Patterns for Parallel Application Programs

We are involved in an ongoing effort to design a pattern language for parallel application programs. The pattern language consists of a set of patterns that guide the programmer through the entire process of developing a parallel program, including patterns that help find the concurrency in the problem, patterns that help find the appropriate algorithm structure to exploit the concurrency in parallel execution, and patterns describing lower-level implementation issues. The current version of the pattern language can be seen at http://www.cise.ufl.edu/research/~ParallelPatterns. In the current note, we present three selected patterns from our pattern language, selected from the set of patterns that are used after the problem has been analyzed to identify the exploitable concurrency. The EmbarrassinglyParallel pattern is used when the problem can be decomposed into a set of independent tasks. The SeparableDependencies pattern can be used when dependencies between tasks can be pulled outside the concurrent execution by replicating data prior to the concurrent execution and then combining the replicated data afterwards. The GeometricDecomposition pattern is used when the problem space can be decomposed into discrete subspaces and the problem solved by first exchanging information among subspaces and then concurrently computing solutions for the subspaces.