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