Mutual exclusion algorithms are a simple and popular example of concurrent systems. We report about the verification of some of them with verification package EST. In the paper we propose modified models for Dekker’s and Peterson’s algorithm which give a compound system without divergent states. For Hyman’s algorithm, we explain why it does not preserve mutual exclusion.

Mutual exclusion is directly related to a host of selections at both system and component levels; is responsible for diversification; and gives rise to uniqueness. Mutual exclusion is also evident in modelling and flood forecasting, be it in models, software tools, data, modelling practices, flood forecasting and warning issues, and management systems. The emerging picture is that (i) diversity...

The group mutual exclusion (GME) problem was introduced by Joung [6]. The GME solution allows n processes to share m mutually exclusive resources. We first present a group mutual exclusion algorithm (Algorithm GME ) for anonymous token rings. The space requirement and the size of messages of this algorithm depend only on the number of shared resources (O(logm) bits). So, the proposed algorithm ...

Recently in these pages appeared a report by Doran and Thomas [2] which gave partially simplified versions of Dekker-like solutions to the two process mutual exclusion problem with busy-waiting. This report presents a truly simple solution to the problem and attempts in a small way to dispel some myths that seem to have arisen concerning the problem. Briefly, the mutual exclusion problem for tw...

Already in 1968, E.W. Dijkstra [Dij68] proposed to apply a geometric point of view in the consideration of coordination situations in concurrency. His progress graphs were the basis of the Higher Dimensional Automata (HDA) introduced by V. Pratt[Pra91] and developed in the thesis of É. Goubault[Gou95] and in later research (cf. [FGR99]). In this abstract, we stick to a simple continuous geometr...

h-out of-k mutual exclusion is a generalization of 1mutual exclusion problem, where there are k units of shared resources and each process requests h(1 h k) units at the same time. Though k-arbiter has been shown to be a quorum-based solution to this problem, quorums in k-arbiter are much larger than these in the 1-coterie for 1-mutual exclusion. Thus, the algorithm based on k-arbiter needs man...

Quorum-based mutual exclusion algorithms are resilient to node and communication line failures. In order to enter its critical section, a node must obtain permission from a quorum of nodes. A collection of quorums is called a coterie. The most resilient coteries are called nondominated coteries. Recently, k-coteries were proposed to be used in mutual exclusion algorithms that allow up to k entr...

We present an N -process local-spin mutual exclusion algorithm, based on nonatomic reads and writes, in which each processperforms Θ(log N) remote memory references to enter and exit its critical section. This algorithm is derived from Yang andAnderson’s atomic tree-based local-spin algorithm in a way that preserves its time complexity. No atomic read/write algorithm with better asympto...

Iterative bootstrapping techniques are commonly used to extract lexical semantic resources from raw text. Their major weakness is that, without costly human intervention, the extracted terms (often rapidly) drift from the meaning of the original seed terms. In this paper we proposeMutual Exclusion bootstrapping (MEB) in which multiple semantic classes compete for each extracted term. This signi...

We investigate the remote memory references (RMRs) complexity of deterministic processes that communicate by reading and writing shared memory in asynchronous cache-coherent and distributed shared-memory multiprocessors. We define a class of algorithms that we call order encoding. By applying information-theoretic arguments, we prove that every order encoding algorithm, shared by n processes, h...