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dbus/dbus/dbus-connection.c
John (J5) Palmieri da4182fb29 2006-03-02 John (J5) Palmieri <johnp@redhat.com> 
* dbus/dbus-connection.c:
	(_dbus_connection_block_pending_call):
	Check to see if our data has already been read off the connection
	by another blocking pending call before we block in poll.
	(check_for_reply_and_update_dispatch_unlocked):
	Code taken from _dbus_connection_block_pending_call - checks for
	an already read reply and updates the dispatch if there is one.

	* test/name-test/test-pending-call-dispatch.c:
	New test for making sure we don't get stuck polling a
	dbus connection which has no data on the socket when
	blocking out of order on two or more pending calls.
2006-03-02 22:24:28 +00:00

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/* -*- mode: C; c-file-style: "gnu" -*- */
/* dbus-connection.c DBusConnection object
*
* Copyright (C) 2002, 2003, 2004, 2005 Red Hat Inc.
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <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-list.h"
#include "dbus-hash.h"
#include "dbus-message-internal.h"
#include "dbus-threads.h"
#include "dbus-protocol.h"
#include "dbus-dataslot.h"
#include "dbus-string.h"
#include "dbus-pending-call.h"
#include "dbus-object-tree.h"
#include "dbus-threads-internal.h"
#ifdef DBUS_DISABLE_CHECKS
#define TOOK_LOCK_CHECK(connection)
#define RELEASING_LOCK_CHECK(connection)
#define HAVE_LOCK_CHECK(connection)
#else
#define TOOK_LOCK_CHECK(connection) do { \
_dbus_assert (!(connection)->have_connection_lock); \
(connection)->have_connection_lock = TRUE; \
} while (0)
#define RELEASING_LOCK_CHECK(connection) do { \
_dbus_assert ((connection)->have_connection_lock); \
(connection)->have_connection_lock = FALSE; \
} while (0)
#define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock)
/* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */
#endif
#define TRACE_LOCKS 1
#define CONNECTION_LOCK(connection) do { \
if (TRACE_LOCKS) { _dbus_verbose (" LOCK: %s\n", _DBUS_FUNCTION_NAME); } \
_dbus_mutex_lock ((connection)->mutex); \
TOOK_LOCK_CHECK (connection); \
} while (0)
#define CONNECTION_UNLOCK(connection) do { \
if (TRACE_LOCKS) { _dbus_verbose (" UNLOCK: %s\n", _DBUS_FUNCTION_NAME); } \
RELEASING_LOCK_CHECK (connection); \
_dbus_mutex_unlock ((connection)->mutex); \
} while (0)
#define DISPATCH_STATUS_NAME(s) \
((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \
(s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \
(s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \
"???")
/**
* @defgroup DBusConnection DBusConnection
* @ingroup DBus
* @brief Connection to another application
*
* A DBusConnection represents a connection to another
* application. Messages can be sent and received via this connection.
* The other application may be a message bus; for convenience, the
* function dbus_bus_get() is provided to automatically open a
* connection to the well-known message buses.
*
* In brief a DBusConnection is a message queue associated with some
* message transport mechanism such as a socket. The connection
* maintains a queue of incoming messages and a queue of outgoing
* messages.
*
* Incoming messages are normally processed by calling
* dbus_connection_dispatch(). dbus_connection_dispatch() runs any
* handlers registered for the topmost message in the message queue,
* then discards the message, then returns.
*
* dbus_connection_get_dispatch_status() indicates whether
* messages are currently in the queue that need dispatching.
* dbus_connection_set_dispatch_status_function() allows
* you to set a function to be used to monitor the dispatch status.
*
* If you're using GLib or Qt add-on libraries for D-BUS, there are
* special convenience APIs in those libraries that hide
* all the details of dispatch and watch/timeout monitoring.
* For example, dbus_connection_setup_with_g_main().
*
* If you aren't using these add-on libraries, you have to manually
* call dbus_connection_set_dispatch_status_function(),
* dbus_connection_set_watch_functions(),
* dbus_connection_set_timeout_functions() providing appropriate
* functions to integrate the connection with your application's main
* loop.
*
* When you use dbus_connection_send() or one of its variants to send
* a message, the message is added to the outgoing queue. It's
* actually written to the network later; either in
* dbus_watch_handle() invoked by your main loop, or in
* dbus_connection_flush() which blocks until it can write out the
* entire outgoing queue. The GLib/Qt add-on libraries again
* handle the details here for you by setting up watch functions.
*
* When a connection is disconnected, you are guaranteed to get a
* signal "Disconnected" from the interface
* #DBUS_INTERFACE_LOCAL, path
* #DBUS_PATH_LOCAL.
*
* You may not drop the last reference to a #DBusConnection
* until that connection has been disconnected.
*
* You may dispatch the unprocessed incoming message queue even if the
* connection is disconnected. However, "Disconnected" will always be
* the last message in the queue (obviously no messages are received
* after disconnection).
*
* #DBusConnection has thread locks and drops them when invoking user
* callbacks, so in general is transparently threadsafe. However,
* #DBusMessage does NOT have thread locks; you must not send the same
* message to multiple #DBusConnection that will be used from
* different threads.
*/
/**
* @defgroup DBusConnectionInternals DBusConnection implementation details
* @ingroup DBusInternals
* @brief Implementation details of DBusConnection
*
* @{
*/
/**
* Internal struct representing a message filter function
*/
typedef struct DBusMessageFilter DBusMessageFilter;
/**
* Internal struct representing a message filter function
*/
struct DBusMessageFilter
{
DBusAtomic refcount; /**< Reference count */
DBusHandleMessageFunction function; /**< Function to call to filter */
void *user_data; /**< User data for the function */
DBusFreeFunction free_user_data_function; /**< Function to free the user data */
};
/**
* Internals of DBusPreallocatedSend
*/
struct DBusPreallocatedSend
{
DBusConnection *connection; /**< Connection we'd send the message to */
DBusList *queue_link; /**< Preallocated link in the queue */
DBusList *counter_link; /**< Preallocated link in the resource counter */
};
static dbus_bool_t _dbus_modify_sigpipe = TRUE;
/**
* Implementation details of DBusConnection. All fields are private.
*/
struct DBusConnection
{
DBusAtomic refcount; /**< Reference count. */
DBusMutex *mutex; /**< Lock on the entire DBusConnection */
DBusMutex *dispatch_mutex; /**< Protects dispatch_acquired */
DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */
DBusMutex *io_path_mutex; /**< Protects io_path_acquired */
DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */
DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */
DBusMessage *message_borrowed; /**< Filled in if the first incoming message has been borrowed;
* dispatch_acquired will be set by the borrower
*/
int n_outgoing; /**< Length of outgoing queue. */
int n_incoming; /**< Length of incoming queue. */
DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */
DBusTransport *transport; /**< Object that sends/receives messages over network. */
DBusWatchList *watches; /**< Stores active watches. */
DBusTimeoutList *timeouts; /**< Stores active timeouts. */
DBusList *filter_list; /**< List of filters. */
DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */
DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */
dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */
DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */
DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */
void *wakeup_main_data; /**< Application data for wakeup_main_function */
DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */
DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */
void *dispatch_status_data; /**< Application data for dispatch_status_function */
DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */
DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */
DBusList *link_cache; /**< A cache of linked list links to prevent contention
* for the global linked list mempool lock
*/
DBusObjectTree *objects; /**< Object path handlers registered with this connection */
char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */
unsigned int shareable : 1; /**< #TRUE if connection can go in shared_connections once we know the GUID */
unsigned int dispatch_acquired : 1; /**< Someone has dispatch path (can drain incoming queue) */
unsigned int io_path_acquired : 1; /**< Someone has transport io path (can use the transport to read/write messages) */
unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */
#ifndef DBUS_DISABLE_CHECKS
unsigned int have_connection_lock : 1; /**< Used to check locking */
#endif
#ifndef DBUS_DISABLE_CHECKS
int generation; /**< _dbus_current_generation that should correspond to this connection */
#endif
};
static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection);
static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
DBusDispatchStatus new_status);
static void _dbus_connection_last_unref (DBusConnection *connection);
static void _dbus_connection_acquire_dispatch (DBusConnection *connection);
static void _dbus_connection_release_dispatch (DBusConnection *connection);
static DBusMessageFilter *
_dbus_message_filter_ref (DBusMessageFilter *filter)
{
_dbus_assert (filter->refcount.value > 0);
_dbus_atomic_inc (&filter->refcount);
return filter;
}
static void
_dbus_message_filter_unref (DBusMessageFilter *filter)
{
_dbus_assert (filter->refcount.value > 0);
if (_dbus_atomic_dec (&filter->refcount) == 1)
{
if (filter->free_user_data_function)
(* filter->free_user_data_function) (filter->user_data);
dbus_free (filter);
}
}
/**
* Acquires the connection lock.
*
* @param connection the connection.
*/
void
_dbus_connection_lock (DBusConnection *connection)
{
CONNECTION_LOCK (connection);
}
/**
* Releases the connection lock.
*
* @param connection the connection.
*/
void
_dbus_connection_unlock (DBusConnection *connection)
{
CONNECTION_UNLOCK (connection);
}
/**
* Wakes up the main loop if it is sleeping
* Needed if we're e.g. queueing outgoing messages
* on a thread while the mainloop sleeps.
*
* @param connection the connection.
*/
static void
_dbus_connection_wakeup_mainloop (DBusConnection *connection)
{
if (connection->wakeup_main_function)
(*connection->wakeup_main_function) (connection->wakeup_main_data);
}
#ifdef DBUS_BUILD_TESTS
/* For now this function isn't used */
/**
* Adds a message to the incoming message queue, returning #FALSE
* if there's insufficient memory to queue the message.
* Does not take over refcount of the message.
*
* @param connection the connection.
* @param message the message to queue.
* @returns #TRUE on success.
*/
dbus_bool_t
_dbus_connection_queue_received_message (DBusConnection *connection,
DBusMessage *message)
{
DBusList *link;
link = _dbus_list_alloc_link (message);
if (link == NULL)
return FALSE;
dbus_message_ref (message);
_dbus_connection_queue_received_message_link (connection, link);
return TRUE;
}
#endif
/**
* Adds a message-containing list link to the incoming message queue,
* taking ownership of the link and the message's current refcount.
* Cannot fail due to lack of memory.
*
* @param connection the connection.
* @param link the message link to queue.
*/
void
_dbus_connection_queue_received_message_link (DBusConnection *connection,
DBusList *link)
{
DBusPendingCall *pending;
dbus_int32_t reply_serial;
DBusMessage *message;
_dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
_dbus_list_append_link (&connection->incoming_messages,
link);
message = link->data;
/* If this is a reply we're waiting on, remove timeout for it */
reply_serial = dbus_message_get_reply_serial (message);
if (reply_serial != -1)
{
pending = _dbus_hash_table_lookup_int (connection->pending_replies,
reply_serial);
if (pending != NULL)
{
if (pending->timeout_added)
_dbus_connection_remove_timeout_unlocked (connection,
pending->timeout);
pending->timeout_added = FALSE;
}
}
connection->n_incoming += 1;
_dbus_connection_wakeup_mainloop (connection);
_dbus_verbose ("Message %p (%d %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n",
message,
dbus_message_get_type (message),
dbus_message_get_path (message) ?
dbus_message_get_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);
}
/**
* Adds a link + message to the incoming message queue.
* Can't fail. Takes ownership of both link and message.
*
* @param connection the connection.
* @param link the list node and message to queue.
*
* @todo This needs to wake up the mainloop if it is in
* a poll/select and this is a multithreaded app.
*/
static void
_dbus_connection_queue_synthesized_message_link (DBusConnection *connection,
DBusList *link)
{
HAVE_LOCK_CHECK (connection);
_dbus_list_append_link (&connection->incoming_messages, link);
connection->n_incoming += 1;
_dbus_connection_wakeup_mainloop (connection);
_dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n",
link->data, connection, connection->n_incoming);
}
/**
* Checks whether there are messages in the outgoing message queue.
* Called with connection lock held.
*
* @param connection the connection.
* @returns #TRUE if the outgoing queue is non-empty.
*/
dbus_bool_t
_dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
return connection->outgoing_messages != NULL;
}
/**
* Checks whether there are messages in the outgoing message queue.
*
* @param connection the connection.
* @returns #TRUE if the outgoing queue is non-empty.
*/
dbus_bool_t
dbus_connection_has_messages_to_send (DBusConnection *connection)
{
dbus_bool_t v;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
v = _dbus_connection_has_messages_to_send_unlocked (connection);
CONNECTION_UNLOCK (connection);
return v;
}
/**
* Gets the next outgoing message. The message remains in the
* queue, and the caller does not own a reference to it.
*
* @param connection the connection.
* @returns the message to be sent.
*/
DBusMessage*
_dbus_connection_get_message_to_send (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
return _dbus_list_get_last (&connection->outgoing_messages);
}
/**
* Notifies the connection that a message has been sent, so the
* message can be removed from the outgoing queue.
* Called with the connection lock held.
*
* @param connection the connection.
* @param message the message that was sent.
*/
void
_dbus_connection_message_sent (DBusConnection *connection,
DBusMessage *message)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
/* This can be called before we even complete authentication, since
* it's called on disconnect to clean up the outgoing queue.
* It's also called as we successfully send each message.
*/
link = _dbus_list_get_last_link (&connection->outgoing_messages);
_dbus_assert (link != NULL);
_dbus_assert (link->data == message);
/* Save this link in the link cache */
_dbus_list_unlink (&connection->outgoing_messages,
link);
_dbus_list_prepend_link (&connection->link_cache, link);
connection->n_outgoing -= 1;
_dbus_verbose ("Message %p (%d %s %s %s '%s') removed from outgoing queue %p, %d left to send\n",
message,
dbus_message_get_type (message),
dbus_message_get_path (message) ?
dbus_message_get_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);
/* Save this link in the link cache also */
_dbus_message_remove_size_counter (message, connection->outgoing_counter,
&link);
_dbus_list_prepend_link (&connection->link_cache, link);
dbus_message_unref (message);
}
typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list,
DBusWatch *watch);
typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list,
DBusWatch *watch);
typedef void (* DBusWatchToggleFunction) (DBusWatchList *list,
DBusWatch *watch,
dbus_bool_t enabled);
static dbus_bool_t
protected_change_watch (DBusConnection *connection,
DBusWatch *watch,
DBusWatchAddFunction add_function,
DBusWatchRemoveFunction remove_function,
DBusWatchToggleFunction toggle_function,
dbus_bool_t enabled)
{
DBusWatchList *watches;
dbus_bool_t retval;
HAVE_LOCK_CHECK (connection);
/* This isn't really safe or reasonable; a better pattern is the "do everything, then
* drop lock and call out" one; but it has to be propagated up through all callers
*/
watches = connection->watches;
if (watches)
{
connection->watches = NULL;
_dbus_connection_ref_unlocked (connection);
CONNECTION_UNLOCK (connection);
if (add_function)
retval = (* add_function) (watches, watch);
else if (remove_function)
{
retval = TRUE;
(* remove_function) (watches, watch);
}
else
{
retval = TRUE;
(* toggle_function) (watches, watch, enabled);
}
CONNECTION_LOCK (connection);
connection->watches = watches;
_dbus_connection_unref_unlocked (connection);
return retval;
}
else
return FALSE;
}
/**
* Adds a watch using the connection's DBusAddWatchFunction if
* available. Otherwise records the watch to be added when said
* function is available. Also re-adds the watch if the
* DBusAddWatchFunction changes. May fail due to lack of memory.
* 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);
}
typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list,
DBusTimeout *timeout);
typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list,
DBusTimeout *timeout);
typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list,
DBusTimeout *timeout,
dbus_bool_t enabled);
static dbus_bool_t
protected_change_timeout (DBusConnection *connection,
DBusTimeout *timeout,
DBusTimeoutAddFunction add_function,
DBusTimeoutRemoveFunction remove_function,
DBusTimeoutToggleFunction toggle_function,
dbus_bool_t enabled)
{
DBusTimeoutList *timeouts;
dbus_bool_t retval;
HAVE_LOCK_CHECK (connection);
/* This isn't really safe or reasonable; a better pattern is the "do everything, then
* drop lock and call out" one; but it has to be propagated up through all callers
*/
timeouts = connection->timeouts;
if (timeouts)
{
connection->timeouts = NULL;
_dbus_connection_ref_unlocked (connection);
CONNECTION_UNLOCK (connection);
if (add_function)
retval = (* add_function) (timeouts, timeout);
else if (remove_function)
{
retval = TRUE;
(* remove_function) (timeouts, timeout);
}
else
{
retval = TRUE;
(* toggle_function) (timeouts, timeout, enabled);
}
CONNECTION_LOCK (connection);
connection->timeouts = timeouts;
_dbus_connection_unref_unlocked (connection);
return retval;
}
else
return FALSE;
}
/**
* Adds a timeout using the connection's DBusAddTimeoutFunction if
* available. Otherwise records the timeout to be added when said
* function is available. Also re-adds the timeout if the
* DBusAddTimeoutFunction changes. May fail due to lack of memory.
* The timeout will fire repeatedly until removed.
* 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)
{
HAVE_LOCK_CHECK (connection);
_dbus_assert (pending->reply_serial != 0);
if (!_dbus_connection_add_timeout_unlocked (connection, pending->timeout))
return FALSE;
if (!_dbus_hash_table_insert_int (connection->pending_replies,
pending->reply_serial,
pending))
{
_dbus_connection_remove_timeout_unlocked (connection, pending->timeout);
HAVE_LOCK_CHECK (connection);
return FALSE;
}
pending->timeout_added = TRUE;
pending->connection = connection;
dbus_pending_call_ref (pending);
HAVE_LOCK_CHECK (connection);
return TRUE;
}
static void
free_pending_call_on_hash_removal (void *data)
{
DBusPendingCall *pending;
if (data == NULL)
return;
pending = data;
if (pending->connection)
{
if (pending->timeout_added)
{
_dbus_connection_remove_timeout_unlocked (pending->connection,
pending->timeout);
pending->timeout_added = FALSE;
}
pending->connection = NULL;
dbus_pending_call_unref (pending);
}
}
static void
_dbus_connection_detach_pending_call_unlocked (DBusConnection *connection,
DBusPendingCall *pending)
{
/* Can't have a destroy notifier on the pending call if we're going to do this */
dbus_pending_call_ref (pending);
_dbus_hash_table_remove_int (connection->pending_replies,
pending->reply_serial);
_dbus_assert (pending->connection == NULL);
dbus_pending_call_unref (pending);
}
static void
_dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection,
DBusPendingCall *pending)
{
/* The idea here is to avoid finalizing the pending call
* with the lock held, since there's a destroy notifier
* in pending call that goes out to application code.
*/
dbus_pending_call_ref (pending);
_dbus_hash_table_remove_int (connection->pending_replies,
pending->reply_serial);
_dbus_assert (pending->connection == NULL);
CONNECTION_UNLOCK (connection);
dbus_pending_call_unref (pending);
}
/**
* Removes a pending call from the connection, such that
* the pending reply will be ignored. May drop the last
* reference to the pending call.
*
* @param connection the connection
* @param pending the pending call
*/
void
_dbus_connection_remove_pending_call (DBusConnection *connection,
DBusPendingCall *pending)
{
CONNECTION_LOCK (connection);
_dbus_connection_detach_pending_call_and_unlock (connection, pending);
}
/**
* Completes a pending call with the given message,
* or if the message is #NULL, by timing out the pending call.
*
* @param pending the pending call
* @param message the message to complete the call with, or #NULL
* to time out the call
*/
void
_dbus_pending_call_complete_and_unlock (DBusPendingCall *pending,
DBusMessage *message)
{
if (message == NULL)
{
message = pending->timeout_link->data;
_dbus_list_clear (&pending->timeout_link);
}
else
dbus_message_ref (message);
_dbus_verbose (" handing message %p (%s) to pending call serial %u\n",
message,
dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_RETURN ?
"method return" :
dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ?
"error" : "other type",
pending->reply_serial);
_dbus_assert (pending->reply == NULL);
_dbus_assert (pending->reply_serial == dbus_message_get_reply_serial (message));
pending->reply = message;
dbus_pending_call_ref (pending); /* in case there's no app with a ref held */
_dbus_connection_detach_pending_call_and_unlock (pending->connection, pending);
/* Must be called unlocked since it invokes app callback */
_dbus_pending_call_notify (pending);
dbus_pending_call_unref (pending);
}
/**
* Acquire the transporter I/O path. This must be done before
* doing any I/O in the transporter. May sleep and drop the
* IO path mutex while waiting for the I/O path.
*
* @param connection the connection.
* @param timeout_milliseconds maximum blocking time, or -1 for no limit.
* @returns TRUE if the I/O path was acquired.
*/
static dbus_bool_t
_dbus_connection_acquire_io_path (DBusConnection *connection,
int timeout_milliseconds)
{
dbus_bool_t we_acquired;
HAVE_LOCK_CHECK (connection);
/* We don't want the connection to vanish */
_dbus_connection_ref_unlocked (connection);
/* We will only touch io_path_acquired which is protected by our mutex */
CONNECTION_UNLOCK (connection);
_dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_lock (connection->io_path_mutex);
_dbus_verbose ("%s start connection->io_path_acquired = %d timeout = %d\n",
_DBUS_FUNCTION_NAME, connection->io_path_acquired, timeout_milliseconds);
we_acquired = FALSE;
if (connection->io_path_acquired)
{
if (timeout_milliseconds != -1)
{
_dbus_verbose ("%s waiting %d for IO path to be acquirable\n",
_DBUS_FUNCTION_NAME, timeout_milliseconds);
_dbus_condvar_wait_timeout (connection->io_path_cond,
connection->io_path_mutex,
timeout_milliseconds);
}
else
{
while (connection->io_path_acquired)
{
_dbus_verbose ("%s waiting for IO path to be acquirable\n", _DBUS_FUNCTION_NAME);
_dbus_condvar_wait (connection->io_path_cond, connection->io_path_mutex);
}
}
}
if (!connection->io_path_acquired)
{
we_acquired = TRUE;
connection->io_path_acquired = TRUE;
}
_dbus_verbose ("%s end connection->io_path_acquired = %d we_acquired = %d\n",
_DBUS_FUNCTION_NAME, connection->io_path_acquired, we_acquired);
_dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_unlock (connection->io_path_mutex);
CONNECTION_LOCK (connection);
HAVE_LOCK_CHECK (connection);
_dbus_connection_unref_unlocked (connection);
return we_acquired;
}
/**
* Release the I/O path when you're done with it. Only call
* after you've acquired the I/O. Wakes up at most one thread
* currently waiting to acquire the I/O path.
*
* @param connection the connection.
*/
static void
_dbus_connection_release_io_path (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_lock (connection->io_path_mutex);
_dbus_assert (connection->io_path_acquired);
_dbus_verbose ("%s start connection->io_path_acquired = %d\n",
_DBUS_FUNCTION_NAME, connection->io_path_acquired);
connection->io_path_acquired = FALSE;
_dbus_condvar_wake_one (connection->io_path_cond);
_dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_unlock (connection->io_path_mutex);
}
/**
* Queues incoming messages and sends outgoing messages for this
* connection, optionally blocking in the process. Each call to
* _dbus_connection_do_iteration_unlocked() will call select() or poll() one
* time and then read or write data if possible.
*
* The purpose of this function is to be able to flush outgoing
* messages or queue up incoming messages without returning
* control to the application and causing reentrancy weirdness.
*
* The flags parameter allows you to specify whether to
* read incoming messages, write outgoing messages, or both,
* and whether to block if no immediate action is possible.
*
* The timeout_milliseconds parameter does nothing unless the
* iteration is blocking.
*
* If there are no outgoing messages and DBUS_ITERATION_DO_READING
* wasn't specified, then it's impossible to block, even if
* you specify DBUS_ITERATION_BLOCK; in that case the function
* returns immediately.
*
* Called with connection lock held.
*
* @param connection the connection.
* @param flags iteration flags.
* @param timeout_milliseconds maximum blocking time, or -1 for no limit.
*/
void
_dbus_connection_do_iteration_unlocked (DBusConnection *connection,
unsigned int flags,
int timeout_milliseconds)
{
_dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
HAVE_LOCK_CHECK (connection);
if (connection->n_outgoing == 0)
flags &= ~DBUS_ITERATION_DO_WRITING;
if (_dbus_connection_acquire_io_path (connection,
(flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0))
{
HAVE_LOCK_CHECK (connection);
_dbus_transport_do_iteration (connection->transport,
flags, timeout_milliseconds);
_dbus_connection_release_io_path (connection);
}
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
}
/**
* Creates a new connection for the given transport. A transport
* represents a message stream that uses some concrete mechanism, such
* as UNIX domain sockets. May return #NULL if insufficient
* memory exists to create the connection.
*
* @param transport the transport.
* @returns the new connection, or #NULL on failure.
*/
DBusConnection*
_dbus_connection_new_for_transport (DBusTransport *transport)
{
DBusConnection *connection;
DBusWatchList *watch_list;
DBusTimeoutList *timeout_list;
DBusHashTable *pending_replies;
DBusMutex *mutex;
DBusMutex *io_path_mutex;
DBusMutex *dispatch_mutex;
DBusCondVar *dispatch_cond;
DBusCondVar *io_path_cond;
DBusList *disconnect_link;
DBusMessage *disconnect_message;
DBusCounter *outgoing_counter;
DBusObjectTree *objects;
watch_list = NULL;
connection = NULL;
pending_replies = NULL;
timeout_list = NULL;
mutex = NULL;
io_path_mutex = NULL;
dispatch_mutex = NULL;
dispatch_cond = NULL;
io_path_cond = NULL;
disconnect_link = NULL;
disconnect_message = NULL;
outgoing_counter = NULL;
objects = NULL;
watch_list = _dbus_watch_list_new ();
if (watch_list == NULL)
goto error;
timeout_list = _dbus_timeout_list_new ();
if (timeout_list == NULL)
goto error;
pending_replies =
_dbus_hash_table_new (DBUS_HASH_INT,
NULL,
(DBusFreeFunction)free_pending_call_on_hash_removal);
if (pending_replies == NULL)
goto error;
connection = dbus_new0 (DBusConnection, 1);
if (connection == NULL)
goto error;
mutex = _dbus_mutex_new ();
if (mutex == NULL)
goto error;
io_path_mutex = _dbus_mutex_new ();
if (io_path_mutex == NULL)
goto error;
dispatch_mutex = _dbus_mutex_new ();
if (dispatch_mutex == NULL)
goto error;
dispatch_cond = _dbus_condvar_new ();
if (dispatch_cond == NULL)
goto error;
io_path_cond = _dbus_condvar_new ();
if (io_path_cond == NULL)
goto error;
disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL,
DBUS_INTERFACE_LOCAL,
"Disconnected");
if (disconnect_message == NULL)
goto error;
disconnect_link = _dbus_list_alloc_link (disconnect_message);
if (disconnect_link == NULL)
goto error;
outgoing_counter = _dbus_counter_new ();
if (outgoing_counter == NULL)
goto error;
objects = _dbus_object_tree_new (connection);
if (objects == NULL)
goto error;
if (_dbus_modify_sigpipe)
_dbus_disable_sigpipe ();
connection->refcount.value = 1;
connection->mutex = mutex;
connection->dispatch_cond = dispatch_cond;
connection->dispatch_mutex = dispatch_mutex;
connection->io_path_cond = io_path_cond;
connection->io_path_mutex = io_path_mutex;
connection->transport = transport;
connection->watches = watch_list;
connection->timeouts = timeout_list;
connection->pending_replies = pending_replies;
connection->outgoing_counter = outgoing_counter;
connection->filter_list = NULL;
connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */
connection->objects = objects;
connection->exit_on_disconnect = FALSE;
connection->shareable = FALSE;
#ifndef DBUS_DISABLE_CHECKS
connection->generation = _dbus_current_generation;
#endif
_dbus_data_slot_list_init (&connection->slot_list);
connection->client_serial = 1;
connection->disconnect_message_link = disconnect_link;
CONNECTION_LOCK (connection);
if (!_dbus_transport_set_connection (transport, connection))
goto error;
_dbus_transport_ref (transport);
CONNECTION_UNLOCK (connection);
return connection;
error:
if (disconnect_message != NULL)
dbus_message_unref (disconnect_message);
if (disconnect_link != NULL)
_dbus_list_free_link (disconnect_link);
if (io_path_cond != NULL)
_dbus_condvar_free (io_path_cond);
if (dispatch_cond != NULL)
_dbus_condvar_free (dispatch_cond);
if (mutex != NULL)
_dbus_mutex_free (mutex);
if (io_path_mutex != NULL)
_dbus_mutex_free (io_path_mutex);
if (dispatch_mutex != NULL)
_dbus_mutex_free (dispatch_mutex);
if (connection != NULL)
dbus_free (connection);
if (pending_replies)
_dbus_hash_table_unref (pending_replies);
if (watch_list)
_dbus_watch_list_free (watch_list);
if (timeout_list)
_dbus_timeout_list_free (timeout_list);
if (outgoing_counter)
_dbus_counter_unref (outgoing_counter);
if (objects)
_dbus_object_tree_unref (objects);
return NULL;
}
/**
* Increments the reference count of a DBusConnection.
* Requires that the caller already holds the connection lock.
*
* @param connection the connection.
* @returns the connection.
*/
DBusConnection *
_dbus_connection_ref_unlocked (DBusConnection *connection)
{
_dbus_assert (connection != NULL);
_dbus_assert (connection->generation == _dbus_current_generation);
HAVE_LOCK_CHECK (connection);
#ifdef DBUS_HAVE_ATOMIC_INT
_dbus_atomic_inc (&connection->refcount);
#else
_dbus_assert (connection->refcount.value > 0);
connection->refcount.value += 1;
#endif
return connection;
}
/**
* Decrements the reference count of a DBusConnection.
* Requires that the caller already holds the connection lock.
*
* @param connection the connection.
*/
void
_dbus_connection_unref_unlocked (DBusConnection *connection)
{
dbus_bool_t last_unref;
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection != NULL);
/* The connection lock is better than the global
* lock in the atomic increment fallback
*/
#ifdef DBUS_HAVE_ATOMIC_INT
last_unref = (_dbus_atomic_dec (&connection->refcount) == 1);
#else
_dbus_assert (connection->refcount.value > 0);
connection->refcount.value -= 1;
last_unref = (connection->refcount.value == 0);
#if 0
printf ("unref_unlocked() connection %p count = %d\n", connection, connection->refcount.value);
#endif
#endif
if (last_unref)
_dbus_connection_last_unref (connection);
}
static dbus_uint32_t
_dbus_connection_get_next_client_serial (DBusConnection *connection)
{
int serial;
serial = connection->client_serial++;
if (connection->client_serial < 0)
connection->client_serial = 1;
return serial;
}
/**
* A callback for use with dbus_watch_new() to create a DBusWatch.
*
* @todo This is basically a hack - we could delete _dbus_transport_handle_watch()
* and the virtual handle_watch in DBusTransport if we got rid of it.
* The reason this is some work is threading, see the _dbus_connection_handle_watch()
* implementation.
*
* @param watch the watch.
* @param condition the current condition of the file descriptors being watched.
* @param data must be a pointer to a #DBusConnection
* @returns #FALSE if the IO condition may not have been fully handled due to lack of memory
*/
dbus_bool_t
_dbus_connection_handle_watch (DBusWatch *watch,
unsigned int condition,
void *data)
{
DBusConnection *connection;
dbus_bool_t retval;
DBusDispatchStatus status;
connection = data;
_dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
CONNECTION_LOCK (connection);
_dbus_connection_acquire_io_path (connection, -1);
HAVE_LOCK_CHECK (connection);
retval = _dbus_transport_handle_watch (connection->transport,
watch, condition);
_dbus_connection_release_io_path (connection);
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
_dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
return retval;
}
_DBUS_DEFINE_GLOBAL_LOCK (shared_connections);
static DBusHashTable *shared_connections = NULL;
static void
shared_connections_shutdown (void *data)
{
_DBUS_LOCK (shared_connections);
_dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0);
_dbus_hash_table_unref (shared_connections);
shared_connections = NULL;
_DBUS_UNLOCK (shared_connections);
}
static dbus_bool_t
connection_lookup_shared (DBusAddressEntry *entry,
DBusConnection **result)
{
_dbus_verbose ("checking for existing connection\n");
*result = NULL;
_DBUS_LOCK (shared_connections);
if (shared_connections == NULL)
{
_dbus_verbose ("creating shared_connections hash table\n");
shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING,
dbus_free,
NULL);
if (shared_connections == NULL)
{
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL))
{
_dbus_hash_table_unref (shared_connections);
shared_connections = NULL;
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
_dbus_verbose (" successfully created shared_connections\n");
_DBUS_UNLOCK (shared_connections);
return TRUE; /* no point looking up in the hash we just made */
}
else
{
const char *guid;
guid = dbus_address_entry_get_value (entry, "guid");
if (guid != NULL)
{
*result = _dbus_hash_table_lookup_string (shared_connections,
guid);
if (*result)
{
/* The DBusConnection can't have been disconnected
* between the lookup and this code, because the
* disconnection will take the shared_connections lock to
* remove the connection. It can't have been finalized
* since you have to disconnect prior to finalize.
*
* Thus it's safe to ref the connection.
*/
dbus_connection_ref (*result);
_dbus_verbose ("looked up existing connection to server guid %s\n",
guid);
}
}
_DBUS_UNLOCK (shared_connections);
return TRUE;
}
}
static dbus_bool_t
connection_record_shared_unlocked (DBusConnection *connection,
const char *guid)
{
char *guid_key;
char *guid_in_connection;
/* A separate copy of the key is required in the hash table, because
* we don't have a lock on the connection when we are doing a hash
* lookup.
*/
_dbus_assert (connection->server_guid == NULL);
_dbus_assert (connection->shareable);
guid_key = _dbus_strdup (guid);
if (guid_key == NULL)
return FALSE;
guid_in_connection = _dbus_strdup (guid);
if (guid_in_connection == NULL)
{
dbus_free (guid_key);
return FALSE;
}
_DBUS_LOCK (shared_connections);
_dbus_assert (shared_connections != NULL);
if (!_dbus_hash_table_insert_string (shared_connections,
guid_key, connection))
{
dbus_free (guid_key);
dbus_free (guid_in_connection);
_DBUS_UNLOCK (shared_connections);
return FALSE;
}
connection->server_guid = guid_in_connection;
_dbus_verbose ("stored connection to %s to be shared\n",
connection->server_guid);
_DBUS_UNLOCK (shared_connections);
_dbus_assert (connection->server_guid != NULL);
return TRUE;
}
static void
connection_forget_shared_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
if (connection->server_guid == NULL)
return;
_dbus_verbose ("dropping connection to %s out of the shared table\n",
connection->server_guid);
_DBUS_LOCK (shared_connections);
if (!_dbus_hash_table_remove_string (shared_connections,
connection->server_guid))
_dbus_assert_not_reached ("connection was not in the shared table");
dbus_free (connection->server_guid);
connection->server_guid = NULL;
_DBUS_UNLOCK (shared_connections);
}
static DBusConnection*
connection_try_from_address_entry (DBusAddressEntry *entry,
DBusError *error)
{
DBusTransport *transport;
DBusConnection *connection;
transport = _dbus_transport_open (entry, error);
if (transport == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
return NULL;
}
connection = _dbus_connection_new_for_transport (transport);
_dbus_transport_unref (transport);
if (connection == NULL)
{
_DBUS_SET_OOM (error);
return NULL;
}
#ifndef DBUS_DISABLE_CHECKS
_dbus_assert (!connection->have_connection_lock);
#endif
return connection;
}
/*
* If the shared parameter is true, then any existing connection will
* be used (and if a new connection is created, it will be available
* for use by others). If the shared parameter is false, a new
* connection will always be created, and the new connection will
* never be returned to other callers.
*
* @param address the address
* @param shared whether the connection is shared or private
* @param error error return
* @returns the connection or #NULL on error
*/
static DBusConnection*
_dbus_connection_open_internal (const char *address,
dbus_bool_t shared,
DBusError *error)
{
DBusConnection *connection;
DBusAddressEntry **entries;
DBusError tmp_error;
DBusError first_error;
int len, i;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
_dbus_verbose ("opening %s connection to: %s\n",
shared ? "shared" : "private", address);
if (!dbus_parse_address (address, &entries, &len, error))
return NULL;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
connection = NULL;
dbus_error_init (&tmp_error);
dbus_error_init (&first_error);
for (i = 0; i < len; i++)
{
if (shared)
{
if (!connection_lookup_shared (entries[i], &connection))
_DBUS_SET_OOM (&tmp_error);
}
if (connection == NULL)
{
connection = connection_try_from_address_entry (entries[i],
&tmp_error);
if (connection != NULL && shared)
{
const char *guid;
connection->shareable = TRUE;
guid = dbus_address_entry_get_value (entries[i], "guid");
/* we don't have a connection lock but we know nobody
* else has a handle to the connection
*/
if (guid &&
!connection_record_shared_unlocked (connection, guid))
{
_DBUS_SET_OOM (&tmp_error);
dbus_connection_close (connection);
dbus_connection_unref (connection);
connection = NULL;
}
/* but as of now the connection is possibly shared
* since another thread could have pulled it from the table
*/
}
}
if (connection)
break;
_DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
if (i == 0)
dbus_move_error (&tmp_error, &first_error);
else
dbus_error_free (&tmp_error);
}
/* NOTE we don't have a lock on a possibly-shared connection object */
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
_DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
if (connection == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (&first_error);
dbus_move_error (&first_error, error);
}
else
{
dbus_error_free (&first_error);
}
dbus_address_entries_free (entries);
return connection;
}
/** @} */
/**
* @addtogroup DBusConnection
*
* @{
*/
/**
* Gets a connection to a remote address. If a connection to the given
* address already exists, returns the existing connection with its
* reference count incremented. Otherwise, returns a new connection
* and saves the new connection for possible re-use if a future call
* to dbus_connection_open() asks to connect to the same server.
*
* Use dbus_connection_open_private() to get a dedicated connection
* not shared with other callers of dbus_connection_open().
*
* If the open fails, the function returns #NULL, and provides a
* reason for the failure in the error parameter. Pass #NULL for the
* error parameter if you aren't interested in the reason for
* failure.
*
* @param address the address.
* @param error address where an error can be returned.
* @returns new connection, or #NULL on failure.
*/
DBusConnection*
dbus_connection_open (const char *address,
DBusError *error)
{
DBusConnection *connection;
_dbus_return_val_if_fail (address != NULL, NULL);
_dbus_return_val_if_error_is_set (error, NULL);
connection = _dbus_connection_open_internal (address,
TRUE,
error);
return connection;
}
/**
* Opens a new, dedicated connection to a remote address. Unlike
* dbus_connection_open(), always creates a new connection.
* This connection will not be saved or recycled by libdbus.
*
* If the open fails, the function returns #NULL, and provides a
* reason for the failure in the error parameter. Pass #NULL for the
* error parameter if you aren't interested in the reason for
* failure.
*
* @param address the address.
* @param error address where an error can be returned.
* @returns new connection, or #NULL on failure.
*/
DBusConnection*
dbus_connection_open_private (const char *address,
DBusError *error)
{
DBusConnection *connection;
_dbus_return_val_if_fail (address != NULL, NULL);
_dbus_return_val_if_error_is_set (error, NULL);
connection = _dbus_connection_open_internal (address,
FALSE,
error);
return connection;
}
/**
* Increments the reference count of a DBusConnection.
*
* @param connection the connection.
* @returns the connection.
*/
DBusConnection *
dbus_connection_ref (DBusConnection *connection)
{
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL);
/* The connection lock is better than the global
* lock in the atomic increment fallback
*/
#ifdef DBUS_HAVE_ATOMIC_INT
_dbus_atomic_inc (&connection->refcount);
#else
CONNECTION_LOCK (connection);
_dbus_assert (connection->refcount.value > 0);
connection->refcount.value += 1;
CONNECTION_UNLOCK (connection);
#endif
return connection;
}
static void
free_outgoing_message (void *element,
void *data)
{
DBusMessage *message = element;
DBusConnection *connection = data;
_dbus_message_remove_size_counter (message,
connection->outgoing_counter,
NULL);
dbus_message_unref (message);
}
/* This is run without the mutex held, but after the last reference
* to the connection has been dropped we should have no thread-related
* problems
*/
static void
_dbus_connection_last_unref (DBusConnection *connection)
{
DBusList *link;
_dbus_verbose ("Finalizing connection %p\n", connection);
_dbus_assert (connection->refcount.value == 0);
/* You have to disconnect the connection before unref:ing it. Otherwise
* you won't get the disconnected message.
*/
_dbus_assert (!_dbus_transport_get_is_connected (connection->transport));
_dbus_assert (connection->server_guid == NULL);
/* ---- We're going to call various application callbacks here, hope it doesn't break anything... */
_dbus_object_tree_free_all_unlocked (connection->objects);
dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL);
dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL);
dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL);
_dbus_watch_list_free (connection->watches);
connection->watches = NULL;
_dbus_timeout_list_free (connection->timeouts);
connection->timeouts = NULL;
_dbus_data_slot_list_free (&connection->slot_list);
link = _dbus_list_get_first_link (&connection->filter_list);
while (link != NULL)
{
DBusMessageFilter *filter = link->data;
DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
filter->function = NULL;
_dbus_message_filter_unref (filter); /* calls app callback */
link->data = NULL;
link = next;
}
_dbus_list_clear (&connection->filter_list);
/* ---- Done with stuff that invokes application callbacks */
_dbus_object_tree_unref (connection->objects);
_dbus_hash_table_unref (connection->pending_replies);
connection->pending_replies = NULL;
_dbus_list_clear (&connection->filter_list);
_dbus_list_foreach (&connection->outgoing_messages,
free_outgoing_message,
connection);
_dbus_list_clear (&connection->outgoing_messages);
_dbus_list_foreach (&connection->incoming_messages,
(DBusForeachFunction) dbus_message_unref,
NULL);
_dbus_list_clear (&connection->incoming_messages);
_dbus_counter_unref (connection->outgoing_counter);
_dbus_transport_unref (connection->transport);
if (connection->disconnect_message_link)
{
DBusMessage *message = connection->disconnect_message_link->data;
dbus_message_unref (message);
_dbus_list_free_link (connection->disconnect_message_link);
}
_dbus_list_clear (&connection->link_cache);
_dbus_condvar_free (connection->dispatch_cond);
_dbus_condvar_free (connection->io_path_cond);
_dbus_mutex_free (connection->io_path_mutex);
_dbus_mutex_free (connection->dispatch_mutex);
_dbus_mutex_free (connection->mutex);
dbus_free (connection);
}
/**
* Decrements the reference count of a DBusConnection, and finalizes
* it if the count reaches zero. It is a bug to drop the last reference
* to a connection that has not been disconnected.
*
* @todo in practice it can be quite tricky to never unref a connection
* that's still connected; maybe there's some way we could avoid
* the requirement.
*
* @param connection the connection.
*/
void
dbus_connection_unref (DBusConnection *connection)
{
dbus_bool_t last_unref;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (connection->generation == _dbus_current_generation);
/* The connection lock is better than the global
* lock in the atomic increment fallback
*/
#ifdef DBUS_HAVE_ATOMIC_INT
last_unref = (_dbus_atomic_dec (&connection->refcount) == 1);
#else
CONNECTION_LOCK (connection);
_dbus_assert (connection->refcount.value > 0);
connection->refcount.value -= 1;
last_unref = (connection->refcount.value == 0);
#if 0
printf ("unref() connection %p count = %d\n", connection, connection->refcount.value);
#endif
CONNECTION_UNLOCK (connection);
#endif
if (last_unref)
_dbus_connection_last_unref (connection);
}
/**
* Closes the connection, so no further data can be sent or received.
* Any further attempts to send data will result in errors. This
* function does not affect the connection's reference count. It's
* safe to disconnect a connection more than once; all calls after the
* first do nothing. It's impossible to "reopen" a connection, a
* new connection must be created. This function may result in a call
* to the DBusDispatchStatusFunction set with
* dbus_connection_set_dispatch_status_function(), as the disconnect
* message it generates needs to be dispatched.
*
* @param connection the connection.
*/
void
dbus_connection_close (DBusConnection *connection)
{
DBusDispatchStatus status;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (connection->generation == _dbus_current_generation);
_dbus_verbose ("Disconnecting %p\n", connection);
CONNECTION_LOCK (connection);
_dbus_transport_disconnect (connection->transport);
_dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
}
/** Alias for dbus_connection_close(). This method is DEPRECATED and will be
* removed for 1.0. Change your code to use dbus_connection_close() instead.
*
* @param connection the connection.
* @deprecated
*/
void
dbus_connection_disconnect (DBusConnection *connection)
{
dbus_connection_close (connection);
}
static dbus_bool_t
_dbus_connection_get_is_connected_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
return _dbus_transport_get_is_connected (connection->transport);
}
/**
* Gets whether the connection is currently connected. All
* connections are connected when they are opened. A connection may
* become disconnected when the remote application closes its end, or
* exits; a connection may also be disconnected with
* dbus_connection_close().
*
* @param connection the connection.
* @returns #TRUE if the connection is still alive.
*/
dbus_bool_t
dbus_connection_get_is_connected (DBusConnection *connection)
{
dbus_bool_t res;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
res = _dbus_connection_get_is_connected_unlocked (connection);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Gets whether the connection was authenticated. (Note that
* if the connection was authenticated then disconnected,
* this function still returns #TRUE)
*
* @param connection the connection
* @returns #TRUE if the connection was ever authenticated
*/
dbus_bool_t
dbus_connection_get_is_authenticated (DBusConnection *connection)
{
dbus_bool_t res;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_is_authenticated (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Set whether _exit() should be called when the connection receives a
* disconnect signal. The call to _exit() comes after any handlers for
* the disconnect signal run; handlers can cancel the exit by calling
* this function.
*
* By default, exit_on_disconnect is #FALSE; but for message bus
* connections returned from dbus_bus_get() it will be toggled on
* by default.
*
* @param connection the connection
* @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal
*/
void
dbus_connection_set_exit_on_disconnect (DBusConnection *connection,
dbus_bool_t exit_on_disconnect)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
connection->exit_on_disconnect = exit_on_disconnect != FALSE;
CONNECTION_UNLOCK (connection);
}
static DBusPreallocatedSend*
_dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
{
DBusPreallocatedSend *preallocated;
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection != NULL);
preallocated = dbus_new (DBusPreallocatedSend, 1);
if (preallocated == NULL)
return NULL;
if (connection->link_cache != NULL)
{
preallocated->queue_link =
_dbus_list_pop_first_link (&connection->link_cache);
preallocated->queue_link->data = NULL;
}
else
{
preallocated->queue_link = _dbus_list_alloc_link (NULL);
if (preallocated->queue_link == NULL)
goto failed_0;
}
if (connection->link_cache != NULL)
{
preallocated->counter_link =
_dbus_list_pop_first_link (&connection->link_cache);
preallocated->counter_link->data = connection->outgoing_counter;
}
else
{
preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
if (preallocated->counter_link == NULL)
goto failed_1;
}
_dbus_counter_ref (preallocated->counter_link->data);
preallocated->connection = connection;
return preallocated;
failed_1:
_dbus_list_free_link (preallocated->queue_link);
failed_0:
dbus_free (preallocated);
return NULL;
}
/**
* Preallocates resources needed to send a message, allowing the message
* to be sent without the possibility of memory allocation failure.
* Allows apps to create a future guarantee that they can send
* a message regardless of memory shortages.
*
* @param connection the connection we're preallocating for.
* @returns the preallocated resources, or #NULL
*/
DBusPreallocatedSend*
dbus_connection_preallocate_send (DBusConnection *connection)
{
DBusPreallocatedSend *preallocated;
_dbus_return_val_if_fail (connection != NULL, NULL);
CONNECTION_LOCK (connection);
preallocated =
_dbus_connection_preallocate_send_unlocked (connection);
CONNECTION_UNLOCK (connection);
return preallocated;
}
/**
* Frees preallocated message-sending resources from
* dbus_connection_preallocate_send(). Should only
* be called if the preallocated resources are not used
* to send a message.
*
* @param connection the connection
* @param preallocated the resources
*/
void
dbus_connection_free_preallocated_send (DBusConnection *connection,
DBusPreallocatedSend *preallocated)
{
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (preallocated != NULL);
_dbus_return_if_fail (connection == preallocated->connection);
_dbus_list_free_link (preallocated->queue_link);
_dbus_counter_unref (preallocated->counter_link->data);
_dbus_list_free_link (preallocated->counter_link);
dbus_free (preallocated);
}
/* Called with lock held, does not update dispatch status */
static void
_dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection,
DBusPreallocatedSend *preallocated,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
dbus_uint32_t serial;
const char *sig;
preallocated->queue_link->data = message;
_dbus_list_prepend_link (&connection->outgoing_messages,
preallocated->queue_link);
_dbus_message_add_size_counter_link (message,
preallocated->counter_link);
dbus_free (preallocated);
preallocated = NULL;
dbus_message_ref (message);
connection->n_outgoing += 1;
sig = dbus_message_get_signature (message);
_dbus_verbose ("Message %p (%d %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n",
message,
dbus_message_get_type (message),
dbus_message_get_path (message) ?
dbus_message_get_path (message) :
"no path",
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
sig,
dbus_message_get_destination (message) ?
dbus_message_get_destination (message) :
"null",
connection,
connection->n_outgoing);
if (dbus_message_get_serial (message) == 0)
{
serial = _dbus_connection_get_next_client_serial (connection);
_dbus_message_set_serial (message, serial);
if (client_serial)
*client_serial = serial;
}
else
{
if (client_serial)
*client_serial = dbus_message_get_serial (message);
}
_dbus_verbose ("Message %p serial is %u\n",
message, dbus_message_get_serial (message));
_dbus_message_lock (message);
/* Now we need to run an iteration to hopefully just write the messages
* out immediately, and otherwise get them queued up
*/
_dbus_connection_do_iteration_unlocked (connection,
DBUS_ITERATION_DO_WRITING,
-1);
/* If stuff is still queued up, be sure we wake up the main loop */
if (connection->n_outgoing > 0)
_dbus_connection_wakeup_mainloop (connection);
}
static void
_dbus_connection_send_preallocated_and_unlock (DBusConnection *connection,
DBusPreallocatedSend *preallocated,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
DBusDispatchStatus status;
HAVE_LOCK_CHECK (connection);
_dbus_connection_send_preallocated_unlocked_no_update (connection,
preallocated,
message, client_serial);
_dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
}
/**
* Sends a message using preallocated resources. This function cannot fail.
* It works identically to dbus_connection_send() in other respects.
* Preallocated resources comes from dbus_connection_preallocate_send().
* This function "consumes" the preallocated resources, they need not
* be freed separately.
*
* @param connection the connection
* @param preallocated the preallocated resources
* @param message the message to send
* @param client_serial return location for client serial assigned to the message
*/
void
dbus_connection_send_preallocated (DBusConnection *connection,
DBusPreallocatedSend *preallocated,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (preallocated != NULL);
_dbus_return_if_fail (message != NULL);
_dbus_return_if_fail (preallocated->connection == connection);
_dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL ||
(dbus_message_get_interface (message) != NULL &&
dbus_message_get_member (message) != NULL));
_dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL ||
(dbus_message_get_interface (message) != NULL &&
dbus_message_get_member (message) != NULL));
CONNECTION_LOCK (connection);
_dbus_connection_send_preallocated_and_unlock (connection,
preallocated,
message, client_serial);
}
static dbus_bool_t
_dbus_connection_send_unlocked_no_update (DBusConnection *connection,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
DBusPreallocatedSend *preallocated;
_dbus_assert (connection != NULL);
_dbus_assert (message != NULL);
preallocated = _dbus_connection_preallocate_send_unlocked (connection);
if (preallocated == NULL)
return FALSE;
_dbus_connection_send_preallocated_unlocked_no_update (connection,
preallocated,
message,
client_serial);
return TRUE;
}
dbus_bool_t
_dbus_connection_send_and_unlock (DBusConnection *connection,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
DBusPreallocatedSend *preallocated;
_dbus_assert (connection != NULL);
_dbus_assert (message != NULL);
preallocated = _dbus_connection_preallocate_send_unlocked (connection);
if (preallocated == NULL)
{
CONNECTION_UNLOCK (connection);
return FALSE;
}
_dbus_connection_send_preallocated_and_unlock (connection,
preallocated,
message,
client_serial);
return TRUE;
}
/**
* Adds a message to the outgoing message queue. Does not block to
* write the message to the network; that happens asynchronously. To
* force the message to be written, call dbus_connection_flush().
* Because this only queues the message, the only reason it can
* fail is lack of memory. Even if the connection is disconnected,
* no error will be returned.
*
* If the function fails due to lack of memory, it returns #FALSE.
* The function will never fail for other reasons; even if the
* connection is disconnected, you can queue an outgoing message,
* though obviously it won't be sent.
*
* @param connection the connection.
* @param message the message to write.
* @param client_serial return location for client serial.
* @returns #TRUE on success.
*/
dbus_bool_t
dbus_connection_send (DBusConnection *connection,
DBusMessage *message,
dbus_uint32_t *client_serial)
{
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (message != NULL, FALSE);
CONNECTION_LOCK (connection);
return _dbus_connection_send_and_unlock (connection,
message,
client_serial);
}
static dbus_bool_t
reply_handler_timeout (void *data)
{
DBusConnection *connection;
DBusDispatchStatus status;
DBusPendingCall *pending = data;
connection = pending->connection;
CONNECTION_LOCK (connection);
if (pending->timeout_link)
{
_dbus_connection_queue_synthesized_message_link (connection,
pending->timeout_link);
pending->timeout_link = NULL;
}
_dbus_connection_remove_timeout_unlocked (connection,
pending->timeout);
pending->timeout_added = FALSE;
_dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* Unlocks, and calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
return TRUE;
}
/**
* Queues a message to send, as with dbus_connection_send_message(),
* but also returns a #DBusPendingCall used to receive a reply to the
* message. If no reply is received in the given timeout_milliseconds,
* this function expires the pending reply and generates a synthetic
* error reply (generated in-process, not by the remote application)
* indicating that a timeout occurred.
*
* A #DBusPendingCall will see a reply message after any filters, but
* before any object instances or other handlers. A #DBusPendingCall
* will always see exactly one reply message, unless it's cancelled
* with dbus_pending_call_cancel().
*
* If a filter filters out the reply before the handler sees it, the
* reply is immediately timed out and a timeout error reply is
* generated. If a filter removes the timeout error reply then the
* #DBusPendingCall will get confused. Filtering the timeout error
* is thus considered a bug and will print a warning.
*
* If #NULL is passed for the pending_return, the #DBusPendingCall
* will still be generated internally, and used to track
* the message reply timeout. This means a timeout error will
* occur if no reply arrives, unlike with dbus_connection_send().
*
* If -1 is passed for the timeout, a sane default timeout is used. -1
* is typically the best value for the timeout for this reason, unless
* you want a very short or very long timeout. There is no way to
* avoid a timeout entirely, other than passing INT_MAX for the
* timeout to postpone it indefinitely.
*
* @param connection the connection
* @param message the message to send
* @param pending_return return location for a #DBusPendingCall object, or #NULL
* @param timeout_milliseconds timeout in milliseconds or -1 for default
* @returns #TRUE if the message is successfully queued, #FALSE if no memory.
*
*/
dbus_bool_t
dbus_connection_send_with_reply (DBusConnection *connection,
DBusMessage *message,
DBusPendingCall **pending_return,
int timeout_milliseconds)
{
DBusPendingCall *pending;
DBusMessage *reply;
DBusList *reply_link;
dbus_int32_t serial = -1;
DBusDispatchStatus status;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (message != NULL, FALSE);
_dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
if (pending_return)
*pending_return = NULL;
pending = _dbus_pending_call_new (connection,
timeout_milliseconds,
reply_handler_timeout);
if (pending == NULL)
return FALSE;
CONNECTION_LOCK (connection);
/* Assign a serial to the message */
if (dbus_message_get_serial (message) == 0)
{
serial = _dbus_connection_get_next_client_serial (connection);
_dbus_message_set_serial (message, serial);
}
pending->reply_serial = serial;
reply = dbus_message_new_error (message, DBUS_ERROR_NO_REPLY,
"No reply within specified time");
if (reply == NULL)
goto error;
reply_link = _dbus_list_alloc_link (reply);
if (reply_link == NULL)
{
CONNECTION_UNLOCK (connection);
dbus_message_unref (reply);
goto error_unlocked;
}
pending->timeout_link = reply_link;
/* Insert the serial in the pending replies hash;
* hash takes a refcount on DBusPendingCall.
* Also, add the timeout.
*/
if (!_dbus_connection_attach_pending_call_unlocked (connection,
pending))
goto error;
if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL))
{
_dbus_connection_detach_pending_call_and_unlock (connection,
pending);
goto error_unlocked;
}
if (pending_return)
*pending_return = pending;
else
{
_dbus_connection_detach_pending_call_unlocked (connection, pending);
dbus_pending_call_unref (pending);
}
_dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* this calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
return TRUE;
error:
CONNECTION_UNLOCK (connection);
error_unlocked:
dbus_pending_call_unref (pending);
return FALSE;
}
/* This is slightly strange since we can pop a message here without
* the dispatch lock.
*/
static DBusMessage*
check_for_reply_unlocked (DBusConnection *connection,
dbus_uint32_t client_serial)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
link = _dbus_list_get_first_link (&connection->incoming_messages);
while (link != NULL)
{
DBusMessage *reply = link->data;
if (dbus_message_get_reply_serial (reply) == client_serial)
{
_dbus_list_remove_link (&connection->incoming_messages, link);
connection->n_incoming -= 1;
return reply;
}
link = _dbus_list_get_next_link (&connection->incoming_messages, link);
}
return NULL;
}
static dbus_bool_t
check_for_reply_and_update_dispatch_unlocked (DBusPendingCall *pending)
{
DBusMessage *reply;
DBusDispatchStatus status;
DBusConnection *connection;
connection = pending->connection;
reply = check_for_reply_unlocked (connection, pending->reply_serial);
if (reply != NULL)
{
_dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME);
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");
_dbus_pending_call_complete_and_unlock (pending, reply);
dbus_message_unref (reply);
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_pending_call_unref (pending);
return TRUE;
}
return FALSE;
}
/**
* When a function that blocks has been called with a timeout, and we
* run out of memory, the time to wait for memory is based on the
* timeout. If the caller was willing to block a long time we wait a
* relatively long time for memory, if they were only willing to block
* briefly then we retry for memory at a rapid rate.
*
* @timeout_milliseconds the timeout requested for blocking
*/
static void
_dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
{
if (timeout_milliseconds == -1)
_dbus_sleep_milliseconds (1000);
else if (timeout_milliseconds < 100)
; /* just busy loop */
else if (timeout_milliseconds <= 1000)
_dbus_sleep_milliseconds (timeout_milliseconds / 3);
else
_dbus_sleep_milliseconds (1000);
}
/**
* Blocks until a pending call times out or gets a reply.
*
* Does not re-enter the main loop or run filter/path-registered
* callbacks. The reply to the message will not be seen by
* filter callbacks.
*
* Returns immediately if pending call already got a reply.
*
* @todo could use performance improvements (it keeps scanning
* the whole message queue for example)
*
* @param pending the pending call we block for a reply on
*/
void
_dbus_connection_block_pending_call (DBusPendingCall *pending)
{
long start_tv_sec, start_tv_usec;
long end_tv_sec, end_tv_usec;
long tv_sec, tv_usec;
DBusDispatchStatus status;
DBusConnection *connection;
dbus_uint32_t client_serial;
int timeout_milliseconds;
_dbus_assert (pending != NULL);
if (dbus_pending_call_get_completed (pending))
return;
if (pending->connection == NULL)
return; /* call already detached */
dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
connection = pending->connection;
client_serial = pending->reply_serial;
/* note that timeout_milliseconds is limited to a smallish value
* in _dbus_pending_call_new() so overflows aren't possible
* below
*/
timeout_milliseconds = dbus_timeout_get_interval (pending->timeout);
/* Flush message queue */
dbus_connection_flush (connection);
CONNECTION_LOCK (connection);
_dbus_get_current_time (&start_tv_sec, &start_tv_usec);
end_tv_sec = start_tv_sec + timeout_milliseconds / 1000;
end_tv_usec = start_tv_usec + (timeout_milliseconds % 1000) * 1000;
end_tv_sec += end_tv_usec / _DBUS_USEC_PER_SECOND;
end_tv_usec = end_tv_usec % _DBUS_USEC_PER_SECOND;
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec to %ld sec %ld usec\n",
timeout_milliseconds,
client_serial,
start_tv_sec, start_tv_usec,
end_tv_sec, end_tv_usec);
/* 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 (pending))
return;
/* Now we wait... */
/* always block at least once as we know we don't have the reply yet */
_dbus_connection_do_iteration_unlocked (connection,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds);
recheck_status:
_dbus_verbose ("%s top of recheck\n", _DBUS_FUNCTION_NAME);
HAVE_LOCK_CHECK (connection);
/* queue messages and get status */
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* the get_completed() is in case a dispatch() while we were blocking
* got the reply instead of us.
*/
if (dbus_pending_call_get_completed (pending))
{
_dbus_verbose ("Pending call completed by dispatch in %s\n", _DBUS_FUNCTION_NAME);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_pending_call_unref (pending);
return;
}
if (status == DBUS_DISPATCH_DATA_REMAINS)
if (check_for_reply_and_update_dispatch_unlocked (pending))
return;
_dbus_get_current_time (&tv_sec, &tv_usec);
if (!_dbus_connection_get_is_connected_unlocked (connection))
{
/* FIXME send a "DBUS_ERROR_DISCONNECTED" instead, just to help
* programmers understand what went wrong since the timeout is
* confusing
*/
_dbus_pending_call_complete_and_unlock (pending, NULL);
dbus_pending_call_unref (pending);
return;
}
else if (tv_sec < start_tv_sec)
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n");
else if (connection->disconnect_message_link == NULL)
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n");
else if (tv_sec < end_tv_sec ||
(tv_sec == end_tv_sec && tv_usec < end_tv_usec))
{
timeout_milliseconds = (end_tv_sec - tv_sec) * 1000 +
(end_tv_usec - tv_usec) / 1000;
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds);
_dbus_assert (timeout_milliseconds >= 0);
if (status == DBUS_DISPATCH_NEED_MEMORY)
{
/* Try sleeping a bit, as we aren't sure we need to block for reading,
* we may already have a reply in the buffer and just can't process
* it.
*/
_dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");
_dbus_memory_pause_based_on_timeout (timeout_milliseconds);
}
else
{
/* block again, we don't have the reply buffered yet. */
_dbus_connection_do_iteration_unlocked (connection,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds);
}
goto recheck_status;
}
_dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %ld milliseconds and got no reply\n",
(tv_sec - start_tv_sec) * 1000 + (tv_usec - start_tv_usec) / 1000);
_dbus_assert (!dbus_pending_call_get_completed (pending));
/* unlock and call user code */
_dbus_pending_call_complete_and_unlock (pending, NULL);
/* update user code on dispatch status */
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_pending_call_unref (pending);
}
/**
* Sends a message and blocks a certain time period while waiting for
* a reply. This function does not reenter the main loop,
* i.e. messages other than the reply are queued up but not
* processed. This function is used to do non-reentrant "method
* calls."
*
* If a normal reply is received, it is returned, and removed from the
* incoming message queue. If it is not received, #NULL is returned
* and the error is set to #DBUS_ERROR_NO_REPLY. If an error reply is
* received, it is converted to a #DBusError and returned as an error,
* then the reply message is deleted. If something else goes wrong,
* result is set to whatever is appropriate, such as
* #DBUS_ERROR_NO_MEMORY or #DBUS_ERROR_DISCONNECTED.
*
* @param connection the connection
* @param message the message to send
* @param timeout_milliseconds timeout in milliseconds or -1 for default
* @param error return location for error message
* @returns the message that is the reply or #NULL with an error code if the
* function fails.
*/
DBusMessage*
dbus_connection_send_with_reply_and_block (DBusConnection *connection,
DBusMessage *message,
int timeout_milliseconds,
DBusError *error)
{
DBusMessage *reply;
DBusPendingCall *pending;
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_return_val_if_fail (message != NULL, NULL);
_dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL);
_dbus_return_val_if_error_is_set (error, NULL);
if (!dbus_connection_send_with_reply (connection, message,
&pending, timeout_milliseconds))
{
_DBUS_SET_OOM (error);
return NULL;
}
_dbus_assert (pending != NULL);
dbus_pending_call_block (pending);
reply = dbus_pending_call_steal_reply (pending);
dbus_pending_call_unref (pending);
/* call_complete_and_unlock() called from pending_call_block() should
* always fill this in.
*/
_dbus_assert (reply != NULL);
if (dbus_set_error_from_message (error, reply))
{
dbus_message_unref (reply);
return NULL;
}
else
return reply;
}
/**
* Blocks until the outgoing message queue is empty.
*
* @param connection the connection.
*/
void
dbus_connection_flush (DBusConnection *connection)
{
/* We have to specify DBUS_ITERATION_DO_READING here because
* otherwise we could have two apps deadlock if they are both doing
* a flush(), and the kernel buffers fill up. This could change the
* dispatch status.
*/
DBusDispatchStatus status;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
while (connection->n_outgoing > 0 &&
_dbus_connection_get_is_connected_unlocked (connection))
{
_dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME);
HAVE_LOCK_CHECK (connection);
_dbus_connection_do_iteration_unlocked (connection,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_DO_WRITING |
DBUS_ITERATION_BLOCK,
-1);
}
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
HAVE_LOCK_CHECK (connection);
/* Unlocks and calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
_dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
}
/**
* This function is intended for use with applications that don't want
* to write a main loop and deal with #DBusWatch and #DBusTimeout. An
* example usage would be:
*
* @code
* while (dbus_connection_read_write_dispatch (connection, -1))
* ; // empty loop body
* @endcode
*
* In this usage you would normally have set up a filter function to look
* at each message as it is dispatched. The loop terminates when the last
* message from the connection (the disconnected signal) is processed.
*
* If there are messages to dispatch and the dispatch flag is set, this
* function will dbus_connection_dispatch() once, and return. If there are no
* messages to dispatch, this function will block until it can read or write,
* then read or write, then return.
*
* The way to think of this function is that it either makes some sort
* of progress, or it blocks.
*
* The return value indicates whether the disconnect message has been
* processed, NOT whether the connection is connected. This is
* important because even after disconnecting, you want to process any
* messages you received prior to the disconnect.
*
* @param connection the connection
* @param timeout_milliseconds max time to block or -1 for infinite
* @param dispatch dispatch new messages or leave them on the incoming queue
* @returns #TRUE if the disconnect message has not been processed
*/
dbus_bool_t
_dbus_connection_read_write_dispatch (DBusConnection *connection,
int timeout_milliseconds,
dbus_bool_t dispatch)
{
DBusDispatchStatus dstatus;
dbus_bool_t dispatched_disconnected;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
dstatus = dbus_connection_get_dispatch_status (connection);
if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS)
{
_dbus_verbose ("doing dispatch in %s\n", _DBUS_FUNCTION_NAME);
dbus_connection_dispatch (connection);
CONNECTION_LOCK (connection);
}
else if (dstatus == DBUS_DISPATCH_NEED_MEMORY)
{
_dbus_verbose ("pausing for memory in %s\n", _DBUS_FUNCTION_NAME);
_dbus_memory_pause_based_on_timeout (timeout_milliseconds);
CONNECTION_LOCK (connection);
}
else
{
CONNECTION_LOCK (connection);
if (_dbus_connection_get_is_connected_unlocked (connection))
{
_dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME);
_dbus_connection_do_iteration_unlocked (connection,
DBUS_ITERATION_DO_READING |
DBUS_ITERATION_DO_WRITING |
DBUS_ITERATION_BLOCK,
timeout_milliseconds);
}
}
HAVE_LOCK_CHECK (connection);
dispatched_disconnected = connection->n_incoming == 0 &&
connection->disconnect_message_link == NULL;
CONNECTION_UNLOCK (connection);
return !dispatched_disconnected; /* TRUE if we have not processed disconnected */
}
/**
* This function is intended for use with applications that don't want
* to write a main loop and deal with #DBusWatch and #DBusTimeout. An
* example usage would be:
*
* @code
* while (dbus_connection_read_write_dispatch (connection, -1))
* ; // empty loop body
* @endcode
*
* In this usage you would normally have set up a filter function to look
* at each message as it is dispatched. The loop terminates when the last
* message from the connection (the disconnected signal) is processed.
*
* If there are messages to dispatch, this function will
* dbus_connection_dispatch() once, and return. If there are no
* messages to dispatch, this function will block until it can read or
* write, then read or write, then return.
*
* The way to think of this function is that it either makes some sort
* of progress, or it blocks.
*
* The return value indicates whether the disconnect message has been
* processed, NOT whether the connection is connected. This is
* important because even after disconnecting, you want to process any
* messages you received prior to the disconnect.
*
* @param connection the connection
* @param timeout_milliseconds max time to block or -1 for infinite
* @returns #TRUE if the disconnect message has not been processed
*/
dbus_bool_t
dbus_connection_read_write_dispatch (DBusConnection *connection,
int timeout_milliseconds)
{
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.
*
* If there are no messages to dispatch, this function will block until it can
* read or write, then read or write, then return.
*
* 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 (DBusConnection *connection,
int timeout_milliseconds)
{
return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE);
}
/**
* Returns the first-received message from the incoming message queue,
* leaving it in the queue. If the queue is empty, returns #NULL.
*
* The caller does not own a reference to the returned message, and
* must either return it using dbus_connection_return_message() or
* keep it after calling dbus_connection_steal_borrowed_message(). No
* one can get at the message while its borrowed, so return it as
* quickly as possible and don't keep a reference to it after
* returning it. If you need to keep the message, make a copy of it.
*
* dbus_connection_dispatch() will block if called while a borrowed
* message is outstanding; only one piece of code can be playing with
* the incoming queue at a time. This function will block if called
* during a dbus_connection_dispatch().
*
* @param connection the connection.
* @returns next message in the incoming queue.
*/
DBusMessage*
dbus_connection_borrow_message (DBusConnection *connection)
{
DBusDispatchStatus status;
DBusMessage *message;
_dbus_return_val_if_fail (connection != NULL, NULL);
_dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
/* this is called for the side effect that it queues
* up any messages from the transport
*/
status = dbus_connection_get_dispatch_status (connection);
if (status != DBUS_DISPATCH_DATA_REMAINS)
return NULL;
CONNECTION_LOCK (connection);
_dbus_connection_acquire_dispatch (connection);
/* While a message is outstanding, the dispatch lock is held */
_dbus_assert (connection->message_borrowed == NULL);
connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages);
message = connection->message_borrowed;
/* Note that we KEEP the dispatch lock until the message is returned */
if (message == NULL)
_dbus_connection_release_dispatch (connection);
CONNECTION_UNLOCK (connection);
return message;
}
/**
* Used to return a message after peeking at it using
* dbus_connection_borrow_message(). Only called if
* message from dbus_connection_borrow_message() was non-#NULL.
*
* @param connection the connection
* @param message the message from dbus_connection_borrow_message()
*/
void
dbus_connection_return_message (DBusConnection *connection,
DBusMessage *message)
{
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (message != NULL);
_dbus_return_if_fail (message == connection->message_borrowed);
_dbus_return_if_fail (connection->dispatch_acquired);
CONNECTION_LOCK (connection);
_dbus_assert (message == connection->message_borrowed);
connection->message_borrowed = NULL;
_dbus_connection_release_dispatch (connection);
CONNECTION_UNLOCK (connection);
}
/**
* Used to keep a message after peeking at it using
* dbus_connection_borrow_message(). Before using this function, see
* the caveats/warnings in the documentation for
* dbus_connection_pop_message().
*
* @param connection the connection
* @param message the message from dbus_connection_borrow_message()
*/
void
dbus_connection_steal_borrowed_message (DBusConnection *connection,
DBusMessage *message)
{
DBusMessage *pop_message;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (message != NULL);
_dbus_return_if_fail (message == connection->message_borrowed);
_dbus_return_if_fail (connection->dispatch_acquired);
CONNECTION_LOCK (connection);
_dbus_assert (message == connection->message_borrowed);
pop_message = _dbus_list_pop_first (&connection->incoming_messages);
_dbus_assert (message == pop_message);
connection->n_incoming -= 1;
_dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
message, connection->n_incoming);
connection->message_borrowed = NULL;
_dbus_connection_release_dispatch (connection);
CONNECTION_UNLOCK (connection);
}
/* See dbus_connection_pop_message, but requires the caller to own
* the lock before calling. May drop the lock while running.
*/
static DBusList*
_dbus_connection_pop_message_link_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_assert (connection->message_borrowed == NULL);
if (connection->n_incoming > 0)
{
DBusList *link;
link = _dbus_list_pop_first_link (&connection->incoming_messages);
connection->n_incoming -= 1;
_dbus_verbose ("Message %p (%d %s %s %s '%s') removed from incoming queue %p, %d incoming\n",
link->data,
dbus_message_get_type (link->data),
dbus_message_get_path (link->data) ?
dbus_message_get_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),
connection, connection->n_incoming);
return link;
}
else
return NULL;
}
/* See dbus_connection_pop_message, but requires the caller to own
* the lock before calling. May drop the lock while running.
*/
static DBusMessage*
_dbus_connection_pop_message_unlocked (DBusConnection *connection)
{
DBusList *link;
HAVE_LOCK_CHECK (connection);
link = _dbus_connection_pop_message_link_unlocked (connection);
if (link != NULL)
{
DBusMessage *message;
message = link->data;
_dbus_list_free_link (link);
return message;
}
else
return NULL;
}
static void
_dbus_connection_putback_message_link_unlocked (DBusConnection *connection,
DBusList *message_link)
{
HAVE_LOCK_CHECK (connection);
_dbus_assert (message_link != NULL);
/* You can't borrow a message while a link is outstanding */
_dbus_assert (connection->message_borrowed == NULL);
/* We had to have the dispatch lock across the pop/putback */
_dbus_assert (connection->dispatch_acquired);
_dbus_list_prepend_link (&connection->incoming_messages,
message_link);
connection->n_incoming += 1;
_dbus_verbose ("Message %p (%d %s %s '%s') put back into queue %p, %d incoming\n",
message_link->data,
dbus_message_get_type (message_link->data),
dbus_message_get_interface (message_link->data) ?
dbus_message_get_interface (message_link->data) :
"no interface",
dbus_message_get_member (message_link->data) ?
dbus_message_get_member (message_link->data) :
"no member",
dbus_message_get_signature (message_link->data),
connection, connection->n_incoming);
}
/**
* Returns the first-received message from the incoming message queue,
* removing it from the queue. The caller owns a reference to the
* returned message. If the queue is empty, returns #NULL.
*
* This function bypasses any message handlers that are registered,
* and so using it is usually wrong. Instead, let the main loop invoke
* dbus_connection_dispatch(). Popping messages manually is only
* useful in very simple programs that don't share a #DBusConnection
* with any libraries or other modules.
*
* There is a lock that covers all ways of accessing the incoming message
* queue, so dbus_connection_dispatch(), dbus_connection_pop_message(),
* dbus_connection_borrow_message(), etc. will all block while one of the others
* in the group is running.
*
* @param connection the connection.
* @returns next message in the incoming queue.
*/
DBusMessage*
dbus_connection_pop_message (DBusConnection *connection)
{
DBusMessage *message;
DBusDispatchStatus status;
_dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
/* this is called for the side effect that it queues
* up any messages from the transport
*/
status = dbus_connection_get_dispatch_status (connection);
if (status != DBUS_DISPATCH_DATA_REMAINS)
return NULL;
CONNECTION_LOCK (connection);
_dbus_connection_acquire_dispatch (connection);
HAVE_LOCK_CHECK (connection);
message = _dbus_connection_pop_message_unlocked (connection);
_dbus_verbose ("Returning popped message %p\n", message);
_dbus_connection_release_dispatch (connection);
CONNECTION_UNLOCK (connection);
return message;
}
/**
* Acquire the dispatcher. This is a separate lock so the main
* connection lock can be dropped to call out to application dispatch
* handlers.
*
* @param connection the connection.
*/
static void
_dbus_connection_acquire_dispatch (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_connection_ref_unlocked (connection);
CONNECTION_UNLOCK (connection);
_dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_lock (connection->dispatch_mutex);
while (connection->dispatch_acquired)
{
_dbus_verbose ("%s waiting for dispatch to be acquirable\n", _DBUS_FUNCTION_NAME);
_dbus_condvar_wait (connection->dispatch_cond, connection->dispatch_mutex);
}
_dbus_assert (!connection->dispatch_acquired);
connection->dispatch_acquired = TRUE;
_dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_unlock (connection->dispatch_mutex);
CONNECTION_LOCK (connection);
_dbus_connection_unref_unlocked (connection);
}
/**
* Release the dispatcher when you're done with it. Only call
* after you've acquired the dispatcher. Wakes up at most one
* thread currently waiting to acquire the dispatcher.
*
* @param connection the connection.
*/
static void
_dbus_connection_release_dispatch (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_lock (connection->dispatch_mutex);
_dbus_assert (connection->dispatch_acquired);
connection->dispatch_acquired = FALSE;
_dbus_condvar_wake_one (connection->dispatch_cond);
_dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
_dbus_mutex_unlock (connection->dispatch_mutex);
}
static void
_dbus_connection_failed_pop (DBusConnection *connection,
DBusList *message_link)
{
_dbus_list_prepend_link (&connection->incoming_messages,
message_link);
connection->n_incoming += 1;
}
static DBusDispatchStatus
_dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
{
HAVE_LOCK_CHECK (connection);
if (connection->n_incoming > 0)
return DBUS_DISPATCH_DATA_REMAINS;
else if (!_dbus_transport_queue_messages (connection->transport))
return DBUS_DISPATCH_NEED_MEMORY;
else
{
DBusDispatchStatus status;
dbus_bool_t is_connected;
status = _dbus_transport_get_dispatch_status (connection->transport);
is_connected = _dbus_transport_get_is_connected (connection->transport);
_dbus_verbose ("dispatch status = %s is_connected = %d\n",
DISPATCH_STATUS_NAME (status), is_connected);
if (!is_connected)
{
if (status == DBUS_DISPATCH_COMPLETE &&
connection->disconnect_message_link)
{
_dbus_verbose ("Sending disconnect message from %s\n",
_DBUS_FUNCTION_NAME);
connection_forget_shared_unlocked (connection);
/* We haven't sent the disconnect message already,
* and all real messages have been queued up.
*/
_dbus_connection_queue_synthesized_message_link (connection,
connection->disconnect_message_link);
connection->disconnect_message_link = NULL;
status = DBUS_DISPATCH_DATA_REMAINS;
}
/* Dump the outgoing queue, we aren't going to be able to
* send it now, and we'd like accessors like
* dbus_connection_get_outgoing_size() to be accurate.
*/
if (connection->n_outgoing > 0)
{
DBusList *link;
_dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n",
connection->n_outgoing);
while ((link = _dbus_list_get_last_link (&connection->outgoing_messages)))
{
_dbus_connection_message_sent (connection, link->data);
}
}
}
if (status != DBUS_DISPATCH_COMPLETE)
return status;
else if (connection->n_incoming > 0)
return DBUS_DISPATCH_DATA_REMAINS;
else
return DBUS_DISPATCH_COMPLETE;
}
}
static void
_dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
DBusDispatchStatus new_status)
{
dbus_bool_t changed;
DBusDispatchStatusFunction function;
void *data;
HAVE_LOCK_CHECK (connection);
_dbus_connection_ref_unlocked (connection);
changed = new_status != connection->last_dispatch_status;
connection->last_dispatch_status = new_status;
function = connection->dispatch_status_function;
data = connection->dispatch_status_data;
/* We drop the lock */
CONNECTION_UNLOCK (connection);
if (changed && function)
{
_dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n",
connection, new_status,
DISPATCH_STATUS_NAME (new_status));
(* function) (connection, new_status, data);
}
dbus_connection_unref (connection);
}
/**
* Gets the current state (what we would currently return
* from dbus_connection_dispatch()) but doesn't actually
* dispatch any messages.
*
* @param connection the connection.
* @returns current dispatch status
*/
DBusDispatchStatus
dbus_connection_get_dispatch_status (DBusConnection *connection)
{
DBusDispatchStatus status;
_dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
_dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
CONNECTION_UNLOCK (connection);
return status;
}
/**
* Filter funtion for handling the Peer standard interface
**/
static DBusHandlerResult
_dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection,
DBusMessage *message)
{
if (dbus_message_is_method_call (message,
DBUS_INTERFACE_PEER,
"Ping"))
{
DBusMessage *ret;
dbus_bool_t sent;
ret = dbus_message_new_method_return (message);
if (ret == NULL)
return DBUS_HANDLER_RESULT_NEED_MEMORY;
sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
dbus_message_unref (ret);
if (!sent)
return DBUS_HANDLER_RESULT_NEED_MEMORY;
return DBUS_HANDLER_RESULT_HANDLED;
}
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
/**
* Processes all builtin filter functions
*
* If the spec specifies a standard interface
* they should be processed from this method
**/
static DBusHandlerResult
_dbus_connection_run_builtin_filters_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 data buffered while handling watches, queueing zero or
* more incoming messages. Then pops the first-received message from
* the current incoming message queue, runs any handlers for it, and
* unrefs the message. Returns a status indicating whether messages/data
* remain, more memory is needed, or all data has been processed.
*
* Even if the dispatch status is #DBUS_DISPATCH_DATA_REMAINS,
* does not necessarily dispatch a message, as the data may
* be part of authentication or the like.
*
* @todo some FIXME in here about handling DBUS_HANDLER_RESULT_NEED_MEMORY
*
* @todo FIXME what if we call out to application code to handle a
* message, holding the dispatch lock, and the application code runs
* the main loop and dispatches again? Probably deadlocks at the
* moment. Maybe we want a dispatch status of DBUS_DISPATCH_IN_PROGRESS,
* and then the GSource etc. could handle the situation? Right now
* our GSource is NO_RECURSE
*
* @param connection the connection
* @returns dispatch status
*/
DBusDispatchStatus
dbus_connection_dispatch (DBusConnection *connection)
{
DBusMessage *message;
DBusList *link, *filter_list_copy, *message_link;
DBusHandlerResult result;
DBusPendingCall *pending;
dbus_int32_t reply_serial;
DBusDispatchStatus status;
_dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
_dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME);
CONNECTION_LOCK (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
if (status != DBUS_DISPATCH_DATA_REMAINS)
{
/* unlocks and calls out to user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
return status;
}
/* We need to ref the connection since the callback could potentially
* drop the last ref to it
*/
_dbus_connection_ref_unlocked (connection);
_dbus_connection_acquire_dispatch (connection);
HAVE_LOCK_CHECK (connection);
message_link = _dbus_connection_pop_message_link_unlocked (connection);
if (message_link == NULL)
{
/* another thread dispatched our stuff */
_dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n");
_dbus_connection_release_dispatch (connection);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_connection_unref (connection);
return status;
}
message = message_link->data;
_dbus_verbose (" dispatching message %p (%d %s %s '%s')\n",
message,
dbus_message_get_type (message),
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
dbus_message_get_signature (message));
result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
/* Pending call handling must be first, because if you do
* dbus_connection_send_with_reply_and_block() or
* dbus_pending_call_block() then no handlers/filters will be run on
* the reply. We want consistent semantics in the case where we
* dbus_connection_dispatch() the reply.
*/
reply_serial = dbus_message_get_reply_serial (message);
pending = _dbus_hash_table_lookup_int (connection->pending_replies,
reply_serial);
if (pending)
{
_dbus_verbose ("Dispatching a pending reply\n");
_dbus_pending_call_complete_and_unlock (pending, message);
pending = NULL; /* it's probably unref'd */
CONNECTION_LOCK (connection);
_dbus_verbose ("pending call completed in dispatch\n");
result = DBUS_HANDLER_RESULT_HANDLED;
goto out;
}
result = _dbus_connection_run_builtin_filters_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);
if (pending)
dbus_pending_call_unref (pending);
dbus_connection_unref (connection);
return DBUS_DISPATCH_NEED_MEMORY;
}
_dbus_list_foreach (&filter_list_copy,
(DBusForeachFunction)_dbus_message_filter_ref,
NULL);
/* We're still protected from dispatch() reentrancy here
* since we acquired the dispatcher
*/
CONNECTION_UNLOCK (connection);
link = _dbus_list_get_first_link (&filter_list_copy);
while (link != NULL)
{
DBusMessageFilter *filter = link->data;
DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link);
_dbus_verbose (" running filter on message %p\n", message);
result = (* filter->function) (connection, message, filter->user_data);
if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
break;
link = next;
}
_dbus_list_foreach (&filter_list_copy,
(DBusForeachFunction)_dbus_message_filter_unref,
NULL);
_dbus_list_clear (&filter_list_copy);
CONNECTION_LOCK (connection);
if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
{
_dbus_verbose ("No memory in %s\n", _DBUS_FUNCTION_NAME);
goto out;
}
else if (result == DBUS_HANDLER_RESULT_HANDLED)
{
_dbus_verbose ("filter handled message in dispatch\n");
goto out;
}
/* We're still protected from dispatch() reentrancy here
* since we acquired the dispatcher
*/
_dbus_verbose (" running object path dispatch on message %p (%d %s %s '%s')\n",
message,
dbus_message_get_type (message),
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
dbus_message_get_signature (message));
HAVE_LOCK_CHECK (connection);
result = _dbus_object_tree_dispatch_and_unlock (connection->objects,
message);
CONNECTION_LOCK (connection);
if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
{
_dbus_verbose ("object tree handled message in dispatch\n");
goto out;
}
if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL)
{
DBusMessage *reply;
DBusString str;
DBusPreallocatedSend *preallocated;
_dbus_verbose (" sending error %s\n",
DBUS_ERROR_UNKNOWN_METHOD);
if (!_dbus_string_init (&str))
{
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error string in dispatch\n");
goto out;
}
if (!_dbus_string_append_printf (&str,
"Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n",
dbus_message_get_member (message),
dbus_message_get_signature (message),
dbus_message_get_interface (message)))
{
_dbus_string_free (&str);
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error string in dispatch\n");
goto out;
}
reply = dbus_message_new_error (message,
DBUS_ERROR_UNKNOWN_METHOD,
_dbus_string_get_const_data (&str));
_dbus_string_free (&str);
if (reply == NULL)
{
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error reply in dispatch\n");
goto out;
}
preallocated = _dbus_connection_preallocate_send_unlocked (connection);
if (preallocated == NULL)
{
dbus_message_unref (reply);
result = DBUS_HANDLER_RESULT_NEED_MEMORY;
_dbus_verbose ("no memory for error send in dispatch\n");
goto out;
}
_dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated,
reply, NULL);
dbus_message_unref (reply);
result = DBUS_HANDLER_RESULT_HANDLED;
}
_dbus_verbose (" done dispatching %p (%d %s %s '%s') on connection %p\n", message,
dbus_message_get_type (message),
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) :
"no interface",
dbus_message_get_member (message) ?
dbus_message_get_member (message) :
"no member",
dbus_message_get_signature (message),
connection);
out:
if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
{
_dbus_verbose ("out of memory in %s\n", _DBUS_FUNCTION_NAME);
/* Put message back, and we'll start over.
* Yes this means handlers must be idempotent if they
* don't return HANDLED; c'est la vie.
*/
_dbus_connection_putback_message_link_unlocked (connection,
message_link);
}
else
{
_dbus_verbose (" ... done dispatching in %s\n", _DBUS_FUNCTION_NAME);
if (connection->exit_on_disconnect &&
dbus_message_is_signal (message,
DBUS_INTERFACE_LOCAL,
"Disconnected"))
{
_dbus_verbose ("Exiting on Disconnected signal\n");
CONNECTION_UNLOCK (connection);
_dbus_exit (1);
_dbus_assert_not_reached ("Call to exit() returned");
}
_dbus_list_free_link (message_link);
dbus_message_unref (message); /* don't want the message to count in max message limits
* in computing dispatch status below
*/
}
_dbus_connection_release_dispatch (connection);
HAVE_LOCK_CHECK (connection);
_dbus_verbose ("%s before final status update\n", _DBUS_FUNCTION_NAME);
status = _dbus_connection_get_dispatch_status_unlocked (connection);
/* unlocks and calls user code */
_dbus_connection_update_dispatch_status_and_unlock (connection, status);
dbus_connection_unref (connection);
return status;
}
/**
* Sets the watch functions for the connection. These functions are
* responsible for making the application's main loop aware of file
* descriptors that need to be monitored for events, using select() or
* poll(). When using Qt, typically the DBusAddWatchFunction would
* create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
* could call g_io_add_watch(), or could be used as part of a more
* elaborate GSource. Note that when a watch is added, it may
* not be enabled.
*
* The DBusWatchToggledFunction notifies the application that the
* watch has been enabled or disabled. Call dbus_watch_get_enabled()
* to check this. A disabled watch should have no effect, and enabled
* watch should be added to the main loop. This feature is used
* instead of simply adding/removing the watch because
* enabling/disabling can be done without memory allocation. The
* toggled function may be NULL if a main loop re-queries
* dbus_watch_get_enabled() every time anyway.
*
* The DBusWatch can be queried for the file descriptor to watch using
* dbus_watch_get_fd(), and for the events to watch for using
* dbus_watch_get_flags(). The flags returned by
* dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and
* DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR;
* all watches implicitly include a watch for hangups, errors, and
* other exceptional conditions.
*
* Once a file descriptor becomes readable or writable, or an exception
* occurs, dbus_watch_handle() should be called to
* notify the connection of the file descriptor's condition.
*
* dbus_watch_handle() cannot be called during the
* DBusAddWatchFunction, as the connection will not be ready to handle
* that watch yet.
*
* It is not allowed to reference a DBusWatch after it has been passed
* to remove_function.
*
* If #FALSE is returned due to lack of memory, the failure may be due
* to a #FALSE return from the new add_function. If so, the
* add_function may have been called successfully one or more times,
* but the remove_function will also have been called to remove any
* successful adds. i.e. if #FALSE is returned the net result
* should be that dbus_connection_set_watch_functions() has no effect,
* but the add_function and remove_function may have been called.
*
* @todo We need to drop the lock when we call the
* add/remove/toggled functions which can be a side effect
* of setting the watch functions.
*
* @param connection the connection.
* @param add_function function to begin monitoring a new descriptor.
* @param remove_function function to stop monitoring a descriptor.
* @param toggled_function function to notify of enable/disable
* @param data data to pass to add_function and remove_function.
* @param free_data_function function to be called to free the data.
* @returns #FALSE on failure (no memory)
*/
dbus_bool_t
dbus_connection_set_watch_functions (DBusConnection *connection,
DBusAddWatchFunction add_function,
DBusRemoveWatchFunction remove_function,
DBusWatchToggledFunction toggled_function,
void *data,
DBusFreeFunction free_data_function)
{
dbus_bool_t retval;
DBusWatchList *watches;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
#ifndef DBUS_DISABLE_CHECKS
if (connection->watches == NULL)
{
_dbus_warn ("Re-entrant call to %s is not allowed\n",
_DBUS_FUNCTION_NAME);
return FALSE;
}
#endif
/* ref connection for slightly better reentrancy */
_dbus_connection_ref_unlocked (connection);
/* This can call back into user code, and we need to drop the
* connection lock when it does. This is kind of a lame
* way to do it.
*/
watches = connection->watches;
connection->watches = NULL;
CONNECTION_UNLOCK (connection);
retval = _dbus_watch_list_set_functions (watches,
add_function, remove_function,
toggled_function,
data, free_data_function);
CONNECTION_LOCK (connection);
connection->watches = watches;
CONNECTION_UNLOCK (connection);
/* drop our paranoid refcount */
dbus_connection_unref (connection);
return retval;
}
/**
* Sets the timeout functions for the connection. These functions are
* responsible for making the application's main loop aware of timeouts.
* When using Qt, typically the DBusAddTimeoutFunction would create a
* QTimer. When using GLib, the DBusAddTimeoutFunction would call
* g_timeout_add.
*
* The DBusTimeoutToggledFunction notifies the application that the
* timeout has been enabled or disabled. Call
* dbus_timeout_get_enabled() to check this. A disabled timeout should
* have no effect, and enabled timeout should be added to the main
* loop. This feature is used instead of simply adding/removing the
* timeout because enabling/disabling can be done without memory
* allocation. With Qt, QTimer::start() and QTimer::stop() can be used
* to enable and disable. The toggled function may be NULL if a main
* loop re-queries dbus_timeout_get_enabled() every time anyway.
* Whenever a timeout is toggled, its interval may change.
*
* The DBusTimeout can be queried for the timer interval using
* dbus_timeout_get_interval(). dbus_timeout_handle() should be called
* repeatedly, each time the interval elapses, starting after it has
* elapsed once. The timeout stops firing when it is removed with the
* given remove_function. The timer interval may change whenever the
* timeout is added, removed, or toggled.
*
* @param connection the connection.
* @param add_function function to add a timeout.
* @param remove_function function to remove a timeout.
* @param toggled_function function to notify of enable/disable
* @param data data to pass to add_function and remove_function.
* @param free_data_function function to be called to free the data.
* @returns #FALSE on failure (no memory)
*/
dbus_bool_t
dbus_connection_set_timeout_functions (DBusConnection *connection,
DBusAddTimeoutFunction add_function,
DBusRemoveTimeoutFunction remove_function,
DBusTimeoutToggledFunction toggled_function,
void *data,
DBusFreeFunction free_data_function)
{
dbus_bool_t retval;
DBusTimeoutList *timeouts;
_dbus_return_val_if_fail (connection != NULL, FALSE);
CONNECTION_LOCK (connection);
#ifndef DBUS_DISABLE_CHECKS
if (connection->timeouts == NULL)
{
_dbus_warn ("Re-entrant call to %s is not allowed\n",
_DBUS_FUNCTION_NAME);
return FALSE;
}
#endif
/* ref connection for slightly better reentrancy */
_dbus_connection_ref_unlocked (connection);
timeouts = connection->timeouts;
connection->timeouts = NULL;
CONNECTION_UNLOCK (connection);
retval = _dbus_timeout_list_set_functions (timeouts,
add_function, remove_function,
toggled_function,
data, free_data_function);
CONNECTION_LOCK (connection);
connection->timeouts = timeouts;
CONNECTION_UNLOCK (connection);
/* drop our paranoid refcount */
dbus_connection_unref (connection);
return retval;
}
/**
* Sets the mainloop wakeup function for the connection. This function is
* responsible for waking up the main loop (if its sleeping) when some some
* change has happened to the connection that the mainloop needs to reconsider
* (e.g. a message has been queued for writing).
* When using Qt, this typically results in a call to QEventLoop::wakeUp().
* When using GLib, it would call g_main_context_wakeup().
*
*
* @param connection the connection.
* @param wakeup_main_function function to wake up the mainloop
* @param data data to pass wakeup_main_function
* @param free_data_function function to be called to free the data.
*/
void
dbus_connection_set_wakeup_main_function (DBusConnection *connection,
DBusWakeupMainFunction wakeup_main_function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data;
DBusFreeFunction old_free_data;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
old_data = connection->wakeup_main_data;
old_free_data = connection->free_wakeup_main_data;
connection->wakeup_main_function = wakeup_main_function;
connection->wakeup_main_data = data;
connection->free_wakeup_main_data = free_data_function;
CONNECTION_UNLOCK (connection);
/* Callback outside the lock */
if (old_free_data)
(*old_free_data) (old_data);
}
/**
* Set a function to be invoked when the dispatch status changes.
* If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then
* dbus_connection_dispatch() needs to be called to process incoming
* messages. However, dbus_connection_dispatch() MUST NOT BE CALLED
* from inside the DBusDispatchStatusFunction. Indeed, almost
* any reentrancy in this function is a bad idea. Instead,
* the DBusDispatchStatusFunction should simply save an indication
* that messages should be dispatched later, when the main loop
* is re-entered.
*
* @param connection the connection
* @param function function to call on dispatch status changes
* @param data data for function
* @param free_data_function free the function data
*/
void
dbus_connection_set_dispatch_status_function (DBusConnection *connection,
DBusDispatchStatusFunction function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data;
DBusFreeFunction old_free_data;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
old_data = connection->dispatch_status_data;
old_free_data = connection->free_dispatch_status_data;
connection->dispatch_status_function = function;
connection->dispatch_status_data = data;
connection->free_dispatch_status_data = free_data_function;
CONNECTION_UNLOCK (connection);
/* Callback outside the lock */
if (old_free_data)
(*old_free_data) (old_data);
}
/**
* Get the UNIX file descriptor of the connection, if any. This can
* be used for SELinux access control checks with getpeercon() for
* example. DO NOT read or write to the file descriptor, or try to
* select() on it; use DBusWatch for main loop integration. Not all
* connections will have a file descriptor. So for adding descriptors
* to the main loop, use dbus_watch_get_fd() and so forth.
*
* @param connection the connection
* @param fd return location for the file descriptor.
* @returns #TRUE if fd is successfully obtained.
*/
dbus_bool_t
dbus_connection_get_unix_fd (DBusConnection *connection,
int *fd)
{
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (connection->transport != NULL, FALSE);
CONNECTION_LOCK (connection);
retval = _dbus_transport_get_unix_fd (connection->transport,
fd);
CONNECTION_UNLOCK (connection);
return retval;
}
/**
* Gets the UNIX user ID of the connection if any.
* Returns #TRUE if the uid is filled in.
* Always returns #FALSE on non-UNIX platforms.
* Always returns #FALSE prior to authenticating the
* connection.
*
* @param connection the connection
* @param uid return location for the user ID
* @returns #TRUE if uid is filled in with a valid user ID
*/
dbus_bool_t
dbus_connection_get_unix_user (DBusConnection *connection,
unsigned long *uid)
{
dbus_bool_t result;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (uid != NULL, FALSE);
CONNECTION_LOCK (connection);
if (!_dbus_transport_get_is_authenticated (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_unix_user (connection->transport,
uid);
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Gets the process ID of the connection if any.
* Returns #TRUE if the uid is filled in.
* Always returns #FALSE prior to authenticating the
* connection.
*
* @param connection the connection
* @param pid return location for the process ID
* @returns #TRUE if uid is filled in with a valid process ID
*/
dbus_bool_t
dbus_connection_get_unix_process_id (DBusConnection *connection,
unsigned long *pid)
{
dbus_bool_t result;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (pid != NULL, FALSE);
CONNECTION_LOCK (connection);
if (!_dbus_transport_get_is_authenticated (connection->transport))
result = FALSE;
else
result = _dbus_transport_get_unix_process_id (connection->transport,
pid);
CONNECTION_UNLOCK (connection);
return result;
}
/**
* Sets a predicate function used to determine whether a given user ID
* is allowed to connect. When an incoming connection has
* authenticated with a particular user ID, this function is called;
* if it returns #TRUE, the connection is allowed to proceed,
* otherwise the connection is disconnected.
*
* If the function is set to #NULL (as it is by default), then
* only the same UID as the server process will be allowed to
* connect.
*
* @param connection the connection
* @param function the predicate
* @param data data to pass to the predicate
* @param free_data_function function to free the data
*/
void
dbus_connection_set_unix_user_function (DBusConnection *connection,
DBusAllowUnixUserFunction function,
void *data,
DBusFreeFunction free_data_function)
{
void *old_data = NULL;
DBusFreeFunction old_free_function = NULL;
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_unix_user_function (connection->transport,
function, data, free_data_function,
&old_data, &old_free_function);
CONNECTION_UNLOCK (connection);
if (old_free_function != NULL)
(* old_free_function) (old_data);
}
/**
* Adds a message filter. Filters are handlers that are run on all
* incoming messages, prior to the objects registered with
* dbus_connection_register_object_path(). Filters are run in the
* order that they were added. The same handler can be added as a
* filter more than once, in which case it will be run more than once.
* Filters added during a filter callback won't be run on the message
* being processed.
*
* @todo we don't run filters on messages while blocking without
* entering the main loop, since filters are run as part of
* dbus_connection_dispatch(). This is probably a feature, as filters
* could create arbitrary reentrancy. But kind of sucks if you're
* trying to filter METHOD_RETURN for some reason.
*
* @param connection the connection
* @param function function to handle messages
* @param user_data user data to pass to the function
* @param free_data_function function to use for freeing user data
* @returns #TRUE on success, #FALSE if not enough memory.
*/
dbus_bool_t
dbus_connection_add_filter (DBusConnection *connection,
DBusHandleMessageFunction function,
void *user_data,
DBusFreeFunction free_data_function)
{
DBusMessageFilter *filter;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (function != NULL, FALSE);
filter = dbus_new0 (DBusMessageFilter, 1);
if (filter == NULL)
return FALSE;
filter->refcount.value = 1;
CONNECTION_LOCK (connection);
if (!_dbus_list_append (&connection->filter_list,
filter))
{
_dbus_message_filter_unref (filter);
CONNECTION_UNLOCK (connection);
return FALSE;
}
/* Fill in filter after all memory allocated,
* so we don't run the free_user_data_function
* if the add_filter() fails
*/
filter->function = function;
filter->user_data = user_data;
filter->free_user_data_function = free_data_function;
CONNECTION_UNLOCK (connection);
return TRUE;
}
/**
* Removes a previously-added message filter. It is a programming
* error to call this function for a handler that has not been added
* as a filter. If the given handler was added more than once, only
* one instance of it will be removed (the most recently-added
* instance).
*
* @param connection the connection
* @param function the handler to remove
* @param user_data user data for the handler to remove
*
*/
void
dbus_connection_remove_filter (DBusConnection *connection,
DBusHandleMessageFunction function,
void *user_data)
{
DBusList *link;
DBusMessageFilter *filter;
_dbus_return_if_fail (connection != NULL);
_dbus_return_if_fail (function != NULL);
CONNECTION_LOCK (connection);
filter = NULL;
link = _dbus_list_get_last_link (&connection->filter_list);
while (link != NULL)
{
filter = link->data;
if (filter->function == function &&
filter->user_data == user_data)
{
_dbus_list_remove_link (&connection->filter_list, link);
filter->function = NULL;
break;
}
link = _dbus_list_get_prev_link (&connection->filter_list, link);
}
CONNECTION_UNLOCK (connection);
#ifndef DBUS_DISABLE_CHECKS
if (filter == NULL)
{
_dbus_warn ("Attempt to remove filter function %p user data %p, but no such filter has been added\n",
function, user_data);
return;
}
#endif
/* Call application code */
if (filter->free_user_data_function)
(* filter->free_user_data_function) (filter->user_data);
filter->free_user_data_function = NULL;
filter->user_data = NULL;
_dbus_message_filter_unref (filter);
}
/**
* Registers a handler for a given path in the object hierarchy.
* The given vtable handles messages sent to exactly the given path.
*
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @returns #FALSE if not enough memory
*/
dbus_bool_t
dbus_connection_register_object_path (DBusConnection *connection,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data)
{
char **decomposed_path;
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
_dbus_return_val_if_fail (vtable != NULL, FALSE);
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
retval = _dbus_object_tree_register (connection->objects,
FALSE,
(const char **) decomposed_path, vtable,
user_data);
CONNECTION_UNLOCK (connection);
dbus_free_string_array (decomposed_path);
return retval;
}
/**
* Registers a fallback handler for a given subsection of the object
* hierarchy. The given vtable handles messages at or below the given
* path. You can use this to establish a default message handling
* policy for a whole "subdirectory."
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @param vtable the virtual table
* @param user_data data to pass to functions in the vtable
* @returns #FALSE if not enough memory
*/
dbus_bool_t
dbus_connection_register_fallback (DBusConnection *connection,
const char *path,
const DBusObjectPathVTable *vtable,
void *user_data)
{
char **decomposed_path;
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
_dbus_return_val_if_fail (vtable != NULL, FALSE);
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
retval = _dbus_object_tree_register (connection->objects,
TRUE,
(const char **) decomposed_path, vtable,
user_data);
CONNECTION_UNLOCK (connection);
dbus_free_string_array (decomposed_path);
return retval;
}
/**
* Unregisters the handler registered with exactly the given path.
* It's a bug to call this function for a path that isn't registered.
* Can unregister both fallback paths and object paths.
*
* @param connection the connection
* @param path a '/' delimited string of path elements
* @returns #FALSE if not enough memory
*/
dbus_bool_t
dbus_connection_unregister_object_path (DBusConnection *connection,
const char *path)
{
char **decomposed_path;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (path[0] == '/', FALSE);
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
_dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path);
dbus_free_string_array (decomposed_path);
return TRUE;
}
/**
* Gets the user data passed to dbus_connection_register_object_path()
* or dbus_connection_register_fallback(). If nothing was registered
* at this path, the data is filled in with #NULL.
*
* @param connection the connection
* @param path the path you registered with
* @param data_p location to store the user data, or #NULL
* @returns #FALSE if not enough memory
*/
dbus_bool_t
dbus_connection_get_object_path_data (DBusConnection *connection,
const char *path,
void **data_p)
{
char **decomposed_path;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (path != NULL, FALSE);
_dbus_return_val_if_fail (data_p != NULL, FALSE);
*data_p = NULL;
if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
*data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path);
CONNECTION_UNLOCK (connection);
dbus_free_string_array (decomposed_path);
return TRUE;
}
/**
* Lists the registered fallback handlers and object path handlers at
* the given parent_path. The returned array should be freed with
* dbus_free_string_array().
*
* @param connection the connection
* @param parent_path the path to list the child handlers of
* @param child_entries returns #NULL-terminated array of children
* @returns #FALSE if no memory to allocate the child entries
*/
dbus_bool_t
dbus_connection_list_registered (DBusConnection *connection,
const char *parent_path,
char ***child_entries)
{
char **decomposed_path;
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (parent_path != NULL, FALSE);
_dbus_return_val_if_fail (parent_path[0] == '/', FALSE);
_dbus_return_val_if_fail (child_entries != NULL, FALSE);
if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL))
return FALSE;
CONNECTION_LOCK (connection);
retval = _dbus_object_tree_list_registered_and_unlock (connection->objects,
(const char **) decomposed_path,
child_entries);
dbus_free_string_array (decomposed_path);
return retval;
}
static DBusDataSlotAllocator slot_allocator;
_DBUS_DEFINE_GLOBAL_LOCK (connection_slots);
/**
* Allocates an integer ID to be used for storing application-specific
* data on any DBusConnection. The allocated ID may then be used
* with dbus_connection_set_data() and dbus_connection_get_data().
* The passed-in slot must be initialized to -1, and is filled in
* with the slot ID. If the passed-in slot is not -1, it's assumed
* to be already allocated, and its refcount is incremented.
*
* The allocated slot is global, i.e. all DBusConnection objects will
* have a slot with the given integer ID reserved.
*
* @param slot_p address of a global variable storing the slot
* @returns #FALSE on failure (no memory)
*/
dbus_bool_t
dbus_connection_allocate_data_slot (dbus_int32_t *slot_p)
{
return _dbus_data_slot_allocator_alloc (&slot_allocator,
_DBUS_LOCK_NAME (connection_slots),
slot_p);
}
/**
* Deallocates a global ID for connection data slots.
* dbus_connection_get_data() and dbus_connection_set_data() may no
* longer be used with this slot. Existing data stored on existing
* DBusConnection objects will be freed when the connection is
* finalized, but may not be retrieved (and may only be replaced if
* someone else reallocates the slot). When the refcount on the
* passed-in slot reaches 0, it is set to -1.
*
* @param slot_p address storing the slot to deallocate
*/
void
dbus_connection_free_data_slot (dbus_int32_t *slot_p)
{
_dbus_return_if_fail (*slot_p >= 0);
_dbus_data_slot_allocator_free (&slot_allocator, slot_p);
}
/**
* Stores a pointer on a DBusConnection, along
* with an optional function to be used for freeing
* the data when the data is set again, or when
* the connection is finalized. The slot number
* must have been allocated with dbus_connection_allocate_data_slot().
*
* @param connection the connection
* @param slot the slot number
* @param data the data to store
* @param free_data_func finalizer function for the data
* @returns #TRUE if there was enough memory to store the data
*/
dbus_bool_t
dbus_connection_set_data (DBusConnection *connection,
dbus_int32_t slot,
void *data,
DBusFreeFunction free_data_func)
{
DBusFreeFunction old_free_func;
void *old_data;
dbus_bool_t retval;
_dbus_return_val_if_fail (connection != NULL, FALSE);
_dbus_return_val_if_fail (slot >= 0, FALSE);
CONNECTION_LOCK (connection);
retval = _dbus_data_slot_list_set (&slot_allocator,
&connection->slot_list,
slot, data, free_data_func,
&old_free_func, &old_data);
CONNECTION_UNLOCK (connection);
if (retval)
{
/* Do the actual free outside the connection lock */
if (old_free_func)
(* old_free_func) (old_data);
}
return retval;
}
/**
* Retrieves data previously set with dbus_connection_set_data().
* The slot must still be allocated (must not have been freed).
*
* @param connection the connection
* @param slot the slot to get data from
* @returns the data, or #NULL if not found
*/
void*
dbus_connection_get_data (DBusConnection *connection,
dbus_int32_t slot)
{
void *res;
_dbus_return_val_if_fail (connection != NULL, NULL);
CONNECTION_LOCK (connection);
res = _dbus_data_slot_list_get (&slot_allocator,
&connection->slot_list,
slot);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* This function sets a global flag for whether dbus_connection_new()
* will set SIGPIPE behavior to SIG_IGN.
*
* @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN
*/
void
dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
{
_dbus_modify_sigpipe = will_modify_sigpipe != FALSE;
}
/**
* Specifies the maximum size message this connection is allowed to
* receive. Larger messages will result in disconnecting the
* connection.
*
* @param connection a #DBusConnection
* @param size maximum message size the connection can receive, in bytes
*/
void
dbus_connection_set_max_message_size (DBusConnection *connection,
long size)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_max_message_size (connection->transport,
size);
CONNECTION_UNLOCK (connection);
}
/**
* Gets the value set by dbus_connection_set_max_message_size().
*
* @param connection the connection
* @returns the max size of a single message
*/
long
dbus_connection_get_max_message_size (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_max_message_size (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Sets the maximum total number of bytes that can be used for all messages
* received on this connection. Messages count toward the maximum until
* they are finalized. When the maximum is reached, the connection will
* not read more data until some messages are finalized.
*
* The semantics of the maximum are: if outstanding messages are
* already above the maximum, additional messages will not be read.
* The semantics are not: if the next message would cause us to exceed
* the maximum, we don't read it. The reason is that we don't know the
* size of a message until after we read it.
*
* Thus, the max live messages size can actually be exceeded
* by up to the maximum size of a single message.
*
* Also, if we read say 1024 bytes off the wire in a single read(),
* and that contains a half-dozen small messages, we may exceed the
* size max by that amount. But this should be inconsequential.
*
* This does imply that we can't call read() with a buffer larger
* than we're willing to exceed this limit by.
*
* @param connection the connection
* @param size the maximum size in bytes of all outstanding messages
*/
void
dbus_connection_set_max_received_size (DBusConnection *connection,
long size)
{
_dbus_return_if_fail (connection != NULL);
CONNECTION_LOCK (connection);
_dbus_transport_set_max_received_size (connection->transport,
size);
CONNECTION_UNLOCK (connection);
}
/**
* Gets the value set by dbus_connection_set_max_received_size().
*
* @param connection the connection
* @returns the max size of all live messages
*/
long
dbus_connection_get_max_received_size (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_transport_get_max_received_size (connection->transport);
CONNECTION_UNLOCK (connection);
return res;
}
/**
* Gets the approximate size in bytes of all messages in the outgoing
* message queue. The size is approximate in that you shouldn't use
* it to decide how many bytes to read off the network or anything
* of that nature, as optimizations may choose to tell small white lies
* to avoid performance overhead.
*
* @param connection the connection
* @returns the number of bytes that have been queued up but not sent
*/
long
dbus_connection_get_outgoing_size (DBusConnection *connection)
{
long res;
_dbus_return_val_if_fail (connection != NULL, 0);
CONNECTION_LOCK (connection);
res = _dbus_counter_get_value (connection->outgoing_counter);
CONNECTION_UNLOCK (connection);
return res;
}
/** @} */
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