Getting more flexible scheduling in the RTSJ

This paper illustrates how the real-time specification for Java (RTSJ) can be modified to allow applications to implement more flexible scheduling. The proposed approach is a two-level scheduling mechanism where the first level is the RTSJ priority scheduler and the second level is under application control. Minimum, backward-compatible changes to the RTSJ specification are discussed to motivate the required interface. The only assumptions made about the underlying real-time operating system are that it supports pre-emptive priority-based dispatching and that changes to priorities have immediate effect.