__sigev_alloc
*sn = __sigev_alloc(SI_ASYNCIO, sigevent, NULL, 1);
sn = __sigev_alloc(SI_MESGQ, evp, mqd->node, 1);
struct sigev_node *__sigev_alloc(int, const struct sigevent *,
sn = __sigev_alloc(SI_TIMER, evp, NULL, 0);