A Profile for Safety Critical Java
by Martin Schoeberl, Institute of Computer Engineering, Vienna University of Technology, Austria mschoebe@mail.tuwien.ac.at Hans Søndergaard, University College - Vitus Bering Denmark, DK-8700 Horsens hso@vitusbering.dk Bent Thomsen & Anders P. Ravn, Department of Computer Science, Aalborg University, DK-9220 Aalborg {bt, apr}@cs.aau.dk January 2007 Abstract In this paper we propose a new, minimal specification for real-time Java for safety critical applications. The intention is to provide a profile that supports programming of applications that can be validated against safety critical standards such as DO-178B. The proposed profile is in line with the Java specification request JSR-302: Safety Critical Java Technology, which is still under discussion. In contrast to the current direction of the expert group for the JSR-302 we do not subset the rather complex Real-Time Specification for Java (RTSJ). Nevertheless, our profile can be implemented on top of an RTSJ compliant JVM. The paper is presented at ISORC 2007 - 10th IEEE International Symposium on Object/component/service-oriented Real-time distributed Computing, May 7-9, 2007.
[The presentation in PDF-format will appear later].A Ravenscar-Java Profile Implementation
by Hans Søndergaard, University College - Vitus Bering Denmark hso@vitusbering.dk Bent Thomsen & Anders P. Ravn, Department of Computer Science, Aalborg University {bt, apr}@cs.aau.dk June 2006 Abstract This paper presents an implementation of the Ravenscar-Java profile. While most implementations of the profile are reference-implementations showing that it is possible to implement the profile, our implementation is aimed at industrial applications. It uses a dedicated real-time Java processor, since we want to investigate if the Ravenscar-Java profile, implemented on a Java processor, is efficient for real applications. During the implementation some ambiguities and weaknesses of the profile were uncovered. However, test examples indicate that the profile is suitable for development of realistic real-time programs. The paper is presented at JTRES 2006 - The 4th International Workshop on Java Technologies for Real-time and Embedded Systems, October 11-13, 2006.
[The presentation in PDF-format].Periodic threads on aJ-100
by
Hans Søndergaard
hso@vitusbering.dk
December 2004
Abstract
At Vitus Bering Denmark we want to use the aJ-100 Java processor as a real-time processor for industrial purposes. To meet the condition of real-time, the aJile API has a class PeriodicThread together with a class PianoRoll.
However, the documentation of these classes is inadequate. Therefore we have described and tested the conditions which must be satisfied for using the piano roll and the periodic threads.
Because there are many conditions that must hold when initializing the piano roll and the periodic threads, we have implemented a class CheckCylicSetup to check these setup conditions. This class uses the Rate Monotonic scheme to setup the periodic threads.