Strategies for the efficient exploitation of loop-level parallelism in Java

This paper analyzes the overheads incurred in the exploitation of loop-leve l parallelism using Java Threads and proposes some code transformations tha t minimize them. The transformations avoid the intensive use of Java Thread s and reduce the number of classes used to specify the parallelism in the a pplication (which reduces the time for class loading). The use of such tran sformations results in promising performance gains that may encourage the u se of Java for exploiting loop-level parallelism in the framework of OpenMP , On average, the execution time for our synthetic benchmarks is reduced by 50% from the simplest transformation when eight threads are used. The pape r explores some possible enhancements to the Java threading API oriented to wards improving the application-runtime interaction. Copyright (C) 2001 Joh n Wiley & Sons, Ltd.