gio/gdbusnameowning.c

   1 /* GDBus - GLib D-Bus Library
   2  *
   3  * Copyright (C) 2008-2010 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_call_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                                             G_DBUS_SIGNAL_FLAGS_NONE,
 343                                             on_name_lost_or_acquired,
 344                                             client,
 345                                             NULL);
 346       client->name_acquired_subscription_id =
 347         g_dbus_connection_signal_subscribe (client->connection,
 348                                             "org.freedesktop.DBus",
 349                                             "org.freedesktop.DBus",
 350                                             "NameAcquired",
 351                                             "/org/freedesktop/DBus",
 352                                             client->name,
 353                                             G_DBUS_SIGNAL_FLAGS_NONE,
 354                                             on_name_lost_or_acquired,
 355                                             client,
 356                                             NULL);
 357     }
 358
 359   client_unref (client);
 360 }
 361
 362 /* ---------------------------------------------------------------------------------------------------- */
 363
 364 static void
 365 on_connection_disconnected (GDBusConnection *connection,
 366                             gboolean         remote_peer_vanished,
 367                             GError          *error,
 368                             gpointer         user_data)
 369 {
 370   Client *client = user_data;
 371
 372   if (client->disconnected_signal_handler_id > 0)
 373     g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 374   if (client->name_acquired_subscription_id > 0)
 375     g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 376   if (client->name_lost_subscription_id > 0)
 377     g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 378   g_object_unref (client->connection);
 379   client->disconnected_signal_handler_id = 0;
 380   client->name_acquired_subscription_id = 0;
 381   client->name_lost_subscription_id = 0;
 382   client->connection = NULL;
 383
 384   call_lost_handler (client);
 385 }
 386
 387 /* ---------------------------------------------------------------------------------------------------- */
 388
 389 static void
 390 has_connection (Client *client)
 391 {
 392   /* listen for disconnection */
 393   client->disconnected_signal_handler_id = g_signal_connect (client->connection,
 394                                                              "closed",
 395                                                              G_CALLBACK (on_connection_disconnected),
 396                                                              client);
 397
 398   /* attempt to acquire the name */
 399   g_dbus_connection_call (client->connection,
 400                           "org.freedesktop.DBus",  /* bus name */
 401                           "/org/freedesktop/DBus", /* object path */
 402                           "org.freedesktop.DBus",  /* interface name */
 403                           "RequestName",           /* method name */
 404                           g_variant_new ("(su)",
 405                                          client->name,
 406                                          client->flags),
 407                           G_VARIANT_TYPE ("(u)"),
 408                           G_DBUS_CALL_FLAGS_NONE,
 409                           -1,
 410                           NULL,
 411                           (GAsyncReadyCallback) request_name_cb,
 412                           client_ref (client));
 413 }
 414
 415
 416 static void
 417 connection_get_cb (GObject      *source_object,
 418                    GAsyncResult *res,
 419                    gpointer      user_data)
 420 {
 421   Client *client = user_data;
 422
 423   client->connection = g_bus_get_finish (res, NULL);
 424   if (client->connection == NULL)
 425     {
 426       call_lost_handler (client);
 427       goto out;
 428     }
 429
 430   /* No need to schedule this in idle as we're already in the thread
 431    * that the user called g_bus_own_name() from. This is because
 432    * g_bus_get() guarantees that.
 433    *
 434    * Also, we need to ensure that the handler is invoked *before*
 435    * we call RequestName(). Otherwise there is a race.
 436    */
 437   if (client->bus_acquired_handler != NULL)
 438     {
 439       client->bus_acquired_handler (client->connection,
 440                                     client->name,
 441                                     client->user_data);
 442     }
 443
 444   has_connection (client);
 445
 446  out:
 447   client_unref (client);
 448 }
 449
 450 /* ---------------------------------------------------------------------------------------------------- */
 451
 452 /**
 453  * g_bus_own_name_on_connection:
 454  * @connection: A #GDBusConnection.
 455  * @name: The well-known name to own.
 456  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 457  * @name_acquired_handler: Handler to invoke when @name is acquired or %NULL.
 458  * @name_lost_handler: Handler to invoke when @name is lost or %NULL.
 459  * @user_data: User data to pass to handlers.
 460  * @user_data_free_func: Function for freeing @user_data or %NULL.
 461  *
 462  * Like g_bus_own_name() but takes a #GDBusConnection instead of a
 463  * #GBusType.
 464  *
 465  * Returns: An identifier (never 0) that an be used with
 466  * g_bus_unown_name() to stop owning the name.
 467  *
 468  * Since: 2.26
 469  */
 470 guint
 471 g_bus_own_name_on_connection (GDBusConnection          *connection,
 472                               const gchar              *name,
 473                               GBusNameOwnerFlags        flags,
 474                               GBusNameAcquiredCallback  name_acquired_handler,
 475                               GBusNameLostCallback      name_lost_handler,
 476                               gpointer                  user_data,
 477                               GDestroyNotify            user_data_free_func)
 478 {
 479   Client *client;
 480
 481   g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
 482   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 483
 484   G_LOCK (lock);
 485
 486   client = g_new0 (Client, 1);
 487   client->ref_count = 1;
 488   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 489   client->name = g_strdup (name);
 490   client->flags = flags;
 491   client->name_acquired_handler = name_acquired_handler;
 492   client->name_lost_handler = name_lost_handler;
 493   client->user_data = user_data;
 494   client->user_data_free_func = user_data_free_func;
 495   client->main_context = g_main_context_get_thread_default ();
 496   if (client->main_context != NULL)
 497     g_main_context_ref (client->main_context);
 498
 499   client->connection = g_object_ref (connection);
 500
 501   if (map_id_to_client == NULL)
 502     {
 503       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 504     }
 505   g_hash_table_insert (map_id_to_client,
 506                        GUINT_TO_POINTER (client->id),
 507                        client);
 508
 509   G_UNLOCK (lock);
 510
 511   has_connection (client);
 512
 513   return client->id;
 514 }
 515
 516 /**
 517  * g_bus_own_name:
 518  * @bus_type: The type of bus to own a name on.
 519  * @name: The well-known name to own.
 520  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 521  * @bus_acquired_handler: Handler to invoke when connected to the bus of type @bus_type or %NULL.
 522  * @name_acquired_handler: Handler to invoke when @name is acquired or %NULL.
 523  * @name_lost_handler: Handler to invoke when @name is lost or %NULL.
 524  * @user_data: User data to pass to handlers.
 525  * @user_data_free_func: Function for freeing @user_data or %NULL.
 526  *
 527  * Starts acquiring @name on the bus specified by @bus_type and calls
 528  * @name_acquired_handler and @name_lost_handler when the name is
 529  * acquired respectively lost. Callbacks will be invoked in the <link
 530  * linkend="g-main-context-push-thread-default">thread-default main
 531  * loop</link> of the thread you are calling this function from.
 532  *
 533  * You are guaranteed that one of the @name_acquired_handler and @name_lost_handler
 534  * callbacks will be invoked after calling this function - there are three
 535  * possible cases:
 536  * <itemizedlist>
 537  *   <listitem><para>
 538  *     @name_lost_handler with a %NULL connection (if a connection to the bus can't be made).
 539  *   </para></listitem>
 540  *   <listitem><para>
 541  *     @bus_acquired_handler then @name_lost_handler (if the name can't be obtained)
 542  *   </para></listitem>
 543  *   <listitem><para>
 544  *     @bus_acquired_handler then @name_acquired_handler (if the name was obtained).
 545  *   </para></listitem>
 546  * </itemizedlist>
 547  * When you are done owning the name, just call g_bus_unown_name()
 548  * with the owner id this function returns.
 549  *
 550  * If the name is acquired or lost (for example another application
 551  * could acquire the name if you allow replacement or the application
 552  * currently owning the name exits), the handlers are also invoked. If the
 553  * #GDBusConnection that is used for attempting to own the name
 554  * closes, then @name_lost_handler is invoked since it is no
 555  * longer possible for other processes to access the process.
 556  *
 557  * You cannot use g_bus_own_name() several times for the same name (unless
 558  * interleaved with calls to g_bus_unown_name()) - only the first call
 559  * will work.
 560  *
 561  * Another guarantee is that invocations of @name_acquired_handler
 562  * and @name_lost_handler are guaranteed to alternate; that
 563  * is, if @name_acquired_handler is invoked then you are
 564  * guaranteed that the next time one of the handlers is invoked, it
 565  * will be @name_lost_handler. The reverse is also true.
 566  *
 567  * If you plan on exporting objects (using e.g.
 568  * g_dbus_connection_register_object()), note that it is generally too late
 569  * to export the objects in @name_acquired_handler. Instead, you can do this
 570  * in @bus_acquired_handler since you are guaranteed that this will run
 571  * before @name is requested from the bus.
 572  *
 573  * This behavior makes it very simple to write applications that wants
 574  * to own names and export objects, see <xref linkend="gdbus-owning-names"/>.
 575  * Simply register objects to be exported in @bus_acquired_handler and
 576  * unregister the objects (if any) in @name_lost_handler.
 577  *
 578  * Returns: An identifier (never 0) that an be used with
 579  * g_bus_unown_name() to stop owning the name.
 580  *
 581  * Since: 2.26
 582  */
 583 guint
 584 g_bus_own_name (GBusType                  bus_type,
 585                 const gchar              *name,
 586                 GBusNameOwnerFlags        flags,
 587                 GBusAcquiredCallback      bus_acquired_handler,
 588                 GBusNameAcquiredCallback  name_acquired_handler,
 589                 GBusNameLostCallback      name_lost_handler,
 590                 gpointer                  user_data,
 591                 GDestroyNotify            user_data_free_func)
 592 {
 593   Client *client;
 594
 595   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 596
 597   G_LOCK (lock);
 598
 599   client = g_new0 (Client, 1);
 600   client->ref_count = 1;
 601   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 602   client->name = g_strdup (name);
 603   client->flags = flags;
 604   client->bus_acquired_handler = bus_acquired_handler;
 605   client->name_acquired_handler = name_acquired_handler;
 606   client->name_lost_handler = name_lost_handler;
 607   client->user_data = user_data;
 608   client->user_data_free_func = user_data_free_func;
 609   client->main_context = g_main_context_get_thread_default ();
 610   if (client->main_context != NULL)
 611     g_main_context_ref (client->main_context);
 612
 613   if (map_id_to_client == NULL)
 614     {
 615       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 616     }
 617   g_hash_table_insert (map_id_to_client,
 618                        GUINT_TO_POINTER (client->id),
 619                        client);
 620
 621   g_bus_get (bus_type,
 622              NULL,
 623              connection_get_cb,
 624              client_ref (client));
 625
 626   G_UNLOCK (lock);
 627
 628   return client->id;
 629 }
 630
 631 typedef struct {
 632   GClosure *bus_acquired_closure;
 633   GClosure *name_acquired_closure;
 634   GClosure *name_lost_closure;
 635 } OwnNameData;
 636
 637 static OwnNameData *
 638 own_name_data_new (GClosure *bus_acquired_closure,
 639                    GClosure *name_acquired_closure,
 640                    GClosure *name_lost_closure)
 641 {
 642   OwnNameData *data;
 643
 644   data = g_new0 (OwnNameData, 1);
 645
 646   if (bus_acquired_closure != NULL)
 647     {
 648       data->bus_acquired_closure = g_closure_ref (bus_acquired_closure);
 649       g_closure_sink (bus_acquired_closure);
 650       if (G_CLOSURE_NEEDS_MARSHAL (bus_acquired_closure))
 651         g_closure_set_marshal (bus_acquired_closure, g_cclosure_marshal_generic);
 652     }
 653
 654   if (name_acquired_closure != NULL)
 655     {
 656       data->name_acquired_closure = g_closure_ref (name_acquired_closure);
 657       g_closure_sink (name_acquired_closure);
 658       if (G_CLOSURE_NEEDS_MARSHAL (name_acquired_closure))
 659         g_closure_set_marshal (name_acquired_closure, g_cclosure_marshal_generic);
 660     }
 661
 662   if (name_lost_closure != NULL)
 663     {
 664       data->name_lost_closure = g_closure_ref (name_lost_closure);
 665       g_closure_sink (name_lost_closure);
 666       if (G_CLOSURE_NEEDS_MARSHAL (name_lost_closure))
 667         g_closure_set_marshal (name_lost_closure, g_cclosure_marshal_generic);
 668     }
 669
 670   return data;
 671 }
 672
 673 static void
 674 own_with_closures_on_bus_acquired (GDBusConnection *connection,
 675                                    const gchar     *name,
 676                                    gpointer         user_data)
 677 {
 678   OwnNameData *data = user_data;
 679   GValue params[2] = { { 0, }, { 0, } };
 680
 681   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 682   g_value_set_object (&params[0], connection);
 683
 684   g_value_init (&params[1], G_TYPE_STRING);
 685   g_value_set_string (&params[1], name);
 686
 687   g_closure_invoke (data->bus_acquired_closure, NULL, 2, params, NULL);
 688
 689   g_value_unset (params + 0);
 690   g_value_unset (params + 1);
 691 }
 692
 693 static void
 694 own_with_closures_on_name_acquired (GDBusConnection *connection,
 695                                     const gchar     *name,
 696                                     gpointer         user_data)
 697 {
 698   OwnNameData *data = user_data;
 699   GValue params[2] = { { 0, }, { 0, } };
 700
 701   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 702   g_value_set_object (&params[0], connection);
 703
 704   g_value_init (&params[1], G_TYPE_STRING);
 705   g_value_set_string (&params[1], name);
 706
 707   g_closure_invoke (data->name_acquired_closure, NULL, 2, params, NULL);
 708
 709   g_value_unset (params + 0);
 710   g_value_unset (params + 1);
 711 }
 712
 713 static void
 714 own_with_closures_on_name_lost (GDBusConnection *connection,
 715                                 const gchar     *name,
 716                                 gpointer         user_data)
 717 {
 718   OwnNameData *data = user_data;
 719   GValue params[2] = { { 0, }, { 0, } };
 720
 721   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 722   g_value_set_object (&params[0], connection);
 723
 724   g_value_init (&params[1], G_TYPE_STRING);
 725   g_value_set_string (&params[1], name);
 726
 727   g_closure_invoke (data->name_lost_closure, NULL, 2, params, NULL);
 728
 729   g_value_unset (params + 0);
 730   g_value_unset (params + 1);
 731 }
 732
 733 static void
 734 bus_own_name_free_func (gpointer user_data)
 735 {
 736   OwnNameData *data = user_data;
 737
 738   if (data->bus_acquired_closure != NULL)
 739     g_closure_unref (data->bus_acquired_closure);
 740
 741   if (data->name_acquired_closure != NULL)
 742     g_closure_unref (data->name_acquired_closure);
 743
 744   if (data->name_lost_closure != NULL)
 745     g_closure_unref (data->name_lost_closure);
 746
 747   g_free (data);
 748 }
 749
 750 /**
 751  * g_bus_own_name_with_closures:
 752  * @bus_type: The type of bus to own a name on.
 753  * @name: The well-known name to own.
 754  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 755  * @bus_acquired_closure: (allow-none): #GClosure to invoke when connected to
 756  * the bus of type @bus_type or %NULL.
 757  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 758  * acquired or %NULL.
 759  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 760  * %NULL.
 761  *
 762  * Version of g_bus_own_name() using closures instead of callbacks for
 763  * easier binding in other languages.
 764  *
 765  * Returns: An identifier (never 0) that an be used with
 766  * g_bus_unown_name() to stop owning the name.
 767  *
 768  * Rename to: g_bus_own_name
 769  *
 770  * Since: 2.26
 771  */
 772 guint
 773 g_bus_own_name_with_closures (GBusType                  bus_type,
 774                               const gchar              *name,
 775                               GBusNameOwnerFlags        flags,
 776                               GClosure                 *bus_acquired_closure,
 777                               GClosure                 *name_acquired_closure,
 778                               GClosure                 *name_lost_closure)
 779 {
 780   return g_bus_own_name (bus_type,
 781           name,
 782           flags,
 783           bus_acquired_closure != NULL ? own_with_closures_on_bus_acquired : NULL,
 784           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 785           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 786           own_name_data_new (bus_acquired_closure,
 787                              name_acquired_closure,
 788                              name_lost_closure),
 789           bus_own_name_free_func);
 790 }
 791
 792 /**
 793  * g_bus_own_name_on_connection_with_closures:
 794  * @connection: A #GDBusConnection.
 795  * @name: The well-known name to own.
 796  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 797  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 798  * acquired or %NULL.
 799  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 800  * %NULL.
 801  *
 802  * Version of g_bus_own_name_on_connection() using closures instead of callbacks for
 803  * easier binding in other languages.
 804  *
 805  * Returns: An identifier (never 0) that an be used with
 806  * g_bus_unown_name() to stop owning the name.
 807  *
 808  * Rename to: g_bus_own_name_on_connection
 809  *
 810  * Since: 2.26
 811  */
 812 guint
 813 g_bus_own_name_on_connection_with_closures (GDBusConnection          *connection,
 814                                             const gchar              *name,
 815                                             GBusNameOwnerFlags        flags,
 816                                             GClosure                 *name_acquired_closure,
 817                                             GClosure                 *name_lost_closure)
 818 {
 819   return g_bus_own_name_on_connection (connection,
 820           name,
 821           flags,
 822           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 823           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 824           own_name_data_new (NULL,
 825                              name_acquired_closure,
 826                              name_lost_closure),
 827           bus_own_name_free_func);
 828 }
 829
 830 /**
 831  * g_bus_unown_name:
 832  * @owner_id: An identifier obtained from g_bus_own_name()
 833  *
 834  * Stops owning a name.
 835  *
 836  * Since: 2.26
 837  */
 838 void
 839 g_bus_unown_name (guint owner_id)
 840 {
 841   Client *client;
 842
 843   g_return_if_fail (owner_id > 0);
 844
 845   client = NULL;
 846
 847   G_LOCK (lock);
 848   if (owner_id == 0 || map_id_to_client == NULL ||
 849       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (owner_id))) == NULL)
 850     {
 851       g_warning ("Invalid id %d passed to g_bus_unown_name()", owner_id);
 852       goto out;
 853     }
 854
 855   client->cancelled = TRUE;
 856   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (owner_id)));
 857
 858  out:
 859   G_UNLOCK (lock);
 860
 861   /* do callback without holding lock */
 862   if (client != NULL)
 863     {
 864       /* Release the name if needed */
 865       if (client->needs_release && client->connection != NULL)
 866         {
 867           GVariant *result;
 868           GError *error;
 869           guint32 release_name_reply;
 870
 871           /* TODO: it kinda sucks having to do a sync call to release the name - but if
 872            * we don't, then a subsequent grab of the name will make the bus daemon return
 873            * IN_QUEUE which will trigger name_lost().
 874            *
 875            * I believe this is a bug in the bus daemon.
 876            */
 877           error = NULL;
 878           result = g_dbus_connection_call_sync (client->connection,
 879                                                 "org.freedesktop.DBus",  /* bus name */
 880                                                 "/org/freedesktop/DBus", /* object path */
 881                                                 "org.freedesktop.DBus",  /* interface name */
 882                                                 "ReleaseName",           /* method name */
 883                                                 g_variant_new ("(s)", client->name),
 884                                                 G_VARIANT_TYPE ("(u)"),
 885                                                 G_DBUS_CALL_FLAGS_NONE,
 886                                                 -1,
 887                                                 NULL,
 888                                                 &error);
 889           if (result == NULL)
 890             {
 891               g_warning ("Error releasing name %s: %s", client->name, error->message);
 892               g_error_free (error);
 893             }
 894           else
 895             {
 896               g_variant_get (result, "(u)", &release_name_reply);
 897               if (release_name_reply != 1 /* DBUS_RELEASE_NAME_REPLY_RELEASED */)
 898                 {
 899                   g_warning ("Unexpected reply %d when releasing name %s", release_name_reply, client->name);
 900                 }
 901               g_variant_unref (result);
 902             }
 903         }
 904
 905       if (client->disconnected_signal_handler_id > 0)
 906         g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 907       if (client->name_acquired_subscription_id > 0)
 908         g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 909       if (client->name_lost_subscription_id > 0)
 910         g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 911       client->disconnected_signal_handler_id = 0;
 912       client->name_acquired_subscription_id = 0;
 913       client->name_lost_subscription_id = 0;
 914       if (client->connection != NULL)
 915         {
 916           g_object_unref (client->connection);
 917           client->connection = NULL;
 918         }
 919
 920       client_unref (client);
 921     }
 922 }