, provided
event-loop-close! has not been applied to the loop.  If
event-loop-close! has previously been invoked, this procedure will
throw an &rsquo;event-loop-error exception.
</p>
<p>From version 0.21, this procedure will also throw an &rsquo;event-loop-error
exception if it is applied to an event loop which is currently running
(prior to version 0.21, doing so would fail in a less helpful way).
</p>
<p>If something else throws in the implementation or a callback throws,
then this procedure will clean up