unsafe void ListenIocpComplete(object o)
        {
            IntPtr lpNumberOfBytes;
            IntPtr lpCompletionKey;
            RioNativeOverlapped *lpOverlapped = stackalloc RioNativeOverlapped[1];
            int lpcbTransfer;
            int lpdwFlags;

            while (true)
            {
                if (Kernel32.GetQueuedCompletionStatusRio(_listenIocp, out lpNumberOfBytes, out lpCompletionKey, out lpOverlapped, -1))
                {
                    if (WinSock.WSAGetOverlappedResult(_listenerSocket, lpOverlapped, out lpcbTransfer, false, out lpdwFlags))
                    {
                        var res = allSockets[lpOverlapped->SocketIndex];
                        activeSockets.TryAdd(res.GetHashCode(), res);
                        OnAccepted(res);
                    }
                    else
                    {
                        //recycle socket
                    }
                }
                else
                {
                    var error = Marshal.GetLastWin32Error();

                    if (error != 0 && error != 64) //connection no longer available
                    {
                        throw new Win32Exception(error);
                    }
                }
            }
        }
        protected override unsafe void SocketIocpComplete(object o)
        {
            IntPtr lpNumberOfBytes;
            IntPtr lpCompletionKey;
            RioNativeOverlapped *lpOverlapped = stackalloc RioNativeOverlapped[1];
            TaskCompletionSource <RioConnectionOrientedSocket> r;
            RioConnectionOrientedSocket res;
            int lpcbTransfer;
            int lpdwFlags;

            while (true)
            {
                if (Kernel32.GetQueuedCompletionStatusRio(socketIocp, out lpNumberOfBytes, out lpCompletionKey, out lpOverlapped, -1))
                {
                    if (lpOverlapped->Status == 1)
                    {
                        _freeSockets.Enqueue(allSockets[lpOverlapped->SocketIndex]);
                    }
                    else if (lpOverlapped->Status == 2)
                    {
                        if (WinSock.WSAGetOverlappedResult(allSockets[lpOverlapped->SocketIndex].Socket, lpOverlapped, out lpcbTransfer, false, out lpdwFlags))
                        {
                            res = allSockets[lpOverlapped->SocketIndex];
                            activeSockets.TryAdd(res.GetHashCode(), res);
                            if (_ongoingConnections.TryRemove(res, out r))
                            {
                                r.SetResult(res);
                            }
                        }
                        else
                        {
                            //recycle socket
                        }
                    }
                } //1225
                else
                {
                    var error = Marshal.GetLastWin32Error();

                    if (error != 0 && error != 64 & error != 1225) //connection no longer available
                    {
                        throw new Win32Exception(error);
                    }
                    else
                    {
                        res = allSockets[lpOverlapped->SocketIndex];
                        _freeSockets.Enqueue(allSockets[lpOverlapped->SocketIndex]);
                        if (_ongoingConnections.TryRemove(res, out r))
                        {
                            r.SetException(new Win32Exception(error));
                        }
                    }
                }
            }
        }