From owner-freebsd-arch@FreeBSD.ORG Sun Dec 18 11:55:10 2011 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9B76D106566B; Sun, 18 Dec 2011 11:55:10 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id E4A6E8FC16; Sun, 18 Dec 2011 11:55:09 +0000 (UTC) Received: from alf.home (alf.kiev.zoral.com.ua [10.1.1.177]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id pBIBrR7V052781 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 18 Dec 2011 13:53:27 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from alf.home (kostik@localhost [127.0.0.1]) by alf.home (8.14.5/8.14.5) with ESMTP id pBIBrRBJ063596; Sun, 18 Dec 2011 13:53:27 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by alf.home (8.14.5/8.14.5/Submit) id pBIBrQ7A063595; Sun, 18 Dec 2011 13:53:26 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: alf.home: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 18 Dec 2011 13:53:26 +0200 From: Kostik Belousov To: Dag-Erling Sm??rgrav Message-ID: <20111218115326.GD50300@deviant.kiev.zoral.com.ua> References: <85477.1324155737@critter.freebsd.dk> <86ty4y4rj5.fsf@ds4.des.no> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ub6V6mHXHR6pEqUf" Content-Disposition: inline In-Reply-To: <86ty4y4rj5.fsf@ds4.des.no> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-3.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: Kostik Belousov , arch@freebsd.org, Poul-Henning Kamp , threads@freebsd.org, Ed Schouten Subject: Re: [Patch] C1X threading support X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 18 Dec 2011 11:55:10 -0000 --ub6V6mHXHR6pEqUf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Dec 18, 2011 at 02:06:38AM +0100, Dag-Erling Sm??rgrav wrote: > "Poul-Henning Kamp" writes: > > Ohhh, but I know: Lets make a rival to the POSIX threads, we can do it > > much better and slightly incompatible, big market there I'm sure. >=20 > That's not the point. The point is that C until now did not have a > concurrency model. The threading API in itself is not important; I'm > sure the committee knows perfectly well that nobody is going to use it. > What's important is that the standard now defines how C behaves in a > concurrent environment. Well, the reverse was exactly _my_ point. I cannot find the description of how the abstract C machine behaves, in the presence of multiple threads of execution. The atomics chapter covers only some special operations, which are added in the new revision. E.g., there is absolutely no mention of the memory changes visibility, or guarantees of atimicity of the assignments/reads etc. IMO, the threading was slapped nearby, and the standard is not useful as-is. I am sorry if I missed the parts. --ub6V6mHXHR6pEqUf Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iEYEARECAAYFAk7t1DUACgkQC3+MBN1Mb4gUAwCg2c2BM7NGPRcI/wlKmRaZqAJR EtUAoMuh2Gm61rRBSXn5W+VfZsSlM8Ma =3FGP -----END PGP SIGNATURE----- --ub6V6mHXHR6pEqUf--