[mutter/wip/texture-purge-on-nvidia: 3/4] backend: add signals for reporting suspend and resume

[Ray Strode <halfline src gnome org>]

commit 945fbcdbc4a8677fbad232715b96cceb0f3c813d
Author: Ray Strode <rstrode redhat com>
Date:   Thu Jan 10 10:47:19 2019 -0500

    backend: add signals for reporting suspend and resume
    
    This commit adds "suspending" and "resuming" signals
    to MetaBackend.
    
    It's preliminary work needed for tracking when to purge
    and recreate all textures (needed by nvidia).

 src/backends/meta-backend.c | 84 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 72 insertions(+), 12 deletions(-)
---
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index 2f090e233..f9734defd 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -60,7 +60,8 @@ enum
   KEYMAP_CHANGED,
   KEYMAP_LAYOUT_GROUP_CHANGED,
   LAST_DEVICE_CHANGED,
-
+  SUSPENDING,
+  RESUMING,
   N_SIGNALS
 };
 
@@ -550,6 +551,20 @@ meta_backend_class_init (MetaBackendClass *klass)
                   0,
                   NULL, NULL, NULL,
                   G_TYPE_NONE, 1, G_TYPE_INT);
+  signals[SUSPENDING] =
+    g_signal_new ("suspending",
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 0);
+  signals[RESUMING] =
+    g_signal_new ("resuming",
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 0);
 
   mutter_stage_views = g_getenv ("MUTTER_STAGE_VIEWS");
   stage_views_disabled = g_strcmp0 (mutter_stage_views, "0") == 0;
@@ -584,15 +599,53 @@ lid_is_closed_changed_cb (UpClient   *client,
   meta_idle_monitor_reset_idletime (meta_idle_monitor_get_core ());
 }
 
+static void
+inhibit_sleep (MetaBackend *backend)
+{
+  MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
+  g_autoptr (GVariant) fd_variant = NULL;
+  g_autoptr (GError) error = NULL;
+
+  if (priv->inhibit_sleep_fd >= 0)
+    return;
+
+  if (!login1_manager_call_inhibit_sync (priv->logind_proxy,
+                                         "sleep",
+                                         "Display Server",
+                                         "Prepare for suspend",
+                                         "delay",
+                                         &fd_variant,
+                                         priv->cancellable,
+                                         &error))
+    {
+      g_warning ("Failed to inhibit sleep: %s", error->message);
+      return;
+    }
+
+  priv->inhibit_sleep_fd = g_variant_get_handle (fd_variant);
+}
+
+static void
+uninhibit_sleep (MetaBackend *backend)
+{
+  MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
+
+  close (priv->inhibit_sleep_fd);
+  priv->inhibit_sleep_fd = -1;
+}
+
 static void
 prepare_for_sleep_cb (MetaBackend *backend,
                       gboolean     suspending)
 {
-  gboolean suspending;
-
-  g_variant_get (parameters, "(b)", &suspending);
-  if (suspending)
+  if (suspending) {
+    g_signal_emit (backend, signals[SUSPENDING], 0);
+    uninhibit_sleep (backend);
     return;
+  }
+
+  inhibit_sleep (backend);
+  g_signal_emit (backend, signals[RESUMING], 0);
   meta_idle_monitor_reset_idletime (meta_idle_monitor_get_core ());
 }
 
@@ -619,6 +672,7 @@ system_bus_gotten_cb (GObject      *object,
                       GAsyncResult *res,
                       gpointer      user_data)
 {
+  MetaBackend *backend = META_BACKEND (user_data);
   MetaBackendPrivate *priv;
   g_autoptr (GError) error = NULL;
   GDBusConnection *bus;
@@ -630,15 +684,21 @@ system_bus_gotten_cb (GObject      *object,
   priv = meta_backend_get_instance_private (user_data);
   priv->system_bus = bus;
   priv->logind_proxy = get_logind_proxy (priv->cancellable, &error);
+  priv->inhibit_sleep_fd = -1;
 
   if (!priv->logind_proxy)
-    g_warning ("Failed to get logind proxy: %s", error->message);
-
-  g_signal_connect_object (priv->logind_proxy,
-                           "prepare-for-sleep",
-                           G_CALLBACK (prepare_for_sleep_cb),
-                           user_data,
-                           G_CONNECT_SWAPPED);
+    {
+      g_warning ("Failed to get logind proxy: %s", error->message);
+    }
+  else
+    {
+      inhibit_sleep (backend);
+      g_signal_connect_object (priv->logind_proxy,
+                               "prepare-for-sleep",
+                               G_CALLBACK (prepare_for_sleep_cb),
+                               user_data,
+                               G_CONNECT_SWAPPED);
+    }
 }
 
 static gboolean