A (perhaps silly) kqueue question

Vlad GALU dudu at dudu.ro
Sat Mar 8 08:09:52 UTC 2008

On 3/8/08, Robert Watson <rwatson at freebsd.org> wrote:
> On Fri, 7 Mar 2008, Vlad GALU wrote:
> > I see an unusual symptom with one of our in-house applications. The main I/O
>  > loop calls kevent(), which in turn returns two events with EV_EOF error set,
>  > always for the same descriptors (they're both socket descriptors). As the
>  > man page is not pretty clear about it and I don't have my UNP copy at hand,
>  > I would like to ask the list whether the error events are supposed to be
>  > one-shot or not.
> I wonder if it's returning one event for the read socket buffer, and one event
>  for the write socket buffer, since there are really two event sources for each
>  socket?  Not that this is desirable behavior, but it might explain it.  If you
>  shutdown() only read, do you get back one EOF kevent and one writable kevent?

   I'll try that and see. The only issue being the low frequency this
symptom appears at. I'll get back to the list once I have more info.

>  Robert N M Watson
>  Computer Laboratory
>  University of Cambridge


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