From: Andy Wingo <wingo@pobox.com>
To: ludo@gnu.org (Ludovic Courtès)
Cc: guile-user@gnu.org
Subject: Re: smob mark functions in 2.0
Date: Thu, 24 Nov 2011 11:56:21 +0100 [thread overview]
Message-ID: <8739ddeqlm.fsf@pobox.com> (raw)
In-Reply-To: <874nxumo1m.fsf@gnu.org> ("Ludovic Courtès"'s message of "Thu, 24 Nov 2011 00:12:05 +0100")
On Thu 24 Nov 2011 00:12, ludo@gnu.org (Ludovic Courtès) writes:
>> So, your mark function might see freed objects. This is terrible, but
>> it is the way that it is. The key is that, if you touch a Scheme object
>> in your mark function, to first do a check on that object, to see that
>> it is valid. You can check the TC bits of the first word, or otherwise
>> check that other words are non-NULL.
>
> What about making that check in libguile before invoking the user’s mark
> function?
Yes, we do that. I think you wrote that code! The problem was in a
mark function, accessing *other* Scheme objects.
Andy
--
http://wingolog.org/
next prev parent reply other threads:[~2011-11-24 10:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-23 21:20 smob mark functions in 2.0 Andy Wingo
2011-11-23 23:12 ` Ludovic Courtès
2011-11-24 10:56 ` Andy Wingo [this message]
2011-11-24 23:24 ` Ludovic Courtès
2011-11-30 15:29 ` Mark H Weaver
2014-09-26 4:50 ` Mark H Weaver
2014-09-27 15:29 ` Andy Wingo
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