prefinalizer-handler.h

Go to the documentation of this file.

// 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 V8_HEAP_CPPGC_PREFINALIZER_HANDLER_H_
#define V8_HEAP_CPPGC_PREFINALIZER_HANDLER_H_
 
#include <utility>
#include <vector>
 
#include "include/cppgc/prefinalizer.h"
 
namespace cppgc {
namespace internal {
 
class HeapBase;
 
struct PreFinalizer final {
  using Callback = PrefinalizerRegistration::Callback;
 
  void* object;
  Callback callback;
 
  bool operator==(const PreFinalizer& other) const;
};
 
class PreFinalizerHandler final {
 public:
  explicit PreFinalizerHandler(HeapBase& heap);
 
  void RegisterPrefinalizer(PreFinalizer pre_finalizer);
 
  void InvokePreFinalizers();
 
  bool IsInvokingPreFinalizers() const { return is_invoking_; }
 
  void NotifyAllocationInPrefinalizer(size_t);
  size_t ExtractBytesAllocatedInPrefinalizers() {
    return std::exchange(bytes_allocated_in_prefinalizers, 0);
  }
 
 private:
  // Checks that the current thread is the thread that created the heap.
  bool CurrentThreadIsCreationThread();
 
  // Pre-finalizers are called in the reverse order in which they are
  // registered by the constructors (including constructors of Mixin
  // objects) for an object, by processing the ordered_pre_finalizers_
  // back-to-front.
  std::vector<PreFinalizer> ordered_pre_finalizers_;
  std::vector<PreFinalizer>* current_ordered_pre_finalizers_;
 
  HeapBase& heap_;
  bool is_invoking_ = false;
 
  // Counter of bytes allocated during prefinalizers.
  size_t bytes_allocated_in_prefinalizers = 0u;
};
 
}  // namespace internal
}  // namespace cppgc
 
#endif  // V8_HEAP_CPPGC_PREFINALIZER_HANDLER_H_