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=0.6 required=5.0 tests=BAYES_00,TO_NO_BRKTS_FROM_MSSP autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,7efbdbcd2058c74e X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-04-30 07:03:56 PST Path: newsfeed.google.com!newsfeed.stanford.edu!feed.textport.net!newsranger.com!www.newsranger.com!not-for-mail Newsgroups: comp.lang.ada From: Ted Dennison References: Subject: Re: GtkAda with several task (or distributed solution?)? Message-ID: X-Abuse-Info: When contacting newsranger.com regarding abuse please X-Abuse-Info: forward the entire news article including headers or X-Abuse-Info: else we will not be able to process your request X-Complaints-To: abuse@newsranger.com NNTP-Posting-Date: Mon, 30 Apr 2001 10:03:17 EDT Organization: http://www.newsranger.com Date: Mon, 30 Apr 2001 14:03:17 GMT Xref: newsfeed.google.com comp.lang.ada:7050 Date: 2001-04-30T14:03:17+00:00 List-Id: In article , Frank says... >> Any multi-word data they share may need to be protected from "tearing" >I'm not sure I understand what you mean here; >do you mean that if I try to pass a GUI object (the data structure of it) >between partitions it can be destroyed when (can imagine that)? No. "Data tearing" is the term I've heard simulation folk use for what CS people like to call "race conditions" on data. What I'm saying is that if you have one task updating multi-word data (eg: the xyz acceleration vector of an object), and another accessing it from over the network, its quite possible for the reader to see a snapshot of the object with time 1's values for z and time 2's values for x and y. That would essentially make the overall value complete garbage. You have to place some kind of read protection (locking, protected object, etc.) around multi-word objects to prevent this. In many cases (I don't know about annex E), this can also happen with 64-bit floats. --- T.E.D. homepage - http://www.telepath.com/dennison/Ted/TED.html home email - mailto:dennison@telepath.com