From mutual exclusion to group mutual exclusion: A token-based general scheme

The group mutual exclusion deals with two contradictory issues of mutual exclusion and concurrency. Nevertheless, the concurrency can be increased by giving a higher priority to a group for which more requests are pending and/or by applying a liberal entry policy. However, this increased concurrency comes at the cost of fairness. In the present paper, we propose a general scheme to solve the group mutual exclusion problem. The major constituents of the scheme are a token-based mutual exclusion algorithm, an entry policy and a group selection policy. The most striking feature of the scheme is its easy convertibility into a self adaptive one. The scheme allows an application to go for an entry policy as well as a group selection policy of its choice to meet its pre specified goals.