Enhance Visualizer behavior in the case of mediaserver death.

Bring the Visualizer class into line with the SDK documentation by
returning ERROR_DEAD_OBJECT instead of ERROR_INVALID_OPERATION when
the Visualizer loses its binder connection to the mediaserver because
of a mediaserver restart.

Also add a new callback interface to allow clients to be
asynchronously notified in the case of server death.  Right now, the
interface definition and the registration method are flagged as hidden
pending API council review/approval.

See http://b/issue?id=5717519 for details.

Change-Id: Ic15856f27ed5a950a583ac11ca81f79bd7e9b1a0
Signed-off-by: John Grossman <johngro@google.com>

5 files changed, 112 insertions, 18 deletions

diff --git a/media/java/android/media/audiofx/Visualizer.java b/media/java/android/media/audiofx/Visualizer.java
index 1f1e60d6436d..91d0addde5f8 100755
--- a/media/java/android/media/audiofx/Visualizer.java
+++ b/media/java/android/media/audiofx/Visualizer.java
@@ -84,6 +84,7 @@ public class Visualizer {
     // to keep in sync with frameworks/base/media/jni/audioeffect/android_media_Visualizer.cpp
     private static final int NATIVE_EVENT_PCM_CAPTURE = 0;
     private static final int NATIVE_EVENT_FFT_CAPTURE = 1;
+    private static final int NATIVE_EVENT_SERVER_DIED = 2;
 
     // Error codes:
     /**
@@ -147,6 +148,10 @@ public class Visualizer {
      *  PCM and FFT capture listener registered by client
      */
     private OnDataCaptureListener mCaptureListener = null;
+    /**
+     *  Server Died listener registered by client
+     */
+    private OnServerDiedListener mServerDiedListener = null;
 
     // accessed by native methods
     private int mNativeVisualizer;
@@ -458,6 +463,43 @@ public class Visualizer {
     }
 
     /**
+     * @hide
+     *
+     * The OnServerDiedListener interface defines a method called by the Visualizer to indicate that
+     * the connection to the native media server has been broken and that the Visualizer object will
+     * need to be released and re-created.
+     * The client application can implement this interface and register the listener with the
+     * {@link #setServerDiedListener(OnServerDiedListener)} method.
+     */
+    public interface OnServerDiedListener  {
+        /**
+         * @hide
+         *
+         * Method called when the native media server has died.
+         * <p>If the native media server encounters a fatal error and needs to restart, the binder
+         * connection from the {@link #Visualizer} to the media server will be broken.  Data capture
+         * callbacks will stop happening, and client initiated calls to the {@link #Visualizer}
+         * instance will fail with the error code {@link #DEAD_OBJECT}.  To restore functionality,
+         * clients should {@link #release()} their old visualizer and create a new instance.
+         */
+        void onServerDied();
+    }
+
+    /**
+     * @hide
+     *
+     * Registers an OnServerDiedListener interface.
+     * <p>Call this method with a null listener to stop receiving server death notifications.
+     * @return {@link #SUCCESS} in case of success,
+     */
+    public int setServerDiedListener(OnServerDiedListener listener) {
+        synchronized (mListenerLock) {
+            mServerDiedListener = listener;
+        }
+        return SUCCESS;
+    }
+
+    /**
      * Helper class to handle the forwarding of native events to the appropriate listeners
      */
     private class NativeEventHandler extends Handler
@@ -469,11 +511,7 @@ public class Visualizer {
             mVisualizer = v;
         }
 
-        @Override
-        public void handleMessage(Message msg) {
-            if (mVisualizer == null) {
-                return;
-            }
+        private void handleCaptureMessage(Message msg) {
             OnDataCaptureListener l = null;
             synchronized (mListenerLock) {
                 l = mVisualizer.mCaptureListener;
@@ -482,6 +520,7 @@ public class Visualizer {
             if (l != null) {
                 byte[] data = (byte[])msg.obj;
                 int samplingRate = msg.arg1;
+
                 switch(msg.what) {
                 case NATIVE_EVENT_PCM_CAPTURE:
                     l.onWaveFormDataCapture(mVisualizer, data, samplingRate);
@@ -490,11 +529,41 @@ public class Visualizer {
                     l.onFftDataCapture(mVisualizer, data, samplingRate);
                     break;
                 default:
-                    Log.e(TAG,"Unknown native event: "+msg.what);
+                    Log.e(TAG,"Unknown native event in handleCaptureMessge: "+msg.what);
                     break;
                 }
             }
         }
+
+        private void handleServerDiedMessage(Message msg) {
+            OnServerDiedListener l = null;
+            synchronized (mListenerLock) {
+                l = mVisualizer.mServerDiedListener;
+            }
+
+            if (l != null)
+                l.onServerDied();
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            if (mVisualizer == null) {
+                return;
+            }
+
+            switch(msg.what) {
+            case NATIVE_EVENT_PCM_CAPTURE:
+            case NATIVE_EVENT_FFT_CAPTURE:
+                handleCaptureMessage(msg);
+                break;
+            case NATIVE_EVENT_SERVER_DIED:
+                handleServerDiedMessage(msg);
+                break;
+            default:
+                Log.e(TAG,"Unknown native event: "+msg.what);
+                break;
+            }
+        }
     }
 
     //---------------------------------------------------------
diff --git a/media/jni/audioeffect/android_media_Visualizer.cpp b/media/jni/audioeffect/android_media_Visualizer.cpp
index 433c459c32b2..f015afbaf209 100644
--- a/media/jni/audioeffect/android_media_Visualizer.cpp
+++ b/media/jni/audioeffect/android_media_Visualizer.cpp
@@ -39,6 +39,7 @@ using namespace android;
 
 #define NATIVE_EVENT_PCM_CAPTURE                0
 #define NATIVE_EVENT_FFT_CAPTURE                1
+#define NATIVE_EVENT_SERVER_DIED                2
 
 // ----------------------------------------------------------------------------
 static const char* const kClassPathName = "android/media/audiofx/Visualizer";
@@ -284,6 +285,23 @@ android_media_visualizer_native_init(JNIEnv *env)
 
 }
 
+static void android_media_visualizer_effect_callback(int32_t event,
+                                                     void *user,
+                                                     void *info) {
+    if ((event == AudioEffect::EVENT_ERROR) &&
+        (*((status_t*)info) == DEAD_OBJECT)) {
+        visualizerJniStorage* lpJniStorage = (visualizerJniStorage*)user;
+        visualizer_callback_cookie* callbackInfo = &lpJniStorage->mCallbackData;
+        JNIEnv *env = AndroidRuntime::getJNIEnv();
+
+        env->CallStaticVoidMethod(
+            callbackInfo->visualizer_class,
+            fields.midPostNativeEvent,
+            callbackInfo->visualizer_ref,
+            NATIVE_EVENT_SERVER_DIED,
+            0, 0, 0);
+    }
+}
 
 static jint
 android_media_visualizer_native_setup(JNIEnv *env, jobject thiz, jobject weak_this,
@@ -319,8 +337,8 @@ android_media_visualizer_native_setup(JNIEnv *env, jobject thiz, jobject weak_th
 
     // create the native Visualizer object
     lpVisualizer = new Visualizer(0,
-                                  NULL,
-                                  NULL,
+                                  android_media_visualizer_effect_callback,
+                                  lpJniStorage,
                                   sessionId);
     if (lpVisualizer == NULL) {
         ALOGE("Error creating Visualizer");
diff --git a/media/libmedia/AudioEffect.cpp b/media/libmedia/AudioEffect.cpp
index f9f997fe6a32..19b7e324b32b 100644
--- a/media/libmedia/AudioEffect.cpp
+++ b/media/libmedia/AudioEffect.cpp
@@ -202,7 +202,7 @@ bool AudioEffect::getEnabled() const
 status_t AudioEffect::setEnabled(bool enabled)
 {
     if (mStatus != NO_ERROR) {
-        return INVALID_OPERATION;
+        return (mStatus == ALREADY_EXISTS) ? INVALID_OPERATION : mStatus;
     }
 
     status_t status = NO_ERROR;
@@ -231,7 +231,7 @@ status_t AudioEffect::command(uint32_t cmdCode,
 {
     if (mStatus != NO_ERROR && mStatus != ALREADY_EXISTS) {
         ALOGV("command() bad status %d", mStatus);
-        return INVALID_OPERATION;
+        return mStatus;
     }
 
     if (cmdCode == EFFECT_CMD_ENABLE || cmdCode == EFFECT_CMD_DISABLE) {
@@ -263,7 +263,7 @@ status_t AudioEffect::command(uint32_t cmdCode,
 status_t AudioEffect::setParameter(effect_param_t *param)
 {
     if (mStatus != NO_ERROR) {
-        return INVALID_OPERATION;
+        return (mStatus == ALREADY_EXISTS) ? INVALID_OPERATION : mStatus;
     }
 
     if (param == NULL || param->psize == 0 || param->vsize == 0) {
@@ -281,7 +281,7 @@ status_t AudioEffect::setParameter(effect_param_t *param)
 status_t AudioEffect::setParameterDeferred(effect_param_t *param)
 {
     if (mStatus != NO_ERROR) {
-        return INVALID_OPERATION;
+        return (mStatus == ALREADY_EXISTS) ? INVALID_OPERATION : mStatus;
     }
 
     if (param == NULL || param->psize == 0 || param->vsize == 0) {
@@ -307,7 +307,7 @@ status_t AudioEffect::setParameterDeferred(effect_param_t *param)
 status_t AudioEffect::setParameterCommit()
 {
     if (mStatus != NO_ERROR) {
-        return INVALID_OPERATION;
+        return (mStatus == ALREADY_EXISTS) ? INVALID_OPERATION : mStatus;
     }
 
     Mutex::Autolock _l(mCblk->lock);
@@ -321,7 +321,7 @@ status_t AudioEffect::setParameterCommit()
 status_t AudioEffect::getParameter(effect_param_t *param)
 {
     if (mStatus != NO_ERROR && mStatus != ALREADY_EXISTS) {
-        return INVALID_OPERATION;
+        return mStatus;
     }
 
     if (param == NULL || param->psize == 0 || param->vsize == 0) {
@@ -341,7 +341,7 @@ status_t AudioEffect::getParameter(effect_param_t *param)
 void AudioEffect::binderDied()
 {
     ALOGW("IEffect died");
-    mStatus = NO_INIT;
+    mStatus = DEAD_OBJECT;
     if (mCbf != NULL) {
         status_t status = DEAD_OBJECT;
         mCbf(EVENT_ERROR, mUserData, &status);
diff --git a/media/libmedia/IEffect.cpp b/media/libmedia/IEffect.cpp
index d469e280f647..5d40cc82af48 100644
--- a/media/libmedia/IEffect.cpp
+++ b/media/libmedia/IEffect.cpp
@@ -83,8 +83,15 @@ public:
             size = *pReplySize;
         }
         data.writeInt32(size);
-        remote()->transact(COMMAND, data, &reply);
-        status_t status = reply.readInt32();
+
+        status_t status = remote()->transact(COMMAND, data, &reply);
+        if (status != NO_ERROR) {
+            if (pReplySize != NULL)
+                *pReplySize = 0;
+            return status;
+        }
+
+        status = reply.readInt32();
         size = reply.readInt32();
         if (size != 0 && pReplyData != NULL && pReplySize != NULL) {
             reply.read(pReplyData, size);
diff --git a/media/libmedia/Visualizer.cpp b/media/libmedia/Visualizer.cpp
index 13b64e9f2917..70f8c0c28e8e 100644
--- a/media/libmedia/Visualizer.cpp
+++ b/media/libmedia/Visualizer.cpp
@@ -168,7 +168,7 @@ status_t Visualizer::getWaveForm(uint8_t *waveform)
         uint32_t replySize = mCaptureSize;
         status = command(VISUALIZER_CMD_CAPTURE, 0, NULL, &replySize, waveform);
         ALOGV("getWaveForm() command returned %d", status);
-        if (replySize == 0) {
+        if ((status == NO_ERROR) && (replySize == 0)) {
             status = NOT_ENOUGH_DATA;
         }
     } else {