monitor-manager: Connect assigned CRTCs to their outputs both ways

We had a pointer from the output to the assigned CRTC, but had no way to
get the outputs an CRTC was assigned to. Add that connection.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488>

src/backends/meta-crtc.c

@@ -44,6 +44,7 @@ typedef struct _MetaCrtcPrivate
 
   MetaMonitorTransform all_transforms;
 
+  GList *outputs;
   MetaCrtcConfig *config;
 } MetaCrtcPrivate;
 
@@ -65,6 +66,34 @@ meta_crtc_get_gpu (MetaCrtc *crtc)
   return priv->gpu;
 }
 
+const GList *
+meta_crtc_get_outputs (MetaCrtc *crtc)
+{
+  MetaCrtcPrivate *priv = meta_crtc_get_instance_private (crtc);
+
+  return priv->outputs;
+}
+
+void
+meta_crtc_assign_output (MetaCrtc   *crtc,
+                         MetaOutput *output)
+{
+  MetaCrtcPrivate *priv = meta_crtc_get_instance_private (crtc);
+
+  priv->outputs = g_list_append (priv->outputs, output);
+}
+
+void
+meta_crtc_unassign_output (MetaCrtc   *crtc,
+                           MetaOutput *output)
+{
+  MetaCrtcPrivate *priv = meta_crtc_get_instance_private (crtc);
+
+  g_return_if_fail (g_list_find (priv->outputs, output));
+
+  priv->outputs = g_list_remove (priv->outputs, output);
+}
+
 MetaMonitorTransform
 meta_crtc_get_all_transforms (MetaCrtc *crtc)
 {
@@ -165,6 +194,7 @@ meta_crtc_finalize (GObject *object)
   MetaCrtcPrivate *priv = meta_crtc_get_instance_private (crtc);
 
   g_clear_pointer (&priv->config, g_free);
+  g_clear_pointer (&priv->outputs, g_list_free);
 
   G_OBJECT_CLASS (meta_crtc_parent_class)->finalize (object);
 }

src/backends/meta-crtc.h

@@ -50,6 +50,16 @@ uint64_t meta_crtc_get_id (MetaCrtc *crtc);
 META_EXPORT_TEST
 MetaGpu * meta_crtc_get_gpu (MetaCrtc *crtc);
 
+META_EXPORT_TEST
+const GList * meta_crtc_get_outputs (MetaCrtc *crtc);
+
+void meta_crtc_assign_output (MetaCrtc   *crtc,
+                              MetaOutput *output);
+
+META_EXPORT_TEST
+void meta_crtc_unassign_output (MetaCrtc   *crtc,
+                                MetaOutput *output);
+
 MetaMonitorTransform meta_crtc_get_all_transforms (MetaCrtc *crtc);
 
 META_EXPORT_TEST

src/backends/meta-output.c

@@ -22,6 +22,8 @@
 #include "backends/edid.h"
 #include "backends/meta-output.h"
 
+#include "backends/meta-crtc.h"
+
 enum
 {
   PROP_0,
@@ -191,8 +193,12 @@ meta_output_assign_crtc (MetaOutput                 *output,
 
   g_assert (crtc);
 
+  meta_output_unassign_crtc (output);
+
   g_set_object (&priv->crtc, crtc);
 
+  meta_crtc_assign_output (crtc, output);
+
   priv->is_primary = output_assignment->is_primary;
   priv->is_presentation = output_assignment->is_presentation;
   priv->is_underscanning = output_assignment->is_underscanning;
@@ -203,7 +209,11 @@ meta_output_unassign_crtc (MetaOutput *output)
 {
   MetaOutputPrivate *priv = meta_output_get_instance_private (output);
 
-  g_clear_object (&priv->crtc);
+  if (priv->crtc)
+    {
+      meta_crtc_unassign_output (priv->crtc, output);
+      g_clear_object (&priv->crtc);
+    }
 
   priv->is_primary = FALSE;
   priv->is_presentation = FALSE;

src/tests/monitor-test-utils.c

@@ -226,8 +226,9 @@ logical_monitor_from_layout (MetaMonitorManager *monitor_manager,
 }
 
 static void
-check_logical_monitor (MetaMonitorManager            *monitor_manager,
-                       MonitorTestCaseLogicalMonitor *test_logical_monitor)
+check_logical_monitor (MetaMonitorManager             *monitor_manager,
+                       MonitorTestCaseLogicalMonitor  *test_logical_monitor,
+                       GList                         **all_crtcs)
 {
   MetaLogicalMonitor *logical_monitor;
   MetaOutput *primary_output;
@@ -295,8 +296,19 @@ check_logical_monitor (MetaMonitorManager            *monitor_manager,
             }
 
           crtc = meta_output_get_assigned_crtc (output);
-          g_assert (!crtc ||
-                    meta_monitor_get_logical_monitor (monitor) == logical_monitor);
+          if (crtc)
+            {
+              g_assert (meta_monitor_get_logical_monitor (monitor) ==
+                        logical_monitor);
+              g_assert (g_list_find ((GList *) meta_crtc_get_outputs (crtc),
+                                     output));
+              *all_crtcs = g_list_remove (*all_crtcs, crtc);
+            }
+          else
+            {
+              g_assert_null (crtc);
+            }
+
           g_assert_cmpint (logical_monitor->is_presentation,
                            ==,
                            meta_output_is_presentation (output));
@@ -320,6 +332,7 @@ check_monitor_configuration (MonitorTestCaseExpect *expect)
   GList *monitors;
   GList *crtcs;
   int n_logical_monitors;
+  GList *all_crtcs;
   GList *l;
   int i;
 
@@ -488,15 +501,32 @@ check_monitor_configuration (MonitorTestCaseExpect *expect)
       g_assert (logical_monitor == monitor_manager->primary_logical_monitor);
     }
 
+  all_crtcs = NULL;
+  for (l = meta_backend_get_gpus (backend); l; l = l->next)
+    {
+      MetaGpu *gpu = l->data;
+
+      all_crtcs = g_list_concat (all_crtcs,
+                                 g_list_copy (meta_gpu_get_crtcs (gpu)));
+    }
+
   for (i = 0; i < expect->n_logical_monitors; i++)
     {
       MonitorTestCaseLogicalMonitor *test_logical_monitor =
         &expect->logical_monitors[i];
 
-      check_logical_monitor (monitor_manager, test_logical_monitor);
+      check_logical_monitor (monitor_manager, test_logical_monitor, &all_crtcs);
     }
   g_assert_cmpint (n_logical_monitors, ==, i);
 
+  for (l = all_crtcs; l; l = l->next)
+    {
+      MetaCrtc *crtc = l->data;
+
+      g_assert_null (meta_crtc_get_outputs (crtc));
+    }
+  g_list_free (all_crtcs);
+
   crtcs = meta_gpu_get_crtcs (gpu);
   for (l = crtcs, i = 0; l; l = l->next, i++)
     {
@@ -505,11 +535,23 @@ check_monitor_configuration (MonitorTestCaseExpect *expect)
 
       if (expect->crtcs[i].current_mode == -1)
         {
+          g_assert_null (meta_crtc_get_outputs (crtc));
           g_assert_null (crtc_config);
         }
       else
         {
           MetaCrtcMode *expected_current_mode;
+          const GList *l_output;
+
+          for (l_output = meta_crtc_get_outputs (crtc);
+               l_output;
+               l_output = l_output->next)
+            {
+              MetaOutput *output = l_output->data;
+
+              g_assert (meta_output_get_assigned_crtc (output) == crtc);
+              g_assert_null (g_list_find (l_output->next, output));
+            }
 
           g_assert_nonnull (crtc_config);