Application of Design Patterns to Geometric Decompositio：设计模式的几何分解中的应用.pptVIP

Application of Design Patterns to Geometric Decompositions V. Balaji, Thomas L. Clune, Robert W. Numrich and Brice T. Womack Our prototype example A grid-based code implements finite-difference operators over fields defined on a grid of coordinates representing physical space. Solution of these problems typically involve: decomposition of data distribution of data across a parallel architecture assignment of work to that data. A typical Approach Partition the physical coordinate space into subdomains. subdomains are extended to include regions of overlap with neighbors. i.e. - halo cells, ghost cells, or guard cells subdomains interact with each other in some manner so they know when to update their halo cells with fresh data from their neighbors. The size, number and distribution of subdomains needs to be balanced to keep each processor busy and allow efficient exchange of halo data Gof Patterns Applied Here Our prototype uses the following OO design patterns to solve a geometric decomposition problem Composite Builder Strategy Mediator Iterator … GoF Composite Pattern GoF Composite Pattern Allows us to maintain a unified picture of subdomains whether we want to think of them in: a global setting, the problem as a whole a local setting, the problem as local pieces. Methods associated with the composite provide a common interface at each level of the decomposition and allow the software developer to move from one view of the problem to another in a consistent manner. Composite Tree Structure Composite features Application code is written to expect a block of data from a leaf. It shouldn’t assume any specific : index order data layout or decomposition Blocks of data are assigned to processors by the object map structure migration of work is done by simply moving one or more leaves to a different location within the composite Pieces of work (leaves) can be adaptively refined(AMR splitting/combining of sub elements) by replacing a leaf with a composite