Object surrogate with active computation and probablistic counter
US5918235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 1997 |
| Grant date | Jun 29, 1999 |
| Priority date | — |
| Expiry date | Apr 4, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99957
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
To prevent dangling pointers, an object is annotated with a reference counted Object Surrogate which will outlive the object and which knows whether the referenced object is valid or not. Rather than directly referring to the underlying object, long lived external pointers (those which exist outside of an active computation) are maintained as pointers to the object surrogate. The object surrogate maintains a count of the number of active computations executing within the object. While there are active computations executing within the object, the object surrogate will not allow the object to be destroyed. The object may ask its surrogate to consider the object invalid to prevent new active computations from starting. This is done within the object's destructor. To allow an object to delete itself (potentially within an active computation) rather than deleting itself explicitly, the object requests of its object surrogate that the object be deleted when the number of active computations hits zero. In another technique, the active computation count comprises multiple counters. One of the multiple counters is selected pseudo-randomly and incremented when a new active computation begin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.