From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#12446: port better to POSIX hosts lacking _setjmp Date: Sat, 15 Sep 2012 12:44:24 +0300 Message-ID: <83haqztybr.fsf@gnu.org> References: <50538925.3010608@cs.ucla.edu> <83txv0tkho.fsf@gnu.org> <5053A177.1020608@cs.ucla.edu> <83sjaju5ca.fsf@gnu.org> <50543339.3090500@cs.ucla.edu> <83ligbu1uk.fsf@gnu.org> <50544272.2020602@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1347702310 23663 80.91.229.3 (15 Sep 2012 09:45:10 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 15 Sep 2012 09:45:10 +0000 (UTC) Cc: lekktu@gmail.com, 12446@debbugs.gnu.org To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sat Sep 15 11:45:11 2012 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1TCow0-00073m-0O for geb-bug-gnu-emacs@m.gmane.org; Sat, 15 Sep 2012 11:45:08 +0200 Original-Received: from localhost ([::1]:54022 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TCovw-0000Ge-69 for geb-bug-gnu-emacs@m.gmane.org; Sat, 15 Sep 2012 05:45:04 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:44003) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TCovt-0000FR-9L for bug-gnu-emacs@gnu.org; Sat, 15 Sep 2012 05:45:02 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TCovs-00082c-8H for bug-gnu-emacs@gnu.org; Sat, 15 Sep 2012 05:45:01 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:53431) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TCovs-00082X-5E for bug-gnu-emacs@gnu.org; Sat, 15 Sep 2012 05:45:00 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.72) (envelope-from ) id 1TCows-0007Nb-1s for bug-gnu-emacs@gnu.org; Sat, 15 Sep 2012 05:46:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 15 Sep 2012 09:46:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 12446 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 12446-submit@debbugs.gnu.org id=B12446.134770232928331 (code B ref 12446); Sat, 15 Sep 2012 09:46:02 +0000 Original-Received: (at 12446) by debbugs.gnu.org; 15 Sep 2012 09:45:29 +0000 Original-Received: from localhost ([127.0.0.1]:34744 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1TCowL-0007Mu-8R for submit@debbugs.gnu.org; Sat, 15 Sep 2012 05:45:29 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]:45554) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1TCowI-0007Mj-Q0 for 12446@debbugs.gnu.org; Sat, 15 Sep 2012 05:45:27 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0MAD00M00XONN200@a-mtaout22.012.net.il> for 12446@debbugs.gnu.org; Sat, 15 Sep 2012 12:44:23 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MAD00LCHXPYCRP0@a-mtaout22.012.net.il>; Sat, 15 Sep 2012 12:44:23 +0300 (IDT) In-reply-to: <50544272.2020602@cs.ucla.edu> X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.13 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 140.186.70.43 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.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:64344 Archived-At: > Date: Sat, 15 Sep 2012 01:55:14 -0700 > From: Paul Eggert > CC: 12446@debbugs.gnu.org, lekktu@gmail.com > > On 09/15/2012 01:28 AM, Eli Zaretskii wrote: > > So what was the rationale of turning away from _setjmp > > Some POSIXish hosts lack _setjmp, but have sigsetjmp, How did those hosts succeed to compile Emacs before your changes, then? > >> > Messups are trickier, because they involve rare race conditions. > >> > They can occur if Emacs or a system call has set the signal mask to X, > >> > but a longjump unexpectedly changes it to Y, where Y is not equal to X. > > Why is that a messup? > > Because Emacs then continues with the wrong sigmask, which can > cause signals to be blocked when they shouldn't be. longjmp restores the environment, including the signal mask, to what it was when setjmp was called. How can this restored mask be wrong, unless it was already wrong when setjmp was called?