This function has no parameters.
The return value is zero if the operation was successful. Otherwise, the value SOCKET_ERROR is returned, and a specific error number can be retrieved by calling WSAGetLastError.
In a multithreaded environment, WSACleanup terminates Windows Sockets operations for all threads.
|WSANOTINITIALISED||A successful WSAStartup call must occur before using this function.|
|WSAENETDOWN||The network subsystem has failed.|
|WSAEINPROGRESS||A blocking Windows Sockets 1.1 call is in progress, or the service provider is still processing a callback function.|