page_slots
page_slots(p->signal_page)[id] = UNSIGNALED_EVENT_SLOT;
if (page_slots(p->signal_page)[id] == UNSIGNALED_EVENT_SLOT)
if (page_slots(p->signal_page)[id] == UNSIGNALED_EVENT_SLOT)
WRITE_ONCE(page_slots(p->signal_page)[ev->event_id], UNSIGNALED_EVENT_SLOT);
uint64_t *slots = page_slots(p->signal_page);