21' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>This is a convenience procedure for use in an event loop, which will
start a write watch on &rsquo;port&rsquo; for writing the contents of a bytevector
&rsquo;bv&rsquo; to the port, which must be non-blocking.  It calls &rsquo;await&rsquo; if it
has to wait for output to become available.  Provided &rsquo;port&rsquo; is a
non-blocking port, the event loop will not be blocked by this
procedure even if only individual bytes can be written at any one
t