Memory Management in Java Processor Optimized for RTSJ

With the advantages as an object-oriented and concurrent programming language, Java is increasingly expected to become the leading programming language in embedded real- time systems. However, the unpredictability caused by the interference of garbage collection is intolerable for the real-time systems. To solve this problem, there are two main approaches were proposed: real-time garbage collectors and region-based memory management. In this paper, the memory management implemented in the JPOR processor is introduced. It employs the two kinds of memory classes ScopedMemory and ImmortalMemory proposed in the RTSJ to allow the definition of memory regions outside of the traditional Java heap. Furthermore, the Java platform based on JPOR offers a simpler programming model than the standard RTSJ's through ameliorating the scoped memory.

[1]  David Detlefs.  A hard look at hard real-time garbage collection , 2004, Seventh IEEE International Symposium onObject-Oriented Real-Time Distributed Computing, 2004. Proceedings..

[2]  ZhiLei Chai,et al.  An effective instruction optimization method for embedded real-time Java processor , 2005, 2005 International Conference on Parallel Processing Workshops (ICPPW'05).

[3]  Martin Schoeberl,et al.  JOP: A Java Optimized Processor for Embedded Real-Time Systems , 2008 .

[4]  Wenbo Xu,et al.  Real-time Java processor optimized for RTSJ , 2007, SAC '07.

[5]  Roger Henriksson,et al.  Scheduling Garbage Collection in Embedded Systems , 1998 .

[6]  Uwe Brinkschulte,et al.  The Komodo project: thread-based event handling supported by a multithreaded Java microcontroller , 1999, Proceedings 25th EUROMICRO Conference. Informatics: Theory and Practice for the New Millennium.

[7]  V. T. Rajan,et al.  The Metronome: A Simpler Approach to Garbage Collection in Real-Time Systems , 2003, OTM Workshops.

[8]  M. Teresa Higuera-Toledano.  Towards an understanding of the behavior of the single parent rule in the RTSJ scoped memory model , 2005, 11th IEEE Real Time and Embedded Technology and Applications Symposium.

[9]  Andy J. Wellings,et al.  Memory Management Based on Method Invocation in RTSJ , 2004, OTM Workshops.

[10]  Lisa Carnahan,et al.  Report from the requirements group for real-time extensions for the Java platform , 1999 .

[11]  Chai Zhi Lei,et al.  An effective instruction optimization method for embedded real-time Java processor , 2005 .

[12]  James Gosling,et al.  The Java Language Specification, 3rd Edition , 2005 .

[13]  James Gosling,et al.  The Real-Time Specification for Java , 2000, Computer.

[14]  James Gosling.  The Java Language Specification - Second Edition , 2000 .

[15]  Guy L. Steele,et al.  The Java Language Specification , 1996 .