From owner-freebsd-hackers@FreeBSD.ORG Thu Aug 4 19:06:13 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org 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 A335816A41F; Thu, 4 Aug 2005 19:06:13 +0000 (GMT) (envelope-from dwmalone@maths.tcd.ie) Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11]) by mx1.FreeBSD.org (Postfix) with SMTP id B88CD43D45; Thu, 4 Aug 2005 19:06:12 +0000 (GMT) (envelope-from dwmalone@maths.tcd.ie) Received: from walton.maths.tcd.ie ([134.226.81.10] helo=walton.maths.tcd.ie) by salmon.maths.tcd.ie with SMTP id ; 4 Aug 2005 20:05:22 +0100 (BST) Date: Thu, 4 Aug 2005 20:05:21 +0100 From: David Malone To: Hans Petter Selasky Message-ID: <20050804190521.GA28831@walton.maths.tcd.ie> References: <200508030023.04748.hselasky@c2i.net> <200508041340.58851.hselasky@c2i.net> <200508040953.59316.jhb@FreeBSD.org> <200508041850.14253.hselasky@c2i.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200508041850.14253.hselasky@c2i.net> User-Agent: Mutt/1.5.6i Sender: dwmalone@maths.tcd.ie Cc: freebsd-hackers@freebsd.org Subject: Re: How to do proper locking X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Aug 2005 19:06:13 -0000 On Thu, Aug 04, 2005 at 06:50:12PM +0200, Hans Petter Selasky wrote: > 2) nonblocking: increment some other refcount that the > callback checks before accessing any data. I think people usually call this something like a "generation count". This sort of scheme used to be used for vnodes in FreeBSD. If you look through the archives for people talking about type-stable storage, you'll probably find some details. David.