On the minimal synchronism needed for distributed consensus
Journal of the ACM (JACM)
On processor coordination using asynchronous hardware
PODC '87 Proceedings of the sixth annual ACM Symposium on Principles of distributed computing
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)
Agreement is harder than consensus: set consensus problems in totally asynchronous systems
PODC '90 Proceedings of the ninth annual ACM symposium on Principles of distributed computing
ACM Transactions on Programming Languages and Systems (TOPLAS)
Resource bounds and combinations of consensus objects
PODC '93 Proceedings of the twelfth annual ACM symposium on Principles of distributed computing
On the robustness of Herlihy's hierarchy
PODC '93 Proceedings of the twelfth annual ACM symposium on Principles of distributed computing
Wait-free k-set agreement is impossible: the topology of public knowledge
STOC '93 Proceedings of the twenty-fifth annual ACM symposium on Theory of computing
The asynchronous computability theorem for t-resilient tasks
STOC '93 Proceedings of the twenty-fifth annual ACM symposium on Theory of computing
Set consensus using arbitrary objects (preliminary version)
PODC '94 Proceedings of the thirteenth annual ACM symposium on Principles of distributed computing
Wait-freedom vs. t-resiliency and the robustness of wait-free hierarchies (extended abstract)
PODC '94 Proceedings of the thirteenth annual ACM symposium on Principles of distributed computing
A gap theorem for consensus types extended abstract
PODC '94 Proceedings of the thirteenth annual ACM symposium on Principles of distributed computing
On the use of registers in achieving wait-free consensus
PODC '94 Proceedings of the thirteenth annual ACM symposium on Principles of distributed computing
Consensus power makes (some) sense! (extended abstract)
PODC '94 Proceedings of the thirteenth annual ACM symposium on Principles of distributed computing
All of us are smarter than any of us: wait-free hierarchies are not robust
STOC '97 Proceedings of the twenty-ninth annual ACM symposium on Theory of computing
The consensus hierarchy is not robust
PODC '97 Proceedings of the sixteenth annual ACM symposium on Principles of distributed computing
Some Results on the Impossibility, Universality, and Decidability of Consensus
WDAG '92 Proceedings of the 6th International Workshop on Distributed Algorithms
Anomalies in the Wait-Free Hierarchy
WDAG '94 Proceedings of the 8th International Workshop on Distributed Algorithms
WDAG '95 Proceedings of the 9th International Workshop on Distributed Algorithms
WDAG '96 Proceedings of the 10th International Workshop on Distributed Algorithms
Consensus numbers of multi-objects
PODC '98 Proceedings of the seventeenth annual ACM symposium on Principles of distributed computing
Consensus Numbers of Transactional Objects
Proceedings of the 13th International Symposium on Distributed Computing
Lower Bounds in Distributed Computing
DISC '00 Proceedings of the 14th International Conference on Distributed Computing
On the Importance of Having an Identity or is Consensus Really Universal?
DISC '00 Proceedings of the 14th International Conference on Distributed Computing
Hundreds of impossibility results for distributed computing
Distributed Computing - Papers in celebration of the 20th anniversary of PODC
Randomized protocols for asynchronous consensus
Distributed Computing - Papers in celebration of the 20th anniversary of PODC
Geometry and concurrency: a user's guide
Mathematical Structures in Computer Science
On the importance of having an identity or, is consensus really universal?
Distributed Computing - Special issue: DISC 04
Relationships between broadcast and shared memory in reliable anonymous distributed systems
Distributed Computing - Special issue: DISC 04
Algebraic topology and concurrency
Theoretical Computer Science - Clifford lectures and the mathematical foundations of programming semantics
On the weakest failure detector ever
Proceedings of the twenty-sixth annual ACM symposium on Principles of distributed computing
The gap in circumventing the impossibility of consensus
Journal of Computer and System Sciences
On obstruction-free transactions
Proceedings of the twentieth annual symposium on Parallelism in algorithms and architectures
Transactional Memory: Glimmer of a Theory
CAV '09 Proceedings of the 21st International Conference on Computer Aided Verification
On the Computational Power of Shared Objects
OPODIS '09 Proceedings of the 13th International Conference on Principles of Distributed Systems
The computational structure of progress conditions
DISC'10 Proceedings of the 24th international conference on Distributed computing
From bounded to unbounded concurrency objects and back
Proceedings of the 30th annual ACM SIGACT-SIGOPS symposium on Principles of distributed computing
The weakest failure detectors to boost obstruction-freedom
DISC'06 Proceedings of the 20th international conference on Distributed Computing
Weakening failure detectors for k-set agreement via the partition approach
DISC'07 Proceedings of the 21st international conference on Distributed Computing
| Hi-index | 0.00 |
The problem of implementing a shared object of one type from shared objects of other types has been extensively researched. Recent focus has mostly been on wait-free implementations, which permit every process to complete its operations on implemented objects, regardless of the speeds of other processes. It is known that shared objects of different types have differing abilities to support wait-free implementations. It is therefore natural to want to arrange types in a hierarchy that reflects their relative abilities to support wait-free implementations. In this paper, we formally define robustness and other desirable properties of hierarchies. Roughly speaking, a hierarchy is robust if each type is “stronger” than any combination of lower level types. We study two specific hierarchies: one, that we call hrm in which the level of a type is based on the ability of an unbounded number of objects of that type, and another hierarchy, that we call hr1, in which a type's level is based on the ability of a fixed number of objects of that type. We prove that resource bounded hierarchies, such as hr1 and its variants, are not robust. We also establish the unique importance of hrm: every nontrivial robust hierarchy, if one exists, is necessarily a “coarsening” of hrm.