WSAEALREADY - Error 10037

Question/Problem: WSAEALREADY (10037) Operation already in progress.

Answer/Solution: An operation was attempted on a non-blocking object that already had an operation in progress.

WinSock description: WSAEALREADY means that the asynchronous operation you attempted to cancel has already been canceled. However, there's little distinction between WSAEALREADY and WSAEINVAL since a WinSock DLL cannot tell the difference between an asynchronous operation that has been cancelled and one that was never valid.

Additional functions: Berkeley sockets connect returns this error on subsequent calls, after an initial call on a non-blocking socket. However, some WinSocks fail with WSAEINVAL you call connect.  a second time (or subsequent) on a non-blocking socket.