orientation-manager: Use an idle to apply monitor orientation changes

In X11 when we switch to another tty all the the signals are blocked (as
the display fd is not replying back to polling, causing the main loop to
stop), and they are all handled once we switch back to the tty.

This is not a problem for most of external events, but in case of
accelerometer changes, once we reactivate a mutter session we'll get
them all together, causing lots of monitor reconfigurations leading to
black screen for some seconds and most of the times to a wrong
configuration being applied.

To avoid this, batch all these events using an idle to only apply the
last one we got in a loop.

Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1217
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1233>

src/backends/meta-orientation-manager.c

@@ -52,6 +52,7 @@ struct _MetaOrientationManager
   GCancellable *cancellable;
 
   guint iio_watch_id;
+  guint sync_idle_id;
   GDBusProxy *iio_proxy;
   MetaOrientation prev_orientation;
   MetaOrientation curr_orientation;
@@ -135,13 +136,39 @@ sync_state (MetaOrientationManager *self)
   g_signal_emit (self, signals[ORIENTATION_CHANGED], 0);
 }
 
+static gboolean
+changed_idle (gpointer user_data)
+{
+  MetaOrientationManager *self = user_data;
+
+  self->sync_idle_id = 0;
+  sync_state (self);
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+queue_sync_state (MetaOrientationManager *self)
+{
+  /* We need this idle to avoid triggering events happening while the session
+   * is not active (under X11), ideally this should be handled by stopping
+   * events if the session is not active, but we'll need a MetaLogind available
+   * in all the backends for having this working.
+   */
+
+  if (self->sync_idle_id)
+    return;
+
+  self->sync_idle_id = g_idle_add (changed_idle, self);
+}
+
 static void
 orientation_lock_changed (GSettings *settings,
                           gchar     *key,
                           gpointer   user_data)
 {
   MetaOrientationManager *self = user_data;
-  sync_state (self);
+  queue_sync_state (self);
 }
 
 static void
@@ -151,7 +178,7 @@ iio_properties_changed (GDBusProxy *proxy,
                         gpointer    user_data)
 {
   MetaOrientationManager *self = user_data;
-  sync_state (self);
+  queue_sync_state (self);
 }
 
 static void
@@ -288,6 +315,7 @@ meta_orientation_manager_finalize (GObject *object)
   g_clear_object (&self->cancellable);
 
   g_bus_unwatch_name (self->iio_watch_id);
+  g_clear_handle_id (&self->sync_idle_id, g_source_remove);
   g_clear_object (&self->iio_proxy);
 
   g_clear_object (&self->settings);

src/tests/monitor-unit-tests.c

@@ -36,6 +36,7 @@
 #include "tests/monitor-test-utils.h"
 #include "tests/meta-test-utils.h"
 #include "tests/unit-tests.h"
+#include "tests/orientation-manager-unit-tests.h"
 #include "x11/meta-x11-display-private.h"
 
 static MonitorTestCase initial_test_case = {
@@ -3551,8 +3552,13 @@ typedef MetaSensorsProxyMock MetaSensorsProxyAutoResetMock;
 static void
 meta_sensors_proxy_reset (MetaSensorsProxyMock *proxy)
 {
+  MetaBackend *backend = meta_get_backend ();
+  MetaOrientationManager *orientation_manager =
+    meta_backend_get_orientation_manager (backend);
+
   meta_sensors_proxy_mock_set_orientation (proxy,
                                            META_ORIENTATION_NORMAL);
+  wait_for_orientation_changes (orientation_manager);
   g_object_unref (proxy);
 }
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (MetaSensorsProxyAutoResetMock,
@@ -3875,6 +3881,7 @@ meta_test_monitor_orientation_initial_rotated (void)
   touch_device = meta_test_add_touch_device (backend);
   orientation = META_ORIENTATION_LEFT_UP;
   meta_sensors_proxy_mock_set_orientation (orientation_mock, orientation);
+  wait_for_orientation_changes (orientation_manager);
   g_assert_cmpuint (
     meta_orientation_manager_get_orientation (orientation_manager),
     ==,
@@ -3981,6 +3988,7 @@ meta_test_monitor_orientation_initial_rotated_no_touch_mode (void)
   orientation_mock = meta_sensors_proxy_mock_get ();
   orientation = META_ORIENTATION_LEFT_UP;
   meta_sensors_proxy_mock_set_orientation (orientation_mock, orientation);
+  wait_for_orientation_changes (orientation_manager);
   g_assert_cmpuint (
     meta_orientation_manager_get_orientation (orientation_manager),
     ==,
@@ -4097,6 +4105,7 @@ meta_test_monitor_orientation_initial_stored_rotated (void)
   touch_device = meta_test_add_touch_device (backend);
   orientation = META_ORIENTATION_RIGHT_UP;
   meta_sensors_proxy_mock_set_orientation (orientation_mock, orientation);
+  wait_for_orientation_changes (orientation_manager);
   g_assert_cmpuint (
     meta_orientation_manager_get_orientation (orientation_manager),
     ==,
@@ -4122,6 +4131,11 @@ meta_test_monitor_orientation_initial_stored_rotated (void)
 
   orientation = META_ORIENTATION_LEFT_UP;
   meta_sensors_proxy_mock_set_orientation (orientation_mock, orientation);
+  wait_for_orientation_changes (orientation_manager);
+  g_assert_cmpuint (
+    meta_orientation_manager_get_orientation (orientation_manager),
+    ==,
+    orientation);
 
   meta_backend_test_set_is_lid_closed (META_BACKEND_TEST (backend), FALSE);
   meta_monitor_manager_lid_is_closed_changed (monitor_manager);
@@ -4136,6 +4150,7 @@ meta_test_monitor_orientation_initial_stored_rotated (void)
 
   orientation = META_ORIENTATION_RIGHT_UP;
   meta_sensors_proxy_mock_set_orientation (orientation_mock, orientation);
+  wait_for_orientation_changes (orientation_manager);
   g_assert_cmpuint (
     meta_orientation_manager_get_orientation (orientation_manager),
     ==,
@@ -4247,6 +4262,7 @@ meta_test_monitor_orientation_initial_stored_rotated_no_touch (void)
   orientation_mock = meta_sensors_proxy_mock_get ();
   orientation = META_ORIENTATION_RIGHT_UP;
   meta_sensors_proxy_mock_set_orientation (orientation_mock, orientation);
+  wait_for_orientation_changes (orientation_manager);
   g_assert_cmpuint (
     meta_orientation_manager_get_orientation (orientation_manager),
     ==,
@@ -4390,6 +4406,7 @@ meta_test_monitor_orientation_changes (void)
       MetaMonitorsConfig *previous;
 
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (orientation_manager);
       g_assert_cmpuint (
         meta_orientation_manager_get_orientation (orientation_manager),
         ==, i);
@@ -4418,6 +4435,7 @@ meta_test_monitor_orientation_changes (void)
 
   meta_sensors_proxy_mock_set_orientation (orientation_mock,
                                            META_ORIENTATION_NORMAL);
+  wait_for_orientation_changes (orientation_manager);
   META_TEST_LOG_CALL ("Checking configuration per orientation",
                       check_monitor_configuration_per_orientation (
                         &test_case.expect, 0, META_ORIENTATION_NORMAL,
@@ -4435,6 +4453,7 @@ meta_test_monitor_orientation_changes (void)
       MetaMonitorsConfig *previous;
 
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (orientation_manager);
       g_assert_cmpuint (
         meta_orientation_manager_get_orientation (orientation_manager),
         ==, i);
@@ -4611,6 +4630,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
   for (i = META_N_ORIENTATIONS - 1; i > META_ORIENTATION_UNDEFINED; i--)
     {
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (orientation_manager);
       g_assert_cmpuint (
         meta_orientation_manager_get_orientation (orientation_manager),
         ==, i);
@@ -4622,6 +4642,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
 
   meta_sensors_proxy_mock_set_orientation (orientation_mock,
                                            META_ORIENTATION_NORMAL);
+  wait_for_orientation_changes (orientation_manager);
   check_monitor_configuration (&test_case.expect);
 
   /* External monitor connected */
@@ -4642,6 +4663,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
   for (i = META_N_ORIENTATIONS - 1; i > META_ORIENTATION_UNDEFINED; i--)
     {
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (orientation_manager);
       g_assert_cmpuint (
         meta_orientation_manager_get_orientation (orientation_manager),
         ==, i);
@@ -4653,6 +4675,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
 
   meta_sensors_proxy_mock_set_orientation (orientation_mock,
                                            META_ORIENTATION_NORMAL);
+  wait_for_orientation_changes (orientation_manager);
   check_monitor_configuration (&test_case.expect);
 
   /* Lid closed */
@@ -4672,11 +4695,13 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
   for (i = META_N_ORIENTATIONS - 1; i > META_ORIENTATION_UNDEFINED; i--)
     {
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (orientation_manager);
       check_monitor_configuration (&test_case.expect);
     }
 
   meta_sensors_proxy_mock_set_orientation (orientation_mock,
                                            META_ORIENTATION_NORMAL);
+  wait_for_orientation_changes (orientation_manager);
 
   /*
    * The second part of this test emulate the following at each device rotation:
@@ -4719,6 +4744,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
 
       /* Change orientation */
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (orientation_manager);
       check_monitor_configuration (&test_case.expect);
 
       /* Open the lid */
@@ -4734,6 +4760,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
       meta_backend_test_set_is_lid_closed (META_BACKEND_TEST (backend), FALSE);
       emulate_hotplug (test_setup);
 
+      wait_for_orientation_changes (orientation_manager);
       META_TEST_LOG_CALL ("Checking configuration per orientation",
                           check_monitor_configuration_per_orientation (
                             &test_case.expect, 0, i, 1024, 768));
@@ -4770,6 +4797,7 @@ meta_test_monitor_orientation_changes_with_hotplugging (void)
 
   meta_sensors_proxy_mock_set_orientation (orientation_mock,
                                            META_ORIENTATION_NORMAL);
+  wait_for_orientation_changes (orientation_manager);
 }
 
 static void

src/tests/orientation-manager-unit-tests.c

@@ -24,6 +24,44 @@
 
 #include "tests/meta-sensors-proxy-mock.h"
 
+static void
+on_orientation_changed (gpointer data)
+{
+  gboolean *changed = data;
+
+  *changed = TRUE;
+}
+
+static gboolean
+on_max_wait_timeout (gpointer data)
+{
+  guint *timeout_id = data;
+
+  *timeout_id = 0;
+
+  return G_SOURCE_REMOVE;
+}
+
+void
+wait_for_orientation_changes (MetaOrientationManager *orientation_manager)
+{
+  gboolean changed = FALSE;
+  gulong connection_id;
+  guint timeout_id;
+
+  timeout_id = g_timeout_add (300, on_max_wait_timeout, &timeout_id);
+  connection_id = g_signal_connect_swapped (orientation_manager,
+                                            "orientation-changed",
+                                            G_CALLBACK (on_orientation_changed),
+                                            &changed);
+
+  while (!changed && timeout_id)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_clear_handle_id (&timeout_id, g_source_remove);
+  g_signal_handler_disconnect (orientation_manager, connection_id);
+}
+
 static void
 meta_test_orientation_manager_no_daemon (void)
 {
@@ -64,6 +102,7 @@ meta_test_orientation_manager_has_accelerometer (void)
   meta_sensors_proxy_mock_set_property (orientation_mock,
                                         "HasAccelerometer",
                                         g_variant_new_boolean (TRUE));
+  wait_for_orientation_changes (manager);
 
   g_debug ("Checking whether accelerometer is present");
   g_assert_true (meta_orientation_manager_has_accelerometer (manager));
@@ -104,6 +143,7 @@ meta_test_orientation_manager_accelerometer_orientations (void)
     {
       changed_called = FALSE;
       meta_sensors_proxy_mock_set_orientation (orientation_mock, i);
+      wait_for_orientation_changes (manager);
 
       g_debug ("Checking orientation %d", i);
       g_assert_cmpuint (meta_orientation_manager_get_orientation (manager),

src/tests/orientation-manager-unit-tests.h

@@ -21,6 +21,10 @@
 #ifndef ORIENTATION_MANAGER_UNIT_TESTS_H
 #define ORIENTATION_MANAGER_UNIT_TESTS_H
 
+#include "backends/meta-orientation-manager.h"
+
 void init_orientation_manager_tests (void);
 
+void wait_for_orientation_changes (MetaOrientationManager *orientation_manager);
+
 #endif /* ORIENTATION_MANAGER_UNIT_TESTS_H */