diff options
| -rw-r--r-- | src/Makefile.test.include | 1 | ||||
| -rw-r--r-- | src/test/validation_flush_tests.cpp | 174 | ||||
| -rw-r--r-- | src/txdb.h | 2 | ||||
| -rw-r--r-- | src/validation.cpp | 41 | ||||
| -rw-r--r-- | src/validation.h | 20 |
5 files changed, 230 insertions, 8 deletions
diff --git a/src/Makefile.test.include b/src/Makefile.test.include index 091ef50349..f7b5994714 100644 --- a/src/Makefile.test.include +++ b/src/Makefile.test.include @@ -185,6 +185,7 @@ BITCOIN_TESTS =\ test/uint256_tests.cpp \ test/util_tests.cpp \ test/validation_block_tests.cpp \ + test/validation_flush_tests.cpp \ test/versionbits_tests.cpp if ENABLE_PROPERTY_TESTS diff --git a/src/test/validation_flush_tests.cpp b/src/test/validation_flush_tests.cpp new file mode 100644 index 0000000000..ab8b957f7d --- /dev/null +++ b/src/test/validation_flush_tests.cpp @@ -0,0 +1,174 @@ +// Copyright (c) 2019 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 <txmempool.h> +#include <validation.h> +#include <sync.h> +#include <test/util/setup_common.h> + +#include <boost/test/unit_test.hpp> + +BOOST_FIXTURE_TEST_SUITE(validation_flush_tests, BasicTestingSetup) + +//! Test utilities for detecting when we need to flush the coins cache based +//! on estimated memory usage. +//! +//! @sa CChainState::GetCoinsCacheSizeState() +//! +BOOST_AUTO_TEST_CASE(getcoinscachesizestate) +{ + BlockManager blockman{}; + CChainState chainstate{blockman}; + chainstate.InitCoinsDB(/*cache_size_bytes*/ 1 << 10, /*in_memory*/ true, /*should_wipe*/ false); + WITH_LOCK(::cs_main, chainstate.InitCoinsCache()); + CTxMemPool tx_pool{}; + + constexpr bool is_64_bit = sizeof(void*) == 8; + + LOCK(::cs_main); + auto& view = chainstate.CoinsTip(); + + //! Create and add a Coin with DynamicMemoryUsage of 80 bytes to the given view. + auto add_coin = [](CCoinsViewCache& coins_view) -> COutPoint { + Coin newcoin; + uint256 txid = InsecureRand256(); + COutPoint outp{txid, 0}; + newcoin.nHeight = 1; + newcoin.out.nValue = InsecureRand32(); + newcoin.out.scriptPubKey.assign((uint32_t)56, 1); + coins_view.AddCoin(outp, std::move(newcoin), false); + + return outp; + }; + + // The number of bytes consumed by coin's heap data, i.e. CScript + // (prevector<28, unsigned char>) when assigned 56 bytes of data per above. + // + // See also: Coin::DynamicMemoryUsage(). + constexpr int COIN_SIZE = is_64_bit ? 80 : 64; + + auto print_view_mem_usage = [](CCoinsViewCache& view) { + BOOST_TEST_MESSAGE("CCoinsViewCache memory usage: " << view.DynamicMemoryUsage()); + }; + + constexpr size_t MAX_COINS_CACHE_BYTES = 1024; + + // Without any coins in the cache, we shouldn't need to flush. + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 0), + CoinsCacheSizeState::OK); + + // If the initial memory allocations of cacheCoins don't match these common + // cases, we can't really continue to make assertions about memory usage. + // End the test early. + if (view.DynamicMemoryUsage() != 32 && view.DynamicMemoryUsage() != 16) { + // Add a bunch of coins to see that we at least flip over to CRITICAL. + + for (int i{0}; i < 1000; ++i) { + COutPoint res = add_coin(view); + BOOST_CHECK_EQUAL(view.AccessCoin(res).DynamicMemoryUsage(), COIN_SIZE); + } + + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 0), + CoinsCacheSizeState::CRITICAL); + + BOOST_TEST_MESSAGE("Exiting cache flush tests early due to unsupported arch"); + return; + } + + print_view_mem_usage(view); + BOOST_CHECK_EQUAL(view.DynamicMemoryUsage(), is_64_bit ? 32 : 16); + + // We should be able to add COINS_UNTIL_CRITICAL coins to the cache before going CRITICAL. + // This is contingent not only on the dynamic memory usage of the Coins + // that we're adding (COIN_SIZE bytes per), but also on how much memory the + // cacheCoins (unordered_map) preallocates. + // + // I came up with the count by examining the printed memory usage of the + // CCoinsCacheView, so it's sort of arbitrary - but it shouldn't change + // unless we somehow change the way the cacheCoins map allocates memory. + // + constexpr int COINS_UNTIL_CRITICAL = is_64_bit ? 4 : 5; + + for (int i{0}; i < COINS_UNTIL_CRITICAL; ++i) { + COutPoint res = add_coin(view); + print_view_mem_usage(view); + BOOST_CHECK_EQUAL(view.AccessCoin(res).DynamicMemoryUsage(), COIN_SIZE); + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 0), + CoinsCacheSizeState::OK); + } + + // Adding an additional coin will push us over the edge to CRITICAL. + add_coin(view); + print_view_mem_usage(view); + + auto size_state = chainstate.GetCoinsCacheSizeState( + tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 0); + + if (!is_64_bit && size_state == CoinsCacheSizeState::LARGE) { + // On 32 bit hosts, we may hit LARGE before CRITICAL. + add_coin(view); + print_view_mem_usage(view); + } + + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 0), + CoinsCacheSizeState::CRITICAL); + + // Passing non-zero max mempool usage should allow us more headroom. + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 1 << 10), + CoinsCacheSizeState::OK); + + for (int i{0}; i < 3; ++i) { + add_coin(view); + print_view_mem_usage(view); + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, /*max_mempool_size_bytes*/ 1 << 10), + CoinsCacheSizeState::OK); + } + + // Adding another coin with the additional mempool room will put us >90% + // but not yet critical. + add_coin(view); + print_view_mem_usage(view); + + // Only perform these checks on 64 bit hosts; I haven't done the math for 32. + if (is_64_bit) { + float usage_percentage = (float)view.DynamicMemoryUsage() / (MAX_COINS_CACHE_BYTES + (1 << 10)); + BOOST_TEST_MESSAGE("CoinsTip usage percentage: " << usage_percentage); + BOOST_CHECK(usage_percentage >= 0.9); + BOOST_CHECK(usage_percentage < 1); + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, 1 << 10), + CoinsCacheSizeState::LARGE); + } + + // Using the default max_* values permits way more coins to be added. + for (int i{0}; i < 1000; ++i) { + add_coin(view); + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool), + CoinsCacheSizeState::OK); + } + + // Flushing the view doesn't take us back to OK because cacheCoins has + // preallocated memory that doesn't get reclaimed even after flush. + + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, 0), + CoinsCacheSizeState::CRITICAL); + + view.SetBestBlock(InsecureRand256()); + BOOST_CHECK(view.Flush()); + print_view_mem_usage(view); + + BOOST_CHECK_EQUAL( + chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, 0), + CoinsCacheSizeState::CRITICAL); +} + +BOOST_AUTO_TEST_SUITE_END() diff --git a/src/txdb.h b/src/txdb.h index f71b4e737d..d661fbc49e 100644 --- a/src/txdb.h +++ b/src/txdb.h @@ -20,8 +20,6 @@ class CBlockIndex; class CCoinsViewDBCursor; class uint256; -//! No need to periodic flush if at least this much space still available. -static constexpr int MAX_BLOCK_COINSDB_USAGE = 10; //! -dbcache default (MiB) static const int64_t nDefaultDbCache = 450; //! -dbbatchsize default (bytes) diff --git a/src/validation.cpp b/src/validation.cpp index cdffec48ab..755f8d43f9 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -2187,13 +2187,44 @@ bool CChainState::ConnectBlock(const CBlock& block, BlockValidationState& state, return true; } +CoinsCacheSizeState CChainState::GetCoinsCacheSizeState(const CTxMemPool& tx_pool) +{ + return this->GetCoinsCacheSizeState( + tx_pool, + nCoinCacheUsage, + gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000); +} + +CoinsCacheSizeState CChainState::GetCoinsCacheSizeState( + const CTxMemPool& tx_pool, + size_t max_coins_cache_size_bytes, + size_t max_mempool_size_bytes) +{ + int64_t nMempoolUsage = tx_pool.DynamicMemoryUsage(); + int64_t cacheSize = CoinsTip().DynamicMemoryUsage(); + int64_t nTotalSpace = + max_coins_cache_size_bytes + std::max<int64_t>(max_mempool_size_bytes - nMempoolUsage, 0); + + //! No need to periodic flush if at least this much space still available. + static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES = 10 * 1024 * 1024; // 10MB + int64_t large_threshold = + std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES); + + if (cacheSize > nTotalSpace) { + LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace); + return CoinsCacheSizeState::CRITICAL; + } else if (cacheSize > large_threshold) { + return CoinsCacheSizeState::LARGE; + } + return CoinsCacheSizeState::OK; +} + bool CChainState::FlushStateToDisk( const CChainParams& chainparams, BlockValidationState &state, FlushStateMode mode, int nManualPruneHeight) { - int64_t nMempoolUsage = mempool.DynamicMemoryUsage(); LOCK(cs_main); assert(this->CanFlushToDisk()); static int64_t nLastWrite = 0; @@ -2208,6 +2239,7 @@ bool CChainState::FlushStateToDisk( { bool fFlushForPrune = false; bool fDoFullFlush = false; + CoinsCacheSizeState cache_state = GetCoinsCacheSizeState(::mempool); LOCK(cs_LastBlockFile); if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) && !fReindex) { if (nManualPruneHeight > 0) { @@ -2236,13 +2268,10 @@ bool CChainState::FlushStateToDisk( if (nLastFlush == 0) { nLastFlush = nNow; } - int64_t nMempoolSizeMax = gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000; - int64_t cacheSize = CoinsTip().DynamicMemoryUsage(); - int64_t nTotalSpace = nCoinCacheUsage + std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0); // The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing). - bool fCacheLarge = mode == FlushStateMode::PERIODIC && cacheSize > std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE * 1024 * 1024); + bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE; // The cache is over the limit, we have to write now. - bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cacheSize > nTotalSpace; + bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL; // It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash. bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow > nLastWrite + (int64_t)DATABASE_WRITE_INTERVAL * 1000000; // It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage. diff --git a/src/validation.h b/src/validation.h index 54f97e7213..81b2ccffc2 100644 --- a/src/validation.h +++ b/src/validation.h @@ -530,6 +530,15 @@ public: void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); }; +enum class CoinsCacheSizeState +{ + //! The coins cache is in immediate need of a flush. + CRITICAL = 2, + //! The cache is at >= 90% capacity. + LARGE = 1, + OK = 0 +}; + /** * CChainState stores and provides an API to update our local knowledge of the * current best chain. @@ -721,6 +730,17 @@ public: /** Update the chain tip based on database information, i.e. CoinsTip()'s best block. */ bool LoadChainTip(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + //! Dictates whether we need to flush the cache to disk or not. + //! + //! @return the state of the size of the coins cache. + CoinsCacheSizeState GetCoinsCacheSizeState(const CTxMemPool& tx_pool) + EXCLUSIVE_LOCKS_REQUIRED(::cs_main); + + CoinsCacheSizeState GetCoinsCacheSizeState( + const CTxMemPool& tx_pool, + size_t max_coins_cache_size_bytes, + size_t max_mempool_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); + private: bool ActivateBestChainStep(BlockValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs); bool ConnectTip(BlockValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs); |