We consider a system of distributed processors that communicate by passing messages and that have inexact information about time. Speciically, a processor knows that a single message is delayed by at most time d and the time between any two of its consecutive steps is at least c 1 and at most c 2 ; it has no other way of estimating elapsed time. This simple model is very close to traditional mo...

A randomized construction of single-writer snapshot objects from atomic registers is given. The cost of each snapshot operation is O(log3 n) atomic register steps with high probability, where n is the number of processes, even against an adaptive adversary. This is an exponential improvement on the linear cost of the previous best known snapshot construction [9, 10] and on the linear lower boun...

We propose obstruction-free step complexity, a new complexity measure for nonblocking algorithms. We believe that this measure provides a more pragmatic quantification of nonblocking algorithms than previous measures, providing better guidance for designers of practical nonblocking algorithms. In our opinion, the main shortcoming of existing complexity measures for nonblocking algorithms is tha...

Abstract Recent advances in non-volatile main memory (NVM) technology have spurred research on algorithms that are resilient to intermittent failures cause processes crash and subsequently restart. In this paper we present a Recoverable Mutual Exclusion (RME) algorithm supports abortability. Our guarantees FCFS strong liveness property: do not starve even runs consisting of infinitely many cras...

Providing efficient emulations of atomic read/write objects in asynchronous, crash-prone, message-passing systems is an important problem in distributed computing. Communication latency is a factor that typically dominates the performance of message-passing systems, consequently the efficiency of algorithms implementing atomic objects is measured in terms of the number of communication exchange...

A distributed system is comprised of a collection of n processes which communicate with one another. Two means of interprocess communication have been heavily studied. Message-passing systems model computer networks where each process can send information over message channels to other processes. In shared-memory systems, processes communicate less directly by accessing information in shared da...

21 Corollary 5.4 If the execution time of any job is then a schedule which approximates the minimal average response time within a factor of +2 3 can be found distributively in O(log 2 n) communication rounds. For the subclass of connict graphs for which a maximum independent set can be found in polynomial time, the minimum average response time can be approximated to within a factor of 4 using...

Consolidation and Ground-Glass Opacities (GGO) are common findings on chest Computed Tomographic (CT) scans. Consolidation and GGO can be divided into segmental, non-segmental and interstitial pneumonia types based upon distribution pattern. The aim of this review is to highlight the importance of the non-segmental distribution pattern, and to explain its relevancy in various conditions. Non-se...

This paper presents robust emulation of multi-writer/multi-reader registers in message-passing systems using dynamic quorum conngurations. In addition to processor and link failures, this emulation tolerates changes in quorum conngurations, i.e., on-line replacements of one quorum system consisting of read and write quorums with another such system. This work extends the results of Attiya, Bar-...

Problem and Motivation. Atomic (linearizable) read/write memory is among the fundamental abstractions in distributed computing. Fault-tolerant implementations of atomic objects in message-passing systems allow processes to share information with precise consistency guarantees in the presence of asynchrony and failures. A seminal implementation of atomic memory of Attiya et al. [1] gives a singl...