From owner-freebsd-hackers Mon Oct 7 13:52:06 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id NAA27591 for hackers-outgoing; Mon, 7 Oct 1996 13:52:06 -0700 (PDT) Received: from rover.village.org (rover.village.org [204.144.255.49]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id NAA27541 for ; Mon, 7 Oct 1996 13:51:53 -0700 (PDT) Received: from rover.village.org (localhost [127.0.0.1]) by rover.village.org (8.7.6/8.6.6) with ESMTP id OAA09190; Mon, 7 Oct 1996 14:50:59 -0600 (MDT) Message-Id: <199610072050.OAA09190@rover.village.org> To: "=?KOI8-R?Q?=E1=CE=C4=D2=C5=CA_=FE=C5=D2=CE=CF=D7?=" (Andrey A. Chernov) Subject: Re: rand() and srand() Cc: hackers@FreeBSD.org In-reply-to: Your message of "Tue, 08 Oct 1996 00:15:20 +0400." <199610072015.AAA00446@nagual.ru> References: <199610072015.AAA00446@nagual.ru> Date: Mon, 07 Oct 1996 14:50:59 -0600 From: Warner Losh Sender: owner-hackers@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk In message <199610072015.AAA00446@nagual.ru> "=?KOI8-R?Q?=E1=CE=C4=D2=C5=CA_=FE=C5=D2=CE=CF=D7?=" writes: : NOBODY HERE WANTS TO BREAK THE "SAME SEEDING" in rand() or random()! : TERRY'S IDEA OF "SAME SEEDING" IS HIS OWN TOY WHICH HAVE NOTHIG : COMMON WITH STANDARD "SAME SEEDING" IDEA. If I understand what you are proposing, you are breaking the same seeding in one case. run program X with seed S get random number sequence R1. upgrade to new rev of FreeBSD run program X with seed S get random number sequence R2. which seems wrong to me and needs to be very loudly documented if that is the case. This obsoletes people's numerical research and a warning is needed. Look at the flack Intel got over the division bug. Not because it would happen so rarely, but the numerical types went non- linear because literally thousands of hours of results were invalidated and had to be done again. If this is well documented, including a blurb in the BUGS section of the man page, then it may be acceptible. It is a big issue that people know these things have changed. It is quite important to a small segment of the population. However, it is reasonable to expect them to cope with the change once they are informed of it. There are many workarounds for this issue. Finally, Terry's "Toy" as you call it is a legitimate use of the system. Many people are using the system in a similar manner. You might not like Terry or his Toys, but that is no excuse to yell at me *ME* about raising the same point he does. In fact, since this is a public forum, that is no excuse for a character attack on Terry (or anyone else). Please keep this discussion technical. If you can't do that, please don't post to hackers. Warner