How does the call stack of a recursive multithreaded function behave?

Question

Java

Actually, I would like to know (at least on the fingers) how does the call stack of such a function lead?

public Result loop(/* params */){
if(/*conditions*/){
   return result;
} else {
/* multithread computations and call loop in another thread with other params*/
}
}

In other words, how does RecursiveTask work inside (at least on the fingers) ?