src/plugin.c: Check "read_loop" when returning from "pthread_cond_timedwait".

[collectd.git] / src / plugin.c

diff --git a/src/plugin.c b/src/plugin.c
index 6fb7520..84a5abf 100644 (file)
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -151,7 +151,7 @@ static void destroy_read_heap (void) /* {{{ */
        {
                callback_func_t *cf;
 
-               cf = c_head_get_root (read_heap);
+               cf = c_heap_get_root (read_heap);
                if (cf == NULL)
                        break;
 
@@ -173,7 +173,7 @@ static int register_callback (llist_t **list, /* {{{ */
                *list = llist_create ();
                if (*list == NULL)
                {
-                       ERROR ("plugin: create_register_callback: "
+                       ERROR ("plugin: register_callback: "
                                        "llist_create failed.");
                        destroy_callback (cf);
                        return (-1);
@@ -183,7 +183,7 @@ static int register_callback (llist_t **list, /* {{{ */
        key = strdup (name);
        if (key == NULL)
        {
-               ERROR ("plugin: create_register_callback: strdup failed.");
+               ERROR ("plugin: register_callback: strdup failed.");
                destroy_callback (cf);
                return (-1);
        }
@@ -194,7 +194,7 @@ static int register_callback (llist_t **list, /* {{{ */
                le = llentry_create (key, cf);
                if (le == NULL)
                {
-                       ERROR ("plugin: create_register_callback: "
+                       ERROR ("plugin: register_callback: "
                                        "llentry_create failed.");
                        free (key);
                        destroy_callback (cf);
@@ -210,6 +210,10 @@ static int register_callback (llist_t **list, /* {{{ */
                old_cf = le->value;
                le->value = cf;
 
+               WARNING ("plugin: register_callback: "
+                               "a callback named `%s' already exists - "
+                               "overwriting the old entry!", name);
+
                destroy_callback (old_cf);
                sfree (key);
        }
@@ -270,7 +274,7 @@ static int plugin_unregister (llist_t *list, const char *name) /* {{{ */
  * object, but it will bitch about a shared object not having a
  * ``module_register'' symbol..
  */
-static int plugin_load_file (char *file)
+static int plugin_load_file (char *file, uint32_t flags)
 {
        lt_dlhandle dlh;
        void (*reg_handle) (void);
@@ -280,7 +284,24 @@ static int plugin_load_file (char *file)
        lt_dlinit ();
        lt_dlerror (); /* clear errors */
 
-       if ((dlh = lt_dlopen (file)) == NULL)
+#if LIBTOOL_VERSION == 2
+       if (flags & PLUGIN_FLAGS_GLOBAL) {
+               lt_dladvise advise;
+               lt_dladvise_init(&advise);
+               lt_dladvise_global(&advise);
+               dlh = lt_dlopenadvise(file, advise);
+               lt_dladvise_destroy(&advise);
+       } else {
+               dlh = lt_dlopen (file);
+       }
+#else /* if LIBTOOL_VERSION == 1 */
+       if (flags & PLUGIN_FLAGS_GLOBAL)
+               ERROR ("plugin_load_file: The global flag is not supported, "
+                               "libtool 2 is required for this.");
+       dlh = lt_dlopen (file);
+#endif
+
+       if (dlh == NULL)
        {
                const char *error = lt_dlerror ();
 
@@ -302,6 +323,13 @@ static int plugin_load_file (char *file)
        return (0);
 }
 
+static _Bool timeout_reached(struct timespec timeout)
+{
+       struct timeval now;
+       gettimeofday(&now, NULL);
+       return (now.tv_sec >= timeout.tv_sec && now.tv_usec >= (timeout.tv_nsec / 1000));
+}
+
 static void *plugin_read_thread (void __attribute__((unused)) *args)
 {
        while (read_loop != 0)
@@ -310,9 +338,10 @@ static void *plugin_read_thread (void __attribute__((unused)) *args)
                struct timeval now;
                int status;
                int rf_type;
+               int rc;
 
                /* Get the read function that needs to be read next. */
-               rf = c_head_get_root (read_heap);
+               rf = c_heap_get_root (read_heap);
                if (rf == NULL)
                {
                        struct timespec abstime;
@@ -345,9 +374,20 @@ static void *plugin_read_thread (void __attribute__((unused)) *args)
                /* sleep until this entry is due,
                 * using pthread_cond_timedwait */
                pthread_mutex_lock (&read_lock);
-               pthread_cond_timedwait (&read_cond, &read_lock,
+               /* In pthread_cond_timedwait, spurious wakeups are possible
+                * (and really happen, at least on NetBSD with > 1 CPU), thus
+                * we need to re-evaluate the condition every time
+                * pthread_cond_timedwait returns. */
+               rc = 0;
+               while ((read_loop != 0)
+                               && !timeout_reached(rf->rf_next_read)
+                               && rc == 0)
+               {
+                       rc = pthread_cond_timedwait (&read_cond, &read_lock,
                                &rf->rf_next_read);
-               /* Must hold `real_lock' when accessing `rf->rf_type'. */
+               }
+
+               /* Must hold `read_lock' when accessing `rf->rf_type'. */
                rf_type = rf->rf_type;
                pthread_mutex_unlock (&read_lock);
 
@@ -535,7 +575,7 @@ void plugin_set_dir (const char *dir)
 }
 
 #define BUFSIZE 512
-int plugin_load (const char *type)
+int plugin_load (const char *type, uint32_t flags)
 {
        DIR  *dh;
        const char *dir;
@@ -597,7 +637,7 @@ int plugin_load (const char *type)
                        continue;
                }
 
-               if (plugin_load_file (filename) == 0)
+               if (plugin_load_file (filename, flags) == 0)
                {
                        /* success */
                        ret = 0;
@@ -1036,7 +1076,7 @@ int plugin_read_all_once (void)
        {
                read_func_t *rf;
 
-               rf = c_head_get_root (read_heap);
+               rf = c_heap_get_root (read_heap);
                if (rf == NULL)
                        break;
 
@@ -1213,8 +1253,14 @@ void plugin_shutdown_all (void)
                (*callback) ();
        }
 
-       destroy_all_callbacks (&list_write);
+       /* Write plugins which use the `user_data' pointer usually need the
+        * same data available to the flush callback. If this is the case, set
+        * the free_function to NULL when registering the flush callback and to
+        * the real free function when registering the write callback. This way
+        * the data isn't freed twice. */
        destroy_all_callbacks (&list_flush);
+       destroy_all_callbacks (&list_write);
+
        destroy_all_callbacks (&list_notification);
        destroy_all_callbacks (&list_shutdown);
        destroy_all_callbacks (&list_log);
@@ -1230,6 +1276,8 @@ int plugin_dispatch_values (value_list_t *vl)
 
        data_set_t *ds;
 
+       int free_meta_data = 0;
+
        if ((vl == NULL) || (vl->type[0] == 0)
                        || (vl->values == NULL) || (vl->values_len < 1))
        {
@@ -1237,6 +1285,12 @@ int plugin_dispatch_values (value_list_t *vl)
                return (-1);
        }
 
+       /* Free meta data only if the calling function didn't specify any. In
+        * this case matches and targets may add some and the calling function
+        * may not expect (and therefore free) that data. */
+       if (vl->meta == NULL)
+               free_meta_data = 1;
+
        if (list_write == NULL)
                c_complain_once (LOG_WARNING, &no_write_complaint,
                                "plugin_dispatch_values: No write callback has been "
@@ -1377,6 +1431,12 @@ int plugin_dispatch_values (value_list_t *vl)
                vl->values_len = saved_values_len;
        }
 
+       if ((free_meta_data != 0) && (vl->meta != NULL))
+       {
+               meta_data_destroy (vl->meta);
+               vl->meta = NULL;
+       }
+
        return (0);
 } /* int plugin_dispatch_values */
 
@@ -1423,9 +1483,6 @@ void plugin_log (int level, const char *format, ...)
        va_list ap;
        llentry_t *le;
 
-       if (list_log == NULL)
-               return;
-
 #if !COLLECT_DEBUG
        if (level >= LOG_DEBUG)
                return;
@@ -1436,6 +1493,12 @@ void plugin_log (int level, const char *format, ...)
        msg[sizeof (msg) - 1] = '\0';
        va_end (ap);
 
+       if (list_log == NULL)
+       {
+               fprintf (stderr, "%s\n", msg);
+               return;
+       }
+
        le = llist_head (list_log);
        while (le != NULL)
        {