audiopolicy: Add AudioSessionInfo API

 * This patch introduces a new API which allows applications to
   query the state of the audio effects system, and receive
   callbacks with the necessary information to attach effects
   to any stream.
 * In the future, this may come as part of the AudioPort system,
   but since that's an active area of development by Google, we
   will dodge it for now.
 * The policy now simply keeps a refcounted list of objects which
   hold various bits of stream metadata. Callbacks are sent on
   stream open/close to applications which might be listening
   for them.

Change-Id: I2d554d36e1378f4eb7b276010a3bfe8345c22ecd

1 files changed, 3 insertions, 0 deletions

diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index 6b93f6f..1df91ee 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -165,6 +165,9 @@ public:
                                       const audio_attributes_t *attributes,
                                       audio_io_handle_t *handle) = 0;
     virtual status_t stopAudioSource(audio_io_handle_t handle) = 0;
+
+    virtual status_t listAudioSessions(audio_stream_type_t streams,
+                                       Vector< sp<AudioSessionInfo>> &sessions) = 0;
 };