From: Florian Weimer <fw@deneb.enyo.de>
To: Stefan Monnier <monnier@IRO.UMontreal.CA>
Cc: Eli Zaretskii <eliz@gnu.org>,
Fabrice Popineau <fabrice.popineau@gmail.com>,
emacs-devel@gnu.org
Subject: Re: GC and stack marking
Date: Sat, 31 May 2014 08:31:10 +0200 [thread overview]
Message-ID: <87ha46v4r5.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <jwvbnusio3o.fsf-monnier+emacs@gnu.org> (Stefan Monnier's message of "Tue, 20 May 2014 09:44:05 -0400")
* Stefan Monnier:
> The Boehm's GC has developed ways to do this second option
> automatically: if during a GC, a memory cell is found to "point to"
> unallocated memory, then it is assumed to be of non-pointer type and
> this fact is recorded somewhere so that if in subsequent GC's this cell
> ends up "pointing" to allocated memory that won't be considered as an
> actual pointer.
I believe this is not a correct description of the mechanism. What
happens is that the pointer *target* is blacklisted and not used for
allocation. What you propose instead is not safe because it will
result in dangling pointers in some cases.
next prev parent reply other threads:[~2014-05-31 6:31 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-19 16:31 GC and stack marking Eli Zaretskii
2014-05-19 18:47 ` Paul Eggert
2014-05-19 19:14 ` Eli Zaretskii
2014-05-19 19:58 ` Paul Eggert
2014-05-19 20:03 ` Eli Zaretskii
2014-05-19 20:17 ` Paul Eggert
2014-05-20 16:37 ` Eli Zaretskii
2014-05-20 13:44 ` Stefan Monnier
2014-05-20 16:57 ` Eli Zaretskii
2014-05-20 17:54 ` Stefan Monnier
2014-05-20 19:28 ` Eli Zaretskii
2014-05-20 22:01 ` Stefan Monnier
2014-05-21 2:48 ` Eli Zaretskii
2014-05-21 3:01 ` Stefan Monnier
2014-05-21 15:39 ` Eli Zaretskii
2014-05-21 15:57 ` Dmitry Antipov
2014-05-21 16:06 ` Dmitry Antipov
2014-05-21 16:55 ` Eli Zaretskii
2014-05-21 16:53 ` Eli Zaretskii
2014-05-21 17:40 ` Stefan Monnier
2014-05-21 17:58 ` Eli Zaretskii
2014-05-22 15:20 ` Eli Zaretskii
2014-05-22 16:14 ` Stefan Monnier
2014-05-24 12:03 ` Eli Zaretskii
2014-05-20 19:12 ` Daniel Colascione
2014-05-20 19:43 ` Eli Zaretskii
2014-05-20 22:03 ` Stefan Monnier
2014-05-21 2:51 ` Eli Zaretskii
2014-05-31 6:31 ` Florian Weimer [this message]
2014-05-31 14:24 ` Stefan Monnier
-- strict thread matches above, loose matches on Subject: below --
2014-05-21 19:31 Barry OReilly
2014-05-21 20:13 ` Eli Zaretskii
2014-05-21 20:49 ` Barry OReilly
2014-05-22 2:43 ` Eli Zaretskii
2014-05-22 3:12 ` Daniel Colascione
2014-05-22 5:37 ` David Kastrup
2014-05-22 13:57 ` Stefan Monnier
2014-05-22 15:49 ` Eli Zaretskii
2014-05-22 14:59 ` Barry OReilly
2014-05-22 17:03 ` Eli Zaretskii
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87ha46v4r5.fsf@mid.deneb.enyo.de \
--to=fw@deneb.enyo.de \
--cc=eliz@gnu.org \
--cc=emacs-devel@gnu.org \
--cc=fabrice.popineau@gmail.com \
--cc=monnier@IRO.UMontreal.CA \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).