Shibboleth Developers

[André Cruz <>]

On 2008/01/03, at 17:50, Scott Cantor wrote:

> > The plot thickens... The RPC code on the GNU libc has that exact code
> > also. Calling svc_unregister and/or svc_destroy before the run() ends
> > has no effect.
>
> I'm surprised at that, I would have expected a crash. I'm fairly  
> certain I
> tried that a long time ago and that's what I got. That's why I  
> traced all
> that code to begin with. If it doesn't crash, something is really  
> wrong,
> because that should be a double-free. If it's not, then it isn't  
> freeing the
> memory inside svc.c like it appears to be.

The memory checker complains, but the program lives on:

==2431== Invalid free() / delete / delete[]
==2431==    at 0x4A1B96E: free (vg_replace_malloc.c:323)
==2431==    by 0x62AAE35: svctcp_destroy (in /lib/libc-2.3.6.so)
==2431==    by 0x4057C0: SharChild::svc_clean(SVCXPRT*) (shar- 
utils.cpp:179)
==2431==    by 0x405E8D: SharChild::run() (shar-utils.cpp:162)
==2431==    by 0x406220: shar_client_thread(void*) (shar-utils.cpp:89)
==2431==    by 0x60ACF19: start_thread (in /lib/libpthread-2.3.6.so)
==2431==    by 0x62855D1: clone (in /lib/libc-2.3.6.so)
==2431==  Address 0x9038700 is 0 bytes inside a block of size 464 free'd
==2431==    at 0x4A1B96E: free (vg_replace_malloc.c:323)
==2431==    by 0x62AAE35: svctcp_destroy (in /lib/libc-2.3.6.so)
==2431==    by 0x62AA1C5: svc_getreq_common (in /lib/libc-2.3.6.so)
==2431==    by 0x62A9AA9: svc_getreqset (in /lib/libc-2.3.6.so)
==2431==    by 0x405E75: SharChild::run() (shar-utils.cpp:157)
==2431==    by 0x406220: shar_client_thread(void*) (shar-utils.cpp:89)
==2431==    by 0x60ACF19: start_thread (in /lib/libpthread-2.3.6.so)
==2431==    by 0x62855D1: clone (in /lib/libc-2.3.6.so)

> But Unix servers that are also threaded. I don't really understand  
> the need
> to use prefork in 2008. If you have a PHP extension that's still not
> thread-safe, it's time to cut bait. Or use somebody else's SAML
> implementation for that matter, maybe that simplePHP code.

The application in question here is a mod_perl webapp on apache 1.3.  
Perl applications tend not to return the memory they use so apache  
processes have to be recycled every 1000 requests or so since mod_perl  
is builtin.

That's the price you pay for using The Best Language In The World.  
Kidding. :)

André