Subject: bug#13611: SEGV during SMOB GC

From: [email-masked] (Ludovic Courtès)
Date: Tue, 05 Feb 2013 17:41:22 +0100

Hi,

Mike Gran <[email-masked]> skribis:

>> From: Ludovic Courtès <[email-masked]>
>
>> Is there any chance that you’re using a GC 7.3 pre-release?
>
> Using gc-7.2b-2.fc17.i686

OK.

>> There was a similar report on IRC, and the fix appears to be:
>
> It does fix my SEGV

Good.

[...]

>  Count of GC SMOB marks from null thread: 176
>  Count of GC SMOB marks from current thread: 825
>
> Is that expected that GC is sometimes called from a 
> thread where scm_i_current_thread is null and sometimes
> called from a thread where scm_i_current_thread is
> not null?

Can you check whether your GC was built with --enable-parallel-mark?

I’m confident that the SMOB mark procedure is never called with null
scm_i_current_thread with 7.2 compiled with the default options (the
GnuTLS bindings rely on this, and I had not seen any such report until
someone tried with GC 7.3pre, which uses the parallel marker by
default.)

Thanks!

Ludo’.