A Methodology for Deriving Parallel Programs with a Family of Parallel Abstract Machines

Any parallel programming language provides a model of par-allelism, and one can write a program directly in the language, accepting the xed given model. We propose an alternative methodology: the program is derived in a sequence of steps, where each step incorporates just one decision, and is based on a speciic model of parallelism, called an abstract parallel machine, which is chosen to be suitable for that step. Each step is proved equivalent to the previous one. There is a family of related abstract parallel machines; each one is described by a set of parallel operations describing its behavior, and is related to similar abstract parallel machines by transformation theorems. In this paper we present the formalism for abstract parallel machines and illustrate the derivation process with two case studies.