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Date: Thu, 30 Jun 2011 11:38:25 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: bug in pipe() and pipe2()
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On Jun 29 15:30, Eric Blake wrote:
> I was testing the behavior when pipe() fails, in order to propose an
> update to POSIX wording: http://austingroupbugs.net/view.php?id=467
> 
> However, cygwin's pipe implementation dumps core when it runs out of
> fds, [...]
> Expected behavior is EMFILE and fd unchanged, after however many
> iterations it takes to reach the ulimit on max fd.

The problem is that Cygwin uses a placement new operator to allocate
new fhandlers.  This type of new operator calls the constructor even
if the placement pointer is NULL.  This in turn crashes in a rather
obvious way.

Since we need the placement new for fhandlers to make sure they are
allocated on the cygheap, and since there is no such operator which
only calls the constructor, I only see a very ugly workaround for this
problem.

I checked it in, together with two more fixes to avoid a crash.
If somebody has a better solution, feel free to mention it.


Thanks for the report,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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