seat/native: Explicitly destroy MetaSeatImpl

We can't post tasks to the input thread when cleaning up the
MetaSeatImpl, as that will make the GTask complain about adding
references to a to be purged object. Avoid this by adding an explicit
meta_seat_impl_destroy() function that handles the destruction of the
MetaSeatImpl properly.

This also does more of the cleanup in the input thread, as that is where
it was managed. Will likely not make a difference as before this
happened after tearing down the thread, but lets tear down things in the
thread they were managed for good measure.

This fixes the last log spew I see right now when terminating mutter.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1670>

3 files changed, 32 insertions, 25 deletions

diff --git a/src/backends/native/meta-seat-impl.c b/src/backends/native/meta-seat-impl.c
index 9e33f70be..9e7f99e40 100644
--- a/src/backends/native/meta-seat-impl.c
+++ b/src/backends/native/meta-seat-impl.c
@@ -2753,7 +2753,8 @@ meta_seat_impl_get_property (GObject    *object,
 static gboolean
 destroy_in_impl (GTask *task)
 {
-  MetaSeatImpl *seat_impl = g_task_get_task_data (task);
+  MetaSeatImpl *seat_impl = g_task_get_source_object (task);
+  gboolean numlock_active;
 
   g_slist_foreach (seat_impl->devices,
                    (GFunc) meta_input_device_native_detach_libinput_in_impl,
@@ -2762,6 +2763,21 @@ destroy_in_impl (GTask *task)
   seat_impl->devices = NULL;
 
   g_clear_pointer (&seat_impl->libinput, libinput_unref);
+  g_clear_pointer (&seat_impl->tools, g_hash_table_unref);
+  g_clear_pointer (&seat_impl->touch_states, g_hash_table_destroy);
+  g_clear_object (&seat_impl->udev_client);
+  g_clear_pointer (&seat_impl->event_source, meta_event_source_free);
+
+  numlock_active =
+    xkb_state_mod_name_is_active (seat_impl->xkb, XKB_MOD_NAME_NUM,
+                                  XKB_STATE_MODS_LATCHED |
+                                  XKB_STATE_MODS_LOCKED);
+  meta_input_settings_maybe_save_numlock_state (seat_impl->input_settings,
+                                                numlock_active);
+
+  g_clear_pointer (&seat_impl->xkb, xkb_state_unref);
+
+  meta_seat_impl_clear_repeat_source (seat_impl);
 
   g_main_loop_quit (seat_impl->input_loop);
   g_task_return_boolean (task, TRUE);
@@ -2769,18 +2785,14 @@ destroy_in_impl (GTask *task)
   return G_SOURCE_REMOVE;
 }
 
-static void
-meta_seat_impl_finalize (GObject *object)
+void
+meta_seat_impl_destroy (MetaSeatImpl *seat_impl)
 {
-  MetaSeatImpl *seat_impl = META_SEAT_IMPL (object);
-  gboolean numlock_active;
-
   if (seat_impl->libinput)
     {
       GTask *task;
 
       task = g_task_new (seat_impl, NULL, NULL, NULL);
-      g_task_set_task_data (task, seat_impl, NULL);
       meta_seat_impl_run_input_task (seat_impl, task,
                                      (GSourceFunc) destroy_in_impl);
       g_object_unref (task);
@@ -2789,25 +2801,18 @@ meta_seat_impl_finalize (GObject *object)
       g_assert (!seat_impl->libinput);
     }
 
-  g_clear_pointer (&seat_impl->tools, g_hash_table_unref);
-
-  if (seat_impl->touch_states)
-    g_hash_table_destroy (seat_impl->touch_states);
-
-  g_object_unref (seat_impl->udev_client);
-
-  meta_event_source_free (seat_impl->event_source);
-
-  numlock_active =
-    xkb_state_mod_name_is_active (seat_impl->xkb, XKB_MOD_NAME_NUM,
-                                  XKB_STATE_MODS_LATCHED |
-                                  XKB_STATE_MODS_LOCKED);
-  meta_input_settings_maybe_save_numlock_state (seat_impl->input_settings,
-                                                numlock_active);
+  g_object_unref (seat_impl);
+}
 
-  xkb_state_unref (seat_impl->xkb);
+static void
+meta_seat_impl_finalize (GObject *object)
+{
+  MetaSeatImpl *seat_impl = META_SEAT_IMPL (object);
 
-  meta_seat_impl_clear_repeat_source (seat_impl);
+  g_assert (!seat_impl->libinput);
+  g_assert (!seat_impl->tools);
+  g_assert (!seat_impl->udev_client);
+  g_assert (!seat_impl->event_source);
 
   g_free (seat_impl->seat_id);
 
diff --git a/src/backends/native/meta-seat-impl.h b/src/backends/native/meta-seat-impl.h
index ab0ef75d3..05f8d6fd3 100644
--- a/src/backends/native/meta-seat-impl.h
+++ b/src/backends/native/meta-seat-impl.h
@@ -129,6 +129,8 @@ G_DECLARE_FINAL_TYPE (MetaSeatImpl, meta_seat_impl,
 MetaSeatImpl * meta_seat_impl_new (MetaSeatNative *seat_native,
                                    const char     *seat_id);
 
+void meta_seat_impl_destroy (MetaSeatImpl *seat_impl);
+
 void meta_seat_impl_run_input_task (MetaSeatImpl *seat_impl,
                                     GTask        *task,
                                     GSourceFunc   dispatch_func);
diff --git a/src/backends/native/meta-seat-native.c b/src/backends/native/meta-seat-native.c
index 9b931932b..99ca974f2 100644
--- a/src/backends/native/meta-seat-native.c
+++ b/src/backends/native/meta-seat-native.c
@@ -225,7 +225,7 @@ meta_seat_native_finalize (GObject *object)
     xkb_keymap_unref (seat->xkb_keymap);
   g_clear_object (&seat->core_pointer);
   g_clear_object (&seat->core_keyboard);
-  g_clear_object (&seat->impl);
+  g_clear_pointer (&seat->impl, meta_seat_impl_destroy);
 
   for (iter = seat->devices; iter; iter = g_list_next (iter))
     {