Add rudimentary mode setting test

Add a test that uses vkms to test that mode setting works, and that
rendering works. It renders 10 frames in a row after mode setting, then
exits.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2151>

src/tests/meson.build

@@ -273,6 +273,17 @@ if have_native_tests
     install: have_installed_tests,
     install_dir: mutter_installed_tests_libexecdir,
   )
+
+  native_kms_render_tests = executable('mutter-native-kms-render',
+    sources: [
+      'native-kms-render.c',
+    ],
+    include_directories: tests_includes,
+    c_args: tests_c_args,
+    dependencies: libmutter_test_dep,
+    install: have_installed_tests,
+    install_dir: mutter_installed_tests_libexecdir,
+  )
 endif
 
 stacking_tests = [
@@ -380,4 +391,11 @@ if have_native_tests
     is_parallel: false,
     timeout: 60,
   )
+
+  test('native-kms-render', native_kms_render_tests,
+    suite: ['core', 'mutter/native/kms/render'],
+    env: test_env,
+    is_parallel: false,
+    timeout: 60,
+  )
 endif

src/tests/meta-context-test.c

@@ -162,6 +162,17 @@ create_headless_backend (MetaContext  *context,
                          "mode", META_BACKEND_NATIVE_MODE_HEADLESS,
                          NULL);
 }
+
+static MetaBackend *
+create_native_backend (MetaContext  *context,
+                       GError      **error)
+{
+  return g_initable_new (META_TYPE_BACKEND_NATIVE,
+                         NULL, error,
+                         "context", context,
+                         "mode", META_BACKEND_NATIVE_MODE_TEST,
+                         NULL);
+}
 #endif /* HAVE_NATIVE_BACKEND */
 
 static MetaBackend *
@@ -179,6 +190,8 @@ meta_context_test_create_backend (MetaContext  *context,
 #ifdef HAVE_NATIVE_BACKEND
     case META_CONTEXT_TEST_TYPE_HEADLESS:
       return create_headless_backend (context, error);
+    case META_CONTEXT_TEST_TYPE_VKMS:
+      return create_native_backend (context, error);
 #endif /* HAVE_NATIVE_BACKEND */
     }
 
@@ -233,8 +246,22 @@ meta_context_test_run_tests (MetaContextTest  *context_test,
 
   if (!meta_context_setup (context, &error))
     {
-      g_printerr ("Test case failed to start: %s\n", error->message);
-      return EXIT_FAILURE;
+      if ((flags & META_TEST_RUN_FLAG_CAN_SKIP) &&
+          ((g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND) &&
+            strstr (error->message, "No GPUs found")) ||
+           (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_DBUS_ERROR) &&
+            strstr (error->message, "Could not take control")) ||
+           (g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_UNKNOWN_METHOD) &&
+            strstr (error->message, "Could not take control"))))
+        {
+          g_printerr ("Test skipped: %s\n", error->message);
+          return 77;
+        }
+      else
+        {
+          g_printerr ("Test case failed to setup: %s\n", error->message);
+          return EXIT_FAILURE;
+        }
     }
 
   if (!meta_context_start (context, &error))

src/tests/meta-test/meta-context-test.h

@@ -27,6 +27,7 @@
 typedef enum _MetaContextTestType
 {
   META_CONTEXT_TEST_TYPE_HEADLESS,
+  META_CONTEXT_TEST_TYPE_VKMS,
   META_CONTEXT_TEST_TYPE_NESTED,
 } MetaContextTestType;
 
@@ -40,6 +41,7 @@ typedef enum _MetaContextTestFlag
 typedef enum _MetaTestRunFlags
 {
   META_TEST_RUN_FLAG_NONE = 0,
+  META_TEST_RUN_FLAG_CAN_SKIP = 1 << 0,
 } MetaTestRunFlags;
 
 #define META_TYPE_CONTEXT_TEST (meta_context_test_get_type ())

src/tests/native-kms-render.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2021 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include "meta/meta-backend.h"
+#include "meta-test/meta-context-test.h"
+
+typedef struct
+{
+  int number_of_frames_left;
+  GMainLoop *loop;
+} KmsRenderingTest;
+
+static void
+on_after_update (ClutterStage     *stage,
+                 ClutterStageView *stage_view,
+                 KmsRenderingTest *test)
+{
+  test->number_of_frames_left--;
+  if (test->number_of_frames_left == 0)
+    g_main_loop_quit (test->loop);
+  else
+    clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
+}
+
+static void
+meta_test_kms_render_basic (void)
+{
+  MetaBackend *backend = meta_get_backend ();
+  ClutterActor *stage = meta_backend_get_stage (backend);
+  KmsRenderingTest test;
+
+  test = (KmsRenderingTest) {
+    .number_of_frames_left = 10,
+    .loop = g_main_loop_new (NULL, FALSE),
+  };
+  g_signal_connect (stage, "after-update", G_CALLBACK (on_after_update), &test);
+
+  clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
+  g_main_loop_run (test.loop);
+  g_main_loop_unref (test.loop);
+
+  g_assert_cmpint (test.number_of_frames_left, ==, 0);
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/backends/native/kms/render/basic",
+                   meta_test_kms_render_basic);
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  g_autoptr (MetaContext) context = NULL;
+  g_autoptr (GError) error = NULL;
+
+  context = meta_create_test_context (META_CONTEXT_TEST_TYPE_VKMS,
+                                      META_CONTEXT_TEST_FLAG_NO_X11);
+  g_assert (meta_context_configure (context, &argc, &argv, NULL));
+
+  init_tests ();
+
+  return meta_context_test_run_tests (META_CONTEXT_TEST (context),
+                                      META_TEST_RUN_FLAG_CAN_SKIP);
+}