Method for managing concurrent processes using dual locking
US6401110B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1998 |
| Grant date | Jun 4, 2002 |
| Priority date | — |
| Expiry date | Nov 30, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2209/522
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Multiple competing processors cooperatively manage access to a shared resource. Each processor separately stores a lock table, listing shared resource subparts, such as memory addresses of a data storage device, for example. The lock tables are stored in nonvolatile storage. In each lock table, each subpart is associated with a “state,” such as; LOCAL or REMOTE. In response to access requests from the hosts, the processors exchange various messages to cooperatively elect a single processor to have exclusive access to the subparts involved in the access requests. After one processor is elected, the lock-holding processor configures its lock table to show the identified subpart in the LOCAL state, and all non-lock-holding processors configure their lock tables to show the identified subpart in the REMOTE state. Thus, rather than replicating one lock table for all processors, the processors separately maintain lock tables that are coordinated with each other. Importantly, each processor honors its lock table by refraining from accessing a subpart of the shared resource unless the processor's lock table indicates a LOCAL state for that subpart. In one embodiment, optimized …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.