RC_LOCKED
rp->rc_flag &= ~RC_LOCKED;
rp->rc_flag = RC_LOCKED;
while ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_LOCKED;
rp->rc_flag &= (RC_LOCKED | RC_WANTED);
rp->rc_flag &= ~RC_LOCKED;
rp->rc_flag &= ~RC_LOCKED;
if ((rp->rc_flag & RC_LOCKED)) {
rp->rc_flag |= RC_LOCKED;