A distributed object model for the java TM system

Abstract

We show a distributed object model for the JavaTM System [1,6] (hereafter referred to simply as Java) that retains as much of the semantics of the Java object model as possible, and only includes differences where they make sense for distributed objects. The distributed object system is simple, in that a) distributed objects are easy to use and to implement, and b) the system itself is easily extensible and maintainable. We have designed such a model and implemented a system that supports remote method invocation (RMI) for distributed objects in Java. This system combines aspects of both the Modula-3 Network Objects system [3] and Spring's subcontract [8] and includes some novel features. To achieve its goal of seamless integration in the language, the system exploits the use of pickling [14] to transmit arguments and return values and also exploits unique features of Java in order to dynamically load stub code to clients. The final system will include distributed reference-counting garbage collection for distributed objects as well as lazy activation [11,16].