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  * <itemizedlist>
 574  *   <listitem><para>
 575  *     @name_lost_handler with a %NULL connection (if a connection to the bus can't be made).
 576  *   </para></listitem>
 577  *   <listitem><para>
 578  *     @bus_acquired_handler then @name_lost_handler (if the name can't be obtained)
 579  *   </para></listitem>
 580  *   <listitem><para>
 581  *     @bus_acquired_handler then @name_acquired_handler (if the name was obtained).
 582  *   </para></listitem>
 583  * </itemizedlist>
 584  * When you are done owning the name, just call g_bus_unown_name()
 585  * with the owner id this function returns.
 586  *
 587  * If the name is acquired or lost (for example another application
 588  * could acquire the name if you allow replacement or the application
 589  * currently owning the name exits), the handlers are also invoked. If the
 590  * #GDBusConnection that is used for attempting to own the name
 591  * closes, then @name_lost_handler is invoked since it is no
 592  * longer possible for other processes to access the process.
 593  *
 594  * You cannot use g_bus_own_name() several times for the same name (unless
 595  * interleaved with calls to g_bus_unown_name()) - only the first call
 596  * will work.
 597  *
 598  * Another guarantee is that invocations of @name_acquired_handler
 599  * and @name_lost_handler are guaranteed to alternate; that
 600  * is, if @name_acquired_handler is invoked then you are
 601  * guaranteed that the next time one of the handlers is invoked, it
 602  * will be @name_lost_handler. The reverse is also true.
 603  *
 604  * If you plan on exporting objects (using e.g.
 605  * g_dbus_connection_register_object()), note that it is generally too late
 606  * to export the objects in @name_acquired_handler. Instead, you can do this
 607  * in @bus_acquired_handler since you are guaranteed that this will run
 608  * before @name is requested from the bus.
 609  *
 610  * This behavior makes it very simple to write applications that wants
 611  * to own names and export objects, see <xref linkend="gdbus-owning-names"/>.
 612  * Simply register objects to be exported in @bus_acquired_handler and
 613  * unregister the objects (if any) in @name_lost_handler.
 614  *
 615  * Returns: An identifier (never 0) that an be used with
 616  * g_bus_unown_name() to stop owning the name.
 617  *
 618  * Since: 2.26
 619  */
 620 guint
 621 g_bus_own_name (GBusType                  bus_type,
 622                 const gchar              *name,
 623                 GBusNameOwnerFlags        flags,
 624                 GBusAcquiredCallback      bus_acquired_handler,
 625                 GBusNameAcquiredCallback  name_acquired_handler,
 626                 GBusNameLostCallback      name_lost_handler,
 627                 gpointer                  user_data,
 628                 GDestroyNotify            user_data_free_func)
 629 {
 630   Client *client;
 631
 632   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 633
 634   G_LOCK (lock);
 635
 636   client = g_new0 (Client, 1);
 637   client->ref_count = 1;
 638   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 639   client->name = g_strdup (name);
 640   client->flags = flags;
 641   client->bus_acquired_handler = bus_acquired_handler;
 642   client->name_acquired_handler = name_acquired_handler;
 643   client->name_lost_handler = name_lost_handler;
 644   client->user_data = user_data;
 645   client->user_data_free_func = user_data_free_func;
 646   client->main_context = g_main_context_ref_thread_default ();
 647
 648   if (map_id_to_client == NULL)
 649     {
 650       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 651     }
 652   g_hash_table_insert (map_id_to_client,
 653                        GUINT_TO_POINTER (client->id),
 654                        client);
 655
 656   g_bus_get (bus_type,
 657              NULL,
 658              connection_get_cb,
 659              client_ref (client));
 660
 661   G_UNLOCK (lock);
 662
 663   return client->id;
 664 }
 665
 666 typedef struct {
 667   GClosure *bus_acquired_closure;
 668   GClosure *name_acquired_closure;
 669   GClosure *name_lost_closure;
 670 } OwnNameData;
 671
 672 static OwnNameData *
 673 own_name_data_new (GClosure *bus_acquired_closure,
 674                    GClosure *name_acquired_closure,
 675                    GClosure *name_lost_closure)
 676 {
 677   OwnNameData *data;
 678
 679   data = g_new0 (OwnNameData, 1);
 680
 681   if (bus_acquired_closure != NULL)
 682     {
 683       data->bus_acquired_closure = g_closure_ref (bus_acquired_closure);
 684       g_closure_sink (bus_acquired_closure);
 685       if (G_CLOSURE_NEEDS_MARSHAL (bus_acquired_closure))
 686         g_closure_set_marshal (bus_acquired_closure, g_cclosure_marshal_generic);
 687     }
 688
 689   if (name_acquired_closure != NULL)
 690     {
 691       data->name_acquired_closure = g_closure_ref (name_acquired_closure);
 692       g_closure_sink (name_acquired_closure);
 693       if (G_CLOSURE_NEEDS_MARSHAL (name_acquired_closure))
 694         g_closure_set_marshal (name_acquired_closure, g_cclosure_marshal_generic);
 695     }
 696
 697   if (name_lost_closure != NULL)
 698     {
 699       data->name_lost_closure = g_closure_ref (name_lost_closure);
 700       g_closure_sink (name_lost_closure);
 701       if (G_CLOSURE_NEEDS_MARSHAL (name_lost_closure))
 702         g_closure_set_marshal (name_lost_closure, g_cclosure_marshal_generic);
 703     }
 704
 705   return data;
 706 }
 707
 708 static void
 709 own_with_closures_on_bus_acquired (GDBusConnection *connection,
 710                                    const gchar     *name,
 711                                    gpointer         user_data)
 712 {
 713   OwnNameData *data = user_data;
 714   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 715
 716   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 717   g_value_set_object (&params[0], connection);
 718
 719   g_value_init (&params[1], G_TYPE_STRING);
 720   g_value_set_string (&params[1], name);
 721
 722   g_closure_invoke (data->bus_acquired_closure, NULL, 2, params, NULL);
 723
 724   g_value_unset (params + 0);
 725   g_value_unset (params + 1);
 726 }
 727
 728 static void
 729 own_with_closures_on_name_acquired (GDBusConnection *connection,
 730                                     const gchar     *name,
 731                                     gpointer         user_data)
 732 {
 733   OwnNameData *data = user_data;
 734   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 735
 736   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 737   g_value_set_object (&params[0], connection);
 738
 739   g_value_init (&params[1], G_TYPE_STRING);
 740   g_value_set_string (&params[1], name);
 741
 742   g_closure_invoke (data->name_acquired_closure, NULL, 2, params, NULL);
 743
 744   g_value_unset (params + 0);
 745   g_value_unset (params + 1);
 746 }
 747
 748 static void
 749 own_with_closures_on_name_lost (GDBusConnection *connection,
 750                                 const gchar     *name,
 751                                 gpointer         user_data)
 752 {
 753   OwnNameData *data = user_data;
 754   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 755
 756   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 757   g_value_set_object (&params[0], connection);
 758
 759   g_value_init (&params[1], G_TYPE_STRING);
 760   g_value_set_string (&params[1], name);
 761
 762   g_closure_invoke (data->name_lost_closure, NULL, 2, params, NULL);
 763
 764   g_value_unset (params + 0);
 765   g_value_unset (params + 1);
 766 }
 767
 768 static void
 769 bus_own_name_free_func (gpointer user_data)
 770 {
 771   OwnNameData *data = user_data;
 772
 773   if (data->bus_acquired_closure != NULL)
 774     g_closure_unref (data->bus_acquired_closure);
 775
 776   if (data->name_acquired_closure != NULL)
 777     g_closure_unref (data->name_acquired_closure);
 778
 779   if (data->name_lost_closure != NULL)
 780     g_closure_unref (data->name_lost_closure);
 781
 782   g_free (data);
 783 }
 784
 785 /**
 786  * g_bus_own_name_with_closures:
 787  * @bus_type: The type of bus to own a name on.
 788  * @name: The well-known name to own.
 789  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 790  * @bus_acquired_closure: (allow-none): #GClosure to invoke when connected to
 791  * the bus of type @bus_type or %NULL.
 792  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 793  * acquired or %NULL.
 794  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 795  * %NULL.
 796  *
 797  * Version of g_bus_own_name() using closures instead of callbacks for
 798  * easier binding in other languages.
 799  *
 800  * Returns: An identifier (never 0) that an be used with
 801  * g_bus_unown_name() to stop owning the name.
 802  *
 803  * Rename to: g_bus_own_name
 804  *
 805  * Since: 2.26
 806  */
 807 guint
 808 g_bus_own_name_with_closures (GBusType                  bus_type,
 809                               const gchar              *name,
 810                               GBusNameOwnerFlags        flags,
 811                               GClosure                 *bus_acquired_closure,
 812                               GClosure                 *name_acquired_closure,
 813                               GClosure                 *name_lost_closure)
 814 {
 815   return g_bus_own_name (bus_type,
 816           name,
 817           flags,
 818           bus_acquired_closure != NULL ? own_with_closures_on_bus_acquired : NULL,
 819           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 820           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 821           own_name_data_new (bus_acquired_closure,
 822                              name_acquired_closure,
 823                              name_lost_closure),
 824           bus_own_name_free_func);
 825 }
 826
 827 /**
 828  * g_bus_own_name_on_connection_with_closures:
 829  * @connection: A #GDBusConnection.
 830  * @name: The well-known name to own.
 831  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 832  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 833  * acquired or %NULL.
 834  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 835  * %NULL.
 836  *
 837  * Version of g_bus_own_name_on_connection() using closures instead of callbacks for
 838  * easier binding in other languages.
 839  *
 840  * Returns: An identifier (never 0) that an be used with
 841  * g_bus_unown_name() to stop owning the name.
 842  *
 843  * Rename to: g_bus_own_name_on_connection
 844  *
 845  * Since: 2.26
 846  */
 847 guint
 848 g_bus_own_name_on_connection_with_closures (GDBusConnection          *connection,
 849                                             const gchar              *name,
 850                                             GBusNameOwnerFlags        flags,
 851                                             GClosure                 *name_acquired_closure,
 852                                             GClosure                 *name_lost_closure)
 853 {
 854   return g_bus_own_name_on_connection (connection,
 855           name,
 856           flags,
 857           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 858           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 859           own_name_data_new (NULL,
 860                              name_acquired_closure,
 861                              name_lost_closure),
 862           bus_own_name_free_func);
 863 }
 864
 865 /**
 866  * g_bus_unown_name:
 867  * @owner_id: An identifier obtained from g_bus_own_name()
 868  *
 869  * Stops owning a name.
 870  *
 871  * Since: 2.26
 872  */
 873 void
 874 g_bus_unown_name (guint owner_id)
 875 {
 876   Client *client;
 877
 878   g_return_if_fail (owner_id > 0);
 879
 880   client = NULL;
 881
 882   G_LOCK (lock);
 883   if (owner_id == 0 || map_id_to_client == NULL ||
 884       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (owner_id))) == NULL)
 885     {
 886       g_warning ("Invalid id %d passed to g_bus_unown_name()", owner_id);
 887       goto out;
 888     }
 889
 890   client->cancelled = TRUE;
 891   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (owner_id)));
 892
 893  out:
 894   G_UNLOCK (lock);
 895
 896   /* do callback without holding lock */
 897   if (client != NULL)
 898     {
 899       /* Release the name if needed */
 900       if (client->needs_release &&
 901           client->connection != NULL &&
 902           !g_dbus_connection_is_closed (client->connection))
 903         {
 904           GVariant *result;
 905           GError *error;
 906           guint32 release_name_reply;
 907
 908           /* TODO: it kinda sucks having to do a sync call to release the name - but if
 909            * we don't, then a subsequent grab of the name will make the bus daemon return
 910            * IN_QUEUE which will trigger name_lost().
 911            *
 912            * I believe this is a bug in the bus daemon.
 913            */
 914           error = NULL;
 915           result = g_dbus_connection_call_sync (client->connection,
 916                                                 "org.freedesktop.DBus",  /* bus name */
 917                                                 "/org/freedesktop/DBus", /* object path */
 918                                                 "org.freedesktop.DBus",  /* interface name */
 919                                                 "ReleaseName",           /* method name */
 920                                                 g_variant_new ("(s)", client->name),
 921                                                 G_VARIANT_TYPE ("(u)"),
 922                                                 G_DBUS_CALL_FLAGS_NONE,
 923                                                 -1,
 924                                                 NULL,
 925                                                 &error);
 926           if (result == NULL)
 927             {
 928               g_warning ("Error releasing name %s: %s", client->name, error->message);
 929               g_error_free (error);
 930             }
 931           else
 932             {
 933               g_variant_get (result, "(u)", &release_name_reply);
 934               if (release_name_reply != 1 /* DBUS_RELEASE_NAME_REPLY_RELEASED */)
 935                 {
 936                   g_warning ("Unexpected reply %d when releasing name %s", release_name_reply, client->name);
 937                 }
 938               g_variant_unref (result);
 939             }
 940         }
 941
 942       if (client->disconnected_signal_handler_id > 0)
 943         g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 944       if (client->name_acquired_subscription_id > 0)
 945         g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 946       if (client->name_lost_subscription_id > 0)
 947         g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 948       client->disconnected_signal_handler_id = 0;
 949       client->name_acquired_subscription_id = 0;
 950       client->name_lost_subscription_id = 0;
 951       if (client->connection != NULL)
 952         {
 953           g_object_unref (client->connection);
 954           client->connection = NULL;
 955         }
 956
 957       client_unref (client);
 958     }
 959 }