Kanor: A Declarative Language for Explicit Communication

摘要

Programmers of high-performance applications face two major implementation options: to use a high-level language which manages communication implicitly or to use a low-level language while specifying communication explicitly. The high-level approach offers safety and convenience, but forces programmers to give up control, making it difficult to hand-tune communications or to estimate communication cost. The low-level approach retains this control, but forces programmers to express communication at a verbose, tedious, and error-prone level of detail. We advocate a complementary third approach in which the programmer declar-atively, but explicitly, specifies the essence of the communication pattern. The programmer lets the implementation handle the details when appropriate, but retains enough control to hand-encode communications when necessary. In this paper we present Kanor, a language for declaratively expressing explicit communication patterns, and demonstrate how Kanor safely, succinctly, and efficiently expresses both point-to-point and collective communications.