Re: delay until and GNAT

["David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>]

isaac buchwald wrote in message ...
>
>  Does  someone  know  the   upper bound  on the lateness of  delay  until
>and delay relative
> for  Gnat  implement.  on  Win95 , WinNT   or  Linux.
>
>   Thanks
RM 95 9.6(29) says:
An implementation may raise Time_Error if the value of a delay_expression in
a delay_until_statement of a select_statement represents a time more than
90 days past the current time. The actual limit, if any, is
implementation-defined.

And, in accordance with the requirement that implementations document
whatever implementation permissions are taken, the GNAT Reference Manual
says in the obscurely-named section entitled
"Implementation Defined Characteristics":

26. Any limit on delay_until_statements of select_statements. See 9.6(29).
There are no such limits.

As far as GNAT's time representation is concerned the GNAT  RM says:

9.6(30-31): Duration'Small
Whenever possible in an implementation, the value of Duration'Small
should be no greater than 100 microseconds.
Followed. (Duration'Small = 10**(-9)).

In GNAT time and duration are represented in 64 bits, so delay until could
be
until 23:59.999999999 December 31, 2099 -- i.e., until the end of time
as defined by the Ada.Calendar package.