gio/gmemorymonitordbus.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright 2019 Red Hat, Inc.
   4  *
   5  * SPDX-License-Identifier: LGPL-2.1-or-later
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "config.h"
  22
  23 #include "gmemorymonitor.h"
  24 #include "gmemorymonitordbus.h"
  25 #include "gioerror.h"
  26 #include "ginitable.h"
  27 #include "giomodule-priv.h"
  28 #include "glibintl.h"
  29 #include "glib/gstdio.h"
  30 #include "gcancellable.h"
  31 #include "gdbusproxy.h"
  32 #include "gdbusnamewatching.h"
  33
  34 #define G_MEMORY_MONITOR_DBUS_GET_INITABLE_IFACE(o) (G_TYPE_INSTANCE_GET_INTERFACE ((o), G_TYPE_INITABLE, GInitable))
  35
  36 static void g_memory_monitor_dbus_iface_init (GMemoryMonitorInterface *iface);
  37 static void g_memory_monitor_dbus_initable_iface_init (GInitableIface *iface);
  38
  39 struct _GMemoryMonitorDBus
  40 {
  41   GObject parent_instance;
  42
  43   guint watch_id;
  44   GCancellable *cancellable;
  45   GDBusProxy *proxy;
  46   gulong signal_id;
  47 };
  48
  49 G_DEFINE_TYPE_WITH_CODE (GMemoryMonitorDBus, g_memory_monitor_dbus, G_TYPE_OBJECT,
  50                          G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
  51                                                 g_memory_monitor_dbus_initable_iface_init)
  52                          G_IMPLEMENT_INTERFACE (G_TYPE_MEMORY_MONITOR,
  53                                                 g_memory_monitor_dbus_iface_init)
  54                          _g_io_modules_ensure_extension_points_registered ();
  55                          g_io_extension_point_implement (G_MEMORY_MONITOR_EXTENSION_POINT_NAME,
  56                                                          g_define_type_id,
  57                                                          "dbus",
  58                                                          30))
  59
  60 static void
  61 g_memory_monitor_dbus_init (GMemoryMonitorDBus *dbus)
  62 {
  63 }
  64
  65 static void
  66 proxy_signal_cb (GDBusProxy         *proxy,
  67                  const gchar        *sender_name,
  68                  const gchar        *signal_name,
  69                  GVariant           *parameters,
  70                  GMemoryMonitorDBus *dbus)
  71 {
  72   guint8 level;
  73
  74   if (g_strcmp0 (signal_name, "LowMemoryWarning") != 0)
  75     return;
  76   if (parameters == NULL)
  77     return;
  78
  79   g_variant_get (parameters, "(y)", &level);
  80   g_signal_emit_by_name (dbus, "low-memory-warning", level);
  81 }
  82
  83 static void
  84 lmm_proxy_cb (GObject      *source_object,
  85               GAsyncResult *res,
  86               gpointer      user_data)
  87 {
  88   GMemoryMonitorDBus *dbus = user_data;
  89   GDBusProxy *proxy;
  90   GError *error = NULL;
  91
  92   proxy = g_dbus_proxy_new_finish (res, &error);
  93   if (!proxy)
  94     {
  95       g_debug ("Failed to create LowMemoryMonitor D-Bus proxy: %s",
  96                error->message);
  97       g_error_free (error);
  98       return;
  99     }
 100
 101   dbus->signal_id = g_signal_connect (G_OBJECT (proxy), "g-signal",
 102                                       G_CALLBACK (proxy_signal_cb), dbus);
 103   dbus->proxy = proxy;
 104
 105 }
 106
 107 static void
 108 lmm_appeared_cb (GDBusConnection *connection,
 109                  const gchar     *name,
 110                  const gchar     *name_owner,
 111                  gpointer         user_data)
 112 {
 113   GMemoryMonitorDBus *dbus = user_data;
 114
 115   g_dbus_proxy_new (connection,
 116                     G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
 117                     NULL,
 118                     "org.freedesktop.LowMemoryMonitor",
 119                     "/org/freedesktop/LowMemoryMonitor",
 120                     "org.freedesktop.LowMemoryMonitor",
 121                     dbus->cancellable,
 122                     lmm_proxy_cb,
 123                     dbus);
 124 }
 125
 126 static void
 127 lmm_vanished_cb (GDBusConnection *connection,
 128                  const gchar     *name,
 129                  gpointer         user_data)
 130 {
 131   GMemoryMonitorDBus *dbus = user_data;
 132
 133   g_clear_signal_handler (&dbus->signal_id, dbus->proxy);
 134   g_clear_object (&dbus->proxy);
 135 }
 136
 137 static gboolean
 138 g_memory_monitor_dbus_initable_init (GInitable     *initable,
 139                                      GCancellable  *cancellable,
 140                                      GError       **error)
 141 {
 142   GMemoryMonitorDBus *dbus = G_MEMORY_MONITOR_DBUS (initable);
 143
 144   dbus->cancellable = g_cancellable_new ();
 145   dbus->watch_id = g_bus_watch_name (G_BUS_TYPE_SYSTEM,
 146                                      "org.freedesktop.LowMemoryMonitor",
 147                                      G_BUS_NAME_WATCHER_FLAGS_AUTO_START,
 148                                      lmm_appeared_cb,
 149                                      lmm_vanished_cb,
 150                                      dbus,
 151                                      NULL);
 152
 153   return TRUE;
 154 }
 155
 156 static void
 157 g_memory_monitor_dbus_finalize (GObject *object)
 158 {
 159   GMemoryMonitorDBus *dbus = G_MEMORY_MONITOR_DBUS (object);
 160
 161   g_cancellable_cancel (dbus->cancellable);
 162   g_clear_object (&dbus->cancellable);
 163   g_clear_signal_handler (&dbus->signal_id, dbus->proxy);
 164   g_clear_object (&dbus->proxy);
 165   g_clear_handle_id (&dbus->watch_id, g_bus_unwatch_name);
 166
 167   G_OBJECT_CLASS (g_memory_monitor_dbus_parent_class)->finalize (object);
 168 }
 169
 170 static void
 171 g_memory_monitor_dbus_class_init (GMemoryMonitorDBusClass *nl_class)
 172 {
 173   GObjectClass *gobject_class = G_OBJECT_CLASS (nl_class);
 174
 175   gobject_class->finalize = g_memory_monitor_dbus_finalize;
 176 }
 177
 178 static void
 179 g_memory_monitor_dbus_iface_init (GMemoryMonitorInterface *monitor_iface)
 180 {
 181 }
 182
 183 static void
 184 g_memory_monitor_dbus_initable_iface_init (GInitableIface *iface)
 185 {
 186   iface->init = g_memory_monitor_dbus_initable_init;
 187 }