函数式语言FP中并行的开发和控制

EXPLOITATION AND CONTROL OF PARALLELISM IN FP SYSTEMS

函数式语言的突出特点是特别适合于并行处理.本文着重讨论函数式语言——FP在多处理机系统中并行实现的方法.文中的FP语言是在John Backus’FP的基础上增加了流的功能和类型定义.在[1,2]原有的理论基础上,提出了一个改进的结合LE计值语义的多步向前驱动法.LE计值中由于引进了延迟对象,使得延迟计值统一为函数对对象的作用,因而简化了编译系统的代码生成.多步向前驱动法是一种结合需求驱动和数据驱动的方法,该方法在开发了尽可能多的并行的同时,又保证了程序并行归约的终止性.根据这些方法,一分布式内存的多处理机软件模拟系统已在MIC-VAX Ⅱ上实现.文中最后给出了一些实验数据,这些数据有力地证明了多步向前驱动法的有效性,从而揭示了函数式语言并行处理是一非常有发展前途的研究方向.

This paper studies some aspects of parallel execution of FP programs inthe multiprocessor system. As extensions, the concepts of stream and type definition is introduced to the John Backus' FP system. On the basis of previous work, an improved LE-evaluation Multi-Step Proceeding Driven (MSPD) mechanism is put forward, which is the combination of data-driven and demand-driven mechanism. This method makes ir easy to explore as much parallelism as possible while making sure of the termination of the parallel reduction of FP programs. At the end of this paper, some data about the MSPD mechanism is presented, which shows the advantages of the driven mechanism.