1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-connection.c DBusConnection object
4 * Copyright (C) 2002, 2003 Red Hat Inc.
6 * Licensed under the Academic Free License version 1.2
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include "dbus-connection.h"
25 #include "dbus-list.h"
26 #include "dbus-timeout.h"
27 #include "dbus-transport.h"
28 #include "dbus-watch.h"
29 #include "dbus-connection-internal.h"
30 #include "dbus-list.h"
31 #include "dbus-hash.h"
32 #include "dbus-message-internal.h"
33 #include "dbus-threads.h"
36 * @defgroup DBusConnection DBusConnection
38 * @brief Connection to another application
40 * A DBusConnection represents a connection to another
41 * application. Messages can be sent and received via this connection.
43 * The connection maintains a queue of incoming messages and a queue
44 * of outgoing messages. dbus_connection_pop_message() and friends
45 * can be used to read incoming messages from the queue.
46 * Outgoing messages are automatically discarded as they are
47 * written to the network.
49 * In brief a DBusConnection is a message queue associated with some
50 * message transport mechanism such as a socket.
55 * @defgroup DBusConnectionInternals DBusConnection implementation details
56 * @ingroup DBusInternals
57 * @brief Implementation details of DBusConnection
62 /** default timeout value when waiting for a message reply */
63 #define DEFAULT_TIMEOUT_VALUE (15 * 1000)
65 /** Opaque typedef for DBusDataSlot */
66 typedef struct DBusDataSlot DBusDataSlot;
67 /** DBusDataSlot is used to store application data on the connection */
70 void *data; /**< The application data */
71 DBusFreeFunction free_data_func; /**< Free the application data */
75 * Implementation details of DBusConnection. All fields are private.
79 int refcount; /**< Reference count. */
81 DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
82 DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */
84 int n_outgoing; /**< Length of outgoing queue. */
85 int n_incoming; /**< Length of incoming queue. */
87 DBusTransport *transport; /**< Object that sends/receives messages over network. */
88 DBusWatchList *watches; /**< Stores active watches. */
89 DBusTimeoutList *timeouts; /**< Stores active timeouts. */
91 DBusDisconnectFunction disconnect_function; /**< Callback on disconnect. */
92 void *disconnect_data; /**< Data for disconnect callback. */
93 DBusFreeFunction disconnect_free_data_function; /**< Free function for disconnect callback data. */
94 DBusHashTable *handler_table; /**< Table of registered DBusMessageHandler */
95 DBusList *filter_list; /**< List of filters. */
96 int filters_serial; /**< Increments when the list of filters is changed. */
97 int handlers_serial; /**< Increments when the handler table is changed. */
98 DBusDataSlot *data_slots; /**< Data slots */
99 int n_slots; /**< Slots allocated so far. */
101 DBusCounter *connection_counter; /**< Counter that we decrement when finalized */
103 int client_serial; /**< Client serial. Increments each time a message is sent */
104 unsigned int disconnect_notified : 1; /**< Already called disconnect_function */
107 static void _dbus_connection_free_data_slots (DBusConnection *connection);
110 * Adds a message to the incoming message queue, returning #FALSE
111 * if there's insufficient memory to queue the message.
113 * @param connection the connection.
114 * @param message the message to queue.
115 * @returns #TRUE on success.
118 _dbus_connection_queue_received_message (DBusConnection *connection,
119 DBusMessage *message)
121 _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
123 if (!_dbus_list_append (&connection->incoming_messages,
127 dbus_message_ref (message);
128 connection->n_incoming += 1;
130 _dbus_verbose ("Incoming message %p added to queue, %d incoming\n",
131 message, connection->n_incoming);
137 * Checks whether there are messages in the outgoing message queue.
139 * @param connection the connection.
140 * @returns #TRUE if the outgoing queue is non-empty.
143 _dbus_connection_have_messages_to_send (DBusConnection *connection)
145 return connection->outgoing_messages != NULL;
149 * Gets the next outgoing message. The message remains in the
150 * queue, and the caller does not own a reference to it.
152 * @param connection the connection.
153 * @returns the message to be sent.
156 _dbus_connection_get_message_to_send (DBusConnection *connection)
158 return _dbus_list_get_last (&connection->outgoing_messages);
162 * Notifies the connection that a message has been sent, so the
163 * message can be removed from the outgoing queue.
165 * @param connection the connection.
166 * @param message the message that was sent.
169 _dbus_connection_message_sent (DBusConnection *connection,
170 DBusMessage *message)
172 _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
173 _dbus_assert (message == _dbus_list_get_last (&connection->outgoing_messages));
175 _dbus_list_pop_last (&connection->outgoing_messages);
176 dbus_message_unref (message);
178 connection->n_outgoing -= 1;
180 _dbus_verbose ("Message %p removed from outgoing queue, %d left to send\n",
181 message, connection->n_outgoing);
183 if (connection->n_outgoing == 0)
184 _dbus_transport_messages_pending (connection->transport,
185 connection->n_outgoing);
189 * Adds a watch using the connection's DBusAddWatchFunction if
190 * available. Otherwise records the watch to be added when said
191 * function is available. Also re-adds the watch if the
192 * DBusAddWatchFunction changes. May fail due to lack of memory.
194 * @param connection the connection.
195 * @param watch the watch to add.
196 * @returns #TRUE on success.
199 _dbus_connection_add_watch (DBusConnection *connection,
202 if (connection->watches) /* null during finalize */
203 return _dbus_watch_list_add_watch (connection->watches,
210 * Removes a watch using the connection's DBusRemoveWatchFunction
211 * if available. It's an error to call this function on a watch
212 * that was not previously added.
214 * @param connection the connection.
215 * @param watch the watch to remove.
218 _dbus_connection_remove_watch (DBusConnection *connection,
221 if (connection->watches) /* null during finalize */
222 _dbus_watch_list_remove_watch (connection->watches,
227 _dbus_connection_add_timeout (DBusConnection *connection,
228 DBusTimeout *timeout)
230 if (connection->timeouts) /* null during finalize */
231 return _dbus_timeout_list_add_timeout (connection->timeouts,
238 _dbus_connection_remove_timeout (DBusConnection *connection,
239 DBusTimeout *timeout)
241 if (connection->timeouts) /* null during finalize */
242 _dbus_timeout_list_remove_timeout (connection->timeouts,
247 * Tells the connection that the transport has been disconnected.
248 * Results in calling the application disconnect callback.
249 * Only has an effect the first time it's called.
251 * @param connection the connection
254 _dbus_connection_notify_disconnected (DBusConnection *connection)
256 if (connection->disconnect_function != NULL &&
257 !connection->disconnect_notified)
259 connection->disconnect_notified = TRUE;
260 dbus_connection_ref (connection);
261 (* connection->disconnect_function) (connection,
262 connection->disconnect_data);
263 dbus_connection_unref (connection);
268 * Queues incoming messages and sends outgoing messages for this
269 * connection, optionally blocking in the process. Each call to
270 * _dbus_connection_do_iteration() will call select() or poll() one
271 * time and then read or write data if possible.
273 * The purpose of this function is to be able to flush outgoing
274 * messages or queue up incoming messages without returning
275 * control to the application and causing reentrancy weirdness.
277 * The flags parameter allows you to specify whether to
278 * read incoming messages, write outgoing messages, or both,
279 * and whether to block if no immediate action is possible.
281 * The timeout_milliseconds parameter does nothing unless the
282 * iteration is blocking.
284 * If there are no outgoing messages and DBUS_ITERATION_DO_READING
285 * wasn't specified, then it's impossible to block, even if
286 * you specify DBUS_ITERATION_BLOCK; in that case the function
287 * returns immediately.
289 * @param connection the connection.
290 * @param flags iteration flags.
291 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
294 _dbus_connection_do_iteration (DBusConnection *connection,
296 int timeout_milliseconds)
298 if (connection->n_outgoing == 0)
299 flags &= ~DBUS_ITERATION_DO_WRITING;
301 _dbus_transport_do_iteration (connection->transport,
302 flags, timeout_milliseconds);
306 * Creates a new connection for the given transport. A transport
307 * represents a message stream that uses some concrete mechanism, such
308 * as UNIX domain sockets. May return #NULL if insufficient
309 * memory exists to create the connection.
311 * @param transport the transport.
312 * @returns the new connection, or #NULL on failure.
315 _dbus_connection_new_for_transport (DBusTransport *transport)
317 DBusConnection *connection;
318 DBusWatchList *watch_list;
319 DBusTimeoutList *timeout_list;
320 DBusHashTable *handler_table;
324 handler_table = NULL;
327 watch_list = _dbus_watch_list_new ();
328 if (watch_list == NULL)
331 timeout_list = _dbus_timeout_list_new ();
332 if (timeout_list == NULL)
336 _dbus_hash_table_new (DBUS_HASH_STRING,
338 if (handler_table == NULL)
341 connection = dbus_new0 (DBusConnection, 1);
342 if (connection == NULL)
345 connection->refcount = 1;
346 connection->transport = transport;
347 connection->watches = watch_list;
348 connection->timeouts = timeout_list;
349 connection->handler_table = handler_table;
350 connection->filter_list = NULL;
352 connection->data_slots = NULL;
353 connection->n_slots = 0;
354 connection->client_serial = 1;
355 connection->disconnect_notified = FALSE;
357 _dbus_transport_ref (transport);
358 _dbus_transport_set_connection (transport, connection);
364 if (connection != NULL)
365 dbus_free (connection);
368 _dbus_hash_table_unref (handler_table);
371 _dbus_watch_list_free (watch_list);
374 _dbus_timeout_list_free (timeout_list);
380 _dbus_connection_get_next_client_serial (DBusConnection *connection)
384 serial = connection->client_serial++;
386 if (connection->client_serial < 0)
387 connection->client_serial = 1;
393 * Used to notify a connection when a DBusMessageHandler is
394 * destroyed, so the connection can drop any reference
397 * @param connection the connection
398 * @param handler the handler
401 _dbus_connection_handler_destroyed (DBusConnection *connection,
402 DBusMessageHandler *handler)
407 _dbus_hash_iter_init (connection->handler_table, &iter);
408 while (_dbus_hash_iter_next (&iter))
410 DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter);
413 _dbus_hash_iter_remove_entry (&iter);
416 link = _dbus_list_get_first_link (&connection->filter_list);
419 DBusMessageHandler *h = link->data;
420 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
423 _dbus_list_remove_link (&connection->filter_list,
431 * Adds the counter used to count the number of open connections.
432 * Increments the counter by one, and saves it to be decremented
433 * again when this connection is finalized.
435 * @param connection a #DBusConnection
436 * @param counter counter that tracks number of connections
439 _dbus_connection_set_connection_counter (DBusConnection *connection,
440 DBusCounter *counter)
442 _dbus_assert (connection->connection_counter == NULL);
444 connection->connection_counter = counter;
445 _dbus_counter_ref (connection->connection_counter);
446 _dbus_counter_adjust (connection->connection_counter, 1);
452 * @addtogroup DBusConnection
458 * Opens a new connection to a remote address.
460 * @todo specify what the address parameter is. Right now
461 * it's just the name of a UNIX domain socket. It should be
462 * something more complex that encodes which transport to use.
464 * If the open fails, the function returns #NULL, and provides
465 * a reason for the failure in the result parameter. Pass
466 * #NULL for the result parameter if you aren't interested
467 * in the reason for failure.
469 * @param address the address.
470 * @param result address where a result code can be returned.
471 * @returns new connection, or #NULL on failure.
474 dbus_connection_open (const char *address,
475 DBusResultCode *result)
477 DBusConnection *connection;
478 DBusTransport *transport;
480 transport = _dbus_transport_open (address, result);
481 if (transport == NULL)
484 connection = _dbus_connection_new_for_transport (transport);
486 _dbus_transport_unref (transport);
488 if (connection == NULL)
490 dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
498 * Increments the reference count of a DBusConnection.
500 * @param connection the connection.
503 dbus_connection_ref (DBusConnection *connection)
505 connection->refcount += 1;
509 * Decrements the reference count of a DBusConnection, and finalizes
510 * it if the count reaches zero. If a connection is still connected
511 * when it's finalized, it will be disconnected (that is, associated
512 * file handles will be closed).
514 * @param connection the connection.
517 dbus_connection_unref (DBusConnection *connection)
519 _dbus_assert (connection != NULL);
520 _dbus_assert (connection->refcount > 0);
522 connection->refcount -= 1;
523 if (connection->refcount == 0)
528 dbus_connection_disconnect (connection);
530 /* free disconnect data as a side effect */
531 dbus_connection_set_disconnect_function (connection,
534 if (connection->connection_counter != NULL)
536 /* subtract ourselves from the counter */
537 _dbus_counter_adjust (connection->connection_counter, - 1);
538 _dbus_counter_unref (connection->connection_counter);
539 connection->connection_counter = NULL;
542 _dbus_watch_list_free (connection->watches);
543 connection->watches = NULL;
545 _dbus_timeout_list_free (connection->timeouts);
546 connection->timeouts = NULL;
548 _dbus_connection_free_data_slots (connection);
550 _dbus_hash_iter_init (connection->handler_table, &iter);
551 while (_dbus_hash_iter_next (&iter))
553 DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter);
555 _dbus_message_handler_remove_connection (h, connection);
558 link = _dbus_list_get_first_link (&connection->filter_list);
561 DBusMessageHandler *h = link->data;
562 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
564 _dbus_message_handler_remove_connection (h, connection);
569 _dbus_hash_table_unref (connection->handler_table);
570 connection->handler_table = NULL;
572 _dbus_list_clear (&connection->filter_list);
574 _dbus_list_foreach (&connection->outgoing_messages,
575 (DBusForeachFunction) dbus_message_unref,
577 _dbus_list_clear (&connection->outgoing_messages);
579 _dbus_list_foreach (&connection->incoming_messages,
580 (DBusForeachFunction) dbus_message_unref,
582 _dbus_list_clear (&connection->incoming_messages);
584 _dbus_transport_unref (connection->transport);
586 dbus_free (connection);
591 * Closes the connection, so no further data can be sent or received.
592 * Any further attempts to send data will result in errors. This
593 * function does not affect the connection's reference count. It's
594 * safe to disconnect a connection more than once; all calls after the
595 * first do nothing. It's impossible to "reconnect" a connection, a
596 * new connection must be created.
598 * @param connection the connection.
601 dbus_connection_disconnect (DBusConnection *connection)
603 _dbus_transport_disconnect (connection->transport);
607 * Gets whether the connection is currently connected. All
608 * connections are connected when they are opened. A connection may
609 * become disconnected when the remote application closes its end, or
610 * exits; a connection may also be disconnected with
611 * dbus_connection_disconnect().
613 * @param connection the connection.
614 * @returns #TRUE if the connection is still alive.
617 dbus_connection_get_is_connected (DBusConnection *connection)
619 return _dbus_transport_get_is_connected (connection->transport);
623 * Gets whether the connection was authenticated. (Note that
624 * if the connection was authenticated then disconnected,
625 * this function still returns #TRUE)
627 * @param connection the connection
628 * @returns #TRUE if the connection was ever authenticated
631 dbus_connection_get_is_authenticated (DBusConnection *connection)
633 return _dbus_transport_get_is_authenticated (connection->transport);
637 * Adds a message to the outgoing message queue. Does not block to
638 * write the message to the network; that happens asynchronously. to
639 * force the message to be written, call dbus_connection_flush().
641 * If the function fails, it returns #FALSE and returns the
642 * reason for failure via the result parameter.
643 * The result parameter can be #NULL if you aren't interested
644 * in the reason for the failure.
646 * @param connection the connection.
647 * @param message the message to write.
648 * @param client_serial return location for client serial.
649 * @param result address where result code can be placed.
650 * @returns #TRUE on success.
653 dbus_connection_send_message (DBusConnection *connection,
654 DBusMessage *message,
655 dbus_int32_t *client_serial,
656 DBusResultCode *result)
661 if (!_dbus_list_prepend (&connection->outgoing_messages,
664 dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
668 dbus_message_ref (message);
669 connection->n_outgoing += 1;
671 _dbus_verbose ("Message %p added to outgoing queue, %d pending to send\n",
672 message, connection->n_outgoing);
674 if (_dbus_message_get_client_serial (message) == -1)
676 serial = _dbus_connection_get_next_client_serial (connection);
677 _dbus_message_set_client_serial (message, serial);
681 *client_serial = _dbus_message_get_client_serial (message);
683 _dbus_message_lock (message);
685 if (connection->n_outgoing == 1)
686 _dbus_transport_messages_pending (connection->transport,
687 connection->n_outgoing);
693 * Queues a message to send, as with dbus_connection_send_message(),
694 * but also sets up a DBusMessageHandler to receive a reply to the
695 * message. If no reply is received in the given timeout_milliseconds,
696 * expires the pending reply and sends the DBusMessageHandler a
697 * synthetic error reply (generated in-process, not by the remote
698 * application) indicating that a timeout occurred.
700 * Reply handlers see their replies after message filters see them,
701 * but before message handlers added with
702 * dbus_connection_register_handler() see them, regardless of the
703 * reply message's name. Reply handlers are only handed a single
704 * message as a reply, after a reply has been seen the handler is
705 * removed. If a filter filters out the reply before the handler sees
706 * it, the handler is not removed but the timeout will immediately
707 * fire again. If a filter was dumb and kept removing the timeout
708 * reply then we'd get in an infinite loop.
710 * If #NULL is passed for the reply_handler, the timeout reply will
711 * still be generated and placed into the message queue, but no
712 * specific message handler will receive the reply.
714 * If -1 is passed for the timeout, a sane default timeout is used. -1
715 * is typically the best value for the timeout for this reason, unless
716 * you want a very short or very long timeout. There is no way to
717 * avoid a timeout entirely, other than passing INT_MAX for the
718 * timeout to postpone it indefinitely.
720 * @param connection the connection
721 * @param message the message to send
722 * @param reply_handler message handler expecting the reply, or #NULL
723 * @param timeout_milliseconds timeout in milliseconds or -1 for default
724 * @param result return location for result code
725 * @returns #TRUE if the message is successfully queued, #FALSE if no memory.
727 * @todo this function isn't implemented because we need message serials
728 * and other slightly more rich DBusMessage implementation in order to
729 * implement it. The basic idea will be to keep a hash of serials we're
730 * expecting a reply to, and also to add a way to tell GLib or Qt to
731 * install a timeout. Then install a timeout which is the shortest
732 * timeout of any pending reply.
736 dbus_connection_send_message_with_reply (DBusConnection *connection,
737 DBusMessage *message,
738 DBusMessageHandler *reply_handler,
739 int timeout_milliseconds,
740 DBusResultCode *result)
743 return dbus_connection_send_message (connection, message, NULL, result);
747 * Sends a message and blocks a certain time period while waiting for a reply.
748 * This function does not dispatch any message handlers until the main loop
749 * has been reached. This function is used to do non-reentrant "method calls."
750 * If a reply is received, it is returned, and removed from the incoming
751 * message queue. If it is not received, #NULL is returned and the
752 * result is set to #DBUS_RESULT_NO_REPLY. If something else goes
753 * wrong, result is set to whatever is appropriate, such as
754 * #DBUS_RESULT_NO_MEMORY.
756 * @todo I believe if we get EINTR or otherwise interrupt the
757 * do_iteration call in here, we won't block the required length of
758 * time. I think there probably has to be a loop: "while (!timeout_elapsed)
759 * { check_for_reply_in_queue(); iterate_with_remaining_timeout(); }"
761 * @param connection the connection
762 * @param message the message to send
763 * @param timeout_milliseconds timeout in milliseconds or -1 for default
764 * @param result return location for result code
765 * @returns the message that is the reply or #NULL with an error code if the
769 dbus_connection_send_message_with_reply_and_block (DBusConnection *connection,
770 DBusMessage *message,
771 int timeout_milliseconds,
772 DBusResultCode *result)
774 dbus_int32_t client_serial;
777 if (timeout_milliseconds == -1)
778 timeout_milliseconds = DEFAULT_TIMEOUT_VALUE;
780 if (!dbus_connection_send_message (connection, message, &client_serial, result))
783 /* Flush message queue */
784 dbus_connection_flush (connection);
787 _dbus_connection_do_iteration (connection,
788 DBUS_ITERATION_DO_READING |
789 DBUS_ITERATION_BLOCK,
790 timeout_milliseconds);
792 /* Check if we've gotten a reply */
793 link = _dbus_list_get_first_link (&connection->incoming_messages);
797 DBusMessage *reply = link->data;
799 if (_dbus_message_get_reply_serial (reply) == client_serial)
801 _dbus_list_remove (&connection->incoming_messages, link);
802 dbus_message_ref (message);
805 *result = DBUS_RESULT_SUCCESS;
809 link = _dbus_list_get_next_link (&connection->incoming_messages, link);
813 *result = DBUS_RESULT_NO_REPLY;
819 * Blocks until the outgoing message queue is empty.
821 * @param connection the connection.
824 dbus_connection_flush (DBusConnection *connection)
826 while (connection->n_outgoing > 0)
827 _dbus_connection_do_iteration (connection,
828 DBUS_ITERATION_DO_WRITING |
829 DBUS_ITERATION_BLOCK,
834 * Gets the number of messages in the incoming message queue.
836 * @param connection the connection.
837 * @returns the number of messages in the queue.
840 dbus_connection_get_n_messages (DBusConnection *connection)
842 return connection->n_incoming;
846 * Returns the first-received message from the incoming message queue,
847 * leaving it in the queue. The caller does not own a reference to the
848 * returned message. If the queue is empty, returns #NULL.
850 * @param connection the connection.
851 * @returns next message in the incoming queue.
854 dbus_connection_peek_message (DBusConnection *connection)
856 return _dbus_list_get_first (&connection->incoming_messages);
860 * Returns the first-received message from the incoming message queue,
861 * removing it from the queue. The caller owns a reference to the
862 * returned message. If the queue is empty, returns #NULL.
864 * @param connection the connection.
865 * @returns next message in the incoming queue.
868 dbus_connection_pop_message (DBusConnection *connection)
870 if (connection->n_incoming > 0)
872 DBusMessage *message;
874 message = _dbus_list_pop_first (&connection->incoming_messages);
875 connection->n_incoming -= 1;
877 _dbus_verbose ("Incoming message %p removed from queue, %d incoming\n",
878 message, connection->n_incoming);
887 * Pops the first-received message from the current incoming message
888 * queue, runs any handlers for it, then unrefs the message.
890 * @param connection the connection
891 * @returns #TRUE if the queue is not empty after dispatch
893 * @todo this function is not properly robust against reentrancy,
894 * that is, if handlers are added/removed while dispatching
895 * a message, things will get messed up.
898 dbus_connection_dispatch_message (DBusConnection *connection)
900 DBusMessage *message;
904 DBusHandlerResult result;
907 dbus_connection_ref (connection);
909 message = dbus_connection_pop_message (connection);
912 dbus_connection_unref (connection);
916 filter_serial = connection->filters_serial;
917 handler_serial = connection->handlers_serial;
919 result = DBUS_HANDLER_RESULT_ALLOW_MORE_HANDLERS;
921 link = _dbus_list_get_first_link (&connection->filter_list);
924 DBusMessageHandler *handler = link->data;
925 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
927 result = _dbus_message_handler_handle_message (handler, connection,
930 if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
933 if (filter_serial != connection->filters_serial)
935 _dbus_warn ("Message filters added or removed while dispatching filters - not currently supported!\n");
942 name = dbus_message_get_name (message);
945 DBusMessageHandler *handler;
947 handler = _dbus_hash_table_lookup_string (connection->handler_table,
952 result = _dbus_message_handler_handle_message (handler, connection,
955 if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
958 if (handler_serial != connection->handlers_serial)
960 _dbus_warn ("Message handlers added or removed while dispatching handlers - not currently supported!\n");
967 dbus_connection_unref (connection);
968 dbus_message_unref (message);
970 return connection->n_incoming > 0;
974 * Sets the disconnect handler function for the connection.
975 * Will be called exactly once, when the connection is
978 * @param connection the connection.
979 * @param disconnect_function the disconnect handler.
980 * @param data data to pass to the disconnect handler.
981 * @param free_data_function function to be called to free the data.
984 dbus_connection_set_disconnect_function (DBusConnection *connection,
985 DBusDisconnectFunction disconnect_function,
987 DBusFreeFunction free_data_function)
989 if (connection->disconnect_free_data_function != NULL)
990 (* connection->disconnect_free_data_function) (connection->disconnect_data);
992 connection->disconnect_function = disconnect_function;
993 connection->disconnect_data = data;
994 connection->disconnect_free_data_function = free_data_function;
998 * Sets the watch functions for the connection. These functions are
999 * responsible for making the application's main loop aware of file
1000 * descriptors that need to be monitored for events, using select() or
1001 * poll(). When using Qt, typically the DBusAddWatchFunction would
1002 * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
1003 * could call g_io_add_watch(), or could be used as part of a more
1004 * elaborate GSource.
1006 * The DBusWatch can be queried for the file descriptor to watch using
1007 * dbus_watch_get_fd(), and for the events to watch for using
1008 * dbus_watch_get_flags(). The flags returned by
1009 * dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and
1010 * DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR;
1011 * all watches implicitly include a watch for hangups, errors, and
1012 * other exceptional conditions.
1014 * Once a file descriptor becomes readable or writable, or an exception
1015 * occurs, dbus_connection_handle_watch() should be called to
1016 * notify the connection of the file descriptor's condition.
1018 * dbus_connection_handle_watch() cannot be called during the
1019 * DBusAddWatchFunction, as the connection will not be ready to handle
1022 * It is not allowed to reference a DBusWatch after it has been passed
1023 * to remove_function.
1025 * @param connection the connection.
1026 * @param add_function function to begin monitoring a new descriptor.
1027 * @param remove_function function to stop monitoring a descriptor.
1028 * @param data data to pass to add_function and remove_function.
1029 * @param free_data_function function to be called to free the data.
1032 dbus_connection_set_watch_functions (DBusConnection *connection,
1033 DBusAddWatchFunction add_function,
1034 DBusRemoveWatchFunction remove_function,
1036 DBusFreeFunction free_data_function)
1038 /* ref connection for slightly better reentrancy */
1039 dbus_connection_ref (connection);
1041 _dbus_watch_list_set_functions (connection->watches,
1042 add_function, remove_function,
1043 data, free_data_function);
1045 /* drop our paranoid refcount */
1046 dbus_connection_unref (connection);
1050 * Sets the timeout functions for the connection. These functions are
1051 * responsible for making the application's main loop aware of timeouts.
1052 * When using Qt, typically the DBusAddTimeoutFunction would create a
1053 * QTimer. When using GLib, the DBusAddTimeoutFunction would call
1056 * The DBusTimeout can be queried for the timer interval using
1057 * dbus_timeout_get_interval.
1059 * Once a timeout occurs, dbus_timeout_handle should be called to invoke
1060 * the timeout's callback.
1062 * @param connection the connection.
1063 * @param add_function function to add a timeout.
1064 * @param remove_function function to remove a timeout.
1065 * @param data data to pass to add_function and remove_function.
1066 * @param free_data_function function to be called to free the data.
1069 dbus_connection_set_timeout_functions (DBusConnection *connection,
1070 DBusAddTimeoutFunction add_function,
1071 DBusRemoveTimeoutFunction remove_function,
1073 DBusFreeFunction free_data_function)
1075 /* ref connection for slightly better reentrancy */
1076 dbus_connection_ref (connection);
1078 _dbus_timeout_list_set_functions (connection->timeouts,
1079 add_function, remove_function,
1080 data, free_data_function);
1082 /* drop our paranoid refcount */
1083 dbus_connection_unref (connection);
1087 * Called to notify the connection when a previously-added watch
1088 * is ready for reading or writing, or has an exception such
1091 * @param connection the connection.
1092 * @param watch the watch.
1093 * @param condition the current condition of the file descriptors being watched.
1096 dbus_connection_handle_watch (DBusConnection *connection,
1098 unsigned int condition)
1100 _dbus_transport_handle_watch (connection->transport,
1105 * Adds a message filter. Filters are handlers that are run on
1106 * all incoming messages, prior to the normal handlers
1107 * registered with dbus_connection_register_handler().
1108 * Filters are run in the order that they were added.
1109 * The same handler can be added as a filter more than once, in
1110 * which case it will be run more than once.
1112 * @param connection the connection
1113 * @param handler the handler
1114 * @returns #TRUE on success, #FALSE if not enough memory.
1117 dbus_connection_add_filter (DBusConnection *connection,
1118 DBusMessageHandler *handler)
1120 if (!_dbus_message_handler_add_connection (handler, connection))
1123 if (!_dbus_list_append (&connection->filter_list,
1126 _dbus_message_handler_remove_connection (handler, connection);
1130 connection->filters_serial += 1;
1136 * Removes a previously-added message filter. It is a programming
1137 * error to call this function for a handler that has not
1138 * been added as a filter. If the given handler was added
1139 * more than once, only one instance of it will be removed
1140 * (the most recently-added instance).
1142 * @param connection the connection
1143 * @param handler the handler to remove
1147 dbus_connection_remove_filter (DBusConnection *connection,
1148 DBusMessageHandler *handler)
1150 if (!_dbus_list_remove_last (&connection->filter_list, handler))
1152 _dbus_warn ("Tried to remove a DBusConnection filter that had not been added\n");
1156 _dbus_message_handler_remove_connection (handler, connection);
1158 connection->filters_serial += 1;
1162 * Registers a handler for a list of message names. A single handler
1163 * can be registered for any number of message names, but each message
1164 * name can only have one handler at a time. It's not allowed to call
1165 * this function with the name of a message that already has a
1166 * handler. If the function returns #FALSE, the handlers were not
1167 * registered due to lack of memory.
1169 * @param connection the connection
1170 * @param handler the handler
1171 * @param messages_to_handle the messages to handle
1172 * @param n_messages the number of message names in messages_to_handle
1173 * @returns #TRUE on success, #FALSE if no memory or another handler already exists
1177 dbus_connection_register_handler (DBusConnection *connection,
1178 DBusMessageHandler *handler,
1179 const char **messages_to_handle,
1185 while (i < n_messages)
1190 key = _dbus_strdup (messages_to_handle[i]);
1194 if (!_dbus_hash_iter_lookup (connection->handler_table,
1202 if (_dbus_hash_iter_get_value (&iter) != NULL)
1204 _dbus_warn ("Bug in application: attempted to register a second handler for %s\n",
1205 messages_to_handle[i]);
1206 dbus_free (key); /* won't have replaced the old key with the new one */
1210 if (!_dbus_message_handler_add_connection (handler, connection))
1212 _dbus_hash_iter_remove_entry (&iter);
1213 /* key has freed on nuking the entry */
1217 _dbus_hash_iter_set_value (&iter, handler);
1219 connection->handlers_serial += 1;
1227 /* unregister everything registered so far,
1228 * so we don't fail partially
1230 dbus_connection_unregister_handler (connection,
1239 * Unregisters a handler for a list of message names. The handlers
1240 * must have been previously registered.
1242 * @param connection the connection
1243 * @param handler the handler
1244 * @param messages_to_handle the messages to handle
1245 * @param n_messages the number of message names in messages_to_handle
1249 dbus_connection_unregister_handler (DBusConnection *connection,
1250 DBusMessageHandler *handler,
1251 const char **messages_to_handle,
1257 while (i < n_messages)
1261 if (!_dbus_hash_iter_lookup (connection->handler_table,
1262 (char*) messages_to_handle[i], FALSE,
1265 _dbus_warn ("Bug in application: attempted to unregister handler for %s which was not registered\n",
1266 messages_to_handle[i]);
1268 else if (_dbus_hash_iter_get_value (&iter) != handler)
1270 _dbus_warn ("Bug in application: attempted to unregister handler for %s which was registered by a different handler\n",
1271 messages_to_handle[i]);
1275 _dbus_hash_iter_remove_entry (&iter);
1276 _dbus_message_handler_remove_connection (handler, connection);
1282 connection->handlers_serial += 1;
1285 static int *allocated_slots = NULL;
1286 static int n_allocated_slots = 0;
1287 static int n_used_slots = 0;
1288 static DBusStaticMutex allocated_slots_lock = DBUS_STATIC_MUTEX_INIT;
1291 * Allocates an integer ID to be used for storing application-specific
1292 * data on any DBusConnection. The allocated ID may then be used
1293 * with dbus_connection_set_data() and dbus_connection_get_data().
1294 * If allocation fails, -1 is returned.
1296 * @returns -1 on failure, otherwise the data slot ID
1299 dbus_connection_allocate_data_slot (void)
1303 if (!dbus_static_mutex_lock (&allocated_slots_lock))
1306 if (n_used_slots < n_allocated_slots)
1309 while (slot < n_allocated_slots)
1311 if (allocated_slots[slot] < 0)
1313 allocated_slots[slot] = slot;
1320 _dbus_assert (slot < n_allocated_slots);
1327 tmp = dbus_realloc (allocated_slots,
1328 sizeof (int) * (n_allocated_slots + 1));
1332 allocated_slots = tmp;
1333 slot = n_allocated_slots;
1334 n_allocated_slots += 1;
1336 allocated_slots[slot] = slot;
1339 _dbus_assert (slot >= 0);
1340 _dbus_assert (slot < n_allocated_slots);
1343 dbus_static_mutex_unlock (&allocated_slots_lock);
1348 * Deallocates a global ID for connection data slots.
1349 * dbus_connection_get_data() and dbus_connection_set_data()
1350 * may no longer be used with this slot.
1351 * Existing data stored on existing DBusConnection objects
1352 * will be freed when the connection is finalized,
1353 * but may not be retrieved (and may only be replaced
1354 * if someone else reallocates the slot).
1356 * @param slot the slot to deallocate
1359 dbus_connection_free_data_slot (int slot)
1361 dbus_static_mutex_lock (&allocated_slots_lock);
1363 _dbus_assert (slot < n_allocated_slots);
1364 _dbus_assert (allocated_slots[slot] == slot);
1366 allocated_slots[slot] = -1;
1369 if (n_used_slots == 0)
1371 dbus_free (allocated_slots);
1372 allocated_slots = NULL;
1373 n_allocated_slots = 0;
1376 dbus_static_mutex_unlock (&allocated_slots_lock);
1380 * Stores a pointer on a DBusConnection, along
1381 * with an optional function to be used for freeing
1382 * the data when the data is set again, or when
1383 * the connection is finalized. The slot number
1384 * must have been allocated with dbus_connection_allocate_data_slot().
1386 * @param connection the connection
1387 * @param slot the slot number
1388 * @param data the data to store
1389 * @param free_data_func finalizer function for the data
1390 * @returns #TRUE if there was enough memory to store the data
1393 dbus_connection_set_data (DBusConnection *connection,
1396 DBusFreeFunction free_data_func)
1398 _dbus_assert (slot < n_allocated_slots);
1399 _dbus_assert (allocated_slots[slot] == slot);
1401 if (slot >= connection->n_slots)
1406 tmp = dbus_realloc (connection->data_slots,
1407 sizeof (DBusDataSlot) * (slot + 1));
1411 connection->data_slots = tmp;
1412 i = connection->n_slots;
1413 connection->n_slots = slot + 1;
1414 while (i < connection->n_slots)
1416 connection->data_slots[i].data = NULL;
1417 connection->data_slots[i].free_data_func = NULL;
1422 _dbus_assert (slot < connection->n_slots);
1424 if (connection->data_slots[slot].free_data_func)
1425 (* connection->data_slots[slot].free_data_func) (connection->data_slots[slot].data);
1427 connection->data_slots[slot].data = data;
1428 connection->data_slots[slot].free_data_func = free_data_func;
1434 * Retrieves data previously set with dbus_connection_set_data().
1435 * The slot must still be allocated (must not have been freed).
1437 * @param connection the connection
1438 * @param slot the slot to get data from
1439 * @returns the data, or #NULL if not found
1442 dbus_connection_get_data (DBusConnection *connection,
1445 _dbus_assert (slot < n_allocated_slots);
1446 _dbus_assert (allocated_slots[slot] == slot);
1448 if (slot >= connection->n_slots)
1451 return connection->data_slots[slot].data;
1455 _dbus_connection_free_data_slots (DBusConnection *connection)
1460 while (i < connection->n_slots)
1462 if (connection->data_slots[i].free_data_func)
1463 (* connection->data_slots[i].free_data_func) (connection->data_slots[i].data);
1464 connection->data_slots[i].data = NULL;
1465 connection->data_slots[i].free_data_func = NULL;
1469 dbus_free (connection->data_slots);
1470 connection->data_slots = NULL;
1471 connection->n_slots = 0;
1475 * Specifies the maximum size message this connection is allowed to
1476 * receive. Larger messages will result in disconnecting the
1479 * @param connection a #DBusConnection
1480 * @param size maximum message size the connection can receive, in bytes
1483 dbus_connection_set_max_message_size (DBusConnection *connection,
1486 _dbus_transport_set_max_message_size (connection->transport,
1491 * Gets the value set by dbus_connection_set_max_message_size().
1493 * @param connection the connection
1494 * @returns the max size of a single message
1497 dbus_connection_get_max_message_size (DBusConnection *connection)
1499 return _dbus_transport_get_max_message_size (connection->transport);
1503 * Sets the maximum total number of bytes that can be used for all messages
1504 * received on this connection. Messages count toward the maximum until
1505 * they are finalized. When the maximum is reached, the connection will
1506 * not read more data until some messages are finalized.
1508 * The semantics of the maximum are: if outstanding messages are
1509 * already above the maximum, additional messages will not be read.
1510 * The semantics are not: if the next message would cause us to exceed
1511 * the maximum, we don't read it. The reason is that we don't know the
1512 * size of a message until after we read it.
1514 * Thus, the max live messages size can actually be exceeded
1515 * by up to the maximum size of a single message.
1517 * Also, if we read say 1024 bytes off the wire in a single read(),
1518 * and that contains a half-dozen small messages, we may exceed the
1519 * size max by that amount. But this should be inconsequential.
1521 * @param connection the connection
1522 * @param size the maximum size in bytes of all outstanding messages
1525 dbus_connection_set_max_live_messages_size (DBusConnection *connection,
1528 _dbus_transport_set_max_live_messages_size (connection->transport,
1533 * Gets the value set by dbus_connection_set_max_live_messages_size().
1535 * @param connection the connection
1536 * @returns the max size of all live messages
1539 dbus_connection_get_max_live_messages_size (DBusConnection *connection)
1541 return _dbus_transport_get_max_live_messages_size (connection->transport);