PI OT - PARALLEL I O TEMPLATES

This paper presents a novel, top-down, high-level approach to parallel izing file I/O. Each parallel file descriptor is annotated with a high -level specification, or template, of the expected parallel behavior. The annotations are external to and independent of the source code, At run-time, all I/O using a parallel file descriptor adheres to the sem antics of the selected template. By separating the parallel I/O specif ications from the code, a user can quickly change the I/O behavior wit hout rewriting the code. Templates can be composed hierarchically to c onstruct complex access patterns. Two sample parallel programs using t hese templates are compared against versions implemented in an existin g parallel I/O system (PIOUS). The sample programs show that the use o f parallel I/O templates are beneficial from both the performance and software engineering points of view.