www.delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2009/03/31/10:08:00

X-Recipient: archive-cygwin AT delorie DOT com
X-Spam-Check-By: sourceware.org
Date: Tue, 31 Mar 2009 17:07:28 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: IPC,FORK on Windows 2008 Server
Message-ID: <20090331150728.GE12738@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <bc2e28c70903310234p1fa23e9esfe4e4ca8f293fbef AT mail DOT gmail DOT com> <20090331112111 DOT GB12738 AT calimero DOT vinschen DOT de> <bc2e28c70903310441h7f354e5br99ecf91825231227 AT mail DOT gmail DOT com> <20090331120843 DOT GD12738 AT calimero DOT vinschen DOT de>
MIME-Version: 1.0
In-Reply-To: <20090331120843.GD12738@calimero.vinschen.de>
User-Agent: Mutt/1.5.19 (2009-02-20)
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

On Mar 31 14:08, Corinna Vinschen wrote:
> On Mar 31 17:11, Yarlagadda Suresh wrote:
> > Hi,
> > 
> > I am using shmget()/shmat() methods for getting the shared memory.
> > 
> > I had tried running the same program which is given in the previous
> > mention thread, the results are same as mentioned over there.
> 
> I just tried that testcase with Cygwin 1.7 and it appears to work most
> of the time.   Unfortunately I can still reproduce the problem once per
> about 30 forks.
> 
> I'll look into fixing this for Cygwin 1.7.  However, please note that
> there is no *really* foolproof method to fix this due to the way fork
> has to be implemented using Win32 calls.  I can only make it much more
> unlikely than today.

I applied a patch to Cygwin which allocates the shmat() shared memory
regions top-down, same as the mmap() regions.  This should make the
observed effect at fork() pretty unlikely.  The patch will be in the
next Cygwin 1.7.0 test release (in a couple of days).


Thanks for the report,
Corinna

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

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019