Fixed
Status Update
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Comments
il...@google.com
[Deleted User] <[Deleted User]>
Yigit, do you have time to fix it?
reemission of the same liveData is racy
reemission of the same liveData is racy
[Deleted User] <[Deleted User]>
yea i'll take it.
ap...@google.com
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.
[Deleted User] <[Deleted User]>
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()
}
}
@Test
fun raceTest() {
val subLiveData = MutableLiveData(1)
val subject = liveData(testScope.coroutineContext) {
emitSource(subLiveData)
emitSource(subLiveData) //crashes
}
subject.addObserver().apply {
testScope.advanceUntilIdle()
}
}
se...@google.com
da...@gmail.com
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)
ni...@gmail.com
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} )
}
I actually have a WIP fix for it:
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} )
}
Description
STEPS TO REPRODUCE
1. Set up a Kotlin Activity that
a. Uses a ViewModel with the SavedState library
b. Declares the ViewModel with by viewModels()
c. Doesn't touch the ViewModel
2. Start another Activity using startActivityForResult()
3. In the onActivityResult() method, touch the viewModel
RESULTS
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=0, result=-1, data=Intent { } to activity {com.twofortyfouram.locale.x.debug/com.twofortyfouram.ui.screen.setting_wallpaper.activity.alias.WallpaperSettingActivity}: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.app.ActivityThread.deliverResults(ActivityThread.java:4398)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:4440)
at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:49)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1816)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6718)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at androidx.savedstate.SavedStateRegistry.runOnNextRecreation(SavedStateRegistry.java:168)
at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:71)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:177)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:145)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelProvider.kt:54)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelProvider.kt:41)
at com.twofortyfouram.ui.screen.setting_wallpaper.activity.WallpaperSettingActivity.getVm(Unknown Source:11)
at com.twofortyfouram.ui.screen.setting_wallpaper.activity.WallpaperSettingActivity.onActivityResult(WallpaperSettingActivity.kt:74)
at android.app.Activity.dispatchActivityResult(Activity.java:7462)
at android.app.ActivityThread.deliverResults(ActivityThread.java:4391)
... 11 more
WORKAROUND
Touch the ViewModel before starting the other Activity, e.g. vm.getApplicationContext() is sufficient