validation: Move block into BlockConnected signal
What the developer wrote
Authored by sedited
validation: Move block into BlockConnected signal
This makes existing behaviour of the block's destructor triggering on
the scheduler thread more explicit by moving it to the thread. The
scheduler thread doing so is useful, since it does not block the thread
doing validation while releasing a block's memory.
Previously, both the caller and the queued event lambda held copies of
the shared_ptr. The block would typically be freed on the scheduler
thread - but only because it went out of scope before the queued event
on the scheduler thread ran. If the scheduler ran first, the block would
instead be freed on the validation thread.
Now, ownership is transferred at each step when invoking the
BlockConnected signal: connected_blocks yields via std::move,
BlockConnected takes by value, and the event lambda move-captures the
shared_ptr. Though it is possible that this only decrements the block's
reference count, blocks are also read from disk in `ConnectTip`, which
now explicitly results in their memory being released on the scheduler
thread.
What changed, and why it matters
This commit is a small internal cleanup in how Bitcoin Core hands off newly connected blocks to background notification threads. It moves a block's shared ownership explicitly onto the scheduler thread so the heavy validation thread is not delayed by memory cleanup. There is no user-facing bug fix or security vulnerability being patched; it is a performance and clarity improvement.
No security action required. Treat as routine code-quality/performance improvement during normal review.
Security signals we found
No memory-safety bug is fixed; the change is defensive and deterministic
No input validation, cryptography, or network parsing changes
No privilege boundary or authorization change
No CVE, advisory, or vendor security disclosure referenced in commit
Evidence from the diff
The change transfers ownership of std::shared_ptr
Changed components
src/validation.cppsrc/validationinterface.cppsrc/validationinterface.hInspect captured patch +5 / −5
diff --git a/src/validation.cpp b/src/validation.cpp
index 1efe109b..f9cc7d78 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -3391,9 +3391,9 @@ bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<
}
pindexNewTip = m_chain.Tip();
- for (const auto& [index, block] : connected_blocks) {
+ for (auto& [index, block] : std::move(connected_blocks)) {
if (m_chainman.m_options.signals) {
- m_chainman.m_options.signals->BlockConnected(chainstate_role, Assert(block), Assert(index));
+ m_chainman.m_options.signals->BlockConnected(chainstate_role, std::move(Assert(block)), Assert(index));
}
}
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index 3c142f8d..3e939de9 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -219,12 +219,12 @@ void ValidationSignals::TransactionRemovedFromMempool(const CTransactionRef& tx,
ENQUEUE_AND_LOG_EVENT(std::move(event), std::move(log_msg));
}
-void ValidationSignals::BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex)
+void ValidationSignals::BlockConnected(const ChainstateRole& role, std::shared_ptr<const CBlock> pblock, const CBlockIndex* pindex)
{
auto log_msg = LOG_MSG("%s: block hash=%s block height=%d", __func__,
pblock->GetHash().ToString(),
pindex->nHeight);
- auto event = [role, pblock, pindex, this] {
+ auto event = [role, pblock = std::move(pblock), pindex, this] {
m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.BlockConnected(role, pblock, pindex); });
};
ENQUEUE_AND_LOG_EVENT(std::move(event), std::move(log_msg));
diff --git a/src/validationinterface.h b/src/validationinterface.h
index 4777e8dc..641afd55 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -223,7 +223,7 @@ public:
void TransactionAddedToMempool(const NewMempoolTransactionInfo&, uint64_t mempool_sequence);
void TransactionRemovedFromMempool(const CTransactionRef&, MemPoolRemovalReason, uint64_t mempool_sequence);
void MempoolTransactionsRemovedForBlock(const std::vector<RemovedMempoolTransactionInfo>&, unsigned int nBlockHeight);
- void BlockConnected(const kernel::ChainstateRole&, const std::shared_ptr<const CBlock>&, const CBlockIndex* pindex);
+ void BlockConnected(const kernel::ChainstateRole&, std::shared_ptr<const CBlock>, const CBlockIndex* pindex);
void BlockDisconnected(const std::shared_ptr<const CBlock> &, const CBlockIndex* pindex);
void ChainStateFlushed(const kernel::ChainstateRole&, const CBlockLocator&);
void BlockChecked(const std::shared_ptr<const CBlock>&, const BlockValidationState&);
Why this scored 17/100
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