Computer-implemented method, system and program product for establishing multiple read-only locks on a shared data object
US7823150B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2005 |
| Grant date | Oct 26, 2010 |
| Priority date | — |
| Expiry date | Aug 13, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2209/523
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Under the present invention, a locking primitive associated with a shared data object is automatically transformed to allow multiple read-only locks if certain conditions are met. To this extent, when a read-only lock on a shared data object is desired, a thread identifier of an object header lock word (hereinafter “lock word”) associated with the shared data object is examined to determine if a read-write lock on the shared data object already exists. If not, then the thread identifier is set to a predetermined value indicative of read-only locks, and a thread count in the lock word is incremented. If another thread attempts a read-only lock, the thread identifier will be examined for the predetermined value. If it is present, the thread count will be incremented again, and a second read-only lock will be simultaneously established.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.