From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andy Wingo Newsgroups: gmane.lisp.guile.devel Subject: Re: redoing SCM representation in 2.2 Date: Sun, 15 May 2011 17:35:04 +0200 Message-ID: References: <87ei42qmmf.fsf@netris.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: dough.gmane.org 1305473724 18505 80.91.229.12 (15 May 2011 15:35:24 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 15 May 2011 15:35:24 +0000 (UTC) Cc: Mark H Weaver , guile-devel To: Ken Raeburn Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Sun May 15 17:35:20 2011 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QLdLj-00037S-Lz for guile-devel@m.gmane.org; Sun, 15 May 2011 17:35:19 +0200 Original-Received: from localhost ([::1]:53642 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QLdLi-0003w7-TO for guile-devel@m.gmane.org; Sun, 15 May 2011 11:35:18 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:37114) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QLdLg-0003vg-5l for guile-devel@gnu.org; Sun, 15 May 2011 11:35:17 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QLdLe-00052a-Nc for guile-devel@gnu.org; Sun, 15 May 2011 11:35:16 -0400 Original-Received: from a-pb-sasl-sd.pobox.com ([64.74.157.62]:52774 helo=sasl.smtp.pobox.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QLdLe-00051x-Ih for guile-devel@gnu.org; Sun, 15 May 2011 11:35:14 -0400 Original-Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 380844A4C; Sun, 15 May 2011 11:37:19 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=X97MGJF+ACqLW5GiXHRGsM0LmUU=; b=HnwPSH Sh/cAJKBSLhsF9x5qXlq2YjWoWO4rlolfZ2olcrnxcbahFwtgg8zHGOIj6/msHWb 0bZbCewgXHutKgzb4/Ao4AwdKThsJnUKO2ub+1VVMxdScPybjGnTS9MC6XIeufPd xGt8+z+rQjnvs/IEW4CwBKlqTW4/nmbDz3UP0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=yTuAwLrAkZwlzJmCXX+TXIS8BnwjYlRH KFp9X7xWI9tN53yFhTp/afU+rKIy2VSuR+rCfvCXql3d3b75GaWL9sEgKXKBqu4q LzDbxTtFeKHGCqEqgxMimjqhfzTUuAo9m9KVRxU+PNyHXsdpx0CIB/FddFhywR8m sFzAO3C1nQU= Original-Received: from a-pb-sasl-sd.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 15C654A4B; Sun, 15 May 2011 11:37:17 -0400 (EDT) Original-Received: from unquote.localdomain (unknown [90.164.198.39]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTPSA id 4224A4A4A; Sun, 15 May 2011 11:37:13 -0400 (EDT) In-Reply-To: (Ken Raeburn's message of "Sun, 15 May 2011 05:02:17 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) X-Pobox-Relay-ID: 36ADCA28-7F09-11E0-91E9-BBB7F5B2FB1A-02397024!a-pb-sasl-sd.pobox.com X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 64.74.157.62 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:12495 Archived-At: On Sun 15 May 2011 11:02, Ken Raeburn writes: > Is that really any more of an issue this way than with the current > encoding -- if not for SCM, then for heap data structures including both > SCM objects and integers or characters? I thought the GC code already > had to cope with things looking like they could be pointers but not > actually corresponding to anything allocated via the GC library. It's not an issue for SCM values. The Scheme stack has only Scheme values, so there's no problem there either; and the C stack is small, mostly ephemeral, and there is good blacklisting, so no problem there either, AFAIK. Heap values which contain no GC-controlled pointers are allocated "atomically", which means the GC doesn't trace them. So the issue would only be with structures which are traced by GC and include both, and there are very few of those. Regards, Andy -- http://wingolog.org/