SDL-News: SDL Questions

Subject: SDL-News: SDL Questions
From: M T Chan (
Date: Sun Nov 16 1997 - 10:35:31 GMT

The originator of this message is responsible for its content.
-----From M T Chan <> (by way of Rick Reed TSE) to sdlnews -----

Hello SDL users,

We would like to have some help from SDL experts concerning the following :-

1. We noted the reference of SDL-96, has it been standardised yet ?
any new features compared to SDL-92 ?

2. Is there any discussion about the pros and cons of using ACT-ONE
and ASN.1 ? With respect to Rick Reed's recent mail re : Lutterwork Q.6/10
meeting results, there mentioned about the start of revision of the data
model, what will be the direction of revision ? e.g. towards a total object
orientation ?

3. Is there any way to model threads ? i.e. concurrency with total
shared memory variables

4. We wish to model concurrency within operators of datatypes and
propose the following :-

newtype a
    op1 : a,b -> c;
  operator op1 referenced;
endnewtype a;

operator op1; fpar x a, y b; returns v c;
    task v := call remote-proc(x,y);
endoperator op1;

In some process specification, there exists :

exported procedure remote-proc; fpar x a. y b; returns v c;
    create process1;
    create process2; /* etc. handling the operator's detail actions */
    return v;
endprocedure remote-proc;

The application of operator op1 will be within a process which has an
import of remote-proc.

Wish to confirm whether the above is correct in SDL.


M T Chan

-----End text from M T Chan <> (by way of Rick Reed TSE) to sdlnews -----
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