[comp.sys.encore] VADS Ada parallel features

dcourte@eve.wright.edu (Dale Emery Courte) (09/22/89)

I have a user here who is interested in utilizing the parallel aspects
of Encore's VADS Ada implementation. The VADS docs from Encore don't
give much insight into this (according to the user). Specifically, he is
interested in whether there are ways to explicitely parallelize code, or
if the amount of parallelization is at all under user control.

I am not an Ada user myself. Is there anyone out there who is and who
has looked closely enough at VADS on the Encore to answer these
questions?

-----------------------------       -------------------------------------
Dale Courte                         CSNET: dcourte@eve.wright.edu
University Computing Services       BITNET: dcourte@wsu
Wright State University             UUCP: ..!uunet!ncrlink!wright!dcourte
Dayton, Ohio 45435                  phone: (513) 873-4030
-----------------------------       -------------------------------------

guzzi@multimax (Mark D. Guzzi) (09/26/89)

> I have a user here who is interested in utilizing the parallel aspects
> of Encore's VADS Ada implementation. The VADS docs from Encore don't
> give much insight into this (according to the user). Specifically, he is
> interested in whether there are ways to explicitely parallelize code, or
> if the amount of parallelization is at all under user control.

Ada is a multitasking language.  You get parallel execution if the Ada
program contains multiple ada tasks that can be executed in parallel.
There is no re-structuring of the user's Ada code.  The user has
complete control over the amount of parallelism in the program -- it
depends on the tasks that he/she codes.  Currently, Ada tasks are
multiplexed on a fixed number of Unix processes or Mach tasks.  The
number of processes is controlled by the "AdaRT" environment variable
-- no recompilation is necessary.

	%setenv AdaRT "-N4" 

would give you 4 unix processes (or 4 Mach tasks).  How much speedup
you get depends on the structure and number of ada tasks in your
program.

All this is explained in detail in the Release Notes for Parallel Ada
(doc #735-06027).  This is not part of the standard VADS
documentation, but additional documentation provided by Encore.  If
you can't find this document, you should contact your salesman or
customer service representative.
-- 
				       -- Mark Guzzi
					  Encore Computer Corporation
					  guzzi@encore.com
					     (or guzzi@multimax.encore.com)