From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Concurrency, again Date: Thu, 20 Oct 2016 10:54:39 +0300 Message-ID: <83r37btpz4.fsf@gnu.org> References: <87wq97i78i.fsf@earlgrey.lan> <86k2dk77w6.fsf@molnjunk.nocrew.org> <9D64B8EA-DB52-413D-AE6A-264416C391F3@iotcl.com> <83int1g0s5.fsf@gnu.org> <83twckekqq.fsf@gnu.org> <874m4aic0g.fsf@tromey.com> <7D150317-7A01-464D-8352-942631A3116B@raeburn.org> <8337juxb8h.fsf@gnu.org> <31A629C9-7C3B-4B5D-A5B5-38F556C4E064@raeburn.org> <83wph6vt0f.fsf@gnu.org> <646C7DAF-F7AB-48C2-AFDF-6881D2990617@raeburn.org> <83mvi0v9f2.fsf@gnu.org> <9DABFA8E-064D-4647-A4FE-0041C8B0051C@raeburn.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: blaine.gmane.org 1476950156 24794 195.159.176.226 (20 Oct 2016 07:55:56 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 20 Oct 2016 07:55:56 +0000 (UTC) Cc: emacs-devel@gnu.org To: Ken Raeburn Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 20 09:55:51 2016 Return-path: Envelope-to: ged-emacs-devel@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 1bx8CF-00035g-Tg for ged-emacs-devel@m.gmane.org; Thu, 20 Oct 2016 09:55:28 +0200 Original-Received: from localhost ([::1]:52992 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bx8CI-0001qQ-84 for ged-emacs-devel@m.gmane.org; Thu, 20 Oct 2016 03:55:30 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53778) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bx8Bk-0001qI-U0 for emacs-devel@gnu.org; Thu, 20 Oct 2016 03:54:57 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bx8Bg-0004BJ-NQ for emacs-devel@gnu.org; Thu, 20 Oct 2016 03:54:56 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:40195) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bx8Bg-0004BD-Jt; Thu, 20 Oct 2016 03:54:52 -0400 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:4718 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1bx8Bf-0002DO-CL; Thu, 20 Oct 2016 03:54:51 -0400 In-reply-to: <9DABFA8E-064D-4647-A4FE-0041C8B0051C@raeburn.org> (message from Ken Raeburn on Thu, 20 Oct 2016 02:08:14 -0400) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:208531 Archived-At: > From: Ken Raeburn > Date: Thu, 20 Oct 2016 02:08:14 -0400 > Cc: emacs-devel@gnu.org > > I just tried a test with a breakpoint in redisplay_internal; it can get called from threads other than the main thread. As far as I know, we can’t have multiple threads in the redisplay code at the same time, though. But redisplay_internal will return immediately without doing anything if it's already running in some other thread. (And this "running in some other thread could only happen if that other thread somehow succeeded to block or yield in the middle of redisplay, which I think is only possible if it calls Lisp.)