Re: ADA task

["Marin David Condic, 407.796.8997, M/S 731-93" <condicma@PWFL.COM>]

"Norman H. Cohen" <ncohen@WATSON.IBM.COM> writes:
>The "delay until" statement is a new feature in Ada 95.  In Ada 83 you
>would write
>
>   delay Next_Wakeup - Calendar.Clock;
>
>which delays for the specified amount of time (in this case, the time
>from now until Next_Wakeup).
>
    Out of curiosity & ignorance, is there anything in the LRM which
    guarantees some minimal latency or predictability with the "delay
    until" statement? I recall one of the big criticisms of Ada83 was
    that the "delay" statement (and other language semantics) made it
    very difficult, if not impossible, to write a task which could
    schedule itself in a predictable manner. (That is, if one wanted
    to fire off a task every 20 milliseconds, one would like to know
    that any fraction of scheduling error is detected and corrected in
    the next pass to the limit of the accuracy of the clock and that,
    if at all possible, you get no "jitter" in the interval between
    cycles.)

    MDC

Marin David Condic, Senior Computer Engineer    ATT:        561.796.8997
M/S 731-96                                      Technet:    796.8997
Pratt & Whitney, GESP                           Fax:        561.796.4669
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