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Date: Tue, 9 Feb 2010 09:54:26 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: poll() on fifo read descriptor with non-zero timeout ==>  segfault
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On Feb  6 20:52, Steven Monai wrote:
> Hi folks,
> 
> Here is a short test case I've named "fifo-read.c":
> [...]
> Here's what happens at the command line:
> 
> $ uname -a
> CYGWIN_NT-5.1 lonestar 1.7.1(0.218/5/3) 2009-12-07 11:48 i686 Cygwin
> 
> $ gcc-4 -Wall -Werror -ansi -pedantic -o fifo-read fifo-read.c
> 
> $ mkfifo -m0600 myfifo
> 
> $ ls -l
> total 29
> -rw-r--r--+ 1 steve None   939 2010-02-06 20:25 fifo-read.c
> -rwxr-xr-x+ 1 steve None 22792 2010-02-06 20:25 fifo-read.exe
> prw-------  1 steve None     0 2010-02-06 20:25 myfifo
> 
> $ ./fifo-read
> About to enter poll()
> Segmentation fault (core dumped)
> 
> 
> If I change the timeout to a positive number, it also segfaults.
> 
> If I change the timeout to zero, it works, but poll() returns
> immediately with no descriptor ready to read. Not very useful.
> 
> I get identical results on two different machines, with two different
> OSes (XP and 2000). Can anyone else reproduce this? Am I using poll()
> incorrectly?

Can you check with the latest snapshot from http://cygwin.com/snapshots,
please?  I can not reproduce the above crash with your test application
when using Cygwin from CVS, neither on XP, nor on Windows 7.


Corinna

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

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