Mechanism for managing the locking and unlocking of objects in Java

摘要

A mechanism for managing the locking and unlocking of objects. The mechanism comprises a transition vector having an ordered set of transition elements. Each of the transition elements includes a locking function or a pointer to the locking function and an unlocking function or a pointer to the unlocking function. When an object is created a transition vector is assigned to the object. The object includes a reference element which references a transition element in the vector. In response to a request to lock the object, the locking function in the transition element is invoked and the next transition element is assigned to the object and the reference element in the object is updated. For a request to unlock the object, the unlocking function in the transition element is invoked and the previous transition element is assigned to the object and the reference element is updated. The mechanism improves execution overhead by providing an implicit count for determining the lock count on an object. The mechanism also features typed transition vectors for structured locking/unlocking and unstructured locking/unlocking operations.