The Real-Time Specification for Java (RTSJ), also know by it’s Java Specification Request number (JSR-01), was formalized in June of 2000. Since then a number of commercial implementations have become available. The RTSJ approaches the solution to the problem of writing real-time code from a different direction than other available software development platforms such as a typical real-time operating system application programming interface (API). The approach of the RTSJ embraces the notion of real-time scheduling theory as a fundamental principle for the development of programs which have temporal correctness requirements and as an environment which enhances the ability of developers to write more portable real-time code.

This paper explains the scheduling subsystem, or framework, in RTSJ 1.0.1(b) and some new features scheduled for RTSJ 1.1 and show how to use the features in programs.