ADMIN_SIG_RUNNING
if ((sc->admin_signal & ADMIN_SIG_RUNNING) == 0)
while (sc->admin_signal & ADMIN_SIG_RUNNING)
atomic_set_int(&sc->admin_signal, ADMIN_SIG_RUNNING);
atomic_clear_int(&sc->admin_signal, ADMIN_SIG_RUNNING);
while ((sc->admin_signal & ADMIN_SIG_RUNNING) == 0)