State-based object transition control and nested locking
US6546412B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1997 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Nov 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/52
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Temporary states are used transitionally in run-time situations and are unknown to the object database. A temporary state is created if, when an object is performing a requested event, interim work needs to be performed before the object reaches a permanent destination state. Use of a temporary state is transparent to the caller of the requested event. Within a single flow of control, an unlimited number of nested locks may be acquired. A request to unlock an object will only truly unlock the object if the unlock requester is at the highest level of locking. For recursive or embedded functions, no knowledge of the previous locking condition is necessary. Attribute-based locking provides a mechanism for allowing only certain members of the system to lock an object for writing while the object is in a predetermined state. However, any thread may obtain a read lock on an object in order to examine its attributes. This may be expanded to state that the system may restrict locking of an object or entity based upon any attribute in the database or upon any combination or logical expression of these attributes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.