Hello! We have just upgraded kotlin and coroutines for our service. One thing noted was that main can now be a suspend method. What happens if main gets suspended? Is there any considerations when having long-lived applications? (previously we did a runBlocking { application.start() }, now we just do application.start())

I'm pretty sure

suspend fun main() { ... }

is equivalent to

fun main() = runBlocking { ... }

.

thanks! how sure is pretty sure?

I think I've read it somewhere. Trying to find it in the docs now 🙂

awesome! thank you!

You need that if you want to start other coroutines within

main

. Like the `async`s in that example.

I'm not sure I follow tbh. When would I/wouldn't I want that? What is the effect of either?

You need a

coroutineScope

to start coroutines like

async

,

launch

,

produce

and so on. It's part of something called "structured concurrency". You can read more about it here: https://medium.com/@elizarov/structured-concurrency-722d765aa952

ahh - of course. async and the others start new coroutines - I was confused with just calling other suspend functions. Thanks for the link, will give it a read!

Right. You don't need a scope if you just want to call other suspend functions.