what s the recommended way of doing something like this ```

Question

what s the recommended way of doing something like this ``` fun refreshData networkStatus = Status ACTIVE class member launch CommonPool asyncAwait remoteSource fetchData forEach roomDatabase dao insertData it networkStatus = Status INACTIVE ``` i d like to be able to unit test that the status is updated while the coroutine is running

Jonathan Walsh · Answer

I m not a coroutine expert but maybe checkout <https kotlin github io kotlinx coroutines kotlinx coroutines core kotlinx coroutines experimental channels conflated broadcast channel >

Jonathan Walsh · Answer

having a channel will make it much easier to be notified when the status changes

Jonathan Walsh · Answer

and conflated channels only have the most recent value

Dico · Answer

are you looking for this ``` runBlocking remoteSource fetchData forEach roomDatabase dao insertData it networkStatus = Status INACTIVE ```

Dico · Answer

it doesn t make very much sense to do this when you re already in a coroutine suspend function though You can just inline the code

Dico · Answer

Alternatively ``` launch code here join ```

gildor · Answer

What is `asyncAwait` Shortcut for async await If so it doesn t make any sense there are not cases when you call async and await immidiately Probably you can just call the function or use withContext instead

gildor · Answer

also `CommonPool` in probably redundant

gildor · Answer

In general such function is actually bad style in most cases instead function should be suspend without `launch CommonPool ` and `asyncAwait` so it allows you to wait suspend until function finish and check side effect after It s exactly the same bad style as launch thread in a function you just cannot test it and have other problems with lifecycle of such function concurrent updates and so on

gildor · Answer

One more issue with your code that your Room method calls are blocking so you block threads from CommonPool and it s not good and can cause deadlocks and general performance problems with coroutine dispatching I recommend to wrap such calls to new IO coroutine dispatcher like `withContext IO ` or use async API of Room there are adapters for RxJava and LiveData

gildor · Answer

<https kotlinlang slack com archives C1CFAFJSK p1536267046000100 thread ts=1536257585 000100 amp cid=C1CFAFJSK> What is use case for such idiom If you already inside coroutine can use join you don t need launch use withContext instead

Dico · Answer

Yeah you are right I was a bit confused by the question myself

Dico · Answer

^^^ He brought up some good points