From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.devel Subject: Re: Emacs design and architecture. How about copy-on-write? Date: Wed, 20 Sep 2023 12:09:24 +0000 Message-ID: <871qet82rv.fsf@localhost> References: <87sf7fc7kd.fsf@dataswamp.org> <834jjuk68t.fsf@gnu.org> <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> <8734zbyu6o.fsf@dataswamp.org> <835y46e8o9.fsf@gnu.org> <87zg1ixvnc.fsf@dataswamp.org> <83sf7acp86.fsf@gnu.org> <87msxiuxqd.fsf@yahoo.com> <83bkdycjqu.fsf@gnu.org> <878r91vel8.fsf@yahoo.com> <83ttrpaw8r.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="24496"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Po Lu , incal@dataswamp.org, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Sep 20 14:09:06 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 1qiw0t-000613-Lm for ged-emacs-devel@m.gmane-mx.org; Wed, 20 Sep 2023 14:09:03 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qiw0E-0004iM-BJ; Wed, 20 Sep 2023 08:08:22 -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 1qiw0B-0004hk-VX for emacs-devel@gnu.org; Wed, 20 Sep 2023 08:08:19 -0400 Original-Received: from mout02.posteo.de ([185.67.36.66]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiw04-0003KJ-7I for emacs-devel@gnu.org; Wed, 20 Sep 2023 08:08:19 -0400 Original-Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 746BF240103 for ; Wed, 20 Sep 2023 14:08:10 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1695211690; bh=JYep39oKtHt7Qeqs8jEpAbYYRoE+fGhOcNXfUI+a1cM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:From; b=Cptrx5ZqPw2Uu/A4Fc8NkPJGzXTG3DVEXdRJdFl5CDV2AOruJCQr1VAm75C3/tGyy 7O8EwU4f6zQG+ECYyllAYRIx170eG3WXrvjuQGKat7PCuKXZJXgAC34qeKWQkcghRY Hb3OIeQIKZDnydRZIcAMAsDOdpJRIp67n9WK+gmYhbMPbmf5l1ZoNfs0rTcVQH3MVu NBmFZKsSWMwGeyI1j7mHbUhAfpzIOykYxgsHDNrRrHGRNr+ectxrE7XXvfKwRzo5Fm ueTO6gQWhXThf9KsjkOnUIWn3e+1ERTVhXyZmKYlYfiXKuaoSvndMo2XoUf/8SaoBV ICR0NLVKtyAsw== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4RrHNn0QDfz6tvr; Wed, 20 Sep 2023 14:08:08 +0200 (CEST) In-Reply-To: <83ttrpaw8r.fsf@gnu.org> Received-SPF: pass client-ip=185.67.36.66; envelope-from=yantar92@posteo.net; helo=mout02.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action 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:310826 Archived-At: Eli Zaretskii writes: >> My solution (which I've put into practice in redisplay) is to save those >> values before sensitive code is executed, and to refer to those saved >> values within said code. > > That is _everyone's_ solution, not just yours. But it is not as easy > in practice as it may sound. E.g., imagine a subroutine that is > called by some higher-level functions, where both the callers and the > subroutine need to access the same variable. When other threads are > running, there's no longer a guarantee that both the caller and the > callee will see the same value of that variable. If they must use the > same value, you now need to pass that variable to the callee via its > API, and this is not scalable when you have more than a couple, > especially if the callee is not called directly, but via several > intermediate callers. May the state be captured and passed to the callee under the hood? Something like forking, but using thread-local state. For lexical bindings, it is just a matter of passing over current Vinternal_interpreter_environment; and for global bindings, it is a matter of passing whatever is altered by the caller thread (with copy-on-write, this info should be available). -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at