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.devel Subject: Re: Concurrency via isolated process/thread Date: Mon, 10 Jul 2023 19:03:03 +0300 Message-ID: <83h6qb92ko.fsf@gnu.org> References: <871qhnr4ty.fsf@localhost> <87o7knbxr7.fsf@localhost> <838rbrg4mg.fsf@gnu.org> <87ilavbvdr.fsf@localhost> <834jmffvhy.fsf@gnu.org> <878rbrbmwr.fsf@localhost> <83fs5zecpo.fsf@gnu.org> <87351zbi72.fsf@localhost> <83351yevde.fsf@gnu.org> <87cz12ad2w.fsf@localhost> <83a5w6cwdr.fsf@gnu.org> <87pm518m0g.fsf@localhost> <83o7kl9tyj.fsf@gnu.org> <874jmd89us.fsf@localhost> <83cz119lxu.fsf@gnu.org> <87v8et6q5m.fsf@localhost> <838rbp9h6c.fsf@gnu.org> <87edlg6m2l.fsf@localhost> <83o7kj9alq.fsf@gnu.org> <87y1jn6f6v.fsf@localhost> <83ilar96iv.fsf@gnu.org> <87v8er6ck7.fsf@localhost> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="15894"; mail-complaints-to="usenet@ciao.gmane.io" Cc: monnier@iro.umontreal.ca, luangruo@yahoo.com, emacs-devel@gnu.org To: Ihor Radchenko Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Jul 10 18:04:11 2023 Return-path: Envelope-to: ged-emacs-devel@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 1qItMw-0003uo-Nv for ged-emacs-devel@m.gmane-mx.org; Mon, 10 Jul 2023 18:04:10 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qItLn-00010B-Q4; Mon, 10 Jul 2023 12:02:59 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qItLl-0000x0-W1 for emacs-devel@gnu.org; Mon, 10 Jul 2023 12:02:58 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qItLk-0003n2-09; Mon, 10 Jul 2023 12:02:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=HKT7h5cWdQvEfSS3wQyod0ILalT0Z7o4JWLu++7huTw=; b=cy8oVUsOQz8A VTqGFiOPJuJujxnQumTxqMFf36hWe4cUFR8ikvdfPHELLFw2rGN9TFjI6ulofZLoePD+AZJPj7Tu3 aeXlKen542GbSAPdrmVD3rl0CPs7VVnC39NqrnF8iNIQOHYyzH1HieB8UToH4FKyLY1u0LqWowtQ0 qXatnfiG1TB7f/fKs7NE3dcJNL978iP2FFkiMyTUPzeWVUfCiocGAAIl+OccWaz/911jZqOLTldGC OWXyGQ+Rki8ZEIHIZj7+JwCwAxPlOLiSe71DKQmI0+7Pz5vpThr6aZ63/yWnqtPIXdxpB5otwJboX yCmOhuJYV7E5nrJmAZEPtw==; Original-Received: from [87.69.77.57] (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 1qItLj-0007Ez-CX; Mon, 10 Jul 2023 12:02:55 -0400 In-Reply-To: <87v8er6ck7.fsf@localhost> (message from Ihor Radchenko on Mon, 10 Jul 2023 14:55:36 +0000) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:307727 Archived-At: > From: Ihor Radchenko > Cc: monnier@iro.umontreal.ca, luangruo@yahoo.com, emacs-devel@gnu.org > Date: Mon, 10 Jul 2023 14:55:36 +0000 > > Eli Zaretskii writes: > > > You are asking questions that would require me to do a lot of code > > scanning and investigating to produce a full answer. So please > > forgive me if I can afford only some random examples that pop up in my > > mind, not even close to the exhaustive list: > > Thanks, that is good enough. > I mostly wanted to get pointers to interesting places in that 1.2Mb > xdisp.c file to save myself from reading it from top to bottom. You'd still need to do that, because the list I posted is nowhere near complete. > > . the window tree (redisplay traverses it depth-first) > > . point position of displayed buffers (needed to decide whether to > > scroll the window) > > Maybe point position in window? No, point of the buffer. We copy the window-point to the buffer point once, but assume it stays put thereafter, until we are done with the window. > > . narrowing of each displayed buffer > > . text properties and overlays of each displayed buffer > > . which window is selected on each frame > > . window-start position of each window > > . variables affecting display: display-line-numbers, > > show-trailing-whitespace, line-spacing, auto-compression-mode, > > auto-hscroll-mode, mode-line-format, etc. > > These lay in 4 categories: > 1. Data attached to frame object (window tree) > 2. Data attached to window object (point position, window-start, etc) > 3. Data attached to buffer object (buffer-local variables, narrowing) > 4. Global Lisp variables Beware: you categorize and are making conclusions based on incomplete information. > I have a suspicion that at least windows in a frame might be redisplayed > in parallel, unless some strange Elisp code is allowed to modify things > affecting redisplay. Mostly, yes. But there are things like resize-mini-windows that can affect other windows. Also, this is limited to GUI redisplay; TTY frames have additional subtleties. > May I know what happens if redisplay code sets variables like > line-spacing or display-line-numbers? Is it allowed? In a nutshell, we need to abort the current redisplay cycle and start anew. So doing that is a very bad idea.