Toward a Unified Standard for Worst-Case Execution Time Annotations in Real-Time Java

As real-time systems become more prevalent, there is a need to guarantee that these increasingly complex systems perform as designed. One technique involves a static analysis to place an upper bound on worst-case execution time (WCET). This temporal analysis cannot be made automatic and normally requires source annotations to assist a WCET analysis tool. At the same time, there is a growing interest in using Java for real-time systems. Several WCET analysis prototypes for Java have been created, and more are under development. Each relies on a competing and incompatible convention for annotations, resulting in portability problems and duplication of effort. We propose that Java´s own annotation mechanism should be used to address such issues. These built-in annotations provide a common platform for WCET analysis, improving portability and reducing the effort necessary to create these vital tools. We examine the features that make Java´s annotation standard attractive for WCET analysis, then discuss its current failings and make recommendations for future improvements.