s->max_fileno = -1;
clock_get_realtime(&now_struct);
sched_preselect(s);
ret = s->select_function(s->max_fileno + 1, &s->rfds, &s->wfds,
s->max_fileno = -1;
clock_get_realtime(&now_struct);
sched_preselect(s);
ret = s->select_function(s->max_fileno + 1, &s->rfds, &s->wfds,