A Data Transfer Library for Communicating Data-Parallel Tasks

Many computations can be structured as sets of communicating data-parallel tasks. Individual tasks may be coded in HPF, pC++, etc.; periodically, tasks exchange distributed arrays via channel operations, virtual file operations, message passing, etc. The implementation of these operations is complicated by the fact that the processes engaging in the communication may execute on different numbers of processors and may have different distributions for communicated data structures. In addition, they may be connected by different sorts of networks. In this paper, we describe a communicating data-parallel tasks (CDT) library that we are developing for constructing applications of this sort. We outline the techniques used to implement this library, and we describe a range of data transfer strategies and several algorithms based on these strategies. We also present performance results for several algorithms. The CDT library is being used as a compiler target for an HPF compiler augmented with..