Re: More details on:--- ADA vs JAVA sockets---

[Ole-Hjalmar Kristensen <ole-hjalmar.kristensen@substitute_employer_here.com>]

>>>>> "R" == Riccardo  <kk@kk.com> writes:

    R> <tmoran@acm.org> ha scritto nel messaggio
    R> news:qUiLb.782498$Tr4.2238587@attbi_s03...
    >> >The possibility of loss due to UDP (I believe) is not the case ...
    >> An easy test would be to insert delays to artificially slow down the
    >> transmitting side.

    R> Yes, I tried it and depending on what I do in the receiving phase, some
    R> times I miss messages:

    R> -- when I try to print them directly on the screen
    R> -- when I redirect the output on a file
    R> (both operations time consuming that really delay the receiver operations)
    R> Also in those cases, introducing delays, the problem seems to be solved..

    R> May I set (as in UNIX SYSTEM V) , although I use SUN SOLARIS 5.8-SPARK, the
    R> OS message queue lenght and the message size (in bytes) for the socket
    R> communications?

No. UDP messages may be lost no matter what you do, that's the nature
of the beast. If you want 'reliable' communication, use TCP with your
sockets, or implement a retransmission scheme yourself.

pragma(RANT MODE ON)

(Reliable communication protocols do not really exist, all you get is
a guarantee that if the message is not delivered, you will get a
notice, so if you want application-level reliability, you, have to be
prepared to retry in some way. Going to a transactional message system
does help a little, but then transactions may fail, so you have to
retry here as well...)

pragma(RANT MODE OFF)

    R> The introduction of a sincronization mechanism made by a buffer queue
    R> doesn't help in any way.



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