Exclusive control method with each node controlling issue of an exclusive use request to a shared resource, a computer system therefor and a computer system with a circuit for detecting writing of an event flag into a shared main storage

摘要

A computer system including a plurality of processing nodes, at least one resource provided for use by any of the processing nodes and a plurality of register sets. Each register set is provided in each of the processing nodes for storing in parallel use status information indicating whether the resource is in exclusive use status or not. The computer system can also include a plurality of request issue circuits, each being provided in each of the processing nodes, for issuing individually requests for exclusive use of the resource, a message exchanging circuit for serializing requests issued by the request issue circuits into a serialized order and broadcasting the request to all of the processing nodes in the serialized order and a plurality of status control circuits. Each status control circuit is provided in each of the processing nodes corresponding to each of the register sets to update individually a corresponding register set depending on use status information stored in the corresponding register set and each of the requests for exclusive use of the resource received at a corresponding node.