Calling ExecutorService submit() inside an infinite loop

Question

My question is regarding the shutdown() method from the ExecutorService class. If i am calling the submit() method in an infinite loop... do i ever need to call shutdown()? Essentially i have something like this (pseudo-code here):

for(;;){
    for(some event){

     if(some event does something i want to capture){
        threadPool.submit()     
     }
    }
}

So with a set up like the above when is it appropriate to call shutdown() ? In my actual code when i try to call shutdown() outside the infinite loop i get unreachable code error - which i understand. But it seems to me that i would probably not call the shutdown() method. What do you guys think?

Answer 1

Suggest passing a stop event type that instructs the loop to break:

boolean have_received_stop_event = false;
while (!have_received_stop_event)
{
    for(some event)
    {
        if(stop-event)
        {
            have_received_stop_event = true;
            break;
        }

        if(some event does something i want to capture)
        {
            threadPool.submit()     
        }
    }
}

Then call shutdown() after main loop exits.

Answer 2

If there is a try-catch block enclosing this infinite loop, you could call shutdown in the catch block. This would allow you to tidy up when an exception is thrown.