In this paper, we discuss one of our experiments using the coordination language MANIFOLD to restructure an existing sequential numerical application into a concurrent application. The application was written in ANSI C and deals with a sparse-grid method for a transport problem. Our approach is simple and is in fact a cut-and-paste method. First, we try to identify and isolate components in the legacy source code (the cut). Second, we glue them together by writing coordinator modules (glue modules) with the help of a coordination language (the paste). We also give some performance results.

A workable approach for modernization of existing software into parallel/distributed applications is through coarse-grain restructuring. If, for instance, entire subroutines of legacy code can be plugged into a new structure, the investment required for the rediscovery of the details of what they do can be spared. The resulting renovated software can then take advantage of the improved performance offered by modern parallel/distributed computing environments, without rethinking or rewriting the bulk of their existing code. The authors discuss one of their experiments using the coordination language MANIFOLD to restructure an existing sequential numerical application written in Fortran 77, into a concurrent application.

In this paper we describe one experiment in which a new co-ordination language, called Manifold, is used to restructure an existing sequential Fortran 77 code from computational fluid dynamics (CFD), into a parallel application. Manifold is a co-ordination language developed at CWI (Centrum voor Wiskunde en Informatica) in the Netherlands. It is very well suited for applications involving dynamic process creation and dynamically changing (ir)regular communication patterns among sets of independent concurrent co-operating processes. With a simple but generic master/worker protocol, written in the Manifold language, we are able to reuse the existing code without rethinking or rewriting it. The performance evaluation of a standard 3D CFD problem shows that Manifold performs very well. Copyright © 2000 John Wiley & Sons, Ltd.