I have tried to convert my Paging 2 implementation to Paging 3 with Flow in my app, but are plagued by a "Channel was closed" Exception. The app works fine, but crashes after some time (from a few seconds up to many minutes). It loads data from web, which may be slow. Uses Room as internal db. The crashes are far more often on emulator than on real device.
I am not to familiar with Flow, are there any known culprits in the Flow system which I should be aware of ?
Any other of you experiencing similar using Paging 3 from androidx ?
So if this is a known problem (maybe with an obvious fix), please give me a hint; or not, I may publish the Paging 3 codeparts (which will take some time).
My exception looks like this:
2020-06-29 09:23:59.929 28295-28295/no.rogo.emptyfuel E/AndroidRuntime: FATAL EXCEPTION: main
Process: no.rogo.emptyfuel, PID: 28295
kotlinx.coroutines.channels.ClosedSendChannelException: Channel was closed
at kotlinx.coroutines.channels.Closed.getSendException(AbstractChannel.kt:1035)
at kotlinx.coroutines.channels.AbstractSendChannel.helpCloseAndResumeWithSendException(AbstractChannel.kt:206)
at kotlinx.coroutines.channels.AbstractSendChannel.access$helpCloseAndResumeWithSendException(AbstractChannel.kt:19)
at kotlinx.coroutines.channels.AbstractSendChannel.sendSuspend(AbstractChannel.kt:196)
at kotlinx.coroutines.channels.AbstractSendChannel.send(AbstractChannel.kt:135)
at kotlinx.coroutines.channels.ChannelCoroutine.send$suspendImpl(Unknown Source:2)
at kotlinx.coroutines.channels.ChannelCoroutine.send(Unknown Source:0)
at androidx.paging.PageFetcherSnapshot$pageEventFlow$1$2$invokeSuspend$$inlined$collect$1.emit(Collect.kt:137)
at kotlinx.coroutines.flow.FlowKt__ChannelsKt.emitAllImpl$FlowKt__ChannelsKt(Channels.kt:58)
at kotlinx.coroutines.flow.FlowKt__ChannelsKt$emitAllImpl$1.invokeSuspend(Unknown Source:11)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:56)
at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:69)
at kotlinx.coroutines.DispatchedTaskKt.resumeUnconfined(DispatchedTask.kt:184)
at kotlinx.coroutines.DispatchedTaskKt.dispatch(DispatchedTask.kt:108)
at kotlinx.coroutines.CancellableContinuationImpl.dispatchResume(CancellableContinuationImpl.kt:308)
at kotlinx.coroutines.CancellableContinuationImpl.completeResume(CancellableContinuationImpl.kt:395)
at kotlinx.coroutines.channels.AbstractChannel$ReceiveElement.completeResumeReceive(AbstractChannel.kt:872)
at kotlinx.coroutines.channels.ConflatedChannel.offerInternal(ConflatedChannel.kt:61)
at kotlinx.coroutines.channels.ConflatedBroadcastChannel$Subscriber.offerInternal(ConflatedBroadcastChannel.kt:293)
at kotlinx.coroutines.channels.ConflatedBroadcastChannel.offerInternal(ConflatedBroadcastChannel.kt:255)
at kotlinx.coroutines.channels.ConflatedBroadcastChannel.offer(ConflatedBroadcastChannel.kt:236)
at androidx.paging.PageFetcherSnapshot.addHint(PageFetcherSnapshot.kt:189)
at androidx.paging.PageFetcher$PagerUiReceiver.addHint(PageFetcher.kt:118)
at androidx.paging.PagingDataDiffer$collectFrom$2$invokeSuspend$$inlined$collect$1$lambda$1.invokeSuspend(PagingDataDiffer.kt:93)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.UndispatchedCoroutine.afterResume(Builders.common.kt:214)
at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:113)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:46)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:56)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7523)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)
