From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Dmitry Antipov Newsgroups: gmane.emacs.devel Subject: Re: Note on 109327 Date: Tue, 31 Jul 2012 17:50:43 +0400 Message-ID: <5017E2B3.1060608@yandex.ru> References: <5017D1D4.2050601@yandex.ru> <5017DCBE.6020606@yandex.ru> <877gtk12e1.fsf@fleche.redhat.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1343742673 9244 80.91.229.3 (31 Jul 2012 13:51:13 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 31 Jul 2012 13:51:13 +0000 (UTC) Cc: Dan Nicolaescu , Emacs development discussions To: Tom Tromey Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jul 31 15:51:11 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 1SwCqp-00021c-4c for ged-emacs-devel@m.gmane.org; Tue, 31 Jul 2012 15:51:07 +0200 Original-Received: from localhost ([::1]:52896 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwCqo-0001Cy-EF for ged-emacs-devel@m.gmane.org; Tue, 31 Jul 2012 09:51:06 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:49435) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwCqg-0001CS-TP for emacs-devel@gnu.org; Tue, 31 Jul 2012 09:51:04 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SwCqb-0004wM-9B for emacs-devel@gnu.org; Tue, 31 Jul 2012 09:50:58 -0400 Original-Received: from forward17.mail.yandex.net ([95.108.253.142]:51026) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwCqU-0004sU-W5; Tue, 31 Jul 2012 09:50:47 -0400 Original-Received: from smtp16.mail.yandex.net (smtp16.mail.yandex.net [95.108.252.16]) by forward17.mail.yandex.net (Yandex) with ESMTP id 20B551061768; Tue, 31 Jul 2012 17:50:45 +0400 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1343742645; bh=3XOq8VjuwqU8EfaYIoN4STPAR1YyjLMsPRSoCjVJrZo=; h=Message-ID:Date:From:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type:Content-Transfer-Encoding; b=U9rvJPTuTRyh8krw+IKqHNkWYt5dKYD0mPLH9nwECp8yc2nMk5udlH47+9R58bSyj +m9urYaA2eg0gLI+M3xlmBrNuwSWnT4wfjNxPmWqimbz4ARqlHHIP0RL935HCZz8ol wDLOtJw3tY4HwWQTRY/6kIbnX259fPYw/0/6Gcf8= Original-Received: from smtp16.mail.yandex.net (localhost [127.0.0.1]) by smtp16.mail.yandex.net (Yandex) with ESMTP id E33F06A05F0; Tue, 31 Jul 2012 17:50:44 +0400 (MSK) Original-Received: from 155.gprs.mts.ru (155.gprs.mts.ru [213.87.130.155]) by smtp16.mail.yandex.net (nwsmtp/Yandex) with ESMTP id ohhC93Gj-oihmhRSe; Tue, 31 Jul 2012 17:50:44 +0400 X-Yandex-Rcpt-Suid: tromey@redhat.com X-Yandex-Rcpt-Suid: dann@gnu.org X-Yandex-Rcpt-Suid: emacs-devel@gnu.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1343742644; bh=3XOq8VjuwqU8EfaYIoN4STPAR1YyjLMsPRSoCjVJrZo=; h=Message-ID:Date:From:User-Agent:MIME-Version:To:CC:Subject: References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=NCWA+fhPOdRhBPCizAzdGlg8gNowJo/cRH3CKqFbm7QDOXA68Mqh13RQ0HyeRu+y6 jyM0D7H6HmdIZa5ThTy5ZSPoRp3Vz9NOTHgvYHeQzEN/vKU5azUY7Zo+x6TYBfgEGr nmT3Yh2jQmMwWWjKegRF6fhd6gIGkNS9RJxJ4KHE= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120713 Thunderbird/14.0 In-Reply-To: <877gtk12e1.fsf@fleche.redhat.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 95.108.253.142 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:152000 Archived-At: On 07/31/2012 05:33 PM, Tom Tromey wrote: > Dmitry> Yes. I'm always thinking about improving internal stuff, GC at first. > Dmitry> For me, the main motivation for BVAR, KVAR, FVAR etc. is the ability > Dmitry> to catch the moment when the pointer (e.g. Lisp_Object) within buffer, > Dmitry> or keyboard, of frame, etc. is read or written, which may be useful > Dmitry> to implement write barriers (see, for exmaple, > Dmitry> http://www.hoelzle.org/publications/write-barrier.pdf, but do not > Dmitry> get confused with http://en.wikipedia.org/wiki/Memory_barrier). > > I think to do this well you will need separate macros for getting and > setting. Sure, but it's almost impossible to do this at once. At the very beginning, it's possible to "overestimate" barrier assuming that each XVAR (obj, field) changes FIELD in OBJ; in the future, reads and writes may be separated, thus giving a precise write barrier. Dmitry