I have a question related to coroutines and blocking IO integration. For integrating with a blocking...

# coroutines

[Norbi]

I have a question related to coroutines and blocking IO integration.
For integrating with a blocking library, I need a conversion similar to this:

// This is my asynchronous/suspending input stream
interface AsyncInputStream {
    // This method has semantics similar to InputStream.read() but suspends instead of blocking
    suspend fun read(): Int
}

fun AsyncInputStream.asInputStream() = object : java.io.InputStream() {
    override fun read(): Int {
        return runBlocking { [e-mail]() } // Is runBlocking() correct here?
    }
}

If I understand correctly, using runBlocking is incorrect because it "should not be used from a coroutine", and AsyncInputStream.asInputStream() would possibly be called from coroutines.
Thanks.

[Zach Klippenstein (he/him) [MOD]]

asInputStream doesn’t call runBlocking though, read does.

[uli]

Could you go for callback-based or future-based instead of blocking?

[Norbi]

asInputStream doesn’t call runBlocking though

Yes... although this is a general problem: in case of a non-suspend function how could I know that it won't be "used from a coroutine"?

[Zach Klippenstein (he/him) [MOD]]

You can’t, but you can add documentation that says hey there’s a suspending version of this function, use that instead