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, LOTS_OF_MONEY autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,fd0ee7c9be011576 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-03-05 08:38:06 PST Path: supernews.google.com!sn-xit-03!supernews.com!freenix!isdnet!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 Annex E (Just curious :-) Date: Mon, 5 Mar 2001 11:24:11 -0500 Organization: Posted on a server owned by Pace Micro Technology plc Message-ID: <980ekl$p4h$1@nh.pace.co.uk> References: <3AA29386.E60A686D@linuxchip.demon.co.uk> NNTP-Posting-Host: 136.170.200.133 X-Trace: nh.pace.co.uk 983809493 25745 136.170.200.133 (5 Mar 2001 16:24:53 GMT) X-Complaints-To: newsmaster@pace.co.uk NNTP-Posting-Date: 5 Mar 2001 16:24:53 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: supernews.google.com comp.lang.ada:5431 Date: 2001-03-05T16:24:53+00:00 List-Id: "Ted Dennison" wrote in message news:FONo6.1740$45.2180@www.newsranger.com... > I'd like to have an answer to that one too. I don't think its really usable for > a hard real-time system, as there is no way to guarantee response time. In fact, > its tough to achieve this with any networking software. You pretty much have to > control the transmission method used for everything from the application layer > down to the physical layer. > I would agree that the lack of predictable latency makes it of somewhat dubious value for realtime systems. It would seem that it might be useful if you had some form of background workload that you could pass off to another processor and it didn't matter if the work got done in some predictable timeframe. (For example, you might have some kind of diagnostics performed on your realtime data that needed to be done as often as possible, but just to issue some sort of display info to the operator. An unusual delay might not be a big deal.) Or possibly if you had multiple processors in a system that controlled different hardware? Say, having a graphics processor to which you performed RPC's to get certain things rendered? (Of course, this would require either a very standardized processor/communications-interface or you'd never get the compiler modified to suit the environment. :-) It would seem that it might be useful for either computationally intensive applications that lend themselves to distribution (I've seen it done with CFD calculations) or database systems such as, say, teller machines that want to verify a bank balance with a central computer before allowing a withdrawal. Of course, one could achieve any of these things by other means than having an RPC. One could pass messages through pipes or TCP/IP sockets or any other means & establish some kind of protocol between the applications. However, it seems (all other things being equal - as seldom they are ;-) that an RPC might be more invisible to the application programmer than other solutions might be. ("Here you go: Just call this procedure and don't worry about the rest. We'll handle all the distribution for you...") > >is "cool", easy to use and effective... all I need now is an application > >that would benefit significantly from it. > > I'm with you. Maybe its just the application domain you are usually involved in? Remember, it is a "Special Needs Annex" and may just be the kind of thing that is more common for a different problem domain. (I'd think it would be used heavily in business applications where there was at most a soft-realtime requirement.) 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/