/* -*- mode: C; c-file-style: "gnu" -*- */ /* dbus-connection.c DBusConnection object * * Copyright (C) 2002, 2003, 2004, 2005 Red Hat Inc. * * Licensed under the Academic Free License version 2.1 * * 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-shared.h" #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-threads.h" #include "dbus-protocol.h" #include "dbus-dataslot.h" #include "dbus-string.h" #include "dbus-pending-call.h" #include "dbus-object-tree.h" #include "dbus-threads-internal.h" #ifdef DBUS_DISABLE_CHECKS #define TOOK_LOCK_CHECK(connection) #define RELEASING_LOCK_CHECK(connection) #define HAVE_LOCK_CHECK(connection) #else #define TOOK_LOCK_CHECK(connection) do { \ _dbus_assert (!(connection)->have_connection_lock); \ (connection)->have_connection_lock = TRUE; \ } while (0) #define RELEASING_LOCK_CHECK(connection) do { \ _dbus_assert ((connection)->have_connection_lock); \ (connection)->have_connection_lock = FALSE; \ } while (0) #define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock) /* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */ #endif #define TRACE_LOCKS 1 #define CONNECTION_LOCK(connection) do { \ if (TRACE_LOCKS) { _dbus_verbose (" LOCK: %s\n", _DBUS_FUNCTION_NAME); } \ _dbus_mutex_lock ((connection)->mutex); \ TOOK_LOCK_CHECK (connection); \ } while (0) #define CONNECTION_UNLOCK(connection) do { \ if (TRACE_LOCKS) { _dbus_verbose (" UNLOCK: %s\n", _DBUS_FUNCTION_NAME); } \ RELEASING_LOCK_CHECK (connection); \ _dbus_mutex_unlock ((connection)->mutex); \ } while (0) #define DISPATCH_STATUS_NAME(s) \ ((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \ (s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \ (s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \ "???") /** * @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 APIs 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 * signal "Disconnected" from the interface * #DBUS_INTERFACE_LOCAL, path * #DBUS_PATH_LOCAL. * * 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, "Disconnected" 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 * * @{ */ /** * Internal struct representing a message filter function */ typedef struct DBusMessageFilter DBusMessageFilter; /** * Internal struct representing a message filter function */ struct DBusMessageFilter { DBusAtomic refcount; /**< Reference count */ DBusHandleMessageFunction function; /**< Function to call to filter */ void *user_data; /**< User data for the function */ DBusFreeFunction free_user_data_function; /**< Function to free the user data */ }; /** * Internals of DBusPreallocatedSend */ struct DBusPreallocatedSend { DBusConnection *connection; /**< Connection we'd send the message to */ DBusList *queue_link; /**< Preallocated link in the queue */ DBusList *counter_link; /**< Preallocated link in the resource counter */ }; 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 */ DBusMutex *dispatch_mutex; /**< Protects dispatch_acquired */ DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */ DBusMutex *io_path_mutex; /**< Protects io_path_acquired */ DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */ 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; /**< Filled in if the first incoming message has been borrowed; * dispatch_acquired will be set by the borrower */ 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. */ DBusList *filter_list; /**< List of filters. */ DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */ DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */ 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 */ DBusObjectTree *objects; /**< Object path handlers registered with this connection */ char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */ unsigned int shareable : 1; /**< #TRUE if connection can go in shared_connections once we know the GUID */ unsigned int dispatch_acquired : 1; /**< Someone has dispatch path (can drain incoming queue) */ unsigned int io_path_acquired : 1; /**< Someone has transport io path (can use the transport to read/write messages) */ unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */ #ifndef DBUS_DISABLE_CHECKS unsigned int have_connection_lock : 1; /**< Used to check locking */ #endif #ifndef DBUS_DISABLE_CHECKS int generation; /**< _dbus_current_generation that should correspond to this connection */ #endif }; static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection); static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, DBusDispatchStatus new_status); static void _dbus_connection_last_unref (DBusConnection *connection); static void _dbus_connection_acquire_dispatch (DBusConnection *connection); static void _dbus_connection_release_dispatch (DBusConnection *connection); static DBusMessageFilter * _dbus_message_filter_ref (DBusMessageFilter *filter) { _dbus_assert (filter->refcount.value > 0); _dbus_atomic_inc (&filter->refcount); return filter; } static void _dbus_message_filter_unref (DBusMessageFilter *filter) { _dbus_assert (filter->refcount.value > 0); if (_dbus_atomic_dec (&filter->refcount) == 1) { if (filter->free_user_data_function) (* filter->free_user_data_function) (filter->user_data); dbus_free (filter); } } /** * 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) { DBusPendingCall *pending; 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) { pending = _dbus_hash_table_lookup_int (connection->pending_replies, reply_serial); if (pending != NULL) { if (pending->timeout_added) _dbus_connection_remove_timeout (connection, pending->timeout); pending->timeout_added = FALSE; } } connection->n_incoming += 1; _dbus_connection_wakeup_mainloop (connection); _dbus_verbose ("Message %p (%d %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n", message, dbus_message_get_type (message), dbus_message_get_path (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message), dbus_message_get_reply_serial (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) { HAVE_LOCK_CHECK (connection); _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. * Called with connection lock held. * * @param connection the connection. * @returns #TRUE if the outgoing queue is non-empty. */ dbus_bool_t _dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); return connection->outgoing_messages != NULL; } /** * 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_has_messages_to_send (DBusConnection *connection) { dbus_bool_t v; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); v = _dbus_connection_has_messages_to_send_unlocked (connection); CONNECTION_UNLOCK (connection); return v; } /** * 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) { HAVE_LOCK_CHECK (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; HAVE_LOCK_CHECK (connection); /* This can be called before we even complete authentication, since * it's called on disconnect to clean up the outgoing queue. * It's also called as we successfully send each message. */ 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 (%d %s %s %s '%s') removed from outgoing queue %p, %d left to send\n", message, dbus_message_get_type (message), dbus_message_get_path (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (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); } typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list, DBusWatch *watch); typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list, DBusWatch *watch); typedef void (* DBusWatchToggleFunction) (DBusWatchList *list, DBusWatch *watch, dbus_bool_t enabled); static dbus_bool_t protected_change_watch (DBusConnection *connection, DBusWatch *watch, DBusWatchAddFunction add_function, DBusWatchRemoveFunction remove_function, DBusWatchToggleFunction toggle_function, dbus_bool_t enabled) { DBusWatchList *watches; dbus_bool_t retval; HAVE_LOCK_CHECK (connection); /* This isn't really safe or reasonable; a better pattern is the "do everything, then * drop lock and call out" one; but it has to be propagated up through all callers */ watches = connection->watches; if (watches) { connection->watches = NULL; _dbus_connection_ref_unlocked (connection); CONNECTION_UNLOCK (connection); if (add_function) retval = (* add_function) (watches, watch); else if (remove_function) { retval = TRUE; (* remove_function) (watches, watch); } else { retval = TRUE; (* toggle_function) (watches, watch, enabled); } CONNECTION_LOCK (connection); connection->watches = watches; _dbus_connection_unref_unlocked (connection); return retval; } else return FALSE; } /** * 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) { return protected_change_watch (connection, watch, _dbus_watch_list_add_watch, NULL, NULL, 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) { protected_change_watch (connection, watch, NULL, _dbus_watch_list_remove_watch, NULL, FALSE); } /** * 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. * Connection lock should be held when calling this. * * @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) { _dbus_assert (watch != NULL); protected_change_watch (connection, watch, NULL, NULL, _dbus_watch_list_toggle_watch, enabled); } typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list, DBusTimeout *timeout); typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list, DBusTimeout *timeout); typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list, DBusTimeout *timeout, dbus_bool_t enabled); static dbus_bool_t protected_change_timeout (DBusConnection *connection, DBusTimeout *timeout, DBusTimeoutAddFunction add_function, DBusTimeoutRemoveFunction remove_function, DBusTimeoutToggleFunction toggle_function, dbus_bool_t enabled) { DBusTimeoutList *timeouts; dbus_bool_t retval; HAVE_LOCK_CHECK (connection); /* This isn't really safe or reasonable; a better pattern is the "do everything, then * drop lock and call out" one; but it has to be propagated up through all callers */ timeouts = connection->timeouts; if (timeouts) { connection->timeouts = NULL; _dbus_connection_ref_unlocked (connection); CONNECTION_UNLOCK (connection); if (add_function) retval = (* add_function) (timeouts, timeout); else if (remove_function) { retval = TRUE; (* remove_function) (timeouts, timeout); } else { retval = TRUE; (* toggle_function) (timeouts, timeout, enabled); } CONNECTION_LOCK (connection); connection->timeouts = timeouts; _dbus_connection_unref_unlocked (connection); return retval; } else return FALSE; } /** * 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) { return protected_change_timeout (connection, timeout, _dbus_timeout_list_add_timeout, NULL, NULL, 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) { protected_change_timeout (connection, timeout, NULL, _dbus_timeout_list_remove_timeout, NULL, FALSE); } /** * 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) { protected_change_timeout (connection, timeout, NULL, NULL, _dbus_timeout_list_toggle_timeout, enabled); } static dbus_bool_t _dbus_connection_attach_pending_call_unlocked (DBusConnection *connection, DBusPendingCall *pending) { HAVE_LOCK_CHECK (connection); _dbus_assert (pending->reply_serial != 0); if (!_dbus_connection_add_timeout (connection, pending->timeout)) return FALSE; if (!_dbus_hash_table_insert_int (connection->pending_replies, pending->reply_serial, pending)) { _dbus_connection_remove_timeout (connection, pending->timeout); HAVE_LOCK_CHECK (connection); return FALSE; } pending->timeout_added = TRUE; pending->connection = connection; dbus_pending_call_ref (pending); HAVE_LOCK_CHECK (connection); return TRUE; } static void free_pending_call_on_hash_removal (void *data) { DBusPendingCall *pending; if (data == NULL) return; pending = data; if (pending->connection) { if (pending->timeout_added) { _dbus_connection_remove_timeout (pending->connection, pending->timeout); pending->timeout_added = FALSE; } pending->connection = NULL; dbus_pending_call_unref (pending); } } static void _dbus_connection_detach_pending_call_unlocked (DBusConnection *connection, DBusPendingCall *pending) { /* Can't have a destroy notifier on the pending call if we're going to do this */ dbus_pending_call_ref (pending); _dbus_hash_table_remove_int (connection->pending_replies, pending->reply_serial); _dbus_assert (pending->connection == NULL); dbus_pending_call_unref (pending); } static void _dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection, DBusPendingCall *pending) { /* The idea here is to avoid finalizing the pending call * with the lock held, since there's a destroy notifier * in pending call that goes out to application code. */ dbus_pending_call_ref (pending); _dbus_hash_table_remove_int (connection->pending_replies, pending->reply_serial); _dbus_assert (pending->connection == NULL); CONNECTION_UNLOCK (connection); dbus_pending_call_unref (pending); } /** * Removes a pending call from the connection, such that * the pending reply will be ignored. May drop the last * reference to the pending call. * * @param connection the connection * @param pending the pending call */ void _dbus_connection_remove_pending_call (DBusConnection *connection, DBusPendingCall *pending) { CONNECTION_LOCK (connection); _dbus_connection_detach_pending_call_and_unlock (connection, pending); } /** * Completes a pending call with the given message, * or if the message is #NULL, by timing out the pending call. * * @param pending the pending call * @param message the message to complete the call with, or #NULL * to time out the call */ void _dbus_pending_call_complete_and_unlock (DBusPendingCall *pending, DBusMessage *message) { if (message == NULL) { message = pending->timeout_link->data; _dbus_list_clear (&pending->timeout_link); } else dbus_message_ref (message); _dbus_verbose (" handing message %p (%s) to pending call serial %u\n", message, dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_RETURN ? "method return" : dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" : "other type", pending->reply_serial); _dbus_assert (pending->reply == NULL); _dbus_assert (pending->reply_serial == dbus_message_get_reply_serial (message)); pending->reply = message; dbus_pending_call_ref (pending); /* in case there's no app with a ref held */ _dbus_connection_detach_pending_call_and_unlock (pending->connection, pending); /* Must be called unlocked since it invokes app callback */ _dbus_pending_call_notify (pending); dbus_pending_call_unref (pending); } /** * Acquire the transporter I/O path. This must be done before * doing any I/O in the transporter. May sleep and drop the * IO path 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 we_acquired; HAVE_LOCK_CHECK (connection); /* We don't want the connection to vanish */ _dbus_connection_ref_unlocked (connection); /* We will only touch io_path_acquired which is protected by our mutex */ CONNECTION_UNLOCK (connection); _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->io_path_mutex); _dbus_verbose ("%s start connection->io_path_acquired = %d timeout = %d\n", _DBUS_FUNCTION_NAME, connection->io_path_acquired, timeout_milliseconds); we_acquired = FALSE; if (connection->io_path_acquired) { if (timeout_milliseconds != -1) { _dbus_verbose ("%s waiting %d for IO path to be acquirable\n", _DBUS_FUNCTION_NAME, timeout_milliseconds); _dbus_condvar_wait_timeout (connection->io_path_cond, connection->io_path_mutex, timeout_milliseconds); } else { while (connection->io_path_acquired) { _dbus_verbose ("%s waiting for IO path to be acquirable\n", _DBUS_FUNCTION_NAME); _dbus_condvar_wait (connection->io_path_cond, connection->io_path_mutex); } } } if (!connection->io_path_acquired) { we_acquired = TRUE; connection->io_path_acquired = TRUE; } _dbus_verbose ("%s end connection->io_path_acquired = %d we_acquired = %d\n", _DBUS_FUNCTION_NAME, connection->io_path_acquired, we_acquired); _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->io_path_mutex); CONNECTION_LOCK (connection); HAVE_LOCK_CHECK (connection); _dbus_connection_unref_unlocked (connection); return we_acquired; } /** * 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) { HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->io_path_mutex); _dbus_assert (connection->io_path_acquired); _dbus_verbose ("%s start connection->io_path_acquired = %d\n", _DBUS_FUNCTION_NAME, connection->io_path_acquired); connection->io_path_acquired = FALSE; _dbus_condvar_wake_one (connection->io_path_cond); _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->io_path_mutex); } /** * Queues incoming messages and sends outgoing messages for this * connection, optionally blocking in the process. Each call to * _dbus_connection_do_iteration_unlocked() 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. * * Called with connection lock held. * * @param connection the connection. * @param flags iteration flags. * @param timeout_milliseconds maximum blocking time, or -1 for no limit. */ void _dbus_connection_do_iteration_unlocked (DBusConnection *connection, unsigned int flags, int timeout_milliseconds) { _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); HAVE_LOCK_CHECK (connection); if (connection->n_outgoing == 0) flags &= ~DBUS_ITERATION_DO_WRITING; if (_dbus_connection_acquire_io_path (connection, (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0)) { HAVE_LOCK_CHECK (connection); _dbus_transport_do_iteration (connection->transport, flags, timeout_milliseconds); _dbus_connection_release_io_path (connection); } HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); } /** * 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 *pending_replies; DBusMutex *mutex; DBusMutex *io_path_mutex; DBusMutex *dispatch_mutex; DBusCondVar *message_returned_cond; DBusCondVar *dispatch_cond; DBusCondVar *io_path_cond; DBusList *disconnect_link; DBusMessage *disconnect_message; DBusCounter *outgoing_counter; DBusObjectTree *objects; watch_list = NULL; connection = NULL; pending_replies = NULL; timeout_list = NULL; mutex = NULL; io_path_mutex = NULL; dispatch_mutex = NULL; message_returned_cond = NULL; dispatch_cond = NULL; io_path_cond = NULL; disconnect_link = NULL; disconnect_message = NULL; outgoing_counter = NULL; objects = 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; pending_replies = _dbus_hash_table_new (DBUS_HASH_INT, NULL, (DBusFreeFunction)free_pending_call_on_hash_removal); 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; io_path_mutex = _dbus_mutex_new (); if (io_path_mutex == NULL) goto error; dispatch_mutex = _dbus_mutex_new (); if (dispatch_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_signal (DBUS_PATH_LOCAL, DBUS_INTERFACE_LOCAL, "Disconnected"); 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; objects = _dbus_object_tree_new (connection); if (objects == NULL) goto error; if (_dbus_modify_sigpipe) _dbus_disable_sigpipe (); connection->refcount.value = 1; connection->mutex = mutex; connection->dispatch_cond = dispatch_cond; connection->dispatch_mutex = dispatch_mutex; connection->io_path_cond = io_path_cond; connection->io_path_mutex = io_path_mutex; connection->transport = transport; connection->watches = watch_list; connection->timeouts = timeout_list; 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 */ connection->objects = objects; connection->exit_on_disconnect = FALSE; connection->shareable = FALSE; #ifndef DBUS_DISABLE_CHECKS connection->generation = _dbus_current_generation; #endif _dbus_data_slot_list_init (&connection->slot_list); connection->client_serial = 1; connection->disconnect_message_link = disconnect_link; CONNECTION_LOCK (connection); if (!_dbus_transport_set_connection (transport, connection)) goto error; _dbus_transport_ref (transport); CONNECTION_UNLOCK (connection); 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 (io_path_mutex != NULL) _dbus_mutex_free (io_path_mutex); if (dispatch_mutex != NULL) _dbus_mutex_free (dispatch_mutex); if (connection != NULL) dbus_free (connection); 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); if (objects) _dbus_object_tree_unref (objects); return NULL; } /** * Increments the reference count of a DBusConnection. * Requires that the caller already holds the connection lock. * * @param connection the connection. * @returns the connection. */ DBusConnection * _dbus_connection_ref_unlocked (DBusConnection *connection) { _dbus_assert (connection != NULL); _dbus_assert (connection->generation == _dbus_current_generation); HAVE_LOCK_CHECK (connection); #ifdef DBUS_HAVE_ATOMIC_INT _dbus_atomic_inc (&connection->refcount); #else _dbus_assert (connection->refcount.value > 0); connection->refcount.value += 1; #endif return connection; } /** * Decrements the reference count of a DBusConnection. * Requires that the caller already holds the connection lock. * * @param connection the connection. */ void _dbus_connection_unref_unlocked (DBusConnection *connection) { dbus_bool_t last_unref; HAVE_LOCK_CHECK (connection); _dbus_assert (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 _dbus_assert (connection->refcount.value > 0); connection->refcount.value -= 1; last_unref = (connection->refcount.value == 0); #if 0 printf ("unref_unlocked() connection %p count = %d\n", connection, connection->refcount.value); #endif #endif if (last_unref) _dbus_connection_last_unref (connection); } 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; } /** * 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; _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); CONNECTION_LOCK (connection); _dbus_connection_acquire_io_path (connection, -1); HAVE_LOCK_CHECK (connection); retval = _dbus_transport_handle_watch (connection->transport, watch, condition); _dbus_connection_release_io_path (connection); HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); return retval; } _DBUS_DEFINE_GLOBAL_LOCK (shared_connections); static DBusHashTable *shared_connections = NULL; static void shared_connections_shutdown (void *data) { _DBUS_LOCK (shared_connections); _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0); _dbus_hash_table_unref (shared_connections); shared_connections = NULL; _DBUS_UNLOCK (shared_connections); } static dbus_bool_t connection_lookup_shared (DBusAddressEntry *entry, DBusConnection **result) { _dbus_verbose ("checking for existing connection\n"); *result = NULL; _DBUS_LOCK (shared_connections); if (shared_connections == NULL) { _dbus_verbose ("creating shared_connections hash table\n"); shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING, dbus_free, NULL); if (shared_connections == NULL) { _DBUS_UNLOCK (shared_connections); return FALSE; } if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL)) { _dbus_hash_table_unref (shared_connections); shared_connections = NULL; _DBUS_UNLOCK (shared_connections); return FALSE; } _dbus_verbose (" successfully created shared_connections\n"); _DBUS_UNLOCK (shared_connections); return TRUE; /* no point looking up in the hash we just made */ } else { const char *guid; guid = dbus_address_entry_get_value (entry, "guid"); if (guid != NULL) { *result = _dbus_hash_table_lookup_string (shared_connections, guid); if (*result) { /* The DBusConnection can't have been disconnected * between the lookup and this code, because the * disconnection will take the shared_connections lock to * remove the connection. It can't have been finalized * since you have to disconnect prior to finalize. * * Thus it's safe to ref the connection. */ dbus_connection_ref (*result); _dbus_verbose ("looked up existing connection to server guid %s\n", guid); } } _DBUS_UNLOCK (shared_connections); return TRUE; } } static dbus_bool_t connection_record_shared_unlocked (DBusConnection *connection, const char *guid) { char *guid_key; char *guid_in_connection; /* A separate copy of the key is required in the hash table, because * we don't have a lock on the connection when we are doing a hash * lookup. */ _dbus_assert (connection->server_guid == NULL); _dbus_assert (connection->shareable); guid_key = _dbus_strdup (guid); if (guid_key == NULL) return FALSE; guid_in_connection = _dbus_strdup (guid); if (guid_in_connection == NULL) { dbus_free (guid_key); return FALSE; } _DBUS_LOCK (shared_connections); _dbus_assert (shared_connections != NULL); if (!_dbus_hash_table_insert_string (shared_connections, guid_key, connection)) { dbus_free (guid_key); dbus_free (guid_in_connection); _DBUS_UNLOCK (shared_connections); return FALSE; } connection->server_guid = guid_in_connection; _dbus_verbose ("stored connection to %s to be shared\n", connection->server_guid); _DBUS_UNLOCK (shared_connections); _dbus_assert (connection->server_guid != NULL); return TRUE; } static void connection_forget_shared_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); if (connection->server_guid == NULL) return; _dbus_verbose ("dropping connection to %s out of the shared table\n", connection->server_guid); _DBUS_LOCK (shared_connections); if (!_dbus_hash_table_remove_string (shared_connections, connection->server_guid)) _dbus_assert_not_reached ("connection was not in the shared table"); dbus_free (connection->server_guid); connection->server_guid = NULL; _DBUS_UNLOCK (shared_connections); } static DBusConnection* connection_try_from_address_entry (DBusAddressEntry *entry, DBusError *error) { DBusTransport *transport; DBusConnection *connection; transport = _dbus_transport_open (entry, 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_OOM (error); return NULL; } #ifndef DBUS_DISABLE_CHECKS _dbus_assert (!connection->have_connection_lock); #endif return connection; } /* * If the shared parameter is true, then any existing connection will * be used (and if a new connection is created, it will be available * for use by others). If the shared parameter is false, a new * connection will always be created, and the new connection will * never be returned to other callers. * * @param address the address * @param shared whether the connection is shared or private * @param error error return * @returns the connection or #NULL on error */ static DBusConnection* _dbus_connection_open_internal (const char *address, dbus_bool_t shared, DBusError *error) { DBusConnection *connection; DBusAddressEntry **entries; DBusError tmp_error; DBusError first_error; int len, i; _DBUS_ASSERT_ERROR_IS_CLEAR (error); _dbus_verbose ("opening %s connection to: %s\n", shared ? "shared" : "private", address); if (!dbus_parse_address (address, &entries, &len, error)) return NULL; _DBUS_ASSERT_ERROR_IS_CLEAR (error); connection = NULL; dbus_error_init (&tmp_error); dbus_error_init (&first_error); for (i = 0; i < len; i++) { if (shared) { if (!connection_lookup_shared (entries[i], &connection)) _DBUS_SET_OOM (&tmp_error); } if (connection == NULL) { connection = connection_try_from_address_entry (entries[i], &tmp_error); if (connection != NULL && shared) { const char *guid; connection->shareable = TRUE; guid = dbus_address_entry_get_value (entries[i], "guid"); /* we don't have a connection lock but we know nobody * else has a handle to the connection */ if (guid && !connection_record_shared_unlocked (connection, guid)) { _DBUS_SET_OOM (&tmp_error); dbus_connection_close (connection); dbus_connection_unref (connection); connection = NULL; } /* but as of now the connection is possibly shared * since another thread could have pulled it from the table */ } } if (connection) break; _DBUS_ASSERT_ERROR_IS_SET (&tmp_error); if (i == 0) dbus_move_error (&tmp_error, &first_error); else dbus_error_free (&tmp_error); } /* NOTE we don't have a lock on a possibly-shared connection object */ _DBUS_ASSERT_ERROR_IS_CLEAR (error); _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error); if (connection == NULL) { _DBUS_ASSERT_ERROR_IS_SET (&first_error); dbus_move_error (&first_error, error); } else { dbus_error_free (&first_error); } dbus_address_entries_free (entries); return connection; } /** @} */ /** * @addtogroup DBusConnection * * @{ */ /** * Gets a connection to a remote address. If a connection to the given * address already exists, returns the existing connection with its * reference count incremented. Otherwise, returns a new connection * and saves the new connection for possible re-use if a future call * to dbus_connection_open() asks to connect to the same server. * * Use dbus_connection_open_private() to get a dedicated connection * not shared with other callers of dbus_connection_open(). * * If the open fails, the function returns #NULL, and provides a * reason for the failure in the error parameter. Pass #NULL for the * error 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; _dbus_return_val_if_fail (address != NULL, NULL); _dbus_return_val_if_error_is_set (error, NULL); connection = _dbus_connection_open_internal (address, TRUE, error); return connection; } /** * Opens a new, dedicated connection to a remote address. Unlike * dbus_connection_open(), always creates a new connection. * This connection will not be saved or recycled by libdbus. * * If the open fails, the function returns #NULL, and provides a * reason for the failure in the error parameter. Pass #NULL for the * error 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_private (const char *address, DBusError *error) { DBusConnection *connection; _dbus_return_val_if_fail (address != NULL, NULL); _dbus_return_val_if_error_is_set (error, NULL); connection = _dbus_connection_open_internal (address, FALSE, error); return connection; } /** * Increments the reference count of a DBusConnection. * * @param connection the connection. * @returns the connection. */ DBusConnection * dbus_connection_ref (DBusConnection *connection) { _dbus_return_val_if_fail (connection != NULL, NULL); _dbus_return_val_if_fail (connection->generation == _dbus_current_generation, 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 return connection; } 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) { 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)); _dbus_assert (connection->server_guid == NULL); /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */ _dbus_object_tree_free_all_unlocked (connection->objects); 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); link = _dbus_list_get_first_link (&connection->filter_list); while (link != NULL) { DBusMessageFilter *filter = link->data; DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link); filter->function = NULL; _dbus_message_filter_unref (filter); /* calls app callback */ link->data = NULL; link = next; } _dbus_list_clear (&connection->filter_list); /* ---- Done with stuff that invokes application callbacks */ _dbus_object_tree_unref (connection->objects); _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_mutex_free (connection->io_path_mutex); _dbus_mutex_free (connection->dispatch_mutex); _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); _dbus_return_if_fail (connection->generation == _dbus_current_generation); /* 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 "reopen" a connection, a * new connection must be created. This function may result in a call * to the DBusDispatchStatusFunction set with * dbus_connection_set_dispatch_status_function(), as the disconnect * message it generates needs to be dispatched. * * @param connection the connection. */ void dbus_connection_close (DBusConnection *connection) { DBusDispatchStatus status; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (connection->generation == _dbus_current_generation); _dbus_verbose ("Disconnecting %p\n", connection); CONNECTION_LOCK (connection); _dbus_transport_disconnect (connection->transport); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); } /** Alias for dbus_connection_close(). This method is DEPRECATED and will be * removed for 1.0. Change your code to use dbus_connection_close() instead. * * @param connection the connection. * @deprecated */ void dbus_connection_disconnect (DBusConnection *connection) { dbus_connection_close (connection); } static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (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_close(). * * @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; } /** * Set whether _exit() should be called when the connection receives a * disconnect signal. The call to _exit() comes after any handlers for * the disconnect signal run; handlers can cancel the exit by calling * this function. * * By default, exit_on_disconnect is #FALSE; but for message bus * connections returned from dbus_bus_get() it will be toggled on * by default. * * @param connection the connection * @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal */ void dbus_connection_set_exit_on_disconnect (DBusConnection *connection, dbus_bool_t exit_on_disconnect) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); connection->exit_on_disconnect = exit_on_disconnect != FALSE; CONNECTION_UNLOCK (connection); } static DBusPreallocatedSend* _dbus_connection_preallocate_send_unlocked (DBusConnection *connection) { DBusPreallocatedSend *preallocated; HAVE_LOCK_CHECK (connection); _dbus_assert (connection != 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); } /* Called with lock held, does not update dispatch status */ static void _dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { dbus_uint32_t serial; const char *sig; 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; sig = dbus_message_get_signature (message); _dbus_verbose ("Message %p (%d %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n", message, dbus_message_get_type (message), dbus_message_get_path (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", sig, dbus_message_get_destination (message) ? dbus_message_get_destination (message) : "null", 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_verbose ("Message %p serial is %u\n", message, dbus_message_get_serial (message)); _dbus_message_lock (message); /* Now we need to run an iteration to hopefully just write the messages * out immediately, and otherwise get them queued up */ _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_WRITING, -1); /* If stuff is still queued up, be sure we wake up the main loop */ if (connection->n_outgoing > 0) _dbus_connection_wakeup_mainloop (connection); } static void _dbus_connection_send_preallocated_and_unlock (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { DBusDispatchStatus status; HAVE_LOCK_CHECK (connection); _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, message, client_serial); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); } /** * 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_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL || (dbus_message_get_interface (message) != NULL && dbus_message_get_member (message) != NULL)); _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL || (dbus_message_get_interface (message) != NULL && dbus_message_get_member (message) != NULL)); CONNECTION_LOCK (connection); _dbus_connection_send_preallocated_and_unlock (connection, preallocated, message, client_serial); } static dbus_bool_t _dbus_connection_send_unlocked_no_update (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *client_serial) { DBusPreallocatedSend *preallocated; _dbus_assert (connection != NULL); _dbus_assert (message != NULL); preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) return FALSE; _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, message, client_serial); return TRUE; } dbus_bool_t _dbus_connection_send_and_unlock (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *client_serial) { DBusPreallocatedSend *preallocated; _dbus_assert (connection != NULL); _dbus_assert (message != NULL); preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) { CONNECTION_UNLOCK (connection); return FALSE; } _dbus_connection_send_preallocated_and_unlock (connection, preallocated, message, client_serial); return TRUE; } /** * 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) { _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); CONNECTION_LOCK (connection); return _dbus_connection_send_and_unlock (connection, message, client_serial); } static dbus_bool_t reply_handler_timeout (void *data) { DBusConnection *connection; DBusDispatchStatus status; DBusPendingCall *pending = data; connection = pending->connection; CONNECTION_LOCK (connection); if (pending->timeout_link) { _dbus_connection_queue_synthesized_message_link (connection, pending->timeout_link); pending->timeout_link = NULL; } _dbus_connection_remove_timeout (connection, pending->timeout); pending->timeout_added = FALSE; _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); 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; } /** * Queues a message to send, as with dbus_connection_send_message(), * but also returns a #DBusPendingCall used to receive a reply to the * message. If no reply is received in the given timeout_milliseconds, * this function expires the pending reply and generates a synthetic * error reply (generated in-process, not by the remote application) * indicating that a timeout occurred. * * A #DBusPendingCall will see a reply message after any filters, but * before any object instances or other handlers. A #DBusPendingCall * will always see exactly one reply message, unless it's cancelled * with dbus_pending_call_cancel(). * * 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 * #DBusPendingCall will get confused. Filtering the timeout error * is thus considered a bug and will print a warning. * * If #NULL is passed for the pending_return, the #DBusPendingCall * will still be generated internally, and used to track * the message reply timeout. This means a timeout error will * occur if no reply arrives, unlike with dbus_connection_send(). * * 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 pending_return return location for a #DBusPendingCall object, 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, DBusPendingCall **pending_return, int timeout_milliseconds) { DBusPendingCall *pending; DBusMessage *reply; DBusList *reply_link; dbus_int32_t serial = -1; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); if (pending_return) *pending_return = NULL; pending = _dbus_pending_call_new (connection, timeout_milliseconds, reply_handler_timeout); if (pending == NULL) return FALSE; CONNECTION_LOCK (connection); /* 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); } pending->reply_serial = serial; reply = dbus_message_new_error (message, DBUS_ERROR_NO_REPLY, "No reply within specified time"); if (reply == NULL) goto error; reply_link = _dbus_list_alloc_link (reply); if (reply_link == NULL) { CONNECTION_UNLOCK (connection); dbus_message_unref (reply); goto error_unlocked; } pending->timeout_link = reply_link; /* Insert the serial in the pending replies hash; * hash takes a refcount on DBusPendingCall. * Also, add the timeout. */ if (!_dbus_connection_attach_pending_call_unlocked (connection, pending)) goto error; if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL)) { _dbus_connection_detach_pending_call_and_unlock (connection, pending); goto error_unlocked; } if (pending_return) *pending_return = pending; else { _dbus_connection_detach_pending_call_unlocked (connection, pending); dbus_pending_call_unref (pending); } _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return TRUE; error: CONNECTION_UNLOCK (connection); error_unlocked: dbus_pending_call_unref (pending); return FALSE; } /* This is slightly strange since we can pop a message here without * the dispatch lock. */ static DBusMessage* check_for_reply_unlocked (DBusConnection *connection, dbus_uint32_t client_serial) { DBusList *link; HAVE_LOCK_CHECK (connection); 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; return reply; } link = _dbus_list_get_next_link (&connection->incoming_messages, link); } return NULL; } /** * When a function that blocks has been called with a timeout, and we * run out of memory, the time to wait for memory is based on the * timeout. If the caller was willing to block a long time we wait a * relatively long time for memory, if they were only willing to block * briefly then we retry for memory at a rapid rate. * * @timeout_milliseconds the timeout requested for blocking */ static void _dbus_memory_pause_based_on_timeout (int timeout_milliseconds) { if (timeout_milliseconds == -1) _dbus_sleep_milliseconds (1000); else if (timeout_milliseconds < 100) ; /* just busy loop */ else if (timeout_milliseconds <= 1000) _dbus_sleep_milliseconds (timeout_milliseconds / 3); else _dbus_sleep_milliseconds (1000); } /** * Blocks until a pending call times out or gets a reply. * * Does not re-enter the main loop or run filter/path-registered * callbacks. The reply to the message will not be seen by * filter callbacks. * * Returns immediately if pending call already got a reply. * * @todo could use performance improvements (it keeps scanning * the whole message queue for example) * * @param pending the pending call we block for a reply on */ void _dbus_connection_block_pending_call (DBusPendingCall *pending) { long start_tv_sec, start_tv_usec; long end_tv_sec, end_tv_usec; long tv_sec, tv_usec; DBusDispatchStatus status; DBusConnection *connection; dbus_uint32_t client_serial; int timeout_milliseconds; _dbus_assert (pending != NULL); if (dbus_pending_call_get_completed (pending)) return; if (pending->connection == NULL) return; /* call already detached */ dbus_pending_call_ref (pending); /* necessary because the call could be canceled */ connection = pending->connection; client_serial = pending->reply_serial; /* note that timeout_milliseconds is limited to a smallish value * in _dbus_pending_call_new() so overflows aren't possible * below */ timeout_milliseconds = dbus_timeout_get_interval (pending->timeout); /* 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... */ /* always block at least once as we know we don't have the reply yet */ _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK, timeout_milliseconds); recheck_status: _dbus_verbose ("%s top of recheck\n", _DBUS_FUNCTION_NAME); HAVE_LOCK_CHECK (connection); /* queue messages and get status */ status = _dbus_connection_get_dispatch_status_unlocked (connection); /* the get_completed() is in case a dispatch() while we were blocking * got the reply instead of us. */ if (dbus_pending_call_get_completed (pending)) { _dbus_verbose ("Pending call completed by dispatch in %s\n", _DBUS_FUNCTION_NAME); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_pending_call_unref (pending); return; } if (status == DBUS_DISPATCH_DATA_REMAINS) { DBusMessage *reply; reply = check_for_reply_unlocked (connection, client_serial); if (reply != NULL) { _dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME); _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n"); _dbus_pending_call_complete_and_unlock (pending, reply); dbus_message_unref (reply); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_pending_call_unref (pending); return; } } _dbus_get_current_time (&tv_sec, &tv_usec); if (!_dbus_connection_get_is_connected_unlocked (connection)) { /* FIXME send a "DBUS_ERROR_DISCONNECTED" instead, just to help * programmers understand what went wrong since the timeout is * confusing */ _dbus_pending_call_complete_and_unlock (pending, NULL); dbus_pending_call_unref (pending); return; } else 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"); _dbus_memory_pause_based_on_timeout (timeout_milliseconds); } else { /* block again, we don't have the reply buffered yet. */ _dbus_connection_do_iteration_unlocked (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); _dbus_assert (!dbus_pending_call_get_completed (pending)); /* unlock and call user code */ _dbus_pending_call_complete_and_unlock (pending, NULL); /* update user code on dispatch status */ CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_pending_call_unref (pending); } /** * Sends a message and blocks a certain time period while waiting for * a reply. This function does not reenter the main loop, * i.e. messages other than the reply are queued up but not * processed. This function is used to do non-reentrant "method * calls." * * If a normal 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 an error reply is * received, it is converted to a #DBusError and returned as an error, * then the reply message is deleted. If something else goes wrong, * result is set to whatever is appropriate, such as * #DBUS_ERROR_NO_MEMORY or #DBUS_ERROR_DISCONNECTED. * * @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) { DBusMessage *reply; DBusPendingCall *pending; _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 (!dbus_connection_send_with_reply (connection, message, &pending, timeout_milliseconds)) { _DBUS_SET_OOM (error); return NULL; } _dbus_assert (pending != NULL); dbus_pending_call_block (pending); reply = dbus_pending_call_steal_reply (pending); dbus_pending_call_unref (pending); /* call_complete_and_unlock() called from pending_call_block() should * always fill this in. */ _dbus_assert (reply != NULL); if (dbus_set_error_from_message (error, reply)) { dbus_message_unref (reply); return NULL; } else return reply; } /** * 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_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME); HAVE_LOCK_CHECK (connection); _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_DO_WRITING | DBUS_ITERATION_BLOCK, -1); } HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); HAVE_LOCK_CHECK (connection); /* Unlocks and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); } /** * This function is intended for use with applications that don't want * to write a main loop and deal with #DBusWatch and #DBusTimeout. An * example usage would be: * * @code * while (dbus_connection_read_write_dispatch (connection, -1)) * ; // empty loop body * @endcode * * In this usage you would normally have set up a filter function to look * at each message as it is dispatched. The loop terminates when the last * message from the connection (the disconnected signal) is processed. * * If there are messages to dispatch, this function will * dbus_connection_dispatch() once, and return. If there are no * messages to dispatch, this function will block until it can read or * write, then read or write, then return. * * The way to think of this function is that it either makes some sort * of progress, or it blocks. * * The return value indicates whether the disconnect message has been * processed, NOT whether the connection is connected. This is * important because even after disconnecting, you want to process any * messages you received prior to the disconnect. * * @param connection the connection * @param timeout_milliseconds max time to block or -1 for infinite * @returns #TRUE if the disconnect message has not been processed */ dbus_bool_t dbus_connection_read_write_dispatch (DBusConnection *connection, int timeout_milliseconds) { DBusDispatchStatus dstatus; dbus_bool_t dispatched_disconnected; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); dstatus = dbus_connection_get_dispatch_status (connection); if (dstatus == DBUS_DISPATCH_DATA_REMAINS) { _dbus_verbose ("doing dispatch in %s\n", _DBUS_FUNCTION_NAME); dbus_connection_dispatch (connection); CONNECTION_LOCK (connection); } else if (dstatus == DBUS_DISPATCH_NEED_MEMORY) { _dbus_verbose ("pausing for memory in %s\n", _DBUS_FUNCTION_NAME); _dbus_memory_pause_based_on_timeout (timeout_milliseconds); CONNECTION_LOCK (connection); } else { CONNECTION_LOCK (connection); if (_dbus_connection_get_is_connected_unlocked (connection)) { _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME); _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_DO_WRITING | DBUS_ITERATION_BLOCK, timeout_milliseconds); } } HAVE_LOCK_CHECK (connection); dispatched_disconnected = connection->n_incoming == 0 && connection->disconnect_message_link == NULL; CONNECTION_UNLOCK (connection); return !dispatched_disconnected; /* TRUE if we have not processed disconnected */ } /** * 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. * * dbus_connection_dispatch() will block if called while a borrowed * message is outstanding; only one piece of code can be playing with * the incoming queue at a time. This function will block if called * during a dbus_connection_dispatch(). * * @param connection the connection. * @returns next message in the incoming queue. */ DBusMessage* dbus_connection_borrow_message (DBusConnection *connection) { DBusDispatchStatus status; DBusMessage *message; _dbus_return_val_if_fail (connection != NULL, NULL); _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); /* 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); _dbus_connection_acquire_dispatch (connection); /* While a message is outstanding, the dispatch lock is held */ _dbus_assert (connection->message_borrowed == NULL); connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages); message = connection->message_borrowed; /* Note that we KEEP the dispatch lock until the message is returned */ if (message == NULL) _dbus_connection_release_dispatch (connection); CONNECTION_UNLOCK (connection); return message; } /** * Used to return a message after peeking at it using * dbus_connection_borrow_message(). Only called if * message from dbus_connection_borrow_message() was non-#NULL. * * @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); _dbus_return_if_fail (message == connection->message_borrowed); _dbus_return_if_fail (connection->dispatch_acquired); CONNECTION_LOCK (connection); _dbus_assert (message == connection->message_borrowed); connection->message_borrowed = NULL; _dbus_connection_release_dispatch (connection); 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); _dbus_return_if_fail (message == connection->message_borrowed); _dbus_return_if_fail (connection->dispatch_acquired); 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_connection_release_dispatch (connection); 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) { HAVE_LOCK_CHECK (connection); _dbus_assert (connection->message_borrowed == NULL); if (connection->n_incoming > 0) { DBusList *link; link = _dbus_list_pop_first_link (&connection->incoming_messages); connection->n_incoming -= 1; _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from incoming queue %p, %d incoming\n", link->data, dbus_message_get_type (link->data), dbus_message_get_path (link->data), dbus_message_get_interface (link->data) ? dbus_message_get_interface (link->data) : "no interface", dbus_message_get_member (link->data) ? dbus_message_get_member (link->data) : "no member", dbus_message_get_signature (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; HAVE_LOCK_CHECK (connection); 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; } static void _dbus_connection_putback_message_link_unlocked (DBusConnection *connection, DBusList *message_link) { HAVE_LOCK_CHECK (connection); _dbus_assert (message_link != NULL); /* You can't borrow a message while a link is outstanding */ _dbus_assert (connection->message_borrowed == NULL); /* We had to have the dispatch lock across the pop/putback */ _dbus_assert (connection->dispatch_acquired); _dbus_list_prepend_link (&connection->incoming_messages, message_link); connection->n_incoming += 1; _dbus_verbose ("Message %p (%d %s %s '%s') put back into queue %p, %d incoming\n", message_link->data, dbus_message_get_type (message_link->data), dbus_message_get_interface (message_link->data) ? dbus_message_get_interface (message_link->data) : "no interface", dbus_message_get_member (message_link->data) ? dbus_message_get_member (message_link->data) : "no member", dbus_message_get_signature (message_link->data), connection, connection->n_incoming); } /** * 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. * * There is a lock that covers all ways of accessing the incoming message * queue, so dbus_connection_dispatch(), dbus_connection_pop_message(), * dbus_connection_borrow_message(), etc. will all block while one of the others * in the group is running. * * @param connection the connection. * @returns next message in the incoming queue. */ DBusMessage* dbus_connection_pop_message (DBusConnection *connection) { DBusMessage *message; DBusDispatchStatus status; _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); /* 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); _dbus_connection_acquire_dispatch (connection); HAVE_LOCK_CHECK (connection); message = _dbus_connection_pop_message_unlocked (connection); _dbus_verbose ("Returning popped message %p\n", message); _dbus_connection_release_dispatch (connection); CONNECTION_UNLOCK (connection); return message; } /** * Acquire the dispatcher. This is a separate lock so the main * connection lock can be dropped to call out to application dispatch * handlers. * * @param connection the connection. */ static void _dbus_connection_acquire_dispatch (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); _dbus_connection_ref_unlocked (connection); CONNECTION_UNLOCK (connection); _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->dispatch_mutex); while (connection->dispatch_acquired) { _dbus_verbose ("%s waiting for dispatch to be acquirable\n", _DBUS_FUNCTION_NAME); _dbus_condvar_wait (connection->dispatch_cond, connection->dispatch_mutex); } _dbus_assert (!connection->dispatch_acquired); connection->dispatch_acquired = TRUE; _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->dispatch_mutex); CONNECTION_LOCK (connection); _dbus_connection_unref_unlocked (connection); } /** * 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) { HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->dispatch_mutex); _dbus_assert (connection->dispatch_acquired); connection->dispatch_acquired = FALSE; _dbus_condvar_wake_one (connection->dispatch_cond); _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->dispatch_mutex); } 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) { HAVE_LOCK_CHECK (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; dbus_bool_t is_connected; status = _dbus_transport_get_dispatch_status (connection->transport); is_connected = _dbus_transport_get_is_connected (connection->transport); _dbus_verbose ("dispatch status = %s is_connected = %d\n", DISPATCH_STATUS_NAME (status), is_connected); if (!is_connected) { if (status == DBUS_DISPATCH_COMPLETE && connection->disconnect_message_link) { _dbus_verbose ("Sending disconnect message from %s\n", _DBUS_FUNCTION_NAME); connection_forget_shared_unlocked (connection); /* We haven't sent the disconnect message already, * and all real messages have been queued up. */ _dbus_connection_queue_synthesized_message_link (connection, connection->disconnect_message_link); connection->disconnect_message_link = NULL; } /* Dump the outgoing queue, we aren't going to be able to * send it now, and we'd like accessors like * dbus_connection_get_outgoing_size() to be accurate. */ if (connection->n_outgoing > 0) { DBusList *link; _dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n", connection->n_outgoing); while ((link = _dbus_list_get_last_link (&connection->outgoing_messages))) { _dbus_connection_message_sent (connection, link->data); } } } 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; HAVE_LOCK_CHECK (connection); _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, DISPATCH_STATUS_NAME (new_status)); (* 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); _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); CONNECTION_UNLOCK (connection); return status; } /** * Filter funtion for handling the Peer standard interface **/ static DBusHandlerResult _dbus_connection_peer_filter (DBusConnection *connection, DBusMessage *message) { if (dbus_message_is_method_call (message, DBUS_INTERFACE_PEER, "Ping")) { DBusMessage *ret; dbus_bool_t sent; ret = dbus_message_new_method_return (message); if (ret == NULL) return DBUS_HANDLER_RESULT_NEED_MEMORY; sent = dbus_connection_send (connection, ret, NULL); dbus_message_unref (ret); if (!sent) return DBUS_HANDLER_RESULT_NEED_MEMORY; return DBUS_HANDLER_RESULT_HANDLED; } return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; } /** * Processes all builtin filter functions * * If the spec specifies a standard interface * they should be processed from this method **/ static DBusHandlerResult _dbus_connection_run_builtin_filters (DBusConnection *connection, DBusMessage *message) { /* We just run one filter for now but have the option to run more if the spec calls for it in the future */ return _dbus_connection_peer_filter (connection, message); } /** * 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. * * @todo some FIXME in here about handling DBUS_HANDLER_RESULT_NEED_MEMORY * * @todo FIXME what if we call out to application code to handle a * message, holding the dispatch lock, and the application code runs * the main loop and dispatches again? Probably deadlocks at the * moment. Maybe we want a dispatch status of DBUS_DISPATCH_IN_PROGRESS, * and then the GSource etc. could handle the situation? Right now * our GSource is NO_RECURSE * * @param connection the connection * @returns dispatch status */ DBusDispatchStatus dbus_connection_dispatch (DBusConnection *connection) { DBusMessage *message; DBusList *link, *filter_list_copy, *message_link; DBusHandlerResult result; DBusPendingCall *pending; dbus_int32_t reply_serial; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); _dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME); 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); HAVE_LOCK_CHECK (connection); message_link = _dbus_connection_pop_message_link_unlocked (connection); if (message_link == NULL) { /* another thread dispatched our stuff */ _dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n"); _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; _dbus_verbose (" dispatching message %p (%d %s %s '%s')\n", message, dbus_message_get_type (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message)); result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED; /* Pending call handling must be first, because if you do * dbus_connection_send_with_reply_and_block() or * dbus_pending_call_block() then no handlers/filters will be run on * the reply. We want consistent semantics in the case where we * dbus_connection_dispatch() the reply. */ reply_serial = dbus_message_get_reply_serial (message); pending = _dbus_hash_table_lookup_int (connection->pending_replies, reply_serial); if (pending) { _dbus_verbose ("Dispatching a pending reply\n"); _dbus_pending_call_complete_and_unlock (pending, message); pending = NULL; /* it's probably unref'd */ CONNECTION_LOCK (connection); _dbus_verbose ("pending call completed in dispatch\n"); result = DBUS_HANDLER_RESULT_HANDLED; goto out; } result = _dbus_connection_run_builtin_filters (connection, message); if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) goto out; if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy)) { _dbus_connection_release_dispatch (connection); HAVE_LOCK_CHECK (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); if (pending) dbus_pending_call_unref (pending); dbus_connection_unref (connection); return DBUS_DISPATCH_NEED_MEMORY; } _dbus_list_foreach (&filter_list_copy, (DBusForeachFunction)_dbus_message_filter_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) { DBusMessageFilter *filter = link->data; DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link); _dbus_verbose (" running filter on message %p\n", message); result = (* filter->function) (connection, message, filter->user_data); if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) break; link = next; } _dbus_list_foreach (&filter_list_copy, (DBusForeachFunction)_dbus_message_filter_unref, NULL); _dbus_list_clear (&filter_list_copy); CONNECTION_LOCK (connection); if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) { _dbus_verbose ("No memory in %s\n", _DBUS_FUNCTION_NAME); goto out; } else if (result == DBUS_HANDLER_RESULT_HANDLED) { _dbus_verbose ("filter handled message in dispatch\n"); goto out; } /* We're still protected from dispatch() reentrancy here * since we acquired the dispatcher */ _dbus_verbose (" running object path dispatch on message %p (%d %s %s '%s')\n", message, dbus_message_get_type (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message)); HAVE_LOCK_CHECK (connection); result = _dbus_object_tree_dispatch_and_unlock (connection->objects, message); CONNECTION_LOCK (connection); if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) { _dbus_verbose ("object tree handled message in dispatch\n"); goto out; } if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL) { DBusMessage *reply; DBusString str; DBusPreallocatedSend *preallocated; _dbus_verbose (" sending error %s\n", DBUS_ERROR_UNKNOWN_METHOD); if (!_dbus_string_init (&str)) { result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error string in dispatch\n"); goto out; } if (!_dbus_string_append_printf (&str, "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n", dbus_message_get_member (message), dbus_message_get_signature (message), dbus_message_get_interface (message))) { _dbus_string_free (&str); result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error string in dispatch\n"); goto out; } reply = dbus_message_new_error (message, DBUS_ERROR_UNKNOWN_METHOD, _dbus_string_get_const_data (&str)); _dbus_string_free (&str); if (reply == NULL) { result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error reply in dispatch\n"); goto out; } preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) { dbus_message_unref (reply); result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error send in dispatch\n"); goto out; } _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, reply, NULL); dbus_message_unref (reply); result = DBUS_HANDLER_RESULT_HANDLED; } _dbus_verbose (" done dispatching %p (%d %s %s '%s') on connection %p\n", message, dbus_message_get_type (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message), connection); out: if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) { _dbus_verbose ("out of memory in %s\n", _DBUS_FUNCTION_NAME); /* Put message back, and we'll start over. * Yes this means handlers must be idempotent if they * don't return HANDLED; c'est la vie. */ _dbus_connection_putback_message_link_unlocked (connection, message_link); } else { _dbus_verbose (" ... done dispatching in %s\n", _DBUS_FUNCTION_NAME); if (connection->exit_on_disconnect && dbus_message_is_signal (message, DBUS_INTERFACE_LOCAL, "Disconnected")) { _dbus_verbose ("Exiting on Disconnected signal\n"); CONNECTION_UNLOCK (connection); _dbus_exit (1); _dbus_assert_not_reached ("Call to exit() returned"); } _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 below */ } _dbus_connection_release_dispatch (connection); HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s before final status update\n", _DBUS_FUNCTION_NAME); 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; DBusWatchList *watches; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (connection->watches == NULL) { _dbus_warn ("Re-entrant call to %s is not allowed\n", _DBUS_FUNCTION_NAME); return FALSE; } #endif /* ref connection for slightly better reentrancy */ _dbus_connection_ref_unlocked (connection); /* This can call back into user code, and we need to drop the * connection lock when it does. This is kind of a lame * way to do it. */ watches = connection->watches; connection->watches = NULL; CONNECTION_UNLOCK (connection); retval = _dbus_watch_list_set_functions (watches, add_function, remove_function, toggled_function, data, free_data_function); CONNECTION_LOCK (connection); connection->watches = watches; 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; DBusTimeoutList *timeouts; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (connection->timeouts == NULL) { _dbus_warn ("Re-entrant call to %s is not allowed\n", _DBUS_FUNCTION_NAME); return FALSE; } #endif /* ref connection for slightly better reentrancy */ _dbus_connection_ref_unlocked (connection); timeouts = connection->timeouts; connection->timeouts = NULL; CONNECTION_UNLOCK (connection); retval = _dbus_timeout_list_set_functions (timeouts, add_function, remove_function, toggled_function, data, free_data_function); CONNECTION_LOCK (connection); connection->timeouts = timeouts; 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); } /** * Get the UNIX file descriptor of the connection, if any. This can * be used for SELinux access control checks with getpeercon() for * example. DO NOT read or write to the file descriptor, or try to * select() on it; use DBusWatch for main loop integration. Not all * connections will have a file descriptor. So for adding descriptors * to the main loop, use dbus_watch_get_fd() and so forth. * * @param connection the connection * @param fd return location for the file descriptor. * @returns #TRUE if fd is successfully obtained. */ dbus_bool_t dbus_connection_get_unix_fd (DBusConnection *connection, int *fd) { dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (connection->transport != NULL, FALSE); CONNECTION_LOCK (connection); retval = _dbus_transport_get_unix_fd (connection->transport, fd); CONNECTION_UNLOCK (connection); return retval; } /** * 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; } /** * Gets the process ID of the connection if any. * Returns #TRUE if the uid is filled in. * Always returns #FALSE prior to authenticating the * connection. * * @param connection the connection * @param pid return location for the process ID * @returns #TRUE if uid is filled in with a valid process ID */ dbus_bool_t dbus_connection_get_unix_process_id (DBusConnection *connection, unsigned long *pid) { dbus_bool_t result; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (pid != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_transport_get_is_authenticated (connection->transport)) result = FALSE; else result = _dbus_transport_get_unix_process_id (connection->transport, pid); 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 objects registered with * dbus_connection_register_object_path(). 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. * * @todo we don't run filters on messages while blocking without * entering the main loop, since filters are run as part of * dbus_connection_dispatch(). This is probably a feature, as filters * could create arbitrary reentrancy. But kind of sucks if you're * trying to filter METHOD_RETURN for some reason. * * @param connection the connection * @param function function to handle messages * @param user_data user data to pass to the function * @param free_data_function function to use for freeing user data * @returns #TRUE on success, #FALSE if not enough memory. */ dbus_bool_t dbus_connection_add_filter (DBusConnection *connection, DBusHandleMessageFunction function, void *user_data, DBusFreeFunction free_data_function) { DBusMessageFilter *filter; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (function != NULL, FALSE); filter = dbus_new0 (DBusMessageFilter, 1); if (filter == NULL) return FALSE; filter->refcount.value = 1; CONNECTION_LOCK (connection); if (!_dbus_list_append (&connection->filter_list, filter)) { _dbus_message_filter_unref (filter); CONNECTION_UNLOCK (connection); return FALSE; } /* Fill in filter after all memory allocated, * so we don't run the free_user_data_function * if the add_filter() fails */ filter->function = function; filter->user_data = user_data; filter->free_user_data_function = free_data_function; 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 function the handler to remove * @param user_data user data for the handler to remove * */ void dbus_connection_remove_filter (DBusConnection *connection, DBusHandleMessageFunction function, void *user_data) { DBusList *link; DBusMessageFilter *filter; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (function != NULL); CONNECTION_LOCK (connection); filter = NULL; link = _dbus_list_get_last_link (&connection->filter_list); while (link != NULL) { filter = link->data; if (filter->function == function && filter->user_data == user_data) { _dbus_list_remove_link (&connection->filter_list, link); filter->function = NULL; break; } link = _dbus_list_get_prev_link (&connection->filter_list, link); } CONNECTION_UNLOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (filter == NULL) { _dbus_warn ("Attempt to remove filter function %p user data %p, but no such filter has been added\n", function, user_data); return; } #endif /* Call application code */ if (filter->free_user_data_function) (* filter->free_user_data_function) (filter->user_data); filter->free_user_data_function = NULL; filter->user_data = NULL; _dbus_message_filter_unref (filter); } /** * Registers a handler for a given path in the object hierarchy. * The given vtable handles messages sent to exactly the given path. * * * @param connection the connection * @param path a '/' delimited string of path elements * @param vtable the virtual table * @param user_data data to pass to functions in the vtable * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_register_object_path (DBusConnection *connection, const char *path, const DBusObjectPathVTable *vtable, void *user_data) { char **decomposed_path; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); _dbus_return_val_if_fail (vtable != NULL, FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_register (connection->objects, FALSE, (const char **) decomposed_path, vtable, user_data); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); return retval; } /** * Registers a fallback handler for a given subsection of the object * hierarchy. The given vtable handles messages at or below the given * path. You can use this to establish a default message handling * policy for a whole "subdirectory." * * @param connection the connection * @param path a '/' delimited string of path elements * @param vtable the virtual table * @param user_data data to pass to functions in the vtable * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_register_fallback (DBusConnection *connection, const char *path, const DBusObjectPathVTable *vtable, void *user_data) { char **decomposed_path; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); _dbus_return_val_if_fail (vtable != NULL, FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_register (connection->objects, TRUE, (const char **) decomposed_path, vtable, user_data); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); return retval; } /** * Unregisters the handler registered with exactly the given path. * It's a bug to call this function for a path that isn't registered. * Can unregister both fallback paths and object paths. * * @param connection the connection * @param path a '/' delimited string of path elements * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_unregister_object_path (DBusConnection *connection, const char *path) { char **decomposed_path; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); _dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path); dbus_free_string_array (decomposed_path); return TRUE; } /** * Gets the user data passed to dbus_connection_register_object_path() * or dbus_connection_register_fallback(). If nothing was registered * at this path, the data is filled in with #NULL. * * @param connection the connection * @param path the path you registered with * @param data_p location to store the user data, or #NULL * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_get_object_path_data (DBusConnection *connection, const char *path, void **data_p) { char **decomposed_path; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (data_p != NULL, FALSE); *data_p = NULL; if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); *data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); return TRUE; } /** * Lists the registered fallback handlers and object path handlers at * the given parent_path. The returned array should be freed with * dbus_free_string_array(). * * @param connection the connection * @param parent_path the path to list the child handlers of * @param child_entries returns #NULL-terminated array of children * @returns #FALSE if no memory to allocate the child entries */ dbus_bool_t dbus_connection_list_registered (DBusConnection *connection, const char *parent_path, char ***child_entries) { char **decomposed_path; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (parent_path != NULL, FALSE); _dbus_return_val_if_fail (parent_path[0] == '/', FALSE); _dbus_return_val_if_fail (child_entries != NULL, FALSE); if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_list_registered_and_unlock (connection->objects, (const char **) decomposed_path, child_entries); dbus_free_string_array (decomposed_path); return retval; } 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; } /** @} */