Websocket nullpointerexceptions for subscribeTo

[dshokouhi]

Home Assistant Android version:

beta-2646-84aa4454

Android version:

12/13

Phone model:

Pixel 5

Home Assistant version:

unknown

Last working Home Assistant release (if known):

unknown

Description of problem:

3 very similar null pointer errors in Sentry for the latest beta in the play store

Traceback (if applicable, to get the logs you may refer to: https://companion.home-assistant.io/docs/troubleshooting/faqs/#android-crash-logs):

java.lang.NullPointerException: null
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeTo(WebSocketRepositoryImpl.kt:244)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeToEventsForType(WebSocketRepositoryImpl.kt:189)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.getStateChanges(WebSocketRepositoryImpl.kt:177)
    at io.homeassistant.companion.android.common.data.integration.impl.IntegrationRepositoryImpl.getEntityUpdates(IntegrationRepositoryImpl.kt:578)
    at io.homeassistant.companion.android.widgets.BaseWidgetProvider$onScreenOn$1.invokeSuspend(BaseWidgetProvider.kt:86)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:201)
    at android.os.Looper.loop(Looper.java:288)
    at android.app.ActivityThread.main(ActivityThread.java:7911)
    at java.lang.reflect.Method.invoke(Method.java)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1009)

java.lang.NullPointerException: null
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeTo(WebSocketRepositoryImpl.kt:244)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeToEventsForType(WebSocketRepositoryImpl.kt:189)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.getStateChanges(WebSocketRepositoryImpl.kt:177)
    at io.homeassistant.companion.android.common.data.integration.impl.IntegrationRepositoryImpl.getEntityUpdates(IntegrationRepositoryImpl.kt:578)
    at io.homeassistant.companion.android.controls.HaControlsProviderService$createPublisherFor$1$1$request$1$2.invokeSuspend(HaControlsProviderService.kt:160)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at kotlinx.coroutines.internal.LimitedDispatcher.run(LimitedDispatcher.kt:42)
    at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:95)
    at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:570)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:677)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:664)

java.lang.NullPointerException: null
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeTo(WebSocketRepositoryImpl.kt:244)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.getTemplateUpdates(WebSocketRepositoryImpl.kt:192)
    at io.homeassistant.companion.android.common.data.integration.impl.IntegrationRepositoryImpl.getTemplateUpdates(IntegrationRepositoryImpl.kt:180)
    at io.homeassistant.companion.android.widgets.template.TemplateWidget$onScreenOn$1.invokeSuspend(TemplateWidget.kt:143)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:226)
    at android.os.Looper.loop(Looper.java:313)
    at android.app.ActivityThread.main(ActivityThread.java:8663)
    at java.lang.reflect.Method.invoke(Method.java)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:567)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)

Screenshot of problem:

Additional information:

[jpelgrom]

It's failing on this line:

android/common/src/main/java/io/homeassistant/companion/android/common/data/websocket/impl/WebSocketRepositoryImpl.kt

Line 244 in 84aa445

return eventSubscriptionFlow[subscribeMessage]!! as Flow<T>

The check before it uses the subscription ID instead of the flow to determine if it needs to create a new flow, so it looks like the subscription ID is still set while the flow is already null. I think it's a race condition in the unsubscribe logic because it sends the unsubscribe message in a suspending function and only removes the subscription ID when finished, whereas the flow is removed immediately:

android/common/src/main/java/io/homeassistant/companion/android/common/data/websocket/impl/WebSocketRepositoryImpl.kt

Lines 226 to 239 in 84aa445

	if (eventSubscriptionId[subscribeMessage] != null) {
	Log.d(TAG, "Unsubscribing from $type with data $data")
	ioScope.launch {
	sendMessage(
	mapOf(
	"type" to "unsubscribe_events",
	"subscription" to eventSubscriptionId[subscribeMessage]!!
	)
	)
	eventSubscriptionId.remove(subscribeMessage)
	}
	}
	eventSubscriptionProducerScope.remove(subscribeMessage)
	eventSubscriptionFlow.remove(subscribeMessage)

I'll do some tests to verify this and (hopefully) submit a fix soon.

---

Edit: add a delay(5000L) before the sendMessage that unsubscribes, add an entity state widget, quickly turn the screen off and on, and the exception has been reproduced on the latest version:

Stacktrace

2022-09-05 21:06:08.939 13983-13983/io.homeassistant.companion.android.debug E/AndroidRuntime: FATAL EXCEPTION: main
    Process: io.homeassistant.companion.android.debug, PID: 13983
    java.lang.NullPointerException
        at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeTo(WebSocketRepositoryImpl.kt:257)
        at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeToTrigger(WebSocketRepositoryImpl.kt:203)
        at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.getStateChanges(WebSocketRepositoryImpl.kt:182)
        at io.homeassistant.companion.android.common.data.integration.impl.IntegrationRepositoryImpl.getEntityUpdates(IntegrationRepositoryImpl.kt:615)
        at io.homeassistant.companion.android.widgets.BaseWidgetProvider$onScreenOn$1.invokeSuspend(BaseWidgetProvider.kt:108)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
        at android.os.Handler.handleCallback(Handler.java:942)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loopOnce(Looper.java:201)
        at android.os.Looper.loop(Looper.java:288)
        at android.app.ActivityThread.main(ActivityThread.java:7898)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)
    	Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@d80ecfc, Dispatchers.Main]

[jpelgrom]

I believe this is the result of changes in #2801 so the latest stable release should be fine, but if you do spot it in other versions please mention it @dshokouhi !

[dshokouhi]

I believe this is the result of changes in #2801 so the latest stable release should be fine, but if you do spot it in other versions please mention it @dshokouhi !

So far only in Beta 2646, lets see what happens after the next beta push on Saturday.

Also I think you are right about the race, most (if not all) of the events are related to screen turning on. I suspect if its not widgets it may be the users who have persistent connection set to Screen On and never changed the setting.

[jpelgrom]

I suspect if its not widgets it may be the users who have persistent connection set to Screen On and never changed the setting.

The current stacktraces show widgets and device controls as the source. The persistent connection uses a different function to handle subscribing/unsubscribing (for now), so I would expect a slightly different stacktrace in that case, line 277 for beta-2646:

android/common/src/main/java/io/homeassistant/companion/android/common/data/websocket/impl/WebSocketRepositoryImpl.kt

Line 277 in 84aa445

return notificationFlow

[dshokouhi]

Found one more thats similar

java.lang.NullPointerException: null
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.subscribeTo(WebSocketRepositoryImpl.kt:244)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl.access$subscribeTo(WebSocketRepositoryImpl.kt:60)
    at io.homeassistant.companion.android.common.data.websocket.impl.WebSocketRepositoryImpl$subscribeTo$1.invokeSuspend
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at kotlinx.coroutines.internal.LimitedDispatcher.run(LimitedDispatcher.kt:42)
    at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:95)
    at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:570)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:677)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:664)