From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: dick.r.chiang@gmail.com Newsgroups: gmane.emacs.bugs Subject: bug#36609: 27.0.50; Possible race-condition in threading implementation Date: Sun, 06 Jun 2021 15:10:43 -0400 Message-ID: <875yyqg66k.fsf@dick> References: <87muhks3b5.fsf@hochschule-trier.de> <87fsxv8182.fsf@dick> <83wnr7gdd8.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="35262"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: larsi@gnus.org, pipcet@gmail.com, politza@hochschule-trier.de, 36609@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Jun 06 21:11:12 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 1lpyAv-0008wv-9f for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 06 Jun 2021 21:11:09 +0200 Original-Received: from localhost ([::1]:51220 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lpyAu-0002X3-B7 for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 06 Jun 2021 15:11:08 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34046) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lpyAo-0002Wv-VU for bug-gnu-emacs@gnu.org; Sun, 06 Jun 2021 15:11:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:42385) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lpyAo-0003N3-Hq for bug-gnu-emacs@gnu.org; Sun, 06 Jun 2021 15:11:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1lpyAo-0003LG-9e for bug-gnu-emacs@gnu.org; Sun, 06 Jun 2021 15:11:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: dick.r.chiang@gmail.com Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 06 Jun 2021 19:11:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 36609 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: fixed Original-Received: via spool by 36609-submit@debbugs.gnu.org id=B36609.162300665312830 (code B ref 36609); Sun, 06 Jun 2021 19:11:02 +0000 Original-Received: (at 36609) by debbugs.gnu.org; 6 Jun 2021 19:10:53 +0000 Original-Received: from localhost ([127.0.0.1]:53931 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lpyAe-0003Ks-SH for submit@debbugs.gnu.org; Sun, 06 Jun 2021 15:10:53 -0400 Original-Received: from mail-qt1-f172.google.com ([209.85.160.172]:41889) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lpyAc-0003Ke-J8 for 36609@debbugs.gnu.org; Sun, 06 Jun 2021 15:10:52 -0400 Original-Received: by mail-qt1-f172.google.com with SMTP id t20so11106063qtx.8 for <36609@debbugs.gnu.org>; Sun, 06 Jun 2021 12:10:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version; bh=Ii2/Rl1Fw+a5g8FFIrlPqc75+C/SZyw+VDsLidLI4zg=; b=gehuvzjASn3FJz7He/4ycY2HcsMI3LzRTHgXrBbAY1InrfWFUxDBFgEZbY7hJ1aS7U Rwl9tkY7bjCw4/u8OygJQyfW/Imxsmx+DvO05IhHxTDqLiKY09ZO7vUsjwW/OW1zpccY swL8KeQAFWwldRwaZgsn3WCUY77VjTfHNbg/MmR4HWMZViELwpIh93iixNns0c449Zb+ IDD2SI+gEYJIZiqzAoISu7ZGuUpjQNF0Z1m1jGKYLbHbKdrbz1oeXnEjeUhe8v9Fr7Rh 2ZvnKjtM/zYUXiTYZmmO8V7lVBUS4Wa2mXxyTJAJZNFvjN/eB8CFFglJopxJJUo8Fg4f T/pA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:references:date:in-reply-to :message-id:user-agent:mime-version; bh=Ii2/Rl1Fw+a5g8FFIrlPqc75+C/SZyw+VDsLidLI4zg=; b=g0OnxP3V0FGZRiB4Z1E6XCzcvUx94Hi84CYnb17++vM3DUsNiAZO47Ys0ufoUmxRVe fsUEpJ1nCLRFhPmWi2on+ZZdllW0SzLGdDLsl8F1MKRDeqGQ5re685rNT8nu4P+cE+WD 0qbitUQ8fVkV9R1VOZoxM/Dw65TgZCisG94w50ZzSswCso87ikWsxsyS5XLQeBPn5Zx7 llz5bP5aZxkkY4wrBtAzlJBkJDqwgCbmTVwowccGVdH7Gyn7WutBIP0eD26BR8TWuHQr tLpgfJYaDpeBRGpXTGVB+Ze0wQowPqz2V9Qfmm9WP5P5jLIfOzTetEh4VYIvVv0EaIs3 kJVQ== X-Gm-Message-State: AOAM5318iTNnewg25jNZYG9rRAt/zxJIKEm1spPWyBztN8DO5l+ygtc4 tTrWDGZV0glq6TjQDqA9oYY= X-Google-Smtp-Source: ABdhPJw+WShAN5HHm+9ljRf9M+ffbwMFHwB7znfm2L6ZD8bQ1ofT3tHPc9ka2Gd1QDfsHkljJjl80g== X-Received: by 2002:aed:210f:: with SMTP id 15mr13784398qtc.149.1623006645070; Sun, 06 Jun 2021 12:10:45 -0700 (PDT) Original-Received: from localhost (pool-71-190-212-171.nycmny.fios.verizon.net. [71.190.212.171]) by smtp.gmail.com with ESMTPSA id a191sm8374803qkg.61.2021.06.06.12.10.44 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 06 Jun 2021 12:10:44 -0700 (PDT) In-Reply-To: <83wnr7gdd8.fsf@gnu.org> (Eli Zaretskii's message of "Sun, 06 Jun 2021 19:35:31 +0300") 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:208152 Archived-At: EZ> This will bring back bug#36609, so we cannot do that without EZ> discussing first why you think that commit was wrong. By enforcing bijection between acquires and releases in xgselect.c -- cavalierly so as the releases now come out-of-band from another module thread.c -- commit 9c62ffb admits deadlock. The conditions under which that happens are not at all rarefied as evidenced by `for i in 1 2 3 ; do src/emacs -Q -l ./42.el & done ;` Generally, a commit made to remedy a phantom problem should always be suspect. In this case OP was squatting on the main thread, so he deserves what he got. EZ> Yes, race conditions can be solved by using sleep-for, but that's not EZ> really a clean solution, at least not in my book. Case #4 was not meant to solve anything, only to set OP straight on what he really wanted. You can remove the sleep-for. Still works under patch #1.