Parallel programs are typically written in an explicitly parallel fashion using either message passing or shared memory primitives. Message passing is attractive for performance and portability since shared memory machines can efficiently execute message passing programs, however message passing machines cannot in general effectively execute shared memory programs. In order to write a parallel program using message passing, the programmer is often obliged to develop a significant amount of code which manages distributed data and events and parallel input/output, and such code may have little or nothing to do with the application. However many parallel applications have common structural elements and much of this additional code can be encapsulated within a parallel library and reused in several programs. We discuss the requirements the library writer and user makes of the basic message passing interface and describe how we have addressed these requirements in our Common High-Level Inte...

The lack of a portable programming interface for parallel computers has inhibited the development of applications for such systems, and thus restricted the exploitation of this technology. In this paper we discuss various efforts to provide a portable interface to parallel computers, and present the Edinburgh CHIMP (Common High-level Interface to Message-Passing), and PUL (Parallel Utilities Library) activities in this context. The concepts behind these projects are described, with details of the range of parallel systems on which they are available.