UBLKS_T_STOPPING
t->state |= UBLKS_T_STOPPING;
io->flags, !!(t->state & UBLKS_T_STOPPING));
return (t->state & UBLKS_T_STOPPING) && ublk_thread_is_idle(t) && !t->cmd_inflight;
!(t->state & UBLKS_T_STOPPING);
t->state |= UBLKS_T_STOPPING;
(t->state & UBLKS_T_STOPPING));
(t->state & UBLKS_T_STOPPING));
ret, reapped, (t->state & UBLKS_T_STOPPING),