Distributed Shared Memory Management for Java

Jackal is a fine-grained distributed shared memory system that can run multithreaded Java programs on distributedmemory systems. The Jackal compiler generates an access check for every use of an object field or array element. The overhead of the access checks is reduced using compiler optimizations. The runtime system uses a homebased consistency protocol that manages (and caches) objects and array partitions. In addition, the runtime system manages the virtual address space and dynamically maps and unmaps pages, to support large data structures. Jackal uses local and global mark-and-sweep garbage collectors, which also deal with replicated objects and partitioned arrays. The paper discusses the various distributed memory management techniques used in the system and presents performance results on a cluster of workstations.