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)

1 files changed, 13 insertions, 6 deletions

diff --git a/variablespeed/jni/variablespeed.cc b/variablespeed/jni/variablespeed.cc
index 73ac609..4bdbbcc 100644
--- a/variablespeed/jni/variablespeed.cc
+++ b/variablespeed/jni/variablespeed.cc
@@ -129,14 +129,21 @@ void AudioEngine::SetEngine(AudioEngine* engine) {
   audioEngine_ = engine;
 }
 
+bool AudioEngine::CompareAndSetEngine(AudioEngine* expect, AudioEngine* update) {
+  android::Mutex::Autolock autoLock(publishEngineLock_);
+  if (audioEngine_ == expect) {
+    DeleteEngine();
+    audioEngine_ = update;
+    return true;
+  }
+  return false;
+}
+
 void AudioEngine::DeleteEngine() {
-  if (audioEngine_ == NULL) {
-    LOGE("you haven't initialized the audio engine");
-    CHECK(false);
-    return;
+  if (audioEngine_ != NULL) {
+    delete audioEngine_;
+    audioEngine_ = NULL;
   }
-  delete audioEngine_;
-  audioEngine_ = NULL;
 }
 
 // ****************************************************************************