custom: plugins: Add cb_destroy callback for Golang custom plugins

Signed-off-by: Hiroshi Hatake <[email protected]>

Author: cosmo0920

include/fluent-bit/flb_custom.h

@@ -60,6 +60,9 @@ struct flb_custom_plugin {
                    void *, struct flb_config *);
     int (*cb_exit) (void *, struct flb_config *);
 
+    /* Destroy */
+    void (*cb_destroy) (struct flb_custom_plugin *);
+
     struct mk_list _head;  /* Link to parent list (config->custom) */
 };
 

include/fluent-bit/flb_plugins.h.in

@@ -64,6 +64,9 @@ void flb_plugins_unregister(struct flb_config *config)
 
     mk_list_foreach_safe(head, tmp, &config->custom_plugins) {
         custom = mk_list_entry(head, struct flb_custom_plugin, _head);
+        if(custom->cb_destroy) {
+            custom->cb_destroy(custom);
+        }
         mk_list_del(&custom->_head);
         flb_free(custom);
     }