timer_add(&res_timeout, timeout_resolver, NULL, TT_ABSOLUTE, when);
else if (when < t_expire(&res_timeout))
timer_chg(&res_timeout, TT_ABSOLUTE, when);
timer_add(&res_timeout, timeout_resolver, NULL, TT_ABSOLUTE, when);
else if (when < t_expire(&res_timeout))
timer_chg(&res_timeout, TT_ABSOLUTE, when);