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From: quester@cadlab.UUCP (Remco Quester)
Newsgroups: comp.protocols.iso.dev-environ
Subject: distributed programming language/ISODE
Message-ID: <9106101309.AA07743@cadlab.cadlab.de>
Date: 12 Jun 91 05:41:56 GMT
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subject:   Questions regarding the usefulness of ISODE to build a (low level)
--------   communication basis for a distributed programming language (DPL)
	   based on C++.


Dear members of the ISODE discussion group,

I do research on distributed programming languages (DPL) which is aimed to
build a DPL based on C++ to support cooperation of integrated tools (like
editors, simulators, compilers, ...) for VLSI-design in an open integrated
framework for building CAD-environments.

My understanding of a DPL is what is described in [Tanenbaum89] and where
examples of DPLs are given: Concurrent C, SR, ORCA, CSP, ADA ... .
Those DPLs support (syntactically) a broad supply of different (more or less)
high level communication semantics (guarded receive of messages, Rendezvous,
RPC, shared objects, ...).

My intention is:
"to build the one-to-many RPC/Rendezvous-like communication aspect of my
 DPL on top of the transport layer (or higher layers) of the ISO/OSI reference
 model using multicast communication semantics (n * point-to-point)".
I intend to use ISODE to implement the communication aspects of my DPL.


Reference
=========
[Tanenbaum89]
Bal, Steiner, Tanenbaum, "Programming Languages for Distributed Computing
Systems", ACM Computing Survey 21(3), pp. 261-322, September 1989.



So my questions are:
====================

1.
As far as I know there is no DPL which communication aspects are based on
ISO/OSI-communication. Therefore I want to start with a fundamental question.

Are there fundamental reasons against basing the (low level) communication
aspects of a DPL on the transport layer (or higher ones) using ISODE ?
(Why and are there articles which discuss/demonstrate usefulness or not?)

2.
Should the inherent performance-lack of the ISO/OSI-communication be an
arguement not to use it for DPLs? (Are there other arguements that dominate
performance-issues?)

3.
How can I use ISODE to build protocols that use (reliable) multicast
communication? (Do you have some simple examples?)

4.
How can I use ISODE to build protocols that use nonblocking/asynchron
communication (send/receive)? (Do you have some simple examples?)

5.
Can I use the ISODE-libraries ( those that are based on light-weight
processes) to handle a send/receive-operation as a co-routine?
(Do you have some simple examples?)

6.
Can there problems arise if I use C++-Code and ISODE libraries together?
(resp. will there be a C++ version of ISODE) ?

7.
Do you know about research in building (object-based, object-oriented, ...)
DPLs which use ISO/OSI-communication (resp. ISODE)?



I would be pleased if you have references/authors/examples that answer
(parts of) the questions or if you can give some short remarks to the
questions. A quick response would be very kind.



Yours Sincerely

R. Quester




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  Remco Quester                          e-mail: quester@cadlab.cadlab.de
  University of Paderborn (CADLAB)
  Bahnhofstrasse 32                      phone:  +49 5251 284 135
  D-4790 Paderborn
  Germany                                fax:    +49 5251 284 140
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