Merge ac9fa6ec78 into merged_master (Bitcoin PR bitcoin/bitcoin#28385)

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Byron Hambly 2025-08-04 12:47:38 +02:00
commit 4537155dea
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9 changed files with 317 additions and 127 deletions

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@ -195,6 +195,7 @@ BITCOIN_CORE_H = \
kernel/coinstats.h \
kernel/context.h \
kernel/cs_main.h \
kernel/disconnected_transactions.h \
kernel/mempool_entry.h \
kernel/mempool_limits.h \
kernel/mempool_options.h \

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@ -28,6 +28,7 @@ bench_bench_bitcoin_SOURCES = \
bench/data.cpp \
bench/data.h \
bench/descriptors.cpp \
bench/disconnected_transactions.cpp \
bench/duplicate_inputs.cpp \
bench/ellswift.cpp \
bench/examples.cpp \

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@ -0,0 +1,130 @@
// Copyright (c) 2023 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 <bench/bench.h>
#include <kernel/disconnected_transactions.h>
#include <primitives/block.h>
#include <test/util/random.h>
#include <test/util/setup_common.h>
constexpr size_t BLOCK_VTX_COUNT{4000};
constexpr size_t BLOCK_VTX_COUNT_10PERCENT{400};
using BlockTxns = decltype(CBlock::vtx);
/** Reorg where 1 block is disconnected and 2 blocks are connected. */
struct ReorgTxns {
/** Disconnected block. */
BlockTxns disconnected_txns;
/** First connected block. */
BlockTxns connected_txns_1;
/** Second connected block, new chain tip. Has no overlap with disconnected_txns. */
BlockTxns connected_txns_2;
/** Transactions shared between disconnected_txns and connected_txns_1. */
size_t num_shared;
};
static BlockTxns CreateRandomTransactions(size_t num_txns)
{
// Ensure every transaction has a different txid by having each one spend the previous one.
static uint256 prevout_hash{uint256::ZERO};
BlockTxns txns;
txns.reserve(num_txns);
// Simplest spk for every tx
CScript spk = CScript() << OP_TRUE;
for (uint32_t i = 0; i < num_txns; ++i) {
CMutableTransaction tx;
tx.vin.emplace_back(CTxIn{COutPoint{prevout_hash, 0}});
tx.vout.emplace_back(CTxOut{CAsset(), CENT, spk});
auto ptx{MakeTransactionRef(tx)};
txns.emplace_back(ptx);
prevout_hash = ptx->GetHash();
}
return txns;
}
/** Creates blocks for a Reorg, each with BLOCK_VTX_COUNT transactions. Between the disconnected
* block and the first connected block, there will be num_not_shared transactions that are
* different, and all other transactions the exact same. The second connected block has all unique
* transactions. This is to simulate a reorg in which all but num_not_shared transactions are
* confirmed in the new chain. */
static ReorgTxns CreateBlocks(size_t num_not_shared)
{
auto num_shared{BLOCK_VTX_COUNT - num_not_shared};
const auto shared_txns{CreateRandomTransactions(/*num_txns=*/num_shared)};
// Create different sets of transactions...
auto disconnected_block_txns{CreateRandomTransactions(/*num_txns=*/num_not_shared)};
std::copy(shared_txns.begin(), shared_txns.end(), std::back_inserter(disconnected_block_txns));
auto connected_block_txns{CreateRandomTransactions(/*num_txns=*/num_not_shared)};
std::copy(shared_txns.begin(), shared_txns.end(), std::back_inserter(connected_block_txns));
assert(disconnected_block_txns.size() == BLOCK_VTX_COUNT);
assert(connected_block_txns.size() == BLOCK_VTX_COUNT);
return ReorgTxns{/*disconnected_txns=*/disconnected_block_txns,
/*connected_txns_1=*/connected_block_txns,
/*connected_txns_2=*/CreateRandomTransactions(BLOCK_VTX_COUNT),
/*num_shared=*/num_shared};
}
static void Reorg(const ReorgTxns& reorg)
{
DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_SIZE * 1000};
// Disconnect block
const auto evicted = disconnectpool.AddTransactionsFromBlock(reorg.disconnected_txns);
assert(evicted.empty());
// Connect first block
disconnectpool.removeForBlock(reorg.connected_txns_1);
// Connect new tip
disconnectpool.removeForBlock(reorg.connected_txns_2);
// Sanity Check
assert(disconnectpool.size() == BLOCK_VTX_COUNT - reorg.num_shared);
disconnectpool.clear();
}
/** Add transactions from DisconnectedBlockTransactions, remove all but one (the disconnected
* block's coinbase transaction) of them, and then pop from the front until empty. This is a reorg
* in which all of the non-coinbase transactions in the disconnected chain also exist in the new
* chain. */
static void AddAndRemoveDisconnectedBlockTransactionsAll(benchmark::Bench& bench)
{
const auto chains{CreateBlocks(/*num_not_shared=*/1)};
assert(chains.num_shared == BLOCK_VTX_COUNT - 1);
bench.minEpochIterations(10).run([&]() NO_THREAD_SAFETY_ANALYSIS {
Reorg(chains);
});
}
/** Add transactions from DisconnectedBlockTransactions, remove 90% of them, and then pop from the front until empty. */
static void AddAndRemoveDisconnectedBlockTransactions90(benchmark::Bench& bench)
{
const auto chains{CreateBlocks(/*num_not_shared=*/BLOCK_VTX_COUNT_10PERCENT)};
assert(chains.num_shared == BLOCK_VTX_COUNT - BLOCK_VTX_COUNT_10PERCENT);
bench.minEpochIterations(10).run([&]() NO_THREAD_SAFETY_ANALYSIS {
Reorg(chains);
});
}
/** Add transactions from DisconnectedBlockTransactions, remove 10% of them, and then pop from the front until empty. */
static void AddAndRemoveDisconnectedBlockTransactions10(benchmark::Bench& bench)
{
const auto chains{CreateBlocks(/*num_not_shared=*/BLOCK_VTX_COUNT - BLOCK_VTX_COUNT_10PERCENT)};
assert(chains.num_shared == BLOCK_VTX_COUNT_10PERCENT);
bench.minEpochIterations(10).run([&]() NO_THREAD_SAFETY_ANALYSIS {
Reorg(chains);
});
}
BENCHMARK(AddAndRemoveDisconnectedBlockTransactionsAll, benchmark::PriorityLevel::HIGH);
BENCHMARK(AddAndRemoveDisconnectedBlockTransactions90, benchmark::PriorityLevel::HIGH);
BENCHMARK(AddAndRemoveDisconnectedBlockTransactions10, benchmark::PriorityLevel::HIGH);

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@ -0,0 +1,137 @@
// Copyright (c) 2023 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_KERNEL_DISCONNECTED_TRANSACTIONS_H
#define BITCOIN_KERNEL_DISCONNECTED_TRANSACTIONS_H
#include <core_memusage.h>
#include <memusage.h>
#include <primitives/transaction.h>
#include <util/hasher.h>
#include <list>
#include <unordered_map>
#include <vector>
/** Maximum kilobytes for transactions to store for processing during reorg */
static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE = 20'000;
/**
* DisconnectedBlockTransactions
* During the reorg, it's desirable to re-add previously confirmed transactions
* to the mempool, so that anything not re-confirmed in the new chain is
* available to be mined. However, it's more efficient to wait until the reorg
* is complete and process all still-unconfirmed transactions at that time,
* since we expect most confirmed transactions to (typically) still be
* confirmed in the new chain, and re-accepting to the memory pool is expensive
* (and therefore better to not do in the middle of reorg-processing).
* Instead, store the disconnected transactions (in order!) as we go, remove any
* that are included in blocks in the new chain, and then process the remaining
* still-unconfirmed transactions at the end.
*
* Order of queuedTx:
* The front of the list should be the most recently-confirmed transactions (transactions at the
* end of vtx of blocks closer to the tip). If memory usage grows too large, we trim from the front
* of the list. After trimming, transactions can be re-added to the mempool from the back of the
* list to the front without running into missing inputs.
*/
class DisconnectedBlockTransactions {
private:
/** Cached dynamic memory usage for the CTransactions (memory for the shared pointers is
* included in the container calculations). */
uint64_t cachedInnerUsage = 0;
const size_t m_max_mem_usage;
std::list<CTransactionRef> queuedTx;
using TxList = decltype(queuedTx);
std::unordered_map<uint256, TxList::iterator, SaltedTxidHasher> iters_by_txid;
/** Trim the earliest-added entries until we are within memory bounds. */
std::vector<CTransactionRef> LimitMemoryUsage()
{
std::vector<CTransactionRef> evicted;
while (!queuedTx.empty() && DynamicMemoryUsage() > m_max_mem_usage) {
evicted.emplace_back(queuedTx.front());
cachedInnerUsage -= RecursiveDynamicUsage(*queuedTx.front());
iters_by_txid.erase(queuedTx.front()->GetHash());
queuedTx.pop_front();
}
return evicted;
}
public:
DisconnectedBlockTransactions(size_t max_mem_usage) : m_max_mem_usage{max_mem_usage} {}
// It's almost certainly a logic bug if we don't clear out queuedTx before
// destruction, as we add to it while disconnecting blocks, and then we
// need to re-process remaining transactions to ensure mempool consistency.
// For now, assert() that we've emptied out this object on destruction.
// This assert() can always be removed if the reorg-processing code were
// to be refactored such that this assumption is no longer true (for
// instance if there was some other way we cleaned up the mempool after a
// reorg, besides draining this object).
~DisconnectedBlockTransactions() {
assert(queuedTx.empty());
assert(iters_by_txid.empty());
assert(cachedInnerUsage == 0);
}
size_t DynamicMemoryUsage() const {
return cachedInnerUsage + memusage::DynamicUsage(iters_by_txid) + memusage::DynamicUsage(queuedTx);
}
/** Add transactions from the block, iterating through vtx in reverse order. Callers should call
* this function for blocks in descending order by block height.
* We assume that callers never pass multiple transactions with the same txid, otherwise things
* can go very wrong in removeForBlock due to queuedTx containing an item without a
* corresponding entry in iters_by_txid.
* @returns vector of transactions that were evicted for size-limiting.
*/
[[nodiscard]] std::vector<CTransactionRef> AddTransactionsFromBlock(const std::vector<CTransactionRef>& vtx)
{
iters_by_txid.reserve(iters_by_txid.size() + vtx.size());
for (auto block_it = vtx.rbegin(); block_it != vtx.rend(); ++block_it) {
auto it = queuedTx.insert(queuedTx.end(), *block_it);
iters_by_txid.emplace((*block_it)->GetHash(), it);
cachedInnerUsage += RecursiveDynamicUsage(**block_it);
}
return LimitMemoryUsage();
}
/** Remove any entries that are in this block. */
void removeForBlock(const std::vector<CTransactionRef>& vtx)
{
// Short-circuit in the common case of a block being added to the tip
if (queuedTx.empty()) {
return;
}
for (const auto& tx : vtx) {
auto iter = iters_by_txid.find(tx->GetHash());
if (iter != iters_by_txid.end()) {
auto list_iter = iter->second;
iters_by_txid.erase(iter);
cachedInnerUsage -= RecursiveDynamicUsage(**list_iter);
queuedTx.erase(list_iter);
}
}
}
size_t size() const { return queuedTx.size(); }
void clear()
{
cachedInnerUsage = 0;
iters_by_txid.clear();
queuedTx.clear();
}
/** Clear all data structures and return the list of transactions. */
std::list<CTransactionRef> take()
{
std::list<CTransactionRef> ret = std::move(queuedTx);
clear();
return ret;
}
};
#endif // BITCOIN_KERNEL_DISCONNECTED_TRANSACTIONS_H

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@ -11,6 +11,7 @@
#include <cassert>
#include <cstdlib>
#include <list>
#include <map>
#include <memory>
#include <set>
@ -148,6 +149,21 @@ static inline size_t DynamicUsage(const std::shared_ptr<X>& p)
return p ? MallocUsage(sizeof(X)) + MallocUsage(sizeof(stl_shared_counter)) : 0;
}
template<typename X>
struct list_node
{
private:
void* ptr_next;
void* ptr_prev;
X x;
};
template<typename X>
static inline size_t DynamicUsage(const std::list<X>& l)
{
return MallocUsage(sizeof(list_node<X>)) * l.size();
}
template<typename X>
struct unordered_node : private X
{

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@ -4,6 +4,7 @@
//
#include <chainparams.h>
#include <consensus/validation.h>
#include <kernel/disconnected_transactions.h>
#include <node/kernel_notifications.h>
#include <node/utxo_snapshot.h>
#include <random.h>
@ -539,7 +540,7 @@ BOOST_FIXTURE_TEST_CASE(chainstatemanager_snapshot_init, SnapshotTestSetup)
// it will initialize instead of attempting to complete validation.
//
// Note that this is not a realistic use of DisconnectTip().
DisconnectedBlockTransactions unused_pool;
DisconnectedBlockTransactions unused_pool{MAX_DISCONNECTED_TX_POOL_SIZE * 1000};
BlockValidationState unused_state;
{
LOCK2(::cs_main, bg_chainstate.MempoolMutex());

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@ -907,96 +907,4 @@ public:
// ELEMENTS:
bool IsPeginSpent(const std::pair<uint256, COutPoint> &outpoint) const override;
};
/**
* DisconnectedBlockTransactions
* During the reorg, it's desirable to re-add previously confirmed transactions
* to the mempool, so that anything not re-confirmed in the new chain is
* available to be mined. However, it's more efficient to wait until the reorg
* is complete and process all still-unconfirmed transactions at that time,
* since we expect most confirmed transactions to (typically) still be
* confirmed in the new chain, and re-accepting to the memory pool is expensive
* (and therefore better to not do in the middle of reorg-processing).
* Instead, store the disconnected transactions (in order!) as we go, remove any
* that are included in blocks in the new chain, and then process the remaining
* still-unconfirmed transactions at the end.
*/
// multi_index tag names
struct txid_index {};
struct insertion_order {};
struct DisconnectedBlockTransactions {
typedef boost::multi_index_container<
CTransactionRef,
boost::multi_index::indexed_by<
// sorted by txid
boost::multi_index::hashed_unique<
boost::multi_index::tag<txid_index>,
mempoolentry_txid,
SaltedTxidHasher
>,
// sorted by order in the blockchain
boost::multi_index::sequenced<
boost::multi_index::tag<insertion_order>
>
>
> indexed_disconnected_transactions;
// It's almost certainly a logic bug if we don't clear out queuedTx before
// destruction, as we add to it while disconnecting blocks, and then we
// need to re-process remaining transactions to ensure mempool consistency.
// For now, assert() that we've emptied out this object on destruction.
// This assert() can always be removed if the reorg-processing code were
// to be refactored such that this assumption is no longer true (for
// instance if there was some other way we cleaned up the mempool after a
// reorg, besides draining this object).
~DisconnectedBlockTransactions() { assert(queuedTx.empty()); }
indexed_disconnected_transactions queuedTx;
uint64_t cachedInnerUsage = 0;
// Estimate the overhead of queuedTx to be 6 pointers + an allocation, as
// no exact formula for boost::multi_index_contained is implemented.
size_t DynamicMemoryUsage() const {
return memusage::MallocUsage(sizeof(CTransactionRef) + 6 * sizeof(void*)) * queuedTx.size() + cachedInnerUsage;
}
void addTransaction(const CTransactionRef& tx)
{
queuedTx.insert(tx);
cachedInnerUsage += RecursiveDynamicUsage(tx);
}
// Remove entries based on txid_index, and update memory usage.
void removeForBlock(const std::vector<CTransactionRef>& vtx)
{
// Short-circuit in the common case of a block being added to the tip
if (queuedTx.empty()) {
return;
}
for (auto const &tx : vtx) {
auto it = queuedTx.find(tx->GetHash());
if (it != queuedTx.end()) {
cachedInnerUsage -= RecursiveDynamicUsage(*it);
queuedTx.erase(it);
}
}
}
// Remove an entry by insertion_order index, and update memory usage.
void removeEntry(indexed_disconnected_transactions::index<insertion_order>::type::iterator entry)
{
cachedInnerUsage -= RecursiveDynamicUsage(*entry);
queuedTx.get<insertion_order>().erase(entry);
}
void clear()
{
cachedInnerUsage = 0;
queuedTx.clear();
}
};
#endif // BITCOIN_TXMEMPOOL_H

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@ -22,6 +22,7 @@
#include <flatfile.h>
#include <hash.h>
#include <kernel/chainparams.h>
#include <kernel/disconnected_transactions.h>
#include <kernel/mempool_entry.h>
#include <kernel/messagestartchars.h>
#include <kernel/notifications_interface.h>
@ -89,8 +90,6 @@ using node::CBlockIndexWorkComparator;
using node::fReindex;
using node::SnapshotMetadata;
/** Maximum kilobytes for transactions to store for processing during reorg */
static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE = 20000;
/** Time to wait between writing blocks/block index to disk. */
static constexpr std::chrono::minutes DATABASE_WRITE_INTERVAL{5};
/** Time to wait between flushing chainstate to disk. */
@ -310,28 +309,30 @@ void Chainstate::MaybeUpdateMempoolForReorg(
AssertLockHeld(cs_main);
AssertLockHeld(m_mempool->cs);
std::vector<uint256> vHashUpdate;
// disconnectpool's insertion_order index sorts the entries from
// oldest to newest, but the oldest entry will be the last tx from the
// latest mined block that was disconnected.
// Iterate disconnectpool in reverse, so that we add transactions
// back to the mempool starting with the earliest transaction that had
// been previously seen in a block.
auto it = disconnectpool.queuedTx.get<insertion_order>().rbegin();
while (it != disconnectpool.queuedTx.get<insertion_order>().rend()) {
// ignore validation errors in resurrected transactions
if (!fAddToMempool || (*it)->IsCoinBase() ||
AcceptToMemoryPool(*this, *it, GetTime(),
/*bypass_limits=*/true, /*test_accept=*/false).m_result_type !=
MempoolAcceptResult::ResultType::VALID) {
// If the transaction doesn't make it in to the mempool, remove any
// transactions that depend on it (which would now be orphans).
m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
} else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) {
vHashUpdate.push_back((*it)->GetHash());
{
// disconnectpool is ordered so that the front is the most recently-confirmed
// transaction (the last tx of the block at the tip) in the disconnected chain.
// Iterate disconnectpool in reverse, so that we add transactions
// back to the mempool starting with the earliest transaction that had
// been previously seen in a block.
const auto queuedTx = disconnectpool.take();
auto it = queuedTx.rbegin();
while (it != queuedTx.rend()) {
// ignore validation errors in resurrected transactions
if (!fAddToMempool || (*it)->IsCoinBase() ||
AcceptToMemoryPool(*this, *it, GetTime(),
/*bypass_limits=*/true, /*test_accept=*/false).m_result_type !=
MempoolAcceptResult::ResultType::VALID) {
// If the transaction doesn't make it in to the mempool, remove any
// transactions that depend on it (which would now be orphans).
m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
} else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) {
vHashUpdate.push_back((*it)->GetHash());
}
++it;
}
++it;
}
disconnectpool.queuedTx.clear();
// AcceptToMemoryPool/addUnchecked all assume that new mempool entries have
// no in-mempool children, which is generally not true when adding
// previously-confirmed transactions back to the mempool.
@ -3101,15 +3102,10 @@ bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTra
}
if (disconnectpool && m_mempool) {
// Save transactions to re-add to mempool at end of reorg
for (auto it = block.vtx.rbegin(); it != block.vtx.rend(); ++it) {
disconnectpool->addTransaction(*it);
}
while (disconnectpool->DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE * 1000) {
// Drop the earliest entry, and remove its children from the mempool.
auto it = disconnectpool->queuedTx.get<insertion_order>().begin();
m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
disconnectpool->removeEntry(it);
// Save transactions to re-add to mempool at end of reorg. If any entries are evicted for
// exceeding memory limits, remove them and their descendants from the mempool.
for (auto&& evicted_tx : disconnectpool->AddTransactionsFromBlock(block.vtx)) {
m_mempool->removeRecursive(*evicted_tx, MemPoolRemovalReason::REORG);
}
}
@ -3373,7 +3369,7 @@ bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex*
// Disconnect active blocks which are no longer in the best chain.
bool fBlocksDisconnected = false;
DisconnectedBlockTransactions disconnectpool;
DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_SIZE * 1000};
while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
if (!DisconnectTip(state, &disconnectpool)) {
// This is likely a fatal error, but keep the mempool consistent,
@ -3725,7 +3721,7 @@ bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* pinde
// ActivateBestChain considers blocks already in m_chain
// unconditionally valid already, so force disconnect away from it.
DisconnectedBlockTransactions disconnectpool;
DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_SIZE * 1000};
bool ret = DisconnectTip(state, &disconnectpool);
// DisconnectTip will add transactions to disconnectpool.
// Adjust the mempool to be consistent with the new tip, adding

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@ -53,7 +53,7 @@ class Chainstate;
class CTxMemPool;
class ChainstateManager;
struct ChainTxData;
struct DisconnectedBlockTransactions;
class DisconnectedBlockTransactions;
struct PrecomputedTransactionData;
struct LockPoints;
struct AssumeutxoData;