gio/gdbusnamewatching.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 #include <string.h>
  27
  28 #include "gdbusutils.h"
  29 #include "gdbusnamewatching.h"
  30 #include "gdbuserror.h"
  31 #include "gdbusprivate.h"
  32 #include "gdbusconnection.h"
  33
  34 #include "glibintl.h"
  35 #include "gioalias.h"
  36
  37 /**
  38  * SECTION:gdbusnamewatching
  39  * @title: Watching Bus Names
  40  * @short_description: Simple API for watching bus names
  41  * @include: gio/gio.h
  42  *
  43  * Convenience API for watching bus names.
  44  *
  45  * <example id="gdbus-watching-names"><title>Simple application watching a name</title><programlisting><xi:include xmlns:xi="http://www.w3.org/2001/XInclude" parse="text" href="../../../../gio/tests/gdbus-example-watch-name.c"><xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback></xi:include></programlisting></example>
  46  */
  47
  48 G_LOCK_DEFINE_STATIC (lock);
  49
  50 /* ---------------------------------------------------------------------------------------------------- */
  51
  52 typedef enum
  53 {
  54   PREVIOUS_CALL_NONE = 0,
  55   PREVIOUS_CALL_APPEARED,
  56   PREVIOUS_CALL_VANISHED,
  57 } PreviousCall;
  58
  59 typedef struct
  60 {
  61   volatile gint             ref_count;
  62   guint                     id;
  63   gchar                    *name;
  64   GBusNameWatcherFlags      flags;
  65   gchar                    *name_owner;
  66   GBusNameAppearedCallback  name_appeared_handler;
  67   GBusNameVanishedCallback  name_vanished_handler;
  68   gpointer                  user_data;
  69   GDestroyNotify            user_data_free_func;
  70   GMainContext             *main_context;
  71
  72   GDBusConnection          *connection;
  73   gulong                    disconnected_signal_handler_id;
  74   guint                     name_owner_changed_subscription_id;
  75
  76   PreviousCall              previous_call;
  77
  78   gboolean                  cancelled;
  79   gboolean                  initialized;
  80 } Client;
  81
  82 static guint next_global_id = 1;
  83 static GHashTable *map_id_to_client = NULL;
  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->name_owner_changed_subscription_id > 0)
 100             g_dbus_connection_signal_unsubscribe (client->connection, client->name_owner_changed_subscription_id);
 101           if (client->disconnected_signal_handler_id > 0)
 102             g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 103           g_object_unref (client->connection);
 104         }
 105       g_free (client->name);
 106       g_free (client->name_owner);
 107       if (client->main_context != NULL)
 108         g_main_context_unref (client->main_context);
 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 typedef enum
 118 {
 119   CALL_TYPE_NAME_APPEARED,
 120   CALL_TYPE_NAME_VANISHED
 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   /* ditto */
 133   gchar *name_owner;
 134
 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   g_free (data->name_owner);
 144   client_unref (data->client);
 145   g_free (data);
 146 }
 147
 148 static void
 149 actually_do_call (Client *client, GDBusConnection *connection, const gchar *name_owner, CallType call_type)
 150 {
 151   switch (call_type)
 152     {
 153     case CALL_TYPE_NAME_APPEARED:
 154       if (client->name_appeared_handler != NULL)
 155         {
 156           client->name_appeared_handler (connection,
 157                                          client->name,
 158                                          name_owner,
 159                                          client->user_data);
 160         }
 161       break;
 162
 163     case CALL_TYPE_NAME_VANISHED:
 164       if (client->name_vanished_handler != NULL)
 165         {
 166           client->name_vanished_handler (connection,
 167                                          client->name,
 168                                          client->user_data);
 169         }
 170       break;
 171
 172     default:
 173       g_assert_not_reached ();
 174       break;
 175     }
 176 }
 177
 178 static gboolean
 179 call_in_idle_cb (gpointer _data)
 180 {
 181   CallHandlerData *data = _data;
 182   actually_do_call (data->client, data->connection, data->name_owner, data->call_type);
 183   return FALSE;
 184 }
 185
 186 static void
 187 schedule_call_in_idle (Client *client, CallType call_type)
 188 {
 189   CallHandlerData *data;
 190   GSource *idle_source;
 191
 192   data = g_new0 (CallHandlerData, 1);
 193   data->client = client_ref (client);
 194   data->connection = client->connection != NULL ? g_object_ref (client->connection) : NULL;
 195   data->name_owner = g_strdup (client->name_owner);
 196   data->call_type = call_type;
 197
 198   idle_source = g_idle_source_new ();
 199   g_source_set_priority (idle_source, G_PRIORITY_HIGH);
 200   g_source_set_callback (idle_source,
 201                          call_in_idle_cb,
 202                          data,
 203                          (GDestroyNotify) call_handler_data_free);
 204   g_source_attach (idle_source, client->main_context);
 205   g_source_unref (idle_source);
 206 }
 207
 208 static void
 209 do_call (Client *client, CallType call_type)
 210 {
 211   /* only schedule in idle if we're not in the right thread */
 212   if (g_main_context_get_thread_default () != client->main_context)
 213     schedule_call_in_idle (client, call_type);
 214   else
 215     actually_do_call (client, client->connection, client->name_owner, call_type);
 216 }
 217
 218 static void
 219 call_appeared_handler (Client *client)
 220 {
 221   if (client->previous_call != PREVIOUS_CALL_APPEARED)
 222     {
 223       client->previous_call = PREVIOUS_CALL_APPEARED;
 224       if (!client->cancelled && client->name_appeared_handler != NULL)
 225         {
 226           do_call (client, CALL_TYPE_NAME_APPEARED);
 227         }
 228     }
 229 }
 230
 231 static void
 232 call_vanished_handler (Client  *client,
 233                        gboolean ignore_cancelled)
 234 {
 235   if (client->previous_call != PREVIOUS_CALL_VANISHED)
 236     {
 237       client->previous_call = PREVIOUS_CALL_VANISHED;
 238       if (((!client->cancelled) || ignore_cancelled) && client->name_vanished_handler != NULL)
 239         {
 240           do_call (client, CALL_TYPE_NAME_VANISHED);
 241         }
 242     }
 243 }
 244
 245 /* ---------------------------------------------------------------------------------------------------- */
 246
 247 static void
 248 on_connection_disconnected (GDBusConnection *connection,
 249                             gboolean         remote_peer_vanished,
 250                             GError          *error,
 251                             gpointer         user_data)
 252 {
 253   Client *client = user_data;
 254
 255   if (client->name_owner_changed_subscription_id > 0)
 256     g_dbus_connection_signal_unsubscribe (client->connection, client->name_owner_changed_subscription_id);
 257   if (client->disconnected_signal_handler_id > 0)
 258     g_signal_handler_disconnect (client->connection, client->disconnected_signal_handler_id);
 259   g_object_unref (client->connection);
 260   client->disconnected_signal_handler_id = 0;
 261   client->name_owner_changed_subscription_id = 0;
 262   client->connection = NULL;
 263
 264   call_vanished_handler (client, FALSE);
 265 }
 266
 267 /* ---------------------------------------------------------------------------------------------------- */
 268
 269 static void
 270 on_name_owner_changed (GDBusConnection *connection,
 271                        const gchar      *sender_name,
 272                        const gchar      *object_path,
 273                        const gchar      *interface_name,
 274                        const gchar      *signal_name,
 275                        GVariant         *parameters,
 276                        gpointer          user_data)
 277 {
 278   Client *client = user_data;
 279   const gchar *name;
 280   const gchar *old_owner;
 281   const gchar *new_owner;
 282
 283   if (!client->initialized)
 284     goto out;
 285
 286   if (g_strcmp0 (object_path, "/org/freedesktop/DBus") != 0 ||
 287       g_strcmp0 (interface_name, "org.freedesktop.DBus") != 0 ||
 288       g_strcmp0 (sender_name, "org.freedesktop.DBus") != 0)
 289     goto out;
 290
 291   g_variant_get (parameters,
 292                  "(&s&s&s)",
 293                  &name,
 294                  &old_owner,
 295                  &new_owner);
 296
 297   /* we only care about a specific name */
 298   if (g_strcmp0 (name, client->name) != 0)
 299     goto out;
 300
 301   if ((old_owner != NULL && strlen (old_owner) > 0) && client->name_owner != NULL)
 302     {
 303       g_free (client->name_owner);
 304       client->name_owner = NULL;
 305       call_vanished_handler (client, FALSE);
 306     }
 307
 308   if (new_owner != NULL && strlen (new_owner) > 0)
 309     {
 310       g_warn_if_fail (client->name_owner == NULL);
 311       g_free (client->name_owner);
 312       client->name_owner = g_strdup (new_owner);
 313       call_appeared_handler (client);
 314     }
 315
 316  out:
 317   ;
 318 }
 319
 320 /* ---------------------------------------------------------------------------------------------------- */
 321
 322 static void
 323 get_name_owner_cb (GObject      *source_object,
 324                    GAsyncResult *res,
 325                    gpointer      user_data)
 326 {
 327   Client *client = user_data;
 328   GVariant *result;
 329   const char *name_owner;
 330
 331   name_owner = NULL;
 332   result = NULL;
 333
 334   result = g_dbus_connection_call_finish (client->connection,
 335                                           res,
 336                                           NULL);
 337   if (result != NULL)
 338     {
 339       g_variant_get (result, "(&s)", &name_owner);
 340     }
 341
 342   if (name_owner != NULL)
 343     {
 344       g_warn_if_fail (client->name_owner == NULL);
 345       client->name_owner = g_strdup (name_owner);
 346       call_appeared_handler (client);
 347     }
 348   else
 349     {
 350       call_vanished_handler (client, FALSE);
 351     }
 352
 353   client->initialized = TRUE;
 354
 355   if (result != NULL)
 356     g_variant_unref (result);
 357   client_unref (client);
 358 }
 359
 360 /* ---------------------------------------------------------------------------------------------------- */
 361
 362 static void
 363 invoke_get_name_owner (Client *client)
 364 {
 365   g_dbus_connection_call (client->connection,
 366                           "org.freedesktop.DBus",  /* bus name */
 367                           "/org/freedesktop/DBus", /* object path */
 368                           "org.freedesktop.DBus",  /* interface name */
 369                           "GetNameOwner",          /* method name */
 370                           g_variant_new ("(s)", client->name),
 371                           G_VARIANT_TYPE ("(s)"),
 372                           G_DBUS_CALL_FLAGS_NONE,
 373                           -1,
 374                           NULL,
 375                           (GAsyncReadyCallback) get_name_owner_cb,
 376                           client_ref (client));
 377 }
 378
 379 /* ---------------------------------------------------------------------------------------------------- */
 380
 381 static void
 382 start_service_by_name_cb (GObject      *source_object,
 383                           GAsyncResult *res,
 384                           gpointer      user_data)
 385 {
 386   Client *client = user_data;
 387   GVariant *result;
 388
 389   result = NULL;
 390
 391   result = g_dbus_connection_call_finish (client->connection,
 392                                           res,
 393                                           NULL);
 394   if (result != NULL)
 395     {
 396       guint32 start_service_result;
 397       g_variant_get (result, "(u)", &start_service_result);
 398
 399       if (start_service_result == 1) /* DBUS_START_REPLY_SUCCESS */
 400         {
 401           invoke_get_name_owner (client);
 402         }
 403       else if (start_service_result == 2) /* DBUS_START_REPLY_ALREADY_RUNNING */
 404         {
 405           invoke_get_name_owner (client);
 406         }
 407       else
 408         {
 409           g_warning ("Unexpected reply %d from StartServiceByName() method", start_service_result);
 410           call_vanished_handler (client, FALSE);
 411           client->initialized = TRUE;
 412         }
 413     }
 414   else
 415     {
 416       /* Errors are not unexpected; the bus will reply e.g.
 417        *
 418        *   org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.Epiphany2
 419        *   was not provided by any .service files
 420        *
 421        * This doesn't mean that the name doesn't have an owner, just
 422        * that it's not provided by a .service file. So proceed to
 423        * invoke GetNameOwner().
 424        */
 425       invoke_get_name_owner (client);
 426     }
 427
 428   if (result != NULL)
 429     g_variant_unref (result);
 430   client_unref (client);
 431 }
 432
 433 /* ---------------------------------------------------------------------------------------------------- */
 434
 435 static void
 436 has_connection (Client *client)
 437 {
 438   /* listen for disconnection */
 439   client->disconnected_signal_handler_id = g_signal_connect (client->connection,
 440                                                              "closed",
 441                                                              G_CALLBACK (on_connection_disconnected),
 442                                                              client);
 443
 444   /* start listening to NameOwnerChanged messages immediately */
 445   client->name_owner_changed_subscription_id = g_dbus_connection_signal_subscribe (client->connection,
 446                                                                                    "org.freedesktop.DBus",  /* name */
 447                                                                                    "org.freedesktop.DBus",  /* if */
 448                                                                                    "NameOwnerChanged",      /* signal */
 449                                                                                    "/org/freedesktop/DBus", /* path */
 450                                                                                    client->name,
 451                                                                                    on_name_owner_changed,
 452                                                                                    client,
 453                                                                                    NULL);
 454
 455   if (client->flags & G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
 456     {
 457       g_dbus_connection_call (client->connection,
 458                               "org.freedesktop.DBus",  /* bus name */
 459                               "/org/freedesktop/DBus", /* object path */
 460                               "org.freedesktop.DBus",  /* interface name */
 461                               "StartServiceByName",    /* method name */
 462                               g_variant_new ("(su)", client->name, 0),
 463                               G_VARIANT_TYPE ("(u)"),
 464                               G_DBUS_CALL_FLAGS_NONE,
 465                               -1,
 466                               NULL,
 467                               (GAsyncReadyCallback) start_service_by_name_cb,
 468                               client_ref (client));
 469     }
 470   else
 471     {
 472       /* check owner */
 473       invoke_get_name_owner (client);
 474     }
 475 }
 476
 477
 478 static void
 479 connection_get_cb (GObject      *source_object,
 480                    GAsyncResult *res,
 481                    gpointer      user_data)
 482 {
 483   Client *client = user_data;
 484
 485   client->connection = g_bus_get_finish (res, NULL);
 486   if (client->connection == NULL)
 487     {
 488       call_vanished_handler (client, FALSE);
 489       goto out;
 490     }
 491
 492   has_connection (client);
 493
 494  out:
 495   client_unref (client);
 496 }
 497
 498 /* ---------------------------------------------------------------------------------------------------- */
 499
 500 /**
 501  * g_bus_watch_name:
 502  * @bus_type: The type of bus to watch a name on.
 503  * @name: The name (well-known or unique) to watch.
 504  * @flags: Flags from the #GBusNameWatcherFlags enumeration.
 505  * @name_appeared_handler: Handler to invoke when @name is known to exist or %NULL.
 506  * @name_vanished_handler: Handler to invoke when @name is known to not exist or %NULL.
 507  * @user_data: User data to pass to handlers.
 508  * @user_data_free_func: Function for freeing @user_data or %NULL.
 509  *
 510  * Starts watching @name on the bus specified by @bus_type and calls
 511  * @name_appeared_handler and @name_vanished_handler when the name is
 512  * known to have a owner respectively known to lose its
 513  * owner. Callbacks will be invoked in the <link
 514  * linkend="g-main-context-push-thread-default">thread-default main
 515  * loop</link> of the thread you are calling this function from.
 516  *
 517  * You are guaranteed that one of the handlers will be invoked after
 518  * calling this function. When you are done watching the name, just
 519  * call g_bus_unwatch_name() with the watcher id this function
 520  * returns.
 521  *
 522  * If the name vanishes or appears (for example the application owning
 523  * the name could restart), the handlers are also invoked. If the
 524  * #GDBusConnection that is used for watching the name disconnects, then
 525  * @name_vanished_handler is invoked since it is no longer
 526  * possible to access the name.
 527  *
 528  * Another guarantee is that invocations of @name_appeared_handler
 529  * and @name_vanished_handler are guaranteed to alternate; that
 530  * is, if @name_appeared_handler is invoked then you are
 531  * guaranteed that the next time one of the handlers is invoked, it
 532  * will be @name_vanished_handler. The reverse is also true.
 533  *
 534  * This behavior makes it very simple to write applications that wants
 535  * to take action when a certain name exists, see <xref
 536  * linkend="gdbus-watching-names"/>. Basically, the application
 537  * should create object proxies in @name_appeared_handler and destroy
 538  * them again (if any) in @name_vanished_handler.
 539  *
 540  * Returns: An identifier (never 0) that an be used with
 541  * g_bus_unwatch_name() to stop watching the name.
 542  *
 543  * Since: 2.26
 544  */
 545 guint
 546 g_bus_watch_name (GBusType                  bus_type,
 547                   const gchar              *name,
 548                   GBusNameWatcherFlags      flags,
 549                   GBusNameAppearedCallback  name_appeared_handler,
 550                   GBusNameVanishedCallback  name_vanished_handler,
 551                   gpointer                  user_data,
 552                   GDestroyNotify            user_data_free_func)
 553 {
 554   Client *client;
 555
 556   g_return_val_if_fail (g_dbus_is_name (name), 0);
 557
 558   G_LOCK (lock);
 559
 560   client = g_new0 (Client, 1);
 561   client->ref_count = 1;
 562   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 563   client->name = g_strdup (name);
 564   client->flags = flags;
 565   client->name_appeared_handler = name_appeared_handler;
 566   client->name_vanished_handler = name_vanished_handler;
 567   client->user_data = user_data;
 568   client->user_data_free_func = user_data_free_func;
 569   client->main_context = g_main_context_get_thread_default ();
 570   if (client->main_context != NULL)
 571     g_main_context_ref (client->main_context);
 572
 573   if (map_id_to_client == NULL)
 574     {
 575       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 576     }
 577   g_hash_table_insert (map_id_to_client,
 578                        GUINT_TO_POINTER (client->id),
 579                        client);
 580
 581   g_bus_get (bus_type,
 582              NULL,
 583              connection_get_cb,
 584              client_ref (client));
 585
 586   G_UNLOCK (lock);
 587
 588   return client->id;
 589 }
 590
 591 /**
 592  * g_bus_watch_name_on_connection:
 593  * @connection: A #GDBusConnection that is not closed.
 594  * @name: The name (well-known or unique) to watch.
 595  * @flags: Flags from the #GBusNameWatcherFlags enumeration.
 596  * @name_appeared_handler: Handler to invoke when @name is known to exist or %NULL.
 597  * @name_vanished_handler: Handler to invoke when @name is known to not exist or %NULL.
 598  * @user_data: User data to pass to handlers.
 599  * @user_data_free_func: Function for freeing @user_data or %NULL.
 600  *
 601  * Like g_bus_watch_name() but takes a #GDBusConnection instead of a
 602  * #GBusType.
 603  *
 604  * Returns: An identifier (never 0) that an be used with
 605  * g_bus_unwatch_name() to stop watching the name.
 606  *
 607  * Since: 2.26
 608  */
 609 guint g_bus_watch_name_on_connection (GDBusConnection          *connection,
 610                                       const gchar              *name,
 611                                       GBusNameWatcherFlags      flags,
 612                                       GBusNameAppearedCallback  name_appeared_handler,
 613                                       GBusNameVanishedCallback  name_vanished_handler,
 614                                       gpointer                  user_data,
 615                                       GDestroyNotify            user_data_free_func)
 616 {
 617   Client *client;
 618
 619   g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
 620   g_return_val_if_fail (g_dbus_is_name (name), 0);
 621
 622   G_LOCK (lock);
 623
 624   client = g_new0 (Client, 1);
 625   client->ref_count = 1;
 626   client->id = next_global_id++; /* TODO: uh oh, handle overflow */
 627   client->name = g_strdup (name);
 628   client->flags = flags;
 629   client->name_appeared_handler = name_appeared_handler;
 630   client->name_vanished_handler = name_vanished_handler;
 631   client->user_data = user_data;
 632   client->user_data_free_func = user_data_free_func;
 633   client->main_context = g_main_context_get_thread_default ();
 634   if (client->main_context != NULL)
 635     g_main_context_ref (client->main_context);
 636
 637   if (map_id_to_client == NULL)
 638     {
 639       map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
 640     }
 641   g_hash_table_insert (map_id_to_client,
 642                        GUINT_TO_POINTER (client->id),
 643                        client);
 644
 645   client->connection = g_object_ref (connection);
 646   G_UNLOCK (lock);
 647
 648   has_connection (client);
 649
 650   return client->id;
 651 }
 652
 653 typedef struct {
 654   GClosure *name_appeared_closure;
 655   GClosure *name_vanished_closure;
 656 } WatchNameData;
 657
 658 static void
 659 watch_with_closures_on_name_appeared (GDBusConnection *connection,
 660                                       const gchar     *name,
 661                                       const gchar     *name_owner,
 662                                       gpointer         user_data)
 663 {
 664   WatchNameData *data = user_data;
 665   GValue params[3] = { { 0, }, { 0, }, { 0, } };
 666
 667   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 668   g_value_set_object (&params[0], connection);
 669
 670   g_value_init (&params[1], G_TYPE_STRING);
 671   g_value_set_string (&params[1], name);
 672
 673   g_value_init (&params[2], G_TYPE_STRING);
 674   g_value_set_string (&params[2], name_owner);
 675
 676   g_closure_invoke (data->name_appeared_closure, NULL, 3, params, NULL);
 677 }
 678
 679 static void
 680 watch_with_closures_on_name_vanished (GDBusConnection *connection,
 681                                       const gchar     *name,
 682                                       gpointer         user_data)
 683 {
 684   WatchNameData *data = user_data;
 685   GValue params[2] = { { 0, }, { 0, } };
 686
 687   g_value_init (&params[0], G_TYPE_DBUS_CONNECTION);
 688   g_value_set_object (&params[0], connection);
 689
 690   g_value_init (&params[1], G_TYPE_STRING);
 691   g_value_set_string (&params[1], name);
 692
 693   g_closure_invoke (data->name_vanished_closure, NULL, 2, params, NULL);
 694 }
 695
 696 static void
 697 bus_watch_name_free_func (gpointer user_data)
 698 {
 699   WatchNameData *data = user_data;
 700
 701   if (data->name_appeared_closure != NULL)
 702     g_closure_unref (data->name_appeared_closure);
 703
 704   if (data->name_vanished_closure != NULL)
 705     g_closure_unref (data->name_vanished_closure);
 706
 707   g_free (data);
 708 }
 709
 710 /**
 711  * g_bus_watch_name_with_closures:
 712  * @bus_type: The type of bus to watch a name on.
 713  * @name: The name (well-known or unique) to watch.
 714  * @flags: Flags from the #GBusNameWatcherFlags enumeration.
 715  * @name_appeared_closure: (allow-none): #GClosure to invoke when @name is known
 716  * to exist or %NULL.
 717  * @name_vanished_closure: (allow-none): #GClosure to invoke when @name is known
 718  * to not exist or %NULL.
 719  *
 720  * Version of g_bus_watch_name() using closures instead of callbacks for
 721  * easier binding in other languages.
 722  *
 723  * Returns: An identifier (never 0) that an be used with
 724  * g_bus_unwatch_name() to stop watching the name.
 725  *
 726  * Rename to: g_bus_watch_name
 727  *
 728  * Since: 2.26
 729  */
 730 guint
 731 g_bus_watch_name_with_closures (GBusType                 bus_type,
 732                                 const gchar             *name,
 733                                 GBusNameWatcherFlags     flags,
 734                                 GClosure                *name_appeared_closure,
 735                                 GClosure                *name_vanished_closure)
 736 {
 737   WatchNameData *data;
 738
 739   data = g_new0 (WatchNameData, 1);
 740
 741   if (name_appeared_closure != NULL)
 742     data->name_appeared_closure = g_closure_ref (name_appeared_closure);
 743
 744   if (name_vanished_closure != NULL)
 745     data->name_vanished_closure = g_closure_ref (name_vanished_closure);
 746
 747   return g_bus_watch_name (bus_type,
 748           name,
 749           flags,
 750           name_appeared_closure != NULL ? watch_with_closures_on_name_appeared : NULL,
 751           name_vanished_closure != NULL ? watch_with_closures_on_name_vanished : NULL,
 752           data,
 753           bus_watch_name_free_func);
 754 }
 755
 756 /**
 757  * g_bus_watch_name_on_connection_with_closures:
 758  * @connection: A #GDBusConnection that is not closed.
 759  * @name: The name (well-known or unique) to watch.
 760  * @flags: Flags from the #GBusNameWatcherFlags enumeration.
 761  * @name_appeared_closure: (allow-none): #GClosure to invoke when @name is known
 762  * to exist or %NULL.
 763  * @name_vanished_closure: (allow-none): #GClosure to invoke when @name is known
 764  * to not exist or %NULL.
 765  *
 766  * Version of g_bus_watch_name_on_connection() using closures instead of callbacks for
 767  * easier binding in other languages.
 768  *
 769  * Returns: An identifier (never 0) that an be used with
 770  * g_bus_unwatch_name() to stop watching the name.
 771  *
 772  * Rename to: g_bus_watch_name_on_connection
 773  *
 774  * Since: 2.26
 775  */
 776 guint g_bus_watch_name_on_connection_with_closures (
 777                                       GDBusConnection          *connection,
 778                                       const gchar              *name,
 779                                       GBusNameWatcherFlags      flags,
 780                                       GClosure                 *name_appeared_closure,
 781                                       GClosure                 *name_vanished_closure)
 782 {
 783   WatchNameData *data;
 784
 785   data = g_new0 (WatchNameData, 1);
 786
 787   if (name_appeared_closure != NULL)
 788     data->name_appeared_closure = g_closure_ref (name_appeared_closure);
 789
 790   if (name_vanished_closure != NULL)
 791     data->name_vanished_closure = g_closure_ref (name_vanished_closure);
 792
 793   return g_bus_watch_name_on_connection (connection,
 794           name,
 795           flags,
 796           name_appeared_closure != NULL ? watch_with_closures_on_name_appeared : NULL,
 797           name_vanished_closure != NULL ? watch_with_closures_on_name_vanished : NULL,
 798           data,
 799           bus_watch_name_free_func);
 800 }
 801
 802 /**
 803  * g_bus_unwatch_name:
 804  * @watcher_id: An identifier obtained from g_bus_watch_name()
 805  *
 806  * Stops watching a name.
 807  *
 808  * Since: 2.26
 809  */
 810 void
 811 g_bus_unwatch_name (guint watcher_id)
 812 {
 813   Client *client;
 814
 815   g_return_if_fail (watcher_id > 0);
 816
 817   client = NULL;
 818
 819   G_LOCK (lock);
 820   if (watcher_id == 0 ||
 821       map_id_to_client == NULL ||
 822       (client = g_hash_table_lookup (map_id_to_client, GUINT_TO_POINTER (watcher_id))) == NULL)
 823     {
 824       g_warning ("Invalid id %d passed to g_bus_unwatch_name()", watcher_id);
 825       goto out;
 826     }
 827
 828   client->cancelled = TRUE;
 829   g_warn_if_fail (g_hash_table_remove (map_id_to_client, GUINT_TO_POINTER (watcher_id)));
 830
 831  out:
 832   G_UNLOCK (lock);
 833
 834   /* do callback without holding lock */
 835   if (client != NULL)
 836     {
 837       client_unref (client);
 838     }
 839 }
 840
 841 #define __G_DBUS_NAME_WATCHING_C__
 842 #include "gioaliasdef.c"