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.bugs Subject: bug#49261: 28.0.50; File Locking Breaks Presumptuous Toolchains Date: Wed, 07 Jul 2021 22:20:50 +0300 Message-ID: <83v95mdj71.fsf@gnu.org> References: <87o8bn7bie.fsf@gnus.org> <87zgv6vuon.fsf@gmx.de> <837di9lwbm.fsf@gnu.org> <87a6n5vuu4.fsf@gnus.org> <8735sqnmei.fsf@gnus.org> <834kd6f1dw.fsf@gnu.org> <87h7h6m1jh.fsf@gnus.org> <83zguydkyz.fsf@gnu.org> <878s2i3q96.fsf@gnus.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="21208"; mail-complaints-to="usenet@ciao.gmane.io" Cc: michael.albinus@gmx.de, ncaprisunfan@gmail.com, 49261@debbugs.gnu.org To: Lars Ingebrigtsen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jul 07 21:21:55 2021 Return-path: Envelope-to: geb-bug-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 1m1D7K-0005HM-SE for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 07 Jul 2021 21:21:54 +0200 Original-Received: from localhost ([::1]:41224 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m1D7J-0005gA-Sn for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 07 Jul 2021 15:21:53 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:42506) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m1D6U-0004rX-Rr for bug-gnu-emacs@gnu.org; Wed, 07 Jul 2021 15:21:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:41987) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m1D6U-0005is-Jw for bug-gnu-emacs@gnu.org; Wed, 07 Jul 2021 15:21:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1m1D6U-00021C-1T for bug-gnu-emacs@gnu.org; Wed, 07 Jul 2021 15:21:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 07 Jul 2021 19:21:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 49261 X-GNU-PR-Package: emacs Original-Received: via spool by 49261-submit@debbugs.gnu.org id=B49261.16256856497732 (code B ref 49261); Wed, 07 Jul 2021 19:21:01 +0000 Original-Received: (at 49261) by debbugs.gnu.org; 7 Jul 2021 19:20:49 +0000 Original-Received: from localhost ([127.0.0.1]:53533 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1m1D6H-00020d-Dg for submit@debbugs.gnu.org; Wed, 07 Jul 2021 15:20:49 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:44688) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1m1D6E-00020N-Ha for 49261@debbugs.gnu.org; Wed, 07 Jul 2021 15:20:48 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:42836) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m1D68-0005cY-Q9; Wed, 07 Jul 2021 15:20:41 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:1709 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 1m1D68-0001q2-C2; Wed, 07 Jul 2021 15:20:40 -0400 In-Reply-To: <878s2i3q96.fsf@gnus.org> (message from Lars Ingebrigtsen on Wed, 07 Jul 2021 20:58:29 +0200) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:209621 Archived-At: > From: Lars Ingebrigtsen > Cc: michael.albinus@gmx.de, ncaprisunfan@gmail.com, 49261@debbugs.gnu.org > Date: Wed, 07 Jul 2021 20:58:29 +0200 > > Eli Zaretskii writes: > > > Even if it currently works, it's unsafe, IMO, to not have any > > protection there. No one will remember that we rely on this not being > > called early enough. > > Right. My reasoning was that it seemed unlikely to be a problem here, > since the same function also (possibly) calls the Lisp functions > userlock--ask-user-about-supersession-threat and ask-user-about-lock. > But those are only called in some cases, so we're calling out to Lisp > more now than before, and that may indeed be a problem. Right, the call to userlock--ask-user-about-supersession-threat is under some conditions that are rarely satisfied. > I can add a check to whether the Lisp function is defined before calling > (and then not do locking if it isn't) to be more defensive here? I guess so. > > So I'm asking whether the simplicity justifies the costs, here and > > elsewhere. > > I agree with you 100% that it's important to take this into > consideration when moving things from C to Lisp. In this particular > case, I think the cost is justified, because this isn't a function > that's called in a loop, and the other things it does (calling > Fverify_visited_file_modtime and Ffile_exists_p, and actually creating > the lock file) totally swamps any extra string consing, I think. (That > is, it won't take measurably longer.) If it triggers GC, it _will_ take significantly longer. But I won't argue more about this, it's a lost battle anyway with current Emacs development trends.