gettimeofday，如何翻译一个linux函数

Question

如何将此功能从 linux 翻译到 Windows？我无法使用 gettimeofday 功能

  double getSysTime() {
    struct timeval tp; gettimeofday(&tp,NULL); 
    return double(tp.tv_sec) + double(tp.tv_usec)/1E6; 
  }

Answer 1

使用http://support.microsoft.com/kb/167296中给出的例子：

double getSysTime() {
    FILETIME time;
    int64_t now;

    GetSystemTimeAsFileTime(&time);

    now = ((LONGLONG) time.dwHighDateTime) << 32 | time.dwLowDateTime;
    now = now - 116444736000000000;

    /* (now * 100) is number of nanoseconds since Unix epoch */
    return ((double) now) / 1e7;
}