DVSA and SHOB: Support to Shared Data Structures on Distributed Memory Architectures

With reference to nunierical iterative algorithnis, this paper exemplifies a methodology to design the runtime support uf applications sharing N set of datu structures on a distributed nieniory architectire. According to the methodology, the support is decomposed into two layers: an application independent one, supplying the basic functionalities to access a shared strucfure, and an application dependent luyer that inzplements the cnching and prefetching strutegies niost appropriate for the considered application. Starting from this nssitnzption. w e introduce DVSA, U package that iinplernerits the application independent luyer and SHOB, one of the packages that can be developed on top of DVSA. SHOB dejines U weak consistency nzemoty model where the user controls the amount of inconsistency due to caching and prefetching. The model is well suitable to iniplenzent iterative numerical algorithnzs. Experinientcil 'results of the methodology ure presented in the ca.x of an uiiifornz multigrid method to solve purtial dijferentiul equatioris.