device_notifier.cc 2.3 KB

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  1. // Copyright 2018 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. #include "services/audio/device_notifier.h"
  5. #include <utility>
  6. #include "base/bind.h"
  7. #include "base/task/sequenced_task_runner.h"
  8. #include "base/threading/sequenced_task_runner_handle.h"
  9. #include "base/trace_event/trace_event.h"
  10. namespace audio {
  11. DeviceNotifier::DeviceNotifier()
  12. : task_runner_(base::SequencedTaskRunnerHandle::Get()) {
  13. base::SystemMonitor::Get()->AddDevicesChangedObserver(this);
  14. }
  15. DeviceNotifier::~DeviceNotifier() {
  16. DCHECK(task_runner_->RunsTasksInCurrentSequence());
  17. base::SystemMonitor::Get()->RemoveDevicesChangedObserver(this);
  18. }
  19. void DeviceNotifier::Bind(
  20. mojo::PendingReceiver<mojom::DeviceNotifier> receiver) {
  21. DCHECK(task_runner_->RunsTasksInCurrentSequence());
  22. receivers_.Add(this, std::move(receiver));
  23. }
  24. void DeviceNotifier::RegisterListener(
  25. mojo::PendingRemote<mojom::DeviceListener> listener) {
  26. DCHECK(task_runner_->RunsTasksInCurrentSequence());
  27. TRACE_EVENT1("audio", "audio::DeviceNotifier::RegisterListener", "id",
  28. next_listener_id_);
  29. int listener_id = next_listener_id_++;
  30. auto& new_listener = listeners_[listener_id];
  31. new_listener.Bind(std::move(listener));
  32. new_listener.set_disconnect_handler(
  33. base::BindOnce(&DeviceNotifier::RemoveListener,
  34. weak_factory_.GetWeakPtr(), listener_id));
  35. }
  36. void DeviceNotifier::OnDevicesChanged(
  37. base::SystemMonitor::DeviceType device_type) {
  38. if (device_type != base::SystemMonitor::DEVTYPE_AUDIO)
  39. return;
  40. TRACE_EVENT0("audio", "audio::DeviceNotifier::OnDevicesChanged");
  41. task_runner_->PostTask(FROM_HERE,
  42. base::BindOnce(&DeviceNotifier::UpdateListeners,
  43. weak_factory_.GetWeakPtr()));
  44. }
  45. void DeviceNotifier::UpdateListeners() {
  46. DCHECK(task_runner_->RunsTasksInCurrentSequence());
  47. TRACE_EVENT0("audio", "audio::DeviceNotifier::UpdateListeners");
  48. for (const auto& listener : listeners_)
  49. listener.second->DevicesChanged();
  50. }
  51. void DeviceNotifier::RemoveListener(int listener_id) {
  52. DCHECK(task_runner_->RunsTasksInCurrentSequence());
  53. TRACE_EVENT1("audio", "audio::DeviceNotifier::RemoveListener", "id",
  54. listener_id);
  55. listeners_.erase(listener_id);
  56. }
  57. } // namespace audio