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   volatile gboolean         cancelled; /* must hold lock when reading or modifying */
  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       g_main_context_unref (client->main_context);
 109       g_free (client->name);
 110       if (client->user_data_free_func != NULL)
 111         client->user_data_free_func (client->user_data);
 112       g_free (client);
 113     }
 114 }
 115
 116 /* ---------------------------------------------------------------------------------------------------- */
 117
 118
 119 typedef enum
 120 {
 121   CALL_TYPE_NAME_ACQUIRED,
 122   CALL_TYPE_NAME_LOST
 123 } CallType;
 124
 125 typedef struct
 126 {
 127   Client *client;
 128
 129   /* keep this separate because client->connection may
 130    * be set to NULL after scheduling the call
 131    */
 132   GDBusConnection *connection;
 133
 134   /* set to TRUE to call acquired */
 135   CallType call_type;
 136 } CallHandlerData;
 137
 138 static void
 139 call_handler_data_free (CallHandlerData *data)
 140 {
 141   if (data->connection != NULL)
 142     g_object_unref (data->connection);
 143   client_unref (data->client);
 144   g_free (data);
 145 }
 146
 147 static void
 148 actually_do_call (Client *client, GDBusConnection *connection, CallType call_type)
 149 {
 150   switch (call_type)
 151     {
 152     case CALL_TYPE_NAME_ACQUIRED:
 153       if (client->name_acquired_handler != NULL)
 154         {
 155           client->name_acquired_handler (connection,
 156                                          client->name,
 157                                          client->user_data);
 158         }
 159       break;
 160
 161     case CALL_TYPE_NAME_LOST:
 162       if (client->name_lost_handler != NULL)
 163         {
 164           client->name_lost_handler (connection,
 165                                      client->name,
 166                                      client->user_data);
 167         }
 168       break;
 169
 170     default:
 171       g_assert_not_reached ();
 172       break;
 173     }
 174 }
 175
 176 static gboolean
 177 call_in_idle_cb (gpointer _data)
 178 {
 179   CallHandlerData *data = _data;
 180   actually_do_call (data->client, data->connection, data->call_type);
 181   return FALSE;
 182 }
 183
 184 static void
 185 schedule_call_in_idle (Client *client, CallType  call_type)
 186 {
 187   CallHandlerData *data;
 188   GSource *idle_source;
 189
 190   data = g_new0 (CallHandlerData, 1);
 191   data->client = client_ref (client);
 192   data->connection = client->connection != NULL ? g_object_ref (client->connection) : NULL;
 193   data->call_type = call_type;
 194
 195   idle_source = g_idle_source_new ();
 196   g_source_set_priority (idle_source, G_PRIORITY_HIGH);
 197   g_source_set_callback (idle_source,
 198                          call_in_idle_cb,
 199                          data,
 200                          (GDestroyNotify) call_handler_data_free);
 201   g_source_attach (idle_source, client->main_context);
 202   g_source_unref (idle_source);
 203 }
 204
 205 static void
 206 do_call (Client *client, CallType call_type)
 207 {
 208   GMainContext *current_context;
 209
 210   /* only schedule in idle if we're not in the right thread */
 211   current_context = g_main_context_ref_thread_default ();
 212   if (current_context != client->main_context)
 213     schedule_call_in_idle (client, call_type);
 214   else
 215     actually_do_call (client, client->connection, call_type);
 216   g_main_context_unref (current_context);
 217 }
 218
 219 static void
 220 call_acquired_handler (Client *client)
 221 {
 222   G_LOCK (lock);
 223   if (client->previous_call != PREVIOUS_CALL_ACQUIRED)
 224     {
 225       client->previous_call = PREVIOUS_CALL_ACQUIRED;
 226       if (!client->cancelled)
 227         {
 228           G_UNLOCK (lock);
 229           do_call (client, CALL_TYPE_NAME_ACQUIRED);
 230           goto out;
 231         }
 232     }
 233   G_UNLOCK (lock);
 234  out:
 235   ;
 236 }
 237
 238 static void
 239 call_lost_handler (Client  *client)
 240 {
 241   G_LOCK (lock);
 242   if (client->previous_call != PREVIOUS_CALL_LOST)
 243     {
 244       client->previous_call = PREVIOUS_CALL_LOST;
 245       if (!client->cancelled)
 246         {
 247           G_UNLOCK (lock);
 248           do_call (client, CALL_TYPE_NAME_LOST);
 249           goto out;
 250         }
 251     }
 252   G_UNLOCK (lock);
 253  out:
 254   ;
 255 }
 256
 257 /* ---------------------------------------------------------------------------------------------------- */
 258
 259 static void
 260 on_name_lost_or_acquired (GDBusConnection  *connection,
 261                           const gchar      *sender_name,
 262                           const gchar      *object_path,
 263                           const gchar      *interface_name,
 264                           const gchar      *signal_name,
 265                           GVariant         *parameters,
 266                           gpointer          user_data)
 267 {
 268   Client *client = user_data;
 269   const gchar *name;
 270
 271   if (g_strcmp0 (object_path, "/org/freedesktop/DBus") != 0 ||
 272       g_strcmp0 (interface_name, "org.freedesktop.DBus") != 0 ||
 273       g_strcmp0 (sender_name, "org.freedesktop.DBus") != 0)
 274     goto out;
 275
 276   if (g_strcmp0 (signal_name, "NameLost") == 0)
 277     {
 278       g_variant_get (parameters, "(&s)", &name);
 279       if (g_strcmp0 (name, client->name) == 0)
 280         {
 281           call_lost_handler (client);
 282         }
 283     }
 284   else if (g_strcmp0 (signal_name, "NameAcquired") == 0)
 285     {
 286       g_variant_get (parameters, "(&s)", &name);
 287       if (g_strcmp0 (name, client->name) == 0)
 288         {
 289           call_acquired_handler (client);
 290         }
 291     }
 292  out:
 293   ;
 294 }
 295
 296 /* ---------------------------------------------------------------------------------------------------- */
 297
 298 static void
 299 request_name_cb (GObject      *source_object,
 300                  GAsyncResult *res,
 301                  gpointer      user_data)
 302 {
 303   Client *client = user_data;
 304   GVariant *result;
 305   guint32 request_name_reply;
 306   gboolean subscribe;
 307
 308   request_name_reply = 0;
 309   result = NULL;
 310
 311   /* don't use client->connection - it may be NULL already */
 312   result = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source_object),
 313                                           res,
 314                                           NULL);
 315   if (result != NULL)
 316     {
 317       g_variant_get (result, "(u)", &request_name_reply);
 318       g_variant_unref (result);
 319     }
 320
 321   subscribe = FALSE;
 322
 323   switch (request_name_reply)
 324     {
 325     case 1: /* DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER */
 326       /* We got the name - now listen for NameLost and NameAcquired */
 327       call_acquired_handler (client);
 328       subscribe = TRUE;
 329       client->needs_release = TRUE;
 330       break;
 331
 332     case 2: /* DBUS_REQUEST_NAME_REPLY_IN_QUEUE */
 333       /* Waiting in line - listen for NameLost and NameAcquired */
 334       call_lost_handler (client);
 335       subscribe = TRUE;
 336       client->needs_release = TRUE;
 337       break;
 338
 339     default:
 340       /* assume we couldn't get the name - explicit fallthrough */
 341     case 3: /* DBUS_REQUEST_NAME_REPLY_EXISTS */
 342     case 4: /* DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER */
 343       /* Some other part of the process is already owning the name */
 344       call_lost_handler (client);
 345       break;
 346     }
 347
 348
 349   if (subscribe)
 350     {
 351       GDBusConnection *connection = NULL;
 352
 353       /* if cancelled, there is no point in subscribing to signals - if not, make sure
 354        * we use a known good Connection object since it may be set to NULL at any point
 355        * after being cancelled
 356        */
 357       G_LOCK (lock);
 358       if (!client->cancelled)
 359         connection = g_object_ref (client->connection);
 360       G_UNLOCK (lock);
 361
 362       /* start listening to NameLost and NameAcquired messages */
 363       if (connection != NULL)
 364         {
 365           client->name_lost_subscription_id =
 366             g_dbus_connection_signal_subscribe (connection,
 367                                                 "org.freedesktop.DBus",
 368                                                 "org.freedesktop.DBus",
 369                                                 "NameLost",
 370                                                 "/org/freedesktop/DBus",
 371                                                 client->name,
 372                                                 G_DBUS_SIGNAL_FLAGS_NONE,
 373                                                 on_name_lost_or_acquired,
 374                                                 client,
 375                                                 NULL);
 376           client->name_acquired_subscription_id =
 377             g_dbus_connection_signal_subscribe (connection,
 378                                                 "org.freedesktop.DBus",
 379                                                 "org.freedesktop.DBus",
 380                                                 "NameAcquired",
 381                                                 "/org/freedesktop/DBus",
 382                                                 client->name,
 383                                                 G_DBUS_SIGNAL_FLAGS_NONE,
 384                                                 on_name_lost_or_acquired,
 385                                                 client,
 386                                                 NULL);
 387           g_object_unref (connection);
 388         }
 389     }
 390
 391   client_unref (client);
 392 }
 393
 394 /* ---------------------------------------------------------------------------------------------------- */
 395
 396 static void
 397 on_connection_disconnected (GDBusConnection *connection,
 398                             gboolean         remote_peer_vanished,
 399                             GError          *error,
 400                             gpointer         user_data)
 401 {
 402   Client *client = user_data;
 403
 404   if (client->disconnected_signal_handler_id > 0)
 405     g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 406   if (client->name_acquired_subscription_id > 0)
 407     g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 408   if (client->name_lost_subscription_id > 0)
 409     g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 410   g_object_unref (client->connection);
 411   client->disconnected_signal_handler_id = 0;
 412   client->name_acquired_subscription_id = 0;
 413   client->name_lost_subscription_id = 0;
 414   client->connection = NULL;
 415
 416   call_lost_handler (client);
 417 }
 418
 419 /* ---------------------------------------------------------------------------------------------------- */
 420
 421 static void
 422 has_connection (Client *client)
 423 {
 424   /* listen for disconnection */
 425   client->disconnected_signal_handler_id = g_signal_connect (client->connection,
 426                                                              "closed",
 427                                                              G_CALLBACK (on_connection_disconnected),
 428                                                              client);
 429
 430   /* attempt to acquire the name */
 431   g_dbus_connection_call (client->connection,
 432                           "org.freedesktop.DBus",  /* bus name */
 433                           "/org/freedesktop/DBus", /* object path */
 434                           "org.freedesktop.DBus",  /* interface name */
 435                           "RequestName",           /* method name */
 436                           g_variant_new ("(su)",
 437                                          client->name,
 438                                          client->flags),
 439                           G_VARIANT_TYPE ("(u)"),
 440                           G_DBUS_CALL_FLAGS_NONE,
 441                           -1,
 442                           NULL,
 443                           (GAsyncReadyCallback) request_name_cb,
 444                           client_ref (client));
 445 }
 446
 447
 448 static void
 449 connection_get_cb (GObject      *source_object,
 450                    GAsyncResult *res,
 451                    gpointer      user_data)
 452 {
 453   Client *client = user_data;
 454
 455   /* must not do anything if already cancelled */
 456   G_LOCK (lock);
 457   if (client->cancelled)
 458     {
 459       G_UNLOCK (lock);
 460       goto out;
 461     }
 462   G_UNLOCK (lock);
 463
 464   client->connection = g_bus_get_finish (res, NULL);
 465   if (client->connection == NULL)
 466     {
 467       call_lost_handler (client);
 468       goto out;
 469     }
 470
 471   /* No need to schedule this in idle as we're already in the thread
 472    * that the user called g_bus_own_name() from. This is because
 473    * g_bus_get() guarantees that.
 474    *
 475    * Also, we need to ensure that the handler is invoked *before*
 476    * we call RequestName(). Otherwise there is a race.
 477    */
 478   if (client->bus_acquired_handler != NULL)
 479     {
 480       client->bus_acquired_handler (client->connection,
 481                                     client->name,
 482                                     client->user_data);
 483     }
 484
 485   has_connection (client);
 486
 487  out:
 488   client_unref (client);
 489 }
 490
 491 /* ---------------------------------------------------------------------------------------------------- */
 492
 493 /**
 494  * g_bus_own_name_on_connection:
 495  * @connection: A #GDBusConnection.
 496  * @name: The well-known name to own.
 497  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 498  * @name_acquired_handler: (allow-none): Handler to invoke when @name is acquired or %NULL.
 499  * @name_lost_handler: (allow-none): Handler to invoke when @name is lost or %NULL.
 500  * @user_data: User data to pass to handlers.
 501  * @user_data_free_func: (allow-none): Function for freeing @user_data or %NULL.
 502  *
 503  * Like g_bus_own_name() but takes a #GDBusConnection instead of a
 504  * #GBusType.
 505  *
 506  * Returns: An identifier (never 0) that an be used with
 507  * g_bus_unown_name() to stop owning the name.
 508  *
 509  * Since: 2.26
 510  */
 511 guint
 512 g_bus_own_name_on_connection (GDBusConnection          *connection,
 513                               const gchar              *name,
 514                               GBusNameOwnerFlags        flags,
 515                               GBusNameAcquiredCallback  name_acquired_handler,
 516                               GBusNameLostCallback      name_lost_handler,
 517                               gpointer                  user_data,
 518                               GDestroyNotify            user_data_free_func)
 519 {
 520   Client *client;
 521
 522   g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
 523   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 524
 525   G_LOCK (lock);
 526
 527   client = g_new0 (Client, 1);
 528   client->ref_count = 1;
 529   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 530   client->name = g_strdup (name);
 531   client->flags = flags;
 532   client->name_acquired_handler = name_acquired_handler;
 533   client->name_lost_handler = name_lost_handler;
 534   client->user_data = user_data;
 535   client->user_data_free_func = user_data_free_func;
 536   client->main_context = g_main_context_ref_thread_default ();
 537
 538   client->connection = g_object_ref (connection);
 539
 540   if (map_id_to_client == NULL)
 541     {
 542       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 543     }
 544   g_hash_table_insert (map_id_to_client,
 545                        GUINT_TO_POINTER (client->id),
 546                        client);
 547
 548   G_UNLOCK (lock);
 549
 550   has_connection (client);
 551
 552   return client->id;
 553 }
 554
 555 /**
 556  * g_bus_own_name:
 557  * @bus_type: The type of bus to own a name on.
 558  * @name: The well-known name to own.
 559  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 560  * @bus_acquired_handler: (allow-none): Handler to invoke when connected to the bus of type @bus_type or %NULL.
 561  * @name_acquired_handler: (allow-none): Handler to invoke when @name is acquired or %NULL.
 562  * @name_lost_handler: (allow-none): Handler to invoke when @name is lost or %NULL.
 563  * @user_data: User data to pass to handlers.
 564  * @user_data_free_func: (allow-none): Function for freeing @user_data or %NULL.
 565  *
 566  * Starts acquiring @name on the bus specified by @bus_type and calls
 567  * @name_acquired_handler and @name_lost_handler when the name is
 568  * acquired respectively lost. Callbacks will be invoked in the <link
 569  * linkend="g-main-context-push-thread-default">thread-default main
 570  * loop</link> of the thread you are calling this function from.
 571  *
 572  * You are guaranteed that one of the @name_acquired_handler and @name_lost_handler
 573  * callbacks will be invoked after calling this function - there are three
 574  * possible cases:
 575  * <itemizedlist>
 576  *   <listitem><para>
 577  *     @name_lost_handler with a %NULL connection (if a connection to the bus can't be made).
 578  *   </para></listitem>
 579  *   <listitem><para>
 580  *     @bus_acquired_handler then @name_lost_handler (if the name can't be obtained)
 581  *   </para></listitem>
 582  *   <listitem><para>
 583  *     @bus_acquired_handler then @name_acquired_handler (if the name was obtained).
 584  *   </para></listitem>
 585  * </itemizedlist>
 586  * When you are done owning the name, just call g_bus_unown_name()
 587  * with the owner id this function returns.
 588  *
 589  * If the name is acquired or lost (for example another application
 590  * could acquire the name if you allow replacement or the application
 591  * currently owning the name exits), the handlers are also invoked. If the
 592  * #GDBusConnection that is used for attempting to own the name
 593  * closes, then @name_lost_handler is invoked since it is no
 594  * longer possible for other processes to access the process.
 595  *
 596  * You cannot use g_bus_own_name() several times for the same name (unless
 597  * interleaved with calls to g_bus_unown_name()) - only the first call
 598  * will work.
 599  *
 600  * Another guarantee is that invocations of @name_acquired_handler
 601  * and @name_lost_handler are guaranteed to alternate; that
 602  * is, if @name_acquired_handler is invoked then you are
 603  * guaranteed that the next time one of the handlers is invoked, it
 604  * will be @name_lost_handler. The reverse is also true.
 605  *
 606  * If you plan on exporting objects (using e.g.
 607  * g_dbus_connection_register_object()), note that it is generally too late
 608  * to export the objects in @name_acquired_handler. Instead, you can do this
 609  * in @bus_acquired_handler since you are guaranteed that this will run
 610  * before @name is requested from the bus.
 611  *
 612  * This behavior makes it very simple to write applications that wants
 613  * to own names and export objects, see <xref linkend="gdbus-owning-names"/>.
 614  * Simply register objects to be exported in @bus_acquired_handler and
 615  * unregister the objects (if any) in @name_lost_handler.
 616  *
 617  * Returns: An identifier (never 0) that an be used with
 618  * g_bus_unown_name() to stop owning the name.
 619  *
 620  * Since: 2.26
 621  */
 622 guint
 623 g_bus_own_name (GBusType                  bus_type,
 624                 const gchar              *name,
 625                 GBusNameOwnerFlags        flags,
 626                 GBusAcquiredCallback      bus_acquired_handler,
 627                 GBusNameAcquiredCallback  name_acquired_handler,
 628                 GBusNameLostCallback      name_lost_handler,
 629                 gpointer                  user_data,
 630                 GDestroyNotify            user_data_free_func)
 631 {
 632   Client *client;
 633
 634   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 635
 636   G_LOCK (lock);
 637
 638   client = g_new0 (Client, 1);
 639   client->ref_count = 1;
 640   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 641   client->name = g_strdup (name);
 642   client->flags = flags;
 643   client->bus_acquired_handler = bus_acquired_handler;
 644   client->name_acquired_handler = name_acquired_handler;
 645   client->name_lost_handler = name_lost_handler;
 646   client->user_data = user_data;
 647   client->user_data_free_func = user_data_free_func;
 648   client->main_context = g_main_context_ref_thread_default ();
 649
 650   if (map_id_to_client == NULL)
 651     {
 652       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 653     }
 654   g_hash_table_insert (map_id_to_client,
 655                        GUINT_TO_POINTER (client->id),
 656                        client);
 657
 658   g_bus_get (bus_type,
 659              NULL,
 660              connection_get_cb,
 661              client_ref (client));
 662
 663   G_UNLOCK (lock);
 664
 665   return client->id;
 666 }
 667
 668 typedef struct {
 669   GClosure *bus_acquired_closure;
 670   GClosure *name_acquired_closure;
 671   GClosure *name_lost_closure;
 672 } OwnNameData;
 673
 674 static OwnNameData *
 675 own_name_data_new (GClosure *bus_acquired_closure,
 676                    GClosure *name_acquired_closure,
 677                    GClosure *name_lost_closure)
 678 {
 679   OwnNameData *data;
 680
 681   data = g_new0 (OwnNameData, 1);
 682
 683   if (bus_acquired_closure != NULL)
 684     {
 685       data->bus_acquired_closure = g_closure_ref (bus_acquired_closure);
 686       g_closure_sink (bus_acquired_closure);
 687       if (G_CLOSURE_NEEDS_MARSHAL (bus_acquired_closure))
 688         g_closure_set_marshal (bus_acquired_closure, g_cclosure_marshal_generic);
 689     }
 690
 691   if (name_acquired_closure != NULL)
 692     {
 693       data->name_acquired_closure = g_closure_ref (name_acquired_closure);
 694       g_closure_sink (name_acquired_closure);
 695       if (G_CLOSURE_NEEDS_MARSHAL (name_acquired_closure))
 696         g_closure_set_marshal (name_acquired_closure, g_cclosure_marshal_generic);
 697     }
 698
 699   if (name_lost_closure != NULL)
 700     {
 701       data->name_lost_closure = g_closure_ref (name_lost_closure);
 702       g_closure_sink (name_lost_closure);
 703       if (G_CLOSURE_NEEDS_MARSHAL (name_lost_closure))
 704         g_closure_set_marshal (name_lost_closure, g_cclosure_marshal_generic);
 705     }
 706
 707   return data;
 708 }
 709
 710 static void
 711 own_with_closures_on_bus_acquired (GDBusConnection *connection,
 712                                    const gchar     *name,
 713                                    gpointer         user_data)
 714 {
 715   OwnNameData *data = user_data;
 716   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 717
 718   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 719   g_value_set_object (&params[0], connection);
 720
 721   g_value_init (&params[1], G_TYPE_STRING);
 722   g_value_set_string (&params[1], name);
 723
 724   g_closure_invoke (data->bus_acquired_closure, NULL, 2, params, NULL);
 725
 726   g_value_unset (params + 0);
 727   g_value_unset (params + 1);
 728 }
 729
 730 static void
 731 own_with_closures_on_name_acquired (GDBusConnection *connection,
 732                                     const gchar     *name,
 733                                     gpointer         user_data)
 734 {
 735   OwnNameData *data = user_data;
 736   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 737
 738   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 739   g_value_set_object (&params[0], connection);
 740
 741   g_value_init (&params[1], G_TYPE_STRING);
 742   g_value_set_string (&params[1], name);
 743
 744   g_closure_invoke (data->name_acquired_closure, NULL, 2, params, NULL);
 745
 746   g_value_unset (params + 0);
 747   g_value_unset (params + 1);
 748 }
 749
 750 static void
 751 own_with_closures_on_name_lost (GDBusConnection *connection,
 752                                 const gchar     *name,
 753                                 gpointer         user_data)
 754 {
 755   OwnNameData *data = user_data;
 756   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 757
 758   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 759   g_value_set_object (&params[0], connection);
 760
 761   g_value_init (&params[1], G_TYPE_STRING);
 762   g_value_set_string (&params[1], name);
 763
 764   g_closure_invoke (data->name_lost_closure, NULL, 2, params, NULL);
 765
 766   g_value_unset (params + 0);
 767   g_value_unset (params + 1);
 768 }
 769
 770 static void
 771 bus_own_name_free_func (gpointer user_data)
 772 {
 773   OwnNameData *data = user_data;
 774
 775   if (data->bus_acquired_closure != NULL)
 776     g_closure_unref (data->bus_acquired_closure);
 777
 778   if (data->name_acquired_closure != NULL)
 779     g_closure_unref (data->name_acquired_closure);
 780
 781   if (data->name_lost_closure != NULL)
 782     g_closure_unref (data->name_lost_closure);
 783
 784   g_free (data);
 785 }
 786
 787 /**
 788  * g_bus_own_name_with_closures:
 789  * @bus_type: The type of bus to own a name on.
 790  * @name: The well-known name to own.
 791  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 792  * @bus_acquired_closure: (allow-none): #GClosure to invoke when connected to
 793  * the bus of type @bus_type or %NULL.
 794  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 795  * acquired or %NULL.
 796  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 797  * %NULL.
 798  *
 799  * Version of g_bus_own_name() using closures instead of callbacks for
 800  * easier binding in other languages.
 801  *
 802  * Returns: An identifier (never 0) that an be used with
 803  * g_bus_unown_name() to stop owning the name.
 804  *
 805  * Rename to: g_bus_own_name
 806  *
 807  * Since: 2.26
 808  */
 809 guint
 810 g_bus_own_name_with_closures (GBusType                  bus_type,
 811                               const gchar              *name,
 812                               GBusNameOwnerFlags        flags,
 813                               GClosure                 *bus_acquired_closure,
 814                               GClosure                 *name_acquired_closure,
 815                               GClosure                 *name_lost_closure)
 816 {
 817   return g_bus_own_name (bus_type,
 818           name,
 819           flags,
 820           bus_acquired_closure != NULL ? own_with_closures_on_bus_acquired : NULL,
 821           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 822           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 823           own_name_data_new (bus_acquired_closure,
 824                              name_acquired_closure,
 825                              name_lost_closure),
 826           bus_own_name_free_func);
 827 }
 828
 829 /**
 830  * g_bus_own_name_on_connection_with_closures:
 831  * @connection: A #GDBusConnection.
 832  * @name: The well-known name to own.
 833  * @flags: A set of flags from the #GBusNameOwnerFlags enumeration.
 834  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 835  * acquired or %NULL.
 836  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 837  * %NULL.
 838  *
 839  * Version of g_bus_own_name_on_connection() using closures instead of callbacks for
 840  * easier binding in other languages.
 841  *
 842  * Returns: An identifier (never 0) that an be used with
 843  * g_bus_unown_name() to stop owning the name.
 844  *
 845  * Rename to: g_bus_own_name_on_connection
 846  *
 847  * Since: 2.26
 848  */
 849 guint
 850 g_bus_own_name_on_connection_with_closures (GDBusConnection          *connection,
 851                                             const gchar              *name,
 852                                             GBusNameOwnerFlags        flags,
 853                                             GClosure                 *name_acquired_closure,
 854                                             GClosure                 *name_lost_closure)
 855 {
 856   return g_bus_own_name_on_connection (connection,
 857           name,
 858           flags,
 859           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 860           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 861           own_name_data_new (NULL,
 862                              name_acquired_closure,
 863                              name_lost_closure),
 864           bus_own_name_free_func);
 865 }
 866
 867 /**
 868  * g_bus_unown_name:
 869  * @owner_id: An identifier obtained from g_bus_own_name()
 870  *
 871  * Stops owning a name.
 872  *
 873  * Since: 2.26
 874  */
 875 void
 876 g_bus_unown_name (guint owner_id)
 877 {
 878   Client *client;
 879
 880   g_return_if_fail (owner_id > 0);
 881
 882   client = NULL;
 883
 884   G_LOCK (lock);
 885   if (owner_id == 0 || map_id_to_client == NULL ||
 886       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (owner_id))) == NULL)
 887     {
 888       g_warning ("Invalid id %d passed to g_bus_unown_name()", owner_id);
 889       goto out;
 890     }
 891
 892   client->cancelled = TRUE;
 893   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (owner_id)));
 894
 895  out:
 896   G_UNLOCK (lock);
 897
 898   /* do callback without holding lock */
 899   if (client != NULL)
 900     {
 901       /* Release the name if needed */
 902       if (client->needs_release &&
 903           client->connection != NULL &&
 904           !g_dbus_connection_is_closed (client->connection))
 905         {
 906           GVariant *result;
 907           GError *error;
 908           guint32 release_name_reply;
 909
 910           /* TODO: it kinda sucks having to do a sync call to release the name - but if
 911            * we don't, then a subsequent grab of the name will make the bus daemon return
 912            * IN_QUEUE which will trigger name_lost().
 913            *
 914            * I believe this is a bug in the bus daemon.
 915            */
 916           error = NULL;
 917           result = g_dbus_connection_call_sync (client->connection,
 918                                                 "org.freedesktop.DBus",  /* bus name */
 919                                                 "/org/freedesktop/DBus", /* object path */
 920                                                 "org.freedesktop.DBus",  /* interface name */
 921                                                 "ReleaseName",           /* method name */
 922                                                 g_variant_new ("(s)", client->name),
 923                                                 G_VARIANT_TYPE ("(u)"),
 924                                                 G_DBUS_CALL_FLAGS_NONE,
 925                                                 -1,
 926                                                 NULL,
 927                                                 &error);
 928           if (result == NULL)
 929             {
 930               g_warning ("Error releasing name %s: %s", client->name, error->message);
 931               g_error_free (error);
 932             }
 933           else
 934             {
 935               g_variant_get (result, "(u)", &release_name_reply);
 936               if (release_name_reply != 1 /* DBUS_RELEASE_NAME_REPLY_RELEASED */)
 937                 {
 938                   g_warning ("Unexpected reply %d when releasing name %s", release_name_reply, client->name);
 939                 }
 940               g_variant_unref (result);
 941             }
 942         }
 943
 944       if (client->disconnected_signal_handler_id > 0)
 945         g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 946       if (client->name_acquired_subscription_id > 0)
 947         g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 948       if (client->name_lost_subscription_id > 0)
 949         g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 950       client->disconnected_signal_handler_id = 0;
 951       client->name_acquired_subscription_id = 0;
 952       client->name_lost_subscription_id = 0;
 953       if (client->connection != NULL)
 954         {
 955           g_object_unref (client->connection);
 956           client->connection = NULL;
 957         }
 958
 959       client_unref (client);
 960     }
 961 }