From owner-freebsd-current Mon Mar 9 00:44:36 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA18079 for freebsd-current-outgoing; Mon, 9 Mar 1998 00:44:36 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from parkplace.cet.co.jp (parkplace.cet.co.jp [202.32.64.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id AAA18029 for ; Mon, 9 Mar 1998 00:44:22 -0800 (PST) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by parkplace.cet.co.jp (8.8.8/CET-v2.2) with SMTP id IAA21744; Mon, 9 Mar 1998 08:12:24 GMT Date: Mon, 9 Mar 1998 17:12:24 +0900 (JST) From: Michael Hancock To: Nate Williams cc: Terry Lambert , dima@tejblum.dnttm.rssi.ru, current@FreeBSD.ORG Subject: Re: vnode_pager: *** WARNING *** stale FS code in system In-Reply-To: <199803090805.BAA16882@mt.sri.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 9 Mar 1998, Nate Williams wrote: > > 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. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message