+/**
+ * Afs command handlers run as a process which is not related to the afs
+ * process, i.e. they can not change the address space of afs directly.
+ * Therefore afs commands typically consist of two functions: The command
+ * handler and the corresponding callback function that runs in afs context.
+ *
+ * \sa send_callback_request().
+ */
+typedef void callback_function(int fd, const struct osl_object *);
+typedef int callback_result_handler(struct osl_object *result, void *private);
+int send_result(struct osl_object *result, void *private_result_data);
+int pass_buffer_as_shm(char *buf, size_t size, void *private_data);
+