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dbus/dbus/dbus-connection.c
Simon McVittie bf20f73873 _dbus_modify_sigpipe: be thread-safe 
This needs new atomic primitives: we don't have "set to a value",
and in fact that's a bit annoying to implement in terms of gcc
intrinsics. "Set to 0" and "set to nonzero" are easy, though.
2019-12-12 09:36:32 +01:00

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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-connection.c DBusConnection object
*
* Copyright (C) 2002-2006 Red Hat Inc.
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "dbus-shared.h"
#include "dbus-connection.h"
#include "dbus-list.h"
#include "dbus-timeout.h"
#include "dbus-transport.h"
#include "dbus-watch.h"
#include "dbus-connection-internal.h"
#include "dbus-pending-call-internal.h"
#include "dbus-list.h"
#include "dbus-hash.h"
#include "dbus-message-internal.h"
#include "dbus-message-private.h"
#include "dbus-threads.h"
#include "dbus-protocol.h"
#include "dbus-dataslot.h"
#include "dbus-string.h"
#include "dbus-signature.h"
#include "dbus-pending-call.h"
#include "dbus-object-tree.h"
#include "dbus-threads-internal.h"
#include "dbus-bus.h"
#include "dbus-marshal-basic.h"
#ifdef DBUS_DISABLE_CHECKS
#define TOOK_LOCK_CHECK(connection)
#define RELEASING_LOCK_CHECK(connection)
#define HAVE_LOCK_CHECK(connection)
#else
#define TOOK_LOCK_CHECK(connection) do { \
_dbus_assert (!(connection)->have_connection_lock); \
(connection)->have_connection_lock = TRUE; \
} while (0)
#define RELEASING_LOCK_CHECK(connection) do { \
_dbus_assert ((connection)->have_connection_lock); \
(connection)->have_connection_lock = FALSE; \
} while (0)
#define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock)
/* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */
#endif
#define TRACE_LOCKS 1
#define CONNECTION_LOCK(connection) do { \
if (TRACE_LOCKS) { _dbus_verbose ("LOCK\n"); } \
_dbus_rmutex_lock ((connection)->mutex); \
TOOK_LOCK_CHECK (connection); \
} while (0)
#define CONNECTION_UNLOCK(connection) _dbus_connection_unlock (connection)
#define SLOTS_LOCK(connection) do { \
_dbus_rmutex_lock ((connection)->slot_mutex); \
} while (0)
#define SLOTS_UNLOCK(connection) do { \
_dbus_rmutex_unlock ((connection)->slot_mutex); \
} while (0)
#define DISPATCH_STATUS_NAME(s) \
((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \
(s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \
(s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \
"???")
/**
* @defgroup DBusConnection DBusConnection
* @ingroup DBus
* @brief Connection to another application
*
* A DBusConnection represents a connection to another
* application. Messages can be sent and received via this connection.
* The other application may be a message bus; for convenience, the
* function dbus_bus_get() is provided to automatically open a
* connection to the well-known message buses.
*
* In brief a DBusConnection is a message queue associated with some
* message transport mechanism such as a socket. The connection
* maintains a queue of incoming messages and a queue of outgoing
* messages.
*
* 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, 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. 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
* dbus_watch_handle() invoked by your main loop, or in
* dbus_connection_flush() which blocks until it can write out the
* entire outgoing queue. The GLib/Qt add-on libraries again
* handle the details here for you by setting up watch functions.
*
* When a connection is disconnected, you are guaranteed to get a
* signal "Disconnected" from the interface
* #DBUS_INTERFACE_LOCAL, path
* #DBUS_PATH_LOCAL.
*
* You may not drop the last reference to a #DBusConnection
* until that connection has been disconnected.
*
* You may dispatch the unprocessed incoming message queue even if the
* connection is disconnected. However, "Disconnected" will always be
* the last message in the queue (obviously no messages are received
* after disconnection).
*
* 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.
*/
/**
* @defgroup DBusConnectionInternals DBusConnection implementation details
* @ingroup DBusInternals
* @brief Implementation details of DBusConnection
*
* @{
*/
static void
_dbus_connection_trace_ref (DBusConnection *connection,
int old_refcount,
int new_refcount,
const char *why)
{
#ifdef DBUS_ENABLE_VERBOSE_MODE
static int enabled = -1;
_dbus_trace_ref ("DBusConnection", connection, old_refcount, new_refcount,
why, "DBUS_CONNECTION_TRACE", &enabled);
#endif
}
/**
* Internal struct representing a message filter function
*/
typedef struct DBusMessageFilter DBusMessageFilter;
/**
* Internal struct representing a message filter function
*/
struct DBusMessageFilter
{
DBusAtomic refcount; /**< Reference count */
DBusHandleMessageFunction function; /**< Function to call to filter */
void *user_data; /**< User data for the function */
DBusFreeFunction free_user_data_function; /**< Function to free the user data */
};
/**
* Internals of DBusPreallocatedSend
*/
struct DBusPreallocatedSend
{
DBusConnection *connection; /**< Connection we'd send the message to */
DBusList *queue_link; /**< Preallocated link in the queue */
DBusList *counter_link; /**< Preallocated link in the resource counter */
};
#if HAVE_DECL_MSG_NOSIGNAL
static DBusAtomic _dbus_modify_sigpipe = { FALSE };
#else
static DBusAtomic _dbus_modify_sigpipe = { TRUE };
#endif
/**
* Implementation details of DBusConnection. All fields are private.
*/
struct DBusConnection
{
DBusAtomic refcount; /**< Reference count. */
DBusRMutex *mutex; /**< Lock on the entire DBusConnection */
DBusCMutex *dispatch_mutex; /**< Protects dispatch_acquired */
DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */
DBusCMutex *io_path_mutex; /**< Protects io_path_acquired */
DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */
DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */
DBusList *expired_messages; /**< Messages that will be released when we next unlock. */
DBusMessage *message_borrowed; /**< Filled in if the first incoming message has been borrowed;
* dispatch_acquired will be set by the borrower
*/
int n_outgoing; /**< Length of outgoing queue. */
int n_incoming; /**< Length of incoming queue. */
DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */
DBusTransport *transport; /**< Object that sends/receives messages over network. */
DBusWatchList *watches; /**< Stores active watches. */
DBusTimeoutList *timeouts; /**< Stores active timeouts. */
DBusList *filter_list; /**< List of filters. */
DBusRMutex *slot_mutex; /**< Lock on slot_list so overall connection lock need not be taken */
DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */
DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */
dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */
DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */
DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */
void *wakeup_main_data; /**< Application data for wakeup_main_function */
DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */
DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */
void *dispatch_status_data; /**< Application data for dispatch_status_function */
DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */
DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */
DBusObjectTree *objects; /**< Object path handlers registered with this connection */
char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */
/* These two MUST be bools and not bitfields, because they are protected by a separate lock
* from connection->mutex and all bitfields in a word have to be read/written together.
* So you can't have a different lock for different bitfields in the same word.
*/
dbus_bool_t dispatch_acquired; /**< Someone has dispatch path (can drain incoming queue) */
dbus_bool_t io_path_acquired; /**< Someone has transport io path (can use the transport to read/write messages) */
unsigned int shareable : 1; /**< #TRUE if libdbus owns a reference to the connection and can return it from dbus_connection_open() more than once */
unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */
unsigned int route_peer_messages : 1; /**< If #TRUE, if org.freedesktop.DBus.Peer messages have a bus name, don't handle them automatically */
unsigned int disconnected_message_arrived : 1; /**< We popped or are dispatching the disconnected message.
* if the disconnect_message_link is NULL then we queued it, but
* this flag is whether it got to the head of the queue.
*/
unsigned int disconnected_message_processed : 1; /**< We did our default handling of the disconnected message,
* such as closing the connection.
*/
#ifndef DBUS_DISABLE_CHECKS
unsigned int have_connection_lock : 1; /**< Used to check locking */
#endif
#if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT)
int generation; /**< _dbus_current_generation that should correspond to this connection */
#endif
};
static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection);
static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
DBusDispatchStatus new_status);
static void _dbus_connection_last_unref (DBusConnection *connection);
static void _dbus_connection_acquire_dispatch (DBusConnection *connection);
static void _dbus_connection_release_dispatch (DBusConnection *connection);
static DBusDispatchStatus _dbus_connection_flush_unlocked (DBusConnection *connection);
static void _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection);
static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection);
static dbus_bool_t _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
dbus_uint32_t client_serial);
static DBusMessageFilter *
_dbus_message_filter_ref (DBusMessageFilter *filter)
{
#ifdef DBUS_DISABLE_ASSERT
_dbus_atomic_inc (&filter->refcount);
#else
dbus_int32_t old_value;
old_value = _dbus_atomic_inc (&filter->refcount);
_dbus_assert (old_value > 0);
#endif
return filter;
}
static void
_dbus_message_filter_unref (DBusMessageFilter *filter)
{
dbus_int32_t old_value;
old_value = _dbus_atomic_dec (&filter->refcount);
_dbus_assert (old_value > 0);
if (old_value == 1)
{
if (filter->free_user_data_function)
(* filter->free_user_data_function) (filter->user_data);
dbus_free (filter);
}
}
/**
* Acquires the connection lock.
*
* @param connection the connection.
*/
void
_dbus_connection_lock (DBusConnection *connection)
{
CONNECTION_LOCK (connection);
}
/**
* Releases the connection lock.
*
* @param connection the connection.
*/
void
_dbus_connection_unlock (DBusConnection *connection)
{
DBusList *expired_messages;
DBusList *iter;
if (TRACE_LOCKS)
{
_dbus_verbose ("UNLOCK\n");
}
/* If we had messages that expired (fell off the incoming or outgoing
* queues) while we were locked, actually release them now */
expired_messages = connection->expired_messages;
connection->expired_messages = NULL;
RELEASING_LOCK_CHECK (connection);
_dbus_rmutex_unlock (connection->mutex);
for (iter = _dbus_list_pop_first_link (&expired_messages);
iter != NULL;
iter = _dbus_list_pop_first_link (&expired_messages))
{
DBusMessage *message = iter->data;
dbus_message_unref (message);
_dbus_list_free_link (iter);
}
}
/**
* Wakes up the main loop if it is sleeping
* Needed if we're e.g. queueing outgoing messages
* on a thread while the mainloop sleeps.
*
* @param connection the connection.
*/
static void
_dbus_connection_wakeup_mainloop (DBusConnection *connection)
{
if (connection->wakeup_main_function)
(*connection->wakeup_main_function) (connection->wakeup_main_data);
}
#ifdef DBUS_ENABLE_EMBEDDED_TESTS
/**
* Gets the locks so we can examine them
*
* @param connection the connection.
* @param mutex_loc return for the location of the main mutex pointer
* @param dispatch_mutex_loc return location of the dispatch mutex pointer
* @param io_path_mutex_loc return location of the io_path mutex pointer
* @param dispatch_cond_loc return location of the dispatch conditional
* variable pointer
* @param io_path_cond_loc return location of the io_path conditional
* variable pointer
*/
void
_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 = (DBusMutex *) connection->mutex;
*dispatch_mutex_loc = (DBusMutex *) connection->dispatch_mutex;
*io_path_mutex_loc = (DBusMutex *) connection->io_path_mutex;
*dispatch_cond_loc = connection->dispatch_cond;
*io_path_cond_loc = connection->io_path_cond;
}
#endif
/**
* Adds a message-containing list link to the incoming message queue,
* taking ownership of the link and the message's current refcount.
* Cannot fail due to lack of memory.
*
* @param connection the connection.
* @param link the message link to queue.
*/
void
_dbus_connection_queue_received_message_link (DBusConnection *connection,
DBusList *link)
{
DBusPendingCall *pending;
dbus_uint32_t reply_serial;
DBusMessage *message;
_dbus_assert (_dbus_transport_peek_is_authenticated (connection->transport));
_dbus_list_append_link (&connection->incoming_messages,
link);
message = link->data;
/* If this is a reply we're waiting on, remove timeout for it */
reply_serial = dbus_message_get_reply_serial (message);
if (reply_serial != 0)
{
pending = _dbus_hash_table_lookup_int (connection->pending_replies,
reply_serial);
if (pending != NULL)
{
if (_dbus_pending_call_is_timeout_added_unlocked (pending))
_dbus_connection_remove_timeout_unlocked (connection,
_dbus_pending_call_get_timeout_unlocked (pending));
_dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
}
}
connection->n_incoming += 1;
_dbus_connection_wakeup_mainloop (connection);
_dbus_verbose ("Message %p (%s %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n",
message,
dbus_message_type_to_string (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",
dbus_message_get_signature (message),
dbus_message_get_reply_serial (message),
connection,
connection->n_incoming);
_dbus_message_trace_ref (message, -1, -1,
"_dbus_conection_queue_received_message_link");
}
/**
* Adds a link + message to the incoming message queue.
* Can't fail. Takes ownership of both link and message.
*
* @param connection the connection.
* @param link the list node and message to queue.
*
*/
void
_dbus_connection_queue_synthesized_message_link (DBusConnection *connection,
DBusList *link)
{
HAVE_LOCK_CHECK (connection);
_dbus_list_append_link (&connection->incoming_messages, link);
connection->n_incoming += 1;
_dbus_connection_wakeup_mainloop (connection);
_dbus_message_trace_ref (link->data, -1, -1,
"_dbus_connection_queue_synthesized_message_link");
_dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n",
link->data, connection, connection->n_incoming);
}
/**
* Checks whether there are messages in the outgoing message queue.
* Called with connection lock held.
*
* @param connection the connection.
* @returns #TRUE if the outgoing queue is non-empty.
*/
dbus_bool_t
_dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
return connection->outgoing_messages != NULL;
}
/**
* Checks whether there are messages in the outgoing message queue.
* 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_bool_t
dbus_connection_has_messages_to_send (DBusConnection *connection)
{
dbus_bool_t v;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
v = _dbus_connection_has_messages_to_send_unlocked (connection);
CONNECTION_UNLOCK (connection);
return v;
}
/**
* Gets the next outgoing message. The message remains in the
* queue, and the caller does not own a reference to it.
*
* @param connection the connection.
* @returns the message to be sent.
*/
DBusMessage*
_dbus_connection_get_message_to_send (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
return _dbus_list_get_last (&connection->outgoing_messages);
}
/**
* Notifies the connection that a message has been sent, so the
* message can be removed from the outgoing queue.
* Called with the connection lock held.
*
* @param connection the connection.
* @param message the message that was sent.
*/
void
_dbus_connection_message_sent_unlocked (DBusConnection *connection,
DBusMessage *message)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
/* This can be called before we even complete authentication, since
* it's called on disconnect to clean up the outgoing queue.
* It's also called as we successfully send each message.
*/
link = _dbus_list_get_last_link (&connection->outgoing_messages);
_dbus_assert (link != NULL);
_dbus_assert (link->data == message);
_dbus_list_unlink (&connection->outgoing_messages,
link);
_dbus_list_prepend_link (&connection->expired_messages, link);
connection->n_outgoing -= 1;
_dbus_verbose ("Message %p (%s %s %s %s '%s') removed from outgoing queue %p, %d left to send\n",
message,
dbus_message_type_to_string (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",
dbus_message_get_signature (message),
connection, connection->n_outgoing);
/* It's OK that in principle we call the notify function, because for the
* outgoing limit, there isn't one */
_dbus_message_remove_counter (message, connection->outgoing_counter);
/* The message will actually be unreffed when we unlock */
}
/** 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);
static dbus_bool_t
protected_change_watch (DBusConnection *connection,
DBusWatch *watch,
DBusWatchAddFunction add_function,
DBusWatchRemoveFunction remove_function,
DBusWatchToggleFunction toggle_function,
dbus_bool_t enabled)
{
dbus_bool_t retval;
HAVE_LOCK_CHECK (connection);
/* The original purpose of protected_change_watch() was to hold a
* ref on the connection while dropping the connection lock, then
* calling out to the app. This was a broken hack that did not
* work, since the connection was in a hosed state (no WatchList
* field) while calling out.
*
* So for now we'll just keep the lock while calling out. This means
* apps are not allowed to call DBusConnection methods inside a
* watch function or they will deadlock.
*
* The "real fix" is to use the _and_unlock() pattern found
* elsewhere in the code, to defer calling out to the app until
* we're about to drop locks and return flow of control to the app
* anyway.
*
* See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
*/
if (connection->watches)
{
if (add_function)
retval = (* add_function) (connection->watches, watch);
else if (remove_function)
{
retval = TRUE;
(* remove_function) (connection->watches, watch);
}
else
{
retval = TRUE;
(* toggle_function) (connection->watches, watch, enabled);
}
return retval;
}
else
return FALSE;
}
/**
* Adds a watch using the connection's DBusAddWatchFunction if
* available. Otherwise records the watch to be added when said
* function is available. Also re-adds the watch if the
* DBusAddWatchFunction changes. May fail due to lack of memory.
* Connection lock should be held when calling this.
*
* @param connection the connection.
* @param watch the watch to add.
* @returns #TRUE on success.
*/
dbus_bool_t
_dbus_connection_add_watch_unlocked (DBusConnection *connection,
DBusWatch *watch)
{
return protected_change_watch (connection, watch,
_dbus_watch_list_add_watch,
NULL, NULL, FALSE);
}
/**
* Removes a watch using the connection's DBusRemoveWatchFunction
* if available. It's an error to call this function on a watch
* that was not previously added.
* Connection lock should be held when calling this.
*
* @param connection the connection.
* @param watch the watch to remove.
*/
void
_dbus_connection_remove_watch_unlocked (DBusConnection *connection,
DBusWatch *watch)
{
protected_change_watch (connection, watch,
NULL,
_dbus_watch_list_remove_watch,
NULL, FALSE);
}
/**
* Toggles a watch and notifies app via connection's
* DBusWatchToggledFunction if available. It's an error to call this
* function on a watch that was not previously added.
* Connection lock should be held when calling this.
*
* @param connection the connection.
* @param watch the watch to toggle.
* @param enabled whether to enable or disable
*/
void
_dbus_connection_toggle_watch_unlocked (DBusConnection *connection,
DBusWatch *watch,
dbus_bool_t enabled)
{
_dbus_assert (watch != NULL);
protected_change_watch (connection, watch,
NULL, NULL,
_dbus_watch_list_toggle_watch,
enabled);
}
/** 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);
static dbus_bool_t
protected_change_timeout (DBusConnection *connection,
DBusTimeout *timeout,
DBusTimeoutAddFunction add_function,
DBusTimeoutRemoveFunction remove_function,
DBusTimeoutToggleFunction toggle_function,
dbus_bool_t enabled)
{
dbus_bool_t retval;
HAVE_LOCK_CHECK (connection);
/* The original purpose of protected_change_timeout() was to hold a
* ref on the connection while dropping the connection lock, then
* calling out to the app. This was a broken hack that did not
* work, since the connection was in a hosed state (no TimeoutList
* field) while calling out.
*
* So for now we'll just keep the lock while calling out. This means
* apps are not allowed to call DBusConnection methods inside a
* timeout function or they will deadlock.
*
* The "real fix" is to use the _and_unlock() pattern found
* elsewhere in the code, to defer calling out to the app until
* we're about to drop locks and return flow of control to the app
* anyway.
*
* See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
*/
if (connection->timeouts)
{
if (add_function)
retval = (* add_function) (connection->timeouts, timeout);
else if (remove_function)
{
retval = TRUE;
(* remove_function) (connection->timeouts, timeout);
}
else
{
retval = TRUE;
(* toggle_function) (connection->timeouts, timeout, enabled);
}
return retval;
}
else
return FALSE;
}
/**
* Adds a timeout using the connection's DBusAddTimeoutFunction if
* available. Otherwise records the timeout to be added when said
* function is available. Also re-adds the timeout if the
* DBusAddTimeoutFunction changes. May fail due to lack of memory.
* The timeout will fire repeatedly until removed.
* Connection lock should be held when calling this.
*
* @param connection the connection.
* @param timeout the timeout to add.
* @returns #TRUE on success.
*/
dbus_bool_t
_dbus_connection_add_timeout_unlocked (DBusConnection *connection,
DBusTimeout *timeout)
{
return protected_change_timeout (connection, timeout,
_dbus_timeout_list_add_timeout,
NULL, NULL, FALSE);
}
/**
* Removes a timeout using the connection's DBusRemoveTimeoutFunction
* if available. It's an error to call this function on a timeout
* that was not previously added.
* Connection lock should be held when calling this.
*
* @param connection the connection.
* @param timeout the timeout to remove.
*/
void
_dbus_connection_remove_timeout_unlocked (DBusConnection *connection,
DBusTimeout *timeout)
{
protected_change_timeout (connection, timeout,
NULL,
_dbus_timeout_list_remove_timeout,
NULL, FALSE);
}
/**
* Toggles a timeout and notifies app via connection's
* DBusTimeoutToggledFunction if available. It's an error to call this
* function on a timeout that was not previously added.
* Connection lock should be held when calling this.
*
* @param connection the connection.
* @param timeout the timeout to toggle.
* @param enabled whether to enable or disable
*/
void
_dbus_connection_toggle_timeout_unlocked (DBusConnection *connection,
DBusTimeout *timeout,
dbus_bool_t enabled)
{
protected_change_timeout (connection, timeout,
NULL, NULL,
_dbus_timeout_list_toggle_timeout,
enabled);
}
static dbus_bool_t
_dbus_connection_attach_pending_call_unlocked (DBusConnection *connection,
DBusPendingCall *pending)
{
dbus_uint32_t reply_serial;
DBusTimeout *timeout;
HAVE_LOCK_CHECK (connection);
reply_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
_dbus_assert (reply_serial != 0);
timeout = _dbus_pending_call_get_timeout_unlocked (pending);
if (timeout)
{
if (!_dbus_connection_add_timeout_unlocked (connection, timeout))
return FALSE;
if (!_dbus_hash_table_insert_int (connection->pending_replies,
reply_serial,
pending))
{
_dbus_connection_remove_timeout_unlocked (connection, timeout);
_dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
HAVE_LOCK_CHECK (connection);
return FALSE;
}
_dbus_pending_call_set_timeout_added_unlocked (pending, TRUE);
}
else
{
if (!_dbus_hash_table_insert_int (connection->pending_replies,
reply_serial,
pending))
{
HAVE_LOCK_CHECK (connection);
return FALSE;
}
}
_dbus_pending_call_ref_unlocked (pending);
HAVE_LOCK_CHECK (connection);
return TRUE;
}
static void
free_pending_call_on_hash_removal (void *data)
{
DBusPendingCall *pending;
DBusConnection *connection;
if (data == NULL)
return;
pending = data;
connection = _dbus_pending_call_get_connection_unlocked (pending);
HAVE_LOCK_CHECK (connection);
if (_dbus_pending_call_is_timeout_added_unlocked (pending))
{
_dbus_connection_remove_timeout_unlocked (connection,
_dbus_pending_call_get_timeout_unlocked (pending));
_dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
}
/* FIXME 1.0? this is sort of dangerous and undesirable to drop the lock
* here, but the pending call finalizer could in principle call out to
* application code so we pretty much have to... some larger code reorg
* might be needed.
*/
_dbus_connection_ref_unlocked (connection);
_dbus_pending_call_unref_and_unlock (pending);
CONNECTION_LOCK (connection);
_dbus_connection_unref_unlocked (connection);
}
static void
_dbus_connection_detach_pending_call_unlocked (DBusConnection *connection,
DBusPendingCall *pending)
{
/* This ends up unlocking to call the pending call finalizer, which is unexpected to
* say the least.
*/
_dbus_hash_table_remove_int (connection->pending_replies,
_dbus_pending_call_get_reply_serial_unlocked (pending));
}
static void
_dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection,
DBusPendingCall *pending)
{
/* The idea here is to avoid finalizing the pending call
* with the lock held, since there's a destroy notifier
* in pending call that goes out to application code.
*
* There's an extra unlock inside the hash table
* "free pending call" function FIXME...
*/
_dbus_pending_call_ref_unlocked (pending);
_dbus_hash_table_remove_int (connection->pending_replies,
_dbus_pending_call_get_reply_serial_unlocked (pending));
if (_dbus_pending_call_is_timeout_added_unlocked (pending))
_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_unref_and_unlock (pending);
}
/**
* Removes a pending call from the connection, such that
* the pending reply will be ignored. May drop the last
* reference to the pending call.
*
* @param connection the connection
* @param pending the pending call
*/
void
_dbus_connection_remove_pending_call (DBusConnection *connection,
DBusPendingCall *pending)
{
CONNECTION_LOCK (connection);
_dbus_connection_detach_pending_call_and_unlock (connection, pending);
}
/**
* Acquire the transporter I/O path. This must be done before
* doing any I/O in the transporter. May sleep and drop the
* IO path mutex while waiting for the I/O path.
*
* @param connection the connection.
* @param timeout_milliseconds maximum blocking time, or -1 for no limit.
* @returns TRUE if the I/O path was acquired.
*/
static dbus_bool_t
_dbus_connection_acquire_io_path (DBusConnection *connection,
int timeout_milliseconds)
{
dbus_bool_t we_acquired;
HAVE_LOCK_CHECK (connection);
/* We don't want the connection to vanish */
_dbus_connection_ref_unlocked (connection);
/* We will only touch io_path_acquired which is protected by our mutex */
CONNECTION_UNLOCK (connection);
_dbus_verbose ("locking io_path_mutex\n");
_dbus_cmutex_lock (connection->io_path_mutex);
_dbus_verbose ("start connection->io_path_acquired = %d timeout = %d\n",
connection->io_path_acquired, timeout_milliseconds);
we_acquired = FALSE;
if (connection->io_path_acquired)
{
if (timeout_milliseconds != -1)
{
_dbus_verbose ("waiting %d for IO path to be acquirable\n",
timeout_milliseconds);
if (!_dbus_condvar_wait_timeout (connection->io_path_cond,
connection->io_path_mutex,
timeout_milliseconds))
{
/* We timed out before anyone signaled. */
/* (writing the loop to handle the !timedout case by
* waiting longer if needed is a pain since dbus
* wraps pthread_cond_timedwait to take a relative
* time instead of absolute, something kind of stupid
* on our part. for now it doesn't matter, we will just
* end up back here eventually.)
*/
}
}
else
{
while (connection->io_path_acquired)
{
_dbus_verbose ("waiting for IO path to be acquirable\n");
_dbus_condvar_wait (connection->io_path_cond,
connection->io_path_mutex);
}
}
}
if (!connection->io_path_acquired)
{
we_acquired = TRUE;
connection->io_path_acquired = TRUE;
}
_dbus_verbose ("end connection->io_path_acquired = %d we_acquired = %d\n",
connection->io_path_acquired, we_acquired);
_dbus_verbose ("unlocking io_path_mutex\n");
_dbus_cmutex_unlock (connection->io_path_mutex);
CONNECTION_LOCK (connection);
HAVE_LOCK_CHECK (connection);
_dbus_connection_unref_unlocked (connection);
return we_acquired;
}
/**
* Release the I/O path when you're done with it. Only call
* after you've acquired the I/O. Wakes up at most one thread
* currently waiting to acquire the I/O path.
*
* @param connection the connection.
*/
static void
_dbus_connection_release_io_path (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("locking io_path_mutex\n");
_dbus_cmutex_lock (connection->io_path_mutex);
_dbus_assert (connection->io_path_acquired);
_dbus_verbose ("start connection->io_path_acquired = %d\n",
connection->io_path_acquired);
connection->io_path_acquired = FALSE;
_dbus_condvar_wake_one (connection->io_path_cond);
_dbus_verbose ("unlocking io_path_mutex\n");
_dbus_cmutex_unlock (connection->io_path_mutex);
}
/**
* Queues incoming messages and sends outgoing messages for this
* connection, optionally blocking in the process. Each call to
* _dbus_connection_do_iteration_unlocked() will call select() or poll() one
* time and then read or write data if possible.
*
* The purpose of this function is to be able to flush outgoing
* messages or queue up incoming messages without returning
* control to the application and causing reentrancy weirdness.
*
* The flags parameter allows you to specify whether to
* read incoming messages, write outgoing messages, or both,
* and whether to block if no immediate action is possible.
*
* The timeout_milliseconds parameter does nothing unless the
* iteration is blocking.
*
* If there are no outgoing messages and DBUS_ITERATION_DO_READING
* wasn't specified, then it's impossible to block, even if
* you specify DBUS_ITERATION_BLOCK; in that case the function
* returns immediately.
*
* If pending is not NULL then a check is made if the pending call
* is completed after the io path has been required. If the call
* has been completed nothing is done. This must be done since
* the _dbus_connection_acquire_io_path releases the connection
* lock for a while.
*
* Called with connection lock held.
*
* @param connection the connection.
* @param pending the pending call that should be checked or NULL
* @param flags iteration flags.
* @param timeout_milliseconds maximum blocking time, or -1 for no limit.
*/
void
_dbus_connection_do_iteration_unlocked (DBusConnection *connection,
DBusPendingCall *pending,
unsigned int flags,
int timeout_milliseconds)
{
_dbus_verbose ("start\n");
HAVE_LOCK_CHECK (connection);
if (connection->n_outgoing == 0)
flags &= ~DBUS_ITERATION_DO_WRITING;
if (_dbus_connection_acquire_io_path (connection,
(flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0))
{
HAVE_LOCK_CHECK (connection);
if ( (pending != NULL) && _dbus_pending_call_get_completed_unlocked(pending))
{
_dbus_verbose ("pending call completed while acquiring I/O path");
}
else if ( (pending != NULL) &&
_dbus_connection_peek_for_reply_unlocked (connection,
_dbus_pending_call_get_reply_serial_unlocked (pending)))
{
_dbus_verbose ("pending call completed while acquiring I/O path (reply found in queue)");
}
else
{
_dbus_transport_do_iteration (connection->transport,
flags, timeout_milliseconds);
}
_dbus_connection_release_io_path (connection);
}
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("end\n");
}
/**
* Creates a new connection for the given transport. A transport
* represents a message stream that uses some concrete mechanism, such
* as UNIX domain sockets. May return #NULL if insufficient
* memory exists to create the connection.
*
* @param transport the transport.
* @returns the new connection, or #NULL on failure.
*/
DBusConnection*
_dbus_connection_new_for_transport (DBusTransport *transport)
{
DBusConnection *connection;
DBusWatchList *watch_list;
DBusTimeoutList *timeout_list;
DBusHashTable *pending_replies;
DBusList *disconnect_link;
DBusMessage *disconnect_message;
DBusCounter *outgoing_counter;
DBusObjectTree *objects;
watch_list = NULL;
connection = NULL;
pending_replies = NULL;
timeout_list = NULL;
disconnect_link = NULL;
disconnect_message = NULL;
outgoing_counter = NULL;
objects = NULL;
watch_list = _dbus_watch_list_new ();
if (watch_list == NULL)
goto error;
timeout_list = _dbus_timeout_list_new ();
if (timeout_list == NULL)
goto error;
pending_replies =
_dbus_hash_table_new (DBUS_HASH_INT,
NULL,
(DBusFreeFunction)free_pending_call_on_hash_removal);
if (pending_replies == NULL)
goto error;
connection = dbus_new0 (DBusConnection, 1);
if (connection == NULL)
goto error;
_dbus_rmutex_new_at_location (&connection->mutex);
if (connection->mutex == NULL)
goto error;
_dbus_cmutex_new_at_location (&connection->io_path_mutex);
if (connection->io_path_mutex == NULL)
goto error;
_dbus_cmutex_new_at_location (&connection->dispatch_mutex);
if (connection->dispatch_mutex == NULL)
goto error;
_dbus_condvar_new_at_location (&connection->dispatch_cond);
if (connection->dispatch_cond == NULL)
goto error;
_dbus_condvar_new_at_location (&connection->io_path_cond);
if (connection->io_path_cond == NULL)
goto error;
_dbus_rmutex_new_at_location (&connection->slot_mutex);
if (connection->slot_mutex == NULL)
goto error;
disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL,
DBUS_INTERFACE_LOCAL,
"Disconnected");
if (disconnect_message == NULL)
goto error;
disconnect_link = _dbus_list_alloc_link (disconnect_message);
if (disconnect_link == NULL)
goto error;
outgoing_counter = _dbus_counter_new ();
if (outgoing_counter == NULL)
goto error;
objects = _dbus_object_tree_new (connection);
if (objects == NULL)
goto error;
if (_dbus_atomic_get (&_dbus_modify_sigpipe) != 0)
_dbus_disable_sigpipe ();
/* initialized to 0: use atomic op to avoid mixing atomic and non-atomic */
_dbus_atomic_inc (&connection->refcount);
connection->transport = transport;
connection->watches = watch_list;
connection->timeouts = timeout_list;
connection->pending_replies = pending_replies;
connection->outgoing_counter = outgoing_counter;
connection->filter_list = NULL;
connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */
connection->objects = objects;
connection->exit_on_disconnect = FALSE;
connection->shareable = FALSE;
connection->route_peer_messages = FALSE;
connection->disconnected_message_arrived = FALSE;
connection->disconnected_message_processed = FALSE;
#if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT)
connection->generation = _dbus_current_generation;
#endif
_dbus_data_slot_list_init (&connection->slot_list);
connection->client_serial = 1;
connection->disconnect_message_link = disconnect_link;
CONNECTION_LOCK (connection);
if (!_dbus_transport_set_connection (transport, connection))
{
CONNECTION_UNLOCK (connection);
goto error;
}
_dbus_transport_ref (transport);
CONNECTION_UNLOCK (connection);
_dbus_connection_trace_ref (connection, 0, 1, "new_for_transport");
return connection;
error:
if (disconnect_message != NULL)
dbus_message_unref (disconnect_message);
if (disconnect_link != NULL)
_dbus_list_free_link (disconnect_link);
if (connection != NULL)
{
_dbus_condvar_free_at_location (&connection->io_path_cond);
_dbus_condvar_free_at_location (&connection->dispatch_cond);
_dbus_rmutex_free_at_location (&connection->mutex);
_dbus_cmutex_free_at_location (&connection->io_path_mutex);
_dbus_cmutex_free_at_location (&connection->dispatch_mutex);
_dbus_rmutex_free_at_location (&connection->slot_mutex);
dbus_free (connection);
}
if (pending_replies)
_dbus_hash_table_unref (pending_replies);
if (watch_list)
_dbus_watch_list_free (watch_list);
if (timeout_list)
_dbus_timeout_list_free (timeout_list);
if (outgoing_counter)
_dbus_counter_unref (outgoing_counter);
if (objects)
_dbus_object_tree_unref (objects);
return NULL;
}
/**
* Increments the reference count of a DBusConnection.
* Requires that the caller already holds the connection lock.
*
* @param connection the connection.
* @returns the connection.
*/
DBusConnection *
_dbus_connection_ref_unlocked (DBusConnection *connection)
{
dbus_int32_t old_refcount;
_dbus_assert (connection != NULL);
_dbus_assert (connection->generation == _dbus_current_generation);
HAVE_LOCK_CHECK (connection);
old_refcount = _dbus_atomic_inc (&connection->refcount);
_dbus_connection_trace_ref (connection, old_refcount, old_refcount + 1,
"ref_unlocked");
return connection;
}
/**
* Decrements the reference count of a DBusConnection.
* Requires that the caller already holds the connection lock.
*
* @param connection the connection.
*/
void
_dbus_connection_unref_unlocked (DBusConnection *connection)
{
dbus_int32_t old_refcount;
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection != NULL);
old_refcount = _dbus_atomic_dec (&connection->refcount);
_dbus_connection_trace_ref (connection, old_refcount, old_refcount - 1,
"unref_unlocked");
if (old_refcount == 1)
_dbus_connection_last_unref (connection);
}
static dbus_uint32_t
_dbus_connection_get_next_client_serial (DBusConnection *connection)
{
dbus_uint32_t serial;
serial = connection->client_serial++;
if (connection->client_serial == 0)
connection->client_serial = 1;
return serial;
}
/**
* A callback for use with dbus_watch_new() to create a DBusWatch.
*
* @todo This is basically a hack - we could delete _dbus_transport_handle_watch()
* and the virtual handle_watch in DBusTransport if we got rid of it.
* The reason this is some work is threading, see the _dbus_connection_handle_watch()
* implementation.
*
* @param watch the watch.
* @param condition the current condition of the file descriptors being watched.
* @param data must be a pointer to a #DBusConnection
* @returns #FALSE if the IO condition may not have been fully handled due to lack of memory
*/
dbus_bool_t
_dbus_connection_handle_watch (DBusWatch *watch,
unsigned int condition,
void *data)
{
DBusConnection *connection;
dbus_bool_t retval;
DBusDispatchStatus status;
connection = data;
_dbus_verbose ("start\n");
CONNECTION_LOCK (connection);
if (!_dbus_connection_acquire_io_path (connection, 1))
{
/* another thread is handling the message */
CONNECTION_UNLOCK (connection);
return TRUE;
}
HAVE_LOCK_CHECK (connection);
retval = _dbus_transport_handle_watch (connection->transport,
watch, condition);
_dbus_connection_release_io_path (connection);
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("middle\n");
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
_dbus_verbose ("end\n");
return retval;
}
/* Protected by _DBUS_LOCK (shared_connections) */
static DBusHashTable *shared_connections = NULL;
static DBusList *shared_connections_no_guid = NULL;
static void
close_connection_on_shutdown (DBusConnection *connection)
{
DBusMessage *message;
dbus_connection_ref (connection);
_dbus_connection_close_possibly_shared (connection);
/* Churn through to the Disconnected message */
while ((message = dbus_connection_pop_message (connection)))
{
dbus_message_unref (message);
}
dbus_connection_unref (connection);
}
static void
shared_connections_shutdown (void *data)
{
int n_entries;
if (!_DBUS_LOCK (shared_connections))
{
/* We'd have initialized locks before adding anything, so there
* can't be anything there. */
return;
}
/* This is a little bit unpleasant... better ideas? */
while ((n_entries = _dbus_hash_table_get_n_entries (shared_connections)) > 0)
{
DBusConnection *connection;
DBusHashIter iter;
_dbus_hash_iter_init (shared_connections, &iter);
_dbus_hash_iter_next (&iter);
connection = _dbus_hash_iter_get_value (&iter);
_DBUS_UNLOCK (shared_connections);
close_connection_on_shutdown (connection);
if (!_DBUS_LOCK (shared_connections))
_dbus_assert_not_reached ("global locks were already initialized");
/* The connection should now be dead and not in our hash ... */
_dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) < n_entries);
}
_dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0);
_dbus_hash_table_unref (shared_connections);
shared_connections = NULL;
if (shared_connections_no_guid != NULL)
{
DBusConnection *connection;
connection = _dbus_list_pop_first (&shared_connections_no_guid);
while (connection != NULL)
{
_DBUS_UNLOCK (shared_connections);
close_connection_on_shutdown (connection);
if (!_DBUS_LOCK (shared_connections))
_dbus_assert_not_reached ("global locks were already initialized");
connection = _dbus_list_pop_first (&shared_connections_no_guid);
}
}
shared_connections_no_guid = NULL;
_DBUS_UNLOCK (shared_connections);
}
static dbus_bool_t
connection_lookup_shared (DBusAddressEntry *entry,
DBusConnection **result)
{
_dbus_verbose ("checking for existing connection\n");
*result = NULL;
if (!_DBUS_LOCK (shared_connections))
{
/* If it was shared, we'd have initialized global locks when we put
* it in shared_connections. */
return FALSE;
}
if (shared_connections == NULL)
{
_dbus_verbose ("creating shared_connections hash table\n");
shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING,
dbus_free,
NULL);
if (shared_connections == NULL)
{
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL))
{
_dbus_hash_table_unref (shared_connections);
shared_connections = NULL;
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
_dbus_verbose (" successfully created shared_connections\n");
_DBUS_UNLOCK (shared_connections);
return TRUE; /* no point looking up in the hash we just made */
}
else
{
const char *guid;
guid = dbus_address_entry_get_value (entry, "guid");
if (guid != NULL)
{
DBusConnection *connection;
connection = _dbus_hash_table_lookup_string (shared_connections,
guid);
if (connection)
{
/* The DBusConnection can't be finalized without taking
* the shared_connections lock to remove it from the
* hash. So it's safe to ref the connection here.
* However, it may be disconnected if the Disconnected
* message hasn't been processed yet, in which case we
* want to pretend it isn't in the hash and avoid
* returning it.
*
* The idea is to avoid ever returning a disconnected connection
* from dbus_connection_open(). We could just synchronously
* drop our shared ref to the connection on connection disconnect,
* and then assert here that the connection is connected, but
* that causes reentrancy headaches.
*/
CONNECTION_LOCK (connection);
if (_dbus_connection_get_is_connected_unlocked (connection))
{
_dbus_connection_ref_unlocked (connection);
*result = connection;
_dbus_verbose ("looked up existing connection to server guid %s\n",
guid);
}
else
{
_dbus_verbose ("looked up existing connection to server guid %s but it was disconnected so ignoring it\n",
guid);
}
CONNECTION_UNLOCK (connection);
}
}
_DBUS_UNLOCK (shared_connections);
return TRUE;
}
}
static dbus_bool_t
connection_record_shared_unlocked (DBusConnection *connection,
const char *guid)
{
char *guid_key;
char *guid_in_connection;
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection->server_guid == NULL);
_dbus_assert (connection->shareable);
/* get a hard ref on this connection, even if
* we won't in fact store it in the hash, we still
* need to hold a ref on it until it's disconnected.
*/
_dbus_connection_ref_unlocked (connection);
if (guid == NULL)
{
if (!_DBUS_LOCK (shared_connections))
return FALSE;
if (!_dbus_list_prepend (&shared_connections_no_guid, connection))
{
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
_DBUS_UNLOCK (shared_connections);
return TRUE; /* don't store in the hash */
}
/* A separate copy of the key is required in the hash table, because
* we don't have a lock on the connection when we are doing a hash
* lookup.
*/
guid_key = _dbus_strdup (guid);
if (guid_key == NULL)
return FALSE;
guid_in_connection = _dbus_strdup (guid);
if (guid_in_connection == NULL)
{
dbus_free (guid_key);
return FALSE;
}
if (!_DBUS_LOCK (shared_connections))
{
dbus_free (guid_in_connection);
dbus_free (guid_key);
return FALSE;
}
_dbus_assert (shared_connections != NULL);
if (!_dbus_hash_table_insert_string (shared_connections,
guid_key, connection))
{
dbus_free (guid_key);
dbus_free (guid_in_connection);
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
connection->server_guid = guid_in_connection;
_dbus_verbose ("stored connection to %s to be shared\n",
connection->server_guid);
_DBUS_UNLOCK (shared_connections);
_dbus_assert (connection->server_guid != NULL);
return TRUE;
}
static void
connection_forget_shared_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
if (!connection->shareable)
return;
if (!_DBUS_LOCK (shared_connections))
{
/* If it was shared, we'd have initialized global locks when we put
* it in the table; so it can't be there. */
return;
}
if (connection->server_guid != NULL)
{
_dbus_verbose ("dropping connection to %s out of the shared table\n",
connection->server_guid);
if (!_dbus_hash_table_remove_string (shared_connections,
connection->server_guid))
_dbus_assert_not_reached ("connection was not in the shared table");
dbus_free (connection->server_guid);
connection->server_guid = NULL;
}
else
{
_dbus_list_remove (&shared_connections_no_guid, connection);
}
_DBUS_UNLOCK (shared_connections);
/* remove our reference held on all shareable connections */
_dbus_connection_unref_unlocked (connection);
}
static DBusConnection*
connection_try_from_address_entry (DBusAddressEntry *entry,
DBusError *error)
{
DBusTransport *transport;
DBusConnection *connection;
transport = _dbus_transport_open (entry, error);
if (transport == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
return NULL;
}
connection = _dbus_connection_new_for_transport (transport);
_dbus_transport_unref (transport);
if (connection == NULL)
{
_DBUS_SET_OOM (error);
return NULL;
}
#ifndef DBUS_DISABLE_CHECKS
_dbus_assert (!connection->have_connection_lock);
#endif
return connection;
}
/*
* If the shared parameter is true, then any existing connection will
* be used (and if a new connection is created, it will be available
* for use by others). If the shared parameter is false, a new
* connection will always be created, and the new connection will
* never be returned to other callers.
*
* @param address the address
* @param shared whether the connection is shared or private
* @param error error return
* @returns the connection or #NULL on error
*/
static DBusConnection*
_dbus_connection_open_internal (const char *address,
dbus_bool_t shared,
DBusError *error)
{
DBusConnection *connection;
DBusAddressEntry **entries;
DBusError tmp_error = DBUS_ERROR_INIT;
DBusError first_error = DBUS_ERROR_INIT;
int len, i;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
_dbus_verbose ("opening %s connection to: %s\n",
shared ? "shared" : "private", address);
if (!dbus_parse_address (address, &entries, &len, error))
return NULL;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
connection = NULL;
for (i = 0; i < len; i++)
{
if (shared)
{
if (!connection_lookup_shared (entries[i], &connection))
_DBUS_SET_OOM (&tmp_error);
}
if (connection == NULL)
{
connection = connection_try_from_address_entry (entries[i],
&tmp_error);
if (connection != NULL && shared)
{
const char *guid;
connection->shareable = TRUE;
/* guid may be NULL */
guid = dbus_address_entry_get_value (entries[i], "guid");
CONNECTION_LOCK (connection);
if (!connection_record_shared_unlocked (connection, guid))
{
_DBUS_SET_OOM (&tmp_error);
_dbus_connection_close_possibly_shared_and_unlock (connection);
dbus_connection_unref (connection);
connection = NULL;
}
else
CONNECTION_UNLOCK (connection);
}
}
if (connection)
break;
_DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
if (i == 0)
dbus_move_error (&tmp_error, &first_error);
else
dbus_error_free (&tmp_error);
}
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
_DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
if (connection == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (&first_error);
dbus_move_error (&first_error, error);
}
else
dbus_error_free (&first_error);
dbus_address_entries_free (entries);
return connection;
}
/**
* 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 connection the 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);
}
static DBusPreallocatedSend*
_dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
{
DBusPreallocatedSend *preallocated;
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection != NULL);
preallocated = dbus_new (DBusPreallocatedSend, 1);
if (preallocated == NULL)
return NULL;
preallocated->queue_link = _dbus_list_alloc_link (NULL);
if (preallocated->queue_link == NULL)
goto failed_0;
preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
if (preallocated->counter_link == NULL)
goto failed_1;
_dbus_counter_ref (preallocated->counter_link->data);
preallocated->connection = connection;
return preallocated;
failed_1:
_dbus_list_free_link (preallocated->queue_link);
failed_0:
dbus_free (preallocated);
return NULL;
}
/* 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;
preallocated->queue_link->data = message;
_dbus_list_prepend_link (&connection->outgoing_messages,
preallocated->queue_link);
/* It's OK that we'll never call the notify function, because for the
* outgoing limit, there isn't one */
_dbus_message_add_counter_link (message,
preallocated->counter_link);
dbus_free (preallocated);
preallocated = NULL;
dbus_message_ref (message);
connection->n_outgoing += 1;
_dbus_verbose ("Message %p (%s %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n",
message,
dbus_message_type_to_string (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",
dbus_message_get_signature (message),
dbus_message_get_destination (message) ?
dbus_message_get_destination (message) :
"null",
connection,
connection->n_outgoing);
if (dbus_message_get_serial (message) == 0)
{
serial = _dbus_connection_get_next_client_serial (connection);
dbus_message_set_serial (message, serial);
if (client_serial)
*client_serial = serial;
}
else
{
if (client_serial)
*client_serial = dbus_message_get_serial (message);
}
_dbus_verbose ("Message %p serial is %u\n",
message, dbus_message_get_serial (message));
dbus_message_lock (message);
/* Now we need to run an iteration to hopefully just write the messages
* out immediately, and otherwise get them queued up
*/
_dbus_connection_do_iteration_unlocked (connection,
NULL,
DBUS_ITERATION_DO_WRITING,
-1);
/* If stuff is still queued up, be sure we wake up the main loop */
if (connection->n_outgoing > 0)
_dbus_connection_wakeup_mainloop (connection);
}
static void
_dbus_connection_send_preallocated_and_unlock (DBusConnection *connection,
DBusPreallocatedSend *preallocated,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
DBusDispatchStatus status;
HAVE_LOCK_CHECK (connection);
_dbus_connection_send_preallocated_unlocked_no_update (connection,
preallocated,
message, client_serial);
_dbus_verbose ("middle\n");
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
}
/**
* Like dbus_connection_send(), but assumes the connection
* is already locked on function entry, and unlocks before returning.
*
* @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
*/
dbus_bool_t
_dbus_connection_send_and_unlock (DBusConnection *connection,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
DBusPreallocatedSend *preallocated;
_dbus_assert (connection != NULL);
_dbus_assert (message != NULL);
preallocated = _dbus_connection_preallocate_send_unlocked (connection);
if (preallocated == NULL)
{
CONNECTION_UNLOCK (connection);
return FALSE;
}
_dbus_connection_send_preallocated_and_unlock (connection,
preallocated,
message,
client_serial);
return TRUE;
}
/**
* Used internally to handle the semantics of dbus_server_set_new_connection_function().
* If the new connection function does not ref the connection, we want to close it.
*
* A bit of a hack, probably the new connection function should have returned a value
* for whether to close, or should have had to close the connection itself if it
* didn't want it.
*
* But, this works OK as long as the new connection function doesn't do anything
* crazy like keep the connection around without ref'ing it.
*
* We have to lock the connection across refcount check and close in case
* the new connection function spawns a thread that closes and unrefs.
* In that case, if the app thread
* closes and unrefs first, we'll harmlessly close again; if the app thread
* still has the ref, we'll close and then the app will close harmlessly.
* If the app unrefs without closing, the app is broken since if the
* app refs from the new connection function it is supposed to also close.
*
* If we didn't atomically check the refcount and close with the lock held
* though, we could screw this up.
*
* @param connection the connection
*/
void
_dbus_connection_close_if_only_one_ref (DBusConnection *connection)
{
dbus_int32_t refcount;
CONNECTION_LOCK (connection);
refcount = _dbus_atomic_get (&connection->refcount);
/* The caller should have at least one ref */
_dbus_assert (refcount >= 1);
if (refcount == 1)
_dbus_connection_close_possibly_shared_and_unlock (connection);
else
CONNECTION_UNLOCK (connection);
}
/**
* 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 timeout_milliseconds the timeout requested for blocking
*/
static void
_dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
{
if (timeout_milliseconds == -1)
_dbus_sleep_milliseconds (1000);
else if (timeout_milliseconds < 100)
; /* just busy loop */
else if (timeout_milliseconds <= 1000)
_dbus_sleep_milliseconds (timeout_milliseconds / 3);
else
_dbus_sleep_milliseconds (1000);
}
static DBusMessage *
generate_local_error_message (dbus_uint32_t serial,
const char *error_name,
const char *error_msg)
{
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;
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;
}
/*
* Peek the incoming queue to see if we got reply for a specific serial
*/
static dbus_bool_t
_dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
dbus_uint32_t client_serial)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
link = _dbus_list_get_first_link (&connection->incoming_messages);
while (link != NULL)
{
DBusMessage *reply = link->data;
if (dbus_message_get_reply_serial (reply) == client_serial)
{
_dbus_verbose ("%s reply to %d found in queue\n", _DBUS_FUNCTION_NAME, client_serial);
return TRUE;
}
link = _dbus_list_get_next_link (&connection->incoming_messages, link);
}
return FALSE;
}
/* This is slightly strange since we can pop a message here without
* the dispatch lock.
*/
static DBusMessage*
check_for_reply_unlocked (DBusConnection *connection,
dbus_uint32_t client_serial)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
link = _dbus_list_get_first_link (&connection->incoming_messages);
while (link != NULL)
{
DBusMessage *reply = link->data;
if (dbus_message_get_reply_serial (reply) == client_serial)
{
_dbus_list_remove_link (&connection->incoming_messages, link);
connection->n_incoming -= 1;
return reply;
}
link = _dbus_list_get_next_link (&connection->incoming_messages, link);
}
return NULL;
}
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)
{
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);
if (_dbus_pending_call_is_timeout_added_unlocked (pending))
_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);
}
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_pending_call_start_completion_unlocked(pending);
_dbus_connection_detach_pending_call_and_unlock (connection, pending);
/* Must be called unlocked since it invokes app callback */
_dbus_pending_call_finish_completion (pending);
dbus_pending_call_unref (pending);
}
static dbus_bool_t
check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection,
DBusPendingCall *pending)
{
DBusMessage *reply;
DBusDispatchStatus status;
reply = check_for_reply_unlocked (connection,
_dbus_pending_call_get_reply_serial_unlocked (pending));
if (reply != NULL)
{
_dbus_verbose ("checked for reply\n");
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");
complete_pending_call_and_unlock (connection, pending, reply);
dbus_message_unref (reply);
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_pending_call_unref (pending);
return TRUE;
}
return FALSE;
}
/**
* Blocks until a pending call times out or gets a reply.
*
* Does not re-enter the main loop or run filter/path-registered
* callbacks. The reply to the message will not be seen by
* filter callbacks.
*
* Returns immediately if pending call already got a reply.
*
* @todo could use performance improvements (it keeps scanning
* the whole message queue for example)
*
* @param pending the pending call we block for a reply on
*/
void
_dbus_connection_block_pending_call (DBusPendingCall *pending)
{
long start_tv_sec, start_tv_usec;
long tv_sec, tv_usec;
DBusDispatchStatus status;
DBusConnection *connection;
dbus_uint32_t client_serial;
DBusTimeout *timeout;
int timeout_milliseconds, elapsed_milliseconds;
_dbus_assert (pending != NULL);
if (dbus_pending_call_get_completed (pending))
return;
dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
connection = _dbus_pending_call_get_connection_and_lock (pending);
/* Flush message queue - note, can affect dispatch status */
_dbus_connection_flush_unlocked (connection);
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 = _dbus_pending_call_get_timeout_unlocked (pending);
_dbus_get_monotonic_time (&start_tv_sec, &start_tv_usec);
if (timeout)
{
timeout_milliseconds = dbus_timeout_get_interval (timeout);
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec\n",
timeout_milliseconds,
client_serial,
start_tv_sec, start_tv_usec);
}
else
{
timeout_milliseconds = -1;
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block for reply serial %u\n", client_serial);
}
/* 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,
pending,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds);
recheck_status:
_dbus_verbose ("top of recheck\n");
HAVE_LOCK_CHECK (connection);
/* queue messages and get status */
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* the get_completed() is in case a dispatch() while we were blocking
* got the reply instead of us.
*/
if (_dbus_pending_call_get_completed_unlocked (pending))
{
_dbus_verbose ("Pending call completed by dispatch\n");
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_pending_call_unref (pending);
return;
}
if (status == DBUS_DISPATCH_DATA_REMAINS)
{
if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
return;
}
_dbus_get_monotonic_time (&tv_sec, &tv_usec);
elapsed_milliseconds = (tv_sec - start_tv_sec) * 1000 +
(tv_usec - start_tv_usec) / 1000;
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);
if (error_msg != NULL)
dbus_message_unref (error_msg);
dbus_pending_call_unref (pending);
return;
}
else if (connection->disconnect_message_link == NULL)
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n");
else if (timeout == NULL)
{
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 - elapsed_milliseconds);
}
else
{
/* block again, we don't have the reply buffered yet. */
_dbus_connection_do_iteration_unlocked (connection,
pending,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds - elapsed_milliseconds);
}
goto recheck_status;
}
else if (tv_sec < start_tv_sec)
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n");
else if (elapsed_milliseconds < timeout_milliseconds)
{
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds - elapsed_milliseconds);
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 - elapsed_milliseconds);
}
else
{
/* block again, we don't have the reply buffered yet. */
_dbus_connection_do_iteration_unlocked (connection,
pending,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds - elapsed_milliseconds);
}
goto recheck_status;
}
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %d milliseconds and got no reply\n",
elapsed_milliseconds);
_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);
}
/**
* Return how many file descriptors are pending in the loader
*
* @param connection the connection
*/
int
_dbus_connection_get_pending_fds_count (DBusConnection *connection)
{
return _dbus_transport_get_pending_fds_count (connection->transport);
}
/**
* Register a function to be called whenever the number of pending file
* descriptors in the loader change.
*
* @param connection the connection
* @param callback the callback
*/
void
_dbus_connection_set_pending_fds_function (DBusConnection *connection,
DBusPendingFdsChangeFunction callback,
void *data)
{
_dbus_transport_set_pending_fds_function (connection->transport,
callback, data);
}
/** @} */
/**
* @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().
*
* @note Prefer dbus_connection_open() to dbus_connection_open_private()
* unless you have good reason; connections are expensive enough
* that it's wasteful to create lots of connections to the same
* server.
*
* @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.)
*
* @note Prefer dbus_connection_open() to dbus_connection_open_private()
* unless you have good reason; connections are expensive enough
* that it's wasteful to create lots of connections to the same
* server.
*
* @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_int32_t old_refcount;
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL);
old_refcount = _dbus_atomic_inc (&connection->refcount);
_dbus_connection_trace_ref (connection, old_refcount, old_refcount + 1,
"ref");
return connection;
}
static void
free_outgoing_message (void *element,
void *data)
{
DBusMessage *message = element;
DBusConnection *connection = data;
_dbus_message_remove_counter (message, connection->outgoing_counter);
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 (_dbus_atomic_get (&connection->refcount) == 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_connection_set_windows_user_function (connection, NULL, NULL, NULL);
_dbus_watch_list_free (connection->watches);
connection->watches = NULL;
_dbus_timeout_list_free (connection->timeouts);
connection->timeouts = NULL;
_dbus_data_slot_list_free (&connection->slot_list);
link = _dbus_list_get_first_link (&connection->filter_list);
while (link != NULL)
{
DBusMessageFilter *filter = link->data;
DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
filter->function = NULL;
_dbus_message_filter_unref (filter); /* calls app callback */
link->data = NULL;
link = next;
}
_dbus_list_clear (&connection->filter_list);
/* ---- Done with stuff that invokes application callbacks */
_dbus_object_tree_unref (connection->objects);
_dbus_hash_table_unref (connection->pending_replies);
connection->pending_replies = NULL;
_dbus_list_foreach (&connection->outgoing_messages,
free_outgoing_message,
connection);
_dbus_list_clear (&connection->outgoing_messages);
_dbus_list_clear_full (&connection->incoming_messages,
(DBusFreeFunction) dbus_message_unref);
_dbus_counter_unref (connection->outgoing_counter);
_dbus_transport_unref (connection->transport);
if (connection->disconnect_message_link)
{
DBusMessage *message = connection->disconnect_message_link->data;
dbus_message_unref (message);
_dbus_list_free_link (connection->disconnect_message_link);
}
_dbus_condvar_free_at_location (&connection->dispatch_cond);
_dbus_condvar_free_at_location (&connection->io_path_cond);
_dbus_cmutex_free_at_location (&connection->io_path_mutex);
_dbus_cmutex_free_at_location (&connection->dispatch_mutex);
_dbus_rmutex_free_at_location (&connection->slot_mutex);
_dbus_rmutex_free_at_location (&connection->mutex);
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. 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_unref (DBusConnection *connection)
{
dbus_int32_t old_refcount;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (connection->generation == _dbus_current_generation);
old_refcount = _dbus_atomic_dec (&connection->refcount);
_dbus_connection_trace_ref (connection, old_refcount, old_refcount - 1,
"unref");
if (old_refcount == 1)
{
#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." :
"Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.");
return;
}
#endif
_dbus_connection_last_unref (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)
{
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);
/* 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);
}
/**
* 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.
*
* 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
*/
void
dbus_connection_close (DBusConnection *connection)
{
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (connection->generation == _dbus_current_generation);
CONNECTION_LOCK (connection);
#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.");
return;
}
#endif
_dbus_connection_close_possibly_shared_and_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.
*
* @param connection the connection.
* @returns #TRUE if the connection is still alive.
*/
dbus_bool_t
dbus_connection_get_is_connected (DBusConnection *connection)
{
dbus_bool_t res;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
res = _dbus_connection_get_is_connected_unlocked (connection);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Gets whether the connection was authenticated. (Note that
* if the connection was authenticated then disconnected,
* this function still returns #TRUE)
*
* @param connection the connection
* @returns #TRUE if the connection was ever authenticated
*/
dbus_bool_t
dbus_connection_get_is_authenticated (DBusConnection *connection)
{
dbus_bool_t res;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
res = _dbus_transport_try_to_authenticate (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Gets whether the connection is not authenticated as a specific
* user. If the connection is not authenticated, this function
* returns #TRUE, and if it is authenticated but as an anonymous user,
* it returns #TRUE. If it is authenticated as a specific user, then
* this returns #FALSE. (Note that if the connection was authenticated
* as anonymous then disconnected, this function still returns #TRUE.)
*
* If the connection is not anonymous, you can use
* dbus_connection_get_unix_user() and
* dbus_connection_get_windows_user() to see who it's authorized as.
*
* If you want to prevent non-anonymous authorization, use
* dbus_server_set_auth_mechanisms() to remove the mechanisms that
* allow proving user identity (i.e. only allow the ANONYMOUS
* mechanism).
*
* @param connection the connection
* @returns #TRUE if not authenticated or authenticated as anonymous
*/
dbus_bool_t
dbus_connection_get_is_anonymous (DBusConnection *connection)
{
dbus_bool_t res;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_is_anonymous (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Gets the ID of the server address we are authenticated to, if this
* connection is on the client side. If the connection is on the
* server side, this will always return #NULL - use dbus_server_get_id()
* to get the ID of your own server, if you are the server side.
*
* If a client-side connection is not authenticated yet, the ID may be
* available if it was included in the server address, but may not be
* available. The only way to be sure the server ID is available
* is to wait for authentication to complete.
*
* In general, each mode of connecting to a given server will have
* its own ID. So for example, if the session bus daemon is listening
* on UNIX domain sockets and on TCP, then each of those modalities
* will have its own server ID.
*
* If you want an ID that identifies an entire session bus, look at
* dbus_bus_get_id() instead (which is just a convenience wrapper
* around the org.freedesktop.DBus.GetId method invoked on the bus).
*
* You can also get a machine ID; see dbus_try_get_local_machine_id() to
* get the machine you are on. There isn't a convenience wrapper, but
* you can invoke org.freedesktop.DBus.Peer.GetMachineId on any peer
* to get the machine ID on the other end.
*
* The D-Bus specification describes the server ID and other IDs in a
* bit more detail.
*
* @param connection the connection
* @returns the server ID or #NULL if no memory or the connection is server-side
*/
char*
dbus_connection_get_server_id (DBusConnection *connection)
{
char *id;
_dbus_return_val_if_fail (connection != NULL, NULL);
CONNECTION_LOCK (connection);
id = _dbus_strdup (_dbus_transport_get_server_id (connection->transport));
CONNECTION_UNLOCK (connection);
return id;
}
/**
* Tests whether a certain type can be send via the connection. This
* will always return TRUE for all types, with the exception of
* DBUS_TYPE_UNIX_FD. The function will return TRUE for
* DBUS_TYPE_UNIX_FD only on systems that know Unix file descriptors
* and can send them via the chosen transport and when the remote side
* supports this.
*
* This function can be used to do runtime checking for types that
* might be unknown to the specific D-Bus client implementation
* version, i.e. it will return FALSE for all types this
* implementation does not know, including invalid or reserved types.
*
* @param connection the connection
* @param type the type to check
* @returns TRUE if the type may be send via the connection
*/
dbus_bool_t
dbus_connection_can_send_type(DBusConnection *connection,
int type)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
if (!dbus_type_is_valid (type))
return FALSE;
if (type != DBUS_TYPE_UNIX_FD)
return TRUE;
#ifdef HAVE_UNIX_FD_PASSING
{
dbus_bool_t b;
CONNECTION_LOCK(connection);
b = _dbus_transport_can_pass_unix_fd(connection->transport);
CONNECTION_UNLOCK(connection);
return b;
}
#endif
return FALSE;
}
/**
* Set whether _exit() should be called when the connection receives a
* disconnect signal. The call to _exit() comes after any handlers for
* the disconnect signal run; handlers can cancel the exit by calling
* this function.
*
* By default, exit_on_disconnect is #FALSE; but for message bus
* connections returned from dbus_bus_get() it will be toggled on
* by default.
*
* @param connection the connection
* @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal
*/
void
dbus_connection_set_exit_on_disconnect (DBusConnection *connection,
dbus_bool_t exit_on_disconnect)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
connection->exit_on_disconnect = exit_on_disconnect != FALSE;
CONNECTION_UNLOCK (connection);
}
/**
* Preallocates resources needed to send a message, allowing the message
* to be sent without the possibility of memory allocation failure.
* Allows apps to create a future guarantee that they can send
* a message regardless of memory shortages.
*
* @param connection the connection we're preallocating for.
* @returns the preallocated resources, or #NULL
*/
DBusPreallocatedSend*
dbus_connection_preallocate_send (DBusConnection *connection)
{
DBusPreallocatedSend *preallocated;
_dbus_return_val_if_fail (connection != NULL, NULL);
CONNECTION_LOCK (connection);
preallocated =
_dbus_connection_preallocate_send_unlocked (connection);
CONNECTION_UNLOCK (connection);
return preallocated;
}
/**
* Frees preallocated message-sending resources from
* dbus_connection_preallocate_send(). Should only
* be called if the preallocated resources are not used
* to send a message.
*
* @param connection the connection
* @param preallocated the resources
*/
void
dbus_connection_free_preallocated_send (DBusConnection *connection,
DBusPreallocatedSend *preallocated)
{
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (preallocated != NULL);
_dbus_return_if_fail (connection == preallocated->connection);
_dbus_list_free_link (preallocated->queue_link);
_dbus_counter_unref (preallocated->counter_link->data);
_dbus_list_free_link (preallocated->counter_link);
dbus_free (preallocated);
}
/**
* Sends a message using preallocated resources. This function cannot fail.
* It works identically to dbus_connection_send() in other respects.
* Preallocated resources comes from dbus_connection_preallocate_send().
* This function "consumes" the preallocated resources, they need not
* be freed separately.
*
* @param connection the connection
* @param preallocated the preallocated resources
* @param message the message to send
* @param client_serial return location for client serial assigned to the message
*/
void
dbus_connection_send_preallocated (DBusConnection *connection,
DBusPreallocatedSend *preallocated,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (preallocated != NULL);
_dbus_return_if_fail (message != NULL);
_dbus_return_if_fail (preallocated->connection == connection);
_dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL ||
dbus_message_get_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);
#ifdef HAVE_UNIX_FD_PASSING
if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
message->n_unix_fds > 0)
{
/* Refuse to send fds on a connection that cannot handle
them. Unfortunately we cannot return a proper error here, so
the best we can is just return. */
CONNECTION_UNLOCK (connection);
return;
}
#endif
_dbus_connection_send_preallocated_and_unlock (connection,
preallocated,
message, client_serial);
}
static dbus_bool_t
_dbus_connection_send_unlocked_no_update (DBusConnection *connection,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
DBusPreallocatedSend *preallocated;
_dbus_assert (connection != NULL);
_dbus_assert (message != NULL);
preallocated = _dbus_connection_preallocate_send_unlocked (connection);
if (preallocated == NULL)
return FALSE;
_dbus_connection_send_preallocated_unlocked_no_update (connection,
preallocated,
message,
client_serial);
return TRUE;
}
/**
* 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() however
* it is not necessary to call dbus_connection_flush() by hand; the
* message will be sent the next time the main loop is run.
* dbus_connection_flush() should only be used, for example, if
* the application was expected to exit before running the main loop.
*
* Because this only queues the message, the only reason it can
* fail is lack of memory. Even if the connection is disconnected,
* no error will be returned. If the function fails due to lack of memory,
* it returns #FALSE. The function will never fail for other reasons; even
* if the connection is disconnected, you can queue an outgoing message,
* though obviously it won't be sent.
*
* The message serial is used by the remote application to send a
* reply; see dbus_message_get_serial() or the D-Bus specification.
*
* dbus_message_unref() can be called as soon as this method returns
* as the message queue will hold its own ref until the message is sent.
*
* @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.
*/
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);
#ifdef HAVE_UNIX_FD_PASSING
if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
message->n_unix_fds > 0)
{
/* Refuse to send fds on a connection that cannot handle
them. Unfortunately we cannot return a proper error here, so
the best we can is just return. */
CONNECTION_UNLOCK (connection);
return FALSE;
}
#endif
return _dbus_connection_send_and_unlock (connection,
message,
serial);
}
static dbus_bool_t
reply_handler_timeout (void *data)
{
DBusConnection *connection;
DBusDispatchStatus status;
DBusPendingCall *pending = data;
connection = _dbus_pending_call_get_connection_and_lock (pending);
_dbus_connection_ref_unlocked (connection);
_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 ("middle\n");
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* Unlocks, and calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_connection_unref (connection);
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. If #DBUS_TIMEOUT_INFINITE is
* passed for the timeout, no timeout will be set and the call will block
* forever.
*
* @warning if the connection is disconnected or you try to send Unix
* file descriptors on a connection that does not support them, 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 or when you try to
* send Unix file descriptors on a connection that does not support
* them.
* @param timeout_milliseconds timeout in milliseconds, -1 (or
* #DBUS_TIMEOUT_USE_DEFAULT) for default or #DBUS_TIMEOUT_INFINITE for no
* timeout
* @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;
_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);
#ifdef HAVE_UNIX_FD_PASSING
if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
message->n_unix_fds > 0)
{
/* Refuse to send fds on a connection that cannot handle
them. Unfortunately we cannot return a proper error here, so
the best we can do is return TRUE but leave *pending_return
as NULL. */
CONNECTION_UNLOCK (connection);
return TRUE;
}
#endif
if (!_dbus_connection_get_is_connected_unlocked (connection))
{
CONNECTION_UNLOCK (connection);
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_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 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 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
* @param timeout_milliseconds timeout in milliseconds, -1 (or
* #DBUS_TIMEOUT_USE_DEFAULT) for default or #DBUS_TIMEOUT_INFINITE for no
* timeout
* @param error return location for error message
* @returns the message that is the reply or #NULL with an error code if the
* function fails.
*/
DBusMessage*
dbus_connection_send_with_reply_and_block (DBusConnection *connection,
DBusMessage *message,
int timeout_milliseconds,
DBusError *error)
{
DBusMessage *reply;
DBusPendingCall *pending;
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_return_val_if_fail (message != NULL, NULL);
_dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL);
_dbus_return_val_if_error_is_set (error, NULL);
#ifdef HAVE_UNIX_FD_PASSING
CONNECTION_LOCK (connection);
if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
message->n_unix_fds > 0)
{
CONNECTION_UNLOCK (connection);
dbus_set_error(error, DBUS_ERROR_FAILED, "Cannot send file descriptors on this connection.");
return NULL;
}
CONNECTION_UNLOCK (connection);
#endif
if (!dbus_connection_send_with_reply (connection, message,
&pending, timeout_milliseconds))
{
_DBUS_SET_OOM (error);
return NULL;
}
if (pending == NULL)
{
dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed");
return NULL;
}
dbus_pending_call_block (pending);
reply = dbus_pending_call_steal_reply (pending);
dbus_pending_call_unref (pending);
/* call_complete_and_unlock() called from pending_call_block() should
* always fill this in.
*/
_dbus_assert (reply != NULL);
if (dbus_set_error_from_message (error, reply))
{
dbus_message_unref (reply);
return NULL;
}
else
return reply;
}
/**
* Blocks until the outgoing message queue is empty.
* Assumes connection lock already held.
*
* If you call this, you MUST call update_dispatch_status afterword...
*
* @param connection the connection.
*/
static DBusDispatchStatus
_dbus_connection_flush_unlocked (DBusConnection *connection)
{
/* We have to specify DBUS_ITERATION_DO_READING here because
* otherwise we could have two apps deadlock if they are both doing
* a flush(), and the kernel buffers fill up. This could change the
* dispatch status.
*/
DBusDispatchStatus status;
HAVE_LOCK_CHECK (connection);
while (connection->n_outgoing > 0 &&
_dbus_connection_get_is_connected_unlocked (connection))
{
_dbus_verbose ("doing iteration in\n");
HAVE_LOCK_CHECK (connection);
_dbus_connection_do_iteration_unlocked (connection,
NULL,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_DO_WRITING |
DBUS_ITERATION_BLOCK,
-1);
}
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("middle\n");
status = _dbus_connection_get_dispatch_status_unlocked (connection);
HAVE_LOCK_CHECK (connection);
return status;
}
/**
* Blocks until the outgoing message queue is empty.
*
* @param connection the connection.
*/
void
dbus_connection_flush (DBusConnection *connection)
{
/* We have to specify DBUS_ITERATION_DO_READING here because
* otherwise we could have two apps deadlock if they are both doing
* a flush(), and the kernel buffers fill up. This could change the
* dispatch status.
*/
DBusDispatchStatus status;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
status = _dbus_connection_flush_unlocked (connection);
HAVE_LOCK_CHECK (connection);
/* Unlocks and calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
_dbus_verbose ("end\n");
}
/**
* This function implements dbus_connection_read_write_dispatch() and
* dbus_connection_read_write() (they pass a different value for the
* dispatch parameter).
*
* @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
* @returns #TRUE if the disconnect message has not been processed
*/
static dbus_bool_t
_dbus_connection_read_write_dispatch (DBusConnection *connection,
int timeout_milliseconds,
dbus_bool_t dispatch)
{
DBusDispatchStatus dstatus;
dbus_bool_t progress_possible;
/* Need to grab a ref here in case we're a private connection and
* the user drops the last ref in a handler we call; see bug
* https://bugs.freedesktop.org/show_bug.cgi?id=15635
*/
dbus_connection_ref (connection);
dstatus = dbus_connection_get_dispatch_status (connection);
if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS)
{
_dbus_verbose ("doing dispatch\n");
dbus_connection_dispatch (connection);
CONNECTION_LOCK (connection);
}
else if (dstatus == DBUS_DISPATCH_NEED_MEMORY)
{
_dbus_verbose ("pausing for memory\n");
_dbus_memory_pause_based_on_timeout (timeout_milliseconds);
CONNECTION_LOCK (connection);
}
else
{
CONNECTION_LOCK (connection);
if (_dbus_connection_get_is_connected_unlocked (connection))
{
_dbus_verbose ("doing iteration\n");
_dbus_connection_do_iteration_unlocked (connection,
NULL,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_DO_WRITING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds);
}
}
HAVE_LOCK_CHECK (connection);
/* 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)
progress_possible = connection->n_incoming != 0 ||
connection->disconnect_message_link != NULL;
else
progress_possible = _dbus_connection_get_is_connected_unlocked (connection);
CONNECTION_UNLOCK (connection);
dbus_connection_unref (connection);
return 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. An
* example usage would be:
*
* @code
* while (dbus_connection_read_write_dispatch (connection, -1))
* ; // empty loop body
* @endcode
*
* In this usage you would normally have set up a filter function to look
* at each message as it is dispatched. The loop terminates when the last
* message from the connection (the disconnected signal) is processed.
*
* If there are messages to dispatch, this function will
* dbus_connection_dispatch() once, and return. If there are no
* messages to dispatch, this function will block until it can read or
* write, then read or write, then return.
*
* The way to think of this function is that it either makes some sort
* of progress, or it blocks. Note that, while it is blocked on I/O, it
* cannot be interrupted (even by other threads), which makes this function
* unsuitable for applications that do more than just react to received
* messages.
*
* The return value indicates whether the disconnect message has been
* processed, NOT whether the connection is connected. This is
* important because even after disconnecting, you want to process any
* messages you received prior to the disconnect.
*
* @param connection the connection
* @param timeout_milliseconds max time to block or -1 for infinite
* @returns #TRUE if the disconnect message has not been processed
*/
dbus_bool_t
dbus_connection_read_write_dispatch (DBusConnection *connection,
int timeout_milliseconds)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, TRUE);
}
/**
* This function is intended for use with applications that don't want to
* write a main loop and deal with #DBusWatch and #DBusTimeout. See also
* dbus_connection_read_write_dispatch().
*
* As long as the connection is open, this function will block until it can
* read or write, then read or write, then return #TRUE.
*
* 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 still connected
*/
dbus_bool_t
dbus_connection_read_write (DBusConnection *connection,
int timeout_milliseconds)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE);
}
/* We need to call this anytime we pop the head of the queue, and then
* update_dispatch_status_and_unlock needs to be called afterward
* which will "process" the disconnected message and set
* disconnected_message_processed.
*/
static void
check_disconnected_message_arrived_unlocked (DBusConnection *connection,
DBusMessage *head_of_queue)
{
HAVE_LOCK_CHECK (connection);
/* checking that the link is NULL is an optimization to avoid the is_signal call */
if (connection->disconnect_message_link == NULL &&
dbus_message_is_signal (head_of_queue,
DBUS_INTERFACE_LOCAL,
"Disconnected"))
{
connection->disconnected_message_arrived = TRUE;
}
}
/**
* Returns the first-received message from the incoming message queue,
* leaving it in the queue. If the queue is empty, returns #NULL.
*
* The caller does not own a reference to the returned message, and
* must either return it using dbus_connection_return_message() or
* keep it after calling dbus_connection_steal_borrowed_message(). No
* one can get at the message while its borrowed, so return it as
* quickly as possible and don't keep a reference to it after
* returning it. If you need to keep the message, make a copy of it.
*
* dbus_connection_dispatch() will block if called while a borrowed
* message is outstanding; only one piece of code can be playing with
* the incoming queue at a time. This function will block if called
* during a dbus_connection_dispatch().
*
* @param connection the connection.
* @returns next message in the incoming queue.
*/
DBusMessage*
dbus_connection_borrow_message (DBusConnection *connection)
{
DBusDispatchStatus status;
DBusMessage *message;
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_verbose ("start\n");
/* this is called for the side effect that it queues
* up any messages from the transport
*/
status = dbus_connection_get_dispatch_status (connection);
if (status != DBUS_DISPATCH_DATA_REMAINS)
return NULL;
CONNECTION_LOCK (connection);
_dbus_connection_acquire_dispatch (connection);
/* While a message is outstanding, the dispatch lock is held */
_dbus_assert (connection->message_borrowed == NULL);
connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages);
message = connection->message_borrowed;
check_disconnected_message_arrived_unlocked (connection, message);
/* Note that we KEEP the dispatch lock until the message is returned */
if (message == NULL)
_dbus_connection_release_dispatch (connection);
CONNECTION_UNLOCK (connection);
_dbus_message_trace_ref (message, -1, -1, "dbus_connection_borrow_message");
/* We don't update dispatch status until it's returned or stolen */
return message;
}
/**
* Used to return a message after peeking at it using
* dbus_connection_borrow_message(). Only called if
* message from dbus_connection_borrow_message() was non-#NULL.
*
* @param connection the connection
* @param message the message from dbus_connection_borrow_message()
*/
void
dbus_connection_return_message (DBusConnection *connection,
DBusMessage *message)
{
DBusDispatchStatus status;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (message != NULL);
_dbus_return_if_fail (message == connection->message_borrowed);
_dbus_return_if_fail (connection->dispatch_acquired);
CONNECTION_LOCK (connection);
_dbus_assert (message == connection->message_borrowed);
connection->message_borrowed = NULL;
_dbus_connection_release_dispatch (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
_dbus_message_trace_ref (message, -1, -1, "dbus_connection_return_message");
}
/**
* Used to keep a message after peeking at it using
* dbus_connection_borrow_message(). Before using this function, see
* the caveats/warnings in the documentation for
* dbus_connection_pop_message().
*
* @param connection the connection
* @param message the message from dbus_connection_borrow_message()
*/
void
dbus_connection_steal_borrowed_message (DBusConnection *connection,
DBusMessage *message)
{
DBusMessage *pop_message;
DBusDispatchStatus status;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (message != NULL);
_dbus_return_if_fail (message == connection->message_borrowed);
_dbus_return_if_fail (connection->dispatch_acquired);
CONNECTION_LOCK (connection);
_dbus_assert (message == connection->message_borrowed);
pop_message = _dbus_list_pop_first (&connection->incoming_messages);
_dbus_assert (message == pop_message);
(void) pop_message; /* unused unless asserting */
connection->n_incoming -= 1;
_dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
message, connection->n_incoming);
connection->message_borrowed = NULL;
_dbus_connection_release_dispatch (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
_dbus_message_trace_ref (message, -1, -1,
"dbus_connection_steal_borrowed_message");
}
/* See dbus_connection_pop_message, but requires the caller to own
* the lock before calling. May drop the lock while running.
*/
static DBusList*
_dbus_connection_pop_message_link_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection->message_borrowed == NULL);
if (connection->n_incoming > 0)
{
DBusList *link;
link = _dbus_list_pop_first_link (&connection->incoming_messages);
connection->n_incoming -= 1;
_dbus_verbose ("Message %p (%s %s %s %s sig:'%s' serial:%u) removed from incoming queue %p, %d incoming\n",
link->data,
dbus_message_type_to_string (dbus_message_get_type (link->data)),
dbus_message_get_path (link->data) ?
dbus_message_get_path (link->data) :
"no path",
dbus_message_get_interface (link->data) ?
dbus_message_get_interface (link->data) :
"no interface",
dbus_message_get_member (link->data) ?
dbus_message_get_member (link->data) :
"no member",
dbus_message_get_signature (link->data),
dbus_message_get_serial (link->data),
connection, connection->n_incoming);
_dbus_message_trace_ref (link->data, -1, -1,
"_dbus_connection_pop_message_link_unlocked");
check_disconnected_message_arrived_unlocked (connection, link->data);
return link;
}
else
return NULL;
}
/* See dbus_connection_pop_message, but requires the caller to own
* the lock before calling. May drop the lock while running.
*/
static DBusMessage*
_dbus_connection_pop_message_unlocked (DBusConnection *connection)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
link = _dbus_connection_pop_message_link_unlocked (connection);
if (link != NULL)
{
DBusMessage *message;
message = link->data;
_dbus_list_free_link (link);
return message;
}
else
return NULL;
}
static void
_dbus_connection_putback_message_link_unlocked (DBusConnection *connection,
DBusList *message_link)
{
HAVE_LOCK_CHECK (connection);
_dbus_assert (message_link != NULL);
/* You can't borrow a message while a link is outstanding */
_dbus_assert (connection->message_borrowed == NULL);
/* We had to have the dispatch lock across the pop/putback */
_dbus_assert (connection->dispatch_acquired);
_dbus_list_prepend_link (&connection->incoming_messages,
message_link);
connection->n_incoming += 1;
_dbus_verbose ("Message %p (%s %s %s '%s') put back into queue %p, %d incoming\n",
message_link->data,
dbus_message_type_to_string (dbus_message_get_type (message_link->data)),
dbus_message_get_interface (message_link->data) ?
dbus_message_get_interface (message_link->data) :
"no interface",
dbus_message_get_member (message_link->data) ?
dbus_message_get_member (message_link->data) :
"no member",
dbus_message_get_signature (message_link->data),
connection, connection->n_incoming);
_dbus_message_trace_ref (message_link->data, -1, -1,
"_dbus_connection_putback_message_link_unlocked");
}
/**
* Returns the first-received message from the incoming message queue,
* removing it from the queue. The caller owns a reference to the
* returned message. If the queue is empty, returns #NULL.
*
* This function bypasses any message handlers that are registered,
* and so using it is usually wrong. Instead, let the main loop invoke
* dbus_connection_dispatch(). Popping messages manually is only
* useful in very simple programs that don't share a #DBusConnection
* with any libraries or other modules.
*
* There is a lock that covers all ways of accessing the incoming message
* queue, so dbus_connection_dispatch(), dbus_connection_pop_message(),
* dbus_connection_borrow_message(), etc. will all block while one of the others
* in the group is running.
*
* @param connection the connection.
* @returns next message in the incoming queue.
*/
DBusMessage*
dbus_connection_pop_message (DBusConnection *connection)
{
DBusMessage *message;
DBusDispatchStatus status;
_dbus_verbose ("start\n");
/* this is called for the side effect that it queues
* up any messages from the transport
*/
status = dbus_connection_get_dispatch_status (connection);
if (status != DBUS_DISPATCH_DATA_REMAINS)
return NULL;
CONNECTION_LOCK (connection);
_dbus_connection_acquire_dispatch (connection);
HAVE_LOCK_CHECK (connection);
message = _dbus_connection_pop_message_unlocked (connection);
_dbus_verbose ("Returning popped message %p\n", message);
_dbus_connection_release_dispatch (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
return message;
}
/**
* Acquire the dispatcher. This is a separate lock so the main
* connection lock can be dropped to call out to application dispatch
* handlers.
*
* @param connection the connection.
*/
static void
_dbus_connection_acquire_dispatch (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_connection_ref_unlocked (connection);
CONNECTION_UNLOCK (connection);
_dbus_verbose ("locking dispatch_mutex\n");
_dbus_cmutex_lock (connection->dispatch_mutex);
while (connection->dispatch_acquired)
{
_dbus_verbose ("waiting for dispatch to be acquirable\n");
_dbus_condvar_wait (connection->dispatch_cond,
connection->dispatch_mutex);
}
_dbus_assert (!connection->dispatch_acquired);
connection->dispatch_acquired = TRUE;
_dbus_verbose ("unlocking dispatch_mutex\n");
_dbus_cmutex_unlock (connection->dispatch_mutex);
CONNECTION_LOCK (connection);
_dbus_connection_unref_unlocked (connection);
}
/**
* Release the dispatcher when you're done with it. Only call
* after you've acquired the dispatcher. Wakes up at most one
* thread currently waiting to acquire the dispatcher.
*
* @param connection the connection.
*/
static void
_dbus_connection_release_dispatch (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("locking dispatch_mutex\n");
_dbus_cmutex_lock (connection->dispatch_mutex);
_dbus_assert (connection->dispatch_acquired);
connection->dispatch_acquired = FALSE;
_dbus_condvar_wake_one (connection->dispatch_cond);
_dbus_verbose ("unlocking dispatch_mutex\n");
_dbus_cmutex_unlock (connection->dispatch_mutex);
}
static void
_dbus_connection_failed_pop (DBusConnection *connection,
DBusList *message_link)
{
_dbus_list_prepend_link (&connection->incoming_messages,
message_link);
connection->n_incoming += 1;
}
/* 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_unlocked (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\n");
/* 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)
{
HAVE_LOCK_CHECK (connection);
if (connection->n_incoming > 0)
return DBUS_DISPATCH_DATA_REMAINS;
else if (!_dbus_transport_queue_messages (connection->transport))
return DBUS_DISPATCH_NEED_MEMORY;
else
{
DBusDispatchStatus status;
dbus_bool_t is_connected;
status = _dbus_transport_get_dispatch_status (connection->transport);
is_connected = _dbus_transport_get_is_connected (connection->transport);
_dbus_verbose ("dispatch status = %s is_connected = %d\n",
DISPATCH_STATUS_NAME (status), is_connected);
if (!is_connected)
{
/* 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.
*/
notify_disconnected_unlocked (connection);
/* 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 (status == DBUS_DISPATCH_COMPLETE)
status = notify_disconnected_and_dispatch_complete_unlocked (connection);
}
if (status != DBUS_DISPATCH_COMPLETE)
return status;
else if (connection->n_incoming > 0)
return DBUS_DISPATCH_DATA_REMAINS;
else
return DBUS_DISPATCH_COMPLETE;
}
}
static void
_dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
DBusDispatchStatus new_status)
{
dbus_bool_t changed;
DBusDispatchStatusFunction function;
void *data;
HAVE_LOCK_CHECK (connection);
_dbus_connection_ref_unlocked (connection);
changed = new_status != connection->last_dispatch_status;
connection->last_dispatch_status = new_status;
function = connection->dispatch_status_function;
data = connection->dispatch_status_data;
if (connection->disconnected_message_arrived &&
!connection->disconnected_message_processed)
{
connection->disconnected_message_processed = TRUE;
/* this does an unref, but we have a ref
* so we should not run the finalizer here
* inside the lock.
*/
connection_forget_shared_unlocked (connection);
if (connection->exit_on_disconnect)
{
CONNECTION_UNLOCK (connection);
_dbus_verbose ("Exiting on Disconnected signal\n");
_dbus_exit (1);
_dbus_assert_not_reached ("Call to exit() returned");
}
}
/* We drop the lock */
CONNECTION_UNLOCK (connection);
if (changed && function)
{
_dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n",
connection, new_status,
DISPATCH_STATUS_NAME (new_status));
(* function) (connection, new_status, data);
}
dbus_connection_unref (connection);
}
/**
* Gets the current state 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
*/
DBusDispatchStatus
dbus_connection_get_dispatch_status (DBusConnection *connection)
{
DBusDispatchStatus status;
_dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
_dbus_verbose ("start\n");
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
CONNECTION_UNLOCK (connection);
return status;
}
/**
* Filter funtion for handling the Peer standard interface.
*/
static DBusHandlerResult
_dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection,
DBusMessage *message)
{
dbus_bool_t sent = FALSE;
DBusMessage *ret = NULL;
DBusList *expire_link;
if (connection->route_peer_messages && dbus_message_get_destination (message) != NULL)
{
/* This means we're letting the bus route this message */
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
if (!dbus_message_has_interface (message, DBUS_INTERFACE_PEER))
{
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
/* Preallocate a linked-list link, so that if we need to dispose of a
* message, we can attach it to the expired list */
expire_link = _dbus_list_alloc_link (NULL);
if (!expire_link)
return DBUS_HANDLER_RESULT_NEED_MEMORY;
if (dbus_message_is_method_call (message,
DBUS_INTERFACE_PEER,
"Ping"))
{
ret = dbus_message_new_method_return (message);
if (ret == NULL)
goto out;
sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
}
else if (dbus_message_is_method_call (message,
DBUS_INTERFACE_PEER,
"GetMachineId"))
{
DBusString uuid;
DBusError error = DBUS_ERROR_INIT;
if (!_dbus_string_init (&uuid))
goto out;
if (_dbus_get_local_machine_uuid_encoded (&uuid, &error))
{
const char *v_STRING;
ret = dbus_message_new_method_return (message);
if (ret == NULL)
{
_dbus_string_free (&uuid);
goto out;
}
v_STRING = _dbus_string_get_const_data (&uuid);
if (dbus_message_append_args (ret,
DBUS_TYPE_STRING, &v_STRING,
DBUS_TYPE_INVALID))
{
sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
}
}
else if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
goto out;
}
else
{
ret = dbus_message_new_error (message, error.name, error.message);
dbus_error_free (&error);
if (ret == NULL)
goto out;
sent = _dbus_connection_send_unlocked_no_update (connection, ret,
NULL);
}
_dbus_string_free (&uuid);
}
else
{
/* We need to bounce anything else with this interface, otherwise apps
* could start extending the interface and when we added extensions
* here to DBusConnection we'd break those apps.
*/
ret = dbus_message_new_error (message,
DBUS_ERROR_UNKNOWN_METHOD,
"Unknown method invoked on org.freedesktop.DBus.Peer interface");
if (ret == NULL)
goto out;
sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
}
out:
if (ret == NULL)
{
_dbus_list_free_link (expire_link);
}
else
{
/* It'll be safe to unref the reply when we unlock */
expire_link->data = ret;
_dbus_list_prepend_link (&connection->expired_messages, expire_link);
}
if (!sent)
return DBUS_HANDLER_RESULT_NEED_MEMORY;
return DBUS_HANDLER_RESULT_HANDLED;
}
/**
* Processes all builtin filter functions
*
* If the spec specifies a standard interface
* they should be processed from this method
**/
static DBusHandlerResult
_dbus_connection_run_builtin_filters_unlocked_no_update (DBusConnection *connection,
DBusMessage *message)
{
/* We just run one filter for now but have the option to run more
if the spec calls for it in the future */
return _dbus_connection_peer_filter_unlocked_no_update (connection, message);
}
/**
* 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().
*
* 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
*
* @param connection the connection
* @returns dispatch status, see dbus_connection_get_dispatch_status()
*/
DBusDispatchStatus
dbus_connection_dispatch (DBusConnection *connection)
{
DBusMessage *message;
DBusList *link, *filter_list_copy, *message_link;
DBusHandlerResult result;
DBusPendingCall *pending;
dbus_int32_t reply_serial;
DBusDispatchStatus status;
dbus_bool_t found_object;
_dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
_dbus_verbose ("\n");
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
if (status != DBUS_DISPATCH_DATA_REMAINS)
{
/* unlocks and calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
return status;
}
/* We need to ref the connection since the callback could potentially
* drop the last ref to it
*/
_dbus_connection_ref_unlocked (connection);
_dbus_connection_acquire_dispatch (connection);
HAVE_LOCK_CHECK (connection);
message_link = _dbus_connection_pop_message_link_unlocked (connection);
if (message_link == NULL)
{
/* another thread dispatched our stuff */
_dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n");
_dbus_connection_release_dispatch (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_connection_unref (connection);
return status;
}
message = message_link->data;
_dbus_verbose (" dispatching message %p (%s %s %s '%s')\n",
message,
dbus_message_type_to_string (dbus_message_get_type (message)),
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
dbus_message_get_signature (message));
result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
/* Pending call handling must be first, because if you do
* dbus_connection_send_with_reply_and_block() or
* dbus_pending_call_block() then no handlers/filters will be run on
* the reply. We want consistent semantics in the case where we
* dbus_connection_dispatch() the reply.
*/
reply_serial = dbus_message_get_reply_serial (message);
pending = _dbus_hash_table_lookup_int (connection->pending_replies,
reply_serial);
if (pending)
{
_dbus_verbose ("Dispatching a pending reply\n");
complete_pending_call_and_unlock (connection, pending, message);
pending = NULL; /* it's probably unref'd */
CONNECTION_LOCK (connection);
_dbus_verbose ("pending call completed in dispatch\n");
result = DBUS_HANDLER_RESULT_HANDLED;
goto out;
}
result = _dbus_connection_run_builtin_filters_unlocked_no_update (connection, message);
if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
goto out;
if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy))
{
_dbus_connection_release_dispatch (connection);
HAVE_LOCK_CHECK (connection);
_dbus_connection_failed_pop (connection, message_link);
/* unlocks and calls user code */
_dbus_connection_update_dispatch_status_and_unlock (connection,
DBUS_DISPATCH_NEED_MEMORY);
dbus_connection_unref (connection);
return DBUS_DISPATCH_NEED_MEMORY;
}
for (link = _dbus_list_get_first_link (&filter_list_copy);
link != NULL;
link = _dbus_list_get_next_link (&filter_list_copy, link))
_dbus_message_filter_ref (link->data);
/* We're still protected from dispatch() reentrancy here
* since we acquired the dispatcher
*/
CONNECTION_UNLOCK (connection);
link = _dbus_list_get_first_link (&filter_list_copy);
while (link != NULL)
{
DBusMessageFilter *filter = link->data;
DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link);
if (filter->function == NULL)
{
_dbus_verbose (" filter was removed in a callback function\n");
link = next;
continue;
}
_dbus_verbose (" running filter on message %p\n", message);
result = (* filter->function) (connection, message, filter->user_data);
if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
break;
link = next;
}
_dbus_list_clear_full (&filter_list_copy,
(DBusFreeFunction) _dbus_message_filter_unref);
CONNECTION_LOCK (connection);
if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
{
_dbus_verbose ("No memory\n");
goto out;
}
else if (result == DBUS_HANDLER_RESULT_HANDLED)
{
_dbus_verbose ("filter handled message in dispatch\n");
goto out;
}
/* We're still protected from dispatch() reentrancy here
* since we acquired the dispatcher
*/
_dbus_verbose (" running object path dispatch on message %p (%s %s %s '%s')\n",
message,
dbus_message_type_to_string (dbus_message_get_type (message)),
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
dbus_message_get_signature (message));
HAVE_LOCK_CHECK (connection);
result = _dbus_object_tree_dispatch_and_unlock (connection->objects,
message,
&found_object);
CONNECTION_LOCK (connection);
if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
{
_dbus_verbose ("object tree handled message in dispatch\n");
goto out;
}
if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL)
{
DBusMessage *reply;
DBusString str;
DBusPreallocatedSend *preallocated;
DBusList *expire_link;
_dbus_verbose (" sending error %s\n",
DBUS_ERROR_UNKNOWN_METHOD);
if (!_dbus_string_init (&str))
{
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error string in dispatch\n");
goto out;
}
if (!_dbus_string_append_printf (&str,
"Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n",
dbus_message_get_member (message),
dbus_message_get_signature (message),
dbus_message_get_interface (message)))
{
_dbus_string_free (&str);
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error string in dispatch\n");
goto out;
}
reply = dbus_message_new_error (message,
found_object ? DBUS_ERROR_UNKNOWN_METHOD : DBUS_ERROR_UNKNOWN_OBJECT,
_dbus_string_get_const_data (&str));
_dbus_string_free (&str);
if (reply == NULL)
{
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error reply in dispatch\n");
goto out;
}
expire_link = _dbus_list_alloc_link (reply);
if (expire_link == NULL)
{
dbus_message_unref (reply);
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error send in dispatch\n");
goto out;
}
preallocated = _dbus_connection_preallocate_send_unlocked (connection);
if (preallocated == NULL)
{
_dbus_list_free_link (expire_link);
/* It's OK that this is finalized, because it hasn't been seen by
* anything that could attach user callbacks */
dbus_message_unref (reply);
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error send in dispatch\n");
goto out;
}
_dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated,
reply, NULL);
/* reply will be freed when we release the lock */
_dbus_list_prepend_link (&connection->expired_messages, expire_link);
result = DBUS_HANDLER_RESULT_HANDLED;
}
_dbus_verbose (" done dispatching %p (%s %s %s '%s') on connection %p\n", message,
dbus_message_type_to_string (dbus_message_get_type (message)),
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
dbus_message_get_signature (message),
connection);
out:
if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
{
_dbus_verbose ("out of memory\n");
/* Put message back, and we'll start over.
* Yes this means handlers must be idempotent if they
* don't return HANDLED; c'est la vie.
*/
_dbus_connection_putback_message_link_unlocked (connection,
message_link);
/* now we don't want to free them */
message_link = NULL;
message = NULL;
}
else
{
_dbus_verbose (" ... done dispatching\n");
}
_dbus_connection_release_dispatch (connection);
HAVE_LOCK_CHECK (connection);
if (message != NULL)
{
/* We don't want this message to count in maximum message limits when
* computing the dispatch status, below. We have to drop the lock
* temporarily, because finalizing a message can trigger callbacks.
*
* We have a reference to the connection, and we don't use any cached
* pointers to the connection's internals below this point, so it should
* be safe to drop the lock and take it back. */
CONNECTION_UNLOCK (connection);
dbus_message_unref (message);
CONNECTION_LOCK (connection);
}
if (message_link != NULL)
_dbus_list_free_link (message_link);
_dbus_verbose ("before final status update\n");
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* unlocks and calls user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_connection_unref (connection);
return status;
}
/**
* Sets the watch functions for the connection. These functions are
* responsible for making the application's main loop aware of file
* descriptors that need to be monitored for events, using select() or
* poll(). When using Qt, typically the DBusAddWatchFunction would
* create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
* could call g_io_add_watch(), or could be used as part of a more
* elaborate GSource. Note that when a watch is added, it may
* not be enabled.
*
* The DBusWatchToggledFunction notifies the application that the
* watch has been enabled or disabled. Call dbus_watch_get_enabled()
* to check this. A disabled watch should have no effect, and enabled
* watch should be added to the main loop. This feature is used
* instead of simply adding/removing the watch because
* enabling/disabling can be done without memory allocation. The
* toggled function may be NULL if a main loop re-queries
* dbus_watch_get_enabled() every time anyway.
*
* The DBusWatch can be queried for the file descriptor to watch using
* dbus_watch_get_unix_fd() or dbus_watch_get_socket(), and for the
* events to watch for using dbus_watch_get_flags(). The flags
* returned by dbus_watch_get_flags() will only contain
* DBUS_WATCH_READABLE and DBUS_WATCH_WRITABLE, never
* DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR; all watches implicitly
* include a watch for hangups, errors, and other exceptional
* conditions.
*
* Once a file descriptor becomes readable or writable, or an exception
* occurs, dbus_watch_handle() should be called to
* notify the connection of the file descriptor's condition.
*
* dbus_watch_handle() cannot be called during the
* DBusAddWatchFunction, as the connection will not be ready to handle
* that watch yet.
*
* It is not allowed to reference a DBusWatch after it has been passed
* to remove_function.
*
* If #FALSE is returned due to lack of memory, the failure may be due
* to a #FALSE return from the new add_function. If so, the
* add_function may have been called successfully one or more times,
* but the remove_function will also have been called to remove any
* successful adds. i.e. if #FALSE is returned the net result
* should be that dbus_connection_set_watch_functions() has no effect,
* but the add_function and remove_function may have been called.
*
* @note The thread lock on DBusConnection is held while
* watch functions are invoked, so inside these functions you
* may not invoke any methods on DBusConnection or it will deadlock.
* See the comments in the code or http://lists.freedesktop.org/archives/dbus/2007-July/tread.html#8144
* if you encounter this issue and want to attempt writing a patch.
*
* @param connection the connection.
* @param add_function function to begin monitoring a new descriptor.
* @param remove_function function to stop monitoring a descriptor.
* @param toggled_function function to notify of enable/disable
* @param data data to pass to add_function and remove_function.
* @param free_data_function function to be called to free the data.
* @returns #FALSE on failure (no memory)
*/
dbus_bool_t
dbus_connection_set_watch_functions (DBusConnection *connection,
DBusAddWatchFunction add_function,
DBusRemoveWatchFunction remove_function,
DBusWatchToggledFunction toggled_function,
void *data,
DBusFreeFunction free_data_function)
{
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
retval = _dbus_watch_list_set_functions (connection->watches,
add_function, remove_function,
toggled_function,
data, free_data_function);
CONNECTION_UNLOCK (connection);
return retval;
}
/**
* Sets the timeout functions for the connection. These functions are
* responsible for making the application's main loop aware of timeouts.
* When using Qt, typically the DBusAddTimeoutFunction would create a
* QTimer. When using GLib, the DBusAddTimeoutFunction would call
* g_timeout_add.
*
* The DBusTimeoutToggledFunction notifies the application that the
* timeout has been enabled or disabled. Call
* dbus_timeout_get_enabled() to check this. A disabled timeout should
* have no effect, and enabled timeout should be added to the main
* loop. This feature is used instead of simply adding/removing the
* timeout because enabling/disabling can be done without memory
* allocation. With Qt, QTimer::start() and QTimer::stop() can be used
* to enable and disable. The toggled function may be NULL if a main
* loop re-queries dbus_timeout_get_enabled() every time anyway.
* Whenever a timeout is toggled, its interval may change.
*
* The DBusTimeout can be queried for the timer interval using
* dbus_timeout_get_interval(). dbus_timeout_handle() should be called
* repeatedly, each time the interval elapses, starting after it has
* elapsed once. The timeout stops firing when it is removed with the
* given remove_function. The timer interval may change whenever the
* timeout is added, removed, or toggled.
*
* @note The thread lock on DBusConnection is held while
* timeout functions are invoked, so inside these functions you
* may not invoke any methods on DBusConnection or it will deadlock.
* See the comments in the code or http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
* if you encounter this issue and want to attempt writing a patch.
*
* @param connection the connection.
* @param add_function function to add a timeout.
* @param remove_function function to remove a timeout.
* @param toggled_function function to notify of enable/disable
* @param data data to pass to add_function and remove_function.
* @param free_data_function function to be called to free the data.
* @returns #FALSE on failure (no memory)
*/
dbus_bool_t
dbus_connection_set_timeout_functions (DBusConnection *connection,
DBusAddTimeoutFunction add_function,
DBusRemoveTimeoutFunction remove_function,
DBusTimeoutToggledFunction toggled_function,
void *data,
DBusFreeFunction free_data_function)
{
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
retval = _dbus_timeout_list_set_functions (connection->timeouts,
add_function, remove_function,
toggled_function,
data, free_data_function);
CONNECTION_UNLOCK (connection);
return retval;
}
/**
* 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
* @param data data to pass wakeup_main_function
* @param free_data_function function to be called to free the data.
*/
void
dbus_connection_set_wakeup_main_function (DBusConnection *connection,
DBusWakeupMainFunction wakeup_main_function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data;
DBusFreeFunction old_free_data;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
old_data = connection->wakeup_main_data;
old_free_data = connection->free_wakeup_main_data;
connection->wakeup_main_function = wakeup_main_function;
connection->wakeup_main_data = data;
connection->free_wakeup_main_data = free_data_function;
CONNECTION_UNLOCK (connection);
/* Callback outside the lock */
if (old_free_data)
(*old_free_data) (old_data);
}
/**
* Set a function to be invoked when the dispatch status changes.
* If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then
* dbus_connection_dispatch() needs to be called to process incoming
* messages. However, dbus_connection_dispatch() MUST NOT BE CALLED
* from inside the DBusDispatchStatusFunction. Indeed, almost
* any reentrancy in this function is a bad idea. Instead,
* the DBusDispatchStatusFunction should simply save an indication
* that messages should be dispatched later, when the main loop
* is re-entered.
*
* 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
* @param free_data_function free the function data
*/
void
dbus_connection_set_dispatch_status_function (DBusConnection *connection,
DBusDispatchStatusFunction function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data;
DBusFreeFunction old_free_data;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
old_data = connection->dispatch_status_data;
old_free_data = connection->free_dispatch_status_data;
connection->dispatch_status_function = function;
connection->dispatch_status_data = data;
connection->free_dispatch_status_data = free_data_function;
CONNECTION_UNLOCK (connection);
/* Callback outside the lock */
if (old_free_data)
(*old_free_data) (old_data);
}
/**
* Get the UNIX file descriptor of the connection, if any. This can
* be used for SELinux access control checks with getpeercon() for
* example. DO NOT read or write to the file descriptor, or try to
* select() on it; use DBusWatch for main loop integration. Not all
* connections will have a file descriptor. So for adding descriptors
* to the main loop, use dbus_watch_get_unix_fd() and so forth.
*
* If the connection is socket-based, you can also use
* dbus_connection_get_socket(), which will work on Windows too.
* This function always fails on Windows.
*
* Right now the returned descriptor is always a socket, but
* that is not guaranteed.
*
* @param connection the connection
* @param fd return location for the file descriptor.
* @returns #TRUE if fd is successfully obtained.
*/
dbus_bool_t
dbus_connection_get_unix_fd (DBusConnection *connection,
int *fd)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (connection->transport != NULL, FALSE);
#ifdef DBUS_WIN
/* FIXME do this on a lower level */
return FALSE;
#endif
return dbus_connection_get_socket(connection, fd);
}
/**
* Gets the underlying Windows or UNIX socket file descriptor
* of the connection, if any. DO NOT read or write to the file descriptor, or try to
* select() on it; use DBusWatch for main loop integration. Not all
* connections will have a socket. So for adding descriptors
* to the main loop, use dbus_watch_get_socket() and so forth.
*
* If the connection is not socket-based, this function will return FALSE,
* even if the connection does have a file descriptor of some kind.
* i.e. this function always returns specifically a socket file descriptor.
*
* @param connection the connection
* @param fd return location for the file descriptor.
* @returns #TRUE if fd is successfully obtained.
*/
dbus_bool_t
dbus_connection_get_socket(DBusConnection *connection,
int *fd)
{
dbus_bool_t retval;
DBusSocket s = DBUS_SOCKET_INIT;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (connection->transport != NULL, FALSE);
CONNECTION_LOCK (connection);
retval = _dbus_transport_get_socket_fd (connection->transport, &s);
if (retval)
{
*fd = _dbus_socket_get_int (s);
}
CONNECTION_UNLOCK (connection);
return retval;
}
/**
* Gets the UNIX user ID of the connection if known. Returns #TRUE if
* the uid is filled in. Always returns #FALSE on non-UNIX platforms
* for now, though in theory someone could hook Windows to NIS or
* something. Always returns #FALSE prior to authenticating the
* connection.
*
* The UID is only read by servers from clients; clients can't usually
* get the UID of servers, because servers do not authenticate to
* clients. The returned UID is the UID the connection authenticated
* as.
*
* The message bus is a server and the apps connecting to the bus
* are clients.
*
* You can ask the bus to tell you the UID of another connection though
* if you like; this is done with dbus_bus_get_unix_user().
*
* @param connection the connection
* @param uid return location for the user ID
* @returns #TRUE if uid is filled in with a valid user ID
*/
dbus_bool_t
dbus_connection_get_unix_user (DBusConnection *connection,
unsigned long *uid)
{
dbus_bool_t result;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (uid != NULL, FALSE);
CONNECTION_LOCK (connection);
if (!_dbus_transport_try_to_authenticate (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_unix_user (connection->transport,
uid);
#ifdef DBUS_WIN
_dbus_assert (!result);
#endif
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Gets the process ID of the connection if any.
* Returns #TRUE if the pid is filled in.
* Always returns #FALSE prior to authenticating the
* connection.
*
* @param connection the connection
* @param pid return location for the process ID
* @returns #TRUE if uid is filled in with a valid process ID
*/
dbus_bool_t
dbus_connection_get_unix_process_id (DBusConnection *connection,
unsigned long *pid)
{
dbus_bool_t result;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (pid != NULL, FALSE);
CONNECTION_LOCK (connection);
if (!_dbus_transport_try_to_authenticate (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_unix_process_id (connection->transport,
pid);
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Gets the ADT audit data of the connection if any.
* Returns #TRUE if the structure pointer is returned.
* Always returns #FALSE prior to authenticating the
* connection.
*
* @param connection the connection
* @param data return location for audit data
* @param data_size return location for length of audit data
* @returns #TRUE if audit data is filled in with a valid ucred pointer
*/
dbus_bool_t
dbus_connection_get_adt_audit_session_data (DBusConnection *connection,
void **data,
dbus_int32_t *data_size)
{
dbus_bool_t result;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (data != NULL, FALSE);
_dbus_return_val_if_fail (data_size != NULL, FALSE);
CONNECTION_LOCK (connection);
if (!_dbus_transport_try_to_authenticate (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_adt_audit_session_data (connection->transport,
data,
data_size);
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Sets a predicate function used to determine whether a given user ID
* is allowed to connect. When an incoming connection has
* authenticated with a particular user ID, this function is called;
* if it returns #TRUE, the connection is allowed to proceed,
* otherwise the connection is disconnected.
*
* If the function is set to #NULL (as it is by default), then
* only the same UID as the server process will be allowed to
* connect. Also, root is always allowed to connect.
*
* On Windows, the function will be set and its free_data_function will
* be invoked when the connection is freed or a new function is set.
* However, the function will never be called, because there are
* no UNIX user ids to pass to it, or at least none of the existing
* auth protocols would allow authenticating as a UNIX user on Windows.
*
* @param connection the connection
* @param function the predicate
* @param data data to pass to the predicate
* @param free_data_function function to free the data
*/
void
dbus_connection_set_unix_user_function (DBusConnection *connection,
DBusAllowUnixUserFunction function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data = NULL;
DBusFreeFunction old_free_function = NULL;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_unix_user_function (connection->transport,
function, data, free_data_function,
&old_data, &old_free_function);
CONNECTION_UNLOCK (connection);
if (old_free_function != NULL)
(* old_free_function) (old_data);
}
/* Same calling convention as dbus_connection_get_windows_user */
dbus_bool_t
_dbus_connection_get_linux_security_label (DBusConnection *connection,
char **label_p)
{
dbus_bool_t result;
_dbus_assert (connection != NULL);
_dbus_assert (label_p != NULL);
CONNECTION_LOCK (connection);
if (!_dbus_transport_try_to_authenticate (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_linux_security_label (connection->transport,
label_p);
#ifndef __linux__
_dbus_assert (!result);
#endif
CONNECTION_UNLOCK (connection);
return result;
}
DBusCredentials *
_dbus_connection_get_credentials (DBusConnection *connection)
{
DBusCredentials *result;
_dbus_assert (connection != NULL);
CONNECTION_LOCK (connection);
if (!_dbus_transport_try_to_authenticate (connection->transport))
result = NULL;
else
result = _dbus_transport_get_credentials (connection->transport);
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Gets the Windows user SID of the connection if known. Returns
* #TRUE if the ID is filled in. Always returns #FALSE on non-Windows
* platforms for now, though in theory someone could hook UNIX to
* Active Directory or something. Always returns #FALSE prior to
* authenticating the connection.
*
* The user is only read by servers from clients; clients can't usually
* get the user of servers, because servers do not authenticate to
* clients. The returned user is the user the connection authenticated
* as.
*
* The message bus is a server and the apps connecting to the bus
* are clients.
*
* The returned user string has to be freed with dbus_free().
*
* The return value indicates whether the user SID is available;
* if it's available but we don't have the memory to copy it,
* then the return value is #TRUE and #NULL is given as the SID.
*
* @todo We would like to be able to say "You can ask the bus to tell
* you the user of another connection though if you like; this is done
* with dbus_bus_get_windows_user()." But this has to be implemented
* in bus/driver.c and dbus/dbus-bus.c, and is pointless anyway
* since on Windows we only use the session bus for now.
*
* @param connection the connection
* @param windows_sid_p return location for an allocated copy of the user ID, or #NULL if no memory
* @returns #TRUE if user is available (returned value may be #NULL anyway if no memory)
*/
dbus_bool_t
dbus_connection_get_windows_user (DBusConnection *connection,
char **windows_sid_p)
{
dbus_bool_t result;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (windows_sid_p != NULL, FALSE);
CONNECTION_LOCK (connection);
if (!_dbus_transport_try_to_authenticate (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_windows_user (connection->transport,
windows_sid_p);
#ifdef DBUS_UNIX
_dbus_assert (!result);
#endif
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Sets a predicate function used to determine whether a given user ID
* is allowed to connect. When an incoming connection has
* authenticated with a particular user ID, this function is called;
* if it returns #TRUE, the connection is allowed to proceed,
* otherwise the connection is disconnected.
*
* If the function is set to #NULL (as it is by default), then
* only the same user owning the server process will be allowed to
* connect.
*
* On UNIX, the function will be set and its free_data_function will
* be invoked when the connection is freed or a new function is set.
* However, the function will never be called, because there is no
* way right now to authenticate as a Windows user on UNIX.
*
* @param connection the connection
* @param function the predicate
* @param data data to pass to the predicate
* @param free_data_function function to free the data
*/
void
dbus_connection_set_windows_user_function (DBusConnection *connection,
DBusAllowWindowsUserFunction function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data = NULL;
DBusFreeFunction old_free_function = NULL;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_windows_user_function (connection->transport,
function, data, free_data_function,
&old_data, &old_free_function);
CONNECTION_UNLOCK (connection);
if (old_free_function != NULL)
(* old_free_function) (old_data);
}
/**
* This function must be called on the server side of a connection when the
* connection is first seen in the #DBusNewConnectionFunction. If set to
* #TRUE (the default is #FALSE), then the connection can proceed even if
* the client does not authenticate as some user identity, i.e. clients
* can connect anonymously.
*
* This setting interacts with the available authorization mechanisms
* (see dbus_server_set_auth_mechanisms()). Namely, an auth mechanism
* such as ANONYMOUS that supports anonymous auth must be included in
* the list of available mechanisms for anonymous login to work.
*
* This setting also changes the default rule for connections
* authorized as a user; normally, if a connection authorizes as
* a user identity, it is permitted if the user identity is
* root or the user identity matches the user identity of the server
* process. If anonymous connections are allowed, however,
* then any user identity is allowed.
*
* You can override the rules for connections authorized as a
* user identity with dbus_connection_set_unix_user_function()
* and dbus_connection_set_windows_user_function().
*
* @param connection the connection
* @param value whether to allow authentication as an anonymous user
*/
void
dbus_connection_set_allow_anonymous (DBusConnection *connection,
dbus_bool_t value)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_allow_anonymous (connection->transport, value);
CONNECTION_UNLOCK (connection);
}
/**
*
* Normally #DBusConnection automatically handles all messages to the
* org.freedesktop.DBus.Peer interface. However, the message bus wants
* to be able to route methods on that interface through the bus and
* to other applications. If routing peer messages is enabled, then
* messages with the org.freedesktop.DBus.Peer interface that also
* have a bus destination name set will not be automatically
* handled by the #DBusConnection and instead will be dispatched
* normally to the application.
*
* If a normal application sets this flag, it can break things badly.
* So don't set this unless you are the message bus.
*
* @param connection the connection
* @param value #TRUE to pass through org.freedesktop.DBus.Peer messages with a bus name set
*/
void
dbus_connection_set_route_peer_messages (DBusConnection *connection,
dbus_bool_t value)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
connection->route_peer_messages = value;
CONNECTION_UNLOCK (connection);
}
/**
* Adds a message filter. Filters are handlers that are run on all
* incoming messages, prior to the objects registered with
* dbus_connection_register_object_path(). Filters are run in the
* order that they were added. The same handler can be added as a
* filter more than once, in which case it will be run more than once.
* Filters added during a filter callback won't be run on the message
* being processed.
*
* @todo we don't run filters on messages while blocking without
* entering the main loop, since filters are run as part of
* dbus_connection_dispatch(). This is probably a feature, as filters
* could create arbitrary reentrancy. But kind of sucks if you're
* trying to filter METHOD_RETURN for some reason.
*
* @param connection the connection
* @param function function to handle messages
* @param user_data user data to pass to the function
* @param free_data_function function to use for freeing user data
* @returns #TRUE on success, #FALSE if not enough memory.
*/
dbus_bool_t
dbus_connection_add_filter (DBusConnection *connection,
DBusHandleMessageFunction function,
void *user_data,
DBusFreeFunction free_data_function)
{
DBusMessageFilter *filter;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (function != NULL, FALSE);
filter = dbus_new0 (DBusMessageFilter, 1);
if (filter == NULL)
return FALSE;
_dbus_atomic_inc (&filter->refcount);
CONNECTION_LOCK (connection);
if (!_dbus_list_append (&connection->filter_list,
filter))
{
_dbus_message_filter_unref (filter);
CONNECTION_UNLOCK (connection);
return FALSE;
}
/* Fill in filter after all memory allocated,
* so we don't run the free_user_data_function
* if the add_filter() fails
*/
filter->function = function;
filter->user_data = user_data;
filter->free_user_data_function = free_data_function;
CONNECTION_UNLOCK (connection);
return TRUE;
}
/**
* Removes a previously-added message filter. It is a programming
* error to call this function for a handler that has not been added
* as a filter. If the given handler was added more than once, only
* one instance of it will be removed (the most recently-added
* instance).
*
* @param connection the connection
* @param function the handler to remove
* @param user_data user data for the handler to remove
*
*/
void
dbus_connection_remove_filter (DBusConnection *connection,
DBusHandleMessageFunction function,
void *user_data)
{
DBusList *link;
DBusMessageFilter *filter;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (function != NULL);
CONNECTION_LOCK (connection);
filter = NULL;
link = _dbus_list_get_last_link (&connection->filter_list);
while (link != NULL)
{
filter = link->data;
if (filter->function == function &&
filter->user_data == user_data)
{
_dbus_list_remove_link (&connection->filter_list, link);
filter->function = NULL;
break;
}
link = _dbus_list_get_prev_link (&connection->filter_list, link);
filter = NULL;
}
CONNECTION_UNLOCK (connection);
#ifndef DBUS_DISABLE_CHECKS
if (filter == NULL)
{
_dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added",
function, user_data);
return;
}
#endif
/* Call application code */
if (filter->free_user_data_function)
(* filter->free_user_data_function) (filter->user_data);
filter->free_user_data_function = NULL;
filter->user_data = NULL;
_dbus_message_filter_unref (filter);
}
/**
* Registers a handler for a given path or subsection in the object
* hierarchy. The given vtable handles messages sent to exactly the
* given path or also for paths bellow that, depending on fallback
* parameter.
*
* @param connection the connection
* @param fallback whether to handle messages also for "subdirectory"
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @param error address where an error can be returned
* @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
* #DBUS_ERROR_OBJECT_PATH_IN_USE) is reported
*/
static dbus_bool_t
_dbus_connection_register_object_path (DBusConnection *connection,
dbus_bool_t fallback,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data,
DBusError *error)
{
char **decomposed_path;
dbus_bool_t retval;
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
retval = _dbus_object_tree_register (connection->objects,
fallback,
(const char **) decomposed_path, vtable,
user_data, error);
CONNECTION_UNLOCK (connection);
dbus_free_string_array (decomposed_path);
return retval;
}
/**
* Registers a handler for a given path in the object hierarchy.
* The given vtable handles messages sent to exactly the given path.
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @param error address where an error can be returned
* @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
* #DBUS_ERROR_OBJECT_PATH_IN_USE) is reported
*/
dbus_bool_t
dbus_connection_try_register_object_path (DBusConnection *connection,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data,
DBusError *error)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
_dbus_return_val_if_fail (vtable != NULL, FALSE);
return _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, error);
}
/**
* Registers a handler for a given path in the object hierarchy.
* The given vtable handles messages sent to exactly the given path.
*
* It is a bug to call this function for object paths which already
* have a handler. Use dbus_connection_try_register_object_path() if this
* might be the case.
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
* #DBUS_ERROR_OBJECT_PATH_IN_USE) ocurred
*/
dbus_bool_t
dbus_connection_register_object_path (DBusConnection *connection,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data)
{
dbus_bool_t retval;
DBusError error = DBUS_ERROR_INIT;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
_dbus_return_val_if_fail (vtable != NULL, FALSE);
retval = _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, &error);
if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE))
{
_dbus_warn ("%s", error.message);
dbus_error_free (&error);
return FALSE;
}
return retval;
}
/**
* Registers a fallback handler for a given subsection of the object
* hierarchy. The given vtable handles messages at or below the given
* path. You can use this to establish a default message handling
* policy for a whole "subdirectory."
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @param error address where an error can be returned
* @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
* #DBUS_ERROR_OBJECT_PATH_IN_USE) is reported
*/
dbus_bool_t
dbus_connection_try_register_fallback (DBusConnection *connection,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data,
DBusError *error)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
_dbus_return_val_if_fail (vtable != NULL, FALSE);
return _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, error);
}
/**
* Registers a fallback handler for a given subsection of the object
* hierarchy. The given vtable handles messages at or below the given
* path. You can use this to establish a default message handling
* policy for a whole "subdirectory."
*
* It is a bug to call this function for object paths which already
* have a handler. Use dbus_connection_try_register_fallback() if this
* might be the case.
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
* #DBUS_ERROR_OBJECT_PATH_IN_USE) occured
*/
dbus_bool_t
dbus_connection_register_fallback (DBusConnection *connection,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data)
{
dbus_bool_t retval;
DBusError error = DBUS_ERROR_INIT;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
_dbus_return_val_if_fail (vtable != NULL, FALSE);
retval = _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, &error);
if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE))
{
_dbus_warn ("%s", error.message);
dbus_error_free (&error);
return FALSE;
}
return retval;
}
/**
* Unregisters the handler registered with exactly the given path.
* It's a bug to call this function for a path that isn't registered.
* Can unregister both fallback paths and object paths.
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @returns #FALSE if not enough memory
*/
dbus_bool_t
dbus_connection_unregister_object_path (DBusConnection *connection,
const char *path)
{
char **decomposed_path;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
_dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path);
dbus_free_string_array (decomposed_path);
return TRUE;
}
/**
* Gets the user data passed to dbus_connection_register_object_path()
* or dbus_connection_register_fallback(). If nothing was registered
* at this path, the data is filled in with #NULL.
*
* @param connection the connection
* @param path the path you registered with
* @param data_p location to store the user data, or #NULL
* @returns #FALSE if not enough memory
*/
dbus_bool_t
dbus_connection_get_object_path_data (DBusConnection *connection,
const char *path,
void **data_p)
{
char **decomposed_path;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (data_p != NULL, FALSE);
*data_p = NULL;
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
*data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path);
CONNECTION_UNLOCK (connection);
dbus_free_string_array (decomposed_path);
return TRUE;
}
/**
* Lists the registered fallback handlers and object path handlers at
* the given parent_path. The returned array should be freed with
* dbus_free_string_array().
*
* @param connection the connection
* @param parent_path the path to list the child handlers of
* @param child_entries returns #NULL-terminated array of children
* @returns #FALSE if no memory to allocate the child entries
*/
dbus_bool_t
dbus_connection_list_registered (DBusConnection *connection,
const char *parent_path,
char ***child_entries)
{
char **decomposed_path;
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (parent_path != NULL, FALSE);
_dbus_return_val_if_fail (parent_path[0] == '/', FALSE);
_dbus_return_val_if_fail (child_entries != NULL, FALSE);
if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
retval = _dbus_object_tree_list_registered_and_unlock (connection->objects,
(const char **) decomposed_path,
child_entries);
dbus_free_string_array (decomposed_path);
return retval;
}
static DBusDataSlotAllocator slot_allocator =
_DBUS_DATA_SLOT_ALLOCATOR_INIT (_DBUS_LOCK_NAME (connection_slots));
/**
* Allocates an integer ID to be used for storing application-specific
* data on any DBusConnection. The allocated ID may then be used
* with dbus_connection_set_data() and dbus_connection_get_data().
* The passed-in slot must be initialized to -1, and is filled in
* with the slot ID. If the passed-in slot is not -1, it's assumed
* to be already allocated, and its refcount is incremented.
*
* The allocated slot is global, i.e. all DBusConnection objects will
* have a slot with the given integer ID reserved.
*
* @param slot_p address of a global variable storing the slot
* @returns #FALSE on failure (no memory)
*/
dbus_bool_t
dbus_connection_allocate_data_slot (dbus_int32_t *slot_p)
{
return _dbus_data_slot_allocator_alloc (&slot_allocator,
slot_p);
}
/**
* Deallocates a global ID for connection data slots.
* dbus_connection_get_data() and dbus_connection_set_data() may no
* longer be used with this slot. Existing data stored on existing
* DBusConnection objects will be freed when the connection is
* finalized, but may not be retrieved (and may only be replaced if
* someone else reallocates the slot). When the refcount on the
* passed-in slot reaches 0, it is set to -1.
*
* @param slot_p address storing the slot to deallocate
*/
void
dbus_connection_free_data_slot (dbus_int32_t *slot_p)
{
_dbus_return_if_fail (*slot_p >= 0);
_dbus_data_slot_allocator_free (&slot_allocator, slot_p);
}
/**
* Stores a pointer on a DBusConnection, along
* with an optional function to be used for freeing
* the data when the data is set again, or when
* the connection is finalized. The slot number
* must have been allocated with dbus_connection_allocate_data_slot().
*
* @note This function does not take the
* main thread lock on DBusConnection, which allows it to be
* used from inside watch and timeout functions. (See the
* note in docs for dbus_connection_set_watch_functions().)
* A side effect of this is that you need to know there's
* a reference held on the connection while invoking
* dbus_connection_set_data(), or the connection could be
* finalized during dbus_connection_set_data().
*
* @param connection the connection
* @param slot the slot number
* @param data the data to store
* @param free_data_func finalizer function for the data
* @returns #TRUE if there was enough memory to store the data
*/
dbus_bool_t
dbus_connection_set_data (DBusConnection *connection,
dbus_int32_t slot,
void *data,
DBusFreeFunction free_data_func)
{
DBusFreeFunction old_free_func;
void *old_data;
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (slot >= 0, FALSE);
SLOTS_LOCK (connection);
retval = _dbus_data_slot_list_set (&slot_allocator,
&connection->slot_list,
slot, data, free_data_func,
&old_free_func, &old_data);
SLOTS_UNLOCK (connection);
if (retval)
{
/* Do the actual free outside the connection lock */
if (old_free_func)
(* old_free_func) (old_data);
}
return retval;
}
/**
* Retrieves data previously set with dbus_connection_set_data().
* The slot must still be allocated (must not have been freed).
*
* @note This function does not take the
* main thread lock on DBusConnection, which allows it to be
* used from inside watch and timeout functions. (See the
* note in docs for dbus_connection_set_watch_functions().)
* A side effect of this is that you need to know there's
* a reference held on the connection while invoking
* dbus_connection_get_data(), or the connection could be
* finalized during dbus_connection_get_data().
*
* @param connection the connection
* @param slot the slot to get data from
* @returns the data, or #NULL if not found
*/
void*
dbus_connection_get_data (DBusConnection *connection,
dbus_int32_t slot)
{
void *res;
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_return_val_if_fail (slot >= 0, NULL);
SLOTS_LOCK (connection);
res = _dbus_data_slot_list_get (&slot_allocator,
&connection->slot_list,
slot);
SLOTS_UNLOCK (connection);
return res;
}
/**
* This function sets a global flag for whether dbus_connection_new()
* will set SIGPIPE behavior to SIG_IGN.
*
* @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN
*/
void
dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
{
if (will_modify_sigpipe)
_dbus_atomic_set_nonzero (&_dbus_modify_sigpipe);
else
_dbus_atomic_set_zero (&_dbus_modify_sigpipe);
}
/**
* Specifies the maximum size message this connection is allowed to
* receive. Larger messages will result in disconnecting the
* connection.
*
* @param connection a #DBusConnection
* @param size maximum message size the connection can receive, in bytes
*/
void
dbus_connection_set_max_message_size (DBusConnection *connection,
long size)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_max_message_size (connection->transport,
size);
CONNECTION_UNLOCK (connection);
}
/**
* Gets the value set by dbus_connection_set_max_message_size().
*
* @param connection the connection
* @returns the max size of a single message
*/
long
dbus_connection_get_max_message_size (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_max_message_size (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Specifies the maximum number of unix fds a message on this
* connection is allowed to receive. Messages with more unix fds will
* result in disconnecting the connection.
*
* @param connection a #DBusConnection
* @param n maximum message unix fds the connection can receive
*/
void
dbus_connection_set_max_message_unix_fds (DBusConnection *connection,
long n)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_max_message_unix_fds (connection->transport,
n);
CONNECTION_UNLOCK (connection);
}
/**
* Gets the value set by dbus_connection_set_max_message_unix_fds().
*
* @param connection the connection
* @returns the max numer of unix fds of a single message
*/
long
dbus_connection_get_max_message_unix_fds (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_max_message_unix_fds (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Sets the maximum total number of bytes that can be used for all messages
* received on this connection. Messages count toward the maximum until
* they are finalized. When the maximum is reached, the connection will
* not read more data until some messages are finalized.
*
* The semantics of the maximum are: if outstanding messages are
* already above the maximum, additional messages will not be read.
* The semantics are not: if the next message would cause us to exceed
* the maximum, we don't read it. The reason is that we don't know the
* size of a message until after we read it.
*
* Thus, the max live messages size can actually be exceeded
* by up to the maximum size of a single message.
*
* Also, if we read say 1024 bytes off the wire in a single read(),
* and that contains a half-dozen small messages, we may exceed the
* size max by that amount. But this should be inconsequential.
*
* This does imply that we can't call read() with a buffer larger
* than we're willing to exceed this limit by.
*
* @param connection the connection
* @param size the maximum size in bytes of all outstanding messages
*/
void
dbus_connection_set_max_received_size (DBusConnection *connection,
long size)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_max_received_size (connection->transport,
size);
CONNECTION_UNLOCK (connection);
}
/**
* Gets the value set by dbus_connection_set_max_received_size().
*
* @param connection the connection
* @returns the max size of all live messages
*/
long
dbus_connection_get_max_received_size (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_max_received_size (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Sets the maximum total number of unix fds that can be used for all messages
* received on this connection. Messages count toward the maximum until
* they are finalized. When the maximum is reached, the connection will
* not read more data until some messages are finalized.
*
* The semantics are analogous to those of dbus_connection_set_max_received_size().
*
* @param connection the connection
* @param n the maximum size in bytes of all outstanding messages
*/
void
dbus_connection_set_max_received_unix_fds (DBusConnection *connection,
long n)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_max_received_unix_fds (connection->transport,
n);
CONNECTION_UNLOCK (connection);
}
/**
* Gets the value set by dbus_connection_set_max_received_unix_fds().
*
* @param connection the connection
* @returns the max unix fds of all live messages
*/
long
dbus_connection_get_max_received_unix_fds (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_max_received_unix_fds (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Gets the approximate size in bytes of all messages in the outgoing
* message queue. The size is approximate in that you shouldn't use
* it to decide how many bytes to read off the network or anything
* of that nature, as optimizations may choose to tell small white lies
* to avoid performance overhead.
*
* @param connection the connection
* @returns the number of bytes that have been queued up but not sent
*/
long
dbus_connection_get_outgoing_size (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_counter_get_size_value (connection->outgoing_counter);
CONNECTION_UNLOCK (connection);
return res;
}
#ifdef DBUS_ENABLE_STATS
void
_dbus_connection_get_stats (DBusConnection *connection,
dbus_uint32_t *in_messages,
dbus_uint32_t *in_bytes,
dbus_uint32_t *in_fds,
dbus_uint32_t *in_peak_bytes,
dbus_uint32_t *in_peak_fds,
dbus_uint32_t *out_messages,
dbus_uint32_t *out_bytes,
dbus_uint32_t *out_fds,
dbus_uint32_t *out_peak_bytes,
dbus_uint32_t *out_peak_fds)
{
CONNECTION_LOCK (connection);
if (in_messages != NULL)
*in_messages = connection->n_incoming;
_dbus_transport_get_stats (connection->transport,
in_bytes, in_fds, in_peak_bytes, in_peak_fds);
if (out_messages != NULL)
*out_messages = connection->n_outgoing;
if (out_bytes != NULL)
*out_bytes = _dbus_counter_get_size_value (connection->outgoing_counter);
if (out_fds != NULL)
*out_fds = _dbus_counter_get_unix_fd_value (connection->outgoing_counter);
if (out_peak_bytes != NULL)
*out_peak_bytes = _dbus_counter_get_peak_size_value (connection->outgoing_counter);
if (out_peak_fds != NULL)
*out_peak_fds = _dbus_counter_get_peak_unix_fd_value (connection->outgoing_counter);
CONNECTION_UNLOCK (connection);
}
#endif /* DBUS_ENABLE_STATS */
/**
* Gets the approximate number of uni fds of all messages in the
* outgoing message queue.
*
* @param connection the connection
* @returns the number of unix fds that have been queued up but not sent
*/
long
dbus_connection_get_outgoing_unix_fds (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_counter_get_unix_fd_value (connection->outgoing_counter);
CONNECTION_UNLOCK (connection);
return res;
}
#ifdef DBUS_ENABLE_EMBEDDED_TESTS
/**
* Returns the address of the transport object of this connection
*
* @param connection the connection
* @returns the address string
*/
const char*
_dbus_connection_get_address (DBusConnection *connection)
{
return _dbus_transport_get_address (connection->transport);
}
#endif
/** @} */
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