gio/gmemorymonitordbus.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright 2019 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "config.h"
  20
  21 #include "gmemorymonitor.h"
  22 #include "gmemorymonitordbus.h"
  23 #include "gioerror.h"
  24 #include "ginitable.h"
  25 #include "giomodule-priv.h"
  26 #include "glibintl.h"
  27 #include "glib/gstdio.h"
  28 #include "gdbusproxy.h"
  29 #include "gdbusnamewatching.h"
  30
  31 #define G_MEMORY_MONITOR_DBUS_GET_INITABLE_IFACE(o) (G_TYPE_INSTANCE_GET_INTERFACE ((o), G_TYPE_INITABLE, GInitable))
  32
  33 static void g_memory_monitor_dbus_iface_init (GMemoryMonitorInterface *iface);
  34 static void g_memory_monitor_dbus_initable_iface_init (GInitableIface *iface);
  35
  36 struct _GMemoryMonitorDBus
  37 {
  38   GObject parent_instance;
  39
  40   guint watch_id;
  41   GDBusProxy *proxy;
  42   gulong signal_id;
  43 };
  44
  45 G_DEFINE_TYPE_WITH_CODE (GMemoryMonitorDBus, g_memory_monitor_dbus, G_TYPE_OBJECT,
  46                          G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
  47                                                 g_memory_monitor_dbus_initable_iface_init)
  48                          G_IMPLEMENT_INTERFACE (G_TYPE_MEMORY_MONITOR,
  49                                                 g_memory_monitor_dbus_iface_init)
  50                          _g_io_modules_ensure_extension_points_registered ();
  51                          g_io_extension_point_implement (G_MEMORY_MONITOR_EXTENSION_POINT_NAME,
  52                                                          g_define_type_id,
  53                                                          "dbus",
  54                                                          30))
  55
  56 static void
  57 g_memory_monitor_dbus_init (GMemoryMonitorDBus *dbus)
  58 {
  59 }
  60
  61 static void
  62 proxy_signal_cb (GDBusProxy         *proxy,
  63                  const gchar        *sender_name,
  64                  const gchar        *signal_name,
  65                  GVariant           *parameters,
  66                  GMemoryMonitorDBus *dbus)
  67 {
  68   guint8 level;
  69
  70   if (g_strcmp0 (signal_name, "LowMemoryWarning") != 0)
  71     return;
  72   if (parameters == NULL)
  73     return;
  74
  75   g_variant_get (parameters, "(y)", &level);
  76   g_signal_emit_by_name (dbus, "low-memory-warning", level);
  77 }
  78
  79 static void
  80 lmm_appeared_cb (GDBusConnection *connection,
  81                  const gchar     *name,
  82                  const gchar     *name_owner,
  83                  gpointer         user_data)
  84 {
  85   GMemoryMonitorDBus *dbus = user_data;
  86   GDBusProxy *proxy;
  87   GError *error = NULL;
  88
  89   proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
  90                                          G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
  91                                          NULL,
  92                                          "org.freedesktop.LowMemoryMonitor",
  93                                          "/org/freedesktop/LowMemoryMonitor",
  94                                          "org.freedesktop.LowMemoryMonitor",
  95                                          NULL,
  96                                          &error);
  97
  98   if (!proxy)
  99     {
 100       g_debug ("Failed to create LowMemoryMonitor D-Bus proxy: %s",
 101                error->message);
 102       g_error_free (error);
 103       return;
 104     }
 105
 106   dbus->signal_id = g_signal_connect (G_OBJECT (proxy), "g-signal",
 107                                       G_CALLBACK (proxy_signal_cb), dbus);
 108   dbus->proxy = proxy;
 109 }
 110
 111 static void
 112 lmm_vanished_cb (GDBusConnection *connection,
 113                  const gchar     *name,
 114                  gpointer         user_data)
 115 {
 116   GMemoryMonitorDBus *dbus = user_data;
 117
 118   if (dbus->proxy != NULL)
 119     g_clear_signal_handler (&dbus->signal_id, dbus->proxy);
 120   g_clear_object (&dbus->proxy);
 121 }
 122
 123 static gboolean
 124 g_memory_monitor_dbus_initable_init (GInitable     *initable,
 125                                      GCancellable  *cancellable,
 126                                      GError       **error)
 127 {
 128   GMemoryMonitorDBus *dbus = G_MEMORY_MONITOR_DBUS (initable);
 129
 130   dbus->watch_id = g_bus_watch_name (G_BUS_TYPE_SYSTEM,
 131                                      "org.freedesktop.LowMemoryMonitor",
 132                                      G_BUS_NAME_WATCHER_FLAGS_AUTO_START,
 133                                      lmm_appeared_cb,
 134                                      lmm_vanished_cb,
 135                                      dbus,
 136                                      NULL);
 137
 138   return TRUE;
 139 }
 140
 141 static void
 142 g_memory_monitor_dbus_finalize (GObject *object)
 143 {
 144   GMemoryMonitorDBus *dbus = G_MEMORY_MONITOR_DBUS (object);
 145
 146   if (dbus->proxy != NULL)
 147     g_clear_signal_handler (&dbus->signal_id, dbus->proxy);
 148   g_clear_object (&dbus->proxy);
 149   g_clear_handle_id (&dbus->watch_id, g_bus_unwatch_name);
 150
 151   G_OBJECT_CLASS (g_memory_monitor_dbus_parent_class)->finalize (object);
 152 }
 153
 154 static void
 155 g_memory_monitor_dbus_class_init (GMemoryMonitorDBusClass *nl_class)
 156 {
 157   GObjectClass *gobject_class = G_OBJECT_CLASS (nl_class);
 158
 159   gobject_class->finalize = g_memory_monitor_dbus_finalize;
 160 }
 161
 162 static void
 163 g_memory_monitor_dbus_iface_init (GMemoryMonitorInterface *monitor_iface)
 164 {
 165 }
 166
 167 static void
 168 g_memory_monitor_dbus_initable_iface_init (GInitableIface *iface)
 169 {
 170   iface->init = g_memory_monitor_dbus_initable_init;
 171 }