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:
Apr. 05, 1994
Filed:
Mar. 14, 1990
William H Tetzlaff, Mount Kisco, NY (US);
Jay H Unger, Mohegan Lake, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A computer implemented method for minimizing the grant of pages locks and the number of outstanding locks while ensuring consistency of the copies of pages resident among a first, and a second data cache with the original pages in shared external storage. A first processor requesting a lock on a designated page is granted a lock over the group of pages including the designated page in the absence of a concurrent lock to the page or group held by another processor. Any changed page is copied through to external storage. Otherwise, a processor intending to alter a page causes a global lock manager to notify concurrent lock holders, invalidate copies of the page in their local caches, and obtain an exclusive lock to the requesting process for the duration of its operation on the page. After this the lock is demoted to share and the changed page also copied through to external storage.