Product Line Architecture for a Family of Meshing

Tools

María Cecilia Bastarrica, Nancy Hitschfeld-Kahler, Pedro O. Rossel

Computer Science Department, Universidad de Chile{cecilia|nancy|prossel}@dcc.uchile.cl

Agenda Meshing Tools Software Product Lines Product Line Architecture Our Proposal: A Meshing Tool PLA Product Instantiation Future Work and Conclusions

Meshing Tools Meshing tools manage discretizations of

certain application domains. Independently of the application domain,

all meshing tools share functionality: Read the domain geometry and physical values Generate an initial mesh Refine, improve, derefine or smooth the mesh

according to a quality criterion Store the mesh into a file

Refined Volume Mesh

Software Product Lines A software product line (SPL) is a

collection of products that serve the needs of a market segment, and that are built from a set of reusable assets.

Management

DomainEngineering

ApplicationEngineering Software

applicationsSoftware

assets

Domain Engineering:Typical Reusable Assets Executable software components Software source code Reusable libraries Test sets and test cases

…and the Product Line Architecture

PLA for the Meshing Tool SPL Flexibility and interchangeability as the

main goals, so we propose a layered architecture: User Interface Algorithms Model Input/output

xADL PLA specification:

Primitives for optional elements (dashed components and connectors)

Graphical intuitive representation

Tool support for modeling and code generation

Application Engineering: Product Instantiation Generating products using the proposed

PLA implies two steps: Component type selection Implementation selection

2D Control Volume MeshComponent

TypeDescription

Selector Allows to enter a specific improvement region and criterion, and also to choose the following algorithm to be applied (either Improve or Final)

Initial Reads the already generated Delaunay mesh

Improve Applies the Delaunay_improvement_algorithm to the specified region with a particular criterion

Final Post-processes the mesh eliminating obtuse angles opposite to the boundary (Non_obtuse_boundary_algorithm)

Criterion Improvement criteria such as Maximum_edge_vertex connectivity and Maximum_angle

Region Region where the improvement is applied; in the example only Whole_geometry is used, but it may also be Circle

3D Control Volume MeshComponent Type

Description

Selector Allows to enter a list of criteria and their associated regions, and then the whole process is invoked

Initial Reads the device geometry and generates a first coarse mixed element mesh (Fit_Device_Geometry)

Refine Divides element in order to fit physical and geometric parameter values (Refine_Grid)

Final Improves elements in order to fulfill the Voronoi region requirement and generates the final mixed element mesh (Make_Irregular_Leaves_Splittable)

Region Regions where the refinement is applied, e.g. cuboid or rectangle, among others

Criterion Doping_Difference and Longest_Edge as the main refinement criteria

Format Outputs the mesh in a format understandable by the visualizer (Write_Geometrical_Information and Write_Doping_Information)

Conclusions SPL are specially suited for meshing tools Having a tested PLA helps defining new

family products Clearly defining the PLA brought multiple

benefits: Basis for communication Possibility of consistency analysis Potential for instance meshing tool generation

Conclusions (cont.) Formally defining the PLA makes it

possible to (semi) automate the process of instance tool generation: The PLA can be considered as a high

abstraction level model The component type selection is a model

transformation into another one where there are no optional elements

The implementation selection precisely determines which pieces of code form part of the specific tool

In a last transformation, all pieces are put together to generate the tool code

Work in Progress Refine the PLA definition so that it includes

all the guard conditions required for each transformation step.

Meshing tool component adaptation so that they comply with the interfaces defined by the PLA.

Implement a framework that supports all the tool generation process using MDE concepts.