The Peterson-Fischer 2-process mutual exclusion algorithm [PF] is introduced in a slightly modified form. An invariant-assertional proof of mutual exclusion is presented for the 2-process algorithm. Next, the Peterson-Fischer n-process mutual exclusion algorithm is introduced conceptually as a tournament of [lg n] 2-process competitions. A mutual-exclusion proof of the n-process algorithm is pr...

In the problem of mutual exclusion concurrent access to a shared resource using a struc tural program abstraction called a Critical Section CS must be synchronized such that at any time only one process can enter the CS In a distributed system due to the lack of both a shared memory and a global clock and due to unpredictable message delay the design of a distributed mutual exclusion algorithm ...

The group mutual exclusion (GME) problem is a variant of the mutual exclusion problem. In the present paper a token-based group mutual exclusion algorithm, capable of handling transient faults, is proposed. The algorithm uses the concept of dynamic request sets. A time out mechanism is used to detect the token loss; also, a distributed scheme is used to regenerate the token. The worst case mess...

Quorum-based mutual exclusion algorithms enjoy many advantages such as low message complexity and high failure resiliency. The use of quorums is a well-known approach to achieving mutual exclusion in distributed environments. Several distributed based quorum mutual exclusion was presented. The number of messages required by these algorithms require between 3 and 5 , where n is the size of under...

In a distributed system where scalability is an issue, the problem of enforcing mutual exclusion often arises in a soft form: the infrequent failure of the mutual exclusion predicate is tolerated, without compromising the consistent operation of the overall system. For instance this occurs when the operation subject to mutual exclusion requires massive use of a shared resource. We introduce a s...

In a distributed system, mutual exclusion is a condition which ensures that a shared resource in the system can be accessed by one and only one process at a time. Mutual exclusion ensures that only one process can be in its critical section at a time. Many distributed mutual exclusion algorithms have been proposed and verified [1][2][3][4][5]. In this paper, we have modeled and verified the dyn...

In this paper, we present a dynamic information-structure mutual exclusion algorithm for distributed systems whose informationstructure evolves with time as sites learn about the state of the system through messages. An interesting feature of the algorithm is that it adapts itself to heterogeneous or fluctuating traffic conditions to optimize the performance (the number of messages exchanged). ...

Coteries may be used to construct permission based distributed mutual exclusion algorithms. One such algorithm is Maekawa's p N algorithm in which the co-terie is constructed based on nite projective planes. This paper presents a token based mutual exclusion algorithm which uses data structures similar to coter-ies, called quorum agreements. The performance of the algorithm depends upon the quo...

Eliminating interference between concurrently executing activities through mutual exclusion is one of the most fundamental problems in computer systems. The problem of mutual exclusion in a distributed system is especially interesting owing to the lack of global knowledge in the presence of variable communication delays. In this paper, a new token-based distributed mutual exclusion algorithm is...

The paper presents a token based distributed mutual exclusion algorithm. The algorithm assumes a fully connected, reliable physical network and a directed acyclic graph (dag) structured logical network. The number of messages required to provide mutual exclusion is dependent upon the logical topology imposed on the nodes. Using the best topology, the algorithm attains comparable performance to ...