managed-inl.h

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// Copyright 2021 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_OBJECTS_MANAGED_INL_H_
#define V8_OBJECTS_MANAGED_INL_H_
 
#include "src/objects/managed.h"
// Include the non-inl header before the rest of the headers.
 
#include "src/handles/global-handles-inl.h"
 
namespace v8::internal {
 
namespace detail {
// Called by either isolate shutdown or the {ManagedObjectFinalizer} in order
// to actually delete the shared pointer and decrement the shared refcount.
template <typename CppType>
static void Destructor(void* ptr) {
  auto shared_ptr_ptr = reinterpret_cast<std::shared_ptr<CppType>*>(ptr);
  delete shared_ptr_ptr;
}
}  // namespace detail
 
// static
template <class CppType>
DirectHandle<Managed<CppType>> Managed<CppType>::From(
    Isolate* isolate, size_t estimated_size,
    std::shared_ptr<CppType> shared_ptr, AllocationType allocation_type) {
  static constexpr ExternalPointerTag kTag = TagForManaged<CppType>::value;
  static_assert(IsManagedExternalPointerType(kTag));
  auto destructor = new ManagedPtrDestructor(
      estimated_size, new std::shared_ptr<CppType>{std::move(shared_ptr)},
      detail::Destructor<CppType>);
  destructor->external_memory_accounter_.Increase(
      reinterpret_cast<v8::Isolate*>(isolate), estimated_size);
  DirectHandle<Managed<CppType>> handle =
      Cast<Managed<CppType>>(isolate->factory()->NewForeign<kTag>(
          reinterpret_cast<Address>(destructor), allocation_type));
  IndirectHandle<Object> global_handle =
      isolate->global_handles()->Create(*handle);
  destructor->global_handle_location_ = global_handle.location();
  GlobalHandles::MakeWeak(destructor->global_handle_location_, destructor,
                          &ManagedObjectFinalizer,
                          v8::WeakCallbackType::kParameter);
  isolate->RegisterManagedPtrDestructor(destructor);
  return handle;
}
 
// static
template <class CppType>
DirectHandle<TrustedManaged<CppType>> TrustedManaged<CppType>::From(
    Isolate* isolate, size_t estimated_size,
    std::shared_ptr<CppType> shared_ptr) {
  auto destructor = new ManagedPtrDestructor(
      estimated_size, new std::shared_ptr<CppType>{std::move(shared_ptr)},
      detail::Destructor<CppType>);
  destructor->external_memory_accounter_.Increase(
      reinterpret_cast<v8::Isolate*>(isolate), estimated_size);
  DirectHandle<TrustedManaged<CppType>> handle =
      Cast<TrustedManaged<CppType>>(isolate->factory()->NewTrustedForeign(
          reinterpret_cast<Address>(destructor)));
  IndirectHandle<Object> global_handle =
      isolate->global_handles()->Create(*handle);
  destructor->global_handle_location_ = global_handle.location();
  GlobalHandles::MakeWeak(destructor->global_handle_location_, destructor,
                          &ManagedObjectFinalizer,
                          v8::WeakCallbackType::kParameter);
  isolate->RegisterManagedPtrDestructor(destructor);
  return handle;
}
 
}  // namespace v8::internal
 
#endif  // V8_OBJECTS_MANAGED_INL_H_