Abstracts of publications by Rick van Rein

We propose an alternative notation and semantics for process models in object analysis, to resolve problems with current diagram languages. Our dynamic life cycles are communicating state diagrams. Our life cycles support polymorphic creation, and they are straightforwardly composed. We provide an operational semantics, and demonstrate how to interact with a system of life cycles.

Keywords: object orientation, polymorphic creation and deletion, conceptual modelling, communication, state diagrams, life cycles, process algebra, component composition.

©2000 Springer-Verlag.

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Conventionally, interfaces of objects export a set of messages with their types, and suggest nothing about the order in which these services may be accessed. This leaves room for a large number of run-time errors or misbehaviours in type correct designs. To mend this, we introduce the notion of protocol, expressing offered and expected orderings of messages, along with a notion of protocol correctness. We do this by defining the Protocol Assuring Universal Language Paul, which describes protocol aspects of classes, and a semantics of in terms of CSP.

Keywords: object orientation, interface, behaviour, role, protocol, process, type checking, CSP, Paul.

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This article describes a new approach to compiler technology. The project in which this approach evolved demands some special properties from compilers, such as language independence and dynamically extensible and orthogonal attributes. These properties cannot be modelled in conventional compiler technology. Therefore, existing technology is fitted in an object oriented framework, which is a solution for the above problems.

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Because the field of parallel computer systems evolves rapidly, most parallel software has the opportunity to live longer than the hardware it was designed for. This opportunity is not always exploited in pratice, because most applications are not protable between different parallel platforms.

An attempt to solve this problem has been the development of more or less standardized methods for parallel operating systems. This approach makes software more portable, but cannot fully exploit the computational power of the hardware. This is caused by the genericity of the standardized interface between application software and operating system. Most manufacturers therefore add routines for actions that their hardware can perform more efficient, but with the penablty of reduced portability.

To overcome the above problems, this Master's thesis presents ParMod, a framework for encapsulating many types of already existing parallel techniques and tools. ParMod generates an extension to hardware and firmware that is fine-tuned for efficient execution of a given application on a specific machine.

The objective of this research project is finding a generic description that captures all parallel and distributed architectures that exist or are likely to be built in the future. This description is exploited for mapping concurrent programs onto any of these architectures, without loss of efficiency.

To make this possible, ParMod is generic with respect to the target architecture and source code language. Furthermore, it is possible to extend ParMod with techniques for optimizing or simulating some desired functionality iun a portable way without recompilation of the ParMod system.

ParMod models its problem domain in a set of orthogonal object oriented frameworks. Orthogonaliy makes decomposition of problems easier, while the object oriented nature of the framework allows for specialization of generic descriptions, by simply inheriting them.

A part of ParMod which is actually just support of the rest of the system, but seems rather promising, is the object oriented compiler framework, which allows for desirable features like source language independent code generation and attribution, or extensibility of a language's syntax and semantics without the need to extend any other compiler part in many cases.

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This report summarizes the presentations, discussions and outcomes of the ECOOP'99 Workshop on Object Interoperability, held in Lisbon on Monday, June 14, 1999. Divided into four main sessions, the workshop covered some of the most important issues related to object interoperability at different levels (such as protocols, semantics, or mediated architectures). Two are the main goals of this report. First, it tries to provide a snapshot of some of the current research being carried out within the object-oriented community in these areas. And second, it summarizes some of the open questions and issues related to object interoperability, in order to set the basis for further research activities.