From 231b399952fd620ee0f72b1947024dba9651630d Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Sat, 24 Nov 2012 14:26:51 +0100 Subject: [PATCH] Bugfix: remove conflicting transactions from memory pool When a transaction A is in the memory pool, while a transaction B (which shares an input with A) gets accepted into a block, A was kept forever in the memory pool. This commit adds a CTxMemPool::removeConflicts method, which removes transactions that conflict with a given transaction, and all their children. This results in less transactions in the memory pool, and faster construction of new blocks. --- src/main.cpp | 28 ++++++++++++++++++++++++++-- src/main.h | 3 ++- 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index e2e993a1..22a8e036 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -818,7 +818,7 @@ bool CTxMemPool::addUnchecked(const uint256& hash, CTransaction &tx) } -bool CTxMemPool::remove(CTransaction &tx) +bool CTxMemPool::remove(const CTransaction &tx, bool fRecursive) { // Remove transaction from memory pool { @@ -826,6 +826,13 @@ bool CTxMemPool::remove(CTransaction &tx) uint256 hash = tx.GetHash(); if (mapTx.count(hash)) { + if (fRecursive) { + for (unsigned int i = 0; i < tx.vout.size(); i++) { + std::map::iterator it = mapNextTx.find(COutPoint(hash, i)); + if (it != mapNextTx.end()) + remove(*it->second.ptx, true); + } + } BOOST_FOREACH(const CTxIn& txin, tx.vin) mapNextTx.erase(txin.prevout); mapTx.erase(hash); @@ -835,6 +842,21 @@ bool CTxMemPool::remove(CTransaction &tx) return true; } +bool CTxMemPool::removeConflicts(const CTransaction &tx) +{ + // Remove transactions which depend on inputs of tx, recursively + LOCK(cs); + BOOST_FOREACH(const CTxIn &txin, tx.vin) { + std::map::iterator it = mapNextTx.find(txin.prevout); + if (it != mapNextTx.end()) { + const CTransaction &txConflict = *it->second.ptx; + if (txConflict != tx) + remove(txConflict, true); + } + } + return true; +} + void CTxMemPool::clear() { LOCK(cs); @@ -1762,8 +1784,10 @@ bool SetBestChain(CBlockIndex* pindexNew) tx.AcceptToMemoryPool(false); // Delete redundant memory transactions that are in the connected branch - BOOST_FOREACH(CTransaction& tx, vDelete) + BOOST_FOREACH(CTransaction& tx, vDelete) { mempool.remove(tx); + mempool.removeConflicts(tx); + } // Update best block in wallet (so we can detect restored wallets) if (!fIsInitialDownload) diff --git a/src/main.h b/src/main.h index 83271412..7a164c77 100644 --- a/src/main.h +++ b/src/main.h @@ -1814,7 +1814,8 @@ public: bool accept(CTransaction &tx, bool fCheckInputs, bool* pfMissingInputs); bool addUnchecked(const uint256& hash, CTransaction &tx); - bool remove(CTransaction &tx); + bool remove(const CTransaction &tx, bool fRecursive = false); + bool removeConflicts(const CTransaction &tx); void clear(); void queryHashes(std::vector& vtxid); void pruneSpent(const uint256& hash, CCoins &coins);