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Diffstat (limited to 'src/node/miner.cpp')
| -rw-r--r-- | src/node/miner.cpp | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/src/node/miner.cpp b/src/node/miner.cpp new file mode 100644 index 0000000000..6e9bde84d8 --- /dev/null +++ b/src/node/miner.cpp @@ -0,0 +1,466 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2020 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 <node/miner.h> + +#include <chain.h> +#include <chainparams.h> +#include <coins.h> +#include <consensus/amount.h> +#include <consensus/consensus.h> +#include <consensus/merkle.h> +#include <consensus/tx_verify.h> +#include <consensus/validation.h> +#include <deploymentstatus.h> +#include <policy/feerate.h> +#include <policy/policy.h> +#include <pow.h> +#include <primitives/transaction.h> +#include <timedata.h> +#include <util/moneystr.h> +#include <util/system.h> +#include <validation.h> + +#include <algorithm> +#include <utility> + +int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev) +{ + int64_t nOldTime = pblock->nTime; + int64_t nNewTime = std::max(pindexPrev->GetMedianTimePast() + 1, GetAdjustedTime()); + + if (nOldTime < nNewTime) { + pblock->nTime = nNewTime; + } + + // Updating time can change work required on testnet: + if (consensusParams.fPowAllowMinDifficultyBlocks) { + pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, consensusParams); + } + + return nNewTime - nOldTime; +} + +void RegenerateCommitments(CBlock& block, ChainstateManager& chainman) +{ + CMutableTransaction tx{*block.vtx.at(0)}; + tx.vout.erase(tx.vout.begin() + GetWitnessCommitmentIndex(block)); + block.vtx.at(0) = MakeTransactionRef(tx); + + CBlockIndex* prev_block = WITH_LOCK(::cs_main, return chainman.m_blockman.LookupBlockIndex(block.hashPrevBlock)); + GenerateCoinbaseCommitment(block, prev_block, Params().GetConsensus()); + + block.hashMerkleRoot = BlockMerkleRoot(block); +} + +BlockAssembler::Options::Options() +{ + blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE); + nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT; +} + +BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const CChainParams& params, const Options& options) + : chainparams(params), + m_mempool(mempool), + m_chainstate(chainstate) +{ + blockMinFeeRate = options.blockMinFeeRate; + // Limit weight to between 4K and MAX_BLOCK_WEIGHT-4K for sanity: + nBlockMaxWeight = std::max<size_t>(4000, std::min<size_t>(MAX_BLOCK_WEIGHT - 4000, options.nBlockMaxWeight)); +} + +static BlockAssembler::Options DefaultOptions() +{ + // Block resource limits + // If -blockmaxweight is not given, limit to DEFAULT_BLOCK_MAX_WEIGHT + BlockAssembler::Options options; + options.nBlockMaxWeight = gArgs.GetIntArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT); + if (gArgs.IsArgSet("-blockmintxfee")) { + std::optional<CAmount> parsed = ParseMoney(gArgs.GetArg("-blockmintxfee", "")); + options.blockMinFeeRate = CFeeRate{parsed.value_or(DEFAULT_BLOCK_MIN_TX_FEE)}; + } else { + options.blockMinFeeRate = CFeeRate{DEFAULT_BLOCK_MIN_TX_FEE}; + } + return options; +} + +BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const CChainParams& params) + : BlockAssembler(chainstate, mempool, params, DefaultOptions()) {} + +void BlockAssembler::resetBlock() +{ + inBlock.clear(); + + // Reserve space for coinbase tx + nBlockWeight = 4000; + nBlockSigOpsCost = 400; + fIncludeWitness = false; + + // These counters do not include coinbase tx + nBlockTx = 0; + nFees = 0; +} + +std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& scriptPubKeyIn) +{ + int64_t nTimeStart = GetTimeMicros(); + + resetBlock(); + + pblocktemplate.reset(new CBlockTemplate()); + + if (!pblocktemplate.get()) { + return nullptr; + } + CBlock* const pblock = &pblocktemplate->block; // pointer for convenience + + // Add dummy coinbase tx as first transaction + pblock->vtx.emplace_back(); + pblocktemplate->vTxFees.push_back(-1); // updated at end + pblocktemplate->vTxSigOpsCost.push_back(-1); // updated at end + + LOCK2(cs_main, m_mempool.cs); + CBlockIndex* pindexPrev = m_chainstate.m_chain.Tip(); + assert(pindexPrev != nullptr); + nHeight = pindexPrev->nHeight + 1; + + pblock->nVersion = g_versionbitscache.ComputeBlockVersion(pindexPrev, chainparams.GetConsensus()); + // -regtest only: allow overriding block.nVersion with + // -blockversion=N to test forking scenarios + if (chainparams.MineBlocksOnDemand()) { + pblock->nVersion = gArgs.GetIntArg("-blockversion", pblock->nVersion); + } + + pblock->nTime = GetAdjustedTime(); + m_lock_time_cutoff = pindexPrev->GetMedianTimePast(); + + // Decide whether to include witness transactions + // This is only needed in case the witness softfork activation is reverted + // (which would require a very deep reorganization). + // Note that the mempool would accept transactions with witness data before + // the deployment is active, but we would only ever mine blocks after activation + // unless there is a massive block reorganization with the witness softfork + // not activated. + // TODO: replace this with a call to main to assess validity of a mempool + // transaction (which in most cases can be a no-op). + fIncludeWitness = DeploymentActiveAfter(pindexPrev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT); + + int nPackagesSelected = 0; + int nDescendantsUpdated = 0; + addPackageTxs(nPackagesSelected, nDescendantsUpdated); + + int64_t nTime1 = GetTimeMicros(); + + m_last_block_num_txs = nBlockTx; + m_last_block_weight = nBlockWeight; + + // Create coinbase transaction. + CMutableTransaction coinbaseTx; + coinbaseTx.vin.resize(1); + coinbaseTx.vin[0].prevout.SetNull(); + 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(std::move(coinbaseTx)); + pblocktemplate->vchCoinbaseCommitment = GenerateCoinbaseCommitment(*pblock, pindexPrev, chainparams.GetConsensus()); + pblocktemplate->vTxFees[0] = -nFees; + + LogPrintf("CreateNewBlock(): block weight: %u txs: %u fees: %ld sigops %d\n", GetBlockWeight(*pblock), nBlockTx, nFees, nBlockSigOpsCost); + + // Fill in header + pblock->hashPrevBlock = pindexPrev->GetBlockHash(); + UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev); + pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus()); + pblock->nNonce = 0; + pblocktemplate->vTxSigOpsCost[0] = WITNESS_SCALE_FACTOR * GetLegacySigOpCount(*pblock->vtx[0]); + + BlockValidationState state; + if (!TestBlockValidity(state, chainparams, m_chainstate, *pblock, pindexPrev, false, false)) { + throw std::runtime_error(strprintf("%s: TestBlockValidity failed: %s", __func__, state.ToString())); + } + 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); +} + +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 packageSigOpsCost) const +{ + // TODO: switch to weight-based accounting for packages instead of vsize-based accounting. + if (nBlockWeight + WITNESS_SCALE_FACTOR * packageSize >= nBlockMaxWeight) { + return false; + } + if (nBlockSigOpsCost + packageSigOpsCost >= MAX_BLOCK_SIGOPS_COST) { + return false; + } + return true; +} + +// Perform transaction-level checks before adding to block: +// - transaction finality (locktime) +// - premature witness (in case segwit transactions are added to mempool before +// segwit activation) +bool BlockAssembler::TestPackageTransactions(const CTxMemPool::setEntries& package) const +{ + for (CTxMemPool::txiter it : package) { + if (!IsFinalTx(it->GetTx(), nHeight, m_lock_time_cutoff)) { + return false; + } + if (!fIncludeWitness && it->GetTx().HasWitness()) { + return false; + } + } + return true; +} + +void BlockAssembler::AddToBlock(CTxMemPool::txiter iter) +{ + pblocktemplate->block.vtx.emplace_back(iter->GetSharedTx()); + pblocktemplate->vTxFees.push_back(iter->GetFee()); + pblocktemplate->vTxSigOpsCost.push_back(iter->GetSigOpCost()); + nBlockWeight += iter->GetTxWeight(); + ++nBlockTx; + nBlockSigOpsCost += iter->GetSigOpCost(); + nFees += iter->GetFee(); + inBlock.insert(iter); + + bool fPrintPriority = gArgs.GetBoolArg("-printpriority", DEFAULT_PRINTPRIORITY); + if (fPrintPriority) { + LogPrintf("fee rate %s txid %s\n", + CFeeRate(iter->GetModifiedFee(), iter->GetTxSize()).ToString(), + iter->GetTx().GetHash().ToString()); + } +} + +int BlockAssembler::UpdatePackagesForAdded(const CTxMemPool::setEntries& alreadyAdded, + indexed_modified_transaction_set &mapModifiedTx) +{ + AssertLockHeld(m_mempool.cs); + + int nDescendantsUpdated = 0; + for (CTxMemPool::txiter it : alreadyAdded) { + CTxMemPool::setEntries descendants; + m_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.nSigOpCostWithAncestors -= it->GetSigOpCost(); + 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) +{ + AssertLockHeld(m_mempool.cs); + + assert(it != m_mempool.mapTx.end()); + return mapModifiedTx.count(it) || inBlock.count(it) || failedTx.count(it); +} + +void BlockAssembler::SortForBlock(const CTxMemPool::setEntries& package, std::vector<CTxMemPool::txiter>& 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()); +} + +// This transaction 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. +void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpdated) +{ + AssertLockHeld(m_mempool.cs); + + // 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<ancestor_score>::type::iterator mi = m_mempool.mapTx.get<ancestor_score>().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 != m_mempool.mapTx.get<ancestor_score>().end() || !mapModifiedTx.empty()) { + // First try to find a new transaction in mapTx to evaluate. + if (mi != m_mempool.mapTx.get<ancestor_score>().end() && + SkipMapTxEntry(m_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<ancestor_score>().begin(); + if (mi == m_mempool.mapTx.get<ancestor_score>().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 = m_mempool.mapTx.project<0>(mi); + if (modit != mapModifiedTx.get<ancestor_score>().end() && + CompareTxMemPoolEntryByAncestorFee()(*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(); + CAmount packageFees = iter->GetModFeesWithAncestors(); + int64_t packageSigOpsCost = iter->GetSigOpCostWithAncestors(); + if (fUsingModified) { + packageSize = modit->nSizeWithAncestors; + packageFees = modit->nModFeesWithAncestors; + packageSigOpsCost = modit->nSigOpCostWithAncestors; + } + + if (packageFees < blockMinFeeRate.GetFee(packageSize)) { + // Everything else we might consider has a lower fee rate + return; + } + + if (!TestPackage(packageSize, packageSigOpsCost)) { + 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<ancestor_score>().erase(modit); + failedTx.insert(iter); + } + + ++nConsecutiveFailed; + + if (nConsecutiveFailed > MAX_CONSECUTIVE_FAILURES && nBlockWeight > + nBlockMaxWeight - 4000) { + // 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<uint64_t>::max(); + std::string dummy; + m_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<ancestor_score>().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<CTxMemPool::txiter> sortedEntries; + SortForBlock(ancestors, sortedEntries); + + for (size_t i = 0; i < sortedEntries.size(); ++i) { + AddToBlock(sortedEntries[i]); + // Erase from the modified set, if present + mapModifiedTx.erase(sortedEntries[i]); + } + + ++nPackagesSelected; + + // Update transactions that depend on each of these + nDescendantsUpdated += UpdatePackagesForAdded(ancestors, mapModifiedTx); + } +} + +void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned int& nExtraNonce) +{ + // Update nExtraNonce + static uint256 hashPrevBlock; + if (hashPrevBlock != pblock->hashPrevBlock) { + nExtraNonce = 0; + hashPrevBlock = pblock->hashPrevBlock; + } + ++nExtraNonce; + unsigned int nHeight = pindexPrev->nHeight + 1; // Height first in coinbase required for block.version=2 + CMutableTransaction txCoinbase(*pblock->vtx[0]); + txCoinbase.vin[0].scriptSig = (CScript() << nHeight << CScriptNum(nExtraNonce)); + assert(txCoinbase.vin[0].scriptSig.size() <= 100); + + pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase)); + pblock->hashMerkleRoot = BlockMerkleRoot(*pblock); +} |