From a25c5d88d17f251262307ce31e799c9cf361d145 Mon Sep 17 00:00:00 2001
From: Eric Laurent <elaurent@google.com>
Date: Thu, 10 Feb 2011 11:04:34 -0800
Subject: Fix issue 3435692

The problem is that the AudioService is not notified of the death of
IAudioFlinger binder interface because no methods was called on AudioFlinger
from system_server since the device booted. Therefore, AudioSystem did not created any
IAudioFlinger interface in the system_server process.
The root cause was always present but more likely to happen on a tablet than on a phone
as for instance no beeps are played when volume is adjusted.

The fix consists in having AudioSystem explicitly call a method on AudioFlinger when a
callback is installed to make sure that an IAudioFlinger binder interface is created
regardless of any other activity in the client process.

Change-Id: I9df34a36825af0b25cd0246dd02edbd712263f41
---
 media/java/android/media/AudioService.java |  5 +++--
 media/java/android/media/AudioSystem.java  | 19 ++++++++++++++++---
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/media/java/android/media/AudioService.java b/media/java/android/media/AudioService.java
index 6c85490bb1c5..1fe3ccc2c83c 100644
--- a/media/java/android/media/AudioService.java
+++ b/media/java/android/media/AudioService.java
@@ -1945,10 +1945,11 @@ public class AudioService extends IAudioService.Stub {
                     break;
 
                 case MSG_MEDIA_SERVER_DIED:
-                    // Force creation of new IAudioflinger interface
                     if (!mMediaServerOk) {
                         Log.e(TAG, "Media server died.");
-                        AudioSystem.isMicrophoneMuted();
+                        // Force creation of new IAudioFlinger interface so that we are notified
+                        // when new media_server process is back to life.
+                        AudioSystem.setErrorCallback(mAudioSystemCallback);
                         sendMsg(mAudioHandler, MSG_MEDIA_SERVER_DIED, SHARED_MSG, SENDMSG_NOOP, 0, 0,
                                 null, 500);
                     }
diff --git a/media/java/android/media/AudioSystem.java b/media/java/android/media/AudioSystem.java
index e20bb2510d9f..ca881afb9cf4 100644
--- a/media/java/android/media/AudioSystem.java
+++ b/media/java/android/media/AudioSystem.java
@@ -218,13 +218,26 @@ public class AudioSystem
      */
     public static void setErrorCallback(ErrorCallback cb)
     {
-        mErrorCallback = cb;
+        synchronized (AudioSystem.class) {
+            mErrorCallback = cb;
+        }
+        // Calling a method on AudioFlinger here makes sure that we bind to IAudioFlinger
+        // binder interface death. Not doing that would result in not being notified of
+        // media_server process death if no other method is called on AudioSystem that reaches
+        // to AudioFlinger.
+        isMicrophoneMuted();
     }
 
     private static void errorCallbackFromNative(int error)
     {
-        if (mErrorCallback != null) {
-            mErrorCallback.onError(error);
+        ErrorCallback errorCallback = null;
+        synchronized (AudioSystem.class) {
+            if (mErrorCallback != null) {
+                errorCallback = mErrorCallback;
+            }
+        }
+        if (errorCallback != null) {
+            errorCallback.onError(error);
         }
     }
 
-- 
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