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From: robert@droopy.laas.fr (Robert Valette)
Newsgroups: comp.object
Subject: Re: concurrency control
Message-ID: <5558@laas.laas.fr>
Date: 9 Apr 91 08:50:54 GMT
References: <1991Apr4.215238.14067@bingvaxu.cc.binghamton.edu>
Sender: news@laas.laas.fr
Reply-To: robert@droopy.laas.fr (Robert Valette)
Organization: LAAS-CNRS, Toulouse, France
Lines: 39

In article <1991Apr4.215238.14067@bingvaxu.cc.binghamton.edu> yunyau@bingvaxu.cc.binghamton.edu (Yun Yau Shih) writes:
>
>What does it mean by "Several threads can simultaneously enter an object
>and execute concurrently." Does it mean REAL CONCURRENCY? How about the
>concurrency control, then? Or an object should have a machanism like a
>monitor. Any comment/hint/reference is welcomed. Thanks in advance.
>-- 

Hi,

At LAAS-CNRS, Toulouse, France, we are a small group
working on OOD (Object Oriented Design) in the case of distributed/concurrent
object oriented systems. We try to handle real concurrency
within an object and between a collection of objects.

Our starting point is HOOD (Hierarchical OOD) and its notion of active objects
which are provided with OBCSs (OBject Control Structures).

We think that Petri nets are well suited for describing OBCS
and analyzing the behavior of a collection of active objects
(i.e. a situation with concurrency). We think also that a formal
description of the OBCS of an object by means of a Petri net
may be an hint to answer to the question: how this object
is to be refined? (Objects with internal concurrency are to be
refined into a collection of active objects until the obtaining
of processes). Then, we think that eventually, at the OOP level
(coding) objects do not encapsulate true (or real) concurrency.

Is there anybody working in the same direction?

.---------------------------------------------------------------------.
|         Mario PALUDETTO, LAAS-CNRS, 7 Av. du Colonel Roche,         |
| F-31077 TOULOUSE Cedex France, TEL:++33 61336260, FAX:++33 61553577 |
|                      NET: mario@laas.laas.fr                        |
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|         Robert VALETTE, LAAS-CNRS, 7 Av. du Colonel Roche,          |
| F-31077 TOULOUSE Cedex France, TEL:++33 61336409, FAX:++33 61553577 |
|                      NET: robert@laas.laas.fr                       |
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