Exception when creating a ViewModel for a View in a Fragment - IllegalStateException: Internal error: OnRecreation should be registered only on componentsthat implement ViewModelStoreOwner [181577191]

Fixed

Bug

Status Update

No update yet.

Description

tf...@gmail.com

created issue #1

Mar 2, 2021 12:15PM

Component used: lifecycle-viewmodel-ktx

Version used: 2.3.0

Devices/Android versions reproduced on: Pixel 4 running Android 10

Sample project to trigger the issue: https://github.com/tfcporciuncula/view-tree-owner-bug

You can repro the issue by cloning that repo, running it, and then rotating the screen causing a config change.

This is the code I'm using to create a ViewModel in a View (as you can see here):

private val viewModel by lazy {
  val factory = object : AbstractSavedStateViewModelFactory(findViewTreeSavedStateRegistryOwner()!!, null) {
    override fun <T : ViewModel?> create(key: String, modelClass: Class<T>, handle: SavedStateHandle): T {
      return MyViewModel() as T
    }
  }
  ViewModelProvider(findViewTreeViewModelStoreOwner()!!, factory).get(MyViewModel::class.java)
}

Everything works fine, but the app crashes on orientation change with the following stacktrace:

Process: com.tfcporciuncula.viewtreeownerbug, PID: 3467
    java.lang.IllegalStateException: Internal error: OnRecreation should be registered only on componentsthat implement ViewModelStoreOwner
        at androidx.lifecycle.SavedStateHandleController$OnRecreation.onRecreated(SavedStateHandleController.java:80)
        at androidx.savedstate.Recreator.reflectiveNew(Recreator.java:92)
        at androidx.savedstate.Recreator.onStateChanged(Recreator.java:64)
        at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.java:354)
        at androidx.lifecycle.LifecycleRegistry.forwardPass(LifecycleRegistry.java:265)
        at androidx.lifecycle.LifecycleRegistry.sync(LifecycleRegistry.java:307)
        at androidx.lifecycle.LifecycleRegistry.moveToState(LifecycleRegistry.java:148)
        at androidx.lifecycle.LifecycleRegistry.handleLifecycleEvent(LifecycleRegistry.java:134)
        at androidx.fragment.app.FragmentViewLifecycleOwner.handleLifecycleEvent(FragmentViewLifecycleOwner.java:62)
        at androidx.fragment.app.Fragment.restoreViewState(Fragment.java:650)
        at androidx.fragment.app.Fragment.restoreViewState(Fragment.java:2997)
        at androidx.fragment.app.Fragment.performActivityCreated(Fragment.java:2988)
        at androidx.fragment.app.FragmentStateManager.activityCreated(FragmentStateManager.java:577)
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:285)
        at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:112)
        at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1636)
        at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3112)
        at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3056)
        at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:251)
        at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:473)
        at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:210)
        at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1425)
        at android.app.Activity.performStart(Activity.java:7825)
        at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3294)
        at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
        at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
        at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

The crash has a pretty clear cause which is this:

if (!(owner instanceof ViewModelStoreOwner)) {
    throw new IllegalStateException(
            "Internal error: OnRecreation should be registered only on components"
                    + "that implement ViewModelStoreOwner");
}

So it seems there's this implicit requirement of having the SavedStateRegistryOwner also be a ViewModelStoreOwner, and that's not the case for the view when it's in a fragment: its SavedStateRegistryOwner is a FragmentViewLifecycleOwner, which is only a SavedStateRegistryOwner and not a ViewModelStoreOwner.

It feels like findViewTreeSavedStateRegistryOwner() should return the fragment itself (like findViewTreeSavedStateRegistryOwner()) instead of the FragmentViewLifecycleOwner, so this would work. Or am I doing something wrong here?

If the view is in an activity everything works fine -- findViewTreeSavedStateRegistryOwner() returns the activity in this case, which is also a ViewModelStoreOwner so everything is good.

Comments

il...@google.com <il...@google.com> #2Mar 2, 2021 05:18PM

Reassigned to il...@google.com.

Yigit, do you have time to fix it?

reemission of the same liveData is racy

ap...@google.com <ap...@google.com> #3Mar 2, 2021 08:30PM

yea i'll take it.

il...@google.com <il...@google.com> #4Mar 2, 2021 08:38PM

Marked as fixed.

Thanks for the detailed analysis. This may not be an issue anymore since we've started using Main.immediate there but I' not sure; I'll try to create a test case.

tf...@gmail.com <tf...@gmail.com> #5Mar 24, 2021 09:54PM

just emitting same live data reproduces the issue.

@Test
fun raceTest() {
val subLiveData = MutableLiveData(1)
val subject = liveData(testScope.coroutineContext) {
emitSource(subLiveData)
emitSource(subLiveData) //crashes
}
subject.addObserver().apply {
testScope.advanceUntilIdle()
}
}

il...@google.com <il...@google.com> #6Mar 24, 2021 10:53PM

With 2.2.0-alpha04 (that use Main.immediate), the issue seems to be still there (I tested it by calling emitSource() twice, like your test case)

b9...@gmail.com <b9...@gmail.com> #7Apr 22, 2021 03:27PM

yea sorry immediate does not fix it.
I actually have a WIP fix for it:

https://android-review.googlesource.com/c/platform/frameworks/support/+/1112186

if your case is the one i found (emitting same LiveData multiple times, as shown in #5) you can work around it by adding a dummy transformation.

val subLiveData = MutableLiveData(1)
val subject = liveData(testScope.coroutineContext) {
emitSource(subLiveData.map {it })
emitSource(subLiveData.map {it} )
}

il...@google.com <il...@google.com> #8Apr 22, 2021 03:28PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit af12e75e6b4110f48e44ca121466943909de8f06
Author: Yigit Boyar <yboyar@google.com>
Date: Tue Sep 03 12:58:11 2019

Fix coroutine livedata race condition

This CL fixes a bug in liveData builder where emitting same
LiveData source twice would make it crash because the second
emission registry could possibly happen before first one is
removed as source.

We fix it by using a suspending dispose function. It does feel
a bit hacky but we cannot make DisposableHandle.dispose async
and we do not want to block there. This does not mean that there
is a problem if developer disposes it manually since our emit
functions take care of making sure it disposes (and there is
no other way to add source to the underlying MediatorLiveData)

Bug: 140249349
Test: BuildLiveDataTest#raceTest_*

Change-Id: I0b464c242a583da4669af195cf2504e2adc4de40

M lifecycle/lifecycle-livedata-ktx/api/2.2.0-alpha05.txt
M lifecycle/lifecycle-livedata-ktx/api/current.txt
M lifecycle/lifecycle-livedata-ktx/api/public_plus_experimental_2.2.0-alpha05.txt
M lifecycle/lifecycle-livedata-ktx/api/public_plus_experimental_current.txt
M lifecycle/lifecycle-livedata-ktx/api/restricted_2.2.0-alpha05.txt
M lifecycle/lifecycle-livedata-ktx/api/restricted_current.txt
M lifecycle/lifecycle-livedata-ktx/src/main/java/androidx/lifecycle/CoroutineLiveData.kt
M lifecycle/lifecycle-livedata-ktx/src/test/java/androidx/lifecycle/BuildLiveDataTest.kt

https://android-review.googlesource.com/1112186

https://goto.google.com/android-sha1/af12e75e6b4110f48e44ca121466943909de8f06

b9...@gmail.com <b9...@gmail.com> #9Apr 22, 2021 05:28PM

Re #8 I could point out the code directly. I don't know how to describe the issue.

    public ViewModelProvider(@NonNull ViewModelStoreOwner owner) {
        this(owner.getViewModelStore(), owner instanceof HasDefaultViewModelProviderFactory
                ? ((HasDefaultViewModelProviderFactory) owner).getDefaultViewModelProviderFactory()
                : NewInstanceFactory.getInstance());
    }

ViewModel compose extension use this constructor by default. Because FragmentViewLifecycleOwner didn't implement HasDefaultViewModelProviderFactory, so that NewInstanceFactory will be used to create ViewModel. Which means DI framework like Hilt will failed.

il...@google.com <il...@google.com> #10Apr 22, 2021 05:31PM

Re #9 - please file a new bug so we can track that work.

b9...@gmail.com <b9...@gmail.com> #11Apr 22, 2021 06:02PM

Re #10, here it is