Abstract: In a system for use in exclusively controlling a plurality of resources by successively putting each resource selectively into a locked state and an unlocked state, the resources are successively put into the locked state or the unlocked state in accordance with a lock order or a lock release order previously memorized in a lock order memory when a lock request or a lock release request is issued from a program. Thus, a single request can render a plurality of the resources into the locked or the unlocked state. The resources may be put into the locked and the unlocked state by the use of a lock execution unit and a lock release unit. The lock order and the lock release order may be memorized in the lock order memory in the form of a following lock table address and a preceding lock table address. Similar operation may be carried out in relation to subdivisions into which each resource is divided.