I'm having difficulty with latency when running an async asio udp socket. I don't have the same problems with an identical application that uses synchronous udp. I'm communicating with a physical device which permits a maximum 5ms latency for each UDP packet, and I'm currently getting a latency of 8ms with a std dev of 0.065ms which is surprisingly precise. I'm on Mac OS X 10.10.4 with Xcode 6.3.2 (6D2105). Here are some of the key details about this problem: - Sync UDP test program - works, staying under 5ms latency 100% of the time for over an hour - Code - main file KukaFRIClientDataTest.cpp https://github.com/ahundt/grl/blob/master/test/KukaFRIClientDataTest.cpp - UDP socket communication class KukaFriClientData.hpp https://github.com/ahundt/grl/blob/master/include/grl/KukaFriClientData.hpp - Key lines - calls socket.receive_from() then socket.send() at the lowest level. - receive_from call https://github.com/ahundt/grl/blob/master/include/grl/KukaFriClientData.hpp#... - send call https://github.com/ahundt/grl/blob/master/include/grl/KukaFriClientData.hpp#... - Async UDP test program - buggy, 8ms w/ 0.065 ms std dev, continuously high latency - Code - main file KukaFRITest.cpp https://github.com/ahundt/grl/blob/master/test/KukaFRITest.cpp - High level wrapper class KukaFRIThreadSeparator.hpp https://github.com/ahundt/grl/blob/master/include/grl/KukaFRIThreadSeparator... - Low level wrapper class KukaFRI.hpp https://github.com/ahundt/grl/blob/master/include/grl/KukaFRI.hpp . - Key lines - calls socket_.async_receive_from() then that handler calls socket_.async_send_to(), which calls the final callback with the results. - async_receive_from call https://github.com/ahundt/grl/blob/master/include/grl/KukaFRI.hpp#L374 - async_send_to_call https://github.com/ahundt/grl/blob/master/include/grl/KukaFRI.hpp#L432 Does anyone have insight into why this latency issue may be occurring in the Async UDP version? Thanks. Cheers! Andrew Hundt