summaryrefslogtreecommitdiffstats
path: root/dbus/dbus-connection.c
blob: 4990cff30c6fdafa89042441ebf8be781213ccda (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
/* -*- mode: C; c-file-style: "gnu" -*- */
/* dbus-connection.c DBusConnection object
 *
 * Copyright (C) 2002, 2003  Red Hat Inc.
 *
 * Licensed under the Academic Free License version 1.2
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "dbus-connection.h"
#include "dbus-list.h"
#include "dbus-timeout.h"
#include "dbus-transport.h"
#include "dbus-watch.h"
#include "dbus-connection-internal.h"
#include "dbus-list.h"
#include "dbus-hash.h"
#include "dbus-message-internal.h"
#include "dbus-message-handler.h"
#include "dbus-threads.h"
#include "dbus-protocol.h"
#include "dbus-dataslot.h"

/**
 * @defgroup DBusConnection DBusConnection
 * @ingroup  DBus
 * @brief Connection to another application
 *
 * A DBusConnection represents a connection to another
 * application. Messages can be sent and received via this connection.
 *
 * The connection maintains a queue of incoming messages and a queue
 * of outgoing messages. dbus_connection_pop_message() and friends
 * can be used to read incoming messages from the queue.
 * Outgoing messages are automatically discarded as they are
 * written to the network.
 *
 * In brief a DBusConnection is a message queue associated with some
 * message transport mechanism such as a socket.
 * 
 */

/**
 * @defgroup DBusConnectionInternals DBusConnection implementation details
 * @ingroup  DBusInternals
 * @brief Implementation details of DBusConnection
 *
 * @{
 */

/** default timeout value when waiting for a message reply */
#define DEFAULT_TIMEOUT_VALUE (15 * 1000)

static dbus_bool_t _dbus_modify_sigpipe = TRUE;

/**
 * Implementation details of DBusConnection. All fields are private.
 */
struct DBusConnection
{
  int refcount; /**< Reference count. */

  DBusMutex *mutex; /**< Lock on the entire DBusConnection */

  dbus_bool_t dispatch_acquired; /**< Protects dispatch_message */
  DBusCondVar *dispatch_cond;    /**< Protects dispatch_message */

  dbus_bool_t io_path_acquired;  /**< Protects transport io path */
  DBusCondVar *io_path_cond;     /**< Protects transport io path */
  
  DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
  DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */

  DBusMessage *message_borrowed; /**< True if the first incoming message has been borrowed */
  DBusCondVar *message_returned_cond; /**< Used with dbus_connection_borrow_message() */
  
  int n_outgoing;              /**< Length of outgoing queue. */
  int n_incoming;              /**< Length of incoming queue. */
  
  DBusTransport *transport;    /**< Object that sends/receives messages over network. */
  DBusWatchList *watches;      /**< Stores active watches. */
  DBusTimeoutList *timeouts;   /**< Stores active timeouts. */
  
  DBusHashTable *handler_table; /**< Table of registered DBusMessageHandler */
  DBusList *filter_list;        /**< List of filters. */

  DBusDataSlotList slot_list;   /**< Data stored by allocated integer ID */

  DBusHashTable *pending_replies;  /**< Hash of message serials and their message handlers. */  
  DBusCounter *connection_counter; /**< Counter that we decrement when finalized */
  
  int client_serial;            /**< Client serial. Increments each time a message is sent  */
  DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */

  DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop  */
  void *wakeup_main_data; /**< Application data for wakeup_main_function */
  DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */
};

typedef struct
{
  DBusConnection *connection;
  DBusMessageHandler *handler;
  DBusTimeout *timeout;
  int serial;

  DBusList *timeout_link; /* Preallocated timeout response */
  
  dbus_bool_t timeout_added;
  dbus_bool_t connection_added;
} ReplyHandlerData;

static void reply_handler_data_free (ReplyHandlerData *data);

static void _dbus_connection_remove_timeout_locked (DBusConnection *connection,
						    DBusTimeout    *timeout);

/**
 * Acquires the connection lock.
 *
 * @param connection the connection.
 */
void
_dbus_connection_lock (DBusConnection *connection)
{
  dbus_mutex_lock (connection->mutex);
}

/**
 * Releases the connection lock.
 *
 * @param connection the connection.
 */
void
_dbus_connection_unlock (DBusConnection *connection)
{
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Wakes up the main loop if it is sleeping
 * Needed if we're e.g. queueing outgoing messages
 * on a thread while the mainloop sleeps.
 *
 * @param connection the connection.
 */
static void
_dbus_connection_wakeup_mainloop (DBusConnection *connection)
{
  if (connection->wakeup_main_function)
    (*connection->wakeup_main_function) (connection->wakeup_main_data);
}

/**
 * Adds a message to the incoming message queue, returning #FALSE
 * if there's insufficient memory to queue the message.
 *
 * @param connection the connection.
 * @param message the message to queue.
 * @returns #TRUE on success.
 */
dbus_bool_t
_dbus_connection_queue_received_message (DBusConnection *connection,
                                         DBusMessage    *message)
{
  ReplyHandlerData *reply_handler_data;
  dbus_int32_t reply_serial;
  
  _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
  
  if (!_dbus_list_append (&connection->incoming_messages,
                          message))
    return FALSE;

  /* If this is a reply we're waiting on, remove timeout for it */
  reply_serial = _dbus_message_get_reply_serial (message);
  if (reply_serial != -1)
    {
      reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies,
							reply_serial);
      if (reply_handler_data != NULL)
	{
	  if (reply_handler_data->timeout_added)
	    _dbus_connection_remove_timeout_locked (connection,
						    reply_handler_data->timeout);
	  reply_handler_data->timeout_added = FALSE;
	}
    }
  
  dbus_message_ref (message);
  connection->n_incoming += 1;

  _dbus_connection_wakeup_mainloop (connection);
  
  _dbus_verbose ("Incoming message %p added to queue, %d incoming\n",
                 message, connection->n_incoming);
  
  return TRUE;
}

/**
 * Adds a link + message to the incoming message queue.
 * Can't fail. Takes ownership of both link and message.
 *
 * @param connection the connection.
 * @param link the list node and message to queue.
 *
 * @todo This needs to wake up the mainloop if it is in
 * a poll/select and this is a multithreaded app.
 */
static void
_dbus_connection_queue_synthesized_message_link (DBusConnection *connection,
						 DBusList *link)
{
  _dbus_list_append_link (&connection->incoming_messages, link);

  connection->n_incoming += 1;

  _dbus_connection_wakeup_mainloop (connection);
  
  _dbus_verbose ("Incoming synthesized message %p added to queue, %d incoming\n",
                 link->data, connection->n_incoming);
}


/**
 * Checks whether there are messages in the outgoing message queue.
 *
 * @param connection the connection.
 * @returns #TRUE if the outgoing queue is non-empty.
 */
dbus_bool_t
_dbus_connection_have_messages_to_send (DBusConnection *connection)
{
  return connection->outgoing_messages != NULL;
}

/**
 * Gets the next outgoing message. The message remains in the
 * queue, and the caller does not own a reference to it.
 *
 * @param connection the connection.
 * @returns the message to be sent.
 */ 
DBusMessage*
_dbus_connection_get_message_to_send (DBusConnection *connection)
{
  return _dbus_list_get_last (&connection->outgoing_messages);
}

/**
 * Notifies the connection that a message has been sent, so the
 * message can be removed from the outgoing queue.
 *
 * @param connection the connection.
 * @param message the message that was sent.
 */
void
_dbus_connection_message_sent (DBusConnection *connection,
                               DBusMessage    *message)
{
  _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
  _dbus_assert (message == _dbus_list_get_last (&connection->outgoing_messages));
  
  _dbus_list_pop_last (&connection->outgoing_messages);
  dbus_message_unref (message);
  
  connection->n_outgoing -= 1;

  _dbus_verbose ("Message %p removed from outgoing queue, %d left to send\n",
                 message, connection->n_outgoing);
  
  if (connection->n_outgoing == 0)
    _dbus_transport_messages_pending (connection->transport,
                                      connection->n_outgoing);  
}

/**
 * Adds a watch using the connection's DBusAddWatchFunction if
 * available. Otherwise records the watch to be added when said
 * function is available. Also re-adds the watch if the
 * DBusAddWatchFunction changes. May fail due to lack of memory.
 *
 * @param connection the connection.
 * @param watch the watch to add.
 * @returns #TRUE on success.
 */
dbus_bool_t
_dbus_connection_add_watch (DBusConnection *connection,
                            DBusWatch      *watch)
{
  if (connection->watches) /* null during finalize */
    return _dbus_watch_list_add_watch (connection->watches,
                                       watch);
  else
    return FALSE;
}

/**
 * Removes a watch using the connection's DBusRemoveWatchFunction
 * if available. It's an error to call this function on a watch
 * that was not previously added.
 *
 * @param connection the connection.
 * @param watch the watch to remove.
 */
void
_dbus_connection_remove_watch (DBusConnection *connection,
                               DBusWatch      *watch)
{
  if (connection->watches) /* null during finalize */
    _dbus_watch_list_remove_watch (connection->watches,
                                   watch);
}

/**
 * Adds a timeout using the connection's DBusAddTimeoutFunction if
 * available. Otherwise records the timeout to be added when said
 * function is available. Also re-adds the timeout if the
 * DBusAddTimeoutFunction changes. May fail due to lack of memory.
 *
 * @param connection the connection.
 * @param timeout the timeout to add.
 * @returns #TRUE on success.
 */
dbus_bool_t
_dbus_connection_add_timeout (DBusConnection *connection,
			      DBusTimeout    *timeout)
{
 if (connection->timeouts) /* null during finalize */
    return _dbus_timeout_list_add_timeout (connection->timeouts,
					   timeout);
  else
    return FALSE;  
}

/**
 * Removes a timeout using the connection's DBusRemoveTimeoutFunction
 * if available. It's an error to call this function on a timeout
 * that was not previously added.
 *
 * @param connection the connection.
 * @param timeout the timeout to remove.
 */
void
_dbus_connection_remove_timeout (DBusConnection *connection,
				 DBusTimeout    *timeout)
{
  if (connection->timeouts) /* null during finalize */
    _dbus_timeout_list_remove_timeout (connection->timeouts,
				       timeout);
}

static void
_dbus_connection_remove_timeout_locked (DBusConnection *connection,
					DBusTimeout    *timeout)
{
  dbus_mutex_lock (connection->mutex);
  _dbus_connection_remove_timeout (connection, timeout);
  dbus_mutex_unlock (connection->mutex);
}


/**
 * Tells the connection that the transport has been disconnected.
 * Results in posting a disconnect message on the incoming message
 * queue.  Only has an effect the first time it's called.
 *
 * @param connection the connection
 */
void
_dbus_connection_notify_disconnected (DBusConnection *connection)
{
  if (connection->disconnect_message_link)
    {
      /* We haven't sent the disconnect message already */
      _dbus_connection_queue_synthesized_message_link (connection,
						       connection->disconnect_message_link);
      connection->disconnect_message_link = NULL;
    }
}


/**
 * Acquire the transporter I/O path. This must be done before
 * doing any I/O in the transporter. May sleep and drop the
 * connection mutex while waiting for the I/O path.
 *
 * @param connection the connection.
 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
 * @returns TRUE if the I/O path was acquired.
 */
static dbus_bool_t
_dbus_connection_acquire_io_path (DBusConnection *connection,
				  int timeout_milliseconds)
{
  dbus_bool_t res = TRUE;

  if (connection->io_path_acquired)
    {
      if (timeout_milliseconds != -1) 
	res = dbus_condvar_wait_timeout (connection->io_path_cond,
					 connection->mutex,
					 timeout_milliseconds);
      else
	dbus_condvar_wait (connection->io_path_cond, connection->mutex);
    }
  
  if (res)
    {
      _dbus_assert (!connection->io_path_acquired);

      connection->io_path_acquired = TRUE;
    }
  
  return res;
}

/**
 * Release the I/O path when you're done with it. Only call
 * after you've acquired the I/O. Wakes up at most one thread
 * currently waiting to acquire the I/O path.
 *
 * @param connection the connection.
 */
static void
_dbus_connection_release_io_path (DBusConnection *connection)
{
  _dbus_assert (connection->io_path_acquired);

  connection->io_path_acquired = FALSE;
  dbus_condvar_wake_one (connection->io_path_cond);
}


/**
 * Queues incoming messages and sends outgoing messages for this
 * connection, optionally blocking in the process. Each call to
 * _dbus_connection_do_iteration() will call select() or poll() one
 * time and then read or write data if possible.
 *
 * The purpose of this function is to be able to flush outgoing
 * messages or queue up incoming messages without returning
 * control to the application and causing reentrancy weirdness.
 *
 * The flags parameter allows you to specify whether to
 * read incoming messages, write outgoing messages, or both,
 * and whether to block if no immediate action is possible.
 *
 * The timeout_milliseconds parameter does nothing unless the
 * iteration is blocking.
 *
 * If there are no outgoing messages and DBUS_ITERATION_DO_READING
 * wasn't specified, then it's impossible to block, even if
 * you specify DBUS_ITERATION_BLOCK; in that case the function
 * returns immediately.
 * 
 * @param connection the connection.
 * @param flags iteration flags.
 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
 */
void
_dbus_connection_do_iteration (DBusConnection *connection,
                               unsigned int    flags,
                               int             timeout_milliseconds)
{
  if (connection->n_outgoing == 0)
    flags &= ~DBUS_ITERATION_DO_WRITING;

  if (_dbus_connection_acquire_io_path (connection,
					(flags & DBUS_ITERATION_BLOCK)?timeout_milliseconds:0))
    {
      _dbus_transport_do_iteration (connection->transport,
				    flags, timeout_milliseconds);
      _dbus_connection_release_io_path (connection);
    }
}

/**
 * Creates a new connection for the given transport.  A transport
 * represents a message stream that uses some concrete mechanism, such
 * as UNIX domain sockets. May return #NULL if insufficient
 * memory exists to create the connection.
 *
 * @param transport the transport.
 * @returns the new connection, or #NULL on failure.
 */
DBusConnection*
_dbus_connection_new_for_transport (DBusTransport *transport)
{
  DBusConnection *connection;
  DBusWatchList *watch_list;
  DBusTimeoutList *timeout_list;
  DBusHashTable *handler_table, *pending_replies;
  DBusMutex *mutex;
  DBusCondVar *message_returned_cond;
  DBusCondVar *dispatch_cond;
  DBusCondVar *io_path_cond;
  DBusList *disconnect_link;
  DBusMessage *disconnect_message;

  watch_list = NULL;
  connection = NULL;
  handler_table = NULL;
  pending_replies = NULL;
  timeout_list = NULL;
  mutex = NULL;
  message_returned_cond = NULL;
  dispatch_cond = NULL;
  io_path_cond = NULL;
  disconnect_link = NULL;
  disconnect_message = 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;
  
  handler_table =
    _dbus_hash_table_new (DBUS_HASH_STRING,
                          dbus_free, NULL);
  if (handler_table == NULL)
    goto error;

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

  mutex = dbus_mutex_new ();
  if (mutex == NULL)
    goto error;
  
  message_returned_cond = dbus_condvar_new ();
  if (message_returned_cond == NULL)
    goto error;
  
  dispatch_cond = dbus_condvar_new ();
  if (dispatch_cond == NULL)
    goto error;
  
  io_path_cond = dbus_condvar_new ();
  if (io_path_cond == NULL)
    goto error;

  disconnect_message = dbus_message_new (NULL, DBUS_MESSAGE_LOCAL_DISCONNECT);
  if (disconnect_message == NULL)
    goto error;

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

  if (_dbus_modify_sigpipe)
    _dbus_disable_sigpipe ();
  
  connection->refcount = 1;
  connection->mutex = mutex;
  connection->dispatch_cond = dispatch_cond;
  connection->io_path_cond = io_path_cond;
  connection->message_returned_cond = message_returned_cond;
  connection->transport = transport;
  connection->watches = watch_list;
  connection->timeouts = timeout_list;
  connection->handler_table = handler_table;
  connection->pending_replies = pending_replies;
  connection->filter_list = NULL;

  _dbus_data_slot_list_init (&connection->slot_list);

  connection->client_serial = 1;

  connection->disconnect_message_link = disconnect_link;
  
  _dbus_transport_ref (transport);
  _dbus_transport_set_connection (transport, connection);
  
  return connection;
  
 error:
  if (disconnect_message != NULL)
    dbus_message_unref (disconnect_message);
  
  if (disconnect_link != NULL)
    _dbus_list_free_link (disconnect_link);
  
  if (io_path_cond != NULL)
    dbus_condvar_free (io_path_cond);
  
  if (dispatch_cond != NULL)
    dbus_condvar_free (dispatch_cond);
  
  if (message_returned_cond != NULL)
    dbus_condvar_free (message_returned_cond);
  
  if (mutex != NULL)
    dbus_mutex_free (mutex);

  if (connection != NULL)
    dbus_free (connection);

  if (handler_table)
    _dbus_hash_table_unref (handler_table);

  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);
  
  return NULL;
}

static dbus_int32_t
_dbus_connection_get_next_client_serial (DBusConnection *connection)
{
  int serial;

  serial = connection->client_serial++;

  if (connection->client_serial < 0)
    connection->client_serial = 1;
  
  return serial;
}

/**
 * Used to notify a connection when a DBusMessageHandler is
 * destroyed, so the connection can drop any reference
 * to the handler. This is a private function, but still
 * takes the connection lock. Don't call it with the lock held.
 *
 * @todo needs to check in pending_replies too.
 * 
 * @param connection the connection
 * @param handler the handler
 */
void
_dbus_connection_handler_destroyed_locked (DBusConnection     *connection,
					   DBusMessageHandler *handler)
{
  DBusHashIter iter;
  DBusList *link;

  dbus_mutex_lock (connection->mutex);
  
  _dbus_hash_iter_init (connection->handler_table, &iter);
  while (_dbus_hash_iter_next (&iter))
    {
      DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter);

      if (h == handler)
        _dbus_hash_iter_remove_entry (&iter);
    }

  link = _dbus_list_get_first_link (&connection->filter_list);
  while (link != NULL)
    {
      DBusMessageHandler *h = link->data;
      DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);

      if (h == handler)
        _dbus_list_remove_link (&connection->filter_list,
                                link);
      
      link = next;
    }
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Adds the counter used to count the number of open connections.
 * Increments the counter by one, and saves it to be decremented
 * again when this connection is finalized.
 *
 * @param connection a #DBusConnection
 * @param counter counter that tracks number of connections
 */
void
_dbus_connection_set_connection_counter (DBusConnection *connection,
                                         DBusCounter    *counter)
{
  _dbus_assert (connection->connection_counter == NULL);
  
  connection->connection_counter = counter;
  _dbus_counter_ref (connection->connection_counter);
  _dbus_counter_adjust (connection->connection_counter, 1);
}

/** @} */

/**
 * @addtogroup DBusConnection
 *
 * @{
 */

/**
 * Opens a new connection to a remote address.
 *
 * @todo specify what the address parameter is. Right now
 * it's just the name of a UNIX domain socket. It should be
 * something more complex that encodes which transport to use.
 *
 * If the open fails, the function returns #NULL, and provides
 * a reason for the failure in the result parameter. Pass
 * #NULL for the result parameter if you aren't interested
 * in the reason for failure.
 * 
 * @param address the address.
 * @param result address where a result code can be returned.
 * @returns new connection, or #NULL on failure.
 */
DBusConnection*
dbus_connection_open (const char     *address,
                      DBusResultCode *result)
{
  DBusConnection *connection;
  DBusTransport *transport;
  
  transport = _dbus_transport_open (address, result);
  if (transport == NULL)
    return NULL;
  
  connection = _dbus_connection_new_for_transport (transport);

  _dbus_transport_unref (transport);
  
  if (connection == NULL)
    {
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return NULL;
    }
  
  return connection;
}

/**
 * Increments the reference count of a DBusConnection.
 *
 * @param connection the connection.
 */
void
dbus_connection_ref (DBusConnection *connection)
{
  dbus_mutex_lock (connection->mutex);
  _dbus_assert (connection->refcount > 0);

  connection->refcount += 1;
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Increments the reference count of a DBusConnection.
 * Requires that the caller already holds the connection lock.
 *
 * @param connection the connection.
 */
void
_dbus_connection_ref_unlocked (DBusConnection *connection)
{
  _dbus_assert (connection->refcount > 0);
  connection->refcount += 1;
}


/* 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)
{
  DBusHashIter iter;
  DBusList *link;

  /* 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));
  
  if (connection->connection_counter != NULL)
    {
      /* subtract ourselves from the counter */
      _dbus_counter_adjust (connection->connection_counter, - 1);
      _dbus_counter_unref (connection->connection_counter);
      connection->connection_counter = NULL;
    }
  
  _dbus_watch_list_free (connection->watches);
  connection->watches = NULL;
  
  _dbus_timeout_list_free (connection->timeouts);
  connection->timeouts = NULL;

  /* calls out to application code... */
  _dbus_data_slot_list_free (&connection->slot_list);
  
  _dbus_hash_iter_init (connection->handler_table, &iter);
  while (_dbus_hash_iter_next (&iter))
    {
      DBusMessageHandler *h = _dbus_hash_iter_get_value (&iter);
      
      _dbus_message_handler_remove_connection (h, connection);
    }
  
  link = _dbus_list_get_first_link (&connection->filter_list);
  while (link != NULL)
    {
      DBusMessageHandler *h = link->data;
      DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
      
      _dbus_message_handler_remove_connection (h, connection);
      
      link = next;
    }

  _dbus_hash_table_unref (connection->handler_table);
  connection->handler_table = NULL;

  _dbus_hash_table_unref (connection->pending_replies);
  connection->pending_replies = NULL;
  
  _dbus_list_clear (&connection->filter_list);
  
  _dbus_list_foreach (&connection->outgoing_messages,
		      (DBusForeachFunction) dbus_message_unref,
		      NULL);
  _dbus_list_clear (&connection->outgoing_messages);
  
  _dbus_list_foreach (&connection->incoming_messages,
		      (DBusForeachFunction) dbus_message_unref,
		      NULL);
  _dbus_list_clear (&connection->incoming_messages);
  
  _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 (connection->dispatch_cond);
  dbus_condvar_free (connection->io_path_cond);
  dbus_condvar_free (connection->message_returned_cond);
  
  dbus_mutex_free (connection->mutex);
  
  dbus_free (connection);
}

/**
 * Decrements the reference count of a DBusConnection, and finalizes
 * it if the count reaches zero.  It is a bug to drop the last reference
 * to a connection that has not been disconnected.
 *
 * @param connection the connection.
 */
void
dbus_connection_unref (DBusConnection *connection)
{
  dbus_bool_t last_unref;
  
  dbus_mutex_lock (connection->mutex);
  
  _dbus_assert (connection != NULL);
  _dbus_assert (connection->refcount > 0);

  connection->refcount -= 1;
  last_unref = (connection->refcount == 0);

  dbus_mutex_unlock (connection->mutex);

  if (last_unref)
    _dbus_connection_last_unref (connection);
}

/**
 * Closes the connection, so no further data can be sent or received.
 * Any further attempts to send data will result in errors.  This
 * function does not affect the connection's reference count.  It's
 * safe to disconnect a connection more than once; all calls after the
 * first do nothing. It's impossible to "reconnect" a connection, a
 * new connection must be created.
 *
 * @param connection the connection.
 */
void
dbus_connection_disconnect (DBusConnection *connection)
{
  dbus_mutex_lock (connection->mutex);
  _dbus_transport_disconnect (connection->transport);
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Gets whether the connection is currently connected.  All
 * connections are connected when they are opened.  A connection may
 * become disconnected when the remote application closes its end, or
 * exits; a connection may also be disconnected with
 * dbus_connection_disconnect().
 *
 * @param connection the connection.
 * @returns #TRUE if the connection is still alive.
 */
dbus_bool_t
dbus_connection_get_is_connected (DBusConnection *connection)
{
  dbus_bool_t res;
  
  dbus_mutex_lock (connection->mutex);
  res = _dbus_transport_get_is_connected (connection->transport);
  dbus_mutex_unlock (connection->mutex);
  
  return res;
}

/**
 * Gets whether the connection was authenticated. (Note that
 * if the connection was authenticated then disconnected,
 * this function still returns #TRUE)
 *
 * @param connection the connection
 * @returns #TRUE if the connection was ever authenticated
 */
dbus_bool_t
dbus_connection_get_is_authenticated (DBusConnection *connection)
{
  dbus_bool_t res;
  
  dbus_mutex_lock (connection->mutex);
  res = _dbus_transport_get_is_authenticated (connection->transport);
  dbus_mutex_unlock (connection->mutex);
  
  return res;
}

/**
 * Adds a message to the outgoing message queue. Does not block to
 * write the message to the network; that happens asynchronously. to
 * force the message to be written, call dbus_connection_flush().
 *
 * If the function fails, it returns #FALSE and returns the
 * reason for failure via the result parameter.
 * The result parameter can be #NULL if you aren't interested
 * in the reason for the failure.
 * 
 * @param connection the connection.
 * @param message the message to write.
 * @param client_serial return location for client serial.
 * @param result address where result code can be placed.
 * @returns #TRUE on success.
 */
dbus_bool_t
dbus_connection_send_message (DBusConnection *connection,
                              DBusMessage    *message,
			      dbus_int32_t   *client_serial,
                              DBusResultCode *result)

{
  dbus_int32_t serial;

  dbus_mutex_lock (connection->mutex);

  if (!_dbus_list_prepend (&connection->outgoing_messages,
                           message))
    {
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      dbus_mutex_unlock (connection->mutex);
      return FALSE;
    }

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

  _dbus_verbose ("Message %p added to outgoing queue, %d pending to send\n",
                 message, connection->n_outgoing);

  if (_dbus_message_get_client_serial (message) == -1)
    {
      serial = _dbus_connection_get_next_client_serial (connection);
      _dbus_message_set_client_serial (message, serial);
    }
  
  if (client_serial)
    *client_serial = _dbus_message_get_client_serial (message);
  
  _dbus_message_lock (message);

  if (connection->n_outgoing == 1)
    _dbus_transport_messages_pending (connection->transport,
				      connection->n_outgoing);
  
  _dbus_connection_wakeup_mainloop (connection);

  dbus_mutex_unlock (connection->mutex);
  
  return TRUE;
}

static void
reply_handler_timeout (void *data)
{
  DBusConnection *connection;
  ReplyHandlerData *reply_handler_data = data;

  connection = reply_handler_data->connection;
  
  dbus_mutex_lock (connection->mutex);
  if (reply_handler_data->timeout_link)
    {
      _dbus_connection_queue_synthesized_message_link (connection,
						       reply_handler_data->timeout_link);
      reply_handler_data->timeout_link = NULL;
    }

  _dbus_connection_remove_timeout (connection,
				   reply_handler_data->timeout);
  reply_handler_data->timeout_added = FALSE;
  
  dbus_mutex_unlock (connection->mutex);
}

static void
reply_handler_data_free (ReplyHandlerData *data)
{
  if (!data)
    return;

  if (data->timeout_added)
    _dbus_connection_remove_timeout_locked (data->connection,
					    data->timeout);

  if (data->connection_added)
    _dbus_message_handler_remove_connection (data->handler,
					     data->connection);

  if (data->timeout_link)
    {
      dbus_message_unref ((DBusMessage *)data->timeout_link->data);
      _dbus_list_free_link (data->timeout_link);
    }
  
  dbus_message_handler_unref (data->handler);
  
  dbus_free (data);
}

/**
 * Queues a message to send, as with dbus_connection_send_message(),
 * but also sets up a DBusMessageHandler to receive a reply to the
 * message. If no reply is received in the given timeout_milliseconds,
 * expires the pending reply and sends the DBusMessageHandler a
 * synthetic error reply (generated in-process, not by the remote
 * application) indicating that a timeout occurred.
 *
 * Reply handlers see their replies after message filters see them,
 * but before message handlers added with
 * dbus_connection_register_handler() see them, regardless of the
 * reply message's name. Reply handlers are only handed a single
 * message as a reply, after one reply has been seen the handler is
 * removed. If a filter filters out the reply before the handler sees
 * it, the reply is immediately timed out and a timeout error reply is
 * generated. If a filter removes the timeout error reply then the
 * reply handler will never be called. Filters should not do this.
 * 
 * If #NULL is passed for the reply_handler, the timeout reply will
 * still be generated and placed into the message queue, but no
 * specific message handler will receive the reply.
 *
 * If -1 is passed for the timeout, a sane default timeout is used. -1
 * is typically the best value for the timeout for this reason, unless
 * you want a very short or very long timeout.  There is no way to
 * avoid a timeout entirely, other than passing INT_MAX for the
 * timeout to postpone it indefinitely.
 *
 * @todo I think we should rename this function family
 * dbus_connection_send(), send_with_reply(), etc. (i.e.
 * drop the "message" part), the names are too long.
 * 
 * @param connection the connection
 * @param message the message to send
 * @param reply_handler message handler expecting the reply, or #NULL
 * @param timeout_milliseconds timeout in milliseconds or -1 for default
 * @param result return location for result code
 * @returns #TRUE if the message is successfully queued, #FALSE if no memory.
 *
 */
dbus_bool_t
dbus_connection_send_message_with_reply (DBusConnection     *connection,
                                         DBusMessage        *message,
                                         DBusMessageHandler *reply_handler,
                                         int                 timeout_milliseconds,
                                         DBusResultCode     *result)
{
  DBusTimeout *timeout;
  ReplyHandlerData *data;
  DBusMessage *reply;
  DBusList *reply_link;
  dbus_int32_t serial = -1;
  
  if (timeout_milliseconds == -1)
    timeout_milliseconds = DEFAULT_TIMEOUT_VALUE;

  data = dbus_new0 (ReplyHandlerData, 1);

  if (!data)
    {
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return FALSE;
    }
  
  timeout = _dbus_timeout_new (timeout_milliseconds, reply_handler_timeout,
			       data, NULL);

  if (!timeout)
    {
      reply_handler_data_free (data);
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return FALSE;
    }

  dbus_mutex_lock (connection->mutex);
  
  /* Add timeout */
  if (!_dbus_connection_add_timeout (connection, timeout))
    {
      reply_handler_data_free (data);
      _dbus_timeout_unref (timeout);
      dbus_mutex_unlock (connection->mutex);
      
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return FALSE;
    }

  /* The connection now owns the reference to the timeout. */
  _dbus_timeout_unref (timeout);
  
  data->timeout_added = TRUE;
  data->timeout = timeout;
  data->connection = connection;
  
  if (!_dbus_message_handler_add_connection (reply_handler, connection))
    {
      dbus_mutex_unlock (connection->mutex);
      reply_handler_data_free (data);
      
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return FALSE;
    }
  data->connection_added = TRUE;
  
  /* Assign a serial to the message */
  if (_dbus_message_get_client_serial (message) == -1)
    {
      serial = _dbus_connection_get_next_client_serial (connection);
      _dbus_message_set_client_serial (message, serial);
    }

  data->handler = reply_handler;
  data->serial = serial;

  dbus_message_handler_ref (reply_handler);

  reply = dbus_message_new_error_reply (message, DBUS_ERROR_NO_REPLY,
					"No reply within specified time");
  if (!reply)
    {
      dbus_mutex_unlock (connection->mutex);
      reply_handler_data_free (data);
      
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return FALSE;
    }

  reply_link = _dbus_list_alloc_link (reply);
  if (!reply)
    {
      dbus_mutex_unlock (connection->mutex);
      dbus_message_unref (reply);
      reply_handler_data_free (data);
      
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      return FALSE;
    }

  data->timeout_link = reply_link;
  
  /* Insert the serial in the pending replies hash. */
  if (!_dbus_hash_table_insert_int (connection->pending_replies, serial, data))
    {
      dbus_set_result (result, DBUS_RESULT_NO_MEMORY);
      dbus_mutex_unlock (connection->mutex);
      reply_handler_data_free (data);
      
      return FALSE;
    }

  dbus_mutex_unlock (connection->mutex);
  
  if (!dbus_connection_send_message (connection, message, NULL, result))
    {
      /* This will free the handler data too */
      _dbus_hash_table_remove_int (connection->pending_replies, serial);
      return FALSE;
    }

  dbus_set_result (result, DBUS_RESULT_SUCCESS);  
  return TRUE;
}

/**
 * Sends a message and blocks a certain time period while waiting for a reply.
 * This function does not dispatch any message handlers until the main loop
 * has been reached. This function is used to do non-reentrant "method calls."
 * If a reply is received, it is returned, and removed from the incoming
 * message queue. If it is not received, #NULL is returned and the
 * result is set to #DBUS_RESULT_NO_REPLY. If something else goes
 * wrong, result is set to whatever is appropriate, such as
 * #DBUS_RESULT_NO_MEMORY.
 *
 * @todo could use performance improvements (it keeps scanning
 * the whole message queue for example) and has thread issues,
 * see comments in source
 *
 * @param connection the connection
 * @param message the message to send
 * @param timeout_milliseconds timeout in milliseconds or -1 for default
 * @param result return location for result code
 * @returns the message that is the reply or #NULL with an error code if the
 * function fails.
 */
DBusMessage *
dbus_connection_send_message_with_reply_and_block (DBusConnection     *connection,
						   DBusMessage        *message,
						   int                 timeout_milliseconds,
						   DBusResultCode     *result)
{
  dbus_int32_t client_serial;
  DBusList *link;
  long start_tv_sec, start_tv_usec;
  long end_tv_sec, end_tv_usec;
  long tv_sec, tv_usec;

  if (timeout_milliseconds == -1)
    timeout_milliseconds = DEFAULT_TIMEOUT_VALUE;

  /* it would probably seem logical to pass in _DBUS_INT_MAX
   * for infinite timeout, but then math below would get
   * all overflow-prone, so smack that down.
   */
  if (timeout_milliseconds > _DBUS_ONE_HOUR_IN_MILLISECONDS * 6)
    timeout_milliseconds = _DBUS_ONE_HOUR_IN_MILLISECONDS * 6;
  
  if (!dbus_connection_send_message (connection, message, &client_serial, result))
    return NULL;

  message = NULL;
  
  /* Flush message queue */
  dbus_connection_flush (connection);

  dbus_mutex_lock (connection->mutex);

  _dbus_get_current_time (&start_tv_sec, &start_tv_usec);
  end_tv_sec = start_tv_sec + timeout_milliseconds / 1000;
  end_tv_usec = start_tv_usec + (timeout_milliseconds % 1000) * 1000;
  end_tv_sec += end_tv_usec / _DBUS_USEC_PER_SECOND;
  end_tv_usec = end_tv_usec % _DBUS_USEC_PER_SECOND;

  _dbus_verbose ("will block %d milliseconds from %ld sec %ld usec to %ld sec %ld usec\n",
                 timeout_milliseconds,
                 start_tv_sec, start_tv_usec,
                 end_tv_sec, end_tv_usec);
  
  /* Now we wait... */
  /* THREAD TODO: This is busted. What if a dispatch_message or pop_message
   * gets the message before we do?
   */
 block_again:  
  
  _dbus_connection_do_iteration (connection,
				 DBUS_ITERATION_DO_READING |
				 DBUS_ITERATION_BLOCK,
				 timeout_milliseconds);

  /* Check if we've gotten a reply */
  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 (&connection->incoming_messages, link);
	  dbus_message_ref (reply);

	  if (result)
	    *result = DBUS_RESULT_SUCCESS;
	  
	  dbus_mutex_unlock (connection->mutex);
	  return reply;
	}
      link = _dbus_list_get_next_link (&connection->incoming_messages, link);
    }

  _dbus_get_current_time (&tv_sec, &tv_usec);
  
  if (tv_sec < start_tv_sec)
    ; /* clock set backward, bail out */
  else if (connection->disconnect_message_link == NULL)
    ; /* we're disconnected, bail out */
  else if (tv_sec < end_tv_sec ||
           (tv_sec == end_tv_sec && tv_usec < end_tv_usec))
    {
      timeout_milliseconds = (end_tv_sec - tv_sec) * 1000 +
        (end_tv_usec - tv_usec) / 1000;
      _dbus_verbose ("%d milliseconds remain\n", timeout_milliseconds);
      _dbus_assert (timeout_milliseconds > 0);

      goto block_again; /* not expired yet */
    }

  if (dbus_connection_get_is_connected (connection))
    dbus_set_result (result, DBUS_RESULT_NO_REPLY);
  else
    dbus_set_result (result, DBUS_RESULT_DISCONNECTED);

  dbus_mutex_unlock (connection->mutex);

  return NULL;
}

/**
 * Blocks until the outgoing message queue is empty.
 *
 * @param connection the connection.
 */
void
dbus_connection_flush (DBusConnection *connection)
{
  dbus_mutex_lock (connection->mutex);
  while (connection->n_outgoing > 0)
    _dbus_connection_do_iteration (connection,
                                   DBUS_ITERATION_DO_WRITING |
                                   DBUS_ITERATION_BLOCK,
                                   -1);
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Gets the number of messages in the incoming message queue.
 *
 * @param connection the connection.
 * @returns the number of messages in the queue.
 */
int
dbus_connection_get_n_messages (DBusConnection *connection)
{
  int res;

  dbus_mutex_lock (connection->mutex);
  res = connection->n_incoming;
  dbus_mutex_unlock (connection->mutex);
  return res;
}


/* Call with mutex held. Will drop it while waiting and re-acquire
 * before returning
 */
static void
_dbus_connection_wait_for_borrowed (DBusConnection *connection)
{
  _dbus_assert (connection->message_borrowed != NULL);

  while (connection->message_borrowed != NULL)
    dbus_condvar_wait (connection->message_returned_cond, connection->mutex);
}

/**
 * Returns the first-received message from the incoming message queue,
 * leaving it in the queue. If the queue is empty, returns #NULL.
 * 
 * The caller does not own a reference to the returned message, and must
 * either return it using dbus_connection_return_message or keep it after
 * calling dbus_connection_steal_borrowed_message. No one can get at the
 * message while its borrowed, so return it as quickly as possible and
 * don't keep a reference to it after returning it. If you need to keep
 * the message, make a copy of it.
 *
 * @param connection the connection.
 * @returns next message in the incoming queue.
 */
DBusMessage*
dbus_connection_borrow_message  (DBusConnection *connection)
{
  DBusMessage *message;

  dbus_mutex_lock (connection->mutex);

  if (connection->message_borrowed != NULL)
    _dbus_connection_wait_for_borrowed (connection);
  
  message = _dbus_list_get_first (&connection->incoming_messages);

  if (message) 
    connection->message_borrowed = message;
  
  dbus_mutex_unlock (connection->mutex);
  return message;
}

/**
 * @todo docs
 */
void
dbus_connection_return_message (DBusConnection *connection,
				DBusMessage    *message)
{
  dbus_mutex_lock (connection->mutex);
  
  _dbus_assert (message == connection->message_borrowed);
  
  connection->message_borrowed = NULL;
  dbus_condvar_wake_all (connection->message_returned_cond);
  
  dbus_mutex_unlock (connection->mutex);
}

/**
 * @todo docs
 */
void
dbus_connection_steal_borrowed_message (DBusConnection *connection,
					DBusMessage    *message)
{
  DBusMessage *pop_message;
  
  dbus_mutex_lock (connection->mutex);
 
  _dbus_assert (message == connection->message_borrowed);

  pop_message = _dbus_list_pop_first (&connection->incoming_messages);
  _dbus_assert (message == pop_message);
  
  connection->n_incoming -= 1;
 
  _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
		 message, connection->n_incoming);
 
  connection->message_borrowed = NULL;
  dbus_condvar_wake_all (connection->message_returned_cond);
  
  dbus_mutex_unlock (connection->mutex);
}


/* 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)
{
  if (connection->message_borrowed != NULL)
    _dbus_connection_wait_for_borrowed (connection);
  
  if (connection->n_incoming > 0)
    {
      DBusMessage *message;

      message = _dbus_list_pop_first (&connection->incoming_messages);
      connection->n_incoming -= 1;

      _dbus_verbose ("Incoming message %p removed from queue, %d incoming\n",
                     message, connection->n_incoming);

      return message;
    }
  else
    return NULL;
}


/**
 * Returns the first-received message from the incoming message queue,
 * removing it from the queue. The caller owns a reference to the
 * returned message. If the queue is empty, returns #NULL.
 *
 * @param connection the connection.
 * @returns next message in the incoming queue.
 */
DBusMessage*
dbus_connection_pop_message (DBusConnection *connection)
{
  DBusMessage *message;
  dbus_mutex_lock (connection->mutex);

  message = _dbus_connection_pop_message_unlocked (connection);
  
  dbus_mutex_unlock (connection->mutex);
  
  return message;
}

/**
 * Acquire the dispatcher. This must be done before dispatching
 * messages in order to guarantee the right order of
 * message delivery. May sleep and drop the connection mutex
 * while waiting for the dispatcher.
 *
 * @param connection the connection.
 */
static void
_dbus_connection_acquire_dispatch (DBusConnection *connection)
{
  if (connection->dispatch_acquired)
    dbus_condvar_wait (connection->dispatch_cond, connection->mutex);
  _dbus_assert (!connection->dispatch_acquired);

  connection->dispatch_acquired = TRUE;
}

/**
 * Release the dispatcher when you're done with it. Only call
 * after you've acquired the dispatcher. Wakes up at most one
 * thread currently waiting to acquire the dispatcher.
 *
 * @param connection the connection.
 */
static void
_dbus_connection_release_dispatch (DBusConnection *connection)
{
  _dbus_assert (connection->dispatch_acquired);

  connection->dispatch_acquired = FALSE;
  dbus_condvar_wake_one (connection->dispatch_cond);
}

static void
_dbus_connection_failed_pop (DBusConnection *connection,
			     DBusList *message_link)
{
  _dbus_list_prepend_link (&connection->incoming_messages,
			   message_link);
  connection->n_incoming += 1;
}

/**
 * Pops the first-received message from the current incoming message
 * queue, runs any handlers for it, then unrefs the message.
 *
 * @param connection the connection
 * @returns #TRUE if the queue is not empty after dispatch
 */
dbus_bool_t
dbus_connection_dispatch_message (DBusConnection *connection)
{
  DBusMessageHandler *handler;
  DBusMessage *message;
  DBusList *link, *filter_list_copy, *message_link;
  DBusHandlerResult result;
  ReplyHandlerData *reply_handler_data;
  const char *name;
  dbus_int32_t reply_serial;

  /* Preallocate link so we can put the message back on failure */
  message_link = _dbus_list_alloc_link (NULL);
  if (message_link == NULL)
    return FALSE;
  
  dbus_mutex_lock (connection->mutex);

  /* 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);
  
  /* This call may drop the lock during the execution (if waiting for
   * borrowed messages to be returned) but the order of message
   * dispatch if several threads call dispatch_message is still
   * protected by the lock, since only one will get the lock, and that
   * one will finish the message dispatching
   */
  message = _dbus_connection_pop_message_unlocked (connection);
  if (message == NULL)
    {
      _dbus_connection_release_dispatch (connection);
      dbus_mutex_unlock (connection->mutex);
      dbus_connection_unref (connection);
      return FALSE;
    }
  
  message_link->data = message;
  
  result = DBUS_HANDLER_RESULT_ALLOW_MORE_HANDLERS;

  reply_serial = _dbus_message_get_reply_serial (message);
  reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies,
						    reply_serial);
  
  if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy))
    {
      _dbus_connection_release_dispatch (connection);
      dbus_mutex_unlock (connection->mutex);
      _dbus_connection_failed_pop (connection, message_link);
      dbus_connection_unref (connection);
      return FALSE;
    }
  
  _dbus_list_foreach (&filter_list_copy,
		      (DBusForeachFunction)dbus_message_handler_ref,
		      NULL);

  /* We're still protected from dispatch_message reentrancy here
   * since we acquired the dispatcher
   */
  dbus_mutex_unlock (connection->mutex);
  
  link = _dbus_list_get_first_link (&filter_list_copy);
  while (link != NULL)
    {
      DBusMessageHandler *handler = link->data;
      DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link);

      result = _dbus_message_handler_handle_message (handler, connection,
                                                     message);

      if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
	break;

      link = next;
    }

  _dbus_list_foreach (&filter_list_copy,
		      (DBusForeachFunction)dbus_message_handler_unref,
		      NULL);
  _dbus_list_clear (&filter_list_copy);
  
  dbus_mutex_lock (connection->mutex);

  /* Did a reply we were waiting on get filtered? */
  if (reply_handler_data && result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
    {
      /* Queue the timeout immediately! */
      if (reply_handler_data->timeout_link)
	{
	  _dbus_connection_queue_synthesized_message_link (connection,
							   reply_handler_data->timeout_link);
	  reply_handler_data->timeout_link = NULL;
	}
      else
	{
	  /* We already queued the timeout? Then it was filtered! */
	  _dbus_warn ("The timeout error with reply serial %d was filtered, so the reply handler will never be called.\n", reply_serial);
	}
    }
  
  if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
    goto out;

  if (reply_handler_data)
    {
      dbus_mutex_unlock (connection->mutex);
      result = _dbus_message_handler_handle_message (reply_handler_data->handler,
						     connection, message);
      reply_handler_data_free (reply_handler_data);
      dbus_mutex_lock (connection->mutex);
      goto out;
    }
  
  name = dbus_message_get_name (message);
  if (name != NULL)
    {
      handler = _dbus_hash_table_lookup_string (connection->handler_table,
                                                name);
      if (handler != NULL)
        {
	  /* We're still protected from dispatch_message reentrancy here
	   * since we acquired the dispatcher */
	  dbus_mutex_unlock (connection->mutex);
          result = _dbus_message_handler_handle_message (handler, connection,
                                                         message);
	  dbus_mutex_lock (connection->mutex);
          if (result == DBUS_HANDLER_RESULT_REMOVE_MESSAGE)
            goto out;
        }
    }

 out:
  _dbus_connection_release_dispatch (connection);
  dbus_mutex_unlock (connection->mutex);
  _dbus_list_free_link (message_link);
  dbus_connection_unref (connection);
  dbus_message_unref (message);
  
  return connection->n_incoming > 0;
}

/**
 * Sets the watch functions for the connection. These functions are
 * responsible for making the application's main loop aware of file
 * descriptors that need to be monitored for events, using select() or
 * poll(). When using Qt, typically the DBusAddWatchFunction would
 * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
 * could call g_io_add_watch(), or could be used as part of a more
 * elaborate GSource.
 *
 * The DBusWatch can be queried for the file descriptor to watch using
 * dbus_watch_get_fd(), and for the events to watch for using
 * dbus_watch_get_flags(). The flags returned by
 * dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and
 * DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR;
 * all watches implicitly include a watch for hangups, errors, and
 * other exceptional conditions.
 *
 * Once a file descriptor becomes readable or writable, or an exception
 * occurs, dbus_connection_handle_watch() should be called to
 * notify the connection of the file descriptor's condition.
 *
 * dbus_connection_handle_watch() cannot be called during the
 * DBusAddWatchFunction, as the connection will not be ready to handle
 * that watch yet.
 * 
 * It is not allowed to reference a DBusWatch after it has been passed
 * to remove_function.
 * 
 * @param connection the connection.
 * @param add_function function to begin monitoring a new descriptor.
 * @param remove_function function to stop monitoring a descriptor.
 * @param data data to pass to add_function and remove_function.
 * @param free_data_function function to be called to free the data.
 */
void
dbus_connection_set_watch_functions (DBusConnection              *connection,
                                     DBusAddWatchFunction         add_function,
                                     DBusRemoveWatchFunction      remove_function,
                                     void                        *data,
                                     DBusFreeFunction             free_data_function)
{
  dbus_mutex_lock (connection->mutex);
  /* ref connection for slightly better reentrancy */
  _dbus_connection_ref_unlocked (connection);
  
  _dbus_watch_list_set_functions (connection->watches,
                                  add_function, remove_function,
                                  data, free_data_function);
  
  dbus_mutex_unlock (connection->mutex);
  /* drop our paranoid refcount */
  dbus_connection_unref (connection);
}

/**
 * Sets the timeout functions for the connection. These functions are
 * responsible for making the application's main loop aware of timeouts.
 * When using Qt, typically the DBusAddTimeoutFunction would create a
 * QTimer. When using GLib, the DBusAddTimeoutFunction would call
 * g_timeout_add.
 *
 * The DBusTimeout can be queried for the timer interval using
 * dbus_timeout_get_interval.
 *
 * Once a timeout occurs, dbus_timeout_handle should be called to invoke
 * the timeout's callback.
 *
 * @param connection the connection.
 * @param add_function function to add a timeout.
 * @param remove_function function to remove a timeout.
 * @param data data to pass to add_function and remove_function.
 * @param free_data_function function to be called to free the data.
 */
void
dbus_connection_set_timeout_functions   (DBusConnection            *connection,
					 DBusAddTimeoutFunction     add_function,
					 DBusRemoveTimeoutFunction  remove_function,
					 void                      *data,
					 DBusFreeFunction           free_data_function)
{
  dbus_mutex_lock (connection->mutex);
  /* ref connection for slightly better reentrancy */
  _dbus_connection_ref_unlocked (connection);
  
  _dbus_timeout_list_set_functions (connection->timeouts,
				    add_function, remove_function,
				    data, free_data_function);
  
  dbus_mutex_unlock (connection->mutex);
  /* drop our paranoid refcount */
  dbus_connection_unref (connection);  
}

/**
 * Sets the mainloop wakeup function for the connection. Thi function is
 * responsible for waking up the main loop (if its sleeping) when some some
 * change has happened to the connection that the mainloop needs to reconsiders
 * (e.g. a message has been queued for writing).
 * When using Qt, this typically results in a call to QEventLoop::wakeUp().
 * When using GLib, it would call g_main_context_wakeup().
 *
 *
 * @param connection the connection.
 * @param wakeup_main_function function to wake up the mainloop
 * @param data data to pass wakeup_main_function
 * @param free_data_function function to be called to free the data.
 */
void
dbus_connection_set_wakeup_main_function (DBusConnection            *connection,
					  DBusWakeupMainFunction     wakeup_main_function,
					  void                      *data,
					  DBusFreeFunction           free_data_function)
{
  void *old_data;
  DBusFreeFunction old_free_data;
  
  dbus_mutex_lock (connection->mutex);
  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;
  
  dbus_mutex_unlock (connection->mutex);

  /* Callback outside the lock */
  if (old_free_data)
    (*old_free_data) (old_data);
}

/**
 * Called to notify the connection when a previously-added watch
 * is ready for reading or writing, or has an exception such
 * as a hangup.
 *
 * @param connection the connection.
 * @param watch the watch.
 * @param condition the current condition of the file descriptors being watched.
 */
void
dbus_connection_handle_watch (DBusConnection              *connection,
                              DBusWatch                   *watch,
                              unsigned int                 condition)
{
  dbus_mutex_lock (connection->mutex);
  _dbus_connection_acquire_io_path (connection, -1);
  _dbus_transport_handle_watch (connection->transport,
				watch, condition);
  _dbus_connection_release_io_path (connection);
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Adds a message filter. Filters are handlers that are run on
 * all incoming messages, prior to the normal handlers
 * registered with dbus_connection_register_handler().
 * Filters are run in the order that they were added.
 * The same handler can be added as a filter more than once, in
 * which case it will be run more than once.
 * Filters added during a filter callback won't be run on the
 * message being processed.
 *
 * @param connection the connection
 * @param handler the handler
 * @returns #TRUE on success, #FALSE if not enough memory.
 */
dbus_bool_t
dbus_connection_add_filter (DBusConnection      *connection,
                            DBusMessageHandler  *handler)
{
  dbus_mutex_lock (connection->mutex);
  if (!_dbus_message_handler_add_connection (handler, connection))
    {
      dbus_mutex_unlock (connection->mutex);
      return FALSE;
    }

  if (!_dbus_list_append (&connection->filter_list,
                          handler))
    {
      _dbus_message_handler_remove_connection (handler, connection);
      dbus_mutex_unlock (connection->mutex);
      return FALSE;
    }

  dbus_mutex_unlock (connection->mutex);
  return TRUE;
}

/**
 * Removes a previously-added message filter. It is a programming
 * error to call this function for a handler that has not
 * been added as a filter. If the given handler was added
 * more than once, only one instance of it will be removed
 * (the most recently-added instance).
 *
 * @param connection the connection
 * @param handler the handler to remove
 *
 */
void
dbus_connection_remove_filter (DBusConnection      *connection,
                               DBusMessageHandler  *handler)
{
  dbus_mutex_lock (connection->mutex);
  if (!_dbus_list_remove_last (&connection->filter_list, handler))
    {
      _dbus_warn ("Tried to remove a DBusConnection filter that had not been added\n");
      dbus_mutex_unlock (connection->mutex);
      return;
    }

  _dbus_message_handler_remove_connection (handler, connection);

  dbus_mutex_unlock (connection->mutex);
}

/**
 * Registers a handler for a list of message names. A single handler
 * can be registered for any number of message names, but each message
 * name can only have one handler at a time. It's not allowed to call
 * this function with the name of a message that already has a
 * handler. If the function returns #FALSE, the handlers were not
 * registered due to lack of memory.
 *
 * @todo the messages_to_handle arg may be more convenient if it's a
 * single string instead of an array. Though right now MessageHandler
 * is sort of designed to say be associated with an entire object with
 * multiple methods, that's why for example the connection only
 * weakrefs it.  So maybe the "manual" API should be different.
 * 
 * @param connection the connection
 * @param handler the handler
 * @param messages_to_handle the messages to handle
 * @param n_messages the number of message names in messages_to_handle
 * @returns #TRUE on success, #FALSE if no memory or another handler already exists
 * 
 **/
dbus_bool_t
dbus_connection_register_handler (DBusConnection     *connection,
                                  DBusMessageHandler *handler,
                                  const char        **messages_to_handle,
                                  int                 n_messages)
{
  int i;

  dbus_mutex_lock (connection->mutex);
  i = 0;
  while (i < n_messages)
    {
      DBusHashIter iter;
      char *key;

      key = _dbus_strdup (messages_to_handle[i]);
      if (key == NULL)
        goto failed;
      
      if (!_dbus_hash_iter_lookup (connection->handler_table,
                                   key, TRUE,
                                   &iter))
        {
          dbus_free (key);
          goto failed;
        }

      if (_dbus_hash_iter_get_value (&iter) != NULL)
        {
          _dbus_warn ("Bug in application: attempted to register a second handler for %s\n",
                      messages_to_handle[i]);
          dbus_free (key); /* won't have replaced the old key with the new one */
          goto failed;
        }

      if (!_dbus_message_handler_add_connection (handler, connection))
        {
          _dbus_hash_iter_remove_entry (&iter);
          /* key has freed on nuking the entry */
          goto failed;
        }
      
      _dbus_hash_iter_set_value (&iter, handler);

      ++i;
    }
  
  dbus_mutex_unlock (connection->mutex);
  return TRUE;
  
 failed:
  /* unregister everything registered so far,
   * so we don't fail partially
   */
  dbus_connection_unregister_handler (connection,
                                      handler,
                                      messages_to_handle,
                                      i);

  dbus_mutex_unlock (connection->mutex);
  return FALSE;
}

/**
 * Unregisters a handler for a list of message names. The handlers
 * must have been previously registered.
 *
 * @param connection the connection
 * @param handler the handler
 * @param messages_to_handle the messages to handle
 * @param n_messages the number of message names in messages_to_handle
 * 
 **/
void
dbus_connection_unregister_handler (DBusConnection     *connection,
                                    DBusMessageHandler *handler,
                                    const char        **messages_to_handle,
                                    int                 n_messages)
{
  int i;

  dbus_mutex_lock (connection->mutex);
  i = 0;
  while (i < n_messages)
    {
      DBusHashIter iter;

      if (!_dbus_hash_iter_lookup (connection->handler_table,
                                   (char*) messages_to_handle[i], FALSE,
                                   &iter))
        {
          _dbus_warn ("Bug in application: attempted to unregister handler for %s which was not registered\n",
                      messages_to_handle[i]);
        }
      else if (_dbus_hash_iter_get_value (&iter) != handler)
        {
          _dbus_warn ("Bug in application: attempted to unregister handler for %s which was registered by a different handler\n",
                      messages_to_handle[i]);
        }
      else
        {
          _dbus_hash_iter_remove_entry (&iter);
          _dbus_message_handler_remove_connection (handler, connection);
        }

      ++i;
    }

  dbus_mutex_unlock (connection->mutex);
}

static DBusDataSlotAllocator slot_allocator;

/**
 * Initialize the mutex used for #DBusConnection data
 * slot reservations.
 *
 * @returns the mutex
 */
DBusMutex *
_dbus_connection_slots_init_lock (void)
{
  if (!_dbus_data_slot_allocator_init (&slot_allocator))
    return NULL;
  else
    return slot_allocator.lock;
}

/**
 * Allocates an integer ID to be used for storing application-specific
 * data on any DBusConnection. The allocated ID may then be used
 * with dbus_connection_set_data() and dbus_connection_get_data().
 * If allocation fails, -1 is returned. Again, the allocated
 * slot is global, i.e. all DBusConnection objects will
 * have a slot with the given integer ID reserved.
 *
 * @returns -1 on failure, otherwise the data slot ID
 */
int
dbus_connection_allocate_data_slot (void)
{
  return _dbus_data_slot_allocator_alloc (&slot_allocator);
}

/**
 * Deallocates a global ID for connection data slots.
 * dbus_connection_get_data() and dbus_connection_set_data()
 * may no longer be used with this slot.
 * Existing data stored on existing DBusConnection objects
 * will be freed when the connection is finalized,
 * but may not be retrieved (and may only be replaced
 * if someone else reallocates the slot).
 *
 * @param slot the slot to deallocate
 */
void
dbus_connection_free_data_slot (int slot)
{
  _dbus_data_slot_allocator_free (&slot_allocator, slot);
}

/**
 * Stores a pointer on a DBusConnection, along
 * with an optional function to be used for freeing
 * the data when the data is set again, or when
 * the connection is finalized. The slot number
 * must have been allocated with dbus_connection_allocate_data_slot().
 *
 * @param connection the connection
 * @param slot the slot number
 * @param data the data to store
 * @param free_data_func finalizer function for the data
 * @returns #TRUE if there was enough memory to store the data
 */
dbus_bool_t
dbus_connection_set_data (DBusConnection   *connection,
                          int               slot,
                          void             *data,
                          DBusFreeFunction  free_data_func)
{
  DBusFreeFunction old_free_func;
  void *old_data;
  dbus_bool_t retval;
  
  dbus_mutex_lock (connection->mutex);

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

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

  return retval;
}

/**
 * Retrieves data previously set with dbus_connection_set_data().
 * The slot must still be allocated (must not have been freed).
 *
 * @param connection the connection
 * @param slot the slot to get data from
 * @returns the data, or #NULL if not found
 */
void*
dbus_connection_get_data (DBusConnection   *connection,
                          int               slot)
{
  void *res;
  
  dbus_mutex_lock (connection->mutex);

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

  return res;
}

/**
 * This function sets a global flag for whether dbus_connection_new()
 * will set SIGPIPE behavior to SIG_IGN.
 *
 * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN
 */
void
dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
{
  _dbus_modify_sigpipe = will_modify_sigpipe;
}

/**
 * Specifies the maximum size message this connection is allowed to
 * receive. Larger messages will result in disconnecting the
 * connection.
 * 
 * @param connection a #DBusConnection
 * @param size maximum message size the connection can receive, in bytes
 */
void
dbus_connection_set_max_message_size (DBusConnection *connection,
                                      long            size)
{
  dbus_mutex_lock (connection->mutex);
  _dbus_transport_set_max_message_size (connection->transport,
                                        size);
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Gets the value set by dbus_connection_set_max_message_size().
 *
 * @param connection the connection
 * @returns the max size of a single message
 */
long
dbus_connection_get_max_message_size (DBusConnection *connection)
{
  long res;
  dbus_mutex_lock (connection->mutex);
  res = _dbus_transport_get_max_message_size (connection->transport);
  dbus_mutex_unlock (connection->mutex);
  return res;
}

/**
 * Sets the maximum total number of bytes that can be used for all messages
 * received on this connection. Messages count toward the maximum until
 * they are finalized. When the maximum is reached, the connection will
 * not read more data until some messages are finalized.
 *
 * The semantics of the maximum are: if outstanding messages are
 * already above the maximum, additional messages will not be read.
 * The semantics are not: if the next message would cause us to exceed
 * the maximum, we don't read it. The reason is that we don't know the
 * size of a message until after we read it.
 *
 * Thus, the max live messages size can actually be exceeded
 * by up to the maximum size of a single message.
 * 
 * Also, if we read say 1024 bytes off the wire in a single read(),
 * and that contains a half-dozen small messages, we may exceed the
 * size max by that amount. But this should be inconsequential.
 *
 * @param connection the connection
 * @param size the maximum size in bytes of all outstanding messages
 */
void
dbus_connection_set_max_live_messages_size (DBusConnection *connection,
                                            long            size)
{
  dbus_mutex_lock (connection->mutex);
  _dbus_transport_set_max_live_messages_size (connection->transport,
                                              size);
  dbus_mutex_unlock (connection->mutex);
}

/**
 * Gets the value set by dbus_connection_set_max_live_messages_size().
 *
 * @param connection the connection
 * @returns the max size of all live messages
 */
long
dbus_connection_get_max_live_messages_size (DBusConnection *connection)
{
  long res;
  dbus_mutex_lock (connection->mutex);
  res = _dbus_transport_get_max_live_messages_size (connection->transport);
  dbus_mutex_unlock (connection->mutex);
  return res;
}

/** @} */