *  EB greater or equal to 1MB
  */
 std::string getSubVersionEB(uint64_t MaxBlockSize) {
     // Prepare EB string we are going to add to SubVer:
     // 1) translate from byte to MB and convert to string
     // 2) limit the EB string to the first decimal digit (floored)
     std::stringstream ebMBs;
     ebMBs << (MaxBlockSize / (ONE_MEGABYTE / 10));
     std::string eb = ebMBs.str();
     eb.insert(eb.size() - 1, ".", 1);
     if (eb.substr(0, 1) == ".") {
         eb = "0" + eb;
     }
     return eb;
 }
 
 std::string userAgent(const Config &config) {
     // format excessive blocksize value
     std::string eb = getSubVersionEB(config.GetMaxBlockSize());
     std::vector<std::string> uacomments;
     uacomments.push_back("EB" + eb);
 
     // sanitize comments per BIP-0014, format user agent and check total size
     for (const std::string &cmt : gArgs.GetArgs("-uacomment")) {
         if (cmt != SanitizeString(cmt, SAFE_CHARS_UA_COMMENT)) {
             LogPrintf(
                 "User Agent comment (%s) contains unsafe characters. "
                 "We are going to use a sanitize version of the comment.\n",
                 cmt);
         }
         uacomments.push_back(cmt);
     }
 
     std::string subversion =
         FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, uacomments);
     if (subversion.size() > MAX_SUBVERSION_LENGTH) {
         LogPrintf("Total length of network version string (%i) exceeds maximum "
                   "length (%i). Reduce the number or size of uacomments. "
                   "String has been resized to the max length allowed.\n",
                   subversion.size(), MAX_SUBVERSION_LENGTH);
         subversion.resize(MAX_SUBVERSION_LENGTH - 2);
         subversion.append(")/");
         LogPrintf("Current network string has been set to: %s\n", subversion);
     }
 
     return subversion;
 }
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 34fac0c71..d9acbeb8c 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1,4260 +1,4262 @@
 // 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 "arith_uint256.h"
 #include "blockencodings.h"
 #include "blockvalidity.h"
 #include "chainparams.h"
 #include "config.h"
 #include "consensus/validation.h"
 #include "hash.h"
 #include "init.h"
 #include "merkleblock.h"
 #include "net.h"
 #include "netbase.h"
 #include "netmessagemaker.h"
 #include "policy/fees.h"
 #include "policy/policy.h"
 #include "primitives/block.h"
 #include "primitives/transaction.h"
 #include "random.h"
 #include "scheduler.h"
 #include "tinyformat.h"
 #include "txmempool.h"
 #include "ui_interface.h"
 #include "util.h"
 #include "utilmoneystr.h"
 #include "utilstrencodings.h"
 #include "validation.h"
 #include "validationinterface.h"
 
 #include <boost/range/adaptor/reversed.hpp>
 
 #if defined(NDEBUG)
 #error "Bitcoin cannot be compiled without assertions."
 #endif
 
 // Used only to inform the wallet of when we last received a block.
 std::atomic<int64_t> nTimeBestReceived(0);
 
 struct IteratorComparator {
     template <typename I> bool operator()(const I &a, const I &b) {
         return &(*a) < &(*b);
     }
 };
 
 struct COrphanTx {
     // When modifying, adapt the copy of this definition in tests/DoS_tests.
     CTransactionRef tx;
     NodeId fromPeer;
     int64_t nTimeExpire;
 };
 
 std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(cs_main);
 std::map<COutPoint,
          std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>>
     mapOrphanTransactionsByPrev GUARDED_BY(cs_main);
 void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 static size_t vExtraTxnForCompactIt = 0;
 static std::vector<std::pair<uint256, CTransactionRef>>
     vExtraTxnForCompact GUARDED_BY(cs_main);
 
 // SHA256("main address relay")[0:8]
 static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL;
 
 // Internal stuff
 namespace {
 /** Number of nodes with fSyncStarted. */
 int nSyncStarted GUARDED_BY(cs_main) = 0;
 
 /**
  * Sources of received blocks, saved to be able to send them reject messages or
  * ban 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<uint256, std::pair<NodeId, bool>> mapBlockSource GUARDED_BY(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);
 
 /**
  * Blocks that are in flight, and that are in the queue to be downloaded.
  */
 struct QueuedBlock {
     uint256 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;
 };
 std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator>>
     mapBlocksInFlight GUARDED_BY(cs_main);
 
 /** Stack of nodes which we have set to announce using compact blocks */
 std::list<NodeId> lNodesAnnouncingHeaderAndIDs;
 
 /** Number of preferable block download peers. */
 int nPreferredDownload GUARDED_BY(cs_main) = 0;
 
 /** Number of peers from which we're downloading blocks. */
 int nPeersWithValidatedDownloads GUARDED_BY(cs_main) = 0;
 
 /** Number of outbound peers with m_chain_sync.m_protect. */
 int g_outbound_peers_with_protect_from_disconnect = 0;
 
 /** When our tip was last updated. */
 int64_t g_last_tip_update = 0;
 
 /** Relay map. */
 typedef std::map<uint256, 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<int64_t, MapRelay::iterator>>
     vRelayExpiration GUARDED_BY(cs_main);
 } // namespace
 
 namespace {
 
 struct CBlockReject {
     uint8_t chRejectCode;
     std::string strRejectReason;
     uint256 hashBlock;
 };
 
 /**
  * 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;
     //! Whether we have a fully established connection.
     bool fCurrentlyConnected;
     //! Accumulated misbehaviour score for this peer.
     int nMisbehavior;
     //! Whether this peer should be disconnected and banned (unless
     //! whitelisted).
     bool fShouldBan;
     //! String name of this peer (debugging/logging purposes).
     const std::string name;
     //! List of asynchronously-determined block rejections to notify this peer
     //! about.
     std::vector<CBlockReject> rejects;
     //! The best known block we know this peer has announced.
     const CBlockIndex *pindexBestKnownBlock;
     //! The hash of the last unknown block this peer has announced.
     uint256 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
     int64_t nHeadersSyncTimeout;
     //! Since when we're stalling block download progress (in microseconds), or
     //! 0.
     int64_t nStallingSince;
     std::list<QueuedBlock> vBlocksInFlight;
     //! When the first entry in vBlocksInFlight started downloading. Don't care
     //! when vBlocksInFlight is empty.
     int64_t nDownloadingSince;
     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
      * Only in effect for outbound, non-manual connections,
      * with m_protect == false
      * Algorithm: 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.
      */
     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;
 
     CNodeState(CAddress addrIn, std::string addrNameIn)
         : address(addrIn), name(addrNameIn) {
         fCurrentlyConnected = false;
         nMisbehavior = 0;
         fShouldBan = false;
         pindexBestKnownBlock = nullptr;
         hashLastUnknownBlock.SetNull();
         pindexLastCommonBlock = nullptr;
         pindexBestHeaderSent = nullptr;
         nUnconnectingHeaders = 0;
         fSyncStarted = false;
         nHeadersSyncTimeout = 0;
         nStallingSince = 0;
         nDownloadingSince = 0;
         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;
     }
 };
 
 /** 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;
 }
 
 static void UpdatePreferredDownload(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->fInbound || node->fWhitelisted) &&
                                 !node->fOneShot && !node->fClient;
 
     nPreferredDownload += state->fPreferredDownload;
 }
 
 static void PushNodeVersion(const Config &config, CNode *pnode,
                             CConnman *connman, int64_t nTime) {
     ServiceFlags nLocalNodeServices = pnode->GetLocalServices();
     uint64_t nonce = pnode->GetLocalNonce();
     int nNodeStartingHeight = pnode->GetMyStartingHeight();
     NodeId nodeid = pnode->GetId();
     CAddress addr = pnode->addr;
 
     CAddress addrYou = (addr.IsRoutable() && !IsProxy(addr)
                             ? addr
                             : CAddress(CService(), addr.nServices));
     CAddress addrMe = CAddress(CService(), nLocalNodeServices);
 
     connman->PushMessage(pnode,
                          CNetMsgMaker(INIT_PROTO_VERSION)
                              .Make(NetMsgType::VERSION, PROTOCOL_VERSION,
                                    uint64_t(nLocalNodeServices), nTime, addrYou,
                                    addrMe, nonce, userAgent(config),
                                    nNodeStartingHeight, ::fRelayTxes));
 
     if (fLogIPs) {
         LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, "
                              "us=%s, them=%s, peer=%d\n",
                  PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(),
                  addrYou.ToString(), nodeid);
     } else {
         LogPrint(
             BCLog::NET,
             "send version message: version %d, blocks=%d, us=%s, peer=%d\n",
             PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(), nodeid);
     }
 }
 
 // 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.
 static bool MarkBlockAsReceived(const uint256 &hash)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     std::map<uint256,
              std::pair<NodeId, std::list<QueuedBlock>::iterator>>::iterator
         itInFlight = mapBlocksInFlight.find(hash);
     if (itInFlight != mapBlocksInFlight.end()) {
         CNodeState *state = State(itInFlight->second.first);
         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->nDownloadingSince =
                 std::max(state->nDownloadingSince, GetTimeMicros());
         }
         state->vBlocksInFlight.erase(itInFlight->second.second);
         state->nBlocksInFlight--;
         state->nStallingSince = 0;
         mapBlocksInFlight.erase(itInFlight);
         return true;
     }
 
     return false;
 }
 
 // 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.
 static bool
 MarkBlockAsInFlight(const Config &config, NodeId nodeid, const uint256 &hash,
                     const Consensus::Params &consensusParams,
                     const CBlockIndex *pindex = nullptr,
                     std::list<QueuedBlock>::iterator **pit = nullptr)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     // Short-circuit most stuff in case its from the same node.
     std::map<uint256,
              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, &mempool) : nullptr)});
     state->nBlocksInFlight++;
     state->nBlocksInFlightValidHeaders += it->fValidatedHeaders;
     if (state->nBlocksInFlight == 1) {
         // We're starting a block download (batch) from this peer.
         state->nDownloadingSince = GetTimeMicros();
     }
 
     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;
 }
 
 /** Check whether the last unknown block a peer advertised is not yet known. */
 static void ProcessBlockAvailability(NodeId nodeid)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     if (!state->hashLastUnknownBlock.IsNull()) {
         BlockMap::iterator itOld =
             mapBlockIndex.find(state->hashLastUnknownBlock);
         if (itOld != mapBlockIndex.end() && itOld->second->nChainWork > 0) {
             if (state->pindexBestKnownBlock == nullptr ||
                 itOld->second->nChainWork >=
                     state->pindexBestKnownBlock->nChainWork) {
                 state->pindexBestKnownBlock = itOld->second;
             }
             state->hashLastUnknownBlock.SetNull();
         }
     }
 }
 
 /** Update tracking information about which blocks a peer is assumed to have. */
 static void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     ProcessBlockAvailability(nodeid);
 
     BlockMap::iterator it = mapBlockIndex.find(hash);
     if (it != mapBlockIndex.end() && it->second->nChainWork > 0) {
         // An actually better block was announced.
         if (state->pindexBestKnownBlock == nullptr ||
             it->second->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
             state->pindexBestKnownBlock = it->second;
         }
     } else {
         // An unknown block was announced; just assume that the latest one is
         // the best one.
         state->hashLastUnknownBlock = hash;
     }
 }
 
 /**
  * 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.
  */
 static void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid,
                                                  CConnman *connman) {
     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;
         }
     }
     connman->ForNode(nodeid, [&connman](CNode *pfrom) {
         AssertLockHeld(cs_main);
         bool fAnnounceUsingCMPCTBLOCK = false;
         uint64_t nCMPCTBLOCKVersion = 1;
         if (lNodesAnnouncingHeaderAndIDs.size() >= 3) {
             // As per BIP152, we only get 3 of our peers to announce
             // blocks using compact encodings.
             connman->ForNode(lNodesAnnouncingHeaderAndIDs.front(),
                              [&connman, fAnnounceUsingCMPCTBLOCK,
                               nCMPCTBLOCKVersion](CNode *pnodeStop) {
                                  AssertLockHeld(cs_main);
                                  connman->PushMessage(
                                      pnodeStop,
                                      CNetMsgMaker(pnodeStop->GetSendVersion())
                                          .Make(NetMsgType::SENDCMPCT,
                                                fAnnounceUsingCMPCTBLOCK,
                                                nCMPCTBLOCKVersion));
                                  return true;
                              });
             lNodesAnnouncingHeaderAndIDs.pop_front();
         }
         fAnnounceUsingCMPCTBLOCK = true;
         connman->PushMessage(pfrom,
                              CNetMsgMaker(pfrom->GetSendVersion())
                                  .Make(NetMsgType::SENDCMPCT,
                                        fAnnounceUsingCMPCTBLOCK,
                                        nCMPCTBLOCKVersion));
         lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
         return true;
     });
 }
 
 static bool TipMayBeStale(const Consensus::Params &consensusParams)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     if (g_last_tip_update == 0) {
         g_last_tip_update = GetTime();
     }
     return g_last_tip_update <
                GetTime() - consensusParams.nPowTargetSpacing * 3 &&
            mapBlocksInFlight.empty();
 }
 
 static bool CanDirectFetch(const Consensus::Params &consensusParams)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     return chainActive.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;
 }
 
 /**
  * Update pindexLastCommonBlock and add not-in-flight missing successors to
  * vBlocks, until it has at most count entries.
  */
 static void FindNextBlocksToDownload(NodeId nodeid, unsigned int count,
                                      std::vector<const CBlockIndex *> &vBlocks,
                                      NodeId &nodeStaller,
                                      const Consensus::Params &consensusParams)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     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 <
             chainActive.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 = chainActive[std::min(
             state->pindexBestKnownBlock->nHeight, chainActive.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 mean time, 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() || chainActive.Contains(pindex)) {
                 if (pindex->nChainTx) {
                     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
 
 // This function is used for testing the stale tip eviction logic, see
 // DoS_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;
     }
 }
 
 // Returns true for outbound peers, excluding manual connections, feelers, and
 // one-shots.
 static bool IsOutboundDisconnectionCandidate(const CNode *node) {
     return !(node->fInbound || node->m_manual_connection || node->fFeeler ||
              node->fOneShot);
 }
 
 void PeerLogicValidation::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, std::move(addrName)));
     }
     if (!pnode->fInbound) {
         PushNodeVersion(config, pnode, connman, GetTime());
     }
 }
 
 void PeerLogicValidation::FinalizeNode(const Config &config, NodeId nodeid,
                                        bool &fUpdateConnectionTime) {
     fUpdateConnectionTime = false;
     LOCK(cs_main);
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     if (state->fSyncStarted) {
         nSyncStarted--;
     }
 
     if (state->nMisbehavior == 0 && state->fCurrentlyConnected) {
         fUpdateConnectionTime = true;
     }
 
     for (const QueuedBlock &entry : state->vBlocksInFlight) {
         mapBlocksInFlight.erase(entry.hash);
     }
     EraseOrphansFor(nodeid);
     nPreferredDownload -= state->fPreferredDownload;
     nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0);
     assert(nPeersWithValidatedDownloads >= 0);
     g_outbound_peers_with_protect_from_disconnect -=
         state->m_chain_sync.m_protect;
     assert(g_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(g_outbound_peers_with_protect_from_disconnect == 0);
     }
     LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid);
 }
 
 bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
     LOCK(cs_main);
     CNodeState *state = State(nodeid);
     if (state == nullptr) {
         return false;
     }
     stats.nMisbehavior = state->nMisbehavior;
     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);
         }
     }
     return true;
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // mapOrphanTransactions
 //
 
 static void AddToCompactExtraTransactions(const CTransactionRef &tx)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     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->GetId(), tx);
     vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn;
 }
 
 bool AddOrphanTx(const CTransactionRef &tx, NodeId peer)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     const uint256 &txid = tx->GetId();
     if (mapOrphanTransactions.count(txid)) {
         return false;
     }
 
     // Ignore big transactions, to avoid a send-big-orphans memory exhaustion
     // attack. If a peer has a legitimate large transaction with a missing
     // parent then we assume it will rebroadcast it later, after the parent
     // transaction(s) have been mined or received.
     // 100 orphans, each of which is at most 99,999 bytes big is at most 10
     // megabytes of orphans and somewhat more byprev index (in the worst case):
     unsigned int sz = tx->GetTotalSize();
     if (sz >= MAX_STANDARD_TX_SIZE) {
         LogPrint(BCLog::MEMPOOL,
                  "ignoring large orphan tx (size: %u, hash: %s)\n", sz,
                  txid.ToString());
         return false;
     }
 
     auto ret = mapOrphanTransactions.emplace(
         txid, COrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME});
     assert(ret.second);
     for (const CTxIn &txin : tx->vin) {
         mapOrphanTransactionsByPrev[txin.prevout].insert(ret.first);
     }
 
     AddToCompactExtraTransactions(tx);
 
     LogPrint(BCLog::MEMPOOL, "stored orphan tx %s (mapsz %u outsz %u)\n",
              txid.ToString(), mapOrphanTransactions.size(),
              mapOrphanTransactionsByPrev.size());
     return true;
 }
 
 static int EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     std::map<uint256, COrphanTx>::iterator it =
         mapOrphanTransactions.find(hash);
     if (it == mapOrphanTransactions.end()) {
         return 0;
     }
     for (const CTxIn &txin : it->second.tx->vin) {
         auto itPrev = mapOrphanTransactionsByPrev.find(txin.prevout);
         if (itPrev == mapOrphanTransactionsByPrev.end()) {
             continue;
         }
         itPrev->second.erase(it);
         if (itPrev->second.empty()) {
             mapOrphanTransactionsByPrev.erase(itPrev);
         }
     }
     mapOrphanTransactions.erase(it);
     return 1;
 }
 
 void EraseOrphansFor(NodeId peer) {
     int nErased = 0;
     std::map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
     while (iter != mapOrphanTransactions.end()) {
         // Increment to avoid iterator becoming invalid.
         std::map<uint256, COrphanTx>::iterator maybeErase = iter++;
         if (maybeErase->second.fromPeer == peer) {
             nErased += EraseOrphanTx(maybeErase->second.tx->GetId());
         }
     }
     if (nErased > 0) {
         LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx from peer=%d\n", nErased,
                  peer);
     }
 }
 
 unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     unsigned int nEvicted = 0;
     static int64_t nNextSweep;
     int64_t nNow = GetTime();
     if (nNextSweep <= nNow) {
         // Sweep out expired orphan pool entries:
         int nErased = 0;
         int64_t nMinExpTime =
             nNow + ORPHAN_TX_EXPIRE_TIME - ORPHAN_TX_EXPIRE_INTERVAL;
         std::map<uint256, COrphanTx>::iterator iter =
             mapOrphanTransactions.begin();
         while (iter != mapOrphanTransactions.end()) {
             std::map<uint256, COrphanTx>::iterator maybeErase = iter++;
             if (maybeErase->second.nTimeExpire <= nNow) {
                 nErased += EraseOrphanTx(maybeErase->second.tx->GetId());
             } else {
                 nMinExpTime =
                     std::min(maybeErase->second.nTimeExpire, nMinExpTime);
             }
         }
         // Sweep again 5 minutes after the next entry that expires in order to
         // batch the linear scan.
         nNextSweep = nMinExpTime + ORPHAN_TX_EXPIRE_INTERVAL;
         if (nErased > 0) {
             LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx due to expiration\n",
                      nErased);
         }
     }
     while (mapOrphanTransactions.size() > nMaxOrphans) {
         // Evict a random orphan:
         uint256 randomhash = GetRandHash();
         std::map<uint256, COrphanTx>::iterator it =
             mapOrphanTransactions.lower_bound(randomhash);
         if (it == mapOrphanTransactions.end()) {
             it = mapOrphanTransactions.begin();
         }
         EraseOrphanTx(it->first);
         ++nEvicted;
     }
     return nEvicted;
 }
 
 /**
  * Mark a misbehaving peer to be banned depending upon the value of `-banscore`.
  */
 void Misbehaving(NodeId pnode, int howmuch, const std::string &reason)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     if (howmuch == 0) {
         return;
     }
 
     CNodeState *state = State(pnode);
     if (state == nullptr) {
         return;
     }
 
     state->nMisbehavior += howmuch;
     int banscore = gArgs.GetArg("-banscore", DEFAULT_BANSCORE_THRESHOLD);
     if (state->nMisbehavior >= banscore &&
         state->nMisbehavior - howmuch < banscore) {
         LogPrintf(
             "%s: %s peer=%d (%d -> %d) reason: %s BAN THRESHOLD EXCEEDED\n",
             __func__, state->name, pnode, state->nMisbehavior - howmuch,
             state->nMisbehavior, reason.c_str());
         state->fShouldBan = true;
     } else {
         LogPrintf("%s: %s peer=%d (%d -> %d) reason: %s\n", __func__,
                   state->name, pnode, state->nMisbehavior - howmuch,
                   state->nMisbehavior, reason.c_str());
     }
 }
 
 // overloaded variant of above to operate on CNode*s
 static void Misbehaving(CNode *node, int howmuch, const std::string &reason) {
     Misbehaving(node->GetId(), howmuch, reason);
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // blockchain -> download logic notification
 //
 
 PeerLogicValidation::PeerLogicValidation(CConnman *connmanIn,
                                          CScheduler &scheduler)
     : connman(connmanIn), m_stale_tip_check_time(0) {
     // Initialize global variables that cannot be constructed at startup.
     recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
 
     const Consensus::Params &consensusParams = Params().GetConsensus();
     // 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(
-        std::bind(&PeerLogicValidation::CheckForStaleTipAndEvictPeers, this,
-                  consensusParams),
+        [this, &consensusParams]() {
+            this->CheckForStaleTipAndEvictPeers(consensusParams);
+            return true;
+        },
         EXTRA_PEER_CHECK_INTERVAL * 1000);
 }
 
 void PeerLogicValidation::BlockConnected(
     const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex,
     const std::vector<CTransactionRef> &vtxConflicted) {
     LOCK(cs_main);
 
     std::vector<uint256> vOrphanErase;
 
     for (const CTransactionRef &ptx : pblock->vtx) {
         const CTransaction &tx = *ptx;
 
         // Which orphan pool entries must we evict?
         for (size_t j = 0; j < tx.vin.size(); j++) {
             auto itByPrev = mapOrphanTransactionsByPrev.find(tx.vin[j].prevout);
             if (itByPrev == mapOrphanTransactionsByPrev.end()) {
                 continue;
             }
 
             for (auto mi = itByPrev->second.begin();
                  mi != itByPrev->second.end(); ++mi) {
                 const CTransaction &orphanTx = *(*mi)->second.tx;
                 const uint256 &orphanHash = orphanTx.GetHash();
                 vOrphanErase.push_back(orphanHash);
             }
         }
     }
 
     // Erase orphan transactions include or precluded by this block
     if (vOrphanErase.size()) {
         int nErased = 0;
         for (uint256 &orphanId : vOrphanErase) {
             nErased += EraseOrphanTx(orphanId);
         }
         LogPrint(BCLog::MEMPOOL,
                  "Erased %d orphan tx included or conflicted by block\n",
                  nErased);
     }
 
     g_last_tip_update = GetTime();
 }
 
 static CCriticalSection 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);
 
 void PeerLogicValidation::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;
     }
 
     connman->ForEachNode([this, &pcmpctblock, pindex, &msgMaker,
                           &hashBlock](CNode *pnode) {
         AssertLockHeld(cs_main);
 
         // TODO: Avoid the repeated-serialization here
         if (pnode->nVersion < 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",
                      "PeerLogicValidation::NewPoWValidBlock",
                      hashBlock.ToString(), pnode->GetId());
             connman->PushMessage(
                 pnode, msgMaker.Make(NetMsgType::CMPCTBLOCK, *pcmpctblock));
             state.pindexBestHeaderSent = pindex;
         }
     });
 }
 
 void PeerLogicValidation::UpdatedBlockTip(const CBlockIndex *pindexNew,
                                           const CBlockIndex *pindexFork,
                                           bool fInitialDownload) {
     const int nNewHeight = pindexNew->nHeight;
     connman->SetBestHeight(nNewHeight);
 
     if (!fInitialDownload) {
         // Find the hashes of all blocks that weren't previously in the best
         // chain.
         std::vector<uint256> 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;
             }
         }
         // Relay inventory, but don't relay old inventory during initial block
         // download.
         connman->ForEachNode([nNewHeight, &vHashes](CNode *pnode) {
             if (nNewHeight > (pnode->nStartingHeight != -1
                                   ? pnode->nStartingHeight - 2000
                                   : 0)) {
                 for (const uint256 &hash : boost::adaptors::reverse(vHashes)) {
                     pnode->PushBlockHash(hash);
                 }
             }
         });
         connman->WakeMessageHandler();
     }
 
     nTimeBestReceived = GetTime();
 }
 
 void PeerLogicValidation::BlockChecked(const CBlock &block,
                                        const CValidationState &state) {
     LOCK(cs_main);
 
     const uint256 hash(block.GetHash());
     std::map<uint256, std::pair<NodeId, bool>>::iterator it =
         mapBlockSource.find(hash);
 
     int nDoS = 0;
     if (state.IsInvalid(nDoS)) {
         // Don't send reject message with code 0 or an internal reject code.
         if (it != mapBlockSource.end() && State(it->second.first) &&
             state.GetRejectCode() > 0 &&
             state.GetRejectCode() < REJECT_INTERNAL) {
             CBlockReject reject = {
                 uint8_t(state.GetRejectCode()),
                 state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH),
                 hash};
             State(it->second.first)->rejects.push_back(reject);
             if (nDoS > 0 && it->second.second) {
                 Misbehaving(it->second.first, nDoS, state.GetRejectReason());
             }
         }
     }
     // 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() && !IsInitialBlockDownload() &&
              mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) {
         if (it != mapBlockSource.end()) {
             MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first, connman);
         }
     }
 
     if (it != mapBlockSource.end()) {
         mapBlockSource.erase(it);
     }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // Messages
 //
 
 static bool AlreadyHave(const CInv &inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     switch (inv.type) {
         case MSG_TX: {
             assert(recentRejects);
             if (chainActive.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 = chainActive.Tip()->GetBlockHash();
                 recentRejects->reset();
             }
 
             // Use pcoinsTip->HaveCoinInCache as a quick approximation to
             // exclude requesting or processing some txs which have already been
             // included in a block. As this is best effort, we only check for
             // output 0 and 1. This works well enough in practice and we get
             // diminishing returns with 2 onward.
             return recentRejects->contains(inv.hash) ||
                    mempool.exists(inv.hash) ||
                    mapOrphanTransactions.count(inv.hash) ||
                    pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 0)) ||
                    pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 1));
         }
         case MSG_BLOCK:
             return mapBlockIndex.count(inv.hash);
     }
     // Don't know what it is, just say we already got one
     return true;
 }
 
 static void RelayTransaction(const CTransaction &tx, CConnman *connman) {
     CInv inv(MSG_TX, tx.GetId());
     connman->ForEachNode([&inv](CNode *pnode) { pnode->PushInventory(inv); });
 }
 
 static void RelayAddress(const CAddress &addr, bool fReachable,
                          CConnman *connman) {
     // Limited relaying of addresses outside our network(s)
     unsigned int nRelayNodes = fReachable ? 2 : 1;
 
     // 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 addrKnowns of the chosen nodes prevent repeats.
     uint64_t hashAddr = addr.GetHash();
     const CSipHasher hasher =
         connman->GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY)
             .Write(hashAddr << 32)
             .Write((GetTime() + hashAddr) / (24 * 60 * 60));
     FastRandomContext insecure_rand;
 
     std::array<std::pair<uint64_t, CNode *>, 2> best{
         {{0, nullptr}, {0, nullptr}}};
     assert(nRelayNodes <= best.size());
 
     auto sortfunc = [&best, &hasher, nRelayNodes](CNode *pnode) {
         if (pnode->nVersion >= CADDR_TIME_VERSION) {
             uint64_t hashKey =
                 CSipHasher(hasher).Write(pnode->GetId()).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, pnode);
                     break;
                 }
             }
         }
     };
 
     auto pushfunc = [&addr, &best, nRelayNodes, &insecure_rand] {
         for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) {
             best[i].second->PushAddress(addr, insecure_rand);
         }
     };
 
     connman->ForEachNodeThen(std::move(sortfunc), std::move(pushfunc));
 }
 
 static void ProcessGetData(const Config &config, CNode *pfrom,
                            CConnman *connman,
                            const std::atomic<bool> &interruptMsgProc) {
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
     std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
     std::vector<CInv> vNotFound;
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
     LOCK(cs_main);
 
     while (it != pfrom->vRecvGetData.end()) {
         // Don't bother if send buffer is too full to respond anyway.
         if (pfrom->fPauseSend) {
             break;
         }
 
         const CInv &inv = *it;
         {
             if (interruptMsgProc) {
                 return;
             }
 
             it++;
 
             if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK ||
                 inv.type == MSG_CMPCT_BLOCK) {
                 bool send = false;
                 BlockMap::iterator mi = mapBlockIndex.find(inv.hash);
                 if (mi != mapBlockIndex.end()) {
                     if (mi->second->nChainTx &&
                         !mi->second->IsValid(BlockValidity::SCRIPTS) &&
                         mi->second->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.
                         std::shared_ptr<const CBlock> a_recent_block;
                         {
                             LOCK(cs_most_recent_block);
                             a_recent_block = most_recent_block;
                         }
                         CValidationState dummy;
                         ActivateBestChain(config, dummy, a_recent_block);
                     }
                     if (chainActive.Contains(mi->second)) {
                         send = true;
                     } else {
                         static const int nOneMonth = 30 * 24 * 60 * 60;
                         // To prevent fingerprinting attacks, only send blocks
                         // outside of the active chain if they are valid, and no
                         // more than a month older (both in time, and in best
                         // equivalent proof of work) than the best header chain
                         // we know about.
                         send = mi->second->IsValid(BlockValidity::SCRIPTS) &&
                                (pindexBestHeader != nullptr) &&
                                (pindexBestHeader->GetBlockTime() -
                                     mi->second->GetBlockTime() <
                                 nOneMonth) &&
                                (GetBlockProofEquivalentTime(
                                     *pindexBestHeader, *mi->second,
                                     *pindexBestHeader,
                                     consensusParams) < nOneMonth);
                         if (!send) {
                             LogPrintf("%s: ignoring request from peer=%i for "
                                       "old block that isn't in the main "
                                       "chain\n",
                                       __func__, pfrom->GetId());
                         }
                     }
                 }
 
                 // Disconnect node in case we have reached the outbound limit
                 // for serving historical blocks never disconnect whitelisted
                 // nodes.
                 // assume > 1 week = historical
                 static const int nOneWeek = 7 * 24 * 60 * 60;
                 if (send && connman->OutboundTargetReached(true) &&
                     (((pindexBestHeader != nullptr) &&
                       (pindexBestHeader->GetBlockTime() -
                            mi->second->GetBlockTime() >
                        nOneWeek)) ||
                      inv.type == MSG_FILTERED_BLOCK) &&
                     !pfrom->fWhitelisted) {
                     LogPrint(BCLog::NET, "historical block serving limit "
                                          "reached, disconnect peer=%d\n",
                              pfrom->GetId());
 
                     // disconnect node
                     pfrom->fDisconnect = true;
                     send = false;
                 }
                 // Pruned nodes may have deleted the block, so check whether
                 // it's available before trying to send.
                 if (send && (mi->second->nStatus.hasData())) {
                     // Send block from disk
                     CBlock block;
                     if (!ReadBlockFromDisk(block, (*mi).second, config)) {
                         assert(!"cannot load block from disk");
                     }
 
                     if (inv.type == MSG_BLOCK) {
                         connman->PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::BLOCK, block));
                     } else if (inv.type == MSG_FILTERED_BLOCK) {
                         bool sendMerkleBlock = false;
                         CMerkleBlock merkleBlock;
                         {
                             LOCK(pfrom->cs_filter);
                             if (pfrom->pfilter) {
                                 sendMerkleBlock = true;
                                 merkleBlock =
                                     CMerkleBlock(block, *pfrom->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<unsigned int, uint256> PairType;
                             for (PairType &pair : merkleBlock.vMatchedTxn) {
                                 connman->PushMessage(
                                     pfrom,
                                     msgMaker.Make(NetMsgType::TX,
                                                   *block.vtx[pair.first]));
                             }
                         }
                         // else
                         // no response
                     } else if (inv.type == MSG_CMPCT_BLOCK) {
                         // 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) &&
                             mi->second->nHeight >=
                                 chainActive.Height() - MAX_CMPCTBLOCK_DEPTH) {
                             CBlockHeaderAndShortTxIDs cmpctblock(block);
                             connman->PushMessage(
                                 pfrom,
                                 msgMaker.Make(nSendFlags,
                                               NetMsgType::CMPCTBLOCK,
                                               cmpctblock));
                         } else {
                             connman->PushMessage(
                                 pfrom,
                                 msgMaker.Make(nSendFlags, NetMsgType::BLOCK,
                                               block));
                         }
                     }
 
                     // Trigger the peer node to send a getblocks request for the
                     // next batch of inventory.
                     if (inv.hash == pfrom->hashContinue) {
                         // Bypass PushInventory, 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, chainActive.Tip()->GetBlockHash()));
                         connman->PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::INV, vInv));
                         pfrom->hashContinue.SetNull();
                     }
                 }
             } else if (inv.type == MSG_TX) {
                 // Send stream from relay memory
                 bool push = false;
                 auto mi = mapRelay.find(inv.hash);
                 int nSendFlags = 0;
                 if (mi != mapRelay.end()) {
                     connman->PushMessage(
                         pfrom,
                         msgMaker.Make(nSendFlags, NetMsgType::TX, *mi->second));
                     push = true;
                 } else if (pfrom->timeLastMempoolReq) {
                     auto txinfo = mempool.info(inv.hash);
                     // To protect privacy, do not answer getdata using the
                     // mempool when that TX couldn't have been INVed in reply to
                     // a MEMPOOL request.
                     if (txinfo.tx &&
                         txinfo.nTime <= pfrom->timeLastMempoolReq) {
                         connman->PushMessage(pfrom,
                                              msgMaker.Make(nSendFlags,
                                                            NetMsgType::TX,
                                                            *txinfo.tx));
                         push = true;
                     }
                 }
                 if (!push) {
                     vNotFound.push_back(inv);
                 }
             }
 
             // Track requests for our stuff.
             GetMainSignals().Inventory(inv.hash);
 
             if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK ||
                 inv.type == MSG_CMPCT_BLOCK) {
                 break;
             }
         }
     }
 
     pfrom->vRecvGetData.erase(pfrom->vRecvGetData.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. Currently only SPV clients
         // actually 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.
         connman->PushMessage(pfrom,
                              msgMaker.Make(NetMsgType::NOTFOUND, vNotFound));
     }
 }
 
 inline static void SendBlockTransactions(const CBlock &block,
                                          const BlockTransactionsRequest &req,
                                          CNode *pfrom, CConnman *connman) {
     BlockTransactions resp(req);
     for (size_t i = 0; i < req.indices.size(); i++) {
         if (req.indices[i] >= block.vtx.size()) {
             LOCK(cs_main);
             Misbehaving(pfrom, 100, "out-of-bound-tx-index");
             LogPrintf(
                 "Peer %d sent us a getblocktxn with out-of-bounds tx indices",
                 pfrom->GetId());
             return;
         }
         resp.txn[i] = block.vtx[req.indices[i]];
     }
     LOCK(cs_main);
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
     int nSendFlags = 0;
     connman->PushMessage(pfrom,
                          msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp));
 }
 
 static bool ProcessHeadersMessage(const Config &config, CNode *pfrom,
                                   CConnman *connman,
                                   const std::vector<CBlockHeader> &headers,
                                   bool punish_duplicate_invalid) {
     const CChainParams &chainparams = config.GetChainParams();
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
     size_t nCount = headers.size();
 
     if (nCount == 0) {
         // Nothing interesting. Stop asking this peers for more headers.
         return true;
     }
 
     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 (mapBlockIndex.find(headers[0].hashPrevBlock) ==
                 mapBlockIndex.end() &&
             nCount < MAX_BLOCKS_TO_ANNOUNCE) {
             nodestate->nUnconnectingHeaders++;
             connman->PushMessage(
                 pfrom,
                 msgMaker.Make(NetMsgType::GETHEADERS,
                               chainActive.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, "too-many-unconnected-headers");
             }
             return true;
         }
 
         uint256 hashLastBlock;
         for (const CBlockHeader &header : headers) {
             if (!hashLastBlock.IsNull() &&
                 header.hashPrevBlock != hashLastBlock) {
                 Misbehaving(pfrom, 20, "disconnected-header");
                 return error("non-continuous headers sequence");
             }
             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 (mapBlockIndex.find(hashLastBlock) == mapBlockIndex.end()) {
             received_new_header = true;
         }
     }
 
     CValidationState state;
     CBlockHeader first_invalid_header;
     if (!ProcessNewBlockHeaders(config, headers, state, &pindexLast,
                                 &first_invalid_header)) {
         int nDoS;
         if (state.IsInvalid(nDoS)) {
             if (nDoS > 0) {
                 LOCK(cs_main);
                 Misbehaving(pfrom, nDoS, state.GetRejectReason());
             }
             if (punish_duplicate_invalid &&
                 mapBlockIndex.find(first_invalid_header.GetHash()) !=
                     mapBlockIndex.end()) {
                 // Goal: don't allow outbound peers to use up our outbound
                 // connection slots if they are on incompatible chains.
                 //
                 // We ask the caller to set punish_invalid appropriately based
                 // on the peer and the method of header delivery (compact blocks
                 // are allowed to be invalid in some circumstances, under BIP
                 // 152).
                 // Here, we try to detect the narrow situation that we have a
                 // valid block header (ie it was valid at the time the header
                 // was received, and hence stored in mapBlockIndex) but know the
                 // block is invalid, and that a peer has announced that same
                 // block as being on its active chain. Disconnect the peer in
                 // such a situation.
                 //
                 // Note: if the header that is invalid was not accepted to our
                 // mapBlockIndex at all, that may also be grounds for
                 // disconnecting the peer, as the chain they are on is likely to
                 // be incompatible. However, there is a circumstance where that
                 // does not hold: if the header's timestamp is more than 2 hours
                 // ahead of our current time. In that case, the header may
                 // become valid in the future, and we don't want to disconnect a
                 // peer merely for serving us one too-far-ahead block header, to
                 // prevent an attacker from splitting the network by mining a
                 // block right at the 2 hour boundary.
                 //
                 // TODO: update the DoS logic (or, rather, rewrite the
                 // DoS-interface between validation and net_processing) so that
                 // the interface is cleaner, and so that we disconnect on all
                 // the reasons that a peer's headers chain is incompatible with
                 // ours (eg block->nVersion softforks, MTP violations, etc), and
                 // not just the duplicate-invalid case.
                 pfrom->fDisconnect = true;
             }
             return error("invalid header received");
         }
     }
 
     {
         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 > chainActive.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 chainActive.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(), pfrom->nStartingHeight);
             connman->PushMessage(
                 pfrom,
                 msgMaker.Make(NetMsgType::GETHEADERS,
                               chainActive.GetLocator(pindexLast), uint256()));
         }
 
         bool fCanDirectFetch = CanDirectFetch(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) &&
             chainActive.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 && !chainActive.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 (!chainActive.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 :
                      boost::adaptors::reverse(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(),
                                         chainparams.GetConsensus(), 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);
                     }
                     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 (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 using an outbound slot (unless
                 // whitelisted or addnode).
                 // Note: We compare their tip to nMinimumChainWork (rather than
                 // chainActive.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 (IsOutboundDisconnectionCandidate(pfrom)) {
                     LogPrintf("Disconnecting outbound peer %d -- headers "
                               "chain has insufficient work\n",
                               pfrom->GetId());
                     pfrom->fDisconnect = true;
                 }
             }
         }
 
         if (!pfrom->fDisconnect && IsOutboundDisconnectionCandidate(pfrom) &&
             nodestate->pindexBestKnownBlock != nullptr) {
             // If this is an outbound peer, check to see if we should protect it
             // from the bad/lagging chain logic.
             if (g_outbound_peers_with_protect_from_disconnect <
                     MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT &&
                 nodestate->pindexBestKnownBlock->nChainWork >=
                     chainActive.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;
                 ++g_outbound_peers_with_protect_from_disconnect;
             }
         }
     }
 
     return true;
 }
 
 static bool ProcessMessage(const Config &config, CNode *pfrom,
                            const std::string &strCommand, CDataStream &vRecv,
                            int64_t nTimeReceived, CConnman *connman,
                            const std::atomic<bool> &interruptMsgProc) {
     const CChainParams &chainparams = config.GetChainParams();
     LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n",
              SanitizeString(strCommand), vRecv.size(), pfrom->GetId());
     if (gArgs.IsArgSet("-dropmessagestest") &&
         GetRand(gArgs.GetArg("-dropmessagestest", 0)) == 0) {
         LogPrintf("dropmessagestest DROPPING RECV MESSAGE\n");
         return true;
     }
 
     if (!(pfrom->GetLocalServices() & NODE_BLOOM) &&
         (strCommand == NetMsgType::FILTERLOAD ||
          strCommand == NetMsgType::FILTERADD)) {
         if (pfrom->nVersion >= NO_BLOOM_VERSION) {
             LOCK(cs_main);
             Misbehaving(pfrom, 100, "no-bloom-version");
             return false;
         } else {
             pfrom->fDisconnect = true;
             return false;
         }
     }
 
     if (strCommand == NetMsgType::REJECT) {
         if (LogAcceptCategory(BCLog::NET)) {
             try {
                 std::string strMsg;
                 uint8_t ccode;
                 std::string strReason;
                 vRecv >> LIMITED_STRING(strMsg, CMessageHeader::COMMAND_SIZE) >>
                     ccode >>
                     LIMITED_STRING(strReason, MAX_REJECT_MESSAGE_LENGTH);
 
                 std::ostringstream ss;
                 ss << strMsg << " code " << itostr(ccode) << ": " << strReason;
 
                 if (strMsg == NetMsgType::BLOCK || strMsg == NetMsgType::TX) {
                     uint256 hash;
                     vRecv >> hash;
                     ss << ": hash " << hash.ToString();
                 }
                 LogPrint(BCLog::NET, "Reject %s\n", SanitizeString(ss.str()));
             } catch (const std::ios_base::failure &) {
                 // Avoid feedback loops by preventing reject messages from
                 // triggering a new reject message.
                 LogPrint(BCLog::NET, "Unparseable reject message received\n");
             }
         }
     }
 
     else if (strCommand == NetMsgType::VERSION) {
         // Each connection can only send one version message
         if (pfrom->nVersion != 0) {
             connman->PushMessage(
                 pfrom,
                 CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::REJECT, strCommand, REJECT_DUPLICATE,
                           std::string("Duplicate version message")));
             LOCK(cs_main);
             Misbehaving(pfrom, 1, "multiple-version");
             return false;
         }
 
         int64_t nTime;
         CAddress addrMe;
         CAddress addrFrom;
         uint64_t nNonce = 1;
         uint64_t nServiceInt;
         ServiceFlags nServices;
         int nVersion;
         int nSendVersion;
         std::string strSubVer;
         std::string cleanSubVer;
         int nStartingHeight = -1;
         bool fRelay = true;
 
         vRecv >> nVersion >> nServiceInt >> nTime >> addrMe;
         nSendVersion = std::min(nVersion, PROTOCOL_VERSION);
         nServices = ServiceFlags(nServiceInt);
         if (!pfrom->fInbound) {
             connman->SetServices(pfrom->addr, nServices);
         }
         if (!pfrom->fInbound && !pfrom->fFeeler &&
             !pfrom->m_manual_connection &&
             !HasAllDesirableServiceFlags(nServices)) {
             LogPrint(
                 BCLog::NET, "peer=%d does not offer the expected services "
                             "(%08x offered, %08x expected); disconnecting\n",
                 pfrom->GetId(), nServices, GetDesirableServiceFlags(nServices));
             connman->PushMessage(
                 pfrom,
                 CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD,
                           strprintf("Expected to offer services %08x",
                                     GetDesirableServiceFlags(nServices))));
             pfrom->fDisconnect = true;
             return false;
         }
 
         if (nVersion < MIN_PEER_PROTO_VERSION) {
             // disconnect from peers older than this proto version
             LogPrintf("peer=%d using obsolete version %i; disconnecting\n",
                       pfrom->GetId(), nVersion);
             connman->PushMessage(
                 pfrom,
                 CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
                           strprintf("Version must be %d or greater",
                                     MIN_PEER_PROTO_VERSION)));
             pfrom->fDisconnect = true;
             return false;
         }
 
         if (!vRecv.empty()) {
             vRecv >> addrFrom >> nNonce;
         }
         if (!vRecv.empty()) {
             vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH);
             cleanSubVer = SanitizeString(strSubVer);
         }
         if (!vRecv.empty()) {
             vRecv >> nStartingHeight;
         }
         if (!vRecv.empty()) {
             vRecv >> fRelay;
         }
         // Disconnect if we connected to ourself
         if (pfrom->fInbound && !connman->CheckIncomingNonce(nNonce)) {
             LogPrintf("connected to self at %s, disconnecting\n",
                       pfrom->addr.ToString());
             pfrom->fDisconnect = true;
             return true;
         }
 
         if (pfrom->fInbound && addrMe.IsRoutable()) {
             SeenLocal(addrMe);
         }
 
         // Be shy and don't send version until we hear
         if (pfrom->fInbound) {
             PushNodeVersion(config, pfrom, connman, GetAdjustedTime());
         }
 
         connman->PushMessage(
             pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK));
 
         pfrom->nServices = nServices;
         pfrom->SetAddrLocal(addrMe);
         {
             LOCK(pfrom->cs_SubVer);
             pfrom->strSubVer = strSubVer;
             pfrom->cleanSubVer = cleanSubVer;
         }
         pfrom->nStartingHeight = nStartingHeight;
         pfrom->fClient = !(nServices & NODE_NETWORK);
         {
             LOCK(pfrom->cs_filter);
             // set to true after we get the first filter* message
             pfrom->fRelayTxes = fRelay;
         }
 
         // Change version
         pfrom->SetSendVersion(nSendVersion);
         pfrom->nVersion = nVersion;
 
         // Potentially mark this peer as a preferred download peer.
         {
             LOCK(cs_main);
             UpdatePreferredDownload(pfrom, State(pfrom->GetId()));
         }
 
         if (!pfrom->fInbound) {
             // Advertise our address
             if (fListen && !IsInitialBlockDownload()) {
                 CAddress addr =
                     GetLocalAddress(&pfrom->addr, pfrom->GetLocalServices());
                 FastRandomContext insecure_rand;
                 if (addr.IsRoutable()) {
                     LogPrint(BCLog::NET,
                              "ProcessMessages: advertising address %s\n",
                              addr.ToString());
                     pfrom->PushAddress(addr, insecure_rand);
                 } else if (IsPeerAddrLocalGood(pfrom)) {
                     addr.SetIP(addrMe);
                     LogPrint(BCLog::NET,
                              "ProcessMessages: advertising address %s\n",
                              addr.ToString());
                     pfrom->PushAddress(addr, insecure_rand);
                 }
             }
 
             // Get recent addresses
             if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION ||
                 connman->GetAddressCount() < 1000) {
                 connman->PushMessage(
                     pfrom,
                     CNetMsgMaker(nSendVersion).Make(NetMsgType::GETADDR));
                 pfrom->fGetAddr = true;
             }
             connman->MarkAddressGood(pfrom->addr);
         }
 
         std::string remoteAddr;
         if (fLogIPs) {
             remoteAddr = ", peeraddr=" + pfrom->addr.ToString();
         }
 
         LogPrintf("receive version message: [%s] %s: version %d, blocks=%d, "
                   "us=%s, peer=%d%s\n",
                   pfrom->addr.ToString().c_str(), cleanSubVer, pfrom->nVersion,
                   pfrom->nStartingHeight, addrMe.ToString(), pfrom->GetId(),
                   remoteAddr);
 
         int64_t nTimeOffset = nTime - GetTime();
         pfrom->nTimeOffset = nTimeOffset;
         AddTimeData(pfrom->addr, nTimeOffset);
 
         // If the peer is old enough to have the old alert system, send it the
         // final alert.
         if (pfrom->nVersion <= 70012) {
             CDataStream finalAlert(
                 ParseHex("60010000000000000000000000ffffff7f00000000ffffff7ffef"
                          "fff7f01ffffff7f00000000ffffff7f00ffffff7f002f55524745"
                          "4e543a20416c657274206b657920636f6d70726f6d697365642c2"
                          "075706772616465207265717569726564004630440220653febd6"
                          "410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3ab"
                          "d5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fec"
                          "aae66ecf689bf71b50"),
                 SER_NETWORK, PROTOCOL_VERSION);
             connman->PushMessage(
                 pfrom, CNetMsgMaker(nSendVersion).Make("alert", finalAlert));
         }
 
         // Feeler connections exist only to verify if address is online.
         if (pfrom->fFeeler) {
             assert(pfrom->fInbound == false);
             pfrom->fDisconnect = true;
         }
         return true;
     }
 
     else if (pfrom->nVersion == 0) {
         // Must have a version message before anything else
         LOCK(cs_main);
         Misbehaving(pfrom, 1, "missing-version");
         return false;
     }
 
     // At this point, the outgoing message serialization version can't change.
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
 
     if (strCommand == NetMsgType::VERACK) {
         pfrom->SetRecvVersion(
             std::min(pfrom->nVersion.load(), PROTOCOL_VERSION));
 
         if (!pfrom->fInbound) {
             // Mark this node as currently connected, so we update its timestamp
             // later.
             LOCK(cs_main);
             State(pfrom->GetId())->fCurrentlyConnected = true;
         }
 
         if (pfrom->nVersion >= 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)
             connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDHEADERS));
         }
         if (pfrom->nVersion >= 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;
             connman->PushMessage(pfrom,
                                  msgMaker.Make(NetMsgType::SENDCMPCT,
                                                fAnnounceUsingCMPCTBLOCK,
                                                nCMPCTBLOCKVersion));
         }
         pfrom->fSuccessfullyConnected = true;
     }
 
     else if (!pfrom->fSuccessfullyConnected) {
         // Must have a verack message before anything else
         LOCK(cs_main);
         Misbehaving(pfrom, 1, "missing-verack");
         return false;
     }
 
     else if (strCommand == NetMsgType::ADDR) {
         std::vector<CAddress> vAddr;
         vRecv >> vAddr;
 
         // Don't want addr from older versions unless seeding
         if (pfrom->nVersion < CADDR_TIME_VERSION &&
             connman->GetAddressCount() > 1000) {
             return true;
         }
         if (vAddr.size() > 1000) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "oversized-addr");
             return error("message addr size() = %u", vAddr.size());
         }
 
         // Store the new addresses
         std::vector<CAddress> vAddrOk;
         int64_t nNow = GetAdjustedTime();
         int64_t nSince = nNow - 10 * 60;
         for (CAddress &addr : vAddr) {
             if (interruptMsgProc) {
                 return true;
             }
 
             // 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)) {
                 continue;
             }
 
             if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60) {
                 addr.nTime = nNow - 5 * 24 * 60 * 60;
             }
             pfrom->AddAddressKnown(addr);
             bool fReachable = IsReachable(addr);
             if (addr.nTime > nSince && !pfrom->fGetAddr && vAddr.size() <= 10 &&
                 addr.IsRoutable()) {
                 // Relay to a limited number of other nodes
                 RelayAddress(addr, fReachable, connman);
             }
             // Do not store addresses outside our network
             if (fReachable) {
                 vAddrOk.push_back(addr);
             }
         }
 
         connman->AddNewAddresses(vAddrOk, pfrom->addr, 2 * 60 * 60);
         if (vAddr.size() < 1000) {
             pfrom->fGetAddr = false;
         }
         if (pfrom->fOneShot) {
             pfrom->fDisconnect = true;
         }
     }
 
     else if (strCommand == NetMsgType::SENDHEADERS) {
         LOCK(cs_main);
         State(pfrom->GetId())->fPreferHeaders = true;
     }
 
     else if (strCommand == 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;
             if (!State(pfrom->GetId())->fSupportsDesiredCmpctVersion) {
                 State(pfrom->GetId())->fSupportsDesiredCmpctVersion = true;
             }
         }
     }
 
     else if (strCommand == NetMsgType::INV) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "oversized-inv");
             return error("message inv size() = %u", vInv.size());
         }
 
         bool fBlocksOnly = !fRelayTxes;
 
         // Allow whitelisted peers to send data other than blocks in blocks only
         // mode if whitelistrelay is true
         if (pfrom->fWhitelisted &&
             gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) {
             fBlocksOnly = false;
         }
 
         LOCK(cs_main);
 
         std::vector<CInv> vToFetch;
 
         for (CInv &inv : vInv) {
             if (interruptMsgProc) {
                 return true;
             }
 
             bool fAlreadyHave = AlreadyHave(inv);
             LogPrint(BCLog::NET, "got inv: %s  %s peer=%d\n", inv.ToString(),
                      fAlreadyHave ? "have" : "new", pfrom->GetId());
 
             if (inv.type == MSG_BLOCK) {
                 UpdateBlockAvailability(pfrom->GetId(), inv.hash);
                 if (!fAlreadyHave && !fImporting && !fReindex &&
                     !mapBlocksInFlight.count(inv.hash)) {
                     // We used to request the full block here, but since
                     // headers-announcements are now the primary method of
                     // announcement on the network, and since, in the case that
                     // a node fell back to inv we probably have a reorg which we
                     // should get the headers for first, we now only provide a
                     // getheaders response here. When we receive the headers, we
                     // will then ask for the blocks we need.
                     connman->PushMessage(
                         pfrom,
                         msgMaker.Make(NetMsgType::GETHEADERS,
                                       chainActive.GetLocator(pindexBestHeader),
                                       inv.hash));
                     LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n",
                              pindexBestHeader->nHeight, inv.hash.ToString(),
                              pfrom->GetId());
                 }
             } else {
                 pfrom->AddInventoryKnown(inv);
                 if (fBlocksOnly) {
                     LogPrint(BCLog::NET, "transaction (%s) inv sent in "
                                          "violation of protocol peer=%d\n",
                              inv.hash.ToString(), pfrom->GetId());
                 } else if (!fAlreadyHave && !fImporting && !fReindex &&
                            !IsInitialBlockDownload()) {
                     pfrom->AskFor(inv);
                 }
             }
 
             // Track requests for our stuff
             GetMainSignals().Inventory(inv.hash);
         }
 
         if (!vToFetch.empty()) {
             connman->PushMessage(pfrom,
                                  msgMaker.Make(NetMsgType::GETDATA, vToFetch));
         }
     }
 
     else if (strCommand == NetMsgType::GETDATA) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "too-many-inv");
             return error("message getdata size() = %u", vInv.size());
         }
 
         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());
         }
 
         pfrom->vRecvGetData.insert(pfrom->vRecvGetData.end(), vInv.begin(),
                                    vInv.end());
         ProcessGetData(config, pfrom, connman, interruptMsgProc);
     }
 
     else if (strCommand == NetMsgType::GETBLOCKS) {
         CBlockLocator locator;
         uint256 hashStop;
         vRecv >> locator >> hashStop;
 
         // 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;
             }
             CValidationState dummy;
             ActivateBestChain(config, dummy, a_recent_block);
         }
 
         LOCK(cs_main);
 
         // Find the last block the caller has in the main chain
         const CBlockIndex *pindex = FindForkInGlobalIndex(chainActive, locator);
 
         // Send the rest of the chain
         if (pindex) {
             pindex = chainActive.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 = chainActive.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 / chainparams.GetConsensus().nPowTargetSpacing;
             if (fPruneMode &&
                 (!pindex->nStatus.hasData() ||
                  pindex->nHeight <=
                      chainActive.Tip()->nHeight - nPrunedBlocksLikelyToHave)) {
                 LogPrint(
                     BCLog::NET,
                     " getblocks stopping, pruned or too old block at %d %s\n",
                     pindex->nHeight, pindex->GetBlockHash().ToString());
                 break;
             }
             pfrom->PushInventory(CInv(MSG_BLOCK, 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());
                 pfrom->hashContinue = pindex->GetBlockHash();
                 break;
             }
         }
     }
 
     else if (strCommand == 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(*recent_block, req, pfrom, connman);
             return true;
         }
 
         LOCK(cs_main);
 
         BlockMap::iterator it = mapBlockIndex.find(req.blockhash);
         if (it == mapBlockIndex.end() || !it->second->nStatus.hasData()) {
             LogPrintf("Peer %d sent us a getblocktxn for a block we don't have",
                       pfrom->GetId());
             return true;
         }
 
         if (it->second->nHeight < chainActive.Height() - MAX_BLOCKTXN_DEPTH) {
             // 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",
                      pfrom->GetId(), MAX_BLOCKTXN_DEPTH);
             CInv inv;
             inv.type = MSG_BLOCK;
             inv.hash = req.blockhash;
             pfrom->vRecvGetData.push_back(inv);
             ProcessGetData(config, pfrom, connman, interruptMsgProc);
             return true;
         }
 
         CBlock block;
         bool ret = ReadBlockFromDisk(block, it->second, config);
         assert(ret);
 
         SendBlockTransactions(block, req, pfrom, connman);
     }
 
     else if (strCommand == NetMsgType::GETHEADERS) {
         CBlockLocator locator;
         uint256 hashStop;
         vRecv >> locator >> hashStop;
 
         LOCK(cs_main);
         if (IsInitialBlockDownload() && !pfrom->fWhitelisted) {
             LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because "
                                  "node is in initial block download\n",
                      pfrom->GetId());
             return true;
         }
 
         CNodeState *nodestate = State(pfrom->GetId());
         const CBlockIndex *pindex = nullptr;
         if (locator.IsNull()) {
             // If locator is null, return the hashStop block
             BlockMap::iterator mi = mapBlockIndex.find(hashStop);
             if (mi == mapBlockIndex.end()) {
                 return true;
             }
             pindex = (*mi).second;
         } else {
             // Find the last block the caller has in the main chain
             pindex = FindForkInGlobalIndex(chainActive, locator);
             if (pindex) {
                 pindex = chainActive.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 = chainActive.Next(pindex)) {
             vHeaders.push_back(pindex->GetBlockHeader());
             if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop) {
                 break;
             }
         }
         // pindex can be nullptr either if we sent chainActive.Tip() OR
         // if our peer has chainActive.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 : chainActive.Tip();
         connman->PushMessage(pfrom,
                              msgMaker.Make(NetMsgType::HEADERS, vHeaders));
     }
 
     else if (strCommand == NetMsgType::TX) {
         // Stop processing the transaction early if
         // We are in blocks only mode and peer is either not whitelisted or
         // whitelistrelay is off
         if (!fRelayTxes &&
             (!pfrom->fWhitelisted ||
              !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))) {
             LogPrint(BCLog::NET,
                      "transaction sent in violation of protocol peer=%d\n",
                      pfrom->GetId());
             return true;
         }
 
         std::deque<COutPoint> vWorkQueue;
         std::vector<uint256> vEraseQueue;
         CTransactionRef ptx;
         vRecv >> ptx;
         const CTransaction &tx = *ptx;
 
         CInv inv(MSG_TX, tx.GetId());
         pfrom->AddInventoryKnown(inv);
 
         LOCK(cs_main);
 
         bool fMissingInputs = false;
         CValidationState state;
 
         pfrom->setAskFor.erase(inv.hash);
         mapAlreadyAskedFor.erase(inv.hash);
 
         if (!AlreadyHave(inv) && AcceptToMemoryPool(config, mempool, state, ptx,
                                                     true, &fMissingInputs)) {
             mempool.check(pcoinsTip.get());
             RelayTransaction(tx, connman);
             for (size_t i = 0; i < tx.vout.size(); i++) {
                 vWorkQueue.emplace_back(inv.hash, i);
             }
 
             pfrom->nLastTXTime = GetTime();
 
             LogPrint(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s "
                                      "(poolsz %u txn, %u kB)\n",
                      pfrom->GetId(), tx.GetId().ToString(), mempool.size(),
                      mempool.DynamicMemoryUsage() / 1000);
 
             // Recursively process any orphan transactions that depended on this
             // one
             std::set<NodeId> setMisbehaving;
             while (!vWorkQueue.empty()) {
                 auto itByPrev =
                     mapOrphanTransactionsByPrev.find(vWorkQueue.front());
                 vWorkQueue.pop_front();
                 if (itByPrev == mapOrphanTransactionsByPrev.end()) {
                     continue;
                 }
                 for (auto mi = itByPrev->second.begin();
                      mi != itByPrev->second.end(); ++mi) {
                     const CTransactionRef &porphanTx = (*mi)->second.tx;
                     const CTransaction &orphanTx = *porphanTx;
                     const uint256 &orphanId = orphanTx.GetId();
                     NodeId fromPeer = (*mi)->second.fromPeer;
                     bool fMissingInputs2 = false;
                     // Use a dummy CValidationState so someone can't setup nodes
                     // to counter-DoS based on orphan resolution (that is,
                     // feeding people an invalid transaction based on LegitTxX
                     // in order to get anyone relaying LegitTxX banned)
                     CValidationState stateDummy;
 
                     if (setMisbehaving.count(fromPeer)) {
                         continue;
                     }
                     if (AcceptToMemoryPool(config, mempool, stateDummy,
                                            porphanTx, true, &fMissingInputs2)) {
                         LogPrint(BCLog::MEMPOOL, "   accepted orphan tx %s\n",
                                  orphanId.ToString());
                         RelayTransaction(orphanTx, connman);
                         for (size_t i = 0; i < orphanTx.vout.size(); i++) {
                             vWorkQueue.emplace_back(orphanId, i);
                         }
                         vEraseQueue.push_back(orphanId);
                     } else if (!fMissingInputs2) {
                         int nDos = 0;
                         if (stateDummy.IsInvalid(nDos) && nDos > 0) {
                             // Punish peer that gave us an invalid orphan tx
                             Misbehaving(fromPeer, nDos, "invalid-orphan-tx");
                             setMisbehaving.insert(fromPeer);
                             LogPrint(BCLog::MEMPOOL,
                                      "   invalid orphan tx %s\n",
                                      orphanId.ToString());
                         }
                         // Has inputs but not accepted to mempool
                         // Probably non-standard or insufficient fee/priority
                         LogPrint(BCLog::MEMPOOL, "   removed orphan tx %s\n",
                                  orphanId.ToString());
                         vEraseQueue.push_back(orphanId);
                         if (!stateDummy.CorruptionPossible()) {
                             // Do not use rejection cache for witness
                             // transactions or witness-stripped transactions, as
                             // they can have been malleated. See
                             // https://github.com/bitcoin/bitcoin/issues/8279
                             // for details.
                             assert(recentRejects);
                             recentRejects->insert(orphanId);
                         }
                     }
                     mempool.check(pcoinsTip.get());
                 }
             }
 
             for (const uint256 &hash : vEraseQueue) {
                 EraseOrphanTx(hash);
             }
         } else if (fMissingInputs) {
             // It may be the case that the orphans parents have all been
             // rejected.
             bool fRejectedParents = false;
             for (const CTxIn &txin : tx.vin) {
                 if (recentRejects->contains(txin.prevout.GetTxId())) {
                     fRejectedParents = true;
                     break;
                 }
             }
             if (!fRejectedParents) {
                 for (const CTxIn &txin : tx.vin) {
                     // FIXME: MSG_TX should use a TxHash, not a TxId.
                     CInv _inv(MSG_TX, txin.prevout.GetTxId());
                     pfrom->AddInventoryKnown(_inv);
                     if (!AlreadyHave(_inv)) {
                         pfrom->AskFor(_inv);
                     }
                 }
                 AddOrphanTx(ptx, pfrom->GetId());
 
                 // DoS prevention: do not allow mapOrphanTransactions to grow
                 // unbounded
                 unsigned int nMaxOrphanTx = (unsigned int)std::max(
                     int64_t(0),
                     gArgs.GetArg("-maxorphantx",
                                  DEFAULT_MAX_ORPHAN_TRANSACTIONS));
                 unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx);
                 if (nEvicted > 0) {
                     LogPrint(BCLog::MEMPOOL,
                              "mapOrphan 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());
             }
         } else {
             if (!state.CorruptionPossible()) {
                 // Do not use rejection cache for witness transactions or
                 // witness-stripped transactions, as they can have been
                 // malleated. See https://github.com/bitcoin/bitcoin/issues/8279
                 // for details.
                 assert(recentRejects);
                 recentRejects->insert(tx.GetId());
                 if (RecursiveDynamicUsage(*ptx) < 100000) {
                     AddToCompactExtraTransactions(ptx);
                 }
             }
 
             if (pfrom->fWhitelisted &&
                 gArgs.GetBoolArg("-whitelistforcerelay",
                                  DEFAULT_WHITELISTFORCERELAY)) {
                 // Always relay transactions received from whitelisted peers,
                 // even if they were already in the mempool or rejected from it
                 // due to policy, allowing the node to function as a gateway for
                 // nodes hidden behind it.
                 //
                 // Never relay transactions that we would assign a non-zero DoS
                 // score for, as we expect peers to do the same with us in that
                 // case.
                 int nDoS = 0;
                 if (!state.IsInvalid(nDoS) || nDoS == 0) {
                     LogPrintf("Force relaying tx %s from whitelisted peer=%d\n",
                               tx.GetId().ToString(), pfrom->GetId());
                     RelayTransaction(tx, connman);
                 } else {
                     LogPrintf("Not relaying invalid transaction %s from "
                               "whitelisted peer=%d (%s)\n",
                               tx.GetId().ToString(), pfrom->GetId(),
                               FormatStateMessage(state));
                 }
             }
         }
 
         int nDoS = 0;
         if (state.IsInvalid(nDoS)) {
             LogPrint(BCLog::MEMPOOLREJ,
                      "%s from peer=%d was not accepted: %s\n",
                      tx.GetHash().ToString(), pfrom->GetId(),
                      FormatStateMessage(state));
             // Never send AcceptToMemoryPool's internal codes over P2P.
             if (state.GetRejectCode() > 0 &&
                 state.GetRejectCode() < REJECT_INTERNAL) {
                 connman->PushMessage(
                     pfrom,
                     msgMaker.Make(NetMsgType::REJECT, strCommand,
                                   uint8_t(state.GetRejectCode()),
                                   state.GetRejectReason().substr(
                                       0, MAX_REJECT_MESSAGE_LENGTH),
                                   inv.hash));
             }
             if (nDoS > 0) {
                 Misbehaving(pfrom, nDoS, state.GetRejectReason());
             }
         }
     }
 
     // Ignore blocks received while importing
     else if (strCommand == NetMsgType::CMPCTBLOCK && !fImporting && !fReindex) {
         CBlockHeaderAndShortTxIDs cmpctblock;
         vRecv >> cmpctblock;
 
         bool received_new_header = false;
 
         {
             LOCK(cs_main);
 
             if (mapBlockIndex.find(cmpctblock.header.hashPrevBlock) ==
                 mapBlockIndex.end()) {
                 // Doesn't connect (or is genesis), instead of DoSing in
                 // AcceptBlockHeader, request deeper headers
                 if (!IsInitialBlockDownload()) {
                     connman->PushMessage(
                         pfrom,
                         msgMaker.Make(NetMsgType::GETHEADERS,
                                       chainActive.GetLocator(pindexBestHeader),
                                       uint256()));
                 }
                 return true;
             }
 
             if (mapBlockIndex.find(cmpctblock.header.GetHash()) ==
                 mapBlockIndex.end()) {
                 received_new_header = true;
             }
         }
 
         const CBlockIndex *pindex = nullptr;
         CValidationState state;
         if (!ProcessNewBlockHeaders(config, {cmpctblock.header}, state,
                                     &pindex)) {
             int nDoS;
             if (state.IsInvalid(nDoS)) {
                 if (nDoS > 0) {
                     LOCK(cs_main);
                     Misbehaving(pfrom, nDoS, state.GetRejectReason());
                 }
                 LogPrintf("Peer %d sent us invalid header via cmpctblock\n",
                           pfrom->GetId());
                 return true;
             }
         }
 
         // 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;
 
         {
             LOCK(cs_main);
             // 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 > chainActive.Tip()->nChainWork) {
                 nodestate->m_last_block_announcement = GetTime();
             }
 
             std::map<uint256,
                      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 true;
             }
 
             if (pindex->nChainWork <=
                     chainActive.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());
                     connman->PushMessage(
                         pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                 }
                 return true;
             }
 
             // If we're not close to tip yet, give up and let parallel block
             // fetch work its magic.
             if (!fAlreadyInFlight &&
                 !CanDirectFetch(chainparams.GetConsensus())) {
                 return true;
             }
 
             // We want to be a bit conservative just to be extra careful about
             // DoS possibilities in compact block processing...
             if (pindex->nHeight <= chainActive.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(),
                                              chainparams.GetConsensus(), pindex,
                                              &queuedBlockIt)) {
                         if (!(*queuedBlockIt)->partialBlock) {
                             (*queuedBlockIt)
                                 ->partialBlock.reset(
                                     new PartiallyDownloadedBlock(config,
                                                                  &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 true;
                         }
                     }
 
                     PartiallyDownloadedBlock &partialBlock =
                         *(*queuedBlockIt)->partialBlock;
                     ReadStatus status =
                         partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
                     if (status == READ_STATUS_INVALID) {
                         // Reset in-flight state in case of whitelist
                         MarkBlockAsReceived(pindex->GetBlockHash());
                         Misbehaving(pfrom, 100, "invalid-cmpctblk");
                         LogPrintf("Peer %d sent us invalid compact block\n",
                                   pfrom->GetId());
                         return true;
                     } 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());
                         connman->PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                         return true;
                     }
 
                     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();
                         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, &mempool);
                     ReadStatus status =
                         tempBlock.InitData(cmpctblock, vExtraTxnForCompact);
                     if (status != READ_STATUS_OK) {
                         // TODO: don't ignore failures
                         return true;
                     }
                     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());
                     connman->PushMessage(
                         pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                     return true;
                 } 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, nTimeReceived, connman,
                                   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, connman,
                                          {cmpctblock.header},
                                          /*punish_duplicate_invalid=*/false);
         }
 
         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.
             ProcessNewBlock(config, pblock, /*fForceProcessing=*/true,
                             &fNewBlock);
             if (fNewBlock) {
                 pfrom->nLastBlockTime = GetTime();
             }
 
             // 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());
             }
         }
 
     }
 
     else if (strCommand == NetMsgType::BLOCKTXN && !fImporting &&
              !fReindex) // Ignore blocks received while importing
     {
         BlockTransactions resp;
         vRecv >> resp;
 
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         bool fBlockRead = false;
         {
             LOCK(cs_main);
 
             std::map<uint256,
                      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 true;
             }
 
             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 whitelist.
                 MarkBlockAsReceived(resp.blockhash);
                 Misbehaving(pfrom, 100, "invalid-cmpctblk-txns");
                 LogPrintf("Peer %d sent us invalid compact block/non-matching "
                           "block transactions\n",
                           pfrom->GetId());
                 return true;
             } 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));
                 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, reject messages go out, etc.
 
                 // it is now an empty pointer
                 MarkBlockAsReceived(resp.blockhash);
                 fBlockRead = true;
                 // mapBlockSource is only used for sending reject messages and
                 // DoS scores, 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.
             ProcessNewBlock(config, pblock, /*fForceProcessing=*/true,
                             &fNewBlock);
             if (fNewBlock) {
                 pfrom->nLastBlockTime = GetTime();
             }
         }
     }
 
     // Ignore headers received while importing
     else if (strCommand == NetMsgType::HEADERS && !fImporting && !fReindex) {
         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) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "too-many-headers");
             return error("headers message size = %u", nCount);
         }
         headers.resize(nCount);
         for (unsigned int n = 0; n < nCount; n++) {
             vRecv >> headers[n];
             // Ignore tx count; assume it is 0.
             ReadCompactSize(vRecv);
         }
 
         // Headers received via a HEADERS message should be valid, and reflect
         // the chain the peer is on. If we receive a known-invalid header,
         // disconnect the peer if it is using one of our outbound connection
         // slots.
         bool should_punish = !pfrom->fInbound && !pfrom->m_manual_connection;
         return ProcessHeadersMessage(config, pfrom, connman, headers,
                                      should_punish);
     }
 
     else if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) {
         // Ignore blocks received while importing.
         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->fWhitelisted && !IsInitialBlockDownload();
         const uint256 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 sending reject messages and DoS
             // scores, so the race between here and cs_main in ProcessNewBlock
             // is fine.
             mapBlockSource.emplace(hash, std::make_pair(pfrom->GetId(), true));
         }
         bool fNewBlock = false;
         ProcessNewBlock(config, pblock, forceProcessing, &fNewBlock);
         if (fNewBlock) {
             pfrom->nLastBlockTime = GetTime();
         }
     }
 
     else if (strCommand == 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->fInbound) {
             LogPrint(BCLog::NET,
                      "Ignoring \"getaddr\" from outbound connection. peer=%d\n",
                      pfrom->GetId());
             return true;
         }
 
         // Only send one GetAddr response per connection to reduce resource
         // waste and discourage addr stamping of INV announcements.
         if (pfrom->fSentAddr) {
             LogPrint(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n",
                      pfrom->GetId());
             return true;
         }
         pfrom->fSentAddr = true;
 
         pfrom->vAddrToSend.clear();
         std::vector<CAddress> vAddr = connman->GetAddresses();
         FastRandomContext insecure_rand;
         for (const CAddress &addr : vAddr) {
             pfrom->PushAddress(addr, insecure_rand);
         }
     }
 
     else if (strCommand == NetMsgType::MEMPOOL) {
         if (!(pfrom->GetLocalServices() & NODE_BLOOM) && !pfrom->fWhitelisted) {
             LogPrint(BCLog::NET, "mempool request with bloom filters disabled, "
                                  "disconnect peer=%d\n",
                      pfrom->GetId());
             pfrom->fDisconnect = true;
             return true;
         }
 
         if (connman->OutboundTargetReached(false) && !pfrom->fWhitelisted) {
             LogPrint(BCLog::NET, "mempool request with bandwidth limit "
                                  "reached, disconnect peer=%d\n",
                      pfrom->GetId());
             pfrom->fDisconnect = true;
             return true;
         }
 
         LOCK(pfrom->cs_inventory);
         pfrom->fSendMempool = true;
     }
 
     else if (strCommand == NetMsgType::PING) {
         if (pfrom->nVersion > 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.
             connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::PONG, nonce));
         }
     }
 
     else if (strCommand == NetMsgType::PONG) {
         int64_t pingUsecEnd = nTimeReceived;
         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 (pfrom->nPingNonceSent != 0) {
                 if (nonce == pfrom->nPingNonceSent) {
                     // Matching pong received, this ping is no longer
                     // outstanding
                     bPingFinished = true;
                     int64_t pingUsecTime = pingUsecEnd - pfrom->nPingUsecStart;
                     if (pingUsecTime > 0) {
                         // Successful ping time measurement, replace previous
                         pfrom->nPingUsecTime = pingUsecTime;
                         pfrom->nMinPingUsecTime = std::min(
                             pfrom->nMinPingUsecTime.load(), pingUsecTime);
                     } 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, pfrom->nPingNonceSent, nonce,
                      nAvail);
         }
         if (bPingFinished) {
             pfrom->nPingNonceSent = 0;
         }
     }
 
     else if (strCommand == NetMsgType::FILTERLOAD) {
         CBloomFilter filter;
         vRecv >> filter;
 
         if (!filter.IsWithinSizeConstraints()) {
             // There is no excuse for sending a too-large filter
             LOCK(cs_main);
             Misbehaving(pfrom, 100, "oversized-bloom-filter");
         } else {
             LOCK(pfrom->cs_filter);
             pfrom->pfilter.reset(new CBloomFilter(filter));
             pfrom->pfilter->UpdateEmptyFull();
             pfrom->fRelayTxes = true;
         }
     }
 
     else if (strCommand == NetMsgType::FILTERADD) {
         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 {
             LOCK(pfrom->cs_filter);
             if (pfrom->pfilter) {
                 pfrom->pfilter->insert(vData);
             } else {
                 bad = true;
             }
         }
         if (bad) {
             LOCK(cs_main);
             // The structure of this code doesn't really allow for a good error
             // code. We'll go generic.
             Misbehaving(pfrom, 100, "invalid-filteradd");
         }
     }
 
     else if (strCommand == NetMsgType::FILTERCLEAR) {
         LOCK(pfrom->cs_filter);
         if (pfrom->GetLocalServices() & NODE_BLOOM) {
             pfrom->pfilter.reset(new CBloomFilter());
         }
         pfrom->fRelayTxes = true;
     }
 
     else if (strCommand == NetMsgType::FEEFILTER) {
         Amount newFeeFilter = Amount::zero();
         vRecv >> newFeeFilter;
         if (MoneyRange(newFeeFilter)) {
             {
                 LOCK(pfrom->cs_feeFilter);
                 pfrom->minFeeFilter = newFeeFilter;
             }
             LogPrint(BCLog::NET, "received: feefilter of %s from peer=%d\n",
                      CFeeRate(newFeeFilter).ToString(), pfrom->GetId());
         }
     }
 
     else if (strCommand == NetMsgType::NOTFOUND) {
         // We do not care about the NOTFOUND message, but logging an Unknown
         // Command message would be undesirable as we transmit it ourselves.
     }
 
     else {
         // Ignore unknown commands for extensibility
         LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n",
                  SanitizeString(strCommand), pfrom->GetId());
     }
 
     return true;
 }
 
 static bool SendRejectsAndCheckIfBanned(CNode *pnode, CConnman *connman) {
     AssertLockHeld(cs_main);
     CNodeState &state = *State(pnode->GetId());
 
     for (const CBlockReject &reject : state.rejects) {
         connman->PushMessage(
             pnode,
             CNetMsgMaker(INIT_PROTO_VERSION)
                 .Make(NetMsgType::REJECT, std::string(NetMsgType::BLOCK),
                       reject.chRejectCode, reject.strRejectReason,
                       reject.hashBlock));
     }
     state.rejects.clear();
 
     if (state.fShouldBan) {
         state.fShouldBan = false;
         if (pnode->fWhitelisted) {
             LogPrintf("Warning: not punishing whitelisted peer %s!\n",
                       pnode->addr.ToString());
         } else if (pnode->m_manual_connection) {
             LogPrintf("Warning: not punishing manually-connected peer %s!\n",
                       pnode->addr.ToString());
         } else {
             pnode->fDisconnect = true;
             if (pnode->addr.IsLocal()) {
                 LogPrintf("Warning: not banning local peer %s!\n",
                           pnode->addr.ToString());
             } else {
                 connman->Ban(pnode->addr, BanReasonNodeMisbehaving);
             }
         }
         return true;
     }
     return false;
 }
 
 bool PeerLogicValidation::ProcessMessages(const Config &config, CNode *pfrom,
                                           std::atomic<bool> &interruptMsgProc) {
     const CChainParams &chainparams = config.GetChainParams();
     //
     // Message format
     //  (4) message start
     //  (12) command
     //  (4) size
     //  (4) checksum
     //  (x) data
     //
     bool fMoreWork = false;
 
     if (!pfrom->vRecvGetData.empty()) {
         ProcessGetData(config, pfrom, connman, interruptMsgProc);
     }
 
     if (pfrom->fDisconnect) {
         return false;
     }
 
     // this maintains the order of responses
     if (!pfrom->vRecvGetData.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().vRecv.size() + CMessageHeader::HEADER_SIZE;
         pfrom->fPauseRecv =
             pfrom->nProcessQueueSize > connman->GetReceiveFloodSize();
         fMoreWork = !pfrom->vProcessMsg.empty();
     }
     CNetMessage &msg(msgs.front());
 
     msg.SetVersion(pfrom->GetRecvVersion());
 
     // Scan for message start
     if (memcmp(std::begin(msg.hdr.pchMessageStart),
                std::begin(chainparams.NetMagic()),
                CMessageHeader::MESSAGE_START_SIZE) != 0) {
         LogPrintf("PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n",
                   SanitizeString(msg.hdr.GetCommand()), pfrom->GetId());
 
         // Make sure we ban where that come from for some time.
         connman->Ban(pfrom->addr, BanReasonNodeMisbehaving);
 
         pfrom->fDisconnect = true;
         return false;
     }
 
     // Read header
     CMessageHeader &hdr = msg.hdr;
     if (!hdr.IsValid(config)) {
         LogPrintf("PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n",
                   SanitizeString(hdr.GetCommand()), pfrom->GetId());
         return fMoreWork;
     }
     std::string strCommand = hdr.GetCommand();
 
     // Message size
     unsigned int nMessageSize = hdr.nMessageSize;
 
     // Checksum
     CDataStream &vRecv = msg.vRecv;
     const uint256 &hash = msg.GetMessageHash();
     if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) !=
         0) {
         LogPrintf(
             "%s(%s, %u bytes): CHECKSUM ERROR expected %s was %s\n", __func__,
             SanitizeString(strCommand), nMessageSize,
             HexStr(hash.begin(), hash.begin() + CMessageHeader::CHECKSUM_SIZE),
             HexStr(hdr.pchChecksum,
                    hdr.pchChecksum + CMessageHeader::CHECKSUM_SIZE));
         return fMoreWork;
     }
 
     // Process message
     bool fRet = false;
     try {
         fRet = ProcessMessage(config, pfrom, strCommand, vRecv, msg.nTime,
                               connman, interruptMsgProc);
         if (interruptMsgProc) {
             return false;
         }
         if (!pfrom->vRecvGetData.empty()) {
             fMoreWork = true;
         }
     } catch (const std::ios_base::failure &e) {
         connman->PushMessage(pfrom,
                              CNetMsgMaker(INIT_PROTO_VERSION)
                                  .Make(NetMsgType::REJECT, strCommand,
                                        REJECT_MALFORMED,
                                        std::string("error parsing message")));
         if (strstr(e.what(), "end of data")) {
             // Allow exceptions from under-length message on vRecv
             LogPrintf(
                 "%s(%s, %u bytes): Exception '%s' caught, normally caused by a "
                 "message being shorter than its stated length\n",
                 __func__, SanitizeString(strCommand), nMessageSize, e.what());
         } else if (strstr(e.what(), "size too large")) {
             // Allow exceptions from over-long size
             LogPrintf("%s(%s, %u bytes): Exception '%s' caught\n", __func__,
                       SanitizeString(strCommand), nMessageSize, e.what());
         } else if (strstr(e.what(), "non-canonical ReadCompactSize()")) {
             // Allow exceptions from non-canonical encoding
             LogPrintf("%s(%s, %u bytes): Exception '%s' caught\n", __func__,
                       SanitizeString(strCommand), nMessageSize, e.what());
         } else {
             PrintExceptionContinue(&e, "ProcessMessages()");
         }
     } catch (const std::exception &e) {
         PrintExceptionContinue(&e, "ProcessMessages()");
     } catch (...) {
         PrintExceptionContinue(nullptr, "ProcessMessages()");
     }
 
     if (!fRet) {
         LogPrintf("%s(%s, %u bytes) FAILED peer=%d\n", __func__,
                   SanitizeString(strCommand), nMessageSize, pfrom->GetId());
     }
 
     LOCK(cs_main);
     SendRejectsAndCheckIfBanned(pfrom, connman);
 
     return fMoreWork;
 }
 
 void PeerLogicValidation::ConsiderEviction(CNode *pto,
                                            int64_t time_in_seconds) {
     AssertLockHeld(cs_main);
 
     CNodeState &state = *State(pto->GetId());
     const CNetMsgMaker msgMaker(pto->GetSendVersion());
 
     if (!state.m_chain_sync.m_protect &&
         IsOutboundDisconnectionCandidate(pto) && 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 >=
                 chainActive.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 = chainActive.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 {
                 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());
                 connman->PushMessage(
                     pto,
                     msgMaker.Make(NetMsgType::GETHEADERS,
                                   chainActive.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 PeerLogicValidation::EvictExtraOutboundPeers(int64_t time_in_seconds) {
     // Check whether we have too many outbound peers
     int extra_peers = connman->GetExtraOutboundCount();
     if (extra_peers <= 0) {
         return;
     }
 
     // If we have more outbound peers than we target, disconnect one.
     // Pick the outbound 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();
 
     LOCK(cs_main);
 
     connman->ForEachNode([&](CNode *pnode) {
         AssertLockHeld(cs_main);
 
         // Ignore non-outbound peers, or nodes marked for disconnect already
         if (!IsOutboundDisconnectionCandidate(pnode) || 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 = connman->ForNode(worst_peer, [&](CNode *pnode) {
         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 (time_in_seconds - pnode->nTimeConnected > 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(), pnode->nTimeConnected,
                      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.
         connman->SetTryNewOutboundPeer(false);
     }
 }
 
 void PeerLogicValidation::CheckForStaleTipAndEvictPeers(
     const Consensus::Params &consensusParams) {
     if (connman == nullptr) {
         return;
     }
 
     int64_t time_in_seconds = GetTime();
 
     EvictExtraOutboundPeers(time_in_seconds);
 
     if (time_in_seconds <= m_stale_tip_check_time) {
         return;
     }
 
     LOCK(cs_main);
     // Check whether our tip is stale, and if so, allow using an extra outbound
     // peer.
     if (TipMayBeStale(consensusParams)) {
         LogPrintf("Potential stale tip detected, will try using extra outbound "
                   "peer (last tip update: %d seconds ago)\n",
                   time_in_seconds - g_last_tip_update);
         connman->SetTryNewOutboundPeer(true);
     } else if (connman->GetTryNewOutboundPeer()) {
         connman->SetTryNewOutboundPeer(false);
     }
     m_stale_tip_check_time = time_in_seconds + STALE_CHECK_INTERVAL;
 }
 
 namespace {
 class CompareInvMempoolOrder {
     CTxMemPool *mp;
 
 public:
     explicit CompareInvMempoolOrder(CTxMemPool *_mempool) { mp = _mempool; }
 
     bool operator()(std::set<uint256>::iterator a,
                     std::set<uint256>::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);
     }
 };
 }
 
 bool PeerLogicValidation::SendMessages(const Config &config, CNode *pto,
                                        std::atomic<bool> &interruptMsgProc) {
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
 
     // 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->GetSendVersion());
 
     //
     // Message: ping
     //
     bool pingSend = false;
     if (pto->fPingQueued) {
         // RPC ping request by user
         pingSend = true;
     }
     if (pto->nPingNonceSent == 0 &&
         pto->nPingUsecStart + PING_INTERVAL * 1000000 < GetTimeMicros()) {
         // 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));
         }
         pto->fPingQueued = false;
         pto->nPingUsecStart = GetTimeMicros();
         if (pto->nVersion > BIP0031_VERSION) {
             pto->nPingNonceSent = nonce;
             connman->PushMessage(pto, msgMaker.Make(NetMsgType::PING, nonce));
         } else {
             // Peer is too old to support ping command with nonce, pong will
             // never arrive.
             pto->nPingNonceSent = 0;
             connman->PushMessage(pto, msgMaker.Make(NetMsgType::PING));
         }
     }
 
     // Acquire cs_main for IsInitialBlockDownload() and CNodeState()
     TRY_LOCK(cs_main, lockMain);
     if (!lockMain) {
         return true;
     }
 
     if (SendRejectsAndCheckIfBanned(pto, connman)) {
         return true;
     }
     CNodeState &state = *State(pto->GetId());
 
     // Address refresh broadcast
     int64_t nNow = GetTimeMicros();
     if (!IsInitialBlockDownload() && pto->nNextLocalAddrSend < nNow) {
         AdvertiseLocal(pto);
         pto->nNextLocalAddrSend =
             PoissonNextSend(nNow, AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL);
     }
 
     //
     // Message: addr
     //
     if (pto->nNextAddrSend < nNow) {
         pto->nNextAddrSend =
             PoissonNextSend(nNow, AVG_ADDRESS_BROADCAST_INTERVAL);
         std::vector<CAddress> vAddr;
         vAddr.reserve(pto->vAddrToSend.size());
         for (const CAddress &addr : pto->vAddrToSend) {
             if (!pto->addrKnown.contains(addr.GetKey())) {
                 pto->addrKnown.insert(addr.GetKey());
                 vAddr.push_back(addr);
                 // receiver rejects addr messages larger than 1000
                 if (vAddr.size() >= 1000) {
                     connman->PushMessage(
                         pto, msgMaker.Make(NetMsgType::ADDR, vAddr));
                     vAddr.clear();
                 }
             }
         }
         pto->vAddrToSend.clear();
         if (!vAddr.empty()) {
             connman->PushMessage(pto, msgMaker.Make(NetMsgType::ADDR, vAddr));
         }
 
         // we only send the big addr message once
         if (pto->vAddrToSend.capacity() > 40) {
             pto->vAddrToSend.shrink_to_fit();
         }
     }
 
     // Start block sync
     if (pindexBestHeader == nullptr) {
         pindexBestHeader = chainActive.Tip();
     }
 
     // Download if this is a nice peer, or we have no nice peers and this one
     // might do.
     bool fFetch = state.fPreferredDownload ||
                   (nPreferredDownload == 0 && !pto->fClient && !pto->fOneShot);
 
     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.nHeadersSyncTimeout =
                 GetTimeMicros() + HEADERS_DOWNLOAD_TIMEOUT_BASE +
                 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(), pto->nStartingHeight);
             connman->PushMessage(
                 pto,
                 msgMaker.Make(NetMsgType::GETHEADERS,
                               chainActive.GetLocator(pindexStart), uint256()));
         }
     }
 
     // Resend wallet transactions that haven't gotten in a block yet
     // Except during reindex, importing and IBD, when old wallet transactions
     // become unconfirmed and spams other nodes.
     if (!fReindex && !fImporting && !IsInitialBlockDownload()) {
         GetMainSignals().Broadcast(nTimeBestReceived, connman);
     }
 
     //
     // 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(pto->cs_inventory);
         std::vector<CBlock> vHeaders;
         bool fRevertToInv =
             ((!state.fPreferHeaders &&
               (!state.fPreferHeaderAndIDs ||
                pto->vBlockHashesToAnnounce.size() > 1)) ||
              pto->vBlockHashesToAnnounce.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 chainActive, give up.
             for (const uint256 &hash : pto->vBlockHashesToAnnounce) {
                 BlockMap::iterator mi = mapBlockIndex.find(hash);
                 assert(mi != mapBlockIndex.end());
                 const CBlockIndex *pindex = mi->second;
                 if (chainActive[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 vBlockHashesToAnnounce. 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);
                         connman->PushMessage(
                             pto,
                             msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK,
                                           cmpctblock));
                         fGotBlockFromCache = true;
                     }
                 }
                 if (!fGotBlockFromCache) {
                     CBlock block;
                     bool ret = ReadBlockFromDisk(block, pBestIndex, config);
                     assert(ret);
                     CBlockHeaderAndShortTxIDs cmpctblock(block);
                     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());
                 }
                 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 vBlockHashesToAnnounce was our tip at some point in
             // the past.
             if (!pto->vBlockHashesToAnnounce.empty()) {
                 const uint256 &hashToAnnounce =
                     pto->vBlockHashesToAnnounce.back();
                 BlockMap::iterator mi = mapBlockIndex.find(hashToAnnounce);
                 assert(mi != mapBlockIndex.end());
                 const CBlockIndex *pindex = mi->second;
 
                 // 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 (chainActive[pindex->nHeight] != pindex) {
                     LogPrint(BCLog::NET,
                              "Announcing block %s not on main chain (tip=%s)\n",
                              hashToAnnounce.ToString(),
                              chainActive.Tip()->GetBlockHash().ToString());
                 }
 
                 // If the peer's chain has this block, don't inv it back.
                 if (!PeerHasHeader(&state, pindex)) {
                     pto->PushInventory(CInv(MSG_BLOCK, hashToAnnounce));
                     LogPrint(BCLog::NET, "%s: sending inv peer=%d hash=%s\n",
                              __func__, pto->GetId(), hashToAnnounce.ToString());
                 }
             }
         }
         pto->vBlockHashesToAnnounce.clear();
     }
 
     //
     // Message: inventory
     //
     std::vector<CInv> vInv;
     {
         LOCK(pto->cs_inventory);
         vInv.reserve(std::max<size_t>(pto->vInventoryBlockToSend.size(),
                                       INVENTORY_BROADCAST_MAX_PER_MB *
                                           config.GetMaxBlockSize() / 1000000));
 
         // Add blocks
         for (const uint256 &hash : pto->vInventoryBlockToSend) {
             vInv.push_back(CInv(MSG_BLOCK, hash));
             if (vInv.size() == MAX_INV_SZ) {
                 connman->PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv));
                 vInv.clear();
             }
         }
         pto->vInventoryBlockToSend.clear();
 
         // Check whether periodic sends should happen
         bool fSendTrickle = pto->fWhitelisted;
         if (pto->nNextInvSend < nNow) {
             fSendTrickle = true;
             // Use half the delay for outbound peers, as there is less privacy
             // concern for them.
             pto->nNextInvSend = PoissonNextSend(
                 nNow, INVENTORY_BROADCAST_INTERVAL >> !pto->fInbound);
         }
 
         // Time to send but the peer has requested we not relay transactions.
         if (fSendTrickle) {
             LOCK(pto->cs_filter);
             if (!pto->fRelayTxes) {
                 pto->setInventoryTxToSend.clear();
             }
         }
 
         // Respond to BIP35 mempool requests
         if (fSendTrickle && pto->fSendMempool) {
             auto vtxinfo = mempool.infoAll();
             pto->fSendMempool = false;
             Amount filterrate = Amount::zero();
             {
                 LOCK(pto->cs_feeFilter);
                 filterrate = pto->minFeeFilter;
             }
 
             LOCK(pto->cs_filter);
 
             for (const auto &txinfo : vtxinfo) {
                 const uint256 &txid = txinfo.tx->GetId();
                 CInv inv(MSG_TX, txid);
                 pto->setInventoryTxToSend.erase(txid);
                 if (filterrate != Amount::zero() &&
                     txinfo.feeRate.GetFeePerK() < filterrate) {
                     continue;
                 }
                 if (pto->pfilter &&
                     !pto->pfilter->IsRelevantAndUpdate(*txinfo.tx)) {
                     continue;
                 }
                 pto->filterInventoryKnown.insert(txid);
                 vInv.push_back(inv);
                 if (vInv.size() == MAX_INV_SZ) {
                     connman->PushMessage(pto,
                                          msgMaker.Make(NetMsgType::INV, vInv));
                     vInv.clear();
                 }
             }
             pto->timeLastMempoolReq = GetTime();
         }
 
         // Determine transactions to relay
         if (fSendTrickle) {
             // Produce a vector with all candidates for sending
             std::vector<std::set<uint256>::iterator> vInvTx;
             vInvTx.reserve(pto->setInventoryTxToSend.size());
             for (std::set<uint256>::iterator it =
                      pto->setInventoryTxToSend.begin();
                  it != pto->setInventoryTxToSend.end(); it++) {
                 vInvTx.push_back(it);
             }
             Amount filterrate = Amount::zero();
             {
                 LOCK(pto->cs_feeFilter);
                 filterrate = pto->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(&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->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<uint256>::iterator it = vInvTx.back();
                 vInvTx.pop_back();
                 uint256 hash = *it;
                 // Remove it from the to-be-sent set
                 pto->setInventoryTxToSend.erase(it);
                 // Check if not in the filter already
                 if (pto->filterInventoryKnown.contains(hash)) {
                     continue;
                 }
                 // Not in the mempool anymore? don't bother sending it.
                 auto txinfo = mempool.info(hash);
                 if (!txinfo.tx) {
                     continue;
                 }
                 if (filterrate != Amount::zero() &&
                     txinfo.feeRate.GetFeePerK() < filterrate) {
                     continue;
                 }
                 if (pto->pfilter &&
                     !pto->pfilter->IsRelevantAndUpdate(*txinfo.tx)) {
                     continue;
                 }
                 // Send
                 vInv.push_back(CInv(MSG_TX, hash));
                 nRelayedTransactions++;
                 {
                     // Expire old relay messages
                     while (!vRelayExpiration.empty() &&
                            vRelayExpiration.front().first < nNow) {
                         mapRelay.erase(vRelayExpiration.front().second);
                         vRelayExpiration.pop_front();
                     }
 
                     auto ret = mapRelay.insert(
                         std::make_pair(hash, std::move(txinfo.tx)));
                     if (ret.second) {
                         vRelayExpiration.push_back(std::make_pair(
                             nNow + 15 * 60 * 1000000, ret.first));
                     }
                 }
                 if (vInv.size() == MAX_INV_SZ) {
                     connman->PushMessage(pto,
                                          msgMaker.Make(NetMsgType::INV, vInv));
                     vInv.clear();
                 }
                 pto->filterInventoryKnown.insert(hash);
             }
         }
     }
     if (!vInv.empty()) {
         connman->PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv));
     }
 
     // Detect whether we're stalling
     nNow = GetTimeMicros();
     if (state.nStallingSince &&
         state.nStallingSince < nNow - 1000000 * 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 2 +
     // 0.5 * N times the block interval (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 (nNow > state.nDownloadingSince +
                        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.nHeadersSyncTimeout < std::numeric_limits<int64_t>::max()) {
         // Detect whether this is a stalling initial-headers-sync peer
         if (pindexBestHeader->GetBlockTime() <=
             GetAdjustedTime() - 24 * 60 * 60) {
             if (nNow > state.nHeadersSyncTimeout && nSyncStarted == 1 &&
                 (nPreferredDownload - state.fPreferredDownload >= 1)) {
                 // Disconnect a (non-whitelisted) peer 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->fWhitelisted) {
                     LogPrintf("Timeout downloading headers from peer=%d, "
                               "disconnecting\n",
                               pto->GetId());
                     pto->fDisconnect = true;
                     return true;
                 } else {
                     LogPrintf("Timeout downloading headers from whitelisted "
                               "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.nHeadersSyncTimeout = 0;
                 }
             }
         } else {
             // After we've caught up once, reset the timeout so we can't trigger
             // disconnect later.
             state.nHeadersSyncTimeout = std::numeric_limits<int64_t>::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());
 
     //
     // Message: getdata (blocks)
     //
     std::vector<CInv> vGetData;
     if (!pto->fClient && (fFetch || !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, consensusParams);
         for (const CBlockIndex *pindex : vToDownload) {
             vGetData.push_back(CInv(MSG_BLOCK, pindex->GetBlockHash()));
             MarkBlockAsInFlight(config, pto->GetId(), pindex->GetBlockHash(),
                                 consensusParams, 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)->nStallingSince == 0) {
                 State(staller)->nStallingSince = nNow;
                 LogPrint(BCLog::NET, "Stall started peer=%d\n", staller);
             }
         }
     }
 
     //
     // Message: getdata (non-blocks)
     //
     while (!pto->mapAskFor.empty() && (*pto->mapAskFor.begin()).first <= nNow) {
         const CInv &inv = (*pto->mapAskFor.begin()).second;
         if (!AlreadyHave(inv)) {
             LogPrint(BCLog::NET, "Requesting %s peer=%d\n", inv.ToString(),
                      pto->GetId());
             vGetData.push_back(inv);
             if (vGetData.size() >= 1000) {
                 connman->PushMessage(
                     pto, msgMaker.Make(NetMsgType::GETDATA, vGetData));
                 vGetData.clear();
             }
         } else {
             // If we're not going to ask, don't expect a response.
             pto->setAskFor.erase(inv.hash);
         }
         pto->mapAskFor.erase(pto->mapAskFor.begin());
     }
     if (!vGetData.empty()) {
         connman->PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData));
     }
 
     //
     // Message: feefilter
     //
     // We don't want white listed peers to filter txs to us if we have
     // -whitelistforcerelay
     if (pto->nVersion >= FEEFILTER_VERSION &&
         gArgs.GetBoolArg("-feefilter", DEFAULT_FEEFILTER) &&
         !(pto->fWhitelisted &&
           gArgs.GetBoolArg("-whitelistforcerelay",
                            DEFAULT_WHITELISTFORCERELAY))) {
         Amount currentFilter =
             mempool
                 .GetMinFee(
                     gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                     1000000)
                 .GetFeePerK();
         int64_t timeNow = GetTimeMicros();
         if (timeNow > pto->nextSendTimeFeeFilter) {
             static CFeeRate default_feerate =
                 CFeeRate(DEFAULT_MIN_RELAY_TX_FEE_PER_KB);
             static FeeFilterRounder filterRounder(default_feerate);
             Amount filterToSend = filterRounder.round(currentFilter);
             // If we don't allow free transactions, then we always have a fee
             // filter of at least minRelayTxFee
             if (gArgs.GetArg("-limitfreerelay", DEFAULT_LIMITFREERELAY) <= 0) {
                 filterToSend = std::max(filterToSend,
                                         config.GetMinFeePerKB().GetFeePerK());
             }
 
             if (filterToSend != pto->lastSentFeeFilter) {
                 connman->PushMessage(
                     pto, msgMaker.Make(NetMsgType::FEEFILTER, filterToSend));
                 pto->lastSentFeeFilter = filterToSend;
             }
             pto->nextSendTimeFeeFilter =
                 PoissonNextSend(timeNow, 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 (timeNow + MAX_FEEFILTER_CHANGE_DELAY * 1000000 <
                      pto->nextSendTimeFeeFilter &&
                  (currentFilter < 3 * pto->lastSentFeeFilter / 4 ||
                   currentFilter > 4 * pto->lastSentFeeFilter / 3)) {
             pto->nextSendTimeFeeFilter =
                 timeNow + GetRandInt(MAX_FEEFILTER_CHANGE_DELAY) * 1000000;
         }
     }
     return true;
 }
 
 class CNetProcessingCleanup {
 public:
     CNetProcessingCleanup() {}
     ~CNetProcessingCleanup() {
         // orphan transactions
         mapOrphanTransactions.clear();
         mapOrphanTransactionsByPrev.clear();
     }
 } instance_of_cnetprocessingcleanup;
diff --git a/src/scheduler.cpp b/src/scheduler.cpp
index f819a1822..6d5024463 100644
--- a/src/scheduler.cpp
+++ b/src/scheduler.cpp
@@ -1,213 +1,217 @@
 // Copyright (c) 2015-2016 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 "scheduler.h"
 
 #include "random.h"
 #include "reverselock.h"
 
 #include <boost/bind.hpp>
 #include <cassert>
 #include <utility>
 
 CScheduler::CScheduler()
     : nThreadsServicingQueue(0), stopRequested(false), stopWhenEmpty(false) {}
 
 CScheduler::~CScheduler() {
     assert(nThreadsServicingQueue == 0);
 }
 
 #if BOOST_VERSION < 105000
 static boost::system_time
 toPosixTime(const boost::chrono::system_clock::time_point &t) {
     return boost::posix_time::from_time_t(
         boost::chrono::system_clock::to_time_t(t));
 }
 #endif
 
 void CScheduler::serviceQueue() {
     boost::unique_lock<boost::mutex> lock(newTaskMutex);
     ++nThreadsServicingQueue;
 
     // newTaskMutex is locked throughout this loop EXCEPT when the thread is
     // waiting or when the user's function is called.
     while (!shouldStop()) {
         try {
             if (!shouldStop() && taskQueue.empty()) {
                 reverse_lock<boost::unique_lock<boost::mutex>> rlock(lock);
                 // Use this chance to get a tiny bit more entropy
                 RandAddSeedSleep();
             }
             while (!shouldStop() && taskQueue.empty()) {
                 // Wait until there is something to do.
                 newTaskScheduled.wait(lock);
             }
 
 // Wait until either there is a new task, or until the time of the first item on
 // the queue:
 
 // wait_until needs boost 1.50 or later; older versions have timed_wait:
 #if BOOST_VERSION < 105000
             while (!shouldStop() && !taskQueue.empty() &&
                    newTaskScheduled.timed_wait(
                        lock, toPosixTime(taskQueue.begin()->first))) {
                 // Keep waiting until timeout
             }
 #else
             // Some boost versions have a conflicting overload of wait_until
             // that returns void. Explicitly use a template here to avoid
             // hitting that overload.
             while (!shouldStop() && !taskQueue.empty()) {
                 boost::chrono::system_clock::time_point timeToWaitFor =
                     taskQueue.begin()->first;
                 if (newTaskScheduled.wait_until<>(lock, timeToWaitFor) ==
                     boost::cv_status::timeout) {
                     // Exit loop after timeout, it means we reached the time of
                     // the event
                     break;
                 }
             }
 #endif
             // If there are multiple threads, the queue can empty while we're
             // waiting (another thread may service the task we were waiting on).
-            if (shouldStop() || taskQueue.empty()) continue;
+            if (shouldStop() || taskQueue.empty()) {
+                continue;
+            }
 
             Function f = taskQueue.begin()->second;
             taskQueue.erase(taskQueue.begin());
 
             {
                 // Unlock before calling f, so it can reschedule itself or
                 // another task without deadlocking:
                 reverse_lock<boost::unique_lock<boost::mutex>> rlock(lock);
                 f();
             }
         } catch (...) {
             --nThreadsServicingQueue;
             throw;
         }
     }
     --nThreadsServicingQueue;
     newTaskScheduled.notify_one();
 }
 
 void CScheduler::stop(bool drain) {
     {
         boost::unique_lock<boost::mutex> lock(newTaskMutex);
-        if (drain)
+        if (drain) {
             stopWhenEmpty = true;
-        else
+        } else {
             stopRequested = true;
+        }
     }
     newTaskScheduled.notify_all();
 }
 
 void CScheduler::schedule(CScheduler::Function f,
                           boost::chrono::system_clock::time_point t) {
     {
         boost::unique_lock<boost::mutex> lock(newTaskMutex);
         taskQueue.insert(std::make_pair(t, f));
     }
     newTaskScheduled.notify_one();
 }
 
 void CScheduler::scheduleFromNow(CScheduler::Function f,
                                  int64_t deltaMilliSeconds) {
     schedule(f,
              boost::chrono::system_clock::now() +
                  boost::chrono::milliseconds(deltaMilliSeconds));
 }
 
-static void Repeat(CScheduler *s, CScheduler::Function f,
+static void Repeat(CScheduler *s, CScheduler::Predicate p,
                    int64_t deltaMilliSeconds) {
-    f();
-    s->scheduleFromNow(boost::bind(&Repeat, s, f, deltaMilliSeconds),
-                       deltaMilliSeconds);
+    if (p()) {
+        s->scheduleFromNow(boost::bind(&Repeat, s, p, deltaMilliSeconds),
+                           deltaMilliSeconds);
+    }
 }
 
-void CScheduler::scheduleEvery(CScheduler::Function f,
+void CScheduler::scheduleEvery(CScheduler::Predicate p,
                                int64_t deltaMilliSeconds) {
-    scheduleFromNow(boost::bind(&Repeat, this, f, deltaMilliSeconds),
+    scheduleFromNow(boost::bind(&Repeat, this, p, deltaMilliSeconds),
                     deltaMilliSeconds);
 }
 
 size_t
 CScheduler::getQueueInfo(boost::chrono::system_clock::time_point &first,
                          boost::chrono::system_clock::time_point &last) const {
     boost::unique_lock<boost::mutex> lock(newTaskMutex);
     size_t result = taskQueue.size();
     if (!taskQueue.empty()) {
         first = taskQueue.begin()->first;
         last = taskQueue.rbegin()->first;
     }
     return result;
 }
 
 bool CScheduler::AreThreadsServicingQueue() const {
     return nThreadsServicingQueue;
 }
 
 void SingleThreadedSchedulerClient::MaybeScheduleProcessQueue() {
     {
         LOCK(m_cs_callbacks_pending);
         // Try to avoid scheduling too many copies here, but if we
         // accidentally have two ProcessQueue's scheduled at once its
         // not a big deal.
         if (m_are_callbacks_running) return;
         if (m_callbacks_pending.empty()) return;
     }
     m_pscheduler->schedule(
         std::bind(&SingleThreadedSchedulerClient::ProcessQueue, this));
 }
 
 void SingleThreadedSchedulerClient::ProcessQueue() {
     std::function<void(void)> callback;
     {
         LOCK(m_cs_callbacks_pending);
         if (m_are_callbacks_running) return;
         if (m_callbacks_pending.empty()) return;
         m_are_callbacks_running = true;
 
         callback = std::move(m_callbacks_pending.front());
         m_callbacks_pending.pop_front();
     }
 
     // RAII the setting of fCallbacksRunning and calling
     // MaybeScheduleProcessQueue
     // to ensure both happen safely even if callback() throws.
     struct RAIICallbacksRunning {
         SingleThreadedSchedulerClient *instance;
         RAIICallbacksRunning(SingleThreadedSchedulerClient *_instance)
             : instance(_instance) {}
         ~RAIICallbacksRunning() {
             {
                 LOCK(instance->m_cs_callbacks_pending);
                 instance->m_are_callbacks_running = false;
             }
             instance->MaybeScheduleProcessQueue();
         }
     } raiicallbacksrunning(this);
 
     callback();
 }
 
 void SingleThreadedSchedulerClient::AddToProcessQueue(
     std::function<void(void)> func) {
     assert(m_pscheduler);
 
     {
         LOCK(m_cs_callbacks_pending);
         m_callbacks_pending.emplace_back(std::move(func));
     }
     MaybeScheduleProcessQueue();
 }
 
 void SingleThreadedSchedulerClient::EmptyQueue() {
     assert(!m_pscheduler->AreThreadsServicingQueue());
     bool should_continue = true;
     while (should_continue) {
         ProcessQueue();
         LOCK(m_cs_callbacks_pending);
         should_continue = !m_callbacks_pending.empty();
     }
 }
diff --git a/src/scheduler.h b/src/scheduler.h
index 9ccdc43e5..efd4f9851 100644
--- a/src/scheduler.h
+++ b/src/scheduler.h
@@ -1,119 +1,120 @@
 // Copyright (c) 2015 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_SCHEDULER_H
 #define BITCOIN_SCHEDULER_H
 
 #include "sync.h"
 
 //
 // NOTE:
 // boost::thread / boost::chrono should be ported to
 // std::thread / std::chrono when we support C++11.
 //
 #include <boost/chrono/chrono.hpp>
 #include <boost/thread.hpp>
 
 #include <map>
 
 //
 // Simple class for background tasks that should be run periodically or once
 // "after a while"
 //
 // Usage:
 //
 // CScheduler* s = new CScheduler();
 // s->scheduleFromNow(doSomething, 11); // Assuming a: void doSomething() { }
 // s->scheduleFromNow(std::bind(Class::func, this, argument), 3);
 // boost::thread* t = new boost::thread(boost::bind(CScheduler::serviceQueue,
 // s));
 //
 // ... then at program shutdown, clean up the thread running serviceQueue:
 // t->interrupt();
 // t->join();
 // delete t;
 // delete s; // Must be done after thread is interrupted/joined.
 //
 
 class CScheduler {
 public:
     CScheduler();
     ~CScheduler();
 
     typedef std::function<void(void)> Function;
+    typedef std::function<bool(void)> Predicate;
 
     // Call func at/after time t
     void schedule(Function f,
                   boost::chrono::system_clock::time_point t =
                       boost::chrono::system_clock::now());
 
     // Convenience method: call f once deltaMilliSeconds from now
     void scheduleFromNow(Function f, int64_t deltaMilliSeconds);
 
     // Another convenience method: call f approximately every deltaMilliSeconds
     // forever, starting deltaMilliSeconds from now. To be more precise: every
     // time f is finished, it is rescheduled to run deltaMilliSeconds later. If
     // you need more accurate scheduling, don't use this method.
-    void scheduleEvery(Function f, int64_t deltaMilliSeconds);
+    void scheduleEvery(Predicate p, int64_t deltaMilliSeconds);
 
     // To keep things as simple as possible, there is no unschedule.
 
     // Services the queue 'forever'. Should be run in a thread, and interrupted
     // using boost::interrupt_thread
     void serviceQueue();
 
     // Tell any threads running serviceQueue to stop as soon as they're done
     // servicing whatever task they're currently servicing (drain=false) or when
     // there is no work left to be done (drain=true)
     void stop(bool drain = false);
 
     // Returns number of tasks waiting to be serviced, and first and last task
     // times
     size_t getQueueInfo(boost::chrono::system_clock::time_point &first,
                         boost::chrono::system_clock::time_point &last) const;
 
     // Returns true if there are threads actively running in serviceQueue()
     bool AreThreadsServicingQueue() const;
 
 private:
     std::multimap<boost::chrono::system_clock::time_point, Function> taskQueue;
     boost::condition_variable newTaskScheduled;
     mutable boost::mutex newTaskMutex;
     int nThreadsServicingQueue;
     bool stopRequested;
     bool stopWhenEmpty;
     bool shouldStop() {
         return stopRequested || (stopWhenEmpty && taskQueue.empty());
     }
 };
 
 /**
  * Class used by CScheduler clients which may schedule multiple jobs
  * which are required to be run serially. Does not require such jobs
  * to be executed on the same thread, but no two jobs will be executed
  * at the same time.
  */
 class SingleThreadedSchedulerClient {
 private:
     CScheduler *m_pscheduler;
 
     CCriticalSection m_cs_callbacks_pending;
     std::list<std::function<void(void)>> m_callbacks_pending;
     bool m_are_callbacks_running = false;
 
     void MaybeScheduleProcessQueue();
     void ProcessQueue();
 
 public:
     SingleThreadedSchedulerClient(CScheduler *pschedulerIn)
         : m_pscheduler(pschedulerIn) {}
     void AddToProcessQueue(std::function<void(void)> func);
 
     // Processes all remaining queue members on the calling thread, blocking
     // until queue is empty
     // Must be called after the CScheduler has no remaining processing threads!
     void EmptyQueue();
 };
 
 #endif
diff --git a/src/test/scheduler_tests.cpp b/src/test/scheduler_tests.cpp
index 0b2c61a58..ad09f9369 100644
--- a/src/test/scheduler_tests.cpp
+++ b/src/test/scheduler_tests.cpp
@@ -1,122 +1,177 @@
 // Copyright (c) 2012-2016 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 "random.h"
 #include "scheduler.h"
 
 #include "test/test_bitcoin.h"
 
 #include <boost/bind.hpp>
 #include <boost/random/mersenne_twister.hpp>
 #include <boost/random/uniform_int_distribution.hpp>
 #include <boost/test/unit_test.hpp>
 #include <boost/thread.hpp>
 
+#include <atomic>
+#include <thread>
+
 BOOST_AUTO_TEST_SUITE(scheduler_tests)
 
 static void microTask(CScheduler &s, boost::mutex &mutex, int &counter,
                       int delta,
                       boost::chrono::system_clock::time_point rescheduleTime) {
     {
         boost::unique_lock<boost::mutex> lock(mutex);
         counter += delta;
     }
     boost::chrono::system_clock::time_point noTime =
         boost::chrono::system_clock::time_point::min();
     if (rescheduleTime != noTime) {
         CScheduler::Function f =
             boost::bind(&microTask, std::ref(s), std::ref(mutex),
                         std::ref(counter), -delta + 1, noTime);
         s.schedule(f, rescheduleTime);
     }
 }
 
 static void MicroSleep(uint64_t n) {
     boost::this_thread::sleep_for(boost::chrono::microseconds(n));
 }
 
 BOOST_AUTO_TEST_CASE(manythreads) {
     // Stress test: hundreds of microsecond-scheduled tasks,
     // serviced by 10 threads.
     //
     // So... ten shared counters, which if all the tasks execute
     // properly will sum to the number of tasks done.
     // Each task adds or subtracts a random amount from one of the
     // counters, and then schedules another task 0-1000
     // microseconds in the future to subtract or add from
     // the counter -random_amount+1, so in the end the shared
     // counters should sum to the number of initial tasks performed.
     CScheduler microTasks;
 
     boost::mutex counterMutex[10];
     int counter[10] = {0};
     boost::random::mt19937 rng(42);
     boost::random::uniform_int_distribution<> zeroToNine(0, 9);
     boost::random::uniform_int_distribution<> randomMsec(-11, 1000);
     boost::random::uniform_int_distribution<> randomDelta(-1000, 1000);
 
     boost::chrono::system_clock::time_point start =
         boost::chrono::system_clock::now();
     boost::chrono::system_clock::time_point now = start;
     boost::chrono::system_clock::time_point first, last;
     size_t nTasks = microTasks.getQueueInfo(first, last);
     BOOST_CHECK(nTasks == 0);
 
     for (int i = 0; i < 100; i++) {
         boost::chrono::system_clock::time_point t =
             now + boost::chrono::microseconds(randomMsec(rng));
         boost::chrono::system_clock::time_point tReschedule =
             now + boost::chrono::microseconds(500 + randomMsec(rng));
         int whichCounter = zeroToNine(rng);
         CScheduler::Function f = boost::bind(
             &microTask, std::ref(microTasks),
             std::ref(counterMutex[whichCounter]),
             std::ref(counter[whichCounter]), randomDelta(rng), tReschedule);
         microTasks.schedule(f, t);
     }
     nTasks = microTasks.getQueueInfo(first, last);
     BOOST_CHECK(nTasks == 100);
     BOOST_CHECK(first < last);
     BOOST_CHECK(last > now);
 
     // As soon as these are created they will start running and servicing the
     // queue
     boost::thread_group microThreads;
-    for (int i = 0; i < 5; i++)
+    for (int i = 0; i < 5; i++) {
         microThreads.create_thread(
             boost::bind(&CScheduler::serviceQueue, &microTasks));
+    }
 
     MicroSleep(600);
     now = boost::chrono::system_clock::now();
 
     // More threads and more tasks:
-    for (int i = 0; i < 5; i++)
+    for (int i = 0; i < 5; i++) {
         microThreads.create_thread(
             boost::bind(&CScheduler::serviceQueue, &microTasks));
+    }
+
     for (int i = 0; i < 100; i++) {
         boost::chrono::system_clock::time_point t =
             now + boost::chrono::microseconds(randomMsec(rng));
         boost::chrono::system_clock::time_point tReschedule =
             now + boost::chrono::microseconds(500 + randomMsec(rng));
         int whichCounter = zeroToNine(rng);
         CScheduler::Function f = boost::bind(
             &microTask, std::ref(microTasks),
             std::ref(counterMutex[whichCounter]),
             std::ref(counter[whichCounter]), randomDelta(rng), tReschedule);
         microTasks.schedule(f, t);
     }
 
     // Drain the task queue then exit threads
     microTasks.stop(true);
-    microThreads.join_all(); // ... wait until all the threads are done
+    // ... wait until all the threads are done
+    microThreads.join_all();
 
     int counterSum = 0;
     for (int i = 0; i < 10; i++) {
         BOOST_CHECK(counter[i] != 0);
         counterSum += counter[i];
     }
     BOOST_CHECK_EQUAL(counterSum, 200);
 }
 
+BOOST_AUTO_TEST_CASE(schedule_every) {
+    CScheduler scheduler;
+
+    boost::condition_variable cvar;
+    std::atomic<int> counter{15};
+    std::atomic<bool> keepRunning{true};
+
+    scheduler.scheduleEvery(
+        [&keepRunning, &cvar, &counter, &scheduler]() {
+            BOOST_CHECK(counter > 0);
+            cvar.notify_all();
+            if (--counter > 0) {
+                return true;
+            }
+
+            // We reached the end of our test, make sure nothing run again for
+            // 100ms.
+            scheduler.scheduleFromNow(
+                [&keepRunning, &cvar]() {
+                    keepRunning = false;
+                    cvar.notify_all();
+                },
+                100);
+
+            // We set the counter to some magic value to check the scheduler
+            // empty its queue properly after 120ms.
+            scheduler.scheduleFromNow([&counter]() { counter = 42; }, 120);
+            return false;
+        },
+        5);
+
+    // Start the scheduler thread.
+    std::thread schedulerThread(
+        std::bind(&CScheduler::serviceQueue, &scheduler));
+
+    boost::mutex mutex;
+    boost::unique_lock<boost::mutex> lock(mutex);
+    while (keepRunning) {
+        cvar.wait(lock);
+        BOOST_CHECK(counter >= 0);
+    }
+
+    BOOST_CHECK_EQUAL(counter, 0);
+    scheduler.stop(true);
+    schedulerThread.join();
+    BOOST_CHECK_EQUAL(counter, 42);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index f90691724..b7ac74694 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1,4266 +1,4271 @@
 // 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 "wallet/wallet.h"
 
 #include "chain.h"
 #include "checkpoints.h"
 #include "config.h"
 #include "consensus/consensus.h"
 #include "consensus/validation.h"
 #include "dstencode.h"
 #include "fs.h"
 #include "init.h"
 #include "key.h"
 #include "keystore.h"
 #include "net.h"
 #include "policy/policy.h"
 #include "primitives/block.h"
 #include "primitives/transaction.h"
 #include "scheduler.h"
 #include "script/script.h"
 #include "script/sighashtype.h"
 #include "script/sign.h"
 #include "timedata.h"
 #include "txmempool.h"
 #include "ui_interface.h"
 #include "util.h"
 #include "utilmoneystr.h"
 #include "validation.h"
 #include "wallet/coincontrol.h"
 #include "wallet/fees.h"
 #include "wallet/finaltx.h"
 
 #include <boost/algorithm/string/replace.hpp>
 
 #include <cassert>
 
 std::vector<CWalletRef> vpwallets;
 
 /** Transaction fee set by the user */
 CFeeRate payTxFee(DEFAULT_TRANSACTION_FEE);
 unsigned int nTxConfirmTarget = DEFAULT_TX_CONFIRM_TARGET;
 bool bSpendZeroConfChange = DEFAULT_SPEND_ZEROCONF_CHANGE;
 
 const char *DEFAULT_WALLET_DAT = "wallet.dat";
 const uint32_t BIP32_HARDENED_KEY_LIMIT = 0x80000000;
 
 /**
  * If fee estimation does not have enough data to provide estimates, use this
  * fee instead. Has no effect if not using fee estimation.
  * Override with -fallbackfee
  */
 CFeeRate CWallet::fallbackFee = CFeeRate(DEFAULT_FALLBACK_FEE);
 
 const uint256 CMerkleTx::ABANDON_HASH(uint256S(
     "0000000000000000000000000000000000000000000000000000000000000001"));
 
 /** @defgroup mapWallet
  *
  * @{
  */
 
 struct CompareValueOnly {
     bool operator()(
         const std::pair<Amount, std::pair<const CWalletTx *, unsigned int>> &t1,
         const std::pair<Amount, std::pair<const CWalletTx *, unsigned int>> &t2)
         const {
         return t1.first < t2.first;
     }
 };
 
 std::string COutput::ToString() const {
     return strprintf("COutput(%s, %d, %d) [%s]", tx->GetId().ToString(), i,
                      nDepth, FormatMoney(tx->tx->vout[i].nValue));
 }
 
 class CAffectedKeysVisitor : public boost::static_visitor<void> {
 private:
     const CKeyStore &keystore;
     std::vector<CKeyID> &vKeys;
 
 public:
     CAffectedKeysVisitor(const CKeyStore &keystoreIn,
                          std::vector<CKeyID> &vKeysIn)
         : keystore(keystoreIn), vKeys(vKeysIn) {}
 
     void Process(const CScript &script) {
         txnouttype type;
         std::vector<CTxDestination> vDest;
         int nRequired;
         if (ExtractDestinations(script, type, vDest, nRequired)) {
             for (const CTxDestination &dest : vDest) {
                 boost::apply_visitor(*this, dest);
             }
         }
     }
 
     void operator()(const CKeyID &keyId) {
         if (keystore.HaveKey(keyId)) {
             vKeys.push_back(keyId);
         }
     }
 
     void operator()(const CScriptID &scriptId) {
         CScript script;
         if (keystore.GetCScript(scriptId, script)) {
             Process(script);
         }
     }
 
     void operator()(const CNoDestination &none) {}
 };
 
 const CWalletTx *CWallet::GetWalletTx(const TxId &txid) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator it = mapWallet.find(txid);
     if (it == mapWallet.end()) {
         return nullptr;
     }
 
     return &(it->second);
 }
 
 CPubKey CWallet::GenerateNewKey(CWalletDB &walletdb, bool internal) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     // default to compressed public keys if we want 0.6.0 wallets
     bool fCompressed = CanSupportFeature(FEATURE_COMPRPUBKEY);
 
     CKey secret;
 
     // Create new metadata
     int64_t nCreationTime = GetTime();
     CKeyMetadata metadata(nCreationTime);
 
     // use HD key derivation if HD was enabled during wallet creation
     if (IsHDEnabled()) {
         DeriveNewChildKey(
             walletdb, metadata, secret,
             (CanSupportFeature(FEATURE_HD_SPLIT) ? internal : false));
     } else {
         secret.MakeNewKey(fCompressed);
     }
 
     // Compressed public keys were introduced in version 0.6.0
     if (fCompressed) {
         SetMinVersion(FEATURE_COMPRPUBKEY);
     }
 
     CPubKey pubkey = secret.GetPubKey();
     assert(secret.VerifyPubKey(pubkey));
 
     mapKeyMetadata[pubkey.GetID()] = metadata;
     UpdateTimeFirstKey(nCreationTime);
 
     if (!AddKeyPubKeyWithDB(walletdb, secret, pubkey)) {
         throw std::runtime_error(std::string(__func__) + ": AddKey failed");
     }
 
     return pubkey;
 }
 
 void CWallet::DeriveNewChildKey(CWalletDB &walletdb, CKeyMetadata &metadata,
                                 CKey &secret, bool internal) {
     // for now we use a fixed keypath scheme of m/0'/0'/k
     // master key seed (256bit)
     CKey key;
     // hd master key
     CExtKey masterKey;
     // key at m/0'
     CExtKey accountKey;
     // key at m/0'/0' (external) or m/0'/1' (internal)
     CExtKey chainChildKey;
     // key at m/0'/0'/<n>'
     CExtKey childKey;
 
     // try to get the master key
     if (!GetKey(hdChain.masterKeyID, key)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": Master key not found");
     }
 
     masterKey.SetMaster(key.begin(), key.size());
 
     // derive m/0'
     // use hardened derivation (child keys >= 0x80000000 are hardened after
     // bip32)
     masterKey.Derive(accountKey, BIP32_HARDENED_KEY_LIMIT);
 
     // derive m/0'/0' (external chain) OR m/0'/1' (internal chain)
     assert(internal ? CanSupportFeature(FEATURE_HD_SPLIT) : true);
     accountKey.Derive(chainChildKey,
                       BIP32_HARDENED_KEY_LIMIT + (internal ? 1 : 0));
 
     // derive child key at next index, skip keys already known to the wallet
     do {
         // always derive hardened keys
         // childIndex | BIP32_HARDENED_KEY_LIMIT = derive childIndex in hardened
         // child-index-range
         // example: 1 | BIP32_HARDENED_KEY_LIMIT == 0x80000001 == 2147483649
         if (internal) {
             chainChildKey.Derive(childKey,
                                  hdChain.nInternalChainCounter |
                                      BIP32_HARDENED_KEY_LIMIT);
             metadata.hdKeypath = "m/0'/1'/" +
                                  std::to_string(hdChain.nInternalChainCounter) +
                                  "'";
             hdChain.nInternalChainCounter++;
         } else {
             chainChildKey.Derive(childKey,
                                  hdChain.nExternalChainCounter |
                                      BIP32_HARDENED_KEY_LIMIT);
             metadata.hdKeypath = "m/0'/0'/" +
                                  std::to_string(hdChain.nExternalChainCounter) +
                                  "'";
             hdChain.nExternalChainCounter++;
         }
     } while (HaveKey(childKey.key.GetPubKey().GetID()));
     secret = childKey.key;
     metadata.hdMasterKeyID = hdChain.masterKeyID;
     // update the chain model in the database
     if (!walletdb.WriteHDChain(hdChain)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": Writing HD chain model failed");
     }
 }
 
 bool CWallet::AddKeyPubKeyWithDB(CWalletDB &walletdb, const CKey &secret,
                                  const CPubKey &pubkey) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
 
     // CCryptoKeyStore has no concept of wallet databases, but calls
     // AddCryptedKey
     // which is overridden below.  To avoid flushes, the database handle is
     // tunneled through to it.
     bool needsDB = !pwalletdbEncryption;
     if (needsDB) {
         pwalletdbEncryption = &walletdb;
     }
     if (!CCryptoKeyStore::AddKeyPubKey(secret, pubkey)) {
         if (needsDB) {
             pwalletdbEncryption = nullptr;
         }
         return false;
     }
 
     if (needsDB) {
         pwalletdbEncryption = nullptr;
     }
 
     // Check if we need to remove from watch-only.
     CScript script;
     script = GetScriptForDestination(pubkey.GetID());
     if (HaveWatchOnly(script)) {
         RemoveWatchOnly(script);
     }
 
     script = GetScriptForRawPubKey(pubkey);
     if (HaveWatchOnly(script)) {
         RemoveWatchOnly(script);
     }
 
     if (IsCrypted()) {
         return true;
     }
 
     return walletdb.WriteKey(pubkey, secret.GetPrivKey(),
                              mapKeyMetadata[pubkey.GetID()]);
 }
 
 bool CWallet::AddKeyPubKey(const CKey &secret, const CPubKey &pubkey) {
     CWalletDB walletdb(*dbw);
     return CWallet::AddKeyPubKeyWithDB(walletdb, secret, pubkey);
 }
 
 bool CWallet::AddCryptedKey(const CPubKey &vchPubKey,
                             const std::vector<uint8_t> &vchCryptedSecret) {
     if (!CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret)) {
         return false;
     }
 
     LOCK(cs_wallet);
     if (pwalletdbEncryption) {
         return pwalletdbEncryption->WriteCryptedKey(
             vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
     }
 
     return CWalletDB(*dbw).WriteCryptedKey(vchPubKey, vchCryptedSecret,
                                            mapKeyMetadata[vchPubKey.GetID()]);
 }
 
 bool CWallet::LoadKeyMetadata(const CTxDestination &keyID,
                               const CKeyMetadata &meta) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     UpdateTimeFirstKey(meta.nCreateTime);
     mapKeyMetadata[keyID] = meta;
     return true;
 }
 
 bool CWallet::LoadCryptedKey(const CPubKey &vchPubKey,
                              const std::vector<uint8_t> &vchCryptedSecret) {
     return CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret);
 }
 
 /**
  * Update wallet first key creation time. This should be called whenever keys
  * are added to the wallet, with the oldest key creation time.
  */
 void CWallet::UpdateTimeFirstKey(int64_t nCreateTime) {
     AssertLockHeld(cs_wallet);
     if (nCreateTime <= 1) {
         // Cannot determine birthday information, so set the wallet birthday to
         // the beginning of time.
         nTimeFirstKey = 1;
     } else if (!nTimeFirstKey || nCreateTime < nTimeFirstKey) {
         nTimeFirstKey = nCreateTime;
     }
 }
 
 bool CWallet::AddCScript(const CScript &redeemScript) {
     if (!CCryptoKeyStore::AddCScript(redeemScript)) {
         return false;
     }
 
     return CWalletDB(*dbw).WriteCScript(Hash160(redeemScript), redeemScript);
 }
 
 bool CWallet::LoadCScript(const CScript &redeemScript) {
     /**
      * A sanity check was added in pull #3843 to avoid adding redeemScripts that
      * never can be redeemed. However, old wallets may still contain these. Do
      * not add them to the wallet and warn.
      */
     if (redeemScript.size() > MAX_SCRIPT_ELEMENT_SIZE) {
         std::string strAddr = EncodeDestination(CScriptID(redeemScript));
         LogPrintf("%s: Warning: This wallet contains a redeemScript of size %i "
                   "which exceeds maximum size %i thus can never be redeemed. "
                   "Do not use address %s.\n",
                   __func__, redeemScript.size(), MAX_SCRIPT_ELEMENT_SIZE,
                   strAddr);
         return true;
     }
 
     return CCryptoKeyStore::AddCScript(redeemScript);
 }
 
 bool CWallet::AddWatchOnly(const CScript &dest) {
     if (!CCryptoKeyStore::AddWatchOnly(dest)) {
         return false;
     }
 
     const CKeyMetadata &meta = mapKeyMetadata[CScriptID(dest)];
     UpdateTimeFirstKey(meta.nCreateTime);
     NotifyWatchonlyChanged(true);
     return CWalletDB(*dbw).WriteWatchOnly(dest, meta);
 }
 
 bool CWallet::AddWatchOnly(const CScript &dest, int64_t nCreateTime) {
     mapKeyMetadata[CScriptID(dest)].nCreateTime = nCreateTime;
     return AddWatchOnly(dest);
 }
 
 bool CWallet::RemoveWatchOnly(const CScript &dest) {
     AssertLockHeld(cs_wallet);
     if (!CCryptoKeyStore::RemoveWatchOnly(dest)) {
         return false;
     }
 
     if (!HaveWatchOnly()) {
         NotifyWatchonlyChanged(false);
     }
 
     return CWalletDB(*dbw).EraseWatchOnly(dest);
 }
 
 bool CWallet::LoadWatchOnly(const CScript &dest) {
     return CCryptoKeyStore::AddWatchOnly(dest);
 }
 
 bool CWallet::Unlock(const SecureString &strWalletPassphrase) {
     CCrypter crypter;
     CKeyingMaterial _vMasterKey;
 
     LOCK(cs_wallet);
     for (const MasterKeyMap::value_type &pMasterKey : mapMasterKeys) {
         if (!crypter.SetKeyFromPassphrase(
                 strWalletPassphrase, pMasterKey.second.vchSalt,
                 pMasterKey.second.nDeriveIterations,
                 pMasterKey.second.nDerivationMethod)) {
             return false;
         }
 
         if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey)) {
             // try another master key
             continue;
         }
 
         if (CCryptoKeyStore::Unlock(_vMasterKey)) {
             return true;
         }
     }
 
     return false;
 }
 
 bool CWallet::ChangeWalletPassphrase(
     const SecureString &strOldWalletPassphrase,
     const SecureString &strNewWalletPassphrase) {
     bool fWasLocked = IsLocked();
 
     LOCK(cs_wallet);
     Lock();
 
     CCrypter crypter;
     CKeyingMaterial _vMasterKey;
     for (MasterKeyMap::value_type &pMasterKey : mapMasterKeys) {
         if (!crypter.SetKeyFromPassphrase(
                 strOldWalletPassphrase, pMasterKey.second.vchSalt,
                 pMasterKey.second.nDeriveIterations,
                 pMasterKey.second.nDerivationMethod)) {
             return false;
         }
 
         if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey)) {
             return false;
         }
 
         if (CCryptoKeyStore::Unlock(_vMasterKey)) {
             int64_t nStartTime = GetTimeMillis();
             crypter.SetKeyFromPassphrase(strNewWalletPassphrase,
                                          pMasterKey.second.vchSalt,
                                          pMasterKey.second.nDeriveIterations,
                                          pMasterKey.second.nDerivationMethod);
             pMasterKey.second.nDeriveIterations =
                 pMasterKey.second.nDeriveIterations *
                 (100 / ((double)(GetTimeMillis() - nStartTime)));
 
             nStartTime = GetTimeMillis();
             crypter.SetKeyFromPassphrase(strNewWalletPassphrase,
                                          pMasterKey.second.vchSalt,
                                          pMasterKey.second.nDeriveIterations,
                                          pMasterKey.second.nDerivationMethod);
             pMasterKey.second.nDeriveIterations =
                 (pMasterKey.second.nDeriveIterations +
                  pMasterKey.second.nDeriveIterations * 100 /
                      double(GetTimeMillis() - nStartTime)) /
                 2;
 
             if (pMasterKey.second.nDeriveIterations < 25000) {
                 pMasterKey.second.nDeriveIterations = 25000;
             }
 
             LogPrintf(
                 "Wallet passphrase changed to an nDeriveIterations of %i\n",
                 pMasterKey.second.nDeriveIterations);
 
             if (!crypter.SetKeyFromPassphrase(
                     strNewWalletPassphrase, pMasterKey.second.vchSalt,
                     pMasterKey.second.nDeriveIterations,
                     pMasterKey.second.nDerivationMethod)) {
                 return false;
             }
 
             if (!crypter.Encrypt(_vMasterKey,
                                  pMasterKey.second.vchCryptedKey)) {
                 return false;
             }
 
             CWalletDB(*dbw).WriteMasterKey(pMasterKey.first, pMasterKey.second);
             if (fWasLocked) {
                 Lock();
             }
 
             return true;
         }
     }
 
     return false;
 }
 
 void CWallet::SetBestChain(const CBlockLocator &loc) {
     CWalletDB walletdb(*dbw);
     walletdb.WriteBestBlock(loc);
 }
 
 bool CWallet::SetMinVersion(enum WalletFeature nVersion, CWalletDB *pwalletdbIn,
                             bool fExplicit) {
     // nWalletVersion
     LOCK(cs_wallet);
     if (nWalletVersion >= nVersion) {
         return true;
     }
 
     // When doing an explicit upgrade, if we pass the max version permitted,
     // upgrade all the way.
     if (fExplicit && nVersion > nWalletMaxVersion) {
         nVersion = FEATURE_LATEST;
     }
 
     nWalletVersion = nVersion;
 
     if (nVersion > nWalletMaxVersion) {
         nWalletMaxVersion = nVersion;
     }
 
     CWalletDB *pwalletdb = pwalletdbIn ? pwalletdbIn : new CWalletDB(*dbw);
     if (nWalletVersion > 40000) {
         pwalletdb->WriteMinVersion(nWalletVersion);
     }
 
     if (!pwalletdbIn) {
         delete pwalletdb;
     }
 
     return true;
 }
 
 bool CWallet::SetMaxVersion(int nVersion) {
     // nWalletVersion, nWalletMaxVersion
     LOCK(cs_wallet);
 
     // Cannot downgrade below current version
     if (nWalletVersion > nVersion) {
         return false;
     }
 
     nWalletMaxVersion = nVersion;
 
     return true;
 }
 
 std::set<TxId> CWallet::GetConflicts(const TxId &txid) const {
     std::set<TxId> result;
     AssertLockHeld(cs_wallet);
 
     std::map<TxId, CWalletTx>::const_iterator it = mapWallet.find(txid);
     if (it == mapWallet.end()) {
         return result;
     }
 
     const CWalletTx &wtx = it->second;
 
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range;
 
     for (const CTxIn &txin : wtx.tx->vin) {
         if (mapTxSpends.count(txin.prevout) <= 1) {
             // No conflict if zero or one spends.
             continue;
         }
 
         range = mapTxSpends.equal_range(txin.prevout);
         for (TxSpends::const_iterator _it = range.first; _it != range.second;
              ++_it) {
             result.insert(_it->second);
         }
     }
 
     return result;
 }
 
 bool CWallet::HasWalletSpend(const TxId &txid) const {
     AssertLockHeld(cs_wallet);
     auto iter = mapTxSpends.lower_bound(COutPoint(txid, 0));
     return (iter != mapTxSpends.end() && iter->first.GetTxId() == txid);
 }
 
 void CWallet::Flush(bool shutdown) {
     dbw->Flush(shutdown);
 }
 
 void CWallet::SyncMetaData(
     std::pair<TxSpends::iterator, TxSpends::iterator> range) {
     // We want all the wallet transactions in range to have the same metadata as
     // the oldest (smallest nOrderPos).
     // So: find smallest nOrderPos:
 
     int nMinOrderPos = std::numeric_limits<int>::max();
     const CWalletTx *copyFrom = nullptr;
     for (TxSpends::iterator it = range.first; it != range.second; ++it) {
         const TxId &txid = it->second;
         int n = mapWallet[txid].nOrderPos;
         if (n < nMinOrderPos) {
             nMinOrderPos = n;
             copyFrom = &mapWallet[txid];
         }
     }
 
     // Now copy data from copyFrom to rest:
     for (TxSpends::iterator it = range.first; it != range.second; ++it) {
         const TxId &txid = it->second;
         CWalletTx *copyTo = &mapWallet[txid];
         if (copyFrom == copyTo) {
             continue;
         }
 
         if (!copyFrom->IsEquivalentTo(*copyTo)) {
             continue;
         }
 
         copyTo->mapValue = copyFrom->mapValue;
         copyTo->vOrderForm = copyFrom->vOrderForm;
         // fTimeReceivedIsTxTime not copied on purpose nTimeReceived not copied
         // on purpose.
         copyTo->nTimeSmart = copyFrom->nTimeSmart;
         copyTo->fFromMe = copyFrom->fFromMe;
         copyTo->strFromAccount = copyFrom->strFromAccount;
         // nOrderPos not copied on purpose cached members not copied on purpose.
     }
 }
 
 /**
  * Outpoint is spent if any non-conflicted transaction, spends it:
  */
 bool CWallet::IsSpent(const TxId &txid, uint32_t n) const {
     const COutPoint outpoint(txid, n);
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range =
         mapTxSpends.equal_range(outpoint);
 
     for (TxSpends::const_iterator it = range.first; it != range.second; ++it) {
         const TxId &wtxid = it->second;
         std::map<TxId, CWalletTx>::const_iterator mit = mapWallet.find(wtxid);
         if (mit != mapWallet.end()) {
             int depth = mit->second.GetDepthInMainChain();
             if (depth > 0 || (depth == 0 && !mit->second.isAbandoned())) {
                 // Spent
                 return true;
             }
         }
     }
 
     return false;
 }
 
 void CWallet::AddToSpends(const COutPoint &outpoint, const TxId &wtxid) {
     mapTxSpends.insert(std::make_pair(outpoint, wtxid));
 
     std::pair<TxSpends::iterator, TxSpends::iterator> range;
     range = mapTxSpends.equal_range(outpoint);
     SyncMetaData(range);
 }
 
 void CWallet::AddToSpends(const TxId &wtxid) {
     assert(mapWallet.count(wtxid));
     CWalletTx &thisTx = mapWallet[wtxid];
     // Coinbases don't spend anything!
     if (thisTx.IsCoinBase()) {
         return;
     }
 
     for (const CTxIn &txin : thisTx.tx->vin) {
         AddToSpends(txin.prevout, wtxid);
     }
 }
 
 bool CWallet::EncryptWallet(const SecureString &strWalletPassphrase) {
     if (IsCrypted()) {
         return false;
     }
 
     CKeyingMaterial _vMasterKey;
 
     _vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
     GetStrongRandBytes(&_vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
 
     CMasterKey kMasterKey;
 
     kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
     GetStrongRandBytes(&kMasterKey.vchSalt[0], WALLET_CRYPTO_SALT_SIZE);
 
     CCrypter crypter;
     int64_t nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, 25000,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations =
         2500000 / ((double)(GetTimeMillis() - nStartTime));
 
     nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                  kMasterKey.nDeriveIterations,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations =
         (kMasterKey.nDeriveIterations +
          kMasterKey.nDeriveIterations * 100 /
              ((double)(GetTimeMillis() - nStartTime))) /
         2;
 
     if (kMasterKey.nDeriveIterations < 25000) {
         kMasterKey.nDeriveIterations = 25000;
     }
 
     LogPrintf("Encrypting Wallet with an nDeriveIterations of %i\n",
               kMasterKey.nDeriveIterations);
 
     if (!crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                       kMasterKey.nDeriveIterations,
                                       kMasterKey.nDerivationMethod)) {
         return false;
     }
 
     if (!crypter.Encrypt(_vMasterKey, kMasterKey.vchCryptedKey)) {
         return false;
     }
 
     {
         LOCK(cs_wallet);
         mapMasterKeys[++nMasterKeyMaxID] = kMasterKey;
         assert(!pwalletdbEncryption);
         pwalletdbEncryption = new CWalletDB(*dbw);
         if (!pwalletdbEncryption->TxnBegin()) {
             delete pwalletdbEncryption;
             pwalletdbEncryption = nullptr;
             return false;
         }
         pwalletdbEncryption->WriteMasterKey(nMasterKeyMaxID, kMasterKey);
 
         if (!EncryptKeys(_vMasterKey)) {
             pwalletdbEncryption->TxnAbort();
             delete pwalletdbEncryption;
             // We now probably have half of our keys encrypted in memory, and
             // half not... die and let the user reload the unencrypted wallet.
             assert(false);
         }
 
         // Encryption was introduced in version 0.4.0
         SetMinVersion(FEATURE_WALLETCRYPT, pwalletdbEncryption, true);
 
         if (!pwalletdbEncryption->TxnCommit()) {
             delete pwalletdbEncryption;
             // We now have keys encrypted in memory, but not on disk... die to
             // avoid confusion and let the user reload the unencrypted wallet.
             assert(false);
         }
 
         delete pwalletdbEncryption;
         pwalletdbEncryption = nullptr;
 
         Lock();
         Unlock(strWalletPassphrase);
 
         // If we are using HD, replace the HD master key (seed) with a new one.
         if (IsHDEnabled()) {
             CKey key;
             CPubKey masterPubKey = GenerateNewHDMasterKey();
             // preserve the old chains version to not break backward
             // compatibility
             CHDChain oldChain = GetHDChain();
             if (!SetHDMasterKey(masterPubKey, &oldChain)) {
                 return false;
             }
         }
 
         NewKeyPool();
         Lock();
 
         // Need to completely rewrite the wallet file; if we don't, bdb might
         // keep bits of the unencrypted private key in slack space in the
         // database file.
         dbw->Rewrite();
     }
 
     NotifyStatusChanged(this);
     return true;
 }
 
 DBErrors CWallet::ReorderTransactions() {
     LOCK(cs_wallet);
     CWalletDB walletdb(*dbw);
 
     // Old wallets didn't have any defined order for transactions. Probably a
     // bad idea to change the output of this.
 
     // First: get all CWalletTx and CAccountingEntry into a sorted-by-time
     // multimap.
     TxItems txByTime;
 
     for (std::map<TxId, CWalletTx>::iterator it = mapWallet.begin();
          it != mapWallet.end(); ++it) {
         CWalletTx *wtx = &((*it).second);
         txByTime.insert(
             std::make_pair(wtx->nTimeReceived, TxPair(wtx, nullptr)));
     }
 
     std::list<CAccountingEntry> acentries;
     walletdb.ListAccountCreditDebit("", acentries);
     for (CAccountingEntry &entry : acentries) {
         txByTime.insert(std::make_pair(entry.nTime, TxPair(nullptr, &entry)));
     }
 
     nOrderPosNext = 0;
     std::vector<int64_t> nOrderPosOffsets;
     for (TxItems::iterator it = txByTime.begin(); it != txByTime.end(); ++it) {
         CWalletTx *const pwtx = (*it).second.first;
         CAccountingEntry *const pacentry = (*it).second.second;
         int64_t &nOrderPos =
             (pwtx != 0) ? pwtx->nOrderPos : pacentry->nOrderPos;
 
         if (nOrderPos == -1) {
             nOrderPos = nOrderPosNext++;
             nOrderPosOffsets.push_back(nOrderPos);
 
             if (pwtx) {
                 if (!walletdb.WriteTx(*pwtx)) {
                     return DB_LOAD_FAIL;
                 }
             } else if (!walletdb.WriteAccountingEntry(pacentry->nEntryNo,
                                                       *pacentry)) {
                 return DB_LOAD_FAIL;
             }
         } else {
             int64_t nOrderPosOff = 0;
             for (const int64_t &nOffsetStart : nOrderPosOffsets) {
                 if (nOrderPos >= nOffsetStart) {
                     ++nOrderPosOff;
                 }
             }
 
             nOrderPos += nOrderPosOff;
             nOrderPosNext = std::max(nOrderPosNext, nOrderPos + 1);
 
             if (!nOrderPosOff) {
                 continue;
             }
 
             // Since we're changing the order, write it back.
             if (pwtx) {
                 if (!walletdb.WriteTx(*pwtx)) {
                     return DB_LOAD_FAIL;
                 }
             } else if (!walletdb.WriteAccountingEntry(pacentry->nEntryNo,
                                                       *pacentry)) {
                 return DB_LOAD_FAIL;
             }
         }
     }
 
     walletdb.WriteOrderPosNext(nOrderPosNext);
 
     return DB_LOAD_OK;
 }
 
 int64_t CWallet::IncOrderPosNext(CWalletDB *pwalletdb) {
     // nOrderPosNext
     AssertLockHeld(cs_wallet);
     int64_t nRet = nOrderPosNext++;
     if (pwalletdb) {
         pwalletdb->WriteOrderPosNext(nOrderPosNext);
     } else {
         CWalletDB(*dbw).WriteOrderPosNext(nOrderPosNext);
     }
 
     return nRet;
 }
 
 bool CWallet::AccountMove(std::string strFrom, std::string strTo,
                           const Amount nAmount, std::string strComment) {
     CWalletDB walletdb(*dbw);
     if (!walletdb.TxnBegin()) {
         return false;
     }
 
     int64_t nNow = GetAdjustedTime();
 
     // Debit
     CAccountingEntry debit;
     debit.nOrderPos = IncOrderPosNext(&walletdb);
     debit.strAccount = strFrom;
     debit.nCreditDebit = -nAmount;
     debit.nTime = nNow;
     debit.strOtherAccount = strTo;
     debit.strComment = strComment;
     AddAccountingEntry(debit, &walletdb);
 
     // Credit
     CAccountingEntry credit;
     credit.nOrderPos = IncOrderPosNext(&walletdb);
     credit.strAccount = strTo;
     credit.nCreditDebit = nAmount;
     credit.nTime = nNow;
     credit.strOtherAccount = strFrom;
     credit.strComment = strComment;
     AddAccountingEntry(credit, &walletdb);
 
     return walletdb.TxnCommit();
 }
 
 bool CWallet::GetAccountPubkey(CPubKey &pubKey, std::string strAccount,
                                bool bForceNew) {
     CWalletDB walletdb(*dbw);
 
     CAccount account;
     walletdb.ReadAccount(strAccount, account);
 
     if (!bForceNew) {
         if (!account.vchPubKey.IsValid()) {
             bForceNew = true;
         } else {
             // Check if the current key has been used.
             CScript scriptPubKey =
                 GetScriptForDestination(account.vchPubKey.GetID());
             for (std::map<TxId, CWalletTx>::iterator it = mapWallet.begin();
                  it != mapWallet.end() && account.vchPubKey.IsValid(); ++it) {
                 for (const CTxOut &txout : (*it).second.tx->vout) {
                     if (txout.scriptPubKey == scriptPubKey) {
                         bForceNew = true;
                         break;
                     }
                 }
             }
         }
     }
 
     // Generate a new key
     if (bForceNew) {
         if (!GetKeyFromPool(account.vchPubKey, false)) {
             return false;
         }
 
         SetAddressBook(account.vchPubKey.GetID(), strAccount, "receive");
         walletdb.WriteAccount(strAccount, account);
     }
 
     pubKey = account.vchPubKey;
 
     return true;
 }
 
 void CWallet::MarkDirty() {
     LOCK(cs_wallet);
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         item.second.MarkDirty();
     }
 }
 
 bool CWallet::AddToWallet(const CWalletTx &wtxIn, bool fFlushOnClose) {
     LOCK(cs_wallet);
 
     CWalletDB walletdb(*dbw, "r+", fFlushOnClose);
 
     const TxId &txid = wtxIn.GetId();
 
     // Inserts only if not already there, returns tx inserted or tx found.
     std::pair<std::map<TxId, CWalletTx>::iterator, bool> ret =
         mapWallet.insert(std::make_pair(txid, wtxIn));
     CWalletTx &wtx = (*ret.first).second;
     wtx.BindWallet(this);
     bool fInsertedNew = ret.second;
     if (fInsertedNew) {
         wtx.nTimeReceived = GetAdjustedTime();
         wtx.nOrderPos = IncOrderPosNext(&walletdb);
         wtxOrdered.insert(std::make_pair(wtx.nOrderPos, TxPair(&wtx, nullptr)));
         wtx.nTimeSmart = ComputeTimeSmart(wtx);
         AddToSpends(txid);
     }
 
     bool fUpdated = false;
     if (!fInsertedNew) {
         // Merge
         if (!wtxIn.hashUnset() && wtxIn.hashBlock != wtx.hashBlock) {
             wtx.hashBlock = wtxIn.hashBlock;
             fUpdated = true;
         }
 
         // If no longer abandoned, update
         if (wtxIn.hashBlock.IsNull() && wtx.isAbandoned()) {
             wtx.hashBlock = wtxIn.hashBlock;
             fUpdated = true;
         }
 
         if (wtxIn.nIndex != -1 && (wtxIn.nIndex != wtx.nIndex)) {
             wtx.nIndex = wtxIn.nIndex;
             fUpdated = true;
         }
 
         if (wtxIn.fFromMe && wtxIn.fFromMe != wtx.fFromMe) {
             wtx.fFromMe = wtxIn.fFromMe;
             fUpdated = true;
         }
     }
 
     //// debug print
     LogPrintf("AddToWallet %s  %s%s\n", wtxIn.GetId().ToString(),
               (fInsertedNew ? "new" : ""), (fUpdated ? "update" : ""));
 
     // Write to disk
     if ((fInsertedNew || fUpdated) && !walletdb.WriteTx(wtx)) {
         return false;
     }
 
     // Break debit/credit balance caches:
     wtx.MarkDirty();
 
     // Notify UI of new or updated transaction.
     NotifyTransactionChanged(this, txid, fInsertedNew ? CT_NEW : CT_UPDATED);
 
     // Notify an external script when a wallet transaction comes in or is
     // updated.
     std::string strCmd = gArgs.GetArg("-walletnotify", "");
 
     if (!strCmd.empty()) {
         boost::replace_all(strCmd, "%s", wtxIn.GetId().GetHex());
         std::thread t(runCommand, strCmd);
         // Thread runs free.
         t.detach();
     }
 
     return true;
 }
 
 bool CWallet::LoadToWallet(const CWalletTx &wtxIn) {
     const TxId &txid = wtxIn.GetId();
 
     mapWallet[txid] = wtxIn;
     CWalletTx &wtx = mapWallet[txid];
     wtx.BindWallet(this);
     wtxOrdered.insert(std::make_pair(wtx.nOrderPos, TxPair(&wtx, nullptr)));
     AddToSpends(txid);
     for (const CTxIn &txin : wtx.tx->vin) {
         if (mapWallet.count(txin.prevout.GetTxId())) {
             CWalletTx &prevtx = mapWallet[txin.prevout.GetTxId()];
             if (prevtx.nIndex == -1 && !prevtx.hashUnset()) {
                 MarkConflicted(prevtx.hashBlock, wtx.GetId());
             }
         }
     }
 
     return true;
 }
 
 /**
  * Add a transaction to the wallet, or update it.  pIndex and posInBlock should
  * be set when the transaction was known to be included in a block. When pIndex
  * == nullptr, then wallet state is not updated in AddToWallet, but
  * notifications happen and cached balances are marked dirty.
  *
  * If fUpdate is true, existing transactions will be updated.
  * TODO: One exception to this is that the abandoned state is cleared under the
  * assumption that any further notification of a transaction that was considered
  * abandoned is an indication that it is not safe to be considered abandoned.
  * Abandoned state should probably be more carefuly tracked via different
  * posInBlock signals or by checking mempool presence when necessary.
  */
 bool CWallet::AddToWalletIfInvolvingMe(const CTransactionRef &ptx,
                                        const CBlockIndex *pIndex,
                                        int posInBlock, bool fUpdate) {
     const CTransaction &tx = *ptx;
     AssertLockHeld(cs_wallet);
 
     if (pIndex != nullptr) {
         for (const CTxIn &txin : tx.vin) {
             std::pair<TxSpends::const_iterator, TxSpends::const_iterator>
                 range = mapTxSpends.equal_range(txin.prevout);
             while (range.first != range.second) {
                 if (range.first->second != tx.GetId()) {
                     LogPrintf("Transaction %s (in block %s) conflicts with "
                               "wallet transaction %s (both spend %s:%i)\n",
                               tx.GetId().ToString(),
                               pIndex->GetBlockHash().ToString(),
                               range.first->second.ToString(),
                               range.first->first.GetTxId().ToString(),
                               range.first->first.GetN());
                     MarkConflicted(pIndex->GetBlockHash(), range.first->second);
                 }
                 range.first++;
             }
         }
     }
 
     bool fExisted = mapWallet.count(tx.GetId()) != 0;
     if (fExisted && !fUpdate) {
         return false;
     }
     if (fExisted || IsMine(tx) || IsFromMe(tx)) {
         /**
          * Check if any keys in the wallet keypool that were supposed to be
          * unused have appeared in a new transaction. If so, remove those keys
          * from the keypool. This can happen when restoring an old wallet backup
          * that does not contain the mostly recently created transactions from
          * newer versions of the wallet.
          */
 
         // loop though all outputs
         for (const CTxOut &txout : tx.vout) {
             // extract addresses and check if they match with an unused keypool
             // key
             std::vector<CKeyID> vAffected;
             CAffectedKeysVisitor(*this, vAffected).Process(txout.scriptPubKey);
             for (const CKeyID &keyid : vAffected) {
                 std::map<CKeyID, int64_t>::const_iterator mi =
                     m_pool_key_to_index.find(keyid);
                 if (mi != m_pool_key_to_index.end()) {
                     LogPrintf("%s: Detected a used keypool key, mark all "
                               "keypool key up to this key as used\n",
                               __func__);
                     MarkReserveKeysAsUsed(mi->second);
 
                     if (!TopUpKeyPool()) {
                         LogPrintf(
                             "%s: Topping up keypool failed (locked wallet)\n",
                             __func__);
                     }
                 }
             }
         }
 
         CWalletTx wtx(this, ptx);
 
         // Get merkle branch if transaction was found in a block
         if (pIndex != nullptr) {
             wtx.SetMerkleBranch(pIndex, posInBlock);
         }
 
         return AddToWallet(wtx, false);
     }
 
     return false;
 }
 
 bool CWallet::AbandonTransaction(const TxId &txid) {
     LOCK2(cs_main, cs_wallet);
 
     CWalletDB walletdb(*dbw, "r+");
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     // Can't mark abandoned if confirmed or in mempool.
     assert(mapWallet.count(txid));
     CWalletTx &origtx = mapWallet[txid];
     if (origtx.GetDepthInMainChain() > 0 || origtx.InMempool()) {
         return false;
     }
 
     todo.insert(txid);
 
     while (!todo.empty()) {
         const TxId now = *todo.begin();
         todo.erase(now);
         done.insert(now);
         assert(mapWallet.count(now));
         CWalletTx &wtx = mapWallet[now];
         int currentconfirm = wtx.GetDepthInMainChain();
         // If the orig tx was not in block, none of its spends can be.
         assert(currentconfirm <= 0);
         // If (currentconfirm < 0) {Tx and spends are already conflicted, no
         // need to abandon}
         if (currentconfirm == 0 && !wtx.isAbandoned()) {
             // If the orig tx was not in block/mempool, none of its spends can
             // be in mempool.
             assert(!wtx.InMempool());
             wtx.nIndex = -1;
             wtx.setAbandoned();
             wtx.MarkDirty();
             walletdb.WriteTx(wtx);
             NotifyTransactionChanged(this, wtx.GetId(), CT_UPDATED);
             // Iterate over all its outputs, and mark transactions in the wallet
             // that spend them abandoned too.
             TxSpends::const_iterator iter =
                 mapTxSpends.lower_bound(COutPoint(now, 0));
             while (iter != mapTxSpends.end() && iter->first.GetTxId() == now) {
                 if (!done.count(iter->second)) {
                     todo.insert(iter->second);
                 }
                 iter++;
             }
 
             // If a transaction changes 'conflicted' state, that changes the
             // balance available of the outputs it spends. So force those to be
             // recomputed.
             for (const CTxIn &txin : wtx.tx->vin) {
                 if (mapWallet.count(txin.prevout.GetTxId())) {
                     mapWallet[txin.prevout.GetTxId()].MarkDirty();
                 }
             }
         }
     }
 
     return true;
 }
 
 void CWallet::MarkConflicted(const uint256 &hashBlock, const TxId &txid) {
     LOCK2(cs_main, cs_wallet);
 
     int conflictconfirms = 0;
     if (mapBlockIndex.count(hashBlock)) {
         CBlockIndex *pindex = mapBlockIndex[hashBlock];
         if (chainActive.Contains(pindex)) {
             conflictconfirms = -(chainActive.Height() - pindex->nHeight + 1);
         }
     }
 
     // If number of conflict confirms cannot be determined, this means that the
     // block is still unknown or not yet part of the main chain, for example
     // when loading the wallet during a reindex. Do nothing in that case.
     if (conflictconfirms >= 0) {
         return;
     }
 
     // Do not flush the wallet here for performance reasons.
     CWalletDB walletdb(*dbw, "r+", false);
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     todo.insert(txid);
 
     while (!todo.empty()) {
         const TxId now = *todo.begin();
         todo.erase(now);
         done.insert(now);
         assert(mapWallet.count(now));
         CWalletTx &wtx = mapWallet[now];
         int currentconfirm = wtx.GetDepthInMainChain();
         if (conflictconfirms < currentconfirm) {
             // Block is 'more conflicted' than current confirm; update.
             // Mark transaction as conflicted with this block.
             wtx.nIndex = -1;
             wtx.hashBlock = hashBlock;
             wtx.MarkDirty();
             walletdb.WriteTx(wtx);
             // Iterate over all its outputs, and mark transactions in the wallet
             // that spend them conflicted too.
             TxSpends::const_iterator iter =
                 mapTxSpends.lower_bound(COutPoint(now, 0));
             while (iter != mapTxSpends.end() && iter->first.GetTxId() == now) {
                 if (!done.count(iter->second)) {
                     todo.insert(iter->second);
                 }
                 iter++;
             }
 
             // If a transaction changes 'conflicted' state, that changes the
             // balance available of the outputs it spends. So force those to be
             // recomputed.
             for (const CTxIn &txin : wtx.tx->vin) {
                 if (mapWallet.count(txin.prevout.GetTxId())) {
                     mapWallet[txin.prevout.GetTxId()].MarkDirty();
                 }
             }
         }
     }
 }
 
 void CWallet::SyncTransaction(const CTransactionRef &ptx,
                               const CBlockIndex *pindex, int posInBlock) {
     const CTransaction &tx = *ptx;
 
     if (!AddToWalletIfInvolvingMe(ptx, pindex, posInBlock, true)) {
         // Not one of ours
         return;
     }
 
     // If a transaction changes 'conflicted' state, that changes the balance
     // available of the outputs it spends. So force those to be recomputed,
     // also:
     for (const CTxIn &txin : tx.vin) {
         if (mapWallet.count(txin.prevout.GetTxId())) {
             mapWallet[txin.prevout.GetTxId()].MarkDirty();
         }
     }
 }
 
 void CWallet::TransactionAddedToMempool(const CTransactionRef &ptx) {
     LOCK2(cs_main, cs_wallet);
     SyncTransaction(ptx);
 }
 
 void CWallet::BlockConnected(
     const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex,
     const std::vector<CTransactionRef> &vtxConflicted) {
     LOCK2(cs_main, cs_wallet);
 
     // TODO: Tempoarily ensure that mempool removals are notified before
     // connected transactions. This shouldn't matter, but the abandoned state of
     // transactions in our wallet is currently cleared when we receive another
     // notification and there is a race condition where notification of a
     // connected conflict might cause an outside process to abandon a
     // transaction and then have it inadvertantly cleared by the notification
     // that the conflicted transaction was evicted.
     for (const CTransactionRef &ptx : vtxConflicted) {
         SyncTransaction(ptx);
     }
 
     for (size_t i = 0; i < pblock->vtx.size(); i++) {
         SyncTransaction(pblock->vtx[i], pindex, i);
     }
 }
 
 void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) {
     LOCK2(cs_main, cs_wallet);
 
     for (const CTransactionRef &ptx : pblock->vtx) {
         SyncTransaction(ptx);
     }
 }
 
 isminetype CWallet::IsMine(const CTxIn &txin) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator mi =
         mapWallet.find(txin.prevout.GetTxId());
     if (mi != mapWallet.end()) {
         const CWalletTx &prev = (*mi).second;
         if (txin.prevout.GetN() < prev.tx->vout.size()) {
             return IsMine(prev.tx->vout[txin.prevout.GetN()]);
         }
     }
 
     return ISMINE_NO;
 }
 
 // Note that this function doesn't distinguish between a 0-valued input, and a
 // not-"is mine" (according to the filter) input.
 Amount CWallet::GetDebit(const CTxIn &txin, const isminefilter &filter) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator mi =
         mapWallet.find(txin.prevout.GetTxId());
     if (mi != mapWallet.end()) {
         const CWalletTx &prev = (*mi).second;
         if (txin.prevout.GetN() < prev.tx->vout.size()) {
             if (IsMine(prev.tx->vout[txin.prevout.GetN()]) & filter) {
                 return prev.tx->vout[txin.prevout.GetN()].nValue;
             }
         }
     }
 
     return Amount::zero();
 }
 
 isminetype CWallet::IsMine(const CTxOut &txout) const {
     return ::IsMine(*this, txout.scriptPubKey);
 }
 
 Amount CWallet::GetCredit(const CTxOut &txout,
                           const isminefilter &filter) const {
     if (!MoneyRange(txout.nValue)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": value out of range");
     }
 
     return (IsMine(txout) & filter) ? txout.nValue : Amount::zero();
 }
 
 bool CWallet::IsChange(const CTxOut &txout) const {
     // TODO: fix handling of 'change' outputs. The assumption is that any
     // payment to a script that is ours, but is not in the address book is
     // change. That assumption is likely to break when we implement
     // multisignature wallets that return change back into a
     // multi-signature-protected address; a better way of identifying which
     // outputs are 'the send' and which are 'the change' will need to be
     // implemented (maybe extend CWalletTx to remember which output, if any, was
     // change).
     if (::IsMine(*this, txout.scriptPubKey)) {
         CTxDestination address;
         if (!ExtractDestination(txout.scriptPubKey, address)) {
             return true;
         }
 
         LOCK(cs_wallet);
         if (!mapAddressBook.count(address)) {
             return true;
         }
     }
 
     return false;
 }
 
 Amount CWallet::GetChange(const CTxOut &txout) const {
     if (!MoneyRange(txout.nValue)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": value out of range");
     }
 
     return (IsChange(txout) ? txout.nValue : Amount::zero());
 }
 
 bool CWallet::IsMine(const CTransaction &tx) const {
     for (const CTxOut &txout : tx.vout) {
         if (IsMine(txout)) {
             return true;
         }
     }
 
     return false;
 }
 
 bool CWallet::IsFromMe(const CTransaction &tx) const {
     return GetDebit(tx, ISMINE_ALL) > Amount::zero();
 }
 
 Amount CWallet::GetDebit(const CTransaction &tx,
                          const isminefilter &filter) const {
     Amount nDebit = Amount::zero();
     for (const CTxIn &txin : tx.vin) {
         nDebit += GetDebit(txin, filter);
         if (!MoneyRange(nDebit)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nDebit;
 }
 
 bool CWallet::IsAllFromMe(const CTransaction &tx,
                           const isminefilter &filter) const {
     LOCK(cs_wallet);
 
     for (const CTxIn &txin : tx.vin) {
         auto mi = mapWallet.find(txin.prevout.GetTxId());
         if (mi == mapWallet.end()) {
             // Any unknown inputs can't be from us.
             return false;
         }
 
         const CWalletTx &prev = (*mi).second;
 
         if (txin.prevout.GetN() >= prev.tx->vout.size()) {
             // Invalid input!
             return false;
         }
 
         if (!(IsMine(prev.tx->vout[txin.prevout.GetN()]) & filter)) {
             return false;
         }
     }
 
     return true;
 }
 
 Amount CWallet::GetCredit(const CTransaction &tx,
                           const isminefilter &filter) const {
     Amount nCredit = Amount::zero();
     for (const CTxOut &txout : tx.vout) {
         nCredit += GetCredit(txout, filter);
         if (!MoneyRange(nCredit)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nCredit;
 }
 
 Amount CWallet::GetChange(const CTransaction &tx) const {
     Amount nChange = Amount::zero();
     for (const CTxOut &txout : tx.vout) {
         nChange += GetChange(txout);
         if (!MoneyRange(nChange)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nChange;
 }
 
 CPubKey CWallet::GenerateNewHDMasterKey() {
     CKey key;
     key.MakeNewKey(true);
 
     int64_t nCreationTime = GetTime();
     CKeyMetadata metadata(nCreationTime);
 
     // Calculate the pubkey.
     CPubKey pubkey = key.GetPubKey();
     assert(key.VerifyPubKey(pubkey));
 
     // Set the hd keypath to "m" -> Master, refers the masterkeyid to itself.
     metadata.hdKeypath = "m";
     metadata.hdMasterKeyID = pubkey.GetID();
 
     LOCK(cs_wallet);
 
     // mem store the metadata
     mapKeyMetadata[pubkey.GetID()] = metadata;
 
     // Write the key&metadata to the database.
     if (!AddKeyPubKey(key, pubkey)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": AddKeyPubKey failed");
     }
 
     return pubkey;
 }
 
 bool CWallet::SetHDMasterKey(const CPubKey &pubkey,
                              CHDChain *possibleOldChain) {
     LOCK(cs_wallet);
 
     // Store the keyid (hash160) together with the child index counter in the
     // database as a hdchain object.
     CHDChain newHdChain;
     if (possibleOldChain) {
         // preserve the old chains version
         newHdChain.nVersion = possibleOldChain->nVersion;
     }
     newHdChain.masterKeyID = pubkey.GetID();
     SetHDChain(newHdChain, false);
 
     return true;
 }
 
 bool CWallet::SetHDChain(const CHDChain &chain, bool memonly) {
     LOCK(cs_wallet);
     if (!memonly && !CWalletDB(*dbw).WriteHDChain(chain)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing chain failed");
     }
 
     hdChain = chain;
     return true;
 }
 
 bool CWallet::IsHDEnabled() {
     return !hdChain.masterKeyID.IsNull();
 }
 
 int64_t CWalletTx::GetTxTime() const {
     int64_t n = nTimeSmart;
     return n ? n : nTimeReceived;
 }
 
 int CWalletTx::GetRequestCount() const {
     LOCK(pwallet->cs_wallet);
 
     // Returns -1 if it wasn't being tracked.
     int nRequests = -1;
 
     if (IsCoinBase()) {
         // Generated block.
         if (!hashUnset()) {
             std::map<uint256, int>::const_iterator mi =
                 pwallet->mapRequestCount.find(hashBlock);
             if (mi != pwallet->mapRequestCount.end()) {
                 nRequests = (*mi).second;
             }
         }
     } else {
         // Did anyone request this transaction?
         std::map<uint256, int>::const_iterator mi =
             pwallet->mapRequestCount.find(GetId());
         if (mi != pwallet->mapRequestCount.end()) {
             nRequests = (*mi).second;
 
             // How about the block it's in?
             if (nRequests == 0 && !hashUnset()) {
                 std::map<uint256, int>::const_iterator _mi =
                     pwallet->mapRequestCount.find(hashBlock);
                 if (_mi != pwallet->mapRequestCount.end()) {
                     nRequests = (*_mi).second;
                 } else {
                     // If it's in someone else's block it must have got out.
                     nRequests = 1;
                 }
             }
         }
     }
 
     return nRequests;
 }
 
 void CWalletTx::GetAmounts(std::list<COutputEntry> &listReceived,
                            std::list<COutputEntry> &listSent, Amount &nFee,
                            std::string &strSentAccount,
                            const isminefilter &filter) const {
     nFee = Amount::zero();
     listReceived.clear();
     listSent.clear();
     strSentAccount = strFromAccount;
 
     // Compute fee:
     Amount nDebit = GetDebit(filter);
     // debit>0 means we signed/sent this transaction.
     if (nDebit > Amount::zero()) {
         Amount nValueOut = tx->GetValueOut();
         nFee = (nDebit - nValueOut);
     }
 
     // Sent/received.
     for (unsigned int i = 0; i < tx->vout.size(); ++i) {
         const CTxOut &txout = tx->vout[i];
         isminetype fIsMine = pwallet->IsMine(txout);
         // Only need to handle txouts if AT LEAST one of these is true:
         //   1) they debit from us (sent)
         //   2) the output is to us (received)
         if (nDebit > Amount::zero()) {
             // Don't report 'change' txouts
             if (pwallet->IsChange(txout)) {
                 continue;
             }
         } else if (!(fIsMine & filter)) {
             continue;
         }
 
         // In either case, we need to get the destination address.
         CTxDestination address;
 
         if (!ExtractDestination(txout.scriptPubKey, address) &&
             !txout.scriptPubKey.IsUnspendable()) {
             LogPrintf("CWalletTx::GetAmounts: Unknown transaction type found, "
                       "txid %s\n",
                       this->GetId().ToString());
             address = CNoDestination();
         }
 
         COutputEntry output = {address, txout.nValue, (int)i};
 
         // If we are debited by the transaction, add the output as a "sent"
         // entry.
         if (nDebit > Amount::zero()) {
             listSent.push_back(output);
         }
 
         // If we are receiving the output, add it as a "received" entry.
         if (fIsMine & filter) {
             listReceived.push_back(output);
         }
     }
 }
 
 /**
  * Scan active chain for relevant transactions after importing keys. This should
  * be called whenever new keys are added to the wallet, with the oldest key
  * creation time.
  *
  * @return Earliest timestamp that could be successfully scanned from. Timestamp
  * returned will be higher than startTime if relevant blocks could not be read.
  */
 int64_t CWallet::RescanFromTime(int64_t startTime, bool update) {
     AssertLockHeld(cs_main);
     AssertLockHeld(cs_wallet);
 
     // Find starting block. May be null if nCreateTime is greater than the
     // highest blockchain timestamp, in which case there is nothing that needs
     // to be scanned.
     CBlockIndex *const startBlock =
         chainActive.FindEarliestAtLeast(startTime - TIMESTAMP_WINDOW);
     LogPrintf("%s: Rescanning last %i blocks\n", __func__,
               startBlock ? chainActive.Height() - startBlock->nHeight + 1 : 0);
 
     if (startBlock) {
         const CBlockIndex *const failedBlock =
             ScanForWalletTransactions(startBlock, nullptr, update);
         if (failedBlock) {
             return failedBlock->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1;
         }
     }
     return startTime;
 }
 
 /**
  * Scan the block chain (starting in pindexStart) for transactions from or to
  * us. If fUpdate is true, found transactions that already exist in the wallet
  * will be updated.
  *
  * Returns null if scan was successful. Otherwise, if a complete rescan was not
  * possible (due to pruning or corruption), returns pointer to the most recent
  * block that could not be scanned.
  *
  * If pindexStop is not a nullptr, the scan will stop at the block-index defined
  * by pindexStop.
  */
 CBlockIndex *CWallet::ScanForWalletTransactions(CBlockIndex *pindexStart,
                                                 CBlockIndex *pindexStop,
                                                 bool fUpdate) {
     int64_t nNow = GetTime();
 
     if (pindexStop) {
         assert(pindexStop->nHeight >= pindexStart->nHeight);
     }
 
     CBlockIndex *pindex = pindexStart;
     CBlockIndex *ret = nullptr;
 
     LOCK2(cs_main, cs_wallet);
     fAbortRescan = false;
     fScanningWallet = true;
 
     // Show rescan progress in GUI as dialog or on splashscreen, if -rescan on
     // startup.
     ShowProgress(_("Rescanning..."), 0);
     double dProgressStart =
         GuessVerificationProgress(chainParams.TxData(), pindex);
     double dProgressTip =
         GuessVerificationProgress(chainParams.TxData(), chainActive.Tip());
     while (pindex && !fAbortRescan) {
         if (pindex->nHeight % 100 == 0 && dProgressTip - dProgressStart > 0.0) {
             ShowProgress(
                 _("Rescanning..."),
                 std::max(1, std::min<int>(99,
                                           (GuessVerificationProgress(
                                                chainParams.TxData(), pindex) -
                                            dProgressStart) /
                                               (dProgressTip - dProgressStart) *
                                               100)));
         }
 
         CBlock block;
         if (ReadBlockFromDisk(block, pindex, GetConfig())) {
             for (size_t posInBlock = 0; posInBlock < block.vtx.size();
                  ++posInBlock) {
                 AddToWalletIfInvolvingMe(block.vtx[posInBlock], pindex,
                                          posInBlock, fUpdate);
             }
         } else {
             ret = pindex;
         }
         if (pindex == pindexStop) {
             break;
         }
 
         pindex = chainActive.Next(pindex);
         if (GetTime() >= nNow + 60) {
             nNow = GetTime();
             LogPrintf("Still rescanning. At block %d. Progress=%f\n",
                       pindex->nHeight,
                       GuessVerificationProgress(chainParams.TxData(), pindex));
         }
     }
 
     if (pindex && fAbortRescan) {
         LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight,
                   GuessVerificationProgress(chainParams.TxData(), pindex));
     }
 
     // Hide progress dialog in GUI.
     ShowProgress(_("Rescanning..."), 100);
     fScanningWallet = false;
 
     return ret;
 }
 
 void CWallet::ReacceptWalletTransactions() {
     // If transactions aren't being broadcasted, don't let them into local
     // mempool either.
     if (!fBroadcastTransactions) {
         return;
     }
 
     LOCK2(cs_main, cs_wallet);
     std::map<int64_t, CWalletTx *> mapSorted;
 
     // Sort pending wallet transactions based on their initial wallet insertion
     // order.
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         const TxId &wtxid = item.first;
         CWalletTx &wtx = item.second;
         assert(wtx.GetId() == wtxid);
 
         int nDepth = wtx.GetDepthInMainChain();
 
         if (!wtx.IsCoinBase() && (nDepth == 0 && !wtx.isAbandoned())) {
             mapSorted.insert(std::make_pair(wtx.nOrderPos, &wtx));
         }
     }
 
     // Try to add wallet transactions to memory pool.
     for (std::pair<const int64_t, CWalletTx *> &item : mapSorted) {
         CWalletTx &wtx = *(item.second);
 
         LOCK(mempool.cs);
         CValidationState state;
         wtx.AcceptToMemoryPool(maxTxFee, state);
     }
 }
 
 bool CWalletTx::RelayWalletTransaction(CConnman *connman) {
     assert(pwallet->GetBroadcastTransactions());
     if (IsCoinBase() || isAbandoned() || GetDepthInMainChain() != 0) {
         return false;
     }
 
     CValidationState state;
     // GetDepthInMainChain already catches known conflicts.
     if (InMempool() || AcceptToMemoryPool(maxTxFee, state)) {
         LogPrintf("Relaying wtx %s\n", GetId().ToString());
         if (connman) {
             CInv inv(MSG_TX, GetId());
             connman->ForEachNode(
                 [&inv](CNode *pnode) { pnode->PushInventory(inv); });
             return true;
         }
     }
 
     return false;
 }
 
 std::set<TxId> CWalletTx::GetConflicts() const {
     std::set<TxId> result;
     if (pwallet != nullptr) {
         const TxId &txid = GetId();
         result = pwallet->GetConflicts(txid);
         result.erase(txid);
     }
 
     return result;
 }
 
 Amount CWalletTx::GetDebit(const isminefilter &filter) const {
     if (tx->vin.empty()) {
         return Amount::zero();
     }
 
     Amount debit = Amount::zero();
     if (filter & ISMINE_SPENDABLE) {
         if (fDebitCached) {
             debit += nDebitCached;
         } else {
             nDebitCached = pwallet->GetDebit(*this, ISMINE_SPENDABLE);
             fDebitCached = true;
             debit += nDebitCached;
         }
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         if (fWatchDebitCached) {
             debit += nWatchDebitCached;
         } else {
             nWatchDebitCached = pwallet->GetDebit(*this, ISMINE_WATCH_ONLY);
             fWatchDebitCached = true;
             debit += Amount(nWatchDebitCached);
         }
     }
 
     return debit;
 }
 
 Amount CWalletTx::GetCredit(const isminefilter &filter) const {
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase()) {
         return Amount::zero();
     }
 
     Amount credit = Amount::zero();
     if (filter & ISMINE_SPENDABLE) {
         // GetBalance can assume transactions in mapWallet won't change.
         if (fCreditCached) {
             credit += nCreditCached;
         } else {
             nCreditCached = pwallet->GetCredit(*this, ISMINE_SPENDABLE);
             fCreditCached = true;
             credit += nCreditCached;
         }
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         if (fWatchCreditCached) {
             credit += nWatchCreditCached;
         } else {
             nWatchCreditCached = pwallet->GetCredit(*this, ISMINE_WATCH_ONLY);
             fWatchCreditCached = true;
             credit += nWatchCreditCached;
         }
     }
 
     return credit;
 }
 
 Amount CWalletTx::GetImmatureCredit(bool fUseCache) const {
     if (IsImmatureCoinBase() && IsInMainChain()) {
         if (fUseCache && fImmatureCreditCached) {
             return nImmatureCreditCached;
         }
 
         nImmatureCreditCached = pwallet->GetCredit(*this, ISMINE_SPENDABLE);
         fImmatureCreditCached = true;
         return nImmatureCreditCached;
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetAvailableCredit(bool fUseCache) const {
     if (pwallet == 0) {
         return Amount::zero();
     }
 
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase()) {
         return Amount::zero();
     }
 
     if (fUseCache && fAvailableCreditCached) {
         return nAvailableCreditCached;
     }
 
     Amount nCredit = Amount::zero();
     for (uint32_t i = 0; i < tx->vout.size(); i++) {
         if (!pwallet->IsSpent(GetId(), i)) {
             const CTxOut &txout = tx->vout[i];
             nCredit += pwallet->GetCredit(txout, ISMINE_SPENDABLE);
             if (!MoneyRange(nCredit)) {
                 throw std::runtime_error(
                     "CWalletTx::GetAvailableCredit() : value out of range");
             }
         }
     }
 
     nAvailableCreditCached = nCredit;
     fAvailableCreditCached = true;
     return nCredit;
 }
 
 Amount CWalletTx::GetImmatureWatchOnlyCredit(const bool &fUseCache) const {
     if (IsImmatureCoinBase() && IsInMainChain()) {
         if (fUseCache && fImmatureWatchCreditCached) {
             return nImmatureWatchCreditCached;
         }
 
         nImmatureWatchCreditCached =
             pwallet->GetCredit(*this, ISMINE_WATCH_ONLY);
         fImmatureWatchCreditCached = true;
         return nImmatureWatchCreditCached;
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetAvailableWatchOnlyCredit(const bool &fUseCache) const {
     if (pwallet == 0) {
         return Amount::zero();
     }
 
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsCoinBase() && GetBlocksToMaturity() > 0) {
         return Amount::zero();
     }
 
     if (fUseCache && fAvailableWatchCreditCached) {
         return nAvailableWatchCreditCached;
     }
 
     Amount nCredit = Amount::zero();
     for (uint32_t i = 0; i < tx->vout.size(); i++) {
         if (!pwallet->IsSpent(GetId(), i)) {
             const CTxOut &txout = tx->vout[i];
             nCredit += pwallet->GetCredit(txout, ISMINE_WATCH_ONLY);
             if (!MoneyRange(nCredit)) {
                 throw std::runtime_error(
                     "CWalletTx::GetAvailableCredit() : value out of range");
             }
         }
     }
 
     nAvailableWatchCreditCached = nCredit;
     fAvailableWatchCreditCached = true;
     return nCredit;
 }
 
 Amount CWalletTx::GetChange() const {
     if (fChangeCached) {
         return nChangeCached;
     }
 
     nChangeCached = pwallet->GetChange(*this);
     fChangeCached = true;
     return nChangeCached;
 }
 
 bool CWalletTx::InMempool() const {
     LOCK(mempool.cs);
     if (mempool.exists(GetId())) {
         return true;
     }
 
     return false;
 }
 
 bool CWalletTx::IsTrusted() const {
     // Quick answer in most cases
     if (!CheckFinalTx(*this)) {
         return false;
     }
 
     int nDepth = GetDepthInMainChain();
     if (nDepth >= 1) {
         return true;
     }
 
     if (nDepth < 0) {
         return false;
     }
 
     // using wtx's cached debit
     if (!bSpendZeroConfChange || !IsFromMe(ISMINE_ALL)) {
         return false;
     }
 
     // Don't trust unconfirmed transactions from us unless they are in the
     // mempool.
     if (!InMempool()) {
         return false;
     }
 
     // Trusted if all inputs are from us and are in the mempool:
     for (const CTxIn &txin : tx->vin) {
         // Transactions not sent by us: not trusted
         const CWalletTx *parent = pwallet->GetWalletTx(txin.prevout.GetTxId());
         if (parent == nullptr) {
             return false;
         }
 
         const CTxOut &parentOut = parent->tx->vout[txin.prevout.GetN()];
         if (pwallet->IsMine(parentOut) != ISMINE_SPENDABLE) {
             return false;
         }
     }
 
     return true;
 }
 
 bool CWalletTx::IsEquivalentTo(const CWalletTx &_tx) const {
     CMutableTransaction tx1 = *this->tx;
     CMutableTransaction tx2 = *_tx.tx;
     for (CTxIn &in : tx1.vin) {
         in.scriptSig = CScript();
     }
 
     for (CTxIn &in : tx2.vin) {
         in.scriptSig = CScript();
     }
 
     return CTransaction(tx1) == CTransaction(tx2);
 }
 
 std::vector<uint256>
 CWallet::ResendWalletTransactionsBefore(int64_t nTime, CConnman *connman) {
     std::vector<uint256> result;
 
     LOCK(cs_wallet);
 
     // Sort them in chronological order
     std::multimap<unsigned int, CWalletTx *> mapSorted;
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         CWalletTx &wtx = item.second;
         // Don't rebroadcast if newer than nTime:
         if (wtx.nTimeReceived > nTime) {
             continue;
         }
 
         mapSorted.insert(std::make_pair(wtx.nTimeReceived, &wtx));
     }
 
     for (std::pair<const unsigned int, CWalletTx *> &item : mapSorted) {
         CWalletTx &wtx = *item.second;
         if (wtx.RelayWalletTransaction(connman)) {
             result.push_back(wtx.GetId());
         }
     }
 
     return result;
 }
 
 void CWallet::ResendWalletTransactions(int64_t nBestBlockTime,
                                        CConnman *connman) {
     // Do this infrequently and randomly to avoid giving away that these are our
     // transactions.
     if (GetTime() < nNextResend || !fBroadcastTransactions) {
         return;
     }
 
     bool fFirst = (nNextResend == 0);
     nNextResend = GetTime() + GetRand(30 * 60);
     if (fFirst) {
         return;
     }
 
     // Only do it if there's been a new block since last time
     if (nBestBlockTime < nLastResend) {
         return;
     }
 
     nLastResend = GetTime();
 
     // Rebroadcast unconfirmed txes older than 5 minutes before the last block
     // was found:
     std::vector<uint256> relayed =
         ResendWalletTransactionsBefore(nBestBlockTime - 5 * 60, connman);
     if (!relayed.empty()) {
         LogPrintf("%s: rebroadcast %u unconfirmed transactions\n", __func__,
                   relayed.size());
     }
 }
 
 /** @} */ // end of mapWallet
 
 /**
  * @defgroup Actions
  *
  * @{
  */
 Amount CWallet::GetBalance() const {
     LOCK2(cs_main, cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const std::pair<uint256, CWalletTx> &p : mapWallet) {
         const CWalletTx *pcoin = &p.second;
         if (pcoin->IsTrusted()) {
             nTotal += pcoin->GetAvailableCredit();
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetUnconfirmedBalance() const {
     LOCK2(cs_main, cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const std::pair<uint256, CWalletTx> &p : mapWallet) {
         const CWalletTx *pcoin = &p.second;
         if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 &&
             pcoin->InMempool()) {
             nTotal += pcoin->GetAvailableCredit();
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetImmatureBalance() const {
     LOCK2(cs_main, cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const std::pair<uint256, CWalletTx> &p : mapWallet) {
         const CWalletTx *pcoin = &p.second;
         nTotal += pcoin->GetImmatureCredit();
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetWatchOnlyBalance() const {
     LOCK2(cs_main, cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const std::pair<uint256, CWalletTx> &p : mapWallet) {
         const CWalletTx *pcoin = &p.second;
         if (pcoin->IsTrusted()) {
             nTotal += pcoin->GetAvailableWatchOnlyCredit();
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetUnconfirmedWatchOnlyBalance() const {
     LOCK2(cs_main, cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const std::pair<uint256, CWalletTx> &p : mapWallet) {
         const CWalletTx *pcoin = &p.second;
         if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 &&
             pcoin->InMempool()) {
             nTotal += pcoin->GetAvailableWatchOnlyCredit();
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetImmatureWatchOnlyBalance() const {
     LOCK2(cs_main, cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const std::pair<uint256, CWalletTx> &p : mapWallet) {
         const CWalletTx *pcoin = &p.second;
         nTotal += pcoin->GetImmatureWatchOnlyCredit();
     }
 
     return nTotal;
 }
 
 // Calculate total balance in a different way from GetBalance. The biggest
 // difference is that GetBalance sums up all unspent TxOuts paying to the
 // wallet, while this sums up both spent and unspent TxOuts paying to the
 // wallet, and then subtracts the values of TxIns spending from the wallet. This
 // also has fewer restrictions on which unconfirmed transactions are considered
 // trusted.
 Amount CWallet::GetLegacyBalance(const isminefilter &filter, int minDepth,
                                  const std::string *account) const {
     LOCK2(cs_main, cs_wallet);
 
     Amount balance = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx &wtx = entry.second;
         const int depth = wtx.GetDepthInMainChain();
         if (depth < 0 || !CheckFinalTx(*wtx.tx) || wtx.IsImmatureCoinBase()) {
 
             continue;
         }
 
         // Loop through tx outputs and add incoming payments. For outgoing txs,
         // treat change outputs specially, as part of the amount debited.
         Amount debit = wtx.GetDebit(filter);
         const bool outgoing = debit > Amount::zero();
         for (const CTxOut &out : wtx.tx->vout) {
             if (outgoing && IsChange(out)) {
                 debit -= out.nValue;
             } else if (IsMine(out) & filter && depth >= minDepth &&
                        (!account ||
                         *account == GetAccountName(out.scriptPubKey))) {
                 balance += out.nValue;
             }
         }
 
         // For outgoing txs, subtract amount debited.
         if (outgoing && (!account || *account == wtx.strFromAccount)) {
             balance -= debit;
         }
     }
 
     if (account) {
         balance += CWalletDB(*dbw).GetAccountCreditDebit(*account);
     }
 
     return balance;
 }
 
 void CWallet::AvailableCoins(std::vector<COutput> &vCoins, bool fOnlySafe,
                              const CCoinControl *coinControl,
                              const Amount nMinimumAmount,
                              const Amount nMaximumAmount,
                              const Amount nMinimumSumAmount,
                              const uint64_t &nMaximumCount,
                              const int &nMinDepth, const int &nMaxDepth) const {
     vCoins.clear();
     Amount nTotal = Amount::zero();
 
     LOCK2(cs_main, cs_wallet);
     for (std::map<TxId, CWalletTx>::const_iterator it = mapWallet.begin();
          it != mapWallet.end(); ++it) {
         const TxId &wtxid = it->first;
         const CWalletTx *pcoin = &(*it).second;
 
         if (!CheckFinalTx(*pcoin)) {
             continue;
         }
 
         if (pcoin->IsImmatureCoinBase()) {
             continue;
         }
 
         int nDepth = pcoin->GetDepthInMainChain();
         if (nDepth < 0) {
             continue;
         }
 
         // We should not consider coins which aren't at least in our mempool.
         // It's possible for these to be conflicted via ancestors which we may
         // never be able to detect.
         if (nDepth == 0 && !pcoin->InMempool()) {
             continue;
         }
 
         bool safeTx = pcoin->IsTrusted();
 
         // Bitcoin-ABC: Removed check that prevents consideration of coins from
         // transactions that are replacing other transactions. This check based
         // on pcoin->mapValue.count("replaces_txid") which was not being set
         // anywhere.
 
         // Similarly, we should not consider coins from transactions that have
         // been replaced. In the example above, we would want to prevent
         // creation of a transaction A' spending an output of A, because if
         // transaction B were initially confirmed, conflicting with A and A', we
         // wouldn't want to the user to create a transaction D intending to
         // replace A', but potentially resulting in a scenario where A, A', and
         // D could all be accepted (instead of just B and D, or just A and A'
         // like the user would want).
 
         // Bitcoin-ABC: retained this check as 'replaced_by_txid' is still set
         // in the wallet code.
         if (nDepth == 0 && pcoin->mapValue.count("replaced_by_txid")) {
             safeTx = false;
         }
 
         if (fOnlySafe && !safeTx) {
             continue;
         }
 
         if (nDepth < nMinDepth || nDepth > nMaxDepth) {
             continue;
         }
 
         for (uint32_t i = 0; i < pcoin->tx->vout.size(); i++) {
             if (pcoin->tx->vout[i].nValue < nMinimumAmount ||
                 pcoin->tx->vout[i].nValue > nMaximumAmount) {
                 continue;
             }
 
             if (coinControl && coinControl->HasSelected() &&
                 !coinControl->fAllowOtherInputs &&
                 !coinControl->IsSelected(COutPoint((*it).first, i))) {
                 continue;
             }
 
             if (IsLockedCoin((*it).first, i)) {
                 continue;
             }
 
             if (IsSpent(wtxid, i)) {
                 continue;
             }
 
             isminetype mine = IsMine(pcoin->tx->vout[i]);
 
             if (mine == ISMINE_NO) {
                 continue;
             }
 
             bool fSpendableIn = ((mine & ISMINE_SPENDABLE) != ISMINE_NO) ||
                                 (coinControl && coinControl->fAllowWatchOnly &&
                                  (mine & ISMINE_WATCH_SOLVABLE) != ISMINE_NO);
             bool fSolvableIn =
                 (mine & (ISMINE_SPENDABLE | ISMINE_WATCH_SOLVABLE)) !=
                 ISMINE_NO;
 
             vCoins.push_back(
                 COutput(pcoin, i, nDepth, fSpendableIn, fSolvableIn, safeTx));
 
             // Checks the sum amount of all UTXO's.
             if (nMinimumSumAmount != MAX_MONEY) {
                 nTotal += pcoin->tx->vout[i].nValue;
 
                 if (nTotal >= nMinimumSumAmount) {
                     return;
                 }
             }
 
             // Checks the maximum number of UTXO's.
             if (nMaximumCount > 0 && vCoins.size() >= nMaximumCount) {
                 return;
             }
         }
     }
 }
 
 static void ApproximateBestSubset(
     std::vector<std::pair<Amount, std::pair<const CWalletTx *, unsigned int>>>
         vValue,
     const Amount nTotalLower, const Amount nTargetValue,
     std::vector<char> &vfBest, Amount &nBest, int iterations = 1000) {
     std::vector<char> vfIncluded;
 
     vfBest.assign(vValue.size(), true);
     nBest = nTotalLower;
 
     FastRandomContext insecure_rand;
 
     for (int nRep = 0; nRep < iterations && nBest != nTargetValue; nRep++) {
         vfIncluded.assign(vValue.size(), false);
         Amount nTotal = Amount::zero();
         bool fReachedTarget = false;
         for (int nPass = 0; nPass < 2 && !fReachedTarget; nPass++) {
             for (size_t i = 0; i < vValue.size(); i++) {
                 // The solver here uses a randomized algorithm, the randomness
                 // serves no real security purpose but is just needed to prevent
                 // degenerate behavior and it is important that the rng is fast.
                 // We do not use a constant random sequence, because there may
                 // be some privacy improvement by making the selection random.
                 if (nPass == 0 ? insecure_rand.randbool() : !vfIncluded[i]) {
                     nTotal += vValue[i].first;
                     vfIncluded[i] = true;
                     if (nTotal >= nTargetValue) {
                         fReachedTarget = true;
                         if (nTotal < nBest) {
                             nBest = nTotal;
                             vfBest = vfIncluded;
                         }
 
                         nTotal -= vValue[i].first;
                         vfIncluded[i] = false;
                     }
                 }
             }
         }
     }
 }
 
 bool CWallet::SelectCoinsMinConf(
     const Amount nTargetValue, const int nConfMine, const int nConfTheirs,
     const uint64_t nMaxAncestors, std::vector<COutput> vCoins,
     std::set<std::pair<const CWalletTx *, unsigned int>> &setCoinsRet,
     Amount &nValueRet) const {
     setCoinsRet.clear();
     nValueRet = Amount::zero();
 
     // List of values less than target
     std::pair<Amount, std::pair<const CWalletTx *, unsigned int>>
         coinLowestLarger;
     coinLowestLarger.first = MAX_MONEY;
     coinLowestLarger.second.first = nullptr;
     std::vector<std::pair<Amount, std::pair<const CWalletTx *, unsigned int>>>
         vValue;
     Amount nTotalLower = Amount::zero();
 
     random_shuffle(vCoins.begin(), vCoins.end(), GetRandInt);
 
     for (const COutput &output : vCoins) {
         if (!output.fSpendable) {
             continue;
         }
 
         const CWalletTx *pcoin = output.tx;
 
         if (output.nDepth <
             (pcoin->IsFromMe(ISMINE_ALL) ? nConfMine : nConfTheirs)) {
             continue;
         }
 
         if (!mempool.TransactionWithinChainLimit(pcoin->GetId(),
                                                  nMaxAncestors)) {
             continue;
         }
 
         int i = output.i;
         Amount n = pcoin->tx->vout[i].nValue;
 
         std::pair<Amount, std::pair<const CWalletTx *, unsigned int>> coin =
             std::make_pair(n, std::make_pair(pcoin, i));
 
         if (n == nTargetValue) {
             setCoinsRet.insert(coin.second);
             nValueRet += coin.first;
             return true;
         }
 
         if (n < nTargetValue + MIN_CHANGE) {
             vValue.push_back(coin);
             nTotalLower += n;
         } else if (n < coinLowestLarger.first) {
             coinLowestLarger = coin;
         }
     }
 
     if (nTotalLower == nTargetValue) {
         for (unsigned int i = 0; i < vValue.size(); ++i) {
             setCoinsRet.insert(vValue[i].second);
             nValueRet += vValue[i].first;
         }
 
         return true;
     }
 
     if (nTotalLower < nTargetValue) {
         if (coinLowestLarger.second.first == nullptr) {
             return false;
         }
 
         setCoinsRet.insert(coinLowestLarger.second);
         nValueRet += coinLowestLarger.first;
         return true;
     }
 
     // Solve subset sum by stochastic approximation
     std::sort(vValue.begin(), vValue.end(), CompareValueOnly());
     std::reverse(vValue.begin(), vValue.end());
     std::vector<char> vfBest;
     Amount nBest;
 
     ApproximateBestSubset(vValue, nTotalLower, nTargetValue, vfBest, nBest);
     if (nBest != nTargetValue && nTotalLower >= nTargetValue + MIN_CHANGE) {
         ApproximateBestSubset(vValue, nTotalLower, nTargetValue + MIN_CHANGE,
                               vfBest, nBest);
     }
 
     // If we have a bigger coin and (either the stochastic approximation didn't
     // find a good solution, or the next bigger coin is closer), return the
     // bigger coin.
     if (coinLowestLarger.second.first &&
         ((nBest != nTargetValue && nBest < nTargetValue + MIN_CHANGE) ||
          coinLowestLarger.first <= nBest)) {
         setCoinsRet.insert(coinLowestLarger.second);
         nValueRet += coinLowestLarger.first;
     } else {
         for (unsigned int i = 0; i < vValue.size(); i++) {
             if (vfBest[i]) {
                 setCoinsRet.insert(vValue[i].second);
                 nValueRet += vValue[i].first;
             }
         }
 
         if (LogAcceptCategory(BCLog::SELECTCOINS)) {
             LogPrint(BCLog::SELECTCOINS, "SelectCoins() best subset: ");
             for (size_t i = 0; i < vValue.size(); i++) {
                 if (vfBest[i]) {
                     LogPrint(BCLog::SELECTCOINS, "%s ",
                              FormatMoney(vValue[i].first));
                 }
             }
             LogPrint(BCLog::SELECTCOINS, "total %s\n", FormatMoney(nBest));
         }
     }
 
     return true;
 }
 
 bool CWallet::SelectCoins(
     const std::vector<COutput> &vAvailableCoins, const Amount nTargetValue,
     std::set<std::pair<const CWalletTx *, unsigned int>> &setCoinsRet,
     Amount &nValueRet, const CCoinControl *coinControl) const {
     std::vector<COutput> vCoins(vAvailableCoins);
 
     // coin control -> return all selected outputs (we want all selected to go
     // into the transaction for sure).
     if (coinControl && coinControl->HasSelected() &&
         !coinControl->fAllowOtherInputs) {
         for (const COutput &out : vCoins) {
             if (!out.fSpendable) {
                 continue;
             }
 
             nValueRet += out.tx->tx->vout[out.i].nValue;
             setCoinsRet.insert(std::make_pair(out.tx, out.i));
         }
 
         return (nValueRet >= nTargetValue);
     }
 
     // Calculate value from preset inputs and store them.
     std::set<std::pair<const CWalletTx *, uint32_t>> setPresetCoins;
     Amount nValueFromPresetInputs = Amount::zero();
 
     std::vector<COutPoint> vPresetInputs;
     if (coinControl) {
         coinControl->ListSelected(vPresetInputs);
     }
 
     for (const COutPoint &outpoint : vPresetInputs) {
         std::map<TxId, CWalletTx>::const_iterator it =
             mapWallet.find(outpoint.GetTxId());
         if (it == mapWallet.end()) {
             // TODO: Allow non-wallet inputs
             return false;
         }
 
         const CWalletTx *pcoin = &it->second;
         // Clearly invalid input, fail.
         if (pcoin->tx->vout.size() <= outpoint.GetN()) {
             return false;
         }
 
         nValueFromPresetInputs += pcoin->tx->vout[outpoint.GetN()].nValue;
         setPresetCoins.insert(std::make_pair(pcoin, outpoint.GetN()));
     }
 
     // Remove preset inputs from vCoins.
     for (std::vector<COutput>::iterator it = vCoins.begin();
          it != vCoins.end() && coinControl && coinControl->HasSelected();) {
         if (setPresetCoins.count(std::make_pair(it->tx, it->i))) {
             it = vCoins.erase(it);
         } else {
             ++it;
         }
     }
 
     size_t nMaxChainLength = std::min(
         gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT),
         gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT));
     bool fRejectLongChains = gArgs.GetBoolArg(
         "-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
 
     bool res =
         nTargetValue <= nValueFromPresetInputs ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 1, 6, 0,
                            vCoins, setCoinsRet, nValueRet) ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 1, 1, 0,
                            vCoins, setCoinsRet, nValueRet) ||
         (bSpendZeroConfChange &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1, 2,
                             vCoins, setCoinsRet, nValueRet)) ||
         (bSpendZeroConfChange &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1,
                             std::min((size_t)4, nMaxChainLength / 3), vCoins,
                             setCoinsRet, nValueRet)) ||
         (bSpendZeroConfChange &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1,
                             nMaxChainLength / 2, vCoins, setCoinsRet,
                             nValueRet)) ||
         (bSpendZeroConfChange &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1,
                             nMaxChainLength, vCoins, setCoinsRet, nValueRet)) ||
         (bSpendZeroConfChange && !fRejectLongChains &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1,
                             std::numeric_limits<uint64_t>::max(), vCoins,
                             setCoinsRet, nValueRet));
 
     // Because SelectCoinsMinConf clears the setCoinsRet, we now add the
     // possible inputs to the coinset.
     setCoinsRet.insert(setPresetCoins.begin(), setPresetCoins.end());
 
     // Add preset inputs to the total value selected.
     nValueRet += nValueFromPresetInputs;
 
     return res;
 }
 
 bool CWallet::FundTransaction(CMutableTransaction &tx, Amount &nFeeRet,
                               bool overrideEstimatedFeeRate,
                               const CFeeRate &specificFeeRate,
                               int &nChangePosInOut, std::string &strFailReason,
                               bool includeWatching, bool lockUnspents,
                               const std::set<int> &setSubtractFeeFromOutputs,
                               bool keepReserveKey,
                               const CTxDestination &destChange) {
     std::vector<CRecipient> vecSend;
 
     // Turn the txout set into a CRecipient vector.
     for (size_t idx = 0; idx < tx.vout.size(); idx++) {
         const CTxOut &txOut = tx.vout[idx];
         CRecipient recipient = {txOut.scriptPubKey, txOut.nValue,
                                 setSubtractFeeFromOutputs.count(idx) == 1};
         vecSend.push_back(recipient);
     }
 
     CCoinControl coinControl;
     coinControl.destChange = destChange;
     coinControl.fAllowOtherInputs = true;
     coinControl.fAllowWatchOnly = includeWatching;
     coinControl.fOverrideFeeRate = overrideEstimatedFeeRate;
     coinControl.nFeeRate = specificFeeRate;
 
     for (const CTxIn &txin : tx.vin) {
         coinControl.Select(txin.prevout);
     }
 
     CReserveKey reservekey(this);
     CWalletTx wtx;
     if (!CreateTransaction(vecSend, wtx, reservekey, nFeeRet, nChangePosInOut,
                            strFailReason, &coinControl, false)) {
         return false;
     }
 
     if (nChangePosInOut != -1) {
         tx.vout.insert(tx.vout.begin() + nChangePosInOut,
                        wtx.tx->vout[nChangePosInOut]);
     }
 
     // Copy output sizes from new transaction; they may have had the fee
     // subtracted from them.
     for (size_t idx = 0; idx < tx.vout.size(); idx++) {
         tx.vout[idx].nValue = wtx.tx->vout[idx].nValue;
     }
 
     // Add new txins (keeping original txin scriptSig/order)
     for (const CTxIn &txin : wtx.tx->vin) {
         if (!coinControl.IsSelected(txin.prevout)) {
             tx.vin.push_back(txin);
 
             if (lockUnspents) {
                 LOCK2(cs_main, cs_wallet);
                 LockCoin(txin.prevout);
             }
         }
     }
 
     // Optionally keep the change output key.
     if (keepReserveKey) {
         reservekey.KeepKey();
     }
 
     return true;
 }
 
 bool CWallet::CreateTransaction(const std::vector<CRecipient> &vecSend,
                                 CWalletTx &wtxNew, CReserveKey &reservekey,
                                 Amount &nFeeRet, int &nChangePosInOut,
                                 std::string &strFailReason,
                                 const CCoinControl *coinControl, bool sign) {
     Amount nValue = Amount::zero();
 
     int nChangePosRequest = nChangePosInOut;
     unsigned int nSubtractFeeFromAmount = 0;
     for (const auto &recipient : vecSend) {
         if (nValue < Amount::zero() || recipient.nAmount < Amount::zero()) {
             strFailReason = _("Transaction amounts must not be negative");
             return false;
         }
 
         nValue += recipient.nAmount;
 
         if (recipient.fSubtractFeeFromAmount) {
             nSubtractFeeFromAmount++;
         }
     }
 
     if (vecSend.empty()) {
         strFailReason = _("Transaction must have at least one recipient");
         return false;
     }
 
     wtxNew.fTimeReceivedIsTxTime = true;
     wtxNew.BindWallet(this);
     CMutableTransaction txNew;
 
     // Discourage fee sniping.
     //
     // For a large miner the value of the transactions in the best block and the
     // mempool can exceed the cost of deliberately attempting to mine two blocks
     // to orphan the current best block. By setting nLockTime such that only the
     // next block can include the transaction, we discourage this practice as
     // the height restricted and limited blocksize gives miners considering fee
     // sniping fewer options for pulling off this attack.
     //
     // A simple way to think about this is from the wallet's point of view we
     // always want the blockchain to move forward. By setting nLockTime this way
     // we're basically making the statement that we only want this transaction
     // to appear in the next block; we don't want to potentially encourage
     // reorgs by allowing transactions to appear at lower heights than the next
     // block in forks of the best chain.
     //
     // Of course, the subsidy is high enough, and transaction volume low enough,
     // that fee sniping isn't a problem yet, but by implementing a fix now we
     // ensure code won't be written that makes assumptions about nLockTime that
     // preclude a fix later.
     txNew.nLockTime = chainActive.Height();
 
     // Secondly occasionally randomly pick a nLockTime even further back, so
     // that transactions that are delayed after signing for whatever reason,
     // e.g. high-latency mix networks and some CoinJoin implementations, have
     // better privacy.
     if (GetRandInt(10) == 0) {
         txNew.nLockTime = std::max(0, (int)txNew.nLockTime - GetRandInt(100));
     }
 
     assert(txNew.nLockTime <= (unsigned int)chainActive.Height());
     assert(txNew.nLockTime < LOCKTIME_THRESHOLD);
 
     {
         std::set<std::pair<const CWalletTx *, uint32_t>> setCoins;
         LOCK2(cs_main, cs_wallet);
 
         std::vector<COutput> vAvailableCoins;
         AvailableCoins(vAvailableCoins, true, coinControl);
 
         nFeeRet = Amount::zero();
         // Start with no fee and loop until there is enough fee.
         while (true) {
             nChangePosInOut = nChangePosRequest;
             txNew.vin.clear();
             txNew.vout.clear();
             wtxNew.fFromMe = true;
             bool fFirst = true;
 
             Amount nValueToSelect = nValue;
             if (nSubtractFeeFromAmount == 0) {
                 nValueToSelect += nFeeRet;
             }
 
             double dPriority = 0;
             // vouts to the payees
             for (const auto &recipient : vecSend) {
                 CTxOut txout(recipient.nAmount, recipient.scriptPubKey);
 
                 if (recipient.fSubtractFeeFromAmount) {
                     // Subtract fee equally from each selected recipient.
                     txout.nValue -= nFeeRet / int(nSubtractFeeFromAmount);
 
                     // First receiver pays the remainder not divisible by output
                     // count.
                     if (fFirst) {
                         fFirst = false;
                         txout.nValue -= nFeeRet % int(nSubtractFeeFromAmount);
                     }
                 }
 
                 if (txout.IsDust(dustRelayFee)) {
                     if (recipient.fSubtractFeeFromAmount &&
                         nFeeRet > Amount::zero()) {
                         if (txout.nValue < Amount::zero()) {
                             strFailReason = _("The transaction amount is "
                                               "too small to pay the fee");
                         } else {
                             strFailReason =
                                 _("The transaction amount is too small to "
                                   "send after the fee has been deducted");
                         }
                     } else {
                         strFailReason = _("Transaction amount too small");
                     }
 
                     return false;
                 }
 
                 txNew.vout.push_back(txout);
             }
 
             // Choose coins to use.
             Amount nValueIn = Amount::zero();
             setCoins.clear();
             if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins,
                              nValueIn, coinControl)) {
                 strFailReason = _("Insufficient funds");
                 return false;
             }
 
             for (const auto &pcoin : setCoins) {
                 Amount nCredit = pcoin.first->tx->vout[pcoin.second].nValue;
                 // The coin age after the next block (depth+1) is used instead
                 // of the current, reflecting an assumption the user would
                 // accept a bit more delay for a chance at a free transaction.
                 // But mempool inputs might still be in the mempool, so their
                 // age stays 0.
                 int age = pcoin.first->GetDepthInMainChain();
                 assert(age >= 0);
                 if (age != 0) {
                     age += 1;
                 }
 
                 dPriority += (age * nCredit) / SATOSHI;
             }
 
             const Amount nChange = nValueIn - nValueToSelect;
             if (nChange > Amount::zero()) {
                 // Fill a vout to ourself.
                 // TODO: pass in scriptChange instead of reservekey so change
                 // transaction isn't always pay-to-bitcoin-address.
                 CScript scriptChange;
 
                 // Coin control: send change to custom address.
                 if (coinControl &&
                     !boost::get<CNoDestination>(&coinControl->destChange)) {
                     scriptChange =
                         GetScriptForDestination(coinControl->destChange);
 
                     // No coin control: send change to newly generated address.
                 } else {
                     // Note: We use a new key here to keep it from being obvious
                     // which side is the change. The drawback is that by not
                     // reusing a previous key, the change may be lost if a
                     // backup is restored, if the backup doesn't have the new
                     // private key for the change. If we reused the old key, it
                     // would be possible to add code to look for and rediscover
                     // unknown transactions that were written with keys of ours
                     // to recover post-backup change.
 
                     // Reserve a new key pair from key pool.
                     CPubKey vchPubKey;
                     bool ret;
                     ret = reservekey.GetReservedKey(vchPubKey, true);
                     if (!ret) {
                         strFailReason = _("Keypool ran out, please call "
                                           "keypoolrefill first");
                         return false;
                     }
 
                     scriptChange = GetScriptForDestination(vchPubKey.GetID());
                 }
 
                 CTxOut newTxOut(nChange, scriptChange);
 
                 // We do not move dust-change to fees, because the sender would
                 // end up paying more than requested. This would be against the
                 // purpose of the all-inclusive feature. So instead we raise the
                 // change and deduct from the recipient.
                 if (nSubtractFeeFromAmount > 0 &&
                     newTxOut.IsDust(dustRelayFee)) {
                     Amount nDust = newTxOut.GetDustThreshold(dustRelayFee) -
                                    newTxOut.nValue;
                     // Raise change until no more dust.
                     newTxOut.nValue += nDust;
                     // Subtract from first recipient.
                     for (unsigned int i = 0; i < vecSend.size(); i++) {
                         if (vecSend[i].fSubtractFeeFromAmount) {
                             txNew.vout[i].nValue -= nDust;
                             if (txNew.vout[i].IsDust(dustRelayFee)) {
                                 strFailReason =
                                     _("The transaction amount is too small "
                                       "to send after the fee has been "
                                       "deducted");
                                 return false;
                             }
 
                             break;
                         }
                     }
                 }
 
                 // Never create dust outputs; if we would, just add the dust to
                 // the fee.
                 if (newTxOut.IsDust(dustRelayFee)) {
                     nChangePosInOut = -1;
                     nFeeRet += nChange;
                     reservekey.ReturnKey();
                 } else {
                     if (nChangePosInOut == -1) {
                         // Insert change txn at random position:
                         nChangePosInOut = GetRandInt(txNew.vout.size() + 1);
                     } else if ((unsigned int)nChangePosInOut >
                                txNew.vout.size()) {
                         strFailReason = _("Change index out of range");
                         return false;
                     }
 
                     std::vector<CTxOut>::iterator position =
                         txNew.vout.begin() + nChangePosInOut;
                     txNew.vout.insert(position, newTxOut);
                 }
             } else {
                 reservekey.ReturnKey();
             }
 
             // Fill vin
             //
             // Note how the sequence number is set to non-maxint so that the
             // nLockTime set above actually works.
             for (const auto &coin : setCoins) {
                 txNew.vin.push_back(
                     CTxIn(coin.first->GetId(), coin.second, CScript(),
                           std::numeric_limits<uint32_t>::max() - 1));
             }
 
             // Fill in dummy signatures for fee calculation.
             if (!DummySignTx(txNew, setCoins)) {
                 strFailReason = _("Signing transaction failed");
                 return false;
             }
 
             CTransaction txNewConst(txNew);
             unsigned int nBytes = txNewConst.GetTotalSize();
             dPriority = txNewConst.ComputePriority(dPriority, nBytes);
 
             // Remove scriptSigs to eliminate the fee calculation dummy
             // signatures.
             for (auto &vin : txNew.vin) {
                 vin.scriptSig = CScript();
             }
 
             // Allow to override the default confirmation target over the
             // CoinControl instance.
             int currentConfirmationTarget = nTxConfirmTarget;
             if (coinControl && coinControl->nConfirmTarget > 0) {
                 currentConfirmationTarget = coinControl->nConfirmTarget;
             }
 
             Amount nFeeNeeded =
                 GetMinimumFee(nBytes, currentConfirmationTarget, mempool);
             if (coinControl && nFeeNeeded > Amount::zero() &&
                 coinControl->nMinimumTotalFee > nFeeNeeded) {
                 nFeeNeeded = coinControl->nMinimumTotalFee;
             }
 
             if (coinControl && coinControl->fOverrideFeeRate) {
                 nFeeNeeded = coinControl->nFeeRate.GetFeeCeiling(nBytes);
             }
 
             // If we made it here and we aren't even able to meet the relay fee
             // on the next pass, give up because we must be at the maximum
             // allowed fee.
             Amount minFee = GetConfig().GetMinFeePerKB().GetFeeCeiling(nBytes);
             if (nFeeNeeded < minFee) {
                 strFailReason = _("Transaction too large for fee policy");
                 return false;
             }
 
             if (nFeeRet >= nFeeNeeded) {
                 // Reduce fee to only the needed amount if we have change output
                 // to increase. This prevents potential overpayment in fees if
                 // the coins selected to meet nFeeNeeded result in a transaction
                 // that requires less fee than the prior iteration.
                 // TODO: The case where nSubtractFeeFromAmount > 0 remains to be
                 // addressed because it requires returning the fee to the payees
                 // and not the change output.
                 // TODO: The case where there is no change output remains to be
                 // addressed so we avoid creating too small an output.
                 if (nFeeRet > nFeeNeeded && nChangePosInOut != -1 &&
                     nSubtractFeeFromAmount == 0) {
                     Amount extraFeePaid = nFeeRet - nFeeNeeded;
                     std::vector<CTxOut>::iterator change_position =
                         txNew.vout.begin() + nChangePosInOut;
                     change_position->nValue += extraFeePaid;
                     nFeeRet -= extraFeePaid;
                 }
 
                 // Done, enough fee included.
                 break;
             }
 
             // Try to reduce change to include necessary fee.
             if (nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
                 Amount additionalFeeNeeded = nFeeNeeded - nFeeRet;
                 std::vector<CTxOut>::iterator change_position =
                     txNew.vout.begin() + nChangePosInOut;
                 // Only reduce change if remaining amount is still a large
                 // enough output.
                 if (change_position->nValue >=
                     MIN_FINAL_CHANGE + additionalFeeNeeded) {
                     change_position->nValue -= additionalFeeNeeded;
                     nFeeRet += additionalFeeNeeded;
                     // Done, able to increase fee from change.
                     break;
                 }
             }
 
             // Include more fee and try again.
             nFeeRet = nFeeNeeded;
             continue;
         }
 
         if (sign) {
             SigHashType sigHashType = SigHashType().withForkId();
 
             CTransaction txNewConst(txNew);
             int nIn = 0;
             for (const auto &coin : setCoins) {
                 const CScript &scriptPubKey =
                     coin.first->tx->vout[coin.second].scriptPubKey;
                 SignatureData sigdata;
 
                 if (!ProduceSignature(
                         TransactionSignatureCreator(
                             this, &txNewConst, nIn,
                             coin.first->tx->vout[coin.second].nValue,
                             sigHashType),
                         scriptPubKey, sigdata)) {
                     strFailReason = _("Signing transaction failed");
                     return false;
                 }
 
                 UpdateTransaction(txNew, nIn, sigdata);
                 nIn++;
             }
         }
 
         // Embed the constructed transaction data in wtxNew.
         wtxNew.SetTx(MakeTransactionRef(std::move(txNew)));
 
         // Limit size.
         if (CTransaction(wtxNew).GetTotalSize() >= MAX_STANDARD_TX_SIZE) {
             strFailReason = _("Transaction too large");
             return false;
         }
     }
 
     if (gArgs.GetBoolArg("-walletrejectlongchains",
                          DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
         // Lastly, ensure this tx will pass the mempool's chain limits.
         LockPoints lp;
         CTxMemPoolEntry entry(wtxNew.tx, Amount::zero(), 0, 0, 0,
                               Amount::zero(), false, 0, lp);
         CTxMemPool::setEntries setAncestors;
         size_t nLimitAncestors =
             gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
         size_t nLimitAncestorSize =
             gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT) *
             1000;
         size_t nLimitDescendants =
             gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
         size_t nLimitDescendantSize =
             gArgs.GetArg("-limitdescendantsize",
                          DEFAULT_DESCENDANT_SIZE_LIMIT) *
             1000;
         std::string errString;
         if (!mempool.CalculateMemPoolAncestors(
                 entry, setAncestors, nLimitAncestors, nLimitAncestorSize,
                 nLimitDescendants, nLimitDescendantSize, errString)) {
             strFailReason = _("Transaction has too long of a mempool chain");
             return false;
         }
     }
 
     return true;
 }
 
 /**
  * Call after CreateTransaction unless you want to abort
  */
 bool CWallet::CommitTransaction(CWalletTx &wtxNew, CReserveKey &reservekey,
                                 CConnman *connman, CValidationState &state) {
     LOCK2(cs_main, cs_wallet);
     LogPrintf("CommitTransaction:\n%s", wtxNew.tx->ToString());
 
     // Take key pair from key pool so it won't be used again.
     reservekey.KeepKey();
 
     // Add tx to wallet, because if it has change it's also ours, otherwise just
     // for transaction history.
     AddToWallet(wtxNew);
 
     // Notify that old coins are spent.
     for (const CTxIn &txin : wtxNew.tx->vin) {
         CWalletTx &coin = mapWallet[txin.prevout.GetTxId()];
         coin.BindWallet(this);
         NotifyTransactionChanged(this, coin.GetId(), CT_UPDATED);
     }
 
     // Track how many getdata requests our transaction gets.
     mapRequestCount[wtxNew.GetId()] = 0;
 
     if (fBroadcastTransactions) {
         // Broadcast
         if (!wtxNew.AcceptToMemoryPool(maxTxFee, state)) {
             LogPrintf("CommitTransaction(): Transaction cannot be "
                       "broadcast immediately, %s\n",
                       state.GetRejectReason());
             // TODO: if we expect the failure to be long term or permanent,
             // instead delete wtx from the wallet and return failure.
         } else {
             wtxNew.RelayWalletTransaction(connman);
         }
     }
 
     return true;
 }
 
 void CWallet::ListAccountCreditDebit(const std::string &strAccount,
                                      std::list<CAccountingEntry> &entries) {
     CWalletDB walletdb(*dbw);
     return walletdb.ListAccountCreditDebit(strAccount, entries);
 }
 
 bool CWallet::AddAccountingEntry(const CAccountingEntry &acentry) {
     CWalletDB walletdb(*dbw);
     return AddAccountingEntry(acentry, &walletdb);
 }
 
 bool CWallet::AddAccountingEntry(const CAccountingEntry &acentry,
                                  CWalletDB *pwalletdb) {
     if (!pwalletdb->WriteAccountingEntry(++nAccountingEntryNumber, acentry)) {
         return false;
     }
 
     laccentries.push_back(acentry);
     CAccountingEntry &entry = laccentries.back();
     wtxOrdered.insert(std::make_pair(entry.nOrderPos, TxPair(nullptr, &entry)));
 
     return true;
 }
 
 DBErrors CWallet::LoadWallet(bool &fFirstRunRet) {
     fFirstRunRet = false;
     DBErrors nLoadWalletRet = CWalletDB(*dbw, "cr+").LoadWallet(this);
     if (nLoadWalletRet == DB_NEED_REWRITE) {
         if (dbw->Rewrite("\x04pool")) {
             LOCK(cs_wallet);
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
         }
     }
 
     // This wallet is in its first run if all of these are empty
     fFirstRunRet = mapKeys.empty() && mapCryptedKeys.empty() &&
                    mapWatchKeys.empty() && setWatchOnly.empty() &&
                    mapScripts.empty();
 
     if (nLoadWalletRet != DB_LOAD_OK) {
         return nLoadWalletRet;
     }
 
     uiInterface.LoadWallet(this);
 
     return DB_LOAD_OK;
 }
 
 DBErrors CWallet::ZapSelectTx(std::vector<TxId> &txIdsIn,
                               std::vector<TxId> &txIdsOut) {
     AssertLockHeld(cs_wallet); // mapWallet
     DBErrors nZapSelectTxRet =
         CWalletDB(*dbw, "cr+").ZapSelectTx(txIdsIn, txIdsOut);
     for (const TxId &txid : txIdsOut) {
         mapWallet.erase(txid);
     }
 
     if (nZapSelectTxRet == DB_NEED_REWRITE) {
         if (dbw->Rewrite("\x04pool")) {
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
         }
     }
 
     if (nZapSelectTxRet != DB_LOAD_OK) {
         return nZapSelectTxRet;
     }
 
     MarkDirty();
 
     return DB_LOAD_OK;
 }
 
 DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx> &vWtx) {
     DBErrors nZapWalletTxRet = CWalletDB(*dbw, "cr+").ZapWalletTx(vWtx);
     if (nZapWalletTxRet == DB_NEED_REWRITE) {
         if (dbw->Rewrite("\x04pool")) {
             LOCK(cs_wallet);
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
         }
     }
 
     if (nZapWalletTxRet != DB_LOAD_OK) {
         return nZapWalletTxRet;
     }
 
     return DB_LOAD_OK;
 }
 
 bool CWallet::SetAddressBook(const CTxDestination &address,
                              const std::string &strName,
                              const std::string &strPurpose) {
     bool fUpdated = false;
     {
         // mapAddressBook
         LOCK(cs_wallet);
         std::map<CTxDestination, CAddressBookData>::iterator mi =
             mapAddressBook.find(address);
         fUpdated = mi != mapAddressBook.end();
         mapAddressBook[address].name = strName;
         // Update purpose only if requested.
         if (!strPurpose.empty()) {
             mapAddressBook[address].purpose = strPurpose;
         }
     }
 
     NotifyAddressBookChanged(this, address, strName,
                              ::IsMine(*this, address) != ISMINE_NO, strPurpose,
                              (fUpdated ? CT_UPDATED : CT_NEW));
 
     if (!strPurpose.empty() &&
         !CWalletDB(*dbw).WritePurpose(address, strPurpose)) {
         return false;
     }
 
     return CWalletDB(*dbw).WriteName(address, strName);
 }
 
 bool CWallet::DelAddressBook(const CTxDestination &address) {
     {
         // mapAddressBook
         LOCK(cs_wallet);
 
         // Delete destdata tuples associated with address.
         for (const std::pair<std::string, std::string> &item :
              mapAddressBook[address].destdata) {
             CWalletDB(*dbw).EraseDestData(address, item.first);
         }
 
         mapAddressBook.erase(address);
     }
 
     NotifyAddressBookChanged(this, address, "",
                              ::IsMine(*this, address) != ISMINE_NO, "",
                              CT_DELETED);
 
     CWalletDB(*dbw).ErasePurpose(address);
     return CWalletDB(*dbw).EraseName(address);
 }
 
 const std::string &CWallet::GetAccountName(const CScript &scriptPubKey) const {
     CTxDestination address;
     if (ExtractDestination(scriptPubKey, address) &&
         !scriptPubKey.IsUnspendable()) {
         auto mi = mapAddressBook.find(address);
         if (mi != mapAddressBook.end()) {
             return mi->second.name;
         }
     }
     // A scriptPubKey that doesn't have an entry in the address book is
     // associated with the default account ("").
     const static std::string DEFAULT_ACCOUNT_NAME;
     return DEFAULT_ACCOUNT_NAME;
 }
 
 /**
  * Mark old keypool keys as used, and generate all new keys.
  */
 bool CWallet::NewKeyPool() {
     LOCK(cs_wallet);
     CWalletDB walletdb(*dbw);
 
     for (int64_t nIndex : setInternalKeyPool) {
         walletdb.ErasePool(nIndex);
     }
     setInternalKeyPool.clear();
 
     for (int64_t nIndex : setExternalKeyPool) {
         walletdb.ErasePool(nIndex);
     }
     setExternalKeyPool.clear();
 
     m_pool_key_to_index.clear();
 
     if (!TopUpKeyPool()) {
         return false;
     }
 
     LogPrintf("CWallet::NewKeyPool rewrote keypool\n");
     return true;
 }
 
 size_t CWallet::KeypoolCountExternalKeys() {
     // setExternalKeyPool
     AssertLockHeld(cs_wallet);
     return setExternalKeyPool.size();
 }
 
 void CWallet::LoadKeyPool(int64_t nIndex, const CKeyPool &keypool) {
     AssertLockHeld(cs_wallet);
     if (keypool.fInternal) {
         setInternalKeyPool.insert(nIndex);
     } else {
         setExternalKeyPool.insert(nIndex);
     }
     m_max_keypool_index = std::max(m_max_keypool_index, nIndex);
     m_pool_key_to_index[keypool.vchPubKey.GetID()] = nIndex;
 
     // If no metadata exists yet, create a default with the pool key's
     // creation time. Note that this may be overwritten by actually
     // stored metadata for that key later, which is fine.
     CKeyID keyid = keypool.vchPubKey.GetID();
     if (mapKeyMetadata.count(keyid) == 0) {
         mapKeyMetadata[keyid] = CKeyMetadata(keypool.nTime);
     }
 }
 
 bool CWallet::TopUpKeyPool(unsigned int kpSize) {
     LOCK(cs_wallet);
 
     if (IsLocked()) {
         return false;
     }
 
     // Top up key pool
     unsigned int nTargetSize;
     if (kpSize > 0) {
         nTargetSize = kpSize;
     } else {
         nTargetSize = std::max<int64_t>(
             gArgs.GetArg("-keypool", DEFAULT_KEYPOOL_SIZE), 0);
     }
 
     // count amount of available keys (internal, external)
     // make sure the keypool of external and internal keys fits the user
     // selected target (-keypool)
     int64_t missingExternal = std::max<int64_t>(
         std::max<int64_t>(nTargetSize, 1) - setExternalKeyPool.size(), 0);
     int64_t missingInternal = std::max<int64_t>(
         std::max<int64_t>(nTargetSize, 1) - setInternalKeyPool.size(), 0);
 
     if (!IsHDEnabled() || !CanSupportFeature(FEATURE_HD_SPLIT)) {
         // don't create extra internal keys
         missingInternal = 0;
     }
     bool internal = false;
     CWalletDB walletdb(*dbw);
     for (int64_t i = missingInternal + missingExternal; i--;) {
         if (i < missingInternal) {
             internal = true;
         }
 
         // How in the hell did you use so many keys?
         assert(m_max_keypool_index < std::numeric_limits<int64_t>::max());
         int64_t index = ++m_max_keypool_index;
 
         CPubKey pubkey(GenerateNewKey(walletdb, internal));
         if (!walletdb.WritePool(index, CKeyPool(pubkey, internal))) {
             throw std::runtime_error(std::string(__func__) +
                                      ": writing generated key failed");
         }
 
         if (internal) {
             setInternalKeyPool.insert(index);
         } else {
             setExternalKeyPool.insert(index);
         }
         m_pool_key_to_index[pubkey.GetID()] = index;
     }
     if (missingInternal + missingExternal > 0) {
         LogPrintf(
             "keypool added %d keys (%d internal), size=%u (%u internal)\n",
             missingInternal + missingExternal, missingInternal,
             setInternalKeyPool.size() + setExternalKeyPool.size(),
             setInternalKeyPool.size());
     }
 
     return true;
 }
 
 void CWallet::ReserveKeyFromKeyPool(int64_t &nIndex, CKeyPool &keypool,
                                     bool fRequestedInternal) {
     nIndex = -1;
     keypool.vchPubKey = CPubKey();
 
     LOCK(cs_wallet);
 
     if (!IsLocked()) {
         TopUpKeyPool();
     }
 
     bool fReturningInternal = IsHDEnabled() &&
                               CanSupportFeature(FEATURE_HD_SPLIT) &&
                               fRequestedInternal;
     std::set<int64_t> &setKeyPool =
         fReturningInternal ? setInternalKeyPool : setExternalKeyPool;
 
     // Get the oldest key
     if (setKeyPool.empty()) {
         return;
     }
 
     CWalletDB walletdb(*dbw);
 
     auto it = setKeyPool.begin();
     nIndex = *it;
     setKeyPool.erase(it);
     if (!walletdb.ReadPool(nIndex, keypool)) {
         throw std::runtime_error(std::string(__func__) + ": read failed");
     }
     if (!HaveKey(keypool.vchPubKey.GetID())) {
         throw std::runtime_error(std::string(__func__) +
                                  ": unknown key in key pool");
     }
     if (keypool.fInternal != fReturningInternal) {
         throw std::runtime_error(std::string(__func__) +
                                  ": keypool entry misclassified");
     }
 
     assert(keypool.vchPubKey.IsValid());
     m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
     LogPrintf("keypool reserve %d\n", nIndex);
 }
 
 void CWallet::KeepKey(int64_t nIndex) {
     // Remove from key pool.
     CWalletDB walletdb(*dbw);
     walletdb.ErasePool(nIndex);
     LogPrintf("keypool keep %d\n", nIndex);
 }
 
 void CWallet::ReturnKey(int64_t nIndex, bool fInternal, const CPubKey &pubkey) {
     // Return to key pool
     {
         LOCK(cs_wallet);
         if (fInternal) {
             setInternalKeyPool.insert(nIndex);
         } else {
             setExternalKeyPool.insert(nIndex);
         }
         m_pool_key_to_index[pubkey.GetID()] = nIndex;
     }
 
     LogPrintf("keypool return %d\n", nIndex);
 }
 
 bool CWallet::GetKeyFromPool(CPubKey &result, bool internal) {
     CKeyPool keypool;
     LOCK(cs_wallet);
     int64_t nIndex = 0;
     ReserveKeyFromKeyPool(nIndex, keypool, internal);
     if (nIndex == -1) {
         if (IsLocked()) {
             return false;
         }
         CWalletDB walletdb(*dbw);
         result = GenerateNewKey(walletdb, internal);
         return true;
     }
 
     KeepKey(nIndex);
     result = keypool.vchPubKey;
 
     return true;
 }
 
 static int64_t GetOldestKeyTimeInPool(const std::set<int64_t> &setKeyPool,
                                       CWalletDB &walletdb) {
     if (setKeyPool.empty()) {
         return GetTime();
     }
 
     CKeyPool keypool;
     int64_t nIndex = *(setKeyPool.begin());
     if (!walletdb.ReadPool(nIndex, keypool)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": read oldest key in keypool failed");
     }
 
     assert(keypool.vchPubKey.IsValid());
     return keypool.nTime;
 }
 
 int64_t CWallet::GetOldestKeyPoolTime() {
     LOCK(cs_wallet);
 
     CWalletDB walletdb(*dbw);
 
     // load oldest key from keypool, get time and return
     int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, walletdb);
     if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT)) {
         oldestKey = std::max(
             GetOldestKeyTimeInPool(setInternalKeyPool, walletdb), oldestKey);
     }
 
     return oldestKey;
 }
 
 std::map<CTxDestination, Amount> CWallet::GetAddressBalances() {
     std::map<CTxDestination, Amount> balances;
 
     LOCK(cs_wallet);
     for (std::pair<TxId, CWalletTx> walletEntry : mapWallet) {
         CWalletTx *pcoin = &walletEntry.second;
 
         if (!pcoin->IsTrusted()) {
             continue;
         }
 
         if (pcoin->IsImmatureCoinBase()) {
             continue;
         }
 
         int nDepth = pcoin->GetDepthInMainChain();
         if (nDepth < (pcoin->IsFromMe(ISMINE_ALL) ? 0 : 1)) {
             continue;
         }
 
         for (uint32_t i = 0; i < pcoin->tx->vout.size(); i++) {
             CTxDestination addr;
             if (!IsMine(pcoin->tx->vout[i])) {
                 continue;
             }
 
             if (!ExtractDestination(pcoin->tx->vout[i].scriptPubKey, addr)) {
                 continue;
             }
 
             Amount n = IsSpent(walletEntry.first, i)
                            ? Amount::zero()
                            : pcoin->tx->vout[i].nValue;
 
             if (!balances.count(addr)) {
                 balances[addr] = Amount::zero();
             }
             balances[addr] += n;
         }
     }
 
     return balances;
 }
 
 std::set<std::set<CTxDestination>> CWallet::GetAddressGroupings() {
     // mapWallet
     AssertLockHeld(cs_wallet);
     std::set<std::set<CTxDestination>> groupings;
     std::set<CTxDestination> grouping;
 
     for (std::pair<uint256, CWalletTx> walletEntry : mapWallet) {
         CWalletTx *pcoin = &walletEntry.second;
 
         if (pcoin->tx->vin.size() > 0) {
             bool any_mine = false;
             // Group all input addresses with each other.
             for (CTxIn txin : pcoin->tx->vin) {
                 CTxDestination address;
                 // If this input isn't mine, ignore it.
                 if (!IsMine(txin)) {
                     continue;
                 }
 
                 if (!ExtractDestination(mapWallet[txin.prevout.GetTxId()]
                                             .tx->vout[txin.prevout.GetN()]
                                             .scriptPubKey,
                                         address)) {
                     continue;
                 }
 
                 grouping.insert(address);
                 any_mine = true;
             }
 
             // Group change with input addresses.
             if (any_mine) {
                 for (CTxOut txout : pcoin->tx->vout) {
                     if (IsChange(txout)) {
                         CTxDestination txoutAddr;
                         if (!ExtractDestination(txout.scriptPubKey,
                                                 txoutAddr)) {
                             continue;
                         }
 
                         grouping.insert(txoutAddr);
                     }
                 }
             }
 
             if (grouping.size() > 0) {
                 groupings.insert(grouping);
                 grouping.clear();
             }
         }
 
         // Group lone addrs by themselves.
         for (unsigned int i = 0; i < pcoin->tx->vout.size(); i++)
             if (IsMine(pcoin->tx->vout[i])) {
                 CTxDestination address;
                 if (!ExtractDestination(pcoin->tx->vout[i].scriptPubKey,
                                         address)) {
                     continue;
                 }
 
                 grouping.insert(address);
                 groupings.insert(grouping);
                 grouping.clear();
             }
     }
 
     // A set of pointers to groups of addresses.
     std::set<std::set<CTxDestination> *> uniqueGroupings;
     // Map addresses to the unique group containing it.
     std::map<CTxDestination, std::set<CTxDestination> *> setmap;
     for (std::set<CTxDestination> _grouping : groupings) {
         // Make a set of all the groups hit by this new group.
         std::set<std::set<CTxDestination> *> hits;
         std::map<CTxDestination, std::set<CTxDestination> *>::iterator it;
         for (CTxDestination address : _grouping) {
             if ((it = setmap.find(address)) != setmap.end()) {
                 hits.insert((*it).second);
             }
         }
 
         // Merge all hit groups into a new single group and delete old groups.
         std::set<CTxDestination> *merged =
             new std::set<CTxDestination>(_grouping);
         for (std::set<CTxDestination> *hit : hits) {
             merged->insert(hit->begin(), hit->end());
             uniqueGroupings.erase(hit);
             delete hit;
         }
         uniqueGroupings.insert(merged);
 
         // Update setmap.
         for (CTxDestination element : *merged) {
             setmap[element] = merged;
         }
     }
 
     std::set<std::set<CTxDestination>> ret;
     for (std::set<CTxDestination> *uniqueGrouping : uniqueGroupings) {
         ret.insert(*uniqueGrouping);
         delete uniqueGrouping;
     }
 
     return ret;
 }
 
 std::set<CTxDestination>
 CWallet::GetAccountAddresses(const std::string &strAccount) const {
     LOCK(cs_wallet);
     std::set<CTxDestination> result;
     for (const std::pair<CTxDestination, CAddressBookData> &item :
          mapAddressBook) {
         const CTxDestination &address = item.first;
         const std::string &strName = item.second.name;
         if (strName == strAccount) {
             result.insert(address);
         }
     }
 
     return result;
 }
 
 bool CReserveKey::GetReservedKey(CPubKey &pubkey, bool internal) {
     if (nIndex == -1) {
         CKeyPool keypool;
         pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal);
         if (nIndex == -1) {
             return false;
         }
 
         vchPubKey = keypool.vchPubKey;
         fInternal = keypool.fInternal;
     }
 
     assert(vchPubKey.IsValid());
     pubkey = vchPubKey;
     return true;
 }
 
 void CReserveKey::KeepKey() {
     if (nIndex != -1) {
         pwallet->KeepKey(nIndex);
     }
 
     nIndex = -1;
     vchPubKey = CPubKey();
 }
 
 void CReserveKey::ReturnKey() {
     if (nIndex != -1) {
         pwallet->ReturnKey(nIndex, fInternal, vchPubKey);
     }
     nIndex = -1;
     vchPubKey = CPubKey();
 }
 
 void CWallet::MarkReserveKeysAsUsed(int64_t keypool_id) {
     AssertLockHeld(cs_wallet);
     bool internal = setInternalKeyPool.count(keypool_id);
     if (!internal) {
         assert(setExternalKeyPool.count(keypool_id));
     }
 
     std::set<int64_t> *setKeyPool =
         internal ? &setInternalKeyPool : &setExternalKeyPool;
     auto it = setKeyPool->begin();
 
     CWalletDB walletdb(*dbw);
     while (it != std::end(*setKeyPool)) {
         const int64_t &index = *(it);
         if (index > keypool_id) {
             // set*KeyPool is ordered
             break;
         }
 
         CKeyPool keypool;
         if (walletdb.ReadPool(index, keypool)) {
             // TODO: This should be unnecessary
             m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
         }
         walletdb.ErasePool(index);
         it = setKeyPool->erase(it);
     }
 }
 
 bool CWallet::HasUnusedKeys(size_t min_keys) const {
     return setExternalKeyPool.size() >= min_keys &&
            (setInternalKeyPool.size() >= min_keys ||
             !CanSupportFeature(FEATURE_HD_SPLIT));
 }
 
 void CWallet::GetScriptForMining(std::shared_ptr<CReserveScript> &script) {
     std::shared_ptr<CReserveKey> rKey = std::make_shared<CReserveKey>(this);
     CPubKey pubkey;
     if (!rKey->GetReservedKey(pubkey)) {
         return;
     }
 
     script = rKey;
     script->reserveScript = CScript() << ToByteVector(pubkey) << OP_CHECKSIG;
 }
 
 void CWallet::LockCoin(const COutPoint &output) {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     setLockedCoins.insert(output);
 }
 
 void CWallet::UnlockCoin(const COutPoint &output) {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     setLockedCoins.erase(output);
 }
 
 void CWallet::UnlockAllCoins() {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     setLockedCoins.clear();
 }
 
 bool CWallet::IsLockedCoin(const TxId &txid, uint32_t n) const {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     COutPoint outpt(txid, n);
 
     return setLockedCoins.count(outpt) > 0;
 }
 
 void CWallet::ListLockedCoins(std::vector<COutPoint> &vOutpts) {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     for (COutPoint outpoint : setLockedCoins) {
         vOutpts.push_back(outpoint);
     }
 }
 
 /** @} */ // end of Actions
 
 void CWallet::GetKeyBirthTimes(
     std::map<CTxDestination, int64_t> &mapKeyBirth) const {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     mapKeyBirth.clear();
 
     // Get birth times for keys with metadata.
     for (const auto &entry : mapKeyMetadata) {
         if (entry.second.nCreateTime) {
             mapKeyBirth[entry.first] = entry.second.nCreateTime;
         }
     }
 
     // Map in which we'll infer heights of other keys the tip can be
     // reorganized; use a 144-block safety margin.
     CBlockIndex *pindexMax =
         chainActive[std::max(0, chainActive.Height() - 144)];
     std::map<CKeyID, CBlockIndex *> mapKeyFirstBlock;
     std::set<CKeyID> setKeys;
     GetKeys(setKeys);
     for (const CKeyID &keyid : setKeys) {
         if (mapKeyBirth.count(keyid) == 0) {
             mapKeyFirstBlock[keyid] = pindexMax;
         }
     }
     setKeys.clear();
 
     // If there are no such keys, we're done.
     if (mapKeyFirstBlock.empty()) {
         return;
     }
 
     // Find first block that affects those keys, if there are any left.
     std::vector<CKeyID> vAffected;
     for (std::map<TxId, CWalletTx>::const_iterator it = mapWallet.begin();
          it != mapWallet.end(); it++) {
         // Iterate over all wallet transactions...
         const CWalletTx &wtx = (*it).second;
         BlockMap::const_iterator blit = mapBlockIndex.find(wtx.hashBlock);
         if (blit != mapBlockIndex.end() && chainActive.Contains(blit->second)) {
             // ... which are already in a block.
             int nHeight = blit->second->nHeight;
             for (const CTxOut &txout : wtx.tx->vout) {
                 // Iterate over all their outputs...
                 CAffectedKeysVisitor(*this, vAffected)
                     .Process(txout.scriptPubKey);
                 for (const CKeyID &keyid : vAffected) {
                     // ... and all their affected keys.
                     std::map<CKeyID, CBlockIndex *>::iterator rit =
                         mapKeyFirstBlock.find(keyid);
                     if (rit != mapKeyFirstBlock.end() &&
                         nHeight < rit->second->nHeight) {
                         rit->second = blit->second;
                     }
                 }
                 vAffected.clear();
             }
         }
     }
 
     // Extract block timestamps for those keys.
     for (const std::pair<CKeyID, CBlockIndex *> &p : mapKeyFirstBlock) {
         // Block times can be 2h off.
         mapKeyBirth[p.first] = p.second->GetBlockTime() - TIMESTAMP_WINDOW;
     }
 }
 
 /**
  * Compute smart timestamp for a transaction being added to the wallet.
  *
  * Logic:
  * - If sending a transaction, assign its timestamp to the current time.
  * - If receiving a transaction outside a block, assign its timestamp to the
  *   current time.
  * - If receiving a block with a future timestamp, assign all its (not already
  *   known) transactions' timestamps to the current time.
  * - If receiving a block with a past timestamp, before the most recent known
  *   transaction (that we care about), assign all its (not already known)
  *   transactions' timestamps to the same timestamp as that most-recent-known
  *   transaction.
  * - If receiving a block with a past timestamp, but after the most recent known
  *   transaction, assign all its (not already known) transactions' timestamps to
  *   the block time.
  *
  * For more information see CWalletTx::nTimeSmart,
  * https://bitcointalk.org/?topic=54527, or
  * https://github.com/bitcoin/bitcoin/pull/1393.
  */
 unsigned int CWallet::ComputeTimeSmart(const CWalletTx &wtx) const {
     unsigned int nTimeSmart = wtx.nTimeReceived;
     if (!wtx.hashUnset()) {
         if (mapBlockIndex.count(wtx.hashBlock)) {
             int64_t latestNow = wtx.nTimeReceived;
             int64_t latestEntry = 0;
 
             // Tolerate times up to the last timestamp in the wallet not more
             // than 5 minutes into the future
             int64_t latestTolerated = latestNow + 300;
             const TxItems &txOrdered = wtxOrdered;
             for (auto it = txOrdered.rbegin(); it != txOrdered.rend(); ++it) {
                 CWalletTx *const pwtx = it->second.first;
                 if (pwtx == &wtx) {
                     continue;
                 }
                 CAccountingEntry *const pacentry = it->second.second;
                 int64_t nSmartTime;
                 if (pwtx) {
                     nSmartTime = pwtx->nTimeSmart;
                     if (!nSmartTime) {
                         nSmartTime = pwtx->nTimeReceived;
                     }
                 } else {
                     nSmartTime = pacentry->nTime;
                 }
                 if (nSmartTime <= latestTolerated) {
                     latestEntry = nSmartTime;
                     if (nSmartTime > latestNow) {
                         latestNow = nSmartTime;
                     }
                     break;
                 }
             }
 
             int64_t blocktime = mapBlockIndex[wtx.hashBlock]->GetBlockTime();
             nTimeSmart = std::max(latestEntry, std::min(blocktime, latestNow));
         } else {
             LogPrintf("%s: found %s in block %s not in index\n", __func__,
                       wtx.GetId().ToString(), wtx.hashBlock.ToString());
         }
     }
     return nTimeSmart;
 }
 
 bool CWallet::AddDestData(const CTxDestination &dest, const std::string &key,
                           const std::string &value) {
     if (boost::get<CNoDestination>(&dest)) {
         return false;
     }
 
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
     return CWalletDB(*dbw).WriteDestData(dest, key, value);
 }
 
 bool CWallet::EraseDestData(const CTxDestination &dest,
                             const std::string &key) {
     if (!mapAddressBook[dest].destdata.erase(key)) {
         return false;
     }
 
     return CWalletDB(*dbw).EraseDestData(dest, key);
 }
 
 bool CWallet::LoadDestData(const CTxDestination &dest, const std::string &key,
                            const std::string &value) {
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
     return true;
 }
 
 bool CWallet::GetDestData(const CTxDestination &dest, const std::string &key,
                           std::string *value) const {
     std::map<CTxDestination, CAddressBookData>::const_iterator i =
         mapAddressBook.find(dest);
     if (i != mapAddressBook.end()) {
         CAddressBookData::StringMap::const_iterator j =
             i->second.destdata.find(key);
         if (j != i->second.destdata.end()) {
             if (value) {
                 *value = j->second;
             }
 
             return true;
         }
     }
 
     return false;
 }
 
 CWallet *CWallet::CreateWalletFromFile(const CChainParams &chainParams,
                                        const std::string walletFile) {
     // Needed to restore wallet transaction meta data after -zapwallettxes
     std::vector<CWalletTx> vWtx;
 
     if (gArgs.GetBoolArg("-zapwallettxes", false)) {
         uiInterface.InitMessage(_("Zapping all transactions from wallet..."));
 
         std::unique_ptr<CWalletDBWrapper> dbw(
             new CWalletDBWrapper(&bitdb, walletFile));
         CWallet *tempWallet = new CWallet(chainParams, std::move(dbw));
         DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
         if (nZapWalletRet != DB_LOAD_OK) {
             InitError(
                 strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
             return nullptr;
         }
 
         delete tempWallet;
         tempWallet = nullptr;
     }
 
     uiInterface.InitMessage(_("Loading wallet..."));
 
     int64_t nStart = GetTimeMillis();
     bool fFirstRun = true;
     std::unique_ptr<CWalletDBWrapper> dbw(
         new CWalletDBWrapper(&bitdb, walletFile));
     CWallet *walletInstance = new CWallet(chainParams, std::move(dbw));
     DBErrors nLoadWalletRet = walletInstance->LoadWallet(fFirstRun);
     if (nLoadWalletRet != DB_LOAD_OK) {
         if (nLoadWalletRet == DB_CORRUPT) {
             InitError(
                 strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
             return nullptr;
         }
 
         if (nLoadWalletRet == DB_NONCRITICAL_ERROR) {
             InitWarning(strprintf(
                 _("Error reading %s! All keys read correctly, but transaction "
                   "data"
                   " or address book entries might be missing or incorrect."),
                 walletFile));
         } else if (nLoadWalletRet == DB_TOO_NEW) {
             InitError(strprintf(
                 _("Error loading %s: Wallet requires newer version of %s"),
                 walletFile, _(PACKAGE_NAME)));
             return nullptr;
         } else if (nLoadWalletRet == DB_NEED_REWRITE) {
             InitError(strprintf(
                 _("Wallet needed to be rewritten: restart %s to complete"),
                 _(PACKAGE_NAME)));
             return nullptr;
         } else {
             InitError(strprintf(_("Error loading %s"), walletFile));
             return nullptr;
         }
     }
 
     if (gArgs.GetBoolArg("-upgradewallet", fFirstRun)) {
         int nMaxVersion = gArgs.GetArg("-upgradewallet", 0);
         // The -upgradewallet without argument case
         if (nMaxVersion == 0) {
             LogPrintf("Performing wallet upgrade to %i\n", FEATURE_LATEST);
             nMaxVersion = CLIENT_VERSION;
             // permanently upgrade the wallet immediately
             walletInstance->SetMinVersion(FEATURE_LATEST);
         } else {
             LogPrintf("Allowing wallet upgrade up to %i\n", nMaxVersion);
         }
 
         if (nMaxVersion < walletInstance->GetVersion()) {
             InitError(_("Cannot downgrade wallet"));
             return nullptr;
         }
 
         walletInstance->SetMaxVersion(nMaxVersion);
     }
 
     if (fFirstRun) {
         // Create new keyUser and set as default key.
         if (gArgs.GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET) &&
             !walletInstance->IsHDEnabled()) {
 
             // Ensure this wallet.dat can only be opened by clients supporting
             // HD with chain split.
             walletInstance->SetMinVersion(FEATURE_HD_SPLIT);
 
             // Generate a new master key.
             CPubKey masterPubKey = walletInstance->GenerateNewHDMasterKey();
             if (!walletInstance->SetHDMasterKey(masterPubKey)) {
                 throw std::runtime_error(std::string(__func__) +
                                          ": Storing master key failed");
             }
         }
 
         // Top up the keypool
         if (!walletInstance->TopUpKeyPool()) {
             InitError(_("Unable to generate initial keys") += "\n");
             return nullptr;
         }
 
         walletInstance->SetBestChain(chainActive.GetLocator());
     } else if (gArgs.IsArgSet("-usehd")) {
         bool useHD = gArgs.GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET);
         if (walletInstance->IsHDEnabled() && !useHD) {
             InitError(strprintf(_("Error loading %s: You can't disable HD on a "
                                   "already existing HD wallet"),
                                 walletFile));
             return nullptr;
         }
 
         if (!walletInstance->IsHDEnabled() && useHD) {
             InitError(strprintf(_("Error loading %s: You can't enable HD on a "
                                   "already existing non-HD wallet"),
                                 walletFile));
             return nullptr;
         }
     }
 
     LogPrintf(" wallet      %15dms\n", GetTimeMillis() - nStart);
 
     RegisterValidationInterface(walletInstance);
 
     // Try to top up keypool. No-op if the wallet is locked.
     walletInstance->TopUpKeyPool();
 
     CBlockIndex *pindexRescan = chainActive.Genesis();
     if (!gArgs.GetBoolArg("-rescan", false)) {
         CWalletDB walletdb(*walletInstance->dbw);
         CBlockLocator locator;
         if (walletdb.ReadBestBlock(locator)) {
             pindexRescan = FindForkInGlobalIndex(chainActive, locator);
         }
     }
 
     if (chainActive.Tip() && chainActive.Tip() != pindexRescan) {
         // We can't rescan beyond non-pruned blocks, stop and throw an error.
         // This might happen if a user uses a old wallet within a pruned node or
         // if he ran -disablewallet for a longer time, then decided to
         // re-enable.
         if (fPruneMode) {
             CBlockIndex *block = chainActive.Tip();
             while (block && block->pprev && block->pprev->nStatus.hasData() &&
                    block->pprev->nTx > 0 && pindexRescan != block) {
                 block = block->pprev;
             }
 
             if (pindexRescan != block) {
                 InitError(_("Prune: last wallet synchronisation goes beyond "
                             "pruned data. You need to -reindex (download the "
                             "whole blockchain again in case of pruned node)"));
                 return nullptr;
             }
         }
 
         uiInterface.InitMessage(_("Rescanning..."));
         LogPrintf("Rescanning last %i blocks (from block %i)...\n",
                   chainActive.Height() - pindexRescan->nHeight,
                   pindexRescan->nHeight);
 
         // No need to read and scan block if block was created before our wallet
         // birthday (as adjusted for block time variability)
         while (pindexRescan && walletInstance->nTimeFirstKey &&
                (pindexRescan->GetBlockTime() <
                 (walletInstance->nTimeFirstKey - TIMESTAMP_WINDOW))) {
             pindexRescan = chainActive.Next(pindexRescan);
         }
 
         nStart = GetTimeMillis();
         walletInstance->ScanForWalletTransactions(pindexRescan, nullptr, true);
         LogPrintf(" rescan      %15dms\n", GetTimeMillis() - nStart);
         walletInstance->SetBestChain(chainActive.GetLocator());
         walletInstance->dbw->IncrementUpdateCounter();
 
         // Restore wallet transaction metadata after -zapwallettxes=1
         if (gArgs.GetBoolArg("-zapwallettxes", false) &&
             gArgs.GetArg("-zapwallettxes", "1") != "2") {
             CWalletDB walletdb(*walletInstance->dbw);
 
             for (const CWalletTx &wtxOld : vWtx) {
                 const TxId txid = wtxOld.GetId();
                 std::map<TxId, CWalletTx>::iterator mi =
                     walletInstance->mapWallet.find(txid);
                 if (mi != walletInstance->mapWallet.end()) {
                     const CWalletTx *copyFrom = &wtxOld;
                     CWalletTx *copyTo = &mi->second;
                     copyTo->mapValue = copyFrom->mapValue;
                     copyTo->vOrderForm = copyFrom->vOrderForm;
                     copyTo->nTimeReceived = copyFrom->nTimeReceived;
                     copyTo->nTimeSmart = copyFrom->nTimeSmart;
                     copyTo->fFromMe = copyFrom->fFromMe;
                     copyTo->strFromAccount = copyFrom->strFromAccount;
                     copyTo->nOrderPos = copyFrom->nOrderPos;
                     walletdb.WriteTx(*copyTo);
                 }
             }
         }
     }
 
     walletInstance->SetBroadcastTransactions(
         gArgs.GetBoolArg("-walletbroadcast", DEFAULT_WALLETBROADCAST));
 
     LOCK(walletInstance->cs_wallet);
     LogPrintf("setKeyPool.size() = %u\n", walletInstance->GetKeyPoolSize());
     LogPrintf("mapWallet.size() = %u\n", walletInstance->mapWallet.size());
     LogPrintf("mapAddressBook.size() = %u\n",
               walletInstance->mapAddressBook.size());
 
     return walletInstance;
 }
 
 std::atomic<bool> CWallet::fFlushScheduled(false);
 
 void CWallet::postInitProcess(CScheduler &scheduler) {
     // Add wallet transactions that aren't already in a block to mempool.
     // Do this here as mempool requires genesis block to be loaded.
     ReacceptWalletTransactions();
 
     // Run a thread to flush wallet periodically.
     if (!CWallet::fFlushScheduled.exchange(true)) {
-        scheduler.scheduleEvery(MaybeCompactWalletDB, 500);
+        scheduler.scheduleEvery(
+            []() {
+                MaybeCompactWalletDB();
+                return true;
+            },
+            500);
     }
 }
 
 bool CWallet::BackupWallet(const std::string &strDest) {
     return dbw->Backup(strDest);
 }
 
 CKeyPool::CKeyPool() {
     nTime = GetTime();
     fInternal = false;
 }
 
 CKeyPool::CKeyPool(const CPubKey &vchPubKeyIn, bool internalIn) {
     nTime = GetTime();
     vchPubKey = vchPubKeyIn;
     fInternal = internalIn;
 }
 
 CWalletKey::CWalletKey(int64_t nExpires) {
     nTimeCreated = (nExpires ? GetTime() : 0);
     nTimeExpires = nExpires;
 }
 
 void CMerkleTx::SetMerkleBranch(const CBlockIndex *pindex, int posInBlock) {
     // Update the tx's hashBlock
     hashBlock = pindex->GetBlockHash();
 
     // Set the position of the transaction in the block.
     nIndex = posInBlock;
 }
 
 int CMerkleTx::GetDepthInMainChain(const CBlockIndex *&pindexRet) const {
     if (hashUnset()) {
         return 0;
     }
 
     AssertLockHeld(cs_main);
 
     // Find the block it claims to be in.
     BlockMap::iterator mi = mapBlockIndex.find(hashBlock);
     if (mi == mapBlockIndex.end()) {
         return 0;
     }
 
     CBlockIndex *pindex = (*mi).second;
     if (!pindex || !chainActive.Contains(pindex)) {
         return 0;
     }
 
     pindexRet = pindex;
     return ((nIndex == -1) ? (-1) : 1) *
            (chainActive.Height() - pindex->nHeight + 1);
 }
 
 int CMerkleTx::GetBlocksToMaturity() const {
     if (!IsCoinBase()) {
         return 0;
     }
 
     return std::max(0, (COINBASE_MATURITY + 1) - GetDepthInMainChain());
 }
 
 bool CMerkleTx::IsImmatureCoinBase() const {
     // note GetBlocksToMaturity is 0 for non-coinbase tx
     return GetBlocksToMaturity() > 0;
 }
 
 bool CMerkleTx::AcceptToMemoryPool(const Amount nAbsurdFee,
                                    CValidationState &state) {
     return ::AcceptToMemoryPool(GetConfig(), mempool, state, tx, true, nullptr,
                                 false, nAbsurdFee);
 }