[mutter] backends: Split monitor manager creation into create and setup

[Jonas Ådahl <jadahl src gnome org>]

commit 518fb9fb5eafb7e527049004c7be26ff60330a3d
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Jul 5 18:06:06 2017 +0800

    backends: Split monitor manager creation into create and setup
    
    The monitor manager instance was created and setup in one step; at
    construction. This is problematic if, in the future, the monitor manager
    creation can fail, as the monitor manager is created quite late.
    
    To make it possible to in the future fail creating a monitor manager,
    create the instance very early when initiating the backend, then on
    post init backend setup, "setup" the monitor manager state, i.e. read
    the current state and setup the stage.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=785381

 src/backends/meta-backend.c                    |   26 +++++++------
 src/backends/meta-monitor-manager-private.h    |    2 +
 src/backends/meta-monitor-manager.c            |   23 +++++++----
 src/backends/native/meta-monitor-manager-kms.c |   50 ++++++++++++------------
 4 files changed, 55 insertions(+), 46 deletions(-)
---
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index 2021028..42800b6 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -355,15 +355,6 @@ on_device_removed (ClutterDeviceManager *device_manager,
     }
 }
 
-static MetaMonitorManager *
-create_monitor_manager (MetaBackend *backend)
-{
-  if (g_getenv ("META_DUMMY_MONITORS"))
-    return g_object_new (META_TYPE_MONITOR_MANAGER_DUMMY, NULL);
-
-  return META_BACKEND_GET_CLASS (backend)->create_monitor_manager (backend);
-}
-
 static void
 create_device_monitors (MetaBackend          *backend,
                         ClutterDeviceManager *device_manager)
@@ -441,7 +432,7 @@ meta_backend_real_post_init (MetaBackend *backend)
   clutter_actor_realize (priv->stage);
   META_BACKEND_GET_CLASS (backend)->select_stage_events (backend);
 
-  priv->monitor_manager = create_monitor_manager (backend);
+  meta_monitor_manager_setup (priv->monitor_manager);
 
   meta_backend_sync_screen_size (backend);
 
@@ -579,6 +570,15 @@ experimental_features_changed (MetaSettings            *settings,
 #endif /* HAVE_REMOTE_DESKTOP */
 }
 
+static MetaMonitorManager *
+meta_backend_create_monitor_manager (MetaBackend *backend)
+{
+  if (g_getenv ("META_DUMMY_MONITORS"))
+    return g_object_new (META_TYPE_MONITOR_MANAGER_DUMMY, NULL);
+
+  return META_BACKEND_GET_CLASS (backend)->create_monitor_manager (backend);
+}
+
 static MetaRenderer *
 meta_backend_create_renderer (MetaBackend *backend,
                               GError     **error)
@@ -601,16 +601,18 @@ meta_backend_initable_init (GInitable     *initable,
 
   priv->egl = g_object_new (META_TYPE_EGL, NULL);
 
+  priv->orientation_manager = g_object_new (META_TYPE_ORIENTATION_MANAGER, NULL);
+
   priv->renderer = meta_backend_create_renderer (backend, error);
   if (!priv->renderer)
     return FALSE;
 
+  priv->monitor_manager = meta_backend_create_monitor_manager (backend);
+
   priv->cursor_tracker = g_object_new (META_TYPE_CURSOR_TRACKER, NULL);
 
   priv->dnd = g_object_new (META_TYPE_DND, NULL);
 
-  priv->orientation_manager = g_object_new (META_TYPE_ORIENTATION_MANAGER, NULL);
-
   return TRUE;
 }
 
diff --git a/src/backends/meta-monitor-manager-private.h b/src/backends/meta-monitor-manager-private.h
index fe011b7..ad3bf80 100644
--- a/src/backends/meta-monitor-manager-private.h
+++ b/src/backends/meta-monitor-manager-private.h
@@ -259,6 +259,8 @@ struct _MetaMonitorManagerClass
   MetaLogicalMonitorLayoutMode (*get_default_layout_mode) (MetaMonitorManager *);
 };
 
+void                meta_monitor_manager_setup (MetaMonitorManager *manager);
+
 void                meta_monitor_manager_rebuild (MetaMonitorManager *manager,
                                                   MetaMonitorsConfig *config);
 void                meta_monitor_manager_rebuild_derived (MetaMonitorManager *manager,
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index 3288501..6511926 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -676,6 +676,20 @@ experimental_features_changed (MetaSettings           *settings,
   meta_settings_update_ui_scaling_factor (settings);
 }
 
+void
+meta_monitor_manager_setup (MetaMonitorManager *manager)
+{
+  manager->in_init = TRUE;
+
+  manager->config_manager = meta_monitor_config_manager_new (manager);
+
+  meta_monitor_manager_read_current_state (manager);
+
+  meta_monitor_manager_ensure_initial_config (manager);
+
+  manager->in_init = FALSE;
+}
+
 static void
 meta_monitor_manager_constructed (GObject *object)
 {
@@ -707,17 +721,8 @@ meta_monitor_manager_constructed (GObject *object)
                            manager, 0);
 
   manager->current_switch_config = META_MONITOR_SWITCH_CONFIG_UNKNOWN;
-  manager->in_init = TRUE;
-
-  manager->config_manager = meta_monitor_config_manager_new (manager);
-
-  meta_monitor_manager_read_current_state (manager);
-
-  meta_monitor_manager_ensure_initial_config (manager);
 
   initialize_dbus_interface (manager);
-
-  manager->in_init = FALSE;
 }
 
 static void
diff --git a/src/backends/native/meta-monitor-manager-kms.c b/src/backends/native/meta-monitor-manager-kms.c
index e96dded..b58f5c3 100644
--- a/src/backends/native/meta-monitor-manager-kms.c
+++ b/src/backends/native/meta-monitor-manager-kms.c
@@ -799,31 +799,6 @@ meta_monitor_manager_kms_resume (MetaMonitorManagerKms *manager_kms)
 }
 
 static void
-meta_monitor_manager_kms_init (MetaMonitorManagerKms *manager_kms)
-{
-  MetaBackend *backend = meta_get_backend ();
-  MetaRenderer *renderer = meta_backend_get_renderer (backend);
-  MetaRendererNative *renderer_native = META_RENDERER_NATIVE (renderer);
-  GSource *source;
-
-  manager_kms->fd = meta_renderer_native_get_kms_fd (renderer_native);
-
-  drmSetClientCap (manager_kms->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
-
-  const char *subsystems[2] = { "drm", NULL };
-  manager_kms->udev = g_udev_client_new (subsystems);
-  meta_monitor_manager_kms_connect_uevent_handler (manager_kms);
-
-  source = g_source_new (&kms_event_funcs, sizeof (MetaKmsSource));
-  manager_kms->source = (MetaKmsSource *) source;
-  manager_kms->source->fd_tag = g_source_add_unix_fd (source,
-                                                      manager_kms->fd,
-                                                      G_IO_IN | G_IO_ERR);
-  manager_kms->source->manager_kms = manager_kms;
-  g_source_attach (source, NULL);
-}
-
-static void
 get_crtc_connectors (MetaMonitorManager *manager,
                      MetaCrtc           *crtc,
                      uint32_t          **connectors,
@@ -1123,6 +1098,31 @@ meta_monitor_manager_kms_finalize (GObject *object)
 }
 
 static void
+meta_monitor_manager_kms_init (MetaMonitorManagerKms *manager_kms)
+{
+  MetaBackend *backend = meta_get_backend ();
+  MetaRenderer *renderer = meta_backend_get_renderer (backend);
+  MetaRendererNative *renderer_native = META_RENDERER_NATIVE (renderer);
+  GSource *source;
+
+  manager_kms->fd = meta_renderer_native_get_kms_fd (renderer_native);
+
+  drmSetClientCap (manager_kms->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
+
+  const char *subsystems[2] = { "drm", NULL };
+  manager_kms->udev = g_udev_client_new (subsystems);
+  meta_monitor_manager_kms_connect_uevent_handler (manager_kms);
+
+  source = g_source_new (&kms_event_funcs, sizeof (MetaKmsSource));
+  manager_kms->source = (MetaKmsSource *) source;
+  manager_kms->source->fd_tag = g_source_add_unix_fd (source,
+                                                      manager_kms->fd,
+                                                      G_IO_IN | G_IO_ERR);
+  manager_kms->source->manager_kms = manager_kms;
+  g_source_attach (source, NULL);
+}
+
+static void
 meta_monitor_manager_kms_class_init (MetaMonitorManagerKmsClass *klass)
 {
   MetaMonitorManagerClass *manager_class = META_MONITOR_MANAGER_CLASS (klass);