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Selfstabilizing mutual exclusion and group mutual exclusion for population protocols with covering (extended version
, 2011
"... Abstract. This paper presents and proves correct two selfstabilizing deterministic algorithms solving the mutual exclusion and the group mutual exclusion problems in the model of population protocols with covering. In this variant of the population protocol model, a local fairness is used and bound ..."
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Cited by 2 (1 self)
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Abstract. This paper presents and proves correct two selfstabilizing deterministic algorithms solving the mutual exclusion and the group mutual exclusion problems in the model of population protocols with covering. In this variant of the population protocol model, a local fairness is used and bounded state anonymous mobile agents interact in pairs according to constraints expressed in terms of their cover times. The cover time is an indicator of the “time ” for an agent to communicate with all the other agents. This indicator is expressed in the number of the pairwise communications (events) and is unknown to agents. In the model, we also assume the existence of a particular agent, the base station. In contrast with the other agents, it has a memory size proportional to the number of agents. We prove that without this kind of assumption, the mutual exclusion problem has no solution. The algorithms in the paper use a phase clock tool. This is a synchronization tool that was recently proposed in the model we use. For our needs, we extend the functionality of this tool to support also phases with unbounded (but finite) duration. This extension seems to be useful also in the future works.
Scalable Room Synchronizations
, 2003
"... This paper presents a scalable solution to the group mutual exclusion problem, with applications to linearizable stacks and queues, and related problems. Our solution allows entry and exit from the mutually exclusive regions in O(t r +#) time, where t r is the maximum time spent in a critical regio ..."
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This paper presents a scalable solution to the group mutual exclusion problem, with applications to linearizable stacks and queues, and related problems. Our solution allows entry and exit from the mutually exclusive regions in O(t r +#) time, where t r is the maximum time spent in a critical region by a user, and # is the maximum time taken by any instruction, including a fetchandadd instruction. This bound holds regardless of the number of users. We describe how stacks and queues can be implemented using two regions, one for pushing (enqueueing) and one for popping (dequeueing). These implementations are particularly simple, are linearizable, and support access in time proportional to a fetchandadd operation. In addition, we present experimental results comparing room synchronizations with the KeaneMoir algorithm for group mutual exclusion.
A Crossing with Java Threads and POSIX
"... The primitives for Java threads and POSIX threads are compared by means of a simulation of cars at a crossing. These cars have to be synchronized in such a way that at every moment only cars in one direction proceed. The initial solution is based on compound await statements. ..."
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The primitives for Java threads and POSIX threads are compared by means of a simulation of cars at a crossing. These cars have to be synchronized in such a way that at every moment only cars in one direction proceed. The initial solution is based on compound await statements.
unknown title
, 2007
"... www.elsevier.com/locate/jpdc A prioritybased distributed group mutual exclusion algorithm when group access is nonuniform � ..."
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www.elsevier.com/locate/jpdc A prioritybased distributed group mutual exclusion algorithm when group access is nonuniform �
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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 ..."
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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, where hmax 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.
MUTUAL
"... Abstract—The group mutual exclusion problem extends the traditional mutual exclusion problem by associating a type (or a group) with each critical section. In this problem, processes requesting critical sections of the same type can execute their critical sections concurrently. However, processes re ..."
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Abstract—The group mutual exclusion problem extends the traditional mutual exclusion problem by associating a type (or a group) 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. We present 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 OðqÞ and a low (amortized) bitmessage complexity of OðbqrÞ, where q is the maximum size of a quorum, b is the maximum number of processes from which a node can receive critical section requests, and r is the maximum size of a request while maintaining both synchronization delay and waiting time at two message hops. As opposed to some existing quorumbased algorithms, our algorithm can adapt without performance penalties to dynamic changes in the set of groups. Our simulation results indicate that our algorithm outperforms the existing quorumbased algorithms for group mutual exclusion by as much as 45 percent in some cases. We also discuss how our algorithm can be extended to satisfy certain desirable properties such as concurrent entry and unnecessary blocking freedom. Index Terms—Messagepassing system, resource management, mutual exclusion, group mutual exclusion, quorumbased algorithm. Ç
unknown title
"... This paper proposes a new idea which makes the processes not to wait for a long time to enter into a critical section to access a data structure which is already assigned to the other process and that process enters into critical section. Till date so many approaches and algorithms are proposed to r ..."
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This paper proposes a new idea which makes the processes not to wait for a long time to enter into a critical section to access a data structure which is already assigned to the other process and that process enters into critical section. Till date so many approaches and algorithms are proposed to reduce the delay time between the successive executions of the critical section, but no one proposed how to assign the data structure to all the process who are requesting for the data structure. In this paper the idea we are proposing is to create an instance of the data structure before assigning to the process and allow each and every process into critical section to avoid the delay time permanently. The proposed algorithm every time creates an instance of the data structure before assigning to the requested process and simultaneously it checks for the instance released by the process already assigned instanced data structure. If when a new process is requesting for the data structure and at the same time already assigned process releases the instance then the coordinator will do both creation and deletion of the instance.
Author manuscript, published in "15th International Conference On Principles Of Distributed Systems, OPODIS 2011 (2011)" Selfstabilizing Mutual Exclusion and Group Mutual Exclusion for Population Protocols with Covering
, 2011
"... Abstract. This paper presents and proves correct two selfstabilizing deterministic algorithms solving the mutual exclusion and the group mutual exclusion problems in the model of population protocols with covering. In this variant of the population protocol model, a local fairness is used and bound ..."
Abstract
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Abstract. This paper presents and proves correct two selfstabilizing deterministic algorithms solving the mutual exclusion and the group mutual exclusion problems in the model of population protocols with covering. In this variant of the population protocol model, a local fairness is used and bounded state anonymous mobile agents interact in pairs according to constraints expressed in terms of their cover times. The cover time is an indicator of the “time ” for an agent to communicate with all the other agents. This indicator is expressed in the number of the pairwise communications (events) and is unknown to agents. In the model, we also assume the existence of a particular agent, the base station. In contrast with the other agents, it has a memory size proportional to the number of agents. We prove that without this kind of assumption, the mutual exclusion problem has no solution. The algorithms in the paper use a phase clock tool. This is a synchronization tool that was recently proposed in the model we use. For our needs, we extend the functionality of this tool to support also phases with unbounded (but finite) duration. This extension seems to be useful also in the future works.
A Hybrid Algorithm to Solve Group Mutual Exclusion Problem in Message passing Distributed Systems
"... In the present paper, we propose a hierarchical algorithm to solve the group mutual exclusion (GME) problem in clusterbased systems. We consider a twolevel hierarchy in which the nodes are divided in to clusters and a node in each cluster is designated as coordinator which is essentially the cluste ..."
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In the present paper, we propose a hierarchical algorithm to solve the group mutual exclusion (GME) problem in clusterbased systems. We consider a twolevel hierarchy in which the nodes are divided in to clusters and a node in each cluster is designated as coordinator which is essentially the cluster head. The number of global messages per critical section entry in our algorithm depends upon the number of clusters in the system unlike most of the existing GME algorithms where it depends upon the total number of nodes in the system. Performance of the algorithm directly depends on the coherent behavior of nodes inside clusters. The results have been substantiated with extensive simulation. A fault tolerant extension of the algorithm has also been proposed in the present exposition.
An Improved QuorumBased Algorithm for Extended GME Problem in Distributed Systems
"... The extended GME (group mutual exclusion) problem is a natural extension of the GME problem. In extended GME problem, processes are allowed to request more than one resource at a time, in order that the processes that can proceed by having access to any one of the requested resource can be allowed t ..."
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The extended GME (group mutual exclusion) problem is a natural extension of the GME problem. In extended GME problem, processes are allowed to request more than one resource at a time, in order that the processes that can proceed by having access to any one of the requested resource can be allowed to do so. ManabePark suggested a quorum based solution for the extended GME problem. However, the worst case message complexity of the ManabePark algorithm is 9q, where q is the quorum size. Further, the synchronization delay of ManabePark algorithm is 4T, where T is the maximum message propagation delay. In the present paper, we propose a quorum based solution for the extended GME problem. The worst case message complexity of our algorithm is 7q and synchronization delay is 3T. Moreover, in the best case, the synchronization delay and message complexity come down to 2T and 3q respectively.