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: Emacs design and architecture. How about copy-on-write? Date: Sat, 23 Sep 2023 16:15:57 +0300 Message-ID: <83il813u9e.fsf@gnu.org> References: <87cyyhc7uu.fsf@dataswamp.org> <83ttrsg9nx.fsf@gnu.org> <83h6nrg4eg.fsf@gnu.org> <83v8c7elan.fsf@gnu.org> <877conk5ny.fsf@localhost> <83ttrreeu0.fsf@gnu.org> <87bkdzeas1.fsf@localhost> <83cyyfe5l8.fsf@gnu.org> <87led2o0nb.fsf@localhost> <83ttrqcpfb.fsf@gnu.org> <877comnv4a.fsf@localhost> <83fs3ackrq.fsf@gnu.org> <87ttrp89bx.fsf@localhost> <83led1aqnq.fsf@gnu.org> <87v8c3zun7.fsf@localhost> <83r0mr8w0j.fsf@gnu.org> <87bkduxz3l.fsf@localhost> <83cyya75eb.fsf@gnu.org> <877coh2lmd.fsf@localhost> <83r0mp3zh5.fsf@gnu.org> <55f29d31-947f-4cfc-a90e-36b0592ba12e@gutov.dev> <83lecx3uxt.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="33805"; mail-complaints-to="usenet@ciao.gmane.io" Cc: yantar92@posteo.net, acm@muc.de, incal@dataswamp.org, emacs-devel@gnu.org To: Dmitry Gutov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Sep 23 15:16:46 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 1qk2V3-0008eH-TF for ged-emacs-devel@m.gmane-mx.org; Sat, 23 Sep 2023 15:16:45 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qk2UI-0005PI-In; Sat, 23 Sep 2023 09:15:58 -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 1qk2UH-0005Ot-3d for emacs-devel@gnu.org; Sat, 23 Sep 2023 09:15:57 -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 1qk2U6-0006Aq-9F; Sat, 23 Sep 2023 09:15:54 -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=x+TYv0mA1f6RuEIz3/Dqy9FA0w9KEyYndwn9Ro71+MQ=; b=QMvMekekQVks XmMIWhPrrQKSI9FeAgTazyhwIvhL2Wj+FNAuIAdURot+tSKf/8A//rzgtRYgpxAh+21wevbzSOxBy A6WpsAvio9I8jvOSfY8bPis4R5anKlGl8A6gWfclg8wLnQhB8VE8myPXan5UAD9P7foh6Jz2BxTRd 7cxV+ptcOP0HetZASkCc3WSqknq+3GC+11xe8jEaIU4piqKbSg0nIoqr7szP32lglF1BJClZZkQKq uqIE9bjPi7GiIYx3emhiSWyG+/PLRXzk6zWOMHGcAgSfMlXUG1IRwL9MWutxb/DYpO23kTwP4YGP9 iTe/F9HeX2CeVFAi1jz1AA==; In-Reply-To: (message from Dmitry Gutov on Sat, 23 Sep 2023 16:08:23 +0300) 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:311002 Archived-At: > Date: Sat, 23 Sep 2023 16:08:23 +0300 > Cc: yantar92@posteo.net, acm@muc.de, incal@dataswamp.org, emacs-devel@gnu.org > From: Dmitry Gutov > > On 23/09/2023 16:01, Eli Zaretskii wrote: > >> Date: Sat, 23 Sep 2023 15:53:11 +0300 > >> Cc:acm@muc.de,incal@dataswamp.org,emacs-devel@gnu.org > >> From: Dmitry Gutov > >> > >> On 23/09/2023 14:23, Eli Zaretskii wrote: > >>> As a trivial example, any function that modifies a file-visiting > >>> buffer could prompt the user if the file was meanwhile modified on > >>> disk. This prompt is completely out of control of any Lisp program > >>> which does something that modifies buffer text. How do we handle > >>> these cases? their name is a legion. > >> Any function that prompts the user is not supposed to be fast. So it > >> might as well acquire any number of global locks to do that. > > That's not my point. My point is that if we say that changes to adapt > > existing code to threads are acceptable, we will have to make those > > changes all over our infrastructure, otherwise programs written for > > threads will not ready for threads 100%. > > I agree: functions like yes-or-no-p will have to, internally in their > implementation, acquire the "redisplay lock" or whatever it'll be > called, and do other things to ensure that they work from non-default > threads too. > > This will likely make them a little slower compared to the single-thread > model, but hopefully not to a degree that's humanly noticeable. I'm not bothered by slowness, I'm much more bothered by the magnitude of the changes this will incur. I don't even know how to identify all the places which would need such changes.