PlaybackActivityMonitor.mPlayerLock:
android.media.MediaPlayer.release()
> android.media.PlayerBase.baseRelease()
> synchronized (mLock)
> com.android.server.audio.PlaybackActivityMonitor.releasePlayer()
> synchronized(mPlayerLock)
and:
com.android.server.audio.PlaybackActivityMonitor.unmutePlayersForCall()
> synchronized (mPlayerLock)
> android.media.PlayerProxy.setVolume()
> android.media.PlayerBase$IPlayerWrapper.setVolume()
> android.media.PlayerBase.baseSetVolume()
> synchronized (mLock)
playerSetVolume()
Since system_server can have its own players, the calls to
AudioService from PlayerBase can be synchronous, hence the
deadlock.
The fix consists in never holding the lock in PlayerBase
while calling into AudioService.
Refactor the playstate update into a method used for
start / stop / pause.
Bug: 72294559
Test: see bug
Change-Id: Ib41045de124683a7484184cf63577bd2412d1362
ec4f10df90