From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#28630: 27.0.50; C-g while a non-main thread is sitting crashes Emacs Date: Mon, 09 Oct 2017 11:38:33 +0300 Message-ID: <838tgksol2.fsf@gnu.org> References: <87efqri8x9.fsf@gmail.com> <874lrjy2rz.fsf@gmail.com> <831smm52v4.fsf@gnu.org> <87d166rb6n.fsf@gmail.com> <83o9pq3eix.fsf@gnu.org> <838tgt352c.fsf@gnu.org> <83fuazz7ja.fsf@gnu.org> <83a817z5sd.fsf@gnu.org> <834lrfz2pk.fsf@gnu.org> <83infuxdk4.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1507538432 7797 195.159.176.226 (9 Oct 2017 08:40:32 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 9 Oct 2017 08:40:32 +0000 (UTC) Cc: 28630@debbugs.gnu.org, tom@tromey.com, agrambot@gmail.com To: YAMAMOTO Mitsuharu Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Oct 09 10:40:24 2017 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e1Tbj-0007s9-Gg for geb-bug-gnu-emacs@m.gmane.org; Mon, 09 Oct 2017 10:40:15 +0200 Original-Received: from localhost ([::1]:56717 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1Tbm-0005PP-0z for geb-bug-gnu-emacs@m.gmane.org; Mon, 09 Oct 2017 04:40:18 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48371) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1Tba-0005KZ-Ut for bug-gnu-emacs@gnu.org; Mon, 09 Oct 2017 04:40:12 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1TbW-0006wM-RT for bug-gnu-emacs@gnu.org; Mon, 09 Oct 2017 04:40:06 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:48442) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1e1TbW-0006wI-Nx for bug-gnu-emacs@gnu.org; Mon, 09 Oct 2017 04:40:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1e1TbW-0008NH-GR for bug-gnu-emacs@gnu.org; Mon, 09 Oct 2017 04:40:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 09 Oct 2017 08:40:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 28630 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 28630-submit@debbugs.gnu.org id=B28630.150753835832130 (code B ref 28630); Mon, 09 Oct 2017 08:40:02 +0000 Original-Received: (at 28630) by debbugs.gnu.org; 9 Oct 2017 08:39:18 +0000 Original-Received: from localhost ([127.0.0.1]:57123 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e1Tan-0008MA-TX for submit@debbugs.gnu.org; Mon, 09 Oct 2017 04:39:18 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:57154) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e1Tam-0008Lx-8y for 28630@debbugs.gnu.org; Mon, 09 Oct 2017 04:39:16 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1Tad-0006WY-2f for 28630@debbugs.gnu.org; Mon, 09 Oct 2017 04:39:11 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:53657) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1TaF-0006Qw-Ix; Mon, 09 Oct 2017 04:38:43 -0400 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:4801 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1e1TaD-0006qB-MZ; Mon, 09 Oct 2017 04:38:42 -0400 In-reply-to: (message from YAMAMOTO Mitsuharu on Mon, 09 Oct 2017 17:21:59 +0900) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 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" Xref: news.gmane.org gmane.emacs.bugs:138107 Archived-At: > Date: Mon, 09 Oct 2017 17:21:59 +0900 > From: YAMAMOTO Mitsuharu > Cc: YAMAMOTO Mitsuharu , agrambot@gmail.com, > 28630@debbugs.gnu.org, tom@tromey.com > > > For the record, on MS-Windows, both are interrupted. > > I could make the Mac port interruptible also for Example 2 (with some > delay because it uses polling with SIGALRM rather than SIGIO). I also > confirmed that Motif behaved like Athena. Below is updated one: Thanks, more commonality in behavior is good, I think. > In principle, the method I used for the Mac port is also applicable to > X11 (but probably not for NS where secondary threads cannot read > keyboard input). Each pselect call not involving keyboard input > additionally monitors one side of a socket pair, and the SIGALRM > handler writes to the other side. This way, a pselect call in a > secondary thread is unblocked when the signal arrived, and then it > tries to see if keyboard input is available when none of other threads > is monitoring the keyboard input channel. But the problematic part in these examples is that the main thread always waits for keyboard input, because the non-main thread starts running only when the main thread becomes idle, and becoming idle means calling pselect. And since the main thread is always the first one to call pselect, it is the thread which finds the keyboard descriptor unmonitored, and installs itself as its monitoring thread. So with your proposal, more often than not, the "none of other threads is monitoring the keyboard input channel" part will never be true, except for the main thread. Or am I missing something? > Having said that, I don't think we need the change like this urgently. > For now, we can see if the above method really works for more > complicated situations using the Mac port. I agree. So far, I've only seen toy programs, and it isn't clear to me how serious those problems are in real life.