Hi everyone, Whether this code is recommended or ...

# coroutines

[Irsath Kareem]

Hi everyone,

Whether this code is recommended or anti-pattern

someGameRelatedFlow 
    .onCompletion { cause ->
            println("onCompletion Called")
            if(cause is CancellationException) {
                try {
                    gameDao.invalidateJoinedRooms() // Suspending Call
                } catch (e: CancellationException) {
                    CoroutineScope(Dispatchers.IO).async { //New CoroutineScope,because currentContext is already cancelled
                        launch {
                            delay(5000)
                            [e-mail]()
                        }
                        gameDao.invalidateJoinedRooms() // Suspending Call
                        cancel()
                    }.await()
                    coroutineContext.ensureActive()
                }
            }
        }
    .stateIn(
        scope, SharingStarted.WhileSubscribed(5000), null
    )

My Assumption would be as follows,

When scope is cancelled, onCompletion's New CoroutineScope(IO) would do either of the following.....
1. At most 5000ms only it runs (OR)
2. if gameDao.invalidateJoinedRooms() finishes, onCompletion also finishes.
This pattern recommended?

[Zach Klippenstein (he/him) [MOD]]

withContext(NonCancellable) would probably express your intent better in the catch, and might be a bit more efficient too. And then I would probably use withTimeout instead of implementing it manually.

[Irsath Kareem]

Thank you for your answer.

But, need one small clarification about withContext

By the time withContext(NonCancellable) is called, the current coroutineContext is already cancelled right, So withContext is throwing CancellationException right? (Before switching to NonCancellable context)

Or it will switch to NonCancellable context without regard of Cancelled CoroutineContext?

[Zach Klippenstein (he/him) [MOD]]

no, it won't throw