Managing a resource lock

A method of operating a resource lock for controlling access to a resource by a plurality of resource requesters, the resource lock operating in a contention efficient (heavyweight) operating mode, and the method being responsive to a request from a resource requester to acquire the resource lock, the method comprising the steps of: incrementing a count of a total number of acquisitions of the resource lock in the contention efficient operating mode; in response to a determination that access to the resource is not contended by more than one resource requester, performing the steps of: a) incrementing a count of a number of uncontended acquisitions of the resource lock in the contention efficient operating mode; b) calculating a contention rate as the number of uncontended acquisitions in the contention efficient operating mode divided by the total number of acquisitions in the contention efficient operating mode; and c) in response to a determination that the contention rate meets a threshold contention rate, causing the resource lock to change to a non-contention efficient (lightweight) operating mode.