Using hardware methods to improve time-predictable performance in real-time Java systems

This paper describes hardware methods, a lightweight and platform-independent scheme for linking real-time Java code to co-processors implemented using a hardware description language (HDL). Intended for use in embedded systems, hardware methods have similar semantics to the native methods used to interface Java code to legacy C/C++ software, but are also time-predictable, facilitating accurate worstcase execution time (WCET) analysis. By reference to several examples, the paper demonstrates the applicability of hardware methods and shows that they can (1) reduce the WCET of embedded real-time Java, and (2) improve the quality of WCET estimates in the presence of infeasible paths. 1