make the file descriptor ready for reading.
</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 default glib main loop
runs.
</p>
<p>This procedure should not throw an exception unless memory is
exhausted, or guile-glib throws for some other reason.  If &rsquo;proc&rsquo;
throws, say because of port errors, and the exception is not caught
locally, it will prop