Gradimir Starovic

An Event-Based Object Model for Distributed Programming

This paper describes the rationale and design of a new distributed systems programming model based on events, constraints, and objects. The paper describes the inter-object communication or invocation mechanism, and the way in which concurrency, synchronisation, and timing properties are expressed and controlled. The invocation mechanism is unusual in that it is event-based. It encourages loose coupling among the objects and a high degree of encapsulation for each object. Concurrency, synchronisation, and timing properties are expressed in a uniform way using constraints which may be associated with objects and events.

The Amadeus GRT: generic runtime support for distributed persistent programming

Many object-oriented programming language implementations have been extended to support persistence, distribution or atomicity by integrating the necessary additional support with the languages runtime library. We argue that a better approach is to provide a Generic Runtime library (the GRT) which implements that part of the support which is independent of any language. The GRT should be designed to interface to a languages existing runtime in such a way that the languages local object reference format and invocation mechanism can be retained. Hence existing compilers do not necessarily have to be modified, and a range of different object-oriented languages can be supported simultaneously. This approach has significant merits including: the ease with which a language can be extended; the sophistication of the underlying support immediately available to a language implementer; and the ability to support fine-grained language interworking.

Towards generic support for distributed information systems

The authors are concerned with providing support for a range of object oriented programming languages to be used in multi-user, multi-machine, heterogeneous environments requiring associative access, as well as concurrency and storage management. In order to operate in this environment the implementations of current object oriented languages must however be extended. Their goal is to provide a generic runtime support system open to a range of programming language implementations and requiring no (or only minor) alterations to each supported language.<<ETX>>

Some ideas on support for fault tolerance in COMANDOS, an object oriented distributed system

The distributed systems group in Trinity have been concerned with fault tolerance for a number years and are now turning our attention to the topic with renewed interest (and urgency). Specifically we are concerned to provide mechanisms for fault tolerance in thc Oisin kernel [5] - the local implementation of the COMANDOS object oriented distributed system [12]. This short position paper outlines our experience gained to date, some of the lessons we have learned and the avenues which we are currently investigating in order to make Oisin reliable.