Patent ID: 7912075

Claim:
A method, comprising: (a) providing first and second processing devices, the second processing device providing duplicate functions to the first processing device; (b) determining, by the first processing device, that a token grab value in a memory of the first processing device has a first, but not a second, value, wherein the first value requires the first processing device to attempt to obtain ownership of a duplication token and a second value requires the first processing device not to attempt to obtain ownership of the duplication token; (c) in response to the token grab value having the first value, determining, by the first processing device, whether the second processing device has asserted a duplication token; and (d) in a first mode, determining, by the first processing device, that the second processing device has not asserted the duplication token, and asserting, by the first processing device, the duplication token, wherein, upon assertion by the first processing device, the duplication token is owned by the first processing device and the first processing device is in the active state and the second processing device is in the standby state; and (e) in a second mode, determining, by the first processing device, that the second processing device has asserted the duplication token and that the duplication token is in contention between the first and second processing devices, and applying, by the first processing device, an arbitration rule to determine which of the first and second processing devices is to have ownership of the duplication token.