Using Parallel Processing for Problem Solving

Abstract

Parallel processing as a conceptual aid in the design of programs for problem solving applications is developed. A pattern directed invocation language know as Ether is introduced. Ether embodies tow notions in language design: activities and viewpoints. Activities are the basic parallel processing primitive. Different goals fo the system can be pursued in parallel by placing them in separate activities. Language primitives are provided for manipulating running activities. Viewpoints are a generalization of context mechanisms and serve as a device for representing multiple world models. A number of problem solving schemes are developed making use of viewpoints and activities. It will be demonstrated that many kinds of heuristic search that are commonly implemented using backtracking can be reformulated to use parallel processing with advantage in control over the problem solving behavior. The semantics of Ether are such that such things as deadlock and race conditions that plague many languages for parallel processing cannot occur. The programs presented are quite simple to understand.