Exceptions for algorithmic skeletons

Abstract. Algorithmic skeletons offer high-level abstractions for paral-lel programming based on recurrent parallelism patterns. Patterns can be combined and nested into more complex parallelism behaviors. Pro-grammers fill the skeleton patterns with the functional (business) code, which transforms the generic skeleton into a specific application. How-ever, when the functional code generates exceptions, programmers are exposed to implementation details of the skeleton library, breaking the high-level abstraction principle. Furthermore, related parallel activities must be stopped as the exception is raised. This paper describes how to handle exceptions in algorithmic skeletons without breaking the high-level abstractions of the programming model. We describe both the be-havior of the framework in a formal way, and its implementation in Java: the Skandium Library