From owner-freebsd-current Wed Sep 24 10:36:55 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id KAA13013 for current-outgoing; Wed, 24 Sep 1997 10:36:55 -0700 (PDT) Received: from ns.mt.sri.com (SRI-56K-FR.mt.net [206.127.65.42]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id KAA13004 for ; Wed, 24 Sep 1997 10:36:52 -0700 (PDT) Received: from rocky.mt.sri.com (rocky.mt.sri.com [206.127.76.100]) by ns.mt.sri.com (8.8.7/8.8.7) with ESMTP id LAA01911; Wed, 24 Sep 1997 11:36:41 -0600 (MDT) Received: (from nate@localhost) by rocky.mt.sri.com (8.7.5/8.7.3) id LAA12962; Wed, 24 Sep 1997 11:36:39 -0600 (MDT) Date: Wed, 24 Sep 1997 11:36:39 -0600 (MDT) Message-Id: <199709241736.LAA12962@rocky.mt.sri.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Bruce Evans Cc: nate@mt.sri.com, current@freebsd.org, gibbs@plutotech.com Subject: Re: new timeout routines In-Reply-To: <199709241726.DAA04836@godzilla.zeta.org.au> References: <199709241726.DAA04836@godzilla.zeta.org.au> X-Mailer: VM 6.29 under 19.15 XEmacs Lucid Sender: owner-freebsd-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > >> Hash lookup is non-deterministic, since searching is required to handlle > >> collisions. > > > >You had stated earlier that it would be easy to build a perfect hash > >generator. > > Only for a special case. > > >> handlers where we would prefer deterministic behaviour. Note that hash > >> lookup is not required for timeout() since we don't care about duplicates. > > > >Right, but hash insertion in the case of duplicates is still > >non-deterministic. > > No it isn't, at least for STAILQ chained hash tables. Since we don't care > about duplicates, we can just add to the end of the queue. For an open hash table, yes, for a closed hash table, no. But, that's splitting hairs. (I was thinking of using a closed hash-table.) Nate