Device for controlling the enqueuing and dequeuing operations of messages in a memory
US5214783A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1990 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Aug 9, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2205/123
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The subject device manages the access to message queues in a memory (6) by an enqueuer 2 and a dequeuer 7 when the enqueuer has priority over the dequeuer. It solves the contention problem raised when the dequeuer dequeues the last message from a queue while the enqueuer is enqueuing anew one. A queue control block QCB and queue status bits E, A, D are assigned to each queue and stored in memories 20 and 22. Each time dequeuer 7 performs a dequeuing operation it sets its D bit (dequeuer active) before updating the queue head field in the QCB block. When the enqueuer performs an enqueuing operation it sets an abort bit A, if it finds the D bit active and E bit active indicating that the queue contains at least one message to warn the dequeuer that it has to abort its process if it is dequeuing the last message from the queue.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.