java.lang.IllegalStateException: Future was expected to be done

[Kyant0]

Version

Media3 1.2.0

More version details

Using a thread looper rather than main thread in the custom player, it got crashed.
Then delay few milliseconds at the end of service onCreate, it rarely crashed. But this is not a solution.

Is it an intented behavior or I mis-used the threading? I don't want player run on main thread, because it blocks UI sometimes.

Devices that reproduce the issue

Pixel 4 XL (Android 13)

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Not tested

Reproduction steps

1. Using the code

class AudioPlaybackService : MediaLibraryService() {
    private var mediaSession: MediaLibrarySession? = null

    private val thread: HandlerThread = HandlerThread("AudioPlaybackService").apply { start() }

    override fun getMainLooper(): Looper {
        return thread.looper
    }

    override fun onCreate() {
        super.onCreate()
        val player = AudioPlayer(mainLooper) // A custom Player
        mediaSession = MediaLibrarySession.Builder(this, player, callback)
    }
}

2. Run the app and see crash

Expected result

It won't crash at starup

Actual result

java.lang.IllegalStateException: Future was expected to be done: androidx.media3.session.MediaControllerHolder@7887bc2[status=PENDING]
                                                                                                    	at com.google.common.base.Preconditions.checkState(Preconditions.java:590)
	at com.google.common.base.Preconditions.checkState(Preconditions.java:590)
	at com.google.common.util.concurrent.Futures.getDone(Futures.java:1147)
	at androidx.media3.session.MediaNotificationManager.getConnectedControllerForSession(MediaNotificationManager.java:269)
	at androidx.media3.session.MediaNotificationManager.shouldRunInForeground(MediaNotificationManager.java:192)
	at androidx.media3.session.MediaSessionService.onUpdateNotificationInternal(MediaSessionService.java:565)
	at androidx.media3.session.MediaSessionService$MediaSessionListener.onNotificationRefreshRequired(MediaSessionService.java:624)
	at androidx.media3.session.MediaSessionImpl.lambda$onNotificationRefreshRequired$12$androidx-media3-session-MediaSessionImpl(MediaSessionImpl.java:797)
	at androidx.media3.session.MediaSessionImpl$$ExternalSyntheticLambda10.run(D8$$SyntheticClass:0)
	at android.os.Handler.handleCallback(Handler.java:942)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.app.ActivityThread.main(ActivityThread.java:7924)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

Media

None

Bug Report

• You will email the zip file produced by adb bugreport to android-media-github@google.com after filing this issue.

[Kyant0]

class AudioPlayer(private val service: AudioPlaybackService) : SimpleBasePlayer(service.mainLooper) {

    private val state = object : PlayerState(this) {}

    override fun getState(): State {
        return State.Builder()
            .setAvailableCommands(state.availableCommands)
// Here will crash:
            .setPlayWhenReady(state.playWhenReady, state.playWhenReadyChangeReason)
            .setPlaybackState(state.playbackState)
// Here will crash:
            .setPlaylist(
                service.audioItemTree.getChildren(":songs", 0, Int.MAX_VALUE).map {
                    MediaItemData.Builder(it.mediaId)
                        .setMediaItem(it)
                        .setDurationUs(it.clippingConfiguration.endPositionMs * 1000)
                        .setIsSeekable(true)
                        .build()
                }
            )
            .setCurrentMediaItemIndex(0)
            .build()
    }

    init {
        state.availableCommands = Player.Commands.Builder().addAllCommands().build()
    }

    override fun handleSetPlayWhenReady(playWhenReady: Boolean): ListenableFuture<*> = launchImmediateFuture {
        state.playWhenReady = playWhenReady
        state.playWhenReadyChangeReason = Player.PLAY_WHEN_READY_CHANGE_REASON_USER_REQUEST
        state.playbackState = Player.STATE_READY
    }

    override fun handlePrepare(): ListenableFuture<*> = launchImmediateFuture {
        state.playbackState = Player.STATE_BUFFERING
    }

    override fun handleStop(): ListenableFuture<*> = launchImmediateFuture {
        state.playWhenReady = false
        state.playbackState = Player.STATE_IDLE
    }

    override fun handleRelease(): ListenableFuture<*> = launchImmediateFuture {
        state.release()
    }
}

abstract class PlayerState(private val player: Player) {

    var availableCommands = Player.Commands.EMPTY
    var playWhenReady = false
    var playWhenReadyChangeReason: @Player.PlayWhenReadyChangeReason Int =
        Player.PLAY_WHEN_READY_CHANGE_REASON_USER_REQUEST
    var playbackState: @Player.State Int = Player.STATE_IDLE

    private val listener = object : Player.Listener {

        override fun onAvailableCommandsChanged(availableCommands: Player.Commands) {
            this@PlayerState.availableCommands = availableCommands
        }

        override fun onPlayWhenReadyChanged(playWhenReady: Boolean, reason: Int) {
            this@PlayerState.playWhenReady = playWhenReady
            this@PlayerState.playWhenReadyChangeReason = reason
        }

        override fun onPlaybackStateChanged(playbackState: Int) {
            this@PlayerState.playbackState = playbackState
        }
    }

    init {
        player.addListener(listener)
    }

    fun release() {
        player.removeListener(listener)
    }
}

[marcbaechinger]

Thanks for reporting! From what I see I think you are using threads and the API in a valid way.

My hypothesis is that the player has a state that triggers a code path early that is currently not anticipated by the library. I think Media3 should be able to handle an arbitrary valid player state when the session is built with a Player. So this looks to me like a library bug.

I'm trying to repro with your setup.

The exception seems to be triggered when a bitmap has completed loading and is racing with the media notification controller being connected to the session. It's a bit puzzling that this bitmap completes loading before the media notification controller has connected in which case the Future would be done already. However, we need to anticipate this case and handle this.

Am I right in assuming that you are using an https-URI for the artworkUri of the media item when the first state of the SimpleBasePlayer is built?

[Kyant0]

No, I am using content scheme for artwork uri