v8/include/cppgc/liveness-broker.h
Michael Lippautz bc12982d51 cppgc: LivenessBroker
Introduce LivenessBroker which is a temporary broker object to expose
liveness during specific garbage collection phases.

This broker can be used to handle:
- PreFinalizer
- Custom weak callbacks
- Internal weak callbacks used for WeakMember

Change-Id: I3870c2b89b2538f04feabf2eb7a4676ce2fe7d61
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144059
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67107}
2020-04-14 08:57:12 +00:00

51 lines
1.3 KiB
C++

// 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.
#ifndef INCLUDE_CPPGC_LIVENESS_BROKER_H_
#define INCLUDE_CPPGC_LIVENESS_BROKER_H_
#include "include/cppgc/heap.h"
#include "include/cppgc/member.h"
#include "include/cppgc/trace-trait.h"
#include "include/v8config.h"
namespace cppgc {
namespace internal {
class LivenessBrokerFactory;
} // namespace internal
class V8_EXPORT LivenessBroker final {
public:
template <typename T>
bool IsHeapObjectAlive(const T* object) const {
return object &&
IsHeapObjectAliveImpl(
TraceTrait<T>::GetTraceDescriptor(object).base_object_payload);
}
template <typename T>
bool IsHeapObjectAlive(const WeakMember<T>& weak_member) const {
return (weak_member != kSentinelPointer) &&
IsHeapObjectAlive<T>(weak_member.Get());
}
template <typename T>
bool IsHeapObjectAlive(const UntracedMember<T>& untraced_member) const {
return (untraced_member != kSentinelPointer) &&
IsHeapObjectAlive<T>(untraced_member.Get());
}
private:
LivenessBroker() = default;
bool IsHeapObjectAliveImpl(const void*) const;
friend class internal::LivenessBrokerFactory;
};
} // namespace cppgc
#endif // INCLUDE_CPPGC_LIVENESS_BROKER_H_