Sticky bits and universality of consensus
Proceedings of the eighth annual ACM Symposium on Principles of distributed computing
Linearizability: a correctness condition for concurrent objects
ACM Transactions on Programming Languages and Systems (TOPLAS)
ACM Transactions on Programming Languages and Systems (TOPLAS)
Impossibility results for asynchronous PRAM (extended abstract)
SPAA '91 Proceedings of the third annual ACM symposium on Parallel algorithms and architectures
Atomic snapshots of shared memory
Journal of the ACM (JACM)
A completeness theorem for a class of synchronization objects
PODC '93 Proceedings of the twelfth annual ACM symposium on Principles of distributed computing
Impossibility of distributed consensus with one faulty process
Journal of the ACM (JACM)
Journal of the ACM (JACM)
The concurrency hierarchy, and algorithms for unbounded concurrency
Proceedings of the twentieth annual ACM symposium on Principles of distributed computing
Wait-free consensus with infinite arrivals
STOC '02 Proceedings of the thiry-fourth annual ACM symposium on Theory of computing
Computing with Infinitely Many Processes
DISC '00 Proceedings of the 14th International Conference on Distributed Computing
Active disk Paxos with infinitely many processes
Distributed Computing - Special issue: PODC 02
Common2 extended to stacks and unbounded concurrency
Proceedings of the twenty-fifth annual ACM symposium on Principles of distributed computing
Recursion in distributed computing
SSS'10 Proceedings of the 12th international conference on Stabilization, safety, and security of distributed systems
Restricted stack implementations
DISC'05 Proceedings of the 19th international conference on Distributed Computing
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We consider the power of objects in the unbounded concurrency shared memory model, where there is an infinite set of processes and the number of processes active concurrently may increase without bound. By studying this model we obtain new results and observations that are relevant and meaningful to the standard bounded concurrency model. First we resolve an open problem from 2006 and provide, contrary to what was conjectured, an unbounded concurrency wait-free implementation of a swap object from 2-consensus objects. This construction resolves another puzzle that has eluded us for a long time, that of considerably simplifying a 16 year old complicated bounded concurrency swap construction. A further insight to the traditional bounded concurrency model that we obtain by studying the unbounded concurrency model, is a refinement of the top level of the wait-free hierarchy, the class of infinite-consensus number objects. First we resolve an open question of Merritt and Taubenfeld from 2003, showing that having n-consensus objects for all n does not imply consensus under unbounded concurrency. I.e., consensus alone, treated as a black box, cannot be "boosted" in this way. We continue to show an infinite-number consensus object that while able to perform consensus for any n-bounded concurrency (n unknown in advance) cannot solve consensus in the face of unbounded concurrency. This divides the infinite-consensus class of objects into two, those that can solve consensus for unbounded concurrency, and those that cannot.