--- /dev/null
+int tv_diff(const struct timeval *b, const struct timeval *a, struct timeval *diff);
+long unsigned tv2ms(const struct timeval*);
+void d2tv(double, struct timeval*);
+void tv_add(const struct timeval*, const struct timeval *, struct timeval *);
+void tv_scale(const unsigned long, const struct timeval *, struct timeval *);
+void tv_divide(const unsigned long divisor, const struct timeval *tv,
+ struct timeval *result);
+void ms2tv(const long unsigned n, struct timeval *tv);
+int64_t get_current_time(void);