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  * A simple example for owning a name can be found in
  42  * [gdbus-example-own-name.c](https://git.gnome.org/browse/glib/tree/gio/tests/gdbus-example-own-name.c)
  43  */
  44
  45 G_LOCK_DEFINE_STATIC (lock);
  46
  47 /* ---------------------------------------------------------------------------------------------------- */
  48
  49 typedef enum
  50 {
  51   PREVIOUS_CALL_NONE = 0,
  52   PREVIOUS_CALL_ACQUIRED,
  53   PREVIOUS_CALL_LOST,
  54 } PreviousCall;
  55
  56 typedef struct
  57 {
  58   volatile gint             ref_count;
  59   guint                     id;
  60   GBusNameOwnerFlags        flags;
  61   gchar                    *name;
  62   GBusAcquiredCallback      bus_acquired_handler;
  63   GBusNameAcquiredCallback  name_acquired_handler;
  64   GBusNameLostCallback      name_lost_handler;
  65   gpointer                  user_data;
  66   GDestroyNotify            user_data_free_func;
  67   GMainContext             *main_context;
  68
  69   PreviousCall              previous_call;
  70
  71   GDBusConnection          *connection;
  72   gulong                    disconnected_signal_handler_id;
  73   guint                     name_acquired_subscription_id;
  74   guint                     name_lost_subscription_id;
  75
  76   volatile gboolean         cancelled; /* must hold lock when reading or modifying */
  77
  78   gboolean                  needs_release;
  79 } Client;
  80
  81 static guint next_global_id = 1;
  82 static GHashTable *map_id_to_client = NULL;
  83
  84
  85 static Client *
  86 client_ref (Client *client)
  87 {
  88   g_atomic_int_inc (&client->ref_count);
  89   return client;
  90 }
  91
  92 static void
  93 client_unref (Client *client)
  94 {
  95   if (g_atomic_int_dec_and_test (&client->ref_count))
  96     {
  97       if (client->connection != NULL)
  98         {
  99           if (client->disconnected_signal_handler_id > 0)
 100             g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 101           if (client->name_acquired_subscription_id > 0)
 102             g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 103           if (client->name_lost_subscription_id > 0)
 104             g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 105           g_object_unref (client->connection);
 106         }
 107       g_main_context_unref (client->main_context);
 108       g_free (client->name);
 109       if (client->user_data_free_func != NULL)
 110         client->user_data_free_func (client->user_data);
 111       g_free (client);
 112     }
 113 }
 114
 115 /* ---------------------------------------------------------------------------------------------------- */
 116
 117
 118 typedef enum
 119 {
 120   CALL_TYPE_NAME_ACQUIRED,
 121   CALL_TYPE_NAME_LOST
 122 } CallType;
 123
 124 typedef struct
 125 {
 126   Client *client;
 127
 128   /* keep this separate because client->connection may
 129    * be set to NULL after scheduling the call
 130    */
 131   GDBusConnection *connection;
 132
 133   /* set to TRUE to call acquired */
 134   CallType call_type;
 135 } CallHandlerData;
 136
 137 static void
 138 call_handler_data_free (CallHandlerData *data)
 139 {
 140   if (data->connection != NULL)
 141     g_object_unref (data->connection);
 142   client_unref (data->client);
 143   g_free (data);
 144 }
 145
 146 static void
 147 actually_do_call (Client *client, GDBusConnection *connection, CallType call_type)
 148 {
 149   switch (call_type)
 150     {
 151     case CALL_TYPE_NAME_ACQUIRED:
 152       if (client->name_acquired_handler != NULL)
 153         {
 154           client->name_acquired_handler (connection,
 155                                          client->name,
 156                                          client->user_data);
 157         }
 158       break;
 159
 160     case CALL_TYPE_NAME_LOST:
 161       if (client->name_lost_handler != NULL)
 162         {
 163           client->name_lost_handler (connection,
 164                                      client->name,
 165                                      client->user_data);
 166         }
 167       break;
 168
 169     default:
 170       g_assert_not_reached ();
 171       break;
 172     }
 173 }
 174
 175 static gboolean
 176 call_in_idle_cb (gpointer _data)
 177 {
 178   CallHandlerData *data = _data;
 179   actually_do_call (data->client, data->connection, data->call_type);
 180   return FALSE;
 181 }
 182
 183 static void
 184 schedule_call_in_idle (Client *client, CallType  call_type)
 185 {
 186   CallHandlerData *data;
 187   GSource *idle_source;
 188
 189   data = g_new0 (CallHandlerData, 1);
 190   data->client = client_ref (client);
 191   data->connection = client->connection != NULL ? g_object_ref (client->connection) : NULL;
 192   data->call_type = call_type;
 193
 194   idle_source = g_idle_source_new ();
 195   g_source_set_priority (idle_source, G_PRIORITY_HIGH);
 196   g_source_set_callback (idle_source,
 197                          call_in_idle_cb,
 198                          data,
 199                          (GDestroyNotify) call_handler_data_free);
 200   g_source_set_name (idle_source, "[gio] call_in_idle_cb");
 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
 569  * [thread-default main context][g-main-context-push-thread-default]
 570  * 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  *
 576  * - @name_lost_handler with a %NULL connection (if a connection to the bus
 577  *   can't be made).
 578  *
 579  * - @bus_acquired_handler then @name_lost_handler (if the name can't be
 580  *   obtained)
 581  *
 582  * - @bus_acquired_handler then @name_acquired_handler (if the name was
 583  *   obtained).
 584  *
 585  * When you are done owning the name, just call g_bus_unown_name()
 586  * with the owner id this function returns.
 587  *
 588  * If the name is acquired or lost (for example another application
 589  * could acquire the name if you allow replacement or the application
 590  * currently owning the name exits), the handlers are also invoked.
 591  * If the #GDBusConnection that is used for attempting to own the name
 592  * closes, then @name_lost_handler is invoked since it is no longer
 593  * possible for other processes to access the process.
 594  *
 595  * You cannot use g_bus_own_name() several times for the same name (unless
 596  * interleaved with calls to g_bus_unown_name()) - only the first call
 597  * will work.
 598  *
 599  * Another guarantee is that invocations of @name_acquired_handler
 600  * and @name_lost_handler are guaranteed to alternate; that
 601  * is, if @name_acquired_handler is invoked then you are
 602  * guaranteed that the next time one of the handlers is invoked, it
 603  * will be @name_lost_handler. The reverse is also true.
 604  *
 605  * If you plan on exporting objects (using e.g.
 606  * g_dbus_connection_register_object()), note that it is generally too late
 607  * to export the objects in @name_acquired_handler. Instead, you can do this
 608  * in @bus_acquired_handler since you are guaranteed that this will run
 609  * before @name is requested from the bus.
 610  *
 611  * This behavior makes it very simple to write applications that wants
 612  * to [own names][gdbus-owning-names] and export objects.
 613  * Simply register objects to be exported in @bus_acquired_handler and
 614  * unregister the objects (if any) in @name_lost_handler.
 615  *
 616  * Returns: an identifier (never 0) that an be used with
 617  *     g_bus_unown_name() to stop owning the name.
 618  *
 619  * Since: 2.26
 620  */
 621 guint
 622 g_bus_own_name (GBusType                  bus_type,
 623                 const gchar              *name,
 624                 GBusNameOwnerFlags        flags,
 625                 GBusAcquiredCallback      bus_acquired_handler,
 626                 GBusNameAcquiredCallback  name_acquired_handler,
 627                 GBusNameLostCallback      name_lost_handler,
 628                 gpointer                  user_data,
 629                 GDestroyNotify            user_data_free_func)
 630 {
 631   Client *client;
 632
 633   g_return_val_if_fail (g_dbus_is_name (name) && !g_dbus_is_unique_name (name), 0);
 634
 635   G_LOCK (lock);
 636
 637   client = g_new0 (Client, 1);
 638   client->ref_count = 1;
 639   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 640   client->name = g_strdup (name);
 641   client->flags = flags;
 642   client->bus_acquired_handler = bus_acquired_handler;
 643   client->name_acquired_handler = name_acquired_handler;
 644   client->name_lost_handler = name_lost_handler;
 645   client->user_data = user_data;
 646   client->user_data_free_func = user_data_free_func;
 647   client->main_context = g_main_context_ref_thread_default ();
 648
 649   if (map_id_to_client == NULL)
 650     {
 651       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 652     }
 653   g_hash_table_insert (map_id_to_client,
 654                        GUINT_TO_POINTER (client->id),
 655                        client);
 656
 657   g_bus_get (bus_type,
 658              NULL,
 659              connection_get_cb,
 660              client_ref (client));
 661
 662   G_UNLOCK (lock);
 663
 664   return client->id;
 665 }
 666
 667 typedef struct {
 668   GClosure *bus_acquired_closure;
 669   GClosure *name_acquired_closure;
 670   GClosure *name_lost_closure;
 671 } OwnNameData;
 672
 673 static OwnNameData *
 674 own_name_data_new (GClosure *bus_acquired_closure,
 675                    GClosure *name_acquired_closure,
 676                    GClosure *name_lost_closure)
 677 {
 678   OwnNameData *data;
 679
 680   data = g_new0 (OwnNameData, 1);
 681
 682   if (bus_acquired_closure != NULL)
 683     {
 684       data->bus_acquired_closure = g_closure_ref (bus_acquired_closure);
 685       g_closure_sink (bus_acquired_closure);
 686       if (G_CLOSURE_NEEDS_MARSHAL (bus_acquired_closure))
 687         g_closure_set_marshal (bus_acquired_closure, g_cclosure_marshal_generic);
 688     }
 689
 690   if (name_acquired_closure != NULL)
 691     {
 692       data->name_acquired_closure = g_closure_ref (name_acquired_closure);
 693       g_closure_sink (name_acquired_closure);
 694       if (G_CLOSURE_NEEDS_MARSHAL (name_acquired_closure))
 695         g_closure_set_marshal (name_acquired_closure, g_cclosure_marshal_generic);
 696     }
 697
 698   if (name_lost_closure != NULL)
 699     {
 700       data->name_lost_closure = g_closure_ref (name_lost_closure);
 701       g_closure_sink (name_lost_closure);
 702       if (G_CLOSURE_NEEDS_MARSHAL (name_lost_closure))
 703         g_closure_set_marshal (name_lost_closure, g_cclosure_marshal_generic);
 704     }
 705
 706   return data;
 707 }
 708
 709 static void
 710 own_with_closures_on_bus_acquired (GDBusConnection *connection,
 711                                    const gchar     *name,
 712                                    gpointer         user_data)
 713 {
 714   OwnNameData *data = user_data;
 715   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 716
 717   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 718   g_value_set_object (&params[0], connection);
 719
 720   g_value_init (&params[1], G_TYPE_STRING);
 721   g_value_set_string (&params[1], name);
 722
 723   g_closure_invoke (data->bus_acquired_closure, NULL, 2, params, NULL);
 724
 725   g_value_unset (params + 0);
 726   g_value_unset (params + 1);
 727 }
 728
 729 static void
 730 own_with_closures_on_name_acquired (GDBusConnection *connection,
 731                                     const gchar     *name,
 732                                     gpointer         user_data)
 733 {
 734   OwnNameData *data = user_data;
 735   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 736
 737   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 738   g_value_set_object (&params[0], connection);
 739
 740   g_value_init (&params[1], G_TYPE_STRING);
 741   g_value_set_string (&params[1], name);
 742
 743   g_closure_invoke (data->name_acquired_closure, NULL, 2, params, NULL);
 744
 745   g_value_unset (params + 0);
 746   g_value_unset (params + 1);
 747 }
 748
 749 static void
 750 own_with_closures_on_name_lost (GDBusConnection *connection,
 751                                 const gchar     *name,
 752                                 gpointer         user_data)
 753 {
 754   OwnNameData *data = user_data;
 755   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
 756
 757   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 758   g_value_set_object (&params[0], connection);
 759
 760   g_value_init (&params[1], G_TYPE_STRING);
 761   g_value_set_string (&params[1], name);
 762
 763   g_closure_invoke (data->name_lost_closure, NULL, 2, params, NULL);
 764
 765   g_value_unset (params + 0);
 766   g_value_unset (params + 1);
 767 }
 768
 769 static void
 770 bus_own_name_free_func (gpointer user_data)
 771 {
 772   OwnNameData *data = user_data;
 773
 774   if (data->bus_acquired_closure != NULL)
 775     g_closure_unref (data->bus_acquired_closure);
 776
 777   if (data->name_acquired_closure != NULL)
 778     g_closure_unref (data->name_acquired_closure);
 779
 780   if (data->name_lost_closure != NULL)
 781     g_closure_unref (data->name_lost_closure);
 782
 783   g_free (data);
 784 }
 785
 786 /**
 787  * g_bus_own_name_with_closures:
 788  * @bus_type: the type of bus to own a name on
 789  * @name: the well-known name to own
 790  * @flags: a set of flags from the #GBusNameOwnerFlags enumeration
 791  * @bus_acquired_closure: (allow-none): #GClosure to invoke when connected to
 792  *     the bus of type @bus_type or %NULL
 793  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 794  *     acquired or %NULL
 795  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost or
 796  *     %NULL
 797  *
 798  * Version of g_bus_own_name() using closures instead of callbacks for
 799  * easier binding in other languages.
 800  *
 801  * Returns: an identifier (never 0) that an be used with
 802  *     g_bus_unown_name() to stop owning the name.
 803  *
 804  * Rename to: g_bus_own_name
 805  *
 806  * Since: 2.26
 807  */
 808 guint
 809 g_bus_own_name_with_closures (GBusType            bus_type,
 810                               const gchar        *name,
 811                               GBusNameOwnerFlags  flags,
 812                               GClosure           *bus_acquired_closure,
 813                               GClosure           *name_acquired_closure,
 814                               GClosure           *name_lost_closure)
 815 {
 816   return g_bus_own_name (bus_type,
 817           name,
 818           flags,
 819           bus_acquired_closure != NULL ? own_with_closures_on_bus_acquired : NULL,
 820           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 821           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 822           own_name_data_new (bus_acquired_closure,
 823                              name_acquired_closure,
 824                              name_lost_closure),
 825           bus_own_name_free_func);
 826 }
 827
 828 /**
 829  * g_bus_own_name_on_connection_with_closures:
 830  * @connection: a #GDBusConnection
 831  * @name: the well-known name to own
 832  * @flags: a set of flags from the #GBusNameOwnerFlags enumeration
 833  * @name_acquired_closure: (allow-none): #GClosure to invoke when @name is
 834  *     acquired or %NULL
 835  * @name_lost_closure: (allow-none): #GClosure to invoke when @name is lost
 836  *     or %NULL
 837  *
 838  * Version of g_bus_own_name_on_connection() using closures instead of
 839  * callbacks for easier binding in other languages.
 840  *
 841  * Returns: an identifier (never 0) that an be used with
 842  *     g_bus_unown_name() to stop owning the name.
 843  *
 844  * Rename to: g_bus_own_name_on_connection
 845  *
 846  * Since: 2.26
 847  */
 848 guint
 849 g_bus_own_name_on_connection_with_closures (GDBusConnection    *connection,
 850                                             const gchar        *name,
 851                                             GBusNameOwnerFlags  flags,
 852                                             GClosure           *name_acquired_closure,
 853                                             GClosure           *name_lost_closure)
 854 {
 855   return g_bus_own_name_on_connection (connection,
 856           name,
 857           flags,
 858           name_acquired_closure != NULL ? own_with_closures_on_name_acquired : NULL,
 859           name_lost_closure != NULL ? own_with_closures_on_name_lost : NULL,
 860           own_name_data_new (NULL,
 861                              name_acquired_closure,
 862                              name_lost_closure),
 863           bus_own_name_free_func);
 864 }
 865
 866 /**
 867  * g_bus_unown_name:
 868  * @owner_id: an identifier obtained from g_bus_own_name()
 869  *
 870  * Stops owning a name.
 871  *
 872  * Since: 2.26
 873  */
 874 void
 875 g_bus_unown_name (guint owner_id)
 876 {
 877   Client *client;
 878
 879   g_return_if_fail (owner_id > 0);
 880
 881   client = NULL;
 882
 883   G_LOCK (lock);
 884   if (owner_id == 0 || map_id_to_client == NULL ||
 885       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (owner_id))) == NULL)
 886     {
 887       g_warning ("Invalid id %d passed to g_bus_unown_name()", owner_id);
 888       goto out;
 889     }
 890
 891   client->cancelled = TRUE;
 892   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (owner_id)));
 893
 894  out:
 895   G_UNLOCK (lock);
 896
 897   /* do callback without holding lock */
 898   if (client != NULL)
 899     {
 900       /* Release the name if needed */
 901       if (client->needs_release &&
 902           client->connection != NULL &&
 903           !g_dbus_connection_is_closed (client->connection))
 904         {
 905           GVariant *result;
 906           GError *error;
 907           guint32 release_name_reply;
 908
 909           /* TODO: it kinda sucks having to do a sync call to release the name - but if
 910            * we don't, then a subsequent grab of the name will make the bus daemon return
 911            * IN_QUEUE which will trigger name_lost().
 912            *
 913            * I believe this is a bug in the bus daemon.
 914            */
 915           error = NULL;
 916           result = g_dbus_connection_call_sync (client->connection,
 917                                                 "org.freedesktop.DBus",  /* bus name */
 918                                                 "/org/freedesktop/DBus", /* object path */
 919                                                 "org.freedesktop.DBus",  /* interface name */
 920                                                 "ReleaseName",           /* method name */
 921                                                 g_variant_new ("(s)", client->name),
 922                                                 G_VARIANT_TYPE ("(u)"),
 923                                                 G_DBUS_CALL_FLAGS_NONE,
 924                                                 -1,
 925                                                 NULL,
 926                                                 &error);
 927           if (result == NULL)
 928             {
 929               g_warning ("Error releasing name %s: %s", client->name, error->message);
 930               g_error_free (error);
 931             }
 932           else
 933             {
 934               g_variant_get (result, "(u)", &release_name_reply);
 935               if (release_name_reply != 1 /* DBUS_RELEASE_NAME_REPLY_RELEASED */)
 936                 {
 937                   g_warning ("Unexpected reply %d when releasing name %s", release_name_reply, client->name);
 938                 }
 939               g_variant_unref (result);
 940             }
 941         }
 942
 943       if (client->disconnected_signal_handler_id > 0)
 944         g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 945       if (client->name_acquired_subscription_id > 0)
 946         g_dbus_connection_signal_unsubscribe (client->connection, client->name_acquired_subscription_id);
 947       if (client->name_lost_subscription_id > 0)
 948         g_dbus_connection_signal_unsubscribe (client->connection, client->name_lost_subscription_id);
 949       client->disconnected_signal_handler_id = 0;
 950       client->name_acquired_subscription_id = 0;
 951       client->name_lost_subscription_id = 0;
 952       if (client->connection != NULL)
 953         {
 954           g_object_unref (client->connection);
 955           client->connection = NULL;
 956         }
 957
 958       client_unref (client);
 959     }
 960 }