US Patent 7836170 Suspension and reinstatement of reference handles

A handle administration system is described in which software agents receive handles to various resources that they can use to obtain the resources. The described embodiments provide multiple states that can be assumed by the handles. An unassigned state is provided in which handles are not assigned to a particular resource, nor can they be dereferenced to obtain pointers to any resources. An assigned state is provided in which handles are assigned to a particular resource and can be dereferenced to obtain a pointer to the resource. A suspended state is provided in which the handles are assigned to a particular resource but cannot be dereferenced to obtain a pointer to that resource.