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:
Aug. 12, 2008
Filed:
Aug. 22, 2003
Stephen a Fridella, Newton, MA (US);
Gang MA, Shrewsbury, MA (US);
Xiaoye Jiang, Shrewsbury, MA (US);
Sorin Faibish, Newton, MA (US);
Rui Liang, Natick, MA (US);
Stephen A Fridella, Newton, MA (US);
Gang Ma, Shrewsbury, MA (US);
Xiaoye Jiang, Shrewsbury, MA (US);
Sorin Faibish, Newton, MA (US);
Rui Liang, Natick, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
To permit multiple unsynchronized processors to update the file-modification time attribute of a file during concurrent asynchronous writes to the file, a primary processor having a clock manages access to metadata of the file. A number of secondary processors service client request for access to the file. Each secondary processor has a timer. When the primary processor grants a range lock upon the file to a secondary, it returns its clock time (m). Upon receipt, the secondary starts a local timer (t). When the secondary modifies the file data, it determines a file-modification time that is a function of the clock time and the timer interval, such as a sum (m+t). When the secondary receives an updated file-modification time (mp) from the primary, if mp>m+t, then the secondary updates the clock time (m) to (mp) and resets its local timer.