unixsock plugin: Don't add values to the cache that are older or as old as the values...

diff --git a/src/unixsock.c b/src/unixsock.c
index 8524bea..1ddd03c 100644 (file)
--- a/src/unixsock.c
+++ b/src/unixsock.c
@@ -243,12 +243,24 @@ static int cache_update (const data_set_t *ds, const value_list_t *vl)
 
        vc = cache_search (name);
 
+       /* pthread_mutex_lock is called by cache_insert. */
        if (vc == NULL)
                return (cache_insert (ds, vl));
 
        assert (vc->values_num == ds->ds_num);
        assert (vc->values_num == vl->values_len);
 
+       /* Avoid floating-point exceptions due to division by zero. */
+       if (vc->time >= vl->time)
+       {
+               pthread_mutex_unlock (&cache_lock);
+               ERROR ("unixsock plugin: vc->time >= vl->time. vc->time = %u; "
+                               "vl->time = %u; vl = %s;",
+                               (unsigned int) vc->time, (unsigned int) vl->time,
+                               name);
+               return (-1);
+       } /* if (vc->time >= vl->time) */
+
        /*
         * Update the values. This is possibly a lot more that you'd expect
         * because we honor min and max values and handle counter overflows here.