spatializer: disable head tracker sensor when not neeeded

Only enabled the head tracker sensor when the following conditions
are met:
- Spatialization is enabled
- Head tracking desired mode is not static
- A valid head tracking sensor is set
- At least one audio track is active on the spatializer mixer

Bug: 218273231
Test: manual test with uhid-sample sensor simulator

Change-Id: Ie3acd27f4387a9192f907d99a6798a1d8224df12
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index 4da4ea0..04d023e 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -485,6 +485,7 @@
     status_t status = mAudioPolicyManager->startOutput(portId);
     if (status == NO_ERROR) {
         client->active = true;
+        onUpdateActiveSpatializerTracks_l();
     }
     return binderStatusFromStatusT(status);
 }
@@ -522,6 +523,7 @@
     status_t status = mAudioPolicyManager->stopOutput(portId);
     if (status == NO_ERROR) {
         client->active = false;
+        onUpdateActiveSpatializerTracks_l();
     }
     return status;
 }
@@ -552,8 +554,10 @@
             client->io, client->stream, client->session);
     }
     Mutex::Autolock _l(mLock);
+    if (client != nullptr && client->active) {
+        onUpdateActiveSpatializerTracks_l();
+    }
     mAudioPlaybackClients.removeItem(portId);
-
     // called from internal thread: no need to clear caller identity
     mAudioPolicyManager->releaseOutput(portId);
 }
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp
index 61e2af6..443b9f7 100644
--- a/services/audiopolicy/service/AudioPolicyService.cpp
+++ b/services/audiopolicy/service/AudioPolicyService.cpp
@@ -397,6 +397,7 @@
             if (status == NO_ERROR && currentOutput == newOutput) {
                 return;
             }
+            size_t numActiveTracks = countActiveClientsOnOutput_l(newOutput);
             mLock.unlock();
             // It is OK to call detachOutput() is none is already attached.
             mSpatializer->detachOutput();
@@ -404,7 +405,7 @@
                 mLock.lock();
                 return;
             }
-            status = mSpatializer->attachOutput(newOutput);
+            status = mSpatializer->attachOutput(newOutput, numActiveTracks);
             mLock.lock();
             if (status != NO_ERROR) {
                 mAudioPolicyManager->releaseSpatializerOutput(newOutput);
@@ -421,6 +422,34 @@
     }
 }
 
+size_t AudioPolicyService::countActiveClientsOnOutput_l(audio_io_handle_t output) REQUIRES(mLock) {
+    size_t count = 0;
+    for (size_t i = 0; i < mAudioPlaybackClients.size(); i++) {
+        auto client = mAudioPlaybackClients.valueAt(i);
+        if (client->io == output && client->active) {
+            count++;
+        }
+    }
+    return count;
+}
+
+void AudioPolicyService::onUpdateActiveSpatializerTracks_l() {
+    if (mSpatializer == nullptr) {
+        return;
+    }
+    mOutputCommandThread->updateActiveSpatializerTracksCommand();
+}
+
+void AudioPolicyService::doOnUpdateActiveSpatializerTracks()
+{
+    Mutex::Autolock _l(mLock);
+    if (mSpatializer == nullptr) {
+        return;
+    }
+    mSpatializer->updateActiveTracks(countActiveClientsOnOutput_l(mSpatializer->getOutput()));
+}
+
+
 status_t AudioPolicyService::clientCreateAudioPatch(const struct audio_patch *patch,
                                                 audio_patch_handle_t *handle,
                                                 int delayMs)
@@ -1936,8 +1965,8 @@
                     mLock.lock();
                     } break;
 
-                case CHECK_SPATIALIZER: {
-                    ALOGV("AudioCommandThread() processing updateUID states");
+                case CHECK_SPATIALIZER_OUTPUT: {
+                    ALOGV("AudioCommandThread() processing check spatializer");
                     svc = mService.promote();
                     if (svc == 0) {
                         break;
@@ -1947,6 +1976,17 @@
                     mLock.lock();
                     } break;
 
+                case UPDATE_ACTIVE_SPATIALIZER_TRACKS: {
+                    ALOGV("AudioCommandThread() processing update spatializer tracks");
+                    svc = mService.promote();
+                    if (svc == 0) {
+                        break;
+                    }
+                    mLock.unlock();
+                    svc->doOnUpdateActiveSpatializerTracks();
+                    mLock.lock();
+                    } break;
+
                 default:
                     ALOGW("AudioCommandThread() unknown command %d", command->mCommand);
                 }
@@ -2261,11 +2301,19 @@
 void AudioPolicyService::AudioCommandThread::checkSpatializerCommand()
 {
     sp<AudioCommand>command = new AudioCommand();
-    command->mCommand = CHECK_SPATIALIZER;
+    command->mCommand = CHECK_SPATIALIZER_OUTPUT;
     ALOGV("AudioCommandThread() adding check spatializer");
     sendCommand(command);
 }
 
+void AudioPolicyService::AudioCommandThread::updateActiveSpatializerTracksCommand()
+{
+    sp<AudioCommand>command = new AudioCommand();
+    command->mCommand = UPDATE_ACTIVE_SPATIALIZER_TRACKS;
+    ALOGV("AudioCommandThread() adding update active spatializer tracks");
+    sendCommand(command);
+}
+
 status_t AudioPolicyService::AudioCommandThread::sendCommand(sp<AudioCommand>& command, int delayMs)
 {
     {
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 4944497..d3e0453 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -352,9 +352,13 @@
      * by audio policy manager and attach/detach the spatializer effect accordingly.
      */
     void onCheckSpatializer() override;
-    void onCheckSpatializer_l();
+    void onCheckSpatializer_l() REQUIRES(mLock);
     void doOnCheckSpatializer();
 
+    void onUpdateActiveSpatializerTracks_l() REQUIRES(mLock);
+    void doOnUpdateActiveSpatializerTracks();
+
+
     void setEffectSuspended(int effectId,
                             audio_session_t sessionId,
                             bool suspended);
@@ -526,7 +530,8 @@
             AUDIO_MODULES_UPDATE,
             ROUTING_UPDATED,
             UPDATE_UID_STATES,
-            CHECK_SPATIALIZER
+            CHECK_SPATIALIZER_OUTPUT, // verify if spatializer effect should be created or moved
+            UPDATE_ACTIVE_SPATIALIZER_TRACKS // Update active track counts on spalializer output
         };
 
         AudioCommandThread (String8 name, const wp<AudioPolicyService>& service);
@@ -576,6 +581,8 @@
                     void        routingChangedCommand();
                     void        updateUidStatesCommand();
                     void        checkSpatializerCommand();
+                    void        updateActiveSpatializerTracksCommand();
+
                     void        insertCommand_l(AudioCommand *command, int delayMs = 0);
     private:
         class AudioCommandData;
@@ -1000,6 +1007,8 @@
     void loadAudioPolicyManager();
     void unloadAudioPolicyManager();
 
+    size_t countActiveClientsOnOutput_l(audio_io_handle_t output) REQUIRES(mLock);
+
     mutable Mutex mLock;    // prevents concurrent access to AudioPolicy manager functions changing
                             // device connection state  or routing
     // Note: lock acquisition order is always mLock > mEffectsLock:
diff --git a/services/audiopolicy/service/Spatializer.cpp b/services/audiopolicy/service/Spatializer.cpp
index 54d9094..d9e89aa 100644
--- a/services/audiopolicy/service/Spatializer.cpp
+++ b/services/audiopolicy/service/Spatializer.cpp
@@ -300,6 +300,7 @@
         if (levelChanged && mEngine != nullptr) {
             setEffectParameter_l(SPATIALIZER_PARAM_LEVEL, std::vector<SpatializationLevel>{level});
         }
+        checkHeadSensor_l();
     }
 
     if (levelChanged) {
@@ -374,6 +375,7 @@
 
     if (mPoseController != nullptr) {
         mPoseController->setDesiredMode(mDesiredHeadTrackingMode);
+        checkHeadSensor_l();
     }
 
     return Status::ok();
@@ -448,7 +450,7 @@
     std::lock_guard lock(mLock);
     mHeadSensor = sensorHandle;
     if (mPoseController != nullptr) {
-        mPoseController->setHeadSensor(mHeadSensor);
+        checkHeadSensor_l();
     }
     return Status::ok();
 }
@@ -557,7 +559,6 @@
     auto vec = headToStage.toVector();
     LOG_ALWAYS_FATAL_IF(vec.size() != sHeadPoseKeys.size(),
             "%s invalid head to stage vector size %zu", __func__, vec.size());
-
     sp<AMessage> msg =
             new AMessage(EngineCallbackHandler::kWhatOnHeadToStagePose, mHandler);
     for (size_t i = 0 ; i < sHeadPoseKeys.size(); i++) {
@@ -571,6 +572,9 @@
     sp<media::ISpatializerHeadTrackingCallback> callback;
     {
         std::lock_guard lock(mLock);
+        if (mActualHeadTrackingMode == SpatializerHeadTrackingMode::DISABLED) {
+            return;
+        }
         callback = mHeadTrackingCallback;
         if (mEngine != nullptr) {
             setEffectParameter_l(SPATIALIZER_PARAM_HEAD_TO_STAGE, headToStage);
@@ -621,7 +625,7 @@
     }
 }
 
-status_t Spatializer::attachOutput(audio_io_handle_t output) {
+status_t Spatializer::attachOutput(audio_io_handle_t output, size_t numActiveTracks) {
     std::shared_ptr<SpatializerPoseController> poseController;
     bool outputChanged = false;
     sp<media::INativeSpatializerCallback> callback;
@@ -634,6 +638,7 @@
             // remove FX instance
             mEngine->setEnabled(false);
             mEngine.clear();
+            mPoseController.reset();
         }
         // create FX instance on output
         AttributionSourceState attributionSource = AttributionSourceState();
@@ -663,7 +668,8 @@
                                 "%s could not allocate pose controller", __func__);
 
             mPoseController->setDesiredMode(mDesiredHeadTrackingMode);
-            mPoseController->setHeadSensor(mHeadSensor);
+            mNumActiveTracks = numActiveTracks;
+            checkHeadSensor_l();
             mPoseController->setScreenSensor(mScreenSensor);
             mPoseController->setDisplayOrientation(mDisplayOrientation);
             poseController = mPoseController;
@@ -697,7 +703,6 @@
         output = mOutput;
         mOutput = AUDIO_IO_HANDLE_NONE;
         mPoseController.reset();
-
         callback = mSpatializerCallback;
     }
 
@@ -707,6 +712,24 @@
     return output;
 }
 
+void Spatializer::updateActiveTracks(size_t numActiveTracks) {
+    std::lock_guard lock(mLock);
+    mNumActiveTracks = numActiveTracks;
+    checkHeadSensor_l();
+}
+
+void Spatializer::checkHeadSensor_l() {
+    if (mSupportsHeadTracking && mPoseController != nullptr) {
+        if(mNumActiveTracks > 0 && mLevel != SpatializationLevel::NONE
+            && mDesiredHeadTrackingMode != HeadTrackingMode::STATIC
+            && mHeadSensor != SpatializerPoseController::INVALID_SENSOR) {
+            mPoseController->setHeadSensor(mHeadSensor);
+        } else {
+            mPoseController->setHeadSensor(SpatializerPoseController::INVALID_SENSOR);
+        }
+    }
+}
+
 void Spatializer::calculateHeadPose() {
     ALOGV("%s", __func__);
     std::lock_guard lock(mLock);
diff --git a/services/audiopolicy/service/Spatializer.h b/services/audiopolicy/service/Spatializer.h
index 4d77b78..4ce99d8 100644
--- a/services/audiopolicy/service/Spatializer.h
+++ b/services/audiopolicy/service/Spatializer.h
@@ -135,7 +135,7 @@
     /** Called by audio policy service when the special output mixer dedicated to spatialization
      * is opened and the spatializer engine must be created.
      */
-    status_t attachOutput(audio_io_handle_t output);
+    status_t attachOutput(audio_io_handle_t output, size_t numActiveTracks);
     /** Called by audio policy service when the special output mixer dedicated to spatialization
      * is closed and the spatializer engine must be release.
      */
@@ -143,6 +143,8 @@
     /** Returns the output stream the spatializer is attached to. */
     audio_io_handle_t getOutput() const { std::lock_guard lock(mLock); return mOutput; }
 
+    void updateActiveTracks(size_t numActiveTracks);
+
     /** Gets the channel mask, sampling rate and format set for the spatializer input. */
     audio_config_base_t getAudioInConfig() const;
 
@@ -274,6 +276,8 @@
 
     void postFramesProcessedMsg(int frames);
 
+    void checkHeadSensor_l() REQUIRES(mLock);
+
     /** Effect engine descriptor */
     const effect_descriptor_t mEngineDescriptor;
     /** Callback interface to parent audio policy service */
@@ -328,6 +332,8 @@
     sp<ALooper> mLooper;
     sp<EngineCallbackHandler> mHandler;
 
+    size_t mNumActiveTracks GUARDED_BY(mLock) = 0;
+
     static const std::vector<const char *> sHeadPoseKeys;
 };