Add _g_object_wait_for_single_ref() helper

This is needed to ensure that singletons for bus connections gets
cleared properly when the bus goes away. We want this otherwise we
accidentially reuse a closed bus connection.

Apparently this problem never happened for me with D-Bus 1.2.x but it
is pretty evident with D-Bus 1.3.x.

3 files changed, 98 insertions, 4 deletions

diff --git a/gdbus/tests/connection.c b/gdbus/tests/connection.c
index f0181d7..5c30959 100644
--- a/gdbus/tests/connection.c
+++ b/gdbus/tests/connection.c
@@ -100,6 +100,8 @@ test_connection_life_cycle (void)
   if (!g_dbus_connection_is_closed (c))
     _g_assert_signal_received (c, "closed");
   g_assert (g_dbus_connection_is_closed (c));
+
+  _g_object_wait_for_single_ref (c);
   g_object_unref (c);
 }
 
@@ -313,6 +315,7 @@ test_connection_send (void)
                                    NULL);
   g_main_loop_run (loop);
 
+  _g_object_wait_for_single_ref (c);
   g_object_unref (c);
 }
 
@@ -513,14 +516,19 @@ test_connection_signals (void)
   g_assert_cmpint (count_s2, ==, 2);
   g_assert_cmpint (count_name_owner_changed, ==, 2);
 
-  session_bus_down ();
-
   g_dbus_connection_signal_unsubscribe (c1, s1);
   g_dbus_connection_signal_unsubscribe (c1, s2);
   g_dbus_connection_signal_unsubscribe (c1, s3);
+
+  _g_object_wait_for_single_ref (c1);
+  _g_object_wait_for_single_ref (c2);
+  _g_object_wait_for_single_ref (c3);
+
   g_object_unref (c1);
   g_object_unref (c2);
   g_object_unref (c3);
+
+  session_bus_down ();
 }
 
 /* ---------------------------------------------------------------------------------------------------- */
@@ -560,7 +568,9 @@ test_connection_filter (void)
 
   session_bus_up ();
 
-  c = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, NULL);
+  error = NULL;
+  c = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
+  g_assert_no_error (error);
   g_assert (c != NULL);
 
   filter_id = g_dbus_connection_add_filter (c,
@@ -610,7 +620,7 @@ test_connection_filter (void)
   g_object_unref (r);
   g_assert_cmpint (data.num_handled, ==, 3);
 
-
+  _g_object_wait_for_single_ref (c);
   g_object_unref (c);
   g_object_unref (m);
 
diff --git a/gdbus/tests/tests.c b/gdbus/tests/tests.c
index 76bc35b..512ffdd 100644
--- a/gdbus/tests/tests.c
+++ b/gdbus/tests/tests.c
@@ -155,5 +155,64 @@ _g_bus_get_priv (GBusType            bus_type,
   return ret;
 }
 
+/* ---------------------------------------------------------------------------------------------------- */
+
+typedef struct
+{
+  GMainLoop *loop;
+  gboolean   timed_out;
+} WaitSingleRefData;
+
+static gboolean
+on_wait_single_ref_timeout (gpointer user_data)
+{
+  WaitSingleRefData *data = user_data;
+  data->timed_out = TRUE;
+  g_main_loop_quit (data->loop);
+  return TRUE;
+}
+
+static void
+on_wait_for_single_ref_toggled (gpointer   user_data,
+                                GObject   *object,
+                                gboolean   is_last_ref)
+{
+  WaitSingleRefData *data = user_data;
+  g_main_loop_quit (data->loop);
+}
+
+gboolean
+_g_object_wait_for_single_ref_do (gpointer object)
+{
+  WaitSingleRefData data;
+  guint timeout_id;
+
+  data.timed_out = FALSE;
+
+  if (G_OBJECT (object)->ref_count == 1)
+    goto out;
+
+  data.loop = g_main_loop_new (NULL, FALSE);
+  timeout_id = g_timeout_add (5 * 1000,
+                              on_wait_single_ref_timeout,
+                              &data);
+
+  g_object_add_toggle_ref (G_OBJECT (object),
+                           on_wait_for_single_ref_toggled,
+                           &data);
+  g_object_unref (object);
+
+  g_main_loop_run (data.loop);
+
+  g_object_ref (object);
+  g_object_remove_toggle_ref (object,
+                              on_wait_for_single_ref_toggled,
+                              &data);
+
+  g_source_remove (timeout_id);
+  g_main_loop_unref (data.loop);
+ out:
+  return data.timed_out;
+}
 
 /* ---------------------------------------------------------------------------------------------------- */
diff --git a/gdbus/tests/tests.h b/gdbus/tests/tests.h
index 117570e..366efdc 100644
--- a/gdbus/tests/tests.h
+++ b/gdbus/tests/tests.h
@@ -116,6 +116,31 @@ GDBusConnection *_g_bus_get_priv (GBusType            bus_type,
                                   GCancellable       *cancellable,
                                   GError            **error);
 
+
+#define _g_object_wait_for_single_ref(object) \
+  do \
+    { \
+      if (!G_IS_OBJECT (object))                                        \
+        {                                                               \
+          g_assertion_message (G_LOG_DOMAIN,                            \
+                               __FILE__,                                \
+                               __LINE__,                                \
+                               G_STRFUNC,                               \
+                               "Not a GObject instance");               \
+        }                                                               \
+      if (_g_object_wait_for_single_ref_do (object))                    \
+        {                                                               \
+          g_assertion_message (G_LOG_DOMAIN,                            \
+                               __FILE__,                                \
+                               __LINE__,                                \
+                               G_STRFUNC,                               \
+                               "Timed out waiting for single ref");     \
+        }                                                               \
+    }                                                                   \
+  while (FALSE)
+
+gboolean _g_object_wait_for_single_ref_do (gpointer object);
+
 G_END_DECLS
 
 #endif /* __TESTS_H__ */