From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: [Emacs-diffs] /srv/bzr/emacs/trunk r109327: Generalize INTERNAL_FIELD between buffers, keyboards and frames. Date: Wed, 01 Aug 2012 07:58:58 -0700 Organization: UCLA Computer Science Department Message-ID: <50194432.8000808@cs.ucla.edu> References: <50191B54.2070705@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1343833151 19814 80.91.229.3 (1 Aug 2012 14:59:11 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 1 Aug 2012 14:59:11 +0000 (UTC) Cc: emacs-devel@gnu.org To: Dmitry Antipov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Aug 01 16:59:11 2012 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1SwaOC-0005OT-PK for ged-emacs-devel@m.gmane.org; Wed, 01 Aug 2012 16:59:08 +0200 Original-Received: from localhost ([::1]:60874 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwaOC-00053G-6D for ged-emacs-devel@m.gmane.org; Wed, 01 Aug 2012 10:59:08 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:51159) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwaO5-00052v-Oa for emacs-devel@gnu.org; Wed, 01 Aug 2012 10:59:07 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SwaNx-0005d4-1l for emacs-devel@gnu.org; Wed, 01 Aug 2012 10:59:01 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:40242) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwaNw-0005ch-TB for emacs-devel@gnu.org; Wed, 01 Aug 2012 10:58:52 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id 8FFB8A60008; Wed, 1 Aug 2012 07:58:51 -0700 (PDT) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id K+1YL44thnfQ; Wed, 1 Aug 2012 07:58:51 -0700 (PDT) Original-Received: from [192.168.1.4] (pool-108-23-119-2.lsanca.fios.verizon.net [108.23.119.2]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 31466A60007; Wed, 1 Aug 2012 07:58:51 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 In-Reply-To: <50191B54.2070705@yandex.ru> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:152082 Archived-At: On 08/01/2012 05:04 AM, Dmitry Antipov wrote: > I'm really trying to design some GC bits on top of this. OK, but why bother to do the hugely overestimated write barrier that FVAR implies? Surely that is not what is wanted here, for the garbage collector. As I understand it, what's really wanted for the GC is SET_FVAR. FVAR itself might be useful in that it can be forced to be an rvalue so that code doesn't use FVAR (...) = VAL by mistake, but surely that is secondary. Stefan's point also, is that it'll be easy enough to introduce SET_FVAR when the GC bits are ready, and that there's no pressing need to introduce it now. While we're on the topic, the code is currently sloppy about using ASET; sometimes it uses 'AREF (a, b) = c' rather than 'ASET (a, b, c)'. I suppose this will need fixing too. It probably should be fixed regardless of any GC changes.