Fixed
Status Update
Comments
st...@gmail.com <st...@gmail.com> #2
Yigit, do you have time to fix it?
reemission of the same liveData is racy
reemission of the same liveData is racy
ow...@google.com <ow...@google.com> #3
yea i'll take it.
il...@google.com <il...@google.com>
ap...@google.com <ap...@google.com> #4
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.
jb...@google.com <jb...@google.com> #5
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()
}
}
l....@gmail.com <l....@gmail.com> #6
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)
na...@google.com <na...@google.com> #7
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} )
}
am...@gmail.com <am...@gmail.com> #8
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
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
am...@gmail.com <am...@gmail.com> #9
even after using app:launchSingleTop="false" new instance of fragment is not created
Description
Artifact used (ex. androidx.appcompat:appcompat:1.0.0-alpha1): androidx.navigation:navigation-ui-ktx, androidx.navigation:navigation-fragment-ktx
Version used: 2.4.2 Theme used: Devices/Android versions reproduced on: Pixel XL emulator / API 30
Relevant code to trigger the issue.https://github.com/rahobbs/NavExperiments
I'm updating Jetpack Navigation from 2.3.4 to 2.4.2 and believe I have found a breaking change in my project.
Let's say I have a MainFragment and a SecondFragment. Launching SecondFragment from MainFragment (with safeArgs) works as expected. However, I also need to be able to launch a new instance of SecondFragment from SecondFragment with new arguments. I'm constructing a new navigation action and telling the navController to navigate to it. Before updating, I could see that this navigation action was taken, and I hit onCreateView and other lifecycle methods in my SecondFragment class.
Now with the update, my log statement there is being logged and is correct, but it seems like the navigation action never happens, as I'm never hitting onCreateView or onViewCreated, and my SecondFragment does not update with the new arguments.
I have a small reproducible example here:https://github.com/rahobbs/NavExperiments/tree/main/app/src/main/java/com/example/navexperiments