Socket, как сделать Disconnect

Note The function pointer for the DisconnectEx function must be obtained at run time by making a call to the WSAIoctl function with the SIO_GET_EXTENSION_FUNCTION_POINTER opcode specified. The input buffer passed to the WSAIoctl function must contain WSAID_DISCONNECTEX, a globally unique identifier (GUID) whose value identifies the DisconnectEx extension function. On success, the output returned by the WSAIoctl function contains a pointer to the DisconnectEx function. The WSAID_DISCONNECTEX GUID is defined in the Mswsock.h header file.

When lpOverlapped is not NULL, overlapped I/O might not finish before DisconnectEx returns, resulting in the DisconnectEx function returning FALSE and a call to the WSAGetLastError function returning ERROR_IO_PENDING. This design enables the caller to continue processing while the disconnect operation completes. Upon completion of the request, Windows sets either the event specified by the hEvent member of the OVERLAPPED structure, or the socket specified by hSocket, to the signaled state.