From owner-freebsd-hackers Mon Aug 26 16:49:42 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0DE4237B400 for ; Mon, 26 Aug 2002 16:49:38 -0700 (PDT) Received: from scaup.mail.pas.earthlink.net (scaup.mail.pas.earthlink.net [207.217.120.49]) by mx1.FreeBSD.org (Postfix) with ESMTP id AB63D43E4A for ; Mon, 26 Aug 2002 16:49:37 -0700 (PDT) (envelope-from tlambert2@mindspring.com) Received: from pool0294.cvx21-bradley.dialup.earthlink.net ([209.179.193.39] helo=mindspring.com) by scaup.mail.pas.earthlink.net with esmtp (Exim 3.33 #1) id 17jTbu-000339-00; Mon, 26 Aug 2002 16:49:31 -0700 Message-ID: <3D6ABE51.B93F6B0A@mindspring.com> Date: Mon, 26 Aug 2002 16:48:33 -0700 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Dominic Marks Cc: freebsd-hackers@freebsd.org Subject: Re: kevent and pipes interaction on 4.6-STABLE References: <20020826221727.GB92538@gallium> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Dominic Marks wrote: > I'm attempting the junior userland hacker task of replacing select in > make with kevent. I have written the code and it is, as far as I know > correct. > > The problem is that this code doesn't work. An example being the > following: The problem is that kqueue is known to not work well with pipes; specifically, the available data is not correctly reported. This was noted by Alfred before. BTW: This was one of the motivating factors in my recent set of patches to support System V Message Queues with kqueue: I needed a reliable IPC delivery mechanism that worked via kqueue, and pipes were not it, and I didn't want to have to worry about net based attacks on my IPC mechanism, so I didn't use sockets. Contact Alfred for details on the pipe issue, since he discovered it about the middle of last year. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message