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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,348865ddb50d3a12 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-04-05 08:29:29 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!hub1.nntpserver.com!peer1-sjc1.usenetserver.com!usenetserver.com!pd2nf1so.cg.shawcable.net!residential.shaw.ca!news-out.spamkiller.net!propagator-la!news-in-la.newsfeeds.com!news-in.superfeed.net!dax.net!juliett.dax.net!not-for-mail Newsgroups: comp.lang.ada Subject: Re: Glade :- he distributed Annex References: <3cab031b@filemon.telecable.es> <4519e058.0204050615.4f133f1f@posting.google.com> From: Ole-Hjalmar Kristensen Message-ID: <7vit76kth4.fsf@vlinux.voxelvision.no> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 05 Apr 2002 16:20:24 GMT NNTP-Posting-Host: 193.216.12.150 X-Complaints-To: abuse@tele2.no X-Trace: juliett.dax.net 1018023624 193.216.12.150 (Fri, 05 Apr 2002 18:20:24 MET DST) NNTP-Posting-Date: Fri, 05 Apr 2002 18:20:24 MET DST Organization: Tele2 Norway AS Public Access Xref: archiver1.google.com comp.lang.ada:22154 Date: 2002-04-05T16:20:24+00:00 List-Id: dennison@telepath.com (Ted Dennison) writes: > Toshitaka Kumano wrote in message news:... > > In other malicious words, I consider Glade by itself could not be > > used for practical, fault tolerant or real-time (deterministic response) > > application. This can be "restriction" in your application domain. > > Considering that TCP itself can't be used for that kind of real-time > application (and IP itself can't either, except under certian > circumstances), that's a pretty safe statement. > > > -- > T.E.D. > Home - mailto:dennison@telepath.com (Yahoo: Ted_Dennison) > Homepage - http://www.telepath.com/dennison/Ted/TED.html On the other hand UDP/IP is perfectly good enough to run fault tolerant *soft* real time systems in a workstation cluster. In other words, good enough for a telephone company, but don't try running your engine controller on it. For building a fault tolerant networked application, you don't really need a reliable transport protocol, what you need is a reliable indication of a node or network error. A "reliable" transport protocol usually only gets in your way by insisting that everything is fine until it at last admits that it cannot deliver your message. Then you have to handle the error yourself anyway. Having spent the last years working on such a beast in C++ (a soft real-time, fault-tolerant, scalable RDBMS), it would be very interesting to see if Glade could be used for such applications. A quick guesstimate tells me that there would be great savings both in terms of readability, maintainablity, and code volume (at least a factor of 2 for some modules) by using Ada threads and Glade instead of the homegrown RPC-like mechanism and extremely primitive (but fast) thread system we used. Btw., I've been trying to get Glade to run under Windows 2000, but when running gnatdist, gcc complains that the distribution feature is not supported. This is Glade 3.14p, with ditto GNAT. I used Cygwin to build Glade, apparently with no errors. Any suggestions?