Fatal Exception: java.util.ConcurrentModificationException

[muriloventuroso]

While running the Android app, the following error was reported in the crash log.

Exception java.util.ConcurrentModificationException:
  at java.util.ArrayList$Itr.next (ArrayList.java:860)
  at com.google.firebase.firestore.core.Query.matchesOrderBy (Query.java:401)
  at com.google.firebase.firestore.core.Query.matches (Query.java:425)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$getDocumentsMatchingQuery$3 (SQLiteRemoteDocumentCache.java:257)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$processRowInBackground$2 (SQLiteRemoteDocumentCache.java:242)
  at com.google.firebase.firestore.util.BackgroundQueue.lambda$execute$0 (BackgroundQueue.java:39)
  at com.google.firebase.firestore.util.ThrottledForwardingExecutor.lambda$execute$0 (ThrottledForwardingExecutor.java:54)
  at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1167)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:641)
  at java.lang.Thread.run (Thread.java:919)

Steps to reproduce

I still haven't been able to reproduce the error on my Android devices or the emulator. But I get this error report everyday from my app users.

Additional context

Occurs on Android 10 (SDK 29)
Firebase Android SDK 32.0.0

[google-oss-bot]

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[muriloventuroso]

Another trace:

Exception java.lang.RuntimeException:
  at com.google.firebase.firestore.util.AsyncQueue.lambda$panic$3 (AsyncQueue.java:545)
  at android.os.Handler.handleCallback (Handler.java:883)
  at android.os.Handler.dispatchMessage (Handler.java:100)
  at android.os.Looper.loop (Looper.java:214)
  at android.app.ActivityThread.main (ActivityThread.java:7386)
  at java.lang.reflect.Method.invoke
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:492)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:980)
Caused by java.lang.RuntimeException: java.util.ConcurrentModificationException
  at com.google.firebase.firestore.util.AsyncQueue$SynchronizedShutdownAwareExecutor.lambda$executeAndReportResult$1 (AsyncQueue.java:333)
  at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:462)
  at java.util.concurrent.FutureTask.run (FutureTask.java:266)
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run (ScheduledThreadPoolExecutor.java:301)
  at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1167)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:641)
  at com.google.firebase.firestore.util.AsyncQueue$SynchronizedShutdownAwareExecutor$DelayedStartFactory.run (AsyncQueue.java:235)
  at java.lang.Thread.run (Thread.java:919)
Caused by java.util.ConcurrentModificationException:
  at java.util.ArrayList$Itr.next (ArrayList.java:860)
  at com.google.firebase.firestore.core.Query.matchesOrderBy (Query.java:401)
  at com.google.firebase.firestore.core.Query.matches (Query.java:425)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$getDocumentsMatchingQuery$3 (SQLiteRemoteDocumentCache.java:257)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$processRowInBackground$2 (SQLiteRemoteDocumentCache.java:242)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.processRowInBackground (SQLiteRemoteDocumentCache.java:238)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$getAll$1 (SQLiteRemoteDocumentCache.java:221)
  at com.google.firebase.firestore.local.SQLitePersistence$Query.forEach (SQLitePersistence.java:495)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.getAll (SQLiteRemoteDocumentCache.java:221)
  at com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.getDocumentsMatchingQuery (SQLiteRemoteDocumentCache.java:253)
  at com.google.firebase.firestore.local.LocalDocumentsView.getDocumentsMatchingCollectionQuery (LocalDocumentsView.java:369)
  at com.google.firebase.firestore.local.LocalDocumentsView.getDocumentsMatchingCollectionGroupQuery (LocalDocumentsView.java:300)
  at com.google.firebase.firestore.local.LocalDocumentsView.getDocumentsMatchingQuery (LocalDocumentsView.java:268)
  at com.google.firebase.firestore.local.QueryEngine.executeFullCollectionScan (QueryEngine.java:248)
  at com.google.firebase.firestore.local.QueryEngine.getDocumentsMatchingQuery (QueryEngine.java:90)
  at com.google.firebase.firestore.local.LocalStore.executeQuery (LocalStore.java:858)
  at com.google.firebase.firestore.core.FirestoreClient.lambda$getDocumentsFromLocalCache$11 (FirestoreClient.java:222)
  at com.google.firebase.firestore.util.AsyncQueue$SynchronizedShutdownAwareExecutor.lambda$executeAndReportResult$1 (AsyncQueue.java:330)

[MarkDuckworth]

@muriloventuroso, thanks for reporting this, I've been looking into this issue but don't have a solution yet. If you find a repro, please let me know.

This may be the same issue as firebase/flutterfire#10745

[muriloventuroso]

Yes, I think it's the same problem. And this issue had no updates.

Any new information I have will be shared here.

[Asuveroz]

Some of my app users are experiencing the same problem.

Firebase BoM: 32.0.0
Affected versions: Android 10, 11, 12

Stack trace gathered from the Firebase Crashlytics:

java.util.ConcurrentModificationException: 
    java.util.ArrayList$Itr.next(ArrayList.java:860)
    com.google.firebase.firestore.core.Query.matchesOrderBy(Query.java:401)
    com.google.firebase.firestore.core.Query.matches(Query.java:425)
    com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$getDocumentsMatchingQuery$3(SQLiteRemoteDocumentCache.java:257)
    com.google.firebase.firestore.local.SQLiteRemoteDocumentCache.lambda$processRowInBackground$2(SQLiteRemoteDocumentCache.java:242)
    com.google.firebase.firestore.util.BackgroundQueue.lambda$execute$0(BackgroundQueue.java:39)
    com.google.firebase.firestore.util.ThrottledForwardingExecutor.lambda$execute$0(ThrottledForwardingExecutor.java:54)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    java.lang.Thread.run(Thread.java:920)

[MarkDuckworth]

I haven't been able to reproduce this error, but in reviewing the code in this call stack we identified a possible case of thread interference, which could be the root cause of the ConcurrentModificationException. The fix is in #5099.

[MarkDuckworth]

The fix will release in v24.6.2, which should be out soon. Please let me know if you continue to have issues after updating to v24.6.2.