SS_NONBLOCK
#define CHECK_STATE (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_NDELAY|SS_NONBLOCK| \
so->so_state |= SS_NONBLOCK;
so->so_state &= ~SS_NONBLOCK;
if (state & SS_NONBLOCK)
so->so_state |= SS_NONBLOCK;
if (so1->so_state & SS_NONBLOCK)
ssflags |= SS_NONBLOCK;
if ((ssflags | so->so_state) & (SS_NDELAY|SS_NONBLOCK)) {
if ((ssflags | so->so_state) & SS_NONBLOCK)
nso->so_state |= (sso->so_state & (SS_NDELAY|SS_NONBLOCK));
((KSTOSO(so)->so_state & (SS_NDELAY|SS_NONBLOCK)) ? FNDELAY : 0)