Object-Oriented Programming of Complex Fault-Tolerant Real-Time Systems

The challenge is to build, on top of standard operating systems, complex fault-tolerant real-time systems that operate fast enough to meet real-time deadlines even under fault conditions, using an approach that simplifies the application programming. The Realize system, being developed at the University of California, Santa Barbara, aims to meet that challenge. 1 Introduction Research and design paradigms for real-time systems have focused primarily on hard real-time systems. For relatively simple preplanned synchronous systems, effective strategies have been devised that aim to guarantee real-time deadlines using worst-case workloads and worst-case performance measures. Unfortunately, complex real-time systems involve considerable uncertainty. There is variation in processor performance resulting from caches, cycle stealing, and interrupt handling; there is variation in the execution of the programs caused by many special cases and heuristic algorithms; there is variation in message ..