Search

Object and component technologies play an ever-increasing role in the development of real-time distributed applications. These systems are characterized by the fact that the temporal compatibility of the different objects that are brought together is a condition for success. In this paper, we propose an approach to validate the interoperability of object interfaces with respect to their temporal properties. This approach is based on a recent execution-time calculation technique dedicated to concurrent environments. In this article, we propose a simpler computation framework for this technique, based on Petri nets and J.Y. Girard's (1987, 1990, 1995) linear logic, and we show how it can quite advantageously be adapted to distributed real-time object-oriented systems.

Experiments and flight simulation programs for a research flight simulator can be considered as a combination of real-time distributed calculation processes. Current tools and architectures for implementing these processes are complicated to use and require considerable real-time programming skills. The created programs are not sufficiently flexible. A new middleware layer, DUECA, was developed to facilitate implementation of programs on a research flight simulator. It combines a publish and subscribe mechanism and message passing facilities with some novel elements, namely explicit allocation of process activation and the conditions under which that allocation should take place, synchronisation of data from different sources, and a mechanism to transparently combine processes running at different update rates., Control & Simulation