X-Recipient: archive-cygwin@delorie.com X-Spam-Check-By: sourceware.org Date: Tue, 7 Dec 2010 10:55:58 -0500 From: Christopher Faylor To: cygwin@cygwin.com Subject: Re: Problem with fork() in latest snapshot Message-ID: <20101207155558.GC25822@ednor.casa.cgf.cx> Reply-To: cygwin@cygwin.com Mail-Followup-To: cygwin@cygwin.com References: <4CDAF5D0.8080306@budcat.com> <20101116154141.GA32170@calimero.vinschen.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101116154141.GA32170@calimero.vinschen.de> User-Agent: Mutt/1.5.20 (2009-06-14) Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com On Tue, Nov 16, 2010 at 04:41:41PM +0100, Corinna Vinschen wrote: >On Nov 10 13:43, Heath Kehoe wrote: >> I have ruby 1.9.2 which I built from source. It works fine in cygwin >> 1.7.7 and earlier, but in the current snapshot when it does a fork, >> the child process dies pretty much instantly. >> >> I've put together a test case (see attached) which replicates what >> ruby is doing so that this problem can be repro'd without needing to >> build ruby. It seems that the failure only happens when the fork >> call is in a dll, and it also seems to depend on manipulating >> threads in close proximity to the fork. >> >> Here's the test program under 1.7.7: >> >> $ uname -a >> CYGWIN_NT-6.1-WOW64 hkehoe1 1.7.7(0.230/5/3) 2010-08-31 09:58 i686 >> Cygwin >> $ ./testfork >> Before fork >> After fork pid=5060 >> After fork pid=0 >> subprocess status 0 (0x0) >> >> And here it is in the snapshot: >> >> $ uname -a >> CYGWIN_NT-6.1-WOW64 hkehoe1 1.7.8s(0.233/5/3) 20101102 14:03:08 i686 >> Cygwin >> $ ./testfork >> Before fork >> After fork pid=3808 >> subprocess status 32512 (0x7f00) >> >> >> Note the missing 'After fork' message from the child and the -127 >> exit status. >> >> An strace of testfork will reveal this error occurring shortly after >> the fork returns in the child: >> --- Process 2944, exception C0000005 at 610E4B8C >> (the process ID is the child's) > >Would you mind to test which snapshot introduced this problem? I ran the test case in a loop on my Windows XP system under various conditions - no load, load, no load with most services stopped. I couldn't reproduce the problem. I also tried on a virtual system running Windows 7 64-bit and couldn't duplicate it. So, I'm currently stumped. I guess I'll try to add some instrumentation to catch the case where this fails. cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple