dbus-connection.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-connection.c DBusConnection object
 *
 * Copyright (C) 2002-2006  Red Hat Inc.
 *
 * Licensed under the Academic Free License version 2.1
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <config.h>
#include "dbus-shared.h"
#include "dbus-connection.h"
#include "dbus-list.h"
#include "dbus-timeout.h"
#include "dbus-transport.h"
#include "dbus-watch.h"
#include "dbus-connection-internal.h"
#include "dbus-pending-call-internal.h"
#include "dbus-list.h"
#include "dbus-hash.h"
#include "dbus-message-internal.h"
#include "dbus-message-private.h"
#include "dbus-threads.h"
#include "dbus-protocol.h"
#include "dbus-dataslot.h"
#include "dbus-string.h"
#include "dbus-signature.h"
#include "dbus-pending-call.h"
#include "dbus-object-tree.h"
#include "dbus-threads-internal.h"
#include "dbus-bus.h"
#include "dbus-marshal-basic.h"

#ifdef DBUS_DISABLE_CHECKS
#define TOOK_LOCK_CHECK(connection)
#define RELEASING_LOCK_CHECK(connection)
#define HAVE_LOCK_CHECK(connection)
#else
#define TOOK_LOCK_CHECK(connection) do {                \
    _dbus_assert (!(connection)->have_connection_lock); \
    (connection)->have_connection_lock = TRUE;          \
  } while (0)
#define RELEASING_LOCK_CHECK(connection) do {            \
    _dbus_assert ((connection)->have_connection_lock);   \
    (connection)->have_connection_lock = FALSE;          \
  } while (0)
#define HAVE_LOCK_CHECK(connection)        _dbus_assert ((connection)->have_connection_lock)
/* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */
#endif

#define TRACE_LOCKS 1

#define CONNECTION_LOCK(connection)   do {                                      \
    if (TRACE_LOCKS) { _dbus_verbose ("LOCK\n"); }   \
    _dbus_mutex_lock ((connection)->mutex);                                      \
    TOOK_LOCK_CHECK (connection);                                               \
  } while (0)

#define CONNECTION_UNLOCK(connection) _dbus_connection_unlock (connection)

#define SLOTS_LOCK(connection) do {                     \
    _dbus_mutex_lock ((connection)->slot_mutex);        \
  } while (0)

#define SLOTS_UNLOCK(connection) do {                   \
    _dbus_mutex_unlock ((connection)->slot_mutex);      \
  } while (0)

#define DISPATCH_STATUS_NAME(s)                                            \
                     ((s) == DBUS_DISPATCH_COMPLETE ? "complete" :         \
                      (s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \
                      (s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" :   \
                      "???")

typedef struct DBusMessageFilter DBusMessageFilter;

struct DBusMessageFilter
{
  DBusAtomic refcount; 
  DBusHandleMessageFunction function; 
  void *user_data; 
  DBusFreeFunction free_user_data_function; 
};


struct DBusPreallocatedSend
{
  DBusConnection *connection; 
  DBusList *queue_link;       
  DBusList *counter_link;     
};

#if HAVE_DECL_MSG_NOSIGNAL
static dbus_bool_t _dbus_modify_sigpipe = FALSE;
#else
static dbus_bool_t _dbus_modify_sigpipe = TRUE;
#endif

struct DBusConnection
{
  DBusAtomic refcount; 
  DBusMutex *mutex; 
  DBusMutex *dispatch_mutex;     
  DBusCondVar *dispatch_cond;    
  DBusMutex *io_path_mutex;      
  DBusCondVar *io_path_cond;     
  DBusList *outgoing_messages; 
  DBusList *incoming_messages; 
  DBusList *expired_messages;  
  DBusMessage *message_borrowed; 
  int n_outgoing;              
  int n_incoming;              
  DBusCounter *outgoing_counter; 
  DBusTransport *transport;    
  DBusWatchList *watches;      
  DBusTimeoutList *timeouts;   
  DBusList *filter_list;        
  DBusMutex *slot_mutex;        
  DBusDataSlotList slot_list;   
  DBusHashTable *pending_replies;  
  dbus_uint32_t client_serial;       
  DBusList *disconnect_message_link; 
  DBusWakeupMainFunction wakeup_main_function; 
  void *wakeup_main_data; 
  DBusFreeFunction free_wakeup_main_data; 
  DBusDispatchStatusFunction dispatch_status_function; 
  void *dispatch_status_data; 
  DBusFreeFunction free_dispatch_status_data; 
  DBusDispatchStatus last_dispatch_status; 
  DBusObjectTree *objects; 
  char *server_guid; 
  /* These two MUST be bools and not bitfields, because they are protected by a separate lock
   * from connection->mutex and all bitfields in a word have to be read/written together.
   * So you can't have a different lock for different bitfields in the same word.
   */
  dbus_bool_t dispatch_acquired; 
  dbus_bool_t io_path_acquired;  
  unsigned int shareable : 1; 
  unsigned int exit_on_disconnect : 1; 
  unsigned int route_peer_messages : 1; 
  unsigned int disconnected_message_arrived : 1;   
  unsigned int disconnected_message_processed : 1; 
#ifndef DBUS_DISABLE_CHECKS
  unsigned int have_connection_lock : 1; 
#endif
  
#ifndef DBUS_DISABLE_CHECKS
  int generation; 
#endif 
};

static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked      (DBusConnection     *connection);
static void               _dbus_connection_update_dispatch_status_and_unlock (DBusConnection     *connection,
                                                                              DBusDispatchStatus  new_status);
static void               _dbus_connection_last_unref                        (DBusConnection     *connection);
static void               _dbus_connection_acquire_dispatch                  (DBusConnection     *connection);
static void               _dbus_connection_release_dispatch                  (DBusConnection     *connection);
static DBusDispatchStatus _dbus_connection_flush_unlocked                    (DBusConnection     *connection);
static void               _dbus_connection_close_possibly_shared_and_unlock  (DBusConnection     *connection);
static dbus_bool_t        _dbus_connection_get_is_connected_unlocked         (DBusConnection     *connection);
static dbus_bool_t        _dbus_connection_peek_for_reply_unlocked           (DBusConnection     *connection,
                                                                              dbus_uint32_t       client_serial);

static DBusMessageFilter *
_dbus_message_filter_ref (DBusMessageFilter *filter)
{
#ifdef DBUS_DISABLE_ASSERT
  _dbus_atomic_inc (&filter->refcount);
#else
  dbus_int32_t old_value;

  old_value = _dbus_atomic_inc (&filter->refcount);
  _dbus_assert (old_value > 0);
#endif

  return filter;
}

static void
_dbus_message_filter_unref (DBusMessageFilter *filter)
{
  dbus_int32_t old_value;

  old_value = _dbus_atomic_dec (&filter->refcount);
  _dbus_assert (old_value > 0);

  if (old_value == 1)
    {
      if (filter->free_user_data_function)
        (* filter->free_user_data_function) (filter->user_data);
      
      dbus_free (filter);
    }
}

void
_dbus_connection_lock (DBusConnection *connection)
{
  CONNECTION_LOCK (connection);
}

void
_dbus_connection_unlock (DBusConnection *connection)
{
  DBusList *expired_messages;
  DBusList *iter;

  if (TRACE_LOCKS)
    {
      _dbus_verbose ("UNLOCK\n");
    }

  /* If we had messages that expired (fell off the incoming or outgoing
   * queues) while we were locked, actually release them now */
  expired_messages = connection->expired_messages;
  connection->expired_messages = NULL;

  RELEASING_LOCK_CHECK (connection);
  _dbus_mutex_unlock (connection->mutex);

  for (iter = _dbus_list_pop_first_link (&expired_messages);
      iter != NULL;
      iter = _dbus_list_pop_first_link (&expired_messages))
    {
      DBusMessage *message = iter->data;

      dbus_message_unref (message);
      _dbus_list_free_link (iter);
    }
}

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 */
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;
}

void 
_dbus_connection_test_get_locks (DBusConnection *connection,
                                 DBusMutex     **mutex_loc,
                                 DBusMutex     **dispatch_mutex_loc,
                                 DBusMutex     **io_path_mutex_loc,
                                 DBusCondVar   **dispatch_cond_loc,
                                 DBusCondVar   **io_path_cond_loc)
{
  *mutex_loc = connection->mutex;
  *dispatch_mutex_loc = connection->dispatch_mutex;
  *io_path_mutex_loc = connection->io_path_mutex; 
  *dispatch_cond_loc = connection->dispatch_cond;
  *io_path_cond_loc = connection->io_path_cond;
}
#endif

void
_dbus_connection_queue_received_message_link (DBusConnection  *connection,
                                              DBusList        *link)
{
  DBusPendingCall *pending;
  dbus_uint32_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 != 0)
    {
      pending = _dbus_hash_table_lookup_int (connection->pending_replies,
                                             reply_serial);
      if (pending != NULL)
        {
          if (_dbus_pending_call_is_timeout_added_unlocked (pending))
            _dbus_connection_remove_timeout_unlocked (connection,
                                                      _dbus_pending_call_get_timeout_unlocked (pending));

          _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
        }
    }
  
  

  connection->n_incoming += 1;

  _dbus_connection_wakeup_mainloop (connection);
  
  _dbus_verbose ("Message %p (%s %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n",
                 message,
                 dbus_message_type_to_string (dbus_message_get_type (message)),
                 dbus_message_get_path (message) ?
                 dbus_message_get_path (message) :
                 "no path",
                 dbus_message_get_interface (message) ?
                 dbus_message_get_interface (message) :
                 "no interface",
                 dbus_message_get_member (message) ?
                 dbus_message_get_member (message) :
                 "no member",
                 dbus_message_get_signature (message),
                 dbus_message_get_reply_serial (message),
                 connection,
                 connection->n_incoming);}

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);
}


dbus_bool_t
_dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  return connection->outgoing_messages != NULL;
}

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;
}

DBusMessage*
_dbus_connection_get_message_to_send (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  
  return _dbus_list_get_last (&connection->outgoing_messages);
}

void
_dbus_connection_message_sent_unlocked (DBusConnection *connection,
                                        DBusMessage    *message)
{
  DBusList *link;

  HAVE_LOCK_CHECK (connection);
  
  /* This can be called before we even complete authentication, since
   * it's called on disconnect to clean up the outgoing queue.
   * It's also called as we successfully send each message.
   */
  
  link = _dbus_list_get_last_link (&connection->outgoing_messages);
  _dbus_assert (link != NULL);
  _dbus_assert (link->data == message);

  _dbus_list_unlink (&connection->outgoing_messages,
                     link);
  _dbus_list_prepend_link (&connection->expired_messages, link);

  connection->n_outgoing -= 1;

  _dbus_verbose ("Message %p (%s %s %s %s '%s') removed from outgoing queue %p, %d left to send\n",
                 message,
                 dbus_message_type_to_string (dbus_message_get_type (message)),
                 dbus_message_get_path (message) ?
                 dbus_message_get_path (message) :
                 "no path",
                 dbus_message_get_interface (message) ?
                 dbus_message_get_interface (message) :
                 "no interface",
                 dbus_message_get_member (message) ?
                 dbus_message_get_member (message) :
                 "no member",
                 dbus_message_get_signature (message),
                 connection, connection->n_outgoing);

  /* It's OK that in principle we call the notify function, because for the
   * outgoing limit, there isn't one */
  _dbus_message_remove_counter (message, connection->outgoing_counter);

  /* The message will actually be unreffed when we unlock */
}

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)
{
  dbus_bool_t retval;

  HAVE_LOCK_CHECK (connection);

  /* The original purpose of protected_change_watch() was to hold a
   * ref on the connection while dropping the connection lock, then
   * calling out to the app.  This was a broken hack that did not
   * work, since the connection was in a hosed state (no WatchList
   * field) while calling out.
   *
   * So for now we'll just keep the lock while calling out. This means
   * apps are not allowed to call DBusConnection methods inside a
   * watch function or they will deadlock.
   *
   * The "real fix" is to use the _and_unlock() pattern found
   * elsewhere in the code, to defer calling out to the app until
   * we're about to drop locks and return flow of control to the app
   * anyway.
   *
   * See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
   */

  if (connection->watches)
    {
      if (add_function)
        retval = (* add_function) (connection->watches, watch);
      else if (remove_function)
        {
          retval = TRUE;
          (* remove_function) (connection->watches, watch);
        }
      else
        {
          retval = TRUE;
          (* toggle_function) (connection->watches, watch, enabled);
        }
      return retval;
    }
  else
    return FALSE;
}
     

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);
}

void
_dbus_connection_remove_watch_unlocked (DBusConnection *connection,
                                        DBusWatch      *watch)
{
  protected_change_watch (connection, watch,
                          NULL,
                          _dbus_watch_list_remove_watch,
                          NULL, FALSE);
}

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)
{
  dbus_bool_t retval;

  HAVE_LOCK_CHECK (connection);

  /* The original purpose of protected_change_timeout() was to hold a
   * ref on the connection while dropping the connection lock, then
   * calling out to the app.  This was a broken hack that did not
   * work, since the connection was in a hosed state (no TimeoutList
   * field) while calling out.
   *
   * So for now we'll just keep the lock while calling out. This means
   * apps are not allowed to call DBusConnection methods inside a
   * timeout function or they will deadlock.
   *
   * The "real fix" is to use the _and_unlock() pattern found
   * elsewhere in the code, to defer calling out to the app until
   * we're about to drop locks and return flow of control to the app
   * anyway.
   *
   * See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
   */

  if (connection->timeouts)
    {
      if (add_function)
        retval = (* add_function) (connection->timeouts, timeout);
      else if (remove_function)
        {
          retval = TRUE;
          (* remove_function) (connection->timeouts, timeout);
        }
      else
        {
          retval = TRUE;
          (* toggle_function) (connection->timeouts, timeout, enabled);
        }
      return retval;
    }
  else
    return FALSE;
}

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);
}

void
_dbus_connection_remove_timeout_unlocked (DBusConnection *connection,
                                          DBusTimeout    *timeout)
{
  protected_change_timeout (connection, timeout,
                            NULL,
                            _dbus_timeout_list_remove_timeout,
                            NULL, FALSE);
}

void
_dbus_connection_toggle_timeout_unlocked (DBusConnection   *connection,
                                          DBusTimeout      *timeout,
                                          dbus_bool_t       enabled)
{
  protected_change_timeout (connection, timeout,
                            NULL, NULL,
                            _dbus_timeout_list_toggle_timeout,
                            enabled);
}

static dbus_bool_t
_dbus_connection_attach_pending_call_unlocked (DBusConnection  *connection,
                                               DBusPendingCall *pending)
{
  dbus_uint32_t reply_serial;
  DBusTimeout *timeout;

  HAVE_LOCK_CHECK (connection);

  reply_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);

  _dbus_assert (reply_serial != 0);

  timeout = _dbus_pending_call_get_timeout_unlocked (pending);

  if (timeout)
    {
      if (!_dbus_connection_add_timeout_unlocked (connection, timeout))
        return FALSE;
      
      if (!_dbus_hash_table_insert_int (connection->pending_replies,
                                        reply_serial,
                                        pending))
        {
          _dbus_connection_remove_timeout_unlocked (connection, timeout);

          _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
          HAVE_LOCK_CHECK (connection);
          return FALSE;
        }
      
      _dbus_pending_call_set_timeout_added_unlocked (pending, TRUE);
    }
  else
    {
      if (!_dbus_hash_table_insert_int (connection->pending_replies,
                                        reply_serial,
                                        pending))
        {
          HAVE_LOCK_CHECK (connection);
          return FALSE;
        }
    }

  _dbus_pending_call_ref_unlocked (pending);

  HAVE_LOCK_CHECK (connection);
  
  return TRUE;
}

static void
free_pending_call_on_hash_removal (void *data)
{
  DBusPendingCall *pending;
  DBusConnection  *connection;
  
  if (data == NULL)
    return;

  pending = data;

  connection = _dbus_pending_call_get_connection_unlocked (pending);

  HAVE_LOCK_CHECK (connection);
  
  if (_dbus_pending_call_is_timeout_added_unlocked (pending))
    {
      _dbus_connection_remove_timeout_unlocked (connection,
                                                _dbus_pending_call_get_timeout_unlocked (pending));
      
      _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
    }

  /* FIXME 1.0? this is sort of dangerous and undesirable to drop the lock 
   * here, but the pending call finalizer could in principle call out to 
   * application code so we pretty much have to... some larger code reorg 
   * might be needed.
   */
  _dbus_connection_ref_unlocked (connection);
  _dbus_pending_call_unref_and_unlock (pending);
  CONNECTION_LOCK (connection);
  _dbus_connection_unref_unlocked (connection);
}

static void
_dbus_connection_detach_pending_call_unlocked (DBusConnection  *connection,
                                               DBusPendingCall *pending)
{
  /* This ends up unlocking to call the pending call finalizer, which is unexpected to
   * say the least.
   */
  _dbus_hash_table_remove_int (connection->pending_replies,
                               _dbus_pending_call_get_reply_serial_unlocked (pending));
}

static void
_dbus_connection_detach_pending_call_and_unlock (DBusConnection  *connection,
                                                 DBusPendingCall *pending)
{
  /* The idea here is to avoid finalizing the pending call
   * with the lock held, since there's a destroy notifier
   * in pending call that goes out to application code.
   *
   * There's an extra unlock inside the hash table
   * "free pending call" function FIXME...
   */
  _dbus_pending_call_ref_unlocked (pending);
  _dbus_hash_table_remove_int (connection->pending_replies,
                               _dbus_pending_call_get_reply_serial_unlocked (pending));

  if (_dbus_pending_call_is_timeout_added_unlocked (pending))
      _dbus_connection_remove_timeout_unlocked (connection,
              _dbus_pending_call_get_timeout_unlocked (pending));

  _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);

  _dbus_pending_call_unref_and_unlock (pending);
}

void
_dbus_connection_remove_pending_call (DBusConnection  *connection,
                                      DBusPendingCall *pending)
{
  CONNECTION_LOCK (connection);
  _dbus_connection_detach_pending_call_and_unlock (connection, pending);
}

static dbus_bool_t
_dbus_connection_acquire_io_path (DBusConnection *connection,
                                  int             timeout_milliseconds)
{
  dbus_bool_t we_acquired;
  
  HAVE_LOCK_CHECK (connection);

  /* We don't want the connection to vanish */
  _dbus_connection_ref_unlocked (connection);

  /* We will only touch io_path_acquired which is protected by our mutex */
  CONNECTION_UNLOCK (connection);
  
  _dbus_verbose ("locking io_path_mutex\n");
  _dbus_mutex_lock (connection->io_path_mutex);

  _dbus_verbose ("start connection->io_path_acquired = %d timeout = %d\n",
                 connection->io_path_acquired, timeout_milliseconds);

  we_acquired = FALSE;
  
  if (connection->io_path_acquired)
    {
      if (timeout_milliseconds != -1)
        {
          _dbus_verbose ("waiting %d for IO path to be acquirable\n",
                         timeout_milliseconds);

          if (!_dbus_condvar_wait_timeout (connection->io_path_cond,
                                           connection->io_path_mutex,
                                           timeout_milliseconds))
            {
              /* We timed out before anyone signaled. */
              /* (writing the loop to handle the !timedout case by
               * waiting longer if needed is a pain since dbus
               * wraps pthread_cond_timedwait to take a relative
               * time instead of absolute, something kind of stupid
               * on our part. for now it doesn't matter, we will just
               * end up back here eventually.)
               */
            }
        }
      else
        {
          while (connection->io_path_acquired)
            {
              _dbus_verbose ("waiting for IO path to be acquirable\n");
              _dbus_condvar_wait (connection->io_path_cond, 
                                  connection->io_path_mutex);
            }
        }
    }
  
  if (!connection->io_path_acquired)
    {
      we_acquired = TRUE;
      connection->io_path_acquired = TRUE;
    }
  
  _dbus_verbose ("end connection->io_path_acquired = %d we_acquired = %d\n",
                 connection->io_path_acquired, we_acquired);

  _dbus_verbose ("unlocking io_path_mutex\n");
  _dbus_mutex_unlock (connection->io_path_mutex);

  CONNECTION_LOCK (connection);
  
  HAVE_LOCK_CHECK (connection);

  _dbus_connection_unref_unlocked (connection);
  
  return we_acquired;
}

static void
_dbus_connection_release_io_path (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  
  _dbus_verbose ("locking io_path_mutex\n");
  _dbus_mutex_lock (connection->io_path_mutex);
  
  _dbus_assert (connection->io_path_acquired);

  _dbus_verbose ("start connection->io_path_acquired = %d\n",
                 connection->io_path_acquired);
  
  connection->io_path_acquired = FALSE;
  _dbus_condvar_wake_one (connection->io_path_cond);

  _dbus_verbose ("unlocking io_path_mutex\n");
  _dbus_mutex_unlock (connection->io_path_mutex);
}

void
_dbus_connection_do_iteration_unlocked (DBusConnection *connection,
                                        DBusPendingCall *pending,
                                        unsigned int    flags,
                                        int             timeout_milliseconds)
{
  _dbus_verbose ("start\n");
  
  HAVE_LOCK_CHECK (connection);
  
  if (connection->n_outgoing == 0)
    flags &= ~DBUS_ITERATION_DO_WRITING;

  if (_dbus_connection_acquire_io_path (connection,
                                        (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0))
    {
      HAVE_LOCK_CHECK (connection);
      
      if ( (pending != NULL) && _dbus_pending_call_get_completed_unlocked(pending))
        {
          _dbus_verbose ("pending call completed while acquiring I/O path");
        }
      else if ( (pending != NULL) &&
                _dbus_connection_peek_for_reply_unlocked (connection,
                                                          _dbus_pending_call_get_reply_serial_unlocked (pending)))
        {
          _dbus_verbose ("pending call completed while acquiring I/O path (reply found in queue)");
        }
      else
        {
          _dbus_transport_do_iteration (connection->transport,
                                        flags, timeout_milliseconds);
        }

      _dbus_connection_release_io_path (connection);
    }

  HAVE_LOCK_CHECK (connection);

  _dbus_verbose ("end\n");
}

DBusConnection*
_dbus_connection_new_for_transport (DBusTransport *transport)
{
  DBusConnection *connection;
  DBusWatchList *watch_list;
  DBusTimeoutList *timeout_list;
  DBusHashTable *pending_replies;
  DBusList *disconnect_link;
  DBusMessage *disconnect_message;
  DBusCounter *outgoing_counter;
  DBusObjectTree *objects;
  
  watch_list = NULL;
  connection = NULL;
  pending_replies = NULL;
  timeout_list = NULL;
  disconnect_link = NULL;
  disconnect_message = NULL;
  outgoing_counter = NULL;
  objects = NULL;
  
  watch_list = _dbus_watch_list_new ();
  if (watch_list == NULL)
    goto error;

  timeout_list = _dbus_timeout_list_new ();
  if (timeout_list == NULL)
    goto error;  

  pending_replies =
    _dbus_hash_table_new (DBUS_HASH_INT,
                          NULL,
                          (DBusFreeFunction)free_pending_call_on_hash_removal);
  if (pending_replies == NULL)
    goto error;
  
  connection = dbus_new0 (DBusConnection, 1);
  if (connection == NULL)
    goto error;

  _dbus_mutex_new_at_location (&connection->mutex);
  if (connection->mutex == NULL)
    goto error;

  _dbus_mutex_new_at_location (&connection->io_path_mutex);
  if (connection->io_path_mutex == NULL)
    goto error;

  _dbus_mutex_new_at_location (&connection->dispatch_mutex);
  if (connection->dispatch_mutex == NULL)
    goto error;
  
  _dbus_condvar_new_at_location (&connection->dispatch_cond);
  if (connection->dispatch_cond == NULL)
    goto error;
  
  _dbus_condvar_new_at_location (&connection->io_path_cond);
  if (connection->io_path_cond == NULL)
    goto error;

  _dbus_mutex_new_at_location (&connection->slot_mutex);
  if (connection->slot_mutex == NULL)
    goto error;

  disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL,
                                                DBUS_INTERFACE_LOCAL,
                                                "Disconnected");
  
  if (disconnect_message == NULL)
    goto error;

  disconnect_link = _dbus_list_alloc_link (disconnect_message);
  if (disconnect_link == NULL)
    goto error;

  outgoing_counter = _dbus_counter_new ();
  if (outgoing_counter == NULL)
    goto error;

  objects = _dbus_object_tree_new (connection);
  if (objects == NULL)
    goto error;
  
  if (_dbus_modify_sigpipe)
    _dbus_disable_sigpipe ();

  /* initialized to 0: use atomic op to avoid mixing atomic and non-atomic */
  _dbus_atomic_inc (&connection->refcount);
  connection->transport = transport;
  connection->watches = watch_list;
  connection->timeouts = timeout_list;
  connection->pending_replies = pending_replies;
  connection->outgoing_counter = outgoing_counter;
  connection->filter_list = NULL;
  connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */
  connection->objects = objects;
  connection->exit_on_disconnect = FALSE;
  connection->shareable = FALSE;
  connection->route_peer_messages = FALSE;
  connection->disconnected_message_arrived = FALSE;
  connection->disconnected_message_processed = FALSE;
  
#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))
    {
      CONNECTION_UNLOCK (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 (connection != NULL)
    {
      _dbus_condvar_free_at_location (&connection->io_path_cond);
      _dbus_condvar_free_at_location (&connection->dispatch_cond);
      _dbus_mutex_free_at_location (&connection->mutex);
      _dbus_mutex_free_at_location (&connection->io_path_mutex);
      _dbus_mutex_free_at_location (&connection->dispatch_mutex);
      _dbus_mutex_free_at_location (&connection->slot_mutex);
      dbus_free (connection);
    }
  if (pending_replies)
    _dbus_hash_table_unref (pending_replies);
  
  if (watch_list)
    _dbus_watch_list_free (watch_list);

  if (timeout_list)
    _dbus_timeout_list_free (timeout_list);

  if (outgoing_counter)
    _dbus_counter_unref (outgoing_counter);

  if (objects)
    _dbus_object_tree_unref (objects);
  
  return NULL;
}

DBusConnection *
_dbus_connection_ref_unlocked (DBusConnection *connection)
{  
  _dbus_assert (connection != NULL);
  _dbus_assert (connection->generation == _dbus_current_generation);

  HAVE_LOCK_CHECK (connection);

  _dbus_atomic_inc (&connection->refcount);

  return connection;
}

void
_dbus_connection_unref_unlocked (DBusConnection *connection)
{
  dbus_bool_t last_unref;

  HAVE_LOCK_CHECK (connection);
  
  _dbus_assert (connection != NULL);

  last_unref = (_dbus_atomic_dec (&connection->refcount) == 1);

  if (last_unref)
    _dbus_connection_last_unref (connection);
}

static dbus_uint32_t
_dbus_connection_get_next_client_serial (DBusConnection *connection)
{
  dbus_uint32_t serial;

  serial = connection->client_serial++;

  if (connection->client_serial == 0)
    connection->client_serial = 1;

  return serial;
}

dbus_bool_t
_dbus_connection_handle_watch (DBusWatch                   *watch,
                               unsigned int                 condition,
                               void                        *data)
{
  DBusConnection *connection;
  dbus_bool_t retval;
  DBusDispatchStatus status;

  connection = data;

  _dbus_verbose ("start\n");
  
  CONNECTION_LOCK (connection);

  if (!_dbus_connection_acquire_io_path (connection, 1))
    {
      /* another thread is handling the message */
      CONNECTION_UNLOCK (connection);
      return TRUE;
    }

  HAVE_LOCK_CHECK (connection);
  retval = _dbus_transport_handle_watch (connection->transport,
                                         watch, condition);

  _dbus_connection_release_io_path (connection);

  HAVE_LOCK_CHECK (connection);

  _dbus_verbose ("middle\n");
  
  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* this calls out to user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);

  _dbus_verbose ("end\n");
  
  return retval;
}

_DBUS_DEFINE_GLOBAL_LOCK (shared_connections);
static DBusHashTable *shared_connections = NULL;
static DBusList *shared_connections_no_guid = NULL;

static void
close_connection_on_shutdown (DBusConnection *connection)
{
  DBusMessage *message;

  dbus_connection_ref (connection);
  _dbus_connection_close_possibly_shared (connection);

  /* Churn through to the Disconnected message */
  while ((message = dbus_connection_pop_message (connection)))
    {
      dbus_message_unref (message);
    }
  dbus_connection_unref (connection);
}

static void
shared_connections_shutdown (void *data)
{
  int n_entries;
  
  _DBUS_LOCK (shared_connections);
  
  /* This is a little bit unpleasant... better ideas? */
  while ((n_entries = _dbus_hash_table_get_n_entries (shared_connections)) > 0)
    {
      DBusConnection *connection;
      DBusHashIter iter;
      
      _dbus_hash_iter_init (shared_connections, &iter);
      _dbus_hash_iter_next (&iter);
       
      connection = _dbus_hash_iter_get_value (&iter);

      _DBUS_UNLOCK (shared_connections);
      close_connection_on_shutdown (connection);
      _DBUS_LOCK (shared_connections);

      /* The connection should now be dead and not in our hash ... */
      _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) < n_entries);
    }

  _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0);
  
  _dbus_hash_table_unref (shared_connections);
  shared_connections = NULL;

  if (shared_connections_no_guid != NULL)
    {
      DBusConnection *connection;
      connection = _dbus_list_pop_first (&shared_connections_no_guid);
      while (connection != NULL)
        {
          _DBUS_UNLOCK (shared_connections);
          close_connection_on_shutdown (connection);
          _DBUS_LOCK (shared_connections);
          connection = _dbus_list_pop_first (&shared_connections_no_guid);
        }
    }

  shared_connections_no_guid = NULL;
  
  _DBUS_UNLOCK (shared_connections);
}

static dbus_bool_t
connection_lookup_shared (DBusAddressEntry  *entry,
                          DBusConnection   **result)
{
  _dbus_verbose ("checking for existing connection\n");
  
  *result = NULL;
  
  _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)
        {
          DBusConnection *connection;
          
          connection = _dbus_hash_table_lookup_string (shared_connections,
                                                       guid);

          if (connection)
            {
              /* The DBusConnection can't be finalized without taking
               * the shared_connections lock to remove it from the
               * hash.  So it's safe to ref the connection here.
               * However, it may be disconnected if the Disconnected
               * message hasn't been processed yet, in which case we
               * want to pretend it isn't in the hash and avoid
               * returning it.
               *
               * The idea is to avoid ever returning a disconnected connection
               * from dbus_connection_open(). We could just synchronously
               * drop our shared ref to the connection on connection disconnect,
               * and then assert here that the connection is connected, but
               * that causes reentrancy headaches.
               */
              CONNECTION_LOCK (connection);
              if (_dbus_connection_get_is_connected_unlocked (connection))
                {
                  _dbus_connection_ref_unlocked (connection);
                  *result = connection;
                  _dbus_verbose ("looked up existing connection to server guid %s\n",
                                 guid);
                }
              else
                {
                  _dbus_verbose ("looked up existing connection to server guid %s but it was disconnected so ignoring it\n",
                                 guid);
                }
              CONNECTION_UNLOCK (connection);
            }
        }
      
      _DBUS_UNLOCK (shared_connections);
      return TRUE;
    }
}

static dbus_bool_t
connection_record_shared_unlocked (DBusConnection *connection,
                                   const char     *guid)
{
  char *guid_key;
  char *guid_in_connection;

  HAVE_LOCK_CHECK (connection);
  _dbus_assert (connection->server_guid == NULL);
  _dbus_assert (connection->shareable);

  /* get a hard ref on this connection, even if
   * we won't in fact store it in the hash, we still
   * need to hold a ref on it until it's disconnected.
   */
  _dbus_connection_ref_unlocked (connection);

  if (guid == NULL)
    {
      _DBUS_LOCK (shared_connections);

      if (!_dbus_list_prepend (&shared_connections_no_guid, connection))
        {
          _DBUS_UNLOCK (shared_connections);
          return FALSE;
        }

      _DBUS_UNLOCK (shared_connections);
      return TRUE; /* don't store in the hash */
    }
  
  /* A separate copy of the key is required in the hash table, because
   * we don't have a lock on the connection when we are doing a hash
   * lookup.
   */
  
  guid_key = _dbus_strdup (guid);
  if (guid_key == NULL)
    return FALSE;

  guid_in_connection = _dbus_strdup (guid);
  if (guid_in_connection == NULL)
    {
      dbus_free (guid_key);
      return FALSE;
    }
  
  _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->shareable)
    return;
  
  _DBUS_LOCK (shared_connections);
      
  if (connection->server_guid != NULL)
    {
      _dbus_verbose ("dropping connection to %s out of the shared table\n",
                     connection->server_guid);
      
      if (!_dbus_hash_table_remove_string (shared_connections,
                                           connection->server_guid))
        _dbus_assert_not_reached ("connection was not in the shared table");
      
      dbus_free (connection->server_guid);
      connection->server_guid = NULL;
    }
  else
    {
      _dbus_list_remove (&shared_connections_no_guid, connection);
    }

  _DBUS_UNLOCK (shared_connections);
  
  /* remove our reference held on all shareable connections */
  _dbus_connection_unref_unlocked (connection);
}

static DBusConnection*
connection_try_from_address_entry (DBusAddressEntry *entry,
                                   DBusError        *error)
{
  DBusTransport *transport;
  DBusConnection *connection;

  transport = _dbus_transport_open (entry, error);

  if (transport == NULL)
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      return NULL;
    }

  connection = _dbus_connection_new_for_transport (transport);

  _dbus_transport_unref (transport);
  
  if (connection == NULL)
    {
      _DBUS_SET_OOM (error);
      return NULL;
    }

#ifndef DBUS_DISABLE_CHECKS
  _dbus_assert (!connection->have_connection_lock);
#endif
  return connection;
}

/*
 * If the shared parameter is true, then any existing connection will
 * be used (and if a new connection is created, it will be available
 * for use by others). If the shared parameter is false, a new
 * connection will always be created, and the new connection will
 * never be returned to other callers.
 *
 * @param address the address
 * @param shared whether the connection is shared or private
 * @param error error return
 * @returns the connection or #NULL on error
 */
static DBusConnection*
_dbus_connection_open_internal (const char     *address,
                                dbus_bool_t     shared,
                                DBusError      *error)
{
  DBusConnection *connection;
  DBusAddressEntry **entries;
  DBusError tmp_error = DBUS_ERROR_INIT;
  DBusError first_error = DBUS_ERROR_INIT;
  int len, i;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

  _dbus_verbose ("opening %s connection to: %s\n",
                 shared ? "shared" : "private", address);
  
  if (!dbus_parse_address (address, &entries, &len, error))
    return NULL;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  connection = NULL;

  for (i = 0; i < len; i++)
    {
      if (shared)
        {
          if (!connection_lookup_shared (entries[i], &connection))
            _DBUS_SET_OOM (&tmp_error);
        }

      if (connection == NULL)
        {
          connection = connection_try_from_address_entry (entries[i],
                                                          &tmp_error);

          if (connection != NULL && shared)
            {
              const char *guid;
                  
              connection->shareable = TRUE;
                  
              /* guid may be NULL */
              guid = dbus_address_entry_get_value (entries[i], "guid");
                  
              CONNECTION_LOCK (connection);
          
              if (!connection_record_shared_unlocked (connection, guid))
                {
                  _DBUS_SET_OOM (&tmp_error);
                  _dbus_connection_close_possibly_shared_and_unlock (connection);
                  dbus_connection_unref (connection);
                  connection = NULL;
                }
              else
                CONNECTION_UNLOCK (connection);
            }
        }
      
      if (connection)
        break;

      _DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
      
      if (i == 0)
        dbus_move_error (&tmp_error, &first_error);
      else
        dbus_error_free (&tmp_error);
    }
  
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
  
  if (connection == NULL)
    {
      _DBUS_ASSERT_ERROR_IS_SET (&first_error);
      dbus_move_error (&first_error, error);
    }
  else
    dbus_error_free (&first_error);
  
  dbus_address_entries_free (entries);
  return connection;
}

void
_dbus_connection_close_possibly_shared (DBusConnection *connection)
{
  _dbus_assert (connection != NULL);
  _dbus_assert (connection->generation == _dbus_current_generation);

  CONNECTION_LOCK (connection);
  _dbus_connection_close_possibly_shared_and_unlock (connection);
}

static DBusPreallocatedSend*
_dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
{
  DBusPreallocatedSend *preallocated;

  HAVE_LOCK_CHECK (connection);
  
  _dbus_assert (connection != NULL);
  
  preallocated = dbus_new (DBusPreallocatedSend, 1);
  if (preallocated == NULL)
    return NULL;

  preallocated->queue_link = _dbus_list_alloc_link (NULL);
  if (preallocated->queue_link == NULL)
    goto failed_0;

  preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
  if (preallocated->counter_link == NULL)
    goto failed_1;

  _dbus_counter_ref (preallocated->counter_link->data);

  preallocated->connection = connection;
  
  return preallocated;
  
 failed_1:
  _dbus_list_free_link (preallocated->queue_link);
 failed_0:
  dbus_free (preallocated);
  
  return NULL;
}

/* Called with lock held, does not update dispatch status */
static void
_dbus_connection_send_preallocated_unlocked_no_update (DBusConnection       *connection,
                                                       DBusPreallocatedSend *preallocated,
                                                       DBusMessage          *message,
                                                       dbus_uint32_t        *client_serial)
{
  dbus_uint32_t serial;

  preallocated->queue_link->data = message;
  _dbus_list_prepend_link (&connection->outgoing_messages,
                           preallocated->queue_link);

  /* It's OK that we'll never call the notify function, because for the
   * outgoing limit, there isn't one */
  _dbus_message_add_counter_link (message,
                                  preallocated->counter_link);

  dbus_free (preallocated);
  preallocated = NULL;
  
  dbus_message_ref (message);
  
  connection->n_outgoing += 1;

  _dbus_verbose ("Message %p (%s %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n",
                 message,
                 dbus_message_type_to_string (dbus_message_get_type (message)),
                 dbus_message_get_path (message) ?
                 dbus_message_get_path (message) :
                 "no path",
                 dbus_message_get_interface (message) ?
                 dbus_message_get_interface (message) :
                 "no interface",
                 dbus_message_get_member (message) ?
                 dbus_message_get_member (message) :
                 "no member",
                 dbus_message_get_signature (message),
                 dbus_message_get_destination (message) ?
                 dbus_message_get_destination (message) :
                 "null",
                 connection,
                 connection->n_outgoing);

  if (dbus_message_get_serial (message) == 0)
    {
      serial = _dbus_connection_get_next_client_serial (connection);
      dbus_message_set_serial (message, serial);
      if (client_serial)
        *client_serial = serial;
    }
  else
    {
      if (client_serial)
        *client_serial = dbus_message_get_serial (message);
    }

  _dbus_verbose ("Message %p serial is %u\n",
                 message, dbus_message_get_serial (message));
  
  dbus_message_lock (message);

  /* Now we need to run an iteration to hopefully just write the messages
   * out immediately, and otherwise get them queued up
   */
  _dbus_connection_do_iteration_unlocked (connection,
                                          NULL,
                                          DBUS_ITERATION_DO_WRITING,
                                          -1);

  /* If stuff is still queued up, be sure we wake up the main loop */
  if (connection->n_outgoing > 0)
    _dbus_connection_wakeup_mainloop (connection);
}

static void
_dbus_connection_send_preallocated_and_unlock (DBusConnection       *connection,
                                               DBusPreallocatedSend *preallocated,
                                               DBusMessage          *message,
                                               dbus_uint32_t        *client_serial)
{
  DBusDispatchStatus status;

  HAVE_LOCK_CHECK (connection);
  
  _dbus_connection_send_preallocated_unlocked_no_update (connection,
                                                         preallocated,
                                                         message, client_serial);

  _dbus_verbose ("middle\n");
  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* this calls out to user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
}

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;
}

void
_dbus_connection_close_if_only_one_ref (DBusConnection *connection)
{
  dbus_int32_t refcount;

  CONNECTION_LOCK (connection);

  refcount = _dbus_atomic_get (&connection->refcount);
  /* The caller should have at least one ref */
  _dbus_assert (refcount >= 1);

  if (refcount == 1)
    _dbus_connection_close_possibly_shared_and_unlock (connection);
  else
    CONNECTION_UNLOCK (connection);
}


static void
_dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
{
  if (timeout_milliseconds == -1)
    _dbus_sleep_milliseconds (1000);
  else if (timeout_milliseconds < 100)
    ; /* just busy loop */
  else if (timeout_milliseconds <= 1000)
    _dbus_sleep_milliseconds (timeout_milliseconds / 3);
  else
    _dbus_sleep_milliseconds (1000);
}

static DBusMessage *
generate_local_error_message (dbus_uint32_t serial, 
                              char *error_name, 
                              char *error_msg)
{
  DBusMessage *message;
  message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
  if (!message)
    goto out;

  if (!dbus_message_set_error_name (message, error_name))
    {
      dbus_message_unref (message);
      message = NULL;
      goto out; 
    }

  dbus_message_set_no_reply (message, TRUE); 

  if (!dbus_message_set_reply_serial (message,
                                      serial))
    {
      dbus_message_unref (message);
      message = NULL;
      goto out;
    }

  if (error_msg != NULL)
    {
      DBusMessageIter iter;

      dbus_message_iter_init_append (message, &iter);
      if (!dbus_message_iter_append_basic (&iter,
                                           DBUS_TYPE_STRING,
                                           &error_msg))
        {
          dbus_message_unref (message);
          message = NULL;
          goto out;
        }
    }

 out:
  return message;
}

/*
 * Peek the incoming queue to see if we got reply for a specific serial
 */
static dbus_bool_t
_dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
                                          dbus_uint32_t   client_serial)
{
  DBusList *link;
  HAVE_LOCK_CHECK (connection);

  link = _dbus_list_get_first_link (&connection->incoming_messages);

  while (link != NULL)
    {
      DBusMessage *reply = link->data;

      if (dbus_message_get_reply_serial (reply) == client_serial)
        {
          _dbus_verbose ("%s reply to %d found in queue\n", _DBUS_FUNCTION_NAME, client_serial);
          return TRUE;
        }
      link = _dbus_list_get_next_link (&connection->incoming_messages, link);
    }

  return FALSE;
}

/* This is slightly strange since we can pop a message here without
 * the dispatch lock.
 */
static DBusMessage*
check_for_reply_unlocked (DBusConnection *connection,
                          dbus_uint32_t   client_serial)
{
  DBusList *link;

  HAVE_LOCK_CHECK (connection);
  
  link = _dbus_list_get_first_link (&connection->incoming_messages);

  while (link != NULL)
    {
      DBusMessage *reply = link->data;

      if (dbus_message_get_reply_serial (reply) == client_serial)
        {
          _dbus_list_remove_link (&connection->incoming_messages, link);
          connection->n_incoming  -= 1;
          return reply;
        }
      link = _dbus_list_get_next_link (&connection->incoming_messages, link);
    }

  return NULL;
}

static void
connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection)
{
   /* We can't iterate over the hash in the normal way since we'll be
    * dropping the lock for each item. So we restart the
    * iter each time as we drain the hash table.
    */
   
   while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0)
    {
      DBusPendingCall *pending;
      DBusHashIter iter;
      
      _dbus_hash_iter_init (connection->pending_replies, &iter);
      _dbus_hash_iter_next (&iter);
       
      pending = _dbus_hash_iter_get_value (&iter);
      _dbus_pending_call_ref_unlocked (pending);
       
      _dbus_pending_call_queue_timeout_error_unlocked (pending, 
                                                       connection);

      if (_dbus_pending_call_is_timeout_added_unlocked (pending))
          _dbus_connection_remove_timeout_unlocked (connection,
                                                    _dbus_pending_call_get_timeout_unlocked (pending));
      _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);       
      _dbus_hash_iter_remove_entry (&iter);

      _dbus_pending_call_unref_and_unlock (pending);
      CONNECTION_LOCK (connection);
    }
  HAVE_LOCK_CHECK (connection);
}

static void
complete_pending_call_and_unlock (DBusConnection  *connection,
                                  DBusPendingCall *pending,
                                  DBusMessage     *message)
{
  _dbus_pending_call_set_reply_unlocked (pending, message);
  _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */
  _dbus_connection_detach_pending_call_and_unlock (connection, pending);
 
  /* Must be called unlocked since it invokes app callback */
  _dbus_pending_call_complete (pending);
  dbus_pending_call_unref (pending);
}

static dbus_bool_t
check_for_reply_and_update_dispatch_unlocked (DBusConnection  *connection,
                                              DBusPendingCall *pending)
{
  DBusMessage *reply;
  DBusDispatchStatus status;

  reply = check_for_reply_unlocked (connection, 
                                    _dbus_pending_call_get_reply_serial_unlocked (pending));
  if (reply != NULL)
    {
      _dbus_verbose ("checked for reply\n");

      _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");

      complete_pending_call_and_unlock (connection, pending, reply);
      dbus_message_unref (reply);

      CONNECTION_LOCK (connection);
      status = _dbus_connection_get_dispatch_status_unlocked (connection);
      _dbus_connection_update_dispatch_status_and_unlock (connection, status);
      dbus_pending_call_unref (pending);

      return TRUE;
    }

  return FALSE;
}

void
_dbus_connection_block_pending_call (DBusPendingCall *pending)
{
  long start_tv_sec, start_tv_usec;
  long tv_sec, tv_usec;
  DBusDispatchStatus status;
  DBusConnection *connection;
  dbus_uint32_t client_serial;
  DBusTimeout *timeout;
  int timeout_milliseconds, elapsed_milliseconds;

  _dbus_assert (pending != NULL);

  if (dbus_pending_call_get_completed (pending))
    return;

  dbus_pending_call_ref (pending); /* necessary because the call could be canceled */

  connection = _dbus_pending_call_get_connection_and_lock (pending);
  
  /* Flush message queue - note, can affect dispatch status */
  _dbus_connection_flush_unlocked (connection);

  client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);

  /* note that timeout_milliseconds is limited to a smallish value
   * in _dbus_pending_call_new() so overflows aren't possible
   * below
   */
  timeout = _dbus_pending_call_get_timeout_unlocked (pending);
  _dbus_get_current_time (&start_tv_sec, &start_tv_usec);
  if (timeout)
    {
      timeout_milliseconds = dbus_timeout_get_interval (timeout);

      _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec\n",
                     timeout_milliseconds,
                     client_serial,
                     start_tv_sec, start_tv_usec);
    }
  else
    {
      timeout_milliseconds = -1;

      _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block for reply serial %u\n", client_serial);
    }

  /* check to see if we already got the data off the socket */
  /* from another blocked pending call */
  if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
    return;

  /* Now we wait... */
  /* always block at least once as we know we don't have the reply yet */
  _dbus_connection_do_iteration_unlocked (connection,
                                          pending,
                                          DBUS_ITERATION_DO_READING |
                                          DBUS_ITERATION_BLOCK,
                                          timeout_milliseconds);

 recheck_status:

  _dbus_verbose ("top of recheck\n");
  
  HAVE_LOCK_CHECK (connection);
  
  /* queue messages and get status */

  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* the get_completed() is in case a dispatch() while we were blocking
   * got the reply instead of us.
   */
  if (_dbus_pending_call_get_completed_unlocked (pending))
    {
      _dbus_verbose ("Pending call completed by dispatch\n");
      _dbus_connection_update_dispatch_status_and_unlock (connection, status);
      dbus_pending_call_unref (pending);
      return;
    }
  
  if (status == DBUS_DISPATCH_DATA_REMAINS)
    {
      if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
        return;
    }
  
  _dbus_get_current_time (&tv_sec, &tv_usec);
  elapsed_milliseconds = (tv_sec - start_tv_sec) * 1000 +
          (tv_usec - start_tv_usec) / 1000;
  
  if (!_dbus_connection_get_is_connected_unlocked (connection))
    {
      DBusMessage *error_msg;

      error_msg = generate_local_error_message (client_serial,
                                                DBUS_ERROR_DISCONNECTED, 
                                                "Connection was disconnected before a reply was received"); 

      /* on OOM error_msg is set to NULL */
      complete_pending_call_and_unlock (connection, pending, error_msg);
      dbus_pending_call_unref (pending);
      return;
    }
  else if (connection->disconnect_message_link == NULL)
    _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n");
  else if (timeout == NULL)
    {
       if (status == DBUS_DISPATCH_NEED_MEMORY)
        {
          /* Try sleeping a bit, as we aren't sure we need to block for reading,
           * we may already have a reply in the buffer and just can't process
           * it.
           */
          _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");

          _dbus_memory_pause_based_on_timeout (timeout_milliseconds - elapsed_milliseconds);
        }
      else
        {          
          /* block again, we don't have the reply buffered yet. */
          _dbus_connection_do_iteration_unlocked (connection,
                                                  pending,
                                                  DBUS_ITERATION_DO_READING |
                                                  DBUS_ITERATION_BLOCK,
                                                  timeout_milliseconds - elapsed_milliseconds);
        }

      goto recheck_status;
    }
  else if (tv_sec < start_tv_sec)
    _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n");
  else if (elapsed_milliseconds < timeout_milliseconds)
    {
      _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds - elapsed_milliseconds);
      
      if (status == DBUS_DISPATCH_NEED_MEMORY)
        {
          /* Try sleeping a bit, as we aren't sure we need to block for reading,
           * we may already have a reply in the buffer and just can't process
           * it.
           */
          _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");

          _dbus_memory_pause_based_on_timeout (timeout_milliseconds - elapsed_milliseconds);
        }
      else
        {          
          /* block again, we don't have the reply buffered yet. */
          _dbus_connection_do_iteration_unlocked (connection,
                                                  NULL,
                                                  DBUS_ITERATION_DO_READING |
                                                  DBUS_ITERATION_BLOCK,
                                                  timeout_milliseconds - elapsed_milliseconds);
        }

      goto recheck_status;
    }

  _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %d milliseconds and got no reply\n",
                 elapsed_milliseconds);

  _dbus_assert (!_dbus_pending_call_get_completed_unlocked (pending));
  
  /* unlock and call user code */
  complete_pending_call_and_unlock (connection, pending, NULL);

  /* update user code on dispatch status */
  CONNECTION_LOCK (connection);
  status = _dbus_connection_get_dispatch_status_unlocked (connection);
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
  dbus_pending_call_unref (pending);
}

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;
}

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;
}

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);

  _dbus_atomic_inc (&connection->refcount);

  return connection;
}

static void
free_outgoing_message (void *element,
                       void *data)
{
  DBusMessage *message = element;
  DBusConnection *connection = data;

  _dbus_message_remove_counter (message, connection->outgoing_counter);
  dbus_message_unref (message);
}

/* This is run without the mutex held, but after the last reference
 * to the connection has been dropped we should have no thread-related
 * problems
 */
static void
_dbus_connection_last_unref (DBusConnection *connection)
{
  DBusList *link;

  _dbus_verbose ("Finalizing connection %p\n", connection);

  _dbus_assert (_dbus_atomic_get (&connection->refcount) == 0);

  /* You have to disconnect the connection before unref:ing it. Otherwise
   * you won't get the disconnected message.
   */
  _dbus_assert (!_dbus_transport_get_is_connected (connection->transport));
  _dbus_assert (connection->server_guid == NULL);
  
  /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */
  _dbus_object_tree_free_all_unlocked (connection->objects);
  
  dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL);
  dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL);
  dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL);
  
  _dbus_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_condvar_free_at_location (&connection->dispatch_cond);
  _dbus_condvar_free_at_location (&connection->io_path_cond);

  _dbus_mutex_free_at_location (&connection->io_path_mutex);
  _dbus_mutex_free_at_location (&connection->dispatch_mutex);

  _dbus_mutex_free_at_location (&connection->slot_mutex);

  _dbus_mutex_free_at_location (&connection->mutex);
  
  dbus_free (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);

  last_unref = (_dbus_atomic_dec (&connection->refcount) == 1);

  if (last_unref)
    {
#ifndef DBUS_DISABLE_CHECKS
      if (_dbus_transport_get_is_connected (connection->transport))
        {
          _dbus_warn_check_failed ("The last reference on a connection was dropped without closing the connection. This is a bug in an application. See dbus_connection_unref() documentation for details.\n%s",
                                   connection->shareable ?
                                   "Most likely, the application called unref() too many times and removed a reference belonging to libdbus, since this is a shared connection.\n" : 
                                    "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.\n");
          return;
        }
#endif
      _dbus_connection_last_unref (connection);
    }
}

/*
 * Note that the transport can disconnect itself (other end drops us)
 * and in that case this function never runs. So this function must
 * not do anything more than disconnect the transport and update the
 * dispatch status.
 * 
 * If the transport self-disconnects, then we assume someone will
 * dispatch the connection to cause the dispatch status update.
 */
static void
_dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection)
{
  DBusDispatchStatus status;

  HAVE_LOCK_CHECK (connection);
  
  _dbus_verbose ("Disconnecting %p\n", connection);

  /* We need to ref because update_dispatch_status_and_unlock will unref
   * the connection if it was shared and libdbus was the only remaining
   * refcount holder.
   */
  _dbus_connection_ref_unlocked (connection);
  
  _dbus_transport_disconnect (connection->transport);

  /* This has the side effect of queuing the disconnect message link
   * (unless we don't have enough memory, possibly, so don't assert it).
   * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open
   * should never again return the newly-disconnected connection.
   *
   * However, we only unref the shared connection and exit_on_disconnect when
   * the disconnect message reaches the head of the message queue,
   * NOT when it's first queued.
   */
  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* This calls out to user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);

  /* Could also call out to user code */
  dbus_connection_unref (connection);
}

void
dbus_connection_close (DBusConnection *connection)
{
  _dbus_return_if_fail (connection != NULL);
  _dbus_return_if_fail (connection->generation == _dbus_current_generation);

  CONNECTION_LOCK (connection);

#ifndef DBUS_DISABLE_CHECKS
  if (connection->shareable)
    {
      CONNECTION_UNLOCK (connection);

      _dbus_warn_check_failed ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.\n");
      return;
    }
#endif
  
  _dbus_connection_close_possibly_shared_and_unlock (connection);
}

static dbus_bool_t
_dbus_connection_get_is_connected_unlocked (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  return _dbus_transport_get_is_connected (connection->transport);
}

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;
}

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;
}

dbus_bool_t
dbus_connection_get_is_anonymous (DBusConnection *connection)
{
  dbus_bool_t res;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  
  CONNECTION_LOCK (connection);
  res = _dbus_transport_get_is_anonymous (connection->transport);
  CONNECTION_UNLOCK (connection);
  
  return res;
}

char*
dbus_connection_get_server_id (DBusConnection *connection)
{
  char *id;

  _dbus_return_val_if_fail (connection != NULL, NULL);

  CONNECTION_LOCK (connection);
  id = _dbus_strdup (_dbus_transport_get_server_id (connection->transport));
  CONNECTION_UNLOCK (connection);

  return id;
}

dbus_bool_t
dbus_connection_can_send_type(DBusConnection *connection,
                                  int type)
{
  _dbus_return_val_if_fail (connection != NULL, FALSE);

  if (!dbus_type_is_valid (type))
    return FALSE;

  if (type != DBUS_TYPE_UNIX_FD)
    return TRUE;

#ifdef HAVE_UNIX_FD_PASSING
  {
    dbus_bool_t b;

    CONNECTION_LOCK(connection);
    b = _dbus_transport_can_pass_unix_fd(connection->transport);
    CONNECTION_UNLOCK(connection);

    return b;
  }
#endif

  return FALSE;
}

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);
}

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;
}

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);
}

void
dbus_connection_send_preallocated (DBusConnection       *connection,
                                   DBusPreallocatedSend *preallocated,
                                   DBusMessage          *message,
                                   dbus_uint32_t        *client_serial)
{
  _dbus_return_if_fail (connection != NULL);
  _dbus_return_if_fail (preallocated != NULL);
  _dbus_return_if_fail (message != NULL);
  _dbus_return_if_fail (preallocated->connection == connection);
  _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL ||
                        dbus_message_get_member (message) != NULL);
  _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL ||
                        (dbus_message_get_interface (message) != NULL &&
                         dbus_message_get_member (message) != NULL));

  CONNECTION_LOCK (connection);

#ifdef HAVE_UNIX_FD_PASSING

  if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
      message->n_unix_fds > 0)
    {
      /* Refuse to send fds on a connection that cannot handle
         them. Unfortunately we cannot return a proper error here, so
         the best we can is just return. */
      CONNECTION_UNLOCK (connection);
      return;
    }

#endif

  _dbus_connection_send_preallocated_and_unlock (connection,
                                                 preallocated,
                                                 message, client_serial);
}

static dbus_bool_t
_dbus_connection_send_unlocked_no_update (DBusConnection *connection,
                                          DBusMessage    *message,
                                          dbus_uint32_t  *client_serial)
{
  DBusPreallocatedSend *preallocated;

  _dbus_assert (connection != NULL);
  _dbus_assert (message != NULL);
  
  preallocated = _dbus_connection_preallocate_send_unlocked (connection);
  if (preallocated == NULL)
    return FALSE;

  _dbus_connection_send_preallocated_unlocked_no_update (connection,
                                                         preallocated,
                                                         message,
                                                         client_serial);
  return TRUE;
}

dbus_bool_t
dbus_connection_send (DBusConnection *connection,
                      DBusMessage    *message,
                      dbus_uint32_t  *serial)
{
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (message != NULL, FALSE);

  CONNECTION_LOCK (connection);

#ifdef HAVE_UNIX_FD_PASSING

  if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
      message->n_unix_fds > 0)
    {
      /* Refuse to send fds on a connection that cannot handle
         them. Unfortunately we cannot return a proper error here, so
         the best we can is just return. */
      CONNECTION_UNLOCK (connection);
      return FALSE;
    }

#endif

  return _dbus_connection_send_and_unlock (connection,
                                           message,
                                           serial);
}

static dbus_bool_t
reply_handler_timeout (void *data)
{
  DBusConnection *connection;
  DBusDispatchStatus status;
  DBusPendingCall *pending = data;

  connection = _dbus_pending_call_get_connection_and_lock (pending);
  _dbus_connection_ref_unlocked (connection);

  _dbus_pending_call_queue_timeout_error_unlocked (pending, 
                                                   connection);
  _dbus_connection_remove_timeout_unlocked (connection,
                                            _dbus_pending_call_get_timeout_unlocked (pending));
  _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);

  _dbus_verbose ("middle\n");
  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* Unlocks, and calls out to user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
  dbus_connection_unref (connection);
  
  return TRUE;
}

dbus_bool_t
dbus_connection_send_with_reply (DBusConnection     *connection,
                                 DBusMessage        *message,
                                 DBusPendingCall   **pending_return,
                                 int                 timeout_milliseconds)
{
  DBusPendingCall *pending;
  dbus_int32_t serial = -1;
  DBusDispatchStatus status;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (message != NULL, FALSE);
  _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);

  if (pending_return)
    *pending_return = NULL;

  CONNECTION_LOCK (connection);

#ifdef HAVE_UNIX_FD_PASSING

  if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
      message->n_unix_fds > 0)
    {
      /* Refuse to send fds on a connection that cannot handle
         them. Unfortunately we cannot return a proper error here, so
         the best we can do is return TRUE but leave *pending_return
         as NULL. */
      CONNECTION_UNLOCK (connection);
      return TRUE;
    }

#endif

   if (!_dbus_connection_get_is_connected_unlocked (connection))
    {
      CONNECTION_UNLOCK (connection);

      return TRUE;
    }

  pending = _dbus_pending_call_new_unlocked (connection,
                                             timeout_milliseconds,
                                             reply_handler_timeout);

  if (pending == NULL)
    {
      CONNECTION_UNLOCK (connection);
      return FALSE;
    }

  /* Assign a serial to the message */
  serial = dbus_message_get_serial (message);
  if (serial == 0)
    {
      serial = _dbus_connection_get_next_client_serial (connection);
      dbus_message_set_serial (message, serial);
    }

  if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial))
    goto error;
    
  /* Insert the serial in the pending replies hash;
   * hash takes a refcount on DBusPendingCall.
   * Also, add the timeout.
   */
  if (!_dbus_connection_attach_pending_call_unlocked (connection,
                                                      pending))
    goto error;
 
  if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL))
    {
      _dbus_connection_detach_pending_call_and_unlock (connection,
                                                       pending);
      goto error_unlocked;
    }

  if (pending_return)
    *pending_return = pending; /* hand off refcount */
  else
    {
      _dbus_connection_detach_pending_call_unlocked (connection, pending);
      /* we still have a ref to the pending call in this case, we unref
       * after unlocking, below
       */
    }

  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* this calls out to user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);

  if (pending_return == NULL)
    dbus_pending_call_unref (pending);
  
  return TRUE;

 error:
  CONNECTION_UNLOCK (connection);
 error_unlocked:
  dbus_pending_call_unref (pending);
  return FALSE;
}

DBusMessage*
dbus_connection_send_with_reply_and_block (DBusConnection     *connection,
                                           DBusMessage        *message,
                                           int                 timeout_milliseconds,
                                           DBusError          *error)
{
  DBusMessage *reply;
  DBusPendingCall *pending;

  _dbus_return_val_if_fail (connection != NULL, NULL);
  _dbus_return_val_if_fail (message != NULL, NULL);
  _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL);
  _dbus_return_val_if_error_is_set (error, NULL);

#ifdef HAVE_UNIX_FD_PASSING

  CONNECTION_LOCK (connection);
  if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
      message->n_unix_fds > 0)
    {
      CONNECTION_UNLOCK (connection);
      dbus_set_error(error, DBUS_ERROR_FAILED, "Cannot send file descriptors on this connection.");
      return NULL;
    }
  CONNECTION_UNLOCK (connection);

#endif

  if (!dbus_connection_send_with_reply (connection, message,
                                        &pending, timeout_milliseconds))
    {
      _DBUS_SET_OOM (error);
      return NULL;
    }

  if (pending == NULL)
    {
      dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed");
      return NULL;
    }
  
  dbus_pending_call_block (pending);

  reply = dbus_pending_call_steal_reply (pending);
  dbus_pending_call_unref (pending);

  /* call_complete_and_unlock() called from pending_call_block() should
   * always fill this in.
   */
  _dbus_assert (reply != NULL);
  
   if (dbus_set_error_from_message (error, reply))
    {
      dbus_message_unref (reply);
      return NULL;
    }
  else
    return reply;
}

static DBusDispatchStatus
_dbus_connection_flush_unlocked (DBusConnection *connection)
{
  /* We have to specify DBUS_ITERATION_DO_READING here because
   * otherwise we could have two apps deadlock if they are both doing
   * a flush(), and the kernel buffers fill up. This could change the
   * dispatch status.
   */
  DBusDispatchStatus status;

  HAVE_LOCK_CHECK (connection);
  
  while (connection->n_outgoing > 0 &&
         _dbus_connection_get_is_connected_unlocked (connection))
    {
      _dbus_verbose ("doing iteration in\n");
      HAVE_LOCK_CHECK (connection);
      _dbus_connection_do_iteration_unlocked (connection,
                                              NULL,
                                              DBUS_ITERATION_DO_READING |
                                              DBUS_ITERATION_DO_WRITING |
                                              DBUS_ITERATION_BLOCK,
                                              -1);
    }

  HAVE_LOCK_CHECK (connection);
  _dbus_verbose ("middle\n");
  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  HAVE_LOCK_CHECK (connection);
  return status;
}

void
dbus_connection_flush (DBusConnection *connection)
{
  /* We have to specify DBUS_ITERATION_DO_READING here because
   * otherwise we could have two apps deadlock if they are both doing
   * a flush(), and the kernel buffers fill up. This could change the
   * dispatch status.
   */
  DBusDispatchStatus status;

  _dbus_return_if_fail (connection != NULL);
  
  CONNECTION_LOCK (connection);

  status = _dbus_connection_flush_unlocked (connection);
  
  HAVE_LOCK_CHECK (connection);
  /* Unlocks and calls out to user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);

  _dbus_verbose ("end\n");
}

static dbus_bool_t
_dbus_connection_read_write_dispatch (DBusConnection *connection,
                                     int             timeout_milliseconds, 
                                     dbus_bool_t     dispatch)
{
  DBusDispatchStatus dstatus;
  dbus_bool_t progress_possible;

  /* Need to grab a ref here in case we're a private connection and
   * the user drops the last ref in a handler we call; see bug 
   * https://bugs.freedesktop.org/show_bug.cgi?id=15635
   */
  dbus_connection_ref (connection);
  dstatus = dbus_connection_get_dispatch_status (connection);

  if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS)
    {
      _dbus_verbose ("doing dispatch\n");
      dbus_connection_dispatch (connection);
      CONNECTION_LOCK (connection);
    }
  else if (dstatus == DBUS_DISPATCH_NEED_MEMORY)
    {
      _dbus_verbose ("pausing for memory\n");
      _dbus_memory_pause_based_on_timeout (timeout_milliseconds);
      CONNECTION_LOCK (connection);
    }
  else
    {
      CONNECTION_LOCK (connection);
      if (_dbus_connection_get_is_connected_unlocked (connection))
        {
          _dbus_verbose ("doing iteration\n");
          _dbus_connection_do_iteration_unlocked (connection,
                                                  NULL,
                                                  DBUS_ITERATION_DO_READING |
                                                  DBUS_ITERATION_DO_WRITING |
                                                  DBUS_ITERATION_BLOCK,
                                                  timeout_milliseconds);
        }
    }
  
  HAVE_LOCK_CHECK (connection);
  /* If we can dispatch, we can make progress until the Disconnected message
   * has been processed; if we can only read/write, we can make progress
   * as long as the transport is open.
   */
  if (dispatch)
    progress_possible = connection->n_incoming != 0 ||
      connection->disconnect_message_link != NULL;
  else
    progress_possible = _dbus_connection_get_is_connected_unlocked (connection);

  CONNECTION_UNLOCK (connection);

  dbus_connection_unref (connection);

  return progress_possible; /* TRUE if we can make more progress */
}


dbus_bool_t
dbus_connection_read_write_dispatch (DBusConnection *connection,
                                     int             timeout_milliseconds)
{
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
   return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, TRUE);
}

dbus_bool_t 
dbus_connection_read_write (DBusConnection *connection, 
                            int             timeout_milliseconds) 
{ 
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
   return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE);
}

/* We need to call this anytime we pop the head of the queue, and then
 * update_dispatch_status_and_unlock needs to be called afterward
 * which will "process" the disconnected message and set
 * disconnected_message_processed.
 */
static void
check_disconnected_message_arrived_unlocked (DBusConnection *connection,
                                             DBusMessage    *head_of_queue)
{
  HAVE_LOCK_CHECK (connection);

  /* checking that the link is NULL is an optimization to avoid the is_signal call */
  if (connection->disconnect_message_link == NULL &&
      dbus_message_is_signal (head_of_queue,
                              DBUS_INTERFACE_LOCAL,
                              "Disconnected"))
    {
      connection->disconnected_message_arrived = TRUE;
    }
}

DBusMessage*
dbus_connection_borrow_message (DBusConnection *connection)
{
  DBusDispatchStatus status;
  DBusMessage *message;

  _dbus_return_val_if_fail (connection != NULL, NULL);

  _dbus_verbose ("start\n");
  
  /* this is called for the side effect that it queues
   * up any messages from the transport
   */
  status = dbus_connection_get_dispatch_status (connection);
  if (status != DBUS_DISPATCH_DATA_REMAINS)
    return NULL;
  
  CONNECTION_LOCK (connection);

  _dbus_connection_acquire_dispatch (connection);

  /* While a message is outstanding, the dispatch lock is held */
  _dbus_assert (connection->message_borrowed == NULL);

  connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages);
  
  message = connection->message_borrowed;

  check_disconnected_message_arrived_unlocked (connection, message);
  
  /* Note that we KEEP the dispatch lock until the message is returned */
  if (message == NULL)
    _dbus_connection_release_dispatch (connection);

  CONNECTION_UNLOCK (connection);

  /* We don't update dispatch status until it's returned or stolen */
  
  return message;
}

void
dbus_connection_return_message (DBusConnection *connection,
                                DBusMessage    *message)
{
  DBusDispatchStatus status;
  
  _dbus_return_if_fail (connection != NULL);
  _dbus_return_if_fail (message != NULL);
  _dbus_return_if_fail (message == connection->message_borrowed);
  _dbus_return_if_fail (connection->dispatch_acquired);
  
  CONNECTION_LOCK (connection);
  
  _dbus_assert (message == connection->message_borrowed);
  
  connection->message_borrowed = NULL;

  _dbus_connection_release_dispatch (connection); 

  status = _dbus_connection_get_dispatch_status_unlocked (connection);
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
}

void
dbus_connection_steal_borrowed_message (DBusConnection *connection,
                                        DBusMessage    *message)
{
  DBusMessage *pop_message;
  DBusDispatchStatus status;

  _dbus_return_if_fail (connection != NULL);
  _dbus_return_if_fail (message != NULL);
  _dbus_return_if_fail (message == connection->message_borrowed);
  _dbus_return_if_fail (connection->dispatch_acquired);
  
  CONNECTION_LOCK (connection);
 
  _dbus_assert (message == connection->message_borrowed);

  pop_message = _dbus_list_pop_first (&connection->incoming_messages);
  _dbus_assert (message == pop_message);
  (void) pop_message; /* unused unless asserting */

  connection->n_incoming -= 1;
 
  _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
                 message, connection->n_incoming);
 
  connection->message_borrowed = NULL;

  _dbus_connection_release_dispatch (connection);

  status = _dbus_connection_get_dispatch_status_unlocked (connection);
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
}

/* See dbus_connection_pop_message, but requires the caller to own
 * the lock before calling. May drop the lock while running.
 */
static DBusList*
_dbus_connection_pop_message_link_unlocked (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  
  _dbus_assert (connection->message_borrowed == NULL);
  
  if (connection->n_incoming > 0)
    {
      DBusList *link;

      link = _dbus_list_pop_first_link (&connection->incoming_messages);
      connection->n_incoming -= 1;

      _dbus_verbose ("Message %p (%s %s %s %s '%s') removed from incoming queue %p, %d incoming\n",
                     link->data,
                     dbus_message_type_to_string (dbus_message_get_type (link->data)),
                     dbus_message_get_path (link->data) ?
                     dbus_message_get_path (link->data) :
                     "no path",
                     dbus_message_get_interface (link->data) ?
                     dbus_message_get_interface (link->data) :
                     "no interface",
                     dbus_message_get_member (link->data) ?
                     dbus_message_get_member (link->data) :
                     "no member",
                     dbus_message_get_signature (link->data),
                     connection, connection->n_incoming);

      check_disconnected_message_arrived_unlocked (connection, link->data);
      
      return link;
    }
  else
    return NULL;
}

/* See dbus_connection_pop_message, but requires the caller to own
 * the lock before calling. May drop the lock while running.
 */
static DBusMessage*
_dbus_connection_pop_message_unlocked (DBusConnection *connection)
{
  DBusList *link;

  HAVE_LOCK_CHECK (connection);
  
  link = _dbus_connection_pop_message_link_unlocked (connection);

  if (link != NULL)
    {
      DBusMessage *message;
      
      message = link->data;
      
      _dbus_list_free_link (link);
      
      return message;
    }
  else
    return NULL;
}

static void
_dbus_connection_putback_message_link_unlocked (DBusConnection *connection,
                                                DBusList       *message_link)
{
  HAVE_LOCK_CHECK (connection);
  
  _dbus_assert (message_link != NULL);
  /* You can't borrow a message while a link is outstanding */
  _dbus_assert (connection->message_borrowed == NULL);
  /* We had to have the dispatch lock across the pop/putback */
  _dbus_assert (connection->dispatch_acquired);

  _dbus_list_prepend_link (&connection->incoming_messages,
                           message_link);
  connection->n_incoming += 1;

  _dbus_verbose ("Message %p (%s %s %s '%s') put back into queue %p, %d incoming\n",
                 message_link->data,
                 dbus_message_type_to_string (dbus_message_get_type (message_link->data)),
                 dbus_message_get_interface (message_link->data) ?
                 dbus_message_get_interface (message_link->data) :
                 "no interface",
                 dbus_message_get_member (message_link->data) ?
                 dbus_message_get_member (message_link->data) :
                 "no member",
                 dbus_message_get_signature (message_link->data),
                 connection, connection->n_incoming);
}

DBusMessage*
dbus_connection_pop_message (DBusConnection *connection)
{
  DBusMessage *message;
  DBusDispatchStatus status;

  _dbus_verbose ("start\n");
  
  /* this is called for the side effect that it queues
   * up any messages from the transport
   */
  status = dbus_connection_get_dispatch_status (connection);
  if (status != DBUS_DISPATCH_DATA_REMAINS)
    return NULL;
  
  CONNECTION_LOCK (connection);
  _dbus_connection_acquire_dispatch (connection);
  HAVE_LOCK_CHECK (connection);
  
  message = _dbus_connection_pop_message_unlocked (connection);

  _dbus_verbose ("Returning popped message %p\n", message);    

  _dbus_connection_release_dispatch (connection);

  status = _dbus_connection_get_dispatch_status_unlocked (connection);
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
  
  return message;
}

static void
_dbus_connection_acquire_dispatch (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);

  _dbus_connection_ref_unlocked (connection);
  CONNECTION_UNLOCK (connection);
  
  _dbus_verbose ("locking dispatch_mutex\n");
  _dbus_mutex_lock (connection->dispatch_mutex);

  while (connection->dispatch_acquired)
    {
      _dbus_verbose ("waiting for dispatch to be acquirable\n");
      _dbus_condvar_wait (connection->dispatch_cond, 
                          connection->dispatch_mutex);
    }
  
  _dbus_assert (!connection->dispatch_acquired);

  connection->dispatch_acquired = TRUE;

  _dbus_verbose ("unlocking dispatch_mutex\n");
  _dbus_mutex_unlock (connection->dispatch_mutex);
  
  CONNECTION_LOCK (connection);
  _dbus_connection_unref_unlocked (connection);
}

static void
_dbus_connection_release_dispatch (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  
  _dbus_verbose ("locking dispatch_mutex\n");
  _dbus_mutex_lock (connection->dispatch_mutex);
  
  _dbus_assert (connection->dispatch_acquired);

  connection->dispatch_acquired = FALSE;
  _dbus_condvar_wake_one (connection->dispatch_cond);

  _dbus_verbose ("unlocking dispatch_mutex\n");
  _dbus_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;
}

/* Note this may be called multiple times since we don't track whether we already did it */
static void
notify_disconnected_unlocked (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);

  /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected
   * connection from dbus_bus_get(). We make the same guarantee for
   * dbus_connection_open() but in a different way since we don't want to
   * unref right here; we instead check for connectedness before returning
   * the connection from the hash.
   */
  _dbus_bus_notify_shared_connection_disconnected_unlocked (connection);

  /* Dump the outgoing queue, we aren't going to be able to
   * send it now, and we'd like accessors like
   * dbus_connection_get_outgoing_size() to be accurate.
   */
  if (connection->n_outgoing > 0)
    {
      DBusList *link;
      
      _dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n",
                     connection->n_outgoing);
      
      while ((link = _dbus_list_get_last_link (&connection->outgoing_messages)))
        {
          _dbus_connection_message_sent_unlocked (connection, link->data);
        }
    } 
}

/* Note this may be called multiple times since we don't track whether we already did it */
static DBusDispatchStatus
notify_disconnected_and_dispatch_complete_unlocked (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  
  if (connection->disconnect_message_link != NULL)
    {
      _dbus_verbose ("Sending disconnect message\n");
      
      /* If we have pending calls, queue their timeouts - we want the Disconnected
       * to be the last message, after these timeouts.
       */
      connection_timeout_and_complete_all_pending_calls_unlocked (connection);
      
      /* We haven't sent the disconnect message already,
       * and all real messages have been queued up.
       */
      _dbus_connection_queue_synthesized_message_link (connection,
                                                       connection->disconnect_message_link);
      connection->disconnect_message_link = NULL;

      return DBUS_DISPATCH_DATA_REMAINS;
    }

  return DBUS_DISPATCH_COMPLETE;
}

static DBusDispatchStatus
_dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
{
  HAVE_LOCK_CHECK (connection);
  
  if (connection->n_incoming > 0)
    return DBUS_DISPATCH_DATA_REMAINS;
  else if (!_dbus_transport_queue_messages (connection->transport))
    return DBUS_DISPATCH_NEED_MEMORY;
  else
    {
      DBusDispatchStatus status;
      dbus_bool_t is_connected;
      
      status = _dbus_transport_get_dispatch_status (connection->transport);
      is_connected = _dbus_transport_get_is_connected (connection->transport);

      _dbus_verbose ("dispatch status = %s is_connected = %d\n",
                     DISPATCH_STATUS_NAME (status), is_connected);
      
      if (!is_connected)
        {
          /* It's possible this would be better done by having an explicit
           * notification from _dbus_transport_disconnect() that would
           * synchronously do this, instead of waiting for the next dispatch
           * status check. However, probably not good to change until it causes
           * a problem.
           */
          notify_disconnected_unlocked (connection);

          /* I'm not sure this is needed; the idea is that we want to
           * queue the Disconnected only after we've read all the
           * messages, but if we're disconnected maybe we are guaranteed
           * to have read them all ?
           */
          if (status == DBUS_DISPATCH_COMPLETE)
            status = notify_disconnected_and_dispatch_complete_unlocked (connection);
        }
      
      if (status != DBUS_DISPATCH_COMPLETE)
        return status;
      else if (connection->n_incoming > 0)
        return DBUS_DISPATCH_DATA_REMAINS;
      else
        return DBUS_DISPATCH_COMPLETE;
    }
}

static void
_dbus_connection_update_dispatch_status_and_unlock (DBusConnection    *connection,
                                                    DBusDispatchStatus new_status)
{
  dbus_bool_t changed;
  DBusDispatchStatusFunction function;
  void *data;

  HAVE_LOCK_CHECK (connection);

  _dbus_connection_ref_unlocked (connection);

  changed = new_status != connection->last_dispatch_status;

  connection->last_dispatch_status = new_status;

  function = connection->dispatch_status_function;
  data = connection->dispatch_status_data;

  if (connection->disconnected_message_arrived &&
      !connection->disconnected_message_processed)
    {
      connection->disconnected_message_processed = TRUE;
      
      /* this does an unref, but we have a ref
       * so we should not run the finalizer here
       * inside the lock.
       */
      connection_forget_shared_unlocked (connection);

      if (connection->exit_on_disconnect)
        {
          CONNECTION_UNLOCK (connection);            
          
          _dbus_verbose ("Exiting on Disconnected signal\n");
          _dbus_exit (1);
          _dbus_assert_not_reached ("Call to exit() returned");
        }
    }
  
  /* We drop the lock */
  CONNECTION_UNLOCK (connection);
  
  if (changed && function)
    {
      _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n",
                     connection, new_status,
                     DISPATCH_STATUS_NAME (new_status));
      (* function) (connection, new_status, data);      
    }
  
  dbus_connection_unref (connection);
}

DBusDispatchStatus
dbus_connection_get_dispatch_status (DBusConnection *connection)
{
  DBusDispatchStatus status;

  _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);

  _dbus_verbose ("start\n");
  
  CONNECTION_LOCK (connection);

  status = _dbus_connection_get_dispatch_status_unlocked (connection);
  
  CONNECTION_UNLOCK (connection);

  return status;
}

static DBusHandlerResult
_dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection,
                                                 DBusMessage    *message)
{
  dbus_bool_t sent = FALSE;
  DBusMessage *ret = NULL;
  DBusList *expire_link;

  if (connection->route_peer_messages && dbus_message_get_destination (message) != NULL)
    {
      /* This means we're letting the bus route this message */
      return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
    }

  if (!dbus_message_has_interface (message, DBUS_INTERFACE_PEER))
    {
      return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
    }

  /* Preallocate a linked-list link, so that if we need to dispose of a
   * message, we can attach it to the expired list */
  expire_link = _dbus_list_alloc_link (NULL);

  if (!expire_link)
    return DBUS_HANDLER_RESULT_NEED_MEMORY;

  if (dbus_message_is_method_call (message,
                                   DBUS_INTERFACE_PEER,
                                   "Ping"))
    {
      ret = dbus_message_new_method_return (message);
      if (ret == NULL)
        goto out;

      sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
    }
  else if (dbus_message_is_method_call (message,
                                        DBUS_INTERFACE_PEER,
                                        "GetMachineId"))
    {
      DBusString uuid;
      
      ret = dbus_message_new_method_return (message);
      if (ret == NULL)
        goto out;

      _dbus_string_init (&uuid);
      if (_dbus_get_local_machine_uuid_encoded (&uuid))
        {
          const char *v_STRING = _dbus_string_get_const_data (&uuid);
          if (dbus_message_append_args (ret,
                                        DBUS_TYPE_STRING, &v_STRING,
                                        DBUS_TYPE_INVALID))
            {
              sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
            }
        }
      _dbus_string_free (&uuid);
    }
  else
    {
      /* We need to bounce anything else with this interface, otherwise apps
       * could start extending the interface and when we added extensions
       * here to DBusConnection we'd break those apps.
       */
      ret = dbus_message_new_error (message,
                                    DBUS_ERROR_UNKNOWN_METHOD,
                                    "Unknown method invoked on org.freedesktop.DBus.Peer interface");
      if (ret == NULL)
        goto out;

      sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
    }

out:
  if (ret == NULL)
    {
      _dbus_list_free_link (expire_link);
    }
  else
    {
      /* It'll be safe to unref the reply when we unlock */
      expire_link->data = ret;
      _dbus_list_prepend_link (&connection->expired_messages, expire_link);
    }

  if (!sent)
    return DBUS_HANDLER_RESULT_NEED_MEMORY;

  return DBUS_HANDLER_RESULT_HANDLED;
}

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);
}

DBusDispatchStatus
dbus_connection_dispatch (DBusConnection *connection)
{
  DBusMessage *message;
  DBusList *link, *filter_list_copy, *message_link;
  DBusHandlerResult result;
  DBusPendingCall *pending;
  dbus_int32_t reply_serial;
  DBusDispatchStatus status;
  dbus_bool_t found_object;

  _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);

  _dbus_verbose ("\n");
  
  CONNECTION_LOCK (connection);
  status = _dbus_connection_get_dispatch_status_unlocked (connection);
  if (status != DBUS_DISPATCH_DATA_REMAINS)
    {
      /* unlocks and calls out to user code */
      _dbus_connection_update_dispatch_status_and_unlock (connection, status);
      return status;
    }
  
  /* We need to ref the connection since the callback could potentially
   * drop the last ref to it
   */
  _dbus_connection_ref_unlocked (connection);

  _dbus_connection_acquire_dispatch (connection);
  HAVE_LOCK_CHECK (connection);

  message_link = _dbus_connection_pop_message_link_unlocked (connection);
  if (message_link == NULL)
    {
      /* another thread dispatched our stuff */

      _dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n");
      
      _dbus_connection_release_dispatch (connection);

      status = _dbus_connection_get_dispatch_status_unlocked (connection);

      _dbus_connection_update_dispatch_status_and_unlock (connection, status);
      
      dbus_connection_unref (connection);
      
      return status;
    }

  message = message_link->data;

  _dbus_verbose (" dispatching message %p (%s %s %s '%s')\n",
                 message,
                 dbus_message_type_to_string (dbus_message_get_type (message)),
                 dbus_message_get_interface (message) ?
                 dbus_message_get_interface (message) :
                 "no interface",
                 dbus_message_get_member (message) ?
                 dbus_message_get_member (message) :
                 "no member",
                 dbus_message_get_signature (message));

  result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
  
  /* Pending call handling must be first, because if you do
   * dbus_connection_send_with_reply_and_block() or
   * dbus_pending_call_block() then no handlers/filters will be run on
   * the reply. We want consistent semantics in the case where we
   * dbus_connection_dispatch() the reply.
   */
  
  reply_serial = dbus_message_get_reply_serial (message);
  pending = _dbus_hash_table_lookup_int (connection->pending_replies,
                                         reply_serial);
  if (pending)
    {
      _dbus_verbose ("Dispatching a pending reply\n");
      complete_pending_call_and_unlock (connection, pending, message);
      pending = NULL; /* it's probably unref'd */
      
      CONNECTION_LOCK (connection);
      _dbus_verbose ("pending call completed in dispatch\n");
      result = DBUS_HANDLER_RESULT_HANDLED;
      goto out;
    }

  result = _dbus_connection_run_builtin_filters_unlocked_no_update (connection, message);
  if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
    goto out;
 
  if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy))
    {
      _dbus_connection_release_dispatch (connection);
      HAVE_LOCK_CHECK (connection);
      
      _dbus_connection_failed_pop (connection, message_link);

      /* unlocks and calls user code */
      _dbus_connection_update_dispatch_status_and_unlock (connection,
                                                          DBUS_DISPATCH_NEED_MEMORY);
      dbus_connection_unref (connection);
      
      return DBUS_DISPATCH_NEED_MEMORY;
    }
  
  _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);

      if (filter->function == NULL)
        {
          _dbus_verbose ("  filter was removed in a callback function\n");
          link = next;
          continue;
        }

      _dbus_verbose ("  running filter on message %p\n", message);
      result = (* filter->function) (connection, message, filter->user_data);

      if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
        break;

      link = next;
    }

  _dbus_list_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\n");
      goto out;
    }
  else if (result == DBUS_HANDLER_RESULT_HANDLED)
    {
      _dbus_verbose ("filter handled message in dispatch\n");
      goto out;
    }

  /* We're still protected from dispatch() reentrancy here
   * since we acquired the dispatcher
   */
  _dbus_verbose ("  running object path dispatch on message %p (%s %s %s '%s')\n",
                 message,
                 dbus_message_type_to_string (dbus_message_get_type (message)),
                 dbus_message_get_interface (message) ?
                 dbus_message_get_interface (message) :
                 "no interface",
                 dbus_message_get_member (message) ?
                 dbus_message_get_member (message) :
                 "no member",
                 dbus_message_get_signature (message));

  HAVE_LOCK_CHECK (connection);
  result = _dbus_object_tree_dispatch_and_unlock (connection->objects,
                                                  message,
                                                  &found_object);
  
  CONNECTION_LOCK (connection);

  if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
    {
      _dbus_verbose ("object tree handled message in dispatch\n");
      goto out;
    }

  if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL)
    {
      DBusMessage *reply;
      DBusString str;
      DBusPreallocatedSend *preallocated;
      DBusList *expire_link;

      _dbus_verbose ("  sending error %s\n",
                     DBUS_ERROR_UNKNOWN_METHOD);

      if (!_dbus_string_init (&str))
        {
          result = DBUS_HANDLER_RESULT_NEED_MEMORY;
          _dbus_verbose ("no memory for error string in dispatch\n");
          goto out;
        }
              
      if (!_dbus_string_append_printf (&str,
                                       "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n",
                                       dbus_message_get_member (message),
                                       dbus_message_get_signature (message),
                                       dbus_message_get_interface (message)))
        {
          _dbus_string_free (&str);
          result = DBUS_HANDLER_RESULT_NEED_MEMORY;
          _dbus_verbose ("no memory for error string in dispatch\n");
          goto out;
        }
      
      reply = dbus_message_new_error (message,
                                      found_object ? DBUS_ERROR_UNKNOWN_METHOD : DBUS_ERROR_UNKNOWN_OBJECT,
                                      _dbus_string_get_const_data (&str));
      _dbus_string_free (&str);

      if (reply == NULL)
        {
          result = DBUS_HANDLER_RESULT_NEED_MEMORY;
          _dbus_verbose ("no memory for error reply in dispatch\n");
          goto out;
        }

      expire_link = _dbus_list_alloc_link (reply);

      if (expire_link == NULL)
        {
          dbus_message_unref (reply);
          result = DBUS_HANDLER_RESULT_NEED_MEMORY;
          _dbus_verbose ("no memory for error send in dispatch\n");
          goto out;
        }

      preallocated = _dbus_connection_preallocate_send_unlocked (connection);

      if (preallocated == NULL)
        {
          _dbus_list_free_link (expire_link);
          /* It's OK that this is finalized, because it hasn't been seen by
           * anything that could attach user callbacks */
          dbus_message_unref (reply);
          result = DBUS_HANDLER_RESULT_NEED_MEMORY;
          _dbus_verbose ("no memory for error send in dispatch\n");
          goto out;
        }

      _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated,
                                                             reply, NULL);
      /* reply will be freed when we release the lock */
      _dbus_list_prepend_link (&connection->expired_messages, expire_link);

      result = DBUS_HANDLER_RESULT_HANDLED;
    }
  
  _dbus_verbose ("  done dispatching %p (%s %s %s '%s') on connection %p\n", message,
                 dbus_message_type_to_string (dbus_message_get_type (message)),
                 dbus_message_get_interface (message) ?
                 dbus_message_get_interface (message) :
                 "no interface",
                 dbus_message_get_member (message) ?
                 dbus_message_get_member (message) :
                 "no member",
                 dbus_message_get_signature (message),
                 connection);
  
 out:
  if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
    {
      _dbus_verbose ("out of memory\n");
      
      /* Put message back, and we'll start over.
       * Yes this means handlers must be idempotent if they
       * don't return HANDLED; c'est la vie.
       */
      _dbus_connection_putback_message_link_unlocked (connection,
                                                      message_link);
      /* now we don't want to free them */
      message_link = NULL;
      message = NULL;
    }
  else
    {
      _dbus_verbose (" ... done dispatching\n");
    }

  _dbus_connection_release_dispatch (connection);
  HAVE_LOCK_CHECK (connection);

  if (message != NULL)
    {
      /* We don't want this message to count in maximum message limits when
       * computing the dispatch status, below. We have to drop the lock
       * temporarily, because finalizing a message can trigger callbacks.
       *
       * We have a reference to the connection, and we don't use any cached
       * pointers to the connection's internals below this point, so it should
       * be safe to drop the lock and take it back. */
      CONNECTION_UNLOCK (connection);
      dbus_message_unref (message);
      CONNECTION_LOCK (connection);
    }

  if (message_link != NULL)
    _dbus_list_free_link (message_link);

  _dbus_verbose ("before final status update\n");
  status = _dbus_connection_get_dispatch_status_unlocked (connection);

  /* unlocks and calls user code */
  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
  
  dbus_connection_unref (connection);
  
  return status;
}

dbus_bool_t
dbus_connection_set_watch_functions (DBusConnection              *connection,
                                     DBusAddWatchFunction         add_function,
                                     DBusRemoveWatchFunction      remove_function,
                                     DBusWatchToggledFunction     toggled_function,
                                     void                        *data,
                                     DBusFreeFunction             free_data_function)
{
  dbus_bool_t retval;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  
  CONNECTION_LOCK (connection);

  retval = _dbus_watch_list_set_functions (connection->watches,
                                           add_function, remove_function,
                                           toggled_function,
                                           data, free_data_function);

  CONNECTION_UNLOCK (connection);

  return retval;
}

dbus_bool_t
dbus_connection_set_timeout_functions   (DBusConnection            *connection,
                                         DBusAddTimeoutFunction     add_function,
                                         DBusRemoveTimeoutFunction  remove_function,
                                         DBusTimeoutToggledFunction toggled_function,
                                         void                      *data,
                                         DBusFreeFunction           free_data_function)
{
  dbus_bool_t retval;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  
  CONNECTION_LOCK (connection);

  retval = _dbus_timeout_list_set_functions (connection->timeouts,
                                             add_function, remove_function,
                                             toggled_function,
                                             data, free_data_function);

  CONNECTION_UNLOCK (connection);

  return retval;
}

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);
}

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);
}

dbus_bool_t
dbus_connection_get_unix_fd (DBusConnection *connection,
                             int            *fd)
{
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (connection->transport != NULL, FALSE);

#ifdef DBUS_WIN
  /* FIXME do this on a lower level */
  return FALSE;
#endif
  
  return dbus_connection_get_socket(connection, fd);
}

dbus_bool_t
dbus_connection_get_socket(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_socket_fd (connection->transport,
                                          fd);

  CONNECTION_UNLOCK (connection);

  return retval;
}


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);

#ifdef DBUS_WIN
  _dbus_assert (!result);
#endif
  
  CONNECTION_UNLOCK (connection);

  return result;
}

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;
}

dbus_bool_t
dbus_connection_get_adt_audit_session_data (DBusConnection *connection,
                                            void          **data,
                                            dbus_int32_t   *data_size)
{
  dbus_bool_t result;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (data != NULL, FALSE);
  _dbus_return_val_if_fail (data_size != NULL, FALSE);
  
  CONNECTION_LOCK (connection);

  if (!_dbus_transport_get_is_authenticated (connection->transport))
    result = FALSE;
  else
    result = _dbus_transport_get_adt_audit_session_data (connection->transport,
                                                         data,
                                                         data_size);
  CONNECTION_UNLOCK (connection);

  return result;
}

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);
}

dbus_bool_t
dbus_connection_get_windows_user (DBusConnection             *connection,
                                  char                      **windows_sid_p)
{
  dbus_bool_t result;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (windows_sid_p != NULL, FALSE);
  
  CONNECTION_LOCK (connection);

  if (!_dbus_transport_get_is_authenticated (connection->transport))
    result = FALSE;
  else
    result = _dbus_transport_get_windows_user (connection->transport,
                                               windows_sid_p);

#ifdef DBUS_UNIX
  _dbus_assert (!result);
#endif
  
  CONNECTION_UNLOCK (connection);

  return result;
}

void
dbus_connection_set_windows_user_function (DBusConnection              *connection,
                                           DBusAllowWindowsUserFunction function,
                                           void                        *data,
                                           DBusFreeFunction             free_data_function)
{
  void *old_data = NULL;
  DBusFreeFunction old_free_function = NULL;

  _dbus_return_if_fail (connection != NULL);
  
  CONNECTION_LOCK (connection);
  _dbus_transport_set_windows_user_function (connection->transport,
                                             function, data, free_data_function,
                                             &old_data, &old_free_function);
  CONNECTION_UNLOCK (connection);

  if (old_free_function != NULL)
    (* old_free_function) (old_data);
}

void
dbus_connection_set_allow_anonymous (DBusConnection             *connection,
                                     dbus_bool_t                 value)
{
  _dbus_return_if_fail (connection != NULL);
  
  CONNECTION_LOCK (connection);
  _dbus_transport_set_allow_anonymous (connection->transport, value);
  CONNECTION_UNLOCK (connection);
}

void
dbus_connection_set_route_peer_messages (DBusConnection             *connection,
                                         dbus_bool_t                 value)
{
  _dbus_return_if_fail (connection != NULL);
  
  CONNECTION_LOCK (connection);
  connection->route_peer_messages = TRUE;
  CONNECTION_UNLOCK (connection);
}

dbus_bool_t
dbus_connection_add_filter (DBusConnection            *connection,
                            DBusHandleMessageFunction  function,
                            void                      *user_data,
                            DBusFreeFunction           free_data_function)
{
  DBusMessageFilter *filter;
  
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (function != NULL, FALSE);

  filter = dbus_new0 (DBusMessageFilter, 1);
  if (filter == NULL)
    return FALSE;

  _dbus_atomic_inc (&filter->refcount);

  CONNECTION_LOCK (connection);

  if (!_dbus_list_append (&connection->filter_list,
                          filter))
    {
      _dbus_message_filter_unref (filter);
      CONNECTION_UNLOCK (connection);
      return FALSE;
    }

  /* Fill in filter after all memory allocated,
   * so we don't run the free_user_data_function
   * if the add_filter() fails
   */
  
  filter->function = function;
  filter->user_data = user_data;
  filter->free_user_data_function = free_data_function;
        
  CONNECTION_UNLOCK (connection);
  return TRUE;
}

void
dbus_connection_remove_filter (DBusConnection            *connection,
                               DBusHandleMessageFunction  function,
                               void                      *user_data)
{
  DBusList *link;
  DBusMessageFilter *filter;
  
  _dbus_return_if_fail (connection != NULL);
  _dbus_return_if_fail (function != NULL);
  
  CONNECTION_LOCK (connection);

  filter = NULL;
  
  link = _dbus_list_get_last_link (&connection->filter_list);
  while (link != NULL)
    {
      filter = link->data;

      if (filter->function == function &&
          filter->user_data == user_data)
        {
          _dbus_list_remove_link (&connection->filter_list, link);
          filter->function = NULL;
          
          break;
        }
        
      link = _dbus_list_get_prev_link (&connection->filter_list, link);
      filter = NULL;
    }
  
  CONNECTION_UNLOCK (connection);

#ifndef DBUS_DISABLE_CHECKS
  if (filter == NULL)
    {
      _dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added\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);
}

static dbus_bool_t
_dbus_connection_register_object_path (DBusConnection              *connection,
                                       dbus_bool_t                  fallback,
                                       const char                  *path,
                                       const DBusObjectPathVTable  *vtable,
                                       void                        *user_data,
                                       DBusError                   *error)
{
  char **decomposed_path;
  dbus_bool_t retval;

  if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
    return FALSE;

  CONNECTION_LOCK (connection);

  retval = _dbus_object_tree_register (connection->objects,
                                       fallback,
                                       (const char **) decomposed_path, vtable,
                                       user_data, error);

  CONNECTION_UNLOCK (connection);

  dbus_free_string_array (decomposed_path);

  return retval;
}

dbus_bool_t
dbus_connection_try_register_object_path (DBusConnection              *connection,
                                          const char                  *path,
                                          const DBusObjectPathVTable  *vtable,
                                          void                        *user_data,
                                          DBusError                   *error)
{
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (path != NULL, FALSE);
  _dbus_return_val_if_fail (path[0] == '/', FALSE);
  _dbus_return_val_if_fail (vtable != NULL, FALSE);

  return _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, error);
}

dbus_bool_t
dbus_connection_register_object_path (DBusConnection              *connection,
                                      const char                  *path,
                                      const DBusObjectPathVTable  *vtable,
                                      void                        *user_data)
{
  dbus_bool_t retval;
  DBusError error = DBUS_ERROR_INIT;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (path != NULL, FALSE);
  _dbus_return_val_if_fail (path[0] == '/', FALSE);
  _dbus_return_val_if_fail (vtable != NULL, FALSE);

  retval = _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, &error);

  if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE))
    {
      _dbus_warn ("%s\n", error.message);
      dbus_error_free (&error);
      return FALSE;
    }

  return retval;
}

dbus_bool_t
dbus_connection_try_register_fallback (DBusConnection              *connection,
                                       const char                  *path,
                                       const DBusObjectPathVTable  *vtable,
                                       void                        *user_data,
                                       DBusError                   *error)
{
  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (path != NULL, FALSE);
  _dbus_return_val_if_fail (path[0] == '/', FALSE);
  _dbus_return_val_if_fail (vtable != NULL, FALSE);

  return _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, error);
}

dbus_bool_t
dbus_connection_register_fallback (DBusConnection              *connection,
                                   const char                  *path,
                                   const DBusObjectPathVTable  *vtable,
                                   void                        *user_data)
{
  dbus_bool_t retval;
  DBusError error = DBUS_ERROR_INIT;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (path != NULL, FALSE);
  _dbus_return_val_if_fail (path[0] == '/', FALSE);
  _dbus_return_val_if_fail (vtable != NULL, FALSE);

  retval = _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, &error);

  if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE))
    {
      _dbus_warn ("%s\n", error.message);
      dbus_error_free (&error);
      return FALSE;
    }

  return retval;
}

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;
}

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;
}

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);

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);
}

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);
}

dbus_bool_t
dbus_connection_set_data (DBusConnection   *connection,
                          dbus_int32_t      slot,
                          void             *data,
                          DBusFreeFunction  free_data_func)
{
  DBusFreeFunction old_free_func;
  void *old_data;
  dbus_bool_t retval;

  _dbus_return_val_if_fail (connection != NULL, FALSE);
  _dbus_return_val_if_fail (slot >= 0, FALSE);
  
  SLOTS_LOCK (connection);

  retval = _dbus_data_slot_list_set (&slot_allocator,
                                     &connection->slot_list,
                                     slot, data, free_data_func,
                                     &old_free_func, &old_data);
  
  SLOTS_UNLOCK (connection);

  if (retval)
    {
      /* Do the actual free outside the connection lock */
      if (old_free_func)
        (* old_free_func) (old_data);
    }

  return retval;
}

void*
dbus_connection_get_data (DBusConnection   *connection,
                          dbus_int32_t      slot)
{
  void *res;

  _dbus_return_val_if_fail (connection != NULL, NULL);
  
  SLOTS_LOCK (connection);

  res = _dbus_data_slot_list_get (&slot_allocator,
                                  &connection->slot_list,
                                  slot);
  
  SLOTS_UNLOCK (connection);

  return res;
}

void
dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
{  
  _dbus_modify_sigpipe = will_modify_sigpipe != FALSE;
}

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);
}

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;
}

void
dbus_connection_set_max_message_unix_fds (DBusConnection *connection,
                                          long            n)
{
  _dbus_return_if_fail (connection != NULL);

  CONNECTION_LOCK (connection);
  _dbus_transport_set_max_message_unix_fds (connection->transport,
                                            n);
  CONNECTION_UNLOCK (connection);
}

long
dbus_connection_get_max_message_unix_fds (DBusConnection *connection)
{
  long res;

  _dbus_return_val_if_fail (connection != NULL, 0);

  CONNECTION_LOCK (connection);
  res = _dbus_transport_get_max_message_unix_fds (connection->transport);
  CONNECTION_UNLOCK (connection);
  return res;
}

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);
}

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;
}

void
dbus_connection_set_max_received_unix_fds (DBusConnection *connection,
                                           long            n)
{
  _dbus_return_if_fail (connection != NULL);

  CONNECTION_LOCK (connection);
  _dbus_transport_set_max_received_unix_fds (connection->transport,
                                             n);
  CONNECTION_UNLOCK (connection);
}

long
dbus_connection_get_max_received_unix_fds (DBusConnection *connection)
{
  long res;

  _dbus_return_val_if_fail (connection != NULL, 0);

  CONNECTION_LOCK (connection);
  res = _dbus_transport_get_max_received_unix_fds (connection->transport);
  CONNECTION_UNLOCK (connection);
  return res;
}

long
dbus_connection_get_outgoing_size (DBusConnection *connection)
{
  long res;

  _dbus_return_val_if_fail (connection != NULL, 0);

  CONNECTION_LOCK (connection);
  res = _dbus_counter_get_size_value (connection->outgoing_counter);
  CONNECTION_UNLOCK (connection);
  return res;
}

#ifdef DBUS_ENABLE_STATS
void
_dbus_connection_get_stats (DBusConnection *connection,
                            dbus_uint32_t  *in_messages,
                            dbus_uint32_t  *in_bytes,
                            dbus_uint32_t  *in_fds,
                            dbus_uint32_t  *in_peak_bytes,
                            dbus_uint32_t  *in_peak_fds,
                            dbus_uint32_t  *out_messages,
                            dbus_uint32_t  *out_bytes,
                            dbus_uint32_t  *out_fds,
                            dbus_uint32_t  *out_peak_bytes,
                            dbus_uint32_t  *out_peak_fds)
{
  CONNECTION_LOCK (connection);

  if (in_messages != NULL)
    *in_messages = connection->n_incoming;

  _dbus_transport_get_stats (connection->transport,
                             in_bytes, in_fds, in_peak_bytes, in_peak_fds);

  if (out_messages != NULL)
    *out_messages = connection->n_outgoing;

  if (out_bytes != NULL)
    *out_bytes = _dbus_counter_get_size_value (connection->outgoing_counter);

  if (out_fds != NULL)
    *out_fds = _dbus_counter_get_unix_fd_value (connection->outgoing_counter);

  if (out_peak_bytes != NULL)
    *out_peak_bytes = _dbus_counter_get_peak_size_value (connection->outgoing_counter);

  if (out_peak_fds != NULL)
    *out_peak_fds = _dbus_counter_get_peak_unix_fd_value (connection->outgoing_counter);

  CONNECTION_UNLOCK (connection);
}
#endif /* DBUS_ENABLE_STATS */

long
dbus_connection_get_outgoing_unix_fds (DBusConnection *connection)
{
  long res;

  _dbus_return_val_if_fail (connection != NULL, 0);

  CONNECTION_LOCK (connection);
  res = _dbus_counter_get_unix_fd_value (connection->outgoing_counter);
  CONNECTION_UNLOCK (connection);
  return res;
}