The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation

Distributed real-time systems1 are becoming more per-vasive in many domains including process control, discrete manufacturing, defense systems, air traffic control, and on-line monitoring systems in medicine. The construction of such systems, however, is impeded by the lack of simple yet powerful programming models and the lack of efficient, scalable, dependable and analyzable interfaces and their implementations. We argue that these issues need to be resolved with powerful application-level toolkits similar to that provided by ISIS [2]. In this paper, we consider the inter-process communication requirements which form a fundamental block in the construction of distributed real-time systems. We propose the real-time publisher/subscriber model, a variation of group-based programming and anonmyous communication techniques, as a model for distributed real-time inter-process com-munication which can address issues of programming ease, portability, scalability and analyzability. The model has been used successfully in building a software architecture for building upgradable real-time systems. We provide the programming interface, a detailed design and implemen-tation details of this model along with some preliminary performance benchmarks. The results are encouraging in that the goals we seek look achievable. 1