Use RTCAudioSessionDelegate in AudioDeviceIOS.

webrtc/modules/audio_device/ios/audio_device_ios.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_
 #define WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_
 
 #include <memory>
 
 #include <AudioUnit/AudioUnit.h>
 
+#include "webrtc/base/asyncinvoker.h"
+#include "webrtc/base/objc/RTCMacros.h"
+#include "webrtc/base/thread.h"
 #include "webrtc/base/thread_checker.h"
 #include "webrtc/modules/audio_device/audio_device_generic.h"
+#include "webrtc/modules/audio_device/ios/audio_session_observer.h"
+
+RTC_FWD_DECL_OBJC_CLASS(RTCAudioSessionDelegateAdapter);
 
 namespace webrtc {
 
 class FineAudioBuffer;
 
 // Implements full duplex 16-bit mono PCM audio support for iOS using a
 // Voice-Processing (VP) I/O audio unit in Core Audio. The VP I/O audio unit
 // supports audio echo cancellation. It also adds automatic gain control,
 // adjustment of voice-processing quality and muting.
 //
 // An instance must be created and destroyed on one and the same thread.
 // All supported public methods must also be called on the same thread.
 // A thread checker will RTC_DCHECK if any supported method is called on an
 // invalid thread.
 //
 // Recorded audio will be delivered on a real-time internal I/O thread in the
 // audio unit. The audio unit will also ask for audio data to play out on this
 // same thread.
-class AudioDeviceIOS : public AudioDeviceGeneric {
+class AudioDeviceIOS : public AudioDeviceGeneric,
+                       public AudioSessionObserver {
  public:
   AudioDeviceIOS();
   ~AudioDeviceIOS();
 
   void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer) override;
 
   int32_t Init() override;
   int32_t Terminate() override;
   bool Initialized() const override { return initialized_; }
 
@@ skipping 95 matching lines @@
   int32_t CPULoad(uint16_t& load) const override;
   bool PlayoutWarning() const override;
   bool PlayoutError() const override;
   bool RecordingWarning() const override;
   bool RecordingError() const override;
   void ClearPlayoutWarning() override {}
   void ClearPlayoutError() override {}
   void ClearRecordingWarning() override {}
   void ClearRecordingError() override {}
 
+  // AudioSessionObserver methods. May be called from any thread.
+  void OnInterruptionBegin() override;
+  void OnInterruptionEnd() override;
+  void OnValidRouteChange() override;
+
  private:
+  // Called by the relevant AudioSessionObserver methods on |thread_|.
+  void HandleInterruptionBegin();
+  void HandleInterruptionEnd();
+  void HandleValidRouteChange();
+
   // Uses current |playout_parameters_| and |record_parameters_| to inform the
   // audio device buffer (ADB) about our internal audio parameters.
   void UpdateAudioDeviceBuffer();
 
-  // Registers observers for the AVAudioSessionRouteChangeNotification and
-  // AVAudioSessionInterruptionNotification notifications.
-  void RegisterNotificationObservers();
-  void UnregisterNotificationObservers();
-
   // Since the preferred audio parameters are only hints to the OS, the actual
   // values may be different once the AVAudioSession has been activated.
   // This method asks for the current hardware parameters and takes actions
   // if they should differ from what we have asked for initially. It also
   // defines |playout_parameters_| and |record_parameters_|.
   void SetupAudioBuffersForActiveAudioSession();
 
   // Creates a Voice-Processing I/O unit and configures it for full-duplex
   // audio. The selected stream format is selected to avoid internal resampling
   // and to match the 10ms callback rate for WebRTC as well as possible.
@@ skipping 37 matching lines @@
                                  UInt32 in_bus_number,
                                  UInt32 in_number_frames,
                                  AudioBufferList* io_data);
   OSStatus OnGetPlayoutData(AudioUnitRenderActionFlags* io_action_flags,
                             UInt32 in_number_frames,
                             AudioBufferList* io_data);
 
   // Ensures that methods are called from the same thread as this object is
   // created on.
   rtc::ThreadChecker thread_checker_;
+  // Thread that this object is created on.
+  rtc::Thread* thread_;
+  // Invoker used to execute methods on thread_.
+  std::unique_ptr<rtc::AsyncInvoker> async_invoker_;
 
   // Raw pointer handle provided to us in AttachAudioBuffer(). Owned by the
   // AudioDeviceModuleImpl class and called by AudioDeviceModuleImpl::Create().
   // The AudioDeviceBuffer is a member of the AudioDeviceModuleImpl instance
   // and therefore outlives this object.
   AudioDeviceBuffer* audio_device_buffer_;
 
   // Contains audio parameters (sample rate, #channels, buffer size etc.) for
   // the playout and recording sides. These structure is set in two steps:
   // first, native sample rate and #channels are defined in Init(). Next, the
@@ skipping 48 matching lines @@
 
   // Set to true after successful call to Init(), false otherwise.
   bool initialized_;
 
   // Set to true after successful call to InitRecording(), false otherwise.
   bool rec_is_initialized_;
 
   // Set to true after successful call to InitPlayout(), false otherwise.
   bool play_is_initialized_;
 
+  // Set to true if audio session is interrupted, false otherwise.
+  bool is_interrupted_;
+
   // Audio interruption observer instance.
-  void* audio_interruption_observer_;
-  void* route_change_observer_;
+  RTCAudioSessionDelegateAdapter* audio_session_observer_;
 
   // Contains the audio data format specification for a stream of audio.
   AudioStreamBasicDescription application_format_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_