Elimination of Nondeterminacy for Testing and Debugging Parallel Programs

Nondeterminacy implies two unpleasant properties for testing and debugging parallel programs: successive executions of the same program with the same input values often do not show identical behaviour and watching the program influences the execution. It is therefore not always possible to test and debug parallel programs like sequential ones. This article presents an approach how to make test, regression test and cyclic debugging as easy as in the sequential case. To meet this goal we provide the user with the ability to specify not only input data for tests, but also the sequence of interprocess communications. This also guarantees reproducibility for debugging and regression testing. 1 Introduction Massively parallel systems gain more and more success in commercial markets and try to deal with the Grand Challenges [GC92]. But despite all success it is still hard to exploit the available computing power of these systems. Besides the fact that design and coding of parallel pro..