Handles the clients in selected_set that did not time out, then reports
a timeout to the timed out clients and unregisters them.
Note that any timed out clients will *not* be handled, even if they have
an event fired. Instead they are finalized with status = timeout and
unregistered.
Handles the clients in selected_set that did not time out, then reports a timeout to the timed out clients and unregisters them.
Note that any timed out clients will *not* be handled, even if they have an event fired. Instead they are finalized with status = timeout and unregistered.