From owner-sc22wg5@open-std.org Wed Dec 3 07:27:36 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id D7CE4CA3428; Wed, 3 Dec 2008 07:27:36 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from smtp.llnl.gov (nspiron-3.llnl.gov [128.115.41.83]) by www2.open-std.org (Postfix) with ESMTP id 0D6D0C178E6 for ; Wed, 3 Dec 2008 07:27:35 +0100 (CET) X-Attachments: None Received: from vpna-user-128-15-244-19.llnl.gov (HELO [128.15.244.19]) ([128.15.244.19]) by smtp.llnl.gov with ESMTP; 02 Dec 2008 22:27:34 -0800 Message-ID: <493626D6.9020006@llnl.gov> Date: Tue, 02 Dec 2008 22:27:34 -0800 From: Aleksandar Donev User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.8) Gecko/20071009 SeaMonkey/1.1.5 MIME-Version: 1.0 To: Van.Snyder@jpl.nasa.gov, WG5 Subject: Re: (j3.2006) (SC22WG5.3701) Atomic stuff References: <20081203025222.12F4BC178E0@www2.open-std.org> In-Reply-To: <20081203025222.12F4BC178E0@www2.open-std.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-sc22wg5@open-std.org Precedence: bulk Hi Van, > 1. Provide an attribute for a variable that says accesses to it are > atomic. While this may be preferable to the use of intrinsics, it is also much more complex to get right, especially in terms of matching of the attribute across association (can you point a nonatomic pointer to an atomic, how about arrays, etc.). The other two ideas, while possibly technically useful, have nothing to do with ATOMIC. Until Fortran proper has accessors/updaters their use for atomic operations is out of the question. I prefer alternative mechanisms to specify atomic operations (notably an ATOMIC block), but, that was not the goal. The goal was to provide some simple mechanism for spin loops and the like without the problems of VOLATILE. It is a compromise, and nobody's first preference. Nothing wrong with that, IMO, especially since it is just two intrinsics and not something that fundamentally messes up the language for eternity. Best, Aleks -- Aleksandar Donev, Ph.D. Lawrence Postdoctoral Fellow @ LLNL High Performance Computational Materials Science and Chemistry E-mail: donev1@llnl.gov Phone: (925) 424-6816 Fax: (925) 423-0785 Address: P.O.Box 808, L-367, Livermore, CA 94551-9900 Web: http://cherrypit.princeton.edu/donev