OSL: Optimized Bulk Synchronous Parallel Skeletons on Distributed Arrays

Abstract : The existing solutions to program parallel architectures ran\-ge from parallelizing compilers to distributed concurrent programming. Intermediate approaches propose a more structured parallelism: Algorithmic skeletons are higher-order functions that capture the patterns of parallel algorithms. The user of the library has just to compose some of the skeletons to write her parallel application. When one is designing a parallel program, the parallel performance is important. It is thus very interesting for the programmer to rely on a simple yet realistic parallel performance model such as the Bulk Synchronous Parallel (BSP) model. We present OSL, the Orléans Skeleton Library: it is a library of BSP algorithmic skeletons in C++. It offers data-parallel skeletons on arrays as well as communication oriented skeletons. The performances of OSL are demonstrated with two applications: heat equation and FFT.