alls start_async();</p>
</li>
<li>
<p>processes communicates with proc through .in and .out;</p>
</li>
<li>
<p>closes .in and .out;</p>
</li>
<li>
<p>calls finish_async().</p>
</li>
</ol>
</div>
<div class="paragraph">
<p>The members .in, .out are used to provide a set of fd&#8217;s for
communication between the caller and the callee as follows:</p>
</div>
<div class="olist arabic">
<ol class="arabic">
<li>
<p>Specify 0 to have no file descriptor passed.  The callee will
receive -1 in the corresponding argu