IO Dispatcher creates more than 64 threads

[unnamedw]

Annotation describes IO Dispatcher like this,

It defaults to the limit of 64 threads or the number of cores (whichever is larger).

As I understood, Maximum number of threads that can be created by Dispatchers.IO is up to 64 because I use only 6core and 12 threads CPU, but my result is a little bit tricky.

This is my code.

repeat(500) {
    CoroutineScope(Dispatchers.IO).launch {
        println(Thread.currentThread().name)
    }
}

and this is the result.

...

DefaultDispatcher-worker-18
DefaultDispatcher-worker-46
DefaultDispatcher-worker-17
DefaultDispatcher-worker-47
DefaultDispatcher-worker-69
DefaultDispatcher-worker-64
DefaultDispatcher-worker-66
DefaultDispatcher-worker-67
DefaultDispatcher-worker-68
DefaultDispatcher-worker-41

...

Why is threadpool count bigger than 64?
Does that mean actual threads was created more than 64?

[qwwdfsad]

Thanks for pointing it out, I'll rephrase the doc a bit.

Dispatchers.IO shares underlying threadpool with Dispatchers.Default, so the number of simultaneous threads is 64 + #CORES_SIZE. In your particular example, underlying threadpool starts compensating all 64 IO threads with a few threads for potential tasks in Dispatchers.Default