source: azure_iot_hub_f767zi/trunk/asp_baseplatform/lwip/contrib-2.1.0/ports/win32/check/time.c@ 457

#include <time.h>

#include <windows.h>
#if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
#else
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
#endif

#include "config.h"

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;
}

struct tm *
localtime_r(const time_t *timer, struct tm *result)
{
  struct tm *local_result;

  if (result == NULL) {
    return NULL;
  }

  local_result = localtime (timer);
  if (local_result == NULL) {
    return NULL;
  }

  memcpy(result, local_result, sizeof(*result));
  return result;
}