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Raymond's Algorithm
Raymond's Algorithm is a lock based algorithm for mutual exclusion on a distributed system. It imposes a logical structure (a K-ary tree) on distributed resources. As defined, each node has only a single parent, to which all requests to attain the token are made. Algorithm Nodal properties # Each node has only one parent to whom received requests are forwarded # Each node maintains a FIFO (computing and electronics), FIFO queue of requests each time that it sees the token; # If any node is forwarding privilege to other node and has non-empty queue then it forwards a request message along Algorithm # If a node ''i'' (not holding the token) wishes to receive the token in order to enter into its critical section, it sends a request to its parent, node ''j''. #* If node ''j'' FIFO is empty, node ''j'' shifts ''i'' into its FIFO queue; ''j'' then issues a request to its parent, ''k'', that it desires the token #* If node ''j'' FIFO queue is ''not'' empty, it simply shifts ''i'' in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutual Exclusion
In computer science, mutual exclusion is a property of concurrency control, which is instituted for the purpose of preventing race conditions. It is the requirement that one thread of execution never enters a critical section while a concurrent thread of execution is already accessing said critical section, which refers to an interval of time during which a thread of execution accesses a shared resource or shared memory. The shared resource is a data object, which two or more concurrent threads are trying to modify (where two concurrent read operations are permitted but, no two concurrent write operations or one read and one write are permitted, since it leads to data inconsistency). Mutual exclusion algorithm ensures that if a process is already performing write operation on a data object ritical sectionno other process/thread is allowed to access/modify the same object until the first process has finished writing upon the data object ritical sectionand released the object fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
