MSGF_INTRANSIT
KKASSERT(msg->ms_flags & MSGF_INTRANSIT);
msg->ms_flags &= ~MSGF_INTRANSIT;
KKASSERT((msg->ms_flags & (MSGF_DONE|MSGF_QUEUED|MSGF_INTRANSIT)) == 0);
atomic_set_int(&msg->ms_flags, MSGF_INTRANSIT);
atomic_set_int(&msg->ms_flags, MSGF_INTRANSIT);
KKASSERT(msg->ms_flags & MSGF_INTRANSIT);
atomic_clear_int(&msg->ms_flags, MSGF_INTRANSIT);
atomic_set_int(&msg->ms_flags, MSGF_INTRANSIT);