MultiThread Programming

소켓통신: http://www.codeproject.com/Articles/11740/A-simple-UDP-time-server-and-client-for-beginners

mutex: https://msdn.microsoft.com/ko-kr/library/windows/desktop/ms686927(v=vs.85).aspx

callback함수: http://stackoverflow.com/questions/10555566/difference-between-c11-stdbind-and-boostbind