rrdtool plugin: Make sure the initialization is run only once.

[collectd.git] / src / rrdtool.c

diff --git a/src/rrdtool.c b/src/rrdtool.c
index debb7bd..a205ef2 100644 (file)
--- a/src/rrdtool.c
+++ b/src/rrdtool.c
@@ -279,14 +279,17 @@ static void *rrd_queue_thread (void __attribute__((unused)) *data)
                rrd_cache_t *cache_entry;
                char **values;
                int    values_num;
+               int    status;
                int    i;
 
+               values = NULL;
+               values_num = 0;
+
                 pthread_mutex_lock (&queue_lock);
                 /* Wait for values to arrive */
                 while (true)
                 {
                   struct timespec ts_wait;
-                  int status;
 
                   while ((flushq_head == NULL) && (queue_head == NULL)
                       && (do_shutdown == 0))
@@ -361,17 +364,28 @@ static void *rrd_queue_thread (void __attribute__((unused)) *data)
                 * we make a copy of it's values */
                pthread_mutex_lock (&cache_lock);
 
-               c_avl_get (cache, queue_entry->filename, (void *) &cache_entry);
+               status = c_avl_get (cache, queue_entry->filename,
+                               (void *) &cache_entry);
 
-               values = cache_entry->values;
-               values_num = cache_entry->values_num;
+               if (status == 0)
+               {
+                       values = cache_entry->values;
+                       values_num = cache_entry->values_num;
 
-               cache_entry->values = NULL;
-               cache_entry->values_num = 0;
-               cache_entry->flags = FLAG_NONE;
+                       cache_entry->values = NULL;
+                       cache_entry->values_num = 0;
+                       cache_entry->flags = FLAG_NONE;
+               }
 
                pthread_mutex_unlock (&cache_lock);
 
+               if (status != 0)
+               {
+                       sfree (queue_entry->filename);
+                       sfree (queue_entry);
+                       continue;
+               }
+
                /* Update `tv_next_update' */
                if (write_rate > 0.0) 
                 {
@@ -625,6 +639,15 @@ static int rrd_cache_insert (const char *filename,
 
        pthread_mutex_lock (&cache_lock);
 
+       /* This shouldn't happen, but it did happen at least once, so we'll be
+        * careful. */
+       if (cache == NULL)
+       {
+               pthread_mutex_unlock (&cache_lock);
+               WARNING ("rrdtool plugin: cache == NULL.");
+               return (-1);
+       }
+
        c_avl_get (cache, filename, (void *) &rc);
 
        if (rc == NULL)
@@ -984,8 +1007,13 @@ static int rrd_shutdown (void)
 
 static int rrd_init (void)
 {
+       static int init_once = 0;
        int status;
 
+       if (init_once != 0)
+               return (0);
+       init_once = 1;
+
        if (rrdcreate_config.stepsize < 0)
                rrdcreate_config.stepsize = 0;
        if (rrdcreate_config.heartbeat <= 0)