ABSTRACT

The Java trademark encompasses the Java Virtual Machine (JVM), the 
Java language itself, and a large continuously growing class library. 
Beyond the development of applets in the context of the World Wide Web, 
more and more people use Java for large scaled standalone applications. 
This user group points out the performance disadvantage of the Java 
environment in comparison to sophisticated C/C++ compilers. As a result 
of this highly optimizing Java compilers begin to emerge which compile 
Java to machine code and abandon JVM-platform independence. The Plurix 
project goes one step fur-ther developing a native PC Operating System 
(OS) in Java. The central abstraction of the Plurix OS is a persistent 
Distributed Shared Memory (DSM). Our Plurix Java Compiler (PJC) translates 
Java sources into Intel protected mode code. It is itself written in Java 
and after boostrapping it will become an integral part of the Plurix OS. 
In this paper we shortly review the persistent DSM environment of Plurix 
and give an over-view on the architecture of PJC. We present how the 
basic run-time structures are modeled in Java and how PJC is built on 
top of it. The implementation of the Java language in the persistent 
Plurix DSM reveals interesting semantic issues. We suggest extending 
initialization rules for classes and an additional attribute clarifying 
semantic ambiguities of static variables. Finally, we present how a 
generalized type equivalence check scheme enhances flexibility in the 
Plurix DHS. 


KEYWORDS: 

Distributed Shared Memory, Persistence, Java, Operating Systems, 
Compiler, Run-Time Structures, Plurix..