윈도우/리눅스 non-blocking socket 만들기 - making windows/linux non-blocking socket

Boolean makeSocketNonBlocking(int sock) {
#if defined(WIN32) || defined(_WIN32) || defined(IMN_PIM)
  unsigned long arg = 1;
  return ioctlsocket(sock, FIONBIO, &arg) == 0;
#elif defined(VXWORKS)
  int arg = 1;
  return ioctl(sock, FIONBIO, (int)&arg) == 0;
#else
  int curFlags = fcntl(sock, F_GETFL, 0);
  return fcntl(sock, F_SETFL, curFlags|O_NONBLOCK) >= 0;
#endif
}

윈도우는 ioctlsocket, 리눅스는 fcntl 사용