Hi guys. What is the best way to implement some lo...

# coroutines

[Dmitry Khasanov]

Hi guys. What is the best way to implement some long running background work (like in attached code) using coroutines?

Untitled

[Dominaezzz]

launch(<http://Dispatchers.IO|Dispatchers.IO>) {
    while(isActive) {
        checkNewFilesInDir();
        publishStatus();
        delay(200);
    }
}

[Dominaezzz]

Do you want this to run throughout the application's lifetime? Or is there a scope?

[gildor]

isActive is not really needed here, it will anyway be checked on coroutine start and delay, true will be also fine

[gildor]

But maybe isActive is more explicit

[Dominaezzz]

Force of habit. I don't like seeing while(true)

[gildor]

Yeah, true, also a but uncomfortable with while(true)😅

[Dominaezzz]

Ha

[bezrukov]

Question is too abstract. If we're talkin about specific case you mentioned, probably you need to switch from polling to file observer (e.g. https://developer.android.com/reference/android/os/FileObserver for android / WatchService api gtom nio for jvm) and wrap it for example to callbackFlow

[Dmitry Khasanov]

Yes, the question is abstract to understand different usage of coroutines. Reading file here is just for example, there can be long running network communication for example, or some other work.

[Dmitry Khasanov]

Yes I want this to run throughout the application's lifetime

[Dominaezzz]

In that case GlobalScope.launch should work for you. (Assuming you're not on android, which might be done slightly differently).

[Dmitry Khasanov]

I'm on Android 🙂 I think I can use some Scope for Service

[Dmitry Khasanov]

If I want to put some data into this infinite loop and get some result from it I should use Channels, right? Maybe something else?

[Dominaezzz]

You can use Channels or Flow .

[Dmitry Khasanov]

Ok, Flow is something new for me. Thanks to all

[gildor]

I would recommend to use Flow instead of channel for such case