* 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.
+ * Several functions use the following terms:
+ * <ul>
+ * <li><b>read</b> means to fill the incoming message queue by reading from the socket</li>
+ * <li><b>write</b> means to drain the outgoing queue by writing to the socket</li>
+ * <li><b>dispatch</b> means to drain the incoming queue by invoking application-provided message handlers</li>
+ * </ul>
+ *
+ * The function dbus_connection_read_write_dispatch() for example does all
+ * three of these things, offering a simple alternative to a main loop.
+ *
+ * In an application with a main loop, the read/write/dispatch
+ * operations are usually separate.
+ *
+ * The connection provides #DBusWatch and #DBusTimeout objects to
+ * the main loop. These are used to know when reading, writing, or
+ * dispatching should be performed.
+ *
+ * Incoming messages are 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(),
+ * If you aren't using these add-on libraries, but want to process
+ * messages asynchronously, you must 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.
+ * loop. This can be tricky to get right; main loops are not simple.
+ *
+ * If you don't need to be asynchronous, you can ignore #DBusWatch,
+ * #DBusTimeout, and dbus_connection_dispatch(). Instead,
+ * dbus_connection_read_write_dispatch() can be used.
*
+ * Or, in <em>very</em> simple applications,
+ * dbus_connection_pop_message() may be all you need, allowing you to
+ * avoid setting up any handler functions (see
+ * dbus_connection_add_filter(),
+ * dbus_connection_register_object_path() for more on handlers).
+ *
* 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
* 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.
+ * After calling dbus_threads_init(), #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 if those connections will be used from different threads,
+ * for example.
+ *
+ * Also, if you dispatch or pop messages from multiple threads, it
+ * may work in the sense that it won't crash, but it's tough to imagine
+ * sane results; it will be completely unpredictable which messages
+ * go to which threads.
+ *
+ * It's recommended to dispatch from a single thread.
+ *
+ * The most useful function to call from multiple threads at once
+ * is dbus_connection_send_with_reply_and_block(). That is,
+ * multiple threads can make method calls at the same time.
+ *
+ * If you aren't using threads, you can use a main loop and
+ * dbus_pending_call_set_notify() to achieve a similar result.
*/
/**
* variable pointer
*/
void
-_dbus_connection_test_get_locks (DBusConnection *conn,
+_dbus_connection_test_get_locks (DBusConnection *connection,
DBusMutex **mutex_loc,
DBusMutex **dispatch_mutex_loc,
DBusMutex **io_path_mutex_loc,
DBusCondVar **dispatch_cond_loc,
DBusCondVar **io_path_cond_loc)
{
- *mutex_loc = conn->mutex;
- *dispatch_mutex_loc = conn->dispatch_mutex;
- *io_path_mutex_loc = conn->io_path_mutex;
- *dispatch_cond_loc = conn->dispatch_cond;
- *io_path_cond_loc = conn->io_path_cond;
+ *mutex_loc = connection->mutex;
+ *dispatch_mutex_loc = connection->dispatch_mutex;
+ *io_path_mutex_loc = connection->io_path_mutex;
+ *dispatch_cond_loc = connection->dispatch_cond;
+ *io_path_cond_loc = connection->io_path_cond;
}
#endif
/**
* Checks whether there are messages in the outgoing message queue.
- *
+ * Use dbus_connection_flush() to block until all outgoing
+ * messages have been written to the underlying transport
+ * (such as a socket).
+ *
* @param connection the connection.
* @returns #TRUE if the outgoing queue is non-empty.
*/
dbus_message_unref (message);
}
+/** Function to be called in protected_change_watch() with refcount held */
typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list,
DBusWatch *watch);
+/** Function to be called in protected_change_watch() with refcount held */
typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list,
DBusWatch *watch);
+/** Function to be called in protected_change_watch() with refcount held */
typedef void (* DBusWatchToggleFunction) (DBusWatchList *list,
DBusWatch *watch,
dbus_bool_t enabled);
enabled);
}
+/** Function to be called in protected_change_timeout() with refcount held */
typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list,
DBusTimeout *timeout);
+/** Function to be called in protected_change_timeout() with refcount held */
typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list,
DBusTimeout *timeout);
+/** Function to be called in protected_change_timeout() with refcount held */
typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list,
DBusTimeout *timeout,
dbus_bool_t enabled);
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.
- *
- * Because this connection is shared, no user of the connection
- * may call dbus_connection_close(). However, when you are done with the
- * connection you should call dbus_connection_unref().
+ * Closes a shared OR private connection, while dbus_connection_close() can
+ * only be used on private connections. Should only be called by the
+ * dbus code that owns the connection - an owner must be known,
+ * the open/close state is like malloc/free, not like ref/unref.
*
- * @param address the address.
- * @param error address where an error can be returned.
- * @returns new connection, or #NULL on failure.
+ * @param connection the connection
*/
-DBusConnection*
-dbus_connection_open (const char *address,
- DBusError *error)
+void
+_dbus_connection_close_possibly_shared (DBusConnection *connection)
{
- 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);
+ _dbus_assert (connection != NULL);
+ _dbus_assert (connection->generation == _dbus_current_generation);
- return connection;
+ CONNECTION_LOCK (connection);
+ _dbus_connection_close_possibly_shared_and_unlock (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.
- *
- * When you are done with this connection, you must
- * dbus_connection_close() to disconnect it,
- * and dbus_connection_unref() to free the connection object.
- *
- * (The dbus_connection_close() can be skipped if the
- * connection is already known to be disconnected, for example
- * if you are inside a handler for the Disconnected signal.)
- *
- * @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)
+static DBusPreallocatedSend*
+_dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
{
- DBusConnection *connection;
+ DBusPreallocatedSend *preallocated;
- _dbus_return_val_if_fail (address != NULL, NULL);
- _dbus_return_val_if_error_is_set (error, NULL);
+ HAVE_LOCK_CHECK (connection);
+
+ _dbus_assert (connection != NULL);
+
+ preallocated = dbus_new (DBusPreallocatedSend, 1);
+ if (preallocated == NULL)
+ return NULL;
- connection = _dbus_connection_open_internal (address,
- FALSE,
- error);
+ 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;
+ }
- return connection;
-}
+ _dbus_counter_ref (preallocated->counter_link->data);
-/**
- * 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);
+ preallocated->connection = connection;
- /* The connection lock is better than the global
- * lock in the atomic increment fallback
- */
+ return preallocated;
-#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;
+ failed_1:
+ _dbus_list_free_link (preallocated->queue_link);
+ failed_0:
+ dbus_free (preallocated);
+
+ return NULL;
}
+/* Called with lock held, does not update dispatch status */
static void
-free_outgoing_message (void *element,
- void *data)
+_dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection,
+ DBusPreallocatedSend *preallocated,
+ DBusMessage *message,
+ dbus_uint32_t *client_serial)
{
- DBusMessage *message = element;
- DBusConnection *connection = data;
+ dbus_uint32_t serial;
+ const char *sig;
- _dbus_message_remove_size_counter (message,
- connection->outgoing_counter,
- NULL);
- dbus_message_unref (message);
-}
+ preallocated->queue_link->data = message;
+ _dbus_list_prepend_link (&connection->outgoing_messages,
+ preallocated->queue_link);
-/* 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_message_add_size_counter_link (message,
+ preallocated->counter_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_free (preallocated);
+ preallocated = NULL;
- _dbus_watch_list_free (connection->watches);
- connection->watches = NULL;
+ dbus_message_ref (message);
- _dbus_timeout_list_free (connection->timeouts);
- connection->timeouts = NULL;
+ connection->n_outgoing += 1;
- _dbus_data_slot_list_free (&connection->slot_list);
+ sig = dbus_message_get_signature (message);
- 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);
+ _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_path (message) :
+ "no path",
+ 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);
- filter->function = NULL;
- _dbus_message_filter_unref (filter); /* calls app callback */
- link->data = NULL;
-
- link = next;
+ 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;
}
- _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)
+ else
{
- DBusMessage *message = connection->disconnect_message_link->data;
- dbus_message_unref (message);
- _dbus_list_free_link (connection->disconnect_message_link);
+ if (client_serial)
+ *client_serial = dbus_message_get_serial (message);
}
- _dbus_list_clear (&connection->link_cache);
-
- _dbus_condvar_free_at_location (&connection->dispatch_cond);
- _dbus_condvar_free_at_location (&connection->io_path_cond);
-
- _dbus_mutex_free_at_location (&connection->io_path_mutex);
- _dbus_mutex_free_at_location (&connection->dispatch_mutex);
-
- _dbus_mutex_free_at_location (&connection->mutex);
+ _dbus_verbose ("Message %p serial is %u\n",
+ message, dbus_message_get_serial (message));
- dbus_free (connection);
-}
-
-/**
- * Decrements the reference count of a DBusConnection, and finalizes
- * it if the count reaches zero.
- *
- * Note: it is a bug to drop the last reference to a connection that
- * is still connected.
- *
- * For shared connections, libdbus will own a reference
- * as long as the connection is connected, so you can know that either
- * you don't have the last reference, or it's OK to drop the last reference.
- * Most connections are shared.
- *
- * For private connections, the creator of the connection must arrange for
- * dbus_connection_close() to be called prior to dropping the last reference.
- * Private connections come from dbus_connection_open_private() or dbus_bus_get_private().
- *
- * @param connection the connection.
- */
-void
-dbus_connection_unref (DBusConnection *connection)
-{
- dbus_bool_t last_unref;
+ _dbus_message_lock (message);
- _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
+ /* Now we need to run an iteration to hopefully just write the messages
+ * out immediately, and otherwise get them queued up
*/
-
-#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);
+ _dbus_connection_do_iteration_unlocked (connection,
+ DBUS_ITERATION_DO_WRITING,
+ -1);
-#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);
+ /* If stuff is still queued up, be sure we wake up the main loop */
+ if (connection->n_outgoing > 0)
+ _dbus_connection_wakeup_mainloop (connection);
}
-/*
- * Note that the transport can disconnect itself (other end drops us)
- * and in that case this function never runs. So this function must
- * not do anything more than disconnect the transport and update the
- * dispatch status.
- *
- * If the transport self-disconnects, then we assume someone will
- * dispatch the connection to cause the dispatch status update.
- */
static void
-_dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection)
+_dbus_connection_send_preallocated_and_unlock (DBusConnection *connection,
+ DBusPreallocatedSend *preallocated,
+ DBusMessage *message,
+ dbus_uint32_t *client_serial)
{
DBusDispatchStatus status;
HAVE_LOCK_CHECK (connection);
- _dbus_verbose ("Disconnecting %p\n", connection);
-
- /* We need to ref because update_dispatch_status_and_unlock will unref
- * the connection if it was shared and libdbus was the only remaining
- * refcount holder.
- */
- _dbus_connection_ref_unlocked (connection);
-
- _dbus_transport_disconnect (connection->transport);
+ _dbus_connection_send_preallocated_unlocked_no_update (connection,
+ preallocated,
+ message, client_serial);
- /* This has the side effect of queuing the disconnect message link
- * (unless we don't have enough memory, possibly, so don't assert it).
- * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open
- * should never again return the newly-disconnected connection.
- *
- * However, we only unref the shared connection and exit_on_disconnect when
- * the disconnect message reaches the head of the message queue,
- * NOT when it's first queued.
- */
+ _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
- /* This calls out to user code */
+ /* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
-
- /* Could also call out to user code */
- dbus_connection_unref (connection);
-}
-
-void
-_dbus_connection_close_possibly_shared (DBusConnection *connection)
-{
- _dbus_assert (connection != NULL);
- _dbus_assert (connection->generation == _dbus_current_generation);
-
- CONNECTION_LOCK (connection);
- _dbus_connection_close_possibly_shared_and_unlock (connection);
}
/**
- * Closes a private connection, so no further data can be sent or received.
- * This disconnects the transport (such as a socket) underlying the
- * connection.
- *
- * Attempts to send messages after closing a connection are safe, but will result in
- * error replies generated locally in libdbus.
- *
- * This function does not affect the connection's reference count. It's
- * safe to close 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.
- *
- * If a connection is dropped by the remote application, it will
- * close itself.
- *
- * You must close a connection prior to releasing the last reference to
- * the connection. If you dbus_connection_unref() for the last time
- * without closing the connection, the results are undefined; it
- * is a bug in your program and libdbus will try to print a warning.
- *
- * You may not close a shared connection. Connections created with
- * dbus_connection_open() or dbus_bus_get() are shared.
- * These connections are owned by libdbus, and applications should
- * only unref them, never close them. Applications can know it is
- * safe to unref these connections because libdbus will be holding a
- * reference as long as the connection is open. Thus, either the
- * connection is closed and it is OK to drop the last reference,
- * or the connection is open and the app knows it does not have the
- * last reference.
+ * Like dbus_connection_send(), but assumes the connection
+ * is already locked on function entry, and unlocks before returning.
*
- * Connections created with dbus_connection_open_private() or
- * dbus_bus_get_private() are not kept track of or referenced by
- * libdbus. The creator of these connections is responsible for
- * calling dbus_connection_close() prior to releasing the last
- * reference, if the connection is not already disconnected.
- *
- * @param connection the private (unshared) connection to close
+ * @param connection the connection
+ * @param message the message to send
+ * @param client_serial return location for client serial of sent message
+ * @returns #FALSE on out-of-memory
*/
-void
-dbus_connection_close (DBusConnection *connection)
+dbus_bool_t
+_dbus_connection_send_and_unlock (DBusConnection *connection,
+ DBusMessage *message,
+ dbus_uint32_t *client_serial)
{
- _dbus_return_if_fail (connection != NULL);
- _dbus_return_if_fail (connection->generation == _dbus_current_generation);
-
- CONNECTION_LOCK (connection);
+ DBusPreallocatedSend *preallocated;
- if (connection->shareable)
+ _dbus_assert (connection != NULL);
+ _dbus_assert (message != NULL);
+
+ preallocated = _dbus_connection_preallocate_send_unlocked (connection);
+ if (preallocated == NULL)
{
CONNECTION_UNLOCK (connection);
-
- _dbus_warn ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.\n");
- return;
+ return FALSE;
}
- _dbus_connection_close_possibly_shared_and_unlock (connection);
+ _dbus_connection_send_preallocated_and_unlock (connection,
+ preallocated,
+ message,
+ client_serial);
+ return TRUE;
}
/**
CONNECTION_UNLOCK (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 open. A connection may
- * become disconnected when the remote application closes its end, or
- * exits; a connection may also be disconnected with
- * dbus_connection_close().
- *
- * There are not separate states for "closed" and "disconnected," the two
- * terms are synonymous. This function should really be called
- * get_is_open() but for historical reasons is not.
+ * 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.
*
- * @param connection the connection.
- * @returns #TRUE if the connection is still alive.
+ * @timeout_milliseconds the timeout requested for blocking
*/
-dbus_bool_t
-dbus_connection_get_is_connected (DBusConnection *connection)
+static void
+_dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
{
- 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;
+ 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);
}
-/**
- * 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)
+static DBusMessage *
+generate_local_error_message (dbus_uint32_t serial,
+ char *error_name,
+ char *error_msg)
{
- dbus_bool_t res;
+ DBusMessage *message;
+ message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
+ if (!message)
+ goto out;
- _dbus_return_val_if_fail (connection != NULL, FALSE);
-
- CONNECTION_LOCK (connection);
- res = _dbus_transport_get_is_authenticated (connection->transport);
- CONNECTION_UNLOCK (connection);
-
- return res;
-}
+ if (!dbus_message_set_error_name (message, error_name))
+ {
+ dbus_message_unref (message);
+ message = NULL;
+ goto out;
+ }
-/**
- * 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);
+ dbus_message_set_no_reply (message, TRUE);
- CONNECTION_LOCK (connection);
- connection->exit_on_disconnect = exit_on_disconnect != FALSE;
- CONNECTION_UNLOCK (connection);
+ if (!dbus_message_set_reply_serial (message,
+ serial))
+ {
+ dbus_message_unref (message);
+ message = NULL;
+ goto out;
+ }
+
+ if (error_msg != NULL)
+ {
+ DBusMessageIter iter;
+
+ dbus_message_iter_init_append (message, &iter);
+ if (!dbus_message_iter_append_basic (&iter,
+ DBUS_TYPE_STRING,
+ &error_msg))
+ {
+ dbus_message_unref (message);
+ message = NULL;
+ goto out;
+ }
+ }
+
+ out:
+ return message;
}
-static DBusPreallocatedSend*
-_dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
+
+/* 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)
{
- DBusPreallocatedSend *preallocated;
+ DBusList *link;
HAVE_LOCK_CHECK (connection);
- _dbus_assert (connection != NULL);
-
- preallocated = dbus_new (DBusPreallocatedSend, 1);
- if (preallocated == NULL)
- return NULL;
+ link = _dbus_list_get_first_link (&connection->incoming_messages);
- 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)
+ while (link != NULL)
{
- preallocated->counter_link =
- _dbus_list_pop_first_link (&connection->link_cache);
- preallocated->counter_link->data = connection->outgoing_counter;
+ 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);
}
- else
+
+ return NULL;
+}
+
+static void
+connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection)
+{
+ /* We can't iterate over the hash in the normal way since we'll be
+ * dropping the lock for each item. So we restart the
+ * iter each time as we drain the hash table.
+ */
+
+ while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0)
{
- preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
- if (preallocated->counter_link == NULL)
- goto failed_1;
- }
+ DBusPendingCall *pending;
+ DBusHashIter iter;
+
+ _dbus_hash_iter_init (connection->pending_replies, &iter);
+ _dbus_hash_iter_next (&iter);
+
+ pending = _dbus_hash_iter_get_value (&iter);
+ _dbus_pending_call_ref_unlocked (pending);
+
+ _dbus_pending_call_queue_timeout_error_unlocked (pending,
+ connection);
+ _dbus_connection_remove_timeout_unlocked (connection,
+ _dbus_pending_call_get_timeout_unlocked (pending));
+ _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
+ _dbus_hash_iter_remove_entry (&iter);
- _dbus_counter_ref (preallocated->counter_link->data);
+ _dbus_pending_call_unref_and_unlock (pending);
+ CONNECTION_LOCK (connection);
+ }
+ HAVE_LOCK_CHECK (connection);
+}
- preallocated->connection = connection;
-
- return preallocated;
-
- failed_1:
- _dbus_list_free_link (preallocated->queue_link);
- failed_0:
- dbus_free (preallocated);
-
- return NULL;
+static void
+complete_pending_call_and_unlock (DBusConnection *connection,
+ DBusPendingCall *pending,
+ DBusMessage *message)
+{
+ _dbus_pending_call_set_reply_unlocked (pending, message);
+ _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */
+ _dbus_connection_detach_pending_call_and_unlock (connection, pending);
+
+ /* Must be called unlocked since it invokes app callback */
+ _dbus_pending_call_complete (pending);
+ dbus_pending_call_unref (pending);
}
-/**
- * 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)
+static dbus_bool_t
+check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection,
+ DBusPendingCall *pending)
{
- DBusPreallocatedSend *preallocated;
+ DBusMessage *reply;
+ DBusDispatchStatus status;
- _dbus_return_val_if_fail (connection != NULL, NULL);
+ reply = check_for_reply_unlocked (connection,
+ _dbus_pending_call_get_reply_serial_unlocked (pending));
+ if (reply != NULL)
+ {
+ _dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME);
- CONNECTION_LOCK (connection);
-
- preallocated =
- _dbus_connection_preallocate_send_unlocked (connection);
+ _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");
- CONNECTION_UNLOCK (connection);
+ complete_pending_call_and_unlock (connection, pending, reply);
+ dbus_message_unref (reply);
- return preallocated;
+ 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 TRUE;
+ }
+
+ return FALSE;
}
/**
- * 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.
+ * Blocks until a pending call times out or gets a reply.
*
- * @param connection the connection
- * @param preallocated the resources
+ * 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_free_preallocated_send (DBusConnection *connection,
- DBusPreallocatedSend *preallocated)
+_dbus_connection_block_pending_call (DBusPendingCall *pending)
{
- _dbus_return_if_fail (connection != NULL);
- _dbus_return_if_fail (preallocated != NULL);
- _dbus_return_if_fail (connection == preallocated->connection);
+ 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_list_free_link (preallocated->queue_link);
- _dbus_counter_unref (preallocated->counter_link->data);
- _dbus_list_free_link (preallocated->counter_link);
- dbus_free (preallocated);
-}
+ _dbus_assert (pending != NULL);
-/* 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;
+ if (dbus_pending_call_get_completed (pending))
+ return;
- preallocated->queue_link->data = message;
- _dbus_list_prepend_link (&connection->outgoing_messages,
- preallocated->queue_link);
+ dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
- _dbus_message_add_size_counter_link (message,
- preallocated->counter_link);
+ connection = _dbus_pending_call_get_connection_and_lock (pending);
+
+ /* Flush message queue - note, can affect dispatch status */
+ _dbus_connection_flush_unlocked (connection);
- dbus_free (preallocated);
- preallocated = NULL;
+ client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
+
+ /* 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 (_dbus_pending_call_get_timeout_unlocked (pending));
- dbus_message_ref (message);
+ _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);
+
+ /* check to see if we already got the data off the socket */
+ /* from another blocked pending call */
+ if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
+ return;
+
+ /* 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);
- connection->n_outgoing += 1;
+ HAVE_LOCK_CHECK (connection);
+
+ /* queue messages and get status */
- sig = dbus_message_get_signature (message);
+ 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_unlocked (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;
+ }
- _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_path (message) :
- "no path",
- 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 (status == DBUS_DISPATCH_DATA_REMAINS) {
+ if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
+ return;
+ }
+
+ _dbus_get_current_time (&tv_sec, &tv_usec);
+
+ if (!_dbus_connection_get_is_connected_unlocked (connection))
+ {
+ DBusMessage *error_msg;
- if (dbus_message_get_serial (message) == 0)
+ error_msg = generate_local_error_message (client_serial,
+ DBUS_ERROR_DISCONNECTED,
+ "Connection was disconnected before a reply was received");
+
+ /* on OOM error_msg is set to NULL */
+ complete_pending_call_and_unlock (connection, pending, error_msg);
+ 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))
{
- serial = _dbus_connection_get_next_client_serial (connection);
- _dbus_message_set_serial (message, serial);
- if (client_serial)
- *client_serial = serial;
+ 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;
}
- else
+
+ _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_unlocked (pending));
+
+ /* unlock and call user code */
+ complete_pending_call_and_unlock (connection, 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);
+}
+
+/** @} */
+
+/**
+ * @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.
+ *
+ * Because this connection is shared, no user of the connection
+ * may call dbus_connection_close(). However, when you are done with the
+ * connection you should call dbus_connection_unref().
+ *
+ * @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.
+ *
+ * When you are done with this connection, you must
+ * dbus_connection_close() to disconnect it,
+ * and dbus_connection_unref() to free the connection object.
+ *
+ * (The dbus_connection_close() can be skipped if the
+ * connection is already known to be disconnected, for example
+ * if you are inside a handler for the Disconnected signal.)
+ *
+ * @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)
{
- if (client_serial)
- *client_serial = dbus_message_get_serial (message);
+ 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_verbose ("Message %p serial is %u\n",
- message, dbus_message_get_serial (message));
+ _dbus_object_tree_unref (connection->objects);
+
+ _dbus_hash_table_unref (connection->pending_replies);
+ connection->pending_replies = NULL;
- _dbus_message_lock (message);
+ _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);
- /* 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);
+ _dbus_counter_unref (connection->outgoing_counter);
- /* If stuff is still queued up, be sure we wake up the main loop */
- if (connection->n_outgoing > 0)
- _dbus_connection_wakeup_mainloop (connection);
-}
+ _dbus_transport_unref (connection->transport);
-static void
-_dbus_connection_send_preallocated_and_unlock (DBusConnection *connection,
- DBusPreallocatedSend *preallocated,
- DBusMessage *message,
- dbus_uint32_t *client_serial)
-{
- DBusDispatchStatus status;
+ if (connection->disconnect_message_link)
+ {
+ DBusMessage *message = connection->disconnect_message_link->data;
+ dbus_message_unref (message);
+ _dbus_list_free_link (connection->disconnect_message_link);
+ }
- HAVE_LOCK_CHECK (connection);
+ _dbus_list_clear (&connection->link_cache);
- _dbus_connection_send_preallocated_unlocked_no_update (connection,
- preallocated,
- message, client_serial);
+ _dbus_condvar_free_at_location (&connection->dispatch_cond);
+ _dbus_condvar_free_at_location (&connection->io_path_cond);
- _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
- status = _dbus_connection_get_dispatch_status_unlocked (connection);
+ _dbus_mutex_free_at_location (&connection->io_path_mutex);
+ _dbus_mutex_free_at_location (&connection->dispatch_mutex);
- /* this calls out to user code */
- _dbus_connection_update_dispatch_status_and_unlock (connection, status);
+ _dbus_mutex_free_at_location (&connection->mutex);
+
+ dbus_free (connection);
}
/**
- * Sends a message using preallocated resources. This function cannot fail.
- * It works identically to dbus_connection_send() in other respects.
- * Preallocated resources comes from dbus_connection_preallocate_send().
- * This function "consumes" the preallocated resources, they need not
- * be freed separately.
+ * Decrements the reference count of a DBusConnection, and finalizes
+ * it if the count reaches zero.
*
- * @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
+ * Note: it is a bug to drop the last reference to a connection that
+ * is still connected.
+ *
+ * For shared connections, libdbus will own a reference
+ * as long as the connection is connected, so you can know that either
+ * you don't have the last reference, or it's OK to drop the last reference.
+ * Most connections are shared. dbus_connection_open() and dbus_bus_get()
+ * return shared connections.
+ *
+ * For private connections, the creator of the connection must arrange for
+ * dbus_connection_close() to be called prior to dropping the last reference.
+ * Private connections come from dbus_connection_open_private() or dbus_bus_get_private().
+ *
+ * @param connection the connection.
*/
void
-dbus_connection_send_preallocated (DBusConnection *connection,
- DBusPreallocatedSend *preallocated,
- DBusMessage *message,
- dbus_uint32_t *client_serial)
+dbus_connection_unref (DBusConnection *connection)
{
+ dbus_bool_t last_unref;
+
_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_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));
+ _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_connection_send_preallocated_and_unlock (connection,
- preallocated,
- message, client_serial);
-}
+
+ _dbus_assert (connection->refcount.value > 0);
-static dbus_bool_t
-_dbus_connection_send_unlocked_no_update (DBusConnection *connection,
- DBusMessage *message,
- dbus_uint32_t *client_serial)
-{
- DBusPreallocatedSend *preallocated;
+ connection->refcount.value -= 1;
+ last_unref = (connection->refcount.value == 0);
- _dbus_assert (connection != NULL);
- _dbus_assert (message != NULL);
+#if 0
+ printf ("unref() connection %p count = %d\n", connection, connection->refcount.value);
+#endif
- 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;
+ CONNECTION_UNLOCK (connection);
+#endif
+
+ if (last_unref)
+ {
+#ifndef DBUS_DISABLE_CHECKS
+ if (_dbus_transport_get_is_connected (connection->transport))
+ {
+ _dbus_warn_check_failed ("The last reference on a connection was dropped without closing the connection. This is a bug in an application. See dbus_connection_unref() documentation for details.\n%s",
+ connection->shareable ?
+ "Most likely, the application called unref() too many times and removed a reference belonging to libdbus, since this is a shared connection.\n" :
+ "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.\n");
+ return;
+ }
+#endif
+ _dbus_connection_last_unref (connection);
+ }
}
-dbus_bool_t
-_dbus_connection_send_and_unlock (DBusConnection *connection,
- DBusMessage *message,
- dbus_uint32_t *client_serial)
+/*
+ * Note that the transport can disconnect itself (other end drops us)
+ * and in that case this function never runs. So this function must
+ * not do anything more than disconnect the transport and update the
+ * dispatch status.
+ *
+ * If the transport self-disconnects, then we assume someone will
+ * dispatch the connection to cause the dispatch status update.
+ */
+static void
+_dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection)
{
- DBusPreallocatedSend *preallocated;
+ DBusDispatchStatus status;
- _dbus_assert (connection != NULL);
- _dbus_assert (message != NULL);
+ HAVE_LOCK_CHECK (connection);
- preallocated = _dbus_connection_preallocate_send_unlocked (connection);
- if (preallocated == NULL)
- {
- CONNECTION_UNLOCK (connection);
- return FALSE;
- }
+ _dbus_verbose ("Disconnecting %p\n", connection);
- _dbus_connection_send_preallocated_and_unlock (connection,
- preallocated,
- message,
- client_serial);
- return TRUE;
+ /* We need to ref because update_dispatch_status_and_unlock will unref
+ * the connection if it was shared and libdbus was the only remaining
+ * refcount holder.
+ */
+ _dbus_connection_ref_unlocked (connection);
+
+ _dbus_transport_disconnect (connection->transport);
+
+ /* This has the side effect of queuing the disconnect message link
+ * (unless we don't have enough memory, possibly, so don't assert it).
+ * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open
+ * should never again return the newly-disconnected connection.
+ *
+ * However, we only unref the shared connection and exit_on_disconnect when
+ * the disconnect message reaches the head of the message queue,
+ * NOT when it's first queued.
+ */
+ status = _dbus_connection_get_dispatch_status_unlocked (connection);
+
+ /* This calls out to user code */
+ _dbus_connection_update_dispatch_status_and_unlock (connection, status);
+
+ /* Could also call out to user code */
+ dbus_connection_unref (connection);
}
/**
- * Adds a message to the outgoing message queue. Does not block to
- * write the message to the network; that happens asynchronously. To
- * force the message to be written, call dbus_connection_flush().
- * Because this only queues the message, the only reason it can
- * fail is lack of memory. Even if the connection is disconnected,
- * no error will be returned.
+ * Closes a private connection, so no further data can be sent or received.
+ * This disconnects the transport (such as a socket) underlying the
+ * connection.
*
- * 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.
+ * Attempts to send messages after closing a connection are safe, but will result in
+ * error replies generated locally in libdbus.
*
- * @param connection the connection.
- * @param message the message to write.
- * @param client_serial return location for client serial.
- * @returns #TRUE on success.
+ * This function does not affect the connection's reference count. It's
+ * safe to close 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.
+ *
+ * If a connection is dropped by the remote application, it will
+ * close itself.
+ *
+ * You must close a connection prior to releasing the last reference to
+ * the connection. If you dbus_connection_unref() for the last time
+ * without closing the connection, the results are undefined; it
+ * is a bug in your program and libdbus will try to print a warning.
+ *
+ * You may not close a shared connection. Connections created with
+ * dbus_connection_open() or dbus_bus_get() are shared.
+ * These connections are owned by libdbus, and applications should
+ * only unref them, never close them. Applications can know it is
+ * safe to unref these connections because libdbus will be holding a
+ * reference as long as the connection is open. Thus, either the
+ * connection is closed and it is OK to drop the last reference,
+ * or the connection is open and the app knows it does not have the
+ * last reference.
+ *
+ * Connections created with dbus_connection_open_private() or
+ * dbus_bus_get_private() are not kept track of or referenced by
+ * libdbus. The creator of these connections is responsible for
+ * calling dbus_connection_close() prior to releasing the last
+ * reference, if the connection is not already disconnected.
+ *
+ * @param connection the private (unshared) connection to close
*/
-dbus_bool_t
-dbus_connection_send (DBusConnection *connection,
- DBusMessage *message,
- dbus_uint32_t *client_serial)
+void
+dbus_connection_close (DBusConnection *connection)
{
- _dbus_return_val_if_fail (connection != NULL, FALSE);
- _dbus_return_val_if_fail (message != NULL, FALSE);
+ _dbus_return_if_fail (connection != NULL);
+ _dbus_return_if_fail (connection->generation == _dbus_current_generation);
CONNECTION_LOCK (connection);
- return _dbus_connection_send_and_unlock (connection,
- message,
- client_serial);
+#ifndef DBUS_DISABLE_CHECKS
+ if (connection->shareable)
+ {
+ CONNECTION_UNLOCK (connection);
+
+ _dbus_warn_check_failed ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.\n");
+ return;
+ }
+#endif
+
+ _dbus_connection_close_possibly_shared_and_unlock (connection);
}
static dbus_bool_t
-reply_handler_timeout (void *data)
+_dbus_connection_get_is_connected_unlocked (DBusConnection *connection)
{
- DBusConnection *connection;
- DBusDispatchStatus status;
- DBusPendingCall *pending = data;
-
- connection = _dbus_pending_call_get_connection_and_lock (pending);
-
- _dbus_pending_call_queue_timeout_error_unlocked (pending,
- connection);
- _dbus_connection_remove_timeout_unlocked (connection,
- _dbus_pending_call_get_timeout_unlocked (pending));
- _dbus_pending_call_set_timeout_added_unlocked (pending, 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;
+ HAVE_LOCK_CHECK (connection);
+ return _dbus_transport_get_is_connected (connection->transport);
}
/**
- * 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.
+ * Gets whether the connection is currently open. 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
- * @param message the message to send
- * @param pending_return return location for a #DBusPendingCall object, or #NULLif connection is disconnected
- * @param timeout_milliseconds timeout in milliseconds or -1 for default
- * @returns #FALSE if no memory, #TRUE otherwise.
+ * There are not separate states for "closed" and "disconnected," the two
+ * terms are synonymous. This function should really be called
+ * get_is_open() but for historical reasons is not.
*
+ * @param connection the connection.
+ * @returns #TRUE if the connection is still alive.
*/
dbus_bool_t
-dbus_connection_send_with_reply (DBusConnection *connection,
- DBusMessage *message,
- DBusPendingCall **pending_return,
- int timeout_milliseconds)
+dbus_connection_get_is_connected (DBusConnection *connection)
{
- DBusPendingCall *pending;
- dbus_int32_t serial = -1;
- DBusDispatchStatus status;
+ dbus_bool_t res;
_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;
-
- CONNECTION_LOCK (connection);
-
- if (!_dbus_connection_get_is_connected_unlocked (connection))
- {
- CONNECTION_UNLOCK (connection);
-
- *pending_return = NULL;
-
- return TRUE;
- }
-
- pending = _dbus_pending_call_new_unlocked (connection,
- timeout_milliseconds,
- reply_handler_timeout);
-
- if (pending == NULL)
- {
- CONNECTION_UNLOCK (connection);
- return FALSE;
- }
-
- /* Assign a serial to the message */
- serial = dbus_message_get_serial (message);
- if (serial == 0)
- {
- serial = _dbus_connection_get_next_client_serial (connection);
- _dbus_message_set_serial (message, serial);
- }
-
- if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial))
- goto error;
-
- /* 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; /* hand off refcount */
- else
- {
- _dbus_connection_detach_pending_call_unlocked (connection, pending);
- /* we still have a ref to the pending call in this case, we unref
- * after unlocking, below
- */
- }
-
- status = _dbus_connection_get_dispatch_status_unlocked (connection);
-
- /* this calls out to user code */
- _dbus_connection_update_dispatch_status_and_unlock (connection, status);
-
- if (pending_return == NULL)
- dbus_pending_call_unref (pending);
- return TRUE;
-
- error:
+ CONNECTION_LOCK (connection);
+ res = _dbus_connection_get_is_connected_unlocked (connection);
CONNECTION_UNLOCK (connection);
- error_unlocked:
- dbus_pending_call_unref (pending);
- return FALSE;
+
+ return res;
}
-/* This is slightly strange since we can pop a message here without
- * the dispatch lock.
+/**
+ * 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
*/
-static DBusMessage*
-check_for_reply_unlocked (DBusConnection *connection,
- dbus_uint32_t client_serial)
+dbus_bool_t
+dbus_connection_get_is_authenticated (DBusConnection *connection)
{
- DBusList *link;
+ dbus_bool_t res;
- HAVE_LOCK_CHECK (connection);
+ _dbus_return_val_if_fail (connection != NULL, FALSE);
- 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;
+ CONNECTION_LOCK (connection);
+ res = _dbus_transport_get_is_authenticated (connection->transport);
+ CONNECTION_UNLOCK (connection);
+
+ return res;
}
-static void
-connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection)
+/**
+ * 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)
{
- /* We can't iterate over the hash in the normal way since we'll be
- * dropping the lock for each item. So we restart the
- * iter each time as we drain the hash table.
- */
-
- while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0)
- {
- DBusPendingCall *pending;
- DBusHashIter iter;
-
- _dbus_hash_iter_init (connection->pending_replies, &iter);
- _dbus_hash_iter_next (&iter);
-
- pending = _dbus_hash_iter_get_value (&iter);
- _dbus_pending_call_ref_unlocked (pending);
-
- _dbus_pending_call_queue_timeout_error_unlocked (pending,
- connection);
- _dbus_connection_remove_timeout_unlocked (connection,
- _dbus_pending_call_get_timeout_unlocked (pending));
- _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
- _dbus_hash_iter_remove_entry (&iter);
-
- _dbus_pending_call_unref_and_unlock (pending);
- CONNECTION_LOCK (connection);
- }
- HAVE_LOCK_CHECK (connection);
-}
+ _dbus_return_if_fail (connection != NULL);
-static void
-complete_pending_call_and_unlock (DBusConnection *connection,
- DBusPendingCall *pending,
- DBusMessage *message)
-{
- _dbus_pending_call_set_reply_unlocked (pending, message);
- _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */
- _dbus_connection_detach_pending_call_and_unlock (connection, pending);
-
- /* Must be called unlocked since it invokes app callback */
- _dbus_pending_call_complete (pending);
- dbus_pending_call_unref (pending);
+ CONNECTION_LOCK (connection);
+ connection->exit_on_disconnect = exit_on_disconnect != FALSE;
+ CONNECTION_UNLOCK (connection);
}
-static dbus_bool_t
-check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection,
- DBusPendingCall *pending)
+/**
+ * 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)
{
- DBusMessage *reply;
- DBusDispatchStatus status;
+ DBusPreallocatedSend *preallocated;
- reply = check_for_reply_unlocked (connection,
- _dbus_pending_call_get_reply_serial_unlocked (pending));
- if (reply != NULL)
- {
- _dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME);
+ _dbus_return_val_if_fail (connection != NULL, NULL);
- _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");
+ CONNECTION_LOCK (connection);
+
+ preallocated =
+ _dbus_connection_preallocate_send_unlocked (connection);
- complete_pending_call_and_unlock (connection, pending, reply);
- dbus_message_unref (reply);
+ CONNECTION_UNLOCK (connection);
- 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 preallocated;
+}
- return TRUE;
- }
+/**
+ * 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);
- return FALSE;
+ _dbus_list_free_link (preallocated->queue_link);
+ _dbus_counter_unref (preallocated->counter_link->data);
+ _dbus_list_free_link (preallocated->counter_link);
+ dbus_free (preallocated);
}
/**
- * 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.
+ * 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.
*
- * @timeout_milliseconds the timeout requested for blocking
+ * @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
*/
-static void
-_dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
+void
+dbus_connection_send_preallocated (DBusConnection *connection,
+ DBusPreallocatedSend *preallocated,
+ DBusMessage *message,
+ dbus_uint32_t *client_serial)
{
- 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);
+ _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_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 DBusMessage *
-generate_local_error_message (dbus_uint32_t serial,
- char *error_name,
- char *error_msg)
+static dbus_bool_t
+_dbus_connection_send_unlocked_no_update (DBusConnection *connection,
+ DBusMessage *message,
+ dbus_uint32_t *client_serial)
{
- DBusMessage *message;
- message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
- if (!message)
- goto out;
-
- if (!dbus_message_set_error_name (message, error_name))
- {
- dbus_message_unref (message);
- message = NULL;
- goto out;
- }
-
- dbus_message_set_no_reply (message, TRUE);
-
- if (!dbus_message_set_reply_serial (message,
- serial))
- {
- dbus_message_unref (message);
- message = NULL;
- goto out;
- }
-
- if (error_msg != NULL)
- {
- DBusMessageIter iter;
+ DBusPreallocatedSend *preallocated;
- dbus_message_iter_init_append (message, &iter);
- if (!dbus_message_iter_append_basic (&iter,
- DBUS_TYPE_STRING,
- &error_msg))
- {
- dbus_message_unref (message);
- message = NULL;
- goto out;
- }
- }
+ _dbus_assert (connection != NULL);
+ _dbus_assert (message != NULL);
+
+ preallocated = _dbus_connection_preallocate_send_unlocked (connection);
+ if (preallocated == NULL)
+ return FALSE;
- out:
- return message;
+ _dbus_connection_send_preallocated_unlocked_no_update (connection,
+ preallocated,
+ message,
+ client_serial);
+ return TRUE;
}
/**
- * Blocks until a pending call times out or gets a reply.
+ * 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.
*
- * 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.
+ * 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.
*
- * Returns immediately if pending call already got a reply.
+ * The message serial is used by the remote application to send a
+ * reply; see dbus_message_get_serial() or the D-Bus specification.
*
- * @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
+ * @param connection the connection.
+ * @param message the message to write.
+ * @param serial return location for message serial, or #NULL if you don't care
+ * @returns #TRUE on success.
*/
-void
-_dbus_connection_block_pending_call (DBusPendingCall *pending)
+dbus_bool_t
+dbus_connection_send (DBusConnection *connection,
+ DBusMessage *message,
+ dbus_uint32_t *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,
+ serial);
+}
+
+static dbus_bool_t
+reply_handler_timeout (void *data)
{
- 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;
+ DBusDispatchStatus status;
+ DBusPendingCall *pending = data;
- _dbus_assert (pending != NULL);
+ connection = _dbus_pending_call_get_connection_and_lock (pending);
- if (dbus_pending_call_get_completed (pending))
- return;
+ _dbus_pending_call_queue_timeout_error_unlocked (pending,
+ connection);
+ _dbus_connection_remove_timeout_unlocked (connection,
+ _dbus_pending_call_get_timeout_unlocked (pending));
+ _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
- dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
+ _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(),
+ * 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 before any filters or
+ * registered object path handlers. See dbus_connection_dispatch() for
+ * details on when handlers are run.
+ *
+ * A #DBusPendingCall will always see exactly one reply message,
+ * unless it's cancelled with dbus_pending_call_cancel().
+ *
+ * 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 mean "very long timeout." libdbus clamps an INT_MAX
+ * timeout down to a few hours timeout though.
+ *
+ * @warning if the connection is disconnected, the #DBusPendingCall
+ * will be set to #NULL, so be careful with this.
+ *
+ * @param connection the connection
+ * @param message the message to send
+ * @param pending_return return location for a #DBusPendingCall object, or #NULL if connection is disconnected
+ * @param timeout_milliseconds timeout in milliseconds or -1 for default
+ * @returns #FALSE if no memory, #TRUE otherwise.
+ *
+ */
+dbus_bool_t
+dbus_connection_send_with_reply (DBusConnection *connection,
+ DBusMessage *message,
+ DBusPendingCall **pending_return,
+ int timeout_milliseconds)
+{
+ DBusPendingCall *pending;
+ dbus_int32_t serial = -1;
+ DBusDispatchStatus status;
- connection = _dbus_pending_call_get_connection_and_lock (pending);
-
- /* Flush message queue - note, can affect dispatch status */
- _dbus_connection_flush_unlocked (connection);
+ _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);
- client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
+ if (pending_return)
+ *pending_return = NULL;
- /* 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 (_dbus_pending_call_get_timeout_unlocked (pending));
-
- _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;
+ CONNECTION_LOCK (connection);
- _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);
+ if (!_dbus_connection_get_is_connected_unlocked (connection))
+ {
+ CONNECTION_UNLOCK (connection);
- /* check to see if we already got the data off the socket */
- /* from another blocked pending call */
- if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
- return;
+ *pending_return = NULL;
- /* 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);
+ return TRUE;
+ }
- recheck_status:
+ pending = _dbus_pending_call_new_unlocked (connection,
+ timeout_milliseconds,
+ reply_handler_timeout);
- _dbus_verbose ("%s top of recheck\n", _DBUS_FUNCTION_NAME);
-
- HAVE_LOCK_CHECK (connection);
-
- /* queue messages and get status */
+ if (pending == NULL)
+ {
+ CONNECTION_UNLOCK (connection);
+ return FALSE;
+ }
- status = _dbus_connection_get_dispatch_status_unlocked (connection);
+ /* Assign a serial to the message */
+ serial = dbus_message_get_serial (message);
+ if (serial == 0)
+ {
+ serial = _dbus_connection_get_next_client_serial (connection);
+ _dbus_message_set_serial (message, serial);
+ }
- /* the get_completed() is in case a dispatch() while we were blocking
- * got the reply instead of us.
+ if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial))
+ goto error;
+
+ /* Insert the serial in the pending replies hash;
+ * hash takes a refcount on DBusPendingCall.
+ * Also, add the timeout.
*/
- if (_dbus_pending_call_get_completed_unlocked (pending))
+ if (!_dbus_connection_attach_pending_call_unlocked (connection,
+ pending))
+ goto error;
+
+ if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL))
{
- _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;
+ _dbus_connection_detach_pending_call_and_unlock (connection,
+ pending);
+ goto error_unlocked;
}
-
- if (status == DBUS_DISPATCH_DATA_REMAINS) {
- if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
- return;
- }
-
- _dbus_get_current_time (&tv_sec, &tv_usec);
-
- if (!_dbus_connection_get_is_connected_unlocked (connection))
- {
- DBusMessage *error_msg;
-
- error_msg = generate_local_error_message (client_serial,
- DBUS_ERROR_DISCONNECTED,
- "Connection was disconnected before a reply was received");
- /* on OOM error_msg is set to NULL */
- complete_pending_call_and_unlock (connection, pending, error_msg);
- 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))
+ if (pending_return)
+ *pending_return = pending; /* hand off refcount */
+ else
{
- 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_connection_detach_pending_call_unlocked (connection, pending);
+ /* we still have a ref to the pending call in this case, we unref
+ * after unlocking, below
+ */
}
- _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);
+ status = _dbus_connection_get_dispatch_status_unlocked (connection);
- _dbus_assert (!_dbus_pending_call_get_completed_unlocked (pending));
+ /* this calls out to user code */
+ _dbus_connection_update_dispatch_status_and_unlock (connection, status);
+
+ if (pending_return == NULL)
+ dbus_pending_call_unref (pending);
- /* unlock and call user code */
- complete_pending_call_and_unlock (connection, pending, NULL);
+ return TRUE;
- /* 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);
+ error:
+ CONNECTION_UNLOCK (connection);
+ error_unlocked:
dbus_pending_call_unref (pending);
+ return FALSE;
}
/**
* 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."
+ * processed. This function is used to invoke method calls on a
+ * remote object.
*
* 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.
+ * then the reply message is deleted and #NULL is returned. If
+ * something else goes wrong, result is set to whatever is
+ * appropriate, such as #DBUS_ERROR_NO_MEMORY or
+ * #DBUS_ERROR_DISCONNECTED.
+ *
+ * @warning While this function blocks the calling thread will not be
+ * processing the incoming message queue. This means you can end up
+ * deadlocked if the application you're talking to needs you to reply
+ * to a method. To solve this, either avoid the situation, block in a
+ * separate thread from the main connection-dispatching thread, or use
+ * dbus_pending_call_set_notify() to avoid blocking.
*
* @param connection the connection
* @param message the message to send
return NULL;
}
- _dbus_assert (pending != NULL);
+ if (pending == NULL)
+ {
+ dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed");
+ return NULL;
+ }
dbus_pending_call_block (pending);
}
/**
- * 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
+ * This function implements dbus_connection_read_write_dispatch() and
+ * dbus_connection_read_write() (they pass a different value for the
+ * dispatch parameter).
*
- * 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 and the dispatch flag is set, 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
* @param dispatch dispatch new messages or leave them on the incoming queue
dbus_bool_t dispatch)
{
DBusDispatchStatus dstatus;
- dbus_bool_t dispatched_disconnected;
+ dbus_bool_t no_progress_possible;
dstatus = dbus_connection_get_dispatch_status (connection);
}
HAVE_LOCK_CHECK (connection);
- dispatched_disconnected = connection->n_incoming == 0 &&
- connection->disconnect_message_link == NULL;
+ /* If we can dispatch, we can make progress until the Disconnected message
+ * has been processed; if we can only read/write, we can make progress
+ * as long as the transport is open.
+ */
+ if (dispatch)
+ no_progress_possible = connection->n_incoming == 0 &&
+ connection->disconnect_message_link == NULL;
+ else
+ no_progress_possible = _dbus_connection_get_is_connected_unlocked (connection);
CONNECTION_UNLOCK (connection);
- return !dispatched_disconnected; /* TRUE if we have not processed disconnected */
+ return !no_progress_possible; /* TRUE if we can make more progress */
}
/**
* This function is intended for use with applications that don't want to
- * write a main loop and deal with #DBusWatch and #DBusTimeout.
+ * write a main loop and deal with #DBusWatch and #DBusTimeout. See also
+ * dbus_connection_read_write_dispatch().
*
- * If there are no messages to dispatch, this function will block until it can
- * read or write, then read or write, then return.
+ * As long as the connection is open, this function will block until it can
+ * read or write, then read or write, then return #TRUE.
*
- * 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.
+ * If the connection is closed, the function returns #FALSE.
*
+ * The return value indicates whether reading or writing is still
+ * possible, i.e. whether the connection is connected.
+ *
+ * Note that even after disconnection, messages may remain in the
+ * incoming queue that need to be
+ * processed. dbus_connection_read_write_dispatch() dispatches
+ * incoming messages for you; with dbus_connection_read_write() you
+ * have to arrange to drain the incoming queue yourself.
+ *
* @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
+ * @returns #TRUE if still connected
*/
dbus_bool_t
dbus_connection_read_write (DBusConnection *connection,
connection->n_incoming += 1;
}
+/* Note this may be called multiple times since we don't track whether we already did it */
+static void
+notify_disconnected_unlocked (DBusConnection *connection)
+{
+ HAVE_LOCK_CHECK (connection);
+
+ /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected
+ * connection from dbus_bus_get(). We make the same guarantee for
+ * dbus_connection_open() but in a different way since we don't want to
+ * unref right here; we instead check for connectedness before returning
+ * the connection from the hash.
+ */
+ _dbus_bus_notify_shared_connection_disconnected_unlocked (connection);
+
+ /* 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);
+ }
+ }
+}
+
+/* Note this may be called multiple times since we don't track whether we already did it */
+static DBusDispatchStatus
+notify_disconnected_and_dispatch_complete_unlocked (DBusConnection *connection)
+{
+ HAVE_LOCK_CHECK (connection);
+
+ if (connection->disconnect_message_link != NULL)
+ {
+ _dbus_verbose ("Sending disconnect message from %s\n",
+ _DBUS_FUNCTION_NAME);
+
+ /* If we have pending calls, queue their timeouts - we want the Disconnected
+ * to be the last message, after these timeouts.
+ */
+ connection_timeout_and_complete_all_pending_calls_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;
+
+ return DBUS_DISPATCH_DATA_REMAINS;
+ }
+
+ return DBUS_DISPATCH_COMPLETE;
+}
+
static DBusDispatchStatus
_dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
{
if (!is_connected)
{
- /* It's possible this would be better done by having an
- * explicit notification from
- * _dbus_transport_disconnect() that would synchronously
- * do this, instead of waiting for the next dispatch
- * status check. However, probably not good to change
- * until it causes a problem.
+ /* It's possible this would be better done by having an explicit
+ * notification from _dbus_transport_disconnect() that would
+ * synchronously do this, instead of waiting for the next dispatch
+ * status check. However, probably not good to change until it causes
+ * a problem.
*/
-
- if (status == DBUS_DISPATCH_COMPLETE &&
- connection->disconnect_message_link)
- {
- _dbus_verbose ("Sending disconnect message from %s\n",
- _DBUS_FUNCTION_NAME);
-
- /* If we have pending calls, queue their timeouts - we want the Disconnected
- * to be the last message, after these timeouts.
- */
- connection_timeout_and_complete_all_pending_calls_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;
-
- /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected
- * connection from dbus_bus_get(). We make the same guarantee for
- * dbus_connection_open() but in a different way since we don't want to
- * unref right here; we instead check for connectedness before returning
- * the connection from the hash.
- */
- _dbus_bus_notify_shared_connection_disconnected_unlocked (connection);
-
- status = DBUS_DISPATCH_DATA_REMAINS;
- }
+ notify_disconnected_unlocked (connection);
- /* 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.
+ /* I'm not sure this is needed; the idea is that we want to
+ * queue the Disconnected only after we've read all the
+ * messages, but if we're disconnected maybe we are guaranteed
+ * to have read them all ?
*/
- 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)
+ status = notify_disconnected_and_dispatch_complete_unlocked (connection);
}
if (status != DBUS_DISPATCH_COMPLETE)
}
/**
- * Gets the current state (what we would currently return
- * from dbus_connection_dispatch()) but doesn't actually
- * dispatch any messages.
+ * Gets the current state of the incoming message queue.
+ * #DBUS_DISPATCH_DATA_REMAINS indicates that the message queue
+ * may contain messages. #DBUS_DISPATCH_COMPLETE indicates that the
+ * incoming queue is empty. #DBUS_DISPATCH_NEED_MEMORY indicates that
+ * there could be data, but we can't know for sure without more
+ * memory.
+ *
+ * To process the incoming message queue, use dbus_connection_dispatch()
+ * or (in rare cases) dbus_connection_pop_message().
+ *
+ * Note, #DBUS_DISPATCH_DATA_REMAINS really means that either we
+ * have messages in the queue, or we have raw bytes buffered up
+ * that need to be parsed. When these bytes are parsed, they
+ * may not add up to an entire message. Thus, it's possible
+ * to see a status of #DBUS_DISPATCH_DATA_REMAINS but not
+ * have a message yet.
+ *
+ * In particular this happens on initial connection, because all sorts
+ * of authentication protocol stuff has to be parsed before the
+ * first message arrives.
*
* @param connection the connection.
* @returns current dispatch status
}
/**
- * Processes data buffered while handling watches, queueing zero or
- * more incoming messages. Then pops the first-received message from
- * the current incoming message queue, runs any handlers for it, and
- * unrefs the message. Returns a status indicating whether messages/data
- * remain, more memory is needed, or all data has been processed.
+ * Processes any incoming data.
+ *
+ * If there's incoming raw data that has not yet been parsed, it is
+ * parsed, which may or may not result in adding messages to the
+ * incoming queue.
+ *
+ * The incoming data buffer is filled when the connection reads from
+ * its underlying transport (such as a socket). Reading usually
+ * happens in dbus_watch_handle() or dbus_connection_read_write().
*
- * 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.
+ * If there are complete messages in the incoming queue,
+ * dbus_connection_dispatch() removes one message from the queue and
+ * processes it. Processing has three steps.
*
+ * First, any method replies are passed to #DBusPendingCall or
+ * dbus_connection_send_with_reply_and_block() in order to
+ * complete the pending method call.
+ *
+ * Second, any filters registered with dbus_connection_add_filter()
+ * are run. If any filter returns #DBUS_HANDLER_RESULT_HANDLED
+ * then processing stops after that filter.
+ *
+ * Third, if the message is a method call it is forwarded to
+ * any registered object path handlers added with
+ * dbus_connection_register_object_path() or
+ * dbus_connection_register_fallback().
+ *
+ * A single call to dbus_connection_dispatch() will process at most
+ * one message; it will not clear the entire message queue.
+ *
+ * Be careful about calling dbus_connection_dispatch() from inside a
+ * message handler, i.e. calling dbus_connection_dispatch()
+ * recursively. If threads have been initialized with a recursive
+ * mutex function, then this will not deadlock; however, it can
+ * certainly confuse your application.
+ *
* @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
+ * @returns dispatch status, see dbus_connection_get_dispatch_status()
*/
DBusDispatchStatus
dbus_connection_dispatch (DBusConnection *connection)
#ifndef DBUS_DISABLE_CHECKS
if (connection->watches == NULL)
{
- _dbus_warn ("Re-entrant call to %s is not allowed\n",
- _DBUS_FUNCTION_NAME);
+ _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n",
+ _DBUS_FUNCTION_NAME);
return FALSE;
}
#endif
#ifndef DBUS_DISABLE_CHECKS
if (connection->timeouts == NULL)
{
- _dbus_warn ("Re-entrant call to %s is not allowed\n",
- _DBUS_FUNCTION_NAME);
+ _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n",
+ _DBUS_FUNCTION_NAME);
return FALSE;
}
#endif
}
/**
- * Sets the mainloop wakeup function for the connection. This 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 reconsider
- * (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().
- *
+ * Sets the mainloop wakeup function for the connection. This function
+ * is responsible for waking up the main loop (if its sleeping in
+ * another thread) when some some change has happened to the
+ * connection that the mainloop needs to reconsider (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
* that messages should be dispatched later, when the main loop
* is re-entered.
*
+ * If you don't set a dispatch status function, you have to be sure to
+ * dispatch on every iteration of your main loop, especially if
+ * dbus_watch_handle() or dbus_timeout_handle() were called.
+ *
* @param connection the connection
* @param function function to call on dispatch status changes
* @param data data for function
#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);
+ _dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added\n",
+ function, user_data);
return;
}
#endif
projects / platform / upstream / dbus.git / blobdiff