Files
bitcoin/src/test/validationinterface_tests.cpp
stickies-v 1d9f1cb4bd kernel: improve BlockChecked ownership semantics
Subscribers to the BlockChecked validation interface event may need
access to the block outside of the callback scope. Currently, this
is only possible by copying the block, which makes exposing this
validation interface event publicly either cumbersome or with significant
copy overhead.

By using shared_ptr, we make the shared ownership explicit and allow
users to safely use the block outside of the callback scope.
2025-08-01 15:12:37 +02:00

104 lines
3.4 KiB
C++

// Copyright (c) 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 <boost/test/unit_test.hpp>
#include <consensus/validation.h>
#include <primitives/block.h>
#include <scheduler.h>
#include <test/util/setup_common.h>
#include <util/check.h>
#include <kernel/chain.h>
#include <validationinterface.h>
#include <atomic>
#include <memory>
BOOST_FIXTURE_TEST_SUITE(validationinterface_tests, ChainTestingSetup)
struct TestSubscriberNoop final : public CValidationInterface {
void BlockChecked(const std::shared_ptr<const CBlock>&, const BlockValidationState&) override {}
};
BOOST_AUTO_TEST_CASE(unregister_validation_interface_race)
{
std::atomic<bool> generate{true};
// Start thread to generate notifications
std::thread gen{[&] {
BlockValidationState state_dummy;
while (generate) {
m_node.validation_signals->BlockChecked(std::make_shared<const CBlock>(), state_dummy);
}
}};
// Start thread to consume notifications
std::thread sub{[&] {
// keep going for about 1 sec, which is 250k iterations
for (int i = 0; i < 250000; i++) {
auto sub = std::make_shared<TestSubscriberNoop>();
m_node.validation_signals->RegisterSharedValidationInterface(sub);
m_node.validation_signals->UnregisterSharedValidationInterface(sub);
}
// tell the other thread we are done
generate = false;
}};
gen.join();
sub.join();
BOOST_CHECK(!generate);
}
class TestInterface : public CValidationInterface
{
public:
TestInterface(ValidationSignals& signals, std::function<void()> on_call = nullptr, std::function<void()> on_destroy = nullptr)
: m_on_call(std::move(on_call)), m_on_destroy(std::move(on_destroy)), m_signals{signals}
{
}
virtual ~TestInterface()
{
if (m_on_destroy) m_on_destroy();
}
void BlockChecked(const std::shared_ptr<const CBlock>& block, const BlockValidationState& state) override
{
if (m_on_call) m_on_call();
}
void Call()
{
BlockValidationState state;
m_signals.BlockChecked(std::make_shared<const CBlock>(), state);
}
std::function<void()> m_on_call;
std::function<void()> m_on_destroy;
ValidationSignals& m_signals;
};
// Regression test to ensure UnregisterAllValidationInterfaces calls don't
// destroy a validation interface while it is being called. Bug:
// https://github.com/bitcoin/bitcoin/pull/18551
BOOST_AUTO_TEST_CASE(unregister_all_during_call)
{
bool destroyed = false;
auto shared{std::make_shared<TestInterface>(
*m_node.validation_signals,
[&] {
// First call should decrements reference count 2 -> 1
m_node.validation_signals->UnregisterAllValidationInterfaces();
BOOST_CHECK(!destroyed);
// Second call should not decrement reference count 1 -> 0
m_node.validation_signals->UnregisterAllValidationInterfaces();
BOOST_CHECK(!destroyed);
},
[&] { destroyed = true; })};
m_node.validation_signals->RegisterSharedValidationInterface(shared);
BOOST_CHECK(shared.use_count() == 2);
shared->Call();
BOOST_CHECK(shared.use_count() == 1);
BOOST_CHECK(!destroyed);
shared.reset();
BOOST_CHECK(destroyed);
}
BOOST_AUTO_TEST_SUITE_END()