michael@0: // Copyright (c) 2011 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef PENDING_TASK_H_
michael@0: #define PENDING_TASK_H_
michael@0: 
michael@0: #include <queue>
michael@0: 
michael@0: #include "base/base_export.h"
michael@0: #include "base/callback.h"
michael@0: #include "base/location.h"
michael@0: #include "base/time/time.h"
michael@0: #include "base/tracking_info.h"
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: // Contains data about a pending task. Stored in TaskQueue and DelayedTaskQueue
michael@0: // for use by classes that queue and execute tasks.
michael@0: struct BASE_EXPORT PendingTask : public TrackingInfo {
michael@0: #if _MSC_VER >= 1700
michael@0:   PendingTask();
michael@0: #endif
michael@0:   PendingTask(const tracked_objects::Location& posted_from,
michael@0:               const Closure& task);
michael@0:   PendingTask(const tracked_objects::Location& posted_from,
michael@0:               const Closure& task,
michael@0:               TimeTicks delayed_run_time,
michael@0:               bool nestable);
michael@0:   ~PendingTask();
michael@0: 
michael@0:   // Used to support sorting.
michael@0:   bool operator<(const PendingTask& other) const;
michael@0: 
michael@0:   // The task to run.
michael@0:   Closure task;
michael@0: 
michael@0:   // The site this PendingTask was posted from.
michael@0:   tracked_objects::Location posted_from;
michael@0: 
michael@0:   // Secondary sort key for run time.
michael@0:   int sequence_num;
michael@0: 
michael@0:   // OK to dispatch from a nested loop.
michael@0:   bool nestable;
michael@0: };
michael@0: 
michael@0: // Wrapper around std::queue specialized for PendingTask which adds a Swap
michael@0: // helper method.
michael@0: class BASE_EXPORT TaskQueue : public std::queue<PendingTask> {
michael@0:  public:
michael@0:   void Swap(TaskQueue* queue);
michael@0: };
michael@0: 
michael@0: // PendingTasks are sorted by their |delayed_run_time| property.
michael@0: typedef std::priority_queue<base::PendingTask> DelayedTaskQueue;
michael@0: 
michael@0: }  // namespace base
michael@0: 
michael@0: #endif  // PENDING_TASK_H_