TaskScheduler [12] Support SINGLE_THREADED in SchedulerThreadPool DO NOT SUBMIT

base/task_scheduler/scheduler_thread_pool.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_SCHEDULER_THREAD_POOL_H_
 #define BASE_TASK_SCHEDULER_SCHEDULER_THREAD_POOL_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <stack>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/task_runner.h"
 #include "base/task_scheduler/priority_queue.h"
 #include "base/task_scheduler/scheduler_lock.h"
+#include "base/task_scheduler/scheduler_stack.h"
 #include "base/task_scheduler/scheduler_task_executor.h"
 #include "base/task_scheduler/scheduler_worker_thread.h"
 #include "base/task_scheduler/sequence.h"
 #include "base/task_scheduler/task.h"
 #include "base/task_scheduler/task_traits.h"
 #include "base/threading/platform_thread.h"
 
 namespace base {
 namespace internal {
 
@@ skipping 58 matching lines @@
                       DelayedTaskManager* delayed_task_manager);
 
   bool Initialize(ThreadPriority thread_priority, size_t max_threads);
 
   // Wakes up the last thread from this thread pool to go idle, if any.
   void WakeUpOneThread();
 
   // Adds |worker_thread| to |idle_worker_threads_stack_|.
   void AddToIdleWorkerThreadsStack(SchedulerWorkerThread* worker_thread);
 
-  // Pops one idle worker thread from |idle_worker_thread_stack_| and returns
-  // it. Returns nullptr if |idle_worker_thread_stack_| is empty.
-  SchedulerWorkerThread* PopOneIdleWorkerThread();
+  // Removes |worker_thread| from |idle_worker_threads_stack_|.
+  void RemoveFromIdleWorkerThreadsStack(SchedulerWorkerThread* worker_thread);
 
   // PriorityQueue from which all threads of this thread pool get work.
   PriorityQueue shared_priority_queue_;
 
   // All worker threads owned by this thread pool. Only modified during
   // initialization of the thread pool.
   std::vector<std::unique_ptr<SchedulerWorkerThread>> worker_threads_;
 
+  // Synchronizes the creation of SINGLE_THREADED TaskRunners.
+  SchedulerLock single_thread_task_runner_creation_lock_;
+
   // Synchronizes access to |idle_worker_threads_stack_| and
   // |idle_worker_threads_stack_cv_for_testing_|. Has |shared_priority_queue_|'s
   // lock as its predecessor so that a thread can be pushed to
   // |idle_worker_threads_stack_| within the scope of a Transaction (more
   // details in GetWork()).
   SchedulerLock idle_worker_threads_stack_lock_;
 
   // Stack of idle worker threads.
-  std::stack<SchedulerWorkerThread*> idle_worker_threads_stack_;
+  SchedulerStack<SchedulerWorkerThread*> idle_worker_threads_stack_;
 
   // Signaled when all worker threads become idle.
   std::unique_ptr<ConditionVariable> idle_worker_threads_stack_cv_for_testing_;
 
   // Signaled once JoinForTesting() has returned.
   WaitableEvent join_for_testing_returned_;
 
   // Delegate for all worker threads in this pool.
   std::unique_ptr<SchedulerWorkerThread::Delegate> worker_thread_delegate_;
 
   TaskTracker* const task_tracker_;
   DelayedTaskManager* const delayed_task_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(SchedulerThreadPool);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_SCHEDULER_THREAD_POOL_H_