Lock control for a shared storage in a data processing system

A lock control for a storage having a plurality of addressable storage locations shared by a plurality of storage utilizing units each capable of locking desired storage locations in said storage, comprising a plurality of lock control means each connected to at least one of said storage utilizing units for executing lock control for the storage utilizing unit or units connected thereto, each of said lock control means including:

• lock address holding means for holding addresses of storage locations locked by said storage utilizing unit or units connected thereto;
• lock address copy holding means for holding a copy of addresses of storage locations locked by the storage utilizing unit or units connected to another lock control means;
• lock request receiving means connected to respective lock request receiving means of another lock control means for communicating a requested address involved in a storage location lock request;
• comparing means for comparing a requested address involved in a storage location access request from one of said connected storage utilizing unit or units with the contents of said lock address holding means and said lock address copy holding means, except for the addresses of storage locations locked by the storage utilizing unit which has issued said storage access request;
• and
• means operatively connected to said comparing means for controlling the processing of said storage access request according to the result of comparison by said comparing means.