Distributed binary decision diagrams

Fasan, Mary Oluwasola (2010-12)

Thesis (MSc (Mathematical Sciences)--University of Stellenbosch, 2010.

Thesis

ENGLISH ABSTRACT: Binary Decision Diagrams (BDDs) are data structures that have been used to solve various problems in different aspects of computer aided design and formal verification. The large memory and time requirements of BDD applications are the major constraints that usually prevent the use of BDDs since there is a limited amount of memory available on a machine. One way of overcoming this resource limitation problem is to utilize the memory available on a network of workstations (NOW). This requires the distribution of the computation and memory requirements involved in the manipulation of BDDs over a NOW. In this thesis, an algorithm for manipulating BDDs on a NOW is presented. The algorithm makes use of the breadth-first technique to manipulate BDDs so that various BDD operations can be started concurrently on the different workstations on the NOW. The design and implementation details of the distributed BDD package are described. The various approaches considered in order to optimize the performance of the algorithm are also discussed. Experimental results demonstrating the performance and capabilities of the distributed package and the benefits of the different optimization approaches are given.

AFRIKAANSE OPSOMMING: Binêre besluitnemingsbome (BBBs) is data strukture wat gebruik word om probleme in verskillende areas van Rekenaarwetenskap, soos by voorbeeld rekenaargesteunde ontwerp en formele verifikasie, op te los. Die tyd- en spasiekoste van BBB-gebaseerde toepassings is die hoofrede waarom BBBs nie altyd gebruik kan word nie; die geheue van ’n enkele is ongelukkig te beperkend. Een manier om hierdie hulpbronprobleem te omseil, is om die gedeelde geheue van die werkstasies in ’n netwerk van werkstasies (Engels: “network of workstations”, oftewel, ’n NOW) te benut. Dit is dus nodig om die berekening en geheuevoorvereistes van die BBB bewerking oor die NOW te versprei. Hierdie tesis bied ’n algoritme aan om BBBs op ’n NOW te hanteer. Die algoritme gebruik die breedte-eerste soektegniek, sodat BBB operasies gelyklopend kan uitvoer. Die details van die ontwerp en implementasie van die verspreide BBB bilbioteek word beskryf. Verskeie benaderings om die gedrag van die biblioteek te optimeer word ook aangespreek. Empiriese resultate wat die werkverrigting en kapasiteit van die biblioteek meet, en wat die uitwerking van die onderskeie optimerings aantoon, word verskaf.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/5411