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From: 8440425@wwu.EDU (Richard Golding)
Newsgroups: comp.lang.ada
Subject: Message ordering
Message-ID: <8709222126.AA13646@ucbvax.Berkeley.EDU>
Date: Fri, 11-Sep-87 19:57:00 EDT
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Posted: Fri Sep 11 19:57:00 1987
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"... In a properly designed real-time, multiprocessor, Ada OS, where tasking
     across machine boundaries is implemented via messages, the design of the
     bus insures that the messages are received in the order that they are 
     sent out..."

This may be true in some tightly-coupled multiprocessor systems, but it is
patently *not* the case in a distributed system.  For a discussion of message-
ordering, see Agha's Actors book.  In a widely dispersed system, say across
several millions of miles of space (in the case of remote space probes) there
is simply *no way* you are going to be able to completely guarantee ordering.

    - richard golding
      8440425@wwu.edu