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:
Feb. 28, 1989
Filed:
Oct. 17, 1986
James P Hennessy, Woodstock, NY (US);
Damian L Osisek, Woodstock, NY (US);
Joseph W Seigh, II, Red Hook, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
In a multi-processing computer system, a method for serializing references to shared data objects, such as pages, tables, and the like, that permits the system processes to reference objects on a shared access basis without obtaining a shared lock. A point of execution of the control program is monitored that is common to all processes in the system, which occurs regularly in the execution of each process and across which no references to any data object can be maintained by any process, except references using locks. A system reference point is established, which occurs after each process in the system has passed the monitored point of execution at least once since the last such system reference point. Operations requiring exclusive access, such as modification or destruction of the data object, are performed by, first, obtaining a conventional exclusive lock, then preventing any subsequent references to the data object, waiting until two of the system reference points have occurred, and, finally, performing the operation. Significant reductions in overhead can be achieved through the application of the invention.