Programmatically compute the start time of a process on Windows

Question

Hi,

I'm writing c/c++ code on Windows using Visual Studio. I want to know how to calculate the start time of my process effectively. Can I just use gettimeofday()? I've found the following code from google but I don't understand what it's doing really :

int gettimeofday(struct timeval *tv, struct timezone *tz)
{
  FILETIME ft;
  unsigned __int64 tmpres = 0;
  static int tzflag;

  if (NULL != tv)
  {
    GetSystemTimeAsFileTime(&ft);

    //I'm lost at this point
    tmpres |= ft.dwHighDateTime;
    tmpres <<= 32;
    tmpres |= ft.dwLowDateTime;

    /*converting file time to unix epoch*/
    tmpres /= 10;  /*convert into microseconds*/
    tmpres -= DELTA_EPOCH_IN_MICROSECS; 
    tv->tv_sec = (long)(tmpres / 1000000UL);
    tv->tv_usec = (long)(tmpres % 1000000UL);
  }

  if (NULL != tz)
  {
    if (!tzflag)
    {
      _tzset();
      tzflag++;
    }
    tz->tz_minuteswest = _timezone / 60;
    tz->tz_dsttime = _daylight;
  }

  return 0;
}

Answer 1

If I understand you right you want to know what time your process started, correct? So you'll want to look into GetProcessTimes (http://msdn.microsoft.com/en-us/library/ms683223(VS.85).aspx).

If the process you're interested in is the current process, you can use GetCurrentProcess() to get the process handle that you'll need to call GetProcessTimes(); this returns a pseudo-handle that you don't need to close.