Accurate and Fast Mutual Exclusion Algorithm (original) (raw)

Efficient Mutual Exclusion Algorithm Aasim khurshid

2012

This paper presents an algorithm that can solve the problem in single processing, multiprocessing and distributed systems efficiently with minimal changes. For distributed systems we introduce message passing service while keeping rest of the mechanism same works faster than many other algorithms for distributed systems. Due to this multiple processes can execute in different critical sections concurrently. Performance of the algorithm is analyzed in terms of memory and time.

Comparative Study of Mutual Exclusion Algorithms in Distributed Systems

Mutual Exclusion is an important phenomenon in distributed systems. In this paper, we analyze and compare various mutual exclusion algorithms in distributed systems. In permission based mutual exclusion process waits for permission from other processes to enter into a critical section. In token based mutual exclusion, a special message called token is passed over the system and process holding the token can enter into the critical section. We present a comparative study of quorum based, token ring token asking and multiple token algorithms for mutual exclusion in distributed systems.

A Review of various Mutual Exclusion Algorithms in Distributed Environment

In computer science, mutual exclusion (MUTEX) refers to a way of making sure that if one process is using shared modifiable data or resources then the other processes will be excluded from doing the same thing at the same time. A number of mutual exclusion algorithms are available in the literature, with different performance metrics and with different techniques. The Selection for a " good " mutual exclusion algorithm is a key point. These mutual exclusion algorithms can be broadly classified into token and non-token based algorithm. This paper surveys the algorithms which have been reported in the literature for Mutual exclusion in distributed systems and their comparison.

Parallel and distributed algorithms and implementations: time based mutual exclusion

2009

A parallel algorithm is required to satisfy mutual exclusion in order to execute all processes properly. To execute Mutual exclusion, there must be required to satisfy these two conditions: synchronization and concurrent execution of all processes. Though failure of process inside the critical region may occur and that makes all other processes to wait until that process exit or stop using that critical region. This may lead to infinite time of wait for other process. This problem might be solved by time based mutual exclusion. In this paper we will present one solution for such failure. We create a new data structure of every critical region which is shared by other processes in the parallel and distributed environment. We introduce timestamp based data structure which tries to recover from such process failure. This timestamp based data structure has certain attributes based on that attributed we will recover from the failure of that process.

ANALYSIS OF ROUCAIROL AND CARVALHO APPROACH IN DISTRIBUTED MUTUAL EXCLUSION

Critical section problem is a well known problem in Computer Science. It arises when multiple processes or threads simultaneously try to access shared resources like physical devices or logical objects. In Conventional Operating System Design, we use semaphores to solve this one. In Distributed System due to absence of shared memory we cannot implement the same solution. Various approaches are given to solve the critical section problem in Distributed System. An algorithm that solves critical section problem should have following properties like fairness along with deadlock freedom, freedom from starvation and fault tolerant. Ricart and Agrawala suggested message based approach to get mutual exclusion in Distributed System. This approach fairly deals with the critical section problem. Roucairol and Carvalho suggested an optimization for the given approach. This paper is shedding lights on the proposed optimization. This paper finally concludes that though the optimization has a better performance over the original one yet this one is compromising with the fairness.

A new voting-based mutual exclusion algorithm for distributed systems

2013 Nirma University International Conference on Engineering (NUiCONE), 2013

Concurrency control for a distributed system had been always challenging and is getting even more critical with the increasing sophistication of such systems. There are efficient approaches reported in the existing literature that selects one candidate process from many for allowing it to enter its critical section (CS) on the basis of the number of votes received by the processes. A simple principle that a process that gets majority of the total number of votes is only to be allowed for CS ensures safety for such an algorithm as no two processes can earn majority of the total number of polls. However, this may lead to a live-lock situation where no single process reaches the magic number of majority votes. In this paper, a new voting-based algorithm has been proposed to select a process from all the candidates for CS. The proposed algorithm helps increasing the availability of the distributed system.

Two algorithms for mutual exclusion in real-time distributed computer systems

Journal of Parallel and Distributed Computing, 1990

Two algorithms developed utilizing a priority-based event-ordering which manage mutual exclusion in distributed systemscomputer networks-are proposed. in these systems, processes communicate only by messages and do not share memory. The computer network functions either (a) in an environment requiring priorities or (b) in a real-time environment. The algorithms are based on broadcast requests and token passing service approach, but the token need not be passed if no process wishes to enter the critical section. These algorithms are fully distrihuted and are insensitive to the relative speeds of node computers and communication links. They use only N messages per critical section, where N is the number of nodes (processes). The algorithms are optimal in the sense that a symmetrical, distributed algorithm cannot use fewer messages if requests are processed by each node computer concurrently. Both algorithms ensure freedom from starvation. There are mechanisms to handle node insertion and removal, node failure, the loss of the token, the existence of more than one token, and delivery of messages out of order.

Empirical Evaluation of Mutual Exclusion Algorithms for Distributed Systems

Journal of Parallel and Distributed Computing, 2000

Mutual exclusion in distributed memory systems is realized by passing messages among sites to establish a sequence for the waiting sites to enter the critical section. We have evaluated various distributed mutual exclusion algorithms on the IBM SP2 machine and the Intel iPSCÂ860 system, with their empirical results compared in terms of such criteria as the number of message exchanges and response time. The results take into account the effects of critical section request rate, critical section duration, and system size. Our results indicate that the Star algorithm (1991, M. L. Neilsen and M. Mizuno, in``Proc. 11th Int. Conf. Distributed Computing Systems,'' pp. 354 360) achieves the shortest response time in most cases among all the algorithms on a small to medium-sized system, when sites request the critical section many times before involving any barrier synchronization. This is because (1) it requires the exchange of no more than three messages per critical section entry, and (2) contention can quickly be alleviated after several entries into

Fast mutual exclusion algorithms using read-modify-write and atomic read/write registers

Proceedings 1998 International Conference on Parallel and Distributed Systems (Cat. No.98TB100250)

Three fast mutual exclusion algorithms using read-modify-write and atomic read/write registers are presented in a sequence, with an improvement from one to the next. The last algorithm is shown to be optimal in minimizing the number of remote memory accesses required in a resource busy period. Remote memory access is the key factor of memory access bottleneck in large shared-memory multiprocessors. The algorithm is particularly suitable in such systems for applications with small critical sections and frequent resource requests.

A hybrid distributed mutual exclusion algorithm

Journal of Systems Architecture, 1996

The problem of mutual exclusion has to be solved to prevent race condition and, as a result, prevent the possibility of a program producing an incorrect result. Providing deadlock-free distributed mutual exclusion algorithms is often difficult and it involves passing many messages. The two major types of these algorithms are token-based and permission-based algorithms. In this research, we propose a hybrid distributed mutual exclusion algorithm. By Hybrid, we mean that the algorithm uses both token-based and permission-based techniques. The best case and worst case number of messages passed for every critical region entry and exit is calculated, which are better than many other algorithms.