From owner-freebsd-arch@FreeBSD.ORG Tue May 12 10:55:40 2009 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 C3386106564A for ; Tue, 12 May 2009 10:55:40 +0000 (UTC) (envelope-from des@des.no) Received: from tim.des.no (tim.des.no [194.63.250.121]) by mx1.freebsd.org (Postfix) with ESMTP id 7FCA68FC1D for ; Tue, 12 May 2009 10:55:40 +0000 (UTC) (envelope-from des@des.no) Received: from ds4.des.no (des.no [84.49.246.2]) by smtp.des.no (Postfix) with ESMTP id 6DC586D41B; Tue, 12 May 2009 12:55:39 +0200 (CEST) Received: by ds4.des.no (Postfix, from userid 1001) id 33A5B844C0; Tue, 12 May 2009 12:55:39 +0200 (CEST) From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= To: Lothar Scholz References: <200905100500.n4A50GOa050728@hergotha.csail.mit.edu> <7710650619.20090510075706@scriptolutions.com> <18950.63671.323324.756287@hergotha.csail.mit.edu> <1393224851.20090511112537@scriptolutions.com> <74fe56020905110410y430bf76yacf5c5a308a99865@mail.gmail.com> <981850520.20090511172605@scriptolutions.com> Date: Tue, 12 May 2009 12:55:39 +0200 In-Reply-To: <981850520.20090511172605@scriptolutions.com> (Lothar Scholz's message of "Mon, 11 May 2009 17:26:05 +0200") Message-ID: <86fxfa615g.fsf@ds4.des.no> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.92 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: arch@freebsd.org, Sujit K M , Garrett Wollman Subject: Re: Posix shared memory problem 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: Tue, 12 May 2009 10:55:41 -0000 Lothar Scholz writes: > Sujit K M writes: > > What needs to be fixed? Could you be more specific? > That the name argument is just that "a name" (in its own name space) > not a path. Allow me to quote from the SUSv3 again: DESCRIPTION The shm_open() function shall establish a connection between a shared memory object and a file descriptor. [...] The name argument points to a string naming a shared memory object. It is unspecified whether the name appears in the file system and is visible to other functions that take pathnames as arguments. The name argument conforms to the construction rules for a pathname. [...] RATIONALE [...] Note that such shared memory objects can actually be implemented as mapped files. In both cases, the size can be set after the open using ftruncate(). The shm_open() function itself does not create a shared object of a specified size because this would duplicate an extant function that set the size of an object referenced by a file descriptor. On implementations where memory objects are implemented using the existing file system, the shm_open() function may be implemented using a macro that invokes open(), and the shm_unlink() function may be implemented using a macro that invokes unlink(). [...] DES --=20 Dag-Erling Sm=C3=B8rgrav - des@des.no