base/pending_task.cc

   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
   8 namespace base {
   9
  10 PendingTask::PendingTask() = default;
  11
  12 PendingTask::PendingTask(const Location& posted_from, OnceClosure task)
  13     : PendingTask(posted_from, std::move(task), TimeTicks(), TimeTicks()) {}
  14
  15 PendingTask::PendingTask(const Location& posted_from,
  16                          OnceClosure task,
  17                          TimeTicks queue_time,
  18                          TimeTicks delayed_run_time)
  19     : task(std::move(task)),
  20       posted_from(posted_from),
  21       queue_time(queue_time),
  22       delayed_run_time(delayed_run_time) {}
  23
  24 PendingTask::PendingTask(PendingTask&& other) = default;
  25
  26 PendingTask::~PendingTask() = default;
  27
  28 PendingTask& PendingTask::operator=(PendingTask&& other) = default;
  29
  30 bool PendingTask::operator<(const PendingTask& other) const {
  31   // Since the top of a priority queue is defined as the "greatest" element, we
  32   // need to invert the comparison here.  We want the smaller time to be at the
  33   // top of the heap.
  34
  35   if (delayed_run_time < other.delayed_run_time)
  36     return false;
  37
  38   if (delayed_run_time > other.delayed_run_time)
  39     return true;
  40
  41   // If the times happen to match, then we use the sequence number to decide.
  42   // Compare the difference to support integer roll-over.
  43   return (sequence_num - other.sequence_num) > 0;
  44 }
  45
  46 TimeTicks PendingTask::GetDesiredExecutionTime() const {
  47   if (!delayed_run_time.is_null())
  48     return delayed_run_time;
  49   return queue_time;
  50 }
  51
  52 }  // namespace base