+/** Run a single main loop iteration of this main loop. If sleep_time
+is < 0 this will block until any of the registered events happens,
+then it will execute the attached callback function. If sleep_time is
+0 the routine just checks if any event is pending. If yes the attached
+callback function is called, otherwise the function returns
+immediately. If sleep_time > 0 the function will block for at most the
+specified time in msecs. Returns -1 on error, 0 on success and 1 if a
+quit request has been scheduled. Usually this function should be called
+in a loop until it returns a non-zero value*/
+int avahi_simple_poll_iterate(AvahiSimplePoll *s, int sleep_time);