[Stackless] Segmentation fault when running example wsgi app in linux/win

Jeff Senn senn at maya.com
Thu Mar 11 14:48:50 CET 2010

I had this problem too (embedding Python in a completely different way and on OS/X),
that is: a crash in GC during Py_Finalize.  I spent just a bit of time looking
but didn't resolve much -- my (not very satisfying) solution was *not* to call 
Py_Finalize since my program was exiting anyway.

I seem to recall it was "worse" on a 64-bit compile... 
Håkan, do you have the same problem with a 32-bit compile?
maybe that's a clue... (or a red herring...)

Sorry, not much light shedding, let me know if you figure it out...

On Mar 11, 2010, at 4:55 AM, Håkan Larsson wrote:

> Hello all,
> I have been trying out the wsgi server with the app_sessionless example downloaded from the google stacklessexamples page and i keep getting a assertion and segmentation fault. I have browsed through the mailing list archives and there seems to be a similar error posted about a year ago. http://www.stackless.com/pipermail/stackless/2009-February/003910.html
> I have the same symptoms as jtunney describes. Works great when you do a single request in your web browser but when you stress it a bit the server simply exits. When running this with a debug version of python under windows i also can see a assertion before the server exits.  When stressing it even further under windows i get a segmentation fault.
> Assertion failed: stack_pointer != NULL, file ..\Python\ceval.c, line 914.
> This assertion/crash only happens when the clients are about to disconnect. To reproduce this i used jmeter, 10 looping threads doing a request against /. When starting the test i can see 10 "Accepted connection" print outs and the server serves request. But when i shut down the threads a assertion/segmentation fault occures.
> I have also been able to reproduce this under linux and there i get a segmentation fault right away.
> I have attached some output from gdb, one with standard optimizations and one with the flag turned to -O0 for more information.
> I am running the following setup.
> Windows:
> Win 7 x64, (same thing on Vista 64)
> Linux:
> Redhat 5 x64
> Python 2.6.4 Stackless 3.1b3 060516 (release26-maint:78823M, Mar 11 2010, 10:10:31)
> [GCC 4.1.2 20080704 (Red Hat 4.1.2-46)] on linux2
> python2.6: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.6.9, dynamically linked (uses shared libs), for GNU/Linux 2.6.9, not stripped
> Perhaps someone can help shed some light on this one.
> /Håkan
> <debug 00.txt><debug 03.txt>_______________________________________________
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