The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1992
Filed:
May. 15, 1989
Donavon W Johnson, Georgetown, TX (US);
Stephen P Morgan, Mahopac, NY (US);
Todd A Smith, Austin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The system and method of this invention maintains the latest file attributes such as file size, modify time, and access time, at the server data processing system in a distributed data processing system. The server data processing system combines information requested from the client data processing system that has permission to write to the file with information periodically received from other client data processing systems that may be extending the same file by mapping the file into their own virtual address space. In this way, the server can maintain the latest file size attribute even when some clients are extending the file through system calls and other clients are extending the file through mapped access. To maintain a latest modify time and access time, the server keeps a modify count and access count. The client data processing systems periodically send to the server data processing the modify count and access count that have been incremented whenever the client data processing system modifies and accesses the file. The server data processing system compares the counts at the server with the counts received from the clients to determine a latest corresponding modify time and access time.