pending_task.cc revision 1320f92c476a1ad9d19dba2a48c72b75566198e9 
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#include "base/pending_task.h"
6
7#include "base/tracked_objects.h"
8
9namespace base {
10
11PendingTask::PendingTask(const tracked_objects::Location& posted_from,
12                         const base::Closure& task)
13    : base::TrackingInfo(posted_from, TimeTicks()),
14      task(task),
15      posted_from(posted_from),
16      sequence_num(0),
17      nestable(true),
18      is_high_res(false) {
19}
20
21PendingTask::PendingTask(const tracked_objects::Location& posted_from,
22                         const base::Closure& task,
23                         TimeTicks delayed_run_time,
24                         bool nestable)
25    : base::TrackingInfo(posted_from, delayed_run_time),
26      task(task),
27      posted_from(posted_from),
28      sequence_num(0),
29      nestable(nestable),
30      is_high_res(false) {
31}
32
33PendingTask::~PendingTask() {
34}
35
36bool PendingTask::operator<(const PendingTask& other) const {
37  // Since the top of a priority queue is defined as the "greatest" element, we
38  // need to invert the comparison here.  We want the smaller time to be at the
39  // top of the heap.
40
41  if (delayed_run_time < other.delayed_run_time)
42    return false;
43
44  if (delayed_run_time > other.delayed_run_time)
45    return true;
46
47  // If the times happen to match, then we use the sequence number to decide.
48  // Compare the difference to support integer roll-over.
49  return (sequence_num - other.sequence_num) > 0;
50}
51
52void TaskQueue::Swap(TaskQueue* queue) {
53  c.swap(queue->c);  // Calls std::deque::swap.
54}
55
56}  // namespace base
57