JavaSpMT: A Speculative Thread Pipelining Parallelization Model for Java Programs

This paper presents a new approach to improve performance of Java programs by extending the superthreaded speculative execution model [14, 15] to exploit coarsegrained parallelism on a shared-memory multiprocessor system. The parallelization model, called Java Speculative MultiThreading (JavaSpMT), combines control speculation with run-time dependence checking to parallelize a wide variety of loop constructs, including do-while loops, that cannot be parallelized using standard parallelization techniques. JavaSpMT is implemented using the standard Java multithreading mechanism and the parallelization is expressed using a Java source-to-source transformation. Thus, the transformed programs are still portable to any shared-memory multiprocessor system with a Java Virtual Machine implementation that supports native threads.