diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 60bca6c7a..99cdd226a 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -1,20 +1,47 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <interfaces/chain.h>
 
+#include <sync.h>
 #include <util/system.h>
+#include <validation.h>
+
+#include <memory>
+#include <utility>
 
 namespace interfaces {
 namespace {
 
-    class ChainImpl : public Chain {};
+    class LockImpl : public Chain::Lock {};
+
+    class LockingStateImpl : public LockImpl,
+                             public UniqueLock<CCriticalSection> {
+        using UniqueLock::UniqueLock;
+    };
+
+    class ChainImpl : public Chain {
+    public:
+        std::unique_ptr<Chain::Lock> lock(bool try_lock) override {
+            auto result = std::make_unique<LockingStateImpl>(
+                ::cs_main, "cs_main", __FILE__, __LINE__, try_lock);
+            if (try_lock && result && !*result) {
+                return {};
+            }
+            // std::move necessary on some compilers due to conversion from
+            // LockingStateImpl to Lock pointer
+            return std::move(result);
+        }
+        std::unique_ptr<Chain::Lock> assumeLocked() override {
+            return std::make_unique<LockImpl>();
+        }
+    };
 
 } // namespace
 
 std::unique_ptr<Chain> MakeChain() {
     return std::make_unique<ChainImpl>();
 }
 
 } // namespace interfaces
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 1a03a7705..dd3304bba 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -1,43 +1,62 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_INTERFACES_CHAIN_H
 #define BITCOIN_INTERFACES_CHAIN_H
 
 #include <memory>
 #include <string>
 #include <vector>
 
 namespace interfaces {
 
 //! Interface for giving wallet processes access to blockchain state.
 class Chain {
 public:
     virtual ~Chain() {}
+
+    //! Interface for querying locked chain state, used by legacy code that
+    //! assumes state won't change between calls. New code should avoid using
+    //! the Lock interface and instead call higher-level Chain methods
+    //! that return more information so the chain doesn't need to stay locked
+    //! between calls.
+    class Lock {
+    public:
+        virtual ~Lock() {}
+    };
+
+    //! Return Lock interface. Chain is locked when this is called, and
+    //! unlocked when the returned interface is freed.
+    virtual std::unique_ptr<Lock> lock(bool try_lock = false) = 0;
+
+    //! Return Lock interface assuming chain is already locked. This
+    //! method is temporary and is only used in a few places to avoid changing
+    //! behavior while code is transitioned to use the Chain::Lock interface.
+    virtual std::unique_ptr<Lock> assumeLocked() = 0;
 };
 
 //! Interface to let node manage chain clients (wallets, or maybe tools for
 //! monitoring and analysis in the future).
 class ChainClient {
 public:
     virtual ~ChainClient() {}
 };
 
 //! Return implementation of Chain interface.
 std::unique_ptr<Chain> MakeChain();
 
 //! Return implementation of ChainClient interface for a wallet client. This
 //! function will be undefined in builds where ENABLE_WALLET is false.
 //!
 //! Currently, wallets are the only chain clients. But in the future, other
 //! types of chain clients could be added, such as tools for monitoring,
 //! analysis, or fee estimation. These clients need to expose their own
 //! MakeXXXClient functions returning their implementations of the ChainClient
 //! interface.
 std::unique_ptr<ChainClient>
 MakeWalletClient(Chain &chain, std::vector<std::string> wallet_filenames);
 
 } // namespace interfaces
 
 #endif // BITCOIN_INTERFACES_CHAIN_H
diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index 8146c88f6..e3fa1ff9d 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -1,479 +1,496 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <interfaces/wallet.h>
 
 #include <amount.h>
 #include <chain.h>
 #include <consensus/validation.h>
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <net.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <primitives/transaction.h>
 #include <script/ismine.h>
 #include <script/standard.h>
 #include <support/allocators/secure.h>
 #include <sync.h>
 #include <timedata.h>
 #include <ui_interface.h>
 #include <util/system.h>
 #include <validation.h>
 #include <wallet/fees.h>
 #include <wallet/finaltx.h>
 #include <wallet/wallet.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 namespace interfaces {
 namespace {
 
     class PendingWalletTxImpl : public PendingWalletTx {
     public:
         PendingWalletTxImpl(CWallet &wallet)
             : m_wallet(wallet), m_key(&wallet) {}
 
         const CTransaction &get() override { return *m_tx; }
 
         bool commit(WalletValueMap value_map, WalletOrderForm order_form,
                     std::string from_account,
                     std::string &reject_reason) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             CValidationState state;
             if (!m_wallet.CommitTransaction(
                     m_tx, std::move(value_map), std::move(order_form),
                     std::move(from_account), m_key, g_connman.get(), state)) {
                 reject_reason = state.GetRejectReason();
                 return false;
             }
             return true;
         }
 
         CTransactionRef m_tx;
         CWallet &m_wallet;
         CReserveKey m_key;
     };
 
     //! Construct wallet tx struct.
     static WalletTx MakeWalletTx(CWallet &wallet, const CWalletTx &wtx)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         WalletTx result;
         result.tx = wtx.tx;
         result.txin_is_mine.reserve(wtx.tx->vin.size());
         for (const auto &txin : wtx.tx->vin) {
             result.txin_is_mine.emplace_back(wallet.IsMine(txin));
         }
         result.txout_is_mine.reserve(wtx.tx->vout.size());
         result.txout_address.reserve(wtx.tx->vout.size());
         result.txout_address_is_mine.reserve(wtx.tx->vout.size());
         for (const auto &txout : wtx.tx->vout) {
             result.txout_is_mine.emplace_back(wallet.IsMine(txout));
             result.txout_address.emplace_back();
             result.txout_address_is_mine.emplace_back(
                 ExtractDestination(txout.scriptPubKey,
                                    result.txout_address.back())
                     ? IsMine(wallet, result.txout_address.back())
                     : ISMINE_NO);
         }
         result.credit = wtx.GetCredit(ISMINE_ALL);
         result.debit = wtx.GetDebit(ISMINE_ALL);
         result.change = wtx.GetChange();
         result.time = wtx.GetTxTime();
         result.value_map = wtx.mapValue;
         result.is_coinbase = wtx.IsCoinBase();
         return result;
     }
 
     //! Construct wallet tx status struct.
     static WalletTxStatus MakeWalletTxStatus(const CWalletTx &wtx)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         WalletTxStatus result;
         CBlockIndex *block = LookupBlockIndex(wtx.hashBlock);
         result.block_height =
             (block ? block->nHeight : std::numeric_limits<int>::max());
         result.blocks_to_maturity = wtx.GetBlocksToMaturity();
         result.depth_in_main_chain = wtx.GetDepthInMainChain();
         result.time_received = wtx.nTimeReceived;
         result.lock_time = wtx.tx->nLockTime;
         result.is_final = CheckFinalTx(*wtx.tx);
         result.is_trusted = wtx.IsTrusted();
         result.is_abandoned = wtx.isAbandoned();
         result.is_coinbase = wtx.IsCoinBase();
         result.is_in_main_chain = wtx.IsInMainChain();
         return result;
     }
 
     //! Construct wallet TxOut struct.
     static WalletTxOut MakeWalletTxOut(CWallet &wallet, const CWalletTx &wtx,
                                        int n, int depth)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, wallet.cs_wallet) {
         WalletTxOut result;
         result.txout = wtx.tx->vout[n];
         result.time = wtx.GetTxTime();
         result.depth_in_main_chain = depth;
         result.is_spent = wallet.IsSpent(COutPoint(wtx.GetId(), n));
         return result;
     }
 
     class WalletImpl : public Wallet {
     public:
         WalletImpl(const std::shared_ptr<CWallet> &wallet)
             : m_shared_wallet(wallet), m_wallet(*wallet.get()) {}
 
         bool encryptWallet(const SecureString &wallet_passphrase) override {
             return m_wallet.EncryptWallet(wallet_passphrase);
         }
         bool isCrypted() override { return m_wallet.IsCrypted(); }
         bool lock() override { return m_wallet.Lock(); }
         bool unlock(const SecureString &wallet_passphrase) override {
             return m_wallet.Unlock(wallet_passphrase);
         }
         bool isLocked() override { return m_wallet.IsLocked(); }
         bool changeWalletPassphrase(
             const SecureString &old_wallet_passphrase,
             const SecureString &new_wallet_passphrase) override {
             return m_wallet.ChangeWalletPassphrase(old_wallet_passphrase,
                                                    new_wallet_passphrase);
         }
         void abortRescan() override { m_wallet.AbortRescan(); }
         bool backupWallet(const std::string &filename) override {
             return m_wallet.BackupWallet(filename);
         }
         std::string getWalletName() override { return m_wallet.GetName(); }
         std::set<CTxDestination>
         getLabelAddresses(const std::string &label) override {
             return m_wallet.GetLabelAddresses(label);
         };
         bool getKeyFromPool(bool internal, CPubKey &pub_key) override {
             return m_wallet.GetKeyFromPool(pub_key, internal);
         }
         const CChainParams &getChainParams() override {
             return m_wallet.chainParams;
         }
         bool getPubKey(const CKeyID &address, CPubKey &pub_key) override {
             return m_wallet.GetPubKey(address, pub_key);
         }
         bool getPrivKey(const CKeyID &address, CKey &key) override {
             return m_wallet.GetKey(address, key);
         }
         bool isSpendable(const CTxDestination &dest) override {
             return IsMine(m_wallet, dest) & ISMINE_SPENDABLE;
         }
         bool haveWatchOnly() override { return m_wallet.HaveWatchOnly(); };
         bool setAddressBook(const CTxDestination &dest, const std::string &name,
                             const std::string &purpose) override {
             return m_wallet.SetAddressBook(dest, name, purpose);
         }
         bool delAddressBook(const CTxDestination &dest) override {
             return m_wallet.DelAddressBook(dest);
         }
         bool getAddress(const CTxDestination &dest, std::string *name,
                         isminetype *is_mine, std::string *purpose) override {
             LOCK(m_wallet.cs_wallet);
             auto it = m_wallet.mapAddressBook.find(dest);
             if (it == m_wallet.mapAddressBook.end()) {
                 return false;
             }
             if (name) {
                 *name = it->second.name;
             }
             if (is_mine) {
                 *is_mine = IsMine(m_wallet, dest);
             }
             if (purpose) {
                 *purpose = it->second.purpose;
             }
             return true;
         }
         std::vector<WalletAddress> getAddresses() override {
             LOCK(m_wallet.cs_wallet);
             std::vector<WalletAddress> result;
             for (const auto &item : m_wallet.mapAddressBook) {
                 result.emplace_back(item.first, IsMine(m_wallet, item.first),
                                     item.second.name, item.second.purpose);
             }
             return result;
         }
         void learnRelatedScripts(const CPubKey &key, OutputType type) override {
             m_wallet.LearnRelatedScripts(key, type);
         }
         bool addDestData(const CTxDestination &dest, const std::string &key,
                          const std::string &value) override {
             LOCK(m_wallet.cs_wallet);
             return m_wallet.AddDestData(dest, key, value);
         }
         bool eraseDestData(const CTxDestination &dest,
                            const std::string &key) override {
             LOCK(m_wallet.cs_wallet);
             return m_wallet.EraseDestData(dest, key);
         }
         std::vector<std::string>
         getDestValues(const std::string &prefix) override {
             return m_wallet.GetDestValues(prefix);
         }
         void lockCoin(const COutPoint &output) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.LockCoin(output);
         }
         void unlockCoin(const COutPoint &output) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.UnlockCoin(output);
         }
         bool isLockedCoin(const COutPoint &output) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.IsLockedCoin(output);
         }
         void listLockedCoins(std::vector<COutPoint> &outputs) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.ListLockedCoins(outputs);
         }
         std::unique_ptr<PendingWalletTx>
         createTransaction(const std::vector<CRecipient> &recipients,
                           const CCoinControl &coin_control, bool sign,
                           int &change_pos, Amount &fee,
                           std::string &fail_reason) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             auto pending = std::make_unique<PendingWalletTxImpl>(m_wallet);
             if (!m_wallet.CreateTransaction(recipients, pending->m_tx,
                                             pending->m_key, fee, change_pos,
                                             fail_reason, coin_control, sign)) {
                 return {};
             }
             return pending;
         }
         bool transactionCanBeAbandoned(const TxId &txid) override {
             return m_wallet.TransactionCanBeAbandoned(txid);
         }
         bool abandonTransaction(const TxId &txid) override {
-            LOCK2(cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.AbandonTransaction(txid);
         }
         CTransactionRef getTx(const TxId &txid) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi != m_wallet.mapWallet.end()) {
                 return mi->second.tx;
             }
             return {};
         }
         WalletTx getWalletTx(const TxId &txid) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi != m_wallet.mapWallet.end()) {
                 return MakeWalletTx(m_wallet, mi->second);
             }
             return {};
         }
         std::vector<WalletTx> getWalletTxs() override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             std::vector<WalletTx> result;
             result.reserve(m_wallet.mapWallet.size());
             for (const auto &entry : m_wallet.mapWallet) {
                 result.emplace_back(MakeWalletTx(m_wallet, entry.second));
             }
             return result;
         }
         bool tryGetTxStatus(const TxId &txid,
                             interfaces::WalletTxStatus &tx_status,
                             int &num_blocks, int64_t &block_time) override {
-            TRY_LOCK(::cs_main, locked_chain);
+            auto locked_chain = m_wallet.chain().lock(true /* try_lock */);
             if (!locked_chain) {
                 return false;
             }
             TRY_LOCK(m_wallet.cs_wallet, locked_wallet);
             if (!locked_wallet) {
                 return false;
             }
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi == m_wallet.mapWallet.end()) {
                 return false;
             }
             num_blocks = ::chainActive.Height();
             block_time = ::chainActive.Tip()->GetBlockTime();
             tx_status = MakeWalletTxStatus(mi->second);
             return true;
         }
         WalletTx getWalletTxDetails(const TxId &txid, WalletTxStatus &tx_status,
                                     WalletOrderForm &order_form,
                                     bool &in_mempool,
                                     int &num_blocks) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi != m_wallet.mapWallet.end()) {
                 num_blocks = ::chainActive.Height();
                 in_mempool = mi->second.InMempool();
                 order_form = mi->second.vOrderForm;
                 tx_status = MakeWalletTxStatus(mi->second);
                 return MakeWalletTx(m_wallet, mi->second);
             }
             return {};
         }
         WalletBalances getBalances() override {
             WalletBalances result;
             result.balance = m_wallet.GetBalance();
             result.unconfirmed_balance = m_wallet.GetUnconfirmedBalance();
             result.immature_balance = m_wallet.GetImmatureBalance();
             result.have_watch_only = m_wallet.HaveWatchOnly();
             if (result.have_watch_only) {
                 result.watch_only_balance =
                     m_wallet.GetBalance(ISMINE_WATCH_ONLY);
                 result.unconfirmed_watch_only_balance =
                     m_wallet.GetUnconfirmedWatchOnlyBalance();
                 result.immature_watch_only_balance =
                     m_wallet.GetImmatureWatchOnlyBalance();
             }
             return result;
         }
         bool tryGetBalances(WalletBalances &balances,
                             int &num_blocks) override {
-            TRY_LOCK(cs_main, locked_chain);
+            auto locked_chain = m_wallet.chain().lock(true /* try_lock */);
             if (!locked_chain) {
                 return false;
             }
             TRY_LOCK(m_wallet.cs_wallet, locked_wallet);
             if (!locked_wallet) {
                 return false;
             }
             balances = getBalances();
             num_blocks = ::chainActive.Height();
             return true;
         }
         Amount getBalance() override { return m_wallet.GetBalance(); }
         Amount getAvailableBalance(const CCoinControl &coin_control) override {
             return m_wallet.GetAvailableBalance(&coin_control);
         }
         isminetype txinIsMine(const CTxIn &txin) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.IsMine(txin);
         }
         isminetype txoutIsMine(const CTxOut &txout) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.IsMine(txout);
         }
         Amount getDebit(const CTxIn &txin, isminefilter filter) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.GetDebit(txin, filter);
         }
         Amount getCredit(const CTxOut &txout, isminefilter filter) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             return m_wallet.GetCredit(txout, filter);
         }
         CoinsList listCoins() override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             CoinsList result;
             for (const auto &entry : m_wallet.ListCoins()) {
                 auto &group = result[entry.first];
                 for (const auto &coin : entry.second) {
                     group.emplace_back(COutPoint(coin.tx->GetId(), coin.i),
                                        MakeWalletTxOut(m_wallet, *coin.tx,
                                                        coin.i, coin.nDepth));
                 }
             }
             return result;
         }
         std::vector<WalletTxOut>
         getCoins(const std::vector<COutPoint> &outputs) override {
-            LOCK2(::cs_main, m_wallet.cs_wallet);
+            auto locked_chain = m_wallet.chain().lock();
+            LOCK(m_wallet.cs_wallet);
             std::vector<WalletTxOut> result;
             result.reserve(outputs.size());
             for (const auto &output : outputs) {
                 result.emplace_back();
                 auto it = m_wallet.mapWallet.find(output.GetTxId());
                 if (it != m_wallet.mapWallet.end()) {
                     int depth = it->second.GetDepthInMainChain();
                     if (depth >= 0) {
                         result.back() = MakeWalletTxOut(m_wallet, it->second,
                                                         output.GetN(), depth);
                     }
                 }
             }
             return result;
         }
         bool hdEnabled() override { return m_wallet.IsHDEnabled(); }
         OutputType getDefaultAddressType() override {
             return m_wallet.m_default_address_type;
         }
         bool canGetAddresses() override { return m_wallet.CanGetAddresses(); }
         bool IsWalletFlagSet(uint64_t flag) override {
             return m_wallet.IsWalletFlagSet(flag);
         }
         OutputType getDefaultChangeType() override {
             return m_wallet.m_default_change_type;
         }
         std::unique_ptr<Handler> handleUnload(UnloadFn fn) override {
             return MakeHandler(m_wallet.NotifyUnload.connect(fn));
         }
         std::unique_ptr<Handler>
         handleShowProgress(ShowProgressFn fn) override {
             return MakeHandler(m_wallet.ShowProgress.connect(fn));
         }
         std::unique_ptr<Handler>
         handleStatusChanged(StatusChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyStatusChanged.connect(
                 [fn](CCryptoKeyStore *) { fn(); }));
         }
         std::unique_ptr<Handler>
         handleAddressBookChanged(AddressBookChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyAddressBookChanged.connect(
                 [fn](CWallet *, const CTxDestination &address,
                      const std::string &label, bool is_mine,
                      const std::string &purpose, ChangeType status) {
                     fn(address, label, is_mine, purpose, status);
                 }));
         }
         std::unique_ptr<Handler>
         handleTransactionChanged(TransactionChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyTransactionChanged.connect(
                 [fn](CWallet *, const TxId &txid, ChangeType status) {
                     fn(txid, status);
                 }));
         }
         std::unique_ptr<Handler>
         handleWatchOnlyChanged(WatchOnlyChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyWatchonlyChanged.connect(fn));
         }
         std::unique_ptr<Handler>
         handleCanGetAddressesChanged(CanGetAddressesChangedFn fn) override {
             return MakeHandler(
                 m_wallet.NotifyCanGetAddressesChanged.connect(fn));
         }
         Amount getRequiredFee(unsigned int tx_bytes) override {
             return GetRequiredFee(m_wallet, tx_bytes);
         }
         Amount getMinimumFee(unsigned int tx_bytes,
                              const CCoinControl &coin_control) override {
             return GetMinimumFee(m_wallet, tx_bytes, coin_control, g_mempool);
         }
 
         std::shared_ptr<CWallet> m_shared_wallet;
         CWallet &m_wallet;
     };
 
     class WalletClientImpl : public ChainClient {
     public:
         WalletClientImpl(Chain &chain,
                          std::vector<std::string> wallet_filenames)
             : m_chain(chain), m_wallet_filenames(std::move(wallet_filenames)) {}
 
         Chain &m_chain;
         std::vector<std::string> m_wallet_filenames;
     };
 
 } // namespace
 
 std::unique_ptr<Wallet> MakeWallet(const std::shared_ptr<CWallet> &wallet) {
     return std::make_unique<WalletImpl>(wallet);
 }
 
 std::unique_ptr<ChainClient>
 MakeWalletClient(Chain &chain, std::vector<std::string> wallet_filenames) {
     return std::make_unique<WalletClientImpl>(chain,
                                               std::move(wallet_filenames));
 }
 
 } // namespace interfaces
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index 02acfc736..dbdd56e78 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -1,254 +1,254 @@
 #include <qt/test/util.h>
 #include <qt/test/wallettests.h>
 
 #include <base58.h>
 #include <cashaddrenc.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <interfaces/chain.h>
 #include <interfaces/node.h>
 #include <key_io.h>
 #include <qt/bitcoinamountfield.h>
 #include <qt/optionsmodel.h>
 #include <qt/overviewpage.h>
 #include <qt/platformstyle.h>
 #include <qt/qvalidatedlineedit.h>
 #include <qt/receivecoinsdialog.h>
 #include <qt/receiverequestdialog.h>
 #include <qt/recentrequeststablemodel.h>
 #include <qt/sendcoinsdialog.h>
 #include <qt/sendcoinsentry.h>
 #include <qt/transactiontablemodel.h>
 #include <qt/walletmodel.h>
 #include <validation.h>
 #include <wallet/wallet.h>
 
 #include <test/test_bitcoin.h>
 
 #include <QAbstractButton>
 #include <QApplication>
 #include <QDialogButtonBox>
 #include <QListView>
 #include <QPushButton>
 #include <QTextEdit>
 #include <QTimer>
 #include <QVBoxLayout>
 
 #include <memory>
 
 namespace {
 //! Press "Yes" or "Cancel" buttons in modal send confirmation dialog.
 void ConfirmSend(QString *text = nullptr, bool cancel = false) {
     QTimer::singleShot(0, Qt::PreciseTimer, [text, cancel]() {
         for (QWidget *widget : QApplication::topLevelWidgets()) {
             if (widget->inherits("SendConfirmationDialog")) {
                 SendConfirmationDialog *dialog =
                     qobject_cast<SendConfirmationDialog *>(widget);
                 if (text) {
                     *text = dialog->text();
                 }
                 QAbstractButton *button = dialog->button(
                     cancel ? QMessageBox::Cancel : QMessageBox::Yes);
                 button->setEnabled(true);
                 button->click();
             }
         }
     });
 }
 
 //! Send coins to address and return txid.
 TxId SendCoins(CWallet &wallet, SendCoinsDialog &sendCoinsDialog,
                const CTxDestination &address, Amount amount) {
     QVBoxLayout *entries = sendCoinsDialog.findChild<QVBoxLayout *>("entries");
     SendCoinsEntry *entry =
         qobject_cast<SendCoinsEntry *>(entries->itemAt(0)->widget());
     entry->findChild<QValidatedLineEdit *>("payTo")->setText(
         QString::fromStdString(EncodeCashAddr(address, Params())));
     entry->findChild<BitcoinAmountField *>("payAmount")->setValue(amount);
     TxId txid;
     boost::signals2::scoped_connection c =
         wallet.NotifyTransactionChanged.connect(
             [&txid](CWallet *, const TxId &hash, ChangeType status) {
                 if (status == CT_NEW) {
                     txid = hash;
                 }
             });
     ConfirmSend();
     QMetaObject::invokeMethod(&sendCoinsDialog, "on_sendButton_clicked");
     return txid;
 }
 
 //! Find index of txid in transaction list.
 QModelIndex FindTx(const QAbstractItemModel &model, const uint256 &txid) {
     QString hash = QString::fromStdString(txid.ToString());
     int rows = model.rowCount({});
     for (int row = 0; row < rows; ++row) {
         QModelIndex index = model.index(row, 0, {});
         if (model.data(index, TransactionTableModel::TxHashRole) == hash) {
             return index;
         }
     }
     return {};
 }
 
 //! Simple qt wallet tests.
 //
 // Test widgets can be debugged interactively calling show() on them and
 // manually running the event loop, e.g.:
 //
 //     sendCoinsDialog.show();
 //     QEventLoop().exec();
 //
 // This also requires overriding the default minimal Qt platform:
 //
 //     src/qt/test/test_bitcoin-qt -platform xcb      # Linux
 //     src/qt/test/test_bitcoin-qt -platform windows  # Windows
 //     src/qt/test/test_bitcoin-qt -platform cocoa    # macOS
 void TestGUI() {
     // Set up wallet and chain with 105 blocks (5 mature blocks for spending).
     TestChain100Setup test;
     for (int i = 0; i < 5; ++i) {
         test.CreateAndProcessBlock(
             {}, GetScriptForRawPubKey(test.coinbaseKey.GetPubKey()));
     }
 
     auto chain = interfaces::MakeChain();
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
         Params(), *chain, WalletLocation(), WalletDatabase::CreateMock());
 
     bool firstRun;
     wallet->LoadWallet(firstRun);
     {
         LOCK(wallet->cs_wallet);
         wallet->SetAddressBook(
             GetDestinationForKey(test.coinbaseKey.GetPubKey(),
                                  wallet->m_default_address_type),
             "", "receive");
         wallet->AddKeyPubKey(test.coinbaseKey, test.coinbaseKey.GetPubKey());
     }
     {
-        LOCK(cs_main);
+        auto locked_chain = wallet->chain().lock();
         WalletRescanReserver reserver(wallet.get());
         reserver.reserve();
         wallet->ScanForWalletTransactions(chainActive.Genesis(), nullptr,
                                           reserver, true);
     }
     wallet->SetBroadcastTransactions(true);
 
     // Create widgets for sending coins and listing transactions.
     std::unique_ptr<const PlatformStyle> platformStyle(
         PlatformStyle::instantiate("other"));
     auto node = interfaces::MakeNode();
     OptionsModel optionsModel(*node);
     AddWallet(wallet);
     WalletModel walletModel(std::move(node->getWallets().back()), *node,
                             platformStyle.get(), &optionsModel);
     RemoveWallet(wallet);
 
     // Send two transactions, and verify they are added to transaction list.
     SendCoinsDialog sendCoinsDialog(platformStyle.get(), &walletModel);
     TransactionTableModel *transactionTableModel =
         walletModel.getTransactionTableModel();
     QCOMPARE(transactionTableModel->rowCount({}), 105);
     TxId txid1 = SendCoins(*wallet.get(), sendCoinsDialog,
                            CTxDestination(CKeyID()), 5 * COIN);
     TxId txid2 = SendCoins(*wallet.get(), sendCoinsDialog,
                            CTxDestination(CKeyID()), 10 * COIN);
     QCOMPARE(transactionTableModel->rowCount({}), 107);
     QVERIFY(FindTx(*transactionTableModel, txid1).isValid());
     QVERIFY(FindTx(*transactionTableModel, txid2).isValid());
 
     // Check current balance on OverviewPage
     OverviewPage overviewPage(platformStyle.get());
     overviewPage.setWalletModel(&walletModel);
     QLabel *balanceLabel = overviewPage.findChild<QLabel *>("labelBalance");
     QString balanceText = balanceLabel->text();
     int unit = walletModel.getOptionsModel()->getDisplayUnit();
     Amount balance = walletModel.wallet().getBalance();
     QString balanceComparison = BitcoinUnits::formatWithUnit(
         unit, balance, false, BitcoinUnits::separatorAlways);
     QCOMPARE(balanceText, balanceComparison);
 
     // Check Request Payment button
     ReceiveCoinsDialog receiveCoinsDialog(platformStyle.get());
     receiveCoinsDialog.setModel(&walletModel);
     RecentRequestsTableModel *requestTableModel =
         walletModel.getRecentRequestsTableModel();
 
     // Label input
     QLineEdit *labelInput =
         receiveCoinsDialog.findChild<QLineEdit *>("reqLabel");
     labelInput->setText("TEST_LABEL_1");
 
     // Amount input
     BitcoinAmountField *amountInput =
         receiveCoinsDialog.findChild<BitcoinAmountField *>("reqAmount");
     amountInput->setValue(1 * SATOSHI);
 
     // Message input
     QLineEdit *messageInput =
         receiveCoinsDialog.findChild<QLineEdit *>("reqMessage");
     messageInput->setText("TEST_MESSAGE_1");
     int initialRowCount = requestTableModel->rowCount({});
     QPushButton *requestPaymentButton =
         receiveCoinsDialog.findChild<QPushButton *>("receiveButton");
     requestPaymentButton->click();
     for (QWidget *widget : QApplication::topLevelWidgets()) {
         if (widget->inherits("ReceiveRequestDialog")) {
             ReceiveRequestDialog *receiveRequestDialog =
                 qobject_cast<ReceiveRequestDialog *>(widget);
             QTextEdit *rlist =
                 receiveRequestDialog->QObject::findChild<QTextEdit *>("outUri");
             QString paymentText = rlist->toPlainText();
             QStringList paymentTextList = paymentText.split('\n');
             QCOMPARE(paymentTextList.at(0), QString("Payment information"));
             QVERIFY(paymentTextList.at(1).indexOf(QString("URI: bchreg:")) !=
                     -1);
             QVERIFY(paymentTextList.at(2).indexOf(QString("Address:")) != -1);
             QCOMPARE(paymentTextList.at(3),
                      QString("Amount: 0.00000001 ") +
                          QString::fromStdString(CURRENCY_UNIT));
             QCOMPARE(paymentTextList.at(4), QString("Label: TEST_LABEL_1"));
             QCOMPARE(paymentTextList.at(5), QString("Message: TEST_MESSAGE_1"));
         }
     }
 
     // Clear button
     QPushButton *clearButton =
         receiveCoinsDialog.findChild<QPushButton *>("clearButton");
     clearButton->click();
     QCOMPARE(labelInput->text(), QString(""));
     QCOMPARE(amountInput->value(), Amount::zero());
     QCOMPARE(messageInput->text(), QString(""));
 
     // Check addition to history
     int currentRowCount = requestTableModel->rowCount({});
     QCOMPARE(currentRowCount, initialRowCount + 1);
 
     // Check Remove button
     QTableView *table =
         receiveCoinsDialog.findChild<QTableView *>("recentRequestsView");
     table->selectRow(currentRowCount - 1);
     QPushButton *removeRequestButton =
         receiveCoinsDialog.findChild<QPushButton *>("removeRequestButton");
     removeRequestButton->click();
     QCOMPARE(requestTableModel->rowCount({}), currentRowCount - 1);
 }
 
 } // namespace
 
 void WalletTests::walletTests() {
 #ifdef Q_OS_MAC
     if (QApplication::platformName() == "minimal") {
         // Disable for mac on "minimal" platform to avoid crashes inside the Qt
         // framework when it tries to look up unimplemented cocoa functions,
         // and fails to handle returned nulls
         // (https://bugreports.qt.io/browse/QTBUG-49686).
         QWARN("Skipping WalletTests on mac build with 'minimal' platform set "
               "due to Qt bugs. To run AppTests, invoke with 'test_bitcoin-qt "
               "-platform cocoa' on mac, or else use a linux or windows build.");
         return;
     }
 #endif
     TestGUI();
 }
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index ece81b0fd..886b9e947 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -1,1580 +1,1590 @@
 // 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 <chain.h>
 #include <config.h>
 #include <core_io.h>
+#include <interfaces/chain.h>
 #include <key_io.h>
 #include <merkleblock.h>
 #include <rpc/server.h>
 #include <script/script.h>
 #include <script/standard.h>
 #include <sync.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <validation.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <fstream>
 #include <iostream>
 
 static int64_t DecodeDumpTime(const std::string &str) {
     static const boost::posix_time::ptime epoch =
         boost::posix_time::from_time_t(0);
     static const std::locale loc(
         std::locale::classic(),
         new boost::posix_time::time_input_facet("%Y-%m-%dT%H:%M:%SZ"));
     std::istringstream iss(str);
     iss.imbue(loc);
     boost::posix_time::ptime ptime(boost::date_time::not_a_date_time);
     iss >> ptime;
     if (ptime.is_not_a_date_time()) return 0;
     return (ptime - epoch).total_seconds();
 }
 
 static std::string EncodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (const uint8_t c : str) {
         if (c <= 32 || c >= 128 || c == '%') {
             ret << '%' << HexStr(&c, &c + 1);
         } else {
             ret << c;
         }
     }
     return ret.str();
 }
 
 static std::string DecodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (unsigned int pos = 0; pos < str.length(); pos++) {
         uint8_t c = str[pos];
         if (c == '%' && pos + 2 < str.length()) {
             c = (((str[pos + 1] >> 6) * 9 + ((str[pos + 1] - '0') & 15)) << 4) |
                 ((str[pos + 2] >> 6) * 9 + ((str[pos + 2] - '0') & 15));
             pos += 2;
         }
         ret << c;
     }
     return ret.str();
 }
 
 bool GetWalletAddressesForKey(const Config &config, CWallet *const pwallet,
                               const CKeyID &keyid, std::string &strAddr,
                               std::string &strLabel) {
     bool fLabelFound = false;
     CKey key;
     pwallet->GetKey(keyid, key);
     for (const auto &dest : GetAllDestinationsForKey(key.GetPubKey())) {
         if (pwallet->mapAddressBook.count(dest)) {
             if (!strAddr.empty()) {
                 strAddr += ",";
             }
             strAddr += EncodeDestination(dest, config);
             strLabel = EncodeDumpString(pwallet->mapAddressBook[dest].name);
             fLabelFound = true;
         }
     }
     if (!fLabelFound) {
         strAddr = EncodeDestination(
             GetDestinationForKey(key.GetPubKey(),
                                  pwallet->m_default_address_type),
             config);
     }
     return fLabelFound;
 }
 
 static const int64_t TIMESTAMP_MIN = 0;
 
 static void RescanWallet(CWallet &wallet, const WalletRescanReserver &reserver,
                          int64_t time_begin = TIMESTAMP_MIN,
                          bool update = true) {
     int64_t scanned_time = wallet.RescanFromTime(time_begin, reserver, update);
     if (wallet.IsAbortingRescan()) {
         throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted by user.");
     } else if (scanned_time > time_begin) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan was unable to fully rescan the blockchain. "
                            "Some transactions may be missing.");
     }
 }
 
 UniValue importprivkey(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             "importprivkey \"privkey\" ( \"label\" ) ( rescan )\n"
             "\nAdds a private key (as returned by dumpprivkey) to your wallet. "
             "Requires a new wallet backup.\n"
             "Hint: use importmulti to import more than one private key.\n"
             "\nArguments:\n"
             "1. \"privkey\"   (string, required) The private key (see "
             "dumpprivkey)\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported key exists but related transactions "
             "are still missing, leading to temporarily incorrect/bogus "
             "balances and unspent outputs until rescan completes.\n"
             "\nExamples:\n"
             "\nDump a private key\n" +
             HelpExampleCli("dumpprivkey", "\"myaddress\"") +
             "\nImport the private key with rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             "\nImport using a label and without rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\" \"testing\" false") +
             "\nImport using default blank label and without rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\" \"\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importprivkey", "\"mykey\", \"testing\", false"));
     }
 
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Cannot import private keys to a wallet with "
                            "private keys disabled");
     }
 
     WalletRescanReserver reserver(pwallet);
     bool fRescan = true;
     {
-        LOCK2(cs_main, pwallet->cs_wallet);
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
 
         EnsureWalletIsUnlocked(pwallet);
 
         std::string strSecret = request.params[0].get_str();
         std::string strLabel = "";
         if (!request.params[1].isNull()) {
             strLabel = request.params[1].get_str();
         }
 
         // Whether to perform rescan after import
         if (!request.params[2].isNull()) {
             fRescan = request.params[2].get_bool();
         }
 
         if (fRescan && fPruneMode) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Rescan is disabled in pruned mode");
         }
 
         if (fRescan && !reserver.reserve()) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Wallet is currently rescanning. Abort existing "
                                "rescan or wait.");
         }
 
         CKey key = DecodeSecret(strSecret);
         if (!key.IsValid()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid private key encoding");
         }
 
         CPubKey pubkey = key.GetPubKey();
         assert(key.VerifyPubKey(pubkey));
         CKeyID vchAddress = pubkey.GetID();
         {
             pwallet->MarkDirty();
             // We don't know which corresponding address will be used; label
             // them all
             for (const auto &dest : GetAllDestinationsForKey(pubkey)) {
                 pwallet->SetAddressBook(dest, strLabel, "receive");
             }
 
             // Don't throw error in case a key is already there
             if (pwallet->HaveKey(vchAddress)) {
                 return NullUniValue;
             }
 
             pwallet->LearnAllRelatedScripts(pubkey);
 
             // whenever a key is imported, we need to scan the whole chain
             pwallet->UpdateTimeFirstKey(1);
             pwallet->mapKeyMetadata[vchAddress].nCreateTime = 1;
 
             if (!pwallet->AddKeyPubKey(key, pubkey)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding key to wallet");
             }
         }
     }
     if (fRescan) {
         RescanWallet(*pwallet, reserver);
     }
 
     return NullUniValue;
 }
 
 UniValue abortrescan(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error("abortrescan\n"
                                  "\nStops current wallet rescan triggered by "
                                  "an RPC call, e.g. by an importprivkey call.\n"
                                  "\nExamples:\n"
                                  "\nImport a private key\n" +
                                  HelpExampleCli("importprivkey", "\"mykey\"") +
                                  "\nAbort the running wallet rescan\n" +
                                  HelpExampleCli("abortrescan", "") +
                                  "\nAs a JSON-RPC call\n" +
                                  HelpExampleRpc("abortrescan", ""));
     }
 
     if (!pwallet->IsScanning() || pwallet->IsAbortingRescan()) {
         return false;
     }
     pwallet->AbortRescan();
     return true;
 }
 
 static void ImportAddress(CWallet *, const CTxDestination &dest,
                           const std::string &strLabel);
 static void ImportScript(CWallet *const pwallet, const CScript &script,
                          const std::string &strLabel, bool isRedeemScript)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     if (!isRedeemScript && ::IsMine(*pwallet, script) == ISMINE_SPENDABLE) {
         throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already contains the "
                                              "private key for this address or "
                                              "script");
     }
 
     pwallet->MarkDirty();
 
     if (!pwallet->HaveWatchOnly(script) &&
         !pwallet->AddWatchOnly(script, 0 /* nCreateTime */)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
     }
 
     if (isRedeemScript) {
         const CScriptID id(script);
         if (!pwallet->HaveCScript(id) && !pwallet->AddCScript(script)) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Error adding p2sh redeemScript to wallet");
         }
         ImportAddress(pwallet, id, strLabel);
     } else {
         CTxDestination destination;
         if (ExtractDestination(script, destination)) {
             pwallet->SetAddressBook(destination, strLabel, "receive");
         }
     }
 }
 
 static void ImportAddress(CWallet *const pwallet, const CTxDestination &dest,
                           const std::string &strLabel)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     CScript script = GetScriptForDestination(dest);
     ImportScript(pwallet, script, strLabel, false);
     // add to address book or update label
     if (IsValidDestination(dest)) {
         pwallet->SetAddressBook(dest, strLabel, "receive");
     }
 }
 
 UniValue importaddress(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             "importaddress \"address\" ( \"label\" rescan p2sh )\n"
             "\nAdds an address or script (in hex) that can be watched as if it "
             "were in your wallet but cannot be used to spend. Requires a new "
             "wallet backup.\n"
             "\nArguments:\n"
             "1. \"address\"          (string, required) The Bitcoin address "
             "(or hex-encoded script)\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "4. p2sh                 (boolean, optional, default=false) Add "
             "the P2SH version of the script as well\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported address exists but related "
             "transactions are still missing, leading to temporarily "
             "incorrect/bogus balances and unspent outputs until rescan "
             "completes.\n"
             "If you have the full public key, you should call importpubkey "
             "instead of this.\n"
             "\nNote: If you import a non-standard raw script in hex form, "
             "outputs sending to it will be treated\n"
             "as change, and not show up in many RPCs.\n"
             "\nExamples:\n"
             "\nImport an address with rescan\n" +
             HelpExampleCli("importaddress", "\"myaddress\"") +
             "\nImport using a label without rescan\n" +
             HelpExampleCli("importaddress", "\"myaddress\" \"testing\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importaddress",
                            "\"myaddress\", \"testing\", false"));
     }
 
     std::string strLabel;
     if (!request.params[1].isNull()) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (!request.params[2].isNull()) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     WalletRescanReserver reserver(pwallet);
     if (fRescan && !reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     // Whether to import a p2sh version, too
     bool fP2SH = false;
     if (!request.params[3].isNull()) {
         fP2SH = request.params[3].get_bool();
     }
 
     {
-        LOCK2(cs_main, pwallet->cs_wallet);
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
 
         CTxDestination dest = DecodeDestination(request.params[0].get_str(),
                                                 config.GetChainParams());
         if (IsValidDestination(dest)) {
             if (fP2SH) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Cannot use the p2sh flag with an address - "
                                    "use a script instead");
             }
             ImportAddress(pwallet, dest, strLabel);
         } else if (IsHex(request.params[0].get_str())) {
             std::vector<uint8_t> data(ParseHex(request.params[0].get_str()));
             ImportScript(pwallet, CScript(data.begin(), data.end()), strLabel,
                          fP2SH);
         } else {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid Bitcoin address or script");
         }
     }
     if (fRescan) {
         RescanWallet(*pwallet, reserver);
         pwallet->ReacceptWalletTransactions();
     }
 
     return NullUniValue;
 }
 
 UniValue importprunedfunds(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             "importprunedfunds\n"
             "\nImports funds without rescan. Corresponding address or script "
             "must previously be included in wallet. Aimed towards pruned "
             "wallets. The end-user is responsible to import additional "
             "transactions that subsequently spend the imported outputs or "
             "rescan after the point in the blockchain the transaction is "
             "included.\n"
             "\nArguments:\n"
             "1. \"rawtransaction\" (string, required) A raw transaction in hex "
             "funding an already-existing address in wallet\n"
             "2. \"txoutproof\"     (string, required) The hex output from "
             "gettxoutproof that contains the transaction\n");
     }
 
     CMutableTransaction tx;
     if (!DecodeHexTx(tx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
     uint256 txid = tx.GetId();
     CWalletTx wtx(pwallet, MakeTransactionRef(std::move(tx)));
 
     CDataStream ssMB(ParseHexV(request.params[1], "proof"), SER_NETWORK,
                      PROTOCOL_VERSION);
     CMerkleBlock merkleBlock;
     ssMB >> merkleBlock;
 
     // Search partial merkle tree in proof for our transaction and index in
     // valid block
     std::vector<uint256> vMatch;
     std::vector<size_t> vIndex;
     size_t txnIndex = 0;
     if (merkleBlock.txn.ExtractMatches(vMatch, vIndex) ==
         merkleBlock.header.hashMerkleRoot) {
-        LOCK(cs_main);
+        auto locked_chain = pwallet->chain().lock();
         const CBlockIndex *pindex =
             LookupBlockIndex(merkleBlock.header.GetHash());
         if (!pindex || !chainActive.Contains(pindex)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Block not found in chain");
         }
 
         std::vector<uint256>::const_iterator it;
         if ((it = std::find(vMatch.begin(), vMatch.end(), txid)) ==
             vMatch.end()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Transaction given doesn't exist in proof");
         }
 
         txnIndex = vIndex[it - vMatch.begin()];
     } else {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Something wrong with merkleblock");
     }
 
     wtx.nIndex = txnIndex;
     wtx.hashBlock = merkleBlock.header.GetHash();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (pwallet->IsMine(*wtx.tx)) {
         pwallet->AddToWallet(wtx, false);
         return NullUniValue;
     }
 
     throw JSONRPCError(
         RPC_INVALID_ADDRESS_OR_KEY,
         "No addresses in wallet correspond to included transaction");
 }
 
 UniValue removeprunedfunds(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "removeprunedfunds \"txid\"\n"
             "\nDeletes the specified transaction from the wallet. Meant for "
             "use with pruned wallets and as a companion to importprunedfunds. "
             "This will affect wallet balances.\n"
             "\nArguments:\n"
             "1. \"txid\"           (string, required) The hex-encoded id of "
             "the transaction you are deleting\n"
             "\nExamples:\n" +
             HelpExampleCli("removeprunedfunds", "\"a8d0c0184dde994a09ec054286f1"
                                                 "ce581bebf46446a512166eae762873"
                                                 "4ea0a5\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("removeprunedfunds",
                            "\"a8d0c0184dde994a09ec054286f1ce581bebf46446a512166"
                            "eae7628734ea0a5\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     TxId txid;
     txid.SetHex(request.params[0].get_str());
     std::vector<TxId> txIds;
     txIds.push_back(txid);
     std::vector<TxId> txIdsOut;
 
     if (pwallet->ZapSelectTx(txIds, txIdsOut) != DBErrors::LOAD_OK) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Could not properly delete the transaction.");
     }
 
     if (txIdsOut.empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Transaction does not exist in wallet.");
     }
 
     return NullUniValue;
 }
 
 UniValue importpubkey(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             "importpubkey \"pubkey\" ( \"label\" rescan )\n"
             "\nAdds a public key (in hex) that can be watched as if it were in "
             "your wallet but cannot be used to spend. Requires a new wallet "
             "backup.\n"
             "\nArguments:\n"
             "1. \"pubkey\"           (string, required) The hex-encoded public "
             "key\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported pubkey exists but related "
             "transactions are still missing, leading to temporarily "
             "incorrect/bogus balances and unspent outputs until rescan "
             "completes.\n"
             "\nExamples:\n"
             "\nImport a public key with rescan\n" +
             HelpExampleCli("importpubkey", "\"mypubkey\"") +
             "\nImport using a label without rescan\n" +
             HelpExampleCli("importpubkey", "\"mypubkey\" \"testing\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importpubkey", "\"mypubkey\", \"testing\", false"));
     }
 
     std::string strLabel;
     if (!request.params[1].isNull()) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (!request.params[2].isNull()) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     WalletRescanReserver reserver(pwallet);
     if (fRescan && !reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     if (!IsHex(request.params[0].get_str())) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Pubkey must be a hex string");
     }
     std::vector<uint8_t> data(ParseHex(request.params[0].get_str()));
     CPubKey pubKey(data.begin(), data.end());
     if (!pubKey.IsFullyValid()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Pubkey is not a valid public key");
     }
 
     {
-        LOCK2(cs_main, pwallet->cs_wallet);
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
 
         for (const auto &dest : GetAllDestinationsForKey(pubKey)) {
             ImportAddress(pwallet, dest, strLabel);
         }
         ImportScript(pwallet, GetScriptForRawPubKey(pubKey), strLabel, false);
         pwallet->LearnAllRelatedScripts(pubKey);
     }
     if (fRescan) {
         RescanWallet(*pwallet, reserver);
         pwallet->ReacceptWalletTransactions();
     }
 
     return NullUniValue;
 }
 
 UniValue importwallet(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "importwallet \"filename\"\n"
             "\nImports keys from a wallet dump file (see dumpwallet). Requires "
             "a new wallet backup to include imported keys.\n"
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The wallet file\n"
             "\nExamples:\n"
             "\nDump the wallet\n" +
             HelpExampleCli("dumpwallet", "\"test\"") + "\nImport the wallet\n" +
             HelpExampleCli("importwallet", "\"test\"") +
             "\nImport using the json rpc call\n" +
             HelpExampleRpc("importwallet", "\"test\""));
     }
 
     if (fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Importing wallets is disabled in pruned mode");
     }
 
     WalletRescanReserver reserver(pwallet);
     if (!reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     int64_t nTimeBegin = 0;
     bool fGood = true;
     {
-        LOCK2(cs_main, pwallet->cs_wallet);
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
 
         EnsureWalletIsUnlocked(pwallet);
 
         std::ifstream file;
         file.open(request.params[0].get_str().c_str(),
                   std::ios::in | std::ios::ate);
         if (!file.is_open()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Cannot open wallet dump file");
         }
         nTimeBegin = chainActive.Tip()->GetBlockTime();
 
         int64_t nFilesize = std::max<int64_t>(1, file.tellg());
         file.seekg(0, file.beg);
 
         // Use uiInterface.ShowProgress instead of pwallet.ShowProgress because
         // pwallet.ShowProgress has a cancel button tied to AbortRescan which we
         // don't want for this progress bar showing the import progress.
         // uiInterface.ShowProgress does not have a cancel button.
 
         // show progress dialog in GUI
         uiInterface.ShowProgress(
             strprintf("%s " + _("Importing..."), pwallet->GetDisplayName()), 0,
             false);
         std::vector<std::tuple<CKey, int64_t, bool, std::string>> keys;
         std::vector<std::pair<CScript, int64_t>> scripts;
         while (file.good()) {
             uiInterface.ShowProgress(
                 "",
                 std::max(1, std::min<int>(50, 100 * double(file.tellg()) /
                                                   double(nFilesize))),
                 false);
             std::string line;
             std::getline(file, line);
             if (line.empty() || line[0] == '#') {
                 continue;
             }
 
             std::vector<std::string> vstr;
             boost::split(vstr, line, boost::is_any_of(" "));
             if (vstr.size() < 2) {
                 continue;
             }
             CKey key = DecodeSecret(vstr[0]);
             if (key.IsValid()) {
                 int64_t nTime = DecodeDumpTime(vstr[1]);
                 std::string strLabel;
                 bool fLabel = true;
                 for (size_t nStr = 2; nStr < vstr.size(); nStr++) {
                     if (vstr[nStr].front() == '#') {
                         break;
                     }
                     if (vstr[nStr] == "change=1") {
                         fLabel = false;
                     }
                     if (vstr[nStr] == "reserve=1") {
                         fLabel = false;
                     }
                     if (vstr[nStr].substr(0, 6) == "label=") {
                         strLabel = DecodeDumpString(vstr[nStr].substr(6));
                         fLabel = true;
                     }
                 }
                 keys.push_back(std::make_tuple(key, nTime, fLabel, strLabel));
             } else if (IsHex(vstr[0])) {
                 std::vector<uint8_t> vData(ParseHex(vstr[0]));
                 CScript script = CScript(vData.begin(), vData.end());
                 int64_t birth_time = DecodeDumpTime(vstr[1]);
                 scripts.push_back(
                     std::pair<CScript, int64_t>(script, birth_time));
             }
         }
         file.close();
         // We now know whether we are importing private keys, so we can error if
         // private keys are disabled
         if (keys.size() > 0 &&
             pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
             // hide progress dialog in GUI
             uiInterface.ShowProgress("", 100, false);
             throw JSONRPCError(
                 RPC_WALLET_ERROR,
                 "Importing wallets is disabled when private keys are disabled");
         }
         double total = double(keys.size() + scripts.size());
         double progress = 0;
         for (const auto &key_tuple : keys) {
             uiInterface.ShowProgress(
                 "",
                 std::max(50, std::min<int>(75, 100 * progress / total) + 50),
                 false);
             const CKey &key = std::get<0>(key_tuple);
             int64_t time = std::get<1>(key_tuple);
             bool has_label = std::get<2>(key_tuple);
             std::string label = std::get<3>(key_tuple);
 
             CPubKey pubkey = key.GetPubKey();
             assert(key.VerifyPubKey(pubkey));
             CKeyID keyid = pubkey.GetID();
             if (pwallet->HaveKey(keyid)) {
                 pwallet->WalletLogPrintf(
                     "Skipping import of %s (key already present)\n",
                     EncodeDestination(keyid, config));
                 continue;
             }
             pwallet->WalletLogPrintf("Importing %s...\n",
                                      EncodeDestination(keyid, config));
             if (!pwallet->AddKeyPubKey(key, pubkey)) {
                 fGood = false;
                 continue;
             }
             pwallet->mapKeyMetadata[keyid].nCreateTime = time;
             if (has_label) {
                 pwallet->SetAddressBook(keyid, label, "receive");
             }
             nTimeBegin = std::min(nTimeBegin, time);
             progress++;
         }
         for (const auto &script_pair : scripts) {
             uiInterface.ShowProgress(
                 "",
                 std::max(50, std::min<int>(75, 100 * progress / total) + 50),
                 false);
             const CScript &script = script_pair.first;
             int64_t time = script_pair.second;
             CScriptID id(script);
             if (pwallet->HaveCScript(id)) {
                 pwallet->WalletLogPrintf(
                     "Skipping import of %s (script already present)\n",
                     HexStr(script));
                 continue;
             }
             if (!pwallet->AddCScript(script)) {
                 pwallet->WalletLogPrintf("Error importing script %s\n",
                                          HexStr(script));
                 fGood = false;
                 continue;
             }
             if (time > 0) {
                 pwallet->m_script_metadata[id].nCreateTime = time;
                 nTimeBegin = std::min(nTimeBegin, time);
             }
             progress++;
         }
         // hide progress dialog in GUI
         uiInterface.ShowProgress("", 100, false);
         pwallet->UpdateTimeFirstKey(nTimeBegin);
     }
     // hide progress dialog in GUI
     uiInterface.ShowProgress("", 100, false);
     RescanWallet(*pwallet, reserver, nTimeBegin, false /* update */);
     pwallet->MarkDirty();
 
     if (!fGood) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error adding some keys/scripts to wallet");
     }
 
     return NullUniValue;
 }
 
 UniValue dumpprivkey(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "dumpprivkey \"address\"\n"
             "\nReveals the private key corresponding to 'address'.\n"
             "Then the importprivkey can be used with this output\n"
             "\nArguments:\n"
             "1. \"address\"   (string, required) The bitcoin address for the "
             "private key\n"
             "\nResult:\n"
             "\"key\"                (string) The private key\n"
             "\nExamples:\n" +
             HelpExampleCli("dumpprivkey", "\"myaddress\"") +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             HelpExampleRpc("dumpprivkey", "\"myaddress\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::string strAddress = request.params[0].get_str();
     CTxDestination dest =
         DecodeDestination(strAddress, config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
     auto keyid = GetKeyForDestination(*pwallet, dest);
     if (keyid.IsNull()) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to a key");
     }
     CKey vchSecret;
     if (!pwallet->GetKey(keyid, vchSecret)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Private key for address " +
                                                  strAddress + " is not known");
     }
     return EncodeSecret(vchSecret);
 }
 
 UniValue dumpwallet(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1)
         throw std::runtime_error(
             "dumpwallet \"filename\"\n"
             "\nDumps all wallet keys in a human-readable format to a "
             "server-side file. This does not allow overwriting existing "
             "files.\n"
             "Imported scripts are included in the dumpsfile, but corresponding "
             "addresses may not be added automatically by importwallet.\n"
             "Note that if your wallet contains keys which are not derived from "
             "your HD seed (e.g. imported keys), these are not covered by\n"
             "only backing up the seed itself, and must be backed up too (e.g. "
             "ensure you back up the whole dumpfile).\n"
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The filename with path "
             "(either absolute or relative to bitcoind)\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"filename\" : {        (string) The filename with full "
             "absolute path\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("dumpwallet", "\"test\"") +
             HelpExampleRpc("dumpwallet", "\"test\""));
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     fs::path filepath = request.params[0].get_str();
     filepath = fs::absolute(filepath);
 
     /**
      * Prevent arbitrary files from being overwritten. There have been reports
      * that users have overwritten wallet files this way:
      * https://github.com/bitcoin/bitcoin/issues/9934
      * It may also avoid other security issues.
      */
     if (fs::exists(filepath)) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            filepath.string() + " already exists. If you are "
                                                "sure this is what you want, "
                                                "move it out of the way first");
     }
 
     std::ofstream file;
     file.open(filepath.string().c_str());
     if (!file.is_open()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Cannot open wallet dump file");
     }
 
     std::map<CTxDestination, int64_t> mapKeyBirth;
     const std::map<CKeyID, int64_t> &mapKeyPool = pwallet->GetAllReserveKeys();
     pwallet->GetKeyBirthTimes(mapKeyBirth);
 
     std::set<CScriptID> scripts = pwallet->GetCScripts();
     // TODO: include scripts in GetKeyBirthTimes() output instead of separate
 
     // sort time/key pairs
     std::vector<std::pair<int64_t, CKeyID>> vKeyBirth;
     for (const auto &entry : mapKeyBirth) {
         if (const CKeyID *keyID = boost::get<CKeyID>(&entry.first)) {
             // set and test
             vKeyBirth.push_back(std::make_pair(entry.second, *keyID));
         }
     }
     mapKeyBirth.clear();
     std::sort(vKeyBirth.begin(), vKeyBirth.end());
 
     // produce output
     file << strprintf("# Wallet dump created by Bitcoin %s\n", CLIENT_BUILD);
     file << strprintf("# * Created on %s\n", FormatISO8601DateTime(GetTime()));
     file << strprintf("# * Best block at time of backup was %i (%s),\n",
                       chainActive.Height(),
                       chainActive.Tip()->GetBlockHash().ToString());
     file << strprintf("#   mined on %s\n",
                       FormatISO8601DateTime(chainActive.Tip()->GetBlockTime()));
     file << "\n";
 
     // add the base58check encoded extended master if the wallet uses HD
     CKeyID seed_id = pwallet->GetHDChain().seed_id;
     if (!seed_id.IsNull()) {
         CKey seed;
         if (pwallet->GetKey(seed_id, seed)) {
             CExtKey masterKey;
             masterKey.SetSeed(seed.begin(), seed.size());
 
             file << "# extended private masterkey: " << EncodeExtKey(masterKey)
                  << "\n\n";
         }
     }
     for (std::vector<std::pair<int64_t, CKeyID>>::const_iterator it =
              vKeyBirth.begin();
          it != vKeyBirth.end(); it++) {
         const CKeyID &keyid = it->second;
         std::string strTime = FormatISO8601DateTime(it->first);
         std::string strAddr;
         std::string strLabel;
         CKey key;
         if (pwallet->GetKey(keyid, key)) {
             file << strprintf("%s %s ", EncodeSecret(key), strTime);
             if (GetWalletAddressesForKey(config, pwallet, keyid, strAddr,
                                          strLabel)) {
                 file << strprintf("label=%s", strLabel);
             } else if (keyid == seed_id) {
                 file << "hdseed=1";
             } else if (mapKeyPool.count(keyid)) {
                 file << "reserve=1";
             } else if (pwallet->mapKeyMetadata[keyid].hdKeypath == "s") {
                 file << "inactivehdseed=1";
             } else {
                 file << "change=1";
             }
             file << strprintf(
                 " # addr=%s%s\n", strAddr,
                 (pwallet->mapKeyMetadata[keyid].hdKeypath.size() > 0
                      ? " hdkeypath=" + pwallet->mapKeyMetadata[keyid].hdKeypath
                      : ""));
         }
     }
     file << "\n";
     for (const CScriptID &scriptid : scripts) {
         CScript script;
         std::string create_time = "0";
         std::string address = EncodeDestination(scriptid, config);
         // get birth times for scripts with metadata
         auto it = pwallet->m_script_metadata.find(scriptid);
         if (it != pwallet->m_script_metadata.end()) {
             create_time = FormatISO8601DateTime(it->second.nCreateTime);
         }
         if (pwallet->GetCScript(scriptid, script)) {
             file << strprintf("%s %s script=1",
                               HexStr(script.begin(), script.end()),
                               create_time);
             file << strprintf(" # addr=%s\n", address);
         }
     }
     file << "\n";
     file << "# End of dump\n";
     file.close();
 
     UniValue reply(UniValue::VOBJ);
     reply.pushKV("filename", filepath.string());
 
     return reply;
 }
 
 static UniValue ProcessImport(CWallet *const pwallet, const UniValue &data,
                               const int64_t timestamp)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     try {
         bool success = false;
 
         // Required fields.
         const UniValue &scriptPubKey = data["scriptPubKey"];
 
         // Should have script or JSON with "address".
         if (!(scriptPubKey.getType() == UniValue::VOBJ &&
               scriptPubKey.exists("address")) &&
             !(scriptPubKey.getType() == UniValue::VSTR)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid scriptPubKey");
         }
 
         // Optional fields.
         const std::string &strRedeemScript =
             data.exists("redeemscript") ? data["redeemscript"].get_str() : "";
         const UniValue &pubKeys =
             data.exists("pubkeys") ? data["pubkeys"].get_array() : UniValue();
         const UniValue &keys =
             data.exists("keys") ? data["keys"].get_array() : UniValue();
         const bool internal =
             data.exists("internal") ? data["internal"].get_bool() : false;
         const bool watchOnly =
             data.exists("watchonly") ? data["watchonly"].get_bool() : false;
         const std::string &label =
             data.exists("label") && !internal ? data["label"].get_str() : "";
 
         // If private keys are disabled, abort if private keys are being
         // imported
         if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) &&
             !keys.isNull()) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Cannot import private keys to a wallet with "
                                "private keys disabled");
         }
 
         bool isScript = scriptPubKey.getType() == UniValue::VSTR;
         bool isP2SH = strRedeemScript.length() > 0;
         const std::string &output = isScript
                                         ? scriptPubKey.get_str()
                                         : scriptPubKey["address"].get_str();
 
         // Parse the output.
         CScript script;
         CTxDestination dest;
 
         if (!isScript) {
             dest = DecodeDestination(output, pwallet->chainParams);
             if (!IsValidDestination(dest)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid address");
             }
             script = GetScriptForDestination(dest);
         } else {
             if (!IsHex(output)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid scriptPubKey");
             }
 
             std::vector<uint8_t> vData(ParseHex(output));
             script = CScript(vData.begin(), vData.end());
         }
 
         // Watchonly and private keys
         if (watchOnly && keys.size()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Incompatibility found between watchonly and keys");
         }
 
         // Internal + Label
         if (internal && data.exists("label")) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Incompatibility found between internal and label");
         }
 
         // Not having Internal + Script
         if (!internal && isScript) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Internal must be set for hex scriptPubKey");
         }
 
         // Keys / PubKeys size check.
         if (!isP2SH &&
             (keys.size() > 1 || pubKeys.size() > 1)) { // Address / scriptPubKey
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "More than private key given for one address");
         }
 
         // Invalid P2SH redeemScript
         if (isP2SH && !IsHex(strRedeemScript)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid redeem script");
         }
 
         // Process. //
 
         // P2SH
         if (isP2SH) {
             // Import redeem script.
             std::vector<uint8_t> vData(ParseHex(strRedeemScript));
             CScript redeemScript = CScript(vData.begin(), vData.end());
 
             // Invalid P2SH address
             if (!script.IsPayToScriptHash()) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid P2SH address / script");
             }
 
             pwallet->MarkDirty();
 
             if (!pwallet->AddWatchOnly(redeemScript, timestamp)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding address to wallet");
             }
 
             CScriptID redeem_id(redeemScript);
             if (!pwallet->HaveCScript(redeem_id) &&
                 !pwallet->AddCScript(redeemScript)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding p2sh redeemScript to wallet");
             }
 
             CScript redeemDestination = GetScriptForDestination(redeem_id);
 
             if (::IsMine(*pwallet, redeemDestination) == ISMINE_SPENDABLE) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "The wallet already contains the private "
                                    "key for this address or script");
             }
 
             pwallet->MarkDirty();
 
             if (!pwallet->AddWatchOnly(redeemDestination, timestamp)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding address to wallet");
             }
 
             // add to address book or update label
             if (IsValidDestination(dest)) {
                 pwallet->SetAddressBook(dest, label, "receive");
             }
 
             // Import private keys.
             if (keys.size()) {
                 for (size_t i = 0; i < keys.size(); i++) {
                     const std::string &privkey = keys[i].get_str();
 
                     CKey key = DecodeSecret(privkey);
 
                     if (!key.IsValid()) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Invalid private key encoding");
                     }
 
                     CPubKey pubkey = key.GetPubKey();
                     assert(key.VerifyPubKey(pubkey));
 
                     CKeyID vchAddress = pubkey.GetID();
                     pwallet->MarkDirty();
                     pwallet->SetAddressBook(vchAddress, label, "receive");
 
                     if (pwallet->HaveKey(vchAddress)) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Already have this key");
                     }
 
                     pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
 
                     if (!pwallet->AddKeyPubKey(key, pubkey)) {
                         throw JSONRPCError(RPC_WALLET_ERROR,
                                            "Error adding key to wallet");
                     }
 
                     pwallet->UpdateTimeFirstKey(timestamp);
                 }
             }
 
             success = true;
         } else {
             // Import public keys.
             if (pubKeys.size() && keys.size() == 0) {
                 const std::string &strPubKey = pubKeys[0].get_str();
 
                 if (!IsHex(strPubKey)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Pubkey must be a hex string");
                 }
 
                 std::vector<uint8_t> vData(ParseHex(strPubKey));
                 CPubKey pubKey(vData.begin(), vData.end());
 
                 if (!pubKey.IsFullyValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Pubkey is not a valid public key");
                 }
 
                 CTxDestination pubkey_dest = pubKey.GetID();
 
                 // Consistency check.
                 if (!isScript && !(pubkey_dest == dest)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Consistency check failed");
                 }
 
                 // Consistency check.
                 if (isScript) {
                     CTxDestination destination;
 
                     if (ExtractDestination(script, destination)) {
                         if (!(destination == pubkey_dest)) {
                             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                                "Consistency check failed");
                         }
                     }
                 }
 
                 CScript pubKeyScript = GetScriptForDestination(pubkey_dest);
 
                 if (::IsMine(*pwallet, pubKeyScript) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(pubKeyScript, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 // add to address book or update label
                 if (IsValidDestination(pubkey_dest)) {
                     pwallet->SetAddressBook(pubkey_dest, label, "receive");
                 }
 
                 // TODO Is this necessary?
                 CScript scriptRawPubKey = GetScriptForRawPubKey(pubKey);
 
                 if (::IsMine(*pwallet, scriptRawPubKey) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(scriptRawPubKey, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 success = true;
             }
 
             // Import private keys.
             if (keys.size()) {
                 const std::string &strPrivkey = keys[0].get_str();
 
                 // Checks.
                 CKey key = DecodeSecret(strPrivkey);
 
                 if (!key.IsValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Invalid private key encoding");
                 }
 
                 CPubKey pubKey = key.GetPubKey();
                 assert(key.VerifyPubKey(pubKey));
 
                 CTxDestination pubkey_dest = pubKey.GetID();
 
                 // Consistency check.
                 if (!isScript && !(pubkey_dest == dest)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Consistency check failed");
                 }
 
                 // Consistency check.
                 if (isScript) {
                     CTxDestination destination;
 
                     if (ExtractDestination(script, destination)) {
                         if (!(destination == pubkey_dest)) {
                             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                                "Consistency check failed");
                         }
                     }
                 }
 
                 CKeyID vchAddress = pubKey.GetID();
                 pwallet->MarkDirty();
                 pwallet->SetAddressBook(vchAddress, label, "receive");
 
                 if (pwallet->HaveKey(vchAddress)) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
 
                 if (!pwallet->AddKeyPubKey(key, pubKey)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding key to wallet");
                 }
 
                 pwallet->UpdateTimeFirstKey(timestamp);
 
                 success = true;
             }
 
             // Import scriptPubKey only.
             if (pubKeys.size() == 0 && keys.size() == 0) {
                 if (::IsMine(*pwallet, script) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(script, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 if (scriptPubKey.getType() == UniValue::VOBJ) {
                     // add to address book or update label
                     if (IsValidDestination(dest)) {
                         pwallet->SetAddressBook(dest, label, "receive");
                     }
                 }
 
                 success = true;
             }
         }
 
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(success));
         return result;
     } catch (const UniValue &e) {
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(false));
         result.pushKV("error", e);
         return result;
     } catch (...) {
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(false));
         result.pushKV("error",
                       JSONRPCError(RPC_MISC_ERROR, "Missing required fields"));
         return result;
     }
 }
 
 static int64_t GetImportTimestamp(const UniValue &data, int64_t now) {
     if (data.exists("timestamp")) {
         const UniValue &timestamp = data["timestamp"];
         if (timestamp.isNum()) {
             return timestamp.get_int64();
         } else if (timestamp.isStr() && timestamp.get_str() == "now") {
             return now;
         }
         throw JSONRPCError(RPC_TYPE_ERROR,
                            strprintf("Expected number or \"now\" timestamp "
                                      "value for key. got type %s",
                                      uvTypeName(timestamp.type())));
     }
     throw JSONRPCError(RPC_TYPE_ERROR,
                        "Missing required timestamp field for key");
 }
 
 UniValue importmulti(const Config &config, const JSONRPCRequest &mainRequest) {
     std::shared_ptr<CWallet> const wallet =
         GetWalletForJSONRPCRequest(mainRequest);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, mainRequest.fHelp)) {
         return NullUniValue;
     }
 
     // clang-format off
     if (mainRequest.fHelp || mainRequest.params.size() < 1 || mainRequest.params.size() > 2) {
         throw std::runtime_error(
             "importmulti \"requests\" ( \"options\" )\n\n"
             "Import addresses/scripts (with private or public keys, redeem script (P2SH)), rescanning all addresses in one-shot-only (rescan can be disabled via options). Requires a new wallet backup.\n\n"
             "Arguments:\n"
             "1. requests     (array, required) Data to be imported\n"
             "  [     (array of json objects)\n"
             "    {\n"
             "      \"scriptPubKey\": \"<script>\" | { \"address\":\"<address>\" }, (string / json, required) Type of scriptPubKey (string for script, json for address)\n"
             "      \"timestamp\": timestamp | \"now\"                        , (integer / string, required) Creation time of the key in seconds since epoch (Jan 1 1970 GMT),\n"
             "                                                              or the string \"now\" to substitute the current synced blockchain time. The timestamp of the oldest\n"
             "                                                              key will determine how far back blockchain rescans need to begin for missing wallet transactions.\n"
             "                                                              \"now\" can be specified to bypass scanning, for keys which are known to never have been used, and\n"
             "                                                              0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest key\n"
             "                                                              creation time of all keys being imported by the importmulti call will be scanned.\n"
             "      \"redeemscript\": \"<script>\"                            , (string, optional) Allowed only if the scriptPubKey is a P2SH address or a P2SH scriptPubKey\n"
             "      \"pubkeys\": [\"<pubKey>\", ... ]                         , (array, optional) Array of strings giving pubkeys that must occur in the output or redeemscript\n"
             "      \"keys\": [\"<key>\", ... ]                               , (array, optional) Array of strings giving private keys whose corresponding public keys must occur in the output or redeemscript\n"
             "      \"internal\": <true>                                    , (boolean, optional, default: false) Stating whether matching outputs should be treated as not incoming payments\n"
             "      \"watchonly\": <true>                                   , (boolean, optional, default: false) Stating whether matching outputs should be considered watched even when they're not spendable, only allowed if keys are empty\n"
             "      \"label\": <label>                                      , (string, optional, default: '') Label to assign to the address (aka account name, for now), only allowed with internal=false\n"
             "    }\n"
             "  ,...\n"
             "  ]\n"
             "2. options                 (json, optional)\n"
             "  {\n"
             "     \"rescan\": <false>,         (boolean, optional, default: true) Stating if should rescan the blockchain after all imports\n"
             "  }\n"
             "\nNote: This call can take minutes to complete if rescan is true, during that time, other rpc calls\n"
             "may report that the imported keys, addresses or scripts exists but related transactions are still missing.\n"
             "\nExamples:\n" +
             HelpExampleCli("importmulti", "'[{ \"scriptPubKey\": { \"address\": \"<my address>\" }, \"timestamp\":1455191478 }, "
                                           "{ \"scriptPubKey\": { \"address\": \"<my 2nd address>\" }, \"label\": \"example 2\", \"timestamp\": 1455191480 }]'") +
             HelpExampleCli("importmulti", "'[{ \"scriptPubKey\": { \"address\": \"<my address>\" }, \"timestamp\":1455191478 }]' '{ \"rescan\": false}'") +
 
             "\nResponse is an array with the same size as the input that has the execution result :\n"
             "  [{ \"success\": true } , { \"success\": false, \"error\": { \"code\": -1, \"message\": \"Internal Server Error\"} }, ... ]\n");
     }
 
     // clang-format on
 
     RPCTypeCheck(mainRequest.params, {UniValue::VARR, UniValue::VOBJ});
 
     const UniValue &requests = mainRequest.params[0];
 
     // Default options
     bool fRescan = true;
 
     if (!mainRequest.params[1].isNull()) {
         const UniValue &options = mainRequest.params[1];
 
         if (options.exists("rescan")) {
             fRescan = options["rescan"].get_bool();
         }
     }
 
     WalletRescanReserver reserver(pwallet);
     if (fRescan && !reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     int64_t now = 0;
     bool fRunScan = false;
     int64_t nLowestTimestamp = 0;
     UniValue response(UniValue::VARR);
     {
-        LOCK2(cs_main, pwallet->cs_wallet);
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
         EnsureWalletIsUnlocked(pwallet);
 
         // Verify all timestamps are present before importing any keys.
         now = chainActive.Tip() ? chainActive.Tip()->GetMedianTimePast() : 0;
         for (const UniValue &data : requests.getValues()) {
             GetImportTimestamp(data, now);
         }
 
         const int64_t minimumTimestamp = 1;
 
         if (fRescan && chainActive.Tip()) {
             nLowestTimestamp = chainActive.Tip()->GetBlockTime();
         } else {
             fRescan = false;
         }
 
         for (const UniValue &data : requests.getValues()) {
             const int64_t timestamp =
                 std::max(GetImportTimestamp(data, now), minimumTimestamp);
             const UniValue result = ProcessImport(pwallet, data, timestamp);
             response.push_back(result);
 
             if (!fRescan) {
                 continue;
             }
 
             // If at least one request was successful then allow rescan.
             if (result["success"].get_bool()) {
                 fRunScan = true;
             }
 
             // Get the lowest timestamp.
             if (timestamp < nLowestTimestamp) {
                 nLowestTimestamp = timestamp;
             }
         }
     }
     if (fRescan && fRunScan && requests.size()) {
         int64_t scannedTime = pwallet->RescanFromTime(
             nLowestTimestamp, reserver, true /* update */);
         pwallet->ReacceptWalletTransactions();
 
         if (pwallet->IsAbortingRescan()) {
             throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted by user.");
         }
         if (scannedTime > nLowestTimestamp) {
             std::vector<UniValue> results = response.getValues();
             response.clear();
             response.setArray();
             size_t i = 0;
             for (const UniValue &request : requests.getValues()) {
                 // If key creation date is within the successfully scanned
                 // range, or if the import result already has an error set, let
                 // the result stand unmodified. Otherwise replace the result
                 // with an error message.
                 if (scannedTime <= GetImportTimestamp(request, now) ||
                     results.at(i).exists("error")) {
                     response.push_back(results.at(i));
                 } else {
                     UniValue result = UniValue(UniValue::VOBJ);
                     result.pushKV("success", UniValue(false));
                     result.pushKV(
                         "error",
                         JSONRPCError(
                             RPC_MISC_ERROR,
                             strprintf(
                                 "Rescan failed for key with creation timestamp "
                                 "%d. There was an error reading a block from "
                                 "time %d, which is after or within %d seconds "
                                 "of key creation, and could contain "
                                 "transactions pertaining to the key. As a "
                                 "result, transactions and coins using this key "
                                 "may not appear in the wallet. This error "
                                 "could be caused by pruning or data corruption "
                                 "(see bitcoind log for details) and could be "
                                 "dealt with by downloading and rescanning the "
                                 "relevant blocks (see -reindex and -rescan "
                                 "options).",
                                 GetImportTimestamp(request, now),
                                 scannedTime - TIMESTAMP_WINDOW - 1,
                                 TIMESTAMP_WINDOW)));
                     response.push_back(std::move(result));
                 }
                 ++i;
             }
         }
     }
 
     return response;
 }
 
 // clang-format off
 static const ContextFreeRPCCommand commands[] = {
     //  category            name                        actor (function)          argNames
     //  ------------------- ------------------------    ----------------------    ----------
     { "wallet",             "abortrescan",              abortrescan,              {} },
     { "wallet",             "dumpprivkey",              dumpprivkey,              {"address"}  },
     { "wallet",             "dumpwallet",               dumpwallet,               {"filename"} },
     { "wallet",             "importmulti",              importmulti,              {"requests","options"} },
     { "wallet",             "importprivkey",            importprivkey,            {"privkey","label","rescan"} },
     { "wallet",             "importwallet",             importwallet,             {"filename"} },
     { "wallet",             "importaddress",            importaddress,            {"address","label","rescan","p2sh"} },
     { "wallet",             "importprunedfunds",        importprunedfunds,        {"rawtransaction","txoutproof"} },
     { "wallet",             "importpubkey",             importpubkey,             {"pubkey","label","rescan"} },
     { "wallet",             "removeprunedfunds",        removeprunedfunds,        {"txid"} },
 };
 // clang-format on
 
 void RegisterDumpRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 96d30aad1..5bed5c3ef 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1,5492 +1,5529 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <amount.h>
 #include <chain.h>
 #include <chainparams.h> // for GetConsensus.
 #include <config.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <init.h>
+#include <interfaces/chain.h>
 #include <key_io.h>
 #include <net.h>
 #include <outputtype.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <rpc/mining.h>
 #include <rpc/misc.h>
 #include <rpc/rawtransaction.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <shutdown.h>
 #include <timedata.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 #include <wallet/walletdb.h>
 #include <wallet/walletutil.h>
 
 #include <univalue.h>
 
 #include <event2/http.h>
 
 #include <functional>
 
 static const std::string WALLET_ENDPOINT_BASE = "/wallet/";
 
 static std::string urlDecode(const std::string &urlEncoded) {
     std::string res;
     if (!urlEncoded.empty()) {
         char *decoded = evhttp_uridecode(urlEncoded.c_str(), false, nullptr);
         if (decoded) {
             res = std::string(decoded);
             free(decoded);
         }
     }
     return res;
 }
 
 bool GetWalletNameFromJSONRPCRequest(const JSONRPCRequest &request,
                                      std::string &wallet_name) {
     if (request.URI.substr(0, WALLET_ENDPOINT_BASE.size()) ==
         WALLET_ENDPOINT_BASE) {
         // wallet endpoint was used
         wallet_name =
             urlDecode(request.URI.substr(WALLET_ENDPOINT_BASE.size()));
         return true;
     }
     return false;
 }
 
 std::shared_ptr<CWallet>
 GetWalletForJSONRPCRequest(const JSONRPCRequest &request) {
     std::string wallet_name;
     if (GetWalletNameFromJSONRPCRequest(request, wallet_name)) {
         std::shared_ptr<CWallet> pwallet = GetWallet(wallet_name);
         if (!pwallet) {
             throw JSONRPCError(
                 RPC_WALLET_NOT_FOUND,
                 "Requested wallet does not exist or is not loaded");
         }
         return pwallet;
     }
 
     std::vector<std::shared_ptr<CWallet>> wallets = GetWallets();
     return wallets.size() == 1 || (request.fHelp && wallets.size() > 0)
                ? wallets[0]
                : nullptr;
 }
 
 std::string HelpRequiringPassphrase(CWallet *const pwallet) {
     return pwallet && pwallet->IsCrypted()
                ? "\nRequires wallet passphrase to be set with walletpassphrase "
                  "call."
                : "";
 }
 
 bool EnsureWalletIsAvailable(CWallet *const pwallet, bool avoidException) {
     if (pwallet) {
         return true;
     }
     if (avoidException) {
         return false;
     }
     if (!HasWallets()) {
         throw JSONRPCError(RPC_METHOD_NOT_FOUND,
                            "Method not found (wallet method is disabled "
                            "because no wallet is loaded)");
     }
 
     throw JSONRPCError(RPC_WALLET_NOT_SPECIFIED,
                        "Wallet file not specified (must request wallet RPC "
                        "through /wallet/<filename> uri-path).");
 }
 
 void EnsureWalletIsUnlocked(CWallet *const pwallet) {
     if (pwallet->IsLocked()) {
         throw JSONRPCError(RPC_WALLET_UNLOCK_NEEDED,
                            "Error: Please enter the wallet passphrase with "
                            "walletpassphrase first.");
     }
 }
 
 static void WalletTxToJSON(interfaces::Chain &chain, const CWalletTx &wtx,
                            UniValue &entry) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     int confirms = wtx.GetDepthInMainChain();
     entry.pushKV("confirmations", confirms);
     if (wtx.IsCoinBase()) {
         entry.pushKV("generated", true);
     }
     if (confirms > 0) {
         entry.pushKV("blockhash", wtx.hashBlock.GetHex());
         entry.pushKV("blockindex", wtx.nIndex);
         entry.pushKV("blocktime",
                      LookupBlockIndex(wtx.hashBlock)->GetBlockTime());
     } else {
         entry.pushKV("trusted", wtx.IsTrusted());
     }
     uint256 hash = wtx.GetId();
     entry.pushKV("txid", hash.GetHex());
     UniValue conflicts(UniValue::VARR);
     for (const uint256 &conflict : wtx.GetConflicts()) {
         conflicts.push_back(conflict.GetHex());
     }
     entry.pushKV("walletconflicts", conflicts);
     entry.pushKV("time", wtx.GetTxTime());
     entry.pushKV("timereceived", (int64_t)wtx.nTimeReceived);
 
     for (const std::pair<const std::string, std::string> &item : wtx.mapValue) {
         entry.pushKV(item.first, item.second);
     }
 }
 
 static std::string LabelFromValue(const UniValue &value) {
     std::string label = value.get_str();
     if (label == "*") {
         throw JSONRPCError(RPC_WALLET_INVALID_LABEL_NAME, "Invalid label name");
     }
     return label;
 }
 
 static UniValue getnewaddress(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "getnewaddress ( \"label\" )\n"
             "\nReturns a new Bitcoin address for receiving payments.\n"
             "If 'label' is specified, it is added to the address book \n"
             "so payments received with the address will be associated with "
             "'label'.\n"
             "\nArguments:\n"
             "1. \"label\"          (string, optional) The label name for the "
             "address to be linked to. If not provided, the default label \"\" "
             "is used. It can also be set to the empty string \"\" to represent "
             "the default label. The label does not need to exist, it will be "
             "created if there is no label by the given name.\n"
             "\nResult:\n"
             "\"address\"    (string) The new bitcoin address\n"
             "\nExamples:\n" +
             HelpExampleRpc("getnewaddress", ""));
     }
 
     // Belt and suspenders check for disabled private keys
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: Private keys are disabled for this wallet");
     }
 
     LOCK(pwallet->cs_wallet);
 
     if (!pwallet->CanGetAddresses()) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: This wallet has no available keys");
     }
 
     // Parse the label first so we don't generate a key if there's an error
     std::string label;
     if (!request.params[0].isNull()) {
         label = LabelFromValue(request.params[0]);
     }
 
     OutputType output_type = pwallet->m_default_address_type;
     if (!request.params[1].isNull()) {
         if (!ParseOutputType(request.params[1].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                strprintf("Unknown address type '%s'",
                                          request.params[1].get_str()));
         }
     }
 
     if (!pwallet->IsLocked()) {
         pwallet->TopUpKeyPool();
     }
 
     // Generate a new key that is added to wallet
     CPubKey newKey;
     if (!pwallet->GetKeyFromPool(newKey)) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
     pwallet->LearnRelatedScripts(newKey, output_type);
     CTxDestination dest = GetDestinationForKey(newKey, output_type);
 
     pwallet->SetAddressBook(dest, label, "receive");
 
     return EncodeDestination(dest, config);
 }
 
 static CTxDestination GetLabelDestination(CWallet *const pwallet,
                                           const std::string &label,
                                           bool bForceNew = false)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     CTxDestination dest;
     if (!pwallet->GetLabelDestination(dest, label, bForceNew)) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
 
     return dest;
 }
 
 static UniValue getaccountaddress(const Config &config,
                                   const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         if (request.fHelp) {
             throw std::runtime_error(
                 "getaccountaddress (Deprecated, will be removed in v0.21. To "
                 "use this command, start bitcoind with "
                 "-deprecatedrpc=accounts)");
         }
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "getaccountaddress is deprecated and will be removed in v0.21. To "
             "use this command, start bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "getaccountaddress \"account\"\n"
             "\n\nDEPRECATED. Returns the current Bitcoin address for receiving"
             "payments to this account.\n"
             "\nArguments:\n"
             "1. \"account\"       (string, required) The account for the "
             "address. It can also be set to the empty string \"\" to represent "
             "the default account. The account does not need to exist, it will "
             "be created and a new address created if there is no account by "
             "the given name.\n"
             "\nResult:\n"
             "\"address\"          (string) The account bitcoin address\n"
             "\nExamples:\n" +
             HelpExampleCli("getaccountaddress", "") +
             HelpExampleCli("getaccountaddress", "\"\"") +
             HelpExampleCli("getaccountaddress", "\"myaccount\"") +
             HelpExampleRpc("getaccountaddress", "\"myaccount\""));
     }
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     // Parse the account first so we don't generate a key if there's an error
     std::string account = LabelFromValue(request.params[0]);
 
     UniValue ret(UniValue::VSTR);
 
     ret = EncodeDestination(GetLabelDestination(pwallet, account), config);
     return ret;
 }
 
 static UniValue getrawchangeaddress(const Config &config,
                                     const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             "getrawchangeaddress\n"
             "\nReturns a new Bitcoin address, for receiving change.\n"
             "This is for use with raw transactions, NOT normal use.\n"
             "\nResult:\n"
             "\"address\"    (string) The address\n"
             "\nExamples:\n" +
             HelpExampleCli("getrawchangeaddress", "") +
             HelpExampleRpc("getrawchangeaddress", ""));
     }
 
     // Belt and suspenders check for disabled private keys
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: Private keys are disabled for this wallet");
     }
 
     LOCK(pwallet->cs_wallet);
 
     if (!pwallet->CanGetAddresses(true)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: This wallet has no available keys");
     }
 
     if (!pwallet->IsLocked()) {
         pwallet->TopUpKeyPool();
     }
 
     OutputType output_type =
         pwallet->m_default_change_type != OutputType::CHANGE_AUTO
             ? pwallet->m_default_change_type
             : pwallet->m_default_address_type;
     if (!request.params[0].isNull()) {
         if (!ParseOutputType(request.params[0].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                strprintf("Unknown address type '%s'",
                                          request.params[0].get_str()));
         }
     }
 
     CReserveKey reservekey(pwallet);
     CPubKey vchPubKey;
     if (!reservekey.GetReservedKey(vchPubKey, true)) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
 
     reservekey.KeepKey();
 
     pwallet->LearnRelatedScripts(vchPubKey, output_type);
     CTxDestination dest = GetDestinationForKey(vchPubKey, output_type);
 
     return EncodeDestination(dest, config);
 }
 
 static UniValue setlabel(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts") &&
         request.strMethod == "setaccount") {
         if (request.fHelp) {
             throw std::runtime_error(
                 "setaccount (Deprecated, will be removed in v0.21. To use this "
                 "command, start bitcoind with -deprecatedrpc=accounts)");
         }
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "setaccount is deprecated and will be removed in v0.21. To use "
             "this command, start bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             "setlabel \"address\" \"label\"\n"
             "\nSets the label associated with the given address.\n"
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address to "
             "be associated with a label.\n"
             "2. \"label\"           (string, required) The label to assign to "
             "the address.\n"
             "\nExamples:\n" +
             HelpExampleCli("setlabel",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"tabby\"") +
             HelpExampleRpc(
                 "setlabel",
                 "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"tabby\""));
     }
     LOCK(pwallet->cs_wallet);
 
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
 
     std::string old_label = pwallet->mapAddressBook[dest].name;
     std::string label = LabelFromValue(request.params[1]);
 
     if (IsMine(*pwallet, dest)) {
         pwallet->SetAddressBook(dest, label, "receive");
         if (request.strMethod == "setaccount" && old_label != label &&
             dest == GetLabelDestination(pwallet, old_label)) {
             // for setaccount, call GetLabelDestination so a new receive address
             // is created for the old account
             GetLabelDestination(pwallet, old_label, true);
         }
     } else {
         pwallet->SetAddressBook(dest, label, "send");
     }
 
     // Detect when there are no addresses using this label.
     // If so, delete the account record for it. Labels, unlike addresses, can be
     // deleted, and if we wouldn't do this, the record would stick around
     // forever.
     bool found_address = false;
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          pwallet->mapAddressBook) {
         if (item.second.name == label) {
             found_address = true;
             break;
         }
     }
     if (!found_address) {
         pwallet->DeleteLabel(old_label);
     }
 
     return NullUniValue;
 }
 
 static UniValue getaccount(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         if (request.fHelp) {
             throw std::runtime_error(
                 "getaccount (Deprecated, will be removed in v0.21. To use this "
                 "command, start bitcoind with -deprecatedrpc=accounts)");
         }
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "getaccount is deprecated and will be removed in v0.21. To use "
             "this command, start bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "getaccount \"address\"\n"
             "\nDEPRECATED. Returns the account associated with the given "
             "address.\n"
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address for "
             "account lookup.\n"
             "\nResult:\n"
             "\"accountname\"        (string) the account address\n"
             "\nExamples:\n" +
             HelpExampleCli("getaccount",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\"") +
             HelpExampleRpc("getaccount",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
 
     std::string strAccount;
     std::map<CTxDestination, CAddressBookData>::iterator mi =
         pwallet->mapAddressBook.find(dest);
     if (mi != pwallet->mapAddressBook.end() && !(*mi).second.name.empty()) {
         strAccount = (*mi).second.name;
     }
 
     return strAccount;
 }
 
 static UniValue getaddressesbyaccount(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         if (request.fHelp) {
             throw std::runtime_error(
                 "getaddressbyaccount (Deprecated, will be removed in v0.21. To "
                 "use this command, start bitcoind with "
                 "-deprecatedrpc=accounts)");
         }
         throw JSONRPCError(RPC_METHOD_DEPRECATED,
                            "getaddressesbyaccount is deprecated and will be "
                            "removed in v0.21. To use this command, start "
                            "bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "getaddressesbyaccount \"account\"\n"
             "\nDEPRECATED. Returns the list of addresses for the given "
             "account.\n"
             "\nArguments:\n"
             "1. \"account\"        (string, required) The account name.\n"
             "\nResult:\n"
             "[                     (json array of string)\n"
             "  \"address\"         (string) a bitcoin address associated with "
             "the given account\n"
             "  ,...\n"
             "]\n"
             "\nExamples:\n" +
             HelpExampleCli("getaddressesbyaccount", "\"tabby\"") +
             HelpExampleRpc("getaddressesbyaccount", "\"tabby\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::string strAccount = LabelFromValue(request.params[0]);
 
     // Find all addresses that have the given account
     UniValue ret(UniValue::VARR);
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          pwallet->mapAddressBook) {
         const CTxDestination &dest = item.first;
         const std::string &strName = item.second.name;
         if (strName == strAccount) {
             ret.push_back(EncodeDestination(dest, config));
         }
     }
 
     return ret;
 }
 
 static CTransactionRef SendMoney(CWallet *const pwallet,
                                  const CTxDestination &address, Amount nValue,
                                  bool fSubtractFeeFromAmount,
                                  mapValue_t mapValue, std::string fromAccount) {
     Amount curBalance = pwallet->GetBalance();
 
     // Check amount
     if (nValue <= Amount::zero()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid amount");
     }
 
     if (nValue > curBalance) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, "Insufficient funds");
     }
 
     if (pwallet->GetBroadcastTransactions() && !g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
     // Parse Bitcoin address
     CScript scriptPubKey = GetScriptForDestination(address);
 
     // Create and send the transaction
     CReserveKey reservekey(pwallet);
     Amount nFeeRequired;
     std::string strError;
     std::vector<CRecipient> vecSend;
     int nChangePosRet = -1;
     CRecipient recipient = {scriptPubKey, nValue, fSubtractFeeFromAmount};
     vecSend.push_back(recipient);
 
     CCoinControl coinControl;
     CTransactionRef tx;
     if (!pwallet->CreateTransaction(vecSend, tx, reservekey, nFeeRequired,
                                     nChangePosRet, strError, coinControl)) {
         if (!fSubtractFeeFromAmount && nValue + nFeeRequired > curBalance) {
             strError = strprintf("Error: This transaction requires a "
                                  "transaction fee of at least %s",
                                  FormatMoney(nFeeRequired));
         }
         throw JSONRPCError(RPC_WALLET_ERROR, strError);
     }
     CValidationState state;
     if (!pwallet->CommitTransaction(tx, std::move(mapValue), {} /* orderForm */,
                                     std::move(fromAccount), reservekey,
                                     g_connman.get(), state)) {
         strError =
             strprintf("Error: The transaction was rejected! Reason given: %s",
                       FormatStateMessage(state));
         throw JSONRPCError(RPC_WALLET_ERROR, strError);
     }
     return tx;
 }
 
 static UniValue sendtoaddress(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 5) {
         throw std::runtime_error(
             "sendtoaddress \"address\" amount ( \"comment\" \"comment_to\" "
             "subtractfeefromamount )\n"
             "\nSend an amount to a given address.\n" +
             HelpRequiringPassphrase(pwallet) +
             "\nArguments:\n"
             "1. \"address\"            (string, required) The bitcoin address "
             "to send to.\n"
             "2. \"amount\"             (numeric or string, required) The "
             "amount in " +
             CURRENCY_UNIT +
             " to send. eg 0.1\n"
             "3. \"comment\"            (string, optional) A comment used to "
             "store what the transaction is for. \n"
             "                             This is not part of the transaction, "
             "just kept in your wallet.\n"
             "4. \"comment_to\"         (string, optional) A comment to store "
             "the name of the person or organization \n"
             "                             to which you're sending the "
             "transaction. This is not part of the \n"
             "                             transaction, just kept in your "
             "wallet.\n"
             "5. subtractfeefromamount  (boolean, optional, default=false) The "
             "fee will be deducted from the amount being sent.\n"
             "                             The recipient will receive less "
             "bitcoins than you enter in the amount field.\n"
             "\nResult:\n"
             "\"txid\"                  (string) The transaction id.\n"
             "\nExamples:\n" +
             HelpExampleCli("sendtoaddress",
                            "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 0.1") +
             HelpExampleCli("sendtoaddress", "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvay"
                                             "dd\" 0.1 \"donation\" \"seans "
                                             "outpost\"") +
             HelpExampleCli(
                 "sendtoaddress",
                 "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 0.1 \"\" \"\" true") +
             HelpExampleRpc("sendtoaddress", "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvay"
                                             "dd\", 0.1, \"donation\", \"seans "
                                             "outpost\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
     }
 
     // Amount
     Amount nAmount = AmountFromValue(request.params[1]);
     if (nAmount <= Amount::zero()) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
     }
 
     // Wallet comments
     mapValue_t mapValue;
     if (!request.params[2].isNull() && !request.params[2].get_str().empty()) {
         mapValue["comment"] = request.params[2].get_str();
     }
     if (!request.params[3].isNull() && !request.params[3].get_str().empty()) {
         mapValue["to"] = request.params[3].get_str();
     }
 
     bool fSubtractFeeFromAmount = false;
     if (!request.params[4].isNull()) {
         fSubtractFeeFromAmount = request.params[4].get_bool();
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     CTransactionRef tx =
         SendMoney(pwallet, dest, nAmount, fSubtractFeeFromAmount,
                   std::move(mapValue), {} /* fromAccount */);
     return tx->GetId().GetHex();
 }
 
 static UniValue listaddressgroupings(const Config &config,
                                      const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "listaddressgroupings\n"
             "\nLists groups of addresses which have had their common "
             "ownership\n"
             "made public by common use as inputs or as the resulting change\n"
             "in past transactions\n"
             "\nResult:\n"
             "[\n"
             "  [\n"
             "    [\n"
             "      \"address\",            (string) The bitcoin address\n"
             "      amount,                 (numeric) The amount in " +
             CURRENCY_UNIT +
             "\n"
             "      \"label\"               (string, optional) The label\n"
             "    ]\n"
             "    ,...\n"
             "  ]\n"
             "  ,...\n"
             "]\n"
             "\nExamples:\n" +
             HelpExampleCli("listaddressgroupings", "") +
             HelpExampleRpc("listaddressgroupings", ""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     UniValue jsonGroupings(UniValue::VARR);
     std::map<CTxDestination, Amount> balances = pwallet->GetAddressBalances();
     for (const std::set<CTxDestination> &grouping :
          pwallet->GetAddressGroupings()) {
         UniValue jsonGrouping(UniValue::VARR);
         for (const CTxDestination &address : grouping) {
             UniValue addressInfo(UniValue::VARR);
             addressInfo.push_back(EncodeDestination(address, config));
             addressInfo.push_back(ValueFromAmount(balances[address]));
 
             if (pwallet->mapAddressBook.find(address) !=
                 pwallet->mapAddressBook.end()) {
                 addressInfo.push_back(
                     pwallet->mapAddressBook.find(address)->second.name);
             }
             jsonGrouping.push_back(addressInfo);
         }
         jsonGroupings.push_back(jsonGrouping);
     }
 
     return jsonGroupings;
 }
 
 static UniValue signmessage(const Config &config,
                             const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             "signmessage \"address\" \"message\"\n"
             "\nSign a message with the private key of an address" +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address to "
             "use for the private key.\n"
             "2. \"message\"         (string, required) The message to create a "
             "signature of.\n"
             "\nResult:\n"
             "\"signature\"          (string) The signature of the message "
             "encoded in base 64\n"
             "\nExamples:\n"
             "\nUnlock the wallet for 30 seconds\n" +
             HelpExampleCli("walletpassphrase", "\"mypassphrase\" 30") +
             "\nCreate the signature\n" +
             HelpExampleCli(
                 "signmessage",
                 "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"my message\"") +
             "\nVerify the signature\n" +
             HelpExampleCli("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4"
                                             "XX\" \"signature\" \"my "
                                             "message\"") +
             "\nAs json rpc\n" +
             HelpExampleRpc(
                 "signmessage",
                 "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"my message\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::string strAddress = request.params[0].get_str();
     std::string strMessage = request.params[1].get_str();
 
     CTxDestination dest =
         DecodeDestination(strAddress, config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid address");
     }
 
     const CKeyID *keyID = boost::get<CKeyID>(&dest);
     if (!keyID) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
     }
 
     CKey key;
     if (!pwallet->GetKey(*keyID, key)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Private key not available");
     }
 
     CHashWriter ss(SER_GETHASH, 0);
     ss << strMessageMagic;
     ss << strMessage;
 
     std::vector<uint8_t> vchSig;
     if (!key.SignCompact(ss.GetHash(), vchSig)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Sign failed");
     }
 
     return EncodeBase64(vchSig.data(), vchSig.size());
 }
 
 static UniValue getreceivedbyaddress(const Config &config,
                                      const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "getreceivedbyaddress \"address\" ( minconf )\n"
             "\nReturns the total amount received by the given address in "
             "transactions with at least minconf confirmations.\n"
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address for "
             "transactions.\n"
             "2. minconf             (numeric, optional, default=1) Only "
             "include transactions confirmed at least this many times.\n"
             "\nResult:\n"
             "amount   (numeric) The total amount in " +
             CURRENCY_UNIT +
             " received at this address.\n"
             "\nExamples:\n"
             "\nThe amount from transactions with at least 1 confirmation\n" +
             HelpExampleCli("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\"") +
             "\nThe amount including unconfirmed transactions, zero "
             "confirmations\n" +
             HelpExampleCli("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" 0") +
             "\nThe amount with at least 6 confirmations\n" +
             HelpExampleCli("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" 6") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     // Bitcoin address
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
     CScript scriptPubKey = GetScriptForDestination(dest);
     if (!IsMine(*pwallet, scriptPubKey)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Address not found in wallet");
     }
 
     // Minimum confirmations
     int nMinDepth = 1;
     if (!request.params[1].isNull()) {
         nMinDepth = request.params[1].get_int();
     }
 
     // Tally
     Amount nAmount = Amount::zero();
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
 
         CValidationState state;
         if (wtx.IsCoinBase() ||
             !ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), *wtx.tx, state)) {
             continue;
         }
 
         for (const CTxOut &txout : wtx.tx->vout) {
             if (txout.scriptPubKey == scriptPubKey) {
                 if (wtx.GetDepthInMainChain() >= nMinDepth) {
                     nAmount += txout.nValue;
                 }
             }
         }
     }
 
     return ValueFromAmount(nAmount);
 }
 
 static UniValue getreceivedbylabel(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts") &&
         request.strMethod == "getreceivedbyaccount") {
         if (request.fHelp) {
             throw std::runtime_error(
                 "getreceivedbyaccount (Deprecated, will be removed in v0.21. "
                 "To use this command, start bitcoind with "
                 "-deprecatedrpc=accounts)");
         }
         throw JSONRPCError(RPC_METHOD_DEPRECATED,
                            "getreceivedbyaccount is deprecated and will be "
                            "removed in v0.21. To use this command, start "
                            "bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "getreceivedbylabel \"label\" ( minconf )\n"
             "\nReturns the total amount received by addresses with <label> in "
             "transactions with at least [minconf] confirmations.\n"
             "\nArguments:\n"
             "1. \"label\"        (string, required) The selected label, may be "
             "the default label using \"\".\n"
             "2. minconf          (numeric, optional, default=1) Only include "
             "transactions confirmed at least this many times.\n"
             "\nResult:\n"
             "amount              (numeric) The total amount in " +
             CURRENCY_UNIT +
             " received for this label.\n"
             "\nExamples:\n"
             "\nAmount received by the default label with at least 1 "
             "confirmation\n" +
             HelpExampleCli("getreceivedbylabel", "\"\"") +
             "\nAmount received at the tabby label including unconfirmed "
             "amounts with zero confirmations\n" +
             HelpExampleCli("getreceivedbylabel", "\"tabby\" 0") +
             "\nThe amount with at least 6 confirmations\n" +
             HelpExampleCli("getreceivedbylabel", "\"tabby\" 6") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("getreceivedbylabel", "\"tabby\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     // Minimum confirmations
     int nMinDepth = 1;
     if (!request.params[1].isNull()) {
         nMinDepth = request.params[1].get_int();
     }
 
     // Get the set of pub keys assigned to label
     std::string label = LabelFromValue(request.params[0]);
     std::set<CTxDestination> setAddress = pwallet->GetLabelAddresses(label);
 
     // Tally
     Amount nAmount = Amount::zero();
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
         CValidationState state;
         if (wtx.IsCoinBase() ||
             !ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), *wtx.tx, state)) {
             continue;
         }
 
         for (const CTxOut &txout : wtx.tx->vout) {
             CTxDestination address;
             if (ExtractDestination(txout.scriptPubKey, address) &&
                 IsMine(*pwallet, address) && setAddress.count(address)) {
                 if (wtx.GetDepthInMainChain() >= nMinDepth) {
                     nAmount += txout.nValue;
                 }
             }
         }
     }
 
     return ValueFromAmount(nAmount);
 }
 
 static UniValue getbalance(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || (request.params.size() > 3)) {
         throw std::runtime_error(
             (IsDeprecatedRPCEnabled(gArgs, "accounts")
                  ? std::string(
                        "getbalance ( \"account\" minconf include_watchonly )\n"
                        "\nIf account is not specified, returns the server's "
                        "total available balance.\n"
                        "The available balance is what the wallet considers "
                        "currently spendable,\nand is thus affected by options "
                        "which limit spendability such as "
                        "-spendzeroconfchange.\n"
                        "If account is specified (DEPRECATED), returns the "
                        "balance in the account.\n"
                        "Note that the account \"\" is not the same as leaving "
                        "the parameter out.\nThe server total may be different "
                        "to the balance in the default "
                        "\"\" account.\n"
                        "\nArguments:\n"
                        "1. \"account\"         (string, optional) DEPRECATED. "
                        "This argument will be removed in v0.21. \n"
                        "                     To use this deprecated argument, "
                        "start bitcoind with -deprecatedrpc=accounts. The "
                        "account string may be given as a\n"
                        "                     specific account name to find the "
                        "balance associated with wallet keys in\n"
                        "                     a named account, or as the empty "
                        "string (\"\") to find the balance\n"
                        "                     associated with wallet keys not "
                        "in any named account, or as \"*\" to find\n"
                        "                     the balance associated with all "
                        "wallet keys regardless of account.\n"
                        "                     When this option is specified, it "
                        "calculates the balance in a different\n"
                        "                     way than when it is not "
                        "specified, and which can count spends twice when\n"
                        "                     there are conflicting pending "
                        "transactions temporarily resulting in low\n"
                        "                     or even negative balances.\n"
                        "                     In general, account balance "
                        "calculation is not considered reliable and\n"
                        "                     has resulted in confusing "
                        "outcomes, so it is recommended to avoid passing\n"
                        "                     this argument.\n"
                        "2. minconf           (numeric, optional) Only include "
                        "transactions confirmed at least this many times. \n"
                        "                     The default is 1 if an account is "
                        "provided or 0 if no account is provided\n")
                  : std::string(
                        "getbalance ( \"(dummy)\" minconf include_watchonly )\n"
                        "\nReturns the total available balance.\n"
                        "The available balance is what the wallet considers "
                        "currently spendable, and is\n"
                        "thus affected by options which limit spendability such "
                        "as -spendzeroconfchange.\n"
                        "\nArguments:\n"
                        "1. (dummy)           (string, optional) Remains for "
                        "backward compatibility. Must be excluded or set to "
                        "\"*\".\n"
                        "2. minconf           (numeric, optional, default=0) "
                        "Only include transactions confirmed at least this many "
                        "times.\n")) +
             "3. include_watchonly (bool, optional, default=false) Also include "
             "balance in watch-only addresses (see 'importaddress')\n"
             "\nResult:\n"
             "amount              (numeric) The total amount in " +
             CURRENCY_UNIT +
             " received for this account.\n"
             "\nExamples:\n"
             "\nThe total amount in the wallet with 1 or more confirmations\n" +
             HelpExampleCli("getbalance", "") +
             "\nThe total amount in the wallet at least 6 blocks confirmed\n" +
             HelpExampleCli("getbalance", "\"*\" 6") + "\nAs a json rpc call\n" +
             HelpExampleRpc("getbalance", "\"*\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     const UniValue &account_value = request.params[0];
 
     int min_depth = 0;
     if (IsDeprecatedRPCEnabled(gArgs, "accounts") && !account_value.isNull()) {
         // Default min_depth to 1 when an account is provided.
         min_depth = 1;
     }
     if (!request.params[1].isNull()) {
         min_depth = request.params[1].get_int();
     }
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!request.params[2].isNull() && request.params[2].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     if (!account_value.isNull()) {
         const std::string &account_param = account_value.get_str();
         const std::string *account =
             account_param != "*" ? &account_param : nullptr;
 
         if (!IsDeprecatedRPCEnabled(gArgs, "accounts") &&
             account_param != "*") {
             throw JSONRPCError(
                 RPC_METHOD_DEPRECATED,
                 "dummy first argument must be excluded or set to \"*\".");
         } else if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
             return ValueFromAmount(
                 pwallet->GetLegacyBalance(filter, min_depth, account));
         }
     }
 
     return ValueFromAmount(pwallet->GetBalance(filter, min_depth));
 }
 
 static UniValue getunconfirmedbalance(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(
             "getunconfirmedbalance\n"
             "Returns the server's total unconfirmed balance\n");
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     return ValueFromAmount(pwallet->GetUnconfirmedBalance());
 }
 
 static UniValue movecmd(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         if (request.fHelp) {
             throw std::runtime_error(
                 "move (Deprecated, will be removed in v0.21. To use this "
                 "command, start bitcoind with -deprecatedrpc=accounts)");
         }
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "move is deprecated and will be removed in v0.21. To use this "
             "command, start bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() < 3 ||
         request.params.size() > 5) {
         throw std::runtime_error(
             "move \"fromaccount\" \"toaccount\" amount ( minconf \"comment\" "
             ")\n"
             "\nDEPRECATED. Move a specified amount from one account in your "
             "wallet to another.\n"
             "\nArguments:\n"
             "1. \"fromaccount\"   (string, required) The name of the account "
             "to move funds from. May be the default account using \"\".\n"
             "2. \"toaccount\"     (string, required) The name of the account "
             "to move funds to. May be the default account using \"\".\n"
             "3. amount            (numeric) Quantity of " +
             CURRENCY_UNIT +
             " to move between accounts.\n"
             "4. (dummy)           (numeric, optional) Ignored. Remains for "
             "backward compatibility.\n"
             "5. \"comment\"       (string, optional) An optional comment, "
             "stored in the wallet only.\n"
             "\nResult:\n"
             "true|false           (boolean) true if successful.\n"
             "\nExamples:\n"
             "\nMove 0.01 " +
             CURRENCY_UNIT +
             " from the default account to the account named tabby\n" +
             HelpExampleCli("move", "\"\" \"tabby\" 0.01") + "\nMove 0.01 " +
             CURRENCY_UNIT +
             " timotei to akiko with a comment and funds have 6 "
             "confirmations\n" +
             HelpExampleCli("move",
                            "\"timotei\" \"akiko\" 0.01 6 \"happy birthday!\"") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc(
                 "move",
                 "\"timotei\", \"akiko\", 0.01, 6, \"happy birthday!\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::string strFrom = LabelFromValue(request.params[0]);
     std::string strTo = LabelFromValue(request.params[1]);
     Amount nAmount = AmountFromValue(request.params[2]);
     if (nAmount <= Amount::zero()) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
     }
     if (!request.params[3].isNull()) {
         // Unused parameter, used to be nMinDepth, keep type-checking it though.
         (void)request.params[3].get_int();
     }
 
     std::string strComment;
     if (!request.params[4].isNull()) {
         strComment = request.params[4].get_str();
     }
 
     if (!pwallet->AccountMove(strFrom, strTo, nAmount, strComment)) {
         throw JSONRPCError(RPC_DATABASE_ERROR, "database error");
     }
 
     return true;
 }
 
 static UniValue sendfrom(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         if (request.fHelp) {
             throw std::runtime_error(
                 "sendfrom (Deprecated, will be removed in V0.21. To use this "
                 "command, start bitcoind with -deprecatedrpc=accounts)");
         }
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "sendfrom is deprecated and will be removed in V0.21. To use this "
             "command, start bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() < 3 ||
         request.params.size() > 6) {
         throw std::runtime_error(
             "sendfrom \"fromaccount\" \"toaddress\" amount ( minconf "
             "\"comment\" \"comment_to\" )\n"
             "\nDEPRECATED (use sendtoaddress). Sent an amount from an account "
             "to a bitcoin address." +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments:\n"
             "1. \"fromaccount\"       (string, required) The name of the "
             "account to send funds from. May be the default account using "
             "\"\".\n"
             "                       Specifying an account does not influence "
             "coin selection, but it does associate the newly created\n"
             "                       transaction with the account, so the "
             "account's balance computation and transaction history can "
             "reflect\n"
             "                       the spend.\n"
             "2. \"toaddress\"         (string, required) The bitcoin address "
             "to send funds to.\n"
             "3. amount                (numeric or string, required) The amount "
             "in " +
             CURRENCY_UNIT +
             " (transaction fee is added on top).\n"
             "4. minconf               (numeric, optional, default=1) Only use "
             "funds with at least this many confirmations.\n"
             "5. \"comment\"           (string, optional) A comment used to "
             "store what the transaction is for. \n"
             "                                     This is not part of the "
             "transaction, just kept in your wallet.\n"
             "6. \"comment_to\"        (string, optional) An optional comment "
             "to store the name of the person or organization \n"
             "                                     to which you're sending the "
             "transaction. This is not part of the transaction, \n"
             "                                     it is just kept in your "
             "wallet.\n"
             "\nResult:\n"
             "\"txid\"                 (string) The transaction id.\n"
             "\nExamples:\n"
             "\nSend 0.01 " +
             CURRENCY_UNIT +
             " from the default account to the address, must have at least 1 "
             "confirmation\n" +
             HelpExampleCli("sendfrom",
                            "\"\" \"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 0.01") +
             "\nSend 0.01 from the tabby account to the given address, funds "
             "must have at least 6 confirmations\n" +
             HelpExampleCli("sendfrom",
                            "\"tabby\" \"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" "
                            "0.01 6 \"donation\" \"seans outpost\"") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("sendfrom",
                            "\"tabby\", \"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\", "
                            "0.01, 6, \"donation\", \"seans outpost\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::string label = LabelFromValue(request.params[0]);
     CTxDestination dest =
         DecodeDestination(request.params[1].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
     Amount nAmount = AmountFromValue(request.params[2]);
     if (nAmount <= Amount::zero()) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
     }
 
     int nMinDepth = 1;
     if (!request.params[3].isNull()) {
         nMinDepth = request.params[3].get_int();
     }
 
     mapValue_t mapValue;
     if (!request.params[4].isNull() && !request.params[4].get_str().empty()) {
         mapValue["comment"] = request.params[4].get_str();
     }
 
     if (!request.params[5].isNull() && !request.params[5].get_str().empty()) {
         mapValue["to"] = request.params[5].get_str();
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     // Check funds
     Amount nBalance =
         pwallet->GetLegacyBalance(ISMINE_SPENDABLE, nMinDepth, &label);
     if (nAmount > nBalance) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS,
                            "Account has insufficient funds");
     }
 
     CTransactionRef tx = SendMoney(pwallet, dest, nAmount, false,
                                    std::move(mapValue), std::move(label));
     return tx->GetId().GetHex();
 }
 
 static UniValue sendmany(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     std::string help_text;
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         help_text =
             "sendmany \"fromaccount\" {\"address\":amount,...} ( minconf "
             "\"comment\" [\"address\",...] )\n"
             "\nSend multiple times. Amounts are double-precision floating "
             "point numbers.\n"
             "Note that the \"fromaccount\" argument has been removed in V0.20. "
             "To use this RPC with a \"fromaccount\" argument, restart\n"
             "bitcoind with -deprecatedrpc=accounts\n" +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments:\n"
             "1. \"dummy\"               (string, required) Must be set to \"\" "
             "for backwards compatibility.\n"
             "2. \"amounts\"             (string, required) A json object with "
             "addresses and amounts\n"
             "    {\n"
             "      \"address\":amount   (numeric or string) The bitcoin "
             "address is the key, the numeric amount (can be string) in " +
             CURRENCY_UNIT +
             " is the value\n"
             "      ,...\n"
             "    }\n"
             "3. minconf                 (numeric, optional, default=1) Only "
             "use the balance confirmed at least this many times.\n"
             "4. \"comment\"             (string, optional) A comment\n"
             "5. subtractfeefrom         (array, optional) A json array with "
             "addresses.\n"
             "                           The fee will be equally deducted from "
             "the amount of each selected address.\n"
             "                           Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                           If no addresses are specified here, "
             "the sender pays the fee.\n"
             "    [\n"
             "      \"address\"          (string) Subtract fee from this "
             "address\n"
             "      ,...\n"
             "    ]\n"
             "\nResult:\n"
             "\"txid\"                   (string) The transaction id for the "
             "send. Only 1 transaction is created regardless of \n"
             "                                    the number of addresses.\n"
             "\nExamples:\n"
             "\nSend two amounts to two different addresses:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}"
                            "\"") +
             "\nSend two amounts to two different addresses setting the "
             "confirmation and comment:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\" "
                            "6 \"testing\"") +
             "\nSend two amounts to two different addresses, subtract fee from "
             "amount:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\" "
                            "1 \"\" "
                            "\"[\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\","
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\"]\"") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("sendmany",
                            "\"\", "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\","
                            " 6, \"testing\"");
     } else {
         help_text =
             "sendmany \"\" \"fromaccount\" {\"address\":amount,...} ( "
             "minconf \"comment\" [\"address\",...])\n"
             "\nSend multiple times. Amounts are double-precision floating "
             "point numbers." +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments:\n"
             "1. \"fromaccount\"         (string, required) DEPRECATED. The "
             "account to send the funds from. Should be \"\" for the default "
             "account\n"
             "2. \"amounts\"             (string, required) A json object with "
             "addresses and amounts\n"
             "    {\n"
             "      \"address\":amount   (numeric or string) The bitcoin "
             "address is the key, the numeric amount (can be string) in " +
             CURRENCY_UNIT +
             " is the value\n"
             "      ,...\n"
             "    }\n"
             "3. minconf                 (numeric, optional, default=1) Only "
             "use the balance confirmed at least this many times.\n"
             "4. \"comment\"             (string, optional) A comment\n"
             "5. subtractfeefrom         (array, optional) A json array with "
             "addresses.\n"
             "                           The fee will be equally deducted from "
             "the amount of each selected address.\n"
             "                           Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                           If no addresses are specified here, "
             "the sender pays the fee.\n"
             "    [\n"
             "      \"address\"          (string) Subtract fee from this "
             "address\n"
             "      ,...\n"
             "    ]\n"
             "\nResult:\n"
             "\"txid\"                   (string) The transaction id for the "
             "send. Only 1 transaction is created regardless of \n"
             "                                    the number of addresses.\n"
             "\nExamples:\n"
             "\nSend two amounts to two different addresses:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}"
                            "\"") +
             "\nSend two amounts to two different addresses setting the "
             "confirmation and comment:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\" "
                            "6 \"testing\"") +
             "\nSend two amounts to two different addresses, subtract fee from "
             "amount:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\" "
                            "1 \"\" "
                            "\"[\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\","
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\"]\"") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("sendmany",
                            "\"\", "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\","
                            " 6, \"testing\"");
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 5) {
         throw std::runtime_error(help_text);
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (pwallet->GetBroadcastTransactions() && !g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts") &&
         !request.params[0].get_str().empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Dummy value must be set to \"\"");
     }
     std::string strAccount = LabelFromValue(request.params[0]);
     UniValue sendTo = request.params[1].get_obj();
     int nMinDepth = 1;
     if (!request.params[2].isNull()) {
         nMinDepth = request.params[2].get_int();
     }
 
     mapValue_t mapValue;
     if (!request.params[3].isNull() && !request.params[3].get_str().empty()) {
         mapValue["comment"] = request.params[3].get_str();
     }
 
     UniValue subtractFeeFromAmount(UniValue::VARR);
     if (!request.params[4].isNull()) {
         subtractFeeFromAmount = request.params[4].get_array();
     }
 
     std::set<CTxDestination> destinations;
     std::vector<CRecipient> vecSend;
 
     Amount totalAmount = Amount::zero();
     std::vector<std::string> keys = sendTo.getKeys();
     for (const std::string &name_ : keys) {
         CTxDestination dest = DecodeDestination(name_, config.GetChainParams());
         if (!IsValidDestination(dest)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                std::string("Invalid Bitcoin address: ") +
                                    name_);
         }
 
         if (destinations.count(dest)) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 std::string("Invalid parameter, duplicated address: ") + name_);
         }
         destinations.insert(dest);
 
         CScript scriptPubKey = GetScriptForDestination(dest);
         Amount nAmount = AmountFromValue(sendTo[name_]);
         if (nAmount <= Amount::zero()) {
             throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
         }
         totalAmount += nAmount;
 
         bool fSubtractFeeFromAmount = false;
         for (size_t idx = 0; idx < subtractFeeFromAmount.size(); idx++) {
             const UniValue &addr = subtractFeeFromAmount[idx];
             if (addr.get_str() == name_) {
                 fSubtractFeeFromAmount = true;
             }
         }
 
         CRecipient recipient = {scriptPubKey, nAmount, fSubtractFeeFromAmount};
         vecSend.push_back(recipient);
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     // Check funds
     if (IsDeprecatedRPCEnabled(gArgs, "accounts") &&
         totalAmount > pwallet->GetLegacyBalance(ISMINE_SPENDABLE, nMinDepth,
                                                 &strAccount)) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS,
                            "Account has insufficient funds");
     } else if (!IsDeprecatedRPCEnabled(gArgs, "accounts") &&
                totalAmount > pwallet->GetLegacyBalance(ISMINE_SPENDABLE,
                                                        nMinDepth, nullptr)) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS,
                            "Wallet has insufficient funds");
     }
 
     // Shuffle recipient list
     std::shuffle(vecSend.begin(), vecSend.end(), FastRandomContext());
 
     // Send
     CReserveKey keyChange(pwallet);
     Amount nFeeRequired = Amount::zero();
     int nChangePosRet = -1;
     std::string strFailReason;
     CTransactionRef tx;
     CCoinControl coinControl;
     bool fCreated =
         pwallet->CreateTransaction(vecSend, tx, keyChange, nFeeRequired,
                                    nChangePosRet, strFailReason, coinControl);
     if (!fCreated) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, strFailReason);
     }
     CValidationState state;
     if (!pwallet->CommitTransaction(tx, std::move(mapValue), {} /* orderForm */,
                                     std::move(strAccount), keyChange,
                                     g_connman.get(), state)) {
         strFailReason = strprintf("Transaction commit failed:: %s",
                                   FormatStateMessage(state));
         throw JSONRPCError(RPC_WALLET_ERROR, strFailReason);
     }
 
     return tx->GetId().GetHex();
 }
 
 static UniValue addmultisigaddress(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 3) {
         std::string msg =
             "addmultisigaddress nrequired [\"key\",...] ( \"label\" )\n"
             "\nAdd a nrequired-to-sign multisignature address to the wallet. "
             "Requires a new wallet backup.\n"
             "Each key is a Bitcoin address or hex-encoded public key.\n"
             "If 'label' is specified (DEPRECATED), assign address to that "
             "label.\n"
 
             "\nArguments:\n"
             "1. nrequired        (numeric, required) The number of required "
             "signatures out of the n keys or addresses.\n"
             "2. \"keys\"         (string, required) A json array of bitcoin "
             "addresses or hex-encoded public keys\n"
             "     [\n"
             "       \"address\"  (string) bitcoin address or hex-encoded "
             "public key\n"
             "       ...,\n"
             "     ]\n"
             "3. \"label\"                        (string, optional) A label to "
             "assign the addresses to.\n"
 
             "\nResult:\n"
             "{\n"
             "  \"address\":\"multisigaddress\",    (string) The value of the "
             "new multisig address.\n"
             "  \"redeemScript\":\"script\"         (string) The string value "
             "of the hex-encoded redemption script.\n"
             "}\n"
 
             "\nExamples:\n"
             "\nAdd a multisig address from 2 addresses\n" +
             HelpExampleCli("addmultisigaddress",
                            "2 "
                            "\"[\\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\\","
                            "\\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\\"]\"") +
             "\nAs json rpc call\n" +
             HelpExampleRpc("addmultisigaddress",
                            "2, "
                            "\"[\\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\\","
                            "\\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\\"]\"");
         throw std::runtime_error(msg);
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::string label;
     if (!request.params[2].isNull()) {
         label = LabelFromValue(request.params[2]);
     }
 
     int required = request.params[0].get_int();
 
     // Get the public keys
     const UniValue &keys_or_addrs = request.params[1].get_array();
     std::vector<CPubKey> pubkeys;
     for (size_t i = 0; i < keys_or_addrs.size(); ++i) {
         if (IsHex(keys_or_addrs[i].get_str()) &&
             (keys_or_addrs[i].get_str().length() == 66 ||
              keys_or_addrs[i].get_str().length() == 130)) {
             pubkeys.push_back(HexToPubKey(keys_or_addrs[i].get_str()));
         } else {
             pubkeys.push_back(AddrToPubKey(config.GetChainParams(), pwallet,
                                            keys_or_addrs[i].get_str()));
         }
     }
 
     OutputType output_type = pwallet->m_default_address_type;
 
     // Construct using pay-to-script-hash:
     CScript inner = CreateMultisigRedeemscript(required, pubkeys);
     CTxDestination dest =
         AddAndGetDestinationForScript(*pwallet, inner, output_type);
     pwallet->SetAddressBook(dest, label, "send");
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("address", EncodeDestination(dest, config));
     result.pushKV("redeemScript", HexStr(inner.begin(), inner.end()));
     return result;
 }
 
 struct tallyitem {
     Amount nAmount{Amount::zero()};
     int nConf{std::numeric_limits<int>::max()};
     std::vector<uint256> txids;
     bool fIsWatchonly{false};
     tallyitem() {}
 };
 
 static UniValue ListReceived(const Config &config, CWallet *const pwallet,
                              const UniValue &params, bool by_label)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main, pwallet->cs_wallet) {
     // Minimum confirmations
     int nMinDepth = 1;
     if (!params[0].isNull()) {
         nMinDepth = params[0].get_int();
     }
 
     // Whether to include empty labels
     bool fIncludeEmpty = false;
     if (!params[1].isNull()) {
         fIncludeEmpty = params[1].get_bool();
     }
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!params[2].isNull() && params[2].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     bool has_filtered_address = false;
     CTxDestination filtered_address = CNoDestination();
     if (!by_label && params.size() > 3) {
         if (!IsValidDestinationString(params[3].get_str(),
                                       config.GetChainParams())) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "address_filter parameter was invalid");
         }
         filtered_address =
             DecodeDestination(params[3].get_str(), config.GetChainParams());
         has_filtered_address = true;
     }
 
     // Tally
     std::map<CTxDestination, tallyitem> mapTally;
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
 
         CValidationState state;
         if (wtx.IsCoinBase() ||
             !ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), *wtx.tx, state)) {
             continue;
         }
 
         int nDepth = wtx.GetDepthInMainChain();
         if (nDepth < nMinDepth) {
             continue;
         }
 
         for (const CTxOut &txout : wtx.tx->vout) {
             CTxDestination address;
             if (!ExtractDestination(txout.scriptPubKey, address)) {
                 continue;
             }
 
             if (has_filtered_address && !(filtered_address == address)) {
                 continue;
             }
 
             isminefilter mine = IsMine(*pwallet, address);
             if (!(mine & filter)) {
                 continue;
             }
 
             tallyitem &item = mapTally[address];
             item.nAmount += txout.nValue;
             item.nConf = std::min(item.nConf, nDepth);
             item.txids.push_back(wtx.GetId());
             if (mine & ISMINE_WATCH_ONLY) {
                 item.fIsWatchonly = true;
             }
         }
     }
 
     // Reply
     UniValue ret(UniValue::VARR);
     std::map<std::string, tallyitem> label_tally;
 
     // Create mapAddressBook iterator
     // If we aren't filtering, go from begin() to end()
     auto start = pwallet->mapAddressBook.begin();
     auto end = pwallet->mapAddressBook.end();
     // If we are filtering, find() the applicable entry
     if (has_filtered_address) {
         start = pwallet->mapAddressBook.find(filtered_address);
         if (start != end) {
             end = std::next(start);
         }
     }
 
     for (auto item_it = start; item_it != end; ++item_it) {
         const CTxDestination &address = item_it->first;
         const std::string &label = item_it->second.name;
         std::map<CTxDestination, tallyitem>::iterator it =
             mapTally.find(address);
         if (it == mapTally.end() && !fIncludeEmpty) {
             continue;
         }
 
         Amount nAmount = Amount::zero();
         int nConf = std::numeric_limits<int>::max();
         bool fIsWatchonly = false;
         if (it != mapTally.end()) {
             nAmount = (*it).second.nAmount;
             nConf = (*it).second.nConf;
             fIsWatchonly = (*it).second.fIsWatchonly;
         }
 
         if (by_label) {
             tallyitem &_item = label_tally[label];
             _item.nAmount += nAmount;
             _item.nConf = std::min(_item.nConf, nConf);
             _item.fIsWatchonly = fIsWatchonly;
         } else {
             UniValue obj(UniValue::VOBJ);
             if (fIsWatchonly) {
                 obj.pushKV("involvesWatchonly", true);
             }
             obj.pushKV("address", EncodeDestination(address, config));
             obj.pushKV("account", label);
             obj.pushKV("amount", ValueFromAmount(nAmount));
             obj.pushKV("confirmations",
                        (nConf == std::numeric_limits<int>::max() ? 0 : nConf));
             obj.pushKV("label", label);
             UniValue transactions(UniValue::VARR);
             if (it != mapTally.end()) {
                 for (const uint256 &_item : (*it).second.txids) {
                     transactions.push_back(_item.GetHex());
                 }
             }
             obj.pushKV("txids", transactions);
             ret.push_back(obj);
         }
     }
 
     if (by_label) {
         for (const auto &entry : label_tally) {
             Amount nAmount = entry.second.nAmount;
             int nConf = entry.second.nConf;
             UniValue obj(UniValue::VOBJ);
             if (entry.second.fIsWatchonly) {
                 obj.pushKV("involvesWatchonly", true);
             }
             obj.pushKV("account", entry.first);
             obj.pushKV("amount", ValueFromAmount(nAmount));
             obj.pushKV("confirmations",
                        (nConf == std::numeric_limits<int>::max() ? 0 : nConf));
             obj.pushKV("label", entry.first);
             ret.push_back(obj);
         }
     }
 
     return ret;
 }
 
 static UniValue listreceivedbyaddress(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 4) {
         throw std::runtime_error(
             "listreceivedbyaddress ( minconf include_empty include_watchonly "
             "address_filter )\n"
             "\nList balances by receiving address.\n"
             "\nArguments:\n"
             "1. minconf           (numeric, optional, default=1) The minimum "
             "number of confirmations before payments are included.\n"
             "2. include_empty     (bool, optional, default=false) Whether to "
             "include addresses that haven't received any payments.\n"
             "3. include_watchonly (bool, optional, default=false) Whether to "
             "include watch-only addresses (see 'importaddress').\n"
             "4. address_filter    (string, optional) If present, only return "
             "information on this address.\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"involvesWatchonly\" : true,        (bool) Only returned if "
             "imported addresses were involved in transaction\n"
             "    \"address\" : \"receivingaddress\",  (string) The receiving "
             "address\n"
             "    \"account\" : \"accountname\",       (string) DEPRECATED. "
             "Backwards compatible alias for label.\n \"\".\n"
             "    \"amount\" : x.xxx,                  (numeric) The total "
             "amount in " +
             CURRENCY_UNIT +
             " received by the address\n"
             "    \"confirmations\" : n,               (numeric) The number of "
             "confirmations of the most recent transaction included\n"
             "    \"label\" : \"label\",               (string) The label of "
             "the receiving address. The default label is \"\".\n"
             "    \"txids\": [\n"
             "       \"txid\",                         (string) The ids of "
             "transactions received with the address \n"
             "       ...\n"
             "    ]\n"
             "  }\n"
             "  ,...\n"
             "]\n"
 
             "\nExamples:\n" +
             HelpExampleCli("listreceivedbyaddress", "") +
             HelpExampleCli("listreceivedbyaddress", "6 true") +
             HelpExampleRpc("listreceivedbyaddress", "6, true, true") +
             HelpExampleRpc(
                 "listreceivedbyaddress",
                 "6, true, true, \"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
+
     return ListReceived(config, pwallet, request.params, false);
 }
 
 static UniValue listreceivedbylabel(const Config &config,
                                     const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts") &&
         request.strMethod == "listreceivedbyaccount") {
         if (request.fHelp) {
             throw std::runtime_error(
                 "listreceivedbyaccount (Deprecated, will be removed in v0.21. "
                 "To use this command, start bitcoind with "
                 "-deprecatedrpc=accounts)");
         }
         throw JSONRPCError(RPC_METHOD_DEPRECATED,
                            "listreceivedbyaccount is deprecated and will be "
                            "removed in v0.21. To use this command, start "
                            "bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() > 3) {
         throw std::runtime_error(
             "listreceivedbylabel ( minconf include_empty include_watchonly)\n"
             "\nList received transactions by label.\n"
             "\nArguments:\n"
             "1. minconf           (numeric, optional, default=1) The minimum "
             "number of confirmations before payments are included.\n"
             "2. include_empty     (bool, optional, default=false) Whether to "
             "include labels that haven't received any payments.\n"
             "3. include_watchonly (bool, optional, default=false) Whether to "
             "include watch-only addresses (see 'importaddress').\n"
 
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"involvesWatchonly\" : true,   (bool) Only returned if "
             "imported addresses were involved in transaction\n"
             "    \"account\" : \"accountname\",  (string) DEPRECATED. "
             "Backwards compatible alias for label.\n"
             "    \"amount\" : x.xxx,             (numeric) The total amount "
             "received by addresses with this label\n"
             "    \"confirmations\" : n,          (numeric) The number of "
             "confirmations of the most recent transaction included\n"
             "    \"label\" : \"label\"           (string) The label of the "
             "receiving address. The default label is \"\".\n"
             "  }\n"
             "  ,...\n"
             "]\n"
 
             "\nExamples:\n" +
             HelpExampleCli("listreceivedbylabel", "") +
             HelpExampleCli("listreceivedbylabel", "6 true") +
             HelpExampleRpc("listreceivedbylabel", "6, true, true"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     return ListReceived(config, pwallet, request.params, true);
 }
 
 static void MaybePushAddress(UniValue &entry, const CTxDestination &dest) {
     if (IsValidDestination(dest)) {
         entry.pushKV("address", EncodeDestination(dest, GetConfig()));
     }
 }
 
 /**
  * List transactions based on the given criteria.
  *
  * @param  pwallet    The wallet.
  * @param  wtx        The wallet transaction.
  * @param  strAccount The account, if any, or "*" for all.
  * @param  nMinDepth  The minimum confirmation depth.
  * @param  fLong      Whether to include the JSON version of the transaction.
  * @param  ret        The UniValue into which the result is stored.
  * @param  filter     The "is mine" filter bool.
  */
 static void ListTransactions(CWallet *const pwallet, const CWalletTx &wtx,
                              const std::string &strAccount, int nMinDepth,
                              bool fLong, UniValue &ret,
                              const isminefilter &filter)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     Amount nFee;
     std::string strSentAccount;
     std::list<COutputEntry> listReceived;
     std::list<COutputEntry> listSent;
 
     wtx.GetAmounts(listReceived, listSent, nFee, strSentAccount, filter);
 
     bool fAllAccounts = (strAccount == std::string("*"));
     bool involvesWatchonly = wtx.IsFromMe(ISMINE_WATCH_ONLY);
 
     // Sent
     if ((!listSent.empty() || nFee != Amount::zero()) &&
         (fAllAccounts || strAccount == strSentAccount)) {
         for (const COutputEntry &s : listSent) {
             UniValue entry(UniValue::VOBJ);
             if (involvesWatchonly ||
                 (::IsMine(*pwallet, s.destination) & ISMINE_WATCH_ONLY)) {
                 entry.pushKV("involvesWatchonly", true);
             }
             if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
                 entry.pushKV("account", strSentAccount);
             }
             MaybePushAddress(entry, s.destination);
             entry.pushKV("category", "send");
             entry.pushKV("amount", ValueFromAmount(-s.amount));
             if (pwallet->mapAddressBook.count(s.destination)) {
                 entry.pushKV("label",
                              pwallet->mapAddressBook[s.destination].name);
             }
             entry.pushKV("vout", s.vout);
             entry.pushKV("fee", ValueFromAmount(-1 * nFee));
             if (fLong) {
                 WalletTxToJSON(pwallet->chain(), wtx, entry);
             }
             entry.pushKV("abandoned", wtx.isAbandoned());
             ret.push_back(entry);
         }
     }
 
     // Received
     if (listReceived.size() > 0 && wtx.GetDepthInMainChain() >= nMinDepth) {
         for (const COutputEntry &r : listReceived) {
             std::string account;
             if (pwallet->mapAddressBook.count(r.destination)) {
                 account = pwallet->mapAddressBook[r.destination].name;
             }
             if (fAllAccounts || (account == strAccount)) {
                 UniValue entry(UniValue::VOBJ);
                 if (involvesWatchonly ||
                     (::IsMine(*pwallet, r.destination) & ISMINE_WATCH_ONLY)) {
                     entry.pushKV("involvesWatchonly", true);
                 }
                 if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
                     entry.pushKV("account", account);
                 }
                 MaybePushAddress(entry, r.destination);
                 if (wtx.IsCoinBase()) {
                     if (wtx.GetDepthInMainChain() < 1) {
                         entry.pushKV("category", "orphan");
                     } else if (wtx.IsImmatureCoinBase()) {
                         entry.pushKV("category", "immature");
                     } else {
                         entry.pushKV("category", "generate");
                     }
                 } else {
                     entry.pushKV("category", "receive");
                 }
                 entry.pushKV("amount", ValueFromAmount(r.amount));
                 if (pwallet->mapAddressBook.count(r.destination)) {
                     entry.pushKV("label", account);
                 }
                 entry.pushKV("vout", r.vout);
                 if (fLong) {
                     WalletTxToJSON(pwallet->chain(), wtx, entry);
                 }
                 ret.push_back(entry);
             }
         }
     }
 }
 
 static void AcentryToJSON(const CAccountingEntry &acentry,
                           const std::string &strAccount, UniValue &ret) {
     bool fAllAccounts = (strAccount == std::string("*"));
 
     if (fAllAccounts || acentry.strAccount == strAccount) {
         UniValue entry(UniValue::VOBJ);
         entry.pushKV("account", acentry.strAccount);
         entry.pushKV("category", "move");
         entry.pushKV("time", acentry.nTime);
         entry.pushKV("amount", ValueFromAmount(acentry.nCreditDebit));
         if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
             entry.pushKV("otheraccount", acentry.strOtherAccount);
         }
         entry.pushKV("comment", acentry.strComment);
         ret.push_back(entry);
     }
 }
 
 UniValue listtransactions(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     std::string help_text{};
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         help_text =
             "listtransactions (dummy count skip include_watchonly)\n"
             "\nReturns up to 'count' most recent transactions skipping the "
             "first 'from' transactions for account 'account'.\n"
             "Note that the \"account\" argument and \"otheraccount\" return "
             "value have been removed in V0.20. To use this RPC with an "
             "\"account\" argument, restart\n"
             "bitcoind with -deprecatedrpc=accounts\n"
             "\nArguments:\n"
             "1. \"dummy\"    (string, optional) If set, should be \"*\" for "
             "backwards compatibility.\n"
             "2. count          (numeric, optional, default=10) The number of "
             "transactions to return\n"
             "3. skip           (numeric, optional, default=0) The number of "
             "transactions to skip\n"
             "4. include_watchonly (bool, optional, default=false) Include "
             "transactions to watch-only addresses (see 'importaddress')\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"address\":\"address\",    (string) The bitcoin address of "
             "the transaction.\n"
             "    \"category\":\"send|receive\", (string) The transaction "
             "category.\n"
             "    \"amount\": x.xxx,          (numeric) The amount in " +
             CURRENCY_UNIT +
             ". This is negative for the 'send' category, and is positive\n"
             "                                        for the 'receive' "
             "category,\n"
             "    \"label\": \"label\",       (string) A comment for the "
             "address/transaction, if any\n"
             "    \"vout\": n,                (numeric) the vout value\n"
             "    \"fee\": x.xxx,             (numeric) The amount of the fee "
             "in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                                         'send' category of "
             "transactions.\n"
             "    \"confirmations\": n,       (numeric) The number of "
             "confirmations for the transaction. Negative confirmations "
             "indicate the\n"
             "                                         transaction conflicts "
             "with the block chain\n"
             "    \"trusted\": xxx,           (bool) Whether we consider the "
             "outputs of this unconfirmed transaction safe to spend.\n"
             "    \"blockhash\": \"hashvalue\", (string) The block hash "
             "containing the transaction.\n"
             "    \"blockindex\": n,          (numeric) The index of the "
             "transaction in the block that includes it.\n"
             "    \"blocktime\": xxx,         (numeric) The block time in "
             "seconds since epoch (1 Jan 1970 GMT).\n"
             "    \"txid\": \"transactionid\", (string) The transaction id.\n"
             "    \"time\": xxx,              (numeric) The transaction time in "
             "seconds since epoch (midnight Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in "
             "seconds since epoch (midnight Jan 1 1970 GMT).\n"
             "    \"comment\": \"...\",       (string) If a comment is "
             "associated with the transaction.\n"
             "    \"abandoned\": xxx          (bool) 'true' if the transaction "
             "has been abandoned (inputs are respendable). Only available for "
             "the \n"
             "                                         'send' category of "
             "transactions.\n"
             "  }\n"
             "]\n"
 
             "\nExamples:\n"
             "\nList the most recent 10 transactions in the systems\n" +
             HelpExampleCli("listtransactions", "") +
             "\nList transactions 100 to 120\n" +
             HelpExampleCli("listtransactions", "\"*\" 20 100") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("listtransactions", "\"*\", 20, 100");
     } else {
         help_text =
             "listtransactions ( \"account\" count skip include_watchonly)\n"
             "\nReturns up to 'count' most recent transactions skipping the "
             "first 'from' transactions for account 'account'.\n"
             "\nArguments:\n"
             "1. \"account\"    (string, optional) DEPRECATED. This argument "
             "will be removed in V0.21. The account name. Should be \"*\".\n"
             "2. count          (numeric, optional, default=10) The number of "
             "transactions to return\n"
             "3. skip           (numeric, optional, default=0) The number of "
             "transactions to skip\n"
             "4. include_watchonly (bool, optional, default=false) Include "
             "transactions to watch-only addresses (see 'importaddress')\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"account\":\"accountname\",       (string) DEPRECATED. This "
             "field will be removed in V0.21. The account name associated with "
             "the transaction. \n"
             "                                                It will be \"\" "
             "for the default account.\n"
             "    \"address\":\"address\",    (string) The bitcoin address of "
             "the transaction. Not present for \n"
             "                                                move transactions "
             "(category = move).\n"
             "    \"category\":\"send|receive|move\", (string) The transaction "
             "category. 'move' is a local (off blockchain)\n"
             "                                                transaction "
             "between accounts, and not associated with an address,\n"
             "                                                transaction id or "
             "block. 'send' and 'receive' transactions are \n"
             "                                                associated with "
             "an address, transaction id and block details\n"
             "    \"amount\": x.xxx,          (numeric) The amount in " +
             CURRENCY_UNIT +
             ". This is negative for the 'send' category, and for the\n"
             "                                         'move' category for "
             "moves outbound. It is positive for the 'receive' category,\n"
             "                                         and for the 'move' "
             "category for inbound funds.\n"
             "    \"label\": \"label\",       (string) A comment for the "
             "address/transaction, if any\n"
             "    \"vout\": n,                (numeric) the vout value\n"
             "    \"fee\": x.xxx,             (numeric) The amount of the fee "
             "in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                                         'send' category of "
             "transactions.\n"
             "    \"confirmations\": n,       (numeric) The number of "
             "confirmations for the transaction. Available for 'send' and \n"
             "                                         'receive' category of "
             "transactions. Negative confirmations indicate the\n"
             "                                         transaction conflicts "
             "with the block chain\n"
             "    \"trusted\": xxx,           (bool) Whether we consider the "
             "outputs of this unconfirmed transaction safe to spend.\n"
             "    \"blockhash\": \"hashvalue\", (string) The block hash "
             "containing the transaction. Available for 'send' and 'receive'\n"
             "                                          category of "
             "transactions.\n"
             "    \"blockindex\": n,          (numeric) The index of the "
             "transaction in the block that includes it. Available for 'send' "
             "and 'receive'\n"
             "                                          category of "
             "transactions.\n"
             "    \"blocktime\": xxx,         (numeric) The block time in "
             "seconds since epoch (1 Jan 1970 GMT).\n"
             "    \"txid\": \"transactionid\", (string) The transaction id. "
             "Available for 'send' and 'receive' category of transactions.\n"
             "    \"time\": xxx,              (numeric) The transaction time in "
             "seconds since epoch (midnight Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in "
             "seconds since epoch (midnight Jan 1 1970 GMT). Available \n"
             "                                          for 'send' and "
             "'receive' category of transactions.\n"
             "    \"comment\": \"...\",       (string) If a comment is "
             "associated with the transaction.\n"
             "    \"otheraccount\": \"accountname\",  (string) DEPRECATED. This "
             "field will be removed in V0.21. For the 'move' category of "
             "transactions, the account the funds came \n"
             "                                          from (for receiving "
             "funds, positive amounts), or went to (for sending funds,\n"
             "                                          negative amounts).\n"
             "    \"abandoned\": xxx          (bool) 'true' if the transaction "
             "has been abandoned (inputs are respendable). Only available for "
             "the \n"
             "                                         'send' category of "
             "transactions.\n"
             "  }\n"
             "]\n"
 
             "\nExamples:\n"
             "\nList the most recent 10 transactions in the systems\n" +
             HelpExampleCli("listtransactions", "") +
             "\nList transactions 100 to 120\n" +
             HelpExampleCli("listtransactions", "\"*\" 20 100") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("listtransactions", "\"*\", 20, 100");
     }
     if (request.fHelp || request.params.size() > 4) {
         throw std::runtime_error(help_text);
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::string strAccount = "*";
     if (!request.params[0].isNull()) {
         strAccount = request.params[0].get_str();
         if (!IsDeprecatedRPCEnabled(gArgs, "accounts") && strAccount != "*") {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Dummy value must be set to \"*\"");
         }
     }
     int nCount = 10;
     if (!request.params[1].isNull()) {
         nCount = request.params[1].get_int();
     }
 
     int nFrom = 0;
     if (!request.params[2].isNull()) {
         nFrom = request.params[2].get_int();
     }
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!request.params[3].isNull() && request.params[3].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     if (nCount < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative count");
     }
     if (nFrom < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative from");
     }
     UniValue ret(UniValue::VARR);
 
     const CWallet::TxItems &txOrdered = pwallet->wtxOrdered;
 
     // iterate backwards until we have nCount items to return:
     for (CWallet::TxItems::const_reverse_iterator it = txOrdered.rbegin();
          it != txOrdered.rend(); ++it) {
         CWalletTx *const pwtx = (*it).second.first;
         if (pwtx != nullptr) {
             ListTransactions(pwallet, *pwtx, strAccount, 0, true, ret, filter);
         }
         if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
             CAccountingEntry *const pacentry = (*it).second.second;
             if (pacentry != nullptr) {
                 AcentryToJSON(*pacentry, strAccount, ret);
             }
         }
 
         if ((int)ret.size() >= (nCount + nFrom)) {
             break;
         }
     }
 
     // ret is newest to oldest
 
     if (nFrom > (int)ret.size()) {
         nFrom = ret.size();
     }
     if ((nFrom + nCount) > (int)ret.size()) {
         nCount = ret.size() - nFrom;
     }
 
     std::vector<UniValue> arrTmp = ret.getValues();
 
     std::vector<UniValue>::iterator first = arrTmp.begin();
     std::advance(first, nFrom);
     std::vector<UniValue>::iterator last = arrTmp.begin();
     std::advance(last, nFrom + nCount);
 
     if (last != arrTmp.end()) {
         arrTmp.erase(last, arrTmp.end());
     }
     if (first != arrTmp.begin()) {
         arrTmp.erase(arrTmp.begin(), first);
     }
 
     // Return oldest to newest
     std::reverse(arrTmp.begin(), arrTmp.end());
 
     ret.clear();
     ret.setArray();
     ret.push_backV(arrTmp);
 
     return ret;
 }
 
 static UniValue listaccounts(const Config &config,
                              const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!IsDeprecatedRPCEnabled(gArgs, "accounts")) {
         if (request.fHelp) {
             throw std::runtime_error(
                 "listaccounts (Deprecated, will be removed in v0.21. To use "
                 "this command, start bitcoind with -deprecatedrpc=accounts)");
         }
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "listaccounts is deprecated and will be removed in v0.21. To use "
             "this command, start bitcoind with -deprecatedrpc=accounts.");
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "listaccounts ( minconf include_watchonly)\n"
             "\nDEPRECATED. Returns Object that has account names as keys, "
             "account balances as values.\n"
             "\nArguments:\n"
             "1. minconf             (numeric, optional, default=1) Only "
             "include transactions with at least this many confirmations\n"
             "2. include_watchonly   (bool, optional, default=false) Include "
             "balances in watch-only addresses (see 'importaddress')\n"
             "\nResult:\n"
             "{                      (json object where keys are account names, "
             "and values are numeric balances\n"
             "  \"account\": x.xxx,  (numeric) The property name is the account "
             "name, and the value is the total balance for the account.\n"
             "  ...\n"
             "}\n"
             "\nExamples:\n"
             "\nList account balances where there at least 1 confirmation\n" +
             HelpExampleCli("listaccounts", "") +
             "\nList account balances including zero confirmation "
             "transactions\n" +
             HelpExampleCli("listaccounts", "0") +
             "\nList account balances for 6 or more confirmations\n" +
             HelpExampleCli("listaccounts", "6") + "\nAs json rpc call\n" +
             HelpExampleRpc("listaccounts", "6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     int nMinDepth = 1;
     if (!request.params[0].isNull()) {
         nMinDepth = request.params[0].get_int();
     }
 
     isminefilter includeWatchonly = ISMINE_SPENDABLE;
     if (!request.params[1].isNull() && request.params[1].get_bool()) {
         includeWatchonly = includeWatchonly | ISMINE_WATCH_ONLY;
     }
 
     std::map<std::string, Amount> mapAccountBalances;
     for (const std::pair<const CTxDestination, CAddressBookData> &entry :
          pwallet->mapAddressBook) {
         // This address belongs to me
         if (IsMine(*pwallet, entry.first) & includeWatchonly) {
             mapAccountBalances[entry.second.name] = Amount::zero();
         }
     }
 
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
         Amount nFee;
         std::string strSentAccount;
         std::list<COutputEntry> listReceived;
         std::list<COutputEntry> listSent;
         int nDepth = wtx.GetDepthInMainChain();
         if (wtx.IsImmatureCoinBase() || nDepth < 0) {
             continue;
         }
         wtx.GetAmounts(listReceived, listSent, nFee, strSentAccount,
                        includeWatchonly);
         mapAccountBalances[strSentAccount] -= nFee;
         for (const COutputEntry &s : listSent) {
             mapAccountBalances[strSentAccount] -= s.amount;
         }
         if (nDepth >= nMinDepth) {
             for (const COutputEntry &r : listReceived) {
                 if (pwallet->mapAddressBook.count(r.destination)) {
                     mapAccountBalances[pwallet->mapAddressBook[r.destination]
                                            .name] += r.amount;
                 } else {
                     mapAccountBalances[""] += r.amount;
                 }
             }
         }
     }
 
     const std::list<CAccountingEntry> &acentries = pwallet->laccentries;
     for (const CAccountingEntry &entry : acentries) {
         mapAccountBalances[entry.strAccount] += entry.nCreditDebit;
     }
 
     UniValue ret(UniValue::VOBJ);
     for (const std::pair<const std::string, Amount> &accountBalance :
          mapAccountBalances) {
         ret.pushKV(accountBalance.first,
                    ValueFromAmount(accountBalance.second));
     }
     return ret;
 }
 
 static UniValue listsinceblock(const Config &config,
                                const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 4) {
         throw std::runtime_error(
             "listsinceblock ( \"blockhash\" target_confirmations "
             "include_watchonly include_removed )\n"
             "\nGet all transactions in blocks since block [blockhash], or all "
             "transactions if omitted.\n"
             "If \"blockhash\" is no longer a part of the main chain, "
             "transactions from the fork point onward are included.\n"
             "Additionally, if include_removed is set, transactions affecting "
             "the wallet which were removed are returned in the \"removed\" "
             "array.\n"
             "\nArguments:\n"
             "1. \"blockhash\"            (string, optional) The block hash to "
             "list transactions since\n"
             "2. target_confirmations:    (numeric, optional, default=1) Return "
             "the nth block hash from the main chain. e.g. 1 would mean the "
             "best block hash. Note: this is not used as a filter, but only "
             "affects [lastblock] in the return value\n"
             "3. include_watchonly:       (bool, optional, default=false) "
             "Include transactions to watch-only addresses (see "
             "'importaddress')\n"
             "4. include_removed:         (bool, optional, default=true) Show "
             "transactions that were removed due to a reorg in the \"removed\" "
             "array\n"
             "                                                           (not "
             "guaranteed to work on pruned nodes)\n"
             "\nResult:\n"
             "{\n"
             "  \"transactions\": [\n"
             "    \"account\":\"accountname\",       (string) DEPRECATED. This "
             "field will be removed in V0.21. To see this deprecated field, "
             "start bitcoind with -deprecatedrpc=accounts. The "
             "account name associated with the transaction. Will be \"\" for "
             "the default account.\n"
             "    \"address\":\"address\",    (string) The bitcoin address of "
             "the transaction. Not present for move transactions (category = "
             "move).\n"
             "    \"category\":\"send|receive\",     (string) The transaction "
             "category. 'send' has negative amounts, 'receive' has positive "
             "amounts.\n"
             "    \"amount\": x.xxx,          (numeric) The amount in " +
             CURRENCY_UNIT +
             ". This is negative for the 'send' category, and for the 'move' "
             "category for moves \n"
             "                                          outbound. It is "
             "positive for the 'receive' category, and for the 'move' category "
             "for inbound funds.\n"
             "    \"vout\" : n,               (numeric) the vout value\n"
             "    \"fee\": x.xxx,             (numeric) The amount of the fee "
             "in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the 'send' category of "
             "transactions.\n"
             "    \"confirmations\": n,       (numeric) The number of "
             "confirmations for the transaction. Available for 'send' and "
             "'receive' category of transactions.\n"
             "                                          When it's < 0, it means "
             "the transaction conflicted that many blocks ago.\n"
             "    \"blockhash\": \"hashvalue\",     (string) The block hash "
             "containing the transaction. Available for 'send' and 'receive' "
             "category of transactions.\n"
             "    \"blockindex\": n,          (numeric) The index of the "
             "transaction in the block that includes it. Available for 'send' "
             "and 'receive' category of transactions.\n"
             "    \"blocktime\": xxx,         (numeric) The block time in "
             "seconds since epoch (1 Jan 1970 GMT).\n"
             "    \"txid\": \"transactionid\",  (string) The transaction id. "
             "Available for 'send' and 'receive' category of transactions.\n"
             "    \"time\": xxx,              (numeric) The transaction time in "
             "seconds since epoch (Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in "
             "seconds since epoch (Jan 1 1970 GMT). Available for 'send' and "
             "'receive' category of transactions.\n"
             "    \"abandoned\": xxx,         (bool) 'true' if the transaction "
             "has been abandoned (inputs are respendable). Only available for "
             "the 'send' category of transactions.\n"
             "    \"comment\": \"...\",       (string) If a comment is "
             "associated with the transaction.\n"
             "    \"label\" : \"label\"       (string) A comment for the "
             "address/transaction, if any\n"
             "    \"to\": \"...\",            (string) If a comment to is "
             "associated with the transaction.\n"
             "  ],\n"
             "  \"removed\": [\n"
             "    <structure is the same as \"transactions\" above, only "
             "present if include_removed=true>\n"
             "    Note: transactions that were re-added in the active chain "
             "will appear as-is in this array, and may thus have a positive "
             "confirmation count.\n"
             "  ],\n"
             "  \"lastblock\": \"lastblockhash\"     (string) The hash of the "
             "block (target_confirmations-1) from the best block on the main "
             "chain. This is typically used to feed back into listsinceblock "
             "the next time you call it. So you would generally use a "
             "target_confirmations of say 6, so you will be continually "
             "re-notified of transactions until they've reached 6 confirmations "
             "plus any new ones\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("listsinceblock", "") +
             HelpExampleCli("listsinceblock", "\"000000000000000bacf66f7497b7dc4"
                                              "5ef753ee9a7d38571037cdb1a57f663ad"
                                              "\" 6") +
             HelpExampleRpc("listsinceblock", "\"000000000000000bacf66f7497b7dc4"
                                              "5ef753ee9a7d38571037cdb1a57f663ad"
                                              "\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     // Block index of the specified block or the common ancestor, if the block
     // provided was in a deactivated chain.
     const CBlockIndex *pindex = nullptr;
     // Block index of the specified block, even if it's in a deactivated chain.
     const CBlockIndex *paltindex = nullptr;
     int target_confirms = 1;
     isminefilter filter = ISMINE_SPENDABLE;
 
     if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
         BlockHash blockId(uint256S(request.params[0].get_str()));
         paltindex = pindex = LookupBlockIndex(blockId);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
         if (chainActive[pindex->nHeight] != pindex) {
             // the block being asked for is a part of a deactivated chain;
             // we don't want to depend on its perceived height in the block
             // chain, we want to instead use the last common ancestor
             pindex = chainActive.FindFork(pindex);
         }
     }
 
     if (!request.params[1].isNull()) {
         target_confirms = request.params[1].get_int();
 
         if (target_confirms < 1) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter");
         }
     }
 
     if (!request.params[2].isNull() && request.params[2].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     bool include_removed =
         (request.params[3].isNull() || request.params[3].get_bool());
 
     int depth = pindex ? (1 + chainActive.Height() - pindex->nHeight) : -1;
 
     UniValue transactions(UniValue::VARR);
 
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         CWalletTx tx = pairWtx.second;
 
         if (depth == -1 || tx.GetDepthInMainChain() < depth) {
             ListTransactions(pwallet, tx, "*", 0, true, transactions, filter);
         }
     }
 
     const Consensus::Params &params = config.GetChainParams().GetConsensus();
 
     // when a reorg'd block is requested, we also list any relevant transactions
     // in the blocks of the chain that was detached
     UniValue removed(UniValue::VARR);
     while (include_removed && paltindex && paltindex != pindex) {
         CBlock block;
         if (!ReadBlockFromDisk(block, paltindex, params)) {
             throw JSONRPCError(RPC_INTERNAL_ERROR,
                                "Can't read block from disk");
         }
         for (const CTransactionRef &tx : block.vtx) {
             auto it = pwallet->mapWallet.find(tx->GetId());
             if (it != pwallet->mapWallet.end()) {
                 // We want all transactions regardless of confirmation count to
                 // appear here, even negative confirmation ones, hence the big
                 // negative.
                 ListTransactions(pwallet, it->second, "*", -100000000, true,
                                  removed, filter);
             }
         }
         paltindex = paltindex->pprev;
     }
 
     CBlockIndex *pblockLast =
         chainActive[chainActive.Height() + 1 - target_confirms];
     uint256 lastblock = pblockLast ? pblockLast->GetBlockHash() : uint256();
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("transactions", transactions);
     if (include_removed) {
         ret.pushKV("removed", removed);
     }
     ret.pushKV("lastblock", lastblock.GetHex());
 
     return ret;
 }
 
 static UniValue gettransaction(const Config &config,
                                const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "gettransaction \"txid\" ( include_watchonly )\n"
             "\nGet detailed information about in-wallet transaction <txid>\n"
             "\nArguments:\n"
             "1. \"txid\"                  (string, required) The transaction "
             "id\n"
             "2. \"include_watchonly\"     (bool, optional, default=false) "
             "Whether to include watch-only addresses in balance calculation "
             "and details[]\n"
             "\nResult:\n"
             "{\n"
             "  \"amount\" : x.xxx,        (numeric) The transaction amount "
             "in " +
             CURRENCY_UNIT +
             "\n"
             "  \"fee\": x.xxx,            (numeric) The amount of the fee in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                              'send' category of transactions.\n"
             "  \"confirmations\" : n,     (numeric) The number of "
             "confirmations\n"
             "  \"blockhash\" : \"hash\",  (string) The block hash\n"
             "  \"blockindex\" : xx,       (numeric) The index of the "
             "transaction in the block that includes it\n"
             "  \"blocktime\" : ttt,       (numeric) The time in seconds since "
             "epoch (1 Jan 1970 GMT)\n"
             "  \"txid\" : \"transactionid\",   (string) The transaction id.\n"
             "  \"time\" : ttt,            (numeric) The transaction time in "
             "seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"timereceived\" : ttt,    (numeric) The time received in "
             "seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"bip125-replaceable\": \"yes|no|unknown\",  (string) Whether "
             "this transaction could be replaced due to BIP125 "
             "(replace-by-fee);\n"
             "                                                   may be unknown "
             "for unconfirmed transactions not in the mempool\n"
             "  \"details\" : [\n"
             "    {\n"
             "      \"account\" : \"accountname\",      (string) DEPRECATED. "
             "This field will be removed in a V0.21. To see this deprecated "
             "field, start bitcoind with -deprecatedrpc=accounts. The account "
             "name involved in the transaction, can be \"\" for the default "
             "account.\n"
             "      \"address\" : \"address\",          (string) The bitcoin "
             "address involved in the transaction\n"
             "      \"category\" : \"send|receive\",    (string) The category, "
             "either 'send' or 'receive'\n"
             "      \"amount\" : x.xxx,                 (numeric) The amount "
             "in " +
             CURRENCY_UNIT +
             "\n"
             "      \"label\" : \"label\",              "
             "(string) A comment for the address/transaction, "
             "if any\n"
             "      \"vout\" : n,                       "
             "(numeric) the vout value\n"
             "      \"fee\": x.xxx,                     "
             "(numeric) The amount of the fee in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                                           'send' category of "
             "transactions.\n"
             "      \"abandoned\": xxx                  (bool) 'true' if the "
             "transaction has been abandoned (inputs are respendable). Only "
             "available for the \n"
             "                                           'send' category of "
             "transactions.\n"
             "    }\n"
             "    ,...\n"
             "  ],\n"
             "  \"hex\" : \"data\"         (string) Raw data for transaction\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e211"
                                              "5b9345e16c5cf302fc80e9d5fbf5d48d"
                                              "\"") +
             HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e211"
                                              "5b9345e16c5cf302fc80e9d5fbf5d48d"
                                              "\" true") +
             HelpExampleRpc("gettransaction", "\"1075db55d416d3ca199f55b6084e211"
                                              "5b9345e16c5cf302fc80e9d5fbf5d48d"
                                              "\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     TxId txid;
     txid.SetHex(request.params[0].get_str());
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!request.params[1].isNull() && request.params[1].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     UniValue entry(UniValue::VOBJ);
     auto it = pwallet->mapWallet.find(txid);
     if (it == pwallet->mapWallet.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid or non-wallet transaction id");
     }
     const CWalletTx &wtx = it->second;
 
     Amount nCredit = wtx.GetCredit(filter);
     Amount nDebit = wtx.GetDebit(filter);
     Amount nNet = nCredit - nDebit;
     Amount nFee = (wtx.IsFromMe(filter) ? wtx.tx->GetValueOut() - nDebit
                                         : Amount::zero());
 
     entry.pushKV("amount", ValueFromAmount(nNet - nFee));
     if (wtx.IsFromMe(filter)) {
         entry.pushKV("fee", ValueFromAmount(nFee));
     }
 
     WalletTxToJSON(pwallet->chain(), wtx, entry);
 
     UniValue details(UniValue::VARR);
     ListTransactions(pwallet, wtx, "*", 0, false, details, filter);
     entry.pushKV("details", details);
 
     std::string strHex = EncodeHexTx(*wtx.tx, RPCSerializationFlags());
     entry.pushKV("hex", strHex);
 
     return entry;
 }
 
 static UniValue abandontransaction(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "abandontransaction \"txid\"\n"
             "\nMark in-wallet transaction <txid> as abandoned\n"
             "This will mark this transaction and all its in-wallet descendants "
             "as abandoned which will allow\n"
             "for their inputs to be respent.  It can be used to replace "
             "\"stuck\" or evicted transactions.\n"
             "It only works on transactions which are not included in a block "
             "and are not currently in the mempool.\n"
             "It has no effect on transactions which are already abandoned.\n"
             "\nArguments:\n"
             "1. \"txid\"    (string, required) The transaction id\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("abandontransaction", "\"1075db55d416d3ca199f55b6084"
                                                  "e2115b9345e16c5cf302fc80e9d5f"
                                                  "bf5d48d\"") +
             HelpExampleRpc("abandontransaction", "\"1075db55d416d3ca199f55b6084"
                                                  "e2115b9345e16c5cf302fc80e9d5f"
                                                  "bf5d48d\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     TxId txid;
     txid.SetHex(request.params[0].get_str());
 
     if (!pwallet->mapWallet.count(txid)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid or non-wallet transaction id");
     }
 
     if (!pwallet->AbandonTransaction(txid)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not eligible for abandonment");
     }
 
     return NullUniValue;
 }
 
 static UniValue backupwallet(const Config &config,
                              const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "backupwallet \"destination\"\n"
             "\nSafely copies current wallet file to destination, which can be "
             "a directory or a path with filename.\n"
             "\nArguments:\n"
             "1. \"destination\"   (string) The destination directory or file\n"
             "\nExamples:\n" +
             HelpExampleCli("backupwallet", "\"backup.dat\"") +
             HelpExampleRpc("backupwallet", "\"backup.dat\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::string strDest = request.params[0].get_str();
     if (!pwallet->BackupWallet(strDest)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error: Wallet backup failed!");
     }
 
     return NullUniValue;
 }
 
 static UniValue keypoolrefill(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             "keypoolrefill ( newsize )\n"
             "\nFills the keypool." +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments\n"
             "1. newsize     (numeric, optional, default=100) "
             "The new keypool size\n"
             "\nExamples:\n" +
             HelpExampleCli("keypoolrefill", "") +
             HelpExampleRpc("keypoolrefill", ""));
     }
 
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: Private keys are disabled for this wallet");
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     // 0 is interpreted by TopUpKeyPool() as the default keypool size given by
     // -keypool
     unsigned int kpSize = 0;
     if (!request.params[0].isNull()) {
         if (request.params[0].get_int() < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected valid size.");
         }
         kpSize = (unsigned int)request.params[0].get_int();
     }
 
     EnsureWalletIsUnlocked(pwallet);
     pwallet->TopUpKeyPool(kpSize);
 
     if (pwallet->GetKeyPoolSize() < kpSize) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error refreshing keypool.");
     }
 
     return NullUniValue;
 }
 
 static void LockWallet(CWallet *pWallet) {
     LOCK(pWallet->cs_wallet);
     pWallet->nRelockTime = 0;
     pWallet->Lock();
 }
 
 static UniValue walletpassphrase(const Config &config,
                                  const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (pwallet->IsCrypted() && (request.fHelp || request.params.size() != 2)) {
         throw std::runtime_error(
             "walletpassphrase \"passphrase\" timeout\n"
             "\nStores the wallet decryption key in memory for 'timeout' "
             "seconds.\n"
             "This is needed prior to performing transactions related to "
             "private keys such as sending bitcoins\n"
             "\nArguments:\n"
             "1. \"passphrase\"     (string, required) The wallet passphrase\n"
             "2. timeout            (numeric, required) The time to keep the "
             "decryption key in seconds; capped at 100000000 (~3 years).\n"
             "\nNote:\n"
             "Issuing the walletpassphrase command while the wallet is already "
             "unlocked will set a new unlock\n"
             "time that overrides the old one.\n"
             "\nExamples:\n"
             "\nUnlock the wallet for 60 seconds\n" +
             HelpExampleCli("walletpassphrase", "\"my pass phrase\" 60") +
             "\nLock the wallet again (before 60 seconds)\n" +
             HelpExampleCli("walletlock", "") + "\nAs json rpc call\n" +
             HelpExampleRpc("walletpassphrase", "\"my pass phrase\", 60"));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
 
     if (!pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an unencrypted wallet, but "
                            "walletpassphrase was called.");
     }
 
     // Note that the walletpassphrase is stored in request.params[0] which is
     // not mlock()ed
     SecureString strWalletPass;
     strWalletPass.reserve(100);
     // TODO: get rid of this .c_str() by implementing
     // SecureString::operator=(std::string)
     // Alternately, find a way to make request.params[0] mlock()'d to begin
     // with.
     strWalletPass = request.params[0].get_str().c_str();
 
     // Get the timeout
     int64_t nSleepTime = request.params[1].get_int64();
     // Timeout cannot be negative, otherwise it will relock immediately
     if (nSleepTime < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Timeout cannot be negative.");
     }
     // Clamp timeout
     // larger values trigger a macos/libevent bug?
     constexpr int64_t MAX_SLEEP_TIME = 100000000;
     if (nSleepTime > MAX_SLEEP_TIME) {
         nSleepTime = MAX_SLEEP_TIME;
     }
 
     if (strWalletPass.length() > 0) {
         if (!pwallet->Unlock(strWalletPass)) {
             throw JSONRPCError(
                 RPC_WALLET_PASSPHRASE_INCORRECT,
                 "Error: The wallet passphrase entered was incorrect.");
         }
     } else {
         throw std::runtime_error(
             "walletpassphrase <passphrase> <timeout>\n"
             "Stores the wallet decryption key in memory for "
             "<timeout> seconds.");
     }
 
     pwallet->TopUpKeyPool();
 
     pwallet->nRelockTime = GetTime() + nSleepTime;
     RPCRunLater(strprintf("lockwallet(%s)", pwallet->GetName()),
                 std::bind(LockWallet, pwallet), nSleepTime);
 
     return NullUniValue;
 }
 
 static UniValue walletpassphrasechange(const Config &config,
                                        const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (pwallet->IsCrypted() && (request.fHelp || request.params.size() != 2)) {
         throw std::runtime_error(
             "walletpassphrasechange \"oldpassphrase\" \"newpassphrase\"\n"
             "\nChanges the wallet passphrase from 'oldpassphrase' to "
             "'newpassphrase'.\n"
             "\nArguments:\n"
             "1. \"oldpassphrase\"      (string) The current passphrase\n"
             "2. \"newpassphrase\"      (string) The new passphrase\n"
             "\nExamples:\n" +
             HelpExampleCli("walletpassphrasechange",
                            "\"old one\" \"new one\"") +
             HelpExampleRpc("walletpassphrasechange",
                            "\"old one\", \"new one\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
     if (!pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an unencrypted wallet, but "
                            "walletpassphrasechange was called.");
     }
 
     // TODO: get rid of these .c_str() calls by implementing
     // SecureString::operator=(std::string)
     // Alternately, find a way to make request.params[0] mlock()'d to begin
     // with.
     SecureString strOldWalletPass;
     strOldWalletPass.reserve(100);
     strOldWalletPass = request.params[0].get_str().c_str();
 
     SecureString strNewWalletPass;
     strNewWalletPass.reserve(100);
     strNewWalletPass = request.params[1].get_str().c_str();
 
     if (strOldWalletPass.length() < 1 || strNewWalletPass.length() < 1) {
         throw std::runtime_error(
             "walletpassphrasechange <oldpassphrase> <newpassphrase>\n"
             "Changes the wallet passphrase from <oldpassphrase> to "
             "<newpassphrase>.");
     }
 
     if (!pwallet->ChangeWalletPassphrase(strOldWalletPass, strNewWalletPass)) {
         throw JSONRPCError(
             RPC_WALLET_PASSPHRASE_INCORRECT,
             "Error: The wallet passphrase entered was incorrect.");
     }
 
     return NullUniValue;
 }
 
 static UniValue walletlock(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (pwallet->IsCrypted() && (request.fHelp || request.params.size() != 0)) {
         throw std::runtime_error(
             "walletlock\n"
             "\nRemoves the wallet encryption key from memory, locking the "
             "wallet.\n"
             "After calling this method, you will need to call walletpassphrase "
             "again\n"
             "before being able to call any methods which require the wallet to "
             "be unlocked.\n"
             "\nExamples:\n"
             "\nSet the passphrase for 2 minutes to perform a transaction\n" +
             HelpExampleCli("walletpassphrase", "\"my pass phrase\" 120") +
             "\nPerform a send (requires passphrase set)\n" +
             HelpExampleCli("sendtoaddress",
                            "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 1.0") +
             "\nClear the passphrase since we are done before 2 minutes is "
             "up\n" +
             HelpExampleCli("walletlock", "") + "\nAs json rpc call\n" +
             HelpExampleRpc("walletlock", ""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
     if (!pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an unencrypted wallet, but "
                            "walletlock was called.");
     }
 
     pwallet->Lock();
     pwallet->nRelockTime = 0;
 
     return NullUniValue;
 }
 
 static UniValue encryptwallet(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!pwallet->IsCrypted() &&
         (request.fHelp || request.params.size() != 1)) {
         throw std::runtime_error(
             "encryptwallet \"passphrase\"\n"
             "\nEncrypts the wallet with 'passphrase'. This is for first time "
             "encryption.\n"
             "After this, any calls that interact with private keys such as "
             "sending or signing \n"
             "will require the passphrase to be set prior the making these "
             "calls.\n"
             "Use the walletpassphrase call for this, and then walletlock "
             "call.\n"
             "If the wallet is already encrypted, use the "
             "walletpassphrasechange call.\n"
             "\nArguments:\n"
             "1. \"passphrase\"    (string) The pass phrase to encrypt the "
             "wallet with. It must be at least 1 character, but should be "
             "long.\n"
             "\nExamples:\n"
             "\nEncrypt your wallet\n" +
             HelpExampleCli("encryptwallet", "\"my pass phrase\"") +
             "\nNow set the passphrase to use the wallet, such as for signing "
             "or sending bitcoin\n" +
             HelpExampleCli("walletpassphrase", "\"my pass phrase\"") +
             "\nNow we can do something like sign\n" +
             HelpExampleCli("signmessage", "\"address\" \"test message\"") +
             "\nNow lock the wallet again by removing the passphrase\n" +
             HelpExampleCli("walletlock", "") + "\nAs a json rpc call\n" +
             HelpExampleRpc("encryptwallet", "\"my pass phrase\""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
     if (pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an encrypted wallet, but "
                            "encryptwallet was called.");
     }
 
     // TODO: get rid of this .c_str() by implementing
     // SecureString::operator=(std::string)
     // Alternately, find a way to make request.params[0] mlock()'d to begin
     // with.
     SecureString strWalletPass;
     strWalletPass.reserve(100);
     strWalletPass = request.params[0].get_str().c_str();
 
     if (strWalletPass.length() < 1) {
         throw std::runtime_error("encryptwallet <passphrase>\n"
                                  "Encrypts the wallet with <passphrase>.");
     }
 
     if (!pwallet->EncryptWallet(strWalletPass)) {
         throw JSONRPCError(RPC_WALLET_ENCRYPTION_FAILED,
                            "Error: Failed to encrypt the wallet.");
     }
 
     return "wallet encrypted; The keypool has been flushed and a new HD seed "
            "was generated (if you are using HD). You need to make a new "
            "backup.";
 }
 
 static UniValue lockunspent(const Config &config,
                             const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "lockunspent unlock ([{\"txid\":\"txid\",\"vout\":n},...])\n"
             "\nUpdates list of temporarily unspendable outputs.\n"
             "Temporarily lock (unlock=false) or unlock (unlock=true) specified "
             "transaction outputs.\n"
             "If no transaction outputs are specified when unlocking then all "
             "current locked transaction outputs are unlocked.\n"
             "A locked transaction output will not be chosen by automatic coin "
             "selection, when spending bitcoins.\n"
             "Locks are stored in memory only. Nodes start with zero locked "
             "outputs, and the locked output list\n"
             "is always cleared (by virtue of process exit) when a node stops "
             "or fails.\n"
             "Also see the listunspent call\n"
             "\nArguments:\n"
             "1. unlock            (boolean, required) Whether to unlock (true) "
             "or lock (false) the specified transactions\n"
             "2. \"transactions\"  (string, optional) A json array of objects. "
             "Each object the txid (string) vout (numeric)\n"
             "     [           (json array of json objects)\n"
             "       {\n"
             "         \"txid\":\"id\",    (string) The transaction id\n"
             "         \"vout\": n         (numeric) The output number\n"
             "       }\n"
             "       ,...\n"
             "     ]\n"
 
             "\nResult:\n"
             "true|false    (boolean) Whether the command was successful or "
             "not\n"
 
             "\nExamples:\n"
             "\nList the unspent transactions\n" +
             HelpExampleCli("listunspent", "") +
             "\nLock an unspent transaction\n" +
             HelpExampleCli("lockunspent", "false "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nList the locked transactions\n" +
             HelpExampleCli("listlockunspent", "") +
             "\nUnlock the transaction again\n" +
             HelpExampleCli("lockunspent", "true "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("lockunspent", "false, "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     RPCTypeCheckArgument(request.params[0], UniValue::VBOOL);
 
     bool fUnlock = request.params[0].get_bool();
 
     if (request.params[1].isNull()) {
         if (fUnlock) {
             pwallet->UnlockAllCoins();
         }
         return true;
     }
 
     RPCTypeCheckArgument(request.params[1], UniValue::VARR);
 
     const UniValue &output_params = request.params[1];
 
     // Create and validate the COutPoints first.
 
     std::vector<COutPoint> outputs;
     outputs.reserve(output_params.size());
 
     for (size_t idx = 0; idx < output_params.size(); idx++) {
         const UniValue &o = output_params[idx].get_obj();
 
         RPCTypeCheckObj(o, {
                                {"txid", UniValueType(UniValue::VSTR)},
                                {"vout", UniValueType(UniValue::VNUM)},
                            });
 
         const std::string &strTxId = find_value(o, "txid").get_str();
         if (!IsHex(strTxId)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected hex txid");
         }
 
         const int nOutput = find_value(o, "vout").get_int();
         if (nOutput < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, vout must be positive");
         }
 
         const TxId txid(uint256S(strTxId));
         const auto it = pwallet->mapWallet.find(txid);
         if (it == pwallet->mapWallet.end()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, unknown transaction");
         }
 
         const COutPoint output(txid, nOutput);
         const CWalletTx &trans = it->second;
         if (output.GetN() >= trans.tx->vout.size()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, vout index out of bounds");
         }
 
         if (pwallet->IsSpent(output)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected unspent output");
         }
 
         const bool is_locked = pwallet->IsLockedCoin(output);
         if (fUnlock && !is_locked) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected locked output");
         }
 
         if (!fUnlock && is_locked) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, output already locked");
         }
 
         outputs.push_back(output);
     }
 
     // Atomically set (un)locked status for the outputs.
     for (const COutPoint &output : outputs) {
         if (fUnlock) {
             pwallet->UnlockCoin(output);
         } else {
             pwallet->LockCoin(output);
         }
     }
 
     return true;
 }
 
 static UniValue listlockunspent(const Config &config,
                                 const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(
             "listlockunspent\n"
             "\nReturns list of temporarily unspendable outputs.\n"
             "See the lockunspent call to lock and unlock transactions for "
             "spending.\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"txid\" : \"transactionid\",     (string) The transaction id "
             "locked\n"
             "    \"vout\" : n                      (numeric) The vout value\n"
             "  }\n"
             "  ,...\n"
             "]\n"
             "\nExamples:\n"
             "\nList the unspent transactions\n" +
             HelpExampleCli("listunspent", "") +
             "\nLock an unspent transaction\n" +
             HelpExampleCli("lockunspent", "false "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nList the locked transactions\n" +
             HelpExampleCli("listlockunspent", "") +
             "\nUnlock the transaction again\n" +
             HelpExampleCli("lockunspent", "true "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nAs a json rpc call\n" + HelpExampleRpc("listlockunspent", ""));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     std::vector<COutPoint> vOutpts;
     pwallet->ListLockedCoins(vOutpts);
 
     UniValue ret(UniValue::VARR);
 
     for (const COutPoint &output : vOutpts) {
         UniValue o(UniValue::VOBJ);
 
         o.pushKV("txid", output.GetTxId().GetHex());
         o.pushKV("vout", int(output.GetN()));
         ret.push_back(o);
     }
 
     return ret;
 }
 
 static UniValue settxfee(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 1) {
         throw std::runtime_error(
             "settxfee amount\n"
             "\nSet the transaction fee per kB for this wallet. Overrides the "
             "global -paytxfee command line parameter.\n"
             "\nArguments:\n"
             "1. amount         (numeric or string, required) The transaction "
             "fee in " +
             CURRENCY_UNIT +
             "/kB\n"
             "\nResult\n"
             "true|false        (boolean) Returns true if successful\n"
             "\nExamples:\n" +
             HelpExampleCli("settxfee", "0.00001") +
             HelpExampleRpc("settxfee", "0.00001"));
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     Amount nAmount = AmountFromValue(request.params[0]);
     CFeeRate tx_fee_rate(nAmount, 1000);
     if (tx_fee_rate == CFeeRate()) {
         // automatic selection
     } else if (tx_fee_rate < ::minRelayTxFee) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
             strprintf("txfee cannot be less than min relay tx fee (%s)",
                       ::minRelayTxFee.ToString()));
     } else if (tx_fee_rate < pwallet->m_min_fee) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
             strprintf("txfee cannot be less than wallet min fee (%s)",
                       pwallet->m_min_fee.ToString()));
     }
 
     pwallet->m_pay_tx_fee = tx_fee_rate;
     return true;
 }
 
 static UniValue getwalletinfo(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getwalletinfo\n"
             "Returns an object containing various wallet state info.\n"
             "\nResult:\n"
             "{\n"
             "  \"walletname\": xxxxx,             (string) the wallet name\n"
             "  \"walletversion\": xxxxx,          (numeric) the wallet "
             "version\n"
             "  \"balance\": xxxxxxx,              (numeric) the total "
             "confirmed balance of the wallet in " +
             CURRENCY_UNIT +
             "\n"
             "  \"unconfirmed_balance\": xxx,      (numeric) "
             "the total unconfirmed balance of the wallet in " +
             CURRENCY_UNIT +
             "\n"
             "  \"immature_balance\": xxxxxx,      (numeric) "
             "the total immature balance of the wallet in " +
             CURRENCY_UNIT +
             "\n"
             "  \"txcount\": xxxxxxx,              (numeric) the total number "
             "of transactions in the wallet\n"
             "  \"keypoololdest\": xxxxxx,         (numeric) the timestamp "
             "(seconds since Unix epoch) of the oldest pre-generated key in the "
             "key pool\n"
             "  \"keypoolsize\": xxxx,             (numeric) how many new keys "
             "are pre-generated (only counts external keys)\n"
             "  \"keypoolsize_hd_internal\": xxxx, (numeric) how many new keys "
             "are pre-generated for internal use (used for change outputs, only "
             "appears if the wallet is using this feature, otherwise external "
             "keys are used)\n"
             "  \"unlocked_until\": ttt,           (numeric) the timestamp in "
             "seconds since epoch (midnight Jan 1 1970 GMT) that the wallet is "
             "unlocked for transfers, or 0 if the wallet is locked\n"
             "  \"paytxfee\": x.xxxx,              (numeric) the transaction "
             "fee configuration, set in " +
             CURRENCY_UNIT +
             "/kB\n"
             "  \"hdseedid\": \"<hash160>\"          (string, optional) the "
             "Hash160 of the HD seed (only present when HD is enabled)\n"
             "  \"hdmasterkeyid\": \"<hash160>\"     (string, optional) alias "
             "for hdseedid retained for backwards-compatibility. Will be "
             "removed in V0.21.\n"
             "  \"private_keys_enabled\": true|false (boolean) false if "
             "privatekeys are disabled for this wallet (enforced watch-only "
             "wallet)\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getwalletinfo", "") +
             HelpExampleRpc("getwalletinfo", ""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     UniValue obj(UniValue::VOBJ);
 
     size_t kpExternalSize = pwallet->KeypoolCountExternalKeys();
     obj.pushKV("walletname", pwallet->GetName());
     obj.pushKV("walletversion", pwallet->GetVersion());
     obj.pushKV("balance", ValueFromAmount(pwallet->GetBalance()));
     obj.pushKV("unconfirmed_balance",
                ValueFromAmount(pwallet->GetUnconfirmedBalance()));
     obj.pushKV("immature_balance",
                ValueFromAmount(pwallet->GetImmatureBalance()));
     obj.pushKV("txcount", (int)pwallet->mapWallet.size());
     obj.pushKV("keypoololdest", pwallet->GetOldestKeyPoolTime());
     obj.pushKV("keypoolsize", (int64_t)kpExternalSize);
     CKeyID seed_id = pwallet->GetHDChain().seed_id;
     if (!seed_id.IsNull() && pwallet->CanSupportFeature(FEATURE_HD_SPLIT)) {
         obj.pushKV("keypoolsize_hd_internal",
                    int64_t(pwallet->GetKeyPoolSize() - kpExternalSize));
     }
     if (pwallet->IsCrypted()) {
         obj.pushKV("unlocked_until", pwallet->nRelockTime);
     }
     obj.pushKV("paytxfee", ValueFromAmount(pwallet->m_pay_tx_fee.GetFeePerK()));
     if (!seed_id.IsNull()) {
         obj.pushKV("hdseedid", seed_id.GetHex());
         obj.pushKV("hdmasterkeyid", seed_id.GetHex());
     }
     obj.pushKV("private_keys_enabled",
                !pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
     return obj;
 }
 
 static UniValue listwallets(const Config &config,
                             const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "listwallets\n"
             "Returns a list of currently loaded wallets.\n"
             "For full information on the wallet, use \"getwalletinfo\"\n"
             "\nResult:\n"
             "[                         (json array of strings)\n"
             "  \"walletname\"            (string) the wallet name\n"
             "   ...\n"
             "]\n"
             "\nExamples:\n" +
             HelpExampleCli("listwallets", "") +
             HelpExampleRpc("listwallets", ""));
     }
 
     UniValue obj(UniValue::VARR);
 
     for (const std::shared_ptr<CWallet> &wallet : GetWallets()) {
         if (!EnsureWalletIsAvailable(wallet.get(), request.fHelp)) {
             return NullUniValue;
         }
 
         LOCK(wallet->cs_wallet);
 
         obj.push_back(wallet->GetName());
     }
 
     return obj;
 }
 
 static UniValue loadwallet(const Config &config,
                            const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "loadwallet \"filename\"\n"
             "\nLoads a wallet from a wallet file or directory."
             "\nNote that all wallet command-line options used when starting "
             "bitcoind will be"
             "\napplied to the new wallet (eg -zapwallettxes, upgradewallet, "
             "rescan, etc).\n"
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The wallet directory or "
             ".dat file.\n"
             "\nResult:\n"
             "{\n"
             "  \"name\" :    <wallet_name>,        (string) The wallet name if "
             "loaded successfully.\n"
             "  \"warning\" : <warning>,            (string) Warning message if "
             "wallet was not loaded cleanly.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("loadwallet", "\"test.dat\"") +
             HelpExampleRpc("loadwallet", "\"test.dat\""));
     }
 
     const CChainParams &chainParams = config.GetChainParams();
 
     WalletLocation location(request.params[0].get_str());
     std::string error;
 
     if (!location.Exists()) {
         throw JSONRPCError(RPC_WALLET_NOT_FOUND,
                            "Wallet " + location.GetName() + " not found.");
     } else if (fs::is_directory(location.GetPath())) {
         // The given filename is a directory. Check that there's a wallet.dat
         // file.
         fs::path wallet_dat_file = location.GetPath() / "wallet.dat";
         if (fs::symlink_status(wallet_dat_file).type() == fs::file_not_found) {
             throw JSONRPCError(RPC_WALLET_NOT_FOUND,
                                "Directory " + location.GetName() +
                                    " does not contain a wallet.dat file.");
         }
     }
 
     std::string warning;
     if (!CWallet::Verify(chainParams, *g_rpc_interfaces->chain, location, false,
                          error, warning)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Wallet file verification failed: " + error);
     }
 
     std::shared_ptr<CWallet> const wallet = CWallet::CreateWalletFromFile(
         chainParams, *g_rpc_interfaces->chain, location);
     if (!wallet) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet loading failed.");
     }
     AddWallet(wallet);
 
     wallet->postInitProcess();
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", warning);
 
     return obj;
 }
 
 static UniValue createwallet(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             "createwallet \"wallet_name\" ( disable_private_keys )\n"
             "\nCreates and loads a new wallet.\n"
             "\nArguments:\n"
             "1. \"wallet_name\"    (string, required) The name for the new "
             "wallet. If this is a path, the wallet will be created at the path "
             "location.\n"
             "2. disable_private_keys   (boolean, optional, default: false) "
             "Disable the possibility of private keys (only watchonlys are "
             "possible in this mode).\n"
             "3. blank   (boolean, optional, default: false) Create a blank "
             "wallet. A blank wallet has no keys or HD seed. One can be set "
             "using sethdseed.\n"
             "\nResult:\n"
             "{\n"
             "  \"name\" :    <wallet_name>,        (string) The wallet name if "
             "created successfully. If the wallet was created using a full "
             "path, the wallet_name will be the full path.\n"
             "  \"warning\" : <warning>,            (string) Warning message if "
             "wallet was not loaded cleanly.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("createwallet", "\"testwallet\"") +
             HelpExampleRpc("createwallet", "\"testwallet\""));
     }
 
     const CChainParams &chainParams = config.GetChainParams();
 
     std::string error;
     std::string warning;
 
     uint64_t flags = 0;
     if (!request.params[1].isNull() && request.params[1].get_bool()) {
         flags |= WALLET_FLAG_DISABLE_PRIVATE_KEYS;
     }
 
     if (!request.params[2].isNull() && request.params[2].get_bool()) {
         flags |= WALLET_FLAG_BLANK_WALLET;
     }
 
     WalletLocation location(request.params[0].get_str());
     if (location.Exists()) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Wallet " + location.GetName() + " already exists.");
     }
 
     // Wallet::Verify will check if we're trying to create a wallet with a
     // duplicate name.
     if (!CWallet::Verify(chainParams, *g_rpc_interfaces->chain, location, false,
                          error, warning)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Wallet file verification failed: " + error);
     }
 
     std::shared_ptr<CWallet> const wallet = CWallet::CreateWalletFromFile(
         chainParams, *g_rpc_interfaces->chain, location, flags);
     if (!wallet) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet creation failed.");
     }
     AddWallet(wallet);
 
     wallet->postInitProcess();
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", warning);
 
     return obj;
 }
 
 static UniValue unloadwallet(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             "unloadwallet ( \"wallet_name\" )\n"
             "Unloads the wallet referenced by the request endpoint otherwise "
             "unloads the wallet specified in the argument.\n"
             "Specifying the wallet name on a wallet endpoint is invalid."
             "\nArguments:\n"
             "1. \"wallet_name\"    (string, optional) The name of the wallet "
             "to unload.\n"
             "\nExamples:\n" +
             HelpExampleCli("unloadwallet", "wallet_name") +
             HelpExampleRpc("unloadwallet", "wallet_name"));
     }
 
     std::string wallet_name;
     if (GetWalletNameFromJSONRPCRequest(request, wallet_name)) {
         if (!request.params[0].isNull()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Cannot unload the requested wallet");
         }
     } else {
         wallet_name = request.params[0].get_str();
     }
 
     std::shared_ptr<CWallet> wallet = GetWallet(wallet_name);
     if (!wallet) {
         throw JSONRPCError(RPC_WALLET_NOT_FOUND,
                            "Requested wallet does not exist or is not loaded");
     }
 
     // Release the "main" shared pointer and prevent further notifications.
     // Note that any attempt to load the same wallet would fail until the wallet
     // is destroyed (see CheckUniqueFileid).
     if (!RemoveWallet(wallet)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Requested wallet already unloaded");
     }
     UnregisterValidationInterface(wallet.get());
 
     // The wallet can be in use so it's not possible to explicitly unload here.
     // Just notify the unload intent so that all shared pointers are released.
     // The wallet will be destroyed once the last shared pointer is released.
     wallet->NotifyUnload();
 
     // There's no point in waiting for the wallet to unload.
     // At this point this method should never fail. The unloading could only
     // fail due to an unexpected error which would cause a process termination.
 
     return NullUniValue;
 }
 
 static UniValue resendwallettransactions(const Config &config,
                                          const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "resendwallettransactions\n"
             "Immediately re-broadcast unconfirmed wallet transactions to all "
             "peers.\n"
             "Intended only for testing; the wallet code periodically "
             "re-broadcasts\n"
             "automatically.\n"
             "Returns an RPC error if -walletbroadcast is set to false.\n"
             "Returns array of transaction ids that were re-broadcast.\n");
     }
 
     if (!g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     if (!pwallet->GetBroadcastTransactions()) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error: Wallet transaction "
                                              "broadcasting is disabled with "
                                              "-walletbroadcast");
     }
 
     std::vector<uint256> txids =
         pwallet->ResendWalletTransactionsBefore(GetTime(), g_connman.get());
     UniValue result(UniValue::VARR);
     for (const uint256 &txid : txids) {
         result.push_back(txid.ToString());
     }
 
     return result;
 }
 
 static UniValue listunspent(const Config &config,
                             const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 5) {
         throw std::runtime_error(
             "listunspent ( minconf maxconf  [\"addresses\",...] "
             "[include_unsafe] [query_options])\n"
             "\nReturns array of unspent transaction outputs\n"
             "with between minconf and maxconf (inclusive) confirmations.\n"
             "Optionally filter to only include txouts paid to specified "
             "addresses.\n"
             "\nArguments:\n"
             "1. minconf          (numeric, optional, default=1) The minimum "
             "confirmations to filter\n"
             "2. maxconf          (numeric, optional, default=9999999) The "
             "maximum confirmations to filter\n"
             "3. \"addresses\"      (string) A json array of bitcoin addresses "
             "to filter\n"
             "    [\n"
             "      \"address\"     (string) bitcoin address\n"
             "      ,...\n"
             "    ]\n"
             "4. include_unsafe (bool, optional, default=true) Include outputs "
             "that are not safe to spend\n"
             "                  See description of \"safe\" attribute below.\n"
             "5. query_options    (json, optional) JSON with query options\n"
             "    {\n"
             "      \"minimumAmount\"    (numeric or string, default=0) Minimum "
             "value of each UTXO in " +
             CURRENCY_UNIT +
             "\n"
             "      \"maximumAmount\"    (numeric or string, default=unlimited) "
             "Maximum value of each UTXO in " +
             CURRENCY_UNIT +
             "\n"
             "      \"maximumCount\"     (numeric or string, default=unlimited) "
             "Maximum number of UTXOs\n"
             "      \"minimumSumAmount\" (numeric or string, default=unlimited) "
             "Minimum sum value of all UTXOs in " +
             CURRENCY_UNIT +
             "\n"
             "    }\n"
             "\nResult\n"
             "[                   (array of json object)\n"
             "  {\n"
             "    \"txid\" : \"txid\",          (string) the transaction id \n"
             "    \"vout\" : n,               (numeric) the vout value\n"
             "    \"address\" : \"address\",    (string) the bitcoin address\n"
             "    \"label\" : \"label\",        (string) The associated label, "
             "or \"\" for the default label\n"
             "    \"account\" : \"account\",    (string) DEPRECATED. This field "
             "will be removed in v0.21. To see this deprecated field, start "
             "bitcoind with -deprecatedrpc=accounts. The associated account, or "
             "\"\" for the default account\n"
             "    \"scriptPubKey\" : \"key\",   (string) the script key\n"
             "    \"amount\" : x.xxx,         (numeric) the transaction output "
             "amount in " +
             CURRENCY_UNIT +
             "\n"
             "    \"confirmations\" : n,      (numeric) The number of "
             "confirmations\n"
             "    \"redeemScript\" : n        (string) The redeemScript if "
             "scriptPubKey is P2SH\n"
             "    \"spendable\" : xxx,        (bool) Whether we have the "
             "private keys to spend this output\n"
             "    \"solvable\" : xxx,         (bool) Whether we know how to "
             "spend this output, ignoring the lack of keys\n"
             "    \"safe\" : xxx              (bool) Whether this output is "
             "considered safe to spend. Unconfirmed transactions\n"
             "                              from outside keys are considered "
             "unsafe and are not eligible for spending by\n"
             "                              fundrawtransaction and "
             "sendtoaddress.\n"
             "  }\n"
             "  ,...\n"
             "]\n"
 
             "\nExamples\n" +
             HelpExampleCli("listunspent", "") +
             HelpExampleCli("listunspent",
                            "6 9999999 "
                            "\"[\\\"1PGFqEzfmQch1gKD3ra4k18PNj3tTUUSqg\\\","
                            "\\\"1LtvqCaApEdUGFkpKMM4MstjcaL4dKg8SP\\\"]\"") +
             HelpExampleRpc("listunspent",
                            "6, 9999999 "
                            "\"[\\\"1PGFqEzfmQch1gKD3ra4k18PNj3tTUUSqg\\\","
                            "\\\"1LtvqCaApEdUGFkpKMM4MstjcaL4dKg8SP\\\"]\"") +
             HelpExampleCli(
                 "listunspent",
                 "6 9999999 '[]' true '{ \"minimumAmount\": 0.005 }'") +
             HelpExampleRpc(
                 "listunspent",
                 "6, 9999999, [] , true, { \"minimumAmount\": 0.005 } "));
     }
 
     int nMinDepth = 1;
     if (!request.params[0].isNull()) {
         RPCTypeCheckArgument(request.params[0], UniValue::VNUM);
         nMinDepth = request.params[0].get_int();
     }
 
     int nMaxDepth = 9999999;
     if (!request.params[1].isNull()) {
         RPCTypeCheckArgument(request.params[1], UniValue::VNUM);
         nMaxDepth = request.params[1].get_int();
     }
 
     std::set<CTxDestination> destinations;
     if (!request.params[2].isNull()) {
         RPCTypeCheckArgument(request.params[2], UniValue::VARR);
         UniValue inputs = request.params[2].get_array();
         for (size_t idx = 0; idx < inputs.size(); idx++) {
             const UniValue &input = inputs[idx];
             CTxDestination dest =
                 DecodeDestination(input.get_str(), config.GetChainParams());
             if (!IsValidDestination(dest)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    std::string("Invalid Bitcoin address: ") +
                                        input.get_str());
             }
             if (!destinations.insert(dest).second) {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     std::string("Invalid parameter, duplicated address: ") +
                         input.get_str());
             }
         }
     }
 
     bool include_unsafe = true;
     if (!request.params[3].isNull()) {
         RPCTypeCheckArgument(request.params[3], UniValue::VBOOL);
         include_unsafe = request.params[3].get_bool();
     }
 
     Amount nMinimumAmount = Amount::zero();
     Amount nMaximumAmount = MAX_MONEY;
     Amount nMinimumSumAmount = MAX_MONEY;
     uint64_t nMaximumCount = 0;
 
     if (!request.params[4].isNull()) {
         const UniValue &options = request.params[4].get_obj();
 
         if (options.exists("minimumAmount")) {
             nMinimumAmount = AmountFromValue(options["minimumAmount"]);
         }
 
         if (options.exists("maximumAmount")) {
             nMaximumAmount = AmountFromValue(options["maximumAmount"]);
         }
 
         if (options.exists("minimumSumAmount")) {
             nMinimumSumAmount = AmountFromValue(options["minimumSumAmount"]);
         }
 
         if (options.exists("maximumCount")) {
             nMaximumCount = options["maximumCount"].get_int64();
         }
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     UniValue results(UniValue::VARR);
     std::vector<COutput> vecOutputs;
     {
-        LOCK2(cs_main, pwallet->cs_wallet);
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
         pwallet->AvailableCoins(vecOutputs, !include_unsafe, nullptr,
                                 nMinimumAmount, nMaximumAmount,
                                 nMinimumSumAmount, nMaximumCount, nMinDepth,
                                 nMaxDepth);
     }
 
     LOCK(pwallet->cs_wallet);
 
     for (const COutput &out : vecOutputs) {
         CTxDestination address;
         const CScript &scriptPubKey = out.tx->tx->vout[out.i].scriptPubKey;
         bool fValidAddress = ExtractDestination(scriptPubKey, address);
 
         if (destinations.size() &&
             (!fValidAddress || !destinations.count(address))) {
             continue;
         }
 
         UniValue entry(UniValue::VOBJ);
         entry.pushKV("txid", out.tx->GetId().GetHex());
         entry.pushKV("vout", out.i);
 
         if (fValidAddress) {
             entry.pushKV("address", EncodeDestination(address, config));
 
             auto i = pwallet->mapAddressBook.find(address);
             if (i != pwallet->mapAddressBook.end()) {
                 entry.pushKV("label", i->second.name);
                 if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
                     entry.pushKV("account", i->second.name);
                 }
             }
 
             if (scriptPubKey.IsPayToScriptHash()) {
                 const CScriptID &hash = boost::get<CScriptID>(address);
                 CScript redeemScript;
                 if (pwallet->GetCScript(hash, redeemScript)) {
                     entry.pushKV("redeemScript", HexStr(redeemScript.begin(),
                                                         redeemScript.end()));
                 }
             }
         }
 
         entry.pushKV("scriptPubKey",
                      HexStr(scriptPubKey.begin(), scriptPubKey.end()));
         entry.pushKV("amount", ValueFromAmount(out.tx->tx->vout[out.i].nValue));
         entry.pushKV("confirmations", out.nDepth);
         entry.pushKV("spendable", out.fSpendable);
         entry.pushKV("solvable", out.fSolvable);
         entry.pushKV("safe", out.fSafe);
         results.push_back(entry);
     }
 
     return results;
 }
 
 void FundTransaction(CWallet *const pwallet, CMutableTransaction &tx,
                      Amount &fee_out, int &change_position, UniValue options) {
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     CCoinControl coinControl;
     change_position = -1;
     bool lockUnspents = false;
     UniValue subtractFeeFromOutputs;
     std::set<int> setSubtractFeeFromOutputs;
 
     if (!options.isNull()) {
         if (options.type() == UniValue::VBOOL) {
             // backward compatibility bool only fallback
             coinControl.fAllowWatchOnly = options.get_bool();
         } else {
             RPCTypeCheckArgument(options, UniValue::VOBJ);
             RPCTypeCheckObj(
                 options,
                 {
                     {"changeAddress", UniValueType(UniValue::VSTR)},
                     {"changePosition", UniValueType(UniValue::VNUM)},
                     {"includeWatching", UniValueType(UniValue::VBOOL)},
                     {"lockUnspents", UniValueType(UniValue::VBOOL)},
                     // will be checked below
                     {"feeRate", UniValueType()},
                     {"subtractFeeFromOutputs", UniValueType(UniValue::VARR)},
                 },
                 true, true);
 
             if (options.exists("changeAddress")) {
                 CTxDestination dest = DecodeDestination(
                     options["changeAddress"].get_str(), pwallet->chainParams);
 
                 if (!IsValidDestination(dest)) {
                     throw JSONRPCError(
                         RPC_INVALID_ADDRESS_OR_KEY,
                         "changeAddress must be a valid bitcoin address");
                 }
 
                 coinControl.destChange = dest;
             }
 
             if (options.exists("changePosition")) {
                 change_position = options["changePosition"].get_int();
             }
 
             if (options.exists("includeWatching")) {
                 coinControl.fAllowWatchOnly =
                     options["includeWatching"].get_bool();
             }
 
             if (options.exists("lockUnspents")) {
                 lockUnspents = options["lockUnspents"].get_bool();
             }
 
             if (options.exists("feeRate")) {
                 coinControl.m_feerate =
                     CFeeRate(AmountFromValue(options["feeRate"]));
                 coinControl.fOverrideFeeRate = true;
             }
 
             if (options.exists("subtractFeeFromOutputs")) {
                 subtractFeeFromOutputs =
                     options["subtractFeeFromOutputs"].get_array();
             }
         }
     }
 
     if (tx.vout.size() == 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "TX must have at least one output");
     }
 
     if (change_position != -1 &&
         (change_position < 0 ||
          (unsigned int)change_position > tx.vout.size())) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "changePosition out of bounds");
     }
 
     for (size_t idx = 0; idx < subtractFeeFromOutputs.size(); idx++) {
         int pos = subtractFeeFromOutputs[idx].get_int();
         if (setSubtractFeeFromOutputs.count(pos)) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid parameter, duplicated position: %d", pos));
         }
         if (pos < 0) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid parameter, negative position: %d", pos));
         }
         if (pos >= int(tx.vout.size())) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid parameter, position too large: %d", pos));
         }
         setSubtractFeeFromOutputs.insert(pos);
     }
 
     std::string strFailReason;
 
     if (!pwallet->FundTransaction(tx, fee_out, change_position, strFailReason,
                                   lockUnspents, setSubtractFeeFromOutputs,
                                   coinControl)) {
         throw JSONRPCError(RPC_WALLET_ERROR, strFailReason);
     }
 }
 
 static UniValue fundrawtransaction(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "fundrawtransaction \"hexstring\" ( options )\n"
             "\nAdd inputs to a transaction until it has enough in value to "
             "meet its out value.\n"
             "This will not modify existing inputs, and will add at most one "
             "change output to the outputs.\n"
             "No existing outputs will be modified unless "
             "\"subtractFeeFromOutputs\" is specified.\n"
             "Note that inputs which were signed may need to be resigned after "
             "completion since in/outputs have been added.\n"
             "The inputs added will not be signed, use "
             "signrawtransactionwithkey or signrawtransactionwithwallet for "
             "that.\n"
             "Note that all existing inputs must have their previous output "
             "transaction be in the wallet.\n"
             "Note that all inputs selected must be of standard form and P2SH "
             "scripts must be\n"
             "in the wallet using importaddress or addmultisigaddress (to "
             "calculate fees).\n"
             "You can see whether this is the case by checking the \"solvable\" "
             "field in the listunspent output.\n"
             "Only pay-to-pubkey, multisig, and P2SH versions thereof are "
             "currently supported for watch-only\n"
             "\nArguments:\n"
             "1. \"hexstring\"           (string, required) The hex string of "
             "the raw transaction\n"
             "2. options                 (object, optional)\n"
             "   {\n"
             "     \"changeAddress\"          (string, optional, default pool "
             "address) The bitcoin address to receive the change\n"
             "     \"changePosition\"         (numeric, optional, default "
             "random) The index of the change output\n"
             "     \"includeWatching\"        (boolean, optional, default "
             "false) Also select inputs which are watch only\n"
             "     \"lockUnspents\"           (boolean, optional, default "
             "false) Lock selected unspent outputs\n"
             "     \"feeRate\"                (numeric, optional, default not "
             "set: makes wallet determine the fee) Set a specific fee rate in " +
             CURRENCY_UNIT +
             "/kB\n"
             "     \"subtractFeeFromOutputs\" (array, optional) A json array of "
             "integers.\n"
             "                              The fee will be equally deducted "
             "from the amount of each specified output.\n"
             "                              The outputs are specified by their "
             "zero-based index, before any change output is added.\n"
             "                              Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                              If no outputs are specified here, "
             "the sender pays the fee.\n"
             "                                  [vout_index,...]\n"
             "   }\n"
             "                         for backward compatibility: passing in a "
             "true instead of an object will result in "
             "{\"includeWatching\":true}\n"
             "\nResult:\n"
             "{\n"
             "  \"hex\":       \"value\", (string)  The resulting raw "
             "transaction (hex-encoded string)\n"
             "  \"fee\":       n,         (numeric) Fee in " +
             CURRENCY_UNIT +
             " the resulting transaction pays\n"
             "  \"changepos\": n          (numeric) The position of the added "
             "change output, or -1\n"
             "}\n"
             "\nExamples:\n"
             "\nCreate a transaction with no inputs\n" +
             HelpExampleCli("createrawtransaction",
                            "\"[]\" \"{\\\"myaddress\\\":0.01}\"") +
             "\nAdd sufficient unsigned inputs to meet the output value\n" +
             HelpExampleCli("fundrawtransaction", "\"rawtransactionhex\"") +
             "\nSign the transaction\n" +
             HelpExampleCli("signrawtransactionwithwallet",
                            "\"fundedtransactionhex\"") +
             "\nSend the transaction\n" +
             HelpExampleCli("sendrawtransaction", "\"signedtransactionhex\""));
     }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValueType()});
 
     // parse hex string from parameter
     CMutableTransaction tx;
     if (!DecodeHexTx(tx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
 
     Amount fee;
     int change_position;
     FundTransaction(pwallet, tx, fee, change_position, request.params[1]);
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("hex", EncodeHexTx(CTransaction(tx)));
     result.pushKV("fee", ValueFromAmount(fee));
     result.pushKV("changepos", change_position);
 
     return result;
 }
 
 UniValue signrawtransactionwithwallet(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             "signrawtransactionwithwallet \"hexstring\" ( "
             "[{\"txid\":\"id\",\"vout\":n,\"scriptPubKey\":\"hex\","
             "\"redeemScript\":\"hex\"},...] sighashtype )\n"
             "\nSign inputs for raw transaction (serialized, hex-encoded).\n"
             "The second optional argument (may be null) is an array of "
             "previous transaction outputs that\n"
             "this transaction depends on but may not yet be in the block "
             "chain.\n" +
             HelpRequiringPassphrase(pwallet) +
             "\n"
 
             "\nArguments:\n"
             "1. \"hexstring\"                      (string, required) The "
             "transaction hex string\n"
             "2. \"prevtxs\"                        (string, optional) An json "
             "array of previous dependent transaction outputs\n"
             "     [                              (json array of json objects, "
             "or 'null' if none provided)\n"
             "       {\n"
             "         \"txid\":\"id\",               (string, required) The "
             "transaction id\n"
             "         \"vout\":n,                  (numeric, required) The "
             "output number\n"
             "         \"scriptPubKey\": \"hex\",     (string, required) script "
             "key\n"
             "         \"redeemScript\": \"hex\",     (string, required for "
             "P2SH) redeem script\n"
             "         \"amount\": value            (numeric, required) The "
             "amount spent\n"
             "       }\n"
             "       ,...\n"
             "    ]\n"
             "3. \"sighashtype\"                    (string, optional, "
             "default=ALL) The signature hash type. Must be one of\n"
             "       \"ALL|FORKID\"\n"
             "       \"NONE|FORKID\"\n"
             "       \"SINGLE|FORKID\"\n"
             "       \"ALL|FORKID|ANYONECANPAY\"\n"
             "       \"NONE|FORKID|ANYONECANPAY\"\n"
             "       \"SINGLE|FORKID|ANYONECANPAY\"\n"
 
             "\nResult:\n"
             "{\n"
             "  \"hex\" : \"value\",                  (string) The hex-encoded "
             "raw transaction with signature(s)\n"
             "  \"complete\" : true|false,          (boolean) If the "
             "transaction has a complete set of signatures\n"
             "  \"errors\" : [                      (json array of objects) "
             "Script verification errors (if there are any)\n"
             "    {\n"
             "      \"txid\" : \"hash\",              (string) The hash of the "
             "referenced, previous transaction\n"
             "      \"vout\" : n,                   (numeric) The index of the "
             "output to spent and used as input\n"
             "      \"scriptSig\" : \"hex\",          (string) The hex-encoded "
             "signature script\n"
             "      \"sequence\" : n,               (numeric) Script sequence "
             "number\n"
             "      \"error\" : \"text\"              (string) Verification or "
             "signing error related to the input\n"
             "    }\n"
             "    ,...\n"
             "  ]\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"") +
             HelpExampleRpc("signrawtransactionwithwallet", "\"myhex\""));
     }
 
     RPCTypeCheck(request.params,
                  {UniValue::VSTR, UniValue::VARR, UniValue::VSTR}, true);
 
     CMutableTransaction mtx;
     if (!DecodeHexTx(mtx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
 
     // Sign the transaction
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
     return SignTransaction(pwallet->chain(), mtx, request.params[1], pwallet,
                            false, request.params[2]);
 }
 
 UniValue generate(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "generate nblocks ( maxtries )\n"
             "\nMine up to nblocks blocks immediately (before the RPC call "
             "returns) to an address in the wallet.\n"
             "\nArguments:\n"
             "1. nblocks      (numeric, required) How many blocks are generated "
             "immediately.\n"
             "2. maxtries     (numeric, optional) How many iterations to try "
             "(default = 1000000).\n"
             "\nResult:\n"
             "[ blockhashes ]     (array) hashes of blocks generated\n"
             "\nExamples:\n"
             "\nGenerate 11 blocks\n" +
             HelpExampleCli("generate", "11"));
     }
 
     int num_generate = request.params[0].get_int();
     uint64_t max_tries = 1000000;
     if (!request.params[1].isNull()) {
         max_tries = request.params[1].get_int();
     }
 
     std::shared_ptr<CReserveScript> coinbase_script;
     pwallet->GetScriptForMining(coinbase_script);
 
     // If the keypool is exhausted, no script is returned at all.  Catch this.
     if (!coinbase_script) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
 
     // throw an error if no script was provided
     if (coinbase_script->reserveScript.empty()) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "No coinbase script available");
     }
 
     return generateBlocks(config, coinbase_script, num_generate, max_tries,
                           true);
 }
 
 UniValue rescanblockchain(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "rescanblockchain (\"start_height\") (\"stop_height\")\n"
             "\nRescan the local blockchain for wallet related transactions.\n"
             "\nArguments:\n"
             "1. \"start_height\"    (numeric, optional) block height where the "
             "rescan should start\n"
             "2. \"stop_height\"     (numeric, optional) the last block height "
             "that should be scanned\n"
             "\nResult:\n"
             "{\n"
             "  \"start_height\"     (numeric) The block height where the "
             "rescan has started. If omitted, rescan started from the genesis "
             "block.\n"
             "  \"stop_height\"      (numeric) The height of the last rescanned "
             "block. If omitted, rescan stopped at the chain tip.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("rescanblockchain", "100000 120000") +
             HelpExampleRpc("rescanblockchain", "100000 120000"));
     }
 
     WalletRescanReserver reserver(pwallet);
     if (!reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     CBlockIndex *pindexStart = nullptr;
     CBlockIndex *pindexStop = nullptr;
     CBlockIndex *pChainTip = nullptr;
     {
-        LOCK(cs_main);
+        auto locked_chain = pwallet->chain().lock();
         pindexStart = chainActive.Genesis();
         pChainTip = chainActive.Tip();
 
         if (!request.params[0].isNull()) {
             pindexStart = chainActive[request.params[0].get_int()];
             if (!pindexStart) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "Invalid start_height");
             }
         }
 
         if (!request.params[1].isNull()) {
             pindexStop = chainActive[request.params[1].get_int()];
             if (!pindexStop) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "Invalid stop_height");
             } else if (pindexStop->nHeight < pindexStart->nHeight) {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     "stop_height must be greater than start_height");
             }
         }
     }
 
     // We can't rescan beyond non-pruned blocks, stop and throw an error
     if (fPruneMode) {
-        LOCK(cs_main);
+        auto locked_chain = pwallet->chain().lock();
         CBlockIndex *block = pindexStop ? pindexStop : pChainTip;
         while (block && block->nHeight >= pindexStart->nHeight) {
             if (!block->nStatus.hasData()) {
                 throw JSONRPCError(RPC_MISC_ERROR,
                                    "Can't rescan beyond pruned data. Use RPC "
                                    "call getblockchaininfo to determine your "
                                    "pruned height.");
             }
             block = block->pprev;
         }
     }
 
     CBlockIndex *stopBlock = pwallet->ScanForWalletTransactions(
         pindexStart, pindexStop, reserver, true);
     if (!stopBlock) {
         if (pwallet->IsAbortingRescan()) {
             throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted.");
         }
         // if we got a nullptr returned, ScanForWalletTransactions did rescan up
         // to the requested stopindex
         stopBlock = pindexStop ? pindexStop : pChainTip;
     } else {
         throw JSONRPCError(RPC_MISC_ERROR,
                            "Rescan failed. Potentially corrupted data files.");
     }
     UniValue response(UniValue::VOBJ);
     response.pushKV("start_height", pindexStart->nHeight);
     response.pushKV("stop_height", stopBlock->nHeight);
     return response;
 }
 
 class DescribeWalletAddressVisitor : public boost::static_visitor<UniValue> {
 public:
     CWallet *const pwallet;
 
     void ProcessSubScript(const CScript &subscript, UniValue &obj,
                           bool include_addresses = false) const {
         // Always present: script type and redeemscript
         std::vector<std::vector<uint8_t>> solutions_data;
         txnouttype which_type = Solver(subscript, solutions_data);
         obj.pushKV("script", GetTxnOutputType(which_type));
         obj.pushKV("hex", HexStr(subscript.begin(), subscript.end()));
 
         CTxDestination embedded;
         UniValue a(UniValue::VARR);
         if (ExtractDestination(subscript, embedded)) {
             // Only when the script corresponds to an address.
             UniValue subobj(UniValue::VOBJ);
             UniValue detail = DescribeAddress(embedded);
             subobj.pushKVs(detail);
             UniValue wallet_detail = boost::apply_visitor(*this, embedded);
             subobj.pushKVs(wallet_detail);
             subobj.pushKV("address", EncodeDestination(embedded, GetConfig()));
             subobj.pushKV("scriptPubKey",
                           HexStr(subscript.begin(), subscript.end()));
             // Always report the pubkey at the top level, so that
             // `getnewaddress()['pubkey']` always works.
             if (subobj.exists("pubkey")) {
                 obj.pushKV("pubkey", subobj["pubkey"]);
             }
             obj.pushKV("embedded", std::move(subobj));
             if (include_addresses) {
                 a.push_back(EncodeDestination(embedded, GetConfig()));
             }
         } else if (which_type == TX_MULTISIG) {
             // Also report some information on multisig scripts (which do not
             // have a corresponding address).
             // TODO: abstract out the common functionality between this logic
             // and ExtractDestinations.
             obj.pushKV("sigsrequired", solutions_data[0][0]);
             UniValue pubkeys(UniValue::VARR);
             for (size_t i = 1; i < solutions_data.size() - 1; ++i) {
                 CPubKey key(solutions_data[i].begin(), solutions_data[i].end());
                 if (include_addresses) {
                     a.push_back(EncodeDestination(key.GetID(), GetConfig()));
                 }
                 pubkeys.push_back(HexStr(key.begin(), key.end()));
             }
             obj.pushKV("pubkeys", std::move(pubkeys));
         }
 
         // The "addresses" field is confusing because it refers to public keys
         // using their P2PKH address. For that reason, only add the 'addresses'
         // field when needed for backward compatibility. New applications can
         // use the 'pubkeys' field for inspecting multisig participants.
         if (include_addresses) {
             obj.pushKV("addresses", std::move(a));
         }
     }
 
     explicit DescribeWalletAddressVisitor(CWallet *_pwallet)
         : pwallet(_pwallet) {}
 
     UniValue operator()(const CNoDestination &dest) const {
         return UniValue(UniValue::VOBJ);
     }
 
     UniValue operator()(const CKeyID &keyID) const {
         UniValue obj(UniValue::VOBJ);
         CPubKey vchPubKey;
         if (pwallet && pwallet->GetPubKey(keyID, vchPubKey)) {
             obj.pushKV("pubkey", HexStr(vchPubKey));
             obj.pushKV("iscompressed", vchPubKey.IsCompressed());
         }
         return obj;
     }
 
     UniValue operator()(const CScriptID &scriptID) const {
         UniValue obj(UniValue::VOBJ);
         CScript subscript;
         if (pwallet && pwallet->GetCScript(scriptID, subscript)) {
             ProcessSubScript(subscript, obj, true);
         }
         return obj;
     }
 };
 
 static UniValue DescribeWalletAddress(CWallet *pwallet,
                                       const CTxDestination &dest) {
     UniValue ret(UniValue::VOBJ);
     UniValue detail = DescribeAddress(dest);
     ret.pushKVs(detail);
     ret.pushKVs(
         boost::apply_visitor(DescribeWalletAddressVisitor(pwallet), dest));
     return ret;
 }
 
 /** Convert CAddressBookData to JSON record.  */
 static UniValue AddressBookDataToJSON(const CAddressBookData &data,
                                       const bool verbose) {
     UniValue ret(UniValue::VOBJ);
     if (verbose) {
         ret.pushKV("name", data.name);
     }
     ret.pushKV("purpose", data.purpose);
     return ret;
 }
 
 UniValue getaddressinfo(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "getaddressinfo \"address\"\n"
             "\nReturn information about the given bitcoin address. Some "
             "information requires the address\n"
             "to be in the wallet.\n"
             "\nArguments:\n"
             "1. \"address\"                    (string, required) The bitcoin "
             "address to get the information of.\n"
             "\nResult:\n"
             "{\n"
             "  \"address\" : \"address\",        (string) The bitcoin address "
             "validated\n"
             "  \"scriptPubKey\" : \"hex\",       (string) The hex encoded "
             "scriptPubKey generated by the address\n"
             "  \"ismine\" : true|false,        (boolean) If the address is "
             "yours or not\n"
             "  \"iswatchonly\" : true|false,   (boolean) If the address is "
             "watchonly\n"
             "  \"isscript\" : true|false,      (boolean) If the key is a "
             "script\n"
             "  \"script\" : \"type\"             (string, optional) The output "
             "script type. Only if \"isscript\" is true and the redeemscript is "
             "known. Possible types: nonstandard, pubkey, pubkeyhash, "
             "scripthash, multisig, nulldata\n"
             "  \"hex\" : \"hex\",                (string, optional) The "
             "redeemscript for the p2sh address\n"
             "  \"pubkeys\"                     (string, optional) Array of "
             "pubkeys associated with the known redeemscript (only if "
             "\"script\" is \"multisig\")\n"
             "    [\n"
             "      \"pubkey\"\n"
             "      ,...\n"
             "    ]\n"
             "  \"sigsrequired\" : xxxxx        (numeric, optional) Number of "
             "signatures required to spend multisig output (only if \"script\" "
             "is \"multisig\")\n"
             "  \"pubkey\" : \"publickeyhex\",    (string, optional) The hex "
             "value of the raw public key, for single-key addresses (possibly "
             "embedded in P2SH or P2WSH)\n"
             "  \"embedded\" : {...},           (object, optional) Information "
             "about the address embedded in P2SH or P2WSH, if relevant and "
             "known. It includes all getaddressinfo output fields for the "
             "embedded address, excluding metadata (\"timestamp\", "
             "\"hdkeypath\", \"hdseedid\") and relation to the wallet "
             "(\"ismine\", \"iswatchonly\", \"account\").\n"
             "  \"iscompressed\" : true|false,  (boolean) If the address is "
             "compressed\n"
             "  \"label\" :  \"label\"         (string) The label associated "
             "with the address, \"\" is the default account\n"
             "  \"account\" : \"account\"         (string) DEPRECATED. This "
             "field will be removed in V0.21. To see this deprecated field, "
             "start bitcoind with -deprecatedrpc=accounts. The account "
             "associated with the address, \"\" is the default account\n"
             "  \"timestamp\" : timestamp,      (number, optional) The creation "
             "time of the key if available in seconds since epoch (Jan 1 1970 "
             "GMT)\n"
             "  \"hdkeypath\" : \"keypath\"       (string, optional) The HD "
             "keypath if the key is HD and available\n"
             "  \"hdseedid\" : \"<hash160>\"      (string, optional) The "
             "Hash160 of the HD seed\n"
             "  \"hdmasterkeyid\" : \"<hash160>\" (string, optional) alias for "
             "hdseedid maintained for backwards compatibility. Will be removed "
             "in V0.21.\n"
             "  \"labels\"                      (object) Array of labels "
             "associated with the address.\n"
             "    [\n"
             "      { (json object of label data)\n"
             "        \"name\": \"labelname\" (string) The label\n"
             "        \"purpose\": \"string\" (string) Purpose of address "
             "(\"send\" for sending address, \"receive\" for receiving "
             "address)\n"
             "      },...\n"
             "    ]\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getaddressinfo",
                            "\"1PSSGeFHDnKNxiEyFrD1wcEaHr9hrQDDWc\"") +
             HelpExampleRpc("getaddressinfo",
                            "\"1PSSGeFHDnKNxiEyFrD1wcEaHr9hrQDDWc\""));
     }
 
     LOCK(pwallet->cs_wallet);
 
     UniValue ret(UniValue::VOBJ);
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
 
     // Make sure the destination is valid
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
     }
 
     std::string currentAddress = EncodeDestination(dest, config);
     ret.pushKV("address", currentAddress);
 
     CScript scriptPubKey = GetScriptForDestination(dest);
     ret.pushKV("scriptPubKey",
                HexStr(scriptPubKey.begin(), scriptPubKey.end()));
 
     isminetype mine = IsMine(*pwallet, dest);
     ret.pushKV("ismine", bool(mine & ISMINE_SPENDABLE));
     ret.pushKV("iswatchonly", bool(mine & ISMINE_WATCH_ONLY));
     UniValue detail = DescribeWalletAddress(pwallet, dest);
     ret.pushKVs(detail);
     if (pwallet->mapAddressBook.count(dest)) {
         ret.pushKV("label", pwallet->mapAddressBook[dest].name);
         if (IsDeprecatedRPCEnabled(gArgs, "accounts")) {
             ret.pushKV("account", pwallet->mapAddressBook[dest].name);
         }
     }
     const CKeyMetadata *meta = nullptr;
     CKeyID key_id = GetKeyForDestination(*pwallet, dest);
     if (!key_id.IsNull()) {
         auto it = pwallet->mapKeyMetadata.find(key_id);
         if (it != pwallet->mapKeyMetadata.end()) {
             meta = &it->second;
         }
     }
     if (!meta) {
         auto it = pwallet->m_script_metadata.find(CScriptID(scriptPubKey));
         if (it != pwallet->m_script_metadata.end()) {
             meta = &it->second;
         }
     }
     if (meta) {
         ret.pushKV("timestamp", meta->nCreateTime);
         if (!meta->hdKeypath.empty()) {
             ret.pushKV("hdkeypath", meta->hdKeypath);
             ret.pushKV("hdseedid", meta->hd_seed_id.GetHex());
             ret.pushKV("hdmasterkeyid", meta->hd_seed_id.GetHex());
         }
     }
 
     // Currently only one label can be associated with an address, return an
     // array so the API remains stable if we allow multiple labels to be
     // associated with an address.
     UniValue labels(UniValue::VARR);
     std::map<CTxDestination, CAddressBookData>::iterator mi =
         pwallet->mapAddressBook.find(dest);
     if (mi != pwallet->mapAddressBook.end()) {
         labels.push_back(AddressBookDataToJSON(mi->second, true));
     }
     ret.pushKV("labels", std::move(labels));
 
     return ret;
 }
 
 UniValue getaddressesbylabel(const Config &config,
                              const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1)
         throw std::runtime_error(
             "getaddressesbylabel \"label\"\n"
             "\nReturns the list of addresses assigned the specified label.\n"
             "\nArguments:\n"
             "1. \"label\"  (string, required) The label.\n"
             "\nResult:\n"
             "{ (json object with addresses as keys)\n"
             "  \"address\": { (json object with information about address)\n"
             "    \"purpose\": \"string\" (string)  Purpose of address "
             "(\"send\" for sending address, \"receive\" for receiving "
             "address)\n"
             "  },...\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getaddressesbylabel", "\"tabby\"") +
             HelpExampleRpc("getaddressesbylabel", "\"tabby\""));
 
     LOCK(pwallet->cs_wallet);
 
     std::string label = LabelFromValue(request.params[0]);
 
     // Find all addresses that have the given label
     UniValue ret(UniValue::VOBJ);
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          pwallet->mapAddressBook) {
         if (item.second.name == label) {
             ret.pushKV(EncodeDestination(item.first, config),
                        AddressBookDataToJSON(item.second, false));
         }
     }
 
     if (ret.empty()) {
         throw JSONRPCError(RPC_WALLET_INVALID_LABEL_NAME,
                            std::string("No addresses with label " + label));
     }
 
     return ret;
 }
 
 UniValue listlabels(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 1)
         throw std::runtime_error(
             "listlabels ( \"purpose\" )\n"
             "\nReturns the list of all labels, or labels that are assigned to "
             "addresses with a specific purpose.\n"
             "\nArguments:\n"
             "1. \"purpose\"    (string, optional) Address purpose to list "
             "labels for ('send','receive'). An empty string is the same as not "
             "providing this argument.\n"
             "\nResult:\n"
             "[               (json array of string)\n"
             "  \"label\",      (string) Label name\n"
             "  ...\n"
             "]\n"
             "\nExamples:\n"
             "\nList all labels\n" +
             HelpExampleCli("listlabels", "") +
             "\nList labels that have receiving addresses\n" +
             HelpExampleCli("listlabels", "receive") +
             "\nList labels that have sending addresses\n" +
             HelpExampleCli("listlabels", "send") + "\nAs json rpc call\n" +
             HelpExampleRpc("listlabels", "receive"));
 
     LOCK(pwallet->cs_wallet);
 
     std::string purpose;
     if (!request.params[0].isNull()) {
         purpose = request.params[0].get_str();
     }
 
     // Add to a set to sort by label name, then insert into Univalue array
     std::set<std::string> label_set;
     for (const std::pair<const CTxDestination, CAddressBookData> &entry :
          pwallet->mapAddressBook) {
         if (purpose.empty() || entry.second.purpose == purpose) {
             label_set.insert(entry.second.name);
         }
     }
 
     UniValue ret(UniValue::VARR);
     for (const std::string &name : label_set) {
         ret.push_back(name);
     }
 
     return ret;
 }
 
 static UniValue sethdseed(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "sethdseed ( \"newkeypool\" \"seed\" )\n"
             "\nSet or generate a new HD wallet seed. Non-HD wallets will not "
             "be upgraded to being a HD wallet. Wallets that are already\n"
             "HD will have a new HD seed set so that new keys added to the "
             "keypool will be derived from this new seed.\n"
             "\nNote that you will need to MAKE A NEW BACKUP of your wallet "
             "after setting the HD wallet seed.\n" +
             HelpRequiringPassphrase(pwallet) +
             "\nArguments:\n"
             "1. \"newkeypool\"         (boolean, optional, default=true) "
             "Whether to flush old unused addresses, including change "
             "addresses, from the keypool and regenerate it.\n"
             "                             If true, the next address from "
             "getnewaddress and change address from getrawchangeaddress will be "
             "from this new seed.\n"
             "                             If false, addresses (including "
             "change addresses if the wallet already had HD Chain Split "
             "enabled) from the existing\n"
             "                             keypool will be used until it has "
             "been depleted.\n"
             "2. \"seed\"               (string, optional) The WIF private key "
             "to use as the new HD seed; if not provided a random seed will be "
             "used.\n"
             "                             The seed value can be retrieved "
             "using the dumpwallet command. It is the private key marked "
             "hdseed=1\n"
             "\nExamples:\n" +
             HelpExampleCli("sethdseed", "") +
             HelpExampleCli("sethdseed", "false") +
             HelpExampleCli("sethdseed", "true \"wifkey\"") +
             HelpExampleRpc("sethdseed", "true, \"wifkey\""));
     }
 
     if (IsInitialBlockDownload()) {
         throw JSONRPCError(
             RPC_CLIENT_IN_INITIAL_DOWNLOAD,
             "Cannot set a new HD seed while still in Initial Block Download");
     }
 
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Cannot set a HD seed to a wallet with private keys disabled");
     }
 
-    LOCK2(cs_main, pwallet->cs_wallet);
+    auto locked_chain = pwallet->chain().lock();
+    LOCK(pwallet->cs_wallet);
 
     // Do not do anything to non-HD wallets
     if (!pwallet->CanSupportFeature(FEATURE_HD)) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Cannot set a HD seed on a non-HD wallet. Start with "
             "-upgradewallet in order to upgrade a non-HD wallet to HD");
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     bool flush_key_pool = true;
     if (!request.params[0].isNull()) {
         flush_key_pool = request.params[0].get_bool();
     }
 
     CPubKey master_pub_key;
     if (request.params[1].isNull()) {
         master_pub_key = pwallet->GenerateNewSeed();
     } else {
         CKey key = DecodeSecret(request.params[1].get_str());
         if (!key.IsValid()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid private key");
         }
 
         if (HaveKey(*pwallet, key)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Already have this key (either as an HD seed or "
                                "as a loose private key)");
         }
 
         master_pub_key = pwallet->DeriveNewSeed(key);
     }
 
     pwallet->SetHDSeed(master_pub_key);
     if (flush_key_pool) {
         pwallet->NewKeyPool();
     }
 
     return NullUniValue;
 }
 
 bool FillPSBT(const CWallet *pwallet, PartiallySignedTransaction &psbtx,
               const CTransaction *txConst, SigHashType sighash_type, bool sign,
               bool bip32derivs) {
     LOCK(pwallet->cs_wallet);
     // Get all of the previous transactions
     bool complete = true;
     for (size_t i = 0; i < txConst->vin.size(); ++i) {
         const CTxIn &txin = txConst->vin[i];
         PSBTInput &input = psbtx.inputs.at(i);
 
         // If we don't know about this input, skip it and let someone else deal
         // with it
         const TxId &txid = txin.prevout.GetTxId();
         const auto it = pwallet->mapWallet.find(txid);
         if (it != pwallet->mapWallet.end()) {
             const CWalletTx &wtx = it->second;
             CTxOut utxo = wtx.tx->vout[txin.prevout.GetN()];
             // Update UTXOs from the wallet.
             input.utxo = utxo;
         }
 
         // Get the Sighash type
         if (sign && input.sighash_type.getRawSigHashType() > 0 &&
             input.sighash_type != sighash_type) {
             throw JSONRPCError(
                 RPC_DESERIALIZATION_ERROR,
                 "Specified sighash and sighash in PSBT do not match.");
         }
 
         complete &=
             SignPSBTInput(HidingSigningProvider(pwallet, !sign, !bip32derivs),
                           *psbtx.tx, input, i, sighash_type);
     }
 
     // Fill in the bip32 keypaths and redeemscripts for the outputs so that
     // hardware wallets can identify change
     for (size_t i = 0; i < txConst->vout.size(); ++i) {
         const CTxOut &out = txConst->vout.at(i);
         PSBTOutput &psbt_out = psbtx.outputs.at(i);
 
         // Dummy tx so we can use ProduceSignature to get stuff out
         CMutableTransaction dummy_tx;
         dummy_tx.vin.push_back(CTxIn());
         dummy_tx.vout.push_back(CTxOut());
 
         // Fill a SignatureData with output info
         SignatureData sigdata;
         psbt_out.FillSignatureData(sigdata);
 
         MutableTransactionSignatureCreator creator(
             psbtx.tx.get_ptr(), 0, out.nValue, SigHashType().withForkId());
         ProduceSignature(HidingSigningProvider(pwallet, true, !bip32derivs),
                          creator, out.scriptPubKey, sigdata);
         psbt_out.FromSignatureData(sigdata);
     }
     return complete;
 }
 
 static UniValue walletprocesspsbt(const Config &config,
                                   const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             "walletprocesspsbt \"psbt\" ( sign \"sighashtype\" bip32derivs )\n"
             "\nUpdate a PSBT with input information from our wallet and then "
             "sign inputs\n"
             "that we can sign for.\n" +
             HelpRequiringPassphrase(pwallet) +
             "\n"
 
             "\nArguments:\n"
             "1. \"psbt\"                      (string, required) The "
             "transaction base64 string\n"
             "2. sign                          (boolean, optional, "
             "default=true) Also sign the transaction when updating\n"
             "3. \"sighashtype\"            (string, optional, "
             "default=ALL|FORKID) The signature hash type to sign with if not "
             "specified by the PSBT. Must be one of\n"
             "       \"ALL|FORKID\"\n"
             "       \"NONE|FORKID\"\n"
             "       \"SINGLE|FORKID\"\n"
             "       \"ALL|FORKID|ANYONECANPAY\"\n"
             "       \"NONE|FORKID|ANYONECANPAY\"\n"
             "       \"SINGLE|FORKID|ANYONECANPAY\"\n"
             "4. bip32derivs                    (boolean, optional, "
             "default=false) If true, includes the BIP 32 derivation paths for "
             "public keys if we know them\n"
 
             "\nResult:\n"
             "{\n"
             "  \"psbt\" : \"value\",          (string) The base64-encoded "
             "partially signed transaction\n"
             "  \"complete\" : true|false,   (boolean) If the transaction has a "
             "complete set of signatures\n"
             "  ]\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("walletprocesspsbt", "\"psbt\""));
     }
 
     RPCTypeCheck(request.params,
                  {UniValue::VSTR, UniValue::VBOOL, UniValue::VSTR});
 
     // Unserialize the transaction
     PartiallySignedTransaction psbtx;
     std::string error;
     if (!DecodePSBT(psbtx, request.params[0].get_str(), error)) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                            strprintf("TX decode failed %s", error));
     }
 
     // Get the sighash type
     SigHashType nHashType = ParseSighashString(request.params[2]);
     if (!nHashType.hasForkId()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Signature must use SIGHASH_FORKID");
     }
 
     // Use CTransaction for the constant parts of the
     // transaction to avoid rehashing.
     const CTransaction txConst(*psbtx.tx);
 
     // Fill transaction with our data and also sign
     bool sign =
         request.params[1].isNull() ? true : request.params[1].get_bool();
     bool bip32derivs =
         request.params[3].isNull() ? false : request.params[3].get_bool();
     bool complete =
         FillPSBT(pwallet, psbtx, &txConst, nHashType, sign, bip32derivs);
 
     UniValue result(UniValue::VOBJ);
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
     ssTx << psbtx;
     result.pushKV("psbt", EncodeBase64((uint8_t *)ssTx.data(), ssTx.size()));
     result.pushKV("complete", complete);
 
     return result;
 }
 
 static UniValue walletcreatefundedpsbt(const Config &config,
                                        const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 5) {
         throw std::runtime_error(
             "walletcreatefundedpsbt [{\"txid\":\"id\",\"vout\":n},...] "
             "[{\"address\":amount},{\"data\":\"hex\"},...] ( locktime ) ( "
             "options bip32derivs )\n"
             "\nCreates and funds a transaction in the Partially Signed "
             "Transaction format. Inputs will be added if supplied inputs are "
             "not enough\n"
             "Implements the Creator and Updater roles.\n"
             "\nArguments:\n"
             "1. \"inputs\"                (array, required) A json array of "
             "json objects\n"
             "     [\n"
             "       {\n"
             "         \"txid\":\"id\",      (string, required) The transaction "
             "id\n"
             "         \"vout\":n,         (numeric, required) The output "
             "number\n"
             "         \"sequence\":n      (numeric, optional) The sequence "
             "number\n"
             "       } \n"
             "       ,...\n"
             "     ]\n"
             "2. \"outputs\"               (array, required) a json array with "
             "outputs (key-value pairs)\n"
             "   [\n"
             "    {\n"
             "      \"address\": x.xxx,    (obj, optional) A key-value pair. "
             "The key (string) is the bitcoin address, the value (float or "
             "string) is the amount in " +
             CURRENCY_UNIT +
             "\n"
             "    },\n"
             "    {\n"
             "      \"data\": \"hex\"        (obj, optional) A key-value pair. "
             "The key must be \"data\", the value is hex encoded data\n"
             "    }\n"
             "    ,...                     More key-value pairs of the above "
             "form. For compatibility reasons, a dictionary, which holds the "
             "key-value pairs directly, is also\n"
             "                             accepted as second parameter.\n"
             "   ]\n"
             "3. locktime                  (numeric, optional, default=0) Raw "
             "locktime. Non-0 value also locktime-activates inputs\n"
             "4. options                 (object, optional)\n"
             "   {\n"
             "     \"changeAddress\"          (string, optional, default pool "
             "address) The bitcoin address to receive the change\n"
             "     \"changePosition\"         (numeric, optional, default "
             "random) The index of the change output\n"
             "     \"change_type\"            (string, optional) The output "
             "type to use. Only valid if changeAddress is not specified. "
             "Options are \"legacy\", \"p2sh-segwit\", and \"bech32\". Default "
             "is set by -changetype.\n"
             "     \"includeWatching\"        (boolean, optional, default "
             "false) Also select inputs which are watch only\n"
             "     \"lockUnspents\"           (boolean, optional, default "
             "false) Lock selected unspent outputs\n"
             "     \"feeRate\"                (numeric, optional, default not "
             "set: makes wallet determine the fee) Set a specific fee rate in " +
             CURRENCY_UNIT +
             "/kB\n"
             "     \"subtractFeeFromOutputs\" (array, optional) A json array of "
             "integers.\n"
             "                              The fee will be equally deducted "
             "from the amount of each specified output.\n"
             "                              The outputs are specified by their "
             "zero-based index, before any change output is added.\n"
             "                              Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                              If no outputs are specified here, "
             "the sender pays the fee.\n"
             "                                  [vout_index,...]\n"
             "   }\n"
             "5. bip32derivs                    (boolean, optional, "
             "default=false) If true, includes the BIP 32 derivation paths for "
             "public keys if we know them\n"
             "\nResult:\n"
             "{\n"
             "  \"psbt\": \"value\",        (string)  The resulting raw "
             "transaction (base64-encoded string)\n"
             "  \"fee\":       n,         (numeric) Fee in " +
             CURRENCY_UNIT +
             " the resulting transaction pays\n"
             "  \"changepos\": n          (numeric) The position of the added "
             "change output, or -1\n"
             "}\n"
             "\nExamples:\n"
             "\nCreate a transaction with no inputs\n" +
             HelpExampleCli("walletcreatefundedpsbt",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]\" "
                            "\"[{\\\"data\\\":\\\"00010203\\\"}]\""));
     }
 
     RPCTypeCheck(request.params,
                  {UniValue::VARR,
                   UniValueType(), // ARR or OBJ, checked later
                   UniValue::VNUM, UniValue::VOBJ},
                  true);
 
     Amount fee;
     int change_position;
     CMutableTransaction rawTx =
         ConstructTransaction(config.GetChainParams(), request.params[0],
                              request.params[1], request.params[2]);
     FundTransaction(pwallet, rawTx, fee, change_position, request.params[3]);
 
     // Make a blank psbt
     PartiallySignedTransaction psbtx;
     psbtx.tx = rawTx;
     for (size_t i = 0; i < rawTx.vin.size(); ++i) {
         psbtx.inputs.push_back(PSBTInput());
     }
     for (size_t i = 0; i < rawTx.vout.size(); ++i) {
         psbtx.outputs.push_back(PSBTOutput());
     }
 
     // Use CTransaction for the constant parts of the
     // transaction to avoid rehashing.
     const CTransaction txConst(*psbtx.tx);
 
     // Fill transaction with out data but don't sign
     bool bip32derivs =
         request.params[4].isNull() ? false : request.params[4].get_bool();
     FillPSBT(pwallet, psbtx, &txConst, SigHashType().withForkId(), false,
              bip32derivs);
 
     // Serialize the PSBT
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
     ssTx << psbtx;
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("psbt", EncodeBase64((uint8_t *)ssTx.data(), ssTx.size()));
     result.pushKV("fee", ValueFromAmount(fee));
     result.pushKV("changepos", change_position);
     return result;
 }
 
 // clang-format off
 static const ContextFreeRPCCommand commands[] = {
     //  category            name                            actor (function)              argNames
     //  ------------------- ------------------------        ----------------------        ----------
     { "rawtransactions",    "fundrawtransaction",           fundrawtransaction,           {"hexstring","options"} },
     { "wallet",             "walletprocesspsbt",            walletprocesspsbt,            {"psbt","sign","sighashtype","bip32derivs"} },
     { "wallet",             "walletcreatefundedpsbt",       walletcreatefundedpsbt,       {"inputs","outputs","locktime","options","bip32derivs"} },
     { "hidden",             "resendwallettransactions",     resendwallettransactions,     {} },
     { "wallet",             "abandontransaction",           abandontransaction,           {"txid"} },
     { "wallet",             "addmultisigaddress",           addmultisigaddress,           {"nrequired","keys","label|account"} },
     { "wallet",             "backupwallet",                 backupwallet,                 {"destination"} },
     { "wallet",             "createwallet",                 createwallet,                 {"wallet_name", "disable_private_keys", "blank"} },
     { "wallet",             "encryptwallet",                encryptwallet,                {"passphrase"} },
     { "wallet",             "getaddressinfo",               getaddressinfo,               {"address"} },
     { "wallet",             "getbalance",                   getbalance,                   {"account|dummy","minconf","include_watchonly"} },
     { "wallet",             "getnewaddress",                getnewaddress,                {"label|account", "address_type"} },
     { "wallet",             "getrawchangeaddress",          getrawchangeaddress,          {"address_type"} },
     { "wallet",             "getreceivedbyaddress",         getreceivedbyaddress,         {"address","minconf"} },
     { "wallet",             "gettransaction",               gettransaction,               {"txid","include_watchonly"} },
     { "wallet",             "getunconfirmedbalance",        getunconfirmedbalance,        {} },
     { "wallet",             "getwalletinfo",                getwalletinfo,                {} },
     { "wallet",             "keypoolrefill",                keypoolrefill,                {"newsize"} },
     { "wallet",             "listaddressgroupings",         listaddressgroupings,         {} },
     { "wallet",             "listlockunspent",              listlockunspent,              {} },
     { "wallet",             "listreceivedbyaddress",        listreceivedbyaddress,        {"minconf","include_empty","include_watchonly","address_filter"} },
     { "wallet",             "listsinceblock",               listsinceblock,               {"blockhash","target_confirmations","include_watchonly","include_removed"} },
     { "wallet",             "listtransactions",             listtransactions,             {"account|dummy","count","skip","include_watchonly"} },
     { "wallet",             "listunspent",                  listunspent,                  {"minconf","maxconf","addresses","include_unsafe","query_options"} },
     { "wallet",             "listwallets",                  listwallets,                  {} },
     { "wallet",             "loadwallet",                   loadwallet,                   {"filename"} },
     { "wallet",             "lockunspent",                  lockunspent,                  {"unlock","transactions"} },
     { "wallet",             "rescanblockchain",             rescanblockchain,             {"start_height", "stop_height"} },
     { "wallet",             "sethdseed",                    sethdseed,                    {"newkeypool","seed"} },
     { "wallet",             "sendmany",                     sendmany,                     {"fromaccount|dummy","amounts","minconf","comment","subtractfeefrom"} },
     { "wallet",             "sendtoaddress",                sendtoaddress,                {"address","amount","comment","comment_to","subtractfeefromamount"} },
     { "wallet",             "settxfee",                     settxfee,                     {"amount"} },
     { "wallet",             "signmessage",                  signmessage,                  {"address","message"} },
     { "wallet",             "signrawtransactionwithwallet", signrawtransactionwithwallet, {"hextring","prevtxs","sighashtype"} },
     { "wallet",             "unloadwallet",                 unloadwallet,                 {"wallet_name"} },
     { "wallet",             "walletlock",                   walletlock,                   {} },
     { "wallet",             "walletpassphrasechange",       walletpassphrasechange,       {"oldpassphrase","newpassphrase"} },
     { "wallet",             "walletpassphrase",             walletpassphrase,             {"passphrase","timeout"} },
 
     /** Account functions (deprecated) */
     { "wallet",             "getaccountaddress",            getaccountaddress,              {"account"} },
     { "wallet",             "getaccount",                   getaccount,                   {"address"} },
     { "wallet",             "getaddressesbyaccount",        getaddressesbyaccount,        {"account"} },
     { "wallet",             "getreceivedbyaccount",         getreceivedbylabel,           {"account","minconf"} },
     { "wallet",             "listaccounts",                 listaccounts,                 {"minconf","include_watchonly"} },
     { "wallet",             "listreceivedbyaccount",        listreceivedbylabel,          {"minconf","include_empty","include_watchonly"} },
     { "wallet",             "setaccount",                   setlabel,                     {"address","account"} },
     { "wallet",             "sendfrom",                     sendfrom,                     {"fromaccount","toaddress","amount","minconf","comment","comment_to"} },
     { "wallet",             "move",                         movecmd,                      {"fromaccount","toaccount","amount","minconf","comment"} },
 
     /** Label functions (to replace non-balance account functions) */
     { "wallet",             "getaddressesbylabel",          getaddressesbylabel,          {"label"} },
     { "wallet",             "getreceivedbylabel",           getreceivedbylabel,           {"label","minconf"} },
     { "wallet",             "listlabels",                   listlabels,                   {"purpose"} },
     { "wallet",             "listreceivedbylabel",          listreceivedbylabel,          {"minconf","include_empty","include_watchonly"} },
     { "wallet",             "setlabel",                     setlabel,                     {"address","label"} },
 
     { "generating",         "generate",                     generate,                     {"nblocks","maxtries"} },
 };
 // clang-format on
 
 void RegisterWalletRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 5c14f96dc..819b1f621 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -1,422 +1,427 @@
 // 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 <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/validation.h>
+#include <interfaces/chain.h>
 #include <rpc/server.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/rpcdump.h>
 #include <wallet/wallet.h>
 
 #include <test/test_bitcoin.h>
 #include <wallet/test/wallet_test_fixture.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <memory>
 #include <set>
 #include <utility>
 #include <vector>
 
 BOOST_FIXTURE_TEST_SUITE(wallet_tests, WalletTestingSetup)
 
 static void AddKey(CWallet &wallet, const CKey &key) {
     LOCK(wallet.cs_wallet);
     wallet.AddKeyPubKey(key, key.GetPubKey());
 }
 
 BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
 
     // Cap last block file size, and mine new block in a new block file.
     CBlockIndex *const nullBlock = nullptr;
     CBlockIndex *oldTip = chainActive.Tip();
     GetBlockFileInfo(oldTip->GetBlockPos().nFile)->nSize = MAX_BLOCKFILE_SIZE;
     CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
     CBlockIndex *newTip = chainActive.Tip();
 
-    LOCK(cs_main);
+    auto locked_chain = chain->lock();
 
     // Verify ScanForWalletTransactions picks up transactions in both the old
     // and new block files.
     {
         CWallet wallet(Params(), *chain, WalletLocation(),
                        WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
         BOOST_CHECK_EQUAL(nullBlock, wallet.ScanForWalletTransactions(
                                          oldTip, nullptr, reserver));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 100 * COIN);
     }
 
     // Prune the older block file.
     PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
     // Verify ScanForWalletTransactions only picks transactions in the new block
     // file.
     {
         CWallet wallet(Params(), *chain, WalletLocation(),
                        WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
         BOOST_CHECK_EQUAL(oldTip, wallet.ScanForWalletTransactions(
                                       oldTip, nullptr, reserver));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 50 * COIN);
     }
 
     // Verify importmulti RPC returns failure for a key whose creation time is
     // before the missing block, and success for a key whose creation time is
     // after.
     {
         std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
             Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
         AddWallet(wallet);
         UniValue keys;
         keys.setArray();
         UniValue key;
         key.setObject();
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(coinbaseKey.GetPubKey())));
         key.pushKV("timestamp", 0);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         key.clear();
         key.setObject();
         CKey futureKey;
         futureKey.MakeNewKey(true);
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(futureKey.GetPubKey())));
         key.pushKV("timestamp",
                    newTip->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(keys);
 
         UniValue response = importmulti(GetConfig(), request);
         BOOST_CHECK_EQUAL(
             response.write(),
             strprintf("[{\"success\":false,\"error\":{\"code\":-1,\"message\":"
                       "\"Rescan failed for key with creation timestamp %d. "
                       "There was an error reading a block from time %d, which "
                       "is after or within %d seconds of key creation, and "
                       "could contain transactions pertaining to the key. As a "
                       "result, transactions and coins using this key may not "
                       "appear in the wallet. This error could be caused by "
                       "pruning or data corruption (see bitcoind log for "
                       "details) and could be dealt with by downloading and "
                       "rescanning the relevant blocks (see -reindex and "
                       "-rescan options).\"}},{\"success\":true}]",
                       0, oldTip->GetBlockTimeMax(), TIMESTAMP_WINDOW));
         RemoveWallet(wallet);
     }
 }
 
 // Verify importwallet RPC starts rescan at earliest block with timestamp
 // greater or equal than key birthday. Previously there was a bug where
 // importwallet RPC would start the scan at the latest block with timestamp less
 // than or equal to key birthday.
 BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
 
     // Create two blocks with same timestamp to verify that importwallet rescan
     // will pick up both blocks, not just the first.
     const int64_t BLOCK_TIME = chainActive.Tip()->GetBlockTimeMax() + 5;
     SetMockTime(BLOCK_TIME);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
 
     // Set key birthday to block time increased by the timestamp window, so
     // rescan will start at the block time.
     const int64_t KEY_TIME = BLOCK_TIME + TIMESTAMP_WINDOW;
     SetMockTime(KEY_TIME);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
 
-    LOCK(cs_main);
+    auto locked_chain = chain->lock();
 
     std::string backup_file =
         (SetDataDir("importwallet_rescan") / "wallet.backup").string();
 
     // Import key into wallet and call dumpwallet to create backup file.
     {
         std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
             Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
         LOCK(wallet->cs_wallet);
         wallet->mapKeyMetadata[coinbaseKey.GetPubKey().GetID()].nCreateTime =
             KEY_TIME;
         wallet->AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
 
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(backup_file);
         AddWallet(wallet);
         ::dumpwallet(GetConfig(), request);
         RemoveWallet(wallet);
     }
 
     // Call importwallet RPC and verify all blocks with timestamps >= BLOCK_TIME
     // were scanned, and no prior blocks were scanned.
     {
         std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
             Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
 
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(backup_file);
         AddWallet(wallet);
         ::importwallet(GetConfig(), request);
         RemoveWallet(wallet);
 
         LOCK(wallet->cs_wallet);
         BOOST_CHECK_EQUAL(wallet->mapWallet.size(), 3U);
         BOOST_CHECK_EQUAL(m_coinbase_txns.size(), 103U);
         for (size_t i = 0; i < m_coinbase_txns.size(); ++i) {
             bool found = wallet->GetWalletTx(m_coinbase_txns[i]->GetId());
             bool expected = i >= 100;
             BOOST_CHECK_EQUAL(found, expected);
         }
     }
 
     SetMockTime(0);
 }
 
 // Check that GetImmatureCredit() returns a newly calculated value instead of
 // the cached value after a MarkDirty() call.
 //
 // This is a regression test written to verify a bugfix for the immature credit
 // function. Similar tests probably should be written for the other credit and
 // debit functions.
 BOOST_FIXTURE_TEST_CASE(coin_mark_dirty_immature_credit, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
     CWallet wallet(Params(), *chain, WalletLocation(),
                    WalletDatabase::CreateDummy());
     CWalletTx wtx(&wallet, m_coinbase_txns.back());
-    LOCK2(cs_main, wallet.cs_wallet);
+    auto locked_chain = chain->lock();
+    LOCK(wallet.cs_wallet);
     wtx.hashBlock = chainActive.Tip()->GetBlockHash();
     wtx.nIndex = 0;
 
     // Call GetImmatureCredit() once before adding the key to the wallet to
     // cache the current immature credit amount, which is 0.
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(), Amount::zero());
 
     // Invalidate the cached value, add the key, and make sure a new immature
     // credit amount is calculated.
     wtx.MarkDirty();
     wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(), 50 * COIN);
 }
 
 static int64_t AddTx(CWallet &wallet, uint32_t lockTime, int64_t mockTime,
                      int64_t blockTime) {
     CMutableTransaction tx;
     tx.nLockTime = lockTime;
     SetMockTime(mockTime);
     CBlockIndex *block = nullptr;
     if (blockTime > 0) {
-        LOCK(cs_main);
+        auto locked_chain = wallet.chain().lock();
         auto inserted =
             mapBlockIndex.emplace(BlockHash(GetRandHash()), new CBlockIndex);
         assert(inserted.second);
         const BlockHash &hash = inserted.first->first;
         block = inserted.first->second;
         block->nTime = blockTime;
         block->phashBlock = &hash;
     }
 
     CWalletTx wtx(&wallet, MakeTransactionRef(tx));
     if (block) {
         wtx.SetMerkleBranch(block, 0);
     }
     {
         LOCK(cs_main);
         wallet.AddToWallet(wtx);
     }
     LOCK(wallet.cs_wallet);
     return wallet.mapWallet.at(wtx.GetId()).nTimeSmart;
 }
 
 // Simple test to verify assignment of CWalletTx::nSmartTime value. Could be
 // expanded to cover more corner cases of smart time logic.
 BOOST_AUTO_TEST_CASE(ComputeTimeSmart) {
     // New transaction should use clock time if lower than block time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 1, 100, 120), 100);
 
     // Test that updating existing transaction does not change smart time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 1, 200, 220), 100);
 
     // New transaction should use clock time if there's no block time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 2, 300, 0), 300);
 
     // New transaction should use block time if lower than clock time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 3, 420, 400), 400);
 
     // New transaction should use latest entry time if higher than
     // min(block time, clock time).
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 4, 500, 390), 400);
 
     // If there are future entries, new transaction should use time of the
     // newest entry that is no more than 300 seconds ahead of the clock time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 5, 50, 600), 300);
 
     // Reset mock time for other tests.
     SetMockTime(0);
 }
 
 BOOST_AUTO_TEST_CASE(LoadReceiveRequests) {
     CTxDestination dest = CKeyID();
     LOCK(m_wallet.cs_wallet);
     m_wallet.AddDestData(dest, "misc", "val_misc");
     m_wallet.AddDestData(dest, "rr0", "val_rr0");
     m_wallet.AddDestData(dest, "rr1", "val_rr1");
 
     auto values = m_wallet.GetDestValues("rr");
     BOOST_CHECK_EQUAL(values.size(), 2U);
     BOOST_CHECK_EQUAL(values[0], "val_rr0");
     BOOST_CHECK_EQUAL(values[1], "val_rr1");
 }
 
 class ListCoinsTestingSetup : public TestChain100Setup {
 public:
     ListCoinsTestingSetup() {
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         wallet = std::make_unique<CWallet>(Params(), *m_chain, WalletLocation(),
                                            WalletDatabase::CreateMock());
         bool firstRun;
         wallet->LoadWallet(firstRun);
         AddKey(*wallet, coinbaseKey);
         WalletRescanReserver reserver(wallet.get());
         reserver.reserve();
         wallet->ScanForWalletTransactions(chainActive.Genesis(), nullptr,
                                           reserver);
     }
 
     ~ListCoinsTestingSetup() { wallet.reset(); }
 
     CWalletTx &AddTx(CRecipient recipient) {
         CTransactionRef tx;
         CReserveKey reservekey(wallet.get());
         Amount fee;
         int changePos = -1;
         std::string error;
         CCoinControl dummy;
         BOOST_CHECK(wallet->CreateTransaction({recipient}, tx, reservekey, fee,
                                               changePos, error, dummy));
         CValidationState state;
         BOOST_CHECK(wallet->CommitTransaction(tx, {}, {}, {}, reservekey,
                                               nullptr, state));
         CMutableTransaction blocktx;
         {
             LOCK(wallet->cs_wallet);
             blocktx =
                 CMutableTransaction(*wallet->mapWallet.at(tx->GetId()).tx);
         }
         CreateAndProcessBlock({CMutableTransaction(blocktx)},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         LOCK(wallet->cs_wallet);
         auto it = wallet->mapWallet.find(tx->GetId());
         BOOST_CHECK(it != wallet->mapWallet.end());
         it->second.SetMerkleBranch(chainActive.Tip(), 1);
         return it->second;
     }
 
     std::unique_ptr<interfaces::Chain> m_chain = interfaces::MakeChain();
+    // Temporary. Removed in upcoming lock cleanup
+    std::unique_ptr<interfaces::Chain::Lock> m_locked_chain =
+        m_chain->assumeLocked();
     std::unique_ptr<CWallet> wallet;
 };
 
 BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup) {
     std::string coinbaseAddress = coinbaseKey.GetPubKey().GetID().ToString();
 
     // Confirm ListCoins initially returns 1 coin grouped under coinbaseKey
     // address.
     std::map<CTxDestination, std::vector<COutput>> list;
     {
         LOCK2(cs_main, wallet->cs_wallet);
         list = wallet->ListCoins();
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<CKeyID>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 1U);
 
     // Check initial balance from one mature coinbase transaction.
     BOOST_CHECK_EQUAL(50 * COIN, wallet->GetAvailableBalance());
 
     // Add a transaction creating a change address, and confirm ListCoins still
     // returns the coin associated with the change address underneath the
     // coinbaseKey pubkey, even though the change address has a different
     // pubkey.
     AddTx(CRecipient{GetScriptForRawPubKey({}), 1 * COIN,
                      false /* subtract fee */});
     {
         LOCK2(cs_main, wallet->cs_wallet);
         list = wallet->ListCoins();
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<CKeyID>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 
     // Lock both coins. Confirm number of available coins drops to 0.
     {
         LOCK2(cs_main, wallet->cs_wallet);
         std::vector<COutput> available;
         wallet->AvailableCoins(available);
         BOOST_CHECK_EQUAL(available.size(), 2U);
     }
     for (const auto &group : list) {
         for (const auto &coin : group.second) {
             LOCK(wallet->cs_wallet);
             wallet->LockCoin(COutPoint(coin.tx->GetId(), coin.i));
         }
     }
     {
         LOCK2(cs_main, wallet->cs_wallet);
         std::vector<COutput> available;
         wallet->AvailableCoins(available);
         BOOST_CHECK_EQUAL(available.size(), 0U);
     }
     // Confirm ListCoins still returns same result as before, despite coins
     // being locked.
     {
         LOCK2(cs_main, wallet->cs_wallet);
         list = wallet->ListCoins();
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<CKeyID>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 }
 
 BOOST_FIXTURE_TEST_CASE(wallet_disableprivkeys, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
         Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
     wallet->SetMinVersion(FEATURE_LATEST);
     wallet->SetWalletFlag(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
     BOOST_CHECK(!wallet->TopUpKeyPool(1000));
     CPubKey pubkey;
     BOOST_CHECK(!wallet->GetKeyFromPool(pubkey, false));
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index ba8da68d0..77b3e6943 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1,4957 +1,4982 @@
 // 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 <fs.h>
+#include <interfaces/chain.h>
 #include <key.h>
 #include <key_io.h>
 #include <keystore.h>
 #include <net.h>
 #include <policy/policy.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <script/script.h>
 #include <script/sighashtype.h>
 #include <script/sign.h>
 #include <shutdown.h>
 #include <timedata.h>
 #include <txmempool.h>
 #include <ui_interface.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/coinselection.h>
 #include <wallet/fees.h>
 #include <wallet/finaltx.h>
 
 #include <boost/algorithm/string/replace.hpp>
 
 #include <algorithm>
 #include <cassert>
 #include <future>
 
 static CCriticalSection cs_wallets;
 static std::vector<std::shared_ptr<CWallet>> vpwallets GUARDED_BY(cs_wallets);
 
 bool AddWallet(const std::shared_ptr<CWallet> &wallet) {
     LOCK(cs_wallets);
     assert(wallet);
     std::vector<std::shared_ptr<CWallet>>::const_iterator i =
         std::find(vpwallets.begin(), vpwallets.end(), wallet);
     if (i != vpwallets.end()) {
         return false;
     }
     vpwallets.push_back(wallet);
     return true;
 }
 
 bool RemoveWallet(const std::shared_ptr<CWallet> &wallet) {
     LOCK(cs_wallets);
     assert(wallet);
     std::vector<std::shared_ptr<CWallet>>::iterator i =
         std::find(vpwallets.begin(), vpwallets.end(), wallet);
     if (i == vpwallets.end()) {
         return false;
     }
     vpwallets.erase(i);
     return true;
 }
 
 bool HasWallets() {
     LOCK(cs_wallets);
     return !vpwallets.empty();
 }
 
 std::vector<std::shared_ptr<CWallet>> GetWallets() {
     LOCK(cs_wallets);
     return vpwallets;
 }
 
 std::shared_ptr<CWallet> GetWallet(const std::string &name) {
     LOCK(cs_wallets);
     for (const std::shared_ptr<CWallet> &wallet : vpwallets) {
         if (wallet->GetName() == name) {
             return wallet;
         }
     }
     return nullptr;
 }
 
 // Custom deleter for shared_ptr<CWallet>.
 static void ReleaseWallet(CWallet *wallet) {
     wallet->WalletLogPrintf("Releasing wallet\n");
     wallet->BlockUntilSyncedToCurrentChain();
     wallet->Flush();
     delete wallet;
 }
 
 static const size_t OUTPUT_GROUP_MAX_ENTRIES = 10;
 
 const uint32_t BIP32_HARDENED_KEY_LIMIT = 0x80000000;
 
 const BlockHash CMerkleTx::ABANDON_HASH(uint256S(
     "0000000000000000000000000000000000000000000000000000000000000001"));
 
 /** @defgroup mapWallet
  *
  * @{
  */
 
 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(WalletBatch &batch, bool internal) {
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
     assert(!IsWalletFlagSet(WALLET_FLAG_BLANK_WALLET));
     // 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 and a seed
     // is present
     if (IsHDEnabled()) {
         DeriveNewChildKey(
             batch, 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(batch, secret, pubkey)) {
         throw std::runtime_error(std::string(__func__) + ": AddKey failed");
     }
 
     return pubkey;
 }
 
 void CWallet::DeriveNewChildKey(WalletBatch &batch, CKeyMetadata &metadata,
                                 CKey &secret, bool internal) {
     // for now we use a fixed keypath scheme of m/0'/0'/k
     // seed (256bit)
     CKey seed;
     // 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 seed
     if (!GetKey(hdChain.seed_id, seed)) {
         throw std::runtime_error(std::string(__func__) + ": seed not found");
     }
 
     masterKey.SetSeed(seed.begin(), seed.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.hd_seed_id = hdChain.seed_id;
     // update the chain model in the database
     if (!batch.WriteHDChain(hdChain)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": Writing HD chain model failed");
     }
 }
 
 bool CWallet::AddKeyPubKeyWithDB(WalletBatch &batch, const CKey &secret,
                                  const CPubKey &pubkey) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
 
     // Make sure we aren't adding private keys to private key disabled wallets
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
 
     // 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 = !encrypted_batch;
     if (needsDB) {
         encrypted_batch = &batch;
     }
     if (!CCryptoKeyStore::AddKeyPubKey(secret, pubkey)) {
         if (needsDB) {
             encrypted_batch = nullptr;
         }
         return false;
     }
 
     if (needsDB) {
         encrypted_batch = 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 batch.WriteKey(pubkey, secret.GetPrivKey(),
                               mapKeyMetadata[pubkey.GetID()]);
     }
 
     UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
     return true;
 }
 
 bool CWallet::AddKeyPubKey(const CKey &secret, const CPubKey &pubkey) {
     WalletBatch batch(*database);
     return CWallet::AddKeyPubKeyWithDB(batch, 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 (encrypted_batch) {
         return encrypted_batch->WriteCryptedKey(
             vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
     }
 
     return WalletBatch(*database).WriteCryptedKey(
         vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
 }
 
 void CWallet::LoadKeyMetadata(const CKeyID &keyID, const CKeyMetadata &meta) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     UpdateTimeFirstKey(meta.nCreateTime);
     mapKeyMetadata[keyID] = meta;
 }
 
 void CWallet::LoadScriptMetadata(const CScriptID &script_id,
                                  const CKeyMetadata &meta) {
     // m_script_metadata
     AssertLockHeld(cs_wallet);
     UpdateTimeFirstKey(meta.nCreateTime);
     m_script_metadata[script_id] = meta;
 }
 
 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;
     }
     if (WalletBatch(*database).WriteCScript(Hash160(redeemScript),
                                             redeemScript)) {
         UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
         return true;
     }
     return false;
 }
 
 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), GetConfig());
         WalletLogPrintf("%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 = m_script_metadata[CScriptID(dest)];
     UpdateTimeFirstKey(meta.nCreateTime);
     NotifyWatchonlyChanged(true);
     if (WalletBatch(*database).WriteWatchOnly(dest, meta)) {
         UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
         return true;
     }
     return false;
 }
 
 bool CWallet::AddWatchOnly(const CScript &dest, int64_t nCreateTime) {
     m_script_metadata[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 WalletBatch(*database).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 = static_cast<unsigned int>(
                 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 +
                  static_cast<unsigned int>(
                      pMasterKey.second.nDeriveIterations * 100 /
                      double(GetTimeMillis() - nStartTime))) /
                 2;
 
             if (pMasterKey.second.nDeriveIterations < 25000) {
                 pMasterKey.second.nDeriveIterations = 25000;
             }
 
             WalletLogPrintf(
                 "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;
             }
 
             WalletBatch(*database).WriteMasterKey(pMasterKey.first,
                                                   pMasterKey.second);
             if (fWasLocked) {
                 Lock();
             }
 
             return true;
         }
     }
 
     return false;
 }
 
 void CWallet::ChainStateFlushed(const CBlockLocator &loc) {
     WalletBatch batch(*database);
     batch.WriteBestBlock(loc);
 }
 
 void CWallet::SetMinVersion(enum WalletFeature nVersion, WalletBatch *batch_in,
                             bool fExplicit) {
     // nWalletVersion
     LOCK(cs_wallet);
     if (nWalletVersion >= nVersion) {
         return;
     }
 
     // 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;
     }
 
     WalletBatch *batch = batch_in ? batch_in : new WalletBatch(*database);
     if (nWalletVersion > 40000) {
         batch->WriteMinVersion(nWalletVersion);
     }
     if (!batch_in) {
         delete batch;
     }
 }
 
 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) {
     database->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 CWalletTx *wtx = &mapWallet.at(it->second);
         if (wtx->nOrderPos < nMinOrderPos) {
             nMinOrderPos = wtx->nOrderPos;
             copyFrom = wtx;
         }
     }
 
     // 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.at(txid);
         if (copyFrom == copyTo) {
             continue;
         }
 
         assert(
             copyFrom &&
             "Oldest wallet transaction in range assumed to have been found.");
 
         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 COutPoint &outpoint) const {
     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) {
     auto it = mapWallet.find(wtxid);
     assert(it != mapWallet.end());
     CWalletTx &thisTx = it->second;
     // 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 = static_cast<unsigned int>(
         2500000 / double(GetTimeMillis() - nStartTime));
 
     nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                  kMasterKey.nDeriveIterations,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations =
         (kMasterKey.nDeriveIterations +
          static_cast<unsigned int>(kMasterKey.nDeriveIterations * 100 /
                                    double(GetTimeMillis() - nStartTime))) /
         2;
 
     if (kMasterKey.nDeriveIterations < 25000) {
         kMasterKey.nDeriveIterations = 25000;
     }
 
     WalletLogPrintf("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(!encrypted_batch);
         encrypted_batch = new WalletBatch(*database);
         if (!encrypted_batch->TxnBegin()) {
             delete encrypted_batch;
             encrypted_batch = nullptr;
             return false;
         }
         encrypted_batch->WriteMasterKey(nMasterKeyMaxID, kMasterKey);
 
         if (!EncryptKeys(_vMasterKey)) {
             encrypted_batch->TxnAbort();
             delete encrypted_batch;
             // 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, encrypted_batch, true);
 
         if (!encrypted_batch->TxnCommit()) {
             delete encrypted_batch;
             // 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 encrypted_batch;
         encrypted_batch = nullptr;
 
         Lock();
         Unlock(strWalletPassphrase);
 
         // If we are using HD, replace the HD seed with a new one
         if (IsHDEnabled()) {
             SetHDSeed(GenerateNewSeed());
         }
 
         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.
         database->Rewrite();
 
         // BDB seems to have a bad habit of writing old data into
         // slack space in .dat files; that is bad if the old data is
         // unencrypted private keys. So:
         database->ReloadDbEnv();
     }
 
     NotifyStatusChanged(this);
     return true;
 }
 
 DBErrors CWallet::ReorderTransactions() {
     LOCK(cs_wallet);
     WalletBatch batch(*database);
 
     // 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 (auto &entry : mapWallet) {
         CWalletTx *wtx = &entry.second;
         txByTime.insert(
             std::make_pair(wtx->nTimeReceived, TxPair(wtx, nullptr)));
     }
 
     std::list<CAccountingEntry> acentries;
     batch.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 != nullptr) ? pwtx->nOrderPos : pacentry->nOrderPos;
 
         if (nOrderPos == -1) {
             nOrderPos = nOrderPosNext++;
             nOrderPosOffsets.push_back(nOrderPos);
 
             if (pwtx) {
                 if (!batch.WriteTx(*pwtx)) {
                     return DBErrors::LOAD_FAIL;
                 }
             } else if (!batch.WriteAccountingEntry(pacentry->nEntryNo,
                                                    *pacentry)) {
                 return DBErrors::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 (!batch.WriteTx(*pwtx)) {
                     return DBErrors::LOAD_FAIL;
                 }
             } else if (!batch.WriteAccountingEntry(pacentry->nEntryNo,
                                                    *pacentry)) {
                 return DBErrors::LOAD_FAIL;
             }
         }
     }
 
     batch.WriteOrderPosNext(nOrderPosNext);
 
     return DBErrors::LOAD_OK;
 }
 
 int64_t CWallet::IncOrderPosNext(WalletBatch *batch) {
     // nOrderPosNext
     AssertLockHeld(cs_wallet);
     int64_t nRet = nOrderPosNext++;
     if (batch) {
         batch->WriteOrderPosNext(nOrderPosNext);
     } else {
         WalletBatch(*database).WriteOrderPosNext(nOrderPosNext);
     }
 
     return nRet;
 }
 
 bool CWallet::AccountMove(std::string strFrom, std::string strTo,
                           const Amount nAmount, std::string strComment) {
     WalletBatch batch(*database);
     if (!batch.TxnBegin()) {
         return false;
     }
 
     int64_t nNow = GetAdjustedTime();
 
     // Debit
     CAccountingEntry debit;
     debit.nOrderPos = IncOrderPosNext(&batch);
     debit.strAccount = strFrom;
     debit.nCreditDebit = -nAmount;
     debit.nTime = nNow;
     debit.strOtherAccount = strTo;
     debit.strComment = strComment;
     AddAccountingEntry(debit, &batch);
 
     // Credit
     CAccountingEntry credit;
     credit.nOrderPos = IncOrderPosNext(&batch);
     credit.strAccount = strTo;
     credit.nCreditDebit = nAmount;
     credit.nTime = nNow;
     credit.strOtherAccount = strFrom;
     credit.strComment = strComment;
     AddAccountingEntry(credit, &batch);
 
     return batch.TxnCommit();
 }
 
 bool CWallet::GetLabelDestination(CTxDestination &dest,
                                   const std::string &label, bool bForceNew) {
     WalletBatch batch(*database);
 
     CAccount account;
     batch.ReadAccount(label, account);
 
     if (!bForceNew) {
         if (!account.vchPubKey.IsValid()) {
             bForceNew = true;
         } else {
             // Check if the current key has been used (TODO: check other
             // addresses with the same key)
             CScript scriptPubKey = GetScriptForDestination(GetDestinationForKey(
                 account.vchPubKey, m_default_address_type));
             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;
         }
 
         LearnRelatedScripts(account.vchPubKey, m_default_address_type);
         dest = GetDestinationForKey(account.vchPubKey, m_default_address_type);
         SetAddressBook(dest, label, "receive");
         batch.WriteAccount(label, account);
     } else {
         dest = GetDestinationForKey(account.vchPubKey, m_default_address_type);
     }
 
     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);
 
     WalletBatch batch(*database, "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(&batch);
         wtx.m_it_wtxOrdered = 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
     WalletLogPrintf("AddToWallet %s  %s%s\n", wtxIn.GetId().ToString(),
                     (fInsertedNew ? "new" : ""), (fUpdated ? "update" : ""));
 
     // Write to disk
     if ((fInsertedNew || fUpdated) && !batch.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;
 }
 
 void CWallet::LoadToWallet(const CWalletTx &wtxIn) {
     const TxId &txid = wtxIn.GetId();
     const auto &ins = mapWallet.emplace(txid, wtxIn);
     CWalletTx &wtx = ins.first->second;
     wtx.BindWallet(this);
     if (/* insertion took place */ ins.second) {
         wtx.m_it_wtxOrdered = wtxOrdered.insert(
             std::make_pair(wtx.nOrderPos, TxPair(&wtx, nullptr)));
     }
     AddToSpends(txid);
     for (const CTxIn &txin : wtx.tx->vin) {
         auto it = mapWallet.find(txin.prevout.GetTxId());
         if (it != mapWallet.end()) {
             CWalletTx &prevtx = it->second;
             if (prevtx.nIndex == -1 && !prevtx.hashUnset()) {
                 MarkConflicted(prevtx.hashBlock, wtx.GetId());
             }
         }
     }
 }
 
 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()) {
                     WalletLogPrintf(
                         "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()) {
                     WalletLogPrintf("%s: Detected a used keypool key, mark all "
                                     "keypool key up to this key as used\n",
                                     __func__);
                     MarkReserveKeysAsUsed(mi->second);
 
                     if (!TopUpKeyPool()) {
                         WalletLogPrintf(
                             "%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::TransactionCanBeAbandoned(const TxId &txid) const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
     const CWalletTx *wtx = GetWalletTx(txid);
     return wtx && !wtx->isAbandoned() && wtx->GetDepthInMainChain() == 0 &&
            !wtx->InMempool();
 }
 
 void CWallet::MarkInputsDirty(const CTransactionRef &tx) {
     for (const CTxIn &txin : tx->vin) {
         auto it = mapWallet.find(txin.prevout.GetTxId());
         if (it != mapWallet.end()) {
             it->second.MarkDirty();
         }
     }
 }
 
 bool CWallet::AbandonTransaction(const TxId &txid) {
-    LOCK2(cs_main, cs_wallet);
+    // Temporary. Removed in upcoming lock cleanup
+    auto locked_chain_recursive = chain().lock();
+    LOCK(cs_wallet);
 
     WalletBatch batch(*database, "r+");
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     // Can't mark abandoned if confirmed or in mempool
     auto it = mapWallet.find(txid);
     assert(it != mapWallet.end());
     CWalletTx &origtx = it->second;
     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);
         it = mapWallet.find(now);
         assert(it != mapWallet.end());
         CWalletTx &wtx = it->second;
         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();
             batch.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.
             MarkInputsDirty(wtx.tx);
         }
     }
 
     return true;
 }
 
 void CWallet::MarkConflicted(const BlockHash &hashBlock, const TxId &txid) {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     int conflictconfirms = 0;
     CBlockIndex *pindex = LookupBlockIndex(hashBlock);
     if (pindex && 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.
     WalletBatch batch(*database, "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);
         auto it = mapWallet.find(now);
         assert(it != mapWallet.end());
         CWalletTx &wtx = it->second;
         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();
             batch.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.
             MarkInputsDirty(wtx.tx);
         }
     }
 }
 
 void CWallet::SyncTransaction(const CTransactionRef &ptx,
                               const CBlockIndex *pindex, int posInBlock,
                               bool update_tx) {
     if (!AddToWalletIfInvolvingMe(ptx, pindex, posInBlock, update_tx)) {
         // 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:
     MarkInputsDirty(ptx);
 }
 
 void CWallet::TransactionAddedToMempool(const CTransactionRef &ptx) {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
     SyncTransaction(ptx);
 
     auto it = mapWallet.find(ptx->GetId());
     if (it != mapWallet.end()) {
         it->second.fInMempool = true;
     }
 }
 
 void CWallet::TransactionRemovedFromMempool(const CTransactionRef &ptx) {
     LOCK(cs_wallet);
     auto it = mapWallet.find(ptx->GetId());
     if (it != mapWallet.end()) {
         it->second.fInMempool = false;
     }
 }
 
 void CWallet::BlockConnected(
     const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex,
     const std::vector<CTransactionRef> &vtxConflicted) {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     // TODO: Temporarily 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 inadvertently cleared by the notification
     // that the conflicted transaction was evicted.
     for (const CTransactionRef &ptx : vtxConflicted) {
         SyncTransaction(ptx);
         TransactionRemovedFromMempool(ptx);
     }
 
     for (size_t i = 0; i < pblock->vtx.size(); i++) {
         SyncTransaction(pblock->vtx[i], pindex, i);
         TransactionRemovedFromMempool(pblock->vtx[i]);
     }
 
     m_last_block_processed = pindex;
 }
 
 void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     for (const CTransactionRef &ptx : pblock->vtx) {
         SyncTransaction(ptx);
     }
 }
 
 void CWallet::BlockUntilSyncedToCurrentChain() {
     AssertLockNotHeld(cs_main);
     AssertLockNotHeld(cs_wallet);
 
     {
         // Skip the queue-draining stuff if we know we're caught up with
         // chainActive.Tip()...
         // We could also take cs_wallet here, and call m_last_block_processed
         // protected by cs_wallet instead of cs_main, but as long as we need
         // cs_main here anyway, it's easier to just call it cs_main-protected.
-        LOCK(cs_main);
+        auto locked_chain = chain().lock();
         const CBlockIndex *initialChainTip = chainActive.Tip();
-
         if (m_last_block_processed &&
             m_last_block_processed->GetAncestor(initialChainTip->nHeight) ==
                 initialChainTip) {
             return;
         }
     }
 
     // ...otherwise put a callback in the validation interface queue and wait
     // for the queue to drain enough to execute it (indicating we are caught up
     // at least with the time we entered this function).
     SyncWithValidationInterfaceQueue();
 }
 
 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::GenerateNewSeed() {
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
     CKey key;
     key.MakeNewKey(true);
     return DeriveNewSeed(key);
 }
 
 CPubKey CWallet::DeriveNewSeed(const CKey &key) {
     int64_t nCreationTime = GetTime();
     CKeyMetadata metadata(nCreationTime);
 
     // Calculate the seed
     CPubKey seed = key.GetPubKey();
     assert(key.VerifyPubKey(seed));
 
     // Set the hd keypath to "s" -> Seed, refers the seed to itself
     metadata.hdKeypath = "s";
     metadata.hd_seed_id = seed.GetID();
 
     LOCK(cs_wallet);
 
     // mem store the metadata
     mapKeyMetadata[seed.GetID()] = metadata;
 
     // Write the key&metadata to the database
     if (!AddKeyPubKey(key, seed)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": AddKeyPubKey failed");
     }
 
     return seed;
 }
 
 void CWallet::SetHDSeed(const CPubKey &seed) {
     LOCK(cs_wallet);
 
     // Store the keyid (hash160) together with the child index counter in the
     // database as a hdchain object.
     CHDChain newHdChain;
     newHdChain.nVersion = CanSupportFeature(FEATURE_HD_SPLIT)
                               ? CHDChain::VERSION_HD_CHAIN_SPLIT
                               : CHDChain::VERSION_HD_BASE;
     newHdChain.seed_id = seed.GetID();
     SetHDChain(newHdChain, false);
     NotifyCanGetAddressesChanged();
     UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
 }
 
 void CWallet::SetHDChain(const CHDChain &chain, bool memonly) {
     LOCK(cs_wallet);
     if (!memonly && !WalletBatch(*database).WriteHDChain(chain)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing chain failed");
     }
 
     hdChain = chain;
 }
 
 bool CWallet::IsHDEnabled() const {
     return !hdChain.seed_id.IsNull();
 }
 
 bool CWallet::CanGenerateKeys() {
     // A wallet can generate keys if it has an HD seed (IsHDEnabled) or it is a
     // non-HD wallet (pre FEATURE_HD)
     LOCK(cs_wallet);
     return IsHDEnabled() || !CanSupportFeature(FEATURE_HD);
 }
 
 bool CWallet::CanGetAddresses(bool internal) {
     LOCK(cs_wallet);
     // Check if the keypool has keys
     bool keypool_has_keys;
     if (internal && CanSupportFeature(FEATURE_HD_SPLIT)) {
         keypool_has_keys = setInternalKeyPool.size() > 0;
     } else {
         keypool_has_keys = KeypoolCountExternalKeys() > 0;
     }
     // If the keypool doesn't have keys, check if we can generate them
     if (!keypool_has_keys) {
         return CanGenerateKeys();
     }
     return keypool_has_keys;
 }
 
 void CWallet::SetWalletFlag(uint64_t flags) {
     LOCK(cs_wallet);
     m_wallet_flags |= flags;
     if (!WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 }
 
 void CWallet::UnsetWalletFlag(uint64_t flag) {
     LOCK(cs_wallet);
     m_wallet_flags &= ~flag;
     if (!WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 }
 
 bool CWallet::IsWalletFlagSet(uint64_t flag) {
     return (m_wallet_flags & flag);
 }
 
 bool CWallet::SetWalletFlags(uint64_t overwriteFlags, bool memonly) {
     LOCK(cs_wallet);
     m_wallet_flags = overwriteFlags;
     if (((overwriteFlags & g_known_wallet_flags) >> 32) ^
         (overwriteFlags >> 32)) {
         // contains unknown non-tolerable wallet flags
         return false;
     }
     if (!memonly && !WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 
     return true;
 }
 
 int64_t CWalletTx::GetTxTime() const {
     int64_t n = nTimeSmart;
     return n ? n : nTimeReceived;
 }
 
 // Helper for producing a max-sized low-S low-R signature (eg 71 bytes)
 // or a max-sized low-S signature (e.g. 72 bytes) if use_max_sig is true
 bool CWallet::DummySignInput(CTxIn &tx_in, const CTxOut &txout,
                              bool use_max_sig) const {
     // Fill in dummy signatures for fee calculation.
     const CScript &scriptPubKey = txout.scriptPubKey;
     SignatureData sigdata;
 
     if (!ProduceSignature(*this,
                           use_max_sig ? DUMMY_MAXIMUM_SIGNATURE_CREATOR
                                       : DUMMY_SIGNATURE_CREATOR,
                           scriptPubKey, sigdata)) {
         return false;
     }
 
     UpdateInput(tx_in, sigdata);
     return true;
 }
 
 // Helper for producing a bunch of max-sized low-S low-R signatures (eg 71
 // bytes)
 bool CWallet::DummySignTx(CMutableTransaction &txNew,
                           const std::vector<CTxOut> &txouts,
                           bool use_max_sig) const {
     // Fill in dummy signatures for fee calculation.
     int nIn = 0;
     for (const auto &txout : txouts) {
         if (!DummySignInput(txNew.vin[nIn], txout, use_max_sig)) {
             return false;
         }
 
         nIn++;
     }
     return true;
 }
 
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet, bool use_max_sig) {
     std::vector<CTxOut> txouts;
     // Look up the inputs.  We should have already checked that this transaction
     // IsAllFromMe(ISMINE_SPENDABLE), so every input should already be in our
     // wallet, with a valid index into the vout array, and the ability to sign.
     for (auto &input : tx.vin) {
         const auto mi = wallet->mapWallet.find(input.prevout.GetTxId());
         if (mi == wallet->mapWallet.end()) {
             return -1;
         }
         assert(input.prevout.GetN() < mi->second.tx->vout.size());
         txouts.emplace_back(mi->second.tx->vout[input.prevout.GetN()]);
     }
     return CalculateMaximumSignedTxSize(tx, wallet, txouts, use_max_sig);
 }
 
 // txouts needs to be in the order of tx.vin
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      const std::vector<CTxOut> &txouts,
                                      bool use_max_sig) {
     CMutableTransaction txNew(tx);
     if (!wallet->DummySignTx(txNew, txouts, use_max_sig)) {
         // This should never happen, because IsAllFromMe(ISMINE_SPENDABLE)
         // implies that we can sign for every input.
         return -1;
     }
     return GetSerializeSize(txNew, PROTOCOL_VERSION);
 }
 
 int CalculateMaximumSignedInputSize(const CTxOut &txout, const CWallet *wallet,
                                     bool use_max_sig) {
     CMutableTransaction txn;
     txn.vin.push_back(CTxIn(COutPoint()));
     if (!wallet->DummySignInput(txn.vin[0], txout, use_max_sig)) {
         // This should never happen, because IsAllFromMe(ISMINE_SPENDABLE)
         // implies that we can sign for every input.
         return -1;
     }
     return GetSerializeSize(txn.vin[0], PROTOCOL_VERSION);
 }
 
 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()) {
             pwallet->WalletLogPrintf("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,
                                 const WalletRescanReserver &reserver,
                                 bool update) {
     // 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 *startBlock = nullptr;
     {
-        LOCK(cs_main);
+        auto locked_chain = chain().lock();
         startBlock =
             chainActive.FindEarliestAtLeast(startTime - TIMESTAMP_WINDOW);
         WalletLogPrintf(
             "%s: Rescanning last %i blocks\n", __func__,
             startBlock ? chainActive.Height() - startBlock->nHeight + 1 : 0);
     }
 
     if (startBlock) {
         const CBlockIndex *const failedBlock =
             ScanForWalletTransactions(startBlock, nullptr, reserver, 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
  *
  * Caller needs to make sure pindexStop (and the optional pindexStart) are on
  * the main chain after to the addition of any new keys you want to detect
  * transactions for.
  */
 CBlockIndex *CWallet::ScanForWalletTransactions(
     CBlockIndex *pindexStart, CBlockIndex *pindexStop,
     const WalletRescanReserver &reserver, bool fUpdate) {
     int64_t nNow = GetTime();
 
     assert(reserver.isReserved());
     if (pindexStop) {
         assert(pindexStop->nHeight >= pindexStart->nHeight);
     }
 
     CBlockIndex *pindex = pindexStart;
     CBlockIndex *ret = nullptr;
 
     if (pindex) {
         WalletLogPrintf("Rescan started from block %d...\n", pindex->nHeight);
     }
 
     {
         fAbortRescan = false;
 
         // Show rescan progress in GUI as dialog or on splashscreen, if -rescan
         // on startup.
         ShowProgress(strprintf("%s " + _("Rescanning..."), GetDisplayName()),
                      0);
         CBlockIndex *tip = nullptr;
         double progress_begin;
         double progress_end;
         {
-            LOCK(cs_main);
+            auto locked_chain = chain().lock();
             progress_begin =
                 GuessVerificationProgress(chainParams.TxData(), pindex);
             if (pindexStop == nullptr) {
                 tip = chainActive.Tip();
                 progress_end =
                     GuessVerificationProgress(chainParams.TxData(), tip);
             } else {
                 progress_end =
                     GuessVerificationProgress(chainParams.TxData(), pindexStop);
             }
         }
         double progress_current = progress_begin;
         while (pindex && !fAbortRescan && !ShutdownRequested()) {
             if (pindex->nHeight % 100 == 0 &&
                 progress_end - progress_begin > 0.0) {
                 ShowProgress(
                     strprintf("%s " + _("Rescanning..."), GetDisplayName()),
                     std::max(
                         1,
                         std::min(99, (int)((progress_current - progress_begin) /
                                            (progress_end - progress_begin) *
                                            100))));
             }
             if (GetTime() >= nNow + 60) {
                 nNow = GetTime();
                 WalletLogPrintf("Still rescanning. At block %d. Progress=%f\n",
                                 pindex->nHeight, progress_current);
             }
 
             CBlock block;
             if (ReadBlockFromDisk(block, pindex, chainParams.GetConsensus())) {
-                LOCK2(cs_main, cs_wallet);
+                auto locked_chain = chain().lock();
+                LOCK(cs_wallet);
                 if (pindex && !chainActive.Contains(pindex)) {
                     // Abort scan if current block is no longer active, to
                     // prevent marking transactions as coming from the wrong
                     // block.
                     ret = pindex;
                     break;
                 }
                 for (size_t posInBlock = 0; posInBlock < block.vtx.size();
                      ++posInBlock) {
                     SyncTransaction(block.vtx[posInBlock], pindex, posInBlock,
                                     fUpdate);
                 }
             } else {
                 ret = pindex;
             }
             if (pindex == pindexStop) {
                 break;
             }
             {
-                LOCK(cs_main);
+                auto locked_chain = chain().lock();
                 pindex = chainActive.Next(pindex);
                 progress_current =
                     GuessVerificationProgress(chainParams.TxData(), pindex);
                 if (pindexStop == nullptr && tip != chainActive.Tip()) {
                     tip = chainActive.Tip();
                     // in case the tip has changed, update progress max
                     progress_end =
                         GuessVerificationProgress(chainParams.TxData(), tip);
                 }
             }
         }
 
         if (pindex && fAbortRescan) {
             WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n",
                             pindex->nHeight, progress_current);
         } else if (pindex && ShutdownRequested()) {
             WalletLogPrintf("Rescan interrupted by shutdown request at block "
                             "%d. Progress=%f\n",
                             pindex->nHeight, progress_current);
         }
 
         // Hide progress dialog in GUI.
         ShowProgress(strprintf("%s " + _("Rescanning..."), GetDisplayName()),
                      100);
     }
     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);
+    auto locked_chain = chain().lock();
+    LOCK(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 (const std::pair<const int64_t, CWalletTx *> &item : mapSorted) {
         CWalletTx &wtx = *(item.second);
         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)) {
         pwallet->WalletLogPrintf("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(*tx, ISMINE_SPENDABLE);
             fDebitCached = true;
             debit += nDebitCached;
         }
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         if (fWatchDebitCached) {
             debit += nWatchDebitCached;
         } else {
             nWatchDebitCached = pwallet->GetDebit(*tx, 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(*tx, ISMINE_SPENDABLE);
             fCreditCached = true;
             credit += nCreditCached;
         }
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         if (fWatchCreditCached) {
             credit += nWatchCreditCached;
         } else {
             nWatchCreditCached = pwallet->GetCredit(*tx, 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(*tx, ISMINE_SPENDABLE);
         fImmatureCreditCached = true;
         return nImmatureCreditCached;
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetAvailableCredit(bool fUseCache,
                                      const isminefilter &filter) const {
     if (pwallet == nullptr) {
         return Amount::zero();
     }
 
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase()) {
         return Amount::zero();
     }
 
     Amount *cache = nullptr;
     bool *cache_used = nullptr;
 
     if (filter == ISMINE_SPENDABLE) {
         cache = &nAvailableCreditCached;
         cache_used = &fAvailableCreditCached;
     } else if (filter == ISMINE_WATCH_ONLY) {
         cache = &nAvailableWatchCreditCached;
         cache_used = &fAvailableWatchCreditCached;
     }
 
     if (fUseCache && cache_used && *cache_used) {
         return *cache;
     }
 
     Amount nCredit = Amount::zero();
     const TxId &txid = GetId();
     for (uint32_t i = 0; i < tx->vout.size(); i++) {
         if (!pwallet->IsSpent(COutPoint(txid, i))) {
             const CTxOut &txout = tx->vout[i];
             nCredit += pwallet->GetCredit(txout, filter);
             if (!MoneyRange(nCredit)) {
                 throw std::runtime_error(std::string(__func__) +
                                          " : value out of range");
             }
         }
     }
 
     if (cache) {
         *cache = nCredit;
         *cache_used = true;
     }
     return nCredit;
 }
 
 Amount CWalletTx::GetImmatureWatchOnlyCredit(const bool fUseCache) const {
     if (IsImmatureCoinBase() && IsInMainChain()) {
         if (fUseCache && fImmatureWatchCreditCached) {
             return nImmatureWatchCreditCached;
         }
 
         nImmatureWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
         fImmatureWatchCreditCached = true;
         return nImmatureWatchCreditCached;
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetChange() const {
     if (fChangeCached) {
         return nChangeCached;
     }
 
     nChangeCached = pwallet->GetChange(*tx);
     fChangeCached = true;
     return nChangeCached;
 }
 
 bool CWalletTx::InMempool() const {
     return fInMempool;
 }
 
 bool CWalletTx::IsTrusted() const {
     // Quick answer in most cases
     if (!CheckFinalTx(*tx)) {
         return false;
     }
 
     int nDepth = GetDepthInMainChain();
     if (nDepth >= 1) {
         return true;
     }
 
     if (nDepth < 0) {
         return false;
     }
 
     // using wtx's cached debit
     if (!pwallet->m_spend_zero_conf_change || !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 (auto &txin : tx1.vin) {
         txin.scriptSig = CScript();
     }
 
     for (auto &txin : tx2.vin) {
         txin.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 (const 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();
 
+    // Temporary. Removed in upcoming lock cleanup
+    auto locked_chain = chain().assumeLocked();
     // 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()) {
         WalletLogPrintf("%s: rebroadcast %u unconfirmed transactions\n",
                         __func__, relayed.size());
     }
 }
 
 /** @} */ // end of mapWallet
 
 /**
  * @defgroup Actions
  *
  * @{
  */
 Amount CWallet::GetBalance(const isminefilter &filter,
                            const int min_depth) const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         if (pcoin->IsTrusted() && pcoin->GetDepthInMainChain() >= min_depth) {
             nTotal += pcoin->GetAvailableCredit(true, filter);
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetUnconfirmedBalance() const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 &&
             pcoin->InMempool()) {
             nTotal += pcoin->GetAvailableCredit();
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetImmatureBalance() const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         nTotal += pcoin->GetImmatureCredit();
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetUnconfirmedWatchOnlyBalance() const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 &&
             pcoin->InMempool()) {
             nTotal += pcoin->GetAvailableCredit(true, ISMINE_WATCH_ONLY);
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetImmatureWatchOnlyBalance() const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.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);
+    auto locked_chain = chain().lock();
+    LOCK(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 == GetLabelName(out.scriptPubKey))) {
                 balance += out.nValue;
             }
         }
 
         // For outgoing txs, subtract amount debited.
         if (outgoing && (!account || *account == wtx.strFromAccount)) {
             balance -= debit;
         }
     }
 
     if (account) {
         balance += WalletBatch(*database).GetAccountCreditDebit(*account);
     }
 
     return balance;
 }
 
 Amount CWallet::GetAvailableBalance(const CCoinControl *coinControl) const {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     Amount balance = Amount::zero();
     std::vector<COutput> vCoins;
     AvailableCoins(vCoins, true, coinControl);
     for (const COutput &out : vCoins) {
         if (out.fSpendable) {
             balance += out.tx->tx->vout[out.i].nValue;
         }
     }
     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 {
     AssertLockHeld(cs_main);
     AssertLockHeld(cs_wallet);
 
     vCoins.clear();
     Amount nTotal = Amount::zero();
 
     for (const auto &entry : mapWallet) {
         const TxId &wtxid = entry.first;
         const CWalletTx *pcoin = &entry.second;
 
         if (!CheckFinalTx(*pcoin->tx)) {
             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;
             }
 
             const COutPoint outpoint(wtxid, i);
 
             if (coinControl && coinControl->HasSelected() &&
                 !coinControl->fAllowOtherInputs &&
                 !coinControl->IsSelected(outpoint)) {
                 continue;
             }
 
             if (IsLockedCoin(outpoint)) {
                 continue;
             }
 
             if (IsSpent(outpoint)) {
                 continue;
             }
 
             isminetype mine = IsMine(pcoin->tx->vout[i]);
 
             if (mine == ISMINE_NO) {
                 continue;
             }
 
             bool solvable = IsSolvable(*this, pcoin->tx->vout[i].scriptPubKey);
             bool spendable =
                 ((mine & ISMINE_SPENDABLE) != ISMINE_NO) ||
                 (((mine & ISMINE_WATCH_ONLY) != ISMINE_NO) &&
                  (coinControl && coinControl->fAllowWatchOnly && solvable));
 
             vCoins.push_back(
                 COutput(pcoin, i, nDepth, spendable, solvable, safeTx,
                         (coinControl && coinControl->fAllowWatchOnly)));
 
             // 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;
             }
         }
     }
 }
 
 std::map<CTxDestination, std::vector<COutput>> CWallet::ListCoins() const {
     AssertLockHeld(cs_main);
     AssertLockHeld(cs_wallet);
 
     std::map<CTxDestination, std::vector<COutput>> result;
     std::vector<COutput> availableCoins;
 
     AvailableCoins(availableCoins);
 
     for (const auto &coin : availableCoins) {
         CTxDestination address;
         if (coin.fSpendable &&
             ExtractDestination(
                 FindNonChangeParentOutput(*coin.tx->tx, coin.i).scriptPubKey,
                 address)) {
             result[address].emplace_back(std::move(coin));
         }
     }
 
     std::vector<COutPoint> lockedCoins;
     ListLockedCoins(lockedCoins);
     for (const auto &output : lockedCoins) {
         auto it = mapWallet.find(output.GetTxId());
         if (it != mapWallet.end()) {
             int depth = it->second.GetDepthInMainChain();
             if (depth >= 0 && output.GetN() < it->second.tx->vout.size() &&
                 IsMine(it->second.tx->vout[output.GetN()]) ==
                     ISMINE_SPENDABLE) {
                 CTxDestination address;
                 if (ExtractDestination(
                         FindNonChangeParentOutput(*it->second.tx, output.GetN())
                             .scriptPubKey,
                         address)) {
                     result[address].emplace_back(
                         &it->second, output.GetN(), depth, true /* spendable */,
                         true /* solvable */, false /* safe */);
                 }
             }
         }
     }
 
     return result;
 }
 
 const CTxOut &CWallet::FindNonChangeParentOutput(const CTransaction &tx,
                                                  int output) const {
     const CTransaction *ptx = &tx;
     int n = output;
     while (IsChange(ptx->vout[n]) && ptx->vin.size() > 0) {
         const COutPoint &prevout = ptx->vin[0].prevout;
         auto it = mapWallet.find(prevout.GetTxId());
         if (it == mapWallet.end() ||
             it->second.tx->vout.size() <= prevout.GetN() ||
             !IsMine(it->second.tx->vout[prevout.GetN()])) {
             break;
         }
         ptx = it->second.tx.get();
         n = prevout.GetN();
     }
     return ptx->vout[n];
 }
 
 bool CWallet::SelectCoinsMinConf(
     const Amount nTargetValue, const CoinEligibilityFilter &eligibility_filter,
     std::vector<OutputGroup> groups, std::set<CInputCoin> &setCoinsRet,
     Amount &nValueRet, const CoinSelectionParams &coin_selection_params,
     bool &bnb_used) const {
     setCoinsRet.clear();
     nValueRet = Amount::zero();
 
     std::vector<OutputGroup> utxo_pool;
     if (coin_selection_params.use_bnb) {
         // Get long term estimate
         CCoinControl temp;
         temp.m_confirm_target = 1008;
         CFeeRate long_term_feerate = GetMinimumFeeRate(*this, temp, g_mempool);
 
         // Calculate cost of change
         Amount cost_of_change =
             dustRelayFee.GetFee(coin_selection_params.change_spend_size) +
             coin_selection_params.effective_fee.GetFee(
                 coin_selection_params.change_output_size);
 
         // Filter by the min conf specs and add to utxo_pool and calculate
         // effective value
         for (OutputGroup &group : groups) {
             if (!group.EligibleForSpending(eligibility_filter)) {
                 continue;
             }
 
             group.fee = Amount::zero();
             group.long_term_fee = Amount::zero();
             group.effective_value = Amount::zero();
             for (auto it = group.m_outputs.begin();
                  it != group.m_outputs.end();) {
                 const CInputCoin &coin = *it;
                 Amount effective_value =
                     coin.txout.nValue -
                     (coin.m_input_bytes < 0
                          ? Amount::zero()
                          : coin_selection_params.effective_fee.GetFee(
                                coin.m_input_bytes));
                 // Only include outputs that are positive effective value (i.e.
                 // not dust)
                 if (effective_value > Amount::zero()) {
                     group.fee +=
                         coin.m_input_bytes < 0
                             ? Amount::zero()
                             : coin_selection_params.effective_fee.GetFee(
                                   coin.m_input_bytes);
                     group.long_term_fee +=
                         coin.m_input_bytes < 0
                             ? Amount::zero()
                             : long_term_feerate.GetFee(coin.m_input_bytes);
                     group.effective_value += effective_value;
                     ++it;
                 } else {
                     it = group.Discard(coin);
                 }
             }
             if (group.effective_value > Amount::zero()) {
                 utxo_pool.push_back(group);
             }
         }
         // Calculate the fees for things that aren't inputs
         Amount not_input_fees = coin_selection_params.effective_fee.GetFee(
             coin_selection_params.tx_noinputs_size);
         bnb_used = true;
         return SelectCoinsBnB(utxo_pool, nTargetValue, cost_of_change,
                               setCoinsRet, nValueRet, not_input_fees);
     } else {
         // Filter by the min conf specs and add to utxo_pool
         for (const OutputGroup &group : groups) {
             if (!group.EligibleForSpending(eligibility_filter)) {
                 continue;
             }
             utxo_pool.push_back(group);
         }
         bnb_used = false;
         return KnapsackSolver(nTargetValue, utxo_pool, setCoinsRet, nValueRet);
     }
 }
 
 bool CWallet::SelectCoins(const std::vector<COutput> &vAvailableCoins,
                           const Amount nTargetValue,
                           std::set<CInputCoin> &setCoinsRet, Amount &nValueRet,
                           const CCoinControl &coin_control,
                           CoinSelectionParams &coin_selection_params,
                           bool &bnb_used) const {
     std::vector<COutput> vCoins(vAvailableCoins);
 
     // coin control -> return all selected outputs (we want all selected to go
     // into the transaction for sure)
     if (coin_control.HasSelected() && !coin_control.fAllowOtherInputs) {
         // We didn't use BnB here, so set it to false.
         bnb_used = false;
 
         for (const COutput &out : vCoins) {
             if (!out.fSpendable) {
                 continue;
             }
 
             nValueRet += out.tx->tx->vout[out.i].nValue;
             setCoinsRet.insert(out.GetInputCoin());
         }
 
         return (nValueRet >= nTargetValue);
     }
 
     // Calculate value from preset inputs and store them.
     std::set<CInputCoin> setPresetCoins;
     Amount nValueFromPresetInputs = Amount::zero();
 
     std::vector<COutPoint> vPresetInputs;
     coin_control.ListSelected(vPresetInputs);
 
     for (const COutPoint &outpoint : vPresetInputs) {
         // For now, don't use BnB if preset inputs are selected. TODO: Enable
         // this later
         bnb_used = false;
         coin_selection_params.use_bnb = false;
 
         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;
         }
 
         // Just to calculate the marginal byte size
         nValueFromPresetInputs += pcoin->tx->vout[outpoint.GetN()].nValue;
         setPresetCoins.insert(CInputCoin(pcoin->tx, outpoint.GetN()));
     }
 
     // Remove preset inputs from vCoins
     for (std::vector<COutput>::iterator it = vCoins.begin();
          it != vCoins.end() && coin_control.HasSelected();) {
         if (setPresetCoins.count(it->GetInputCoin())) {
             it = vCoins.erase(it);
         } else {
             ++it;
         }
     }
 
     // form groups from remaining coins; note that preset coins will not
     // automatically have their associated (same address) coins included
     if (coin_control.m_avoid_partial_spends &&
         vCoins.size() > OUTPUT_GROUP_MAX_ENTRIES) {
         // Cases where we have 11+ outputs all pointing to the same destination
         // may result in privacy leaks as they will potentially be
         // deterministically sorted. We solve that by explicitly shuffling the
         // outputs before processing
         Shuffle(vCoins.begin(), vCoins.end(), FastRandomContext());
     }
     std::vector<OutputGroup> groups =
         GroupOutputs(vCoins, !coin_control.m_avoid_partial_spends);
 
     size_t max_ancestors = std::max<size_t>(
         1, gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT));
     size_t max_descendants = std::max<size_t>(
         1, gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT));
     bool fRejectLongChains = gArgs.GetBoolArg(
         "-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
 
     bool res =
         nTargetValue <= nValueFromPresetInputs ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                            CoinEligibilityFilter(1, 6, 0), groups, setCoinsRet,
                            nValueRet, coin_selection_params, bnb_used) ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                            CoinEligibilityFilter(1, 1, 0), groups, setCoinsRet,
                            nValueRet, coin_selection_params, bnb_used) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, 2), groups, setCoinsRet,
                             nValueRet, coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(
              nTargetValue - nValueFromPresetInputs,
              CoinEligibilityFilter(0, 1, std::min<size_t>(4, max_ancestors / 3),
                                    std::min<size_t>(4, max_descendants / 3)),
              groups, setCoinsRet, nValueRet, coin_selection_params,
              bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, max_ancestors / 2,
                                                   max_descendants / 2),
                             groups, setCoinsRet, nValueRet,
                             coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, max_ancestors - 1,
                                                   max_descendants - 1),
                             groups, setCoinsRet, nValueRet,
                             coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change && !fRejectLongChains &&
          SelectCoinsMinConf(
              nTargetValue - nValueFromPresetInputs,
              CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max()),
              groups, setCoinsRet, nValueRet, coin_selection_params, bnb_used));
 
     // Because SelectCoinsMinConf clears the setCoinsRet, we now add the
     // possible inputs to the coinset.
     util::insert(setCoinsRet, setPresetCoins);
 
     // Add preset inputs to the total value selected.
     nValueRet += nValueFromPresetInputs;
 
     return res;
 }
 
 bool CWallet::SignTransaction(CMutableTransaction &tx) {
     // sign the new tx
     int nIn = 0;
     for (CTxIn &input : tx.vin) {
         auto mi = mapWallet.find(input.prevout.GetTxId());
         if (mi == mapWallet.end() ||
             input.prevout.GetN() >= mi->second.tx->vout.size()) {
             return false;
         }
         const CScript &scriptPubKey =
             mi->second.tx->vout[input.prevout.GetN()].scriptPubKey;
         const Amount amount = mi->second.tx->vout[input.prevout.GetN()].nValue;
         SignatureData sigdata;
         SigHashType sigHashType = SigHashType().withForkId();
         if (!ProduceSignature(*this,
                               MutableTransactionSignatureCreator(
                                   &tx, nIn, amount, sigHashType),
                               scriptPubKey, sigdata)) {
             return false;
         }
         UpdateInput(input, sigdata);
         nIn++;
     }
     return true;
 }
 
 bool CWallet::FundTransaction(CMutableTransaction &tx, Amount &nFeeRet,
                               int &nChangePosInOut, std::string &strFailReason,
                               bool lockUnspents,
                               const std::set<int> &setSubtractFeeFromOutputs,
                               CCoinControl coinControl) {
     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);
     }
 
     coinControl.fAllowOtherInputs = true;
 
     for (const CTxIn &txin : tx.vin) {
         coinControl.Select(txin.prevout);
     }
 
     // Acquire the locks to prevent races to the new locked unspents between the
     // CreateTransaction call and LockCoin calls (when lockUnspents is true).
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     CReserveKey reservekey(this);
     CTransactionRef tx_new;
     if (!CreateTransaction(vecSend, tx_new, reservekey, nFeeRet,
                            nChangePosInOut, strFailReason, coinControl,
                            false)) {
         return false;
     }
 
     if (nChangePosInOut != -1) {
         tx.vout.insert(tx.vout.begin() + nChangePosInOut,
                        tx_new->vout[nChangePosInOut]);
         // We don't have the normal Create/Commit cycle, and don't want to
         // risk reusing change, so just remove the key from the keypool
         // here.
         reservekey.KeepKey();
     }
 
     // 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 = tx_new->vout[idx].nValue;
     }
 
     // Add new txins (keeping original txin scriptSig/order)
     for (const CTxIn &txin : tx_new->vin) {
         if (!coinControl.IsSelected(txin.prevout)) {
             tx.vin.push_back(txin);
 
             if (lockUnspents) {
                 LockCoin(txin.prevout);
             }
         }
     }
 
     return true;
 }
 
 OutputType
 CWallet::TransactionChangeType(OutputType change_type,
                                const std::vector<CRecipient> &vecSend) {
     // If -changetype is specified, always use that change type.
     if (change_type != OutputType::CHANGE_AUTO) {
         return change_type;
     }
 
     // if m_default_address_type is legacy, use legacy address as change.
     if (m_default_address_type == OutputType::LEGACY) {
         return OutputType::LEGACY;
     }
 
     // else use m_default_address_type for change
     return m_default_address_type;
 }
 
 bool CWallet::CreateTransaction(const std::vector<CRecipient> &vecSend,
                                 CTransactionRef &tx, 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;
     }
 
     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<CInputCoin> setCoins;
-        LOCK2(cs_main, cs_wallet);
+        auto locked_chain = chain().lock();
+        LOCK(cs_wallet);
 
         std::vector<COutput> vAvailableCoins;
         AvailableCoins(vAvailableCoins, true, &coinControl);
         // Parameters for coin selection, init with dummy
         CoinSelectionParams coin_selection_params;
 
         // Create change script that will be used if we need change
         // 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 (!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
             if (IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
                 strFailReason =
                     _("Can't generate a change-address key. Private keys "
                       "are disabled for this wallet.");
                 return false;
             }
             CPubKey vchPubKey;
             bool ret;
             ret = reservekey.GetReservedKey(vchPubKey, true);
             if (!ret) {
                 strFailReason =
                     _("Keypool ran out, please call keypoolrefill first");
                 return false;
             }
 
             const OutputType change_type = TransactionChangeType(
                 coinControl.m_change_type ? *coinControl.m_change_type
                                           : m_default_change_type,
                 vecSend);
 
             LearnRelatedScripts(vchPubKey, change_type);
             scriptChange = GetScriptForDestination(
                 GetDestinationForKey(vchPubKey, change_type));
         }
         CTxOut change_prototype_txout(Amount::zero(), scriptChange);
         coin_selection_params.change_output_size =
             GetSerializeSize(change_prototype_txout);
 
         // Get the fee rate to use effective values in coin selection
         CFeeRate nFeeRateNeeded =
             GetMinimumFeeRate(*this, coinControl, g_mempool);
 
         nFeeRet = Amount::zero();
         bool pick_new_inputs = true;
         Amount nValueIn = Amount::zero();
 
         // BnB selector is the only selector used when this is true.
         // That should only happen on the first pass through the loop.
         // If we are doing subtract fee from recipient, then don't use BnB
         coin_selection_params.use_bnb = nSubtractFeeFromAmount == 0;
         // Start with no fee and loop until there is enough fee
         while (true) {
             nChangePosInOut = nChangePosRequest;
             txNew.vin.clear();
             txNew.vout.clear();
             bool fFirst = true;
 
             Amount nValueToSelect = nValue;
             if (nSubtractFeeFromAmount == 0) {
                 nValueToSelect += nFeeRet;
             }
 
             // Static size overhead + outputs vsize. 4 nVersion, 4 nLocktime, 1
             // input count, 1 output count
             coin_selection_params.tx_noinputs_size = 10;
             // vouts to the payees
             for (const auto &recipient : vecSend) {
                 CTxOut txout(recipient.nAmount, recipient.scriptPubKey);
 
                 if (recipient.fSubtractFeeFromAmount) {
                     assert(nSubtractFeeFromAmount != 0);
                     // 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);
                     }
                 }
 
                 // Include the fee cost for outputs. Note this is only used for
                 // BnB right now
                 coin_selection_params.tx_noinputs_size +=
                     ::GetSerializeSize(txout, PROTOCOL_VERSION);
 
                 if (IsDust(txout, 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
             bool bnb_used;
             if (pick_new_inputs) {
                 nValueIn = Amount::zero();
                 setCoins.clear();
                 coin_selection_params.change_spend_size =
                     CalculateMaximumSignedInputSize(change_prototype_txout,
                                                     this);
                 coin_selection_params.effective_fee = nFeeRateNeeded;
                 if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins,
                                  nValueIn, coinControl, coin_selection_params,
                                  bnb_used)) {
                     // If BnB was used, it was the first pass. No longer the
                     // first pass and continue loop with knapsack.
                     if (bnb_used) {
                         coin_selection_params.use_bnb = false;
                         continue;
                     } else {
                         strFailReason = _("Insufficient funds");
                         return false;
                     }
                 }
             }
 
             const Amount nChange = nValueIn - nValueToSelect;
             if (nChange > Amount::zero()) {
                 // Fill a vout to ourself.
                 CTxOut newTxOut(nChange, scriptChange);
 
                 // Never create dust outputs; if we would, just add the dust to
                 // the fee.
                 // The nChange when BnB is used is always going to go to fees.
                 if (IsDust(newTxOut, dustRelayFee) || bnb_used) {
                     nChangePosInOut = -1;
                     nFeeRet += nChange;
                 } 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 {
                 nChangePosInOut = -1;
             }
 
             // Dummy fill vin for maximum size estimation
             //
             for (const auto &coin : setCoins) {
                 txNew.vin.push_back(CTxIn(coin.outpoint, CScript()));
             }
 
             CTransaction txNewConst(txNew);
             int nBytes = CalculateMaximumSignedTxSize(
                 txNewConst, this, coinControl.fAllowWatchOnly);
             if (nBytes < 0) {
                 strFailReason = _("Signing transaction failed");
                 return false;
             }
 
             Amount nFeeNeeded =
                 GetMinimumFee(*this, nBytes, coinControl, g_mempool);
 
             // 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.
             if (nFeeNeeded < ::minRelayTxFee.GetFee(nBytes)) {
                 strFailReason = _("Transaction too large for fee policy");
                 return false;
             }
 
             if (nFeeRet >= nFeeNeeded) {
                 // Reduce fee to only the needed amount if possible. 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.
 
                 // If we have no change and a big enough excess fee, then try to
                 // construct transaction again only without picking new inputs.
                 // We now know we only need the smaller fee (because of reduced
                 // tx size) and so we should add a change output. Only try this
                 // once.
                 if (nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 &&
                     pick_new_inputs) {
                     // Add 2 as a buffer in case increasing # of outputs changes
                     // compact size
                     unsigned int tx_size_with_change =
                         nBytes + coin_selection_params.change_output_size + 2;
                     Amount fee_needed_with_change = GetMinimumFee(
                         *this, tx_size_with_change, coinControl, g_mempool);
                     Amount minimum_value_for_change =
                         GetDustThreshold(change_prototype_txout, dustRelayFee);
                     if (nFeeRet >=
                         fee_needed_with_change + minimum_value_for_change) {
                         pick_new_inputs = false;
                         nFeeRet = fee_needed_with_change;
                         continue;
                     }
                 }
 
                 // If we have change output already, just increase it
                 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;
             } else if (!pick_new_inputs) {
                 // This shouldn't happen, we should have had enough excess fee
                 // to pay for the new output and still meet nFeeNeeded.
                 // Or we should have just subtracted fee from recipients and
                 // nFeeNeeded should not have changed.
                 strFailReason =
                     _("Transaction fee and change calculation failed");
                 return false;
             }
 
             // 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;
                 }
             }
 
             // If subtracting fee from recipients, we now know what fee we
             // need to subtract, we have no reason to reselect inputs.
             if (nSubtractFeeFromAmount > 0) {
                 pick_new_inputs = false;
             }
 
             // Include more fee and try again.
             nFeeRet = nFeeNeeded;
             coin_selection_params.use_bnb = false;
             continue;
         }
 
         if (nChangePosInOut == -1) {
             // Return any reserved key if we don't have change
             reservekey.ReturnKey();
         }
 
         // Shuffle selected coins and fill in final vin
         txNew.vin.clear();
         std::vector<CInputCoin> selected_coins(setCoins.begin(),
                                                setCoins.end());
         Shuffle(selected_coins.begin(), selected_coins.end(),
                 FastRandomContext());
 
         // Note how the sequence number is set to non-maxint so that
         // the nLockTime set above actually works.
         for (const auto &coin : selected_coins) {
             txNew.vin.push_back(
                 CTxIn(coin.outpoint, CScript(),
                       std::numeric_limits<uint32_t>::max() - 1));
         }
 
         if (sign) {
             SigHashType sigHashType = SigHashType().withForkId();
 
             int nIn = 0;
             for (const auto &coin : selected_coins) {
                 const CScript &scriptPubKey = coin.txout.scriptPubKey;
                 SignatureData sigdata;
 
                 if (!ProduceSignature(
                         *this,
                         MutableTransactionSignatureCreator(
                             &txNew, nIn, coin.txout.nValue, sigHashType),
                         scriptPubKey, sigdata)) {
                     strFailReason = _("Signing transaction failed");
                     return false;
                 }
 
                 UpdateInput(txNew.vin.at(nIn), sigdata);
                 nIn++;
             }
         }
 
         // Return the constructed transaction data.
         tx = MakeTransactionRef(std::move(txNew));
 
         // Limit size.
         if (tx->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(tx, Amount::zero(), 0, 0, 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;
         LOCK(::g_mempool.cs);
         if (!g_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(
     CTransactionRef tx, mapValue_t mapValue,
     std::vector<std::pair<std::string, std::string>> orderForm,
     std::string fromAccount, CReserveKey &reservekey, CConnman *connman,
     CValidationState &state) {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     CWalletTx wtxNew(this, std::move(tx));
     wtxNew.mapValue = std::move(mapValue);
     wtxNew.vOrderForm = std::move(orderForm);
     wtxNew.strFromAccount = std::move(fromAccount);
     wtxNew.fTimeReceivedIsTxTime = true;
     wtxNew.fFromMe = true;
 
     WalletLogPrintfToBeContinued("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.at(txin.prevout.GetTxId());
         coin.BindWallet(this);
         NotifyTransactionChanged(this, coin.GetId(), CT_UPDATED);
     }
 
     // Get the inserted-CWalletTx from mapWallet so that the
     // fInMempool flag is cached properly
     CWalletTx &wtx = mapWallet.at(wtxNew.GetId());
 
     if (fBroadcastTransactions) {
         // Broadcast
         if (!wtx.AcceptToMemoryPool(maxTxFee, state)) {
             WalletLogPrintf("CommitTransaction(): Transaction cannot be "
                             "broadcast immediately, %s\n",
                             FormatStateMessage(state));
             // TODO: if we expect the failure to be long term or permanent,
             // instead delete wtx from the wallet and return failure.
         } else {
             wtx.RelayWalletTransaction(connman);
         }
     }
 
     return true;
 }
 
 void CWallet::ListAccountCreditDebit(const std::string &strAccount,
                                      std::list<CAccountingEntry> &entries) {
     WalletBatch batch(*database);
     return batch.ListAccountCreditDebit(strAccount, entries);
 }
 
 bool CWallet::AddAccountingEntry(const CAccountingEntry &acentry) {
     WalletBatch batch(*database);
 
     return AddAccountingEntry(acentry, &batch);
 }
 
 bool CWallet::AddAccountingEntry(const CAccountingEntry &acentry,
                                  WalletBatch *batch) {
     if (!batch->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) {
-    LOCK2(cs_main, cs_wallet);
+    auto locked_chain = chain().lock();
+    LOCK(cs_wallet);
 
     fFirstRunRet = false;
     DBErrors nLoadWalletRet = WalletBatch(*database, "cr+").LoadWallet(this);
     if (nLoadWalletRet == DBErrors::NEED_REWRITE) {
         if (database->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.
         }
     }
 
     {
         LOCK(cs_KeyStore);
         // This wallet is in its first run if all of these are empty
         fFirstRunRet = mapKeys.empty() && mapCryptedKeys.empty() &&
                        mapWatchKeys.empty() && setWatchOnly.empty() &&
                        mapScripts.empty() &&
                        !IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) &&
                        !IsWalletFlagSet(WALLET_FLAG_BLANK_WALLET);
     }
 
     if (nLoadWalletRet != DBErrors::LOAD_OK) {
         return nLoadWalletRet;
     }
 
     return DBErrors::LOAD_OK;
 }
 
 DBErrors CWallet::ZapSelectTx(std::vector<TxId> &txIdsIn,
                               std::vector<TxId> &txIdsOut) {
     // mapWallet
     AssertLockHeld(cs_wallet);
     DBErrors nZapSelectTxRet =
         WalletBatch(*database, "cr+").ZapSelectTx(txIdsIn, txIdsOut);
     for (const TxId &txid : txIdsOut) {
         const auto &it = mapWallet.find(txid);
         wtxOrdered.erase(it->second.m_it_wtxOrdered);
         mapWallet.erase(it);
     }
 
     if (nZapSelectTxRet == DBErrors::NEED_REWRITE) {
         if (database->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 != DBErrors::LOAD_OK) {
         return nZapSelectTxRet;
     }
 
     MarkDirty();
 
     return DBErrors::LOAD_OK;
 }
 
 DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx> &vWtx) {
     DBErrors nZapWalletTxRet = WalletBatch(*database, "cr+").ZapWalletTx(vWtx);
     if (nZapWalletTxRet == DBErrors::NEED_REWRITE) {
         if (database->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 != DBErrors::LOAD_OK) {
         return nZapWalletTxRet;
     }
 
     return DBErrors::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() &&
         !WalletBatch(*database).WritePurpose(address, strPurpose)) {
         return false;
     }
     return WalletBatch(*database).WriteName(address, strName);
 }
 
 bool CWallet::DelAddressBook(const CTxDestination &address) {
     {
         // mapAddressBook
         LOCK(cs_wallet);
 
         // Delete destdata tuples associated with address.
         for (const std::pair<const std::string, std::string> &item :
              mapAddressBook[address].destdata) {
             WalletBatch(*database).EraseDestData(address, item.first);
         }
 
         mapAddressBook.erase(address);
     }
 
     NotifyAddressBookChanged(this, address, "",
                              ::IsMine(*this, address) != ISMINE_NO, "",
                              CT_DELETED);
 
     WalletBatch(*database).ErasePurpose(address);
     return WalletBatch(*database).EraseName(address);
 }
 
 const std::string &CWallet::GetLabelName(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 label ("").
     const static std::string DEFAULT_LABEL_NAME;
     return DEFAULT_LABEL_NAME;
 }
 
 /**
  * Mark old keypool keys as used, and generate all new keys.
  */
 bool CWallet::NewKeyPool() {
     if (IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         return false;
     }
     LOCK(cs_wallet);
     WalletBatch batch(*database);
 
     for (const int64_t nIndex : setInternalKeyPool) {
         batch.ErasePool(nIndex);
     }
     setInternalKeyPool.clear();
 
     for (const int64_t nIndex : setExternalKeyPool) {
         batch.ErasePool(nIndex);
     }
     setExternalKeyPool.clear();
 
     for (int64_t nIndex : set_pre_split_keypool) {
         batch.ErasePool(nIndex);
     }
     set_pre_split_keypool.clear();
 
     m_pool_key_to_index.clear();
 
     if (!TopUpKeyPool()) {
         return false;
     }
 
     WalletLogPrintf("CWallet::NewKeyPool rewrote keypool\n");
     return true;
 }
 
 size_t CWallet::KeypoolCountExternalKeys() {
     // setExternalKeyPool
     AssertLockHeld(cs_wallet);
     return setExternalKeyPool.size() + set_pre_split_keypool.size();
 }
 
 void CWallet::LoadKeyPool(int64_t nIndex, const CKeyPool &keypool) {
     AssertLockHeld(cs_wallet);
     if (keypool.m_pre_split) {
         set_pre_split_keypool.insert(nIndex);
     } else 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) {
     if (!CanGenerateKeys()) {
         return false;
     }
     {
         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;
         WalletBatch batch(*database);
         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(batch, internal));
             if (!batch.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) {
             WalletLogPrintf(
                 "keypool added %d keys (%d internal), size=%u (%u internal)\n",
                 missingInternal + missingExternal, missingInternal,
                 setInternalKeyPool.size() + setExternalKeyPool.size() +
                     set_pre_split_keypool.size(),
                 setInternalKeyPool.size());
         }
     }
     NotifyCanGetAddressesChanged();
     return true;
 }
 
 bool 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;
         bool use_split_keypool = set_pre_split_keypool.empty();
         std::set<int64_t> &setKeyPool =
             use_split_keypool
                 ? (fReturningInternal ? setInternalKeyPool : setExternalKeyPool)
                 : set_pre_split_keypool;
 
         // Get the oldest key
         if (setKeyPool.empty()) {
             return false;
         }
 
         WalletBatch batch(*database);
 
         auto it = setKeyPool.begin();
         nIndex = *it;
         setKeyPool.erase(it);
         if (!batch.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 the key was pre-split keypool, we don't care about what type it is
         if (use_split_keypool && keypool.fInternal != fReturningInternal) {
             throw std::runtime_error(std::string(__func__) +
                                      ": keypool entry misclassified");
         }
         if (!keypool.vchPubKey.IsValid()) {
             throw std::runtime_error(std::string(__func__) +
                                      ": keypool entry invalid");
         }
 
         m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
         WalletLogPrintf("keypool reserve %d\n", nIndex);
     }
     NotifyCanGetAddressesChanged();
     return true;
 }
 
 void CWallet::KeepKey(int64_t nIndex) {
     // Remove from key pool.
     WalletBatch batch(*database);
     batch.ErasePool(nIndex);
     WalletLogPrintf("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 if (!set_pre_split_keypool.empty()) {
             set_pre_split_keypool.insert(nIndex);
         } else {
             setExternalKeyPool.insert(nIndex);
         }
         m_pool_key_to_index[pubkey.GetID()] = nIndex;
         NotifyCanGetAddressesChanged();
     }
 
     WalletLogPrintf("keypool return %d\n", nIndex);
 }
 
 bool CWallet::GetKeyFromPool(CPubKey &result, bool internal) {
     if (!CanGetAddresses(internal)) {
         return false;
     }
 
     CKeyPool keypool;
     LOCK(cs_wallet);
     int64_t nIndex;
     if (!ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
         if (IsLocked()) {
             return false;
         }
         WalletBatch batch(*database);
         result = GenerateNewKey(batch, internal);
         return true;
     }
 
     KeepKey(nIndex);
     result = keypool.vchPubKey;
 
     return true;
 }
 
 static int64_t GetOldestKeyTimeInPool(const std::set<int64_t> &setKeyPool,
                                       WalletBatch &batch) {
     if (setKeyPool.empty()) {
         return GetTime();
     }
 
     CKeyPool keypool;
     int64_t nIndex = *(setKeyPool.begin());
     if (!batch.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);
 
     WalletBatch batch(*database);
 
     // load oldest key from keypool, get time and return
     int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, batch);
     if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT)) {
         oldestKey = std::max(GetOldestKeyTimeInPool(setInternalKeyPool, batch),
                              oldestKey);
         if (!set_pre_split_keypool.empty()) {
             oldestKey =
                 std::max(GetOldestKeyTimeInPool(set_pre_split_keypool, batch),
                          oldestKey);
         }
     }
 
     return oldestKey;
 }
 
 std::map<CTxDestination, Amount> CWallet::GetAddressBalances() {
     std::map<CTxDestination, Amount> balances;
 
     LOCK(cs_wallet);
     for (const auto &walletEntry : mapWallet) {
         const 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(COutPoint(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 (const auto &walletEntry : mapWallet) {
         const CWalletTx *pcoin = &walletEntry.second;
 
         if (pcoin->tx->vin.size() > 0) {
             bool any_mine = false;
             // Group all input addresses with each other.
             for (const auto &txin : pcoin->tx->vin) {
                 CTxDestination address;
                 // If this input isn't mine, ignore it.
                 if (!IsMine(txin)) {
                     continue;
                 }
 
                 if (!ExtractDestination(mapWallet.at(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 (const auto &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 (const auto &txout : pcoin->tx->vout) {
             if (IsMine(txout)) {
                 CTxDestination address;
                 if (!ExtractDestination(txout.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 (const 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 (const CTxDestination &element : *merged) {
             setmap[element] = merged;
         }
     }
 
     std::set<std::set<CTxDestination>> ret;
     for (const std::set<CTxDestination> *uniqueGrouping : uniqueGroupings) {
         ret.insert(*uniqueGrouping);
         delete uniqueGrouping;
     }
 
     return ret;
 }
 
 std::set<CTxDestination>
 CWallet::GetLabelAddresses(const std::string &label) const {
     LOCK(cs_wallet);
     std::set<CTxDestination> result;
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          mapAddressBook) {
         const CTxDestination &address = item.first;
         const std::string &strName = item.second.name;
         if (strName == label) {
             result.insert(address);
         }
     }
 
     return result;
 }
 
 void CWallet::DeleteLabel(const std::string &label) {
     WalletBatch batch(*database);
     batch.EraseAccount(label);
 }
 
 bool CReserveKey::GetReservedKey(CPubKey &pubkey, bool internal) {
     if (!pwallet->CanGetAddresses(internal)) {
         return false;
     }
 
     if (nIndex == -1) {
         CKeyPool keypool;
         if (!pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
             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) ||
                set_pre_split_keypool.count(keypool_id));
     }
 
     std::set<int64_t> *setKeyPool =
         internal ? &setInternalKeyPool
                  : (set_pre_split_keypool.empty() ? &setExternalKeyPool
                                                   : &set_pre_split_keypool);
     auto it = setKeyPool->begin();
 
     WalletBatch batch(*database);
     while (it != std::end(*setKeyPool)) {
         const int64_t &index = *(it);
         if (index > keypool_id) {
             // set*KeyPool is ordered
             break;
         }
 
         CKeyPool keypool;
         if (batch.ReadPool(index, keypool)) {
             // TODO: This should be unnecessary
             m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
         }
         LearnAllRelatedScripts(keypool.vchPubKey);
         batch.ErasePool(index);
         WalletLogPrintf("keypool index %d removed\n", index);
         it = setKeyPool->erase(it);
     }
 }
 
 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 COutPoint &outpoint) const {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
 
     return setLockedCoins.count(outpoint) > 0;
 }
 
 void CWallet::ListLockedCoins(std::vector<COutPoint> &vOutpts) const {
     // 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;
     for (const CKeyID &keyid : GetKeys()) {
         if (mapKeyBirth.count(keyid) == 0) {
             mapKeyFirstBlock[keyid] = pindexMax;
         }
     }
 
     // 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 (const auto &entry : mapWallet) {
         // iterate over all wallet transactions...
         const CWalletTx &wtx = entry.second;
         CBlockIndex *pindex = LookupBlockIndex(wtx.hashBlock);
         if (pindex && chainActive.Contains(pindex)) {
             // ... which are already in a block
             int nHeight = pindex->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 = pindex;
                     }
                 }
                 vAffected.clear();
             }
         }
     }
 
     // Extract block timestamps for those keys.
     for (const auto &entry : mapKeyFirstBlock) {
         // block times can be 2h off
         mapKeyBirth[entry.first] =
             entry.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 (const CBlockIndex *pindex = LookupBlockIndex(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 = pindex->GetBlockTime();
             nTimeSmart = std::max(latestEntry, std::min(blocktime, latestNow));
         } else {
             WalletLogPrintf("%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 WalletBatch(*database).WriteDestData(dest, key, value);
 }
 
 bool CWallet::EraseDestData(const CTxDestination &dest,
                             const std::string &key) {
     if (!mapAddressBook[dest].destdata.erase(key)) {
         return false;
     }
 
     return WalletBatch(*database).EraseDestData(dest, key);
 }
 
 void CWallet::LoadDestData(const CTxDestination &dest, const std::string &key,
                            const std::string &value) {
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
 }
 
 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;
 }
 
 std::vector<std::string>
 CWallet::GetDestValues(const std::string &prefix) const {
     LOCK(cs_wallet);
     std::vector<std::string> values;
     for (const auto &address : mapAddressBook) {
         for (const auto &data : address.second.destdata) {
             if (!data.first.compare(0, prefix.size(), prefix)) {
                 values.emplace_back(data.second);
             }
         }
     }
     return values;
 }
 
 bool CWallet::Verify(const CChainParams &chainParams, interfaces::Chain &chain,
                      const WalletLocation &location, bool salvage_wallet,
                      std::string &error_string, std::string &warning_string) {
     // Do some checking on wallet path. It should be either a:
     //
     // 1. Path where a directory can be created.
     // 2. Path to an existing directory.
     // 3. Path to a symlink to a directory.
     // 4. For backwards compatibility, the name of a data file in -walletdir.
     LOCK(cs_wallets);
     const fs::path &wallet_path = location.GetPath();
     fs::file_type path_type = fs::symlink_status(wallet_path).type();
     if (!(path_type == fs::file_not_found || path_type == fs::directory_file ||
           (path_type == fs::symlink_file && fs::is_directory(wallet_path)) ||
           (path_type == fs::regular_file &&
            fs::path(location.GetName()).filename() == location.GetName()))) {
         error_string =
             strprintf("Invalid -wallet path '%s'. -wallet path should point to "
                       "a directory where wallet.dat and "
                       "database/log.?????????? files can be stored, a location "
                       "where such a directory could be created, "
                       "or (for backwards compatibility) the name of an "
                       "existing data file in -walletdir (%s)",
                       location.GetName(), GetWalletDir());
         return false;
     }
 
     // Make sure that the wallet path doesn't clash with an existing wallet path
     if (IsWalletLoaded(wallet_path)) {
         error_string = strprintf(
             "Error loading wallet %s. Duplicate -wallet filename specified.",
             location.GetName());
         return false;
     }
 
     // Keep same database environment instance across Verify/Recover calls
     // below.
     std::unique_ptr<WalletDatabase> database =
         WalletDatabase::Create(wallet_path);
 
     try {
         if (!WalletBatch::VerifyEnvironment(wallet_path, error_string)) {
             return false;
         }
     } catch (const fs::filesystem_error &e) {
         error_string = strprintf("Error loading wallet %s. %s",
                                  location.GetName(), e.what());
         return false;
     }
 
     if (salvage_wallet) {
         // Recover readable keypairs:
         CWallet dummyWallet(chainParams, chain, WalletLocation(),
                             WalletDatabase::CreateDummy());
         std::string backup_filename;
         if (!WalletBatch::Recover(
                 wallet_path, static_cast<void *>(&dummyWallet),
                 WalletBatch::RecoverKeysOnlyFilter, backup_filename)) {
             return false;
         }
     }
 
     return WalletBatch::VerifyDatabaseFile(wallet_path, warning_string,
                                            error_string);
 }
 
 void CWallet::MarkPreSplitKeys() {
     WalletBatch batch(*database);
     for (auto it = setExternalKeyPool.begin();
          it != setExternalKeyPool.end();) {
         int64_t index = *it;
         CKeyPool keypool;
         if (!batch.ReadPool(index, keypool)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": read keypool entry failed");
         }
         keypool.m_pre_split = true;
         if (!batch.WritePool(index, keypool)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": writing modified keypool entry failed");
         }
         set_pre_split_keypool.insert(index);
         it = setExternalKeyPool.erase(it);
     }
 }
 
 std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(
     const CChainParams &chainParams, interfaces::Chain &chain,
     const WalletLocation &location, uint64_t wallet_creation_flags) {
     const std::string &walletFile = location.GetName();
 
     // 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<CWallet> tempWallet = std::make_unique<CWallet>(
             chainParams, chain, location,
             WalletDatabase::Create(location.GetPath()));
         DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
         if (nZapWalletRet != DBErrors::LOAD_OK) {
             InitError(
                 strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
             return nullptr;
         }
     }
 
     uiInterface.InitMessage(_("Loading wallet..."));
 
     int64_t nStart = GetTimeMillis();
     bool fFirstRun = true;
     // TODO: Can't use std::make_shared because we need a custom deleter but
     // should be possible to use std::allocate_shared.
     std::shared_ptr<CWallet> walletInstance(
         new CWallet(chainParams, chain, location,
                     WalletDatabase::Create(location.GetPath())),
         ReleaseWallet);
     DBErrors nLoadWalletRet = walletInstance->LoadWallet(fFirstRun);
     if (nLoadWalletRet != DBErrors::LOAD_OK) {
         if (nLoadWalletRet == DBErrors::CORRUPT) {
             InitError(
                 strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
             return nullptr;
         }
 
         if (nLoadWalletRet == DBErrors::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 == DBErrors::TOO_NEW) {
             InitError(strprintf(
                 _("Error loading %s: Wallet requires newer version of %s"),
                 walletFile, _(PACKAGE_NAME)));
             return nullptr;
         } else if (nLoadWalletRet == DBErrors::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;
         }
     }
 
     int prev_version = walletInstance->nWalletVersion;
     if (gArgs.GetBoolArg("-upgradewallet", fFirstRun)) {
         int nMaxVersion = gArgs.GetArg("-upgradewallet", 0);
         // The -upgradewallet without argument case
         if (nMaxVersion == 0) {
             walletInstance->WalletLogPrintf("Performing wallet upgrade to %i\n",
                                             FEATURE_LATEST);
             nMaxVersion = FEATURE_LATEST;
             // permanently upgrade the wallet immediately
             walletInstance->SetMinVersion(FEATURE_LATEST);
         } else {
             walletInstance->WalletLogPrintf(
                 "Allowing wallet upgrade up to %i\n", nMaxVersion);
         }
 
         if (nMaxVersion < walletInstance->GetVersion()) {
             InitError(_("Cannot downgrade wallet"));
             return nullptr;
         }
 
         walletInstance->SetMaxVersion(nMaxVersion);
     }
 
     // Upgrade to HD if explicit upgrade
     if (gArgs.GetBoolArg("-upgradewallet", false)) {
         LOCK(walletInstance->cs_wallet);
 
         // Do not upgrade versions to any version between HD_SPLIT and
         // FEATURE_PRE_SPLIT_KEYPOOL unless already supporting HD_SPLIT
         int max_version = walletInstance->nWalletVersion;
         if (!walletInstance->CanSupportFeature(FEATURE_HD_SPLIT) &&
             max_version >= FEATURE_HD_SPLIT &&
             max_version < FEATURE_PRE_SPLIT_KEYPOOL) {
             InitError(
                 _("Cannot upgrade a non HD split wallet without upgrading to "
                   "support pre split keypool. Please use -upgradewallet=200300 "
                   "or -upgradewallet with no version specified."));
             return nullptr;
         }
 
         bool hd_upgrade = false;
         bool split_upgrade = false;
         if (walletInstance->CanSupportFeature(FEATURE_HD) &&
             !walletInstance->IsHDEnabled()) {
             walletInstance->WalletLogPrintf("Upgrading wallet to HD\n");
             walletInstance->SetMinVersion(FEATURE_HD);
 
             // generate a new master key
             CPubKey masterPubKey = walletInstance->GenerateNewSeed();
             walletInstance->SetHDSeed(masterPubKey);
             hd_upgrade = true;
         }
         // Upgrade to HD chain split if necessary
         if (walletInstance->CanSupportFeature(FEATURE_HD_SPLIT)) {
             walletInstance->WalletLogPrintf(
                 "Upgrading wallet to use HD chain split\n");
             walletInstance->SetMinVersion(FEATURE_PRE_SPLIT_KEYPOOL);
             split_upgrade = FEATURE_HD_SPLIT > prev_version;
         }
         // Mark all keys currently in the keypool as pre-split
         if (split_upgrade) {
             walletInstance->MarkPreSplitKeys();
         }
         // Regenerate the keypool if upgraded to HD
         if (hd_upgrade) {
             if (!walletInstance->TopUpKeyPool()) {
                 InitError(_("Unable to generate keys"));
                 return nullptr;
             }
         }
     }
 
     if (fFirstRun) {
         // Ensure this wallet.dat can only be opened by clients supporting
         // HD with chain split and expects no default key.
         if (!gArgs.GetBoolArg("-usehd", true)) {
             InitError(strprintf(_("Error creating %s: You can't create non-HD "
                                   "wallets with this version."),
                                 walletFile));
             return nullptr;
         }
         walletInstance->SetMinVersion(FEATURE_LATEST);
 
         if ((wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
             // selective allow to set flags
             walletInstance->SetWalletFlag(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
         } else if (wallet_creation_flags & WALLET_FLAG_BLANK_WALLET) {
             walletInstance->SetWalletFlag(WALLET_FLAG_BLANK_WALLET);
         } else {
             // generate a new seed
             CPubKey seed = walletInstance->GenerateNewSeed();
             walletInstance->SetHDSeed(seed);
         } // Otherwise, do not generate a new seed
 
         // Top up the keypool
         if (walletInstance->CanGenerateKeys() &&
             !walletInstance->TopUpKeyPool()) {
             InitError(_("Unable to generate initial keys"));
             return nullptr;
         }
 
+        // Temporary. Removed in upcoming lock cleanup
+        auto locked_chain = chain.assumeLocked();
         walletInstance->ChainStateFlushed(chainActive.GetLocator());
     } else if (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS) {
         // Make it impossible to disable private keys after creation
         InitError(strprintf(_("Error loading %s: Private keys can only be "
                               "disabled during creation"),
                             walletFile));
         return nullptr;
     } else if (walletInstance->IsWalletFlagSet(
                    WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         LOCK(walletInstance->cs_KeyStore);
         if (!walletInstance->mapKeys.empty() ||
             !walletInstance->mapCryptedKeys.empty()) {
             InitWarning(strprintf(_("Warning: Private keys detected in wallet "
                                     "{%s} with disabled private keys"),
                                   walletFile));
         }
     } else if (gArgs.IsArgSet("-usehd")) {
         bool useHD = gArgs.GetBoolArg("-usehd", true);
         if (walletInstance->IsHDEnabled() && !useHD) {
             InitError(
                 strprintf(_("Error loading %s: You can't disable HD on an "
                             "already existing HD wallet"),
                           walletFile));
             return nullptr;
         }
 
         if (!walletInstance->IsHDEnabled() && useHD) {
             InitError(strprintf(_("Error loading %s: You can't enable HD on an "
                                   "already existing non-HD wallet"),
                                 walletFile));
             return nullptr;
         }
     }
 
     if (gArgs.IsArgSet("-mintxfee")) {
         Amount n = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-mintxfee", ""), n) ||
             n == Amount::zero()) {
             InitError(AmountErrMsg("mintxfee", gArgs.GetArg("-mintxfee", "")));
             return nullptr;
         }
         if (n > HIGH_TX_FEE_PER_KB) {
             InitWarning(AmountHighWarn("-mintxfee") + " " +
                         _("This is the minimum transaction fee you pay on "
                           "every transaction."));
         }
         walletInstance->m_min_fee = CFeeRate(n);
     }
 
     if (gArgs.IsArgSet("-fallbackfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-fallbackfee", ""), nFeePerK)) {
             InitError(
                 strprintf(_("Invalid amount for -fallbackfee=<amount>: '%s'"),
                           gArgs.GetArg("-fallbackfee", "")));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             InitWarning(AmountHighWarn("-fallbackfee") + " " +
                         _("This is the transaction fee you may pay when fee "
                           "estimates are not available."));
         }
         walletInstance->m_fallback_fee = CFeeRate(nFeePerK);
         // disable fallback fee in case value was set to 0, enable if non-null
         // value
         walletInstance->m_allow_fallback_fee = (nFeePerK != Amount::zero());
     }
     if (gArgs.IsArgSet("-paytxfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-paytxfee", ""), nFeePerK)) {
             InitError(AmountErrMsg("paytxfee", gArgs.GetArg("-paytxfee", "")));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             InitWarning(AmountHighWarn("-paytxfee") + " " +
                         _("This is the transaction fee you will pay if you "
                           "send a transaction."));
         }
         walletInstance->m_pay_tx_fee = CFeeRate(nFeePerK, 1000);
         if (walletInstance->m_pay_tx_fee < ::minRelayTxFee) {
             InitError(strprintf(_("Invalid amount for -paytxfee=<amount>: '%s' "
                                   "(must be at least %s)"),
                                 gArgs.GetArg("-paytxfee", ""),
                                 ::minRelayTxFee.ToString()));
             return nullptr;
         }
     }
     walletInstance->m_spend_zero_conf_change =
         gArgs.GetBoolArg("-spendzeroconfchange", DEFAULT_SPEND_ZEROCONF_CHANGE);
 
     walletInstance->m_default_address_type = DEFAULT_ADDRESS_TYPE;
     walletInstance->m_default_change_type = DEFAULT_CHANGE_TYPE;
 
     walletInstance->WalletLogPrintf("Wallet completed loading in %15dms\n",
                                     GetTimeMillis() - nStart);
 
     // Try to top up keypool. No-op if the wallet is locked.
     walletInstance->TopUpKeyPool();
 
-    LOCK2(cs_main, walletInstance->cs_wallet);
+    auto locked_chain = chain.lock();
+    LOCK(walletInstance->cs_wallet);
 
     CBlockIndex *pindexRescan = chainActive.Genesis();
     if (!gArgs.GetBoolArg("-rescan", false)) {
         WalletBatch batch(*walletInstance->database);
         CBlockLocator locator;
         if (batch.ReadBestBlock(locator)) {
             pindexRescan = FindForkInGlobalIndex(chainActive, locator);
         }
     }
 
     walletInstance->m_last_block_processed = chainActive.Tip();
 
     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 an 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..."));
         walletInstance->WalletLogPrintf(
             "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();
         {
             WalletRescanReserver reserver(walletInstance.get());
             if (!reserver.reserve()) {
                 InitError(
                     _("Failed to rescan the wallet during initialization"));
                 return nullptr;
             }
             walletInstance->ScanForWalletTransactions(pindexRescan, nullptr,
                                                       reserver, true);
         }
         walletInstance->WalletLogPrintf("Rescan completed in %15dms\n",
                                         GetTimeMillis() - nStart);
         walletInstance->ChainStateFlushed(chainActive.GetLocator());
         walletInstance->database->IncrementUpdateCounter();
 
         // Restore wallet transaction metadata after -zapwallettxes=1
         if (gArgs.GetBoolArg("-zapwallettxes", false) &&
             gArgs.GetArg("-zapwallettxes", "1") != "2") {
             WalletBatch batch(*walletInstance->database);
 
             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;
                     batch.WriteTx(*copyTo);
                 }
             }
         }
     }
 
     uiInterface.LoadWallet(walletInstance);
 
     // Register with the validation interface. It's ok to do this after rescan
     // since we're still holding cs_main.
     RegisterValidationInterface(walletInstance.get());
 
     walletInstance->SetBroadcastTransactions(
         gArgs.GetBoolArg("-walletbroadcast", DEFAULT_WALLETBROADCAST));
 
     walletInstance->WalletLogPrintf("setKeyPool.size() = %u\n",
                                     walletInstance->GetKeyPoolSize());
     walletInstance->WalletLogPrintf("mapWallet.size() = %u\n",
                                     walletInstance->mapWallet.size());
     walletInstance->WalletLogPrintf("mapAddressBook.size() = %u\n",
                                     walletInstance->mapAddressBook.size());
 
     return walletInstance;
 }
 
 void CWallet::postInitProcess() {
     // Add wallet transactions that aren't already in a block to mempool.
     // Do this here as mempool requires genesis block to be loaded.
     ReacceptWalletTransactions();
 }
 
 bool CWallet::BackupWallet(const std::string &strDest) {
     return database->Backup(strDest);
 }
 
 CKeyPool::CKeyPool() {
     nTime = GetTime();
     fInternal = false;
     m_pre_split = false;
 }
 
 CKeyPool::CKeyPool(const CPubKey &vchPubKeyIn, bool internalIn) {
     nTime = GetTime();
     vchPubKey = vchPubKeyIn;
     fInternal = internalIn;
     m_pre_split = false;
 }
 
 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 {
     if (hashUnset()) {
         return 0;
     }
 
     AssertLockHeld(cs_main);
 
     // Find the block it claims to be in.
     CBlockIndex *pindex = LookupBlockIndex(hashBlock);
     if (!pindex || !chainActive.Contains(pindex)) {
         return 0;
     }
 
     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 CWalletTx::AcceptToMemoryPool(const Amount nAbsurdFee,
                                    CValidationState &state) {
     // We must set fInMempool here - while it will be re-set to true by the
     // entered-mempool callback, if we did not there would be a race where a
     // user could call sendmoney in a loop and hit spurious out of funds errors
     // because we think that this newly generated transaction's change is
     // unavailable as we're not yet aware that it is in the mempool.
     bool ret = ::AcceptToMemoryPool(GetConfig(), g_mempool, state, tx,
                                     nullptr /* pfMissingInputs */,
                                     false /* bypass_limits */, nAbsurdFee);
     fInMempool |= ret;
     return ret;
 }
 
 void CWallet::LearnRelatedScripts(const CPubKey &key, OutputType type) {
     // Nothing to do...
 }
 
 void CWallet::LearnAllRelatedScripts(const CPubKey &key) {
     // Nothing to do...
 }
 
 std::vector<OutputGroup>
 CWallet::GroupOutputs(const std::vector<COutput> &outputs,
                       bool single_coin) const {
     std::vector<OutputGroup> groups;
     std::map<CTxDestination, OutputGroup> gmap;
     CTxDestination dst;
     for (const auto &output : outputs) {
         if (output.fSpendable) {
             CInputCoin input_coin = output.GetInputCoin();
 
             size_t ancestors, descendants;
             g_mempool.GetTransactionAncestry(output.tx->GetId(), ancestors,
                                              descendants);
             if (!single_coin &&
                 ExtractDestination(output.tx->tx->vout[output.i].scriptPubKey,
                                    dst)) {
                 // Limit output groups to no more than 10 entries, to protect
                 // against inadvertently creating a too-large transaction
                 // when using -avoidpartialspends
                 if (gmap[dst].m_outputs.size() >= OUTPUT_GROUP_MAX_ENTRIES) {
                     groups.push_back(gmap[dst]);
                     gmap.erase(dst);
                 }
                 gmap[dst].Insert(input_coin, output.nDepth,
                                  output.tx->IsFromMe(ISMINE_ALL), ancestors,
                                  descendants);
             } else {
                 groups.emplace_back(input_coin, output.nDepth,
                                     output.tx->IsFromMe(ISMINE_ALL), ancestors,
                                     descendants);
             }
         }
     }
     if (!single_coin) {
         for (const auto &it : gmap) {
             groups.push_back(it.second);
         }
     }
     return groups;
 }
 
 bool CWallet::GetKeyOrigin(const CKeyID &keyID, KeyOriginInfo &info) const {
     CKeyMetadata meta;
     {
         LOCK(cs_wallet);
         auto it = mapKeyMetadata.find(keyID);
         if (it != mapKeyMetadata.end()) {
             meta = it->second;
         }
     }
     if (!meta.hdKeypath.empty()) {
         if (!ParseHDKeypath(meta.hdKeypath, info.path)) {
             return false;
         }
         // Get the proper master key id
         CKey key;
         GetKey(meta.hd_seed_id, key);
         CExtKey masterKey;
         masterKey.SetSeed(key.begin(), key.size());
         // Compute identifier
         CKeyID masterid = masterKey.key.GetPubKey().GetID();
         std::copy(masterid.begin(), masterid.begin() + 4, info.fingerprint);
     } else {
         // Single pubkeys get the master fingerprint of themselves
         std::copy(keyID.begin(), keyID.begin() + 4, info.fingerprint);
     }
     return true;
 }