I m a bit confused by the new scoping mechanism I m trying t

Question

I m a bit confused by the new scoping mechanism I m trying to migrate some coroutine based code and stumbled upon this ``` Deprecated No replacement Group child in a coroutineScope block to wait for them public suspend fun Job joinChildren ``` However I don t see how to group child in a coroutineScope For example ``` val networkContext = <http Dispatchers IO|Dispatchers IO> val networkJob = Job private fun onNetworkContext block suspend CoroutineScope gt Unit = GlobalScope launch networkContext + networkJob block = block invoked from another coroutine suspend fun abortAndRetry networkJob cancelChildren how do I replace this properly networkJob joinChildren retry ```

Jonathan · Answer

Depends a but on what you re doing but the concept is roughly ``` var networkScope = CoroutineScope Job + private fun onNetworkContext block suspend CoroutineScope gt Unit = networkScope launch block = block invoked from another coroutine suspend fun abortAndRetry networkScope coroutineContext Job cancelAndJoin retry networkScope = CoroutineScope Job + ```

Jonathan · Answer

The key point is to not use `GlobalScope` if you want to manage the life cycle of child jobs

elizarov · Answer

An interesting use case Can you give more details on why exactly you need to separate `onNetworkContext` and `abortAndRetry` I would be grateful if you create an issue in `<http github com kotlin kotlinx coroutines issues>` so that we can have a discussion here

elizarov · Answer

~Maybe we were too fast to deprecate `joinChildren` but let s see if the use case is strong enough ~

elizarov · Answer

Anyway it is extremely easy to write ``` networkJob children forEach it join ```

elizarov · Answer

But beware the reason that it is deprecated is because you have a race in your code Nothing prevents a new child to be added between `cancelChildren` and `joinChildren` So I strongly suggest to rewrite this code via `networkJob cancelAndJoin` and then create a new non cancelled parent job for all further children

uhe · Answer

I guess my scenario is a bit weird

elizarov · Answer

The code that uses `joinChildren` in inherently racy

uhe · Answer

I m basically bridging events to coroutines e g I receive events handle them on a singlethreaded event coroutine context and launch other network related coroutines from within the event context

uhe · Answer

I ll think about this some more and maybe create an issue like you suggested tomorrow