reduce number of binder calls from mediaserver

Reduce the number of audio port, audio patch and
IO config changed binder calls from mediaserver to
client processes:
- Do not call IO config changed callback if selected
device is the same as previously selected one on a given
audio flinger playback or capture thread.
- Do not call the audio port or audo patch list update
callback on a client if this client as no listener registered.

Bug: 22045560.

Change-Id: If780e105404de79b7cb5c80c27b793ceb6b1c423

2 files changed, 4 insertions, 2 deletions

diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 26cffa6..06116a5 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -408,8 +408,8 @@ private:
         AudioPolicyServiceClient() {
         }
 
-        status_t addAudioPortCallback(const sp<AudioPortCallback>& callback);
-        status_t removeAudioPortCallback(const sp<AudioPortCallback>& callback);
+        int addAudioPortCallback(const sp<AudioPortCallback>& callback);
+        int removeAudioPortCallback(const sp<AudioPortCallback>& callback);
 
         // DeathRecipient
         virtual void binderDied(const wp<IBinder>& who);
diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index ee462a0..6b93f6f 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -149,6 +149,8 @@ public:
 
     virtual void registerClient(const sp<IAudioPolicyServiceClient>& client) = 0;
 
+    virtual void setAudioPortCallbacksEnabled(bool enabled) = 0;
+
     virtual status_t acquireSoundTriggerSession(audio_session_t *session,
                                            audio_io_handle_t *ioHandle,
                                            audio_devices_t *device) = 0;