Efficiency of thread-parallel Java programs from scientific computing

Many applications from scientific computing can benefit from object-oriented programming techniques because of their flexible and modular program development support. On the other hand, acceptable execution time can often only be reached by using a parallel machine. We investigate the support of Java for parallel execution. By using Java´s thread mechanism we study how basic numerical methods can be expressed in parallel and which overhead is caused by thread management. We consider implementations that differ in scheduling, synchronization, and the management of threads. We obtain some guidelines to organize a multithreaded Java program to get best performance.