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// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
#ifndef SRC_BASE_OBJECT_INL_H_
#define SRC_BASE_OBJECT_INL_H_
#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
#include "base_object.h"
#include "env-inl.h"
#include "util.h"
#if (__GNUC__ >= 8) && !defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-function-type"
#endif
#include "v8.h"
#if (__GNUC__ >= 8) && !defined(__clang__)
#pragma GCC diagnostic pop
#endif
namespace node {
BaseObject::BaseObject(Environment* env, v8::Local<v8::Object> object)
: persistent_handle_(env->isolate(), object), env_(env) {
CHECK_EQ(false, object.IsEmpty());
CHECK_GT(object->InternalFieldCount(), 0);
object->SetAlignedPointerInInternalField(
BaseObject::kSlot,
static_cast<void*>(this));
env->AddCleanupHook(DeleteMe, static_cast<void*>(this));
env->modify_base_object_count(1);
}
BaseObject::~BaseObject() {
env()->modify_base_object_count(-1);
env()->RemoveCleanupHook(DeleteMe, static_cast<void*>(this));
if (UNLIKELY(has_pointer_data())) {
PointerData* metadata = pointer_data();
CHECK_EQ(metadata->strong_ptr_count, 0);
metadata->self = nullptr;
if (metadata->weak_ptr_count == 0)
delete metadata;
}
if (persistent_handle_.IsEmpty()) {
// This most likely happened because the weak callback below cleared it.
return;
}
{
v8::HandleScope handle_scope(env()->isolate());
object()->SetAlignedPointerInInternalField(BaseObject::kSlot, nullptr);
}
}
void BaseObject::Detach() {
CHECK_GT(pointer_data()->strong_ptr_count, 0);
pointer_data()->is_detached = true;
}
v8::Global<v8::Object>& BaseObject::persistent() {
return persistent_handle_;
}
v8::Local<v8::Object> BaseObject::object() const {
return PersistentToLocal::Default(env()->isolate(), persistent_handle_);
}
v8::Local<v8::Object> BaseObject::object(v8::Isolate* isolate) const {
v8::Local<v8::Object> handle = object();
DCHECK_EQ(handle->CreationContext()->GetIsolate(), isolate);
DCHECK_EQ(env()->isolate(), isolate);
return handle;
}
Environment* BaseObject::env() const {
return env_;
}
BaseObject* BaseObject::FromJSObject(v8::Local<v8::Object> obj) {
CHECK_GT(obj->InternalFieldCount(), 0);
return static_cast<BaseObject*>(
obj->GetAlignedPointerFromInternalField(BaseObject::kSlot));
}
template <typename T>
T* BaseObject::FromJSObject(v8::Local<v8::Object> object) {
return static_cast<T*>(FromJSObject(object));
}
void BaseObject::MakeWeak() {
if (has_pointer_data()) {
pointer_data()->wants_weak_jsobj = true;
if (pointer_data()->strong_ptr_count > 0) return;
}
persistent_handle_.SetWeak(
this,
[](const v8::WeakCallbackInfo<BaseObject>& data) {
BaseObject* obj = data.GetParameter();
// Clear the persistent handle so that ~BaseObject() doesn't attempt
// to mess with internal fields, since the JS object may have
// transitioned into an invalid state.
// Refs: https://github.com/nodejs/node/issues/18897
obj->persistent_handle_.Reset();
CHECK_IMPLIES(obj->has_pointer_data(),
obj->pointer_data()->strong_ptr_count == 0);
obj->OnGCCollect();
}, v8::WeakCallbackType::kParameter);
}
void BaseObject::OnGCCollect() {
delete this;
}
void BaseObject::ClearWeak() {
if (has_pointer_data())
pointer_data()->wants_weak_jsobj = false;
persistent_handle_.ClearWeak();
}
v8::Local<v8::FunctionTemplate>
BaseObject::MakeLazilyInitializedJSTemplate(Environment* env) {
auto constructor = [](const v8::FunctionCallbackInfo<v8::Value>& args) {
DCHECK(args.IsConstructCall());
DCHECK_GT(args.This()->InternalFieldCount(), 0);
args.This()->SetAlignedPointerInInternalField(BaseObject::kSlot, nullptr);
};
v8::Local<v8::FunctionTemplate> t = env->NewFunctionTemplate(constructor);
t->Inherit(BaseObject::GetConstructorTemplate(env));
t->InstanceTemplate()->SetInternalFieldCount(
BaseObject::kInternalFieldCount);
return t;
}
template <int Field>
void BaseObject::InternalFieldGet(
v8::Local<v8::String> property,
const v8::PropertyCallbackInfo<v8::Value>& info) {
info.GetReturnValue().Set(info.This()->GetInternalField(Field));
}
template <int Field, bool (v8::Value::* typecheck)() const>
void BaseObject::InternalFieldSet(v8::Local<v8::String> property,
v8::Local<v8::Value> value,
const v8::PropertyCallbackInfo<void>& info) {
// This could be e.g. value->IsFunction().
CHECK(((*value)->*typecheck)());
info.This()->SetInternalField(Field, value);
}
bool BaseObject::has_pointer_data() const {
return pointer_data_ != nullptr;
}
BaseObject::PointerData* BaseObject::pointer_data() {
if (!has_pointer_data()) {
PointerData* metadata = new PointerData();
metadata->wants_weak_jsobj = persistent_handle_.IsWeak();
metadata->self = this;
pointer_data_ = metadata;
}
CHECK(has_pointer_data());
return pointer_data_;
}
void BaseObject::decrease_refcount() {
CHECK(has_pointer_data());
PointerData* metadata = pointer_data();
CHECK_GT(metadata->strong_ptr_count, 0);
unsigned int new_refcount = --metadata->strong_ptr_count;
if (new_refcount == 0) {
if (metadata->is_detached) {
delete this;
} else if (metadata->wants_weak_jsobj && !persistent_handle_.IsEmpty()) {
MakeWeak();
}
}
}
void BaseObject::increase_refcount() {
unsigned int prev_refcount = pointer_data()->strong_ptr_count++;
if (prev_refcount == 0 && !persistent_handle_.IsEmpty())
persistent_handle_.ClearWeak();
}
template <typename T, bool kIsWeak>
BaseObject::PointerData*
BaseObjectPtrImpl<T, kIsWeak>::pointer_data() const {
if (kIsWeak) {
return data_.pointer_data;
}
if (get_base_object() == nullptr) {
return nullptr;
}
return get_base_object()->pointer_data();
}
template <typename T, bool kIsWeak>
BaseObject* BaseObjectPtrImpl<T, kIsWeak>::get_base_object() const {
if (kIsWeak) {
if (pointer_data() == nullptr) {
return nullptr;
}
return pointer_data()->self;
}
return data_.target;
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>::~BaseObjectPtrImpl() {
if (kIsWeak) {
if (pointer_data() != nullptr &&
--pointer_data()->weak_ptr_count == 0 &&
pointer_data()->self == nullptr) {
delete pointer_data();
}
} else if (get() != nullptr) {
get()->decrease_refcount();
}
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>::BaseObjectPtrImpl() {
data_.target = nullptr;
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>::BaseObjectPtrImpl(T* target)
: BaseObjectPtrImpl() {
if (target == nullptr) return;
if (kIsWeak) {
data_.pointer_data = target->pointer_data();
CHECK_NOT_NULL(pointer_data());
pointer_data()->weak_ptr_count++;
} else {
data_.target = target;
CHECK_NOT_NULL(pointer_data());
get()->increase_refcount();
}
}
template <typename T, bool kIsWeak>
template <typename U, bool kW>
BaseObjectPtrImpl<T, kIsWeak>::BaseObjectPtrImpl(
const BaseObjectPtrImpl<U, kW>& other)
: BaseObjectPtrImpl(other.get()) {}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>::BaseObjectPtrImpl(const BaseObjectPtrImpl& other)
: BaseObjectPtrImpl(other.get()) {}
template <typename T, bool kIsWeak>
template <typename U, bool kW>
BaseObjectPtrImpl<T, kIsWeak>& BaseObjectPtrImpl<T, kIsWeak>::operator=(
const BaseObjectPtrImpl<U, kW>& other) {
if (other.get() == get()) return *this;
this->~BaseObjectPtrImpl();
return *new (this) BaseObjectPtrImpl(other);
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>& BaseObjectPtrImpl<T, kIsWeak>::operator=(
const BaseObjectPtrImpl& other) {
if (other.get() == get()) return *this;
this->~BaseObjectPtrImpl();
return *new (this) BaseObjectPtrImpl(other);
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>::BaseObjectPtrImpl(BaseObjectPtrImpl&& other)
: data_(other.data_) {
if (kIsWeak)
other.data_.target = nullptr;
else
other.data_.pointer_data = nullptr;
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>& BaseObjectPtrImpl<T, kIsWeak>::operator=(
BaseObjectPtrImpl&& other) {
if (&other == this) return *this;
this->~BaseObjectPtrImpl();
return *new (this) BaseObjectPtrImpl(std::move(other));
}
template <typename T, bool kIsWeak>
void BaseObjectPtrImpl<T, kIsWeak>::reset(T* ptr) {
*this = BaseObjectPtrImpl(ptr);
}
template <typename T, bool kIsWeak>
T* BaseObjectPtrImpl<T, kIsWeak>::get() const {
return static_cast<T*>(get_base_object());
}
template <typename T, bool kIsWeak>
T& BaseObjectPtrImpl<T, kIsWeak>::operator*() const {
return *get();
}
template <typename T, bool kIsWeak>
T* BaseObjectPtrImpl<T, kIsWeak>::operator->() const {
return get();
}
template <typename T, bool kIsWeak>
BaseObjectPtrImpl<T, kIsWeak>::operator bool() const {
return get() != nullptr;
}
template <typename T, bool kIsWeak>
template <typename U, bool kW>
bool BaseObjectPtrImpl<T, kIsWeak>::operator ==(
const BaseObjectPtrImpl<U, kW>& other) const {
return get() == other.get();
}
template <typename T, bool kIsWeak>
template <typename U, bool kW>
bool BaseObjectPtrImpl<T, kIsWeak>::operator !=(
const BaseObjectPtrImpl<U, kW>& other) const {
return get() != other.get();
}
template <typename T, typename... Args>
BaseObjectPtr<T> MakeBaseObject(Args&&... args) {
return BaseObjectPtr<T>(new T(std::forward<Args>(args)...));
}
template <typename T, typename... Args>
BaseObjectPtr<T> MakeDetachedBaseObject(Args&&... args) {
BaseObjectPtr<T> target = MakeBaseObject<T>(std::forward<Args>(args)...);
target->Detach();
return target;
}
} // namespace node
#endif // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
#endif // SRC_BASE_OBJECT_INL_H_
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