 - any thread may call this procedure, including
any callback or task running on the event loop.  The &rsquo;loop&rsquo; argument
is optional: this procedure operates on the event loop passed in as an
argument, or if none is passed (or #f is passed), on the default event
loop.
</p>
<p>Note that the discarding of file watches, timeouts and unexecuted
events remaining in the event loop means that if one of the helper
await-* procedures provided by this library has been called but has
not yet returned, it may 