Merge #9725: CValidationInterface Cleanups

b1a6d4c Take a CTransactionRef in AddToWalletIfInvolvingMe to avoid a copy (Matt Corallo)
1c95e2f Use std::shared_ptr instead of boost::shared_ptr in ScriptForMining (Matt Corallo)
91f1e6c Remove dead-code tracking of requests for blocks we generated (Matt Corallo)
acad82f Add override to functions using CValidationInterface methods (Matt Corallo)
e6d5e6c Hold cs_wallet for whole block [dis]connection processing (Matt Corallo)
461e49f SyncTransaction->TxAddedToMempool/BlockConnected/Disconnected (Matt Corallo)
f404334 Handle SyncTransaction in ActivateBestChain instead of ConnectTrace (Matt Corallo)
a147687 Keep conflictedTxs in ConnectTrace per-block (Matt Corallo)
d3167ba Handle conflicted transactions directly in ConnectTrace (Matt Corallo)
29e6e23 Make ConnectTrace::blocksConnected private, hide behind accessors (Matt Corallo)
822000c Add pblock to connectTrace at the end of ConnectTip, not start (Matt Corallo)
f5e9a01 Include missing #include in zmqnotificationinterface.h (Matt Corallo)

Tree-SHA512: 8893d47559da3b28d2ef7359768547cba8a4b43b6f891d80f5848f995a84b1517bfb0f706fdc8cd43f09a1350349eb440d9724a59363ab517dfcc4fcb31b2018

10 files changed, 197 insertions, 135 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 5846c3a770..d881b8ddda 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -744,21 +744,23 @@ PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) : connman(connmanI
     recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
 }
 
-void PeerLogicValidation::SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int nPosInBlock) {
-    if (nPosInBlock == CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK)
-        return;
-
+void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex, const std::vector<CTransactionRef>& vtxConflicted) {
     LOCK(cs_main);
 
     std::vector<uint256> vOrphanErase;
-    // Which orphan pool entries must we evict?
-    for (size_t j = 0; j < tx.vin.size(); j++) {
-        auto itByPrev = mapOrphanTransactionsByPrev.find(tx.vin[j].prevout);
-        if (itByPrev == mapOrphanTransactionsByPrev.end()) continue;
-        for (auto mi = itByPrev->second.begin(); mi != itByPrev->second.end(); ++mi) {
-            const CTransaction& orphanTx = *(*mi)->second.tx;
-            const uint256& orphanHash = orphanTx.GetHash();
-            vOrphanErase.push_back(orphanHash);
+
+    for (const CTransactionRef& ptx : pblock->vtx) {
+        const CTransaction& tx = *ptx;
+
+        // Which orphan pool entries must we evict?
+        for (size_t j = 0; j < tx.vin.size(); j++) {
+            auto itByPrev = mapOrphanTransactionsByPrev.find(tx.vin[j].prevout);
+            if (itByPrev == mapOrphanTransactionsByPrev.end()) continue;
+            for (auto mi = itByPrev->second.begin(); mi != itByPrev->second.end(); ++mi) {
+                const CTransaction& orphanTx = *(*mi)->second.tx;
+                const uint256& orphanHash = orphanTx.GetHash();
+                vOrphanErase.push_back(orphanHash);
+            }
         }
     }
 
diff --git a/src/net_processing.h b/src/net_processing.h
index 9e3f1b7156..f460595bc1 100644
--- a/src/net_processing.h
+++ b/src/net_processing.h
@@ -30,10 +30,10 @@ private:
 public:
     PeerLogicValidation(CConnman* connmanIn);
 
-    virtual void SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int nPosInBlock);
-    virtual void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload);
-    virtual void BlockChecked(const CBlock& block, const CValidationState& state);
-    virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock);
+    void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected, const std::vector<CTransactionRef>& vtxConflicted) override;
+    void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;
+    void BlockChecked(const CBlock& block, const CValidationState& state) override;
+    void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) override;
 };
 
 struct CNodeStateStats {
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 7e5f0d608e..d234bb69ae 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -27,7 +27,6 @@
 #include <stdint.h>
 
 #include <boost/assign/list_of.hpp>
-#include <boost/shared_ptr.hpp>
 
 #include <univalue.h>
 
@@ -95,7 +94,7 @@ UniValue getnetworkhashps(const JSONRPCRequest& request)
     return GetNetworkHashPS(request.params.size() > 0 ? request.params[0].get_int() : 120, request.params.size() > 1 ? request.params[1].get_int() : -1);
 }
 
-UniValue generateBlocks(boost::shared_ptr<CReserveScript> coinbaseScript, int nGenerate, uint64_t nMaxTries, bool keepScript)
+UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGenerate, uint64_t nMaxTries, bool keepScript)
 {
     static const int nInnerLoopCount = 0x10000;
     int nHeightStart = 0;
@@ -167,7 +166,7 @@ UniValue generate(const JSONRPCRequest& request)
         nMaxTries = request.params[1].get_int();
     }
 
-    boost::shared_ptr<CReserveScript> coinbaseScript;
+    std::shared_ptr<CReserveScript> coinbaseScript;
     GetMainSignals().ScriptForMining(coinbaseScript);
 
     // If the keypool is exhausted, no script is returned at all.  Catch this.
@@ -208,7 +207,7 @@ UniValue generatetoaddress(const JSONRPCRequest& request)
     if (!address.IsValid())
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Error: Invalid address");
 
-    boost::shared_ptr<CReserveScript> coinbaseScript(new CReserveScript());
+    std::shared_ptr<CReserveScript> coinbaseScript = std::make_shared<CReserveScript>();
     coinbaseScript->reserveScript = GetScriptForDestination(address.Get());
 
     return generateBlocks(coinbaseScript, nGenerate, nMaxTries, false);
@@ -710,7 +709,7 @@ public:
     submitblock_StateCatcher(const uint256 &hashIn) : hash(hashIn), found(false), state() {}
 
 protected:
-    virtual void BlockChecked(const CBlock& block, const CValidationState& stateIn) {
+    void BlockChecked(const CBlock& block, const CValidationState& stateIn) override {
         if (block.GetHash() != hash)
             return;
         found = true;
diff --git a/src/validation.cpp b/src/validation.cpp
index 35b957a451..99ce53986f 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -154,39 +154,6 @@ namespace {
     std::set<int> setDirtyFileInfo;
 } // anon namespace
 
-/* Use this class to start tracking transactions that are removed from the
- * mempool and pass all those transactions through SyncTransaction when the
- * object goes out of scope. This is currently only used to call SyncTransaction
- * on conflicts removed from the mempool during block connection.  Applied in
- * ActivateBestChain around ActivateBestStep which in turn calls:
- * ConnectTip->removeForBlock->removeConflicts
- */
-class MemPoolConflictRemovalTracker
-{
-private:
-    std::vector<CTransactionRef> conflictedTxs;
-    CTxMemPool &pool;
-
-public:
-    MemPoolConflictRemovalTracker(CTxMemPool &_pool) : pool(_pool) {
-        pool.NotifyEntryRemoved.connect(boost::bind(&MemPoolConflictRemovalTracker::NotifyEntryRemoved, this, _1, _2));
-    }
-
-    void NotifyEntryRemoved(CTransactionRef txRemoved, MemPoolRemovalReason reason) {
-        if (reason == MemPoolRemovalReason::CONFLICT) {
-            conflictedTxs.push_back(txRemoved);
-        }
-    }
-
-    ~MemPoolConflictRemovalTracker() {
-        pool.NotifyEntryRemoved.disconnect(boost::bind(&MemPoolConflictRemovalTracker::NotifyEntryRemoved, this, _1, _2));
-        for (const auto& tx : conflictedTxs) {
-            GetMainSignals().SyncTransaction(*tx, NULL, CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK);
-        }
-        conflictedTxs.clear();
-    }
-};
-
 CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator)
 {
     // Find the first block the caller has in the main chain
@@ -982,7 +949,7 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C
         }
     }
 
-    GetMainSignals().SyncTransaction(tx, NULL, CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK);
+    GetMainSignals().TransactionAddedToMempool(ptx);
 
     return true;
 }
@@ -2153,7 +2120,8 @@ bool static DisconnectTip(CValidationState& state, const CChainParams& chainpara
     CBlockIndex *pindexDelete = chainActive.Tip();
     assert(pindexDelete);
     // Read block from disk.
-    CBlock block;
+    std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
+    CBlock& block = *pblock;
     if (!ReadBlockFromDisk(block, pindexDelete, chainparams.GetConsensus()))
         return AbortNode(state, "Failed to read block");
     // Apply the block atomically to the chain state.
@@ -2195,9 +2163,7 @@ bool static DisconnectTip(CValidationState& state, const CChainParams& chainpara
     UpdateTip(pindexDelete->pprev, chainparams);
     // Let wallets know transactions went from 1-confirmed to
     // 0-confirmed or conflicted:
-    for (const auto& tx : block.vtx) {
-        GetMainSignals().SyncTransaction(*tx, pindexDelete->pprev, CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK);
-    }
+    GetMainSignals().BlockDisconnected(pblock);
     return true;
 }
 
@@ -2207,36 +2173,92 @@ static int64_t nTimeFlush = 0;
 static int64_t nTimeChainState = 0;
 static int64_t nTimePostConnect = 0;
 
+struct PerBlockConnectTrace {
+    CBlockIndex* pindex = NULL;
+    std::shared_ptr<const CBlock> pblock;
+    std::shared_ptr<std::vector<CTransactionRef>> conflictedTxs;
+    PerBlockConnectTrace() : conflictedTxs(std::make_shared<std::vector<CTransactionRef>>()) {}
+};
 /**
  * Used to track blocks whose transactions were applied to the UTXO state as a
  * part of a single ActivateBestChainStep call.
+ *
+ * This class also tracks transactions that are removed from the mempool as
+ * conflicts (per block) and can be used to pass all those transactions
+ * through SyncTransaction.
+ *
+ * This class assumes (and asserts) that the conflicted transactions for a given
+ * block are added via mempool callbacks prior to the BlockConnected() associated
+ * with those transactions. If any transactions are marked conflicted, it is
+ * assumed that an associated block will always be added.
+ *
+ * This class is single-use, once you call GetBlocksConnected() you have to throw
+ * it away and make a new one.
  */
-struct ConnectTrace {
-    std::vector<std::pair<CBlockIndex*, std::shared_ptr<const CBlock> > > blocksConnected;
+class ConnectTrace {
+private:
+    std::vector<PerBlockConnectTrace> blocksConnected;
+    CTxMemPool &pool;
+
+public:
+    ConnectTrace(CTxMemPool &_pool) : blocksConnected(1), pool(_pool) {
+        pool.NotifyEntryRemoved.connect(boost::bind(&ConnectTrace::NotifyEntryRemoved, this, _1, _2));
+    }
+
+    ~ConnectTrace() {
+        pool.NotifyEntryRemoved.disconnect(boost::bind(&ConnectTrace::NotifyEntryRemoved, this, _1, _2));
+    }
+
+    void BlockConnected(CBlockIndex* pindex, std::shared_ptr<const CBlock> pblock) {
+        assert(!blocksConnected.back().pindex);
+        assert(pindex);
+        assert(pblock);
+        blocksConnected.back().pindex = pindex;
+        blocksConnected.back().pblock = std::move(pblock);
+        blocksConnected.emplace_back();
+    }
+
+    std::vector<PerBlockConnectTrace>& GetBlocksConnected() {
+        // We always keep one extra block at the end of our list because
+        // blocks are added after all the conflicted transactions have
+        // been filled in. Thus, the last entry should always be an empty
+        // one waiting for the transactions from the next block. We pop
+        // the last entry here to make sure the list we return is sane.
+        assert(!blocksConnected.back().pindex);
+        assert(blocksConnected.back().conflictedTxs->empty());
+        blocksConnected.pop_back();
+        return blocksConnected;
+    }
+
+    void NotifyEntryRemoved(CTransactionRef txRemoved, MemPoolRemovalReason reason) {
+        assert(!blocksConnected.back().pindex);
+        if (reason == MemPoolRemovalReason::CONFLICT) {
+            blocksConnected.back().conflictedTxs->emplace_back(std::move(txRemoved));
+        }
+    }
 };
 
 /**
  * Connect a new block to chainActive. pblock is either NULL or a pointer to a CBlock
  * corresponding to pindexNew, to bypass loading it again from disk.
  *
- * The block is always added to connectTrace (either after loading from disk or by copying
- * pblock) - if that is not intended, care must be taken to remove the last entry in
- * blocksConnected in case of failure.
+ * The block is added to connectTrace if connection succeeds.
  */
 bool static ConnectTip(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace)
 {
     assert(pindexNew->pprev == chainActive.Tip());
     // Read block from disk.
     int64_t nTime1 = GetTimeMicros();
+    std::shared_ptr<const CBlock> pthisBlock;
     if (!pblock) {
         std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
-        connectTrace.blocksConnected.emplace_back(pindexNew, pblockNew);
         if (!ReadBlockFromDisk(*pblockNew, pindexNew, chainparams.GetConsensus()))
             return AbortNode(state, "Failed to read block");
+        pthisBlock = pblockNew;
     } else {
-        connectTrace.blocksConnected.emplace_back(pindexNew, pblock);
+        pthisBlock = pblock;
     }
-    const CBlock& blockConnecting = *connectTrace.blocksConnected.back().second;
+    const CBlock& blockConnecting = *pthisBlock;
     // Apply the block atomically to the chain state.
     int64_t nTime2 = GetTimeMicros(); nTimeReadFromDisk += nTime2 - nTime1;
     int64_t nTime3;
@@ -2270,6 +2292,8 @@ bool static ConnectTip(CValidationState& state, const CChainParams& chainparams,
     int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
     LogPrint(BCLog::BENCH, "  - Connect postprocess: %.2fms [%.2fs]\n", (nTime6 - nTime5) * 0.001, nTimePostConnect * 0.000001);
     LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs]\n", (nTime6 - nTime1) * 0.001, nTimeTotal * 0.000001);
+
+    connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
     return true;
 }
 
@@ -2388,8 +2412,6 @@ static bool ActivateBestChainStep(CValidationState& state, const CChainParams& c
                     state = CValidationState();
                     fInvalidFound = true;
                     fContinue = false;
-                    // If we didn't actually connect the block, don't notify listeners about it
-                    connectTrace.blocksConnected.pop_back();
                     break;
                 } else {
                     // A system error occurred (disk space, database error, ...).
@@ -2461,18 +2483,11 @@ bool ActivateBestChain(CValidationState &state, const CChainParams& chainparams,
             break;
 
         const CBlockIndex *pindexFork;
-        ConnectTrace connectTrace;
         bool fInitialDownload;
         {
             LOCK(cs_main);
-            { // 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.
-            MemPoolConflictRemovalTracker mrt(mempool);
+            ConnectTrace connectTrace(mempool); // Destructed before cs_main is unlocked
+
             CBlockIndex *pindexOldTip = chainActive.Tip();
             if (pindexMostWork == NULL) {
                 pindexMostWork = FindMostWorkChain();
@@ -2495,16 +2510,9 @@ bool ActivateBestChain(CValidationState &state, const CChainParams& chainparams,
             pindexFork = chainActive.FindFork(pindexOldTip);
             fInitialDownload = IsInitialBlockDownload();
 
-            // throw all transactions though the signal-interface
-
-            } // MemPoolConflictRemovalTracker destroyed and conflict evictions are notified
-
-            // Transactions in the connected block are notified
-            for (const auto& pair : connectTrace.blocksConnected) {
-                assert(pair.second);
-                const CBlock& block = *(pair.second);
-                for (unsigned int i = 0; i < block.vtx.size(); i++)
-                    GetMainSignals().SyncTransaction(*block.vtx[i], pair.first, i);
+            for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) {
+                assert(trace.pblock && trace.pindex);
+                GetMainSignals().BlockConnected(trace.pblock, trace.pindex, *trace.conflictedTxs);
             }
         }
         // When we reach this point, we switched to a new tip (stored in pindexNewTip).
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index d4121a28bc..0f699328c7 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -14,39 +14,42 @@ CMainSignals& GetMainSignals()
 
 void RegisterValidationInterface(CValidationInterface* pwalletIn) {
     g_signals.UpdatedBlockTip.connect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1, _2, _3));
-    g_signals.SyncTransaction.connect(boost::bind(&CValidationInterface::SyncTransaction, pwalletIn, _1, _2, _3));
+    g_signals.TransactionAddedToMempool.connect(boost::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, _1));
+    g_signals.BlockConnected.connect(boost::bind(&CValidationInterface::BlockConnected, pwalletIn, _1, _2, _3));
+    g_signals.BlockDisconnected.connect(boost::bind(&CValidationInterface::BlockDisconnected, pwalletIn, _1));
     g_signals.UpdatedTransaction.connect(boost::bind(&CValidationInterface::UpdatedTransaction, pwalletIn, _1));
     g_signals.SetBestChain.connect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
     g_signals.Inventory.connect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
     g_signals.Broadcast.connect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1, _2));
     g_signals.BlockChecked.connect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
     g_signals.ScriptForMining.connect(boost::bind(&CValidationInterface::GetScriptForMining, pwalletIn, _1));
-    g_signals.BlockFound.connect(boost::bind(&CValidationInterface::ResetRequestCount, pwalletIn, _1));
     g_signals.NewPoWValidBlock.connect(boost::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, _1, _2));
 }
 
 void UnregisterValidationInterface(CValidationInterface* pwalletIn) {
-    g_signals.BlockFound.disconnect(boost::bind(&CValidationInterface::ResetRequestCount, pwalletIn, _1));
     g_signals.ScriptForMining.disconnect(boost::bind(&CValidationInterface::GetScriptForMining, pwalletIn, _1));
     g_signals.BlockChecked.disconnect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
     g_signals.Broadcast.disconnect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1, _2));
     g_signals.Inventory.disconnect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
     g_signals.SetBestChain.disconnect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
     g_signals.UpdatedTransaction.disconnect(boost::bind(&CValidationInterface::UpdatedTransaction, pwalletIn, _1));
-    g_signals.SyncTransaction.disconnect(boost::bind(&CValidationInterface::SyncTransaction, pwalletIn, _1, _2, _3));
+    g_signals.TransactionAddedToMempool.disconnect(boost::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, _1));
+    g_signals.BlockConnected.disconnect(boost::bind(&CValidationInterface::BlockConnected, pwalletIn, _1, _2, _3));
+    g_signals.BlockDisconnected.disconnect(boost::bind(&CValidationInterface::BlockDisconnected, pwalletIn, _1));
     g_signals.UpdatedBlockTip.disconnect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1, _2, _3));
     g_signals.NewPoWValidBlock.disconnect(boost::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, _1, _2));
 }
 
 void UnregisterAllValidationInterfaces() {
-    g_signals.BlockFound.disconnect_all_slots();
     g_signals.ScriptForMining.disconnect_all_slots();
     g_signals.BlockChecked.disconnect_all_slots();
     g_signals.Broadcast.disconnect_all_slots();
     g_signals.Inventory.disconnect_all_slots();
     g_signals.SetBestChain.disconnect_all_slots();
     g_signals.UpdatedTransaction.disconnect_all_slots();
-    g_signals.SyncTransaction.disconnect_all_slots();
+    g_signals.TransactionAddedToMempool.disconnect_all_slots();
+    g_signals.BlockConnected.disconnect_all_slots();
+    g_signals.BlockDisconnected.disconnect_all_slots();
     g_signals.UpdatedBlockTip.disconnect_all_slots();
     g_signals.NewPoWValidBlock.disconnect_all_slots();
 }
diff --git a/src/validationinterface.h b/src/validationinterface.h
index 7f13a29d23..083c136f2c 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -7,16 +7,16 @@
 #define BITCOIN_VALIDATIONINTERFACE_H
 
 #include <boost/signals2/signal.hpp>
-#include <boost/shared_ptr.hpp>
 #include <memory>
 
+#include "primitives/transaction.h" // CTransaction(Ref)
+
 class CBlock;
 class CBlockIndex;
 struct CBlockLocator;
 class CBlockIndex;
 class CConnman;
 class CReserveScript;
-class CTransaction;
 class CValidationInterface;
 class CValidationState;
 class uint256;
@@ -33,14 +33,15 @@ void UnregisterAllValidationInterfaces();
 class CValidationInterface {
 protected:
     virtual void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {}
-    virtual void SyncTransaction(const CTransaction &tx, const CBlockIndex *pindex, int posInBlock) {}
+    virtual void TransactionAddedToMempool(const CTransactionRef &ptxn) {}
+    virtual void BlockConnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex *pindex, const std::vector<CTransactionRef> &txnConflicted) {}
+    virtual void BlockDisconnected(const std::shared_ptr<const CBlock> &block) {}
     virtual void SetBestChain(const CBlockLocator &locator) {}
     virtual void UpdatedTransaction(const uint256 &hash) {}
     virtual void Inventory(const uint256 &hash) {}
     virtual void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) {}
     virtual void BlockChecked(const CBlock&, const CValidationState&) {}
-    virtual void GetScriptForMining(boost::shared_ptr<CReserveScript>&) {};
-    virtual void ResetRequestCount(const uint256 &hash) {};
+    virtual void GetScriptForMining(std::shared_ptr<CReserveScript>&) {};
     virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {};
     friend void ::RegisterValidationInterface(CValidationInterface*);
     friend void ::UnregisterValidationInterface(CValidationInterface*);
@@ -50,17 +51,15 @@ protected:
 struct CMainSignals {
     /** Notifies listeners of updated block chain tip */
     boost::signals2::signal<void (const CBlockIndex *, const CBlockIndex *, bool fInitialDownload)> UpdatedBlockTip;
-    /** A posInBlock value for SyncTransaction calls for transactions not
-     * included in connected blocks such as transactions removed from mempool,
-     * accepted to mempool or appearing in disconnected blocks.*/
-    static const int SYNC_TRANSACTION_NOT_IN_BLOCK = -1;
-    /** Notifies listeners of updated transaction data (transaction, and
-     * optionally the block it is found in). Called with block data when
-     * transaction is included in a connected block, and without block data when
-     * transaction was accepted to mempool, removed from mempool (only when
-     * removal was due to conflict from connected block), or appeared in a
-     * disconnected block.*/
-    boost::signals2::signal<void (const CTransaction &, const CBlockIndex *pindex, int posInBlock)> SyncTransaction;
+    /** Notifies listeners of a transaction having been added to mempool. */
+    boost::signals2::signal<void (const CTransactionRef &)> TransactionAddedToMempool;
+    /**
+     * Notifies listeners of a block being connected.
+     * Provides a vector of transactions evicted from the mempool as a result.
+     */
+    boost::signals2::signal<void (const std::shared_ptr<const CBlock> &, const CBlockIndex *pindex, const std::vector<CTransactionRef> &)> BlockConnected;
+    /** Notifies listeners of a block being disconnected */
+    boost::signals2::signal<void (const std::shared_ptr<const CBlock> &)> BlockDisconnected;
     /** Notifies listeners of an updated transaction without new data (for now: a coinbase potentially becoming visible). */
     boost::signals2::signal<void (const uint256 &)> UpdatedTransaction;
     /** Notifies listeners of a new active block chain. */
@@ -77,9 +76,7 @@ struct CMainSignals {
      */
     boost::signals2::signal<void (const CBlock&, const CValidationState&)> BlockChecked;
     /** Notifies listeners that a key for mining is required (coinbase) */
-    boost::signals2::signal<void (boost::shared_ptr<CReserveScript>&)> ScriptForMining;
-    /** Notifies listeners that a block has been successfully mined */
-    boost::signals2::signal<void (const uint256 &)> BlockFound;
+    boost::signals2::signal<void (std::shared_ptr<CReserveScript>&)> ScriptForMining;
     /**
      * Notifies listeners that a block which builds directly on our current tip
      * has been received and connected to the headers tree, though not validated yet */
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 99fcb21f68..b0aa743422 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -967,8 +967,9 @@ bool CWallet::LoadToWallet(const CWalletTx& wtxIn)
  * Abandoned state should probably be more carefully tracked via different
  * posInBlock signals or by checking mempool presence when necessary.
  */
-bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate)
+bool CWallet::AddToWalletIfInvolvingMe(const CTransactionRef& ptx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate)
 {
+    const CTransaction& tx = *ptx;
     {
         AssertLockHeld(cs_wallet);
 
@@ -989,7 +990,7 @@ bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex
         if (fExisted && !fUpdate) return false;
         if (fExisted || IsMine(tx) || IsFromMe(tx))
         {
-            CWalletTx wtx(this, MakeTransactionRef(tx));
+            CWalletTx wtx(this, ptx);
 
             // Get merkle branch if transaction was found in a block
             if (posInBlock != -1)
@@ -1117,11 +1118,10 @@ void CWallet::MarkConflicted(const uint256& hashBlock, const uint256& hashTx)
     }
 }
 
-void CWallet::SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock)
-{
-    LOCK2(cs_main, cs_wallet);
+void CWallet::SyncTransaction(const CTransactionRef& ptx, const CBlockIndex *pindexBlockConnected, int posInBlock) {
+    const CTransaction& tx = *ptx;
 
-    if (!AddToWalletIfInvolvingMe(tx, pindex, posInBlock, true))
+    if (!AddToWalletIfInvolvingMe(ptx, pindexBlockConnected, posInBlock, true))
         return; // Not one of ours
 
     // If a transaction changes 'conflicted' state, that changes the balance
@@ -1134,6 +1134,38 @@ void CWallet::SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex,
     }
 }
 
+void CWallet::TransactionAddedToMempool(const CTransactionRef& ptx) {
+    LOCK2(cs_main, cs_wallet);
+    SyncTransaction(ptx, NULL, -1);
+}
+
+void CWallet::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) {
+    LOCK2(cs_main, cs_wallet);
+    // TODO: Tempoarily ensure that mempool removals are notified before
+    // connected transactions.  This shouldn't matter, but the abandoned
+    // state of transactions in our wallet is currently cleared when we
+    // receive another notification and there is a race condition where
+    // notification of a connected conflict might cause an outside process
+    // to abandon a transaction and then have it inadvertantly cleared by
+    // the notification that the conflicted transaction was evicted.
+
+    for (const CTransactionRef& ptx : vtxConflicted) {
+        SyncTransaction(ptx, NULL, -1);
+    }
+    for (size_t i = 0; i < pblock->vtx.size(); i++) {
+        SyncTransaction(pblock->vtx[i], pindex, i);
+    }
+}
+
+void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) {
+    LOCK2(cs_main, cs_wallet);
+
+    for (const CTransactionRef& ptx : pblock->vtx) {
+        SyncTransaction(ptx, NULL, -1);
+    }
+}
+
+
 
 isminetype CWallet::IsMine(const CTxIn &txin) const
 {
@@ -1512,7 +1544,7 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool f
             CBlock block;
             if (ReadBlockFromDisk(block, pindex, Params().GetConsensus())) {
                 for (size_t posInBlock = 0; posInBlock < block.vtx.size(); ++posInBlock) {
-                    AddToWalletIfInvolvingMe(*block.vtx[posInBlock], pindex, posInBlock, fUpdate);
+                    AddToWalletIfInvolvingMe(block.vtx[posInBlock], pindex, posInBlock, fUpdate);
                 }
                 if (!ret) {
                     ret = pindex;
@@ -3365,9 +3397,9 @@ void CWallet::UpdatedTransaction(const uint256 &hashTx)
     }
 }
 
-void CWallet::GetScriptForMining(boost::shared_ptr<CReserveScript> &script)
+void CWallet::GetScriptForMining(std::shared_ptr<CReserveScript> &script)
 {
-    boost::shared_ptr<CReserveKey> rKey(new CReserveKey(this));
+    std::shared_ptr<CReserveKey> rKey = std::make_shared<CReserveKey>(this);
     CPubKey pubkey;
     if (!rKey->GetReservedKey(pubkey))
         return;
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index c714ddd090..cf90d261a5 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -28,8 +28,6 @@
 #include <utility>
 #include <vector>
 
-#include <boost/shared_ptr.hpp>
-
 extern CWallet* pwalletMain;
 
 /**
@@ -661,6 +659,9 @@ private:
 
     void SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator>);
 
+    /* Used by TransactionAddedToMemorypool/BlockConnected/Disconnected */
+    void SyncTransaction(const CTransactionRef& tx, const CBlockIndex *pindexBlockConnected, int posInBlock);
+
     /* the HD chain data model (external chain counters) */
     CHDChain hdChain;
 
@@ -849,8 +850,10 @@ public:
     void MarkDirty();
     bool AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose=true);
     bool LoadToWallet(const CWalletTx& wtxIn);
-    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock) override;
-    bool AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate);
+    void TransactionAddedToMempool(const CTransactionRef& tx) override;
+    void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) override;
+    void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) override;
+    bool AddToWalletIfInvolvingMe(const CTransactionRef& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate);
     CBlockIndex* ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate = false);
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) override;
@@ -959,12 +962,7 @@ public:
         }
     }
 
-    void GetScriptForMining(boost::shared_ptr<CReserveScript> &script) override;
-    void ResetRequestCount(const uint256 &hash) override
-    {
-        LOCK(cs_wallet);
-        mapRequestCount[hash] = 0;
-    };
+    void GetScriptForMining(std::shared_ptr<CReserveScript> &script) override;
     
     unsigned int GetKeyPoolSize()
     {
diff --git a/src/zmq/zmqnotificationinterface.cpp b/src/zmq/zmqnotificationinterface.cpp
index fac2a3c57a..c063898056 100644
--- a/src/zmq/zmqnotificationinterface.cpp
+++ b/src/zmq/zmqnotificationinterface.cpp
@@ -144,8 +144,12 @@ void CZMQNotificationInterface::UpdatedBlockTip(const CBlockIndex *pindexNew, co
     }
 }
 
-void CZMQNotificationInterface::SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int posInBlock)
+void CZMQNotificationInterface::TransactionAddedToMempool(const CTransactionRef& ptx)
 {
+    // Used by BlockConnected and BlockDisconnected as well, because they're
+    // all the same external callback.
+    const CTransaction& tx = *ptx;
+
     for (std::list<CZMQAbstractNotifier*>::iterator i = notifiers.begin(); i!=notifiers.end(); )
     {
         CZMQAbstractNotifier *notifier = *i;
@@ -160,3 +164,19 @@ void CZMQNotificationInterface::SyncTransaction(const CTransaction& tx, const CB
         }
     }
 }
+
+void CZMQNotificationInterface::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected, const std::vector<CTransactionRef>& vtxConflicted)
+{
+    for (const CTransactionRef& ptx : pblock->vtx) {
+        // Do a normal notify for each transaction added in the block
+        TransactionAddedToMempool(ptx);
+    }
+}
+
+void CZMQNotificationInterface::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock)
+{
+    for (const CTransactionRef& ptx : pblock->vtx) {
+        // Do a normal notify for each transaction removed in block disconnection
+        TransactionAddedToMempool(ptx);
+    }
+}
diff --git a/src/zmq/zmqnotificationinterface.h b/src/zmq/zmqnotificationinterface.h
index beabb78da6..eec6f7bc64 100644
--- a/src/zmq/zmqnotificationinterface.h
+++ b/src/zmq/zmqnotificationinterface.h
@@ -8,6 +8,7 @@
 #include "validationinterface.h"
 #include <string>
 #include <map>
+#include <list>
 
 class CBlockIndex;
 class CZMQAbstractNotifier;
@@ -24,8 +25,10 @@ protected:
     void Shutdown();
 
     // CValidationInterface
-    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock);
-    void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload);
+    void TransactionAddedToMempool(const CTransactionRef& tx) override;
+    void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected, const std::vector<CTransactionRef>& vtxConflicted) override;
+    void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) override;
+    void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;
 
 private:
     CZMQNotificationInterface();