[gnome-control-center/wip/benzea/ap-list-cpu-usage] network: Move AP list population into an idle handler

[Benjamin Berg <bberg src gnome org>]

commit a0a2d4bad9829579f5c2d3450e6e7b23456afabc
Author: Benjamin Berg <bberg redhat com>
Date:   Sun Nov 11 21:30:18 2018 +0100

    network: Move AP list population into an idle handler
    
    The AP list needs to be updated every time APs are added or removed.
    However, such addition and removal generally happens in bulk (i.e. scan
    results coming in) and doing so for every AP is wasteful.
    
    So update the widget from an idle handler instead of updating it
    immediately from the signal handler.
    
    Fixes #152

 panels/network/net-device-wifi.c | 39 +++++++++++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 6 deletions(-)
---
diff --git a/panels/network/net-device-wifi.c b/panels/network/net-device-wifi.c
index 4290ac79a..315e39abd 100644
--- a/panels/network/net-device-wifi.c
+++ b/panels/network/net-device-wifi.c
@@ -51,7 +51,7 @@ typedef enum {
 
 static void nm_device_wifi_refresh_ui (NetDeviceWifi *device_wifi);
 static void show_wifi_list (NetDeviceWifi *device_wifi);
-static void populate_ap_list (NetDeviceWifi *device_wifi);
+static void queue_populate_ap_list (NetDeviceWifi *device_wifi);
 static void show_hotspot_ui (NetDeviceWifi *device_wifi);
 
 struct _NetDeviceWifiPrivate
@@ -64,6 +64,7 @@ struct _NetDeviceWifiPrivate
         gchar                   *selected_connection_id;
         gchar                   *selected_ap_id;
         guint                    scan_id;
+        guint                    populate_id;
         GCancellable            *cancellable;
 };
 
@@ -299,7 +300,7 @@ net_device_wifi_access_point_added (NMDeviceWifi *nm_device_wifi,
 {
         NetDeviceWifi *device_wifi = NET_DEVICE_WIFI (user_data);
 
-        populate_ap_list (device_wifi);
+        queue_populate_ap_list (device_wifi);
         nm_device_wifi_connect_access_points (nm_device_wifi, device_wifi);
 }
 
@@ -310,7 +311,7 @@ net_device_wifi_access_point_removed (NMDeviceWifi *nm_device_wifi,
 {
         NetDeviceWifi *device_wifi = NET_DEVICE_WIFI (user_data);
 
-        populate_ap_list (device_wifi);
+        queue_populate_ap_list (device_wifi);
 }
 
 static void
@@ -708,7 +709,7 @@ nm_device_wifi_refresh_ui (NetDeviceWifi *device_wifi)
 
         /* update list of APs */
         show_wifi_list (device_wifi);
-        populate_ap_list (device_wifi);
+        queue_populate_ap_list (device_wifi);
 }
 
 static void
@@ -1520,7 +1521,7 @@ client_connection_added_cb (NMClient           *client,
                 return;
         }
 
-        populate_ap_list (device_wifi);
+        queue_populate_ap_list (device_wifi);
         show_wifi_list (device_wifi);
 }
 
@@ -1615,6 +1616,10 @@ net_device_wifi_finalize (GObject *object)
         NetDeviceWifi *device_wifi = NET_DEVICE_WIFI (object);
         NetDeviceWifiPrivate *priv = device_wifi->priv;
 
+        if (device_wifi->populate_id) {
+                g_source_remove (device_wifi->populate_id);
+                device_wifi->populate_id = 0;
+        }
         if (priv->cancellable) {
                 g_cancellable_cancel (priv->cancellable);
                 g_clear_object (&priv->cancellable);
@@ -1687,7 +1692,7 @@ really_forgotten (GObject            *source_object,
         }
 
         /* remove the entry from the list */
-        populate_ap_list (user_data);
+        queue_populate_ap_list (user_data);
 }
 
 static void
@@ -2220,6 +2225,28 @@ populate_ap_list (NetDeviceWifi *device_wifi)
         g_ptr_array_free (aps_unique, TRUE);
 }
 
+static gboolean
+populate_ap_list_idle_cb (NetDeviceWifi *device_wifi)
+{
+        populate_ap_list (device_wifi);
+
+        device_wifi->populate_id = 0;
+        return G_SOURCE_REMOVE;
+}
+
+static void
+queue_populate_ap_list (NetDeviceWifi *device_wifi)
+{
+        if (device_wifi->populate_id)
+                return;
+
+        /* Using the default idle could cause higher CPU usage. */
+        device_wifi->populate_id = g_idle_add_full (G_PRIORITY_DEFAULT,
+                                                    (GSourceFunc) populate_ap_list_idle_cb,
+                                                    device_wifi,
+                                                    NULL);
+}
+
 static void
 ap_activated (GtkListBox *list, GtkListBoxRow *row, NetDeviceWifi *device_wifi)
 {