 and second the size of the block of
data placed in the bytevector.  The value passed as the size of the
block of data placed in the bytevector will always be the same as
&rsquo;size&rsquo; unless end-of-file has been encountered after receiving only a
partial block of data.
</p>
<p>The event loop will not be blocked by this procedure even if only
individual bytes are available at any one time (although if &rsquo;port&rsquo;
references a socket, it should be non-blocking for this to be
guaranteed).  It is i