Java has become increasingly popular as a general-purpose programming language. Current Java implementations mainly focus on portability and interoperability, which is required for Internet-centric client/server computing. Key to Java’s success is its in- termediate “bytecode” representation that can be exchanged and executed by Java Vir- tual Machines (JVMs) on almost any computing platform. Along with Java’s widespread use, the need for a more efficient execution mode has become apparent. For sequential execution, Just-in-Time (JIT) compilers improve application performance [4]. However, high-performance computing typically requires multiple-processor systems, so efficient interprocessor communication is needed in addition to efficient sequential execution. Being an object-oriented language, Java uses method invocation as its main concept of communication. Inside a single JVM, concurrent threads of control can communicate by synchronized method invocations. On a multiprocessor system with shared mem- ory (SMP), this approach allows for some limited form of true parallelism by mapping threads to different physical processors. For distributed-memory systems, Java offers the concept of a Remote Method Invocation (RMI). Here, the method invocation, along with its parameters and results, is transferred across a network to and from the serving object on a remote JVM.

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