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28
Sharedmemory mutual exclusion: Major research trends since
 Distributed Computing
, 1986
"... * Exclusion: At most one process executes its critical section at any time. ..."
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Cited by 47 (7 self)
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* Exclusion: At most one process executes its critical section at any time.
An Improved Lower Bound for the Time Complexity of Mutual Exclusion (Extended Abstract)
 IN PROCEEDINGS OF THE 20TH ANNUAL ACM SYMPOSIUM ON PRINCIPLES OF DISTRIBUTED COMPUTING
, 2001
"... We establish a lower bound of 23 N= log log N) remote memory references for Nprocess mutual exclusion algorithms based on reads, writes, or comparison primitives such as testandset and compareand swap. Our bound improves an earlier lower bound of 32 log N= log log log N) established by Cyph ..."
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Cited by 41 (12 self)
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We establish a lower bound of 23 N= log log N) remote memory references for Nprocess mutual exclusion algorithms based on reads, writes, or comparison primitives such as testandset and compareand swap. Our bound improves an earlier lower bound of 32 log N= log log log N) established by Cypher. Our lower bound is of importance for two reasons. First, it almost matches the (log N) time complexity of the bestknown algorithms based on reads, writes, or comparison primitives. Second, our lower bound suggests that it is likely that, from an asymptotic standpoint, comparison primitives are no better than reads and writes when implementing localspin mutual exclusion algorithms. Thus, comparison primitives may not be the best choice to provide in hardware if one is interested in scalable synchronization.
A time complexity bound for adaptive mutual exclusion
 In Proceedings of the 15th International Symposium on Distributed Computing
, 2001
"... ..."
Nonatomic Mutual Exclusion with Local Spinning (Extended Abstract)
, 2002
"... We present an Nprocess localspin mutual exclusion algorithm, based on nonatomic reads and writes, in which each process performs \Theta (log N) remote memory references to enter and exit its critical section. This algorithm is derived from Yang and Anderson's atomic treebased localspin algorit ..."
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Cited by 13 (3 self)
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We present an Nprocess localspin mutual exclusion algorithm, based on nonatomic reads and writes, in which each process performs \Theta (log N) remote memory references to enter and exit its critical section. This algorithm is derived from Yang and Anderson's atomic treebased localspin algorithm in a way that preserves its time complexity. No atomic read/write algorithm with better asymptotic worstcase time complexity (under the remotememoryreferences measure) is currently known. This suggests that atomic memory is not fundamentally required if one is interested in worstcase time complexity. The same cannot be said if one is interested in fastpath algorithms (in which contentionfree time complexity is required to be O(1)) or adaptive algorithms (in which time complexity is required to be proportional to the number of contending processes). We show that such algorithms fundamentally require memory accesses to be atomic. In particular, we show that for any Nprocess nonatomic algorithm, there exists a singleprocess execution in which the lone competing process executes \Omega (log N / log log N) remote operations to enter its critical section. Moreover, these operations must access \Omega (plog N / log log N) distinct variables, which implies that fast and adaptive algorithms are impossible even if caching techniques are used to avoid accessing the processorstomemory interconnection network.
A Simple Algorithmic Characterization of Uniform Solvability (Extended Abstract)
 Proceedings of the 43rd Annual IEEE Symposium on Foundations of Computer Science (FOCS 2002
, 2002
"... The HerlihyShavit (HS) conditions characterizing the solvability of asynchronous tasks over n processors have been a milestone in the development of the theory of distributed computing. Yet, they were of no help when researcher sought algorithms that do not depend on n. To help in this pursuit we i ..."
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Cited by 11 (6 self)
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The HerlihyShavit (HS) conditions characterizing the solvability of asynchronous tasks over n processors have been a milestone in the development of the theory of distributed computing. Yet, they were of no help when researcher sought algorithms that do not depend on n. To help in this pursuit we investigate the uniform solvability of an infinite uniform sequence of tasks T 0 , T 1 , T 2 , ..., where T i is a task over processors p 0 , p 1 , ..., p i , and T i extends T i1 . We say that such a sequence is uniformly solvable if there exit protocols to solve each T i and the protocol for T i extends the protocol for T i1 . This paper establishes that although each T i may be solvable, the uniform sequence is not necessarily uniformly solvable. We show this by proposing a novel uniform sequence of solvable tasks and proving that the sequence is not amenable to a uniform solution. We then extend the HS conditions for a task over n processors, to uniform solvability in a natural way. The technique we use to accomplish this is to generalize the alternative algorithmic proof, by Borowsky and Gafni, of the HS conditions, by showing that the infinite uniform sequence of task of Immediate Snapshots is uniformly solvable. A side benefit of the technique is a widely applicable methodology for the development of uniform protocols.
Tight RMR lower bounds for mutual exclusion and other problems
 In Proceedings of the 40th annual ACM symposium on Theory of computing, STOC ’08
, 2008
"... We investigate the remote memory references (RMRs) complexity of deterministic processes that communicate by reading and writing shared memory in asynchronous cachecoherent and distributed sharedmemory multiprocessors. We define a class of algorithms that we call order encoding. By applying inform ..."
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Cited by 11 (5 self)
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We investigate the remote memory references (RMRs) complexity of deterministic processes that communicate by reading and writing shared memory in asynchronous cachecoherent and distributed sharedmemory multiprocessors. We define a class of algorithms that we call order encoding. By applying informationtheoretic arguments, we prove that every order encoding algorithm, shared by n processes, has an execution that incurs Ω(nlogn) RMRs. From this we derive the same lower bound for the mutual exclusion, bounded counter and store/collect synchronization problems. The bounds we obtain for these problems are tight. It follows from the results of [10] that our lower bounds hold also for algorithms that can use comparison primitives and loadlinked/storeconditional in addition to reads and writes. Our mutual exclusion lower bound proves a longstanding conjecture of Anderson and Kim.
Lamport on Mutual Exclusion: 27 Years of Planting Seeds
 In 20th ACM Symposium on Principles of Distributed Computing
, 2001
"... Mutual exclusion is a topic that Leslie Lamport has returned to many times throughout his career. This article, which is being written in celebration of Lamport's sixtieth birthday, is an attempt to survey some of his many contributions to research on this topic. ..."
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Cited by 9 (0 self)
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Mutual exclusion is a topic that Leslie Lamport has returned to many times throughout his career. This article, which is being written in celebration of Lamport's sixtieth birthday, is an attempt to survey some of his many contributions to research on this topic.
A New FastPath Mechanism for Mutual Exclusion
 Distributed Computing
, 1999
"... In 1993, Yang and Anderson presented an Nprocess algorithm for mutual exclusion under read/write atomicity that has \Theta(log N) time complexity, where "time" is measured by counting remote memory references. In this algorithm, instances of a twoprocess mutual exclusion algorithm are embedded w ..."
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Cited by 8 (5 self)
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In 1993, Yang and Anderson presented an Nprocess algorithm for mutual exclusion under read/write atomicity that has \Theta(log N) time complexity, where "time" is measured by counting remote memory references. In this algorithm, instances of a twoprocess mutual exclusion algorithm are embedded within a binary arbitration tree. In the twoprocess algorithm that was used, all busywaiting is done by "local spinning." Performance studies presented by Yang and Anderson showed that their Nprocess algorithm exhibits scalable performance under heavy contention. One drawback of using an arbitration tree, however, is that each process is required to perform \Theta(log N) remote memory operations even when there is no contention. To remedy this problem, Yang and Anderson presented a variant of their algorithm that includes a "fastpath" mechanism that allows the arbitration tree to be bypassed in the absence of contention. This algorithm has the desirable property that contentionfre...
Fast Randomized TestandSet and Renaming ⋆
"... Abstract. Most people believe that renaming is easy: simply choose a name at random; if more than one process selects the same name, then try again. We highlight the issues that occur when trying to implement such a scheme and shed new light on the readwrite complexity of randomized renaming in an ..."
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Cited by 8 (7 self)
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Abstract. Most people believe that renaming is easy: simply choose a name at random; if more than one process selects the same name, then try again. We highlight the issues that occur when trying to implement such a scheme and shed new light on the readwrite complexity of randomized renaming in an asynchronous environment. At the heart of our new perspective stands an adaptive implementation of a randomized testandset object, that has polylogarithmic step complexity per operation, with high probability. Interestingly, our implementation is anonymous, as it does not require process identifiers. Based on this implementation, we present two new randomized renaming algorithms. The first ensures a tight namespace of n names using O(n log 4 n) total steps, with high probability. This significantly improves on the complexity of the best previously known namespaceoptimal algorithms. The second algorithm achieves a namespace of size k(1 + ɛ) using O(k log 4 k / log 2 (1 + ɛ)) total steps, both with high probability, where k is the total contention in the execution. It is the first adaptive randomized renaming algorithm, and it improves on existing deterministic solutions by providing a smaller namespace, and by lowering step complexity. 1
Uniform solvability with a finite number of mwmr registers
 In Proceedings of the 17th International Conference on Distributed Computing
, 2003
"... Abstract. This paper introduces a new interesting research question concerning tasks. The weaktestandset task has a uniform solution that requires only two MultiWriter MultiReader (MWMR) registers. Recently it was shown that if we take the longlived version and require a step complexity that i ..."
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Cited by 7 (5 self)
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Abstract. This paper introduces a new interesting research question concerning tasks. The weaktestandset task has a uniform solution that requires only two MultiWriter MultiReader (MWMR) registers. Recently it was shown that if we take the longlived version and require a step complexity that is adaptive to interval contention then, like mutual exclusion, no solution with finitely many MWMR registers is possible. Here we show that there are simple tasks which provably cannot be solved uniformly with finitely many MWMR registers. This opens up the research question of when a task is uniformly solvable using only finitely many MWMR registers. 1