Theoretical problem: is there any mechanism to clo...

# coroutines

[Youssef Shoaib [MOD]]

Theoretical problem: is there any mechanism to close a resource upon suspension and reopen it open resumption? E.g if I have a file and I want to open it and line-by-line do some processing. That processing includes suspend functions, and so I'd like to close the file when they suspend as to not leave the file open for too long.

[Sam]

I guess you could make a custom continuation interceptor

[Sam]

Wrap the continuation before passing it to the dispatcher, and you can add advice around it

[Youssef Shoaib [MOD]]

That would only work if the call is ever `intercept`ed though, no? I don't think every suspension is guaranteed to intercept the continuation, especially with the presence of suspendCoroutineUninterceptedOrReturn. Or is there a contract I'm unaware of here that every suspension should be resumed with intercepted?

[Sam]

If you're using the coroutines library, everything is intercepted. The only exception is suspend fun main() since it has no dispatcher.

[Sam]

The interceptor is how dispatchers and thread context elements work, so things would break without it

[hfhbd]

BTW do you plan to open source the file implementation?

[Youssef Shoaib [MOD]]

I don't actually have code for any of this. This is a theoretical problem that other languages have to contend with and I was wondering how Kotlin coroutines handles it