The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 25, 1993
Filed:
Aug. 09, 1990
Jean-Pierre Lips, Cagnes sur Mer, FR;
Jean-Marc Millet, Vence, FR;
Bernard Naudin, Saint Laurent du Var, FR;
International Business Machines Corp., Armonk, NY (US);
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.