gio/gdbusnameowning.c

   1 /* GDBus - GLib D-Bus Library
   2  *
   3  * Copyright (C) 2008-2009 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 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, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: David Zeuthen <davidz@redhat.com>
  21  */
  22
  23 #include "config.h"
  24
  25 #include <stdlib.h>
  26
  27 #include "gdbusutils.h"
  28 #include "gdbusnameowning.h"
  29 #include "gdbuserror.h"
  30 #include "gdbusprivate.h"
  31 #include "gdbusconnection.h"
  32
  33 #include "glibintl.h"
  34
  35 /**
  36  * SECTION:gdbusnameowning
  37  * @title: Owning Bus Names
  38  * @short_description: Simple API for owning bus names
  39  * @include: gio/gio.h
  40  *
  41  * Convenience API for owning bus names.
  42  *
  43  * <example id="gdbus-owning-names"><title>Simple application owning a name</title><programlisting><xi:include xmlns:xi="http://www.w3.org/2001/XInclude" parse="text" href="../../../../gio/tests/gdbus-example-own-name.c"><xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback></xi:include></programlisting></example>
  44  */
  45
  46 G_LOCK_DEFINE_STATIC (lock);
  47
  48 /* ---------------------------------------------------------------------------------------------------- */
  49
  50 typedef enum
  51 {
  52   PREVIOUS_CALL_NONE = 0,
  53   PREVIOUS_CALL_ACQUIRED,
  54   PREVIOUS_CALL_LOST,
  55 } PreviousCall;
  56
  57 typedef struct
  58 {
  59   volatile gint             ref_count;
  60   guint                     id;
  61   GBusNameOwnerFlags        flags;
  62   gchar                    *name;
  63   GBusAcquiredCallback      bus_acquired_handler;
  64   GBusNameAcquiredCallback  name_acquired_handler;
  65   GBusNameLostCallback      name_lost_handler;
  66   gpointer                  user_data;
  67   GDestroyNotify            user_data_free_func;
  68   GMainContext             *main_context;
  69
  70   PreviousCall              previous_call;
  71
  72   GDBusConnection          *connection;
  73   gulong                    disconnected_signal_handler_id;
  74   guint                     name_acquired_subscription_id;
  75   guint                     name_lost_subscription_id;
  76
  77   gboolean                  cancelled;
  78
  79   gboolean                  needs_release;
  80 } Client;
  81
  82 static guint next_global_id = 1;
  83 static GHashTable *map_id_to_client = NULL;
  84
  85
  86 static Client *
  87 client_ref (Client *client)
  88 {
  89   g_atomic_int_inc (&client->ref_count);
  90   return client;
  91 }
  92
  93 static void
  94 client_unref (Client *client)
  95 {
  96   if (g_atomic_int_dec_and_test (&client->ref_count))
  97     {
  98       if (client->connection != NULL)
  99         {
 100           if (client->disconnected_signal_handler_id > 0)
 101             g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 102           if (client->name_acquired_subscription_id > 0)
 103             g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 104           if (client->name_lost_subscription_id > 0)
 105             g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 106           g_object_unref (client->connection);
 107         }
 108       if (client->main_context != NULL)
 109         g_main_context_unref (client->main_context);
 110       g_free (client->name);
 111       if (client->user_data_free_func != NULL)
 112         client->user_data_free_func (client->user_data);
 113       g_free (client);
 114     }
 115 }
 116
 117 /* ---------------------------------------------------------------------------------------------------- */
 118
 119
 120 typedef enum
 121 {
 122   CALL_TYPE_NAME_ACQUIRED,
 123   CALL_TYPE_NAME_LOST
 124 } CallType;
 125
 126 typedef struct
 127 {
 128   Client *client;
 129
 130   /* keep this separate because client->connection may
 131    * be set to NULL after scheduling the call
 132    */
 133   GDBusConnection *connection;
 134
 135   /* set to TRUE to call acquired */
 136   CallType call_type;
 137 } CallHandlerData;
 138
 139 static void
 140 call_handler_data_free (CallHandlerData *data)
 141 {
 142   if (data->connection != NULL)
 143     g_object_unref (data->connection);
 144   client_unref (data->client);
 145   g_free (data);
 146 }
 147
 148 static void
 149 actually_do_call (Client *client, GDBusConnection *connection, CallType call_type)
 150 {
 151   switch (call_type)
 152     {
 153     case CALL_TYPE_NAME_ACQUIRED:
 154       if (client->name_acquired_handler != NULL)
 155         {
 156           client->name_acquired_handler (connection,
 157                                          client->name,
 158                                          client->user_data);
 159         }
 160       break;
 161
 162     case CALL_TYPE_NAME_LOST:
 163       if (client->name_lost_handler != NULL)
 164         {
 165           client->name_lost_handler (connection,
 166                                      client->name,
 167                                      client->user_data);
 168         }
 169       break;
 170
 171     default:
 172       g_assert_not_reached ();
 173       break;
 174     }
 175 }
 176
 177 static gboolean
 178 call_in_idle_cb (gpointer _data)
 179 {
 180   CallHandlerData *data = _data;
 181   actually_do_call (data->client, data->connection, data->call_type);
 182   return FALSE;
 183 }
 184
 185 static void
 186 schedule_call_in_idle (Client *client, CallType  call_type)
 187 {
 188   CallHandlerData *data;
 189   GSource *idle_source;
 190
 191   data = g_new0 (CallHandlerData, 1);
 192   data->client = client_ref (client);
 193   data->connection = client->connection != NULL ? g_object_ref (client->connection) : NULL;
 194   data->call_type = call_type;
 195
 196   idle_source = g_idle_source_new ();
 197   g_source_set_priority (idle_source, G_PRIORITY_HIGH);
 198   g_source_set_callback (idle_source,
 199                          call_in_idle_cb,
 200                          data,
 201                          (GDestroyNotify) call_handler_data_free);
 202   g_source_attach (idle_source, client->main_context);
 203   g_source_unref (idle_source);
 204 }
 205
 206 static void
 207 do_call (Client *client, CallType call_type)
 208 {
 209   /* only schedule in idle if we're not in the right thread */
 210   if (g_main_context_get_thread_default () != client->main_context)
 211     schedule_call_in_idle (client, call_type);
 212   else
 213     actually_do_call (client, client->connection, call_type);
 214 }
 215
 216 static void
 217 call_acquired_handler (Client *client)
 218 {
 219   if (client->previous_call != PREVIOUS_CALL_ACQUIRED)
 220     {
 221       client->previous_call = PREVIOUS_CALL_ACQUIRED;
 222       if (!client->cancelled)
 223         {
 224           do_call (client, CALL_TYPE_NAME_ACQUIRED);
 225         }
 226     }
 227 }
 228
 229 static void
 230 call_lost_handler (Client  *client)
 231 {
 232   if (client->previous_call != PREVIOUS_CALL_LOST)
 233     {
 234       client->previous_call = PREVIOUS_CALL_LOST;
 235       if (!client->cancelled)
 236         {
 237           do_call (client, CALL_TYPE_NAME_LOST);
 238         }
 239     }
 240 }
 241
 242 /* ---------------------------------------------------------------------------------------------------- */
 243
 244 static void
 245 on_name_lost_or_acquired (GDBusConnection  *connection,
 246                           const gchar      *sender_name,
 247                           const gchar      *object_path,
 248                           const gchar      *interface_name,
 249                           const gchar      *signal_name,
 250                           GVariant         *parameters,
 251                           gpointer          user_data)
 252 {
 253   Client *client = user_data;
 254   const gchar *name;
 255
 256   if (g_strcmp0 (object_path, "/org/freedesktop/DBus") != 0 ||
 257       g_strcmp0 (interface_name, "org.freedesktop.DBus") != 0 ||
 258       g_strcmp0 (sender_name, "org.freedesktop.DBus") != 0)
 259     goto out;
 260
 261   if (g_strcmp0 (signal_name, "NameLost") == 0)
 262     {
 263       g_variant_get (parameters, "(s)", &name);
 264       if (g_strcmp0 (name, client->name) == 0)
 265         {
 266           call_lost_handler (client);
 267         }
 268     }
 269   else if (g_strcmp0 (signal_name, "NameAcquired") == 0)
 270     {
 271       g_variant_get (parameters, "(s)", &name);
 272       if (g_strcmp0 (name, client->name) == 0)
 273         {
 274           call_acquired_handler (client);
 275         }
 276     }
 277  out:
 278   ;
 279 }
 280
 281 /* ---------------------------------------------------------------------------------------------------- */
 282
 283 static void
 284 request_name_cb (GObject      *source_object,
 285                  GAsyncResult *res,
 286                  gpointer      user_data)
 287 {
 288   Client *client = user_data;
 289   GVariant *result;
 290   guint32 request_name_reply;
 291   gboolean subscribe;
 292
 293   request_name_reply = 0;
 294   result = NULL;
 295
 296   result = g_dbus_connection_invoke_method_finish (client->connection,
 297                                                    res,
 298                                                    NULL);
 299   if (result != NULL)
 300     {
 301       g_variant_get (result, "(u)", &request_name_reply);
 302       g_variant_unref (result);
 303     }
 304
 305   subscribe = FALSE;
 306
 307   switch (request_name_reply)
 308     {
 309     case 1: /* DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER */
 310       /* We got the name - now listen for NameLost and NameAcquired */
 311       call_acquired_handler (client);
 312       subscribe = TRUE;
 313       client->needs_release = TRUE;
 314       break;
 315
 316     case 2: /* DBUS_REQUEST_NAME_REPLY_IN_QUEUE */
 317       /* Waiting in line - listen for NameLost and NameAcquired */
 318       call_lost_handler (client);
 319       subscribe = TRUE;
 320       client->needs_release = TRUE;
 321       break;
 322
 323     default:
 324       /* assume we couldn't get the name - explicit fallthrough */
 325     case 3: /* DBUS_REQUEST_NAME_REPLY_EXISTS */
 326     case 4: /* DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER */
 327       /* Some other part of the process is already owning the name */
 328       call_lost_handler (client);
 329       break;
 330     }
 331
 332   if (subscribe)
 333     {
 334       /* start listening to NameLost and NameAcquired messages */
 335       client->name_lost_subscription_id =
 336         g_dbus_connection_signal_subscribe (client->connection,
 337                                             "org.freedesktop.DBus",
 338                                             "org.freedesktop.DBus",
 339                                             "NameLost",
 340                                             "/org/freedesktop/DBus",
 341                                             client->name,
 342                                             on_name_lost_or_acquired,
 343                                             client,
 344                                             NULL);
 345       client->name_acquired_subscription_id =
 346         g_dbus_connection_signal_subscribe (client->connection,
 347                                             "org.freedesktop.DBus",
 348                                             "org.freedesktop.DBus",
 349                                             "NameAcquired",
 350                                             "/org/freedesktop/DBus",
 351                                             client->name,
 352                                             on_name_lost_or_acquired,
 353                                             client,
 354                                             NULL);
 355     }
 356
 357   client_unref (client);
 358 }
 359
 360 /* ---------------------------------------------------------------------------------------------------- */
 361
 362 static void
 363 on_connection_disconnected (GDBusConnection *connection,
 364                             gboolean         remote_peer_vanished,
 365                             GError          *error,
 366                             gpointer         user_data)
 367 {
 368   Client *client = user_data;
 369
 370   if (client->disconnected_signal_handler_id > 0)
 371     g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 372   if (client->name_acquired_subscription_id > 0)
 373     g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 374   if (client->name_lost_subscription_id > 0)
 375     g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 376   g_object_unref (client->connection);
 377   client->disconnected_signal_handler_id = 0;
 378   client->name_acquired_subscription_id = 0;
 379   client->name_lost_subscription_id = 0;
 380   client->connection = NULL;
 381
 382   call_lost_handler (client);
 383 }
 384
 385 /* ---------------------------------------------------------------------------------------------------- */
 386
 387 static void
 388 has_connection (Client *client)
 389 {
 390   /* listen for disconnection */
 391   client->disconnected_signal_handler_id = g_signal_connect (client->connection,
 392                                                              "closed",
 393                                                              G_CALLBACK (on_connection_disconnected),
 394                                                              client);
 395
 396   /* attempt to acquire the name */
 397   g_dbus_connection_invoke_method (client->connection,
 398                                    "org.freedesktop.DBus",  /* bus name */
 399                                    "/org/freedesktop/DBus", /* object path */
 400                                    "org.freedesktop.DBus",  /* interface name */
 401                                    "RequestName",           /* method name */
 402                                    g_variant_new ("(su)",
 403                                                   client->name,
 404                                                   client->flags),
 405                                    G_DBUS_INVOKE_METHOD_FLAGS_NONE,
 406                                    -1,
 407                                    NULL,
 408                                    (GAsyncReadyCallback) request_name_cb,
 409                                    client_ref (client));
 410 }
 411
 412
 413 static void
 414 connection_get_cb (GObject      *source_object,
 415                    GAsyncResult *res,
 416                    gpointer      user_data)
 417 {
 418   Client *client = user_data;
 419
 420   client->connection = g_bus_get_finish (res, NULL);
 421   if (client->connection == NULL)
 422     {
 423       call_lost_handler (client);
 424       goto out;
 425     }
 426
 427   /* No need to schedule this in idle as we're already in the thread
 428    * that the user called g_bus_own_name() from. This is because
 429    * g_bus_get() guarantees that.
 430    *
 431    * Also, we need to ensure that the handler is invoked *before*
 432    * we call RequestName(). Otherwise there is a race.
 433    */
 434   if (client->bus_acquired_handler != NULL)
 435     {
 436       client->bus_acquired_handler (client->connection,
 437                                     client->name,
 438                                     client->user_data);
 439     }
 440
 441   has_connection (client);
 442
 443  out:
 444   client_unref (client);
 445 }
 446
 447 /* ---------------------------------------------------------------------------------------------------- */
 448
 449 /**
 450  * g_bus_own_name_on_connection:
 451  * @connection: A #GDBusConnection that is not closed.
 452  * @name: The well-known name to own.
 453  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 454  * @name_acquired_handler: Handler to invoke when @name is acquired or %NULL.
 455  * @name_lost_handler: Handler to invoke when @name is lost or %NULL.
 456  * @user_data: User data to pass to handlers.
 457  * @user_data_free_func: Function for freeing @user_data or %NULL.
 458  *
 459  * Like g_bus_own_name() but takes a #GDBusConnection instead of a
 460  * #GBusType.
 461  *
 462  * Returns: An identifier (never 0) that an be used with
 463  * g_bus_unown_name() to stop owning the name.
 464  *
 465  * Since: 2.26
 466  */
 467 guint
 468 g_bus_own_name_on_connection (GDBusConnection          *connection,
 469                               const gchar              *name,
 470                               GBusNameOwnerFlags        flags,
 471                               GBusNameAcquiredCallback  name_acquired_handler,
 472                               GBusNameLostCallback      name_lost_handler,
 473                               gpointer                  user_data,
 474                               GDestroyNotify            user_data_free_func)
 475 {
 476   Client *client;
 477
 478   g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
 479   g_return_val_if_fail (!g_dbus_connection_is_closed (connection), 0);
 480   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 481
 482   G_LOCK (lock);
 483
 484   client = g_new0 (Client, 1);
 485   client->ref_count = 1;
 486   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 487   client->name = g_strdup (name);
 488   client->flags = flags;
 489   client->name_acquired_handler = name_acquired_handler;
 490   client->name_lost_handler = name_lost_handler;
 491   client->user_data = user_data;
 492   client->user_data_free_func = user_data_free_func;
 493   client->main_context = g_main_context_get_thread_default ();
 494   if (client->main_context != NULL)
 495     g_main_context_ref (client->main_context);
 496
 497   client->connection = g_object_ref (connection);
 498
 499   if (map_id_to_client == NULL)
 500     {
 501       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 502     }
 503   g_hash_table_insert (map_id_to_client,
 504                        GUINT_TO_POINTER (client->id),
 505                        client);
 506
 507   G_UNLOCK (lock);
 508
 509   has_connection (client);
 510
 511   return client->id;
 512 }
 513
 514 /**
 515  * g_bus_own_name:
 516  * @bus_type: The type of bus to own a name on.
 517  * @name: The well-known name to own.
 518  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 519  * @bus_acquired_handler: Handler to invoke when connected to the bus of type @bus_type or %NULL.
 520  * @name_acquired_handler: Handler to invoke when @name is acquired or %NULL.
 521  * @name_lost_handler: Handler to invoke when @name is lost or %NULL.
 522  * @user_data: User data to pass to handlers.
 523  * @user_data_free_func: Function for freeing @user_data or %NULL.
 524  *
 525  * Starts acquiring @name on the bus specified by @bus_type and calls
 526  * @name_acquired_handler and @name_lost_handler when the name is
 527  * acquired respectively lost. Callbacks will be invoked in the <link
 528  * linkend="g-main-context-push-thread-default">thread-default main
 529  * loop</link> of the thread you are calling this function from.
 530  *
 531  * You are guaranteed that one of the @name_acquired_handler and @name_lost_handler
 532  * callbacks will be invoked after calling this function - there are three
 533  * possible cases:
 534  * <itemizedlist>
 535  *   <listitem><para>
 536  *     @name_lost_handler with a %NULL connection (if a connection to the bus can't be made).
 537  *   </para></listitem>
 538  *   <listitem><para>
 539  *     @bus_acquired_handler then @name_lost_handler (if the name can't be obtained)
 540  *   </para></listitem>
 541  *   <listitem><para>
 542  *     @bus_acquired_handler then @name_acquired_handler (if the name was obtained).
 543  *   </para></listitem>
 544  * </itemizedlist>
 545  * When you are done owning the name, just call g_bus_unown_name()
 546  * with the owner id this function returns.
 547  *
 548  * If the name is acquired or lost (for example another application
 549  * could acquire the name if you allow replacement or the application
 550  * currently owning the name exits), the handlers are also invoked. If the
 551  * #GDBusConnection that is used for attempting to own the name
 552  * closes, then @name_lost_handler is invoked since it is no
 553  * longer possible for other processes to access the process.
 554  *
 555  * You cannot use g_bus_own_name() several times (unless interleaved
 556  * with calls to g_bus_unown_name()) - only the first call will work.
 557  *
 558  * Another guarantee is that invocations of @name_acquired_handler
 559  * and @name_lost_handler are guaranteed to alternate; that
 560  * is, if @name_acquired_handler is invoked then you are
 561  * guaranteed that the next time one of the handlers is invoked, it
 562  * will be @name_lost_handler. The reverse is also true.
 563  *
 564  * If you plan on exporting objects (using e.g. g_dbus_connection_register_object()), note
 565  * that it is generally too late to export the objects in @name_acquired_handler. Instead,
 566  * you can do this in @bus_acquired_handler since you are guaranteed that this will
 567  * run before @name is requested from the bus.
 568  *
 569  * This behavior makes it very simple to write applications that wants
 570  * to own names and export objects, see <xref linkend="gdbus-owning-names"/>. Simply
 571  * register objects to be exported in @bus_acquired_handler and
 572  * unregister the objects (if any) in @name_lost_handler.
 573  *
 574  * Returns: An identifier (never 0) that an be used with
 575  * g_bus_unown_name() to stop owning the name.
 576  *
 577  * Since: 2.26
 578  */
 579 guint
 580 g_bus_own_name (GBusType                  bus_type,
 581                 const gchar              *name,
 582                 GBusNameOwnerFlags        flags,
 583                 GBusAcquiredCallback      bus_acquired_handler,
 584                 GBusNameAcquiredCallback  name_acquired_handler,
 585                 GBusNameLostCallback      name_lost_handler,
 586                 gpointer                  user_data,
 587                 GDestroyNotify            user_data_free_func)
 588 {
 589   Client *client;
 590
 591   g_return_val_if_fail (bus_type != G_BUS_TYPE_NONE, 0);
 592   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 593
 594   G_LOCK (lock);
 595
 596   client = g_new0 (Client, 1);
 597   client->ref_count = 1;
 598   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 599   client->name = g_strdup (name);
 600   client->flags = flags;
 601   client->bus_acquired_handler = bus_acquired_handler;
 602   client->name_acquired_handler = name_acquired_handler;
 603   client->name_lost_handler = name_lost_handler;
 604   client->user_data = user_data;
 605   client->user_data_free_func = user_data_free_func;
 606   client->main_context = g_main_context_get_thread_default ();
 607   if (client->main_context != NULL)
 608     g_main_context_ref (client->main_context);
 609
 610   if (map_id_to_client == NULL)
 611     {
 612       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 613     }
 614   g_hash_table_insert (map_id_to_client,
 615                        GUINT_TO_POINTER (client->id),
 616                        client);
 617
 618   g_bus_get (bus_type,
 619              NULL,
 620              connection_get_cb,
 621              client_ref (client));
 622
 623   G_UNLOCK (lock);
 624
 625   return client->id;
 626 }
 627
 628 /**
 629  * g_bus_unown_name:
 630  * @owner_id: An identifier obtained from g_bus_own_name()
 631  *
 632  * Stops owning a name.
 633  *
 634  * Since: 2.26
 635  */
 636 void
 637 g_bus_unown_name (guint owner_id)
 638 {
 639   Client *client;
 640
 641   g_return_if_fail (owner_id > 0);
 642
 643   client = NULL;
 644
 645   G_LOCK (lock);
 646   if (owner_id == 0 || map_id_to_client == NULL ||
 647       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (owner_id))) == NULL)
 648     {
 649       g_warning ("Invalid id %d passed to g_bus_unown_name()", owner_id);
 650       goto out;
 651     }
 652
 653   client->cancelled = TRUE;
 654   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (owner_id)));
 655
 656  out:
 657   G_UNLOCK (lock);
 658
 659   /* do callback without holding lock */
 660   if (client != NULL)
 661     {
 662       /* Release the name if needed */
 663       if (client->needs_release && client->connection != NULL)
 664         {
 665           GVariant *result;
 666           GError *error;
 667           guint32 release_name_reply;
 668
 669           /* TODO: it kinda sucks having to do a sync call to release the name - but if
 670            * we don't, then a subsequent grab of the name will make the bus daemon return
 671            * IN_QUEUE which will trigger name_lost().
 672            *
 673            * I believe this is a bug in the bus daemon.
 674            */
 675           error = NULL;
 676           result = g_dbus_connection_invoke_method_sync (client->connection,
 677                                                          "org.freedesktop.DBus",  /* bus name */
 678                                                          "/org/freedesktop/DBus", /* object path */
 679                                                          "org.freedesktop.DBus",  /* interface name */
 680                                                          "ReleaseName",           /* method name */
 681                                                          g_variant_new ("(s)", client->name),
 682                                                          G_DBUS_INVOKE_METHOD_FLAGS_NONE,
 683                                                          -1,
 684                                                          NULL,
 685                                                          &error);
 686           if (result == NULL)
 687             {
 688               g_warning ("Error releasing name %s: %s", client->name, error->message);
 689               g_error_free (error);
 690             }
 691           else
 692             {
 693               g_variant_get (result, "(u)", &release_name_reply);
 694               if (release_name_reply != 1 /* DBUS_RELEASE_NAME_REPLY_RELEASED */)
 695                 {
 696                   g_warning ("Unexpected reply %d when releasing name %s", release_name_reply, client->name);
 697                 }
 698               g_variant_unref (result);
 699             }
 700         }
 701
 702       if (client->disconnected_signal_handler_id > 0)
 703         g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 704       if (client->name_acquired_subscription_id > 0)
 705         g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 706       if (client->name_lost_subscription_id > 0)
 707         g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 708       client->disconnected_signal_handler_id = 0;
 709       client->name_acquired_subscription_id = 0;
 710       client->name_lost_subscription_id = 0;
 711       if (client->connection != NULL)
 712         {
 713           g_object_unref (client->connection);
 714           client->connection = NULL;
 715         }
 716
 717       client_unref (client);
 718     }
 719 }