tests: Add MetaWaylandClient test cases

It only tests indirect clients, i.e. not the subprocess part, so far,
but tests explicitly terminating by destroying the MetaWaylandClient
object, as well as the client self terminating and the signal being
emitted.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2810>

src/tests/meson.build

@@ -418,6 +418,13 @@ if have_native_tests
         wayland_test_utils,
       ],
     },
+    {
+      'name': 'wayland-client-tests',
+      'suite': 'wayland',
+      'sources': [
+        'wayland-client-tests.c',
+      ],
+    },
   ]
   if have_xwayland
     test_cases += [

src/tests/wayland-client-tests.c

@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) 2023 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 <wayland-client.h>
+
+#include "meta-test/meta-context-test.h"
+#include "wayland/meta-wayland-client-private.h"
+
+static MetaContext *test_context;
+
+static gpointer
+test_client_destroyed_thread_func (gpointer user_data)
+{
+  int fd = GPOINTER_TO_INT (user_data);
+  struct wl_display *wl_display;
+
+  wl_display = wl_display_connect_to_fd (fd);
+  g_assert_nonnull (wl_display);
+
+  wl_display_roundtrip (wl_display);
+  wl_display_disconnect (wl_display);
+
+  return GINT_TO_POINTER (TRUE);
+}
+
+static void
+on_client_destroyed (MetaWaylandClient *client,
+                     gboolean          *client_destroyed)
+{
+  *client_destroyed = TRUE;
+}
+
+static void
+meta_test_wayland_client_indirect_self_terminate (void)
+{
+  g_autoptr (MetaWaylandClient) client = NULL;
+  g_autoptr (GError) error = NULL;
+  g_autoptr (GThread) thread = NULL;
+  int fd;
+  gboolean client_destroyed = FALSE;
+
+  client = meta_wayland_client_new_indirect (test_context, &error);
+  g_assert_nonnull (client);
+  g_assert_null (error);
+
+  g_signal_connect (client, "client-destroyed",
+                    G_CALLBACK (on_client_destroyed), &client_destroyed);
+
+  fd = meta_wayland_client_setup_fd (client, &error);
+  g_assert_cmpint (fd, >=, 0);
+  g_assert_null (error);
+
+  thread = g_thread_new ("test client thread (self-terminated)",
+                         test_client_destroyed_thread_func,
+                         GINT_TO_POINTER (fd));
+
+  g_debug ("Waiting for client to disconnect itself");
+
+  while (!client_destroyed)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_debug ("Waiting for thread to terminate");
+  g_thread_join (thread);
+}
+
+typedef struct
+{
+  int fd;
+  volatile gboolean round_tripped;
+} DestroyTestData;
+
+static gpointer
+test_client_indefinite_thread_func (gpointer user_data)
+{
+  DestroyTestData *data = user_data;
+  int fd = data->fd;
+  struct wl_display *wl_display;
+
+  wl_display = wl_display_connect_to_fd (fd);
+  g_assert_nonnull (wl_display);
+
+  wl_display_roundtrip (wl_display);
+  g_atomic_int_set (&data->round_tripped, TRUE);
+
+  while (TRUE)
+    {
+      if (wl_display_dispatch (wl_display) == -1)
+        break;
+    }
+
+  wl_display_disconnect (wl_display);
+
+  return GINT_TO_POINTER (TRUE);
+}
+
+static void
+meta_test_wayland_client_indirect_destroy (void)
+{
+  DestroyTestData data;
+  g_autoptr (MetaWaylandClient) client = NULL;
+  g_autoptr (GError) error = NULL;
+  g_autoptr (GThread) thread = NULL;
+  int fd;
+  gboolean client_destroyed = FALSE;
+
+  client = meta_wayland_client_new_indirect (test_context, &error);
+  g_assert_nonnull (client);
+  g_assert_null (error);
+
+  g_signal_connect (client, "client-destroyed",
+                    G_CALLBACK (on_client_destroyed), &client_destroyed);
+
+  fd = meta_wayland_client_setup_fd (client, &error);
+  g_assert_cmpint (fd, >=, 0);
+  g_assert_null (error);
+
+  data = (DestroyTestData) {
+    .fd = fd,
+    .round_tripped = FALSE,
+  };
+  thread = g_thread_new ("test client thread (indefinite)",
+                         test_client_indefinite_thread_func,
+                         &data);
+
+  g_debug ("Waiting for client to round-trip");
+  while (!g_atomic_int_get (&data.round_tripped))
+    g_main_context_iteration (NULL, FALSE);
+
+  g_debug ("Destroying client");
+  g_clear_object (&client);
+
+  g_debug ("Waiting for client to terminate");
+  while (!client_destroyed)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_debug ("Waiting for thread to terminate");
+  g_thread_join (thread);
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/wayland/client/indirect/self-terminate",
+                   meta_test_wayland_client_indirect_self_terminate);
+  g_test_add_func ("/wayland/client/indirect/destroy",
+                   meta_test_wayland_client_indirect_destroy);
+}
+
+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_HEADLESS,
+                                      META_CONTEXT_TEST_FLAG_NO_X11);
+  g_assert (meta_context_configure (context, &argc, &argv, NULL));
+
+  test_context = context;
+
+  init_tests ();
+
+  return meta_context_test_run_tests (META_CONTEXT_TEST (context),
+                                      META_TEST_RUN_FLAG_CAN_SKIP);
+}