Distributed shared data management system for controlling structured shared data and for serializing access to shared data

A distributed shared memory management system for a computer network system in which a plurality of computers are interconnected by a network and each computer shares data distributed and stored in a storage of each computer, at least one of the plurality of computers comprising:

• a shared data management table for managing said shared data distributed in the storage of each computer by a shared data unit for each computer, an application on a computer designating said shared data according to said shared data unit determined by an address and a size;
• shared data area management means for managing said shared data management table;
• packet sending and receiving means for sending and receiving said shared data to and from another computer by using a packet;
• shared data identifier assigning means for checking a memory area for storing said shared data and for assigning a shared data identifier to said memory area in order to generate a packet to be transmitted via said packet sending and receiving means;
• and
• means for storing a copy of said shared data for read and write operations by an application on the computer.

A distributed shared memory management method for a computer network system in which a plurality of computers are interconnected by a network and each computer shares data distributed and stored in a storage of each computer, comprising the steps of:

• from an application on each computer, designating the data distributed and stored in a storage of each computer using a shared data unit determined by an address and a size;
• determining a management computer for managing said shared data of said designated shared data unit for each computer, and requesting said management computer for using said shared data;
• checking at said management computer whether said designated shared data is in use;
• if not in use, newly registering information on said designated shared data to said management computer;
• if in use, registering information on the computer newly designated a use of said shared data to said management computer and informing said information to another computer;
• and
• obtaining, at said computer which has been requested to use said shared data, said shared data distributed to the storage of each computer, and generating a copy of said shared data;
• wherein a desired area of data areas shared by each computer is designated as a projection to a one-dimensional array in said storage, and the one-dimensional array is designated as said shared data unit.

A distributed shared memory management system for a 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, wherein:

• each computer running a program for reading and changing said shared data comprises a coherence control designation means for designating to enter a mutual exclusion state in which plural computers cannot change said logically single shared data, coherence control release means for designating a release of said mutual exclusion state, and coherence control execution means for reflecting the contents of said shared data which has changed between the operations by said coherence control designation means and said coherence control release means, upon said logically single shared data in another computer;
• at least one of the plurality of computers comprises request message queue means for storing a coherence control request message issued by said coherence control execution means when said coherence control designation means is executed;
• said coherence control designation means includes means for designating an order of reading and changing said shared data;
• and
• said request message queue means includes counter means for storing a current state regarding the control of the order of reading and changing said shared data and means for storing a value regarding the control of the order of reading and changing said shared data.

A distributed shared memory management system for a 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, wherein

• at least one of the plurality of computers comprises:
• coherence control means for receiving a request for shared data, including a coherence control request of said shared data distributed to the storage of each computer during a desired time interval;
• and
• means for storing a request for said shared data from another computer,
• wherein said coherence control means includes shared data designating means for designating said shared data by an identifier and a length common in each computer, coherence control acquire means for designating a coherence control of said shared data during a desired time interval of each program, and coherence control release means for releasing a designation of the coherence control, and
• wherein synchronization is established at the beginning of said designated time interval and continuous until coherence of said shared data is entered.

A distributed shared memory management system for a 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, wherein

• at least one of the plurality of computers comprises:
• coherence control means for receiving a request for shared data, including a coherence control request of said shared data distributed to the storage of each computer during a desired time interval;
• and
• means for storing a request for said shared data from another computer,
• wherein said means for storing a request for said shared data includes a counter for counting a number of queued coherence control requests of said shared data and means for storing a priority of the request for said shared data, and
• wherein said means for storing a request for said shared data from another computer, changes the order of storing the coherence control requests of said shared data.