From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=AWL autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by yquem.inria.fr (Postfix) with ESMTP id 7F639BBAF for ; Wed, 28 May 2008 13:18:38 +0200 (CEST) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Av4AAIPcPEjAXQIno2dsb2JhbACSOwEBAQEBAQcFCAcRm3E X-IronPort-AV: E=Sophos;i="4.27,554,1204498800"; d="scan'208";a="13141756" Received: from concorde.inria.fr ([192.93.2.39]) by mail3-smtp-sop.national.inria.fr with ESMTP; 28 May 2008 13:18:38 +0200 Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id m4SBIbPP003093 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Wed, 28 May 2008 13:18:38 +0200 X-IronPort-AV: E=Sophos;i="4.27,554,1204498800"; d="scan'208";a="11218681" Received: from macabane.inria.fr ([128.93.8.160]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/AES128-SHA; 28 May 2008 13:18:37 +0200 Message-Id: From: Damien Doligez To: caml-list In-Reply-To: <483BD594.7050504@doc.ic.ac.uk> Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v919.2) Subject: Re: [Caml-list] Re: Where's my non-classical shared memory concurrency technology? Date: Wed, 28 May 2008 13:18:37 +0200 References: <200805181735.50621.jon@ffconsultancy.com> <4831686F.8010903@doc.ic.ac.uk> <1211206144.11053.15.camel@flake.lan.gerd-stolpmann.de> <4833D7E8.8060502@doc.ic.ac.uk> <4EDC5A3B-DFD2-47EA-9C22-F0B355D7BBC7@inria.fr> <483BD594.7050504@doc.ic.ac.uk> X-Mailer: Apple Mail (2.919.2) X-Miltered: at concorde with ID 483D3F8D.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; damien:01 damien:01 broadcasting:98 doligez:01 doligez:01 wrote:01 caml-list:01 concurrency:04 concurrency:04 passing:05 barrier:05 shared:06 shared:06 channel:06 channel:06 On 2008-05-27, at 11:34, Martin Berger wrote: >>> Here I disagree. Shared memory concurrency is a specific form >>> of message passing: Writing to a memory cell is in fact sending >>> a message to that cell carrying two items, the new value and a >>> return channel that is used to inform the writer that sending >>> has succeeded, and likewise for reading. >> > [...] > > But broadcasting is a form of message-passing too! That wasn't my point. My point was that there is no return channel. If you want to know when your write is done, you have to use a lock or a memory barrier. Both are very expensive. -- Damien