Renaming is a fundamental problem in distributed computing, in which a set of n processes need to pick unique names from a namespace of limited size. In this paper, we present the first early-deciding upper bounds for synchronous renaming, in which the running time adapts to the actual number of failures f in the execution. We show that, surprisingly, renaming can be solved in constant time if ...

Multireader shared registers are basic objects used as communication medium in asynchronous concurrent computation. We propose a scheme to obtain several wait-free constructions of bounded 1-writer multireader registers from atomic 1-writer 1-reader registers, that is easy to prove correct. Our main construction is the first one that is optimal with respect to the worstcase local use of control...

Consider a system of asynchronous processes that communicate among themselves by only executing read and write operations on a set of shared variables (also known as shared registers). The system has no global clock or other synchronization primitives. Every shared variable is associated with a process (called owner) which writes it and the other processes may read it. An execution of a write (...

We study the problem of disentangling locked processes via code refactoring. We identify and characterise a class of processes that is not lock-free; then we formalise an algorithm that statically detects potential locks and propose refactoring procedures that disentangle detected locks. Our development is cast within a simple setting of a finite linear CCS variant — although it suffices to ill...

A recent paper by Afek, Ellen, and Gafni introduced a family of deterministic objects Om,k, for m, k ≥ 2, with consensus numbers m such that, for each k ≥ 2, Om,k is computationally less powerful than Om,k+1 in systems with at least mk+m+k processes. This paper gives a wait-free implementation of Om,k from (m+ 1)-consensus objects and registers in systems with any finite number of processes. In...

Many practical and important systemic properties of manufacturing systems, like deadlock freeness, liveness, and reversibility, can be formulated as the non-blocking property of discrete-event systems. It can be difficult, however, to verify non-blocking or design a supervisor to guarantee non-blocking control because of state size explosion in the concurrency model. In this paper, we present s...

Linearizability is a consistency condition for concurrent objects (objects shared by concurrent processes) that exploits the semantics of abstract data types. It provides the illusion that each operation applied by concurrent processes takes eeect instantaneously at some point between the beginning and the end of its execution. When compared with other consistency conditions (such as sequential...

We present an efficient and practical lock-free implementation of a concurrent priority queue that is suitable for both fully concurrent (large multi-processor) systems as well as pre-emptive (multi-process) systems. Many algorithms for concurrent priority queues are based on mutual exclusion. However, mutual exclusion causes blocking which has several drawbacks and degrades the overall perform...

We identify a simple relationship that unifies seemingly unrelated progress conditions ranging from the deadlock-free and starvation-free properties common to lock-based systems, to non-blocking conditions such as obstruction-freedom, lock-freedom, and wait-freedom. Properties can be classified along two dimensions based on the demands they make on the operating system scheduler. A gap in the c...

In all non-blocking non-preemptive (NBNP) scheduling techniques for a multicomputer system for processor allocation, Largest-Job-First (LJF) technique proves to possess a unique characteristic in utilizing as many processors as possible compared to others such as First-Come-First-Serve (FCFS) and Smallest-Job-First (SJF). However, a jobbypass limit that is preset to preclude the starvation prob...