Version management system using plural control fields for synchronizing two versions of files in a multiprocessor system
US4875159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1987 |
| Grant date | Oct 17, 1989 |
| Priority date | — |
| Expiry date | Dec 22, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99954
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a data processing system that stores a first and second version of a given data set, a method for synchronizing the first and second versions comprises steps of maintaining a sync-complete control field and a sync-in-progress control field in the inode of each of the first and second versions. Write accesses to the versions are modified so that the sync-complete control field and the sync-in-progress control field are cleared in response to any change in the associated version. The sync-complete control bits for the first and second versions are tested, and if either or both are cleared, then the sync-in-progress control field associated with a select source version is set. Next, a copy of the source version is transferred to a temporary file. After the transfer is complete, the sync-in-progress control field in the source version is tested, and if it is set when the temporary version is complete, then the sync-complete control field is set and the sync-in-progress control field is cleared in the source versions. Next, the sync-complete control field is set in the temporary version. Finally, the temporary version is renamed to the other of the first and second versions and the o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.