Improving the memory management performance of RTSJ

International audienceFrom a real-time perspective, the garbage collector (GC) introduces unpredictable pauses that are not tolerated by real-time tasks. Real-time collectors eliminate this problem but introduce a high overhead. Another approach is to use memory regions (MRs) within which allocation and deallocation is customized. This facility is supported by the memory model of the Real-Time Specification for Java (RTSJ). RTSJ imposes strict access and assignment rules to avoid both the dangling inter-region references and the delays of critical tasks of the GC. A dynamic check solution can incur high overhead, which can be reduced by taking advantage of hardware features. This paper provides an in-depth analytical investigation of the overhead introduced by dynamic assignments checks in RTSJ, describing and analysing several solutions to reduce the introduced overhead

MPJ: MPI-like message passing for Java

Recently, there has been a lot of interest in using Java for parallel programming. Efforts have been hindered by lack of standard Java parallel programming APIs. To alleviate this problem, various groups started projects to develop Java message passing systems modelled on the successful Message Passing Interface (MPI). Official MPI bindings are currently defined only for C, Fortran, and C++, so early MPI-like environments for Java have been divergent. This paper relates an effort undertaken by a working group of the Java Grande Forum, seeking a consensus on an MPI-like API, to enhance the viability of parallel programming using Java