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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: David Zeuthen <davidz@redhat.com>
  19  */
  20
  21 #include "config.h"
  22
  23 #include <stdlib.h>
  24
  25 #include "gdbusutils.h"
  26 #include "gdbusnameowning.h"
  27 #include "gdbuserror.h"
  28 #include "gdbusprivate.h"
  29 #include "gdbusconnection.h"
  30
  31 #include "glibintl.h"
  32
  33 /**
  34  * SECTION:gdbusnameowning
  35  * @title: Owning Bus Names
  36  * @short_description: Simple API for owning bus names
  37  * @include: gio/gio.h
  38  *
  39  * Convenience API for owning bus names.
  40  *
  41  * <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>
  42  */
  43
  44 G_LOCK_DEFINE_STATIC (lock);
  45
  46 /* ---------------------------------------------------------------------------------------------------- */
  47
  48 typedef enum
  49 {
  50   PREVIOUS_CALL_NONE = 0,
  51   PREVIOUS_CALL_ACQUIRED,
  52   PREVIOUS_CALL_LOST,
  53 } PreviousCall;
  54
  55 typedef struct
  56 {
  57   volatile gint             ref_count;
  58   guint                     id;
  59   GBusNameOwnerFlags        flags;
  60   gchar                    *name;
  61   GBusAcquiredCallback      bus_acquired_handler;
  62   GBusNameAcquiredCallback  name_acquired_handler;
  63   GBusNameLostCallback      name_lost_handler;
  64   gpointer                  user_data;
  65   GDestroyNotify            user_data_free_func;
  66   GMainContext             *main_context;
  67
  68   PreviousCall              previous_call;
  69
  70   GDBusConnection          *connection;
  71   gulong                    disconnected_signal_handler_id;
  72   guint                     name_acquired_subscription_id;
  73   guint                     name_lost_subscription_id;
  74
  75   volatile gboolean         cancelled; /* must hold lock when reading or modifying */
  76
  77   gboolean                  needs_release;
  78 } Client;
  79
  80 static guint next_global_id = 1;
  81 static GHashTable *map_id_to_client = NULL;
  82
  83
  84 static Client *
  85 client_ref (Client *client)
  86 {
  87   g_atomic_int_inc (&client->ref_count);
  88   return client;
  89 }
  90
  91 static void
  92 client_unref (Client *client)
  93 {
  94   if (g_atomic_int_dec_and_test (&client->ref_count))
  95     {
  96       if (client->connection != NULL)
  97         {
  98           if (client->disconnected_signal_handler_id > 0)
  99             g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 100           if (client->name_acquired_subscription_id > 0)
 101             g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 102           if (client->name_lost_subscription_id > 0)
 103             g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 104           g_object_unref (client->connection);
 105         }
 106       g_main_context_unref (client->main_context);
 107       g_free (client->name);
 108       if (client->user_data_free_func != NULL)
 109         client->user_data_free_func (client->user_data);
 110       g_free (client);
 111     }
 112 }
 113
 114 /* ---------------------------------------------------------------------------------------------------- */
 115
 116
 117 typedef enum
 118 {
 119   CALL_TYPE_NAME_ACQUIRED,
 120   CALL_TYPE_NAME_LOST
 121 } CallType;
 122
 123 typedef struct
 124 {
 125   Client *client;
 126
 127   /* keep this separate because client->connection may
 128    * be set to NULL after scheduling the call
 129    */
 130   GDBusConnection *connection;
 131
 132   /* set to TRUE to call acquired */
 133   CallType call_type;
 134 } CallHandlerData;
 135
 136 static void
 137 call_handler_data_free (CallHandlerData *data)
 138 {
 139   if (data->connection != NULL)
 140     g_object_unref (data->connection);
 141   client_unref (data->client);
 142   g_free (data);
 143 }
 144
 145 static void
 146 actually_do_call (Client *client, GDBusConnection *connection, CallType call_type)
 147 {
 148   switch (call_type)
 149     {
 150     case CALL_TYPE_NAME_ACQUIRED:
 151       if (client->name_acquired_handler != NULL)
 152         {
 153           client->name_acquired_handler (connection,
 154                                          client->name,
 155                                          client->user_data);
 156         }
 157       break;
 158
 159     case CALL_TYPE_NAME_LOST:
 160       if (client->name_lost_handler != NULL)
 161         {
 162           client->name_lost_handler (connection,
 163                                      client->name,
 164                                      client->user_data);
 165         }
 166       break;
 167
 168     default:
 169       g_assert_not_reached ();
 170       break;
 171     }
 172 }
 173
 174 static gboolean
 175 call_in_idle_cb (gpointer _data)
 176 {
 177   CallHandlerData *data = _data;
 178   actually_do_call (data->client, data->connection, data->call_type);
 179   return FALSE;
 180 }
 181
 182 static void
 183 schedule_call_in_idle (Client *client, CallType  call_type)
 184 {
 185   CallHandlerData *data;
 186   GSource *idle_source;
 187
 188   data = g_new0 (CallHandlerData, 1);
 189   data->client = client_ref (client);
 190   data->connection = client->connection != NULL ? g_object_ref (client->connection) : NULL;
 191   data->call_type = call_type;
 192
 193   idle_source = g_idle_source_new ();
 194   g_source_set_priority (idle_source, G_PRIORITY_HIGH);
 195   g_source_set_callback (idle_source,
 196                          call_in_idle_cb,
 197                          data,
 198                          (GDestroyNotify) call_handler_data_free);
 199   g_source_attach (idle_source, client->main_context);
 200   g_source_unref (idle_source);
 201 }
 202
 203 static void
 204 do_call (Client *client, CallType call_type)
 205 {
 206   GMainContext *current_context;
 207
 208   /* only schedule in idle if we're not in the right thread */
 209   current_context = g_main_context_ref_thread_default ();
 210   if (current_context != client->main_context)
 211     schedule_call_in_idle (client, call_type);
 212   else
 213     actually_do_call (client, client->connection, call_type);
 214   g_main_context_unref (current_context);
 215 }
 216
 217 static void
 218 call_acquired_handler (Client *client)
 219 {
 220   G_LOCK (lock);
 221   if (client->previous_call != PREVIOUS_CALL_ACQUIRED)
 222     {
 223       client->previous_call = PREVIOUS_CALL_ACQUIRED;
 224       if (!client->cancelled)
 225         {
 226           G_UNLOCK (lock);
 227           do_call (client, CALL_TYPE_NAME_ACQUIRED);
 228           goto out;
 229         }
 230     }
 231   G_UNLOCK (lock);
 232  out:
 233   ;
 234 }
 235
 236 static void
 237 call_lost_handler (Client  *client)
 238 {
 239   G_LOCK (lock);
 240   if (client->previous_call != PREVIOUS_CALL_LOST)
 241     {
 242       client->previous_call = PREVIOUS_CALL_LOST;
 243       if (!client->cancelled)
 244         {
 245           G_UNLOCK (lock);
 246           do_call (client, CALL_TYPE_NAME_LOST);
 247           goto out;
 248         }
 249     }
 250   G_UNLOCK (lock);
 251  out:
 252   ;
 253 }
 254
 255 /* ---------------------------------------------------------------------------------------------------- */
 256
 257 static void
 258 on_name_lost_or_acquired (GDBusConnection  *connection,
 259                           const gchar      *sender_name,
 260                           const gchar      *object_path,
 261                           const gchar      *interface_name,
 262                           const gchar      *signal_name,
 263                           GVariant         *parameters,
 264                           gpointer          user_data)
 265 {
 266   Client *client = user_data;
 267   const gchar *name;
 268
 269   if (g_strcmp0 (object_path, "/org/freedesktop/DBus") != 0 ||
 270       g_strcmp0 (interface_name, "org.freedesktop.DBus") != 0 ||
 271       g_strcmp0 (sender_name, "org.freedesktop.DBus") != 0)
 272     goto out;
 273
 274   if (g_strcmp0 (signal_name, "NameLost") == 0)
 275     {
 276       g_variant_get (parameters, "(&s)", &name);
 277       if (g_strcmp0 (name, client->name) == 0)
 278         {
 279           call_lost_handler (client);
 280         }
 281     }
 282   else if (g_strcmp0 (signal_name, "NameAcquired") == 0)
 283     {
 284       g_variant_get (parameters, "(&s)", &name);
 285       if (g_strcmp0 (name, client->name) == 0)
 286         {
 287           call_acquired_handler (client);
 288         }
 289     }
 290  out:
 291   ;
 292 }
 293
 294 /* ---------------------------------------------------------------------------------------------------- */
 295
 296 static void
 297 request_name_cb (GObject      *source_object,
 298                  GAsyncResult *res,
 299                  gpointer      user_data)
 300 {
 301   Client *client = user_data;
 302   GVariant *result;
 303   guint32 request_name_reply;
 304   gboolean subscribe;
 305
 306   request_name_reply = 0;
 307   result = NULL;
 308
 309   /* don't use client->connection - it may be NULL already */
 310   result = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source_object),
 311                                           res,
 312                                           NULL);
 313   if (result != NULL)
 314     {
 315       g_variant_get (result, "(u)", &request_name_reply);
 316       g_variant_unref (result);
 317     }
 318
 319   subscribe = FALSE;
 320
 321   switch (request_name_reply)
 322     {
 323     case 1: /* DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER */
 324       /* We got the name - now listen for NameLost and NameAcquired */
 325       call_acquired_handler (client);
 326       subscribe = TRUE;
 327       client->needs_release = TRUE;
 328       break;
 329
 330     case 2: /* DBUS_REQUEST_NAME_REPLY_IN_QUEUE */
 331       /* Waiting in line - listen for NameLost and NameAcquired */
 332       call_lost_handler (client);
 333       subscribe = TRUE;
 334       client->needs_release = TRUE;
 335       break;
 336
 337     default:
 338       /* assume we couldn't get the name - explicit fallthrough */
 339     case 3: /* DBUS_REQUEST_NAME_REPLY_EXISTS */
 340     case 4: /* DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER */
 341       /* Some other part of the process is already owning the name */
 342       call_lost_handler (client);
 343       break;
 344     }
 345
 346
 347   if (subscribe)
 348     {
 349       GDBusConnection *connection = NULL;
 350
 351       /* if cancelled, there is no point in subscribing to signals - if not, make sure
 352        * we use a known good Connection object since it may be set to NULL at any point
 353        * after being cancelled
 354        */
 355       G_LOCK (lock);
 356       if (!client->cancelled)
 357         connection = g_object_ref (client->connection);
 358       G_UNLOCK (lock);
 359
 360       /* start listening to NameLost and NameAcquired messages */
 361       if (connection != NULL)
 362         {
 363           client->name_lost_subscription_id =
 364             g_dbus_connection_signal_subscribe (connection,
 365                                                 "org.freedesktop.DBus",
 366                                                 "org.freedesktop.DBus",
 367                                                 "NameLost",
 368                                                 "/org/freedesktop/DBus",
 369                                                 client->name,
 370                                                 G_DBUS_SIGNAL_FLAGS_NONE,
 371                                                 on_name_lost_or_acquired,
 372                                                 client,
 373                                                 NULL);
 374           client->name_acquired_subscription_id =
 375             g_dbus_connection_signal_subscribe (connection,
 376                                                 "org.freedesktop.DBus",
 377                                                 "org.freedesktop.DBus",
 378                                                 "NameAcquired",
 379                                                 "/org/freedesktop/DBus",
 380                                                 client->name,
 381                                                 G_DBUS_SIGNAL_FLAGS_NONE,
 382                                                 on_name_lost_or_acquired,
 383                                                 client,
 384                                                 NULL);
 385           g_object_unref (connection);
 386         }
 387     }
 388
 389   client_unref (client);
 390 }
 391
 392 /* ---------------------------------------------------------------------------------------------------- */
 393
 394 static void
 395 on_connection_disconnected (GDBusConnection *connection,
 396                             gboolean         remote_peer_vanished,
 397                             GError          *error,
 398                             gpointer         user_data)
 399 {
 400   Client *client = user_data;
 401
 402   if (client->disconnected_signal_handler_id > 0)
 403     g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 404   if (client->name_acquired_subscription_id > 0)
 405     g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 406   if (client->name_lost_subscription_id > 0)
 407     g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 408   g_object_unref (client->connection);
 409   client->disconnected_signal_handler_id = 0;
 410   client->name_acquired_subscription_id = 0;
 411   client->name_lost_subscription_id = 0;
 412   client->connection = NULL;
 413
 414   call_lost_handler (client);
 415 }
 416
 417 /* ---------------------------------------------------------------------------------------------------- */
 418
 419 static void
 420 has_connection (Client *client)
 421 {
 422   /* listen for disconnection */
 423   client->disconnected_signal_handler_id = g_signal_connect (client->connection,
 424                                                              "closed",
 425                                                              G_CALLBACK (on_connection_disconnected),
 426                                                              client);
 427
 428   /* attempt to acquire the name */
 429   g_dbus_connection_call (client->connection,
 430                           "org.freedesktop.DBus",  /* bus name */
 431                           "/org/freedesktop/DBus", /* object path */
 432                           "org.freedesktop.DBus",  /* interface name */
 433                           "RequestName",           /* method name */
 434                           g_variant_new ("(su)",
 435                                          client->name,
 436                                          client->flags),
 437                           G_VARIANT_TYPE ("(u)"),
 438                           G_DBUS_CALL_FLAGS_NONE,
 439                           -1,
 440                           NULL,
 441                           (GAsyncReadyCallback) request_name_cb,
 442                           client_ref (client));
 443 }
 444
 445
 446 static void
 447 connection_get_cb (GObject      *source_object,
 448                    GAsyncResult *res,
 449                    gpointer      user_data)
 450 {
 451   Client *client = user_data;
 452
 453   /* must not do anything if already cancelled */
 454   G_LOCK (lock);
 455   if (client->cancelled)
 456     {
 457       G_UNLOCK (lock);
 458       goto out;
 459     }
 460   G_UNLOCK (lock);
 461
 462   client->connection = g_bus_get_finish (res, NULL);
 463   if (client->connection == NULL)
 464     {
 465       call_lost_handler (client);
 466       goto out;
 467     }
 468
 469   /* No need to schedule this in idle as we're already in the thread
 470    * that the user called g_bus_own_name() from. This is because
 471    * g_bus_get() guarantees that.
 472    *
 473    * Also, we need to ensure that the handler is invoked *before*
 474    * we call RequestName(). Otherwise there is a race.
 475    */
 476   if (client->bus_acquired_handler != NULL)
 477     {
 478       client->bus_acquired_handler (client->connection,
 479                                     client->name,
 480                                     client->user_data);
 481     }
 482
 483   has_connection (client);
 484
 485  out:
 486   client_unref (client);
 487 }
 488
 489 /* ---------------------------------------------------------------------------------------------------- */
 490
 491 /**
 492  * g_bus_own_name_on_connection:
 493  * @connection: a #GDBusConnection
 494  * @name: the well-known name to own
 495  * @flags: a set of flags from the #GBusNameOwnerFlags enumeration
 496  * @name_acquired_handler: (allow-none): handler to invoke when @name is acquired or %NULL
 497  * @name_lost_handler: (allow-none): handler to invoke when @name is lost or %NULL
 498  * @user_data: user data to pass to handlers
 499  * @user_data_free_func: (allow-none): function for freeing @user_data or %NULL
 500  *
 501  * Like g_bus_own_name() but takes a #GDBusConnection instead of a
 502  * #GBusType.
 503  *
 504  * Returns: an identifier (never 0) that an be used with
 505  *     g_bus_unown_name() to stop owning the name
 506  *
 507  * Since: 2.26
 508  */
 509 guint
 510 g_bus_own_name_on_connection (GDBusConnection          *connection,
 511                               const gchar              *name,
 512                               GBusNameOwnerFlags        flags,
 513                               GBusNameAcquiredCallback  name_acquired_handler,
 514                               GBusNameLostCallback      name_lost_handler,
 515                               gpointer                  user_data,
 516                               GDestroyNotify            user_data_free_func)
 517 {
 518   Client *client;
 519
 520   g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
 521   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 522
 523   G_LOCK (lock);
 524
 525   client = g_new0 (Client, 1);
 526   client->ref_count = 1;
 527   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 528   client->name = g_strdup (name);
 529   client->flags = flags;
 530   client->name_acquired_handler = name_acquired_handler;
 531   client->name_lost_handler = name_lost_handler;
 532   client->user_data = user_data;
 533   client->user_data_free_func = user_data_free_func;
 534   client->main_context = g_main_context_ref_thread_default ();
 535
 536   client->connection = g_object_ref (connection);
 537
 538   if (map_id_to_client == NULL)
 539     {
 540       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 541     }
 542   g_hash_table_insert (map_id_to_client,
 543                        GUINT_TO_POINTER (client->id),
 544                        client);
 545
 546   G_UNLOCK (lock);
 547
 548   has_connection (client);
 549
 550   return client->id;
 551 }
 552
 553 /**
 554  * g_bus_own_name:
 555  * @bus_type: the type of bus to own a name on
 556  * @name: the well-known name to own
 557  * @flags: a set of flags from the #GBusNameOwnerFlags enumeration
 558  * @bus_acquired_handler: (allow-none): handler to invoke when connected to the bus of type @bus_type or %NULL
 559  * @name_acquired_handler: (allow-none): handler to invoke when @name is acquired or %NULL
 560  * @name_lost_handler: (allow-none): handler to invoke when @name is lost or %NULL
 561  * @user_data: user data to pass to handlers
 562  * @user_data_free_func: (allow-none): function for freeing @user_data or %NULL
 563  *
 564  * Starts acquiring @name on the bus specified by @bus_type and calls
 565  * @name_acquired_handler and @name_lost_handler when the name is
 566  * acquired respectively lost. Callbacks will be invoked in the <link
 567  * linkend="g-main-context-push-thread-default">thread-default main
 568  * loop</link> of the thread you are calling this function from.
 569  *
 570  * You are guaranteed that one of the @name_acquired_handler and @name_lost_handler
 571  * callbacks will be invoked after calling this function - there are three
 572  * possible cases:
 573  *
 574  * - @name_lost_handler with a %NULL connection (if a connection to the bus
 575  *   can't be made).
 576  *
 577  * - @bus_acquired_handler then @name_lost_handler (if the name can't be
 578  *   obtained)
 579  *
 580  * - @bus_acquired_handler then @name_acquired_handler (if the name was
 581  *   obtained).
 582  *
 583  * When you are done owning the name, just call g_bus_unown_name()
 584  * with the owner id this function returns.
 585  *
 586  * If the name is acquired or lost (for example another application
 587  * could acquire the name if you allow replacement or the application
 588  * currently owning the name exits), the handlers are also invoked.
 589  * If the #GDBusConnection that is used for attempting to own the name
 590  * closes, then @name_lost_handler is invoked since it is no longer
 591  * possible for other processes to access the process.
 592  *
 593  * You cannot use g_bus_own_name() several times for the same name (unless
 594  * interleaved with calls to g_bus_unown_name()) - only the first call
 595  * will work.
 596  *
 597  * Another guarantee is that invocations of @name_acquired_handler
 598  * and @name_lost_handler are guaranteed to alternate; that
 599  * is, if @name_acquired_handler is invoked then you are
 600  * guaranteed that the next time one of the handlers is invoked, it
 601  * will be @name_lost_handler. The reverse is also true.
 602  *
 603  * If you plan on exporting objects (using e.g.
 604  * g_dbus_connection_register_object()), note that it is generally too late
 605  * to export the objects in @name_acquired_handler. Instead, you can do this
 606  * in @bus_acquired_handler since you are guaranteed that this will run
 607  * before @name is requested from the bus.
 608  *
 609  * This behavior makes it very simple to write applications that wants
 610  * to own names and export objects, see <xref linkend="gdbus-owning-names"/>.
 611  * Simply register objects to be exported in @bus_acquired_handler and
 612  * unregister the objects (if any) in @name_lost_handler.
 613  *
 614  * Returns: an identifier (never 0) that an be used with
 615  *     g_bus_unown_name() to stop owning the name.
 616  *
 617  * Since: 2.26
 618  */
 619 guint
 620 g_bus_own_name (GBusType                  bus_type,
 621                 const gchar              *name,
 622                 GBusNameOwnerFlags        flags,
 623                 GBusAcquiredCallback      bus_acquired_handler,
 624                 GBusNameAcquiredCallback  name_acquired_handler,
 625                 GBusNameLostCallback      name_lost_handler,
 626                 gpointer                  user_data,
 627                 GDestroyNotify            user_data_free_func)
 628 {
 629   Client *client;
 630
 631   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 632
 633   G_LOCK (lock);
 634
 635   client = g_new0 (Client, 1);
 636   client->ref_count = 1;
 637   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 638   client->name = g_strdup (name);
 639   client->flags = flags;
 640   client->bus_acquired_handler = bus_acquired_handler;
 641   client->name_acquired_handler = name_acquired_handler;
 642   client->name_lost_handler = name_lost_handler;
 643   client->user_data = user_data;
 644   client->user_data_free_func = user_data_free_func;
 645   client->main_context = g_main_context_ref_thread_default ();
 646
 647   if (map_id_to_client == NULL)
 648     {
 649       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 650     }
 651   g_hash_table_insert (map_id_to_client,
 652                        GUINT_TO_POINTER (client->id),
 653                        client);
 654
 655   g_bus_get (bus_type,
 656              NULL,
 657              connection_get_cb,
 658              client_ref (client));
 659
 660   G_UNLOCK (lock);
 661
 662   return client->id;
 663 }
 664
 665 typedef struct {
 666   GClosure *bus_acquired_closure;
 667   GClosure *name_acquired_closure;
 668   GClosure *name_lost_closure;
 669 } OwnNameData;
 670
 671 static OwnNameData *
 672 own_name_data_new (GClosure *bus_acquired_closure,
 673                    GClosure *name_acquired_closure,
 674                    GClosure *name_lost_closure)
 675 {
 676   OwnNameData *data;
 677
 678   data = g_new0 (OwnNameData, 1);
 679
 680   if (bus_acquired_closure != NULL)
 681     {
 682       data->bus_acquired_closure = g_closure_ref (bus_acquired_closure);
 683       g_closure_sink (bus_acquired_closure);
 684       if (G_CLOSURE_NEEDS_MARSHAL (bus_acquired_closure))
 685         g_closure_set_marshal (bus_acquired_closure, g_cclosure_marshal_generic);
 686     }
 687
 688   if (name_acquired_closure != NULL)
 689     {
 690       data->name_acquired_closure = g_closure_ref (name_acquired_closure);
 691       g_closure_sink (name_acquired_closure);
 692       if (G_CLOSURE_NEEDS_MARSHAL (name_acquired_closure))
 693         g_closure_set_marshal (name_acquired_closure, g_cclosure_marshal_generic);
 694     }
 695
 696   if (name_lost_closure != NULL)
 697     {
 698       data->name_lost_closure = g_closure_ref (name_lost_closure);
 699       g_closure_sink (name_lost_closure);
 700       if (G_CLOSURE_NEEDS_MARSHAL (name_lost_closure))
 701         g_closure_set_marshal (name_lost_closure, g_cclosure_marshal_generic);
 702     }
 703
 704   return data;
 705 }
 706
 707 static void
 708 own_with_closures_on_bus_acquired (GDBusConnection *connection,
 709                                    const gchar     *name,
 710                                    gpointer         user_data)
 711 {
 712   OwnNameData *data = user_data;
 713   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 714
 715   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 716   g_value_set_object (&params[0], connection);
 717
 718   g_value_init (&params[1], G_TYPE_STRING);
 719   g_value_set_string (&params[1], name);
 720
 721   g_closure_invoke (data->bus_acquired_closure, NULL, 2, params, NULL);
 722
 723   g_value_unset (params + 0);
 724   g_value_unset (params + 1);
 725 }
 726
 727 static void
 728 own_with_closures_on_name_acquired (GDBusConnection *connection,
 729                                     const gchar     *name,
 730                                     gpointer         user_data)
 731 {
 732   OwnNameData *data = user_data;
 733   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 734
 735   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 736   g_value_set_object (&params[0], connection);
 737
 738   g_value_init (&params[1], G_TYPE_STRING);
 739   g_value_set_string (&params[1], name);
 740
 741   g_closure_invoke (data->name_acquired_closure, NULL, 2, params, NULL);
 742
 743   g_value_unset (params + 0);
 744   g_value_unset (params + 1);
 745 }
 746
 747 static void
 748 own_with_closures_on_name_lost (GDBusConnection *connection,
 749                                 const gchar     *name,
 750                                 gpointer         user_data)
 751 {
 752   OwnNameData *data = user_data;
 753   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 754
 755   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 756   g_value_set_object (&params[0], connection);
 757
 758   g_value_init (&params[1], G_TYPE_STRING);
 759   g_value_set_string (&params[1], name);
 760
 761   g_closure_invoke (data->name_lost_closure, NULL, 2, params, NULL);
 762
 763   g_value_unset (params + 0);
 764   g_value_unset (params + 1);
 765 }
 766
 767 static void
 768 bus_own_name_free_func (gpointer user_data)
 769 {
 770   OwnNameData *data = user_data;
 771
 772   if (data->bus_acquired_closure != NULL)
 773     g_closure_unref (data->bus_acquired_closure);
 774
 775   if (data->name_acquired_closure != NULL)
 776     g_closure_unref (data->name_acquired_closure);
 777
 778   if (data->name_lost_closure != NULL)
 779     g_closure_unref (data->name_lost_closure);
 780
 781   g_free (data);
 782 }
 783
 784 /**
 785  * g_bus_own_name_with_closures:
 786  * @bus_type: the type of bus to own a name on
 787  * @name: the well-known name to own
 788  * @flags: a set of flags from the #GBusNameOwnerFlags enumeration
 789  * @bus_acquired_closure: (allow-none): #GClosure to invoke when connected to
 790  *     the bus of type @bus_type or %NULL
 791  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 792  *     acquired or %NULL
 793  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 794  *     %NULL
 795  *
 796  * Version of g_bus_own_name() using closures instead of callbacks for
 797  * easier binding in other languages.
 798  *
 799  * Returns: an identifier (never 0) that an be used with
 800  *     g_bus_unown_name() to stop owning the name.
 801  *
 802  * Rename to: g_bus_own_name
 803  *
 804  * Since: 2.26
 805  */
 806 guint
 807 g_bus_own_name_with_closures (GBusType            bus_type,
 808                               const gchar        *name,
 809                               GBusNameOwnerFlags  flags,
 810                               GClosure           *bus_acquired_closure,
 811                               GClosure           *name_acquired_closure,
 812                               GClosure           *name_lost_closure)
 813 {
 814   return g_bus_own_name (bus_type,
 815           name,
 816           flags,
 817           bus_acquired_closure != NULL ? own_with_closures_on_bus_acquired : NULL,
 818           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 819           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 820           own_name_data_new (bus_acquired_closure,
 821                              name_acquired_closure,
 822                              name_lost_closure),
 823           bus_own_name_free_func);
 824 }
 825
 826 /**
 827  * g_bus_own_name_on_connection_with_closures:
 828  * @connection: a #GDBusConnection
 829  * @name: the well-known name to own
 830  * @flags: a set of flags from the #GBusNameOwnerFlags enumeration
 831  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 832  *     acquired or %NULL
 833  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost
 834  *     or %NULL
 835  *
 836  * Version of g_bus_own_name_on_connection() using closures instead of
 837  * callbacks for easier binding in other languages.
 838  *
 839  * Returns: an identifier (never 0) that an be used with
 840  *     g_bus_unown_name() to stop owning the name.
 841  *
 842  * Rename to: g_bus_own_name_on_connection
 843  *
 844  * Since: 2.26
 845  */
 846 guint
 847 g_bus_own_name_on_connection_with_closures (GDBusConnection    *connection,
 848                                             const gchar        *name,
 849                                             GBusNameOwnerFlags  flags,
 850                                             GClosure           *name_acquired_closure,
 851                                             GClosure           *name_lost_closure)
 852 {
 853   return g_bus_own_name_on_connection (connection,
 854           name,
 855           flags,
 856           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 857           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 858           own_name_data_new (NULL,
 859                              name_acquired_closure,
 860                              name_lost_closure),
 861           bus_own_name_free_func);
 862 }
 863
 864 /**
 865  * g_bus_unown_name:
 866  * @owner_id: an identifier obtained from g_bus_own_name()
 867  *
 868  * Stops owning a name.
 869  *
 870  * Since: 2.26
 871  */
 872 void
 873 g_bus_unown_name (guint owner_id)
 874 {
 875   Client *client;
 876
 877   g_return_if_fail (owner_id > 0);
 878
 879   client = NULL;
 880
 881   G_LOCK (lock);
 882   if (owner_id == 0 || map_id_to_client == NULL ||
 883       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (owner_id))) == NULL)
 884     {
 885       g_warning ("Invalid id %d passed to g_bus_unown_name()", owner_id);
 886       goto out;
 887     }
 888
 889   client->cancelled = TRUE;
 890   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (owner_id)));
 891
 892  out:
 893   G_UNLOCK (lock);
 894
 895   /* do callback without holding lock */
 896   if (client != NULL)
 897     {
 898       /* Release the name if needed */
 899       if (client->needs_release &&
 900           client->connection != NULL &&
 901           !g_dbus_connection_is_closed (client->connection))
 902         {
 903           GVariant *result;
 904           GError *error;
 905           guint32 release_name_reply;
 906
 907           /* TODO: it kinda sucks having to do a sync call to release the name - but if
 908            * we don't, then a subsequent grab of the name will make the bus daemon return
 909            * IN_QUEUE which will trigger name_lost().
 910            *
 911            * I believe this is a bug in the bus daemon.
 912            */
 913           error = NULL;
 914           result = g_dbus_connection_call_sync (client->connection,
 915                                                 "org.freedesktop.DBus",  /* bus name */
 916                                                 "/org/freedesktop/DBus", /* object path */
 917                                                 "org.freedesktop.DBus",  /* interface name */
 918                                                 "ReleaseName",           /* method name */
 919                                                 g_variant_new ("(s)", client->name),
 920                                                 G_VARIANT_TYPE ("(u)"),
 921                                                 G_DBUS_CALL_FLAGS_NONE,
 922                                                 -1,
 923                                                 NULL,
 924                                                 &error);
 925           if (result == NULL)
 926             {
 927               g_warning ("Error releasing name %s: %s", client->name, error->message);
 928               g_error_free (error);
 929             }
 930           else
 931             {
 932               g_variant_get (result, "(u)", &release_name_reply);
 933               if (release_name_reply != 1 /* DBUS_RELEASE_NAME_REPLY_RELEASED */)
 934                 {
 935                   g_warning ("Unexpected reply %d when releasing name %s", release_name_reply, client->name);
 936                 }
 937               g_variant_unref (result);
 938             }
 939         }
 940
 941       if (client->disconnected_signal_handler_id > 0)
 942         g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 943       if (client->name_acquired_subscription_id > 0)
 944         g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 945       if (client->name_lost_subscription_id > 0)
 946         g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 947       client->disconnected_signal_handler_id = 0;
 948       client->name_acquired_subscription_id = 0;
 949       client->name_lost_subscription_id = 0;
 950       if (client->connection != NULL)
 951         {
 952           g_object_unref (client->connection);
 953           client->connection = NULL;
 954         }
 955
 956       client_unref (client);
 957     }
 958 }