1. A method for improving operations in an object-oriented, multithreaded computer system that uses transactional memory, the method comprising: (a) when an attempt is made to access an object in the computer system, determining whether that object is certainly visible to only one thread; and (b) when that object is certainly visible to only one thread, using non-transactional program code to access that object, otherwise using transactional memory system code to access the object.