From owner-freebsd-hackers Sun Apr 11 20:16:38 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from janus.syracuse.net (janus.syracuse.net [205.232.47.15]) by hub.freebsd.org (Postfix) with ESMTP id 63FE3151F3 for ; Sun, 11 Apr 1999 20:16:35 -0700 (PDT) (envelope-from green@unixhelp.org) Received: from localhost (green@localhost) by janus.syracuse.net (8.9.2/8.8.7) with ESMTP id XAA36823; Sun, 11 Apr 1999 23:14:17 -0400 (EDT) Date: Sun, 11 Apr 1999 23:14:16 -0400 (EDT) From: Brian Feldman X-Sender: green@janus.syracuse.net To: Matthew Dillon Cc: Jason Thorpe , jwm@CSUA.Berkeley.EDU, freebsd-hackers@FreeBSD.ORG Subject: Re: read() and pread() syscalls In-Reply-To: <199904120126.SAA11924@apollo.backplane.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, 11 Apr 1999, Matthew Dillon wrote: > :> But, see above about it not being possible to emulate read() with pread() > :> in userspace. > : > :You mean, without lseek(2) =) > > pread/pwrite + lseek is not atomic, so exact emulation is not > possible. That's true (didn't think about atomicity). But on the other hand, I would oppose read being taken away and replaced with readv. It would break backward compatibility. And if the syscall slot was still there and read was there, there's no reason to have a readv wrapper... What was the point of this whole thing? > > -Matt > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message > Brian Feldman _ __ ___ ____ ___ ___ ___ green@unixhelp.org _ __ ___ | _ ) __| \ FreeBSD: The Power to Serve! _ __ | _ \__ \ |) | http://www.freebsd.org _ |___/___/___/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message