Patent · US Active

Scalable reader-writer lock

US8504540B2 · kind B2 · utility

3Cited by
4References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 18, 2009
Grant dateAug 6, 2013
Priority date
Expiry dateJul 16, 2030

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/52
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A reader-writer lock is provided that scales to accommodate multiple readers without contention. The lock comprises a hierarchical C-SNZI (Conditioned Scalable Non-Zero Indicator) structure that scales with the number readers seeking simultaneous acquisition of the lock. All readers that have joined the C-SNZI structure share concurrent acquisition, and additional readers may continue to join until the structure is disabled. The lock may be disabled by a writer, at which time subsequent readers will wait (e.g., in a wait queue) until the lock is again available. The C-SNZI structure may be implemented in a lockword or in reader entries within a wait queue. If implemented in reader entries of a wait queue, the lockword may be omitted, and new readers arriving at the queue may be able join an existing reader entry even if the reader entry is not at the tail of the queue.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.