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: 103376,5bcf30769d6d9599 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-08-28 09:35:07 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!news.ems.psu.edu!news.cis.ohio-state.edu!news.maxwell.syr.edu!newsfeed.icl.net!news-x2.support.nl!news-x.support.nl!psinet-eu-nl!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 os talk Date: Tue, 28 Aug 2001 12:14:15 -0400 Organization: Posted on a server owned by Pace Micro Technology plc Message-ID: <9mgg0p$26j$1@nh.pace.co.uk> References: <9mdmck$rs1$1@nh.pace.co.uk> <9me6q4$aai1@news.cis.okstate.edu> <9mg7fr$rm1$1@nh.pace.co.uk> <3CeB8M0VaOC6@eisner.encompasserve.org> NNTP-Posting-Host: dhcp-200-133.miami.pace.co.uk X-Trace: nh.pace.co.uk 999015257 2259 136.170.200.133 (28 Aug 2001 16:14:17 GMT) X-Complaints-To: newsmaster@news.cam.pace.co.uk NNTP-Posting-Date: 28 Aug 2001 16:14:17 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:12523 Date: 2001-08-28T16:14:17+00:00 List-Id: "Larry Kilgallen" wrote in message news:3CeB8M0VaOC6@eisner.encompasserve.org... > > I don't suppose this "study" time was billed by the hour ? > Of course it is possible the documentation was worse during > the time period you are discussion. > We had VMS guys who had to build up lots of experience with OS calls, etc, to get the job done. You didn't just walk in out of college knowing it. They were quite disappointed when we were forced to switch to some flavor of (realtime) Unix because it meant having to start all over again developing job skills. Maybe the skills were a bit more marketable by then, so I guess it was O.K. Billing it? I think they were mostly overhead - not direct charging to contracts. But it is legitimate to bill the time needed to familiarize with tools, etc, if it is for a specific need on a contract. Like I said, my memory of the situation whas that techniques were possible under VMS to run realtime, but that VMS wasn't designed to specifically provide some kind of realtime mode. Sort of a case where if you had enough privileges and enough priority and could keep anything else from taking precidence, you could convince yourself that you had fixed latency and weren't going to get swapped out. This is different than having a process that the OS manages in realtime mode and guarantees you that none of this is going to fail. > > What would be nice is to have a workstation OS that didn't require you to > > become an expert or circumvent the OS to do realtime - just declare a > > process to be "realtime" and know that it can get certain services with > > certain predictable latencies and be sure that it has priority over anything > > else. (Dangerous, but necessary for realtime programming.) > > Based on the real-time people I have met, I would say that each > shop is still going to study the situation to ensure they > are not making inwarranted assumptions. Well, naturally, you don't just walk in, sit down and start programming real time systems on an OS you've never seen before. You've got to know what the OS is doing for you and how it does it. I'm talking about a difference between "Here's the book on how a realtime process runs on ImaginaryOS..." versus "Here's a bunch of system calls and descriptions of what's going on in the OS and you go figure out some tricks that are going to let you run realtime because we didn't build in a 'realtime' mode of operation..." The latter case can definitely be done, but it usually is going to involve more time and effort. 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/