Audio policy manager changes for audio effects

Added methods for audio effects management by audio policy manager.
- control of total CPU load and memory used by effect engines
- selection of output stream for global effects
- added audio session id in parameter list for startOutput() and stopOutput().
this is not used in default audio policy manager implementation.

Modifications of audio effect framework in AudioFlinger to allow moving and reconfiguring
effect engines from one output mixer thread to another when audio tracks in the same session
are moved or when requested by audio policy manager.
Also fixed mutex deadlock problem with effect chains locks.

Change-Id: Ida43484b06e9b890d6b9e53c13958d042720ebdb

3 files changed, 41 insertions, 4 deletions

diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 194f23a..9fd905f 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -168,6 +168,15 @@ public:
         TX_DISABLE    = 0
     };
 
+    // special audio session values
+    enum audio_sessions {
+        SESSION_OUTPUT_STAGE = -1, // session for effects attached to a particular output stream
+                                   // (value must be less than 0)
+        SESSION_OUTPUT_MIX = 0,    // session for effects applied to output mix. These effects can
+                                   // be moved by audio policy manager to another output stream
+                                   // (value must be 0)
+    };
+
     /* These are static methods to control the system-wide AudioFlinger
      * only privileged processes can have access to them
      */
@@ -353,8 +362,12 @@ public:
                                         uint32_t format = FORMAT_DEFAULT,
                                         uint32_t channels = CHANNEL_OUT_STEREO,
                                         output_flags flags = OUTPUT_FLAG_INDIRECT);
-    static status_t startOutput(audio_io_handle_t output, AudioSystem::stream_type stream);
-    static status_t stopOutput(audio_io_handle_t output, AudioSystem::stream_type stream);
+    static status_t startOutput(audio_io_handle_t output,
+                                AudioSystem::stream_type stream,
+                                int session = 0);
+    static status_t stopOutput(audio_io_handle_t output,
+                               AudioSystem::stream_type stream,
+                               int session = 0);
     static void releaseOutput(audio_io_handle_t output);
     static audio_io_handle_t getInput(int inputSource,
                                     uint32_t samplingRate = 0,
@@ -370,6 +383,16 @@ public:
     static status_t setStreamVolumeIndex(stream_type stream, int index);
     static status_t getStreamVolumeIndex(stream_type stream, int *index);
 
+    static uint32_t getStrategyForStream(stream_type stream);
+
+    static audio_io_handle_t getOutputForEffect(effect_descriptor_t *desc);
+    static status_t registerEffect(effect_descriptor_t *desc,
+                                    audio_io_handle_t output,
+                                    uint32_t strategy,
+                                    int session,
+                                    int id);
+    static status_t unregisterEffect(int id);
+
     static const sp<IAudioPolicyService>& get_audio_policy_service();
 
     // ----------------------------------------------------------------------------
diff --git a/include/media/IAudioFlinger.h b/include/media/IAudioFlinger.h
index 5814fd6..70e505e 100644
--- a/include/media/IAudioFlinger.h
+++ b/include/media/IAudioFlinger.h
@@ -161,6 +161,8 @@ public:
                                     status_t *status,
                                     int *id,
                                     int *enabled) = 0;
+
+    virtual status_t moveEffects(int session, int srcOutput, int dstOutput) = 0;
 };
 
 
diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index 4804bbd..49eee59 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -53,8 +53,12 @@ public:
                                         uint32_t format = AudioSystem::FORMAT_DEFAULT,
                                         uint32_t channels = 0,
                                         AudioSystem::output_flags flags = AudioSystem::OUTPUT_FLAG_INDIRECT) = 0;
-    virtual status_t startOutput(audio_io_handle_t output, AudioSystem::stream_type stream) = 0;
-    virtual status_t stopOutput(audio_io_handle_t output, AudioSystem::stream_type stream) = 0;
+    virtual status_t startOutput(audio_io_handle_t output,
+                                 AudioSystem::stream_type stream,
+                                 int session = 0) = 0;
+    virtual status_t stopOutput(audio_io_handle_t output,
+                                AudioSystem::stream_type stream,
+                                int session = 0) = 0;
     virtual void releaseOutput(audio_io_handle_t output) = 0;
     virtual audio_io_handle_t getInput(int inputSource,
                                     uint32_t samplingRate = 0,
@@ -69,6 +73,14 @@ public:
                                       int indexMax) = 0;
     virtual status_t setStreamVolumeIndex(AudioSystem::stream_type stream, int index) = 0;
     virtual status_t getStreamVolumeIndex(AudioSystem::stream_type stream, int *index) = 0;
+    virtual uint32_t getStrategyForStream(AudioSystem::stream_type stream) = 0;
+    virtual audio_io_handle_t getOutputForEffect(effect_descriptor_t *desc) = 0;
+    virtual status_t registerEffect(effect_descriptor_t *desc,
+                                    audio_io_handle_t output,
+                                    uint32_t strategy,
+                                    int session,
+                                    int id) = 0;
+    virtual status_t unregisterEffect(int id) = 0;
 };