| // Copyright 2016 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_MANAGED_H_ |
| #define V8_MANAGED_H_ |
| |
| #include "src/factory.h" |
| #include "src/global-handles.h" |
| #include "src/handles.h" |
| #include "src/isolate.h" |
| |
| namespace v8 { |
| namespace internal { |
| // An object that wraps a pointer to a C++ object and manages its lifetime. |
| // The C++ object will be deleted when the managed wrapper object is |
| // garbage collected, or, last resort, if the isolate is torn down before GC, |
| // as part of Isolate::Dispose(). |
| // Managed<CppType> may be used polymorphically as Foreign, where the held |
| // address is typed as CppType**. The double indirection is due to the |
| // use, by Managed, of Isolate::ManagedObjectFinalizer, which has a CppType* |
| // first field. |
| template <class CppType> |
| class Managed : public Foreign { |
| public: |
| V8_INLINE CppType* get() { |
| return *(reinterpret_cast<CppType**>(foreign_address())); |
| } |
| |
| static Managed<CppType>* cast(Object* obj) { |
| SLOW_DCHECK(obj->IsForeign()); |
| return reinterpret_cast<Managed<CppType>*>(obj); |
| } |
| |
| static Handle<Managed<CppType>> New(Isolate* isolate, CppType* ptr) { |
| Isolate::ManagedObjectFinalizer* node = |
| isolate->RegisterForReleaseAtTeardown(ptr, |
| Managed<CppType>::NativeDelete); |
| Handle<Managed<CppType>> handle = Handle<Managed<CppType>>::cast( |
| isolate->factory()->NewForeign(reinterpret_cast<Address>(node))); |
| RegisterWeakCallbackForDelete(isolate, handle); |
| return handle; |
| } |
| |
| private: |
| static void RegisterWeakCallbackForDelete(Isolate* isolate, |
| Handle<Managed<CppType>> handle) { |
| Handle<Object> global_handle = isolate->global_handles()->Create(*handle); |
| GlobalHandles::MakeWeak(global_handle.location(), global_handle.location(), |
| &Managed<CppType>::GCDelete, |
| v8::WeakCallbackType::kFinalizer); |
| } |
| |
| static void GCDelete(const v8::WeakCallbackInfo<void>& data) { |
| Managed<CppType>** p = |
| reinterpret_cast<Managed<CppType>**>(data.GetParameter()); |
| |
| Isolate::ManagedObjectFinalizer* finalizer = (*p)->GetFinalizer(); |
| |
| Isolate* isolate = reinterpret_cast<Isolate*>(data.GetIsolate()); |
| finalizer->Dispose(); |
| isolate->UnregisterFromReleaseAtTeardown(&finalizer); |
| |
| (*p)->set_foreign_address(static_cast<Address>(nullptr)); |
| GlobalHandles::Destroy(reinterpret_cast<Object**>(p)); |
| } |
| |
| static void NativeDelete(void* value) { |
| CppType* typed_value = reinterpret_cast<CppType*>(value); |
| delete typed_value; |
| } |
| |
| Isolate::ManagedObjectFinalizer* GetFinalizer() { |
| return reinterpret_cast<Isolate::ManagedObjectFinalizer*>( |
| foreign_address()); |
| } |
| }; |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_MANAGED_H_ |