rrdtool plugin: Make sure "cache_timeout + random_variation" dosn't get negative.

[collectd.git] / src / rrdtool.c

diff --git a/src/rrdtool.c b/src/rrdtool.c
index 9ef0fa1..b366a9c 100644 (file)
--- a/src/rrdtool.c
+++ b/src/rrdtool.c
@@ -109,7 +109,7 @@ static rrdcreate_config_t rrdcreate_config =
  * ALWAYS lock `cache_lock' first! */
 static cdtime_t    cache_timeout = 0;
 static cdtime_t    cache_flush_timeout = 0;
-static cdtime_t    random_timeout = 1;
+static cdtime_t    random_timeout = TIME_T_TO_CDTIME_T (1);
 static cdtime_t    cache_flush_last;
 static c_avl_tree_t *cache = NULL;
 static pthread_mutex_t cache_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -305,7 +305,7 @@ static void *rrd_queue_thread (void __attribute__((unused)) *data)
 
                 pthread_mutex_lock (&queue_lock);
                 /* Wait for values to arrive */
-                while (true)
+                while (42)
                 {
                   struct timespec ts_wait;
 
@@ -344,7 +344,7 @@ static void *rrd_queue_thread (void __attribute__((unused)) *data)
                       &ts_wait);
                   if (status == ETIMEDOUT)
                     break;
-                } /* while (true) */
+                } /* while (42) */
 
                 /* XXX: If you need to lock both, cache_lock and queue_lock, at
                  * the same time, ALWAYS lock `cache_lock' first! */
@@ -512,10 +512,11 @@ static int rrd_queue_dequeue (const char *filename,
   return (0);
 } /* int rrd_queue_dequeue */
 
-static void rrd_cache_flush (int timeout)
+/* XXX: You must hold "cache_lock" when calling this function! */
+static void rrd_cache_flush (cdtime_t timeout)
 {
        rrd_cache_t *rc;
-       time_t       now;
+       cdtime_t     now;
 
        char **keys = NULL;
        int    keys_num = 0;
@@ -524,9 +525,11 @@ static void rrd_cache_flush (int timeout)
        c_avl_iterator_t *iter;
        int i;
 
-       DEBUG ("rrdtool plugin: Flushing cache, timeout = %i", timeout);
+       DEBUG ("rrdtool plugin: Flushing cache, timeout = %.3f",
+                       CDTIME_T_TO_DOUBLE (timeout));
 
-       now = time (NULL);
+       now = cdtime ();
+       timeout = TIME_T_TO_CDTIME_T (timeout);
 
        /* Build a list of entries to be flushed */
        iter = c_avl_get_iterator (cache);
@@ -534,7 +537,9 @@ static void rrd_cache_flush (int timeout)
        {
                if (rc->flags != FLAG_NONE)
                        continue;
-               else if ((now - rc->first_value) < timeout)
+               /* timeout == 0  =>  flush everything */
+               else if ((timeout != 0)
+                               && ((now - rc->first_value) < timeout))
                        continue;
                else if (rc->values_num > 0)
                {
@@ -587,10 +592,11 @@ static void rrd_cache_flush (int timeout)
        cache_flush_last = now;
 } /* void rrd_cache_flush */
 
-static int rrd_cache_flush_identifier (int timeout, const char *identifier)
+static int rrd_cache_flush_identifier (cdtime_t timeout,
+    const char *identifier)
 {
   rrd_cache_t *rc;
-  time_t now;
+  cdtime_t now;
   int status;
   char key[2048];
 
@@ -600,7 +606,7 @@ static int rrd_cache_flush_identifier (int timeout, const char *identifier)
     return (0);
   }
 
-  now = time (NULL);
+  now = cdtime ();
 
   if (datadir == NULL)
     snprintf (key, sizeof (key), "%s.rrd",
@@ -655,6 +661,14 @@ static int64_t rrd_get_random_variation (void)
   if (random_timeout <= 0)
     return (0);
 
+  /* Assure that "cache_timeout + random_variation" is never negative. */
+  if (random_timeout > cache_timeout)
+  {
+         INFO ("rrdtool plugin: Adjusting \"RandomTimeout\" to %.3f seconds.",
+                         CDTIME_T_TO_DOUBLE (cache_timeout));
+         random_timeout = cache_timeout;
+  }
+
   /* This seems a bit complicated, but "random_timeout" is likely larger than
    * RAND_MAX, so we can't simply use modulo here. */
   dbl_timeout = CDTIME_T_TO_DOUBLE (random_timeout);
@@ -668,9 +682,6 @@ static int64_t rrd_get_random_variation (void)
   if (negative)
     ret *= -1;
 
-  DEBUG ("rrdtool plugin: random_variation = %.3f s",
-      (negative ? -1.0 : 1.0) * dbl_timeout * rand_fact);
-
   return (ret);
 } /* int64_t rrd_get_random_variation */
 
@@ -703,7 +714,7 @@ static int rrd_cache_insert (const char *filename,
                rc->values = NULL;
                rc->first_value = 0;
                rc->last_value = 0;
-               rc->random_variation = 0;
+               rc->random_variation = rrd_get_random_variation ();
                rc->flags = FLAG_NONE;
                new_rc = 1;
        }
@@ -774,7 +785,7 @@ static int rrd_cache_insert (const char *filename,
                        filename, rc->values_num,
                        CDTIME_T_TO_DOUBLE (rc->last_value - rc->first_value));
 
-       if ((rc->last_value + rc->random_variation - rc->first_value) >= cache_timeout)
+       if ((rc->last_value - rc->first_value) >= (cache_timeout + rc->random_variation))
        {
                /* XXX: If you need to lock both, cache_lock and queue_lock, at
                 * the same time, ALWAYS lock `cache_lock' first! */
@@ -921,8 +932,8 @@ static int rrd_write (const data_set_t *ds, const value_list_t *vl,
        return (status);
 } /* int rrd_write */
 
-static int rrd_flush (int timeout, const char *identifier,
-               user_data_t __attribute__((unused)) *user_data)
+static int rrd_flush (cdtime_t timeout, const char *identifier,
+               __attribute__((unused)) user_data_t *user_data)
 {
        pthread_mutex_lock (&cache_lock);
 
@@ -1095,7 +1106,7 @@ static int rrd_config (const char *key, const char *value)
                }
                else
                {
-                       cache_timeout = DOUBLE_TO_CDTIME_T (tmp);
+                       random_timeout = DOUBLE_TO_CDTIME_T (tmp);
                }
        }
        else
@@ -1108,7 +1119,7 @@ static int rrd_config (const char *key, const char *value)
 static int rrd_shutdown (void)
 {
        pthread_mutex_lock (&cache_lock);
-       rrd_cache_flush (-1);
+       rrd_cache_flush (0);
        pthread_mutex_unlock (&cache_lock);
 
        pthread_mutex_lock (&queue_lock);
@@ -1156,12 +1167,12 @@ static int rrd_init (void)
                rrdcreate_config.heartbeat = 2 * rrdcreate_config.stepsize;
 
        if ((rrdcreate_config.heartbeat > 0)
-                       && (rrdcreate_config.heartbeat < interval_g))
+                       && (rrdcreate_config.heartbeat < CDTIME_T_TO_TIME_T (interval_g)))
                WARNING ("rrdtool plugin: Your `heartbeat' is "
                                "smaller than your `interval'. This will "
                                "likely cause problems.");
        else if ((rrdcreate_config.stepsize > 0)
-                       && (rrdcreate_config.stepsize < interval_g))
+                       && (rrdcreate_config.stepsize < CDTIME_T_TO_TIME_T (interval_g)))
                WARNING ("rrdtool plugin: Your `stepsize' is "
                                "smaller than your `interval'. This will "
                                "create needlessly big RRD-files.");
@@ -1176,10 +1187,9 @@ static int rrd_init (void)
                return (-1);
        }
 
-       cache_flush_last = time (NULL);
-       if (cache_timeout < 2)
+       cache_flush_last = cdtime ();
+       if (cache_timeout == 0)
        {
-               cache_timeout = 0;
                cache_flush_timeout = 0;
        }
        else if (cache_flush_timeout < cache_timeout)