Mailing-List: contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT sources DOT redhat DOT com
Delivered-To: mailing list cygwin AT sources DOT redhat DOT com
Message-ID: <03f001c0c040$84aaa630$0200a8c0@lifelesswks>
From: "Robert Collins" <robert DOT collins AT itdomain DOT com DOT au>
To: <cygwin AT cygwin DOT com>
Cc: "Joost Kraaijeveld" <J DOT Kraaijeveld AT Askesis DOT nl>
References: <3AD06DB0 DOT 8756E06 AT yahoo DOT com>
Subject: G++ guru's please comment - Re: FW: pthread_create problem in Cygwin 1.1.8-2]
Date: Mon, 9 Apr 2001 01:28:08 +1000
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.50.4133.2400
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400
X-OriginalArrivalTime: 08 Apr 2001 15:21:42.0478 (UTC) FILETIME=[9D87F6E0:01C0C03F]



> -------- Original Message --------
> Subject: FW: pthread_create problem in Cygwin 1.1.8-2
> Date: Sun, 8 Apr 2001 15:40:43 +0200
> From: Joost Kraaijeveld <J DOT Kraaijeveld AT Askesis DOT nl>
> To: "'earnie_boyd AT yahoo DOT com'" <earnie_boyd AT yahoo DOT com>
>
> Hi Earnie,
>
>
> I am using:
>
> Reading specs from /bin/../lib/gcc-lib/i686-pc-cygwin/2.95.3-2/specs
> gcc version 2.95.3-2 (cygwin special)
>
> Additional testing showes that if I insert a Sleep(500) in the
> threadFunction() just before the return 0 it only crahes 3-5 times of
> the 10
> runs. Also, it crashes more often after fast repeated runs of the
> program.
> It also crashes more often on faster hardware (I have tested on two
> machines, PII 400 and a PIII 700, both 256 MB RAM). Running only 1
> thread
> instead of two does not crash the program.

This smells like a threads/exception handling interaction issue of some
sort.

It crashes for me, on i=99 at the same place. It crashes _every time_
for me. Adding a sleep as you did made it crash 8/10 instead of 10/10.
Removing the return 0; from within the try {} stopped it crashing
completely.

Also, printf doesn't appear to be atomic and threadsafe (lines got
interspersed). You might be hitting something there, but I doubt it
(crashing in the wrong place).

some things to test/do:

1) It's possible it's a problem with the thread exiting code, could you
try using a pthread_exit call instead of return and report back.

2) What cygwin1.dll are you using? I'm using a custom build ~= to the
latest snapshot.
2a) Earnie - what are you testing with? (as a control point that doesn't
see the fault).

3) What's the value of ecx when it dies? Mine is
(gdb) info register
eax            0x407004 4222980
ecx            0xc0     192

3a) Earnie - if you have a few minutes, can you put a breakpoint on the
offending instruction, and report back the output o
info registers
info locals
info threads
bt in each thread?

Thanks,
Rob





>
> If I run it through GDB it shows that the crash occurs after the
"return
> 0"
> but before the closing bracket of the for loop (see the mixed output
of
> the
> debugger source window below, the offending line is marked by me with
a
> "+"). It gives a SIGSEGV for both threads.
>
>
>
> Joost
>
> 10       {
> 11          printf("%lu\n",i);
> - 0x4010ac <threadFunction(void *)+96>: add



--
Want to unsubscribe from this list?
Check out: http://cygwin.com/ml/#unsubscribe-simple