Distributed shared data management system for controlling structured

Abstract

A distributed shared memory management system for a distributed shared memory computer system having a plurality of computers interconnected by a network, each computer having an independent address space and logically sharing data physically distributed to a storage of each computer. Each computer running a program for reading/changing the shared data includes a coherence control designation command for designating to enter a mutual exclusion state in which two or more computers cannot change the logically single shared data, a coherence control release command for designating a release of the mutual exclusion state, and a coherence control execution command for reflecting the contents of the shared data changed between the coherence control designation command and the coherence control release command, upon the logically single shared data in another computer. At least one of the plurality of computers includes a request message queue for storing a coherence control request message issued by the coherence control execution command when the coherence control designation command is executed. The coherence control designation command includes data for designating the order of reading/changing the shared data, and the request message queue includes a counter for storing a current state regarding the control of the order of reading/changing the shared data and a unit for storing a value regarding the control of the order of reading/changing the shared data.