+#ifdef WIN32
+#include <sys\timeb.h>
+#endif
+
+double xbt_os_time(void) {
+#ifdef HAVE_GETTIMEOFDAY
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+
+ return (double)(tv.tv_sec + tv.tv_usec / 1000000.0);
+#elsif defined(WIN32)
+
+# if defined(WIN32_WCE) || (_WIN32_WINNT < 0x0400)
+ struct _timeb tm;
+
+ _ftime (&tm);
+
+ tv->tv_sec = tm.time;
+ tv->tv_usec = tm.millitm * 1000;
+
+# else
+ FILETIME ft;
+ unsigned __int64 tm;
+
+ GetSystemTimeAsFileTime (&ft);
+ tm = (unsigned __int64)ft.dwHighDateTime << 32;
+ tm |= ft.dwLowDateTime;
+ tm /=10;
+ tm -= 11644473600000000ULL;
+
+ tv->tv_sec = (long) (tm / 1000000L);
+ tv->tv_usec = (long) (tm % 1000000L);
+#endif /* windows version checker */
+
+
+#else /* not windows, no gettimeofday => poor resolution */
+
+ return (double)(time(NULL));
+#endif /* HAVE_GETTIMEOFDAY? */
+}
+
+void xbt_os_sleep(double sec) {
+#ifdef HAVE_USLEEP
+ sleep(sec);
+ (void)usleep( (sec - floor(sec)) * 1000000);
+
+#elif _WIN32
+
+ Sleep((floor(sec) * 1000) +((sec - floor(sec)) * 1000));
+
+
+#else /* don't have usleep. Use select to sleep less than one second */
+ struct timeval timeout;
+
+
+ timeout.tv_sec = (unsigned long)(sec);
+ timeout.tv_usec = (sec - floor(sec)) * 1000000;
+
+ select(0, NULL, NULL, NULL, &timeout);
+#endif
+}
+