FILE LOCK MANAGEMENT IN A DISTRIBUTED DATA PROCESSING SYSTEM
A distributed data processing system and method in which locks on a file are supported by a data structure that resides on either a client machine or on the file's server. When only a single client's processes are locking a file, the data structure can reside on that client. Whenever a plu...
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Main Authors | , , , |
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Format | Patent |
Language | English |
Published |
06.11.1991
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Edition | 5 |
Subjects | |
Online Access | Get full text |
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Summary: | A distributed data processing system and method in which locks on a file are supported by a data structure that resides on either a client machine or on the file's server. When only a single client's processes are locking a file, the data structure can reside on that client. Whenever a plurality of client machines attempt to place locks on a file, the data structure is moved to the server; this forces the clients locking the file to communicate with the server when performing lock operations. When a client requests a lock from the server that cannot be granted because of an existing blocking lock, the client is informed that it should put the requesting process asleep awaiting a retry notification. When there is a change in the locks on the file that might allow such a client's now sleeping process to acquire the lock, the server sends a retry notice to the client. This awakens the sleeping process at the client, and the process then reattempts the lock operation by sending a message to the server. |
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Bibliography: | Application Number: EP19900303885 |