highperfocused/bitcoin
1
0
Fork 0
mirror of https://github.com/bitcoin/bitcoin.git synced 2026-06-10 22:58:40 +02:00
Code Issues Packages Projects Releases Wiki Activity

validation: make IsInitialBlockDownload() lock-free

Browse Source 
`ChainstateManager::IsInitialBlockDownload()` is queried on hot paths and previously acquired `cs_main` internally, contributing to lock contention.

Cache the IBD status in `m_cached_is_ibd`, and introduce `ChainstateManager::UpdateIBDStatus()` to latch it once block loading has finished and the current chain tip has enough work and is recent.
Call the updater after tip updates and after `ImportBlocks()` completes.

Since `IsInitialBlockDownload()` no longer updates the cache, drop `mutable` from `m_cached_is_ibd` and only update it from `UpdateIBDStatus()` under `cs_main`.

Update the new unit test to showcase the new `UpdateIBDStatus()`.

Co-authored-by: Patrick Strateman <patrick.strateman@gmail.com>
Co-authored-by: Martin Zumsande <mzumsande@gmail.com>
This commit is contained in:
Lőrinc
2026-01-11 23:57:13 +01:00
parent b9c0ab3b75
commit 557b41a38c
5 changed files with 38 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
src/validation.cpp
View File

@@ -1939,23 +1939,15 @@ void Chainstate::InitCoinsCache(size_t cache_size_bytes)
m_coins_views->InitCache();
}
// Note that though this is marked const, we may end up modifying `m_cached_is_ibd`, which
// is a performance-related implementation detail. This function must be marked
// `const` so that `CValidationInterface` clients (which are given a `const Chainstate*`)
// can call it.
// This function must be marked `const` so that `CValidationInterface` clients
// (which are given a `const Chainstate*`) can call it.
//
// It is lock-free and depends on `m_cached_is_ibd`, which is latched by
// `UpdateIBDStatus()`.
//
bool ChainstateManager::IsInitialBlockDownload() const
{
// Optimization: pre-test latch before taking the lock.
if (!m_cached_is_ibd.load(std::memory_order_relaxed)) return false;
LOCK(cs_main);
if (!m_cached_is_ibd.load(std::memory_order_relaxed)) return false;
if (m_blockman.LoadingBlocks()) return true;
if (!ActiveChain().IsTipRecent(MinimumChainWork(), m_options.max_tip_age)) return true;
LogInfo("Leaving InitialBlockDownload (latching to false)");
m_cached_is_ibd.store(false, std::memory_order_relaxed);
return false;
return m_cached_is_ibd.load(std::memory_order_relaxed);
}
void Chainstate::CheckForkWarningConditions()
@@ -2999,6 +2991,7 @@ bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTra
}
m_chain.SetTip(*pindexDelete->pprev);
m_chainman.UpdateIBDStatus();
UpdateTip(pindexDelete->pprev);
// Let wallets know transactions went from 1-confirmed to
@@ -3128,6 +3121,7 @@ bool Chainstate::ConnectTip(
}
// Update m_chain & related variables.
m_chain.SetTip(*pindexNew);
m_chainman.UpdateIBDStatus();
UpdateTip(pindexNew);
const auto time_6{SteadyClock::now()};
@@ -3331,6 +3325,15 @@ static SynchronizationState GetSynchronizationState(bool init, bool blockfiles_i
return SynchronizationState::INIT_DOWNLOAD;
}
void ChainstateManager::UpdateIBDStatus()
{
if (!m_cached_is_ibd.load(std::memory_order_relaxed)) return;
if (m_blockman.LoadingBlocks()) return;
if (!CurrentChainstate().m_chain.IsTipRecent(MinimumChainWork(), m_options.max_tip_age)) return;
LogInfo("Leaving InitialBlockDownload (latching to false)");
m_cached_is_ibd.store(false, std::memory_order_relaxed);
}
bool ChainstateManager::NotifyHeaderTip()
{
bool fNotify = false;
@@ -4614,6 +4617,7 @@ bool Chainstate::LoadChainTip()
return false;
}
m_chain.SetTip(*pindex);
m_chainman.UpdateIBDStatus();
tip = m_chain.Tip();
// Make sure our chain tip before shutting down scores better than any other candidate