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// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/heap/cppgc/prefinalizer-handler.h"
#include <algorithm>
#include <memory>
#include "src/base/platform/platform.h"
#include "src/heap/cppgc/heap-page.h"
#include "src/heap/cppgc/heap.h"
#include "src/heap/cppgc/liveness-broker.h"
#include "src/heap/cppgc/stats-collector.h"
namespace cppgc {
namespace internal {
PrefinalizerRegistration::PrefinalizerRegistration(void* object,
Callback callback) {
auto* page = BasePage::FromPayload(object);
DCHECK(!page->space().is_compactable());
page->heap().prefinalizer_handler()->RegisterPrefinalizer({object, callback});
}
bool PreFinalizer::operator==(const PreFinalizer& other) const {
return (object == other.object) && (callback == other.callback);
}
PreFinalizerHandler::PreFinalizerHandler(HeapBase& heap)
: current_ordered_pre_finalizers_(&ordered_pre_finalizers_),
heap_(heap)
#ifdef DEBUG
,
creation_thread_id_(v8::base::OS::GetCurrentThreadId())
#endif // DEBUG
{
}
void PreFinalizerHandler::RegisterPrefinalizer(PreFinalizer pre_finalizer) {
DCHECK(CurrentThreadIsCreationThread());
DCHECK_EQ(ordered_pre_finalizers_.end(),
std::find(ordered_pre_finalizers_.begin(),
ordered_pre_finalizers_.end(), pre_finalizer));
DCHECK_EQ(current_ordered_pre_finalizers_->end(),
std::find(current_ordered_pre_finalizers_->begin(),
current_ordered_pre_finalizers_->end(), pre_finalizer));
current_ordered_pre_finalizers_->push_back(pre_finalizer);
}
void PreFinalizerHandler::InvokePreFinalizers() {
StatsCollector::EnabledScope stats_scope(heap_.stats_collector(),
StatsCollector::kAtomicSweep);
StatsCollector::EnabledScope nested_stats_scope(
heap_.stats_collector(), StatsCollector::kSweepInvokePreFinalizers);
DCHECK(CurrentThreadIsCreationThread());
LivenessBroker liveness_broker = LivenessBrokerFactory::Create();
is_invoking_ = true;
DCHECK_EQ(0u, bytes_allocated_in_prefinalizers);
// Reset all LABs to force allocations to the slow path for black allocation.
heap_.object_allocator().ResetLinearAllocationBuffers();
// Prefinalizers can allocate other objects with prefinalizers, which will
// modify ordered_pre_finalizers_ and break iterators.
std::vector<PreFinalizer> new_ordered_pre_finalizers;
current_ordered_pre_finalizers_ = &new_ordered_pre_finalizers;
ordered_pre_finalizers_.erase(
ordered_pre_finalizers_.begin(),
std::remove_if(ordered_pre_finalizers_.rbegin(),
ordered_pre_finalizers_.rend(),
[liveness_broker](const PreFinalizer& pf) {
return (pf.callback)(liveness_broker, pf.object);
})
.base());
// Newly added objects with prefinalizers will always survive the current GC
// cycle, so it's safe to add them after clearing out the older prefinalizers.
ordered_pre_finalizers_.insert(ordered_pre_finalizers_.end(),
new_ordered_pre_finalizers.begin(),
new_ordered_pre_finalizers.end());
current_ordered_pre_finalizers_ = &ordered_pre_finalizers_;
is_invoking_ = false;
ordered_pre_finalizers_.shrink_to_fit();
}
bool PreFinalizerHandler::CurrentThreadIsCreationThread() {
#ifdef DEBUG
return creation_thread_id_ == v8::base::OS::GetCurrentThreadId();
#else
return true;
#endif
}
void PreFinalizerHandler::NotifyAllocationInPrefinalizer(size_t size) {
DCHECK_GT(bytes_allocated_in_prefinalizers + size,
bytes_allocated_in_prefinalizers);
bytes_allocated_in_prefinalizers += size;
}
} // namespace internal
} // namespace cppgc
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