LW_CATCHINTR
l->l_flag &= wakeup ? ~(LW_SINTR|LW_CATCHINTR|LW_STIMO) : ~LW_SINTR;
l->l_flag = LW_SINTR | LW_CATCHINTR;
l->l_flag = ~(LW_SINTR | LW_CATCHINTR);
l->l_flag &= ~(LW_SINTR | LW_CATCHINTR | LW_STIMO);
l->l_flag |= LW_CATCHINTR;
l->l_flag &= ~LW_CATCHINTR;
if ((flag & LW_CATCHINTR) == 0 || error != 0)