Message-Passing Interface (MPI) in Java

MPI [#!MPIFORUM!#,#!USINGMPI!#] is a library of functions and macros that can be used in C, FORTRAN, and C++ programs. MPI is intended for use in programs that exploit the existence of multiple processors by message-passing. MPI was developed by a group of researchers from academia, industry, and government. As such, it is one of the first standards for programming parallel processors, and it is the first that is based on message-passing. MPI provides a rich set of communication libraries, application topologies and user defined data types. The first phase of MPI (MPI 1) was focussed on developing a message-passing standard. The second phase of MPI effort (MPI 2) is underway adding parallel I/O, fault tolerance, language binding for C++ and additional communications. Currently there are several known efforts towards the design of MPI interfaces for Java.

• An approach comparable to the work described in this dissertation to creating full Java MPI interfaces has been taken by University of Westminster [#!MINCHEV97!#,#!GETOV98!#]. In their work Java wrappers were automatically generated from the C MPI header using Java-to-C interface generator (JCI). This eases the implementation work, but does not lead to a fully object-oriented API.

• MPIJ [#!MPIJ!#] is a pure Java-based subset of MPI developed at Brigham Young University as part of the Distributed Object Group Meta-computing Architecture (DOGMA) [#!DOGMA!#] system. MPIJ implements a large subset of MPI functionality including point-to-point commnunication, intra-communicator operations, groups, user-defined reduction operations. MPIJ communications uses native marshalling of primitive Java types. This technique allows MPIJ to achieve communication speeds comparable to native MPI implementations.

• jmpi [#!JMPI98a!#,#!JMPI99!#] is a pure Java implementation of MPI built on top of JPVM. Due to the additional wrapper layer to JPVM routines, its performance is expected to be poor compared to JavaPVM.

• JMPI [#!JMPICOM!#] is a commercial effort underway at MPI Software Technology, Inc. to develop a message-passing framework and parallel support environment for Java. It aims to build a pure Java version of the MPI-2 standard specialized for commercial applications.

• Finally, MPJ [#!MPJ!#] is the Java Grande Forum's MPI-like message-passing API proposed for both Java wrappers and a pure-Java versions. The aim is to provide an implementation of MPJ that is maximally portable.