From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Helmut Eller Newsgroups: gmane.emacs.devel Subject: Re: MPS: weak hash tables Date: Tue, 02 Jul 2024 13:23:44 +0200 Message-ID: <87o77gvxz3.fsf@gmail.com> References: <2syUQ04IbTWqDJjMfKSrtzWMWmFGq1GIOwSxv_r6BEyNDtk7ADADKjZk-90g9tSS9SKWppkiq6_zihUtsoE1spiopaOI6-v9inQrGxwMyCs=@protonmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="33858"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: Gerd =?utf-8?Q?M=C3=B6llmann?= , Eli Zaretskii , Emacs Devel To: Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Jul 02 13:24:59 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 1sObd5-0008g6-C2 for ged-emacs-devel@m.gmane-mx.org; Tue, 02 Jul 2024 13:24:59 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sObc4-0002Y1-R2; Tue, 02 Jul 2024 07:23:56 -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 1sObc2-0002XE-Hm for emacs-devel@gnu.org; Tue, 02 Jul 2024 07:23:54 -0400 Original-Received: from mail-lf1-x12e.google.com ([2a00:1450:4864:20::12e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sObbx-0006AQ-Da; Tue, 02 Jul 2024 07:23:54 -0400 Original-Received: by mail-lf1-x12e.google.com with SMTP id 2adb3069b0e04-52e7d2278d8so5505336e87.3; Tue, 02 Jul 2024 04:23:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1719919426; x=1720524226; darn=gnu.org; h=content-transfer-encoding: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=DIEL10+HOH+EH3xdOOpGgR0tSiWW3sbnDslK6Hin1BA=; b=S1Hmin9+f59SzHCj1pwC1eSopRCWDUfOBY8s/U3RaBQnWVGM4pqnz1cbcCvoPam1gK mfnxQWQRIv1SUUeWBHQkwMGkC78HzSGxuNDUTG78e23gUGJHAf0IUTZkwzhUcm7GIljj BJ0uw+bKWfMxNGp3s7O2NPAi8m7TgW7BcGYCADKF3mO4RxsmKqTcRRzv8LHy0XvF1tXZ BIdXhuzaxjmMWwf3+s6QLJD8chIfF6bCV9gV/g3sAgbqa9rHJ1UWdiNLQaFSIbqxPt3U uQSwtXktSIHygteIL2MU6SI58UXSUEBpkq5alUmfeS+rH+nCeSEdHoYWAqrs0iDR9tBQ Plyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719919426; x=1720524226; h=content-transfer-encoding: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=DIEL10+HOH+EH3xdOOpGgR0tSiWW3sbnDslK6Hin1BA=; b=YXOkuslCmpa1MSatPg3lm9j+BfIH3peZNEUDKDVg1VQzpHN2CbWT6H3/baq6FBprNA Xvc6oTHFXjekwT2ctqhiyGZHo/7EtyPb3dYFqQ1F9BEj1d9/LQN3VtU9y5gECgoUeGmV rYHiLF8sGNuWillSsZirkvku+39QUvlUi9Qaqs/rfIIj9pykxsmESCE9IKidkAma+LwZ hfBCPFIkaQhClEooM9JREktbrx/buinNErYw9cnA9TcHFHpQEpJoixb/1++i334eqJkc qlmXtvqoV1Ah5BxMVNaSoOBy/lg8XTnKk7YBN+eOnLVhmSZ2JXbdk9vHQI4P2NgMulL+ HndQ== X-Forwarded-Encrypted: i=1; AJvYcCXFtCvh7kwSleLtqAtMg78Ukic70RDYozJd2py3A2DcXNyh2AtihzklNP9vZRWM44STXCpCdrU5tylu0v1HCZFbcgXhW4Nv++xy8C+eCYssF3Y= X-Gm-Message-State: AOJu0YwK/QKzlNfYG140hEMlAuTA2fVIlPwlNvBT0QmKDPeVaIDzBC5K F8NmC0G6vVsc4EFoXGnNgDLmVbXp7U9pfEcKTpsONte4qrpvA63mBWRP5w== X-Google-Smtp-Source: AGHT+IGcxDsUB2+p2uiyXnB7QXVwqKa6Zd6J56EXZEIVGE22kkSM5a3VfGjwQ295tQgJSDxdmk/YsA== X-Received: by 2002:a05:6512:31cc:b0:52d:3ada:4b6b with SMTP id 2adb3069b0e04-52e8264b5c8mr8123807e87.1.1719919425888; Tue, 02 Jul 2024 04:23:45 -0700 (PDT) Original-Received: from caladan (dial-187254.pool.broadband44.net. [212.46.187.254]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a72aaf62058sm408604066b.56.2024.07.02.04.23.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Jul 2024 04:23:45 -0700 (PDT) In-Reply-To: (Pip Cet's message of "Tue, 02 Jul 2024 06:23:45 +0000") Received-SPF: pass client-ip=2a00:1450:4864:20::12e; envelope-from=eller.helmut@gmail.com; helo=mail-lf1-x12e.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, T_SPF_TEMPERROR=0.01 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:321124 Archived-At: On Tue, Jul 02 2024, Pip Cet wrote: > Also, there's the whole caution thing about weak objects containing > only unaligned words or words pointing directly to a base object, > which is only relevant on Unix/i386, IIRC. (MPS emulates instructions > to simulate fine-grained barriers, which is a really cool idea; I'd > still like an option to turn it off though...). That would mean we > have to replace Lisp_Objects and use the ptr member of our union (and > that's the reason I'm using fixnums rather than plain integers for the > hash). Why do you think that the restriction only applies to 32-bit systems? My interpretation of Section 7.4. Caution ... =E2=80=9CAligned pointer=E2=80=9D means a word whose numeric value (that = is, its value when treated as an unsigned integer) is a multiple of the size of a pointer. If you=E2=80=99re using a 64-bit architecture, that means that an aligned pointer is a multiple of 8 and its bottom three bits are zero. ... is that it applies to 64-bit machines as well.