diff --git a/src/miner.cpp b/src/miner.cpp index e269758941..dade8a9d77 100644 --- a/src/miner.cpp +++ b/src/miner.cpp @@ -1,681 +1,687 @@ // 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 "miner.h" #include "amount.h" #include "chain.h" #include "chainparams.h" #include "coins.h" #include "config.h" #include "consensus/consensus.h" #include "consensus/merkle.h" #include "consensus/validation.h" #include "hash.h" #include "net.h" #include "policy/policy.h" #include "pow.h" #include "primitives/transaction.h" #include "script/standard.h" #include "timedata.h" #include "txmempool.h" #include "util.h" #include "utilmoneystr.h" #include "validation.h" #include "validationinterface.h" #include #include #include #include #include static const int MAX_COINBASE_SCRIPTSIG_SIZE = 100; ////////////////////////////////////////////////////////////////////////////// // // BitcoinMiner // // // Unconfirmed transactions in the memory pool often depend on other // transactions in the memory pool. When we select transactions from the // pool, we select by highest priority or fee rate, so we might consider // transactions that depend on transactions that aren't yet in the block. uint64_t nLastBlockTx = 0; uint64_t nLastBlockSize = 0; int64_t UpdateTime(CBlockHeader *pblock, const Config &config, const CBlockIndex *pindexPrev) { int64_t nOldTime = pblock->nTime; int64_t nNewTime = std::max(pindexPrev->GetMedianTimePast() + 1, GetAdjustedTime()); if (nOldTime < nNewTime) { pblock->nTime = nNewTime; } const Consensus::Params &consensusParams = config.GetChainParams().GetConsensus(); // Updating time can change work required on testnet: if (consensusParams.fPowAllowMinDifficultyBlocks) { pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, config); } return nNewTime - nOldTime; } static uint64_t ComputeMaxGeneratedBlockSize(const Config &config, const CBlockIndex *pindexPrev) { // Block resource limits // If -blockmaxsize is not given, limit to DEFAULT_MAX_GENERATED_BLOCK_SIZE // If only one is given, only restrict the specified resource. // If both are given, restrict both. uint64_t nMaxGeneratedBlockSize = DEFAULT_MAX_GENERATED_BLOCK_SIZE; if (gArgs.IsArgSet("-blockmaxsize")) { nMaxGeneratedBlockSize = gArgs.GetArg("-blockmaxsize", DEFAULT_MAX_GENERATED_BLOCK_SIZE); } // Limit size to between 1K and MaxBlockSize-1K for sanity: nMaxGeneratedBlockSize = std::max(uint64_t(1000), std::min(config.GetMaxBlockSize() - 1000, nMaxGeneratedBlockSize)); return nMaxGeneratedBlockSize; } BlockAssembler::BlockAssembler(const Config &_config) : config(&_config) { if (gArgs.IsArgSet("-blockmintxfee")) { Amount n(0); ParseMoney(gArgs.GetArg("-blockmintxfee", ""), n); blockMinFeeRate = CFeeRate(n); } else { blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE); } LOCK(cs_main); nMaxGeneratedBlockSize = ComputeMaxGeneratedBlockSize(*config, chainActive.Tip()); } void BlockAssembler::resetBlock() { inBlock.clear(); // Reserve space for coinbase tx. nBlockSize = 1000; nBlockSigOps = 100; // These counters do not include coinbase tx. nBlockTx = 0; nFees = Amount(0); lastFewTxs = 0; blockFinished = false; } static const std::vector getExcessiveBlockSizeSig(const Config &config) { std::string cbmsg = "/EB" + getSubVersionEB(config.GetMaxBlockSize()) + "/"; const char *cbcstr = cbmsg.c_str(); std::vector vec(cbcstr, cbcstr + cbmsg.size()); return vec; } std::unique_ptr BlockAssembler::CreateNewBlock(const CScript &scriptPubKeyIn) { int64_t nTimeStart = GetTimeMicros(); resetBlock(); pblocktemplate.reset(new CBlockTemplate()); if (!pblocktemplate.get()) { return nullptr; } // Pointer for convenience. pblock = &pblocktemplate->block; // Add dummy coinbase tx as first transaction. pblock->vtx.emplace_back(); // updated at end pblocktemplate->vTxFees.push_back(Amount(-1)); // updated at end pblocktemplate->vTxSigOpsCount.push_back(-1); LOCK2(cs_main, mempool.cs); CBlockIndex *pindexPrev = chainActive.Tip(); nHeight = pindexPrev->nHeight + 1; const CChainParams &chainparams = config->GetChainParams(); pblock->nVersion = ComputeBlockVersion(pindexPrev, chainparams.GetConsensus()); // -regtest only: allow overriding block.nVersion with // -blockversion=N to test forking scenarios if (chainparams.MineBlocksOnDemand()) { pblock->nVersion = gArgs.GetArg("-blockversion", pblock->nVersion); } pblock->nTime = GetAdjustedTime(); nMaxGeneratedBlockSize = ComputeMaxGeneratedBlockSize(*config, pindexPrev); nLockTimeCutoff = (STANDARD_LOCKTIME_VERIFY_FLAGS & LOCKTIME_MEDIAN_TIME_PAST) ? pindexPrev->GetMedianTimePast() : pblock->GetBlockTime(); addPriorityTxs(); int nPackagesSelected = 0; int nDescendantsUpdated = 0; addPackageTxs(nPackagesSelected, nDescendantsUpdated); if (IsMagneticAnomalyEnabled(*config, pindexPrev)) { // If magnetic anomaly is enabled, we make sure transaction are // canonically ordered. std::sort(std::begin(pblock->vtx) + 1, std::end(pblock->vtx), [](const std::shared_ptr &a, const std::shared_ptr &b) -> bool { return a->GetId() > b->GetId(); }); } int64_t nTime1 = GetTimeMicros(); nLastBlockTx = nBlockTx; nLastBlockSize = nBlockSize; // Create coinbase transaction. CMutableTransaction coinbaseTx; coinbaseTx.vin.resize(1); coinbaseTx.vin[0].prevout = COutPoint(); coinbaseTx.vout.resize(1); coinbaseTx.vout[0].scriptPubKey = scriptPubKeyIn; coinbaseTx.vout[0].nValue = nFees + GetBlockSubsidy(nHeight, chainparams.GetConsensus()); coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0; pblock->vtx[0] = MakeTransactionRef(coinbaseTx); pblocktemplate->vTxFees[0] = -1 * nFees; uint64_t nSerializeSize = GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION); LogPrintf("CreateNewBlock(): total size: %u txs: %u fees: %ld sigops %d\n", nSerializeSize, nBlockTx, nFees, nBlockSigOps); // Fill in header. pblock->hashPrevBlock = pindexPrev->GetBlockHash(); UpdateTime(pblock, *config, pindexPrev); pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, *config); pblock->nNonce = 0; pblocktemplate->vTxSigOpsCount[0] = GetSigOpCountWithoutP2SH(*pblock->vtx[0]); CValidationState state; BlockValidationOptions validationOptions(false, false); if (!TestBlockValidity(*config, state, *pblock, pindexPrev, validationOptions)) { throw std::runtime_error(strprintf("%s: TestBlockValidity failed: %s", __func__, FormatStateMessage(state))); } int64_t nTime2 = GetTimeMicros(); LogPrint( BCLog::BENCH, "CreateNewBlock() packages: %.2fms (%d packages, %d " "updated descendants), validity: %.2fms (total %.2fms)\n", 0.001 * (nTime1 - nTimeStart), nPackagesSelected, nDescendantsUpdated, 0.001 * (nTime2 - nTime1), 0.001 * (nTime2 - nTimeStart)); return std::move(pblocktemplate); } bool BlockAssembler::isStillDependent(CTxMemPool::txiter iter) { for (CTxMemPool::txiter parent : mempool.GetMemPoolParents(iter)) { if (!inBlock.count(parent)) { return true; } } return false; } void BlockAssembler::onlyUnconfirmed(CTxMemPool::setEntries &testSet) { for (CTxMemPool::setEntries::iterator iit = testSet.begin(); iit != testSet.end();) { // Only test txs not already in the block. if (inBlock.count(*iit)) { testSet.erase(iit++); } else { iit++; } } } bool BlockAssembler::TestPackage(uint64_t packageSize, int64_t packageSigOps) { auto blockSizeWithPackage = nBlockSize + packageSize; if (blockSizeWithPackage >= nMaxGeneratedBlockSize) { return false; } if (nBlockSigOps + packageSigOps >= GetMaxBlockSigOpsCount(blockSizeWithPackage)) { return false; } return true; } /** * Perform transaction-level checks before adding to block: * - Transaction finality (locktime) * - Serialized size (in case -blockmaxsize is in use) */ bool BlockAssembler::TestPackageTransactions( const CTxMemPool::setEntries &package) { uint64_t nPotentialBlockSize = nBlockSize; for (const CTxMemPool::txiter it : package) { CValidationState state; if (!ContextualCheckTransaction(*config, it->GetTx(), state, nHeight, nLockTimeCutoff)) { return false; } uint64_t nTxSize = ::GetSerializeSize(it->GetTx(), SER_NETWORK, PROTOCOL_VERSION); if (nPotentialBlockSize + nTxSize >= nMaxGeneratedBlockSize) { return false; } nPotentialBlockSize += nTxSize; } return true; } bool BlockAssembler::TestForBlock(CTxMemPool::txiter it) { auto blockSizeWithTx = nBlockSize + ::GetSerializeSize(it->GetTx(), SER_NETWORK, PROTOCOL_VERSION); if (blockSizeWithTx >= nMaxGeneratedBlockSize) { if (nBlockSize > nMaxGeneratedBlockSize - 100 || lastFewTxs > 50) { blockFinished = true; return false; } if (nBlockSize > nMaxGeneratedBlockSize - 1000) { lastFewTxs++; } return false; } auto maxBlockSigOps = GetMaxBlockSigOpsCount(blockSizeWithTx); if (nBlockSigOps + it->GetSigOpCount() >= maxBlockSigOps) { // If the block has room for no more sig ops then flag that the block is // finished. // TODO: We should consider adding another transaction that isn't very // dense in sigops instead of bailing out so easily. if (nBlockSigOps > maxBlockSigOps - 2) { blockFinished = true; return false; } // Otherwise attempt to find another tx with fewer sigops to put in the // block. return false; } // Must check that lock times are still valid. This can be removed once MTP // is always enforced as long as reorgs keep the mempool consistent. CValidationState state; if (!ContextualCheckTransaction(*config, it->GetTx(), state, nHeight, nLockTimeCutoff)) { return false; } return true; } void BlockAssembler::AddToBlock(CTxMemPool::txiter iter) { pblock->vtx.emplace_back(iter->GetSharedTx()); pblocktemplate->vTxFees.push_back(iter->GetFee()); pblocktemplate->vTxSigOpsCount.push_back(iter->GetSigOpCount()); nBlockSize += iter->GetTxSize(); ++nBlockTx; nBlockSigOps += iter->GetSigOpCount(); nFees += iter->GetFee(); inBlock.insert(iter); bool fPrintPriority = gArgs.GetBoolArg("-printpriority", DEFAULT_PRINTPRIORITY); if (fPrintPriority) { double dPriority = iter->GetPriority(nHeight); Amount dummy; mempool.ApplyDeltas(iter->GetTx().GetId(), dPriority, dummy); LogPrintf( "priority %.1f fee %s txid %s\n", dPriority, CFeeRate(iter->GetModifiedFee(), iter->GetTxSize()).ToString(), iter->GetTx().GetId().ToString()); } } int BlockAssembler::UpdatePackagesForAdded( const CTxMemPool::setEntries &alreadyAdded, indexed_modified_transaction_set &mapModifiedTx) { int nDescendantsUpdated = 0; for (const CTxMemPool::txiter it : alreadyAdded) { CTxMemPool::setEntries descendants; mempool.CalculateDescendants(it, descendants); // Insert all descendants (not yet in block) into the modified set. for (CTxMemPool::txiter desc : descendants) { if (alreadyAdded.count(desc)) { continue; } ++nDescendantsUpdated; modtxiter mit = mapModifiedTx.find(desc); if (mit == mapModifiedTx.end()) { CTxMemPoolModifiedEntry modEntry(desc); modEntry.nSizeWithAncestors -= it->GetTxSize(); modEntry.nModFeesWithAncestors -= it->GetModifiedFee(); modEntry.nSigOpCountWithAncestors -= it->GetSigOpCount(); mapModifiedTx.insert(modEntry); } else { mapModifiedTx.modify(mit, update_for_parent_inclusion(it)); } } } return nDescendantsUpdated; } // Skip entries in mapTx that are already in a block or are present in // mapModifiedTx (which implies that the mapTx ancestor state is stale due to // ancestor inclusion in the block). Also skip transactions that we've already // failed to add. This can happen if we consider a transaction in mapModifiedTx // and it fails: we can then potentially consider it again while walking mapTx. // It's currently guaranteed to fail again, but as a belt-and-suspenders check // we put it in failedTx and avoid re-evaluation, since the re-evaluation would // be using cached size/sigops/fee values that are not actually correct. bool BlockAssembler::SkipMapTxEntry( CTxMemPool::txiter it, indexed_modified_transaction_set &mapModifiedTx, CTxMemPool::setEntries &failedTx) { assert(it != mempool.mapTx.end()); return mapModifiedTx.count(it) || inBlock.count(it) || failedTx.count(it); } void BlockAssembler::SortForBlock( const CTxMemPool::setEntries &package, CTxMemPool::txiter entry, std::vector &sortedEntries) { // Sort package by ancestor count. If a transaction A depends on transaction // B, then A's ancestor count must be greater than B's. So this is // sufficient to validly order the transactions for block inclusion. sortedEntries.clear(); sortedEntries.insert(sortedEntries.begin(), package.begin(), package.end()); std::sort(sortedEntries.begin(), sortedEntries.end(), CompareTxIterByAncestorCount()); } /** * addPackageTx includes transactions paying a fee by ensuring that * the partial ordering of transactions is maintained. That is to say * children come after parents, despite having a potentially larger fee. * @param[out] nPackagesSelected How many packages were selected * @param[out] nDescendantsUpdated Number of descendant transactions updated */ void BlockAssembler::addPackageTxs(int &nPackagesSelected, int &nDescendantsUpdated) { // selection algorithm orders the mempool based on feerate of a // transaction including all unconfirmed ancestors. Since we don't remove // transactions from the mempool as we select them for block inclusion, we // need an alternate method of updating the feerate of a transaction with // its not-yet-selected ancestors as we go. This is accomplished by // walking the in-mempool descendants of selected transactions and storing // a temporary modified state in mapModifiedTxs. Each time through the // loop, we compare the best transaction in mapModifiedTxs with the next // transaction in the mempool to decide what transaction package to work // on next. // mapModifiedTx will store sorted packages after they are modified because // some of their txs are already in the block. indexed_modified_transaction_set mapModifiedTx; // Keep track of entries that failed inclusion, to avoid duplicate work. CTxMemPool::setEntries failedTx; // Start by adding all descendants of previously added txs to mapModifiedTx // and modifying them for their already included ancestors. UpdatePackagesForAdded(inBlock, mapModifiedTx); CTxMemPool::indexed_transaction_set::index::type::iterator mi = mempool.mapTx.get().begin(); CTxMemPool::txiter iter; // Limit the number of attempts to add transactions to the block when it is // close to full; this is just a simple heuristic to finish quickly if the // mempool has a lot of entries. const int64_t MAX_CONSECUTIVE_FAILURES = 1000; int64_t nConsecutiveFailed = 0; while (mi != mempool.mapTx.get().end() || !mapModifiedTx.empty()) { // First try to find a new transaction in mapTx to evaluate. if (mi != mempool.mapTx.get().end() && SkipMapTxEntry(mempool.mapTx.project<0>(mi), mapModifiedTx, failedTx)) { ++mi; continue; } // Now that mi is not stale, determine which transaction to evaluate: // the next entry from mapTx, or the best from mapModifiedTx? bool fUsingModified = false; modtxscoreiter modit = mapModifiedTx.get().begin(); if (mi == mempool.mapTx.get().end()) { // We're out of entries in mapTx; use the entry from mapModifiedTx iter = modit->iter; fUsingModified = true; } else { // Try to compare the mapTx entry to the mapModifiedTx entry. iter = mempool.mapTx.project<0>(mi); if (modit != mapModifiedTx.get().end() && CompareModifiedEntry()(*modit, CTxMemPoolModifiedEntry(iter))) { // The best entry in mapModifiedTx has higher score than the one // from mapTx. Switch which transaction (package) to consider iter = modit->iter; fUsingModified = true; } else { // Either no entry in mapModifiedTx, or it's worse than mapTx. // Increment mi for the next loop iteration. ++mi; } } // We skip mapTx entries that are inBlock, and mapModifiedTx shouldn't // contain anything that is inBlock. assert(!inBlock.count(iter)); uint64_t packageSize = iter->GetSizeWithAncestors(); Amount packageFees = iter->GetModFeesWithAncestors(); int64_t packageSigOps = iter->GetSigOpCountWithAncestors(); if (fUsingModified) { packageSize = modit->nSizeWithAncestors; packageFees = modit->nModFeesWithAncestors; packageSigOps = modit->nSigOpCountWithAncestors; } if (packageFees < blockMinFeeRate.GetFee(packageSize)) { // Everything else we might consider has a lower fee rate return; } if (!TestPackage(packageSize, packageSigOps)) { if (fUsingModified) { // Since we always look at the best entry in mapModifiedTx, we // must erase failed entries so that we can consider the next // best entry on the next loop iteration mapModifiedTx.get().erase(modit); failedTx.insert(iter); } ++nConsecutiveFailed; if (nConsecutiveFailed > MAX_CONSECUTIVE_FAILURES && nBlockSize > nMaxGeneratedBlockSize - 1000) { // Give up if we're close to full and haven't succeeded in a // while. break; } continue; } CTxMemPool::setEntries ancestors; uint64_t nNoLimit = std::numeric_limits::max(); std::string dummy; mempool.CalculateMemPoolAncestors(*iter, ancestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false); onlyUnconfirmed(ancestors); ancestors.insert(iter); // Test if all tx's are Final. if (!TestPackageTransactions(ancestors)) { if (fUsingModified) { mapModifiedTx.get().erase(modit); failedTx.insert(iter); } continue; } // This transaction will make it in; reset the failed counter. nConsecutiveFailed = 0; // Package can be added. Sort the entries in a valid order. std::vector sortedEntries; SortForBlock(ancestors, iter, sortedEntries); for (auto &entry : sortedEntries) { AddToBlock(entry); // Erase from the modified set, if present mapModifiedTx.erase(entry); } ++nPackagesSelected; // Update transactions that depend on each of these nDescendantsUpdated += UpdatePackagesForAdded(ancestors, mapModifiedTx); } } void BlockAssembler::addPriorityTxs() { // How much of the block should be dedicated to high-priority transactions, // included regardless of the fees they pay. if (config->GetBlockPriorityPercentage() == 0) { return; } uint64_t nBlockPrioritySize = nMaxGeneratedBlockSize * config->GetBlockPriorityPercentage() / 100; // This vector will be sorted into a priority queue: std::vector vecPriority; TxCoinAgePriorityCompare pricomparer; std::map waitPriMap; typedef std::map::iterator waitPriIter; double actualPriority = -1; vecPriority.reserve(mempool.mapTx.size()); for (CTxMemPool::indexed_transaction_set::iterator mi = mempool.mapTx.begin(); mi != mempool.mapTx.end(); ++mi) { double dPriority = mi->GetPriority(nHeight); Amount dummy; mempool.ApplyDeltas(mi->GetTx().GetId(), dPriority, dummy); vecPriority.push_back(TxCoinAgePriority(dPriority, mi)); } std::make_heap(vecPriority.begin(), vecPriority.end(), pricomparer); CTxMemPool::txiter iter; // Add a tx from priority queue to fill the part of block reserved to // priority transactions. while (!vecPriority.empty() && !blockFinished) { iter = vecPriority.front().second; actualPriority = vecPriority.front().first; std::pop_heap(vecPriority.begin(), vecPriority.end(), pricomparer); vecPriority.pop_back(); // If tx already in block, skip. if (inBlock.count(iter)) { // Shouldn't happen for priority txs. assert(false); continue; } // If tx is dependent on other mempool txs which haven't yet been // included then put it in the waitSet. if (isStillDependent(iter)) { waitPriMap.insert(std::make_pair(iter, actualPriority)); continue; } // If this tx fits in the block add it, otherwise keep looping. - if (TestForBlock(iter)) { - AddToBlock(iter); - - // If now that this txs is added we've surpassed our desired - // priority size or have dropped below the AllowFreeThreshold, then - // we're done adding priority txs. - if (nBlockSize >= nBlockPrioritySize || - !AllowFree(actualPriority)) { - break; - } + if (!TestForBlock(iter)) { + continue; + } + + AddToBlock(iter); - // This tx was successfully added, so add transactions that depend - // on this one to the priority queue to try again. - for (CTxMemPool::txiter child : mempool.GetMemPoolChildren(iter)) { - waitPriIter wpiter = waitPriMap.find(child); - if (wpiter != waitPriMap.end()) { - vecPriority.push_back( - TxCoinAgePriority(wpiter->second, child)); - std::push_heap(vecPriority.begin(), vecPriority.end(), - pricomparer); - waitPriMap.erase(wpiter); - } + // If now that this txs is added we've surpassed our desired priority + // size, then we're done adding priority transactions. + if (nBlockSize >= nBlockPrioritySize) { + break; + } + + // if we have dropped below the AllowFreeThreshold, then we're done + // adding priority transactions. + if (!AllowFree(actualPriority)) { + break; + } + + // This tx was successfully added, so add transactions that depend + // on this one to the priority queue to try again. + for (CTxMemPool::txiter child : mempool.GetMemPoolChildren(iter)) { + waitPriIter wpiter = waitPriMap.find(child); + if (wpiter == waitPriMap.end()) { + continue; } + + vecPriority.push_back(TxCoinAgePriority(wpiter->second, child)); + std::push_heap(vecPriority.begin(), vecPriority.end(), pricomparer); + waitPriMap.erase(wpiter); } } } void IncrementExtraNonce(const Config &config, CBlock *pblock, const CBlockIndex *pindexPrev, unsigned int &nExtraNonce) { // Update nExtraNonce static uint256 hashPrevBlock; if (hashPrevBlock != pblock->hashPrevBlock) { nExtraNonce = 0; hashPrevBlock = pblock->hashPrevBlock; } ++nExtraNonce; // Height first in coinbase required for block.version=2 unsigned int nHeight = pindexPrev->nHeight + 1; CMutableTransaction txCoinbase(*pblock->vtx[0]); txCoinbase.vin[0].scriptSig = (CScript() << nHeight << CScriptNum(nExtraNonce) << getExcessiveBlockSizeSig(config)) + COINBASE_FLAGS; assert(txCoinbase.vin[0].scriptSig.size() <= MAX_COINBASE_SCRIPTSIG_SIZE); pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase)); pblock->hashMerkleRoot = BlockMerkleRoot(*pblock); }