Patent ID: 6912621

Claim:
A computer system comprising: a first computer comprising: a first control program; a first memory region addressable by a first application program executing in said first computer; and a first buffer; and a second computer comprising: a second control program; a second memory region addressable by a second application program executing in said second computer, and a second buffer; and wherein said first application requests to update data in said first memory region, and in response, said first control program determines if any application in said first or second computer currently has an exclusive lock on both said first memory region and said second memory region, and if not, said first control program obtains the lock for said first application and if said first buffer has a more current version of said data than said first memory region, said first control program copies said more current version of said data from said first buffer to said first memory region for update by said first application, and after said first application updates said data in said first memory region, said first control program writes the updated data from said first memory region to said first buffer, subsequently sends the updated data from said first buffer to said second buffer, and subsequently releases said lock.