[mutter] monitor-manager: Turn MetaCrtcMode into a GObject

[Jonas Ådahl <jadahl src gnome org>]

commit 2db55052168dae091ad561a19069988834a1e0db
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Mar 28 16:52:15 2017 +0800

    monitor-manager: Turn MetaCrtcMode into a GObject
    
    Convert MetaCrtcMode from a plain struct to a GObject. This changes the
    storage format, and also the API, as the API was dependent on the
    storage format.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=785381

 src/backends/meta-crtc.c                       |   26 ++++++
 src/backends/meta-crtc.h                       |    5 +
 src/backends/meta-monitor-manager-dummy.c      |  106 ++++++++++++++++-------
 src/backends/meta-monitor-manager-private.h    |    4 +-
 src/backends/meta-monitor-manager.c            |   50 ++++--------
 src/backends/native/meta-monitor-manager-kms.c |   44 ++++++----
 src/backends/x11/meta-monitor-manager-xrandr.c |   21 +++--
 src/tests/headless-start-test.c                |   22 ++---
 src/tests/meta-monitor-manager-test.c          |    1 -
 src/tests/meta-monitor-manager-test.h          |    3 +-
 src/tests/monitor-unit-tests.c                 |   38 +++++----
 11 files changed, 195 insertions(+), 125 deletions(-)
---
diff --git a/src/backends/meta-crtc.c b/src/backends/meta-crtc.c
index ee16be1..ae92a7e 100644
--- a/src/backends/meta-crtc.c
+++ b/src/backends/meta-crtc.c
@@ -23,6 +23,8 @@
 
 G_DEFINE_TYPE (MetaCrtc, meta_crtc, G_TYPE_OBJECT)
 
+G_DEFINE_TYPE (MetaCrtcMode, meta_crtc_mode, G_TYPE_OBJECT)
+
 static void
 meta_crtc_finalize (GObject *object)
 {
@@ -46,3 +48,27 @@ meta_crtc_class_init (MetaCrtcClass *klass)
 
   object_class->finalize = meta_crtc_finalize;
 }
+
+static void
+meta_crtc_mode_finalize (GObject *object)
+{
+  MetaCrtcMode *crtc_mode = META_CRTC_MODE (object);
+
+  if (crtc_mode->driver_notify)
+    crtc_mode->driver_notify (crtc_mode);
+
+  G_OBJECT_CLASS (meta_crtc_mode_parent_class)->finalize (object);
+}
+
+static void
+meta_crtc_mode_init (MetaCrtcMode *crtc_mode)
+{
+}
+
+static void
+meta_crtc_mode_class_init (MetaCrtcModeClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = meta_crtc_mode_finalize;
+}
diff --git a/src/backends/meta-crtc.h b/src/backends/meta-crtc.h
index 0baa7d6..d9eef4f 100644
--- a/src/backends/meta-crtc.h
+++ b/src/backends/meta-crtc.h
@@ -70,6 +70,8 @@ struct _MetaCrtc
 
 struct _MetaCrtcMode
 {
+  GObject parent;
+
   /* The low-level ID of this mode, used to apply back configuration */
   glong mode_id;
   char *name;
@@ -86,4 +88,7 @@ struct _MetaCrtcMode
 #define META_TYPE_CRTC (meta_crtc_get_type ())
 G_DECLARE_FINAL_TYPE (MetaCrtc, meta_crtc, META, CRTC, GObject)
 
+#define META_TYPE_CRTC_MODE (meta_crtc_mode_get_type ())
+G_DECLARE_FINAL_TYPE (MetaCrtcMode, meta_crtc_mode, META, CRTC_MODE, GObject)
+
 #endif /* META_CRTC_H */
diff --git a/src/backends/meta-monitor-manager-dummy.c b/src/backends/meta-monitor-manager-dummy.c
index 7ef4599..1638f1d 100644
--- a/src/backends/meta-monitor-manager-dummy.c
+++ b/src/backends/meta-monitor-manager-dummy.c
@@ -65,16 +65,36 @@ G_DEFINE_TYPE (MetaMonitorManagerDummy, meta_monitor_manager_dummy, META_TYPE_MO
 static void
 meta_output_dummy_notify_destroy (MetaOutput *output);
 
-#define array_last(a, t) \
-  g_array_index (a, t, a->len - 1)
+typedef struct _CrtcModeSpec
+{
+  int width;
+  int height;
+  float refresh_rate;
+} CrtcModeSpec;
+
+static MetaCrtcMode *
+create_mode (CrtcModeSpec *spec,
+             long          mode_id)
+{
+  MetaCrtcMode *mode;
+
+  mode = g_object_new (META_TYPE_CRTC_MODE, NULL);
+
+  mode->mode_id = mode_id;
+  mode->width = spec->width;
+  mode->height = spec->height;
+  mode->refresh_rate = spec->refresh_rate;
+
+  return mode;
+}
 
 static void
-append_monitor (GArray *modes,
+append_monitor (GList **modes,
                 GList **crtcs,
                 GList **outputs,
                 float   scale)
 {
-  MetaCrtcMode modes_decl[] = {
+  CrtcModeSpec mode_specs[] = {
     {
       .width = 800,
       .height = 600,
@@ -86,15 +106,25 @@ append_monitor (GArray *modes,
       .refresh_rate = 60.0
     }
   };
+  GList *new_modes = NULL;
   MetaCrtc *crtc;
   MetaOutputDummy *output_dummy;
   MetaOutput *output;
   unsigned int i;
   unsigned int number;
+  GList *l;
+
+  for (i = 0; i < G_N_ELEMENTS (mode_specs); i++)
+    {
+      long mode_id;
+      MetaCrtcMode *mode;
 
-  for (i = 0; i < G_N_ELEMENTS (modes_decl); i++)
-    modes_decl[i].mode_id = modes->len + i;
-  g_array_append_vals (modes, modes_decl, G_N_ELEMENTS (modes_decl));
+      mode_id = g_list_length (*modes) + i + 1;
+      mode = create_mode (&mode_specs[i], mode_id);
+
+      new_modes = g_list_append (new_modes, mode);
+    }
+  *modes = g_list_concat (*modes, new_modes);
 
   crtc = g_object_new (META_TYPE_CRTC, NULL);
   crtc->crtc_id = g_list_length (*crtcs) + 1;
@@ -120,7 +150,7 @@ append_monitor (GArray *modes,
   output->width_mm = 222;
   output->height_mm = 125;
   output->subpixel_order = COGL_SUBPIXEL_ORDER_UNKNOWN;
-  output->preferred_mode = &array_last (modes, MetaCrtcMode);
+  output->preferred_mode = g_list_last (*modes)->data;
   output->n_possible_clones = 0;
   output->backlight = -1;
   output->connector_type = META_CONNECTOR_TYPE_LVDS;
@@ -128,11 +158,14 @@ append_monitor (GArray *modes,
   output->driver_notify =
     (GDestroyNotify) meta_output_dummy_notify_destroy;
 
-  output->modes = g_new0 (MetaCrtcMode *, G_N_ELEMENTS (modes_decl));
-  for (i = 0; i < G_N_ELEMENTS (modes_decl); i++)
-    output->modes[i] = &g_array_index (modes, MetaCrtcMode,
-                                       modes->len - (i + 1));
-  output->n_modes = G_N_ELEMENTS (modes_decl);
+  output->modes = g_new0 (MetaCrtcMode *, G_N_ELEMENTS (mode_specs));
+  for (l = new_modes, i = 0; l; l = l->next, i++)
+    {
+      MetaCrtcMode *mode = l->data;
+
+      output->modes[i] = mode;
+    }
+  output->n_modes = G_N_ELEMENTS (mode_specs);
   output->possible_crtcs = g_new0 (MetaCrtc *, 1);
   output->possible_crtcs[0] = g_list_last (*crtcs)->data;
   output->n_possible_crtcs = 1;
@@ -141,12 +174,12 @@ append_monitor (GArray *modes,
 }
 
 static void
-append_tiled_monitor (GArray *modes,
+append_tiled_monitor (GList **modes,
                       GList **crtcs,
                       GList **outputs,
                       int     scale)
 {
-  MetaCrtcMode modes_decl[] = {
+  CrtcModeSpec mode_specs[] = {
     {
       .width = 800,
       .height = 600,
@@ -159,14 +192,23 @@ append_tiled_monitor (GArray *modes,
     }
   };
   unsigned int n_tiles = 2;
+  GList *new_modes = NULL;
   GList *new_crtcs = NULL;
   MetaOutput *output;
   unsigned int i;
   uint32_t tile_group_id;
 
-  for (i = 0; i < G_N_ELEMENTS (modes_decl); i++)
-    modes_decl[i].mode_id = modes->len + i;
-  g_array_append_vals (modes, modes_decl, G_N_ELEMENTS (modes_decl));
+  for (i = 0; i < G_N_ELEMENTS (mode_specs); i++)
+    {
+      long mode_id;
+      MetaCrtcMode *mode;
+
+      mode_id = g_list_length (*modes) + i + 1;
+      mode = create_mode (&mode_specs[i], mode_id);
+
+      new_modes = g_list_append (new_modes, mode);
+    }
+  *modes = g_list_concat (*modes, new_modes);
 
   for (i = 0; i < n_tiles; i++)
     {
@@ -196,7 +238,7 @@ append_tiled_monitor (GArray *modes,
       /* Arbitrary ID unique for this output */
       number = g_list_length (*outputs) + 1;
 
-      preferred_mode = &array_last (modes, MetaCrtcMode);
+      preferred_mode = g_list_last (*modes)->data;
 
       output = g_object_new (META_TYPE_OUTPUT, NULL);
 
@@ -227,11 +269,14 @@ append_tiled_monitor (GArray *modes,
       output->driver_notify =
         (GDestroyNotify) meta_output_dummy_notify_destroy;
 
-      output->modes = g_new0 (MetaCrtcMode *, G_N_ELEMENTS (modes_decl));
-      for (j = 0; j < G_N_ELEMENTS (modes_decl); j++)
-        output->modes[j] = &g_array_index (modes, MetaCrtcMode,
-                                           modes->len - (j + 1));
-      output->n_modes = G_N_ELEMENTS (modes_decl);
+      output->modes = g_new0 (MetaCrtcMode *, G_N_ELEMENTS (mode_specs));
+      for (l = new_modes, j = 0; l; l = l->next, j++)
+        {
+          MetaCrtcMode *mode = l->data;
+
+          output->modes[j] = mode;
+        }
+      output->n_modes = G_N_ELEMENTS (mode_specs);
 
       output->possible_crtcs = g_new0 (MetaCrtc *, n_tiles);
       for (l = new_crtcs, j = 0; l; l = l->next, j++)
@@ -264,7 +309,7 @@ meta_monitor_manager_dummy_read_current (MetaMonitorManager *manager)
   unsigned int i;
   GList *outputs;
   GList *crtcs;
-  GArray *modes;
+  GList *modes;
 
   /* To control what monitor configuration is generated, there are two available
    * environmental variables that can be used:
@@ -333,24 +378,21 @@ meta_monitor_manager_dummy_read_current (MetaMonitorManager *manager)
   tiled_monitors_str = g_getenv ("MUTTER_DEBUG_TILED_DUMMY_MONITORS");
   tiled_monitors = g_strcmp0 (tiled_monitors_str, "1") == 0;
 
-  modes = g_array_sized_new (FALSE, TRUE, sizeof (MetaCrtcMode), MAX_MODES);
+  modes = NULL;
   crtcs = NULL;
   outputs = NULL;
 
   for (i = 0; i < num_monitors; i++)
     {
       if (tiled_monitors)
-        append_tiled_monitor (modes, &crtcs, &outputs, monitor_scales[i]);
+        append_tiled_monitor (&modes, &crtcs, &outputs, monitor_scales[i]);
       else
-        append_monitor (modes, &crtcs, &outputs, monitor_scales[i]);
+        append_monitor (&modes, &crtcs, &outputs, monitor_scales[i]);
     }
 
-  manager->modes = (MetaCrtcMode *) modes->data;
-  manager->n_modes = modes->len;
+  manager->modes = modes;
   manager->crtcs = crtcs;
   manager->outputs = outputs;
-
-  g_array_free (modes, FALSE);
 }
 
 static void
diff --git a/src/backends/meta-monitor-manager-private.h b/src/backends/meta-monitor-manager-private.h
index 676c480..fe011b7 100644
--- a/src/backends/meta-monitor-manager-private.h
+++ b/src/backends/meta-monitor-manager-private.h
@@ -169,9 +169,7 @@ struct _MetaMonitorManager
   */
   GList *outputs;
   GList *crtcs;
-
-  MetaCrtcMode *modes;
-  unsigned int n_modes;
+  GList *modes;
 
   GList *monitors;
 
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index b5c83fc..3288501 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -720,36 +720,13 @@ meta_monitor_manager_constructed (GObject *object)
   manager->in_init = FALSE;
 }
 
-void
-meta_monitor_manager_clear_mode (MetaCrtcMode *mode)
-{
-  g_free (mode->name);
-
-  if (mode->driver_notify)
-    mode->driver_notify (mode);
-
-  memset (mode, 0, sizeof (*mode));
-}
-
-static void
-meta_monitor_manager_free_mode_array (MetaCrtcMode *old_modes,
-                                      int           n_old_modes)
-{
-  int i;
-
-  for (i = 0; i < n_old_modes; i++)
-    meta_monitor_manager_clear_mode (&old_modes[i]);
-
-  g_free (old_modes);
-}
-
 static void
 meta_monitor_manager_finalize (GObject *object)
 {
   MetaMonitorManager *manager = META_MONITOR_MANAGER (object);
 
   g_list_free_full (manager->outputs, g_object_unref);
-  meta_monitor_manager_free_mode_array (manager->modes, manager->n_modes);
+  g_list_free_full (manager->modes, g_object_unref);
   g_list_free_full (manager->crtcs, g_object_unref);
   g_list_free_full (manager->logical_monitors, g_object_unref);
 
@@ -930,12 +907,17 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
     {
       MetaCrtc *crtc = l->data;
       GVariantBuilder transforms;
+      int current_mode_index;
 
       g_variant_builder_init (&transforms, G_VARIANT_TYPE ("au"));
       for (j = 0; j <= META_MONITOR_TRANSFORM_FLIPPED_270; j++)
         if (crtc->all_transforms & (1 << j))
           g_variant_builder_add (&transforms, "u", j);
 
+      if (crtc->current_mode)
+        current_mode_index = g_list_index (manager->modes, crtc->current_mode);
+      else
+        current_mode_index = -1;
       g_variant_builder_add (&crtc_builder, "(uxiiiiiuaua{sv})",
                              i, /* ID */
                              (gint64)crtc->crtc_id,
@@ -943,7 +925,7 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
                              (int)crtc->rect.y,
                              (int)crtc->rect.width,
                              (int)crtc->rect.height,
-                             (int)(crtc->current_mode ? crtc->current_mode - manager->modes : -1),
+                             current_mode_index,
                              (guint32)crtc->transform,
                              &transforms,
                              NULL /* properties */);
@@ -969,8 +951,12 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
 
       g_variant_builder_init (&modes, G_VARIANT_TYPE ("au"));
       for (j = 0; j < output->n_modes; j++)
-        g_variant_builder_add (&modes, "u",
-                               (unsigned)(output->modes[j] - manager->modes));
+        {
+          unsigned mode_index;
+
+          mode_index = g_list_index (manager->modes, output->modes[j]);
+          g_variant_builder_add (&modes, "u", mode_index);
+        }
 
       g_variant_builder_init (&clones, G_VARIANT_TYPE ("au"));
       for (j = 0; j < output->n_possible_clones; j++)
@@ -1057,9 +1043,9 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
                              &properties);
     }
 
-  for (i = 0; i < manager->n_modes; i++)
+  for (l = manager->modes, i = 0; l; l = l->next, i++)
     {
-      MetaCrtcMode *mode = &manager->modes[i];
+      MetaCrtcMode *mode = l->data;
 
       g_variant_builder_add (&mode_builder, "(uxuudu)",
                              i, /* ID */
@@ -2489,8 +2475,7 @@ meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
 {
   GList *old_outputs;
   GList *old_crtcs;
-  MetaCrtcMode *old_modes;
-  unsigned int n_old_modes;
+  GList *old_modes;
 
   /* Some implementations of read_current use the existing information
    * we have available, so don't free the old configuration until after
@@ -2498,7 +2483,6 @@ meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
   old_outputs = manager->outputs;
   old_crtcs = manager->crtcs;
   old_modes = manager->modes;
-  n_old_modes = manager->n_modes;
 
   manager->serial++;
   META_MONITOR_MANAGER_GET_CLASS (manager)->read_current (manager);
@@ -2506,7 +2490,7 @@ meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
   rebuild_monitors (manager);
 
   g_list_free_full (old_outputs, g_object_unref);
-  meta_monitor_manager_free_mode_array (old_modes, n_old_modes);
+  g_list_free_full (old_modes, g_object_unref);
   g_list_free_full (old_crtcs, g_object_unref);
 }
 
diff --git a/src/backends/native/meta-monitor-manager-kms.c b/src/backends/native/meta-monitor-manager-kms.c
index 2458dd9..20751f6 100644
--- a/src/backends/native/meta-monitor-manager-kms.c
+++ b/src/backends/native/meta-monitor-manager-kms.c
@@ -409,12 +409,14 @@ static MetaCrtcMode *
 mode_from_drm_mode (MetaMonitorManager    *manager,
                     const drmModeModeInfo *drm_mode)
 {
-  unsigned k;
+  GList *l;
 
-  for (k = 0; k < manager->n_modes; k++)
+  for (l = manager->modes; l; l = l->next)
     {
-      if (drm_mode_equal (drm_mode, manager->modes[k].driver_private))
-        return &manager->modes[k];
+      MetaCrtcMode *mode = l->data;
+
+      if (drm_mode_equal (drm_mode, mode->driver_private))
+        return mode;
     }
 
   g_assert_not_reached ();
@@ -439,11 +441,13 @@ drm_mode_vrefresh (const drmModeModeInfo *mode)
   return refresh;
 }
 
-static void
-init_mode (MetaCrtcMode          *mode,
-           const drmModeModeInfo *drm_mode,
-           long                   mode_id)
+static MetaCrtcMode *
+create_mode (const drmModeModeInfo *drm_mode,
+             long                   mode_id)
 {
+  MetaCrtcMode *mode;
+
+  mode = g_object_new (META_TYPE_CRTC_MODE, NULL);
   mode->mode_id = mode_id;
   mode->name = g_strndup (drm_mode->name, DRM_DISPLAY_MODE_LEN);
   mode->width = drm_mode->hdisplay;
@@ -452,6 +456,8 @@ init_mode (MetaCrtcMode          *mode,
   mode->refresh_rate = drm_mode_vrefresh (drm_mode);
   mode->driver_private = g_slice_dup (drmModeModeInfo, drm_mode);
   mode->driver_notify = (GDestroyNotify)meta_monitor_mode_destroy_notify;
+
+  return mode;
 }
 
 static int
@@ -669,7 +675,6 @@ create_crtc (MetaMonitorManager *manager,
              drmModeCrtc        *drm_crtc)
 {
   MetaCrtc *crtc;
-  unsigned int i;
 
   crtc = g_object_new (META_TYPE_CRTC, NULL);
 
@@ -685,11 +690,15 @@ create_crtc (MetaMonitorManager *manager,
 
   if (drm_crtc->mode_valid)
     {
-      for (i = 0; i < manager->n_modes; i++)
+      GList *l;
+
+      for (l = manager->modes; l; l = l->next)
         {
-          if (drm_mode_equal (&drm_crtc->mode, manager->modes[i].driver_private))
+          MetaCrtcMode *mode = l->data;
+
+          if (drm_mode_equal (&drm_crtc->mode, mode->driver_private))
             {
-              crtc->current_mode = &manager->modes[i];
+              crtc->current_mode = mode;
               break;
             }
         }
@@ -1015,8 +1024,7 @@ init_modes (MetaMonitorManager *manager,
         }
     }
 
-  manager->n_modes = g_hash_table_size (modes) + G_N_ELEMENTS (meta_default_drm_mode_infos);
-  manager->modes = g_new0 (MetaCrtcMode, manager->n_modes);
+  manager->modes = NULL;
 
   g_hash_table_iter_init (&iter, modes);
   mode_id = 0;
@@ -1024,8 +1032,8 @@ init_modes (MetaMonitorManager *manager,
     {
       MetaCrtcMode *mode;
 
-      mode = &manager->modes[mode_id];
-      init_mode (mode, drm_mode, (long) mode_id);
+      mode = create_mode (drm_mode, (long) mode_id);
+      manager->modes = g_list_append (manager->modes, mode);
 
       mode_id++;
     }
@@ -1036,8 +1044,8 @@ init_modes (MetaMonitorManager *manager,
     {
       MetaCrtcMode *mode;
 
-      mode = &manager->modes[mode_id];
-      init_mode (mode, &meta_default_drm_mode_infos[i], (long) mode_id);
+      mode = create_mode (&meta_default_drm_mode_infos[i], (long) mode_id);
+      manager->modes = g_list_append (manager->modes, mode);
 
       mode_id++;
     }
diff --git a/src/backends/x11/meta-monitor-manager-xrandr.c b/src/backends/x11/meta-monitor-manager-xrandr.c
index 6087010..558bede 100644
--- a/src/backends/x11/meta-monitor-manager-xrandr.c
+++ b/src/backends/x11/meta-monitor-manager-xrandr.c
@@ -659,7 +659,7 @@ output_get_modes (MetaMonitorManager *manager,
                   MetaOutput         *output,
                   XRROutputInfo      *xrandr_output)
 {
-  guint j, k;
+  guint j;
   guint n_actual_modes;
 
   output->modes = g_new0 (MetaCrtcMode *, xrandr_output->nmode);
@@ -667,11 +667,15 @@ output_get_modes (MetaMonitorManager *manager,
   n_actual_modes = 0;
   for (j = 0; j < (guint)xrandr_output->nmode; j++)
     {
-      for (k = 0; k < manager->n_modes; k++)
+      GList *l;
+
+      for (l = manager->modes; l; l = l->next)
         {
-          if (xrandr_output->modes[j] == (XID)manager->modes[k].mode_id)
+          MetaCrtcMode *mode = l->data;
+
+          if (xrandr_output->modes[j] == (XID) mode->mode_id)
             {
-              output->modes[n_actual_modes] = &manager->modes[k];
+              output->modes[n_actual_modes] = mode;
               n_actual_modes += 1;
               break;
             }
@@ -797,9 +801,8 @@ meta_monitor_manager_xrandr_read_current (MetaMonitorManager *manager)
     return;
 
   manager_xrandr->resources = resources;
-  manager->n_modes = resources->nmode;
   manager->outputs = NULL;
-  manager->modes = g_new0 (MetaCrtcMode, manager->n_modes);
+  manager->modes = NULL;
   manager->crtcs = NULL;
 
   for (i = 0; i < (unsigned)resources->nmode; i++)
@@ -807,7 +810,7 @@ meta_monitor_manager_xrandr_read_current (MetaMonitorManager *manager)
       XRRModeInfo *xmode = &resources->modes[i];
       MetaCrtcMode *mode;
 
-      mode = &manager->modes[i];
+      mode = g_object_new (META_TYPE_CRTC_MODE, NULL);
 
       mode->mode_id = xmode->id;
       mode->width = xmode->width;
@@ -816,6 +819,8 @@ meta_monitor_manager_xrandr_read_current (MetaMonitorManager *manager)
                            ((float)xmode->hTotal * xmode->vTotal));
       mode->flags = xmode->modeFlags;
       mode->name = get_xmode_name (xmode);
+
+      manager->modes = g_list_append (manager->modes, mode);
     }
 
   for (i = 0; i < (unsigned)resources->ncrtc; i++)
@@ -843,7 +848,7 @@ meta_monitor_manager_xrandr_read_current (MetaMonitorManager *manager)
        {
          if (resources->modes[j].id == xrandr_crtc->mode)
            {
-             crtc->current_mode = &manager->modes[j];
+             crtc->current_mode = g_list_nth_data (manager->modes, j);
              break;
            }
        }
diff --git a/src/tests/headless-start-test.c b/src/tests/headless-start-test.c
index 22116f3..2e356c0 100644
--- a/src/tests/headless-start-test.c
+++ b/src/tests/headless-start-test.c
@@ -58,9 +58,7 @@ meta_test_headless_start (void)
   MetaMonitorManager *monitor_manager =
     meta_backend_get_monitor_manager (backend);
 
-  g_assert_cmpint ((int) monitor_manager->n_modes,
-                   ==,
-                   0);
+  g_assert_null (monitor_manager->modes);
   g_assert_null (monitor_manager->outputs);
   g_assert_null (monitor_manager->crtcs);
   g_assert_null (monitor_manager->monitors);
@@ -99,6 +97,7 @@ meta_test_headless_monitor_connect (void)
     META_MONITOR_MANAGER_TEST (monitor_manager);
   MetaMonitorTestSetup *test_setup;
   MetaCrtcMode **modes;
+  MetaCrtcMode *crtc_mode;
   MetaCrtc *crtc;
   MetaCrtc **possible_crtcs;
   MetaOutput *output;
@@ -106,14 +105,13 @@ meta_test_headless_monitor_connect (void)
   ClutterActor *stage;
 
   test_setup = g_new0 (MetaMonitorTestSetup, 1);
-  test_setup->n_modes = 1;
-  test_setup->modes = g_new0 (MetaCrtcMode, test_setup->n_modes);
-  test_setup->modes[0] = (MetaCrtcMode) {
-    .mode_id = 1,
-    .width = 1024,
-    .height = 768,
-    .refresh_rate = 60.0
-  };
+
+  crtc_mode = g_object_new (META_TYPE_CRTC_MODE, NULL);
+  crtc_mode->mode_id = 1;
+  crtc_mode->width = 1024;
+  crtc_mode->height = 768;
+  crtc_mode->refresh_rate = 60.0;
+  test_setup->modes = g_list_append (NULL, crtc_mode);
 
   crtc = g_object_new (META_TYPE_CRTC, NULL);
   crtc->crtc_id = 1;
@@ -121,7 +119,7 @@ meta_test_headless_monitor_connect (void)
   test_setup->crtcs = g_list_append (NULL, crtc);
 
   modes = g_new0 (MetaCrtcMode *, 1);
-  modes[0] = &test_setup->modes[0];
+  modes[0] = crtc_mode;
 
   possible_crtcs = g_new0 (MetaCrtc *, 1);
   possible_crtcs[0] = g_list_first (test_setup->crtcs)->data;
diff --git a/src/tests/meta-monitor-manager-test.c b/src/tests/meta-monitor-manager-test.c
index 0fa586f..5227999 100644
--- a/src/tests/meta-monitor-manager-test.c
+++ b/src/tests/meta-monitor-manager-test.c
@@ -95,7 +95,6 @@ meta_monitor_manager_test_read_current (MetaMonitorManager *manager)
   g_assert (manager_test->test_setup);
 
   manager->modes = manager_test->test_setup->modes;
-  manager->n_modes = manager_test->test_setup->n_modes;
 
   manager->crtcs = manager_test->test_setup->crtcs;
 
diff --git a/src/tests/meta-monitor-manager-test.h b/src/tests/meta-monitor-manager-test.h
index 4dcb90a..1d3b2e3 100644
--- a/src/tests/meta-monitor-manager-test.h
+++ b/src/tests/meta-monitor-manager-test.h
@@ -24,8 +24,7 @@
 
 typedef struct _MetaMonitorTestSetup
 {
-  MetaCrtcMode *modes;
-  int n_modes;
+  GList *modes;
   GList *outputs;
   GList *crtcs;
 } MetaMonitorTestSetup;
diff --git a/src/tests/monitor-unit-tests.c b/src/tests/monitor-unit-tests.c
index e6af4b9..9baa177 100644
--- a/src/tests/monitor-unit-tests.c
+++ b/src/tests/monitor-unit-tests.c
@@ -406,7 +406,8 @@ check_monitor_mode (MetaMonitor         *monitor,
   if (expect_crtc_mode_index == -1)
     crtc_mode = NULL;
   else
-    crtc_mode = &monitor_manager->modes[expect_crtc_mode_index];
+    crtc_mode = g_list_nth_data (monitor_manager->modes,
+                                 expect_crtc_mode_index);
 
   g_assert (monitor_crtc_mode->output == output);
   g_assert (monitor_crtc_mode->crtc_mode == crtc_mode);
@@ -800,10 +801,12 @@ check_monitor_configuration (MonitorTestCase *test_case)
       else
         {
           MetaLogicalMonitor *logical_monitor = crtc->logical_monitor;
-          MetaCrtcMode *expected_current_mode =
-            &monitor_manager->modes[test_case->expect.crtcs[i].current_mode];
+          MetaCrtcMode *expected_current_mode;
           int crtc_x, crtc_y;
 
+          expected_current_mode =
+            g_list_nth_data (monitor_manager->modes,
+                             test_case->expect.crtcs[i].current_mode);
           g_assert (crtc->current_mode == expected_current_mode);
 
           g_assert_cmpuint (crtc->transform,
@@ -863,17 +866,19 @@ create_monitor_test_setup (MonitorTestCase *test_case,
 
   test_setup = g_new0 (MetaMonitorTestSetup, 1);
 
-  test_setup->n_modes = test_case->setup.n_modes;
-  test_setup->modes = g_new0 (MetaCrtcMode, test_setup->n_modes);
-  for (i = 0; i < test_setup->n_modes; i++)
+  test_setup->modes = NULL;
+  for (i = 0; i < test_case->setup.n_modes; i++)
     {
-      test_setup->modes[i] = (MetaCrtcMode) {
-        .mode_id = i,
-        .width = test_case->setup.modes[i].width,
-        .height = test_case->setup.modes[i].height,
-        .refresh_rate = test_case->setup.modes[i].refresh_rate,
-        .flags = test_case->setup.modes[i].flags,
-      };
+      MetaCrtcMode *mode;
+
+      mode = g_object_new (META_TYPE_CRTC_MODE, NULL);
+      mode->mode_id = i;
+      mode->width = test_case->setup.modes[i].width;
+      mode->height = test_case->setup.modes[i].height;
+      mode->refresh_rate = test_case->setup.modes[i].refresh_rate;
+      mode->flags = test_case->setup.modes[i].flags;
+
+      test_setup->modes = g_list_append (test_setup->modes, mode);
     }
 
   test_setup->crtcs = NULL;
@@ -887,7 +892,7 @@ create_monitor_test_setup (MonitorTestCase *test_case,
       if (current_mode_index == -1)
         current_mode = NULL;
       else
-        current_mode = &test_setup->modes[current_mode_index];
+        current_mode = g_list_nth_data (test_setup->modes, current_mode_index);
 
       crtc = g_object_new (META_TYPE_CRTC, NULL);
       crtc->crtc_id = i + 1;
@@ -926,7 +931,8 @@ create_monitor_test_setup (MonitorTestCase *test_case,
       if (preferred_mode_index == -1)
         preferred_mode = NULL;
       else
-        preferred_mode = &test_setup->modes[preferred_mode_index];
+        preferred_mode = g_list_nth_data (test_setup->modes,
+                                          preferred_mode_index);
 
       n_modes = test_case->setup.outputs[i].n_modes;
       modes = g_new0 (MetaCrtcMode *, n_modes);
@@ -935,7 +941,7 @@ create_monitor_test_setup (MonitorTestCase *test_case,
           int mode_index;
 
           mode_index = test_case->setup.outputs[i].modes[j];
-          modes[j] = &test_setup->modes[mode_index];
+          modes[j] = g_list_nth_data (test_setup->modes, mode_index);
         }
 
       n_possible_crtcs = test_case->setup.outputs[i].n_possible_crtcs;