From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=AC_FROM_MANY_DOTS,BAYES_00 autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,216b18d81cce4f75 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-06-29 06:35:41 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!skynet.be!freenix!grolier!newsfeed.planete.net!psinet-france!psiuk-f4!psiuk-p4!uknet!psiuk-n!news.pace.co.uk!nh.pace.co.uk!not-for-mail From: "Marin David Condic" Newsgroups: comp.lang.ada Subject: Re: Ada Microkernel? Date: Fri, 29 Jun 2001 09:16:05 -0400 Organization: Posted on a server owned by Pace Micro Technology plc Message-ID: <9hhv2m$ivm$1@nh.pace.co.uk> References: <%3H_6.416$Kf3.3173@www.newsranger.com> <9hfgrm$ngd$1@nh.pace.co.uk> <3B3B6D4C.5DEC7D52@online.no> <9hfv15$s59$1@nh.pace.co.uk> <9hfvo1$sbd$1@nh.pace.co.uk> NNTP-Posting-Host: 136.170.200.133 X-Trace: nh.pace.co.uk 993820566 19446 136.170.200.133 (29 Jun 2001 13:16:06 GMT) X-Complaints-To: newsmaster@pace.co.uk NNTP-Posting-Date: 29 Jun 2001 13:16:06 GMT X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Xref: archiver1.google.com comp.lang.ada:9249 Date: 2001-06-29T13:16:06+00:00 List-Id: My OS book from back in my college days is so old, I don't think it would be anywhere close to up to date with modern OS theory. That's why I'm asking for a recommendation. I'd agree that an RTOS and a "Workstation" OS are going to have fundamentally different design goals. However, I don't know that down at a low level, you couldn't find some common ground and make the rest somehow "switch selectable" IOW, it would be useful to make WindowsNT have a "Real-Time" mode so you could run critical processes on it, yet have all the tools & services available to you that programming in non-real-time usually does. Indeed, there are third-party products to do just that. (From what I've seen, they tend to duplicate most of the Windows API, put a RTOS under it, then run Windows as a lower priority process.) I think the biggest area of contention between the two would be the scheduler. I don't see how things like device drivers, interrupt processing, etc., would be of necessity incompatible. (The non-real-time could use real-time algorithms without penalty to the end user if its done reasonably. The real-time guys just need predictability.) But wouldn't it be possible to specify more than one scheduling algorithm and have it selectable at boot time? Sure, its more work to get a complete product together, but in the end it makes a product that would have a really nice advantage over most of what's out there. MDC -- Marin David Condic Senior Software Engineer Pace Micro Technology Americas www.pacemicro.com Enabling the digital revolution e-Mail: marin.condic@pacemicro.com Web: http://www.mcondic.com/ "Ted Dennison" wrote in message news:eGN_6.942$Kf3.12916@www.newsranger.com... > > The one from my school days explicitly disclaims any intention of covering > RTOS's up front. Their rationale was that general purpose OS's and RTOS's have > design goals that are fundamentally incompatable. For example, an RTOS usually > can't allow time-slicing between equal priority tasks, while general-purpose > user OS's need to in order to achieve fairness in scheduling. Also, RTOS innards > must be carefully crafted to provide a short and determinstic response time. > However, that typically means fixed-length data structures, and thus limits on > resources that a multitasking user OS might find annoyingly constraining. > > I'm curious if this is the unversal perception among OS developers today. > > --- > T.E.D. homepage - http://www.telepath.com/dennison/Ted/TED.html > home email - mailto:dennison@telepath.com