Fix AudioEngine to allow re-initialization - DO NOT MERGE

Add AudioEngine::CompareAndSetEngine and change
VariableSpeed::initializeEngine to use this method so it only initializes
a new engine once rather than asserting on subsequent calls.

Change AudioEngine::DeleteEngine so it ignores repeated calls instead of
asserting. Add VariableSpeed::isReadyToPlay so callers can detect when
the audio library has been properly initialized.

Bug:11511992
Change-Id: I4517cb2ab4c186da43dffc7dbc2a9ad49000059f
(cherry picked from commit 8502b724a9fdc104e7b4a3aba1641e101b4c7be9)

3 files changed, 14 insertions, 1 deletions

diff --git a/variablespeed/src/com/android/ex/variablespeed/MediaPlayerProxy.java b/variablespeed/src/com/android/ex/variablespeed/MediaPlayerProxy.java
index 8489dc1..3b7b576 100644
--- a/variablespeed/src/com/android/ex/variablespeed/MediaPlayerProxy.java
+++ b/variablespeed/src/com/android/ex/variablespeed/MediaPlayerProxy.java
@@ -42,6 +42,7 @@ public interface MediaPlayerProxy {
     int getDuration();
     void seekTo(int startPosition);
     void start();
+    boolean isReadyToPlay();
     boolean isPlaying();
     int getCurrentPosition();
     void pause();
diff --git a/variablespeed/src/com/android/ex/variablespeed/SingleThreadedMediaPlayerProxy.java b/variablespeed/src/com/android/ex/variablespeed/SingleThreadedMediaPlayerProxy.java
index 17692f7..c9a9741 100644
--- a/variablespeed/src/com/android/ex/variablespeed/SingleThreadedMediaPlayerProxy.java
+++ b/variablespeed/src/com/android/ex/variablespeed/SingleThreadedMediaPlayerProxy.java
@@ -85,6 +85,11 @@ public class SingleThreadedMediaPlayerProxy implements MediaPlayerProxy {
     }
 
     @Override
+    public synchronized boolean isReadyToPlay() {
+        return mDelegate.isReadyToPlay();
+    }
+
+    @Override
     public synchronized boolean isPlaying() {
         return mDelegate.isPlaying();
     }
diff --git a/variablespeed/src/com/android/ex/variablespeed/VariableSpeed.java b/variablespeed/src/com/android/ex/variablespeed/VariableSpeed.java
index 5c93d26..e44a375 100644
--- a/variablespeed/src/com/android/ex/variablespeed/VariableSpeed.java
+++ b/variablespeed/src/com/android/ex/variablespeed/VariableSpeed.java
@@ -337,9 +337,16 @@ public class VariableSpeed implements MediaPlayerProxy {
     }
 
     @Override
+    public boolean isReadyToPlay() {
+        synchronized (lock) {
+            return !mHasBeenReleased && mHasDuration;
+        }
+    }
+
+    @Override
     public boolean isPlaying() {
         synchronized (lock) {
-            return mHasStartedPlayback && !hasPlaybackFinished();
+            return isReadyToPlay() && mHasStartedPlayback && !hasPlaybackFinished();
         }
     }