MediaSessionService onCreate ANR error

[xuwang-yuewen]

Media3 Version

1.3.1

Devices that reproduce the issue

Google Play and Firebase report these devices:

• Oppo
• Oppo OP4F2F
• Infinix Infinix-X6516
• Transsion
• Transsion-Unisoc
• TECNO TECNO-BF6
• OPPO OP4C7D

including Android 11, 12, 13, 14

Reproduction steps

（online production environment）

Expected result

not ANR crash

Actual result

many ANR errors

Description

When using media3 exoplayer to implement an audio player, a large number of ANRs are encountered. The basic implementation is as follows.

class AudioService : MediaSessionService() {

	override fun onCreate() {
		super.onCreate()
		exoPlayer = ExoPlayer.Builder(this, RenderersFactory(this)).build()
		exoPlayer?.setAudioAttributes(uAmpAudioAttributes, true)
		exoPlayer?.setHandleAudioBecomingNoisy(true)
		exoPlayer?.addListener(playerListener)

		val sessionBuilder = MediaSession.Builder(this, exoPlayer!!)
		sessionBuilder.setCallback(ExtendMediaSessionCallback())
		sessionBuilder.setId(packageName)
		packageManager?.getLaunchIntentForPackage(packageName)?.let { sessionIntent ->
        sessionBuilder.setSessionActivity(
	          PendingIntent.getActivity(
	            this@AudioService,
	            0,
	            sessionIntent,
	            if (Build.VERSION.SDK_INT >= 23) FLAG_IMMUTABLE else FLAG_UPDATE_CURRENT
	          )
	        )
	      }
      	mediaSession = sessionBuilder.build()
	}
}

import kotlin.coroutines.CoroutineContext
import kotlinx.coroutines.*
import kotlinx.coroutines.guava.await

class AudioConnection(context: Context, serviceComponent: ComponentName) { // serviceComponent is AudioService

	private val coroutineContext: CoroutineContext = Dispatchers.Main
	private val scope = CoroutineScope(coroutineContext + SupervisorJob())

	val player: Player? get() = controller
	var controller: MediaController? = null

	init {
		scope.launch {
	      val newController = MediaController.Builder(context, SessionToken(context, serviceComponent))
	        .setListener(ControllerListener())
	        .buildAsync()
	        .await()
	      newController.addListener(playerListener)
	      controller = newController
	    }
	}
}

AudioConnection is a singleton. Initialize AudioConnection and use it to play audio after initialization is complete.
AudioConnection.getInstance(context, ComponentName(context, AudioService::class.java))

Two examples of stack trace are as follows. There are some other stack traces with slightly different contents.

[xuwang-yuewen]

[xuwang-yuewen]

one more stack trace:

[icbaker]

From the stack traces it looks like calls into the framework are taking too long and causing the ANR?

• In the first one: android.media.AudioAttributes.Builder.setLegacyStreamType
• In the second one: android.media.AudioManager.getAudioDevicesForAttributes

[Tolriq]

There's already a couple of other reported issues, audioManager use IPC binding to access and can ANR, there's a few other places where it's problematic.

[xuwang-yuewen]

@icbaker Yes. The service is started externally in a normal way, with nothing special and no other tasks. Online users report a large number of ANRs.

[xuwang-yuewen]

@Tolriq Thanks. Is there any way to solve this or reduce the number of ANR?

[Tolriq]

Do not instantiate ExoPlayer on mainthread until all those are fixed. I would recommend using a dedicated thread for the whole player access and callbacks, but just instantiate on background and pass the mainthread looper will remove a couple of ANRs due to IPC.

I use the dedicated thread approach + wrote a custom component to workaround #1550 that happens even in that case. No more ANRs due to Media3.

[tonihei]

We are currently working on changes that move all potentially blocking system calls away from the main thread, so that hopefully none of these workarounds should be needed in the future.

[xuwang-yuewen]

@Tolriq Thanks for reply. Some of it can be done in a non-main thread, which should alleviate ANR.

[xuwang-yuewen]

@tonihei Thanks. Looking forward to this solution.

[xuwang-yuewen]

@tonihei Hi, by the way, which version is expected to add these changes?