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il...@google.com
da...@google.com
Yigit, do you have time to fix it?
reemission of the same liveData is racy
reemission of the same liveData is racy
il...@google.com
da...@google.com
yea i'll take it.
da...@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.
jb...@google.com
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()
}
}
jb...@google.com
da...@google.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)
da...@google.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} )
}
jb...@google.com
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
ap...@google.com
Project: platform/frameworks/support
Branch: androidx-main
commit ae6aff9326ce2b4f25731635230f600be18a3ba6
Author: Jeremy Woods <jbwoods@google.com>
Date: Thu Mar 04 15:28:27 2021
Ensure Fragments do not clear view transitionNames
When transitioning views are nested within ViewGroups that have
transitionNames but are not transitioning groups, the views are captured
as sharedElement views multiple times within the DefaultSpecialEffects
controller. As a result of this, as we collect and clear the transition
names, we capture a null name and end up restoring the null name to the
view once the shared element transition has finished.
We should only capture each shared element view once and therefore we
only restore it once, with the proper transition name.
RelNote: "Views within in a shared element hierarchy will no longer have
their transition name cleared when doing a shared element transition."
Test: testNestedSharedElementView
Bug: 179934757
Change-Id: I4d4a6d7770d5c6d54e4c647559d5cabae71f0051
A fragment/fragment/src/androidTest/java/androidx/fragment/app/FragmentSharedElementTransitionTest.kt
A fragment/fragment/src/androidTest/res/layout/nested_transition_groups.xml
M fragment/fragment/src/main/java/androidx/fragment/app/DefaultSpecialEffectsController.java
https://android-review.googlesource.com/1620026
Branch: androidx-main
commit ae6aff9326ce2b4f25731635230f600be18a3ba6
Author: Jeremy Woods <jbwoods@google.com>
Date: Thu Mar 04 15:28:27 2021
Ensure Fragments do not clear view transitionNames
When transitioning views are nested within ViewGroups that have
transitionNames but are not transitioning groups, the views are captured
as sharedElement views multiple times within the DefaultSpecialEffects
controller. As a result of this, as we collect and clear the transition
names, we capture a null name and end up restoring the null name to the
view once the shared element transition has finished.
We should only capture each shared element view once and therefore we
only restore it once, with the proper transition name.
RelNote: "Views within in a shared element hierarchy will no longer have
their transition name cleared when doing a shared element transition."
Test: testNestedSharedElementView
Bug: 179934757
Change-Id: I4d4a6d7770d5c6d54e4c647559d5cabae71f0051
A fragment/fragment/src/androidTest/java/androidx/fragment/app/FragmentSharedElementTransitionTest.kt
A fragment/fragment/src/androidTest/res/layout/nested_transition_groups.xml
M fragment/fragment/src/main/java/androidx/fragment/app/DefaultSpecialEffectsController.java
jb...@google.com
This has been fixed internally and will be available in the next version of Fragments.
da...@google.com
Thanks Jeremy!
Description
Component used:
When using the above components together, there are two problems:
GuidedSupportFragment.add.When using Fragment 1.2.5, there is no problem.
Sample project attached.