A system that associates an identifier with an instance defined within an object-oriented programming system. The system generates an identifier for the instance and associates a new near object with the instance, wherein the new near object points to a class specifying behavior for the object. The system stores the identifier in the new near object, and sets a class pointer located within a header of the instance to point to the new near object. In this way, the class pointer indirectly points to the class for the object through the new near object. The system can lock the instance to facilitate exclusive access to the instance by copying a near object associated with the instance to a method activation on the execution stack, and setting the class pointer of the instance to point to the copy of the near object on the execution stack.