From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: =?utf-8?Q?Gerd_M=C3=B6llmann?= Newsgroups: gmane.emacs.devel Subject: Re: MPS signals and Emacs Date: Mon, 22 Apr 2024 10:27:42 +0200 Message-ID: References: <878r16n5jl.fsf@gmail.com> <87ttjulb16.fsf@gmail.com> <86a5ll7wj9.fsf@gnu.org> <71431fc4-2ab2-4778-88df-25d4e315d737@cs.ucla.edu> <00fec231-a625-406e-a51b-cb66710c6482@cs.ucla.edu> <86wmop6cot.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="38618"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: eggert@cs.ucla.edu, eller.helmut@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Apr 22 10:28:46 2024 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 1ryp2b-0009sW-PF for ged-emacs-devel@m.gmane-mx.org; Mon, 22 Apr 2024 10:28:45 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ryp1h-0002Iw-Jk; Mon, 22 Apr 2024 04:27:49 -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 1ryp1f-0002I0-Ky for emacs-devel@gnu.org; Mon, 22 Apr 2024 04:27:47 -0400 Original-Received: from mail-ej1-x629.google.com ([2a00:1450:4864:20::629]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ryp1e-00070I-4e; Mon, 22 Apr 2024 04:27:47 -0400 Original-Received: by mail-ej1-x629.google.com with SMTP id a640c23a62f3a-a55ab8e8766so115511066b.3; Mon, 22 Apr 2024 01:27:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1713774464; x=1714379264; darn=gnu.org; h=mime-version:user-agent:message-id:date:references:in-reply-to :subject:cc:to:from:from:to:cc:subject:date:message-id:reply-to; bh=tFoF+Ad0ZMdUAqoKXfrDgFoTaEt8kdIbtCyiyybGHUc=; b=mUxf2rANyvajTnN0gnDqOreLFtaT4i2MmwAhwwFpMA/XI95Ygls2npvBC+7kSB3Z+m jXWskz6lTYcqe02JaEgvEhtauhzm7y6ci0Ujk3SIk+a7c3Q+fWLe2oYn9bDDmZB60fIX o8GjxBsoay9kCQzdjg1hKz6cyLac3MJCQRm0H379Wj5UPCjZlD+Sz9QpG9Ky1fN8LexK n5sJJ6sr2gnLDzWYpDlDMVBnbjhCB4EPdK4liMlG1hSVhidxzXSKcXqmAWCxNgofxy1s blRmNKScl50HS+OZTVwGD/zSr80DlfiU054FjZ5BjDBbZeW7wbbSC5Y0r2fE2DL7vPlr gzhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713774464; x=1714379264; h=mime-version:user-agent:message-id:date:references:in-reply-to :subject:cc:to:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=tFoF+Ad0ZMdUAqoKXfrDgFoTaEt8kdIbtCyiyybGHUc=; b=wZdfEB8PnyHRKuO0v95/2WPkoKB4vbs2X3xy3n7kDNkJERor8wmDYC2MFsemcDFlaa SgTTR+QX0qOe87/sykgZT4cqwFFs6ylxsPTG+PizujV5v54q36c+WEXAwO4OlGGNBYMJ CxXYBbsZ5FzKJspmSDwwKh34dHh3jyHG1HG9cZBOEaI9Mi+O6omeq41FSXPVd4kGEMKP kEkusJF79mC9SESEdrxdp0oplHWXWQdLG7XQIu72SuSu/Di3/6j21Lw4g0A5r4vs5y8w cO1GVweZalBFSdVDNIqci3eq1CtRiOpG39slumm38MS9CLEDz5BMVjfusEFiRRjsMvbi vOxg== X-Forwarded-Encrypted: i=1; AJvYcCUyfthfYDAQI42heyQ5/PAR9ShYHh6iadQVnneSrO74rwuSLNSOlfLIrdW+7/Dd+i+OWh3pjxay1+iiDSYqWQ2ojYjv X-Gm-Message-State: AOJu0Yy8TIAy/XhJpbSMBICifRFtsiAuEuQxmBvUY030WdqW0vYcoaWN XzUFvqCLUUErC00CQVr5ZsZLC/yZZ3OZTIErg6HDGPcBsJ9mWbYYHwMzyQ== X-Google-Smtp-Source: AGHT+IFqi5AZNvubhUC83SyGhTEQVojs8abokWqFacT91EWIuvP+OHaWOLAioWEru7uQ6b67qeEk9A== X-Received: by 2002:a17:906:648:b0:a51:c88e:e95a with SMTP id t8-20020a170906064800b00a51c88ee95amr5400550ejb.23.1713774463977; Mon, 22 Apr 2024 01:27:43 -0700 (PDT) Original-Received: from Pro.fritz.box (p4fe3af79.dip0.t-ipconnect.de. [79.227.175.121]) by smtp.gmail.com with ESMTPSA id f15-20020a170906c08f00b00a553574ae71sm5435603ejz.7.2024.04.22.01.27.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Apr 2024 01:27:43 -0700 (PDT) In-Reply-To: <86wmop6cot.fsf@gnu.org> (Eli Zaretskii's message of "Mon, 22 Apr 2024 11:09:38 +0300") Received-SPF: pass client-ip=2a00:1450:4864:20::629; envelope-from=gerd.moellmann@gmail.com; helo=mail-ej1-x629.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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:317964 Archived-At: Eli Zaretskii writes: >> There are ambigupus and there are exact referenes. An object references >> from at least one ambiguos reference cannot be moved, others can. >> >> Where exact and where ambigous references are (or areas of these), one >> has to tell MPS, of course. It's not like Boehm's collector where >> everything is ambiguous. > > What do "exact reference" and "ambiguous reference" mean, in Emacs > terms? Ambiguour references are ones that could be a reference or a could as well be a random bit pattern. An example in Emacs is the control stack marking. I haven't looked at it since I added that, so I don't know if that's still the same, but back then it worked like this: Take a word W from the stack. See if W is something that looks like a pointer into Lisp memeory (the red-black tree, mem_xxx). See if W is a valid Lisp object start if that's the case. If that's also the case, mark W as live. That means W might be marked live, in principle, even if it isn't really. Exact references are all references that aren't ambiguous. For example, the name of a symbol had better be always a valid Lisp_Object.