TF_HIWAT_OUT
tp->t_flags &= ~TF_HIWAT_OUT;
{ TF_HIWAT_OUT, 'o' },
if (tp->t_flags & TF_HIWAT_OUT) {
tp->t_flags &= ~TF_HIWAT_OUT;
tp->t_flags |= TF_HIWAT_OUT;
if ((tp->t_flags & TF_HIWAT_OUT) == 0)
#define TF_HIWAT (TF_HIWAT_IN|TF_HIWAT_OUT)
{ TF_HIWAT_OUT, 'o' },