+static void
+dummy_closure_marshal (GClosure *closure,
+ GValue *return_value,
+ guint n_param_values,
+ const GValue *param_values,
+ gpointer invocation_hint,
+ gpointer marshal_data)
+{
+ if (G_VALUE_HOLDS_BOOLEAN (return_value))
+ g_value_set_boolean (return_value, TRUE);
+}
+
+/**
+ * g_source_set_dummy_callback:
+ * @source: the source
+ *
+ * Sets a dummy callback for @source. The callback will do nothing, and
+ * if the source expects a #gboolean return value, it will return %TRUE.
+ * (If the source expects any other type of return value, it will return
+ * a 0/%NULL value; whatever g_value_init() initializes a #GValue to for
+ * that type.)
+ *
+ * If the source is not one of the standard GLib types, the
+ * @closure_callback and @closure_marshal fields of the #GSourceFuncs
+ * structure must have been filled in with pointers to appropriate
+ * functions.
+ */
+void
+g_source_set_dummy_callback (GSource *source)
+{
+ GClosure *closure;
+
+ closure = g_closure_new_simple (sizeof (GClosure), NULL);
+ g_closure_set_meta_marshal (closure, NULL, dummy_closure_marshal);
+ g_source_set_closure (source, closure);
+}