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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 "third_party/blink/renderer/platform/scheduler/worker/worker_thread.h"
#include <memory>
#include "base/bind.h"
#include "base/location.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/task/sequence_manager/task_queue.h"
#include "base/time/default_tick_clock.h"
#include "third_party/blink/public/platform/task_type.h"
#include "third_party/blink/renderer/platform/scheduler/worker/worker_scheduler_proxy.h"
#include "third_party/blink/renderer/platform/scheduler/worker/worker_thread_scheduler.h"
namespace blink {
namespace scheduler {
WorkerThread::WorkerThread(const ThreadCreationParams& params)
: thread_(new base::Thread(params.name ? params.name : std::string())),
thread_type_(params.thread_type),
worker_scheduler_proxy_(params.frame_or_worker_scheduler
? std::make_unique<WorkerSchedulerProxy>(
params.frame_or_worker_scheduler)
: nullptr) {
bool started = thread_->StartWithOptions(params.thread_options);
CHECK(started);
thread_task_runner_ = thread_->task_runner();
}
void WorkerThread::Init() {
base::WaitableEvent completion(
base::WaitableEvent::ResetPolicy::AUTOMATIC,
base::WaitableEvent::InitialState::NOT_SIGNALED);
thread_task_runner_->PostTask(
FROM_HERE, base::BindOnce(&WorkerThread::InitOnThread,
base::Unretained(this), &completion));
completion.Wait();
}
WorkerThread::~WorkerThread() {
// We want to avoid blocking main thread when the thread was already
// shut down, but calling ShutdownOnThread twice does not cause any problems.
if (!was_shutdown_on_thread_.IsSet()) {
base::WaitableEvent completion(
base::WaitableEvent::ResetPolicy::AUTOMATIC,
base::WaitableEvent::InitialState::NOT_SIGNALED);
thread_task_runner_->PostTask(
FROM_HERE, base::BindOnce(&WorkerThread::ShutdownOnThread,
base::Unretained(this), &completion));
completion.Wait();
}
thread_->Stop();
}
void WorkerThread::InitOnThread(base::WaitableEvent* completion) {
// TODO(alexclarke): Do we need to unify virtual time for workers and the
// main thread?
non_main_thread_scheduler_ = CreateNonMainThreadScheduler();
non_main_thread_scheduler_->Init();
task_queue_ = non_main_thread_scheduler_->DefaultTaskQueue();
task_runner_ =
task_queue_->CreateTaskRunner(TaskType::kWorkerThreadTaskQueueDefault);
base::MessageLoopCurrent::Get()->AddDestructionObserver(this);
completion->Signal();
}
void WorkerThread::ShutdownOnThread(base::WaitableEvent* completion) {
was_shutdown_on_thread_.Set();
task_queue_ = nullptr;
task_runner_ = nullptr;
non_main_thread_scheduler_ = nullptr;
if (completion)
completion->Signal();
}
std::unique_ptr<NonMainThreadSchedulerImpl>
WorkerThread::CreateNonMainThreadScheduler() {
return NonMainThreadSchedulerImpl::Create(thread_type_,
worker_scheduler_proxy_.get());
}
void WorkerThread::WillDestroyCurrentMessageLoop() {
ShutdownOnThread(nullptr);
}
blink::PlatformThreadId WorkerThread::ThreadId() const {
return thread_->GetThreadId();
}
blink::ThreadScheduler* WorkerThread::Scheduler() {
return non_main_thread_scheduler_.get();
}
scoped_refptr<base::SingleThreadTaskRunner> WorkerThread::GetTaskRunner()
const {
return task_runner_;
}
} // namespace scheduler
} // namespace blink
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