ConcurrentModificationException in SlidingPercentile

[ojoNetgem]

Version

Media3 1.1.1

More version details

No response

Devices that reproduce the issue

AndroidTV box

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Not tested

Reproduction steps

Looking for the different methods to compute bandwidth, I'm using in this case the ExperimentalBandwidthMeter without any changes in Builder.

val bandwidthMeter = ExperimentalBandwidthMeter.Builder(context)
    .build()
val player = Exoplayer.Builder(context)
    .setBandwidthMeter(bandwidthMeter)
    .build()

Expected result

No crash

Actual result

Sometimes the app crashes with this call stack:

androidx.media3.exoplayer.ExoPlaybackException: Unexpected runtime error
	at androidx.media3.exoplayer.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:668)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.os.HandlerThread.run(HandlerThread.java:67)
Caused by: java.util.ConcurrentModificationException
	at java.util.ArrayList.sort(ArrayList.java:1472)
	at java.util.Collections.sort(Collections.java:206)
	at androidx.media3.exoplayer.upstream.SlidingPercentile.ensureSortedByValue(SlidingPercentile.java:147)
	at androidx.media3.exoplayer.upstream.SlidingPercentile.getPercentile(SlidingPercentile.java:122)
	at androidx.media3.exoplayer.upstream.experimental.PercentileTimeToFirstByteEstimator.getTimeToFirstByteEstimateUs(PercentileTimeToFirstByteEstimator.java:92)
	at androidx.media3.exoplayer.upstream.experimental.ExperimentalBandwidthMeter.getTimeToFirstByteEstimateUs(ExperimentalBandwidthMeter.java:322)
	at androidx.media3.exoplayer.trackselection.AdaptiveTrackSelection.getTotalAllocatableBandwidth(AdaptiveTrackSelection.java:693)
	at androidx.media3.exoplayer.trackselection.AdaptiveTrackSelection.getAllocatedBandwidth(AdaptiveTrackSelection.java:671)
	at androidx.media3.exoplayer.trackselection.AdaptiveTrackSelection.determineIdealSelectedIndex(AdaptiveTrackSelection.java:600)
	at androidx.media3.exoplayer.trackselection.AdaptiveTrackSelection.evaluateQueueSize(AdaptiveTrackSelection.java:524)
	at androidx.media3.exoplayer.source.MergingMediaPeriod$ForwardingTrackSelection.evaluateQueueSize(MergingMediaPeriod.java:589)
	at androidx.media3.exoplayer.dash.DefaultDashChunkSource.getPreferredQueueSize(DefaultDashChunkSource.java:304)
	at androidx.media3.exoplayer.source.chunk.ChunkSampleStream.reevaluateBuffer(ChunkSampleStream.java:666)
	at androidx.media3.exoplayer.source.CompositeSequenceableLoader.reevaluateBuffer(CompositeSequenceableLoader.java:60)
	at androidx.media3.exoplayer.dash.DashMediaPeriod.reevaluateBuffer(DashMediaPeriod.java:315)
	at androidx.media3.exoplayer.source.CompositeSequenceableLoader.reevaluateBuffer(CompositeSequenceableLoader.java:60)
	at androidx.media3.exoplayer.source.MergingMediaPeriod.reevaluateBuffer(MergingMediaPeriod.java:192)
	at androidx.media3.exoplayer.source.MaskingMediaPeriod.reevaluateBuffer(MaskingMediaPeriod.java:223)
	at androidx.media3.exoplayer.MediaPeriodHolder.reevaluateBuffer(MediaPeriodHolder.java:211)
	at androidx.media3.exoplayer.MediaPeriodQueue.reevaluateBuffer(MediaPeriodQueue.java:140)
	at androidx.media3.exoplayer.ExoPlayerImplInternal.handleContinueLoadingRequested(ExoPlayerImplInternal.java:2354)
	at androidx.media3.exoplayer.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:544)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.os.HandlerThread.run(HandlerThread.java:67)

Media

Any dash stream should retroduce the issue

Bug Report

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

[tonihei]

Thanks for reporting! It looks like we are missing a synchronization block in this code - we'll update the class to fix this.

[ojoNetgem]

Good news, thanks