Hi everybody, is it possible to execute a blocking...

# announcements

[littlelightcz]

Hi everybody, is it possible to execute a blocking IO operation (such as HTTP GET request) in a coroutine and make it suspend instead of blocking the thread?

[karelpeeters]

#coroutines or google 🙂

[littlelightcz]

the point is I tried it and it seems the coroutines are still blocking but not suspending ... so there is still only 1 coroutine per 1 thread - the only benefit is that a coroutine starts faster, but that's it

[littlelightcz]

but thanks for the coroutines channel, I will give it a try there 🙂

[karelpeeters]

Well to call blocking code you'll always need to "dedicate" a thread to that call.

[littlelightcz]

hmh, so that means that basically if (probably) every IO operation in Java is blocking while waiting for an IO response, the coroutines can't do anything about that?

[karelpeeters]

Yes. You can use a non-blocking library like java.nio I think.

[littlelightcz]

hmh so maybe that could be the solution, I will check it, but otherwise it would have been quite pity 🙂

[bj0]

coroutines don't magically turn a blocking call into a non-blocking call, the blocking call will always block the thread it is on. you have to use a non-blocking version/api (like java.nio OR you can push the blocking call into a background thread so it doesn't block any other threads. The coroutine library makes this second option easy, since there are some blocking apis that can't be easily replaced

[karelpeeters]

Well of course it is possible to do IO on coroutines, that's pretty much the point.

[littlelightcz]

Thanks guys, I think that now I understand what is going on 🙂. I am going to look at the NIO Java lib just for the sake of exploration 🙂