/* -*- mode: C; c-file-style: "gnu" -*- */ /* dbus-connection.c DBusConnection object * * Copyright (C) 2002, 2003 Red Hat Inc. * * Licensed under the Academic Free License version 1.2 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include #include "dbus-connection.h" #include "dbus-list.h" #include "dbus-timeout.h" #include "dbus-transport.h" #include "dbus-watch.h" #include "dbus-connection-internal.h" #include "dbus-list.h" #include "dbus-hash.h" #include "dbus-message-internal.h" #include "dbus-message-handler.h" #include "dbus-threads.h" #include "dbus-protocol.h" #include "dbus-dataslot.h" #if 0 #define CONNECTION_LOCK(connection) do { \ _dbus_verbose (" LOCK: %s\n", _DBUS_FUNCTION_NAME); \ dbus_mutex_lock ((connection)->mutex); \ } while (0) #define CONNECTION_UNLOCK(connection) do { \ _dbus_verbose (" UNLOCK: %s\n", _DBUS_FUNCTION_NAME); \ dbus_mutex_unlock ((connection)->mutex); \ } while (0) #else #define CONNECTION_LOCK(connection) dbus_mutex_lock ((connection)->mutex) #define CONNECTION_UNLOCK(connection) dbus_mutex_unlock ((connection)->mutex) #endif /** * @defgroup DBusConnection DBusConnection * @ingroup DBus * @brief Connection to another application * * A DBusConnection represents a connection to another * application. Messages can be sent and received via this connection. * The other application may be a message bus; for convenience, the * function dbus_bus_get() is provided to automatically open a * connection to the well-known message buses. * * In brief a DBusConnection is a message queue associated with some * message transport mechanism such as a socket. The connection * maintains a queue of incoming messages and a queue of outgoing * messages. * * Incoming messages are normally processed by calling * dbus_connection_dispatch(). dbus_connection_dispatch() runs any * handlers registered for the topmost message in the message queue, * then discards the message, then returns. * * dbus_connection_get_dispatch_status() indicates whether * messages are currently in the queue that need dispatching. * dbus_connection_set_dispatch_status_function() allows * you to set a function to be used to monitor the dispatch status. * * If you're using GLib or Qt add-on libraries for D-BUS, there are * special convenience functions in those libraries that hide * all the details of dispatch and watch/timeout monitoring. * For example, dbus_connection_setup_with_g_main(). * * If you aren't using these add-on libraries, you have to manually * call dbus_connection_set_dispatch_status_function(), * dbus_connection_set_watch_functions(), * dbus_connection_set_timeout_functions() providing appropriate * functions to integrate the connection with your application's main * loop. * * When you use dbus_connection_send() or one of its variants to send * a message, the message is added to the outgoing queue. It's * actually written to the network later; either in * dbus_watch_handle() invoked by your main loop, or in * dbus_connection_flush() which blocks until it can write out the * entire outgoing queue. The GLib/Qt add-on libraries again * handle the details here for you by setting up watch functions. * * When a connection is disconnected, you are guaranteed to get a * message with the name #DBUS_MESSAGE_LOCAL_DISCONNECT. * * You may not drop the last reference to a #DBusConnection * until that connection has been disconnected. * * You may dispatch the unprocessed incoming message queue even if the * connection is disconnected. However, #DBUS_MESSAGE_LOCAL_DISCONNECT * will always be the last message in the queue (obviously no messages * are received after disconnection). * * #DBusConnection has thread locks and drops them when invoking user * callbacks, so in general is transparently threadsafe. However, * #DBusMessage does NOT have thread locks; you must not send the same * message to multiple #DBusConnection that will be used from * different threads. */ /** * @defgroup DBusConnectionInternals DBusConnection implementation details * @ingroup DBusInternals * @brief Implementation details of DBusConnection * * @{ */ /** default timeout value when waiting for a message reply */ #define DEFAULT_TIMEOUT_VALUE (15 * 1000) static dbus_bool_t _dbus_modify_sigpipe = TRUE; /** * Implementation details of DBusConnection. All fields are private. */ struct DBusConnection { DBusAtomic refcount; /**< Reference count. */ DBusMutex *mutex; /**< Lock on the entire DBusConnection */ dbus_bool_t dispatch_acquired; /**< Protects dispatch() */ DBusCondVar *dispatch_cond; /**< Protects dispatch() */ dbus_bool_t io_path_acquired; /**< Protects transport io path */ DBusCondVar *io_path_cond; /**< Protects transport io path */ DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */ DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */ DBusMessage *message_borrowed; /**< True if the first incoming message has been borrowed */ DBusCondVar *message_returned_cond; /**< Used with dbus_connection_borrow_message() */ int n_outgoing; /**< Length of outgoing queue. */ int n_incoming; /**< Length of incoming queue. */ DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */ DBusTransport *transport; /**< Object that sends/receives messages over network. */ DBusWatchList *watches; /**< Stores active watches. */ DBusTimeoutList *timeouts; /**< Stores active timeouts. */ DBusHashTable *handler_table; /**< Table of registered DBusMessageHandler */ DBusList *filter_list; /**< List of filters. */ DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */ DBusHashTable *pending_replies; /**< Hash of message serials and their message handlers. */ dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */ DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */ DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */ void *wakeup_main_data; /**< Application data for wakeup_main_function */ DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */ DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */ void *dispatch_status_data; /**< Application data for dispatch_status_function */ DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */ DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */ DBusList *link_cache; /**< A cache of linked list links to prevent contention * for the global linked list mempool lock */ }; typedef struct { DBusConnection *connection; DBusMessageHandler *handler; DBusTimeout *timeout; int serial; DBusList *timeout_link; /* Preallocated timeout response */ dbus_bool_t timeout_added; dbus_bool_t connection_added; } ReplyHandlerData; static void reply_handler_data_free (ReplyHandlerData *data); static void _dbus_connection_remove_timeout_locked (DBusConnection *connection, DBusTimeout *timeout); static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection); static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, DBusDispatchStatus new_status); /** * Acquires the connection lock. * * @param connection the connection. */ void _dbus_connection_lock (DBusConnection *connection) { CONNECTION_LOCK (connection); } /** * Releases the connection lock. * * @param connection the connection. */ void _dbus_connection_unlock (DBusConnection *connection) { CONNECTION_UNLOCK (connection); } /** * Wakes up the main loop if it is sleeping * Needed if we're e.g. queueing outgoing messages * on a thread while the mainloop sleeps. * * @param connection the connection. */ static void _dbus_connection_wakeup_mainloop (DBusConnection *connection) { if (connection->wakeup_main_function) (*connection->wakeup_main_function) (connection->wakeup_main_data); } #ifdef DBUS_BUILD_TESTS /* For now this function isn't used */ /** * Adds a message to the incoming message queue, returning #FALSE * if there's insufficient memory to queue the message. * Does not take over refcount of the message. * * @param connection the connection. * @param message the message to queue. * @returns #TRUE on success. */ dbus_bool_t _dbus_connection_queue_received_message (DBusConnection *connection, DBusMessage *message) { DBusList *link; link = _dbus_list_alloc_link (message); if (link == NULL) return FALSE; dbus_message_ref (message); _dbus_connection_queue_received_message_link (connection, link); return TRUE; } #endif /** * Adds a message-containing list link to the incoming message queue, * taking ownership of the link and the message's current refcount. * Cannot fail due to lack of memory. * * @param connection the connection. * @param link the message link to queue. */ void _dbus_connection_queue_received_message_link (DBusConnection *connection, DBusList *link) { ReplyHandlerData *reply_handler_data; dbus_int32_t reply_serial; DBusMessage *message; _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport)); _dbus_list_append_link (&connection->incoming_messages, link); message = link->data; /* If this is a reply we're waiting on, remove timeout for it */ reply_serial = dbus_message_get_reply_serial (message); if (reply_serial != -1) { reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies, reply_serial); if (reply_handler_data != NULL) { if (reply_handler_data->timeout_added) _dbus_connection_remove_timeout_locked (connection, reply_handler_data->timeout); reply_handler_data->timeout_added = FALSE; } } connection->n_incoming += 1; _dbus_connection_wakeup_mainloop (connection); _dbus_assert (dbus_message_get_name (message) != NULL); _dbus_verbose ("Message %p (%s) added to incoming queue %p, %d incoming\n", message, dbus_message_get_name (message), connection, connection->n_incoming); } /** * Adds a link + message to the incoming message queue. * Can't fail. Takes ownership of both link and message. * * @param connection the connection. * @param link the list node and message to queue. * * @todo This needs to wake up the mainloop if it is in * a poll/select and this is a multithreaded app. */ static void _dbus_connection_queue_synthesized_message_link (DBusConnection *connection, DBusList *link) { _dbus_list_append_link (&connection->incoming_messages, link); connection->n_incoming += 1; _dbus_connection_wakeup_mainloop (connection); _dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n", link->data, connection, connection->n_incoming); } /** * Checks whether there are messages in the outgoing message queue. * * @param connection the connection. * @returns #TRUE if the outgoing queue is non-empty. */ dbus_bool_t _dbus_connection_have_messages_to_send (DBusConnection *connection) { return connection->outgoing_messages != NULL; } /** * Gets the next outgoing message. The message remains in the * queue, and the caller does not own a reference to it. * * @param connection the connection. * @returns the message to be sent. */ DBusMessage* _dbus_connection_get_message_to_send (DBusConnection *connection) { return _dbus_list_get_last (&connection->outgoing_messages); } /** * Notifies the connection that a message has been sent, so the * message can be removed from the outgoing queue. * Called with the connection lock held. * * @param connection the connection. * @param message the message that was sent. */ void _dbus_connection_message_sent (DBusConnection *connection, DBusMessage *message) { DBusList *link; _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport)); link = _dbus_list_get_last_link (&connection->outgoing_messages); _dbus_assert (link != NULL); _dbus_assert (link->data == message); /* Save this link in the link cache */ _dbus_list_unlink (&connection->outgoing_messages, link); _dbus_list_prepend_link (&connection->link_cache, link); connection->n_outgoing -= 1; _dbus_verbose ("Message %p (%s) removed from outgoing queue %p, %d left to send\n", message, dbus_message_get_name (message), connection, connection->n_outgoing); /* Save this link in the link cache also */ _dbus_message_remove_size_counter (message, connection->outgoing_counter, &link); _dbus_list_prepend_link (&connection->link_cache, link); dbus_message_unref (message); if (connection->n_outgoing == 0) _dbus_transport_messages_pending (connection->transport, connection->n_outgoing); } /** * Adds a watch using the connection's DBusAddWatchFunction if * available. Otherwise records the watch to be added when said * function is available. Also re-adds the watch if the * DBusAddWatchFunction changes. May fail due to lack of memory. * * @param connection the connection. * @param watch the watch to add. * @returns #TRUE on success. */ dbus_bool_t _dbus_connection_add_watch (DBusConnection *connection, DBusWatch *watch) { if (connection->watches) /* null during finalize */ return _dbus_watch_list_add_watch (connection->watches, watch); else return FALSE; } /** * Removes a watch using the connection's DBusRemoveWatchFunction * if available. It's an error to call this function on a watch * that was not previously added. * * @param connection the connection. * @param watch the watch to remove. */ void _dbus_connection_remove_watch (DBusConnection *connection, DBusWatch *watch) { if (connection->watches) /* null during finalize */ _dbus_watch_list_remove_watch (connection->watches, watch); } /** * Toggles a watch and notifies app via connection's * DBusWatchToggledFunction if available. It's an error to call this * function on a watch that was not previously added. * * @param connection the connection. * @param watch the watch to toggle. * @param enabled whether to enable or disable */ void _dbus_connection_toggle_watch (DBusConnection *connection, DBusWatch *watch, dbus_bool_t enabled) { if (connection->watches) /* null during finalize */ _dbus_watch_list_toggle_watch (connection->watches, watch, enabled); } /** * Adds a timeout using the connection's DBusAddTimeoutFunction if * available. Otherwise records the timeout to be added when said * function is available. Also re-adds the timeout if the * DBusAddTimeoutFunction changes. May fail due to lack of memory. * The timeout will fire repeatedly until removed. * * @param connection the connection. * @param timeout the timeout to add. * @returns #TRUE on success. */ dbus_bool_t _dbus_connection_add_timeout (DBusConnection *connection, DBusTimeout *timeout) { if (connection->timeouts) /* null during finalize */ return _dbus_timeout_list_add_timeout (connection->timeouts, timeout); else return FALSE; } /** * Removes a timeout using the connection's DBusRemoveTimeoutFunction * if available. It's an error to call this function on a timeout * that was not previously added. * * @param connection the connection. * @param timeout the timeout to remove. */ void _dbus_connection_remove_timeout (DBusConnection *connection, DBusTimeout *timeout) { if (connection->timeouts) /* null during finalize */ _dbus_timeout_list_remove_timeout (connection->timeouts, timeout); } static void _dbus_connection_remove_timeout_locked (DBusConnection *connection, DBusTimeout *timeout) { CONNECTION_LOCK (connection); _dbus_connection_remove_timeout (connection, timeout); CONNECTION_UNLOCK (connection); } /** * Toggles a timeout and notifies app via connection's * DBusTimeoutToggledFunction if available. It's an error to call this * function on a timeout that was not previously added. * * @param connection the connection. * @param timeout the timeout to toggle. * @param enabled whether to enable or disable */ void _dbus_connection_toggle_timeout (DBusConnection *connection, DBusTimeout *timeout, dbus_bool_t enabled) { if (connection->timeouts) /* null during finalize */ _dbus_timeout_list_toggle_timeout (connection->timeouts, timeout, enabled); } /** * Tells the connection that the transport has been disconnected. * Results in posting a disconnect message on the incoming message * queue. Only has an effect the first time it's called. * * @param connection the connection */ void _dbus_connection_notify_disconnected (DBusConnection *connection) { if (connection->disconnect_message_link) { /* We haven't sent the disconnect message already */ _dbus_connection_queue_synthesized_message_link (connection, connection->disconnect_message_link); connection->disconnect_message_link = NULL; } } /** * Acquire the transporter I/O path. This must be done before * doing any I/O in the transporter. May sleep and drop the * connection mutex while waiting for the I/O path. * * @param connection the connection. * @param timeout_milliseconds maximum blocking time, or -1 for no limit. * @returns TRUE if the I/O path was acquired. */ static dbus_bool_t _dbus_connection_acquire_io_path (DBusConnection *connection, int timeout_milliseconds) { dbus_bool_t res = TRUE; if (connection->io_path_acquired) { if (timeout_milliseconds != -1) res = dbus_condvar_wait_timeout (connection->io_path_cond, connection->mutex, timeout_milliseconds); else dbus_condvar_wait (connection->io_path_cond, connection->mutex); } if (res) { _dbus_assert (!connection->io_path_acquired); connection->io_path_acquired = TRUE; } return res; } /** * Release the I/O path when you're done with it. Only call * after you've acquired the I/O. Wakes up at most one thread * currently waiting to acquire the I/O path. * * @param connection the connection. */ static void _dbus_connection_release_io_path (DBusConnection *connection) { _dbus_assert (connection->io_path_acquired); connection->io_path_acquired = FALSE; dbus_condvar_wake_one (connection->io_path_cond); } /** * Queues incoming messages and sends outgoing messages for this * connection, optionally blocking in the process. Each call to * _dbus_connection_do_iteration() will call select() or poll() one * time and then read or write data if possible. * * The purpose of this function is to be able to flush outgoing * messages or queue up incoming messages without returning * control to the application and causing reentrancy weirdness. * * The flags parameter allows you to specify whether to * read incoming messages, write outgoing messages, or both, * and whether to block if no immediate action is possible. * * The timeout_milliseconds parameter does nothing unless the * iteration is blocking. * * If there are no outgoing messages and DBUS_ITERATION_DO_READING * wasn't specified, then it's impossible to block, even if * you specify DBUS_ITERATION_BLOCK; in that case the function * returns immediately. * * @param connection the connection. * @param flags iteration flags. * @param timeout_milliseconds maximum blocking time, or -1 for no limit. */ void _dbus_connection_do_iteration (DBusConnection *connection, unsigned int flags, int timeout_milliseconds) { if (connection->n_outgoing == 0) flags &= ~DBUS_ITERATION_DO_WRITING; if (_dbus_connection_acquire_io_path (connection, (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0)) { _dbus_transport_do_iteration (connection->transport, flags, timeout_milliseconds); _dbus_connection_release_io_path (connection); } } /** * Creates a new connection for the given transport. A transport * represents a message stream that uses some concrete mechanism, such * as UNIX domain sockets. May return #NULL if insufficient * memory exists to create the connection. * * @param transport the transport. * @returns the new connection, or #NULL on failure. */ DBusConnection* _dbus_connection_new_for_transport (DBusTransport *transport) { DBusConnection *connection; DBusWatchList *watch_list; DBusTimeoutList *timeout_list; DBusHashTable *handler_table, *pending_replies; DBusMutex *mutex; DBusCondVar *message_returned_cond; DBusCondVar *dispatch_cond; DBusCondVar *io_path_cond; DBusList *disconnect_link; DBusMessage *disconnect_message; DBusCounter *outgoing_counter; watch_list = NULL; connection = NULL; handler_table = NULL; pending_replies = NULL; timeout_list = NULL; mutex = NULL; message_returned_cond = NULL; dispatch_cond = NULL; io_path_cond = NULL; disconnect_link = NULL; disconnect_message = NULL; outgoing_counter = NULL; watch_list = _dbus_watch_list_new (); if (watch_list == NULL) goto error; timeout_list = _dbus_timeout_list_new (); if (timeout_list == NULL) goto error; handler_table = _dbus_hash_table_new (DBUS_HASH_STRING, dbus_free, NULL); if (handler_table == NULL) goto error; pending_replies = _dbus_hash_table_new (DBUS_HASH_INT, NULL, (DBusFreeFunction)reply_handler_data_free); if (pending_replies == NULL) goto error; connection = dbus_new0 (DBusConnection, 1); if (connection == NULL) goto error; mutex = dbus_mutex_new (); if (mutex == NULL) goto error; message_returned_cond = dbus_condvar_new (); if (message_returned_cond == NULL) goto error; dispatch_cond = dbus_condvar_new (); if (dispatch_cond == NULL) goto error; io_path_cond = dbus_condvar_new (); if (io_path_cond == NULL) goto error; disconnect_message = dbus_message_new (DBUS_MESSAGE_LOCAL_DISCONNECT, NULL); if (disconnect_message == NULL) goto error; disconnect_link = _dbus_list_alloc_link (disconnect_message); if (disconnect_link == NULL) goto error; outgoing_counter = _dbus_counter_new (); if (outgoing_counter == NULL) goto error; if (_dbus_modify_sigpipe) _dbus_disable_sigpipe (); connection->refcount.value = 1; connection->mutex = mutex; connection->dispatch_cond = dispatch_cond; connection->io_path_cond = io_path_cond; connection->message_returned_cond = message_returned_cond; connection->transport = transport; connection->watches = watch_list; connection->timeouts = timeout_list; connection->handler_table = handler_table; connection->pending_replies = pending_replies; connection->outgoing_counter = outgoing_counter; connection->filter_list = NULL; connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */ _dbus_data_slot_list_init (&connection->slot_list); connection->client_serial = 1; connection->disconnect_message_link = disconnect_link; if (!_dbus_transport_set_connection (transport, connection)) goto error; _dbus_transport_ref (transport); return connection; error: if (disconnect_message != NULL) dbus_message_unref (disconnect_message); if (disconnect_link != NULL) _dbus_list_free_link (disconnect_link); if (io_path_cond != NULL) dbus_condvar_free (io_path_cond); if (dispatch_cond != NULL) dbus_condvar_free (dispatch_cond); if (message_returned_cond != NULL) dbus_condvar_free (message_returned_cond); if (mutex != NULL) dbus_mutex_free (mutex); if (connection != NULL) dbus_free (connection); if (handler_table) _dbus_hash_table_unref (handler_table); if (pending_replies) _dbus_hash_table_unref (pending_replies); if (watch_list) _dbus_watch_list_free (watch_list); if (timeout_list) _dbus_timeout_list_free (timeout_list); if (outgoing_counter) _dbus_counter_unref (outgoing_counter); return NULL; } /** * Increments the reference count of a DBusConnection. * Requires that the caller already holds the connection lock. * * @param connection the connection. */ void _dbus_connection_ref_unlocked (DBusConnection *connection) { #ifdef DBUS_HAVE_ATOMIC_INT _dbus_atomic_inc (&connection->refcount); #else _dbus_assert (connection->refcount.value > 0); connection->refcount.value += 1; #endif } static dbus_uint32_t _dbus_connection_get_next_client_serial (DBusConnection *connection) { int serial; serial = connection->client_serial++; if (connection->client_serial < 0) connection->client_serial = 1; return serial; } /** * Used to notify a connection when a DBusMessageHandler is * destroyed, so the connection can drop any reference * to the handler. This is a private function, but still * takes the connection lock. Don't call it with the lock held. * * @todo needs to check in pending_replies too. * * @param connection the connection * @param handler the handler */ void _dbus_connection_handler_destroyed_locked (DBusConnection *connection, DBusMessageHandler *handler) { DBusHashIter iter; DBusList *link; CONNECTION_LOCK (connection); _dbus_hash_iter_init (connection->handler_table, &iter); while (_dbus_hash_iter_next (&iter)) { DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter); if (h == handler) _dbus_hash_iter_remove_entry (&iter); } link = _dbus_list_get_first_link (&connection->filter_list); while (link != NULL) { DBusMessageHandler *h = link->data; DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link); if (h == handler) _dbus_list_remove_link (&connection->filter_list, link); link = next; } CONNECTION_UNLOCK (connection); } /** * A callback for use with dbus_watch_new() to create a DBusWatch. * * @todo This is basically a hack - we could delete _dbus_transport_handle_watch() * and the virtual handle_watch in DBusTransport if we got rid of it. * The reason this is some work is threading, see the _dbus_connection_handle_watch() * implementation. * * @param watch the watch. * @param condition the current condition of the file descriptors being watched. * @param data must be a pointer to a #DBusConnection * @returns #FALSE if the IO condition may not have been fully handled due to lack of memory */ dbus_bool_t _dbus_connection_handle_watch (DBusWatch *watch, unsigned int condition, void *data) { DBusConnection *connection; dbus_bool_t retval; DBusDispatchStatus status; connection = data; CONNECTION_LOCK (connection); _dbus_connection_acquire_io_path (connection, -1); retval = _dbus_transport_handle_watch (connection->transport, watch, condition); _dbus_connection_release_io_path (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return retval; } /** * Get the ID to be used in the high bits of an object ID for an object * registered with this connection. * * @todo implement this function * * @param connection the connection. * @returns the connection portion of the object ID */ dbus_uint32_t _dbus_connection_get_id (DBusConnection *connection) { /* FIXME */ return 1492; } /** @} */ /** * @addtogroup DBusConnection * * @{ */ /** * Opens a new connection to a remote address. * * @todo specify what the address parameter is. Right now * it's just the name of a UNIX domain socket. It should be * something more complex that encodes which transport to use. * * If the open fails, the function returns #NULL, and provides * a reason for the failure in the result parameter. Pass * #NULL for the result parameter if you aren't interested * in the reason for failure. * * @param address the address. * @param error address where an error can be returned. * @returns new connection, or #NULL on failure. */ DBusConnection* dbus_connection_open (const char *address, DBusError *error) { DBusConnection *connection; DBusTransport *transport; _dbus_return_val_if_fail (address != NULL, NULL); _dbus_return_val_if_error_is_set (error, NULL); transport = _dbus_transport_open (address, error); if (transport == NULL) { _DBUS_ASSERT_ERROR_IS_SET (error); return NULL; } connection = _dbus_connection_new_for_transport (transport); _dbus_transport_unref (transport); if (connection == NULL) { dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); return NULL; } return connection; } /** * Increments the reference count of a DBusConnection. * * @param connection the connection. */ void dbus_connection_ref (DBusConnection *connection) { _dbus_return_if_fail (connection != NULL); /* The connection lock is better than the global * lock in the atomic increment fallback */ #ifdef DBUS_HAVE_ATOMIC_INT _dbus_atomic_inc (&connection->refcount); #else CONNECTION_LOCK (connection); _dbus_assert (connection->refcount.value > 0); connection->refcount.value += 1; CONNECTION_UNLOCK (connection); #endif } static void free_outgoing_message (void *element, void *data) { DBusMessage *message = element; DBusConnection *connection = data; _dbus_message_remove_size_counter (message, connection->outgoing_counter, NULL); dbus_message_unref (message); } /* This is run without the mutex held, but after the last reference * to the connection has been dropped we should have no thread-related * problems */ static void _dbus_connection_last_unref (DBusConnection *connection) { DBusHashIter iter; DBusList *link; _dbus_verbose ("Finalizing connection %p\n", connection); _dbus_assert (connection->refcount.value == 0); /* You have to disconnect the connection before unref:ing it. Otherwise * you won't get the disconnected message. */ _dbus_assert (!_dbus_transport_get_is_connected (connection->transport)); /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */ dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL); dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL); dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL); _dbus_watch_list_free (connection->watches); connection->watches = NULL; _dbus_timeout_list_free (connection->timeouts); connection->timeouts = NULL; _dbus_data_slot_list_free (&connection->slot_list); /* ---- Done with stuff that invokes application callbacks */ _dbus_hash_iter_init (connection->handler_table, &iter); while (_dbus_hash_iter_next (&iter)) { DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter); _dbus_message_handler_remove_connection (h, connection); } link = _dbus_list_get_first_link (&connection->filter_list); while (link != NULL) { DBusMessageHandler *h = link->data; DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link); _dbus_message_handler_remove_connection (h, connection); link = next; } _dbus_hash_table_unref (connection->handler_table); connection->handler_table = NULL; _dbus_hash_table_unref (connection->pending_replies); connection->pending_replies = NULL; _dbus_list_clear (&connection->filter_list); _dbus_list_foreach (&connection->outgoing_messages, free_outgoing_message, connection); _dbus_list_clear (&connection->outgoing_messages); _dbus_list_foreach (&connection->incoming_messages, (DBusForeachFunction) dbus_message_unref, NULL); _dbus_list_clear (&connection->incoming_messages); _dbus_counter_unref (connection->outgoing_counter); _dbus_transport_unref (connection->transport); if (connection->disconnect_message_link) { DBusMessage *message = connection->disconnect_message_link->data; dbus_message_unref (message); _dbus_list_free_link (connection->disconnect_message_link); } _dbus_list_clear (&connection->link_cache); dbus_condvar_free (connection->dispatch_cond); dbus_condvar_free (connection->io_path_cond); dbus_condvar_free (connection->message_returned_cond); dbus_mutex_free (connection->mutex); dbus_free (connection); } /** * Decrements the reference count of a DBusConnection, and finalizes * it if the count reaches zero. It is a bug to drop the last reference * to a connection that has not been disconnected. * * @todo in practice it can be quite tricky to never unref a connection * that's still connected; maybe there's some way we could avoid * the requirement. * * @param connection the connection. */ void dbus_connection_unref (DBusConnection *connection) { dbus_bool_t last_unref; _dbus_return_if_fail (connection != NULL); /* The connection lock is better than the global * lock in the atomic increment fallback */ #ifdef DBUS_HAVE_ATOMIC_INT last_unref = (_dbus_atomic_dec (&connection->refcount) == 1); #else CONNECTION_LOCK (connection); _dbus_assert (connection->refcount.value > 0); connection->refcount.value -= 1; last_unref = (connection->refcount.value == 0); #if 0 printf ("unref() connection %p count = %d\n", connection, connection->refcount.value); #endif CONNECTION_UNLOCK (connection); #endif if (last_unref) _dbus_connection_last_unref (connection); } /** * Closes the connection, so no further data can be sent or received. * Any further attempts to send data will result in errors. This * function does not affect the connection's reference count. It's * safe to disconnect a connection more than once; all calls after the * first do nothing. It's impossible to "reconnect" a connection, a * new connection must be created. * * @param connection the connection. */ void dbus_connection_disconnect (DBusConnection *connection) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_disconnect (connection->transport); CONNECTION_UNLOCK (connection); } static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection) { return _dbus_transport_get_is_connected (connection->transport); } /** * Gets whether the connection is currently connected. All * connections are connected when they are opened. A connection may * become disconnected when the remote application closes its end, or * exits; a connection may also be disconnected with * dbus_connection_disconnect(). * * @param connection the connection. * @returns #TRUE if the connection is still alive. */ dbus_bool_t dbus_connection_get_is_connected (DBusConnection *connection) { dbus_bool_t res; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); res = _dbus_connection_get_is_connected_unlocked (connection); CONNECTION_UNLOCK (connection); return res; } /** * Gets whether the connection was authenticated. (Note that * if the connection was authenticated then disconnected, * this function still returns #TRUE) * * @param connection the connection * @returns #TRUE if the connection was ever authenticated */ dbus_bool_t dbus_connection_get_is_authenticated (DBusConnection *connection) { dbus_bool_t res; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); res = _dbus_transport_get_is_authenticated (connection->transport); CONNECTION_UNLOCK (connection); return res; } struct DBusPreallocatedSend { DBusConnection *connection; DBusList *queue_link; DBusList *counter_link; }; static DBusPreallocatedSend* _dbus_connection_preallocate_send_unlocked (DBusConnection *connection) { DBusPreallocatedSend *preallocated; _dbus_return_val_if_fail (connection != NULL, NULL); preallocated = dbus_new (DBusPreallocatedSend, 1); if (preallocated == NULL) return NULL; if (connection->link_cache != NULL) { preallocated->queue_link = _dbus_list_pop_first_link (&connection->link_cache); preallocated->queue_link->data = NULL; } else { preallocated->queue_link = _dbus_list_alloc_link (NULL); if (preallocated->queue_link == NULL) goto failed_0; } if (connection->link_cache != NULL) { preallocated->counter_link = _dbus_list_pop_first_link (&connection->link_cache); preallocated->counter_link->data = connection->outgoing_counter; } else { preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter); if (preallocated->counter_link == NULL) goto failed_1; } _dbus_counter_ref (preallocated->counter_link->data); preallocated->connection = connection; return preallocated; failed_1: _dbus_list_free_link (preallocated->queue_link); failed_0: dbus_free (preallocated); return NULL; } /** * Preallocates resources needed to send a message, allowing the message * to be sent without the possibility of memory allocation failure. * Allows apps to create a future guarantee that they can send * a message regardless of memory shortages. * * @param connection the connection we're preallocating for. * @returns the preallocated resources, or #NULL */ DBusPreallocatedSend* dbus_connection_preallocate_send (DBusConnection *connection) { DBusPreallocatedSend *preallocated; _dbus_return_val_if_fail (connection != NULL, NULL); CONNECTION_LOCK (connection); preallocated = _dbus_connection_preallocate_send_unlocked (connection); CONNECTION_UNLOCK (connection); return preallocated; } /** * Frees preallocated message-sending resources from * dbus_connection_preallocate_send(). Should only * be called if the preallocated resources are not used * to send a message. * * @param connection the connection * @param preallocated the resources */ void dbus_connection_free_preallocated_send (DBusConnection *connection, DBusPreallocatedSend *preallocated) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (preallocated != NULL); _dbus_return_if_fail (connection == preallocated->connection); _dbus_list_free_link (preallocated->queue_link); _dbus_counter_unref (preallocated->counter_link->data); _dbus_list_free_link (preallocated->counter_link); dbus_free (preallocated); } static void _dbus_connection_send_preallocated_unlocked (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { dbus_uint32_t serial; preallocated->queue_link->data = message; _dbus_list_prepend_link (&connection->outgoing_messages, preallocated->queue_link); _dbus_message_add_size_counter_link (message, preallocated->counter_link); dbus_free (preallocated); preallocated = NULL; dbus_message_ref (message); connection->n_outgoing += 1; _dbus_verbose ("Message %p (%s) added to outgoing queue %p, %d pending to send\n", message, dbus_message_get_name (message), connection, connection->n_outgoing); if (dbus_message_get_serial (message) == 0) { serial = _dbus_connection_get_next_client_serial (connection); _dbus_message_set_serial (message, serial); if (client_serial) *client_serial = serial; } else { if (client_serial) *client_serial = dbus_message_get_serial (message); } _dbus_message_lock (message); if (connection->n_outgoing == 1) _dbus_transport_messages_pending (connection->transport, connection->n_outgoing); _dbus_connection_wakeup_mainloop (connection); } /** * Sends a message using preallocated resources. This function cannot fail. * It works identically to dbus_connection_send() in other respects. * Preallocated resources comes from dbus_connection_preallocate_send(). * This function "consumes" the preallocated resources, they need not * be freed separately. * * @param connection the connection * @param preallocated the preallocated resources * @param message the message to send * @param client_serial return location for client serial assigned to the message */ void dbus_connection_send_preallocated (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (preallocated != NULL); _dbus_return_if_fail (message != NULL); _dbus_return_if_fail (preallocated->connection == connection); _dbus_return_if_fail (dbus_message_get_name (message) != NULL); CONNECTION_LOCK (connection); _dbus_connection_send_preallocated_unlocked (connection, preallocated, message, client_serial); CONNECTION_UNLOCK (connection); } /** * Adds a message to the outgoing message queue. Does not block to * write the message to the network; that happens asynchronously. To * force the message to be written, call dbus_connection_flush(). * Because this only queues the message, the only reason it can * fail is lack of memory. Even if the connection is disconnected, * no error will be returned. * * If the function fails due to lack of memory, it returns #FALSE. * The function will never fail for other reasons; even if the * connection is disconnected, you can queue an outgoing message, * though obviously it won't be sent. * * @param connection the connection. * @param message the message to write. * @param client_serial return location for client serial. * @returns #TRUE on success. */ dbus_bool_t dbus_connection_send (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *client_serial) { DBusPreallocatedSend *preallocated; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); CONNECTION_LOCK (connection); preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) { CONNECTION_UNLOCK (connection); return FALSE; } else { _dbus_connection_send_preallocated_unlocked (connection, preallocated, message, client_serial); CONNECTION_UNLOCK (connection); return TRUE; } } static dbus_bool_t reply_handler_timeout (void *data) { DBusConnection *connection; ReplyHandlerData *reply_handler_data = data; DBusDispatchStatus status; connection = reply_handler_data->connection; CONNECTION_LOCK (connection); if (reply_handler_data->timeout_link) { _dbus_connection_queue_synthesized_message_link (connection, reply_handler_data->timeout_link); reply_handler_data->timeout_link = NULL; } _dbus_connection_remove_timeout (connection, reply_handler_data->timeout); reply_handler_data->timeout_added = FALSE; status = _dbus_connection_get_dispatch_status_unlocked (connection); /* Unlocks, and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return TRUE; } static void reply_handler_data_free (ReplyHandlerData *data) { if (!data) return; if (data->timeout_added) _dbus_connection_remove_timeout_locked (data->connection, data->timeout); if (data->connection_added) _dbus_message_handler_remove_connection (data->handler, data->connection); if (data->timeout_link) { dbus_message_unref ((DBusMessage *)data->timeout_link->data); _dbus_list_free_link (data->timeout_link); } dbus_message_handler_unref (data->handler); dbus_free (data); } /** * Queues a message to send, as with dbus_connection_send_message(), * but also sets up a DBusMessageHandler to receive a reply to the * message. If no reply is received in the given timeout_milliseconds, * expires the pending reply and sends the DBusMessageHandler a * synthetic error reply (generated in-process, not by the remote * application) indicating that a timeout occurred. * * Reply handlers see their replies after message filters see them, * but before message handlers added with * dbus_connection_register_handler() see them, regardless of the * reply message's name. Reply handlers are only handed a single * message as a reply, after one reply has been seen the handler is * removed. If a filter filters out the reply before the handler sees * it, the reply is immediately timed out and a timeout error reply is * generated. If a filter removes the timeout error reply then the * reply handler will never be called. Filters should not do this. * * If #NULL is passed for the reply_handler, the timeout reply will * still be generated and placed into the message queue, but no * specific message handler will receive the reply. * * If -1 is passed for the timeout, a sane default timeout is used. -1 * is typically the best value for the timeout for this reason, unless * you want a very short or very long timeout. There is no way to * avoid a timeout entirely, other than passing INT_MAX for the * timeout to postpone it indefinitely. * * @param connection the connection * @param message the message to send * @param reply_handler message handler expecting the reply, or #NULL * @param timeout_milliseconds timeout in milliseconds or -1 for default * @returns #TRUE if the message is successfully queued, #FALSE if no memory. * */ dbus_bool_t dbus_connection_send_with_reply (DBusConnection *connection, DBusMessage *message, DBusMessageHandler *reply_handler, int timeout_milliseconds) { DBusTimeout *timeout; ReplyHandlerData *data; DBusMessage *reply; DBusList *reply_link; dbus_int32_t serial = -1; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); _dbus_return_val_if_fail (reply_handler != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); if (timeout_milliseconds == -1) timeout_milliseconds = DEFAULT_TIMEOUT_VALUE; data = dbus_new0 (ReplyHandlerData, 1); if (!data) return FALSE; timeout = _dbus_timeout_new (timeout_milliseconds, reply_handler_timeout, data, NULL); if (!timeout) { reply_handler_data_free (data); return FALSE; } CONNECTION_LOCK (connection); /* Add timeout */ if (!_dbus_connection_add_timeout (connection, timeout)) { reply_handler_data_free (data); _dbus_timeout_unref (timeout); CONNECTION_UNLOCK (connection); return FALSE; } /* The connection now owns the reference to the timeout. */ _dbus_timeout_unref (timeout); data->timeout_added = TRUE; data->timeout = timeout; data->connection = connection; if (!_dbus_message_handler_add_connection (reply_handler, connection)) { CONNECTION_UNLOCK (connection); reply_handler_data_free (data); return FALSE; } data->connection_added = TRUE; /* Assign a serial to the message */ if (dbus_message_get_serial (message) == 0) { serial = _dbus_connection_get_next_client_serial (connection); _dbus_message_set_serial (message, serial); } data->handler = reply_handler; data->serial = serial; dbus_message_handler_ref (reply_handler); reply = dbus_message_new_error_reply (message, DBUS_ERROR_NO_REPLY, "No reply within specified time"); if (!reply) { CONNECTION_UNLOCK (connection); reply_handler_data_free (data); return FALSE; } reply_link = _dbus_list_alloc_link (reply); if (!reply) { CONNECTION_UNLOCK (connection); dbus_message_unref (reply); reply_handler_data_free (data); return FALSE; } data->timeout_link = reply_link; /* Insert the serial in the pending replies hash. */ if (!_dbus_hash_table_insert_int (connection->pending_replies, serial, data)) { CONNECTION_UNLOCK (connection); reply_handler_data_free (data); return FALSE; } CONNECTION_UNLOCK (connection); if (!dbus_connection_send (connection, message, NULL)) { /* This will free the handler data too */ _dbus_hash_table_remove_int (connection->pending_replies, serial); return FALSE; } return TRUE; } static DBusMessage* check_for_reply_unlocked (DBusConnection *connection, dbus_uint32_t client_serial) { DBusList *link; link = _dbus_list_get_first_link (&connection->incoming_messages); while (link != NULL) { DBusMessage *reply = link->data; if (dbus_message_get_reply_serial (reply) == client_serial) { _dbus_list_remove_link (&connection->incoming_messages, link); connection->n_incoming -= 1; dbus_message_ref (reply); return reply; } link = _dbus_list_get_next_link (&connection->incoming_messages, link); } return NULL; } /** * Sends a message and blocks a certain time period while waiting for a reply. * This function does not dispatch any message handlers until the main loop * has been reached. This function is used to do non-reentrant "method calls." * If a reply is received, it is returned, and removed from the incoming * message queue. If it is not received, #NULL is returned and the * error is set to #DBUS_ERROR_NO_REPLY. If something else goes * wrong, result is set to whatever is appropriate, such as * #DBUS_ERROR_NO_MEMORY or #DBUS_ERROR_DISCONNECTED. * * @todo could use performance improvements (it keeps scanning * the whole message queue for example) and has thread issues, * see comments in source * * @param connection the connection * @param message the message to send * @param timeout_milliseconds timeout in milliseconds or -1 for default * @param error return location for error message * @returns the message that is the reply or #NULL with an error code if the * function fails. */ DBusMessage * dbus_connection_send_with_reply_and_block (DBusConnection *connection, DBusMessage *message, int timeout_milliseconds, DBusError *error) { dbus_uint32_t client_serial; long start_tv_sec, start_tv_usec; long end_tv_sec, end_tv_usec; long tv_sec, tv_usec; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, NULL); _dbus_return_val_if_fail (message != NULL, NULL); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); _dbus_return_val_if_error_is_set (error, NULL); if (timeout_milliseconds == -1) timeout_milliseconds = DEFAULT_TIMEOUT_VALUE; /* it would probably seem logical to pass in _DBUS_INT_MAX * for infinite timeout, but then math below would get * all overflow-prone, so smack that down. */ if (timeout_milliseconds > _DBUS_ONE_HOUR_IN_MILLISECONDS * 6) timeout_milliseconds = _DBUS_ONE_HOUR_IN_MILLISECONDS * 6; if (!dbus_connection_send (connection, message, &client_serial)) { _DBUS_SET_OOM (error); return NULL; } message = NULL; /* Flush message queue */ dbus_connection_flush (connection); CONNECTION_LOCK (connection); _dbus_get_current_time (&start_tv_sec, &start_tv_usec); end_tv_sec = start_tv_sec + timeout_milliseconds / 1000; end_tv_usec = start_tv_usec + (timeout_milliseconds % 1000) * 1000; end_tv_sec += end_tv_usec / _DBUS_USEC_PER_SECOND; end_tv_usec = end_tv_usec % _DBUS_USEC_PER_SECOND; _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", timeout_milliseconds, client_serial, start_tv_sec, start_tv_usec, end_tv_sec, end_tv_usec); /* Now we wait... */ /* THREAD TODO: This is busted. What if a dispatch() or pop_message * gets the message before we do? */ /* always block at least once as we know we don't have the reply yet */ _dbus_connection_do_iteration (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK, timeout_milliseconds); recheck_status: /* queue messages and get status */ status = _dbus_connection_get_dispatch_status_unlocked (connection); if (status == DBUS_DISPATCH_DATA_REMAINS) { DBusMessage *reply; reply = check_for_reply_unlocked (connection, client_serial); if (reply != NULL) { status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply %s\n", dbus_message_get_name (reply)); /* Unlocks, and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return reply; } } _dbus_get_current_time (&tv_sec, &tv_usec); if (tv_sec < start_tv_sec) _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n"); else if (connection->disconnect_message_link == NULL) _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n"); else if (tv_sec < end_tv_sec || (tv_sec == end_tv_sec && tv_usec < end_tv_usec)) { timeout_milliseconds = (end_tv_sec - tv_sec) * 1000 + (end_tv_usec - tv_usec) / 1000; _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds); _dbus_assert (timeout_milliseconds >= 0); if (status == DBUS_DISPATCH_NEED_MEMORY) { /* Try sleeping a bit, as we aren't sure we need to block for reading, * we may already have a reply in the buffer and just can't process * it. */ _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n"); if (timeout_milliseconds < 100) ; /* just busy loop */ else if (timeout_milliseconds <= 1000) _dbus_sleep_milliseconds (timeout_milliseconds / 3); else _dbus_sleep_milliseconds (1000); } else { /* block again, we don't have the reply buffered yet. */ _dbus_connection_do_iteration (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK, timeout_milliseconds); } goto recheck_status; } _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %ld milliseconds and got no reply\n", (tv_sec - start_tv_sec) * 1000 + (tv_usec - start_tv_usec) / 1000); if (dbus_connection_get_is_connected (connection)) dbus_set_error (error, DBUS_ERROR_NO_REPLY, "Message did not receive a reply"); else dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Disconnected prior to receiving a reply"); /* unlocks and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return NULL; } /** * Blocks until the outgoing message queue is empty. * * @param connection the connection. */ void dbus_connection_flush (DBusConnection *connection) { /* We have to specify DBUS_ITERATION_DO_READING here because * otherwise we could have two apps deadlock if they are both doing * a flush(), and the kernel buffers fill up. This could change the * dispatch status. */ DBusDispatchStatus status; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); while (connection->n_outgoing > 0 && _dbus_connection_get_is_connected_unlocked (connection)) _dbus_connection_do_iteration (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_DO_WRITING | DBUS_ITERATION_BLOCK, -1); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* Unlocks and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); } /* Call with mutex held. Will drop it while waiting and re-acquire * before returning */ static void _dbus_connection_wait_for_borrowed (DBusConnection *connection) { _dbus_assert (connection->message_borrowed != NULL); while (connection->message_borrowed != NULL) dbus_condvar_wait (connection->message_returned_cond, connection->mutex); } /** * Returns the first-received message from the incoming message queue, * leaving it in the queue. If the queue is empty, returns #NULL. * * The caller does not own a reference to the returned message, and * must either return it using dbus_connection_return_message() or * keep it after calling dbus_connection_steal_borrowed_message(). No * one can get at the message while its borrowed, so return it as * quickly as possible and don't keep a reference to it after * returning it. If you need to keep the message, make a copy of it. * * @param connection the connection. * @returns next message in the incoming queue. */ DBusMessage* dbus_connection_borrow_message (DBusConnection *connection) { DBusMessage *message; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, NULL); /* this is called for the side effect that it queues * up any messages from the transport */ status = dbus_connection_get_dispatch_status (connection); if (status != DBUS_DISPATCH_DATA_REMAINS) return NULL; CONNECTION_LOCK (connection); if (connection->message_borrowed != NULL) _dbus_connection_wait_for_borrowed (connection); message = _dbus_list_get_first (&connection->incoming_messages); if (message) connection->message_borrowed = message; CONNECTION_UNLOCK (connection); return message; } /** * Used to return a message after peeking at it using * dbus_connection_borrow_message(). * * @param connection the connection * @param message the message from dbus_connection_borrow_message() */ void dbus_connection_return_message (DBusConnection *connection, DBusMessage *message) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (message != NULL); CONNECTION_LOCK (connection); _dbus_assert (message == connection->message_borrowed); connection->message_borrowed = NULL; dbus_condvar_wake_all (connection->message_returned_cond); CONNECTION_UNLOCK (connection); } /** * Used to keep a message after peeking at it using * dbus_connection_borrow_message(). Before using this function, see * the caveats/warnings in the documentation for * dbus_connection_pop_message(). * * @param connection the connection * @param message the message from dbus_connection_borrow_message() */ void dbus_connection_steal_borrowed_message (DBusConnection *connection, DBusMessage *message) { DBusMessage *pop_message; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (message != NULL); CONNECTION_LOCK (connection); _dbus_assert (message == connection->message_borrowed); pop_message = _dbus_list_pop_first (&connection->incoming_messages); _dbus_assert (message == pop_message); connection->n_incoming -= 1; _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n", message, connection->n_incoming); connection->message_borrowed = NULL; dbus_condvar_wake_all (connection->message_returned_cond); CONNECTION_UNLOCK (connection); } /* See dbus_connection_pop_message, but requires the caller to own * the lock before calling. May drop the lock while running. */ static DBusList* _dbus_connection_pop_message_link_unlocked (DBusConnection *connection) { if (connection->message_borrowed != NULL) _dbus_connection_wait_for_borrowed (connection); if (connection->n_incoming > 0) { DBusList *link; link = _dbus_list_pop_first_link (&connection->incoming_messages); connection->n_incoming -= 1; _dbus_verbose ("Message %p (%s) removed from incoming queue %p, %d incoming\n", link->data, dbus_message_get_name (link->data), connection, connection->n_incoming); return link; } else return NULL; } /* See dbus_connection_pop_message, but requires the caller to own * the lock before calling. May drop the lock while running. */ static DBusMessage* _dbus_connection_pop_message_unlocked (DBusConnection *connection) { DBusList *link; link = _dbus_connection_pop_message_link_unlocked (connection); if (link != NULL) { DBusMessage *message; message = link->data; _dbus_list_free_link (link); return message; } else return NULL; } /** * Returns the first-received message from the incoming message queue, * removing it from the queue. The caller owns a reference to the * returned message. If the queue is empty, returns #NULL. * * This function bypasses any message handlers that are registered, * and so using it is usually wrong. Instead, let the main loop invoke * dbus_connection_dispatch(). Popping messages manually is only * useful in very simple programs that don't share a #DBusConnection * with any libraries or other modules. * * @param connection the connection. * @returns next message in the incoming queue. */ DBusMessage* dbus_connection_pop_message (DBusConnection *connection) { DBusMessage *message; DBusDispatchStatus status; /* this is called for the side effect that it queues * up any messages from the transport */ status = dbus_connection_get_dispatch_status (connection); if (status != DBUS_DISPATCH_DATA_REMAINS) return NULL; CONNECTION_LOCK (connection); message = _dbus_connection_pop_message_unlocked (connection); _dbus_verbose ("Returning popped message %p\n", message); CONNECTION_UNLOCK (connection); return message; } /** * Acquire the dispatcher. This must be done before dispatching * messages in order to guarantee the right order of * message delivery. May sleep and drop the connection mutex * while waiting for the dispatcher. * * @param connection the connection. */ static void _dbus_connection_acquire_dispatch (DBusConnection *connection) { if (connection->dispatch_acquired) dbus_condvar_wait (connection->dispatch_cond, connection->mutex); _dbus_assert (!connection->dispatch_acquired); connection->dispatch_acquired = TRUE; } /** * Release the dispatcher when you're done with it. Only call * after you've acquired the dispatcher. Wakes up at most one * thread currently waiting to acquire the dispatcher. * * @param connection the connection. */ static void _dbus_connection_release_dispatch (DBusConnection *connection) { _dbus_assert (connection->dispatch_acquired); connection->dispatch_acquired = FALSE; dbus_condvar_wake_one (connection->dispatch_cond); } static void _dbus_connection_failed_pop (DBusConnection *connection, DBusList *message_link) { _dbus_list_prepend_link (&connection->incoming_messages, message_link); connection->n_incoming += 1; } static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection) { if (connection->n_incoming > 0) return DBUS_DISPATCH_DATA_REMAINS; else if (!_dbus_transport_queue_messages (connection->transport)) return DBUS_DISPATCH_NEED_MEMORY; else { DBusDispatchStatus status; status = _dbus_transport_get_dispatch_status (connection->transport); if (status != DBUS_DISPATCH_COMPLETE) return status; else if (connection->n_incoming > 0) return DBUS_DISPATCH_DATA_REMAINS; else return DBUS_DISPATCH_COMPLETE; } } static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, DBusDispatchStatus new_status) { dbus_bool_t changed; DBusDispatchStatusFunction function; void *data; /* We have the lock */ _dbus_connection_ref_unlocked (connection); changed = new_status != connection->last_dispatch_status; connection->last_dispatch_status = new_status; function = connection->dispatch_status_function; data = connection->dispatch_status_data; /* We drop the lock */ CONNECTION_UNLOCK (connection); if (changed && function) { _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n", connection, new_status, new_status == DBUS_DISPATCH_COMPLETE ? "complete" : new_status == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : new_status == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : "???"); (* function) (connection, new_status, data); } dbus_connection_unref (connection); } /** * Gets the current state (what we would currently return * from dbus_connection_dispatch()) but doesn't actually * dispatch any messages. * * @param connection the connection. * @returns current dispatch status */ DBusDispatchStatus dbus_connection_get_dispatch_status (DBusConnection *connection) { DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); CONNECTION_UNLOCK (connection); return status; } /** * Processes data buffered while handling watches, queueing zero or * more incoming messages. Then pops the first-received message from * the current incoming message queue, runs any handlers for it, and * unrefs the message. Returns a status indicating whether messages/data * remain, more memory is needed, or all data has been processed. * * Even if the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, * does not necessarily dispatch a message, as the data may * be part of authentication or the like. * * @param connection the connection * @returns dispatch status */ DBusDispatchStatus dbus_connection_dispatch (DBusConnection *connection) { DBusMessageHandler *handler; DBusMessage *message; DBusList *link, *filter_list_copy, *message_link; DBusHandlerResult result; ReplyHandlerData *reply_handler_data; const char *name; dbus_int32_t reply_serial; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); if (status != DBUS_DISPATCH_DATA_REMAINS) { /* unlocks and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return status; } /* We need to ref the connection since the callback could potentially * drop the last ref to it */ _dbus_connection_ref_unlocked (connection); _dbus_connection_acquire_dispatch (connection); /* This call may drop the lock during the execution (if waiting for * borrowed messages to be returned) but the order of message * dispatch if several threads call dispatch() is still * protected by the lock, since only one will get the lock, and that * one will finish the message dispatching */ message_link = _dbus_connection_pop_message_link_unlocked (connection); if (message_link == NULL) { /* another thread dispatched our stuff */ _dbus_connection_release_dispatch (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_connection_unref (connection); return status; } message = message_link->data; result = DBUS_HANDLER_RESULT_ALLOW_MORE_HANDLERS; reply_serial = dbus_message_get_reply_serial (message); reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies, reply_serial); if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy)) { _dbus_connection_release_dispatch (connection); _dbus_connection_failed_pop (connection, message_link); /* unlocks and calls user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, DBUS_DISPATCH_NEED_MEMORY); dbus_connection_unref (connection); return DBUS_DISPATCH_NEED_MEMORY; } _dbus_list_foreach (&filter_list_copy, (DBusForeachFunction)dbus_message_handler_ref, NULL); /* We're still protected from dispatch() reentrancy here * since we acquired the dispatcher */ CONNECTION_UNLOCK (connection); link = _dbus_list_get_first_link (&filter_list_copy); while (link != NULL) { DBusMessageHandler *handler = link->data; DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link); _dbus_verbose (" running filter on message %p\n", message); result = _dbus_message_handler_handle_message (handler, connection, message); if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE) break; link = next; } _dbus_list_foreach (&filter_list_copy, (DBusForeachFunction)dbus_message_handler_unref, NULL); _dbus_list_clear (&filter_list_copy); CONNECTION_LOCK (connection); /* Did a reply we were waiting on get filtered? */ if (reply_handler_data && result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE) { /* Queue the timeout immediately! */ if (reply_handler_data->timeout_link) { _dbus_connection_queue_synthesized_message_link (connection, reply_handler_data->timeout_link); reply_handler_data->timeout_link = NULL; } else { /* We already queued the timeout? Then it was filtered! */ _dbus_warn ("The timeout error with reply serial %d was filtered, so the reply handler will never be called.\n", reply_serial); } } if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE) goto out; if (reply_handler_data) { CONNECTION_UNLOCK (connection); _dbus_verbose (" running reply handler on message %p\n", message); result = _dbus_message_handler_handle_message (reply_handler_data->handler, connection, message); reply_handler_data_free (reply_handler_data); CONNECTION_LOCK (connection); goto out; } name = dbus_message_get_name (message); if (name != NULL) { handler = _dbus_hash_table_lookup_string (connection->handler_table, name); if (handler != NULL) { /* We're still protected from dispatch() reentrancy here * since we acquired the dispatcher */ CONNECTION_UNLOCK (connection); _dbus_verbose (" running app handler on message %p (%s)\n", message, dbus_message_get_name (message)); result = _dbus_message_handler_handle_message (handler, connection, message); CONNECTION_LOCK (connection); if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE) goto out; } } _dbus_verbose (" done dispatching %p (%s) on connection %p\n", message, dbus_message_get_name (message), connection); out: _dbus_connection_release_dispatch (connection); _dbus_list_free_link (message_link); dbus_message_unref (message); /* don't want the message to count in max message limits * in computing dispatch status */ status = _dbus_connection_get_dispatch_status_unlocked (connection); /* unlocks and calls user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_connection_unref (connection); return status; } /** * Sets the watch functions for the connection. These functions are * responsible for making the application's main loop aware of file * descriptors that need to be monitored for events, using select() or * poll(). When using Qt, typically the DBusAddWatchFunction would * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction * could call g_io_add_watch(), or could be used as part of a more * elaborate GSource. Note that when a watch is added, it may * not be enabled. * * The DBusWatchToggledFunction notifies the application that the * watch has been enabled or disabled. Call dbus_watch_get_enabled() * to check this. A disabled watch should have no effect, and enabled * watch should be added to the main loop. This feature is used * instead of simply adding/removing the watch because * enabling/disabling can be done without memory allocation. The * toggled function may be NULL if a main loop re-queries * dbus_watch_get_enabled() every time anyway. * * The DBusWatch can be queried for the file descriptor to watch using * dbus_watch_get_fd(), and for the events to watch for using * dbus_watch_get_flags(). The flags returned by * dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and * DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR; * all watches implicitly include a watch for hangups, errors, and * other exceptional conditions. * * Once a file descriptor becomes readable or writable, or an exception * occurs, dbus_watch_handle() should be called to * notify the connection of the file descriptor's condition. * * dbus_watch_handle() cannot be called during the * DBusAddWatchFunction, as the connection will not be ready to handle * that watch yet. * * It is not allowed to reference a DBusWatch after it has been passed * to remove_function. * * If #FALSE is returned due to lack of memory, the failure may be due * to a #FALSE return from the new add_function. If so, the * add_function may have been called successfully one or more times, * but the remove_function will also have been called to remove any * successful adds. i.e. if #FALSE is returned the net result * should be that dbus_connection_set_watch_functions() has no effect, * but the add_function and remove_function may have been called. * * @todo We need to drop the lock when we call the * add/remove/toggled functions which can be a side effect * of setting the watch functions. * * @param connection the connection. * @param add_function function to begin monitoring a new descriptor. * @param remove_function function to stop monitoring a descriptor. * @param toggled_function function to notify of enable/disable * @param data data to pass to add_function and remove_function. * @param free_data_function function to be called to free the data. * @returns #FALSE on failure (no memory) */ dbus_bool_t dbus_connection_set_watch_functions (DBusConnection *connection, DBusAddWatchFunction add_function, DBusRemoveWatchFunction remove_function, DBusWatchToggledFunction toggled_function, void *data, DBusFreeFunction free_data_function) { dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); /* ref connection for slightly better reentrancy */ _dbus_connection_ref_unlocked (connection); /* FIXME this can call back into user code, and we need to drop the * connection lock when it does. */ retval = _dbus_watch_list_set_functions (connection->watches, add_function, remove_function, toggled_function, data, free_data_function); CONNECTION_UNLOCK (connection); /* drop our paranoid refcount */ dbus_connection_unref (connection); return retval; } /** * Sets the timeout functions for the connection. These functions are * responsible for making the application's main loop aware of timeouts. * When using Qt, typically the DBusAddTimeoutFunction would create a * QTimer. When using GLib, the DBusAddTimeoutFunction would call * g_timeout_add. * * The DBusTimeoutToggledFunction notifies the application that the * timeout has been enabled or disabled. Call * dbus_timeout_get_enabled() to check this. A disabled timeout should * have no effect, and enabled timeout should be added to the main * loop. This feature is used instead of simply adding/removing the * timeout because enabling/disabling can be done without memory * allocation. With Qt, QTimer::start() and QTimer::stop() can be used * to enable and disable. The toggled function may be NULL if a main * loop re-queries dbus_timeout_get_enabled() every time anyway. * Whenever a timeout is toggled, its interval may change. * * The DBusTimeout can be queried for the timer interval using * dbus_timeout_get_interval(). dbus_timeout_handle() should be called * repeatedly, each time the interval elapses, starting after it has * elapsed once. The timeout stops firing when it is removed with the * given remove_function. The timer interval may change whenever the * timeout is added, removed, or toggled. * * @param connection the connection. * @param add_function function to add a timeout. * @param remove_function function to remove a timeout. * @param toggled_function function to notify of enable/disable * @param data data to pass to add_function and remove_function. * @param free_data_function function to be called to free the data. * @returns #FALSE on failure (no memory) */ dbus_bool_t dbus_connection_set_timeout_functions (DBusConnection *connection, DBusAddTimeoutFunction add_function, DBusRemoveTimeoutFunction remove_function, DBusTimeoutToggledFunction toggled_function, void *data, DBusFreeFunction free_data_function) { dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); /* ref connection for slightly better reentrancy */ _dbus_connection_ref_unlocked (connection); retval = _dbus_timeout_list_set_functions (connection->timeouts, add_function, remove_function, toggled_function, data, free_data_function); CONNECTION_UNLOCK (connection); /* drop our paranoid refcount */ dbus_connection_unref (connection); return retval; } /** * Sets the mainloop wakeup function for the connection. Thi function is * responsible for waking up the main loop (if its sleeping) when some some * change has happened to the connection that the mainloop needs to reconsiders * (e.g. a message has been queued for writing). * When using Qt, this typically results in a call to QEventLoop::wakeUp(). * When using GLib, it would call g_main_context_wakeup(). * * * @param connection the connection. * @param wakeup_main_function function to wake up the mainloop * @param data data to pass wakeup_main_function * @param free_data_function function to be called to free the data. */ void dbus_connection_set_wakeup_main_function (DBusConnection *connection, DBusWakeupMainFunction wakeup_main_function, void *data, DBusFreeFunction free_data_function) { void *old_data; DBusFreeFunction old_free_data; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); old_data = connection->wakeup_main_data; old_free_data = connection->free_wakeup_main_data; connection->wakeup_main_function = wakeup_main_function; connection->wakeup_main_data = data; connection->free_wakeup_main_data = free_data_function; CONNECTION_UNLOCK (connection); /* Callback outside the lock */ if (old_free_data) (*old_free_data) (old_data); } /** * Set a function to be invoked when the dispatch status changes. * If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then * dbus_connection_dispatch() needs to be called to process incoming * messages. However, dbus_connection_dispatch() MUST NOT BE CALLED * from inside the DBusDispatchStatusFunction. Indeed, almost * any reentrancy in this function is a bad idea. Instead, * the DBusDispatchStatusFunction should simply save an indication * that messages should be dispatched later, when the main loop * is re-entered. * * @param connection the connection * @param function function to call on dispatch status changes * @param data data for function * @param free_data_function free the function data */ void dbus_connection_set_dispatch_status_function (DBusConnection *connection, DBusDispatchStatusFunction function, void *data, DBusFreeFunction free_data_function) { void *old_data; DBusFreeFunction old_free_data; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); old_data = connection->dispatch_status_data; old_free_data = connection->free_dispatch_status_data; connection->dispatch_status_function = function; connection->dispatch_status_data = data; connection->free_dispatch_status_data = free_data_function; CONNECTION_UNLOCK (connection); /* Callback outside the lock */ if (old_free_data) (*old_free_data) (old_data); } /** * Gets the UNIX user ID of the connection if any. * Returns #TRUE if the uid is filled in. * Always returns #FALSE on non-UNIX platforms. * Always returns #FALSE prior to authenticating the * connection. * * @param connection the connection * @param uid return location for the user ID * @returns #TRUE if uid is filled in with a valid user ID */ dbus_bool_t dbus_connection_get_unix_user (DBusConnection *connection, unsigned long *uid) { dbus_bool_t result; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (uid != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_transport_get_is_authenticated (connection->transport)) result = FALSE; else result = _dbus_transport_get_unix_user (connection->transport, uid); CONNECTION_UNLOCK (connection); return result; } /** * Sets a predicate function used to determine whether a given user ID * is allowed to connect. When an incoming connection has * authenticated with a particular user ID, this function is called; * if it returns #TRUE, the connection is allowed to proceed, * otherwise the connection is disconnected. * * If the function is set to #NULL (as it is by default), then * only the same UID as the server process will be allowed to * connect. * * @param connection the connection * @param function the predicate * @param data data to pass to the predicate * @param free_data_function function to free the data */ void dbus_connection_set_unix_user_function (DBusConnection *connection, DBusAllowUnixUserFunction function, void *data, DBusFreeFunction free_data_function) { void *old_data = NULL; DBusFreeFunction old_free_function = NULL; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_unix_user_function (connection->transport, function, data, free_data_function, &old_data, &old_free_function); CONNECTION_UNLOCK (connection); if (old_free_function != NULL) (* old_free_function) (old_data); } /** * Adds a message filter. Filters are handlers that are run on * all incoming messages, prior to the normal handlers * registered with dbus_connection_register_handler(). * Filters are run in the order that they were added. * The same handler can be added as a filter more than once, in * which case it will be run more than once. * Filters added during a filter callback won't be run on the * message being processed. * * The connection does NOT add a reference to the message handler; * instead, if the message handler is finalized, the connection simply * forgets about it. Thus the caller of this function must keep a * reference to the message handler. * * @param connection the connection * @param handler the handler * @returns #TRUE on success, #FALSE if not enough memory. */ dbus_bool_t dbus_connection_add_filter (DBusConnection *connection, DBusMessageHandler *handler) { _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (handler != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_message_handler_add_connection (handler, connection)) { CONNECTION_UNLOCK (connection); return FALSE; } if (!_dbus_list_append (&connection->filter_list, handler)) { _dbus_message_handler_remove_connection (handler, connection); CONNECTION_UNLOCK (connection); return FALSE; } CONNECTION_UNLOCK (connection); return TRUE; } /** * Removes a previously-added message filter. It is a programming * error to call this function for a handler that has not * been added as a filter. If the given handler was added * more than once, only one instance of it will be removed * (the most recently-added instance). * * @param connection the connection * @param handler the handler to remove * */ void dbus_connection_remove_filter (DBusConnection *connection, DBusMessageHandler *handler) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (handler != NULL); CONNECTION_LOCK (connection); if (!_dbus_list_remove_last (&connection->filter_list, handler)) { _dbus_warn ("Tried to remove a DBusConnection filter that had not been added\n"); CONNECTION_UNLOCK (connection); return; } _dbus_message_handler_remove_connection (handler, connection); CONNECTION_UNLOCK (connection); } /** * Registers a handler for a list of message names. A single handler * can be registered for any number of message names, but each message * name can only have one handler at a time. It's not allowed to call * this function with the name of a message that already has a * handler. If the function returns #FALSE, the handlers were not * registered due to lack of memory. * * The connection does NOT add a reference to the message handler; * instead, if the message handler is finalized, the connection simply * forgets about it. Thus the caller of this function must keep a * reference to the message handler. * * @todo the messages_to_handle arg may be more convenient if it's a * single string instead of an array. Though right now MessageHandler * is sort of designed to say be associated with an entire object with * multiple methods, that's why for example the connection only * weakrefs it. So maybe the "manual" API should be different. * * @param connection the connection * @param handler the handler * @param messages_to_handle the messages to handle * @param n_messages the number of message names in messages_to_handle * @returns #TRUE on success, #FALSE if no memory or another handler already exists * **/ dbus_bool_t dbus_connection_register_handler (DBusConnection *connection, DBusMessageHandler *handler, const char **messages_to_handle, int n_messages) { int i; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (handler != NULL, FALSE); _dbus_return_val_if_fail (n_messages >= 0, FALSE); _dbus_return_val_if_fail (n_messages == 0 || messages_to_handle != NULL, FALSE); CONNECTION_LOCK (connection); i = 0; while (i < n_messages) { DBusHashIter iter; char *key; key = _dbus_strdup (messages_to_handle[i]); if (key == NULL) goto failed; if (!_dbus_hash_iter_lookup (connection->handler_table, key, TRUE, &iter)) { dbus_free (key); goto failed; } if (_dbus_hash_iter_get_value (&iter) != NULL) { _dbus_warn ("Bug in application: attempted to register a second handler for %s\n", messages_to_handle[i]); dbus_free (key); /* won't have replaced the old key with the new one */ goto failed; } if (!_dbus_message_handler_add_connection (handler, connection)) { _dbus_hash_iter_remove_entry (&iter); /* key has freed on nuking the entry */ goto failed; } _dbus_hash_iter_set_value (&iter, handler); ++i; } CONNECTION_UNLOCK (connection); return TRUE; failed: /* unregister everything registered so far, * so we don't fail partially */ dbus_connection_unregister_handler (connection, handler, messages_to_handle, i); CONNECTION_UNLOCK (connection); return FALSE; } /** * Unregisters a handler for a list of message names. The handlers * must have been previously registered. * * @param connection the connection * @param handler the handler * @param messages_to_handle the messages to handle * @param n_messages the number of message names in messages_to_handle * **/ void dbus_connection_unregister_handler (DBusConnection *connection, DBusMessageHandler *handler, const char **messages_to_handle, int n_messages) { int i; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (handler != NULL); _dbus_return_if_fail (n_messages >= 0); _dbus_return_if_fail (n_messages == 0 || messages_to_handle != NULL); CONNECTION_LOCK (connection); i = 0; while (i < n_messages) { DBusHashIter iter; if (!_dbus_hash_iter_lookup (connection->handler_table, (char*) messages_to_handle[i], FALSE, &iter)) { _dbus_warn ("Bug in application: attempted to unregister handler for %s which was not registered\n", messages_to_handle[i]); } else if (_dbus_hash_iter_get_value (&iter) != handler) { _dbus_warn ("Bug in application: attempted to unregister handler for %s which was registered by a different handler\n", messages_to_handle[i]); } else { _dbus_hash_iter_remove_entry (&iter); _dbus_message_handler_remove_connection (handler, connection); } ++i; } CONNECTION_UNLOCK (connection); } /** * Registers an object with the connection. This object is assigned an * object ID, and will be visible under this ID and with the provided * interfaces to the peer application on the other end of the * connection. The object instance should be passed in as object_impl; * the instance can be any datatype, as long as it fits in a void*. * * As a side effect of calling this function, the "registered" * callback in the #DBusObjectVTable will be invoked. * * @param connection the connection to register the instance with * @param interfaces #NULL-terminated array of interface names the instance supports * @param vtable virtual table of functions for manipulating the instance * @param object_impl object instance * @param object_id if non-#NULL, object ID to initialize with the new object's ID * @returns #FALSE if not enough memory to register the object instance */ dbus_bool_t dbus_connection_register_object (DBusConnection *connection, const char **interfaces, const DBusObjectVTable *vtable, void *object_impl, DBusObjectID *object_id) { return FALSE; } /** * Reverses the effects of dbus_connection_register_object(), * and invokes the "unregistered" callback in the #DBusObjectVTable * for the given object. The passed-in object ID must be a valid, * registered object ID or the results are undefined. * * @param connection the connection to unregister the object ID from * @param object_id the object ID to unregister */ void dbus_connection_unregister_object (DBusConnection *connection, const DBusObjectID *object_id) { } static DBusDataSlotAllocator slot_allocator; _DBUS_DEFINE_GLOBAL_LOCK (connection_slots); /** * Allocates an integer ID to be used for storing application-specific * data on any DBusConnection. The allocated ID may then be used * with dbus_connection_set_data() and dbus_connection_get_data(). * The passed-in slot must be initialized to -1, and is filled in * with the slot ID. If the passed-in slot is not -1, it's assumed * to be already allocated, and its refcount is incremented. * * The allocated slot is global, i.e. all DBusConnection objects will * have a slot with the given integer ID reserved. * * @param slot_p address of a global variable storing the slot * @returns #FALSE on failure (no memory) */ dbus_bool_t dbus_connection_allocate_data_slot (dbus_int32_t *slot_p) { return _dbus_data_slot_allocator_alloc (&slot_allocator, _DBUS_LOCK_NAME (connection_slots), slot_p); } /** * Deallocates a global ID for connection data slots. * dbus_connection_get_data() and dbus_connection_set_data() may no * longer be used with this slot. Existing data stored on existing * DBusConnection objects will be freed when the connection is * finalized, but may not be retrieved (and may only be replaced if * someone else reallocates the slot). When the refcount on the * passed-in slot reaches 0, it is set to -1. * * @param slot_p address storing the slot to deallocate */ void dbus_connection_free_data_slot (dbus_int32_t *slot_p) { _dbus_return_if_fail (*slot_p >= 0); _dbus_data_slot_allocator_free (&slot_allocator, slot_p); } /** * Stores a pointer on a DBusConnection, along * with an optional function to be used for freeing * the data when the data is set again, or when * the connection is finalized. The slot number * must have been allocated with dbus_connection_allocate_data_slot(). * * @param connection the connection * @param slot the slot number * @param data the data to store * @param free_data_func finalizer function for the data * @returns #TRUE if there was enough memory to store the data */ dbus_bool_t dbus_connection_set_data (DBusConnection *connection, dbus_int32_t slot, void *data, DBusFreeFunction free_data_func) { DBusFreeFunction old_free_func; void *old_data; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (slot >= 0, FALSE); CONNECTION_LOCK (connection); retval = _dbus_data_slot_list_set (&slot_allocator, &connection->slot_list, slot, data, free_data_func, &old_free_func, &old_data); CONNECTION_UNLOCK (connection); if (retval) { /* Do the actual free outside the connection lock */ if (old_free_func) (* old_free_func) (old_data); } return retval; } /** * Retrieves data previously set with dbus_connection_set_data(). * The slot must still be allocated (must not have been freed). * * @param connection the connection * @param slot the slot to get data from * @returns the data, or #NULL if not found */ void* dbus_connection_get_data (DBusConnection *connection, dbus_int32_t slot) { void *res; _dbus_return_val_if_fail (connection != NULL, NULL); CONNECTION_LOCK (connection); res = _dbus_data_slot_list_get (&slot_allocator, &connection->slot_list, slot); CONNECTION_UNLOCK (connection); return res; } /** * This function sets a global flag for whether dbus_connection_new() * will set SIGPIPE behavior to SIG_IGN. * * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN */ void dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe) { _dbus_modify_sigpipe = will_modify_sigpipe != FALSE; } /** * Specifies the maximum size message this connection is allowed to * receive. Larger messages will result in disconnecting the * connection. * * @param connection a #DBusConnection * @param size maximum message size the connection can receive, in bytes */ void dbus_connection_set_max_message_size (DBusConnection *connection, long size) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_max_message_size (connection->transport, size); CONNECTION_UNLOCK (connection); } /** * Gets the value set by dbus_connection_set_max_message_size(). * * @param connection the connection * @returns the max size of a single message */ long dbus_connection_get_max_message_size (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_transport_get_max_message_size (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Sets the maximum total number of bytes that can be used for all messages * received on this connection. Messages count toward the maximum until * they are finalized. When the maximum is reached, the connection will * not read more data until some messages are finalized. * * The semantics of the maximum are: if outstanding messages are * already above the maximum, additional messages will not be read. * The semantics are not: if the next message would cause us to exceed * the maximum, we don't read it. The reason is that we don't know the * size of a message until after we read it. * * Thus, the max live messages size can actually be exceeded * by up to the maximum size of a single message. * * Also, if we read say 1024 bytes off the wire in a single read(), * and that contains a half-dozen small messages, we may exceed the * size max by that amount. But this should be inconsequential. * * This does imply that we can't call read() with a buffer larger * than we're willing to exceed this limit by. * * @param connection the connection * @param size the maximum size in bytes of all outstanding messages */ void dbus_connection_set_max_received_size (DBusConnection *connection, long size) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_max_received_size (connection->transport, size); CONNECTION_UNLOCK (connection); } /** * Gets the value set by dbus_connection_set_max_received_size(). * * @param connection the connection * @returns the max size of all live messages */ long dbus_connection_get_max_received_size (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_transport_get_max_received_size (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Gets the approximate size in bytes of all messages in the outgoing * message queue. The size is approximate in that you shouldn't use * it to decide how many bytes to read off the network or anything * of that nature, as optimizations may choose to tell small white lies * to avoid performance overhead. * * @param connection the connection * @returns the number of bytes that have been queued up but not sent */ long dbus_connection_get_outgoing_size (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_counter_get_value (connection->outgoing_counter); CONNECTION_UNLOCK (connection); return res; } /** @} */