[mutter/wip/texture-purge-on-nvidia: 5/9] backends/native: emit gl-video-memory-purged when becoming active

[Ray Strode <halfline src gnome org>]

commit f9907d197816fc5baad6b54f05283947eabd32d1
Author: Ray Strode <rstrode redhat com>
Date:   Tue Jan 15 10:29:55 2019 -0500

    backends/native: emit gl-video-memory-purged when becoming active
    
    The proprietary NVIDIA driver garbles memory on suspend.  In order
    to work around that limitation, mutter needs to refresh all its
    textures on resuem.
    
    This commit lays the way toward doing that by emitting the
    "gl-video-memory-purged" signal when the compositor becomes active
    by logind (which happens on VT switch and on resume).

 src/backends/native/meta-backend-native.c | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index 042d96ec6..f87c5a066 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -645,9 +645,16 @@ void meta_backend_native_resume (MetaBackendNative *native)
     meta_backend_get_monitor_manager (backend);
   MetaMonitorManagerKms *monitor_manager_kms =
     META_MONITOR_MANAGER_KMS (monitor_manager);
+  MetaDisplay *display = meta_get_display ();
+  ClutterBackend *clutter_backend = clutter_get_default_backend ();
+  CoglContext *cogl_context =
+    clutter_backend_get_cogl_context (clutter_backend);
   ClutterActor *stage;
   MetaIdleMonitor *idle_monitor;
 
+  if (cogl_has_feature (cogl_context, COGL_FEATURE_ID_UNSTABLE_TEXTURES))
+    g_signal_emit_by_name (display, "gl-video-memory-purged");
+
   meta_monitor_manager_kms_resume (monitor_manager_kms);
 
   clutter_evdev_reclaim_devices ();