What do you mean there is no standard way to do this? There is a MetaObject Protocol which is supported by most platforms, and for those that don't have it, there is the widely portable CloserMOP.
Threads are not "standard" but the last thread-less Common Lisp just got them this month. Every maintained Common Lisp implementation today has Threads; and all support Bordeaux-Threads.
Show me a single mainstream language where threads are "standardized" other than Java?