C++ components describing parallel domain decomposition and communication

Abstract

Large-scale parallel codes require the data to be decomposed between the set of processes active in the computation. This data decomposition implies recurring communication schemes.

The paper introduces generic template classes in C++ for describing the data decomposition. The aim is to store the data in arbitrary existent efficient sequential data structures. Each entry in the sequential data structure corresponds to an entry in the virtual global view of the container. Once the decomposition is setup the needed communication schemes can be created automatically and can be used to communicate values from containers of various types. Even containers with a varying number of values associated with an entry are possible.

The framework abstracts the decomposition information and the communication in the client code from the eventual parallel paradigm choice. A prototype based on Message Passing Interface standard is presented. It relieves the user from specifying information that is already known at compile time.

Keywords:

• domain decomposition methods
• data parallel programming
• object-oriented programming
• generic programming
• finite element methods
• iterative solvers