How to Do Socket IOA Synchronizedly?

DNS is built on top of UDP and more recently on top of TCP. Most libraries and frameworks call the existing OS implementation of DNS, which is get address info. Why is it synchronous? Frankly speaking, I couldn't find an answer on the web. It will require the thread pool trick we did with files to call it asynchronously. And in this case, Google.com will resolve to your local host. If you have a observer running there on port 80 or 443, it will just work because that trumps anything else.