From owner-freebsd-arch@FreeBSD.ORG Mon Apr 14 15:18:25 2008 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 564EF1065670 for ; Mon, 14 Apr 2008 15:18:25 +0000 (UTC) (envelope-from babkin@verizon.net) Received: from vms046pub.verizon.net (vms046pub.verizon.net [206.46.252.46]) by mx1.freebsd.org (Postfix) with ESMTP id 37DC88FC15 for ; Mon, 14 Apr 2008 15:18:25 +0000 (UTC) (envelope-from babkin@verizon.net) Received: from vms063.mailsrvcs.net ([172.18.12.132]) by vms046.mailsrvcs.net (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPA id <0JZB00A25MHX7S40@vms046.mailsrvcs.net> for arch@freebsd.org; Mon, 14 Apr 2008 10:17:57 -0500 (CDT) Received: from 65.242.108.162 ([65.242.108.162]) by vms063.mailsrvcs.net (Verizon Webmail) with HTTP; Mon, 14 Apr 2008 10:17:57 -0500 (CDT) Date: Mon, 14 Apr 2008 10:17:57 -0500 (CDT) From: Sergey Babkin X-Originating-IP: [65.242.108.162] To: Ed Schouten , Poul-Henning Kamp Message-id: <25637504.3015221208186277561.JavaMail.root@vms063.mailsrvcs.net> MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 7bit Cc: arch@freebsd.org Subject: Re: Re: f_offset 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: Mon, 14 Apr 2008 15:18:25 -0000 >From: Poul-Henning Kamp >In message <20080414145231.GJ5934@hoeg.nl>, Ed Schouten writes: > >>It's all so confusing that the standards seem to change then. When I >>take a look at the POSIX onlinepubs, the articles seem to mention the >>opposite: >> >>http://www.opengroup.org/onlinepubs/009695399/functions/read.html >> >> "The behavior of multiple concurrent reads on the same pipe, >> FIFO, or terminal device is unspecified." >> >>http://www.opengroup.org/onlinepubs/009695399/functions/write.html >> >> "This volume of IEEE Std 1003.1-2001 does not specify behavior >> of concurrent writes to a file from multiple processes. >> Applications should use some form of concurrency control." > >Remember that POSIX was written so both MVS and Windows could comply, And nowadays Linux too :-) >UNIX may have and need higher standards. Yep. Linux in this respect is not Unix. This behavior of Linux is pretty annoying (the log files get mixed up pretty badly) but I agree that it makes the writes on the highly contested files faster. -SB