base/task_queue.h

   1 // Copyright (c) 2011 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_TASK_QUEUE_H_
   6 #define BASE_TASK_QUEUE_H_
   7 #pragma once
   8
   9 #include <deque>
  10
  11 #include "base/base_export.h"
  12 #include "base/task.h"
  13
  14 // A TaskQueue is a queue of tasks waiting to be run.  To run the tasks, call
  15 // the Run method.  A task queue is itself a Task so that it can be placed in a
  16 // message loop or another task queue.
  17 class BASE_EXPORT TaskQueue : public Task {
  18  public:
  19   TaskQueue();
  20   virtual ~TaskQueue();
  21
  22   // Push the specified task onto the queue.  When the queue is run, the tasks
  23   // will be run in the order they are pushed.
  24   //
  25   // This method takes ownership of |task| and will delete task after it is run
  26   // (or when the TaskQueue is destroyed, if we never got a chance to run it).
  27   void Push(Task* task);
  28
  29   // Remove all tasks from the queue.  The tasks are deleted.
  30   void Clear();
  31
  32   // Returns true if this queue contains no tasks.
  33   bool IsEmpty() const;
  34
  35   // Run all the tasks in the queue.  New tasks pushed onto the queue during
  36   // a run will be run next time |Run| is called.
  37   virtual void Run();
  38
  39  private:
  40    // The list of tasks we are waiting to run.
  41    std::deque<Task*> queue_;
  42 };
  43
  44 #endif  // BASE_TASK_QUEUE_H_