search for: subtract_timeval

...ine TEST_SUBTRACT(tv1, tv2, exp_sec, exp_usec) \ + do { \ + struct timeval z; \ + \ + subtract_timeval (&tv1, &tv2, &z); \ + if (z.tv_sec != (exp_sec) || z.tv_usec != (exp_usec)) { \ + fprintf (stderr, \ + "%s: unexpected (%ld, %d), expecting (%ld, %d)\n", \...

...ine TEST_SUBTRACT(tv1, tv2, exp_sec, exp_usec) \ + do { \ + struct timeval z; \ + \ + subtract_timeval (&tv1, &tv2, &z); \ + if (z.tv_sec != (exp_sec) || z.tv_usec != (exp_usec)) { \ + fprintf (stderr, \ + "%s: unexpected (%ld, %d), expecting (%ld, %d)\n", \...

...ection_can_cache (void *handle) return NBDKIT_CACHE_NATIVE; } +static void +update_time (struct handle *h) +{ + struct timeval tv; + int64_t secs; + int32_t usecs; + char *p; + + gettimeofday (&tv, NULL); + + switch (mode) { + case MODE_TIME: + break; + + case MODE_UPTIME: + subtract_timeval (&load_t, &tv, &tv); + break; + + case MODE_CONNTIME: + subtract_timeval (&h->conn_t, &tv, &tv); + break; + + default: + abort (); + } + + /* Pack the result into the output buffer. */ + secs = tv.tv_sec; + usecs = tv.tv_usec; + secs = htobe64 (secs); +...

...@ info_can_cache (void *handle) return NBDKIT_CACHE_NATIVE; } +static void +update_time (struct handle *h) +{ + struct timeval tv; + int64_t secs; + int32_t usecs; + char *p; + + gettimeofday (&tv, NULL); + + switch (mode) { + case MODE_TIME: + break; + + case MODE_UPTIME: + subtract_timeval (&load_t, &tv, &tv); + break; + + case MODE_CONNTIME: + subtract_timeval (&h->conn_t, &tv, &tv); + break; + + default: + abort (); + } + + /* Pack the result into the output buffer. */ + secs = tv.tv_sec; + usecs = tv.tv_usec; + secs = htobe64 (secs); +...

This commit adds a formal specification of tvdiff_usec and a partial specification of subtract_timeval. These may be proved using Frama-C. The existing functions ignored overflow, but it is possible to call the functions with parameters that will cause overflow. So to create a formal specification I had to modify the functions to signal overflow. Luckily GCC and Clang have convenient __builtin*s...

...meval *x, const struct timeval *y) > { > int64_t usec; > @@ -50,4 +50,15 @@ tvdiff_usec (const struct timeval *x, const struct timeval *y) > return usec; > } > > +/* Return timeval difference as another struct timeval. z = y - x. */ > +static inline void > +subtract_timeval (const struct timeval *x, const struct timeval *y, > + struct timeval *z) > +{ > + int64_t usec = tvdiff_usec (x, y); > + > + z->tv_sec = usec / 1000000; > + z->tv_usec = usec % 1000000; > +} > + > #endif /* NBDKIT_TVDIFF_H */ > -- Eric B...

v1 was: https://www.redhat.com/archives/libguestfs/2019-September/thread.html#00361 v2: - Adds a patch to rename the reflection plugin to the info plugin. - Adds tests. Rich.