From owner-freebsd-current Mon Mar 9 08:55:47 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA11523 for freebsd-current-outgoing; Mon, 9 Mar 1998 08:55:47 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from ns.mt.sri.com (sri-gw.MT.net [206.127.105.141]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA11514 for ; Mon, 9 Mar 1998 08:55:41 -0800 (PST) (envelope-from nate@mt.sri.com) Received: from mt.sri.com (rocky.mt.sri.com [206.127.76.100]) by ns.mt.sri.com (8.8.8/8.8.8) with SMTP id JAA00493; Mon, 9 Mar 1998 09:48:49 -0700 (MST) (envelope-from nate@rocky.mt.sri.com) Received: by mt.sri.com (SMI-8.6/SMI-SVR4) id JAA19175; Mon, 9 Mar 1998 09:48:47 -0700 Date: Mon, 9 Mar 1998 09:48:47 -0700 Message-Id: <199803091648.JAA19175@mt.sri.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Michael Hancock Cc: Nate Williams , Terry Lambert , dima@tejblum.dnttm.rssi.ru, current@FreeBSD.ORG Subject: Re: vnode_pager: *** WARNING *** stale FS code in system In-Reply-To: References: <199803090805.BAA16882@mt.sri.com> X-Mailer: VM 6.29 under 19.15 XEmacs Lucid Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > > I think this is good enough to go forward, but you need to understand that > > > with the Heidemann FS stacking framework you can extend the set of VOP's > > > in interesting ways. For example, suppose you wanted to implement > > > VOP_NEWFEATURE. You could do the following: > > > > > > Layer1 - Supports it and maps results from one below. > > > Layer2 - Doesn't support so does a bypass. > > > Layer3 - Supports it and maps results from one below. > > > Layer4 - Doesn't support so does a bypass. > > > Layer5 - Terminal layer, some support some don't. > > > > > > I'm not sure traditional OOP can do this and this makes finding good > > > analogies difficult. > > > > Traditional OOP does this right, since you inherit from the class below > > you, and not from the base class. If you want to inherit from the base > > class, you inherit from it and not a subclass. > > But do you get the mappings from layer1 and layer3? They both touch the > results that finally get to the top. If you want them to, then yes. Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message