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)
87 bus_data_slot = dbus_connection_allocate_data_slot ();
89 if (bus_data_slot < 0)
91 dbus_mutex_unlock (slot_lock);
95 _dbus_assert (bus_data_slot_refcount == 0);
98 bus_data_slot_refcount += 1;
100 dbus_mutex_unlock (slot_lock);
106 data_slot_unref (void)
108 dbus_mutex_lock (slot_lock);
110 _dbus_assert (bus_data_slot_refcount > 0);
111 _dbus_assert (bus_data_slot >= 0);
113 bus_data_slot_refcount -= 1;
115 if (bus_data_slot_refcount == 0)
117 dbus_connection_free_data_slot (bus_data_slot);
121 dbus_mutex_unlock (slot_lock);
125 bus_data_free (void *data)
129 dbus_free (bd->base_service);
136 ensure_bus_data (DBusConnection *connection)
140 if (!data_slot_ref ())
143 bd = dbus_connection_get_data (connection, bus_data_slot);
146 bd = dbus_new0 (BusData, 1);
153 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
161 /* Data slot refcount now held by the BusData */
171 /** @} */ /* end of implementation details docs */
174 * @addtogroup DBusBus
179 * Registers a connection with the bus. This must be the first
180 * thing an application does when connecting to the message bus.
181 * If registration succeeds, the base service name will be set,
182 * and can be obtained using dbus_bus_get_base_service().
184 * @todo if we get an error reply, it has to be converted into
185 * DBusError and returned
187 * @param connection the connection
188 * @param error place to store errors
189 * @returns #TRUE on success
192 dbus_bus_register (DBusConnection *connection,
195 DBusMessage *message, *reply;
199 bd = ensure_bus_data (connection);
202 _DBUS_SET_OOM (error);
206 if (bd->base_service != NULL)
208 _dbus_warn ("Attempt to register the same DBusConnection with the message bus, but it is already registered\n");
209 /* This isn't an error, it's a programming bug. We'll be nice
210 * and not _dbus_assert_not_reached()
215 message = dbus_message_new (DBUS_SERVICE_DBUS,
220 _DBUS_SET_OOM (error);
224 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
226 dbus_message_unref (message);
230 _DBUS_ASSERT_ERROR_IS_SET (error);
234 if (!dbus_message_get_args (reply, error,
235 DBUS_TYPE_STRING, &name,
238 _DBUS_ASSERT_ERROR_IS_SET (error);
242 bd->base_service = name;
249 * Sets the base service name of the connection.
250 * Can only be used if you registered with the
251 * bus manually (i.e. if you did not call
252 * dbus_bus_register()). Can only be called
253 * once per connection.
255 * @param connection the connection
256 * @param base_service the base service name
257 * @returns #FALSE if not enough memory
260 dbus_bus_set_base_service (DBusConnection *connection,
261 const char *base_service)
265 bd = ensure_bus_data (connection);
269 _dbus_assert (bd->base_service == NULL);
270 _dbus_assert (base_service != NULL);
272 bd->base_service = _dbus_strdup (base_service);
273 return bd->base_service != NULL;
277 * Gets the base service name of the connection.
278 * Only possible after the connection has been registered
279 * with the message bus.
281 * @param connection the connection
282 * @returns the base service name
285 dbus_bus_get_base_service (DBusConnection *connection)
289 bd = ensure_bus_data (connection);
293 return bd->base_service;
297 * Asks the bus to try to acquire a certain service.
299 * @todo these docs are not complete, need to document the
300 * return value and flags
302 * @todo if we get an error reply, it has to be converted into
303 * DBusError and returned
305 * @param connection the connection
306 * @param service_name the service name
308 * @param error location to store the error
309 * @returns a result code, -1 if error is set
312 dbus_bus_acquire_service (DBusConnection *connection,
313 const char *service_name,
317 DBusMessage *message, *reply;
320 message = dbus_message_new (DBUS_SERVICE_DBUS,
321 DBUS_MESSAGE_ACQUIRE_SERVICE);
325 _DBUS_SET_OOM (error);
329 if (!dbus_message_append_args (message,
330 DBUS_TYPE_STRING, service_name,
331 DBUS_TYPE_UINT32, flags,
334 dbus_message_unref (message);
335 _DBUS_SET_OOM (error);
339 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
342 dbus_message_unref (message);
346 _DBUS_ASSERT_ERROR_IS_SET (error);
350 if (!dbus_message_get_args (reply, error,
351 DBUS_TYPE_UINT32, &service_result,
354 _DBUS_ASSERT_ERROR_IS_SET (error);
358 return service_result;
362 * Checks whether a certain service exists.
364 * @todo the SERVICE_EXISTS message should use BOOLEAN not UINT32
366 * @param connection the connection
367 * @param service_name the service name
368 * @param error location to store any errors
369 * @returns #TRUE if the service exists, #FALSE if not or on error
372 dbus_bus_service_exists (DBusConnection *connection,
373 const char *service_name,
376 DBusMessage *message, *reply;
379 message = dbus_message_new (DBUS_SERVICE_DBUS,
380 DBUS_MESSAGE_SERVICE_EXISTS);
383 _DBUS_SET_OOM (error);
387 if (!dbus_message_append_args (message,
388 DBUS_TYPE_STRING, service_name,
391 dbus_message_unref (message);
392 _DBUS_SET_OOM (error);
396 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
397 dbus_message_unref (message);
401 _DBUS_ASSERT_ERROR_IS_SET (error);
405 if (!dbus_message_get_args (reply, error,
406 DBUS_TYPE_UINT32, &exists,
409 _DBUS_ASSERT_ERROR_IS_SET (error);
413 return (exists != FALSE);