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 realtime 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.