Showing papers by "Michael Merritt published in 1995"
TL;DR: The notion of a faulty shared object is introduced, upper and lower bounds on the space complexity of implementing reliable shared objects are provided, and several constructions of nonfaulty wait-free shared objects from a set of shared objects, some of which may suffer any number of faults are presented.
Abstract: This paper investigates the effects of the failure of shared objects on distributed systems. First the notion of a faulty shared object is introduced. Then upper and lower bounds on the space complexity of implementing reliable shared objects are provided, Shared object failures are modeled as instantaneous and arbitraty changes to the state of the object. Several constructions of nonfaulty wait-free shared objects from a set of shared objects, some of which may suffer any number of faults, are presented. Three of these constructions are: (1) A reliable atomic read/write register from 20~ + 8 atomic read/write registers ~ of which may be faulty, (2) a reliable test& set register for n processes from n + 10 primitive test & set registers, one of which may be faulty, and 3n + 13 reliable atomic registers, and (3) a reliable consensus object from 2f + 1read-modify-write registers when f of these may be faulty. Using these constructions a universal construction of any linearizable shared object from a set of either A preliminary version of the results presented in this paper appeared in Proceedings of the llth Annual ACM Symposium on Principles of Distributed Computing (Vancouver, B. C., Canada, Aug.
47 citations
03 Jul 1995
TL;DR: The translation technique generalizes to other interleaving models, although in each case, the translation map must match the specific model, and enables one to verify systems specified by I/O Automata through model-checkers such as COSPAN or SMV, that operate on models with synchronous parallel composition.
Abstract: The I/O Automaton paradigm of Lynch and Tuttle models asynchrony through an interleaving parallel composition and generalizes more common interleaving models based upon message-passing, such as Hoare's CSP. It is not generally recognized that such interleaving models in fact can be viewed as a special cases of synchronous parallel composition, in which components all move in lock-step. Let A be any set of finite-state I/O Automata drawing actions from a fixed finite set containing a subset Δ, In this article we establish a translation T ∶ A → P to a class of ω-automata P closed under a synchronous parallel composition, for which T is monotonic with respect to implementation relative to Δ, and linear with respect to composition. Thus, for A1,..., A m , B1, ..., B n Σ A and A = A1∥ ⋯ ∥A m , B = B1∥ ⋯ ∥B N , if Δ is the set of actions common to both A and B, then A implements B (in the sense of I/O Automata) if and only if the ω-automaton language containment L(T(A1) ⊗ ⋯ ⊗ T(A m )) ⊂ L(T(B1) ⊗ ⋯ ⊗ T(B n )) obtains, where ∥ denotes the interleaving parallel composition on A and ⊗ denotes the synchronous parallel composition on P. For the class P, we use the L-process model of ω-automata. This result enables one to verify systems specified by I/O Automata through model-checkers such as COSPAN or SMV, that operate on models with synchronous parallel composition. The translation technique generalizes to other interleaving models, although in each case, the translation map must match the specific model. Proofs have been eliminated on account of space limitations. A full version (with all proofs) is available upon request.
15 citations