daemon: Finish display if its slave dies

If a slave goes away for whatever reason, we need to
make sure we clean up the display associated with it.

This commit changes the display code to watch its associated
slave on the bus and automatically finish if the slave goes away.

1 files changed, 27 insertions, 0 deletions

diff --git a/daemon/gdm-display.c b/daemon/gdm-display.c
index cc8b433c..4e45379b 100644
--- a/daemon/gdm-display.c
+++ b/daemon/gdm-display.c
@@ -70,6 +70,7 @@ struct GdmDisplayPrivate
 
         GdmSlaveProxy        *slave_proxy;
         char                 *slave_bus_name;
+        int                   slave_name_id;
         GDBusConnection      *connection;
         GdmDisplayAccessFile *user_access_file;
 
@@ -94,6 +95,7 @@ enum {
 static void     gdm_display_class_init  (GdmDisplayClass *klass);
 static void     gdm_display_init        (GdmDisplay      *display);
 static void     gdm_display_finalize    (GObject         *object);
+static void     queue_finish            (GdmDisplay      *display);
 
 G_DEFINE_ABSTRACT_TYPE (GdmDisplay, gdm_display, G_TYPE_OBJECT)
 
@@ -279,6 +281,14 @@ gdm_display_add_user_authorization (GdmDisplay *display,
         return ret;
 }
 
+static void
+on_name_vanished (GDBusConnection *connection,
+                  const char      *name,
+                  gpointer         user_data)
+{
+        queue_finish (GDM_DISPLAY (user_data));
+}
+
 static gboolean
 gdm_display_real_set_slave_bus_name (GdmDisplay *display,
                                      const char *name,
@@ -287,6 +297,17 @@ gdm_display_real_set_slave_bus_name (GdmDisplay *display,
         g_free (display->priv->slave_bus_name);
         display->priv->slave_bus_name = g_strdup (name);
 
+        if (display->priv->slave_name_id > 0) {
+                g_bus_unwatch_name (display->priv->slave_name_id);
+        }
+
+        g_bus_watch_name_on_connection (display->priv->connection,
+                                        name,
+                                        G_BUS_NAME_WATCHER_FLAGS_NONE,
+                                        NULL, /* name appeared */
+                                        on_name_vanished,
+                                        g_object_ref (display),
+                                        NULL);
         return TRUE;
 }
 
@@ -1270,6 +1291,11 @@ gdm_display_dispose (GObject *object)
                 display->priv->access_file = NULL;
         }
 
+        if (display->priv->slave_name_id > 0) {
+                g_bus_unwatch_name (display->priv->slave_name_id);
+                display->priv->slave_name_id = 0;
+        }
+
         G_OBJECT_CLASS (gdm_display_parent_class)->dispose (object);
 }
 
@@ -1403,6 +1429,7 @@ gdm_display_finalize (GObject *object)
         g_free (display->priv->x11_display_name);
         g_free (display->priv->x11_cookie);
         g_free (display->priv->slave_command);
+        g_free (display->priv->slave_bus_name);
 
         g_clear_object (&display->priv->display_skeleton);
         g_clear_object (&display->priv->object_skeleton);