tslist_first
if (tslist_first(cl->arv_tm) == NULL)
oldest_arv = (tslist_first(cl->arv_tm))->timestamp;
return ((int64_t)delay_diff(now, tslist_first(cl->arv_tm)->timestamp));
tslist_first(cl->arv_tm)->timestamp);
while (tslist_first(cl->arv_tm) != NULL)
popped = tslist_first(cl->arv_tm);