pqueue_pop
while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
item = pqueue_pop(queue);
while ((item = pqueue_pop(rl->unprocessed_rcds)) != NULL) {
while ((item = pqueue_pop(rl->processed_rcds)) != NULL) {
item = pqueue_pop(s->rlayer.d->buffered_app_data);
while ((item = pqueue_pop(d->buffered_app_data)) != NULL) {
pitem *pqueue_pop(pqueue *pq);
pqueue_pop(s->d1->buffered_messages);
pqueue_pop(s->d1->buffered_messages);
pqueue_pop(s->d1->buffered_messages);