Quorum-based mutual exclusion in asynchronous distributed systems with unreliable failure detectors

This paper considers the fault-tolerant quorum-based mutual exclusion problem in a message-passing asynchronous system and determines a failure detector to solve the problem. This failure detector, which we call the modal failure detector star, and which we denote by M ^?, is strictly weaker than the perfect failure detector P but strictly stronger than the eventually perfect failure detector ?P. The paper shows that at any environment, the problem is solvable with M ^?. In addition, we make an analysis of our algorithm performance in terms of the number of messages and synchronization delay.