GNU bug report logs - #13611
SEGV during SMOB GC

Previous Next

Package: guile;

Reported by: Mike Gran <spk121 <at> yahoo.com>

Date: Sat, 2 Feb 2013 20:53:02 UTC

Severity: normal

Done: Andy Wingo <wingo <at> pobox.com>

Bug is archived. No further changes may be made.

Full log


Message #11 received at 13611 <at> debbugs.gnu.org (full text, mbox):

From: Mike Gran <spk121 <at> yahoo.com>
To: Ludovic Courtès <ludo <at> gnu.org>
Cc: "13611 <at> debbugs.gnu.org" <13611 <at> debbugs.gnu.org>
Subject: Re: bug#13611: SEGV during SMOB GC
Date: Tue, 5 Feb 2013 08:29:48 -0800 (PST)
[Message part 1 (text/plain, inline)]
> From: Ludovic Courtès <ludo <at> gnu.org>

> Is there any chance that you’re using a GC 7.3 pre-release?

Using gc-7.2b-2.fc17.i686
on Linux 3.6.10-2.fc17.i686 #1 SMP 

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

It does fix my SEGV

> (Note that on 2.0 SMOB mark procedures are unnecessary.)

Cool.  Let's yank it from the manual.  Case closed.

Yet...

For what it is worth, I decided to get som statistics on how
often smob_mark is called from a thread with scm_i_current_thread
== NULL vs how often it is called from a thread where it is 
not null.

I wrote the attached patch, and then, using the same little
library as in my initial report, I ran

 (use-modules (smobbug))
 ;; Create a SMOB type
 (handlesmob-init)
 (for-each (lambda (x) (gc))
       (iota 1000))
 (gc-smob-mark-report)

This returned

 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?

-Mike 
[smob_gc_mark_report.patch (text/x-patch, attachment)]

This bug report was last modified 12 years and 76 days ago.

Previous Next


GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.