The design and performance of real-time Java middleware

More than 90 percent of all microprocessors are now used for real-time and embedded applications. The behavior of these applications is often constrained by the physical world. It is therefore important to devise higher-level languages and middleware that meet conventional functional requirements, as well as dependably and productively enforce real-time constraints. We provide two contributions to the study of languages and middleware for real-time and embedded applications. We first describe the architecture of jRate, which is an open-source ahead-of-timecompiled implementation of the RTSJ middleware. We then show performance results obtained using RTJPerf, which is an open-source benchmarking suite that systematically compares the performance of RTSJ middleware implementations. We show that, while research remains to be done to make RTSJ a bullet-proof technology, the initial results are promising. The performance and predictability of JRate provides a baseline for what can be achieved by using ahead-of-time compilation. Likewise, RTJPerf enables researchers and practitioners to evaluate the pros and cons of RTSJ middleware systematically as implementations mature.