Re: PAR (Was: Embedded languages based on early Ada)

[Pascal Obry <pascal@obry.net>]

Dmitry A. Kazakov a �crit :

> Why is it bad programming? Consider this:
> 
> declare
>    Sum : Numeric := 0.0;
> begin in parallel
>    Sum := Sum + Integrate (Series (1..N);
>    Sum := Sum + Integrate (Series (N+1..2*N);
>    Sum := Sum + Integrate (Series (2*N+1..3*N);
>    ...
> end;

   task type Integrate is
      entry Run (Series : in Series_Type);
      entry Result (Value : in out Numeric);
   end Integrate;

   Max : constant := 30;
   T   : array (1 .. Max) of Integrate;

   declare
      Sum : Numeric := 0.0;
      S   : Numeric;
   begin
      for K in T'Range loop
         T (K).Start (Series ((K-1) * N + 1 .. K * N));
      end loop;

      for K in S'Range loop
         T (K).Result (S);
         Sum := Sum + S;
      end loop;
   end;

Typed directly from my mail client, sorry if it is not compiling :)

I don't see the point of PAR which create dynamically threads all the
time. A waste of time! The T tasks above can be reused during all the
application lifetime if necessary.

Pascal.

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