recvfrom + MSG_PEEK = broken?

Mon Mar 22 17:55:00 GMT 2010

On Mar 22 13:40, Eliot Moss wrote:
> On 3/22/2010 1:37 PM, Christopher Faylor wrote:
> >On Mon, Mar 22, 2010 at 05:01:00PM +0100, Corinna Vinschen wrote:
> >>On Mar 22 10:56, Charles Wilson wrote:
> >>>On 3/22/2010 7:03 AM, Corinna Vinschen wrote:
> >>>>On Mar 22 02:04, Charles Wilson wrote:
> >>>>>I've been tracking down a problem in xinetd. It appears to be an issue
> >>>>>with using MSG_PEEK in recvfrom() on UDP sockets.
> >>>>
> >>>>Yes, that's a bug in Cygwin. The socket event handling got messed up
> >>>>when MSG_PEEK was used. I fixed that in CVS so it will be in 1.7.2.
> >>>
> >>>Confirmed: fixes both my testcase, and the error in xinetd. Thanks for
> >>>the quick turnaround! I was about ready to pull my hair out on this
> >>
> >>Sure. I'm glad I had a simple testcase for a socket problem. If only
> >>somebody would come up with an equally simple testcase for the rsync
> >>problem...
> >
> >I thought the rsync problem was due to the fact that select for write on
> >pipes is unreliable.

The problem has been observed with rsync using socketpairs in the first
place. The first reports claimed that building rsync with pipes fixed
the issue. Only a later report on the list claimed that the problem
still exists even with pipes. I don't dare to make any assumption of
the actual reason :|
Corinna
-- 
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat
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