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Independent Active Object Model

IP.com Disclosure Number: IPCOM000112824D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 88K

Publishing Venue

IBM

Related People

Al-Karmi, AA: AUTHOR [+4]

Abstract

This paper discloses a new object model for object oriented programming. We call this the Independent Active Object Model (IAO model) based on active objects versus the current object model which is based on passive objects where the object behavior depends on pre-defined message invocation. The objects which could be created at run-time, dynamically and could be invoked asynchronously, are called active objects and fall in the category of the IAO model. This model removes some of the restrictions imposed by the passive object model by removing the object invocation dependency on message requests. The active objects are quite independent from external invocation as they start and initiate actions asynchronously without receiving a request. Such objects are very important for applications based on knowledge repositories.

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Independent Active Object Model

      This paper discloses a new object model for object oriented
programming.  We call this the Independent Active Object Model (IAO
model) based on active objects versus the current object model which
is based on passive objects where the object behavior depends on
pre-defined message invocation.  The objects which could be created
at run-time, dynamically and could be invoked asynchronously, are
called active objects and fall in the category of the IAO model.
This model removes some of the restrictions imposed by the passive
object model by removing the object invocation dependency on message
requests.  The active objects are quite independent from external
invocation as they start and initiate actions asynchronously without
receiving a request.  Such objects are very important for
applications based on knowledge repositories.

      There are a number of differences between the IAO model and the
current passive object model.  Included in the differences are those
of object location and object context.  Performance is another one
where the demands of parallel processing and asynchronization are
stretching the current model.  However, the IAO model meets these
requirements as it presents incomparably large number of objects and
allows the creation of objects at run-time.  The key difference
between the two models is, however, that of method invocation.  In
the current model, when an object receives a message, the calling
program or processor halts execution and passes control to the object
to initiate its behavior.  The control remains within the object
method until the object method is completed.  In the IAO model, the
object method is invoked asynchronously.  This allows parallelism and
provide multi-threaded uses without blocking.

Active Object Characteristics - The class definition for the IAO
model and the current model look similar but there are inherent
character differences.  These include the capabilities and the
facilities of dynamic memory management, I/O management, code sharing
and the mechanisms of blocking, deblocking and buffer control.  In
addition to providing a greater granularity of resource management,
the IAO model also provides rich and flexible program support
facilities such as data organization, access control, dispatch
mechanisms, and resource scheduling.  Some of the mechanisms defined
are:

o   Detach

          In the terminology used here, an object that is not
    detached is a passive object.  The detach command is us...