ConcurrentModificationException on trying to reverse a mutableStateListOf [219554654]

Fixed

Bug

Status Update

No update yet.

Description

ph...@gmail.com

created issue #1

Feb 15, 2022 06:38AM

Jetpack Compose release version: 1.1.0 & 1.2.0-alpha03

Here's a sample code to reproduce the issue:

val list = remember { List(100) { it }.toMutableStateList() }
LaunchedEffect(Unit) {
    delay(1.seconds)
    list.reverse()
}
Text(list.toList().toString())

A crash occurs with the next stack trace:

java.util.ConcurrentModificationException
    at androidx.compose.runtime.snapshots.StateListIterator.validateModification(SnapshotStateList.kt:278)
    at androidx.compose.runtime.snapshots.StateListIterator.set(SnapshotStateList.kt:271)
    at java.util.Collections.reverse(Collections.java:435)
    at kotlin.collections.CollectionsKt___CollectionsJvmKt.reverse(_CollectionsJvm.kt:43)
    at com.example.composeplayground.MainActivityKt$TestScreen$1$1.invokeSuspend(MainActivity.kt:748)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch(AndroidUiDispatcher.android.kt:81)
    at androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch(AndroidUiDispatcher.android.kt:41)
    at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.run(AndroidUiDispatcher.android.kt:57)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:201)
    at android.os.Looper.loop(Looper.java:288)
    at android.app.ActivityThread.main(ActivityThread.java:7842)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)

Comments

ry...@google.com <ry...@google.com> Feb 22, 2022 10:14AM

Assigned to je...@google.com.

ch...@google.com <ch...@google.com> Sep 9, 2022 10:24PM

Reassigned to ch...@google.com.

ah...@gmail.com <ah...@gmail.com> #2Sep 13, 2023 01:50PM

Is this really a P1? This seems less priority than the perf work that I am doing but if it is a P1 I will block that and work on this.

ch...@google.com <ch...@google.com> #3Sep 14, 2023 11:02PM

I'm happy to move it to a p2, but it seems like a pretty big correctness issue that we should take a look at in the near future. I'm also happy to help look at this myself if you can give me some pointers on what the issue may be

ap...@google.com <ap...@google.com> #4Sep 15, 2023 07:49PM

Marked as fixed.

This is not simple as and will change once Jim lands the threading of the composer.

ke...@gmail.com <ke...@gmail.com> #5Oct 17, 2023 06:08PM

Sure thing, thanks for the context!

For anyone running into this issue, in the meantime the simple workaround is just consuming the ambient inside the body of the function, you don't explicitly need to use the returned value anywhere.

Issue 219554654