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-message-handler.h"
34 #include "dbus-threads.h"
35 #include "dbus-protocol.h"
36 #include "dbus-dataslot.h"
39 * @defgroup DBusConnection DBusConnection
41 * @brief Connection to another application
43 * A DBusConnection represents a connection to another
44 * application. Messages can be sent and received via this connection.
45 * The other application may be a message bus; for convenience, the
46 * function dbus_bus_get() is provided to automatically open a
47 * connection to the well-known message buses.
49 * In brief a DBusConnection is a message queue associated with some
50 * message transport mechanism such as a socket. The connection
51 * maintains a queue of incoming messages and a queue of outgoing
54 * Incoming messages are normally processed by calling
55 * dbus_connection_dispatch(). dbus_connection_dispatch() runs any
56 * handlers registered for the topmost message in the message queue,
57 * then discards the message, then returns.
59 * dbus_connection_get_dispatch_status() indicates whether
60 * messages are currently in the queue that need dispatching.
61 * dbus_connection_set_dispatch_status_function() allows
62 * you to set a function to be used to monitor the dispatch status.
64 * If you're using GLib or Qt add-on libraries for D-BUS, there are
65 * special convenience functions in those libraries that hide
66 * all the details of dispatch and watch/timeout monitoring.
67 * For example, dbus_connection_setup_with_g_main().
69 * If you aren't using these add-on libraries, you have to manually
70 * call dbus_connection_set_dispatch_status_function(),
71 * dbus_connection_set_watch_functions(),
72 * dbus_connection_set_timeout_functions() providing appropriate
73 * functions to integrate the connection with your application's main
76 * When you use dbus_connection_send() or one of its variants to send
77 * a message, the message is added to the outgoing queue. It's
78 * actually written to the network later; either in
79 * dbus_watch_handle() invoked by your main loop, or in
80 * dbus_connection_flush() which blocks until it can write out the
81 * entire outgoing queue. The GLib/Qt add-on libraries again
82 * handle the details here for you by setting up watch functions.
84 * When a connection is disconnected, you are guaranteed to get a
85 * message with the name #DBUS_MESSAGE_LOCAL_DISCONNECT.
87 * You may not drop the last reference to a #DBusConnection
88 * until that connection has been disconnected.
90 * You may dispatch the unprocessed incoming message queue even if the
91 * connection is disconnected. However, #DBUS_MESSAGE_LOCAL_DISCONNECT
92 * will always be the last message in the queue (obviously no messages
93 * are received after disconnection).
95 * #DBusConnection has thread locks and drops them when invoking user
96 * callbacks, so in general is transparently threadsafe. However,
97 * #DBusMessage does NOT have thread locks; you must not send the same
98 * message to multiple #DBusConnection that will be used from
103 * @defgroup DBusConnectionInternals DBusConnection implementation details
104 * @ingroup DBusInternals
105 * @brief Implementation details of DBusConnection
110 /** default timeout value when waiting for a message reply */
111 #define DEFAULT_TIMEOUT_VALUE (15 * 1000)
113 static dbus_bool_t _dbus_modify_sigpipe = TRUE;
116 * Implementation details of DBusConnection. All fields are private.
118 struct DBusConnection
120 int refcount; /**< Reference count. */
122 DBusMutex *mutex; /**< Lock on the entire DBusConnection */
124 dbus_bool_t dispatch_acquired; /**< Protects dispatch() */
125 DBusCondVar *dispatch_cond; /**< Protects dispatch() */
127 dbus_bool_t io_path_acquired; /**< Protects transport io path */
128 DBusCondVar *io_path_cond; /**< Protects transport io path */
130 DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
131 DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */
133 DBusMessage *message_borrowed; /**< True if the first incoming message has been borrowed */
134 DBusCondVar *message_returned_cond; /**< Used with dbus_connection_borrow_message() */
136 int n_outgoing; /**< Length of outgoing queue. */
137 int n_incoming; /**< Length of incoming queue. */
139 DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */
141 DBusTransport *transport; /**< Object that sends/receives messages over network. */
142 DBusWatchList *watches; /**< Stores active watches. */
143 DBusTimeoutList *timeouts; /**< Stores active timeouts. */
145 DBusHashTable *handler_table; /**< Table of registered DBusMessageHandler */
146 DBusList *filter_list; /**< List of filters. */
148 DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */
150 DBusHashTable *pending_replies; /**< Hash of message serials and their message handlers. */
152 dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */
153 DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */
155 DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */
156 void *wakeup_main_data; /**< Application data for wakeup_main_function */
157 DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */
159 DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */
160 void *dispatch_status_data; /**< Application data for dispatch_status_function */
161 DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */
163 DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */
168 DBusConnection *connection;
169 DBusMessageHandler *handler;
170 DBusTimeout *timeout;
173 DBusList *timeout_link; /* Preallocated timeout response */
175 dbus_bool_t timeout_added;
176 dbus_bool_t connection_added;
179 static void reply_handler_data_free (ReplyHandlerData *data);
181 static void _dbus_connection_remove_timeout_locked (DBusConnection *connection,
182 DBusTimeout *timeout);
183 static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection);
184 static void _dbus_connection_update_dispatch_status_locked (DBusConnection *connection,
185 DBusDispatchStatus new_status);
189 * Acquires the connection lock.
191 * @param connection the connection.
194 _dbus_connection_lock (DBusConnection *connection)
196 dbus_mutex_lock (connection->mutex);
200 * Releases the connection lock.
202 * @param connection the connection.
205 _dbus_connection_unlock (DBusConnection *connection)
207 dbus_mutex_unlock (connection->mutex);
211 * Wakes up the main loop if it is sleeping
212 * Needed if we're e.g. queueing outgoing messages
213 * on a thread while the mainloop sleeps.
215 * @param connection the connection.
218 _dbus_connection_wakeup_mainloop (DBusConnection *connection)
220 if (connection->wakeup_main_function)
221 (*connection->wakeup_main_function) (connection->wakeup_main_data);
225 * Adds a message to the incoming message queue, returning #FALSE
226 * if there's insufficient memory to queue the message.
227 * Does not take over refcount of the message.
229 * @param connection the connection.
230 * @param message the message to queue.
231 * @returns #TRUE on success.
234 _dbus_connection_queue_received_message (DBusConnection *connection,
235 DBusMessage *message)
239 link = _dbus_list_alloc_link (message);
243 dbus_message_ref (message);
244 _dbus_connection_queue_received_message_link (connection, link);
250 * Adds a message-containing list link to the incoming message queue,
251 * taking ownership of the link and the message's current refcount.
252 * Cannot fail due to lack of memory.
254 * @param connection the connection.
255 * @param link the message link to queue.
258 _dbus_connection_queue_received_message_link (DBusConnection *connection,
261 ReplyHandlerData *reply_handler_data;
262 dbus_int32_t reply_serial;
263 DBusMessage *message;
265 _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
267 _dbus_list_append_link (&connection->incoming_messages,
269 message = link->data;
271 /* If this is a reply we're waiting on, remove timeout for it */
272 reply_serial = dbus_message_get_reply_serial (message);
273 if (reply_serial != -1)
275 reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies,
277 if (reply_handler_data != NULL)
279 if (reply_handler_data->timeout_added)
280 _dbus_connection_remove_timeout_locked (connection,
281 reply_handler_data->timeout);
282 reply_handler_data->timeout_added = FALSE;
286 connection->n_incoming += 1;
288 _dbus_connection_wakeup_mainloop (connection);
290 _dbus_assert (dbus_message_get_name (message) != NULL);
291 _dbus_verbose ("Message %p (%s) added to incoming queue %p, %d incoming\n",
292 message, dbus_message_get_name (message),
294 connection->n_incoming);
298 * Adds a link + message to the incoming message queue.
299 * Can't fail. Takes ownership of both link and message.
301 * @param connection the connection.
302 * @param link the list node and message to queue.
304 * @todo This needs to wake up the mainloop if it is in
305 * a poll/select and this is a multithreaded app.
308 _dbus_connection_queue_synthesized_message_link (DBusConnection *connection,
311 _dbus_list_append_link (&connection->incoming_messages, link);
313 connection->n_incoming += 1;
315 _dbus_connection_wakeup_mainloop (connection);
317 _dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n",
318 link->data, connection, connection->n_incoming);
323 * Checks whether there are messages in the outgoing message queue.
325 * @param connection the connection.
326 * @returns #TRUE if the outgoing queue is non-empty.
329 _dbus_connection_have_messages_to_send (DBusConnection *connection)
331 return connection->outgoing_messages != NULL;
335 * Gets the next outgoing message. The message remains in the
336 * queue, and the caller does not own a reference to it.
338 * @param connection the connection.
339 * @returns the message to be sent.
342 _dbus_connection_get_message_to_send (DBusConnection *connection)
344 return _dbus_list_get_last (&connection->outgoing_messages);
348 * Notifies the connection that a message has been sent, so the
349 * message can be removed from the outgoing queue.
351 * @param connection the connection.
352 * @param message the message that was sent.
355 _dbus_connection_message_sent (DBusConnection *connection,
356 DBusMessage *message)
358 _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
359 _dbus_assert (message == _dbus_list_get_last (&connection->outgoing_messages));
361 _dbus_list_pop_last (&connection->outgoing_messages);
363 connection->n_outgoing -= 1;
365 _dbus_verbose ("Message %p (%s) removed from outgoing queue %p, %d left to send\n",
366 message, dbus_message_get_name (message),
367 connection, connection->n_outgoing);
369 _dbus_message_remove_size_counter (message, connection->outgoing_counter);
371 dbus_message_unref (message);
373 if (connection->n_outgoing == 0)
374 _dbus_transport_messages_pending (connection->transport,
375 connection->n_outgoing);
379 * Adds a watch using the connection's DBusAddWatchFunction if
380 * available. Otherwise records the watch to be added when said
381 * function is available. Also re-adds the watch if the
382 * DBusAddWatchFunction changes. May fail due to lack of memory.
384 * @param connection the connection.
385 * @param watch the watch to add.
386 * @returns #TRUE on success.
389 _dbus_connection_add_watch (DBusConnection *connection,
392 if (connection->watches) /* null during finalize */
393 return _dbus_watch_list_add_watch (connection->watches,
400 * Removes a watch using the connection's DBusRemoveWatchFunction
401 * if available. It's an error to call this function on a watch
402 * that was not previously added.
404 * @param connection the connection.
405 * @param watch the watch to remove.
408 _dbus_connection_remove_watch (DBusConnection *connection,
411 if (connection->watches) /* null during finalize */
412 _dbus_watch_list_remove_watch (connection->watches,
417 * Toggles a watch and notifies app via connection's
418 * DBusWatchToggledFunction if available. It's an error to call this
419 * function on a watch that was not previously added.
421 * @param connection the connection.
422 * @param watch the watch to toggle.
423 * @param enabled whether to enable or disable
426 _dbus_connection_toggle_watch (DBusConnection *connection,
430 if (connection->watches) /* null during finalize */
431 _dbus_watch_list_toggle_watch (connection->watches,
436 * Adds a timeout using the connection's DBusAddTimeoutFunction if
437 * available. Otherwise records the timeout to be added when said
438 * function is available. Also re-adds the timeout if the
439 * DBusAddTimeoutFunction changes. May fail due to lack of memory.
440 * The timeout will fire repeatedly until removed.
442 * @param connection the connection.
443 * @param timeout the timeout to add.
444 * @returns #TRUE on success.
447 _dbus_connection_add_timeout (DBusConnection *connection,
448 DBusTimeout *timeout)
450 if (connection->timeouts) /* null during finalize */
451 return _dbus_timeout_list_add_timeout (connection->timeouts,
458 * Removes a timeout using the connection's DBusRemoveTimeoutFunction
459 * if available. It's an error to call this function on a timeout
460 * that was not previously added.
462 * @param connection the connection.
463 * @param timeout the timeout to remove.
466 _dbus_connection_remove_timeout (DBusConnection *connection,
467 DBusTimeout *timeout)
469 if (connection->timeouts) /* null during finalize */
470 _dbus_timeout_list_remove_timeout (connection->timeouts,
475 _dbus_connection_remove_timeout_locked (DBusConnection *connection,
476 DBusTimeout *timeout)
478 dbus_mutex_lock (connection->mutex);
479 _dbus_connection_remove_timeout (connection, timeout);
480 dbus_mutex_unlock (connection->mutex);
484 * Toggles a timeout and notifies app via connection's
485 * DBusTimeoutToggledFunction if available. It's an error to call this
486 * function on a timeout that was not previously added.
488 * @param connection the connection.
489 * @param timeout the timeout to toggle.
490 * @param enabled whether to enable or disable
493 _dbus_connection_toggle_timeout (DBusConnection *connection,
494 DBusTimeout *timeout,
497 if (connection->timeouts) /* null during finalize */
498 _dbus_timeout_list_toggle_timeout (connection->timeouts,
503 * Tells the connection that the transport has been disconnected.
504 * Results in posting a disconnect message on the incoming message
505 * queue. Only has an effect the first time it's called.
507 * @param connection the connection
510 _dbus_connection_notify_disconnected (DBusConnection *connection)
512 if (connection->disconnect_message_link)
514 /* We haven't sent the disconnect message already */
515 _dbus_connection_queue_synthesized_message_link (connection,
516 connection->disconnect_message_link);
517 connection->disconnect_message_link = NULL;
523 * Acquire the transporter I/O path. This must be done before
524 * doing any I/O in the transporter. May sleep and drop the
525 * connection mutex while waiting for the I/O path.
527 * @param connection the connection.
528 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
529 * @returns TRUE if the I/O path was acquired.
532 _dbus_connection_acquire_io_path (DBusConnection *connection,
533 int timeout_milliseconds)
535 dbus_bool_t res = TRUE;
537 if (connection->io_path_acquired)
539 if (timeout_milliseconds != -1)
540 res = dbus_condvar_wait_timeout (connection->io_path_cond,
542 timeout_milliseconds);
544 dbus_condvar_wait (connection->io_path_cond, connection->mutex);
549 _dbus_assert (!connection->io_path_acquired);
551 connection->io_path_acquired = TRUE;
558 * Release the I/O path when you're done with it. Only call
559 * after you've acquired the I/O. Wakes up at most one thread
560 * currently waiting to acquire the I/O path.
562 * @param connection the connection.
565 _dbus_connection_release_io_path (DBusConnection *connection)
567 _dbus_assert (connection->io_path_acquired);
569 connection->io_path_acquired = FALSE;
570 dbus_condvar_wake_one (connection->io_path_cond);
575 * Queues incoming messages and sends outgoing messages for this
576 * connection, optionally blocking in the process. Each call to
577 * _dbus_connection_do_iteration() will call select() or poll() one
578 * time and then read or write data if possible.
580 * The purpose of this function is to be able to flush outgoing
581 * messages or queue up incoming messages without returning
582 * control to the application and causing reentrancy weirdness.
584 * The flags parameter allows you to specify whether to
585 * read incoming messages, write outgoing messages, or both,
586 * and whether to block if no immediate action is possible.
588 * The timeout_milliseconds parameter does nothing unless the
589 * iteration is blocking.
591 * If there are no outgoing messages and DBUS_ITERATION_DO_READING
592 * wasn't specified, then it's impossible to block, even if
593 * you specify DBUS_ITERATION_BLOCK; in that case the function
594 * returns immediately.
596 * @param connection the connection.
597 * @param flags iteration flags.
598 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
601 _dbus_connection_do_iteration (DBusConnection *connection,
603 int timeout_milliseconds)
605 if (connection->n_outgoing == 0)
606 flags &= ~DBUS_ITERATION_DO_WRITING;
608 if (_dbus_connection_acquire_io_path (connection,
609 (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0))
611 _dbus_transport_do_iteration (connection->transport,
612 flags, timeout_milliseconds);
613 _dbus_connection_release_io_path (connection);
618 * Creates a new connection for the given transport. A transport
619 * represents a message stream that uses some concrete mechanism, such
620 * as UNIX domain sockets. May return #NULL if insufficient
621 * memory exists to create the connection.
623 * @param transport the transport.
624 * @returns the new connection, or #NULL on failure.
627 _dbus_connection_new_for_transport (DBusTransport *transport)
629 DBusConnection *connection;
630 DBusWatchList *watch_list;
631 DBusTimeoutList *timeout_list;
632 DBusHashTable *handler_table, *pending_replies;
634 DBusCondVar *message_returned_cond;
635 DBusCondVar *dispatch_cond;
636 DBusCondVar *io_path_cond;
637 DBusList *disconnect_link;
638 DBusMessage *disconnect_message;
639 DBusCounter *outgoing_counter;
643 handler_table = NULL;
644 pending_replies = NULL;
647 message_returned_cond = NULL;
648 dispatch_cond = NULL;
650 disconnect_link = NULL;
651 disconnect_message = NULL;
652 outgoing_counter = NULL;
654 watch_list = _dbus_watch_list_new ();
655 if (watch_list == NULL)
658 timeout_list = _dbus_timeout_list_new ();
659 if (timeout_list == NULL)
663 _dbus_hash_table_new (DBUS_HASH_STRING,
665 if (handler_table == NULL)
669 _dbus_hash_table_new (DBUS_HASH_INT,
670 NULL, (DBusFreeFunction)reply_handler_data_free);
671 if (pending_replies == NULL)
674 connection = dbus_new0 (DBusConnection, 1);
675 if (connection == NULL)
678 mutex = dbus_mutex_new ();
682 message_returned_cond = dbus_condvar_new ();
683 if (message_returned_cond == NULL)
686 dispatch_cond = dbus_condvar_new ();
687 if (dispatch_cond == NULL)
690 io_path_cond = dbus_condvar_new ();
691 if (io_path_cond == NULL)
694 disconnect_message = dbus_message_new (NULL, DBUS_MESSAGE_LOCAL_DISCONNECT);
695 if (disconnect_message == NULL)
698 disconnect_link = _dbus_list_alloc_link (disconnect_message);
699 if (disconnect_link == NULL)
702 outgoing_counter = _dbus_counter_new ();
703 if (outgoing_counter == NULL)
706 if (_dbus_modify_sigpipe)
707 _dbus_disable_sigpipe ();
709 connection->refcount = 1;
710 connection->mutex = mutex;
711 connection->dispatch_cond = dispatch_cond;
712 connection->io_path_cond = io_path_cond;
713 connection->message_returned_cond = message_returned_cond;
714 connection->transport = transport;
715 connection->watches = watch_list;
716 connection->timeouts = timeout_list;
717 connection->handler_table = handler_table;
718 connection->pending_replies = pending_replies;
719 connection->outgoing_counter = outgoing_counter;
720 connection->filter_list = NULL;
721 connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */
723 _dbus_data_slot_list_init (&connection->slot_list);
725 connection->client_serial = 1;
727 connection->disconnect_message_link = disconnect_link;
729 if (!_dbus_transport_set_connection (transport, connection))
732 _dbus_transport_ref (transport);
737 if (disconnect_message != NULL)
738 dbus_message_unref (disconnect_message);
740 if (disconnect_link != NULL)
741 _dbus_list_free_link (disconnect_link);
743 if (io_path_cond != NULL)
744 dbus_condvar_free (io_path_cond);
746 if (dispatch_cond != NULL)
747 dbus_condvar_free (dispatch_cond);
749 if (message_returned_cond != NULL)
750 dbus_condvar_free (message_returned_cond);
753 dbus_mutex_free (mutex);
755 if (connection != NULL)
756 dbus_free (connection);
759 _dbus_hash_table_unref (handler_table);
762 _dbus_hash_table_unref (pending_replies);
765 _dbus_watch_list_free (watch_list);
768 _dbus_timeout_list_free (timeout_list);
770 if (outgoing_counter)
771 _dbus_counter_unref (outgoing_counter);
777 _dbus_connection_get_next_client_serial (DBusConnection *connection)
781 serial = connection->client_serial++;
783 if (connection->client_serial < 0)
784 connection->client_serial = 1;
790 * Used to notify a connection when a DBusMessageHandler is
791 * destroyed, so the connection can drop any reference
792 * to the handler. This is a private function, but still
793 * takes the connection lock. Don't call it with the lock held.
795 * @todo needs to check in pending_replies too.
797 * @param connection the connection
798 * @param handler the handler
801 _dbus_connection_handler_destroyed_locked (DBusConnection *connection,
802 DBusMessageHandler *handler)
807 dbus_mutex_lock (connection->mutex);
809 _dbus_hash_iter_init (connection->handler_table, &iter);
810 while (_dbus_hash_iter_next (&iter))
812 DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter);
815 _dbus_hash_iter_remove_entry (&iter);
818 link = _dbus_list_get_first_link (&connection->filter_list);
821 DBusMessageHandler *h = link->data;
822 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
825 _dbus_list_remove_link (&connection->filter_list,
830 dbus_mutex_unlock (connection->mutex);
836 * @addtogroup DBusConnection
842 * Opens a new connection to a remote address.
844 * @todo specify what the address parameter is. Right now
845 * it's just the name of a UNIX domain socket. It should be
846 * something more complex that encodes which transport to use.
848 * If the open fails, the function returns #NULL, and provides
849 * a reason for the failure in the result parameter. Pass
850 * #NULL for the result parameter if you aren't interested
851 * in the reason for failure.
853 * @param address the address.
854 * @param error address where an error can be returned.
855 * @returns new connection, or #NULL on failure.
858 dbus_connection_open (const char *address,
861 DBusConnection *connection;
862 DBusTransport *transport;
864 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
866 transport = _dbus_transport_open (address, error);
867 if (transport == NULL)
869 _DBUS_ASSERT_ERROR_IS_SET (error);
873 connection = _dbus_connection_new_for_transport (transport);
875 _dbus_transport_unref (transport);
877 if (connection == NULL)
879 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
887 * Increments the reference count of a DBusConnection.
889 * @param connection the connection.
892 dbus_connection_ref (DBusConnection *connection)
894 dbus_mutex_lock (connection->mutex);
895 _dbus_assert (connection->refcount > 0);
897 connection->refcount += 1;
898 dbus_mutex_unlock (connection->mutex);
902 * Increments the reference count of a DBusConnection.
903 * Requires that the caller already holds the connection lock.
905 * @param connection the connection.
908 _dbus_connection_ref_unlocked (DBusConnection *connection)
910 _dbus_assert (connection->refcount > 0);
911 connection->refcount += 1;
915 free_outgoing_message (void *element,
918 DBusMessage *message = element;
919 DBusConnection *connection = data;
921 _dbus_message_remove_size_counter (message,
922 connection->outgoing_counter);
923 dbus_message_unref (message);
926 /* This is run without the mutex held, but after the last reference
927 * to the connection has been dropped we should have no thread-related
931 _dbus_connection_last_unref (DBusConnection *connection)
936 _dbus_verbose ("Finalizing connection %p\n", connection);
938 _dbus_assert (connection->refcount == 0);
940 /* You have to disconnect the connection before unref:ing it. Otherwise
941 * you won't get the disconnected message.
943 _dbus_assert (!_dbus_transport_get_is_connected (connection->transport));
945 /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */
946 dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL);
947 dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL);
948 dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL);
950 _dbus_watch_list_free (connection->watches);
951 connection->watches = NULL;
953 _dbus_timeout_list_free (connection->timeouts);
954 connection->timeouts = NULL;
956 _dbus_data_slot_list_free (&connection->slot_list);
957 /* ---- Done with stuff that invokes application callbacks */
959 _dbus_hash_iter_init (connection->handler_table, &iter);
960 while (_dbus_hash_iter_next (&iter))
962 DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter);
964 _dbus_message_handler_remove_connection (h, connection);
967 link = _dbus_list_get_first_link (&connection->filter_list);
970 DBusMessageHandler *h = link->data;
971 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
973 _dbus_message_handler_remove_connection (h, connection);
978 _dbus_hash_table_unref (connection->handler_table);
979 connection->handler_table = NULL;
981 _dbus_hash_table_unref (connection->pending_replies);
982 connection->pending_replies = NULL;
984 _dbus_list_clear (&connection->filter_list);
986 _dbus_list_foreach (&connection->outgoing_messages,
987 free_outgoing_message,
989 _dbus_list_clear (&connection->outgoing_messages);
991 _dbus_list_foreach (&connection->incoming_messages,
992 (DBusForeachFunction) dbus_message_unref,
994 _dbus_list_clear (&connection->incoming_messages);
996 _dbus_counter_unref (connection->outgoing_counter);
998 _dbus_transport_unref (connection->transport);
1000 if (connection->disconnect_message_link)
1002 DBusMessage *message = connection->disconnect_message_link->data;
1003 dbus_message_unref (message);
1004 _dbus_list_free_link (connection->disconnect_message_link);
1007 dbus_condvar_free (connection->dispatch_cond);
1008 dbus_condvar_free (connection->io_path_cond);
1009 dbus_condvar_free (connection->message_returned_cond);
1011 dbus_mutex_free (connection->mutex);
1013 dbus_free (connection);
1017 * Decrements the reference count of a DBusConnection, and finalizes
1018 * it if the count reaches zero. It is a bug to drop the last reference
1019 * to a connection that has not been disconnected.
1021 * @todo in practice it can be quite tricky to never unref a connection
1022 * that's still connected; maybe there's some way we could avoid
1025 * @param connection the connection.
1028 dbus_connection_unref (DBusConnection *connection)
1030 dbus_bool_t last_unref;
1032 dbus_mutex_lock (connection->mutex);
1034 _dbus_assert (connection != NULL);
1035 _dbus_assert (connection->refcount > 0);
1037 connection->refcount -= 1;
1038 last_unref = (connection->refcount == 0);
1041 printf ("unref() connection %p count = %d\n", connection, connection->refcount);
1044 dbus_mutex_unlock (connection->mutex);
1047 _dbus_connection_last_unref (connection);
1051 * Closes the connection, so no further data can be sent or received.
1052 * Any further attempts to send data will result in errors. This
1053 * function does not affect the connection's reference count. It's
1054 * safe to disconnect a connection more than once; all calls after the
1055 * first do nothing. It's impossible to "reconnect" a connection, a
1056 * new connection must be created.
1058 * @param connection the connection.
1061 dbus_connection_disconnect (DBusConnection *connection)
1063 dbus_mutex_lock (connection->mutex);
1064 _dbus_transport_disconnect (connection->transport);
1065 dbus_mutex_unlock (connection->mutex);
1069 * Gets whether the connection is currently connected. All
1070 * connections are connected when they are opened. A connection may
1071 * become disconnected when the remote application closes its end, or
1072 * exits; a connection may also be disconnected with
1073 * dbus_connection_disconnect().
1075 * @param connection the connection.
1076 * @returns #TRUE if the connection is still alive.
1079 dbus_connection_get_is_connected (DBusConnection *connection)
1083 dbus_mutex_lock (connection->mutex);
1084 res = _dbus_transport_get_is_connected (connection->transport);
1085 dbus_mutex_unlock (connection->mutex);
1091 * Gets whether the connection was authenticated. (Note that
1092 * if the connection was authenticated then disconnected,
1093 * this function still returns #TRUE)
1095 * @param connection the connection
1096 * @returns #TRUE if the connection was ever authenticated
1099 dbus_connection_get_is_authenticated (DBusConnection *connection)
1103 dbus_mutex_lock (connection->mutex);
1104 res = _dbus_transport_get_is_authenticated (connection->transport);
1105 dbus_mutex_unlock (connection->mutex);
1110 struct DBusPreallocatedSend
1112 DBusConnection *connection;
1113 DBusList *queue_link;
1114 DBusList *counter_link;
1119 * Preallocates resources needed to send a message, allowing the message
1120 * to be sent without the possibility of memory allocation failure.
1121 * Allows apps to create a future guarantee that they can send
1122 * a message regardless of memory shortages.
1124 * @param connection the connection we're preallocating for.
1125 * @returns the preallocated resources, or #NULL
1127 DBusPreallocatedSend*
1128 dbus_connection_preallocate_send (DBusConnection *connection)
1130 DBusPreallocatedSend *preallocated;
1132 preallocated = dbus_new (DBusPreallocatedSend, 1);
1133 if (preallocated == NULL)
1136 preallocated->queue_link = _dbus_list_alloc_link (NULL);
1137 if (preallocated->queue_link == NULL)
1140 preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
1141 if (preallocated->counter_link == NULL)
1144 _dbus_counter_ref (preallocated->counter_link->data);
1146 preallocated->connection = connection;
1148 return preallocated;
1151 _dbus_list_free_link (preallocated->queue_link);
1153 dbus_free (preallocated);
1159 * Frees preallocated message-sending resources from
1160 * dbus_connection_preallocate_send(). Should only
1161 * be called if the preallocated resources are not used
1162 * to send a message.
1164 * @param connection the connection
1165 * @param preallocated the resources
1168 dbus_connection_free_preallocated_send (DBusConnection *connection,
1169 DBusPreallocatedSend *preallocated)
1171 _dbus_assert (connection == preallocated->connection);
1173 _dbus_list_free_link (preallocated->queue_link);
1174 _dbus_counter_unref (preallocated->counter_link->data);
1175 _dbus_list_free_link (preallocated->counter_link);
1176 dbus_free (preallocated);
1180 * Sends a message using preallocated resources. This function cannot fail.
1181 * It works identically to dbus_connection_send() in other respects.
1182 * Preallocated resources comes from dbus_connection_preallocate_send().
1183 * This function "consumes" the preallocated resources, they need not
1184 * be freed separately.
1186 * @param connection the connection
1187 * @param preallocated the preallocated resources
1188 * @param message the message to send
1189 * @param client_serial return location for client serial assigned to the message
1192 dbus_connection_send_preallocated (DBusConnection *connection,
1193 DBusPreallocatedSend *preallocated,
1194 DBusMessage *message,
1195 dbus_uint32_t *client_serial)
1197 dbus_uint32_t serial;
1199 _dbus_assert (preallocated->connection == connection);
1200 _dbus_assert (dbus_message_get_name (message) != NULL);
1202 dbus_mutex_lock (connection->mutex);
1204 preallocated->queue_link->data = message;
1205 _dbus_list_prepend_link (&connection->outgoing_messages,
1206 preallocated->queue_link);
1208 _dbus_message_add_size_counter_link (message,
1209 preallocated->counter_link);
1211 dbus_free (preallocated);
1212 preallocated = NULL;
1214 dbus_message_ref (message);
1216 connection->n_outgoing += 1;
1218 _dbus_verbose ("Message %p (%s) added to outgoing queue %p, %d pending to send\n",
1220 dbus_message_get_name (message),
1222 connection->n_outgoing);
1224 if (dbus_message_get_serial (message) == 0)
1226 serial = _dbus_connection_get_next_client_serial (connection);
1227 _dbus_message_set_serial (message, serial);
1229 *client_serial = serial;
1234 *client_serial = dbus_message_get_serial (message);
1237 _dbus_message_lock (message);
1239 if (connection->n_outgoing == 1)
1240 _dbus_transport_messages_pending (connection->transport,
1241 connection->n_outgoing);
1243 _dbus_connection_wakeup_mainloop (connection);
1245 dbus_mutex_unlock (connection->mutex);
1249 * Adds a message to the outgoing message queue. Does not block to
1250 * write the message to the network; that happens asynchronously. To
1251 * force the message to be written, call dbus_connection_flush().
1252 * Because this only queues the message, the only reason it can
1253 * fail is lack of memory. Even if the connection is disconnected,
1254 * no error will be returned.
1256 * If the function fails due to lack of memory, it returns #FALSE.
1257 * The function will never fail for other reasons; even if the
1258 * connection is disconnected, you can queue an outgoing message,
1259 * though obviously it won't be sent.
1261 * @param connection the connection.
1262 * @param message the message to write.
1263 * @param client_serial return location for client serial.
1264 * @returns #TRUE on success.
1267 dbus_connection_send (DBusConnection *connection,
1268 DBusMessage *message,
1269 dbus_uint32_t *client_serial)
1271 DBusPreallocatedSend *preallocated;
1273 preallocated = dbus_connection_preallocate_send (connection);
1274 if (preallocated == NULL)
1280 dbus_connection_send_preallocated (connection, preallocated, message, client_serial);
1286 reply_handler_timeout (void *data)
1288 DBusConnection *connection;
1289 ReplyHandlerData *reply_handler_data = data;
1290 DBusDispatchStatus status;
1292 connection = reply_handler_data->connection;
1294 dbus_mutex_lock (connection->mutex);
1295 if (reply_handler_data->timeout_link)
1297 _dbus_connection_queue_synthesized_message_link (connection,
1298 reply_handler_data->timeout_link);
1299 reply_handler_data->timeout_link = NULL;
1302 _dbus_connection_remove_timeout (connection,
1303 reply_handler_data->timeout);
1304 reply_handler_data->timeout_added = FALSE;
1306 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1308 dbus_mutex_unlock (connection->mutex);
1310 _dbus_connection_update_dispatch_status_locked (connection, status);
1316 reply_handler_data_free (ReplyHandlerData *data)
1321 if (data->timeout_added)
1322 _dbus_connection_remove_timeout_locked (data->connection,
1325 if (data->connection_added)
1326 _dbus_message_handler_remove_connection (data->handler,
1329 if (data->timeout_link)
1331 dbus_message_unref ((DBusMessage *)data->timeout_link->data);
1332 _dbus_list_free_link (data->timeout_link);
1335 dbus_message_handler_unref (data->handler);
1341 * Queues a message to send, as with dbus_connection_send_message(),
1342 * but also sets up a DBusMessageHandler to receive a reply to the
1343 * message. If no reply is received in the given timeout_milliseconds,
1344 * expires the pending reply and sends the DBusMessageHandler a
1345 * synthetic error reply (generated in-process, not by the remote
1346 * application) indicating that a timeout occurred.
1348 * Reply handlers see their replies after message filters see them,
1349 * but before message handlers added with
1350 * dbus_connection_register_handler() see them, regardless of the
1351 * reply message's name. Reply handlers are only handed a single
1352 * message as a reply, after one reply has been seen the handler is
1353 * removed. If a filter filters out the reply before the handler sees
1354 * it, the reply is immediately timed out and a timeout error reply is
1355 * generated. If a filter removes the timeout error reply then the
1356 * reply handler will never be called. Filters should not do this.
1358 * If #NULL is passed for the reply_handler, the timeout reply will
1359 * still be generated and placed into the message queue, but no
1360 * specific message handler will receive the reply.
1362 * If -1 is passed for the timeout, a sane default timeout is used. -1
1363 * is typically the best value for the timeout for this reason, unless
1364 * you want a very short or very long timeout. There is no way to
1365 * avoid a timeout entirely, other than passing INT_MAX for the
1366 * timeout to postpone it indefinitely.
1368 * @param connection the connection
1369 * @param message the message to send
1370 * @param reply_handler message handler expecting the reply, or #NULL
1371 * @param timeout_milliseconds timeout in milliseconds or -1 for default
1372 * @returns #TRUE if the message is successfully queued, #FALSE if no memory.
1376 dbus_connection_send_with_reply (DBusConnection *connection,
1377 DBusMessage *message,
1378 DBusMessageHandler *reply_handler,
1379 int timeout_milliseconds)
1381 DBusTimeout *timeout;
1382 ReplyHandlerData *data;
1384 DBusList *reply_link;
1385 dbus_int32_t serial = -1;
1387 if (timeout_milliseconds == -1)
1388 timeout_milliseconds = DEFAULT_TIMEOUT_VALUE;
1390 data = dbus_new0 (ReplyHandlerData, 1);
1395 timeout = _dbus_timeout_new (timeout_milliseconds, reply_handler_timeout,
1400 reply_handler_data_free (data);
1404 dbus_mutex_lock (connection->mutex);
1407 if (!_dbus_connection_add_timeout (connection, timeout))
1409 reply_handler_data_free (data);
1410 _dbus_timeout_unref (timeout);
1411 dbus_mutex_unlock (connection->mutex);
1415 /* The connection now owns the reference to the timeout. */
1416 _dbus_timeout_unref (timeout);
1418 data->timeout_added = TRUE;
1419 data->timeout = timeout;
1420 data->connection = connection;
1422 if (!_dbus_message_handler_add_connection (reply_handler, connection))
1424 dbus_mutex_unlock (connection->mutex);
1425 reply_handler_data_free (data);
1428 data->connection_added = TRUE;
1430 /* Assign a serial to the message */
1431 if (dbus_message_get_serial (message) == 0)
1433 serial = _dbus_connection_get_next_client_serial (connection);
1434 _dbus_message_set_serial (message, serial);
1437 data->handler = reply_handler;
1438 data->serial = serial;
1440 dbus_message_handler_ref (reply_handler);
1442 reply = dbus_message_new_error_reply (message, DBUS_ERROR_NO_REPLY,
1443 "No reply within specified time");
1446 dbus_mutex_unlock (connection->mutex);
1447 reply_handler_data_free (data);
1451 reply_link = _dbus_list_alloc_link (reply);
1454 dbus_mutex_unlock (connection->mutex);
1455 dbus_message_unref (reply);
1456 reply_handler_data_free (data);
1460 data->timeout_link = reply_link;
1462 /* Insert the serial in the pending replies hash. */
1463 if (!_dbus_hash_table_insert_int (connection->pending_replies, serial, data))
1465 dbus_mutex_unlock (connection->mutex);
1466 reply_handler_data_free (data);
1470 dbus_mutex_unlock (connection->mutex);
1472 if (!dbus_connection_send (connection, message, NULL))
1474 /* This will free the handler data too */
1475 _dbus_hash_table_remove_int (connection->pending_replies, serial);
1484 check_for_reply_unlocked (DBusConnection *connection,
1485 dbus_uint32_t client_serial)
1489 link = _dbus_list_get_first_link (&connection->incoming_messages);
1491 while (link != NULL)
1493 DBusMessage *reply = link->data;
1495 if (dbus_message_get_reply_serial (reply) == client_serial)
1497 _dbus_list_remove_link (&connection->incoming_messages, link);
1498 connection->n_incoming -= 1;
1499 dbus_message_ref (reply);
1502 link = _dbus_list_get_next_link (&connection->incoming_messages, link);
1509 * Sends a message and blocks a certain time period while waiting for a reply.
1510 * This function does not dispatch any message handlers until the main loop
1511 * has been reached. This function is used to do non-reentrant "method calls."
1512 * If a reply is received, it is returned, and removed from the incoming
1513 * message queue. If it is not received, #NULL is returned and the
1514 * error is set to #DBUS_ERROR_NO_REPLY. If something else goes
1515 * wrong, result is set to whatever is appropriate, such as
1516 * #DBUS_ERROR_NO_MEMORY or #DBUS_ERROR_DISCONNECTED.
1518 * @todo could use performance improvements (it keeps scanning
1519 * the whole message queue for example) and has thread issues,
1520 * see comments in source
1522 * @param connection the connection
1523 * @param message the message to send
1524 * @param timeout_milliseconds timeout in milliseconds or -1 for default
1525 * @param error return location for error message
1526 * @returns the message that is the reply or #NULL with an error code if the
1530 dbus_connection_send_with_reply_and_block (DBusConnection *connection,
1531 DBusMessage *message,
1532 int timeout_milliseconds,
1535 dbus_uint32_t client_serial;
1536 long start_tv_sec, start_tv_usec;
1537 long end_tv_sec, end_tv_usec;
1538 long tv_sec, tv_usec;
1539 DBusDispatchStatus status;
1541 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1543 if (timeout_milliseconds == -1)
1544 timeout_milliseconds = DEFAULT_TIMEOUT_VALUE;
1546 /* it would probably seem logical to pass in _DBUS_INT_MAX
1547 * for infinite timeout, but then math below would get
1548 * all overflow-prone, so smack that down.
1550 if (timeout_milliseconds > _DBUS_ONE_HOUR_IN_MILLISECONDS * 6)
1551 timeout_milliseconds = _DBUS_ONE_HOUR_IN_MILLISECONDS * 6;
1553 if (!dbus_connection_send (connection, message, &client_serial))
1555 _DBUS_SET_OOM (error);
1561 /* Flush message queue */
1562 dbus_connection_flush (connection);
1564 dbus_mutex_lock (connection->mutex);
1566 _dbus_get_current_time (&start_tv_sec, &start_tv_usec);
1567 end_tv_sec = start_tv_sec + timeout_milliseconds / 1000;
1568 end_tv_usec = start_tv_usec + (timeout_milliseconds % 1000) * 1000;
1569 end_tv_sec += end_tv_usec / _DBUS_USEC_PER_SECOND;
1570 end_tv_usec = end_tv_usec % _DBUS_USEC_PER_SECOND;
1572 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec to %ld sec %ld usec\n",
1573 timeout_milliseconds,
1575 start_tv_sec, start_tv_usec,
1576 end_tv_sec, end_tv_usec);
1578 /* Now we wait... */
1579 /* THREAD TODO: This is busted. What if a dispatch() or pop_message
1580 * gets the message before we do?
1582 /* always block at least once as we know we don't have the reply yet */
1583 _dbus_connection_do_iteration (connection,
1584 DBUS_ITERATION_DO_READING |
1585 DBUS_ITERATION_BLOCK,
1586 timeout_milliseconds);
1590 /* queue messages and get status */
1591 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1593 if (status == DBUS_DISPATCH_DATA_REMAINS)
1597 reply = check_for_reply_unlocked (connection, client_serial);
1600 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1602 dbus_mutex_unlock (connection->mutex);
1604 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply %s\n",
1605 dbus_message_get_name (reply));
1607 _dbus_connection_update_dispatch_status_locked (connection, status);
1613 _dbus_get_current_time (&tv_sec, &tv_usec);
1615 if (tv_sec < start_tv_sec)
1616 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n");
1617 else if (connection->disconnect_message_link == NULL)
1618 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n");
1619 else if (tv_sec < end_tv_sec ||
1620 (tv_sec == end_tv_sec && tv_usec < end_tv_usec))
1622 timeout_milliseconds = (end_tv_sec - tv_sec) * 1000 +
1623 (end_tv_usec - tv_usec) / 1000;
1624 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds);
1625 _dbus_assert (timeout_milliseconds >= 0);
1627 if (status == DBUS_DISPATCH_NEED_MEMORY)
1629 /* Try sleeping a bit, as we aren't sure we need to block for reading,
1630 * we may already have a reply in the buffer and just can't process
1633 _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");
1635 if (timeout_milliseconds < 100)
1636 ; /* just busy loop */
1637 else if (timeout_milliseconds <= 1000)
1638 _dbus_sleep_milliseconds (timeout_milliseconds / 3);
1640 _dbus_sleep_milliseconds (1000);
1644 /* block again, we don't have the reply buffered yet. */
1645 _dbus_connection_do_iteration (connection,
1646 DBUS_ITERATION_DO_READING |
1647 DBUS_ITERATION_BLOCK,
1648 timeout_milliseconds);
1651 goto recheck_status;
1654 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %ld milliseconds and got no reply\n",
1655 (tv_sec - start_tv_sec) * 1000 + (tv_usec - start_tv_usec) / 1000);
1657 if (dbus_connection_get_is_connected (connection))
1658 dbus_set_error (error, DBUS_ERROR_NO_REPLY, "Message did not receive a reply");
1660 dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Disconnected prior to receiving a reply");
1662 dbus_mutex_unlock (connection->mutex);
1664 _dbus_connection_update_dispatch_status_locked (connection, status);
1670 * Blocks until the outgoing message queue is empty.
1672 * @param connection the connection.
1675 dbus_connection_flush (DBusConnection *connection)
1677 /* We have to specify DBUS_ITERATION_DO_READING here because
1678 * otherwise we could have two apps deadlock if they are both doing
1679 * a flush(), and the kernel buffers fill up. This could change the
1682 DBusDispatchStatus status;
1684 dbus_mutex_lock (connection->mutex);
1685 while (connection->n_outgoing > 0 &&
1686 dbus_connection_get_is_connected (connection))
1687 _dbus_connection_do_iteration (connection,
1688 DBUS_ITERATION_DO_READING |
1689 DBUS_ITERATION_DO_WRITING |
1690 DBUS_ITERATION_BLOCK,
1693 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1695 dbus_mutex_unlock (connection->mutex);
1697 _dbus_connection_update_dispatch_status_locked (connection, status);
1700 /* Call with mutex held. Will drop it while waiting and re-acquire
1704 _dbus_connection_wait_for_borrowed (DBusConnection *connection)
1706 _dbus_assert (connection->message_borrowed != NULL);
1708 while (connection->message_borrowed != NULL)
1709 dbus_condvar_wait (connection->message_returned_cond, connection->mutex);
1713 * Returns the first-received message from the incoming message queue,
1714 * leaving it in the queue. If the queue is empty, returns #NULL.
1716 * The caller does not own a reference to the returned message, and
1717 * must either return it using dbus_connection_return_message() or
1718 * keep it after calling dbus_connection_steal_borrowed_message(). No
1719 * one can get at the message while its borrowed, so return it as
1720 * quickly as possible and don't keep a reference to it after
1721 * returning it. If you need to keep the message, make a copy of it.
1723 * @param connection the connection.
1724 * @returns next message in the incoming queue.
1727 dbus_connection_borrow_message (DBusConnection *connection)
1729 DBusMessage *message;
1730 DBusDispatchStatus status;
1732 /* this is called for the side effect that it queues
1733 * up any messages from the transport
1735 status = dbus_connection_get_dispatch_status (connection);
1736 if (status != DBUS_DISPATCH_DATA_REMAINS)
1739 dbus_mutex_lock (connection->mutex);
1741 if (connection->message_borrowed != NULL)
1742 _dbus_connection_wait_for_borrowed (connection);
1744 message = _dbus_list_get_first (&connection->incoming_messages);
1747 connection->message_borrowed = message;
1749 dbus_mutex_unlock (connection->mutex);
1754 * Used to return a message after peeking at it using
1755 * dbus_connection_borrow_message().
1757 * @param connection the connection
1758 * @param message the message from dbus_connection_borrow_message()
1761 dbus_connection_return_message (DBusConnection *connection,
1762 DBusMessage *message)
1764 dbus_mutex_lock (connection->mutex);
1766 _dbus_assert (message == connection->message_borrowed);
1768 connection->message_borrowed = NULL;
1769 dbus_condvar_wake_all (connection->message_returned_cond);
1771 dbus_mutex_unlock (connection->mutex);
1775 * Used to keep a message after peeking at it using
1776 * dbus_connection_borrow_message(). Before using this function, see
1777 * the caveats/warnings in the documentation for
1778 * dbus_connection_pop_message().
1780 * @param connection the connection
1781 * @param message the message from dbus_connection_borrow_message()
1784 dbus_connection_steal_borrowed_message (DBusConnection *connection,
1785 DBusMessage *message)
1787 DBusMessage *pop_message;
1789 dbus_mutex_lock (connection->mutex);
1791 _dbus_assert (message == connection->message_borrowed);
1793 pop_message = _dbus_list_pop_first (&connection->incoming_messages);
1794 _dbus_assert (message == pop_message);
1796 connection->n_incoming -= 1;
1798 _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
1799 message, connection->n_incoming);
1801 connection->message_borrowed = NULL;
1802 dbus_condvar_wake_all (connection->message_returned_cond);
1804 dbus_mutex_unlock (connection->mutex);
1807 /* See dbus_connection_pop_message, but requires the caller to own
1808 * the lock before calling. May drop the lock while running.
1811 _dbus_connection_pop_message_link_unlocked (DBusConnection *connection)
1813 if (connection->message_borrowed != NULL)
1814 _dbus_connection_wait_for_borrowed (connection);
1816 if (connection->n_incoming > 0)
1820 link = _dbus_list_pop_first_link (&connection->incoming_messages);
1821 connection->n_incoming -= 1;
1823 _dbus_verbose ("Message %p (%s) removed from incoming queue %p, %d incoming\n",
1824 link->data, dbus_message_get_name (link->data),
1825 connection, connection->n_incoming);
1833 /* See dbus_connection_pop_message, but requires the caller to own
1834 * the lock before calling. May drop the lock while running.
1837 _dbus_connection_pop_message_unlocked (DBusConnection *connection)
1841 link = _dbus_connection_pop_message_link_unlocked (connection);
1845 DBusMessage *message;
1847 message = link->data;
1849 _dbus_list_free_link (link);
1859 * Returns the first-received message from the incoming message queue,
1860 * removing it from the queue. The caller owns a reference to the
1861 * returned message. If the queue is empty, returns #NULL.
1863 * This function bypasses any message handlers that are registered,
1864 * and so using it is usually wrong. Instead, let the main loop invoke
1865 * dbus_connection_dispatch(). Popping messages manually is only
1866 * useful in very simple programs that don't share a #DBusConnection
1867 * with any libraries or other modules.
1869 * @param connection the connection.
1870 * @returns next message in the incoming queue.
1873 dbus_connection_pop_message (DBusConnection *connection)
1875 DBusMessage *message;
1876 DBusDispatchStatus status;
1878 /* this is called for the side effect that it queues
1879 * up any messages from the transport
1881 status = dbus_connection_get_dispatch_status (connection);
1882 if (status != DBUS_DISPATCH_DATA_REMAINS)
1885 dbus_mutex_lock (connection->mutex);
1887 message = _dbus_connection_pop_message_unlocked (connection);
1889 _dbus_verbose ("Returning popped message %p\n", message);
1891 dbus_mutex_unlock (connection->mutex);
1897 * Acquire the dispatcher. This must be done before dispatching
1898 * messages in order to guarantee the right order of
1899 * message delivery. May sleep and drop the connection mutex
1900 * while waiting for the dispatcher.
1902 * @param connection the connection.
1905 _dbus_connection_acquire_dispatch (DBusConnection *connection)
1907 if (connection->dispatch_acquired)
1908 dbus_condvar_wait (connection->dispatch_cond, connection->mutex);
1909 _dbus_assert (!connection->dispatch_acquired);
1911 connection->dispatch_acquired = TRUE;
1915 * Release the dispatcher when you're done with it. Only call
1916 * after you've acquired the dispatcher. Wakes up at most one
1917 * thread currently waiting to acquire the dispatcher.
1919 * @param connection the connection.
1922 _dbus_connection_release_dispatch (DBusConnection *connection)
1924 _dbus_assert (connection->dispatch_acquired);
1926 connection->dispatch_acquired = FALSE;
1927 dbus_condvar_wake_one (connection->dispatch_cond);
1931 _dbus_connection_failed_pop (DBusConnection *connection,
1932 DBusList *message_link)
1934 _dbus_list_prepend_link (&connection->incoming_messages,
1936 connection->n_incoming += 1;
1939 static DBusDispatchStatus
1940 _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
1942 if (connection->n_incoming > 0)
1943 return DBUS_DISPATCH_DATA_REMAINS;
1944 else if (!_dbus_transport_queue_messages (connection->transport))
1945 return DBUS_DISPATCH_NEED_MEMORY;
1948 DBusDispatchStatus status;
1950 status = _dbus_transport_get_dispatch_status (connection->transport);
1952 if (status != DBUS_DISPATCH_COMPLETE)
1954 else if (connection->n_incoming > 0)
1955 return DBUS_DISPATCH_DATA_REMAINS;
1957 return DBUS_DISPATCH_COMPLETE;
1962 _dbus_connection_update_dispatch_status_locked (DBusConnection *connection,
1963 DBusDispatchStatus new_status)
1965 dbus_bool_t changed;
1966 DBusDispatchStatusFunction function;
1969 dbus_mutex_lock (connection->mutex);
1970 _dbus_connection_ref_unlocked (connection);
1972 changed = new_status != connection->last_dispatch_status;
1974 connection->last_dispatch_status = new_status;
1976 function = connection->dispatch_status_function;
1977 data = connection->dispatch_status_data;
1979 dbus_mutex_unlock (connection->mutex);
1981 if (changed && function)
1983 _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n",
1984 connection, new_status,
1985 new_status == DBUS_DISPATCH_COMPLETE ? "complete" :
1986 new_status == DBUS_DISPATCH_DATA_REMAINS ? "data remains" :
1987 new_status == DBUS_DISPATCH_NEED_MEMORY ? "need memory" :
1989 (* function) (connection, new_status, data);
1992 dbus_connection_unref (connection);
1996 * Gets the current state (what we would currently return
1997 * from dbus_connection_dispatch()) but doesn't actually
1998 * dispatch any messages.
2000 * @param connection the connection.
2001 * @returns current dispatch status
2004 dbus_connection_get_dispatch_status (DBusConnection *connection)
2006 DBusDispatchStatus status;
2008 dbus_mutex_lock (connection->mutex);
2010 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2012 dbus_mutex_unlock (connection->mutex);
2018 * Processes data buffered while handling watches, queueing zero or
2019 * more incoming messages. Then pops the first-received message from
2020 * the current incoming message queue, runs any handlers for it, and
2021 * unrefs the message. Returns a status indicating whether messages/data
2022 * remain, more memory is needed, or all data has been processed.
2024 * @param connection the connection
2025 * @returns dispatch status
2028 dbus_connection_dispatch (DBusConnection *connection)
2030 DBusMessageHandler *handler;
2031 DBusMessage *message;
2032 DBusList *link, *filter_list_copy, *message_link;
2033 DBusHandlerResult result;
2034 ReplyHandlerData *reply_handler_data;
2036 dbus_int32_t reply_serial;
2037 DBusDispatchStatus status;
2039 status = dbus_connection_get_dispatch_status (connection);
2040 if (status != DBUS_DISPATCH_DATA_REMAINS)
2042 _dbus_connection_update_dispatch_status_locked (connection, status);
2046 dbus_mutex_lock (connection->mutex);
2048 /* We need to ref the connection since the callback could potentially
2049 * drop the last ref to it
2051 _dbus_connection_ref_unlocked (connection);
2053 _dbus_connection_acquire_dispatch (connection);
2055 /* This call may drop the lock during the execution (if waiting for
2056 * borrowed messages to be returned) but the order of message
2057 * dispatch if several threads call dispatch() is still
2058 * protected by the lock, since only one will get the lock, and that
2059 * one will finish the message dispatching
2061 message_link = _dbus_connection_pop_message_link_unlocked (connection);
2062 if (message_link == NULL)
2064 /* another thread dispatched our stuff */
2066 _dbus_connection_release_dispatch (connection);
2067 dbus_mutex_unlock (connection->mutex);
2069 status = dbus_connection_get_dispatch_status (connection);
2071 _dbus_connection_update_dispatch_status_locked (connection, status);
2073 dbus_connection_unref (connection);
2078 message = message_link->data;
2080 result = DBUS_HANDLER_RESULT_ALLOW_MORE_HANDLERS;
2082 reply_serial = dbus_message_get_reply_serial (message);
2083 reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies,
2086 if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy))
2088 _dbus_connection_release_dispatch (connection);
2089 dbus_mutex_unlock (connection->mutex);
2090 _dbus_connection_failed_pop (connection, message_link);
2092 _dbus_connection_update_dispatch_status_locked (connection, DBUS_DISPATCH_NEED_MEMORY);
2094 dbus_connection_unref (connection);
2096 return DBUS_DISPATCH_NEED_MEMORY;
2099 _dbus_list_foreach (&filter_list_copy,
2100 (DBusForeachFunction)dbus_message_handler_ref,
2103 /* We're still protected from dispatch() reentrancy here
2104 * since we acquired the dispatcher
2106 dbus_mutex_unlock (connection->mutex);
2108 link = _dbus_list_get_first_link (&filter_list_copy);
2109 while (link != NULL)
2111 DBusMessageHandler *handler = link->data;
2112 DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link);
2114 _dbus_verbose (" running filter on message %p\n", message);
2115 result = _dbus_message_handler_handle_message (handler, connection,
2118 if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
2124 _dbus_list_foreach (&filter_list_copy,
2125 (DBusForeachFunction)dbus_message_handler_unref,
2127 _dbus_list_clear (&filter_list_copy);
2129 dbus_mutex_lock (connection->mutex);
2131 /* Did a reply we were waiting on get filtered? */
2132 if (reply_handler_data && result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
2134 /* Queue the timeout immediately! */
2135 if (reply_handler_data->timeout_link)
2137 _dbus_connection_queue_synthesized_message_link (connection,
2138 reply_handler_data->timeout_link);
2139 reply_handler_data->timeout_link = NULL;
2143 /* We already queued the timeout? Then it was filtered! */
2144 _dbus_warn ("The timeout error with reply serial %d was filtered, so the reply handler will never be called.\n", reply_serial);
2148 if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
2151 if (reply_handler_data)
2153 dbus_mutex_unlock (connection->mutex);
2155 _dbus_verbose (" running reply handler on message %p\n", message);
2157 result = _dbus_message_handler_handle_message (reply_handler_data->handler,
2158 connection, message);
2159 reply_handler_data_free (reply_handler_data);
2160 dbus_mutex_lock (connection->mutex);
2164 name = dbus_message_get_name (message);
2167 handler = _dbus_hash_table_lookup_string (connection->handler_table,
2169 if (handler != NULL)
2171 /* We're still protected from dispatch() reentrancy here
2172 * since we acquired the dispatcher
2174 dbus_mutex_unlock (connection->mutex);
2176 _dbus_verbose (" running app handler on message %p (%s)\n",
2177 message, dbus_message_get_name (message));
2179 result = _dbus_message_handler_handle_message (handler, connection,
2181 dbus_mutex_lock (connection->mutex);
2182 if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
2187 _dbus_verbose (" done dispatching %p (%s) on connection %p\n", message,
2188 dbus_message_get_name (message), connection);
2191 _dbus_connection_release_dispatch (connection);
2192 dbus_mutex_unlock (connection->mutex);
2193 _dbus_list_free_link (message_link);
2194 dbus_message_unref (message); /* don't want the message to count in max message limits
2195 * in computing dispatch status
2198 status = dbus_connection_get_dispatch_status (connection);
2200 _dbus_connection_update_dispatch_status_locked (connection, status);
2202 dbus_connection_unref (connection);
2208 * Sets the watch functions for the connection. These functions are
2209 * responsible for making the application's main loop aware of file
2210 * descriptors that need to be monitored for events, using select() or
2211 * poll(). When using Qt, typically the DBusAddWatchFunction would
2212 * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
2213 * could call g_io_add_watch(), or could be used as part of a more
2214 * elaborate GSource. Note that when a watch is added, it may
2217 * The DBusWatchToggledFunction notifies the application that the
2218 * watch has been enabled or disabled. Call dbus_watch_get_enabled()
2219 * to check this. A disabled watch should have no effect, and enabled
2220 * watch should be added to the main loop. This feature is used
2221 * instead of simply adding/removing the watch because
2222 * enabling/disabling can be done without memory allocation. The
2223 * toggled function may be NULL if a main loop re-queries
2224 * dbus_watch_get_enabled() every time anyway.
2226 * The DBusWatch can be queried for the file descriptor to watch using
2227 * dbus_watch_get_fd(), and for the events to watch for using
2228 * dbus_watch_get_flags(). The flags returned by
2229 * dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and
2230 * DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR;
2231 * all watches implicitly include a watch for hangups, errors, and
2232 * other exceptional conditions.
2234 * Once a file descriptor becomes readable or writable, or an exception
2235 * occurs, dbus_watch_handle() should be called to
2236 * notify the connection of the file descriptor's condition.
2238 * dbus_watch_handle() cannot be called during the
2239 * DBusAddWatchFunction, as the connection will not be ready to handle
2242 * It is not allowed to reference a DBusWatch after it has been passed
2243 * to remove_function.
2245 * If #FALSE is returned due to lack of memory, the failure may be due
2246 * to a #FALSE return from the new add_function. If so, the
2247 * add_function may have been called successfully one or more times,
2248 * but the remove_function will also have been called to remove any
2249 * successful adds. i.e. if #FALSE is returned the net result
2250 * should be that dbus_connection_set_watch_functions() has no effect,
2251 * but the add_function and remove_function may have been called.
2253 * @todo We need to drop the lock when we call the
2254 * add/remove/toggled functions which can be a side effect
2255 * of setting the watch functions.
2257 * @param connection the connection.
2258 * @param add_function function to begin monitoring a new descriptor.
2259 * @param remove_function function to stop monitoring a descriptor.
2260 * @param toggled_function function to notify of enable/disable
2261 * @param data data to pass to add_function and remove_function.
2262 * @param free_data_function function to be called to free the data.
2263 * @returns #FALSE on failure (no memory)
2266 dbus_connection_set_watch_functions (DBusConnection *connection,
2267 DBusAddWatchFunction add_function,
2268 DBusRemoveWatchFunction remove_function,
2269 DBusWatchToggledFunction toggled_function,
2271 DBusFreeFunction free_data_function)
2275 dbus_mutex_lock (connection->mutex);
2276 /* ref connection for slightly better reentrancy */
2277 _dbus_connection_ref_unlocked (connection);
2279 /* FIXME this can call back into user code, and we need to drop the
2280 * connection lock when it does.
2282 retval = _dbus_watch_list_set_functions (connection->watches,
2283 add_function, remove_function,
2285 data, free_data_function);
2287 dbus_mutex_unlock (connection->mutex);
2288 /* drop our paranoid refcount */
2289 dbus_connection_unref (connection);
2295 * Sets the timeout functions for the connection. These functions are
2296 * responsible for making the application's main loop aware of timeouts.
2297 * When using Qt, typically the DBusAddTimeoutFunction would create a
2298 * QTimer. When using GLib, the DBusAddTimeoutFunction would call
2301 * The DBusTimeoutToggledFunction notifies the application that the
2302 * timeout has been enabled or disabled. Call
2303 * dbus_timeout_get_enabled() to check this. A disabled timeout should
2304 * have no effect, and enabled timeout should be added to the main
2305 * loop. This feature is used instead of simply adding/removing the
2306 * timeout because enabling/disabling can be done without memory
2307 * allocation. With Qt, QTimer::start() and QTimer::stop() can be used
2308 * to enable and disable. The toggled function may be NULL if a main
2309 * loop re-queries dbus_timeout_get_enabled() every time anyway.
2311 * The DBusTimeout can be queried for the timer interval using
2312 * dbus_timeout_get_interval(). dbus_timeout_handle() should
2313 * be called repeatedly, each time the interval elapses, starting
2314 * after it has elapsed once. The timeout stops firing when
2315 * it is removed with the given remove_function.
2317 * @param connection the connection.
2318 * @param add_function function to add a timeout.
2319 * @param remove_function function to remove a timeout.
2320 * @param toggled_function function to notify of enable/disable
2321 * @param data data to pass to add_function and remove_function.
2322 * @param free_data_function function to be called to free the data.
2323 * @returns #FALSE on failure (no memory)
2326 dbus_connection_set_timeout_functions (DBusConnection *connection,
2327 DBusAddTimeoutFunction add_function,
2328 DBusRemoveTimeoutFunction remove_function,
2329 DBusTimeoutToggledFunction toggled_function,
2331 DBusFreeFunction free_data_function)
2335 dbus_mutex_lock (connection->mutex);
2336 /* ref connection for slightly better reentrancy */
2337 _dbus_connection_ref_unlocked (connection);
2339 retval = _dbus_timeout_list_set_functions (connection->timeouts,
2340 add_function, remove_function,
2342 data, free_data_function);
2344 dbus_mutex_unlock (connection->mutex);
2345 /* drop our paranoid refcount */
2346 dbus_connection_unref (connection);
2352 * Sets the mainloop wakeup function for the connection. Thi function is
2353 * responsible for waking up the main loop (if its sleeping) when some some
2354 * change has happened to the connection that the mainloop needs to reconsiders
2355 * (e.g. a message has been queued for writing).
2356 * When using Qt, this typically results in a call to QEventLoop::wakeUp().
2357 * When using GLib, it would call g_main_context_wakeup().
2360 * @param connection the connection.
2361 * @param wakeup_main_function function to wake up the mainloop
2362 * @param data data to pass wakeup_main_function
2363 * @param free_data_function function to be called to free the data.
2366 dbus_connection_set_wakeup_main_function (DBusConnection *connection,
2367 DBusWakeupMainFunction wakeup_main_function,
2369 DBusFreeFunction free_data_function)
2372 DBusFreeFunction old_free_data;
2374 dbus_mutex_lock (connection->mutex);
2375 old_data = connection->wakeup_main_data;
2376 old_free_data = connection->free_wakeup_main_data;
2378 connection->wakeup_main_function = wakeup_main_function;
2379 connection->wakeup_main_data = data;
2380 connection->free_wakeup_main_data = free_data_function;
2382 dbus_mutex_unlock (connection->mutex);
2384 /* Callback outside the lock */
2386 (*old_free_data) (old_data);
2390 * Set a function to be invoked when the dispatch status changes.
2391 * If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then
2392 * dbus_connection_dispatch() needs to be called to process incoming
2393 * messages. However, dbus_connection_dispatch() MUST NOT BE CALLED
2394 * from inside the DBusDispatchStatusFunction. Indeed, almost
2395 * any reentrancy in this function is a bad idea. Instead,
2396 * the DBusDispatchStatusFunction should simply save an indication
2397 * that messages should be dispatched later, when the main loop
2400 * @param connection the connection
2401 * @param function function to call on dispatch status changes
2402 * @param data data for function
2403 * @param free_data_function free the function data
2406 dbus_connection_set_dispatch_status_function (DBusConnection *connection,
2407 DBusDispatchStatusFunction function,
2409 DBusFreeFunction free_data_function)
2412 DBusFreeFunction old_free_data;
2414 dbus_mutex_lock (connection->mutex);
2415 old_data = connection->dispatch_status_data;
2416 old_free_data = connection->free_dispatch_status_data;
2418 connection->dispatch_status_function = function;
2419 connection->dispatch_status_data = data;
2420 connection->free_dispatch_status_data = free_data_function;
2422 dbus_mutex_unlock (connection->mutex);
2424 /* Callback outside the lock */
2426 (*old_free_data) (old_data);
2430 * A callback for use with dbus_watch_new() to create a DBusWatch.
2432 * @todo This is basically a hack - we could delete _dbus_transport_handle_watch()
2433 * and the virtual handle_watch in DBusTransport if we got rid of it.
2434 * The reason this is some work is threading, see the _dbus_connection_handle_watch()
2437 * @param watch the watch.
2438 * @param condition the current condition of the file descriptors being watched.
2439 * @param data must be a pointer to a #DBusConnection
2440 * @returns #FALSE if the IO condition may not have been fully handled due to lack of memory
2443 _dbus_connection_handle_watch (DBusWatch *watch,
2444 unsigned int condition,
2447 DBusConnection *connection;
2449 DBusDispatchStatus status;
2453 dbus_mutex_lock (connection->mutex);
2454 _dbus_connection_acquire_io_path (connection, -1);
2455 retval = _dbus_transport_handle_watch (connection->transport,
2457 _dbus_connection_release_io_path (connection);
2459 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2461 dbus_mutex_unlock (connection->mutex);
2463 _dbus_connection_update_dispatch_status_locked (connection, status);
2469 * Gets the UNIX user ID of the connection if any.
2470 * Returns #TRUE if the uid is filled in.
2471 * Always returns #FALSE on non-UNIX platforms.
2472 * Always returns #FALSE prior to authenticating the
2475 * @param connection the connection
2476 * @param uid return location for the user ID
2477 * @returns #TRUE if uid is filled in with a valid user ID
2480 dbus_connection_get_unix_user (DBusConnection *connection,
2485 dbus_mutex_lock (connection->mutex);
2487 if (!_dbus_transport_get_is_authenticated (connection->transport))
2490 result = _dbus_transport_get_unix_user (connection->transport,
2492 dbus_mutex_unlock (connection->mutex);
2498 * Sets a predicate function used to determine whether a given user ID
2499 * is allowed to connect. When an incoming connection has
2500 * authenticated with a particular user ID, this function is called;
2501 * if it returns #TRUE, the connection is allowed to proceed,
2502 * otherwise the connection is disconnected.
2504 * If the function is set to #NULL (as it is by default), then
2505 * only the same UID as the server process will be allowed to
2508 * @param connection the connection
2509 * @param function the predicate
2510 * @param data data to pass to the predicate
2511 * @param free_data_function function to free the data
2514 dbus_connection_set_unix_user_function (DBusConnection *connection,
2515 DBusAllowUnixUserFunction function,
2517 DBusFreeFunction free_data_function)
2519 void *old_data = NULL;
2520 DBusFreeFunction old_free_function = NULL;
2522 dbus_mutex_lock (connection->mutex);
2523 _dbus_transport_set_unix_user_function (connection->transport,
2524 function, data, free_data_function,
2525 &old_data, &old_free_function);
2526 dbus_mutex_unlock (connection->mutex);
2528 if (old_free_function != NULL)
2529 (* old_free_function) (old_data);
2533 * Adds a message filter. Filters are handlers that are run on
2534 * all incoming messages, prior to the normal handlers
2535 * registered with dbus_connection_register_handler().
2536 * Filters are run in the order that they were added.
2537 * The same handler can be added as a filter more than once, in
2538 * which case it will be run more than once.
2539 * Filters added during a filter callback won't be run on the
2540 * message being processed.
2542 * The connection does NOT add a reference to the message handler;
2543 * instead, if the message handler is finalized, the connection simply
2544 * forgets about it. Thus the caller of this function must keep a
2545 * reference to the message handler.
2547 * @param connection the connection
2548 * @param handler the handler
2549 * @returns #TRUE on success, #FALSE if not enough memory.
2552 dbus_connection_add_filter (DBusConnection *connection,
2553 DBusMessageHandler *handler)
2555 dbus_mutex_lock (connection->mutex);
2556 if (!_dbus_message_handler_add_connection (handler, connection))
2558 dbus_mutex_unlock (connection->mutex);
2562 if (!_dbus_list_append (&connection->filter_list,
2565 _dbus_message_handler_remove_connection (handler, connection);
2566 dbus_mutex_unlock (connection->mutex);
2570 dbus_mutex_unlock (connection->mutex);
2575 * Removes a previously-added message filter. It is a programming
2576 * error to call this function for a handler that has not
2577 * been added as a filter. If the given handler was added
2578 * more than once, only one instance of it will be removed
2579 * (the most recently-added instance).
2581 * @param connection the connection
2582 * @param handler the handler to remove
2586 dbus_connection_remove_filter (DBusConnection *connection,
2587 DBusMessageHandler *handler)
2589 dbus_mutex_lock (connection->mutex);
2590 if (!_dbus_list_remove_last (&connection->filter_list, handler))
2592 _dbus_warn ("Tried to remove a DBusConnection filter that had not been added\n");
2593 dbus_mutex_unlock (connection->mutex);
2597 _dbus_message_handler_remove_connection (handler, connection);
2599 dbus_mutex_unlock (connection->mutex);
2603 * Registers a handler for a list of message names. A single handler
2604 * can be registered for any number of message names, but each message
2605 * name can only have one handler at a time. It's not allowed to call
2606 * this function with the name of a message that already has a
2607 * handler. If the function returns #FALSE, the handlers were not
2608 * registered due to lack of memory.
2610 * The connection does NOT add a reference to the message handler;
2611 * instead, if the message handler is finalized, the connection simply
2612 * forgets about it. Thus the caller of this function must keep a
2613 * reference to the message handler.
2615 * @todo the messages_to_handle arg may be more convenient if it's a
2616 * single string instead of an array. Though right now MessageHandler
2617 * is sort of designed to say be associated with an entire object with
2618 * multiple methods, that's why for example the connection only
2619 * weakrefs it. So maybe the "manual" API should be different.
2621 * @param connection the connection
2622 * @param handler the handler
2623 * @param messages_to_handle the messages to handle
2624 * @param n_messages the number of message names in messages_to_handle
2625 * @returns #TRUE on success, #FALSE if no memory or another handler already exists
2629 dbus_connection_register_handler (DBusConnection *connection,
2630 DBusMessageHandler *handler,
2631 const char **messages_to_handle,
2636 dbus_mutex_lock (connection->mutex);
2638 while (i < n_messages)
2643 key = _dbus_strdup (messages_to_handle[i]);
2647 if (!_dbus_hash_iter_lookup (connection->handler_table,
2655 if (_dbus_hash_iter_get_value (&iter) != NULL)
2657 _dbus_warn ("Bug in application: attempted to register a second handler for %s\n",
2658 messages_to_handle[i]);
2659 dbus_free (key); /* won't have replaced the old key with the new one */
2663 if (!_dbus_message_handler_add_connection (handler, connection))
2665 _dbus_hash_iter_remove_entry (&iter);
2666 /* key has freed on nuking the entry */
2670 _dbus_hash_iter_set_value (&iter, handler);
2675 dbus_mutex_unlock (connection->mutex);
2679 /* unregister everything registered so far,
2680 * so we don't fail partially
2682 dbus_connection_unregister_handler (connection,
2687 dbus_mutex_unlock (connection->mutex);
2692 * Unregisters a handler for a list of message names. The handlers
2693 * must have been previously registered.
2695 * @param connection the connection
2696 * @param handler the handler
2697 * @param messages_to_handle the messages to handle
2698 * @param n_messages the number of message names in messages_to_handle
2702 dbus_connection_unregister_handler (DBusConnection *connection,
2703 DBusMessageHandler *handler,
2704 const char **messages_to_handle,
2709 dbus_mutex_lock (connection->mutex);
2711 while (i < n_messages)
2715 if (!_dbus_hash_iter_lookup (connection->handler_table,
2716 (char*) messages_to_handle[i], FALSE,
2719 _dbus_warn ("Bug in application: attempted to unregister handler for %s which was not registered\n",
2720 messages_to_handle[i]);
2722 else if (_dbus_hash_iter_get_value (&iter) != handler)
2724 _dbus_warn ("Bug in application: attempted to unregister handler for %s which was registered by a different handler\n",
2725 messages_to_handle[i]);
2729 _dbus_hash_iter_remove_entry (&iter);
2730 _dbus_message_handler_remove_connection (handler, connection);
2736 dbus_mutex_unlock (connection->mutex);
2739 static DBusDataSlotAllocator slot_allocator;
2740 _DBUS_DEFINE_GLOBAL_LOCK (connection_slots);
2743 * Allocates an integer ID to be used for storing application-specific
2744 * data on any DBusConnection. The allocated ID may then be used
2745 * with dbus_connection_set_data() and dbus_connection_get_data().
2746 * If allocation fails, -1 is returned. Again, the allocated
2747 * slot is global, i.e. all DBusConnection objects will
2748 * have a slot with the given integer ID reserved.
2750 * @returns -1 on failure, otherwise the data slot ID
2753 dbus_connection_allocate_data_slot (void)
2755 return _dbus_data_slot_allocator_alloc (&slot_allocator,
2756 _DBUS_LOCK_NAME (connection_slots));
2760 * Deallocates a global ID for connection data slots.
2761 * dbus_connection_get_data() and dbus_connection_set_data()
2762 * may no longer be used with this slot.
2763 * Existing data stored on existing DBusConnection objects
2764 * will be freed when the connection is finalized,
2765 * but may not be retrieved (and may only be replaced
2766 * if someone else reallocates the slot).
2768 * @param slot the slot to deallocate
2771 dbus_connection_free_data_slot (int slot)
2773 _dbus_data_slot_allocator_free (&slot_allocator, slot);
2777 * Stores a pointer on a DBusConnection, along
2778 * with an optional function to be used for freeing
2779 * the data when the data is set again, or when
2780 * the connection is finalized. The slot number
2781 * must have been allocated with dbus_connection_allocate_data_slot().
2783 * @param connection the connection
2784 * @param slot the slot number
2785 * @param data the data to store
2786 * @param free_data_func finalizer function for the data
2787 * @returns #TRUE if there was enough memory to store the data
2790 dbus_connection_set_data (DBusConnection *connection,
2793 DBusFreeFunction free_data_func)
2795 DBusFreeFunction old_free_func;
2799 dbus_mutex_lock (connection->mutex);
2801 retval = _dbus_data_slot_list_set (&slot_allocator,
2802 &connection->slot_list,
2803 slot, data, free_data_func,
2804 &old_free_func, &old_data);
2806 dbus_mutex_unlock (connection->mutex);
2810 /* Do the actual free outside the connection lock */
2812 (* old_free_func) (old_data);
2819 * Retrieves data previously set with dbus_connection_set_data().
2820 * The slot must still be allocated (must not have been freed).
2822 * @param connection the connection
2823 * @param slot the slot to get data from
2824 * @returns the data, or #NULL if not found
2827 dbus_connection_get_data (DBusConnection *connection,
2832 dbus_mutex_lock (connection->mutex);
2834 res = _dbus_data_slot_list_get (&slot_allocator,
2835 &connection->slot_list,
2838 dbus_mutex_unlock (connection->mutex);
2844 * This function sets a global flag for whether dbus_connection_new()
2845 * will set SIGPIPE behavior to SIG_IGN.
2847 * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN
2850 dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
2852 _dbus_modify_sigpipe = will_modify_sigpipe;
2856 * Specifies the maximum size message this connection is allowed to
2857 * receive. Larger messages will result in disconnecting the
2860 * @param connection a #DBusConnection
2861 * @param size maximum message size the connection can receive, in bytes
2864 dbus_connection_set_max_message_size (DBusConnection *connection,
2867 dbus_mutex_lock (connection->mutex);
2868 _dbus_transport_set_max_message_size (connection->transport,
2870 dbus_mutex_unlock (connection->mutex);
2874 * Gets the value set by dbus_connection_set_max_message_size().
2876 * @param connection the connection
2877 * @returns the max size of a single message
2880 dbus_connection_get_max_message_size (DBusConnection *connection)
2883 dbus_mutex_lock (connection->mutex);
2884 res = _dbus_transport_get_max_message_size (connection->transport);
2885 dbus_mutex_unlock (connection->mutex);
2890 * Sets the maximum total number of bytes that can be used for all messages
2891 * received on this connection. Messages count toward the maximum until
2892 * they are finalized. When the maximum is reached, the connection will
2893 * not read more data until some messages are finalized.
2895 * The semantics of the maximum are: if outstanding messages are
2896 * already above the maximum, additional messages will not be read.
2897 * The semantics are not: if the next message would cause us to exceed
2898 * the maximum, we don't read it. The reason is that we don't know the
2899 * size of a message until after we read it.
2901 * Thus, the max live messages size can actually be exceeded
2902 * by up to the maximum size of a single message.
2904 * Also, if we read say 1024 bytes off the wire in a single read(),
2905 * and that contains a half-dozen small messages, we may exceed the
2906 * size max by that amount. But this should be inconsequential.
2908 * This does imply that we can't call read() with a buffer larger
2909 * than we're willing to exceed this limit by.
2911 * @param connection the connection
2912 * @param size the maximum size in bytes of all outstanding messages
2915 dbus_connection_set_max_received_size (DBusConnection *connection,
2918 dbus_mutex_lock (connection->mutex);
2919 _dbus_transport_set_max_received_size (connection->transport,
2921 dbus_mutex_unlock (connection->mutex);
2925 * Gets the value set by dbus_connection_set_max_received_size().
2927 * @param connection the connection
2928 * @returns the max size of all live messages
2931 dbus_connection_get_max_received_size (DBusConnection *connection)
2934 dbus_mutex_lock (connection->mutex);
2935 res = _dbus_transport_get_max_received_size (connection->transport);
2936 dbus_mutex_unlock (connection->mutex);
2941 * Gets the approximate size in bytes of all messages in the outgoing
2942 * message queue. The size is approximate in that you shouldn't use
2943 * it to decide how many bytes to read off the network or anything
2944 * of that nature, as optimizations may choose to tell small white lies
2945 * to avoid performance overhead.
2947 * @param connection the connection
2948 * @returns the number of bytes that have been queued up but not sent
2951 dbus_connection_get_outgoing_size (DBusConnection *connection)
2954 dbus_mutex_lock (connection->mutex);
2955 res = _dbus_counter_get_value (connection->outgoing_counter);
2956 dbus_mutex_unlock (connection->mutex);