Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269299AbUJFPiu (ORCPT ); Wed, 6 Oct 2004 11:38:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269298AbUJFPiC (ORCPT ); Wed, 6 Oct 2004 11:38:02 -0400 Received: from ts2-075.twistspace.com ([217.71.122.75]:42397 "EHLO entmoot.nl") by vger.kernel.org with ESMTP id S269314AbUJFPfg (ORCPT ); Wed, 6 Oct 2004 11:35:36 -0400 Message-ID: <001801c4abc2$8908d8c0$161b14ac@boromir> From: "Martijn Sipkema" To: "David S. Miller" , Cc: , References: <20041006080104.76f862e6.davem@davemloft.net> <20041006082145.7b765385.davem@davemloft.net> Subject: Re: UDP recvmsg blocks after select(), 2.6 bug? Date: Wed, 6 Oct 2004 17:35:47 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 X-MailScanner-Information: Please contact the ISP for more information X-MailScanner: Found to be clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1434 Lines: 39 From: "David S. Miller" Sent: Wednesday, October 06, 2004 16:21 > On Wed, 6 Oct 2004 11:15:13 -0400 (EDT) > "Richard B. Johnson" wrote: > > > On Wed, 6 Oct 2004, David S. Miller wrote: > > > > > On Wed, 6 Oct 2004 16:52:27 +0200 (CEST) > > > Joris van Rantwijk wrote: > > > > > >> My understanding of POSIX is limited, but it seems to me that a read call > > >> must never block after select just said that it's ok to read from the > > >> descriptor. So any such behaviour would be a kernel bug. > > > > > > There is no such guarentee. > > > > Huh? Then why would anybody use select()? It can't return a > > 'guess" or it's broken. When select() or poll() claims that > > there are data available, there damn well better be data available > > or software becomes a crap-game. > > So if select returns true, and another one of your threads > reads all the data from the file descriptor, what would you > like the behavior to be for the current thread when it calls > read? > > So like I said, there is no such guarentee. Perhaps you should have elaborated then, because this is obviously not what was meant. --ms - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/