A design pattern for using non-developmental items in real-time Java

This paper addresses the need to reduce the difficulties in developing time-constrained Java applications. We present a design pattern for a class of time-constrained real-time applications that allows developers to use (and re-use) Java code libraries and non-developmental items (NDI). The proposed design pattern simplifies the implementation of the time-constrained tasks substantially by not requiring the use of no-heap real-time threads. We tested the design pattern with the Java Real-Time System (RTS) 2.0 from the Sun Microsystems. This paper also presents a simple methodology for determining the appropriate values for the RTS run-time parameters (thread priorities, memory usage, process load, and task deadlines) in order to ensure the deterministic execution of the time-constrained tasks.