#ifdef WIN32
#include <winsock2.h>
#define NonBlockNormalError WSAEWOULDBLOCK
#define close closesocket //这个也可以反向操作，看怎么方便
#pragma comment(lib, "Ws2_32.lib")
#else
#include <netinet/in.h>
#include <unistd.h>
#include <fcntl.h>
#include <arpa/inet.h>
#define NonBlockNormalError EINPROGRESS
#endif