Many token-based, distributed mutual exclusion algorithms can be generalized by a single algorithm. The algorithm’s performance is dependent upon the logical topology imposed on the nodes and the policy used to forward requests. This paper extends the generalized algorithm to support prioritized, real-time requests in a generalized fashion and presents models that can be used to analyze the per...

We present a detailed description of a machine-assisted veriication of an algorithm for self-stabilizing mutual exclusion that is due to Dijkstra Dij74]. This veriication was constructed using PVS. We compare the mechanical veriication to the informal proof sketch on which it is based. This comparison yields several observations regarding the challenges of formalizing and mechanically verifying...

A self-stabilizing system is a system such that it autonomously converges to a legitimate system state, regardless of the initial system state. The local mutual exclusion problem is the problem of guaranteeing that no two processes neighboring each other execute their critical sections at a time. The process identifiers are said to be chromatic if no two processes neighboring each other have th...

One of the most recent techniques for propagating resource constraints in Constraint Based scheduling is Energy Constraint. This technique focuses in precedence based scheduling, where precedence relations are taken into account rather than the absolute position of activities. Although, this particular technique proved to be efficient on discrete unary resources, it provides only loose bounds f...

UML is a standard modelling language that is able to specify a wide range of object-oriented concepts. However, there are some aspects that UML does not fully discuss. For example, UML has no mechanism to prevent the specification, for semantic reasons, of undesirable relationships. With the fast evolution of the requirements of our nowadays applications we cannot simply rely on omitting what w...

Distributed mutual-exclusion (DME) circuits are an interesting example of asynchronous circuits. They are composed of identical DME cells connected in a ring of arbitrary size. Each DME cell provides a connection point for one user, and all users compete for exclusive access to a shared resource. This paper reports about formal verification of two well-known DME circuit implementations. Externa...

4 Checking the model 6 4.1 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2 Mutual exclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.3 Liveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.4 Freedom from starvation . . . . . . . . . . . . . . . . . . . . . . . 8 4.5 Results . . . . . . . . . . . . . . . . . . . . . . . . . ....

The design issues for group mutual exclusion have been modeled by Joung as the Congenial Talking Philosophers, and solutions for shared-memory models and complete message-passing networks have been proposed [2, 3]. These solutions, however, cannot be straightforwardly and efficiently converted to ring networks where each philosopher can only communicate directly with its two neighboring philoso...

The use of mutual exclusion (mutex) has led to significant advances in propositional planning. However, previous mutex can only detect pairs of actions or facts that cannot be arranged at the same time step. In this paper, we introduce a new class of constraints that significantly generalizes mutex and can be efficiently computed. The proposed long-distance mutual exclusion (londex) can capture...