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19
A Dynamic Group Mutual Exclusion Algorithm using SurrogateQuorums
 in Proceedings of the IEEE International Conference on Distributed Computing Systems (ICDCS
, 2005
"... The group mutual exclusion problem extends the traditional mutual exclusion problem by associating a type with each critical section. In this problem, processes requesting critical sections of the same type can execute their critical sections concurrently. However, processes requesting critical sect ..."
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The group mutual exclusion problem extends the traditional mutual exclusion problem by associating a type with each critical section. In this problem, processes requesting critical sections of the same type can execute their critical sections concurrently. However, processes requesting critical sections of different types must execute their critical sections in a mutually exclusive manner. In this paper, we provide a distributed algorithm for solving the group mutual exclusion problem based on the notion of surrogatequorum. Intuitively, our algorithm uses the quorum that has been successfully locked by a request as a surrogate to service other compatible requests for the same type of critical section. Unlike the existing quorumbased algorithms for group mutual exclusion, our algorithm achieves a low message complexity of O(q), where q is the maximum size of a quorum, while maintaining both synchronization delay and waiting time at two message hops. Moreover, like the existing quorumbased algorithms, our algorithm has high maximum concurrency of n, where n is the number of processes in the system. The existing quorumbased algorithms assume that the number of groups is static and does not change during runtime. However, our algorithm can adapt without performance penalties to dynamic changes in the number of groups. Simulation results indicate that our algorithm outperforms the existing quorumbased algorithms for group mutual exclusion by as much as 50 % in some cases. 1.
efficient distributed group mutual exclusion algorithm for nonuniform group access
 In proceedings of the international
, 2005
"... In the group mutual exclusion problem, each critical section has a type or a group associated with it. Processes requesting critical sections of the same type may execute their critical sections concurrently. However, processes requesting critical sections of different types must execute their criti ..."
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Cited by 9 (2 self)
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In the group mutual exclusion problem, each critical section has a type or a group associated with it. Processes requesting critical sections of the same type may execute their critical sections concurrently. However, processes requesting critical sections of different types must execute their critical sections in a mutually exclusive manner. Most algorithms for group mutual exclusion that have been proposed so far implicitly assume that all groups are equally likely to be requested. In this paper, we propose an efficient algorithm for solving the problem when a relatively small number of groups are requested more frequently than others. Our algorithm has a message complexity of 2n − 1 per request for critical section, where n is the number of processes in the system. It has low synchronization delay of t and low waiting time of 2t, where t denotes the maximum message delay. The maximum concurrency of our algorithm is n, which implies that if all processes have requested critical sections of the same type, then all of them may execute their critical sections concurrently. Finally, the amortized message overhead of our algorithm is O(1). Our experimental results indicate that our algorithm outperforms the existing algorithms by as much as 50 % in some cases. KEY WORDS messagepassing system, resource management, group mutual exclusion, tokenbased algorithm, nonuniform group access 1
Group Mutual Exclusion in Tree Networks
 Journal of Information Science and Engineering
, 2003
"... The group mutual exclusion (GME) problem deals with sharing a set of (m) mutually exclusive resources among all (n) processes of a network. Processes are allowed to be in a critical section simultaneously provided they request the same resource. We present three group mutual exclusion solutions for ..."
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Cited by 8 (0 self)
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The group mutual exclusion (GME) problem deals with sharing a set of (m) mutually exclusive resources among all (n) processes of a network. Processes are allowed to be in a critical section simultaneously provided they request the same resource. We present three group mutual exclusion solutions for tree networks. All three solutions do not use process identifiers and use bounded size messages. They achieve the best contextswitch complexity, which is O(min(n, m)). The first solution uses a fixed root of the tree and uses 0 to O(n) messages per critical section entry. This solution supports an unbounded degree of concurrency, thus providing the maximum resource utilization. The second solution also uses a fixed root, but uses a reduced number of messages for the critical section entry. It generates an average of O(log n) messages per critical section entry and also allows an unbounded degree of concurrency. We remove the restriction of using a fixed root in the third solution in addition to maintaining all other desirable properties of the second solution.
A group mutual exclusion algorithm for ad hoc mobile networks
 in Proceedings of the 6th International Conference on Computer Science and Information, 2002
"... In this paper, we propose a token based algorithm to solve the group mutual exclusion (GME) problem for ad hoc mobile networks. The proposed algorithm is adapted from the RL algorithm in [WWV98] and utilizes the concept of weight throwing in [Tse95]. We prove that the proposed algorithm satisfies th ..."
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Cited by 4 (0 self)
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In this paper, we propose a token based algorithm to solve the group mutual exclusion (GME) problem for ad hoc mobile networks. The proposed algorithm is adapted from the RL algorithm in [WWV98] and utilizes the concept of weight throwing in [Tse95]. We prove that the proposed algorithm satisfies the mutual exclusion, the bounded delay, and the concurrent entering properties. The proposed algorithm is sensitive to link forming and link breaking and thus is suitable for ad hoc mobile networks.
Group Mutual Exclusion in Token Rings
 In SIROCCO 2001, The 8th International Colloquium On Structural Information and Communication Complexity Proceedings
, 2001
"... The group mutual exclusion (GME) problem was introduced by Joung [6]. The GME solution allows n processes to share m mutually exclusive resources. We first present a group mutual exclusion algorithm (Algorithm GME ) for anonymous token rings. The space requirement and the size of messages of thi ..."
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Cited by 4 (1 self)
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The group mutual exclusion (GME) problem was introduced by Joung [6]. The GME solution allows n processes to share m mutually exclusive resources. We first present a group mutual exclusion algorithm (Algorithm GME ) for anonymous token rings. The space requirement and the size of messages of this algorithm depend only on the number of shared resources (O(logm) bits). So, the proposed algorithm solves the problem suggested in [7], which is to obtain a solution using messages of bounded size. All costs related to the time depend on n. We then present two variations of Algorithm GM E . We design the second algorithm (Algorithm mGME) such that its cost depends mainly on the m instead of n. The third algorithm (Algorithm nmGME ) is a general algorithm which takes advantage of the lowest value between n and m. Keywords Distributed algorithms, group mutual exclusion, mutual exclusion. 1
A DelayOptimal Group Mutual Exclusion Algorithm for a Tree Network
, 2006
"... The group mutual exclusion problem is an extension of the traditional mutual exclusion problem in which every critical section is associated with a type or a group. Processes requesting critical sections of the same type can execute their critical sections concurrently. However, processes requesting ..."
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Cited by 2 (1 self)
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The group mutual exclusion problem is an extension of the traditional mutual exclusion problem in which every critical section is associated with a type or a group. Processes requesting critical sections of the same type can execute their critical sections concurrently. However, processes requesting critical sections of different types must execute their critical sections in a mutually exclusive manner. We present an efficient distributed algorithm for solving the group mutual exclusion problem when processes are arranged in the form of a tree. Our algorithm is derived from Beauquier et al.’s group mutual exclusion algorithm for a tree network. The message complexity of our algorithm is at most 3hmax, wherehmax is the maximum height of the tree when rooted at any process. Its waiting time and synchronization delay, measured in terms of number of message hops, are at most 2hmax and hmax, respectively. Our algorithm has optimal synchronization delay for the class of tree network based algorithms for group mutual exclusion in which messages are only exchanged over the edges in the tree. Our simulation experiments indicate that our algorithm outperforms Beauquier et al.’s group mutual exclusion algorithm by as much as 70 % in some cases. Key words: distributed system, resource management, group mutual exclusion, tree network, optimal synchronization delay 1
SelfStabilizing Group Mutual Exclusion For Asynchronous Rings
"... We present the rst selfstabilizing group mutual exclusion algorithm. The protocol is selfstabilizing meaning that starting from an arbitrary state, it is guaranteed to reach a state from where the algorithm behaves according to the group mutual exclusion specication. The proposed algorithm wor ..."
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Cited by 2 (0 self)
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We present the rst selfstabilizing group mutual exclusion algorithm. The protocol is selfstabilizing meaning that starting from an arbitrary state, it is guaranteed to reach a state from where the algorithm behaves according to the group mutual exclusion specication. The proposed algorithm works on unidirectional rings and requires only one distinguished processor. The state requirement of processors is O(m), where m is the number of shared resources. The size of messages is O(log m) bits only. The time to stabilize the system is 2 rotation times (i.e., the time for the token to travel around the ring twice), plus the time that processors can stay in Critical Section. Keywords: Distributed Algorithms, Group Mutual Exclusion, Mutual Exclusion, Selfstabilization. 1.
A TokenBased Fair ALgorithm . . .
, 2007
"... The group mutual exclusion (GME) problem is a generalization of the mutual exclusion problem. In group mutual exclusion, a process requests a session before entering its critical section (CS). Processes requesting the same session are allowed to be in their CS simultaneously, however, processes requ ..."
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The group mutual exclusion (GME) problem is a generalization of the mutual exclusion problem. In group mutual exclusion, a process requests a session before entering its critical section (CS). Processes requesting the same session are allowed to be in their CS simultaneously, however, processes requesting different sessions must execute their CS in mutually exclusive way. The paper presents a tokenbased distributed algorithm for the GME problem in asynchronous message passing systems. The algorithm uses the concept of dynamic request sets. The algorithm does not use any message to be exchanged in the best case and uses n+1 messages in the worst case, where n is the number of processes in the system. The maximum concurrency of the algorithm is n and synchronization delay under heavy load (worst case) is 2T, where T is the maximum message propagation delay. The algorithm uses first come first serve approach in selecting the next session type and satisfies the concurrent occupancy property. The static performance analysis and correctness proof is also included in the present exposition.
Nippon Telegraph and Telephone Corporation,
"... 70 Int. J. of Applied Cryptography, Vol. 1, No. 1, 2008 An optimistic fair exchange protocol and its security in the universal composability framework Yusuke Okada* ..."
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70 Int. J. of Applied Cryptography, Vol. 1, No. 1, 2008 An optimistic fair exchange protocol and its security in the universal composability framework Yusuke Okada*