Shared access serialization featuring second process lock steal and subsequent write access denial to first process
US5305448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1993 |
| Grant date | Apr 19, 1994 |
| Priority date | — |
| Expiry date | Sep 16, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/52
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A Shared Data Access Serialization mechanism for sharing data among a plurality of systems while maintaining data integrity. User data is maintained on a primary and optionally an alternate data store. Each data store contains a set of lock blocks, one for each system sharing the data. The contents of the lock blocks, normally a time-of-day value, indicate system ownership status of the associated data. "Lock Rules" are disclosed for determining resource ownership, as well as a "lock stealing" mechanism for obtaining resource ownership from a temporarily stopped system. Suffix records and check records are used to insure data integrity. Error indications deduced from inconsistent suffix and/or check records are used to trigger a data recovery mechanism, and the recovery mechanism can synchronize a primary and secondary data store without the necessity of suspending access to the primary during the synchronization process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.