From patterns to frameworks to parallel programs

Object-oriented programming, design patterns, and frameworks are abstraction techniques that have been used to reduce the complexity of sequential programming. This paper describes our approach of applying these techniques to the more difficult domain of parallel programming. We combine these three abstraction techniques with a fourth kind of abstraction, programming layers. The result is the Parallel Design Patterns (PDP) process, a new approach to parallel programming that better matches the needs of parallel programmers. The programmer starts by selecting a parallel design pattern that matches the structure of the target application. The system presents the programmer with a pattern template that includes several parameters that can be set to match the requirements of the specific application. After the programmer selects the domain-specific parameters of the pattern template, the system generates a custom framework that encapsulates all of the parallel structure, including synchronization and communication code. The generated code serves as the highest of three layers of application code. At this layer, parallel structure correctness is guaranteed. Lower layers are used only for performance tuning to make the code as efficient as necessary. In addition to the PDP process, this paper briefly describes a parallel programming system called CO2P3S that implements the process. We use two example applications to illustrate the process and the CO2P3S system.