Java Bindings Research Articles

Heterogeneous parallel computing using Java and WMPI

In this paper, we present briefly the implementation of a Java interface for WMPI, a Windows-based implementation of MPI. Then, we describe a system that is oriented for Web-based computing and present a solution to integrate WMPI with this tool by making use of a Java bridge component and the Java bindings for WMPI. This solution allows the execution of meta-applications over a mixed configuration of platforms, execution models and programming languages. The resulting system provides a way to solve the problem of heterogeneity and to unleash the potential of diverse computational resources and programming tools. Copyright © 2000 John Wiley & Sons, Ltd.

Object serialization for marshaling data in a Java interface to MPI

Several Java bindings to Message Passing Interface (MPI) software have been developed recently. Message buffers have usually been restricted to arrays with elements of primitive type. We discuss adoption of the Java object serialization model for marshaling general communication data in MPI-like APIs. This approach is compared with a Java transcription of the standard MPI derived datatype mechanism. We describe an implementation of the mpiJava interface to MPI that incorporates automatic object serialization. Benchmark results confirm that current JDK implementations of serialization are not fast enough for high performance messaging applications. Means of solving this problem are discussed, and benchmarks for greatly improved schemes are presented. Copyright © 2000 John Wiley & Sons, Ltd.

Type-checking OQL queries in the ODMG type systems

Several negative results are proved about the ability to type-check queries in the only existing proposed standard for object-oriented databases. The first of these negative results is that it is not possible to type-check OQL queries in the type system underlying the ODMG object model and its definition language ODL. The second negative result is that OQL queries cannot be type-checked in the type system of the Java binding of the ODMG standard either. A solution proposed in this paper is to extend the ODMG object model with explicit support for parametric polymorphism (universal type quantification). These results show that Java cannot be a viable database programming language unless extended with parametric polymorphism. This is why type-checking OQL queries presents no problem for the type system of the C++ binding of the ODMG standard. However, a type system that is strictly more powerful than any of the type systems of the ODMG standard is required in order to properly type ordered collectgions and indices. The required form of polymorphism is bounded type quantification (constrained genericity) and even F-bounded polymorphism. A further result is that neither static nor the standard dynamic object-oriented type-checking is possible for Java OQL, in spite of the fact that Java OQL combines features of two strongly and mostly statically-typed languages. Contrary to one of the promises of object-oriented database technology, this result shows that the impedance mismatch does not disappear in the ODMG standard. A type-safe reflective technique is proposed for overcoming this mismatch.

High-performance parallel programming in Java: exploiting native libraries

With most of today's fast scientific software written in Fortran and C, Java has a lot of catching up to do. In this paper we discuss how new Java programs can capitalize on high-performance libraries for other languages. With the help of a tool we have automatically created Java bindings for several standard libraries: MPI, BLAS, BLACS, PBLAS and ScaLAPACK. The purpose of the additional software layer introduced by the bindings is to resolve the interface problems between different programming languages such as data type mapping, pointers, multidimensional arrays, etc. For evaluation, performance results are presented for Java versions of two benchmarks from the NPB and PARKBENCH suites on the IBM SP2 using JDK and IBM's high-performance Java compiler, and on the Fujitsu AP3000 using Toba - a Java-to-C translator. The results confirm that fast parallel computing in Java is indeed possible.

High-performance parallel programming in Java: exploiting native libraries

With most of today's fast scientific software written in Fortran and C, Java has a lot of catching up to do. In this paper we discuss how new Java programs can capitalize on high-performance libraries for other languages. With the help of a tool we have automatically created Java bindings for several standard libraries: MPI, BLAS, BLACS, PBLAS and ScaLAPACK. The purpose of the additional software layer introduced by the bindings is to resolve the interface problems between different programming languages such as data type mapping, pointers, multidimensional arrays, etc. For evaluation, performance results are presented for Java versions of two benchmarks from the NPB and PARKBENCH suites on the IBM SP2 using JDK and IBM's high-performance Java compiler, and on the Fujitsu AP3000 using Toba – a Java-to-C translator. The results confirm that fast parallel computing in Java is indeed possible. © 1998 John Wiley & Sons, Ltd.

Solving the Java object storage problem

Today's Internet driven view of information systems is helping to popularize Java as an application development language. Developers are beginning to use Java to create multi tier application architectures that often integrate relational data stores with new data types, in order to package information in easier to use, dynamic ways. Java's object oriented nature is ideally suited to this new world. Using objects, Java developers can encapsulate both data and data manipulation methods to give applications a runtime dynamism and self-contained intelligence that is difficult to achieve using other methods. Java application developers need to be able to store these Java objects-technically, to give them persistence-in order to take advantage of these capabilities. We examine the development issues surrounding Java object storage, including a brief overview of the ODMG Java binding, a standard that adds object persistence to Java. We compare this with the much greater level of effort required to implement the same application using the lower level JDBC interface, which supports Java object storage in relational databases. The ODMG binding for Java and JDBC are not competitive specifications: ODMG interfaces can be built on top of JDBC.