I have read several posts regarding the new 'Doze' Mode in Android M, also the article on Android developers website : https://developer.android.com/training/monitoring-device-state/doze-standby.html yet I still have an issue with a Foreground Service correctly running on a phone (Android 6.0.1).
Issue:
I have a Service which handles playing music using a MediaPlayer object, the Service Implements onCompletion and onPrepared MediaPlayer interfaces.
Pseudo code:
public class MusicService extends Service implements MediaPlayer.OnPreparedListener, MediaPlayer.OnCompletionListener, MediaPlayer.OnErrorListener { // Class Variables/Methods etc... @Override public void onPrepared(MediaPlayer mp) { mp.start(); // update notification using startForeground() } @Override public void onCompletion(MediaPlayer mp) { // Go and get another music track in separate thread // (Have used AsyncTask and RX Java/RX Android to test if problem is here - works fine) } @Override public boolean onError(MediaPlayer mp, int what, int extra) { // handleError return false; } } The app works well, when the phone is plugged into a power source, or when the screen is on, or app is open and screen is on. However when the phone has been sitting idle and playing music (between 5 - 40mins) the Service fails to retrieve the next track once onCompletion() is called.
The Service is setup and meets the following conditions:
- The Service Notification is started with
startForeground - The MediaPlayer Object has a partial wakelock
PARTIAL_WAKE_LOCK - The Service runs in a separate process to the main app/UI
- All Media uses
prepareAsync()(logic to get the next track uri is performed in background thread, prepareAsync() is called only in the Main thread)
Things I have tried:
- Retrieving the next song (after onCompletion is called) in the Main thread instead of a background thread
- Acquiring a separate Partial WakeLock in onCompletion(), and holding and then releasing it when onPrepared() is called.
- Few other trivial things that didn't make a difference...
I have a logcat output, from when the phone is left, untouched for a period of time with the screen off, and UNPLUGGED (logcat was obtained once I plugged it back in and it updated the log) which demonstrates the problem.
06-15 02:31:39.346 musicplayer:music_service E/MusicService: onPrepared : Tom Petty GH - 11 - You Got Lucky 06-15 02:31:39.548 musicplayer:music_service D/MusicService: Releasing wakelock 06-15 02:35:15.467 musicplayer:music_service E/MusicService: onCompletion called 06-15 02:35:15.467 musicplayer:music_service D/MusicService: Acquiring wakelock 06-15 02:35:15.514 musicplayer:music_service D/NextActionStrategy: Retrieving song - rx java - Main Ui Thread =false 06-15 02:35:15.870 musicplayer:music_service D/NextActionStrategy: Song Retrieved : Ten Years- Main Ui Thread = true 06-15 02:35:15.950 musicplayer:music_service E/MusicService: onPrepared : Ten Years 06-15 02:35:16.149 musicplayer:music_service D/MusicService: Releasing wakelock 06-15 02:38:59.002 musicplayer:music_service E/MusicService: onCompletion called 06-15 02:38:59.002 musicplayer:music_service D/MusicService: Acquiring wakelock 06-15 02:38:59.049 musicplayer:music_service D/NextActionStrategy: Retrieving song - rx java - Main Ui Thread =false 06-15 02:38:59.211 musicplayer:music_service D/NextActionStrategy: Song Retrieved : What Am I- Main Ui Thread = true 06-15 02:50:07.642 musicplayer:music_service E/MusicService: onPrepared : What Am I 06-15 02:50:07.976 musicplayer:music_service D/MusicService: Releasing wakelock 06-15 02:50:22.097 musicplayer:music_service D/MusicService: onStartCommand called : action.PAUSE The routine would be
- play a track
- onCompletion() called
- aquire wakelock get the next track
- PrepareAsync()
- onPrepared called - start playing and update notification using startForeground
From the logs you can see at 02:38:59.xxx onCompletion is called, a track is found, and returns to the Main thread where prepareAsync() is called, but then nothing happens for 12mins until I manually wake the phone up, and at which point just code continues where is stopped and the track starts playing.
I don't believe its the device as other music apps I use work fine in this situation, however I am limited to testing on one real device only :(
If you've got this far thanks for bearing with me! Any suggestions would be appreciated (hopefully regarding a solution and not my music tastes!).