<div dir="ltr"><div><div><div>Yes, but given Matthew's code, it first waits (i.e., blocks) with `sync' until a client tries to connect (but does not `accept' it yet).<br></div>Then it goes to atomic (i.e., somewhat non-interruptible) mode and before accepting the client, it checks again that the client is still there.<br> </div>For this last part, I was trying to use sync/timeout; A zero value for the timer thus returns #f only if no event could sync, i.e. (I thought) if no client is waiting.<br></div>(From the docs: "If <span class="">timeout</span> is a procedure, then it is called in tail position if polling the <span class="">evt</span>s discovers no ready events.")<div><div><br></div><div>But it seems that the event has already been processed and is not available anymore or something.<br><br>Laurent<br></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote"> On Mon, Apr 22, 2013 at 12:21 PM, Diogo F. S. Ramos <span dir="ltr"><<a href="mailto:diogofsr@gmail.com" target="_blank">diogofsr@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="im">Laurent <<a href="mailto:laurent.orseau@gmail.com">laurent.orseau@gmail.com</a>> writes:<br> <br> > (sync/timeout 0 (scheme_fd_to_semaphore s MZFD_CREATE_READ #t))<br> ><br> > Unfortunately this does not work :)<br> > It always returns #f.<br> <br> </div>I'm not familiar with `sync/timeout' or `scheme_fd_to_semaphore', but<br> from `sync/timeout's documentation:<br> <br> "A zero value for timeout is equivalent to (lambda () #f). In either<br> case, each evt is checked at least once before returning #f or calling<br> timeout."<br> <br> So, I guess it's not a surprise that your call always returns `#f'. It's<br> not blocking/waiting, how one would want in this situation.<br> </blockquote></div><br></div>