java.util.ConcurrentModificationException at java.util.ArrayList$Itr.next(ArrayList.java:860) at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2184) [236538905]

Fixed

Bug

Status Update

No update yet.

Description

be...@gmail.com

created issue #1

Jun 20, 2022 06:59PM

Component used: Fragment

Version used:
dependencies {
...
implementation 'androidx.appcompat:appcompat:1.4.2'
...

Devices/Android versions reproduced on: Samsung Galaxy Note 10 / Android 12

This is a problem in androidx library:

--------- beginning of crash
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: FATAL EXCEPTION: main
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: Process: sk.alteris.app.kalendarsk, PID: 6643
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: java.util.ConcurrentModificationException
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at java.util.ArrayList$Itr.next(ArrayList.java:860)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2184)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.fragment.app.FragmentManager.execSingleAction(FragmentManager.java:1971)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.fragment.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:311)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.fragment.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:274)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1244)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1092)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.viewpager.widget.ViewPager.onMeasure(ViewPager.java:1622)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7980)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1552)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.measureVertical(LinearLayout.java:842)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.onMeasure(LinearLayout.java:721)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.measureVertical(LinearLayout.java:995)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.onMeasure(LinearLayout.java:721)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7980)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.FrameLayout.onMeasure(FrameLayout.java:197)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:145)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7980)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at androidx.appcompat.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:496)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7980)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.FrameLayout.onMeasure(FrameLayout.java:197)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7980)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1552)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.measureVertical(LinearLayout.java:842)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.LinearLayout.onMeasure(LinearLayout.java:721)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7980)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.widget.FrameLayout.onMeasure(FrameLayout.java:197)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at com.android.internal.policy.DecorView.onMeasure(DecorView.java:1277)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.View.measure(View.java:27129)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:4528)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:3220)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:3525)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:2911)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:10458)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1108)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.Choreographer.doCallbacks(Choreographer.java:866)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.Choreographer.doFrame(Choreographer.java:797)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1092)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:938)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:99)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.os.Looper.loopOnce(Looper.java:226)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.os.Looper.loop(Looper.java:313)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:8663)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:567)
06-20 19:51:20.465 10283 6643 6643 E AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)
06-20 19:51:20.465 10227 7726 7726 I HWRResConfig: [setPreloadRootDirectoryPath] mPreloadRootDirPath is set with /product/HWRDB/
06-20 19:51:20.467 1000 966 1340 D SyncManager: userId - 0 auto - true
06-20 19:51:20.469 1000 966 1544 D Debug : low && ship && 3rdparty app crash, do not dump
06-20 19:51:20.469 1000 966 1544 W ActivityManager: crash : sk.alteris.app.kalendarsk,10283

Comments

il...@google.com <il...@google.com> #2Jun 21, 2022 03:36PM

Seems to be a DNS problem with systems that have 'obtain DNS server address automatically'. Changed my system to a manual setting and the browser etc now work. SDK 2.2 didn't seem to mind the auto setting though.

be...@gmail.com <be...@gmail.com> #3Jun 21, 2022 05:53PM

Could you please describe how/where you changed your system to a manual setting?

il...@google.com <il...@google.com> #4Jun 21, 2022 05:58PM

Based on its date, this issue was originally reported before Android 2.3. Because of the many changes that existed in Android 4.x compared to previous versions, it's very likely that this issue doesn't exist in recent versions of Android like 4.2.2 or newer. Because of the high likelihood that this issue is obsolete, it is getting closed automatically by a script, without a human looking at it in detail. If the issue still exists on a Nexus 4 or Nexus 7 running Android 4.2.2 and is not related to Google applications, please open a new report accordingly.

be...@gmail.com <be...@gmail.com> #5Jun 21, 2022 06:35PM

java.lang.IllegalArgumentException: Unable to locate adb
at com.android.tools.idea.run.editor.DeployTargetPickerDialog.<init>(DeployTargetPickerDialog.java:144)
at com.android.tools.idea.run.editor.ShowChooserTargetProvider.showPrompt(ShowChooserTargetProvider.java:113)
at com.android.tools.idea.run.AndroidRunConfigurationBase.getDeployTarget(AndroidRunConfigurationBase.java:600)
at com.android.tools.idea.run.AndroidRunConfigurationBase.doGetState(AndroidRunConfigurationBase.java:281)
at com.android.tools.idea.run.AndroidRunConfigurationBase.getState(AndroidRunConfigurationBase.java:241)
at com.intellij.execution.runners.ExecutionEnvironment.getState(ExecutionEnvironment.java:158)
at com.intellij.execution.runners.BaseProgramRunner.execute(BaseProgramRunner.java:55)
at com.intellij.execution.runners.BaseProgramRunner.execute(BaseProgramRunner.java:50)
at com.intellij.execution.ProgramRunnerUtil.executeConfigurationAsync(ProgramRunnerUtil.java:92)
at com.intellij.execution.ProgramRunnerUtil.executeConfiguration(ProgramRunnerUtil.java:41)
at com.intellij.execution.impl.ExecutionManagerImpl.restart(ExecutionManagerImpl.java:93)
at com.intellij.execution.impl.ExecutionManagerImpl.access$300(ExecutionManagerImpl.java:44)
at com.intellij.execution.impl.ExecutionManagerImpl$3.run(ExecutionManagerImpl.java:442)
at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:232)
at com.intellij.util.Alarm$Request.runSafely(Alarm.java:356)
at com.intellij.util.Alarm$Request.run(Alarm.java:343)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at com.intellij.util.concurrency.SchedulingWrapper$MyScheduledFutureTask.run(SchedulingWrapper.java:228)
at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:315)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.doRun(LaterInvocator.java:435)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.runNextEvent(LaterInvocator.java:419)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:403)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:762)
at java.awt.EventQueue.access$500(EventQueue.java:98)
at java.awt.EventQueue$3.run(EventQueue.java:715)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:732)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:755)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:704)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:391)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

be...@gmail.com <be...@gmail.com> #6Jul 5, 2022 03:56PM

voilà ce qu'on m'affiche lorsque j’exécute mon programme

App Widgets Demo1.zip

150 KB

Download

be...@gmail.com <be...@gmail.com> #7Jul 5, 2022 04:10PM

je ne vois pas comment résoudre ce problème. svp aidez moi

il...@google.com <il...@google.com> Jul 13, 2022 11:19PM

Assigned to jb...@google.com.

to...@gmail.com <to...@gmail.com> #8Aug 23, 2022 05:11PM

Jumping on this about #4 as I was about to open an issue about the lack of such annotation.

With android Fragment 1.5.2 (and from source 1.6.0 too) there's no Mainthread annotation on anything in that class.

And there's plenty of "Internet" comments about the fact that transaction are asynchronous and work from non main thread.

Would be nice if the annotation was indeed added (Just got caught in a stupid race with findFragmentByTag from a collect that was not done on main thread)

be...@gmail.com <be...@gmail.com> #9Aug 23, 2022 07:08PM

1. Yes I can confirm that some of my issues was caused by operation on the FragmentManager on NON MainThread. And I agree with #8.
2. I found a workaround for #6 (I had to manipulate back stack in manifest and in the code). Now I really suspect the automatic SplashScreen.

jb...@google.com <jb...@google.com> #10Sep 22, 2022 05:21PM

All of our commit*() functions should indeed be marked with @MainThread to ensure they are only executed on the main thread.

ap...@google.com <ap...@google.com> #11Mar 21, 2023 09:50PM

Project: platform/frameworks/support
Branch: androidx-main

commit 95e15d8df12b8ce7cc32abdfd2e80dc667e893d6
Author: Jeremy Woods <jbwoods@google.com>
Date: Tue Mar 21 18:37:17 2023

Add @MainThread annotations to instant commit APIs

Adding @MainThread annotations to the commitNow,
executePendingTransactions, and popBackStackImmediate APIs to ensure we
get build time checks along with the runtime check already in place.

RelNote: "The fragment `commitNow()`, `executePendingTransactions()`,
and `popBackStackImmediate()` APIs will now all throw build errors when
they are not called from the main thread."
Test: all tests pass
Bug: 236538905

Change-Id: Ic966543935dd77a4c149cfc4b796bd912c558fb2

M fragment/fragment-ktx/api/current.txt
M fragment/fragment-ktx/api/public_plus_experimental_current.txt
M fragment/fragment-ktx/api/restricted_current.txt
M fragment/fragment-ktx/src/main/java/androidx/fragment/app/FragmentManager.kt
M fragment/fragment/api/current.txt
M fragment/fragment/api/public_plus_experimental_current.txt
M fragment/fragment/api/restricted_current.txt
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentTransaction.java

https://android-review.googlesource.com/2500415

jb...@google.com <jb...@google.com> #12Mar 21, 2023 10:04PM

Marked as fixed.

This has been fixed internally and will be available in the the Fragment 1.6.0-alpha09 release.

na...@google.com <na...@google.com> #13Apr 5, 2023 06:27PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.fragment:fragment:1.6.0-alpha09
androidx.fragment:fragment-ktx:1.6.0-alpha09

ma...@gmail.com <ma...@gmail.com> #14Aug 25, 2023 09:56PM

I'm using fragment-ktx version 1.6.1, and after an upgrade to androidx.navigation 2.7.1 (from 2.3.x) we started experiencing very similar issue:

E  java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.next(ArrayList.java:860)
    at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1915)
    at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1845)
    at androidx.fragment.app.FragmentManager.popBackStackImmediate(FragmentManager.java:891)
    at androidx.fragment.app.FragmentManager.popBackStackImmediate(FragmentManager.java:797)
    at androidx.fragment.app.FragmentManager.handleOnBackPressed(FragmentManager.java:717)
    at androidx.fragment.app.FragmentManager$1.handleOnBackPressed(FragmentManager.java:447)
    at androidx.activity.OnBackPressedDispatcher.onBackPressed(OnBackPressedDispatcher.kt:213)
    at androidx.activity.OnBackPressedDispatcher$2.invoke(OnBackPressedDispatcher.kt:102)
    at androidx.activity.OnBackPressedDispatcher$2.invoke(OnBackPressedDispatcher.kt:102)
    at androidx.activity.OnBackPressedDispatcher$Api33Impl.createOnBackInvokedCallback$lambda$0(OnBackPressedDispatcher.kt:286)
    at androidx.activity.OnBackPressedDispatcher$Api33Impl.$r8$lambda$tzBBo0FLedRCWSI6_icF8qhF74s(Unknown Source:0)
    at androidx.activity.OnBackPressedDispatcher$Api33Impl$$ExternalSyntheticLambda0.onBackInvoked(Unknown Source:2)
    at android.view.ViewRootImpl$NativePreImeInputStage.onProcess(ViewRootImpl.java:7558)
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:7213)
    at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:10788)
    at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:10676)
    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:10632)
    at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:10926)
    at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:285)
    at android.os.MessageQueue.nativePollOnce(Native Method)
    at android.os.MessageQueue.next(MessageQueue.java:335)
    at android.os.Looper.loopOnce(Looper.java:186)
    at android.os.Looper.loop(Looper.java:313)
    at android.app.ActivityThread.main(ActivityThread.java:8757)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067)

I wasn't able to come up with a repro yet, since this only happens occasionally. It seems it only happens when navigating back from a backstack with multiple entries. The app opts in the predictive back feature, it uses single navigation component graph + I haven't found single FragmentManager interaction that would be called outside of the scope of the main thread.

It looks like adding @MainThread annotations wasn't enough, and people are still able to call FragmentManager methods the wrong way (I'm referring to code from latest stable navigation component library). Have you considered fixing the root cause of ConcurrentModificationException? Or maybe it would be possible to help developers identify offending code (the ones that suposedly calls FragmentManager methods on a wrong thread)? Looking at the stacktrace it looks like the issue is fully within the FragmentManager implementation 🤷‍♂️