Merge "Fix stack traversal order when removing or adding media button receiver" (f2fc1cbb) · Commits · e / os / android_frameworks_base

media/java/android/media/AudioService.java

+31 −19

Original line number	Diff line number	Diff line
		@@ -4963,28 +4963,34 @@ public class AudioService extends IAudioService.Stub implements OnFinished {
		/**
		* Helper function:
		* Set the new remote control receiver at the top of the RC focus stack.
		* Called synchronized on mAudioFocusLock, then mRCStack
		* precondition: mediaIntent != null, target != null
		*/
		private void pushMediaButtonReceiver(PendingIntent mediaIntent, ComponentName target) {
		private void pushMediaButtonReceiver_syncAfRcs(PendingIntent mediaIntent, ComponentName target) {
		// already at top of stack?
		if (!mRCStack.empty() && mRCStack.peek().mMediaIntent.equals(mediaIntent)) {
		return;
		}
		Iterator<RemoteControlStackEntry> stackIterator = mRCStack.iterator();
		RemoteControlStackEntry rcse = null;
		boolean wasInsideStack = false;
		while(stackIterator.hasNext()) {
		rcse = (RemoteControlStackEntry)stackIterator.next();
		try {
		for (int index = mRCStack.size()-1; index >= 0; index--) {
		rcse = mRCStack.elementAt(index);
		if(rcse.mMediaIntent.equals(mediaIntent)) {
		// ok to remove element while traversing the stack since we're leaving the loop
		mRCStack.removeElementAt(index);
		wasInsideStack = true;
		stackIterator.remove();
		break;
		}
		}
		} catch (ArrayIndexOutOfBoundsException e) {
		// not expected to happen, indicates improper concurrent modification
		Log.e(TAG, "Wrong index accessing media button stack, lock error? ", e);
		}
		if (!wasInsideStack) {
		rcse = new RemoteControlStackEntry(mediaIntent, target);
		}
		mRCStack.push(rcse);
		mRCStack.push(rcse); // rcse is never null

		// post message to persist the default media button receiver
		mAudioHandler.sendMessage( mAudioHandler.obtainMessage(
		@@ -4994,18 +5000,24 @@ public class AudioService extends IAudioService.Stub implements OnFinished {
		/**
		* Helper function:
		* Remove the remote control receiver from the RC focus stack.
		* Called synchronized on mAudioFocusLock, then mRCStack
		* precondition: pi != null
		*/
		private void removeMediaButtonReceiver(PendingIntent pi) {
		Iterator<RemoteControlStackEntry> stackIterator = mRCStack.iterator();
		while(stackIterator.hasNext()) {
		RemoteControlStackEntry rcse = (RemoteControlStackEntry)stackIterator.next();
		private void removeMediaButtonReceiver_syncAfRcs(PendingIntent pi) {
		try {
		for (int index = mRCStack.size()-1; index >= 0; index--) {
		final RemoteControlStackEntry rcse = mRCStack.elementAt(index);
		if (rcse.mMediaIntent.equals(pi)) {
		stackIterator.remove();
		rcse.unlinkToRcClientDeath();
		// ok to remove element while traversing the stack since we're leaving the loop
		mRCStack.removeElementAt(index);
		break;
		}
		}
		} catch (ArrayIndexOutOfBoundsException e) {
		// not expected to happen, indicates improper concurrent modification
		Log.e(TAG, "Wrong index accessing media button stack, lock error? ", e);
		}
		}

		/**
		@@ -5242,7 +5254,7 @@ public class AudioService extends IAudioService.Stub implements OnFinished {

		synchronized(mAudioFocusLock) {
		synchronized(mRCStack) {
		pushMediaButtonReceiver(mediaIntent, eventReceiver);
		pushMediaButtonReceiver_syncAfRcs(mediaIntent, eventReceiver);
		// new RC client, assume every type of information shall be queried
		checkUpdateRemoteControlDisplay_syncAfRcs(RC_INFO_ALL);
		}
		@@ -5260,7 +5272,7 @@ public class AudioService extends IAudioService.Stub implements OnFinished {
		synchronized(mAudioFocusLock) {
		synchronized(mRCStack) {
		boolean topOfStackWillChange = isCurrentRcController(mediaIntent);
		removeMediaButtonReceiver(mediaIntent);
		removeMediaButtonReceiver_syncAfRcs(mediaIntent);
		if (topOfStackWillChange) {
		// current RC client will change, assume every type of info needs to be queried
		checkUpdateRemoteControlDisplay_syncAfRcs(RC_INFO_ALL);