ROM 기반의 실시간 자바가상기계를 위한 메모리 할당기법 = Memory Allocation Scheme for ROM-Based Real-Time Java Virtual Machine

다국어 초록 (Multilingual Abstract)

On embedded real-time system with a single processor and no virtual memory, fixed-size memory allocation scheme is used to solve external memory fragmentation and predictability of the computation time problem. The scheme can be applied to embedded Java virtual machine with heap memory as in simpleRTJ for example. Fixed-size memory allocation scheme has an advantage that makes memory management system simple and reduces runtime overhead. We found, however, there are some problems in simpleRTJ adopting the scheme. Firstly it searches memory in linear fashion to find a free space which causes an unpredictable delay. This is a critical problem for real-time guarantee. Additionally, when array and string is allocated in the heap, it uses real size, not fixed-size. So fixed-size memory allocation scheme cannot take its advantage in this case. In this paper we have reconstructed the object, method frame and allocation scheme for the best use of the advantage of fixed-size memory allocation scheme.