Safety-Critical Java (SCJ) is based on the Real-Time Specification for Java. To simplify the certification of Java programs, SCJ supports only a restricted scoped memory model. Individual threads share only immortal memory and the newly introduced mission memory. All other scoped memories are thread private. Furthermore, the notation of a maximum backing store requirement enables implementation of the scoped memories without fragmentation issues. In this paper we explore the implications of this new scoped memory model and possible simplifications in the implementation. It is possible to unify the three memory area types and provide a single class to represent all three memory areas of SCJ. The knowledge of the maximum storage requirements allows using nested backing stores in the implementation of the memory area representation. The proposed design of an SCJ compliant scope implementation is evaluated on an embedded Java processor.
Proceedings of the 9th International Workshop on Java Technologies for Real-time and Embedded Systems (jtres 2011), 2011
Scoped memory; Safety-critical Java
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9th International Workshop on Java Technologies for Real-Time and Embedded Systems, 2011