[mutter] backend/native: Split up KMS shutdown in two phases

[Marge Bot <marge-bot src gnome org>]

commit 22417b8a9460f9aff3119d409130932483365ee3
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Apr 13 18:18:46 2021 +0200

    backend/native: Split up KMS shutdown in two phases
    
    The first phase happens early, which discards pending page flips,
    meaning the references held by those page flip closures are released.
    
    The second phase happens late, after other units depending on the KMS
    abstraction, have been cleaned up.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1822>

 src/backends/native/meta-backend-native.c         |  6 ++++--
 src/backends/native/meta-kms-impl-device-atomic.c | 20 ++++++++++++++------
 src/backends/native/meta-kms-impl-device-simple.c | 16 ++++++++++++++++
 src/backends/native/meta-kms-impl-device.c        |  9 +++++++++
 src/backends/native/meta-kms-impl-device.h        |  3 +++
 src/backends/native/meta-kms-impl.c               | 15 +++++++++++++++
 src/backends/native/meta-kms-impl.h               |  2 ++
 src/backends/native/meta-kms.c                    | 16 ++++++++++++++++
 src/backends/native/meta-kms.h                    |  2 ++
 9 files changed, 81 insertions(+), 8 deletions(-)
---
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index 0fcc00c91b..399560f1e9 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -112,11 +112,13 @@ meta_backend_native_dispose (GObject *object)
       native->udev_device_added_handler_id = 0;
     }
 
-  g_clear_object (&native->kms);
-  g_clear_object (&native->udev);
+  if (native->kms)
+    meta_kms_prepare_shutdown (native->kms);
 
   G_OBJECT_CLASS (meta_backend_native_parent_class)->dispose (object);
 
+  g_clear_object (&native->kms);
+  g_clear_object (&native->udev);
   g_clear_pointer (&native->launcher, meta_launcher_free);
 }
 
diff --git a/src/backends/native/meta-kms-impl-device-atomic.c 
b/src/backends/native/meta-kms-impl-device-atomic.c
index d7c32a2798..d1f2e7b82f 100644
--- a/src/backends/native/meta-kms-impl-device-atomic.c
+++ b/src/backends/native/meta-kms-impl-device-atomic.c
@@ -1012,14 +1012,23 @@ dispose_page_flip_data (gpointer key,
 }
 
 static void
-meta_kms_impl_device_atomic_finalize (GObject *object)
+meta_kms_impl_device_atomic_prepare_shutdown (MetaKmsImplDevice *impl_device)
 {
   MetaKmsImplDeviceAtomic *impl_device_atomic =
-    META_KMS_IMPL_DEVICE_ATOMIC (object);
+    META_KMS_IMPL_DEVICE_ATOMIC (impl_device);
 
   g_hash_table_foreach_remove (impl_device_atomic->page_flip_datas,
                                dispose_page_flip_data,
                                NULL);
+}
+
+static void
+meta_kms_impl_device_atomic_finalize (GObject *object)
+{
+  MetaKmsImplDeviceAtomic *impl_device_atomic =
+    META_KMS_IMPL_DEVICE_ATOMIC (object);
+
+  g_assert (g_hash_table_size (impl_device_atomic->page_flip_datas) == 0);
 
   g_hash_table_unref (impl_device_atomic->page_flip_datas);
 
@@ -1039,10 +1048,7 @@ meta_kms_impl_device_atomic_initable_init (GInitable     *initable,
 static void
 meta_kms_impl_device_atomic_init (MetaKmsImplDeviceAtomic *impl_device_atomic)
 {
-  impl_device_atomic->page_flip_datas =
-    g_hash_table_new_full (NULL, NULL,
-                           NULL,
-                           (GDestroyNotify) meta_kms_page_flip_data_unref);
+  impl_device_atomic->page_flip_datas = g_hash_table_new (NULL, NULL);
 }
 
 static void
@@ -1068,4 +1074,6 @@ meta_kms_impl_device_atomic_class_init (MetaKmsImplDeviceAtomicClass *klass)
     meta_kms_impl_device_atomic_handle_page_flip_callback;
   impl_device_class->discard_pending_page_flips =
     meta_kms_impl_device_atomic_discard_pending_page_flips;
+  impl_device_class->prepare_shutdown =
+    meta_kms_impl_device_atomic_prepare_shutdown;
 }
diff --git a/src/backends/native/meta-kms-impl-device-simple.c 
b/src/backends/native/meta-kms-impl-device-simple.c
index 5b7684efa8..1519962b8e 100644
--- a/src/backends/native/meta-kms-impl-device-simple.c
+++ b/src/backends/native/meta-kms-impl-device-simple.c
@@ -1488,6 +1488,18 @@ meta_kms_impl_device_simple_discard_pending_page_flips (MetaKmsImplDevice *impl_
                    g_source_destroy);
 }
 
+static void
+meta_kms_impl_device_simple_prepare_shutdown (MetaKmsImplDevice *impl_device)
+{
+  MetaKmsImplDeviceSimple *impl_device_simple =
+    META_KMS_IMPL_DEVICE_SIMPLE (impl_device);
+
+  g_list_foreach (impl_device_simple->posted_page_flip_datas,
+                  (GFunc) meta_kms_page_flip_data_discard_in_impl,
+                  impl_device);
+  g_clear_list (&impl_device_simple->posted_page_flip_datas, NULL);
+}
+
 static void
 meta_kms_impl_device_simple_finalize (GObject *object)
 {
@@ -1506,6 +1518,8 @@ meta_kms_impl_device_simple_finalize (GObject *object)
                             (GFunc) meta_kms_page_flip_data_discard_in_impl,
                             NULL);
 
+  g_assert (!impl_device_simple->posted_page_flip_datas);
+
   g_clear_pointer (&impl_device_simple->mode_set_fallback_feedback_source,
                    g_source_destroy);
   g_hash_table_destroy (impl_device_simple->cached_mode_sets);
@@ -1583,4 +1597,6 @@ meta_kms_impl_device_simple_class_init (MetaKmsImplDeviceSimpleClass *klass)
     meta_kms_impl_device_simple_handle_page_flip_callback;
   impl_device_class->discard_pending_page_flips =
     meta_kms_impl_device_simple_discard_pending_page_flips;
+  impl_device_class->prepare_shutdown =
+    meta_kms_impl_device_simple_prepare_shutdown;
 }
diff --git a/src/backends/native/meta-kms-impl-device.c b/src/backends/native/meta-kms-impl-device.c
index 4ed5479d6f..9dc631b577 100644
--- a/src/backends/native/meta-kms-impl-device.c
+++ b/src/backends/native/meta-kms-impl-device.c
@@ -836,6 +836,15 @@ meta_kms_impl_device_init_mode_setting (MetaKmsImplDevice  *impl_device,
   return TRUE;
 }
 
+void
+meta_kms_impl_device_prepare_shutdown (MetaKmsImplDevice *impl_device)
+{
+  MetaKmsImplDeviceClass *klass = META_KMS_IMPL_DEVICE_GET_CLASS (impl_device);
+
+  if (klass->prepare_shutdown)
+    klass->prepare_shutdown (impl_device);
+}
+
 static void
 meta_kms_impl_device_init (MetaKmsImplDevice *impl_device)
 {
diff --git a/src/backends/native/meta-kms-impl-device.h b/src/backends/native/meta-kms-impl-device.h
index 08d0011fb1..6e8ec23787 100644
--- a/src/backends/native/meta-kms-impl-device.h
+++ b/src/backends/native/meta-kms-impl-device.h
@@ -68,6 +68,7 @@ struct _MetaKmsImplDeviceClass
   void (* handle_page_flip_callback) (MetaKmsImplDevice   *impl_device,
                                       MetaKmsPageFlipData *page_flip_data);
   void (* discard_pending_page_flips) (MetaKmsImplDevice *impl_device);
+  void (* prepare_shutdown) (MetaKmsImplDevice *impl_device);
 };
 
 MetaKmsDevice * meta_kms_impl_device_get_device (MetaKmsImplDevice *impl_device);
@@ -143,4 +144,6 @@ int meta_kms_impl_device_close (MetaKmsImplDevice *impl_device);
 gboolean meta_kms_impl_device_init_mode_setting (MetaKmsImplDevice  *impl_device,
                                                  GError            **error);
 
+void meta_kms_impl_device_prepare_shutdown (MetaKmsImplDevice *impl_device);
+
 #endif /* META_KMS_IMPL_DEVICE_H */
diff --git a/src/backends/native/meta-kms-impl.c b/src/backends/native/meta-kms-impl.c
index 87fe45492d..036a0d783d 100644
--- a/src/backends/native/meta-kms-impl.c
+++ b/src/backends/native/meta-kms-impl.c
@@ -103,6 +103,21 @@ meta_kms_impl_discard_pending_page_flips (MetaKmsImpl *impl)
                   NULL);
 }
 
+void
+meta_kms_impl_prepare_shutdown (MetaKmsImpl *impl)
+{
+  MetaKmsImplPrivate *priv = meta_kms_impl_get_instance_private (impl);
+  GList *l;
+
+  for (l = priv->impl_devices; l; l = l->next)
+    {
+      MetaKmsImplDevice *impl_device = l->data;
+
+      meta_kms_impl_device_discard_pending_page_flips (impl_device);
+      meta_kms_impl_device_prepare_shutdown (impl_device);
+    }
+}
+
 MetaKmsImpl *
 meta_kms_impl_new (MetaKms *kms)
 {
diff --git a/src/backends/native/meta-kms-impl.h b/src/backends/native/meta-kms-impl.h
index 372f47721d..723a21cd2e 100644
--- a/src/backends/native/meta-kms-impl.h
+++ b/src/backends/native/meta-kms-impl.h
@@ -42,6 +42,8 @@ void meta_kms_impl_remove_impl_device (MetaKmsImpl       *impl,
 
 void meta_kms_impl_discard_pending_page_flips (MetaKmsImpl *impl);
 
+void meta_kms_impl_prepare_shutdown (MetaKmsImpl *impl);
+
 MetaKmsImpl * meta_kms_impl_new (MetaKms *kms);
 
 #endif /* META_KMS_IMPL_H */
diff --git a/src/backends/native/meta-kms.c b/src/backends/native/meta-kms.c
index 5135c4ca50..57bb88e5f7 100644
--- a/src/backends/native/meta-kms.c
+++ b/src/backends/native/meta-kms.c
@@ -662,6 +662,22 @@ meta_kms_new (MetaBackend   *backend,
   return kms;
 }
 
+static gpointer
+prepare_shutdown_in_impl (MetaKmsImpl  *impl,
+                          gpointer      user_data,
+                          GError      **error)
+{
+  meta_kms_impl_prepare_shutdown (impl);
+  return GINT_TO_POINTER (TRUE);
+}
+
+void
+meta_kms_prepare_shutdown (MetaKms *kms)
+{
+  meta_kms_run_impl_task_sync (kms, prepare_shutdown_in_impl, NULL, NULL);
+  flush_callbacks (kms);
+}
+
 static void
 meta_kms_finalize (GObject *object)
 {
diff --git a/src/backends/native/meta-kms.h b/src/backends/native/meta-kms.h
index 27b4e3537e..79713cc405 100644
--- a/src/backends/native/meta-kms.h
+++ b/src/backends/native/meta-kms.h
@@ -63,6 +63,8 @@ MetaKmsDevice * meta_kms_create_device (MetaKms            *kms,
                                         MetaKmsDeviceFlag   flags,
                                         GError            **error);
 
+void meta_kms_prepare_shutdown (MetaKms *kms);
+
 MetaKms * meta_kms_new (MetaBackend   *backend,
                         MetaKmsFlags   flags,
                         GError       **error);