From owner-freebsd-arch Wed Feb 7 12:36:21 2001 Delivered-To: freebsd-arch@freebsd.org Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (Postfix) with ESMTP id 2D7AF37B4EC for ; Wed, 7 Feb 2001 12:36:03 -0800 (PST) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.3/8.9.3) id PAA46466; Wed, 7 Feb 2001 15:35:57 -0500 (EST) (envelope-from wollman) Date: Wed, 7 Feb 2001 15:35:57 -0500 (EST) From: Garrett Wollman Message-Id: <200102072035.PAA46466@khavrinen.lcs.mit.edu> To: des@ofug.org Cc: arch@freebsd.org Subject: Re: xucred introduction X-Newsgroups: mit.lcs.mail.freebsd-arch In-Reply-To: References: Organization: MIT Laboratory for Computer Science Cc: Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In article you write: >Some structures (specifically, those that are to be stored in zones) >*must* start with two pointers to their own type. No, they don't. See, e.g., struct inpcb. The restriction that you get from the zone allocator is that the beginning of the zone is overlaid with two such pointers *while the object is free*, so you cannot depend on type-stability for values which would be stored there. In the TCP stack, the only thing we really care about being type-stable is the generation count, which was intentionally placed at the end of the structure. -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message