+ // A list of all clients, ordered by the time they connected (first element),
+ // and their file descriptor (second element). It is ordered by connection time
+ // (and thus also by read timeout time) so that we can read clients from the
+ // start and stop processing once we get to one that isn't ready to be
+ // timed out yet (which means we only have to look at each client exactly once,
+ // save for the first element of the queue, which is always checked).
+ //
+ // Note that when we delete a client, we don't update this queue.
+ // This means that when reading it, we need to check if the client it
+ // describes is still exists (ie., that the fd still exists, and that
+ // the timespec matches).
+ std::queue<std::pair<timespec, int> > clients_ordered_by_connect_time;
+