Patent ID: 7073176

Claim:
A method for allocating a resource in a system that includes a plurality of processes executing on a plurality of nodes, the method comprising the steps of: causing a process to obtain, prior to accessing the resource in a particular way, a first lock that grants permission for the process to access the resource in the particular way, wherein the process requests the first lock from a shadow resource object located on the same node as the process; and causing the shadow resource object to obtain, prior to granting the first lock to the process, a second lock that grants permission for the shadow resource object to grant locks that grant permission for processes to access the resource in the particular way, wherein the shadow resource object requests the second lock from a master resource object stored on a different node than said shadow resource object; and using lock information from said shadow resource object to detect deadlocks that involve said resource; wherein the step of causing the shadow resource object to obtain includes the master resource object granting the second lock to the shadow resource object.