From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: unwind-protect and inhibit-quit Date: Sat, 17 Jul 2021 09:20:41 +0300 Message-ID: <83sg0d4g1y.fsf@gnu.org> References: <875yxbr4lr.fsf@sperrhaken.name> <83eeby680s.fsf@gnu.org> <8735seosjs.fsf@sperrhaken.name> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24186"; mail-complaints-to="usenet@ciao.gmane.io" To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sat Jul 17 08:21:17 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m4dhM-00066a-UK for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 17 Jul 2021 08:21:16 +0200 Original-Received: from localhost ([::1]:60694 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m4dhL-0005s6-69 for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 17 Jul 2021 02:21:15 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:38050) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m4dh0-0005ri-Ab for help-gnu-emacs@gnu.org; Sat, 17 Jul 2021 02:20:54 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:33904) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m4dh0-0005BK-3x for help-gnu-emacs@gnu.org; Sat, 17 Jul 2021 02:20:54 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:4403 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m4dgz-0006l2-Nh for help-gnu-emacs@gnu.org; Sat, 17 Jul 2021 02:20:54 -0400 In-Reply-To: <8735seosjs.fsf@sperrhaken.name> (message from Felix Dietrich on Fri, 16 Jul 2021 23:30:31 +0200) X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:131779 Archived-At: > From: Felix Dietrich > Date: Fri, 16 Jul 2021 23:30:31 +0200 > > But at which point is the ‘quit-flag’ actually handled? When the C-level code of the Lisp machine thinks it's a good time to do that. In general, whenever the Lisp evaluation is entered, whenever a Lisp function is called, and inside any loops that might run for a long time or might not exit. There's no magic with handling quit on the C level, it mast be invoked explicitly. > The macro ‘with-local-quit’ states that the “quit-flag” “will not be > handled until the next function call”[1]. Could, therefore, a > careful and cooperative “ftp-setup-buffer” ensure that the process > is either cleaned-up or returned? There's no way to ensure atomicity on the Lisp level, because a Lisp program has no real control of when quit handling happens. Only primitives can do that (and actually do that where we think it's necessary). > I am thinking of something like the following: What problem(s) this is intended to fix/handle?