Carole Delporte-Gallet

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We study the degree of synchrony required to implement the leader election failure detector &#937; and to solve consensus in partially synchronous systems. We show that in a system with <i>n</i> processes and up to <i>f</i> process crashes, one can implement &#937; and solve consensus provided there exists some (unknown) correct process with <i>f</i>(More)
We study the feasibility and cost of implementing &#937;---a fundamental failure detector at the core of many algorithms---in systems with weak reliability and synchrony assumptions. Intuitively, &#937; allows processes to eventually elect a common leader. We first give an algorithm that implements &#937; in a weak system <i>S</i> where processes are(More)
We consider the problem of generic broadcast in asynchronous systems with crashes a problem that was rst studied in Roughly speaking given a con ict relation on the set of messages generic broad cast ensures that any two messages that con ict are delivered in the same order messages that do not con ict may be delivered in di erent order In this paper we de(More)
We determine the weakest failure detectors to solve several fundamental problems in distributed message-passing systems, for <i>all</i> environments -- i.e., regardless of the number and timing of crashes. The problems that we consider are: implementing an atomic register, solving consensus, solving quittable consensus (a variant of consensus in which(More)
This article determines the weakest failure detectors to implement shared atomic objects in a distributed system with crash-prone processes. We first determine the weakest failure detector for the basic register object. We then use that to determine the weakest failure detector for all popular atomic objects including test-and-set, fetch-and-add, queue,(More)
In the set-agreement problem, n processes seek to agree on at most n−1 different values. This paper determines the weakest failure detector to solve this problem in a message-passing system where processes may fail by crashing. This failure detector, called the Loneliness detector and denoted L, outputs one of two values, “true” or “false” such that: (1)(More)
We study consensus in a message-passing system where only some of the n<sup>2</sup> links exhibit some synchrony. This problem was previously studied for systems with process crashes; we now consider Byzantine failures. We show that consensus can be solved in a system where there is at least one non-faulty process whose links are eventually timely; all(More)
The definitions of the predicates Possibly &fgr; and Definitely &fgr;, where &fgr; is a global predicate of a distributed computation, lead to the definitions of two predicate transformers <italic>P</italic> and <italic>D</italic>. We show that <italic>P</italic> plays the same role with respect to <italic>time</italic> as the predicate transformers(More)
This paper defines the fault-tolerant mutual exclusion problem in a message-passing asynchronous system and determines the weakest failure detector to solve the problem. This failure detector, which we call the trusting failure detector, and which we denote by T , is strictly weaker than the perfect failure detector P but strictly stronger than the(More)