Athapascan-1: Parallel Programming with Asynchronous Tasks

Athapascan-1 is a C++ library for multi-threaded parallel programming. It implements a macro data-ow language: both computation and data grains are explicit. Semantics of shared memory access is based on a lexicographic order. The performance of a code (parallel time, communication and arithmetic works, space) can be evaluated from a cost model without need of a machine model. Its important feature is that, forbidding synchronization, it allows eecient on-line analysis of the data ow describing the execution. This enable to separate the scheduling algorithm, that can take beneet of the knowledge of this graph, from the code. On speciic elementary machine models, simple scheduling algorithms can be implemented that provide eecient execution of some speciic class of codes. Portability is then achieved by suiting the scheduling algorithm to both the program and the target machine.