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// Copyright 2018 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 "third_party/blink/renderer/core/dom/scripted_task_queue.h"
#include <memory>
#include <utility>
#include "third_party/blink/public/platform/platform.h"
#include "third_party/blink/renderer/bindings/core/v8/script_promise_resolver.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_task_queue_post_callback.h"
#include "third_party/blink/renderer/core/dom/abort_signal.h"
#include "third_party/blink/renderer/platform/wtf/functional.h"
namespace blink {
namespace {
class TaskQueuePostCallbackWrapper {
public:
static std::unique_ptr<TaskQueuePostCallbackWrapper> Create(
int id,
ScriptedTaskQueue* task_queue) {
return std::unique_ptr<TaskQueuePostCallbackWrapper>(
new TaskQueuePostCallbackWrapper(id, task_queue));
}
void TaskFired() {
if (task_queue_)
task_queue_->CallbackFired(id_);
}
private:
TaskQueuePostCallbackWrapper(int id, ScriptedTaskQueue* task_queue)
: id_(id), task_queue_(task_queue) {}
int id_;
WeakPersistent<ScriptedTaskQueue> task_queue_;
};
} // namespace
class ScriptedTaskQueue::WrappedCallback
: public GarbageCollected<WrappedCallback> {
WTF_MAKE_NONCOPYABLE(WrappedCallback);
public:
WrappedCallback(V8TaskQueuePostCallback* callback,
ScriptPromiseResolver* resolver)
: callback_(callback), resolver_(resolver) {}
void Trace(Visitor* visitor) {
visitor->Trace(callback_);
visitor->Trace(resolver_);
}
void Invoke() {
callback_->InvokeAndReportException(nullptr);
resolver_->Resolve();
}
void Reject() { resolver_->Reject(); }
private:
TraceWrapperMember<V8TaskQueuePostCallback> callback_;
Member<ScriptPromiseResolver> resolver_;
};
ScriptedTaskQueue::ScriptedTaskQueue(ExecutionContext* context,
TaskType task_type)
: PausableObject(context) {
task_runner_ = GetExecutionContext()->GetTaskRunner(task_type);
PauseIfNeeded();
}
void ScriptedTaskQueue::Trace(blink::Visitor* visitor) {
visitor->Trace(pending_tasks_);
ScriptWrappable::Trace(visitor);
PausableObject::Trace(visitor);
}
ScriptPromise ScriptedTaskQueue::postTask(ScriptState* script_state,
V8TaskQueuePostCallback* callback,
AbortSignal* signal) {
CallbackId id = next_callback_id_++;
ScriptPromiseResolver* resolver = ScriptPromiseResolver::Create(script_state);
if (signal) {
if (signal->aborted()) {
resolver->Reject();
return resolver->Promise();
}
signal->AddAlgorithm(
WTF::Bind(&ScriptedTaskQueue::AbortTask, WrapPersistent(this), id));
}
pending_tasks_.Set(id, new WrappedCallback(callback, resolver));
auto callback_wrapper = TaskQueuePostCallbackWrapper::Create(id, this);
task_runner_->PostTask(FROM_HERE,
WTF::Bind(&TaskQueuePostCallbackWrapper::TaskFired,
std::move(callback_wrapper)));
return resolver->Promise();
}
void ScriptedTaskQueue::CallbackFired(CallbackId id) {
if (paused_) {
paused_tasks_.push_back(id);
return;
}
auto task_iter = pending_tasks_.find(id);
if (task_iter == pending_tasks_.end())
return;
task_iter->value->Invoke();
// Can't use the iterator here since running the task
// might invalidate it.
pending_tasks_.erase(id);
}
void ScriptedTaskQueue::AbortTask(CallbackId id) {
auto task_iter = pending_tasks_.find(id);
if (task_iter == pending_tasks_.end())
return;
task_iter->value->Reject();
pending_tasks_.erase(id);
}
void ScriptedTaskQueue::ContextDestroyed(ExecutionContext*) {
pending_tasks_.clear();
paused_tasks_.clear();
}
void ScriptedTaskQueue::Pause() {
paused_ = true;
}
void ScriptedTaskQueue::Unpause() {
paused_ = false;
for (auto& task_id : paused_tasks_) {
auto callback_wrapper = TaskQueuePostCallbackWrapper::Create(task_id, this);
task_runner_->PostTask(FROM_HERE,
WTF::Bind(&TaskQueuePostCallbackWrapper::TaskFired,
std::move(callback_wrapper)));
}
paused_tasks_.clear();
}
} // namespace blink
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