@@ -66,7 +66,8 @@
    infinite loop.
 
    Corollary tasks are the creation and deletion of event sources.  */
-
+#ifndef _EVENT_LOOP_H_
+#define _EVENT_LOOP_H_
 typedef void *gdb_client_data;
 struct async_signal_handler;
 struct async_event_handler;
@@ -127,3 +128,4 @@
 extern void clear_async_event_handler (struct async_event_handler *handler);
 
 extern void initialize_async_signal_handlers (void);
+#endif