Add locking around MediaSession.Callback.mSession (b6e19667) · Commits · e / os / android_frameworks_base

media/java/android/media/session/MediaSession.java

+126 −87

Original line number	Diff line number	Diff line
		@@ -240,15 +240,15 @@ public final class MediaSession {
		synchronized (mLock) {
		if (mCallback != null) {
		// We're updating the callback, clear the session from the old one.
		mCallback.mCallback.mSession = null;
		mCallback.removeCallbacksAndMessages(null);
		mCallback.mCallback.clearSession();

		}
		if (callback == null) {
		mCallback = null;
		return;
		}
		Looper looper = handler != null ? handler.getLooper() : Looper.myLooper();
		callback.mSession = this;
		callback.setSession(this);
		CallbackMessageHandler msgHandler = new CallbackMessageHandler(looper, callback);
		mCallback = msgHandler;
		}
		@@ -916,6 +916,7 @@ public final class MediaSession {
		*/
		public abstract static class Callback {

		private final Object mSessionLock = new Object();
		private MediaSession mSession;
		private CallbackMessageHandler mHandler;
		private boolean mMediaPlayPauseKeyPending;
		@@ -923,6 +924,20 @@ public final class MediaSession {
		public Callback() {
		}

		private void setSession(MediaSession session) {
		synchronized (mSessionLock) {
		mSession = session;
		}
		}

		private void clearSession() {
		synchronized (mSessionLock) {
		mSession = null;
		mMediaPlayPauseKeyPending = false;
		mHandler.removeCallbacksAndMessages(null);
		}
		}

		/**
		* Called when a controller has sent a command to this session.
		* The owner of the session may handle custom commands but is not
		@@ -950,25 +965,39 @@ public final class MediaSession {
		* @return True if the event was handled, false otherwise.
		*/
		public boolean onMediaButtonEvent(@NonNull Intent mediaButtonIntent) {
		if (mSession != null && mHandler != null
		&& Intent.ACTION_MEDIA_BUTTON.equals(mediaButtonIntent.getAction())) {
		KeyEvent ke = mediaButtonIntent.getParcelableExtra(Intent.EXTRA_KEY_EVENT, android.view.KeyEvent.class);
		if (ke != null && ke.getAction() == KeyEvent.ACTION_DOWN) {
		if (mHandler == null
		\|\| !Intent.ACTION_MEDIA_BUTTON.equals(mediaButtonIntent.getAction())) {
		return false;
		}
		KeyEvent ke = mediaButtonIntent.getParcelableExtra(
		Intent.EXTRA_KEY_EVENT, android.view.KeyEvent.class);
		if (ke == null \|\| ke.getAction() != KeyEvent.ACTION_DOWN) {
		return false;
		}
		// Store some results into locals so we can invoke any app-implemented methods (like
		// onSkipToNext()) outside the synchronized block and avoid the risk of a deadlock.
		long validActions;
		boolean eventHandled/* = false*/;
		Runnable doubleTapHandlingAction = null;
		synchronized (mSessionLock) {
		if (mSession == null) {
		return false;
		}
		PlaybackState state = mSession.mPlaybackState;
		long validActions = state == null ? 0 : state.getActions();
		validActions = state == null ? 0 : state.getActions();
		switch (ke.getKeyCode()) {
		case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
		case KeyEvent.KEYCODE_HEADSETHOOK:
		case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE, KeyEvent.KEYCODE_HEADSETHOOK -> {
		if (ke.getRepeatCount() > 0) {
		// Consider long-press as a single tap.
		handleMediaPlayPauseKeySingleTapIfPending();
		doubleTapHandlingAction =
		this::handleMediaPlayPauseKeySingleTapIfPending;
		} else if (mMediaPlayPauseKeyPending) {
		// Consider double tap as the next.
		mHandler.removeMessages(CallbackMessageHandler
		.MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT);
		mMediaPlayPauseKeyPending = false;
		if ((validActions & PlaybackState.ACTION_SKIP_TO_NEXT) != 0) {
		onSkipToNext();
		doubleTapHandlingAction = this::onSkipToNext;
		}
		} else {
		mMediaPlayPauseKeyPending = true;
		@@ -980,70 +1009,80 @@ public final class MediaSession {
		.getDoubleTapTimeoutMillis()
		: ViewConfiguration.getDoubleTapTimeout());
		}
		return true;
		default:
		eventHandled = true;
		}
		default -> {
		// If another key is pressed within double tap timeout, consider the
		// pending play/pause as a single tap to handle media keys in order.
		handleMediaPlayPauseKeySingleTapIfPending();
		break;
		doubleTapHandlingAction = this::handleMediaPlayPauseKeySingleTapIfPending;
		eventHandled = false;
		}
		}
		}
		if (doubleTapHandlingAction != null) {
		doubleTapHandlingAction.run();
		}
		if (eventHandled) {
		return true;
		}

		switch (ke.getKeyCode()) {
		case KeyEvent.KEYCODE_MEDIA_PLAY:
		case KeyEvent.KEYCODE_MEDIA_PLAY -> {
		if ((validActions & PlaybackState.ACTION_PLAY) != 0) {
		onPlay();
		return true;
		}
		break;
		case KeyEvent.KEYCODE_MEDIA_PAUSE:
		}
		case KeyEvent.KEYCODE_MEDIA_PAUSE -> {
		if ((validActions & PlaybackState.ACTION_PAUSE) != 0) {
		onPause();
		return true;
		}
		break;
		case KeyEvent.KEYCODE_MEDIA_NEXT:
		}
		case KeyEvent.KEYCODE_MEDIA_NEXT -> {
		if ((validActions & PlaybackState.ACTION_SKIP_TO_NEXT) != 0) {
		onSkipToNext();
		return true;
		}
		break;
		case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
		}
		case KeyEvent.KEYCODE_MEDIA_PREVIOUS -> {
		if ((validActions & PlaybackState.ACTION_SKIP_TO_PREVIOUS) != 0) {
		onSkipToPrevious();
		return true;
		}
		break;
		case KeyEvent.KEYCODE_MEDIA_STOP:
		}
		case KeyEvent.KEYCODE_MEDIA_STOP -> {
		if ((validActions & PlaybackState.ACTION_STOP) != 0) {
		onStop();
		return true;
		}
		break;
		case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
		}
		case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD -> {
		if ((validActions & PlaybackState.ACTION_FAST_FORWARD) != 0) {
		onFastForward();
		return true;
		}
		break;
		case KeyEvent.KEYCODE_MEDIA_REWIND:
		}
		case KeyEvent.KEYCODE_MEDIA_REWIND -> {
		if ((validActions & PlaybackState.ACTION_REWIND) != 0) {
		onRewind();
		return true;
		}
		break;
		}
		}
		}
		return false;
		}

		private void handleMediaPlayPauseKeySingleTapIfPending() {
		if (!mMediaPlayPauseKeyPending) {
		PlaybackState state;
		synchronized (mSessionLock) {
		if (!mMediaPlayPauseKeyPending \|\| mSession == null) {
		return;
		}
		mMediaPlayPauseKeyPending = false;
		mHandler.removeMessages(CallbackMessageHandler.MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT);
		PlaybackState state = mSession.mPlaybackState;
		mHandler.removeMessages(
		CallbackMessageHandler.MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT);
		state = mSession.mPlaybackState;
		}
		long validActions = state == null ? 0 : state.getActions();
		boolean isPlaying = state != null
		&& state.getState() == PlaybackState.STATE_PLAYING;