From owner-freebsd-newbies Thu Jul 1 7:37:40 1999 Delivered-To: freebsd-newbies@freebsd.org Received: from fellspt.charm.net (fellspt.charm.net [199.0.70.29]) by hub.freebsd.org (Postfix) with ESMTP id 5138914DD0 for ; Thu, 1 Jul 1999 07:37:36 -0700 (PDT) (envelope-from dutch@charm.net) Received: from charm.net (coretel-053.charm.net [209.143.116.53]) by fellspt.charm.net (8.9.3/8.9.3) with ESMTP id KAA08856 for ; Thu, 1 Jul 1999 10:37:30 -0400 (EDT) Message-ID: <377B7D20.402BCAB1@charm.net> Date: Thu, 01 Jul 1999 10:37:20 -0400 From: Dutch Collins X-Mailer: Mozilla 4.61 [en] (Win98; I) X-Accept-Language: en MIME-Version: 1.0 To: freebsd-newbies@FreeBSD.ORG Subject: Reentry-Recursion-dusty books version Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-newbies@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Dusty book is: An Introduction to Operating Systems, revised 1st ED. Harvy M. Deitel, ISBN: 0-201-14501-4 Including Case Studies in: UNIX, VAX, CP/M, MVS, VM The short definition: "Code that cannot be changed while in use os said to be *reentrant*. Code that may be changed but is reinitialized each time it is used is said to *serially reusable*. Reentrant code may be shared by several processes simultaneously whereas serially reusable code may be used by one process at a time." p.131 Now there are a mess of data structures associated with using the above. And the OS tries to handle interrupts, both maskable and unmaskable. That is for later. Also, one must allow for the serial process and deadlock. To keep this short and to the point I will say that part of the problem with x86 hardware is a bad design in the way it/they handle interrupts, both hardware and software. Intel laid this egg back in the CP/M days and has tinkered around it ever since. -dutch/more coffee/collins -- +------------------------------------------------------+ | If you want to make god laugh - tell him your plans. | | Kim Basinger | | Voice Line: 410.922.5805 | +------------------------------------------------------+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-newbies" in the body of the message