/* unset global semaphore */
upqueue_avail = 0;
// with a very small incident, upqueue_avail may be set by mISDN thread and
// another byte may be sent to the pipe, which causes a call to this function
// again with nothing in the upqueue. this is no problem.
/* unset global semaphore */
upqueue_avail = 0;
// with a very small incident, upqueue_avail may be set by mISDN thread and
// another byte may be sent to the pipe, which causes a call to this function
// again with nothing in the upqueue. this is no problem.