Task Scheduler.

base/task_scheduler/task_scheduler_impl.h

+// Copyright 2016 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.
+
+#ifndef BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_
+#define BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_
+
+#include "base/base_export.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/task_scheduler/sequence.h"
+#include "base/task_scheduler/shutdown_manager.h"
+#include "base/task_scheduler/task_scheduler.h"
+#include "base/task_scheduler/thread_pool.h"
+
+namespace base {
+namespace task_scheduler {
+
+class WorkerThread;
+
+class BASE_EXPORT TaskSchedulerImpl : public TaskScheduler {
+ public:
+  TaskSchedulerImpl();
+  ~TaskSchedulerImpl() override;
+
+  // TaskScheduler:
+  void PostTaskWithTraits(const tracked_objects::Location& from_here,
+                          TaskTraits traits,
+                          const Closure& task) override;
+  scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits(
+      TaskTraits traits,
+      ExecutionMode execution_mode) override;
+  void Shutdown() override;
+
+  // Waits until all threads have exited. Shutdown() must have been called
+  // before this is called, otherwise the threads won't exit.
+  void JoinAllThreadsForTesting();

[robliao, 2016/02/11 21:56:27]

Is it ever valid to call this without calling Shutdown()?

Maybe this can be ShutdownAndJoinAllThreadsForTesting().

[fdoray, 2016/02/12 04:16:20]

Done.

+
+ private:
+  // Returns the thread pool that should run tasks with |traits|.
+  ThreadPool* GetThreadPoolForTraits(const TaskTraits& traits);
+
+  // Callback invoked by |worker_thread| to reinsert |sequence| in the
+  // appropriate priority queue after it has executed one of its tasks.
+  void ReinsertSequenceCallback(
+      scoped_refptr<task_scheduler::Sequence> sequence,
+      const task_scheduler::WorkerThread* worker_thread);
+
+  ShutdownManager shutdown_manager_;
+
+  scoped_ptr<ThreadPool> background_thread_pool_;
+  scoped_ptr<ThreadPool> background_file_io_thread_pool_;
+  scoped_ptr<ThreadPool> normal_thread_pool_;
+  scoped_ptr<ThreadPool> normal_file_io_thread_pool_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskSchedulerImpl);
+};
+
+}  // namespace task_scheduler
+}  // namespace base
+
+#endif  // BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_