Massively parallel computing in Java

Although Java was not specifically designed for the computationally intensive numeric applications that are the typical fodder of highly parallel machines, its widespread popularity and portability make it an interesting candidate vehicle for massively parallel programming. With the advent of high-performance optimizing Java compilers, the open question is: How can Java programs best exploit massive parallelism? The authors have been contemplating this question via libraries of Java-routines for specifying and coordinating parallel codes. It would be most desirable to have these routines written in 100%-Pure Java; however, a more expedient solution is to provide Java wrappers (stubs) to existing parallel coordination libraries, such as MPI. MPI is an attractive alternative, as like Java, it is portable. We discuss both approaches here. In undertaking this study, we have also identified some minor modifications of the current language specification that would make 100%-Pure Java parallel programming more natural.