Merge branch 'collectd-4.3' into collectd-4.4

[collectd.git] / src / plugin.c

diff --git a/src/plugin.c b/src/plugin.c
index eaf1a41..fdc0425 100644 (file)
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -148,14 +148,14 @@ static int plugin_load_file (char *file)
        {
                const char *error = lt_dlerror ();
 
-               ERROR ("lt_dlopen failed: %s", error);
-               fprintf (stderr, "lt_dlopen failed: %s\n", error);
+               ERROR ("lt_dlopen (%s) failed: %s", file, error);
+               fprintf (stderr, "lt_dlopen (%s) failed: %s\n", file, error);
                return (1);
        }
 
        if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
        {
-               WARNING ("Couldn't find symbol ``module_register'' in ``%s'': %s\n",
+               WARNING ("Couldn't find symbol `module_register' in `%s': %s\n",
                                file, lt_dlerror ());
                lt_dlclose (dlh);
                return (-1);
@@ -236,6 +236,7 @@ static void *plugin_read_thread (void *args)
        pthread_mutex_unlock (&read_lock);
 
        pthread_exit (NULL);
+       return ((void *) 0);
 } /* void *plugin_read_thread */
 
 static void start_threads (int num)
@@ -313,7 +314,7 @@ int plugin_load (const char *type)
 {
        DIR  *dh;
        const char *dir;
-       char  filename[BUFSIZE];
+       char  filename[BUFSIZE] = "";
        char  typename[BUFSIZE];
        int   typename_len;
        int   ret;
@@ -380,6 +381,9 @@ int plugin_load (const char *type)
 
        closedir (dh);
 
+       if (filename[0] == '\0')
+               fprintf (stderr, "Could not find plugin %s.\n", type);
+
        return (ret);
 }
 
@@ -576,22 +580,15 @@ void plugin_init_all (void)
        llentry_t *le;
        int status;
 
-       /* Start read-threads */
-       if (list_read != NULL)
-       {
-               const char *rt;
-               int num;
-               rt = global_option_get ("ReadThreads");
-               num = atoi (rt);
-               start_threads ((num > 0) ? num : 5);
-       }
-
        /* Init the value cache */
        uc_init ();
 
-       if (list_init == NULL)
+       if ((list_init == NULL) && (list_read == NULL))
                return;
 
+       /* Calling all init callbacks before checking if read callbacks
+        * are available allows the init callbacks to register the read
+        * callback. */
        le = llist_head (list_init);
        while (le != NULL)
        {
@@ -604,12 +601,25 @@ void plugin_init_all (void)
                                        "failed with status %i. "
                                        "Plugin will be unloaded.",
                                        le->key, status);
+                       /* Plugins that register read callbacks from the init
+                        * callback should take care of appropriate error
+                        * handling themselves. */
                        /* FIXME: Unload _all_ functions */
                        plugin_unregister_read (le->key);
                }
 
                le = le->next;
        }
+
+       /* Start read-threads */
+       if (list_read != NULL)
+       {
+               const char *rt;
+               int num;
+               rt = global_option_get ("ReadThreads");
+               num = atoi (rt);
+               start_threads ((num > 0) ? num : 5);
+       }
 } /* void plugin_init_all */
 
 void plugin_read_all (void)
@@ -719,16 +729,29 @@ int plugin_dispatch_values (const char *name, value_list_t *vl)
        data_set_t *ds;
        llentry_t *le;
 
-       if ((list_write == NULL) || (data_sets == NULL))
+       if (list_write == NULL)
+       {
+               ERROR ("plugin_dispatch_values: No write callback has been "
+                               "registered. Please load at least one plugin "
+                               "that provides a write function.");
+               return (-1);
+       }
+
+       if (data_sets == NULL)
+       {
+               ERROR ("plugin_dispatch_values: No data sets registered. "
+                               "Could the types database be read? Check "
+                               "your `TypesDB' setting!");
                return (-1);
+       }
 
        if (c_avl_get (data_sets, name, (void *) &ds) != 0)
        {
-               DEBUG ("No such dataset registered: %s", name);
+               INFO ("plugin_dispatch_values: Dataset not found: %s", name);
                return (-1);
        }
 
-       DEBUG ("plugin: plugin_dispatch_values: time = %u; interval = %i; "
+       DEBUG ("plugin_dispatch_values: time = %u; interval = %i; "
                        "host = %s; "
                        "plugin = %s; plugin_instance = %s; "
                        "type = %s; type_instance = %s;",
@@ -742,7 +765,8 @@ int plugin_dispatch_values (const char *name, value_list_t *vl)
 #else
        if (ds->ds_num != vl->values_len)
        {
-               ERROR ("plugin: ds->type = %s: (ds->ds_num = %i) != "
+               ERROR ("plugin_dispatch_values: ds->type = %s: "
+                               "(ds->ds_num = %i) != "
                                "(vl->values_len = %i)",
                                ds->type, ds->ds_num, vl->values_len);
                return (-1);