remoting/base/auto_thread_task_runner.h

   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 REMOTING_BASE_AUTO_THREAD_TASK_RUNNER_H_
   6 #define REMOTING_BASE_AUTO_THREAD_TASK_RUNNER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/single_thread_task_runner.h"
  13
  14 namespace remoting {
  15
  16 // A wrapper around |SingleThreadTaskRunner| that provides automatic lifetime
  17 // management, by posting a caller-supplied task to the underlying task runner
  18 // when no more references remain.
  19 class AutoThreadTaskRunner : public base::SingleThreadTaskRunner {
  20  public:
  21   // Constructs an instance of |AutoThreadTaskRunner| wrapping |task_runner|.
  22   // |stop_task| is posted to |task_runner| when the last reference to
  23   // the AutoThreadTaskRunner is dropped.
  24   AutoThreadTaskRunner(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
  25                        const base::Closure& stop_task);
  26
  27   // SingleThreadTaskRunner implementation
  28   bool PostDelayedTask(const tracked_objects::Location& from_here,
  29                        const base::Closure& task,
  30                        base::TimeDelta delay) override;
  31   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
  32                                   const base::Closure& task,
  33                                   base::TimeDelta delay) override;
  34   bool RunsTasksOnCurrentThread() const override;
  35
  36  private:
  37   ~AutoThreadTaskRunner() override;
  38
  39   // Task posted to |task_runner_| to notify the caller that it may be stopped.
  40   base::Closure stop_task_;
  41
  42   // The wrapped task runner.
  43   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
  44
  45   DISALLOW_COPY_AND_ASSIGN(AutoThreadTaskRunner);
  46 };
  47
  48 }  // namespace remoting
  49
  50 #endif  // REMOTING_BASE_AUTO_THREAD_TASK_RUNNER_H_