Although I was aware of the concept of such an object, I was unfamiliar with the term. Forgive my lack of knowledge in the ways of objects and OO, but isn't that similar to class values?
You suggest that such an object can be used for limiting connections, for example, but did not mention how. Would you simply set a flag variable to say if or how many connections were in use? If that is so, how would you handle concurrent attempts, or attempt to prevent race conditions?
My thanks to you for the instruction of your posting, as well also to those who commented.