Re: Embedded languages based on early Ada (from "Re: Preferred OS, processor family for running embedded Ada?")

["Dr. Adrian Wrigley" <amtw@linuxchip.demon.co.uk.uk.uk>]

On Thu, 01 Mar 2007 14:57:01 +0100, Dmitry A. Kazakov wrote:

> On Thu, 01 Mar 2007 11:22:32 GMT, Dr. Adrian Wrigley wrote:
> 
>> If you don't have multiple processors, lightweight threading is
>> less attractive than if you do?  Inmos/Occam/Transputer was founded
>> on the basis that lightweight threading was highly relevant to multiple
>> processors.
>> 
>> Ada has no means of saying "Do these bits concurrently, if you like,
>> because I don't care what the order of execution is".  And a compiler
>> can't work it out from the source.  If your CPU has loads of threads,
>> compiling code with "PAR" style language concurrency is rather useful
>> and easy.
> 
> But par is quite low-level. What would be the semantics of:
> 
>    declare
>       Thing : X;
>    begin
>       par
>          Foo Thing);
>       and
>          Bar Thing);
>       and
>          Baz Thing);
>       end par;
>    end;

Do Foo, Bar and Baz in any order or concurrently, all accessing Thing.

Roughly equivalent to doing the same operations in three separate
tasks.  Thing could be a protected object, if concurrent writes
are prohibited.  Seems simple enough!

I'm looking for something like Cilk, but even the concurrent loop
(JPR's for I in all 1 .. n loop?) would be a help.
--
Adrian