Token-based serialisation of instructions in a multiprocessor system

US5761734A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Erwin Pfeffer · Eppelheim, DE
• Klaus J. Getzlaff · Schenefeld, DE
• Ute Gaertner · Schenefeld, DE
• Hans-Werner Tast · Holzgerlingen, DE

Key dates

• Filing date: Aug 13, 1996
• Grant date: Jun 2, 1998
• Expiry date: Aug 13, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F12/1072
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A process is disclosed to serialize instructions that are to be processed serially in a multiprocessor system, with the use of a token, where the token can be assigned on request to one of the processors, which thereupon has the right to execute the command. If the command consists of dristibuted tasks, the token remains blocked until the last dependent task belonging to the command has also been executed. It is only then that the token can be assigned to another instruction. Moreover, a device is described to manage this token, which features three states: a first state, in which the token is available, a second state, in which the token is assigned to one of the processors, and a third state, in which the token is blocked, because dependent tasks still have to be carried out. Moreover, a circuit is disclosed with which the token principle that is introduced can be implemented in a simple manner. The token is only available if none of the processors i is in possession of the token and if no dependent task is pending at any of the processors. The OR chaining of signals to form a signal C which is set if the token is not available represents the basic circuitry with which the serial…