From owner-cvs-all Fri Nov 9 10: 3:59 2001 Delivered-To: cvs-all@freebsd.org Received: from mail-blue.research.att.com (mail-blue.research.att.com [135.207.30.102]) by hub.freebsd.org (Postfix) with ESMTP id 8994637B405; Fri, 9 Nov 2001 10:03:53 -0800 (PST) Received: from alliance.research.att.com (alliance.research.att.com [135.207.26.26]) by mail-blue.research.att.com (Postfix) with ESMTP id AD4644CE47; Fri, 9 Nov 2001 13:03:52 -0500 (EST) Received: from windsor.research.att.com (windsor.research.att.com [135.207.26.46]) by alliance.research.att.com (8.8.7/8.8.7) with ESMTP id NAA02469; Fri, 9 Nov 2001 13:03:51 -0500 (EST) From: Bill Fenner Received: (from fenner@localhost) by windsor.research.att.com (8.8.8+Sun/8.8.5) id KAA24774; Fri, 9 Nov 2001 10:03:51 -0800 (PST) Message-Id: <200111091803.KAA24774@windsor.research.att.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: bde@zeta.org.au Subject: Re: cvs commit: src/sys/fs/fifofs fifo_vnops.c Cc: alfred@freebsd.org, cvs-committers@freebsd.org, cvs-all@freebsd.org Date: Fri, 9 Nov 2001 10:03:50 -0800 Versions: dmail (solaris) 2.2j/makemail 2.9b Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG POSIX FIFOs seem relatively useless, unless there's always a writer present. Without a writer, a reader has to spin (either in select+read or just read) until a writer is present. I can't tell if POSIX really defined FIFOs to be useless, or we're just misinterpreting the standards-speak. I'd prefer if an "empty FIFO with no writers" was really an "empty FIFO with no writers where the EOF condition hasn't been delivered yet"; then read() could block (or return EAGAIN or EWOULDBLOCK) when there were no writers yet, and could go back to that condition after the EOF of all the writers leaving was delivered. Bill To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message