Method and apparatus for scalable exclusive access management in memory systems

A method for exclusive access management comprising:

• receiving, by a request node, a read data complete message including data associated with an exclusive read request for a particular memory address of a shared memory device and indicating the particular memory address has been read;
• arming, by the request node, an exclusive monitor based on the read data complete message;
• sending, by the request node, an exclusive write request for the particular memory address to a home node associated with the shared memory device;
• sending, by the request node, a snoop query response message for the particular memory address to the home node indicating a hit and responsive to a snoop query message from the home node and associated with the exclusive write request;
• receiving, by the request node, a snoop clean message for the particular memory address from the home node responsive to the snoop query response message;
• and
• clearing, by the request node, the exclusive monitor based on the snoop clean message for the particular memory address.

A method for exclusive access management comprising:

• send, from a request node, an exclusive read request for a particular memory address to a home node associated with a shared memory device;
• reading, by the home node, data associated with the particular memory address from the shared memory device;
• sending, by the home node, a read data complete message including the data associated with the particular memory address;
• arming, by the request node, an exclusive monitor based on the read data complete message;
• sending, from the request node, a read completion acknowledgement to the home node;
• sending, from the request node, an exclusive write request for the particular memory address to the home node;
• receiving, by the request node, a snoop query message for the particular memory address from the home node responsive to the exclusive write request for the particular memory address;
• sending, by the request node, a snoop query response message for the particular memory address to the home node indicating a hit;
• writing, by the home node, data to the particular memory address from the shared memory device responsive to the snoop query response message indicating the hit;
• receiving, by the request node, a snoop clean message for the particular memory address from the home node responsive to the snoop query response message indicating the hit;
• clearing, by the request node, the exclusive monitor based on the snoop clean message for the particular memory address;
• and
• sending, by the home node, a write completion message for the particular memory address to the request node responsive to receiving snoop clean responses from each of the request nodes.