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: Dynamic loading progress Date: Sat, 21 Nov 2015 15:10:05 -0800 Organization: UCLA Computer Science Department Message-ID: <5650F9CD.9030707@cs.ucla.edu> References: <876118u6f2.fsf@lifelogs.com> <8737w3qero.fsf@lifelogs.com> <831tbn9g9j.fsf@gnu.org> <878u5upw7o.fsf@lifelogs.com> <83ziya8xph.fsf@gnu.org> <83y4du80xo.fsf@gnu.org> <837fld6lps.fsf@gnu.org> <83610w5o97.fsf@gnu.org> <564FACF5.2080601@cs.ucla.edu> <564FBAA7.5030306@cs.ucla.edu> 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: ger.gmane.org 1448147438 25449 80.91.229.3 (21 Nov 2015 23:10:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 21 Nov 2015 23:10:38 +0000 (UTC) Cc: aurelien.aptel+emacs@gmail.com, tzz@lifelogs.com, emacs-devel@gnu.org To: Philipp Stephani , Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Nov 22 00:10:28 2015 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 1a0HIZ-0002dV-Oa for ged-emacs-devel@m.gmane.org; Sun, 22 Nov 2015 00:10:27 +0100 Original-Received: from localhost ([::1]:54011 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a0HIZ-000377-7f for ged-emacs-devel@m.gmane.org; Sat, 21 Nov 2015 18:10:27 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46358) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a0HIL-00036v-Le for emacs-devel@gnu.org; Sat, 21 Nov 2015 18:10:14 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a0HIK-0006CY-UD for emacs-devel@gnu.org; Sat, 21 Nov 2015 18:10:13 -0500 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:40512) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a0HIH-0006BX-2F; Sat, 21 Nov 2015 18:10:09 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 7132D160D25; Sat, 21 Nov 2015 15:10:07 -0800 (PST) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id BRIfW8vmGSCM; Sat, 21 Nov 2015 15:10:06 -0800 (PST) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 540B3160DFE; Sat, 21 Nov 2015 15:10:06 -0800 (PST) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id lywa0GMRyDxu; Sat, 21 Nov 2015 15:10:06 -0800 (PST) Original-Received: from [192.168.1.9] (pool-100-32-155-148.lsanca.fios.verizon.net [100.32.155.148]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 2A06F160D25; Sat, 21 Nov 2015 15:10:06 -0800 (PST) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 In-Reply-To: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 131.179.128.68 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:194970 Archived-At: Philipp Stephani wrote: >> Many modules will have needs similar to Emacs itself in >> >that >> >respect, and it would be better if they didn't have to reinvent this >> >so-common >> >wheel. >> > > But what should the interface be? There are only three possibilities in C: > return a sentinel value, crash, longjmp. There's a fourth possibility: do what Emacs does. Emacs defines its own throw-catch mechanism built atop C. C modules that need to cleanup when unwound can do so by registering via the equivalent of record_unwind_protect, and Emacs won't longjmp through them without cleaning up. This already works for xmalloc memory-exhaustion failures, and modules can just use the already-existing mechanism.