Quorum-based algorithms for group mutual exclusion

We propose a quorum system, which we referred to as the surficial quorum system, for group mutual exclusion. The surficial quorum system is geometrically evident and is easy to construct. It also has a nice structure based on which a truly distributed algorithm for group mutual exclusion can be obtained and processed loads can be minimized. When used with Maekawa's algorithm, the surficial quorum system allows up to /spl radic/2n/m(m-l) processes to access a resource simultaneously, where n is the total number of processes and m is the total number of groups. We also present two modifications of Maekawa's algorithm so that the number of processes that can access a resource at a time is not limited to the structure of the underlying quorum system, but to the number that the problem definition allows.