1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-bus.c Convenience functions for communicating with the bus.
4 * Copyright (C) 2003 CodeFactory AB
5 * Copyright (C) 2003 Red Hat, Inc.
7 * Licensed under the Academic Free License version 1.2
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 #include "dbus-protocol.h"
27 #include "dbus-internals.h"
30 * @defgroup DBusBus Message bus APIs
32 * @brief Functions for communicating with the message bus
38 * @defgroup DBusBusInternals Message bus APIs internals
39 * @ingroup DBusInternals
40 * @brief Internals of functions for communicating with the message bus
46 * Block of message-bus-related data we attach to each
47 * #DBusConnection used with these convenience functions.
52 char *base_service; /**< Base service name of this connection */
56 /** The slot we have reserved to store BusData
58 static int bus_data_slot = -1;
59 /** Number of connections using the slot
61 static int bus_data_slot_refcount = 0;
64 * Lock for bus_data_slot and bus_data_slot_refcount
66 static DBusMutex *slot_lock;
69 * Initialize the mutex used for bus_data_slot
74 _dbus_bus_init_lock (void)
76 slot_lock = dbus_mutex_new ();
83 dbus_mutex_lock (slot_lock);
85 if (bus_data_slot < 0)
86 bus_data_slot = dbus_connection_allocate_data_slot ();
88 if (bus_data_slot < 0)
90 dbus_mutex_unlock (slot_lock);
94 bus_data_slot_refcount += 1;
96 dbus_mutex_unlock (slot_lock);
102 data_slot_unref (void)
104 dbus_mutex_lock (slot_lock);
106 _dbus_assert (bus_data_slot >= 0);
107 _dbus_assert (bus_data_slot_refcount > 0);
109 bus_data_slot_refcount -= 1;
111 if (bus_data_slot_refcount == 0)
113 dbus_connection_free_data_slot (bus_data_slot);
117 dbus_mutex_unlock (slot_lock);
121 bus_data_free (void *data)
125 dbus_free (bd->base_service);
132 ensure_bus_data (DBusConnection *connection)
136 if (!data_slot_ref ())
139 bd = dbus_connection_get_data (connection, bus_data_slot);
142 bd = dbus_new0 (BusData, 1);
149 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
157 /* Data slot refcount now held by the BusData */
167 /** @} */ /* end of implementation details docs */
170 * @addtogroup DBusBus
175 * Registers a connection with the bus. This must be the first
176 * thing an application does when connecting to the message bus.
177 * If registration succeeds, the base service name will be set,
178 * and can be obtained using dbus_bus_get_base_service().
180 * @todo if we get an error reply, it has to be converted into
181 * DBusError and returned
183 * @param connection the connection
184 * @param error place to store errors
185 * @returns #TRUE on success
188 dbus_bus_register (DBusConnection *connection,
191 DBusMessage *message, *reply;
195 bd = ensure_bus_data (connection);
198 _DBUS_SET_OOM (error);
202 if (bd->base_service != NULL)
204 _dbus_warn ("Attempt to register the same DBusConnection with the message bus, but it is already registered\n");
205 /* This isn't an error, it's a programming bug. We'll be nice
206 * and not _dbus_assert_not_reached()
211 message = dbus_message_new (DBUS_SERVICE_DBUS,
216 _DBUS_SET_OOM (error);
220 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
222 dbus_message_unref (message);
226 _DBUS_ASSERT_ERROR_IS_SET (error);
230 if (!dbus_message_get_args (reply, error,
231 DBUS_TYPE_STRING, &name,
234 _DBUS_ASSERT_ERROR_IS_SET (error);
238 bd->base_service = name;
245 * Sets the base service name of the connection.
246 * Can only be used if you registered with the
247 * bus manually (i.e. if you did not call
248 * dbus_bus_register()). Can only be called
249 * once per connection.
251 * @param connection the connection
252 * @param base_service the base service name
253 * @returns #FALSE if not enough memory
256 dbus_bus_set_base_service (DBusConnection *connection,
257 const char *base_service)
261 bd = ensure_bus_data (connection);
265 _dbus_assert (bd->base_service == NULL);
266 _dbus_assert (base_service != NULL);
268 bd->base_service = _dbus_strdup (base_service);
269 return bd->base_service != NULL;
273 * Gets the base service name of the connection.
274 * Only possible after the connection has been registered
275 * with the message bus.
277 * @param connection the connection
278 * @returns the base service name
281 dbus_bus_get_base_service (DBusConnection *connection)
285 bd = ensure_bus_data (connection);
289 return bd->base_service;
293 * Asks the bus to try to acquire a certain service.
295 * @todo these docs are not complete, need to document the
296 * return value and flags
298 * @todo if we get an error reply, it has to be converted into
299 * DBusError and returned
301 * @param connection the connection
302 * @param service_name the service name
304 * @param error location to store the error
305 * @returns a result code, -1 if error is set
308 dbus_bus_acquire_service (DBusConnection *connection,
309 const char *service_name,
313 DBusMessage *message, *reply;
316 message = dbus_message_new (DBUS_SERVICE_DBUS,
317 DBUS_MESSAGE_ACQUIRE_SERVICE);
321 _DBUS_SET_OOM (error);
325 if (!dbus_message_append_args (message,
326 DBUS_TYPE_STRING, service_name,
327 DBUS_TYPE_UINT32, flags,
330 dbus_message_unref (message);
331 _DBUS_SET_OOM (error);
335 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
338 dbus_message_unref (message);
342 _DBUS_ASSERT_ERROR_IS_SET (error);
346 if (!dbus_message_get_args (reply, error,
347 DBUS_TYPE_UINT32, &service_result,
350 _DBUS_ASSERT_ERROR_IS_SET (error);
354 return service_result;
358 * Checks whether a certain service exists.
360 * @todo the SERVICE_EXISTS message should use BOOLEAN not UINT32
362 * @param connection the connection
363 * @param service_name the service name
364 * @param error location to store any errors
365 * @returns #TRUE if the service exists, #FALSE if not or on error
368 dbus_bus_service_exists (DBusConnection *connection,
369 const char *service_name,
372 DBusMessage *message, *reply;
375 message = dbus_message_new (DBUS_SERVICE_DBUS,
376 DBUS_MESSAGE_SERVICE_EXISTS);
379 _DBUS_SET_OOM (error);
383 if (!dbus_message_append_args (message,
384 DBUS_TYPE_STRING, service_name,
387 dbus_message_unref (message);
388 _DBUS_SET_OOM (error);
392 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
393 dbus_message_unref (message);
397 _DBUS_ASSERT_ERROR_IS_SET (error);
401 if (!dbus_message_get_args (reply, error,
402 DBUS_TYPE_UINT32, &exists,
405 _DBUS_ASSERT_ERROR_IS_SET (error);
409 return (exists != FALSE);