[mutter] monitor-manager: Clean up DPMS state tracking

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 4cae9b5b1132a61cbff7c4aaa2addf83efa5e4c6
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Jan 11 14:45:44 2019 +0100

    monitor-manager: Clean up DPMS state tracking
    
    DPMS is configured from a bit all over the place: via D-Bus, via X11 and
    when reading the current KMS state. Each of these places did it slightly
    differently, directly poking at the field in MetaMonitorManager.
    
    To make things a bit more managable, move the field into a new
    MetaMonitorManagerPrivate, and add helpers to get and set the current
    value. Prior to this, there were for example situations where the DPMS
    setting was changed, but without signal listeners being notified about
    it.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/506

 src/backends/meta-input-settings.c             |  4 +-
 src/backends/meta-monitor-manager-private.h    |  9 ++++-
 src/backends/meta-monitor-manager.c            | 53 ++++++++++++++++++++++----
 src/backends/native/meta-gpu-kms.c             |  9 ++---
 src/backends/native/meta-monitor-manager-kms.c | 16 ++++++++
 src/backends/x11/meta-gpu-xrandr.c             | 32 ----------------
 src/backends/x11/meta-monitor-manager-xrandr.c | 45 ++++++++++++++++++++++
 7 files changed, 120 insertions(+), 48 deletions(-)
---
diff --git a/src/backends/meta-input-settings.c b/src/backends/meta-input-settings.c
index 27e99b574..7b8df561a 100644
--- a/src/backends/meta-input-settings.c
+++ b/src/backends/meta-input-settings.c
@@ -1766,9 +1766,11 @@ power_save_mode_changed_cb (MetaMonitorManager *manager,
   ClutterInputDevice *device;
   MetaLogicalMonitor *logical_monitor;
   MetaMonitor *builtin;
+  MetaPowerSave power_save_mode;
   gboolean on;
 
-  on = (manager->power_save_mode == META_POWER_SAVE_ON);
+  power_save_mode = meta_monitor_manager_get_power_save_mode (manager);
+  on = power_save_mode == META_POWER_SAVE_ON;
   priv = meta_input_settings_get_instance_private (user_data);
 
   builtin = meta_monitor_manager_get_laptop_panel (manager);
diff --git a/src/backends/meta-monitor-manager-private.h b/src/backends/meta-monitor-manager-private.h
index 3b951c64c..cdb8f4209 100644
--- a/src/backends/meta-monitor-manager-private.h
+++ b/src/backends/meta-monitor-manager-private.h
@@ -116,8 +116,6 @@ struct _MetaMonitorManager
   gboolean in_init;
   unsigned int serial;
 
-  MetaPowerSave power_save_mode;
-
   MetaLogicalMonitorLayoutMode layout_mode;
 
   int screen_width;
@@ -192,6 +190,8 @@ struct _MetaMonitorManagerClass
   GBytes* (*read_edid) (MetaMonitorManager *,
                         MetaOutput         *);
 
+  void (*read_current_state) (MetaMonitorManager *);
+
   void (*ensure_initial_config) (MetaMonitorManager *);
 
   gboolean (*apply_monitors_config) (MetaMonitorManager      *,
@@ -305,6 +305,11 @@ void                meta_monitor_manager_get_screen_size   (MetaMonitorManager *
                                                             int                *width,
                                                             int                *height);
 
+MetaPowerSave       meta_monitor_manager_get_power_save_mode (MetaMonitorManager *manager);
+
+void                meta_monitor_manager_power_save_mode_changed (MetaMonitorManager *manager,
+                                                                  MetaPowerSave       mode);
+
 void                meta_monitor_manager_confirm_configuration (MetaMonitorManager *manager,
                                                                 gboolean            ok);
 
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index c4ed24522..2d898c757 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -95,7 +95,13 @@ static gfloat transform_matrices[][6] = {
 
 static int signals[SIGNALS_LAST];
 
-G_DEFINE_TYPE (MetaMonitorManager, meta_monitor_manager, G_TYPE_OBJECT)
+typedef struct _MetaMonitorManagerPrivate
+{
+  MetaPowerSave power_save_mode;
+} MetaMonitorManagerPrivate;
+
+G_DEFINE_TYPE_WITH_PRIVATE (MetaMonitorManager, meta_monitor_manager,
+                            G_TYPE_OBJECT)
 
 static void initialize_dbus_interface (MetaMonitorManager *manager);
 static void monitor_manager_setup_dbus_config_handlers (MetaMonitorManager *manager);
@@ -107,6 +113,9 @@ meta_monitor_manager_is_config_complete (MetaMonitorManager *manager,
 static MetaMonitor *
 meta_monitor_manager_get_active_monitor (MetaMonitorManager *manager);
 
+static void
+meta_monitor_manager_real_read_current_state (MetaMonitorManager *manager);
+
 MetaBackend *
 meta_monitor_manager_get_backend (MetaMonitorManager *manager)
 {
@@ -329,11 +338,24 @@ meta_monitor_manager_rebuild_logical_monitors_derived (MetaMonitorManager *manag
                                                     primary_logical_monitor);
 }
 
+void
+meta_monitor_manager_power_save_mode_changed (MetaMonitorManager *manager,
+                                              MetaPowerSave       mode)
+{
+  MetaMonitorManagerPrivate *priv =
+    meta_monitor_manager_get_instance_private (manager);
+
+  priv->power_save_mode = mode;
+  g_signal_emit (manager, signals[POWER_SAVE_MODE_CHANGED], 0);
+}
+
 static void
 power_save_mode_changed (MetaMonitorManager *manager,
                          GParamSpec         *pspec,
                          gpointer            user_data)
 {
+  MetaMonitorManagerPrivate *priv =
+    meta_monitor_manager_get_instance_private (manager);
   MetaMonitorManagerClass *klass;
   int mode = meta_dbus_display_config_get_power_save_mode (manager->display_config);
 
@@ -341,7 +363,7 @@ power_save_mode_changed (MetaMonitorManager *manager,
     return;
 
   /* If DPMS is unsupported, force the property back. */
-  if (manager->power_save_mode == META_POWER_SAVE_UNSUPPORTED)
+  if (priv->power_save_mode == META_POWER_SAVE_UNSUPPORTED)
     {
       meta_dbus_display_config_set_power_save_mode (manager->display_config, META_POWER_SAVE_UNSUPPORTED);
       return;
@@ -351,9 +373,7 @@ power_save_mode_changed (MetaMonitorManager *manager,
   if (klass->set_power_save_mode)
     klass->set_power_save_mode (manager, mode);
 
-  manager->power_save_mode = mode;
-
-  g_signal_emit (manager, signals[POWER_SAVE_MODE_CHANGED], 0);
+  meta_monitor_manager_power_save_mode_changed (manager, mode);
 }
 
 void
@@ -855,6 +875,7 @@ meta_monitor_manager_class_init (MetaMonitorManagerClass *klass)
   object_class->set_property = meta_monitor_manager_set_property;
 
   klass->read_edid = meta_monitor_manager_real_read_edid;
+  klass->read_current_state = meta_monitor_manager_real_read_current_state;
 
   signals[MONITORS_CHANGED] =
     g_signal_new ("monitors-changed",
@@ -2684,6 +2705,15 @@ meta_monitor_manager_get_screen_size (MetaMonitorManager *manager,
   *height = manager->screen_height;
 }
 
+MetaPowerSave
+meta_monitor_manager_get_power_save_mode (MetaMonitorManager *manager)
+{
+  MetaMonitorManagerPrivate *priv =
+    meta_monitor_manager_get_instance_private (manager);
+
+  return priv->power_save_mode;
+}
+
 static void
 rebuild_monitors (MetaMonitorManager *manager)
 {
@@ -2760,8 +2790,8 @@ meta_monitor_manager_is_transform_handled (MetaMonitorManager  *manager,
   return manager_class->is_transform_handled (manager, crtc, transform);
 }
 
-void
-meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
+static void
+meta_monitor_manager_real_read_current_state (MetaMonitorManager *manager)
 {
   GList *l;
 
@@ -2782,6 +2812,15 @@ meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
   rebuild_monitors (manager);
 }
 
+void
+meta_monitor_manager_read_current_state (MetaMonitorManager *manager)
+{
+  MetaMonitorManagerClass *manager_class =
+    META_MONITOR_MANAGER_GET_CLASS (manager);
+
+  manager_class->read_current_state (manager);
+}
+
 static void
 meta_monitor_manager_notify_monitors_changed (MetaMonitorManager *manager)
 {
diff --git a/src/backends/native/meta-gpu-kms.c b/src/backends/native/meta-gpu-kms.c
index d924466f8..c569b948e 100644
--- a/src/backends/native/meta-gpu-kms.c
+++ b/src/backends/native/meta-gpu-kms.c
@@ -210,7 +210,7 @@ meta_gpu_kms_is_crtc_active (MetaGpuKms *gpu_kms,
 
   g_assert (meta_crtc_get_gpu (crtc) == META_GPU (gpu_kms));
 
-  if (monitor_manager->power_save_mode != META_POWER_SAVE_ON)
+  if (meta_monitor_manager_get_power_save_mode (monitor_manager))
     return FALSE;
 
   connected_crtc_found = FALSE;
@@ -273,7 +273,8 @@ meta_gpu_kms_flip_crtc (MetaGpuKms  *gpu_kms,
   int ret = -1;
 
   g_assert (meta_crtc_get_gpu (crtc) == gpu);
-  g_assert (monitor_manager->power_save_mode == META_POWER_SAVE_ON);
+  g_assert (meta_monitor_manager_get_power_save_mode (monitor_manager) ==
+            META_POWER_SAVE_ON);
 
   get_crtc_drm_connectors (gpu, crtc, &connectors, &n_connectors);
   g_assert (n_connectors > 0);
@@ -836,8 +837,6 @@ meta_gpu_kms_read_current (MetaGpu  *gpu,
                            GError  **error)
 {
   MetaGpuKms *gpu_kms = META_GPU_KMS (gpu);
-  MetaMonitorManager *monitor_manager =
-    meta_gpu_get_monitor_manager (gpu);
   MetaKmsResources resources;
   g_autoptr (GError) local_error = NULL;
 
@@ -855,8 +854,6 @@ meta_gpu_kms_read_current (MetaGpu  *gpu,
   gpu_kms->max_buffer_width = resources.resources->max_width;
   gpu_kms->max_buffer_height = resources.resources->max_height;
 
-  monitor_manager->power_save_mode = META_POWER_SAVE_ON;
-
   /* Note: we must not free the public structures (output, crtc, monitor
      mode and monitor info) here, they must be kept alive until the API
      users are done with them after we emit monitors-changed, and thus
diff --git a/src/backends/native/meta-monitor-manager-kms.c b/src/backends/native/meta-monitor-manager-kms.c
index c9a3cabe2..9a0364441 100644
--- a/src/backends/native/meta-monitor-manager-kms.c
+++ b/src/backends/native/meta-monitor-manager-kms.c
@@ -108,6 +108,21 @@ meta_monitor_manager_kms_read_edid (MetaMonitorManager *manager,
   return meta_output_kms_read_edid (output);
 }
 
+static void
+meta_monitor_manager_kms_read_current_state (MetaMonitorManager *manager)
+{
+  MetaMonitorManagerClass *parent_class =
+    META_MONITOR_MANAGER_CLASS (meta_monitor_manager_kms_parent_class);
+  MetaPowerSave power_save_mode;
+
+  power_save_mode = meta_monitor_manager_get_power_save_mode (manager);
+  if (power_save_mode != META_POWER_SAVE_ON)
+    meta_monitor_manager_power_save_mode_changed (manager,
+                                                  META_POWER_SAVE_ON);
+
+  parent_class->read_current_state (manager);
+}
+
 static void
 meta_monitor_manager_kms_set_power_save_mode (MetaMonitorManager *manager,
                                               MetaPowerSave       mode)
@@ -755,6 +770,7 @@ meta_monitor_manager_kms_class_init (MetaMonitorManagerKmsClass *klass)
   object_class->dispose = meta_monitor_manager_kms_dispose;
 
   manager_class->read_edid = meta_monitor_manager_kms_read_edid;
+  manager_class->read_current_state = meta_monitor_manager_kms_read_current_state;
   manager_class->ensure_initial_config = meta_monitor_manager_kms_ensure_initial_config;
   manager_class->apply_monitors_config = meta_monitor_manager_kms_apply_monitors_config;
   manager_class->set_power_save_mode = meta_monitor_manager_kms_set_power_save_mode;
diff --git a/src/backends/x11/meta-gpu-xrandr.c b/src/backends/x11/meta-gpu-xrandr.c
index 14b46d530..3e8a7318d 100644
--- a/src/backends/x11/meta-gpu-xrandr.c
+++ b/src/backends/x11/meta-gpu-xrandr.c
@@ -97,8 +97,6 @@ meta_gpu_xrandr_read_current (MetaGpu  *gpu,
   GList *l;
   int min_width, min_height;
   Screen *screen;
-  BOOL dpms_capable, dpms_enabled;
-  CARD16 dpms_state;
   GList *outputs = NULL;
   GList *modes = NULL;
   GList *crtcs = NULL;
@@ -107,36 +105,6 @@ meta_gpu_xrandr_read_current (MetaGpu  *gpu,
     XRRFreeScreenResources (gpu_xrandr->resources);
   gpu_xrandr->resources = NULL;
 
-  dpms_capable = DPMSCapable (xdisplay);
-
-  if (dpms_capable &&
-      DPMSInfo (xdisplay, &dpms_state, &dpms_enabled) &&
-      dpms_enabled)
-    {
-      switch (dpms_state)
-        {
-        case DPMSModeOn:
-          monitor_manager->power_save_mode = META_POWER_SAVE_ON;
-          break;
-        case DPMSModeStandby:
-          monitor_manager->power_save_mode = META_POWER_SAVE_STANDBY;
-          break;
-        case DPMSModeSuspend:
-          monitor_manager->power_save_mode = META_POWER_SAVE_SUSPEND;
-          break;
-        case DPMSModeOff:
-          monitor_manager->power_save_mode = META_POWER_SAVE_OFF;
-          break;
-        default:
-          monitor_manager->power_save_mode = META_POWER_SAVE_UNSUPPORTED;
-          break;
-        }
-    }
-  else
-    {
-      monitor_manager->power_save_mode = META_POWER_SAVE_UNSUPPORTED;
-    }
-
   XRRGetScreenSizeRange (xdisplay, DefaultRootWindow (xdisplay),
                          &min_width,
                          &min_height,
diff --git a/src/backends/x11/meta-monitor-manager-xrandr.c b/src/backends/x11/meta-monitor-manager-xrandr.c
index 784bbde7c..45c81f4eb 100644
--- a/src/backends/x11/meta-monitor-manager-xrandr.c
+++ b/src/backends/x11/meta-monitor-manager-xrandr.c
@@ -121,6 +121,50 @@ meta_monitor_manager_xrandr_read_edid (MetaMonitorManager *manager,
   return meta_output_xrandr_read_edid (output);
 }
 
+static MetaPowerSave
+x11_dpms_state_to_power_save (CARD16 dpms_state)
+{
+  switch (dpms_state)
+    {
+    case DPMSModeOn:
+      return META_POWER_SAVE_ON;
+    case DPMSModeStandby:
+      return META_POWER_SAVE_STANDBY;
+    case DPMSModeSuspend:
+      return META_POWER_SAVE_SUSPEND;
+    case DPMSModeOff:
+      return META_POWER_SAVE_OFF;
+    default:
+      return META_POWER_SAVE_UNSUPPORTED;
+    }
+}
+
+static void
+meta_monitor_manager_xrandr_read_current_state (MetaMonitorManager *manager)
+{
+  MetaMonitorManagerXrandr *manager_xrandr =
+    META_MONITOR_MANAGER_XRANDR (manager);
+  MetaMonitorManagerClass *parent_class =
+    META_MONITOR_MANAGER_CLASS (meta_monitor_manager_xrandr_parent_class);
+  Display *xdisplay = meta_monitor_manager_xrandr_get_xdisplay (manager_xrandr);
+  BOOL dpms_capable, dpms_enabled;
+  CARD16 dpms_state;
+  MetaPowerSave power_save_mode;
+
+  dpms_capable = DPMSCapable (xdisplay);
+
+  if (dpms_capable &&
+      DPMSInfo (xdisplay, &dpms_state, &dpms_enabled) &&
+      dpms_enabled)
+    power_save_mode = x11_dpms_state_to_power_save (dpms_state);
+  else
+    power_save_mode = META_POWER_SAVE_UNSUPPORTED;
+
+  meta_monitor_manager_power_save_mode_changed (manager, power_save_mode);
+
+  parent_class->read_current_state (manager);
+}
+
 static void
 meta_monitor_manager_xrandr_set_power_save_mode (MetaMonitorManager *manager,
                                                 MetaPowerSave       mode)
@@ -1046,6 +1090,7 @@ meta_monitor_manager_xrandr_class_init (MetaMonitorManagerXrandrClass *klass)
   object_class->constructed = meta_monitor_manager_xrandr_constructed;
 
   manager_class->read_edid = meta_monitor_manager_xrandr_read_edid;
+  manager_class->read_current_state = meta_monitor_manager_xrandr_read_current_state;
   manager_class->ensure_initial_config = meta_monitor_manager_xrandr_ensure_initial_config;
   manager_class->apply_monitors_config = meta_monitor_manager_xrandr_apply_monitors_config;
   manager_class->set_power_save_mode = meta_monitor_manager_xrandr_set_power_save_mode;