Yup, that's definitely problematic. I think signals are your only hope here, but you've got some significant problems to solve. For example, recent Perls do not guarantee immediate signal delivery, they only check for new signals between op-codes. Start up a long-running regex and you won't see a signal until it returns. That's better than older Perls though, which had immediate delivery but also offered a side of seg-faults with that meal.

You may need to re-think your design - trying to have a single process handle IPC and do "other stuff" simultaneously is not a good design. Maybe you can fork off that "other stuff" and send it a signal to stop, or pause, when something more important arrives.

-sam