Real-Time Java for On-Board Systems

The Java language has several attractive features but cannot at present be used in on-board systems primarily because it lacks support for hard real-time operation. This shortcoming is in being addressed: some suppliers are already providing implementations of Java that are RTcompliant; Sun Microsystem has approved a formal specification for a real-time extension of the language; and an independent consortium is working on an alternative specification for real-time Java. It is therefore expected that, within a year or so, standardized commercial implementations of real-time Java will be on the market. Availability of real-time implementations now opens the way to its use on-board. Within this context, this paper has two objectives. Firstly, it discusses the suitability of Java for on-board applications. Secondly, it reports the results of an ESA study to port a software framework for on-board control systems to a commercial real-time version of Java. 1 Standard Java and On-Board Applications The attractive features of the Java language from the point of view of on-board applications include: greater safety; higher productivity; built-in support for multi-tasking; built-in support for networking operations; support for code documentation to be performed within the language; a wide user bas