media/midi/midi_scheduler.cc

   1 // Copyright 2015 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 "media/midi/midi_scheduler.h"
   6
   7 #include "base/bind.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "base/time/time.h"
  10 #include "media/midi/midi_manager.h"
  11
  12 namespace media {
  13
  14 MidiScheduler::MidiScheduler(MidiManager* manager)
  15   : manager_(manager),
  16     weak_factory_(this) {
  17 }
  18
  19 MidiScheduler::~MidiScheduler() {
  20 }
  21
  22 // TODO(crbug.com/467442): Use CancelableTaskTracker once it supports
  23 // DelayedTask.
  24 void MidiScheduler::PostSendDataTask(MidiManagerClient* client,
  25                                      size_t length,
  26                                      double timestamp,
  27                                      const base::Closure& closure) {
  28   DCHECK(client);
  29
  30   const base::Closure& weak_closure = base::Bind(
  31       &MidiScheduler::InvokeClosure,
  32       weak_factory_.GetWeakPtr(),
  33       client,
  34       length,
  35       closure);
  36
  37   base::TimeDelta delay;
  38   if (timestamp != 0.0) {
  39     base::TimeTicks time_to_send =
  40         base::TimeTicks() + base::TimeDelta::FromMicroseconds(
  41                                 timestamp * base::Time::kMicrosecondsPerSecond);
  42     delay = std::max(time_to_send - base::TimeTicks::Now(), base::TimeDelta());
  43   }
  44   base::MessageLoop::current()->task_runner()->PostDelayedTask(
  45       FROM_HERE, weak_closure, delay);
  46 }
  47
  48 void MidiScheduler::InvokeClosure(MidiManagerClient* client,
  49                                   size_t length,
  50                                   const base::Closure& closure) {
  51   closure.Run();
  52   manager_->AccumulateMidiBytesSent(client, length);
  53 }
  54
  55 }  // namespace media