n the default event
loop
</p>
<p>The documentation on the event-loop-add-write-watch! procedure
explains why this procedure generally works best with an unbuffered
port.
</p>
<p>Because this procedure takes a &rsquo;resume&rsquo; argument derived from the
a-sync procedure, it must (like the a-sync procedure) in practice be
called in the same thread as that in which the event loop runs.
</p>
<p>This procedure should not throw an exception unless memory is
exhausted.  If &rsquo;proc&rsquo; throws, say because