Gain Time Reclaiming in High Performance Real-Time Java Systems

The run-time characteristics of Java, such as high frequency of method invocation, dynamic dispatching and dynamic loading, make Java more difficult than other object-oriented programming languages, such as C++, for conducting Worst-Case Execution Time (WCET) analysis. To offer a more flexible way to develop object-oriented real-time applications in the realtime Java environment without loss of predicability and performance, we propose a novel gain time reclaiming framework integrated with WCET analysis. This paper demonstrates how to improve the utilisation and performance of the whole system by reclaiming gain time at run-time. Our approach shows that integrating WCET with gain time reclaiming can not only provide a more flexible environment, but it also does not necessarily result in unsafe or unpredictable timing behaviour.