trying to understand what happens when a coroutine is launched in an IO dispatcher (to help in code review). my co-worker has code that launches in an IO dispatcher with code that has no suspend functions (mostly to conform to a previous interface, but lets hand wave that part). since there are no suspend functions, does calling this method always start a new thread? i’m not familiar with the IO dispatcher internals and even though its well documented code there is a lot of it to look through

Look at the KDoc of

<http://Dispatchers.IO|Dispatchers.IO>

, it should answer your questions.

yes it switches the execution context to IO. It just never suspend