N4S_CB_WAITER
{"N4S_CB_WAITER", N4S_CB_WAITER, N4S_CB_WAITER},
if ((sp->s_flags & (N4S_CB_PINGED | N4S_CB_WAITER)) == 0) {
sp->s_flags |= N4S_CB_WAITER;
np->s_flags &= ~(N4S_CB_PINGED | N4S_CB_WAITER);