[rrd-developers] segmentation fault with RRDs::graph in 1.2.18

[Tobias Oetiker]

Hi Haroon,

I assumed it was a MT problem since the trace was going on about
LWTs ...

in any event, by looking at the trace it is not obviouse to me what
is going wrong here ... since the line in question apears befor and
works fine there, so the problem may be dealyed effect of a bug
earlier in the code.

cheers
tobi


Today Haroon Rafique wrote:

> On Today at 7:44am, TO=>Tobias Oetiker <tobi at oetiker.ch> wrote:
>
> TO> Hi Haroon,
> TO>
> TO> I looked over the code and I can't curently see what is going wrong
> TO> except that you seem to be running multithreaded and rrd_graph is not
> TO> realy done with thread-savety in mind.
> TO>
> TO> have you ever seen this bug in a non multithreaded environment ?
> TO>
>
> Hi Tobi,
>
> Thanks for the quick response. Actually I was hoping that the example that
> I gave was indeed non-multithreaded.
>
> Here's how I reproduced the segfault:
>
> 1. Logged in as the user that runs apache (su - www)
> 2. gdb perl
> 3. set environment PATH_INFO=/rpc_stats/ (something my perl script needs)
> 4. run /www/PERL/rrd.cgi (path to my script)
>
> The above produces a "Program received signal SIGSEGV, Segmentation
> fault."
>
> Isn't the above usage non-multithreaded?
>
> TO>
> TO> it would be great if you could provide a script to reproduce the
> TO> problem.
> TO>
>
> Sure thing, I can try that. However, I will wait for your response to the
> multi-threaded/non-multi-threaded question above first. In case, you are
> wondering, the script in question is at:
>
> http://haroon.sis.utoronto.ca/rrd/scripts/rrd.cgi
>
> Its a relatively convuluted yet simple script which I use as a front-end
> graphing solution to rrdtool.
>
> TO>
> TO> cheers
> TO> tobi
> TO>
>
> Regards,
> --
> Haroon Rafique
> <haroon.rafique at utoronto.ca>
>
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>
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten
http://it.oetiker.ch tobi at oetiker.ch ++41 62 213 9902