[mutter] backend: Tear down in dispose() instead of finalize()

[Marge Bot <marge-bot src gnome org>]

commit db6bf9d14e279f99e6fbcd99b5ee9379d0685e03
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Jan 19 22:14:01 2021 +0100

    backend: Tear down in dispose() instead of finalize()
    
    This means backend implementations can have more control of the order of
    how things are destroyed. To be precise, this will, in the next commit,
    allow us to destroy the logind integration after the clutter backend
    thus the libinput owning seat, that uses the logind integration to
    release input devices.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1670>

 src/backends/meta-backend.c               | 26 +++++++++++++++++++-------
 src/backends/native/meta-backend-native.c | 13 ++++++++-----
 src/backends/x11/meta-backend-x11.c       |  6 +++---
 3 files changed, 30 insertions(+), 15 deletions(-)
---
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index aca0d6fc99..14f15d66a2 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -191,12 +191,16 @@ G_DEFINE_ABSTRACT_TYPE_WITH_CODE (MetaBackend, meta_backend, G_TYPE_OBJECT,
                                                          initable_iface_init));
 
 static void
-meta_backend_finalize (GObject *object)
+meta_backend_dispose (GObject *object)
 {
   MetaBackend *backend = META_BACKEND (object);
   MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
 
-  g_list_free_full (priv->gpus, g_object_unref);
+  if (priv->gpus)
+    {
+      g_list_free_full (priv->gpus, g_object_unref);
+      priv->gpus = NULL;
+    }
 
   g_clear_object (&priv->current_device);
   g_clear_object (&priv->monitor_manager);
@@ -213,9 +217,17 @@ meta_backend_finalize (GObject *object)
 #endif
 
   if (priv->sleep_signal_id)
-    g_dbus_connection_signal_unsubscribe (priv->system_bus, priv->sleep_signal_id);
+    {
+      g_dbus_connection_signal_unsubscribe (priv->system_bus, priv->sleep_signal_id);
+      priv->sleep_signal_id = 0;
+    }
+
   if (priv->upower_watch_id)
-    g_bus_unwatch_name (priv->upower_watch_id);
+    {
+      g_bus_unwatch_name (priv->upower_watch_id);
+      priv->upower_watch_id = 0;
+    }
+
   g_cancellable_cancel (priv->cancellable);
   g_clear_object (&priv->cancellable);
   g_clear_object (&priv->system_bus);
@@ -223,7 +235,7 @@ meta_backend_finalize (GObject *object)
 
   g_clear_handle_id (&priv->device_update_idle_id, g_source_remove);
 
-  g_hash_table_destroy (priv->device_monitors);
+  g_clear_pointer (&priv->device_monitors, g_hash_table_destroy);
 
   g_clear_object (&priv->settings);
 
@@ -233,7 +245,7 @@ meta_backend_finalize (GObject *object)
 
   g_clear_object (&priv->clutter_backend);
 
-  G_OBJECT_CLASS (meta_backend_parent_class)->finalize (object);
+  G_OBJECT_CLASS (meta_backend_parent_class)->dispose (object);
 }
 
 static void
@@ -805,7 +817,7 @@ meta_backend_class_init (MetaBackendClass *klass)
   const gchar *mutter_stage_views;
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
-  object_class->finalize = meta_backend_finalize;
+  object_class->dispose = meta_backend_dispose;
   object_class->constructed = meta_backend_constructed;
 
   klass->post_init = meta_backend_real_post_init;
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index fee6f76011..473508305f 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -89,18 +89,21 @@ static void
 disconnect_udev_device_added_handler (MetaBackendNative *native);
 
 static void
-meta_backend_native_finalize (GObject *object)
+meta_backend_native_dispose (GObject *object)
 {
   MetaBackendNative *native = META_BACKEND_NATIVE (object);
 
   if (native->udev_device_added_handler_id)
-    disconnect_udev_device_added_handler (native);
+    {
+      disconnect_udev_device_added_handler (native);
+      native->udev_device_added_handler_id = 0;
+    }
 
   g_clear_object (&native->kms);
   g_clear_object (&native->udev);
-  meta_launcher_free (native->launcher);
+  g_clear_pointer (&native->launcher, meta_launcher_free);
 
-  G_OBJECT_CLASS (meta_backend_native_parent_class)->finalize (object);
+  G_OBJECT_CLASS (meta_backend_native_parent_class)->dispose (object);
 }
 
 static ClutterBackend *
@@ -521,7 +524,7 @@ meta_backend_native_class_init (MetaBackendNativeClass *klass)
   MetaBackendClass *backend_class = META_BACKEND_CLASS (klass);
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
-  object_class->finalize = meta_backend_native_finalize;
+  object_class->dispose = meta_backend_native_dispose;
 
   backend_class->create_clutter_backend = meta_backend_native_create_clutter_backend;
 
diff --git a/src/backends/x11/meta-backend-x11.c b/src/backends/x11/meta-backend-x11.c
index f79b0d6d4f..722d7b3d9f 100644
--- a/src/backends/x11/meta-backend-x11.c
+++ b/src/backends/x11/meta-backend-x11.c
@@ -848,7 +848,7 @@ initable_iface_init (GInitableIface *initable_iface)
 }
 
 static void
-meta_backend_x11_finalize (GObject *object)
+meta_backend_x11_dispose (GObject *object)
 {
   MetaBackend *backend = META_BACKEND (object);
   MetaBackendX11 *x11 = META_BACKEND_X11 (object);
@@ -871,7 +871,7 @@ meta_backend_x11_finalize (GObject *object)
       priv->user_active_alarm = None;
     }
 
-  G_OBJECT_CLASS (meta_backend_x11_parent_class)->finalize (object);
+  G_OBJECT_CLASS (meta_backend_x11_parent_class)->dispose (object);
 }
 
 static void
@@ -880,7 +880,7 @@ meta_backend_x11_class_init (MetaBackendX11Class *klass)
   MetaBackendClass *backend_class = META_BACKEND_CLASS (klass);
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
-  object_class->finalize = meta_backend_x11_finalize;
+  object_class->dispose = meta_backend_x11_dispose;
   backend_class->create_clutter_backend = meta_backend_x11_create_clutter_backend;
   backend_class->post_init = meta_backend_x11_post_init;
   backend_class->grab_device = meta_backend_x11_grab_device;