Parallel computer architectures and hardware have evolved impressively in the last few years from the architecture and the hardware point of view. Progress on the software side can be best characterized as moderate. The lack of methodologies and software to support parallel programming is profound even on the most advanced parallel machines. Parallel programming is a complex task and the performance of a parallel program can be influenced by many different factors such as coding of parallel constructs and/or restructuring, scheduling schemes and scheduling overhead, synchronization and/or communication cost, program and data partitioning and memory allocation. In this paper we discuss the major aspects of parallel programming. Parallel programming environments are considered in three fundamental phases: parallelism specification, parallelism exploita tion and supporting environments and tools. A parallel programming environment built at the University of Illinois is discussed as a case study. Finally, we address the influence of parallel programming on multiprocessor operating systems and discuss future research directions.
['Constantine D. Polychronopoulos']
PARALLEL PROGRAMMING ISSUES