关于win32 gettimeofday替代方案

voidngx_gettimeofday(struct timeval *tp){  uint64_t intervals;  FILETIME ft;  GetSystemTimeAsFileTime(&ft);  /*   * A file time is a 64-bit value that represents the number   * of 100-nanosecond intervals that have elapsed since   * January 1, 1601 12:00 A.M. UTC.   *   * Between January 1, 1970 (Epoch) and January 1, 1601 there were   * 134744 days,   * 11644473600 seconds or   * 11644473600,000,000,0 100-nanosecond intervals.   *   * See also MSKB Q167296.   */  intervals = ((uint64_t) ft.dwHighDateTime << 32) | ft.dwLowDateTime;  intervals -= 116444736000000000;  tp->tv_sec = (long) (intervals / 10000000);  tp->tv_usec = (long) ((intervals % 10000000) / 10);}