Merge #7946: Reduce cs_main locks during ConnectTip/SyncWithWallets

b3b3c2a Reduce cs_main locks during ConnectTip/SyncWithWallets (Jonas Schnelli)

Author: sipa

src/main.cpp

@@ -1541,7 +1541,7 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C
         }
     }
 
-    SyncWithWallets(tx, NULL, NULL);
+    SyncWithWallets(tx, NULL);
 
     return true;
 }
@@ -2770,7 +2770,7 @@ bool static DisconnectTip(CValidationState& state, const CChainParams& chainpara
     // Let wallets know transactions went from 1-confirmed to
     // 0-confirmed or conflicted:
     BOOST_FOREACH(const CTransaction &tx, block.vtx) {
-        SyncWithWallets(tx, pindexDelete->pprev, NULL);
+        SyncWithWallets(tx, pindexDelete->pprev);
     }
     return true;
 }
@@ -2785,7 +2785,7 @@ static int64_t nTimePostConnect = 0;
  * 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.
  */
-bool static ConnectTip(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const CBlock* pblock)
+bool static ConnectTip(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const CBlock* pblock, std::list<CTransaction> &txConflicted, std::vector<std::tuple<CTransaction,CBlockIndex*,int> > &txChanged)
 {
     assert(pindexNew->pprev == chainActive.Tip());
     // Read block from disk.
@@ -2821,20 +2821,13 @@ bool static ConnectTip(CValidationState& state, const CChainParams& chainparams,
         return false;
     int64_t nTime5 = GetTimeMicros(); nTimeChainState += nTime5 - nTime4;
     LogPrint("bench", "  - Writing chainstate: %.2fms [%.2fs]\n", (nTime5 - nTime4) * 0.001, nTimeChainState * 0.000001);
-    // Remove conflicting transactions from the mempool.
-    list<CTransaction> txConflicted;
+    // Remove conflicting transactions from the mempool.;
     mempool.removeForBlock(pblock->vtx, pindexNew->nHeight, txConflicted, !IsInitialBlockDownload());
     // Update chainActive & related variables.
     UpdateTip(pindexNew, chainparams);
-    // Tell wallet about transactions that went from mempool
-    // to conflicted:
-    BOOST_FOREACH(const CTransaction &tx, txConflicted) {
-        SyncWithWallets(tx, pindexNew, NULL);
-    }
-    // ... and about transactions that got confirmed:
-    BOOST_FOREACH(const CTransaction &tx, pblock->vtx) {
-        SyncWithWallets(tx, pindexNew, pblock);
-    }
+
+    for(unsigned int i=0; i < pblock->vtx.size(); i++)
+        txChanged.push_back(std::make_tuple(pblock->vtx[i], pindexNew, i));
 
     int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
     LogPrint("bench", "  - Connect postprocess: %.2fms [%.2fs]\n", (nTime6 - nTime5) * 0.001, nTimePostConnect * 0.000001);
@@ -2916,7 +2909,7 @@ static void PruneBlockIndexCandidates() {
  * Try to make some progress towards making pindexMostWork the active block.
  * pblock is either NULL or a pointer to a CBlock corresponding to pindexMostWork.
  */
-static bool ActivateBestChainStep(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const CBlock* pblock, bool& fInvalidFound)
+static bool ActivateBestChainStep(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const CBlock* pblock, bool& fInvalidFound, std::list<CTransaction>& txConflicted, std::vector<std::tuple<CTransaction,CBlockIndex*,int> >& txChanged)
 {
     AssertLockHeld(cs_main);
     const CBlockIndex *pindexOldTip = chainActive.Tip();
@@ -2949,7 +2942,7 @@ static bool ActivateBestChainStep(CValidationState& state, const CChainParams& c
 
         // Connect new blocks.
         BOOST_REVERSE_FOREACH(CBlockIndex *pindexConnect, vpindexToConnect) {
-            if (!ConnectTip(state, chainparams, pindexConnect, pindexConnect == pindexMostWork ? pblock : NULL)) {
+            if (!ConnectTip(state, chainparams, pindexConnect, pindexConnect == pindexMostWork ? pblock : NULL, txConflicted, txChanged)) {
                 if (state.IsInvalid()) {
                     // The block violates a consensus rule.
                     if (!state.CorruptionPossible())
@@ -3024,6 +3017,8 @@ bool ActivateBestChain(CValidationState &state, const CChainParams& chainparams,
             break;
 
         const CBlockIndex *pindexFork;
+        std::list<CTransaction> txConflicted;
+        std::vector<std::tuple<CTransaction,CBlockIndex*,int> > txChanged;
         bool fInitialDownload;
         int nNewHeight;
         {
@@ -3038,7 +3033,7 @@ bool ActivateBestChain(CValidationState &state, const CChainParams& chainparams,
                 return true;
 
             bool fInvalidFound = false;
-            if (!ActivateBestChainStep(state, chainparams, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : NULL, fInvalidFound))
+            if (!ActivateBestChainStep(state, chainparams, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : NULL, fInvalidFound, txConflicted, txChanged))
                 return false;
 
             if (fInvalidFound) {
@@ -3053,6 +3048,17 @@ bool ActivateBestChain(CValidationState &state, const CChainParams& chainparams,
         // When we reach this point, we switched to a new tip (stored in pindexNewTip).
 
         // Notifications/callbacks that can run without cs_main
+
+        // throw all transactions though the signal-interface
+        // while _not_ holding the cs_main lock
+        BOOST_FOREACH(const CTransaction &tx, txConflicted)
+        {
+            SyncWithWallets(tx, pindexNewTip);
+        }
+        // ... and about transactions that got confirmed:
+        for(unsigned int i = 0; i < txChanged.size(); i++)
+            SyncWithWallets(std::get<0>(txChanged[i]), std::get<1>(txChanged[i]), std::get<2>(txChanged[i]));
+
         // Always notify the UI if a new block tip was connected
         if (pindexFork != pindexNewTip) {
             uiInterface.NotifyBlockTip(fInitialDownload, pindexNewTip);

src/validationinterface.cpp

@@ -48,6 +48,6 @@ void UnregisterAllValidationInterfaces() {
     g_signals.UpdatedBlockTip.disconnect_all_slots();
 }
 
-void SyncWithWallets(const CTransaction &tx, const CBlockIndex *pindex, const CBlock *pblock) {
-    g_signals.SyncTransaction(tx, pindex, pblock);
+void SyncWithWallets(const CTransaction &tx, const CBlockIndex *pindex, int posInBlock) {
+    g_signals.SyncTransaction(tx, pindex, posInBlock);
 }

src/validationinterface.h

@@ -28,12 +28,12 @@ void UnregisterValidationInterface(CValidationInterface* pwalletIn);
 /** Unregister all wallets from core */
 void UnregisterAllValidationInterfaces();
 /** Push an updated transaction to all registered wallets */
-void SyncWithWallets(const CTransaction& tx, const CBlockIndex *pindex, const CBlock* pblock = NULL);
+void SyncWithWallets(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock = -1);
 
 class CValidationInterface {
 protected:
     virtual void UpdatedBlockTip(const CBlockIndex *pindex) {}
-    virtual void SyncTransaction(const CTransaction &tx, const CBlockIndex *pindex, const CBlock *pblock) {}
+    virtual void SyncTransaction(const CTransaction &tx, const CBlockIndex *pindex, int posInBlock) {}
     virtual void SetBestChain(const CBlockLocator &locator) {}
     virtual void UpdatedTransaction(const uint256 &hash) {}
     virtual void Inventory(const uint256 &hash) {}
@@ -50,7 +50,7 @@ struct CMainSignals {
     /** Notifies listeners of updated block chain tip */
     boost::signals2::signal<void (const CBlockIndex *)> UpdatedBlockTip;
     /** Notifies listeners of updated transaction data (transaction, and optionally the block it is found in. */
-    boost::signals2::signal<void (const CTransaction &, const CBlockIndex *pindex, const CBlock *)> SyncTransaction;
+    boost::signals2::signal<void (const CTransaction &, const CBlockIndex *pindex, int posInBlock)> SyncTransaction;
     /** 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. */

src/wallet/wallet.cpp

@@ -886,18 +886,18 @@ bool CWallet::LoadToWallet(const CWalletTx& wtxIn)
  * pblock is optional, but should be provided if the transaction is known to be in a block.
  * If fUpdate is true, existing transactions will be updated.
  */
-bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlock* pblock, bool fUpdate)
+bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate)
 {
     {
         AssertLockHeld(cs_wallet);
 
-        if (pblock) {
+        if (posInBlock != -1) {
             BOOST_FOREACH(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.GetHash()) {
-                        LogPrintf("Transaction %s (in block %s) conflicts with wallet transaction %s (both spend %s:%i)\n", tx.GetHash().ToString(), pblock->GetHash().ToString(), range.first->second.ToString(), range.first->first.hash.ToString(), range.first->first.n);
-                        MarkConflicted(pblock->GetHash(), range.first->second);
+                        LogPrintf("Transaction %s (in block %s) conflicts with wallet transaction %s (both spend %s:%i)\n", tx.GetHash().ToString(), pIndex->GetBlockHash().ToString(), range.first->second.ToString(), range.first->first.hash.ToString(), range.first->first.n);
+                        MarkConflicted(pIndex->GetBlockHash(), range.first->second);
                     }
                     range.first++;
                 }
@@ -911,8 +911,8 @@ bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlock* pbl
             CWalletTx wtx(this,tx);
 
             // Get merkle branch if transaction was found in a block
-            if (pblock)
-                wtx.SetMerkleBranch(*pblock);
+            if (posInBlock != -1)
+                wtx.SetMerkleBranch(pIndex, posInBlock);
 
             return AddToWallet(wtx, false);
         }
@@ -1037,11 +1037,11 @@ void CWallet::MarkConflicted(const uint256& hashBlock, const uint256& hashTx)
     }
 }
 
-void CWallet::SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, const CBlock* pblock)
+void CWallet::SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock)
 {
     LOCK2(cs_main, cs_wallet);
 
-    if (!AddToWalletIfInvolvingMe(tx, pblock, true))
+    if (!AddToWalletIfInvolvingMe(tx, pindex, posInBlock, true))
         return; // Not one of ours
 
     // If a transaction changes 'conflicted' state, that changes the balance
@@ -1399,9 +1399,10 @@ int CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
 
             CBlock block;
             ReadBlockFromDisk(block, pindex, Params().GetConsensus());
-            BOOST_FOREACH(CTransaction& tx, block.vtx)
+            int posInBlock;
+            for (posInBlock = 0; posInBlock < (int)block.vtx.size(); posInBlock++)
             {
-                if (AddToWalletIfInvolvingMe(tx, &block, fUpdate))
+                if (AddToWalletIfInvolvingMe(block.vtx[posInBlock], pindex, posInBlock, fUpdate))
                     ret++;
             }
             pindex = chainActive.Next(pindex);
@@ -3526,31 +3527,19 @@ CWalletKey::CWalletKey(int64_t nExpires)
     nTimeExpires = nExpires;
 }
 
-int CMerkleTx::SetMerkleBranch(const CBlock& block)
+int CMerkleTx::SetMerkleBranch(const CBlockIndex* pindex, int posInBlock)
 {
     AssertLockHeld(cs_main);
     CBlock blockTmp;
 
     // Update the tx's hashBlock
-    hashBlock = block.GetHash();
+    hashBlock = pindex->GetBlockHash();
 
-    // Locate the transaction
-    for (nIndex = 0; nIndex < (int)block.vtx.size(); nIndex++)
-        if (block.vtx[nIndex] == *(CTransaction*)this)
-            break;
-    if (nIndex == (int)block.vtx.size())
-    {
-        nIndex = -1;
-        LogPrintf("ERROR: SetMerkleBranch(): couldn't find tx in block\n");
-        return 0;
-    }
+    // set the position of the transaction in the block
+    nIndex = posInBlock;
 
     // Is the tx in a block that's in the main chain
-    BlockMap::iterator mi = mapBlockIndex.find(hashBlock);
-    if (mi == mapBlockIndex.end())
-        return 0;
-    const CBlockIndex* pindex = (*mi).second;
-    if (!pindex || !chainActive.Contains(pindex))
+    if (!chainActive.Contains(pindex))
         return 0;
 
     return chainActive.Height() - pindex->nHeight + 1;

src/wallet/wallet.h

@@ -200,7 +200,7 @@ class CMerkleTx : public CTransaction
         READWRITE(nIndex);
     }
 
-    int SetMerkleBranch(const CBlock& block);
+    int SetMerkleBranch(const CBlockIndex* pIndex, int posInBlock);
 
     /**
      * Return depth of transaction in blockchain:
@@ -731,8 +731,8 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
     void MarkDirty();
     bool AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose=true);
     bool LoadToWallet(const CWalletTx& wtxIn);
-    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, const CBlock* pblock);
-    bool AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlock* pblock, bool fUpdate);
+    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock);
+    bool AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate);
     int ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate = false);
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime);

src/zmq/zmqnotificationinterface.cpp

@@ -141,7 +141,7 @@ void CZMQNotificationInterface::UpdatedBlockTip(const CBlockIndex *pindex)
     }
 }
 
-void CZMQNotificationInterface::SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, const CBlock* pblock)
+void CZMQNotificationInterface::SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int posInBlock)
 {
     for (std::list<CZMQAbstractNotifier*>::iterator i = notifiers.begin(); i!=notifiers.end(); )
     {

src/zmq/zmqnotificationinterface.h

@@ -24,7 +24,7 @@ class CZMQNotificationInterface : public CValidationInterface
     void Shutdown();
 
     // CValidationInterface
-    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, const CBlock* pblock);
+    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock);
     void UpdatedBlockTip(const CBlockIndex *pindex);
 
 private: