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// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "extensions/renderer/gc_callback.h"
#include "base/bind.h"
#include "base/location.h"
#include "base/single_thread_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
#include "extensions/renderer/script_context.h"
namespace extensions {
GCCallback::GCCallback(ScriptContext* context,
const v8::Local<v8::Object>& object,
const v8::Local<v8::Function>& callback,
const base::Closure& fallback)
: context_(context),
object_(context->isolate(), object),
callback_(context->isolate(), callback),
fallback_(fallback),
weak_ptr_factory_(this) {
object_.SetWeak(this, OnObjectGC, v8::WeakCallbackType::kParameter);
context->AddInvalidationObserver(base::Bind(&GCCallback::OnContextInvalidated,
weak_ptr_factory_.GetWeakPtr()));
}
GCCallback::~GCCallback() {}
// static
void GCCallback::OnObjectGC(const v8::WeakCallbackInfo<GCCallback>& data) {
// Usually FirstWeakCallback should do nothing other than reset |object_|
// and then set a second weak callback to run later. We can sidestep that,
// because posting a task to the current message loop is all but free - but
// DO NOT add any more work to this method. The only acceptable place to add
// code is RunCallback.
GCCallback* self = data.GetParameter();
self->object_.Reset();
base::ThreadTaskRunnerHandle::Get()->PostTask(
FROM_HERE, base::Bind(&GCCallback::RunCallback,
self->weak_ptr_factory_.GetWeakPtr()));
}
void GCCallback::RunCallback() {
fallback_.Reset();
v8::Isolate* isolate = context_->isolate();
v8::HandleScope handle_scope(isolate);
context_->SafeCallFunction(v8::Local<v8::Function>::New(isolate, callback_),
0, nullptr);
delete this;
}
void GCCallback::OnContextInvalidated() {
if (!fallback_.is_null()) {
fallback_.Run();
delete this;
}
}
} // namespace extensions
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