A Distributed Java Virtual Machine For DSP Architectures

Java is for sure the most popular programming language today. Its popularity is based on the portability of the code and on the elegant programming framework provided by the language: built in garbage collection and multi-threaded support, easy Internet application development through socket streams, and last but not least familiar syntax. Even if a lot of work has already been done related to Java Virtual Machines (JVMs) and a large number of Java applications are already available, few of these have penetrated the DSP world. Our work aims to bridge this gap between DSP architectures and Java. Such a connection would open the DSP world to a much larger class of consumers, a place now occupied by general-purpose processors. The two main research directions we see in improving the performance of a JVM for DSP architectures are: (1) writing a Java bytecode Just-In-Time compiler optimized for a specific DSP platform, and (2), taking advantage of the available parallelism present in DSP multi-processor architectures. Our work focuses on the last issue. We propose a distributed JVM designed for a multi-processor DSP architecture. Due to the unavailability of the hardware at the moment, we have implemented our ideas on a network of general-purpose processors, emulating the topology of the quad-processor DSP board constructed by Innovative DSP. We emulate the I/O channels connecting the processors through TCP sockets and interrupts with Unix signals. All the protocols use a constant number of messages, making it possible to estimate the costs of all distributed actions. In this document we show the design and test results obtained with DISK. While a distributed JVM architecture may not prove to be an exciting project for highly-specialized DSP processors (such as TI's TMS320 family), we believe that this work may be successfully applied to multiprocessor architectures based on RISC processors enhanced with signal processing capabilities (such as the new ARM9E processor). Other projects are working on porting Java to this class of processors. On top of this we provide a Java parallel-processing platform that binds the power of Java distributed computing with signal processing.