busy-wait

busy-wait vi.  Used of human behavior, conveys that the
   subject is busy waiting for someone or something, intends to move
   instantly as soon as it shows up, and thus cannot do anything else
   at the moment.  "Can't talk now, I'm busy-waiting till Bill gets
   off the phone."

   Technically, `busy-wait' means to wait on an event by
   {spin}ning through a tight or timed-delay loop that polls for
   the event on each pass, as opposed to setting up an interrupt
   handler and continuing execution on another part of the task.  This
   is a wasteful technique, best avoided on time-sharing systems where
   a busy-waiting program may {hog} the processor.