lwq_dequeue
t = lwq_dequeue(&q, struct tnode, n);
while ((t = lwq_dequeue(&q, struct tnode, n)) != NULL) {
wait_var_event(q, (t = lwq_dequeue(q, struct tnode, n)) != NULL);
xprt = lwq_dequeue(&pool->sp_xprts, struct svc_xprt, xpt_ready);
req = lwq_dequeue(&serv->sv_cb_list,