Home | History | Annotate | Download | only in message_loop 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef BASE_MESSAGE_LOOP_MESSAGE_LOOP_TASK_RUNNER_H_
      6 #define BASE_MESSAGE_LOOP_MESSAGE_LOOP_TASK_RUNNER_H_
      7 
      8 #include "base/base_export.h"
      9 #include "base/macros.h"
     10 #include "base/memory/ref_counted.h"
     11 #include "base/pending_task.h"
     12 #include "base/single_thread_task_runner.h"
     13 #include "base/synchronization/lock.h"
     14 #include "base/threading/platform_thread.h"
     15 
     16 namespace base {
     17 namespace internal {
     18 
     19 class IncomingTaskQueue;
     20 
     21 // A stock implementation of SingleThreadTaskRunner that is created and managed
     22 // by a MessageLoop. For now a MessageLoopTaskRunner can only be created as
     23 // part of a MessageLoop.
     24 class BASE_EXPORT MessageLoopTaskRunner : public SingleThreadTaskRunner {
     25  public:
     26   explicit MessageLoopTaskRunner(
     27       scoped_refptr<IncomingTaskQueue> incoming_queue);
     28 
     29   // Initialize this message loop task runner on the current thread.
     30   void BindToCurrentThread();
     31 
     32   // SingleThreadTaskRunner implementation
     33   bool PostDelayedTask(const tracked_objects::Location& from_here,
     34                        const base::Closure& task,
     35                        base::TimeDelta delay) override;
     36   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
     37                                   const base::Closure& task,
     38                                   base::TimeDelta delay) override;
     39   bool RunsTasksOnCurrentThread() const override;
     40 
     41  private:
     42   friend class RefCountedThreadSafe<MessageLoopTaskRunner>;
     43   ~MessageLoopTaskRunner() override;
     44 
     45   // The incoming queue receiving all posted tasks.
     46   scoped_refptr<IncomingTaskQueue> incoming_queue_;
     47 
     48   // ID of the thread |this| was created on.  Could be accessed on multiple
     49   // threads, protected by |valid_thread_id_lock_|.
     50   PlatformThreadId valid_thread_id_;
     51   mutable Lock valid_thread_id_lock_;
     52 
     53   DISALLOW_COPY_AND_ASSIGN(MessageLoopTaskRunner);
     54 };
     55 
     56 }  // namespace internal
     57 }  // namespace base
     58 
     59 #endif  // BASE_MESSAGE_LOOP_MESSAGE_LOOP_TASK_RUNNER_H_
     60