win32port/win32helpers/gettimeofday.c

#include < time.h >
#include <windows.h> //I've ommited context line.
#if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
#else
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
#endif
 
struct timezone 
{
  int  tz_minuteswest; /* minutes W of Greenwich */
  int  tz_dsttime;     /* type of dst correction */
};
 
int gettimeofday(struct timeval *tv, struct timezone *tz)
{
  FILETIME ft;
  unsigned __int64 tmpres = 0;
  static int tzflag;
 
  if (NULL != tv)
  {
	GetSystemTimeAsFileTime(&ft);
 
	tmpres |= ft.dwHighDateTime;
	tmpres <<= 32;
	tmpres |= ft.dwLowDateTime;
 
	/*converting file time to unix epoch*/
	tmpres -= DELTA_EPOCH_IN_MICROSECS; 
	tmpres /= 10;  /*convert into microseconds*/
	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;
}