QS_DONTSEND
q->q_state = QS_DONTSEND;
case QS_DONTSEND:
a->q_state = QS_DONTSEND;
ctladdr->q_state = QS_DONTSEND;
ctladdr->q_state = QS_DONTSEND;
a->q_state = QS_DONTSEND;
#define QS_IS_DEAD(s) ((s) >= QS_DONTSEND)
a->q_state = QS_DONTSEND;