Research Objectives

The main goal of the research presented in this dissertation is to investigate issues pertinent to high performance programming in Java, design Java interfaces to High Performance Computing softwares, and research implementation issues associated with their development. The dissertation has the following objectives:

• Investigate various issues and options for parallel programming in Java--data parallelism and message passing libraries. These include discussing motivations for introducing HPJava, an HPspmd programming model. It allows programs to combine data parallel code and SPMD library calls directly. We present sample code that directly calls to MPI from within the data parallel program.

• Develop mpiJava, an object-oriented Java interface to MPI. This could be implemented by ``native methods'' wrappers around some pre-existing MPI implementation. However, interfacing Java to MPI is not always trivial. The new native thread feature in JDK 1.2 might be a solution to eliminate conflicts between the Java runtime and the interrupt mechanisms used in the MPI implementations. Also, the syntax of mpiJava should be easy to understand and use, thus making it relatively simple for programmers with either a Java or Scientific background to take up.

• Incorporate automatic object serialization in mpiJava. In order to support derived datatypes or handle a multidimensional array, the Java object serialization model for marshalling general communication data in MPI-like APIs should be introduced, because the standard MPI approach describing user-defined types does not map very naturally into Java. In addition, we should evaluate overheads introduced by object serialization in mpiJava, then consider optimized methods that reduce serialization overheads.

• Develop real applications written in mpiJava and evaluate their performance. It is also interesting to compare the results of benchmarks written in Java with equivalent C or Fortran code. Applications include graphical visualization parallel Potts model simulation with GUI using Java AWT.

• Publically release mpiJava on a Web site. This includes complete source, makefiles, configuration scripts, compiled libraries for WMPI, test codes (based on the IBM MPI test suite), example applications, javadoc documentation, and installation and usage notes.