aboutsummaryrefslogtreecommitdiff
path: root/lib/multi.c
blob: 476f058c58fc59c6530d99f99524b8f1a0d858c9 (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
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#include <curl/curl.h>

#include "urldata.h"
#include "transfer.h"
#include "url.h"
#include "connect.h"
#include "progress.h"
#include "easyif.h"
#include "multiif.h"
#include "sendf.h"
#include "timeval.h"
#include "http.h"
#include "select.h"
#include "warnless.h"
#include "speedcheck.h"
#include "conncache.h"
#include "bundles.h"
#include "multihandle.h"
#include "pipeline.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"

/*
  CURL_SOCKET_HASH_TABLE_SIZE should be a prime number. Increasing it from 97
  to 911 takes on a 32-bit machine 4 x 804 = 3211 more bytes.  Still, every
  CURL handle takes 45-50 K memory, therefore this 3K are not significant.
*/
#ifndef CURL_SOCKET_HASH_TABLE_SIZE
#define CURL_SOCKET_HASH_TABLE_SIZE 911
#endif

#define CURL_CONNECTION_HASH_SIZE 97

#define CURL_MULTI_HANDLE 0x000bab1e

#define GOOD_MULTI_HANDLE(x) \
  ((x) && (((struct Curl_multi *)(x))->type == CURL_MULTI_HANDLE))
#define GOOD_EASY_HANDLE(x) \
  ((x) && (((struct SessionHandle *)(x))->magic == CURLEASY_MAGIC_NUMBER))

static void singlesocket(struct Curl_multi *multi,
                         struct SessionHandle *easy);
static int update_timer(struct Curl_multi *multi);

static bool isHandleAtHead(struct SessionHandle *handle,
                           struct curl_llist *pipeline);
static CURLMcode add_next_timeout(struct timeval now,
                                  struct Curl_multi *multi,
                                  struct SessionHandle *d);
static CURLMcode multi_timeout(struct Curl_multi *multi,
                               long *timeout_ms);

#ifdef DEBUGBUILD
static const char * const statename[]={
  "INIT",
  "CONNECT_PEND",
  "CONNECT",
  "WAITRESOLVE",
  "WAITCONNECT",
  "WAITPROXYCONNECT",
  "PROTOCONNECT",
  "WAITDO",
  "DO",
  "DOING",
  "DO_MORE",
  "DO_DONE",
  "WAITPERFORM",
  "PERFORM",
  "TOOFAST",
  "DONE",
  "COMPLETED",
  "MSGSENT",
};
#endif

static void multi_freetimeout(void *a, void *b);

/* always use this function to change state, to make debugging easier */
static void mstate(struct SessionHandle *easy, CURLMstate state
#ifdef DEBUGBUILD
                   , int lineno
#endif
)
{
#ifdef DEBUGBUILD
  long connection_id = -5000;
#endif
  CURLMstate oldstate = easy->mstate;

  if(oldstate == state)
    /* don't bother when the new state is the same as the old state */
    return;

  easy->mstate = state;

#ifdef DEBUGBUILD
  if(easy->mstate >= CURLM_STATE_CONNECT_PEND &&
     easy->mstate < CURLM_STATE_COMPLETED) {
    if(easy->easy_conn)
      connection_id = easy->easy_conn->connection_id;

    infof(easy,
          "STATE: %s => %s handle %p; line %d (connection #%ld) \n",
          statename[oldstate], statename[easy->mstate],
          (void *)easy, lineno, connection_id);
  }
#endif
  if(state == CURLM_STATE_COMPLETED)
    /* changing to COMPLETED means there's one less easy handle 'alive' */
    easy->multi->num_alive--;
}

#ifndef DEBUGBUILD
#define multistate(x,y) mstate(x,y)
#else
#define multistate(x,y) mstate(x,y, __LINE__)
#endif

/*
 * We add one of these structs to the sockhash for a particular socket
 */

struct Curl_sh_entry {
  struct SessionHandle *easy;
  time_t timestamp;
  int action;  /* what action READ/WRITE this socket waits for */
  curl_socket_t socket; /* mainly to ease debugging */
  void *socketp; /* settable by users with curl_multi_assign() */
};
/* bits for 'action' having no bits means this socket is not expecting any
   action */
#define SH_READ  1
#define SH_WRITE 2

/* make sure this socket is present in the hash for this handle */
static struct Curl_sh_entry *sh_addentry(struct curl_hash *sh,
                                         curl_socket_t s,
                                         struct SessionHandle *data)
{
  struct Curl_sh_entry *there =
    Curl_hash_pick(sh, (char *)&s, sizeof(curl_socket_t));
  struct Curl_sh_entry *check;

  if(there)
    /* it is present, return fine */
    return there;

  /* not present, add it */
  check = calloc(1, sizeof(struct Curl_sh_entry));
  if(!check)
    return NULL; /* major failure */
  check->easy = data;
  check->socket = s;

  /* make/add new hash entry */
  if(NULL == Curl_hash_add(sh, (char *)&s, sizeof(curl_socket_t), check)) {
    free(check);
    return NULL; /* major failure */
  }

  return check; /* things are good in sockhash land */
}


/* delete the given socket + handle from the hash */
static void sh_delentry(struct curl_hash *sh, curl_socket_t s)
{
  struct Curl_sh_entry *there =
    Curl_hash_pick(sh, (char *)&s, sizeof(curl_socket_t));

  if(there) {
    /* this socket is in the hash */
    /* We remove the hash entry. (This'll end up in a call to
       sh_freeentry().) */
    Curl_hash_delete(sh, (char *)&s, sizeof(curl_socket_t));
  }
}

/*
 * free a sockhash entry
 */
static void sh_freeentry(void *freethis)
{
  struct Curl_sh_entry *p = (struct Curl_sh_entry *) freethis;

  if(p)
    free(p);
}

static size_t fd_key_compare(void *k1, size_t k1_len, void *k2, size_t k2_len)
{
  (void) k1_len; (void) k2_len;

  return (*((int *) k1)) == (*((int *) k2));
}

static size_t hash_fd(void *key, size_t key_length, size_t slots_num)
{
  int fd = *((int *) key);
  (void) key_length;

  return (fd % (int)slots_num);
}

/*
 * sh_init() creates a new socket hash and returns the handle for it.
 *
 * Quote from README.multi_socket:
 *
 * "Some tests at 7000 and 9000 connections showed that the socket hash lookup
 * is somewhat of a bottle neck. Its current implementation may be a bit too
 * limiting. It simply has a fixed-size array, and on each entry in the array
 * it has a linked list with entries. So the hash only checks which list to
 * scan through. The code I had used so for used a list with merely 7 slots
 * (as that is what the DNS hash uses) but with 7000 connections that would
 * make an average of 1000 nodes in each list to run through. I upped that to
 * 97 slots (I believe a prime is suitable) and noticed a significant speed
 * increase.  I need to reconsider the hash implementation or use a rather
 * large default value like this. At 9000 connections I was still below 10us
 * per call."
 *
 */
static struct curl_hash *sh_init(int hashsize)
{
  return Curl_hash_alloc(hashsize, hash_fd, fd_key_compare,
                         sh_freeentry);
}

/*
 * multi_addmsg()
 *
 * Called when a transfer is completed. Adds the given msg pointer to
 * the list kept in the multi handle.
 */
static CURLMcode multi_addmsg(struct Curl_multi *multi,
                              struct Curl_message *msg)
{
  if(!Curl_llist_insert_next(multi->msglist, multi->msglist->tail, msg))
    return CURLM_OUT_OF_MEMORY;

  return CURLM_OK;
}

/*
 * multi_freeamsg()
 *
 * Callback used by the llist system when a single list entry is destroyed.
 */
static void multi_freeamsg(void *a, void *b)
{
  (void)a;
  (void)b;
}

struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */
                                     int chashsize) /* connection hash */
{
  struct Curl_multi *multi = calloc(1, sizeof(struct Curl_multi));

  if(!multi)
    return NULL;

  multi->type = CURL_MULTI_HANDLE;

  multi->hostcache = Curl_mk_dnscache();
  if(!multi->hostcache)
    goto error;

  multi->sockhash = sh_init(hashsize);
  if(!multi->sockhash)
    goto error;

  multi->conn_cache = Curl_conncache_init(chashsize);
  if(!multi->conn_cache)
    goto error;

  multi->msglist = Curl_llist_alloc(multi_freeamsg);
  if(!multi->msglist)
    goto error;

  multi->max_pipeline_length = 5;
  return (CURLM *) multi;

  error:

  Curl_hash_destroy(multi->sockhash);
  multi->sockhash = NULL;
  Curl_hash_destroy(multi->hostcache);
  multi->hostcache = NULL;
  Curl_conncache_destroy(multi->conn_cache);
  multi->conn_cache = NULL;

  free(multi);
  return NULL;
}

CURLM *curl_multi_init(void)
{
  return Curl_multi_handle(CURL_SOCKET_HASH_TABLE_SIZE,
                           CURL_CONNECTION_HASH_SIZE);
}


CURLMcode curl_multi_add_handle(CURLM *multi_handle,
                                CURL *easy_handle)
{
  struct curl_llist *timeoutlist;
  struct Curl_multi *multi = (struct Curl_multi *)multi_handle;
  struct SessionHandle *data = (struct SessionHandle *)easy_handle;
  struct SessionHandle *new_closure = NULL;
  struct curl_hash *hostcache = NULL;

  /* First, make some basic checks that the CURLM handle is a good handle */
  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  /* Verify that we got a somewhat good easy handle too */
  if(!GOOD_EASY_HANDLE(easy_handle))
    return CURLM_BAD_EASY_HANDLE;

  /* Prevent users from adding same easy handle more than once and prevent
     adding to more than one multi stack */
  if(data->multi)
    /* possibly we should create a new unique error code for this condition */
    return CURLM_BAD_EASY_HANDLE;

  /* Allocate and initialize timeout list for easy handle */
  timeoutlist = Curl_llist_alloc(multi_freetimeout);
  if(!timeoutlist)
    return CURLM_OUT_OF_MEMORY;

  /* In case multi handle has no hostcache yet, allocate one */
  if(!multi->hostcache) {
    hostcache = Curl_mk_dnscache();
    if(!hostcache) {
      free(data);
      Curl_llist_destroy(timeoutlist, NULL);
      return CURLM_OUT_OF_MEMORY;
    }
  }

  /* In case multi handle has no closure_handle yet, allocate
     a new easy handle to use when closing cached connections */
  if(!multi->closure_handle) {
    new_closure = (struct SessionHandle *)curl_easy_init();
    if(!new_closure) {
      Curl_hash_destroy(hostcache);
      free(data);
      Curl_llist_destroy(timeoutlist, NULL);
      return CURLM_OUT_OF_MEMORY;
    }
  }

  /*
  ** No failure allowed in this function beyond this point. And
  ** no modification of easy nor multi handle allowed before this
  ** except for potential multi's connection cache growing which
  ** won't be undone in this function no matter what.
  */

  /* In case a new closure handle has been initialized above, it
     is associated now with the multi handle which lacked one. */
  if(new_closure) {
    multi->closure_handle = new_closure;
    Curl_easy_addmulti(multi->closure_handle, multi_handle);
    multi->closure_handle->state.conn_cache = multi->conn_cache;
  }

  /* In case hostcache has been allocated above,
     it is associated now with the multi handle. */
  if(hostcache)
    multi->hostcache = hostcache;

  /* Make easy handle use timeout list initialized above */
  data->state.timeoutlist = timeoutlist;
  timeoutlist = NULL;

  /* set the easy handle */
  multistate(data, CURLM_STATE_INIT);

  if((data->set.global_dns_cache) &&
     (data->dns.hostcachetype != HCACHE_GLOBAL)) {
    /* global dns cache was requested but still isn't */
    struct curl_hash *global = Curl_global_host_cache_init();
    if(global) {
      /* only do this if the global cache init works */
      data->dns.hostcache = global;
      data->dns.hostcachetype = HCACHE_GLOBAL;
    }
  }
  /* for multi interface connections, we share DNS cache automatically if the
     easy handle's one is currently not set. */
  else if(!data->dns.hostcache ||
     (data->dns.hostcachetype == HCACHE_NONE)) {
    data->dns.hostcache = multi->hostcache;
    data->dns.hostcachetype = HCACHE_MULTI;
  }

  /* Point to the multi's connection cache */
  data->state.conn_cache = multi->conn_cache;

  /* This adds the new entry at the 'end' of the doubly-linked circular
     list of SessionHandle structs to try and maintain a FIFO queue so
     the pipelined requests are in order. */

  /* We add this new entry last in the list. */

  data->next = NULL; /* end of the line */
  if(multi->easyp) {
    struct SessionHandle *last = multi->easylp;
    last->next = data;
    data->prev = last;
    multi->easylp = data; /* the new last node */
  }
  else {
    /* first node, make both prev and next be NULL! */
    data->next = NULL;
    data->prev = NULL;
    multi->easylp = multi->easyp = data; /* both first and last */
  }

  /* make the SessionHandle refer back to this multi handle */
  Curl_easy_addmulti(data, multi_handle);

  /* Set the timeout for this handle to expire really soon so that it will
     be taken care of even when this handle is added in the midst of operation
     when only the curl_multi_socket() API is used. During that flow, only
     sockets that time-out or have actions will be dealt with. Since this
     handle has no action yet, we make sure it times out to get things to
     happen. */
  Curl_expire(data, 1);

  /* increase the node-counter */
  multi->num_easy++;

  /* increase the alive-counter */
  multi->num_alive++;

  /* A somewhat crude work-around for a little glitch in update_timer() that
     happens if the lastcall time is set to the same time when the handle is
     removed as when the next handle is added, as then the check in
     update_timer() that prevents calling the application multiple times with
     the same timer infor will not trigger and then the new handle's timeout
     will not be notified to the app.

     The work-around is thus simply to clear the 'lastcall' variable to force
     update_timer() to always trigger a callback to the app when a new easy
     handle is added */
  memset(&multi->timer_lastcall, 0, sizeof(multi->timer_lastcall));

  update_timer(multi);
  return CURLM_OK;
}

#if 0
/* Debug-function, used like this:
 *
 * Curl_hash_print(multi->sockhash, debug_print_sock_hash);
 *
 * Enable the hash print function first by editing hash.c
 */
static void debug_print_sock_hash(void *p)
{
  struct Curl_sh_entry *sh = (struct Curl_sh_entry *)p;

  fprintf(stderr, " [easy %p/magic %x/socket %d]",
          (void *)sh->easy, sh->easy->magic, (int)sh->socket);
}
#endif

CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
                                   CURL *curl_handle)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct SessionHandle *easy = curl_handle;
  struct SessionHandle *data = easy;

  /* First, make some basic checks that the CURLM handle is a good handle */
  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  /* Verify that we got a somewhat good easy handle too */
  if(!GOOD_EASY_HANDLE(curl_handle))
    return CURLM_BAD_EASY_HANDLE;

  if(easy) {
    bool premature = (easy->mstate < CURLM_STATE_COMPLETED) ? TRUE : FALSE;
    bool easy_owns_conn = (easy->easy_conn &&
                           (easy->easy_conn->data == easy)) ?
                           TRUE : FALSE;

    /* If the 'state' is not INIT or COMPLETED, we might need to do something
       nice to put the easy_handle in a good known state when this returns. */
    if(premature)
      /* this handle is "alive" so we need to count down the total number of
         alive connections when this is removed */
      multi->num_alive--;

    if(easy->easy_conn &&
       (easy->easy_conn->send_pipe->size +
        easy->easy_conn->recv_pipe->size > 1) &&
       easy->mstate > CURLM_STATE_WAITDO &&
       easy->mstate < CURLM_STATE_COMPLETED) {
      /* If the handle is in a pipeline and has started sending off its
         request but not received its response yet, we need to close
         connection. */
      easy->easy_conn->bits.close = TRUE;
      /* Set connection owner so that Curl_done() closes it.
         We can sefely do this here since connection is killed. */
      easy->easy_conn->data = easy;
    }

    /* The timer must be shut down before easy->multi is set to NULL,
       else the timenode will remain in the splay tree after
       curl_easy_cleanup is called. */
    Curl_expire(easy, 0);

    /* destroy the timeout list that is held in the easy handle */
    if(data->state.timeoutlist) {
      Curl_llist_destroy(data->state.timeoutlist, NULL);
      data->state.timeoutlist = NULL;
    }

    if(easy->dns.hostcachetype == HCACHE_MULTI) {
      /* stop using the multi handle's DNS cache */
      easy->dns.hostcache = NULL;
      easy->dns.hostcachetype = HCACHE_NONE;
    }

    if(easy->easy_conn) {

      /* we must call Curl_done() here (if we still "own it") so that we don't
         leave a half-baked one around */
      if(easy_owns_conn) {

        /* Curl_done() clears the conn->data field to lose the association
           between the easy handle and the connection

           Note that this ignores the return code simply because there's
           nothing really useful to do with it anyway! */
        (void)Curl_done(&easy->easy_conn, easy->result, premature);
      }
      else
        /* Clear connection pipelines, if Curl_done above was not called */
        Curl_getoff_all_pipelines(easy, easy->easy_conn);
    }

    /* as this was using a shared connection cache we clear the pointer
       to that since we're not part of that multi handle anymore */
      easy->state.conn_cache = NULL;

    /* change state without using multistate(), only to make singlesocket() do
       what we want */
    easy->mstate = CURLM_STATE_COMPLETED;
    singlesocket(multi, easy); /* to let the application know what sockets
                                  that vanish with this handle */

    /* Remove the association between the connection and the handle */
    if(easy->easy_conn) {
      easy->easy_conn->data = NULL;
      easy->easy_conn = NULL;
    }

    Curl_easy_addmulti(easy, NULL); /* clear the association
                                                    to this multi handle */

    {
      /* make sure there's no pending message in the queue sent from this easy
         handle */
      struct curl_llist_element *e;

      for(e = multi->msglist->head; e; e = e->next) {
        struct Curl_message *msg = e->ptr;

        if(msg->extmsg.easy_handle == easy) {
          Curl_llist_remove(multi->msglist, e, NULL);
          /* there can only be one from this specific handle */
          break;
        }
      }
    }

    /* make the previous node point to our next */
    if(easy->prev)
      easy->prev->next = easy->next;
    else
      multi->easyp = easy->next; /* point to first node */

    /* make our next point to our previous node */
    if(easy->next)
      easy->next->prev = easy->prev;
    else
      multi->easylp = easy->prev; /* point to last node */

    /* NOTE NOTE NOTE
       We do not touch the easy handle here! */

    multi->num_easy--; /* one less to care about now */

    update_timer(multi);
    return CURLM_OK;
  }
  else
    return CURLM_BAD_EASY_HANDLE; /* twasn't found */
}

bool Curl_multi_pipeline_enabled(const struct Curl_multi *multi)
{
  return (multi && multi->pipelining_enabled) ? TRUE : FALSE;
}

void Curl_multi_handlePipeBreak(struct SessionHandle *data)
{
  data->easy_conn = NULL;
}

static int waitconnect_getsock(struct connectdata *conn,
                               curl_socket_t *sock,
                               int numsocks)
{
  if(!numsocks)
    return GETSOCK_BLANK;

  sock[0] = conn->sock[FIRSTSOCKET];

  /* when we've sent a CONNECT to a proxy, we should rather wait for the
     socket to become readable to be able to get the response headers */
  if(conn->tunnel_state[FIRSTSOCKET] == TUNNEL_CONNECT)
    return GETSOCK_READSOCK(0);

  return GETSOCK_WRITESOCK(0);
}

static int domore_getsock(struct connectdata *conn,
                          curl_socket_t *socks,
                          int numsocks)
{
  if(conn && conn->handler->domore_getsock)
    return conn->handler->domore_getsock(conn, socks, numsocks);
  return GETSOCK_BLANK;
}

/* returns bitmapped flags for this handle and its sockets */
static int multi_getsock(struct SessionHandle *easy,
                         curl_socket_t *socks, /* points to numsocks number
                                                  of sockets */
                         int numsocks)
{
  /* If the pipe broke, or if there's no connection left for this easy handle,
     then we MUST bail out now with no bitmask set. The no connection case can
     happen when this is called from curl_multi_remove_handle() =>
     singlesocket() => multi_getsock().
  */
  if(easy->state.pipe_broke || !easy->easy_conn)
    return 0;

  if(easy->mstate > CURLM_STATE_CONNECT &&
     easy->mstate < CURLM_STATE_COMPLETED) {
    /* Set up ownership correctly */
    easy->easy_conn->data = easy;
  }

  switch(easy->mstate) {
  default:
#if 0 /* switch back on these cases to get the compiler to check for all enums
         to be present */
  case CURLM_STATE_TOOFAST:  /* returns 0, so will not select. */
  case CURLM_STATE_COMPLETED:
  case CURLM_STATE_MSGSENT:
  case CURLM_STATE_INIT:
  case CURLM_STATE_CONNECT:
  case CURLM_STATE_WAITDO:
  case CURLM_STATE_DONE:
  case CURLM_STATE_LAST:
    /* this will get called with CURLM_STATE_COMPLETED when a handle is
       removed */
#endif
    return 0;

  case CURLM_STATE_WAITRESOLVE:
    return Curl_resolver_getsock(easy->easy_conn, socks, numsocks);

  case CURLM_STATE_PROTOCONNECT:
    return Curl_protocol_getsock(easy->easy_conn, socks, numsocks);

  case CURLM_STATE_DO:
  case CURLM_STATE_DOING:
    return Curl_doing_getsock(easy->easy_conn, socks, numsocks);

  case CURLM_STATE_WAITPROXYCONNECT:
  case CURLM_STATE_WAITCONNECT:
    return waitconnect_getsock(easy->easy_conn, socks, numsocks);

  case CURLM_STATE_DO_MORE:
    return domore_getsock(easy->easy_conn, socks, numsocks);

  case CURLM_STATE_DO_DONE: /* since is set after DO is completed, we switch
                               to waiting for the same as the *PERFORM
                               states */
  case CURLM_STATE_PERFORM:
  case CURLM_STATE_WAITPERFORM:
    return Curl_single_getsock(easy->easy_conn, socks, numsocks);
  }

}

CURLMcode curl_multi_fdset(CURLM *multi_handle,
                           fd_set *read_fd_set, fd_set *write_fd_set,
                           fd_set *exc_fd_set, int *max_fd)
{
  /* Scan through all the easy handles to get the file descriptors set.
     Some easy handles may not have connected to the remote host yet,
     and then we must make sure that is done. */
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct SessionHandle *easy;
  int this_max_fd=-1;
  curl_socket_t sockbunch[MAX_SOCKSPEREASYHANDLE];
  int bitmap;
  int i;
  (void)exc_fd_set; /* not used */

  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  easy=multi->easyp;
  while(easy) {
    bitmap = multi_getsock(easy, sockbunch, MAX_SOCKSPEREASYHANDLE);

    for(i=0; i< MAX_SOCKSPEREASYHANDLE; i++) {
      curl_socket_t s = CURL_SOCKET_BAD;

      if((bitmap & GETSOCK_READSOCK(i)) && VALID_SOCK((sockbunch[i]))) {
        FD_SET(sockbunch[i], read_fd_set);
        s = sockbunch[i];
      }
      if((bitmap & GETSOCK_WRITESOCK(i)) && VALID_SOCK((sockbunch[i]))) {
        FD_SET(sockbunch[i], write_fd_set);
        s = sockbunch[i];
      }
      if(s == CURL_SOCKET_BAD)
        /* this socket is unused, break out of loop */
        break;
      else {
        if((int)s > this_max_fd)
          this_max_fd = (int)s;
      }
    }

    easy = easy->next; /* check next handle */
  }

  *max_fd = this_max_fd;

  return CURLM_OK;
}

CURLMcode curl_multi_wait(CURLM *multi_handle,
                          struct curl_waitfd extra_fds[],
                          unsigned int extra_nfds,
                          int timeout_ms,
                          int *ret)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct SessionHandle *easy;
  curl_socket_t sockbunch[MAX_SOCKSPEREASYHANDLE];
  int bitmap;
  unsigned int i;
  unsigned int nfds = 0;
  unsigned int curlfds;
  struct pollfd *ufds = NULL;
  long timeout_internal;

  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  /* If the internally desired timeout is actually shorter than requested from
     the outside, then use the shorter time! But only if the internal timer
     is actually larger than 0! */
  (void)multi_timeout(multi, &timeout_internal);
  if((timeout_internal > 0) && (timeout_internal < (long)timeout_ms))
    timeout_ms = (int)timeout_internal;

  /* Count up how many fds we have from the multi handle */
  easy=multi->easyp;
  while(easy) {
    bitmap = multi_getsock(easy, sockbunch, MAX_SOCKSPEREASYHANDLE);

    for(i=0; i< MAX_SOCKSPEREASYHANDLE; i++) {
      curl_socket_t s = CURL_SOCKET_BAD;

      if(bitmap & GETSOCK_READSOCK(i)) {
        ++nfds;
        s = sockbunch[i];
      }
      if(bitmap & GETSOCK_WRITESOCK(i)) {
        ++nfds;
        s = sockbunch[i];
      }
      if(s == CURL_SOCKET_BAD) {
        break;
      }
    }

    easy = easy->next; /* check next handle */
  }

  curlfds = nfds; /* number of internal file descriptors */
  nfds += extra_nfds; /* add the externally provided ones */

  if(nfds) {
    ufds = malloc(nfds * sizeof(struct pollfd));
    if(!ufds)
      return CURLM_OUT_OF_MEMORY;
  }
  nfds = 0;

  /* only do the second loop if we found descriptors in the first stage run
     above */

  if(curlfds) {
    /* Add the curl handles to our pollfds first */
    easy=multi->easyp;
    while(easy) {
      bitmap = multi_getsock(easy, sockbunch, MAX_SOCKSPEREASYHANDLE);

      for(i=0; i< MAX_SOCKSPEREASYHANDLE; i++) {
        curl_socket_t s = CURL_SOCKET_BAD;

        if(bitmap & GETSOCK_READSOCK(i)) {
          ufds[nfds].fd = sockbunch[i];
          ufds[nfds].events = POLLIN;
          ++nfds;
          s = sockbunch[i];
        }
        if(bitmap & GETSOCK_WRITESOCK(i)) {
          ufds[nfds].fd = sockbunch[i];
          ufds[nfds].events = POLLOUT;
          ++nfds;
          s = sockbunch[i];
        }
        if(s == CURL_SOCKET_BAD) {
          break;
        }
      }

      easy = easy->next; /* check next handle */
    }
  }

  /* Add external file descriptions from poll-like struct curl_waitfd */
  for(i = 0; i < extra_nfds; i++) {
    ufds[nfds].fd = extra_fds[i].fd;
    ufds[nfds].events = 0;
    if(extra_fds[i].events & CURL_WAIT_POLLIN)
      ufds[nfds].events |= POLLIN;
    if(extra_fds[i].events & CURL_WAIT_POLLPRI)
      ufds[nfds].events |= POLLPRI;
    if(extra_fds[i].events & CURL_WAIT_POLLOUT)
      ufds[nfds].events |= POLLOUT;
    ++nfds;
  }

  if(nfds) {
    /* wait... */
    i = Curl_poll(ufds, nfds, timeout_ms);

    if(i) {
      unsigned int j;
      /* copy revents results from the poll to the curl_multi_wait poll
         struct, the bit values of the actual underlying poll() implementation
         may not be the same as the ones in the public libcurl API! */
      for(j = 0; j < extra_nfds; j++) {
        unsigned short mask = 0;
        unsigned r = ufds[curlfds + j].revents;

        if(r & POLLIN)
          mask |= CURL_WAIT_POLLIN;
        if(r & POLLOUT)
          mask |= CURL_WAIT_POLLOUT;
        if(r & POLLPRI)
          mask |= CURL_WAIT_POLLPRI;

        extra_fds[j].revents = mask;
      }
    }
  }
  else
    i = 0;

  Curl_safefree(ufds);
  if(ret)
    *ret = i;
  return CURLM_OK;
}

static CURLMcode multi_runsingle(struct Curl_multi *multi,
                                 struct timeval now,
                                 struct SessionHandle *easy)
{
  struct Curl_message *msg = NULL;
  bool connected;
  bool async;
  bool protocol_connect = FALSE;
  bool dophase_done = FALSE;
  bool done = FALSE;
  CURLMcode result = CURLM_OK;
  struct SingleRequest *k;
  struct SessionHandle *data;
  long timeout_ms;
  int control;

  if(!GOOD_EASY_HANDLE(easy))
    return CURLM_BAD_EASY_HANDLE;

  data = easy;

  do {
    /* this is a single-iteration do-while loop just to allow a
       break to skip to the end of it */
    bool disconnect_conn = FALSE;

    /* Handle the case when the pipe breaks, i.e., the connection
       we're using gets cleaned up and we're left with nothing. */
    if(data->state.pipe_broke) {
      infof(data, "Pipe broke: handle 0x%p, url = %s\n",
            (void *)easy, data->state.path);

      if(easy->mstate < CURLM_STATE_COMPLETED) {
        /* Head back to the CONNECT state */
        multistate(easy, CURLM_STATE_CONNECT);
        result = CURLM_CALL_MULTI_PERFORM;
        easy->result = CURLE_OK;
      }

      data->state.pipe_broke = FALSE;
      easy->easy_conn = NULL;
      break;
    }

    if(!easy->easy_conn &&
       easy->mstate > CURLM_STATE_CONNECT &&
       easy->mstate < CURLM_STATE_DONE) {
      /* In all these states, the code will blindly access 'easy->easy_conn'
         so this is precaution that it isn't NULL. And it silences static
         analyzers. */
      failf(data, "In state %d with no easy_conn, bail out!\n", easy->mstate);
      return CURLM_INTERNAL_ERROR;
    }

    if(easy->easy_conn && easy->mstate > CURLM_STATE_CONNECT &&
       easy->mstate < CURLM_STATE_COMPLETED)
      /* Make sure we set the connection's current owner */
      easy->easy_conn->data = data;

    if(easy->easy_conn &&
       (easy->mstate >= CURLM_STATE_CONNECT) &&
       (easy->mstate < CURLM_STATE_COMPLETED)) {
      /* we need to wait for the connect state as only then is the start time
         stored, but we must not check already completed handles */

      timeout_ms = Curl_timeleft(data, &now,
                                 (easy->mstate <= CURLM_STATE_WAITDO)?
                                 TRUE:FALSE);

      if(timeout_ms < 0) {
        /* Handle timed out */
        if(easy->mstate == CURLM_STATE_WAITRESOLVE)
          failf(data, "Resolving timed out after %ld milliseconds",
                Curl_tvdiff(now, data->progress.t_startsingle));
        else if(easy->mstate == CURLM_STATE_WAITCONNECT)
          failf(data, "Connection timed out after %ld milliseconds",
                Curl_tvdiff(now, data->progress.t_startsingle));
        else {
          k = &data->req;
          failf(data, "Operation timed out after %ld milliseconds with %"
                FORMAT_OFF_T " out of %" FORMAT_OFF_T " bytes received",
                Curl_tvdiff(now, data->progress.t_startsingle), k->bytecount,
                k->size);
        }

        /* Force the connection closed because the server could continue to
           send us stuff at any time. (The disconnect_conn logic used below
           doesn't work at this point). */
        easy->easy_conn->bits.close = TRUE;
        easy->result = CURLE_OPERATION_TIMEDOUT;
        multistate(easy, CURLM_STATE_COMPLETED);
        break;
      }
    }

    switch(easy->mstate) {
    case CURLM_STATE_INIT:
      /* init this transfer. */
      easy->result=Curl_pretransfer(data);

      if(CURLE_OK == easy->result) {
        /* after init, go CONNECT */
        multistate(easy, CURLM_STATE_CONNECT);
        result = CURLM_CALL_MULTI_PERFORM;
      }
      break;

    case CURLM_STATE_CONNECT_PEND:
      /* We will stay here until there is a connection available. Then
         we try again in the CURLM_STATE_CONNECT state. */
      break;

    case CURLM_STATE_CONNECT:
      /* Connect. We want to get a connection identifier filled in. */
      Curl_pgrsTime(data, TIMER_STARTSINGLE);
      easy->result = Curl_connect(data, &easy->easy_conn,
                                  &async, &protocol_connect);
      if(CURLE_NO_CONNECTION_AVAILABLE == easy->result) {
        /* There was no connection available. We will go to the pending
           state and wait for an available connection. */
        multistate(easy, CURLM_STATE_CONNECT_PEND);
        easy->result = CURLE_OK;
        break;
      }

      if(CURLE_OK == easy->result) {
        /* Add this handle to the send or pend pipeline */
        easy->result = Curl_add_handle_to_pipeline(data, easy->easy_conn);
        if(CURLE_OK != easy->result)
          disconnect_conn = TRUE;
        else {
          if(async)
            /* We're now waiting for an asynchronous name lookup */
            multistate(easy, CURLM_STATE_WAITRESOLVE);
          else {
            /* after the connect has been sent off, go WAITCONNECT unless the
               protocol connect is already done and we can go directly to
               WAITDO or DO! */
            result = CURLM_CALL_MULTI_PERFORM;

            if(protocol_connect)
              multistate(easy, multi->pipelining_enabled?
                         CURLM_STATE_WAITDO:CURLM_STATE_DO);
            else {
#ifndef CURL_DISABLE_HTTP
              if(easy->easy_conn->tunnel_state[FIRSTSOCKET] == TUNNEL_CONNECT)
                multistate(easy, CURLM_STATE_WAITPROXYCONNECT);
              else
#endif
                multistate(easy, CURLM_STATE_WAITCONNECT);
            }
          }
        }
      }
      break;

    case CURLM_STATE_WAITRESOLVE:
      /* awaiting an asynch name resolve to complete */
    {
      struct Curl_dns_entry *dns = NULL;

      /* check if we have the name resolved by now */
      easy->result = Curl_resolver_is_resolved(easy->easy_conn, &dns);

      /* Update sockets here, because the socket(s) may have been
         closed and the application thus needs to be told, even if it
         is likely that the same socket(s) will again be used further
         down.  If the name has not yet been resolved, it is likely
         that new sockets have been opened in an attempt to contact
         another resolver. */
      singlesocket(multi, easy);

      if(dns) {
        /* Perform the next step in the connection phase, and then move on
           to the WAITCONNECT state */
        easy->result = Curl_async_resolved(easy->easy_conn,
                                           &protocol_connect);

        if(CURLE_OK != easy->result)
          /* if Curl_async_resolved() returns failure, the connection struct
             is already freed and gone */
          easy->easy_conn = NULL;           /* no more connection */
        else {
          /* call again please so that we get the next socket setup */
          result = CURLM_CALL_MULTI_PERFORM;
          if(protocol_connect)
            multistate(easy, multi->pipelining_enabled?
                       CURLM_STATE_WAITDO:CURLM_STATE_DO);
          else {
#ifndef CURL_DISABLE_HTTP
            if(easy->easy_conn->tunnel_state[FIRSTSOCKET] == TUNNEL_CONNECT)
              multistate(easy, CURLM_STATE_WAITPROXYCONNECT);
            else
#endif
              multistate(easy, CURLM_STATE_WAITCONNECT);
          }
        }
      }

      if(CURLE_OK != easy->result) {
        /* failure detected */
        disconnect_conn = TRUE;
        break;
      }
    }
    break;

#ifndef CURL_DISABLE_HTTP
    case CURLM_STATE_WAITPROXYCONNECT:
      /* this is HTTP-specific, but sending CONNECT to a proxy is HTTP... */
      easy->result = Curl_http_connect(easy->easy_conn, &protocol_connect);

      if(easy->easy_conn->bits.proxy_connect_closed) {
        /* reset the error buffer */
        if(data->set.errorbuffer)
          data->set.errorbuffer[0] = '\0';
        data->state.errorbuf = FALSE;

        easy->result = CURLE_OK;
        result = CURLM_CALL_MULTI_PERFORM;
        multistate(easy, CURLM_STATE_CONNECT);
      }
      else if(CURLE_OK == easy->result) {
        if(easy->easy_conn->tunnel_state[FIRSTSOCKET] == TUNNEL_COMPLETE)
          multistate(easy, CURLM_STATE_WAITCONNECT);
      }
      break;
#endif

    case CURLM_STATE_WAITCONNECT:
      /* awaiting a completion of an asynch connect */
      easy->result = Curl_is_connected(easy->easy_conn,
                                       FIRSTSOCKET,
                                       &connected);
      if(connected) {

        if(!easy->result)
          /* if everything is still fine we do the protocol-specific connect
             setup */
          easy->result = Curl_protocol_connect(easy->easy_conn,
                                               &protocol_connect);
      }

      if(CURLE_OK != easy->result) {
        /* failure detected */
        /* Just break, the cleaning up is handled all in one place */
        disconnect_conn = TRUE;
        break;
      }

      if(connected) {
        if(!protocol_connect) {
          /* We have a TCP connection, but 'protocol_connect' may be false
             and then we continue to 'STATE_PROTOCONNECT'. If protocol
             connect is TRUE, we move on to STATE_DO.
             BUT if we are using a proxy we must change to WAITPROXYCONNECT
          */
#ifndef CURL_DISABLE_HTTP
          if(easy->easy_conn->tunnel_state[FIRSTSOCKET] == TUNNEL_CONNECT)
            multistate(easy, CURLM_STATE_WAITPROXYCONNECT);
          else
#endif
            multistate(easy, CURLM_STATE_PROTOCONNECT);

        }
        else
          /* after the connect has completed, go WAITDO or DO */
          multistate(easy, multi->pipelining_enabled?
                     CURLM_STATE_WAITDO:CURLM_STATE_DO);

        result = CURLM_CALL_MULTI_PERFORM;
      }
      break;

    case CURLM_STATE_PROTOCONNECT:
      /* protocol-specific connect phase */
      easy->result = Curl_protocol_connecting(easy->easy_conn,
                                              &protocol_connect);
      if((easy->result == CURLE_OK) && protocol_connect) {
        /* after the connect has completed, go WAITDO or DO */
        multistate(easy, multi->pipelining_enabled?
                   CURLM_STATE_WAITDO:CURLM_STATE_DO);
        result = CURLM_CALL_MULTI_PERFORM;
      }
      else if(easy->result) {
        /* failure detected */
        Curl_posttransfer(data);
        Curl_done(&easy->easy_conn, easy->result, TRUE);
        disconnect_conn = TRUE;
      }
      break;

    case CURLM_STATE_WAITDO:
      /* Wait for our turn to DO when we're pipelining requests */
#ifdef DEBUGBUILD
      infof(data, "WAITDO: Conn %ld send pipe %zu inuse %s athead %s\n",
            easy->easy_conn->connection_id,
            easy->easy_conn->send_pipe->size,
            easy->easy_conn->writechannel_inuse?"TRUE":"FALSE",
            isHandleAtHead(data,
                           easy->easy_conn->send_pipe)?"TRUE":"FALSE");
#endif
      if(!easy->easy_conn->writechannel_inuse &&
         isHandleAtHead(data,
                        easy->easy_conn->send_pipe)) {
        /* Grab the channel */
        easy->easy_conn->writechannel_inuse = TRUE;
        multistate(easy, CURLM_STATE_DO);
        result = CURLM_CALL_MULTI_PERFORM;
      }
      break;

    case CURLM_STATE_DO:
      if(data->set.connect_only) {
        /* keep connection open for application to use the socket */
        easy->easy_conn->bits.close = FALSE;
        multistate(easy, CURLM_STATE_DONE);
        easy->result = CURLE_OK;
        result = CURLM_CALL_MULTI_PERFORM;
      }
      else {
        /* Perform the protocol's DO action */
        easy->result = Curl_do(&easy->easy_conn, &dophase_done);

        /* When Curl_do() returns failure, easy->easy_conn might be NULL! */

        if(CURLE_OK == easy->result) {
          if(!dophase_done) {
            /* some steps needed for wildcard matching */
            if(data->set.wildcardmatch) {
              struct WildcardData *wc = &data->wildcard;
              if(wc->state == CURLWC_DONE || wc->state == CURLWC_SKIP) {
                /* skip some states if it is important */
                Curl_done(&easy->easy_conn, CURLE_OK, FALSE);
                multistate(easy, CURLM_STATE_DONE);
                result = CURLM_CALL_MULTI_PERFORM;
                break;
              }
            }
            /* DO was not completed in one function call, we must continue
               DOING... */
            multistate(easy, CURLM_STATE_DOING);
            result = CURLM_OK;
          }

          /* after DO, go DO_DONE... or DO_MORE */
          else if(easy->easy_conn->bits.do_more) {
            /* we're supposed to do more, but we need to sit down, relax
               and wait a little while first */
            multistate(easy, CURLM_STATE_DO_MORE);
            result = CURLM_OK;
          }
          else {
            /* we're done with the DO, now DO_DONE */
            multistate(easy, CURLM_STATE_DO_DONE);
            result = CURLM_CALL_MULTI_PERFORM;
          }
        }
        else if((CURLE_SEND_ERROR == easy->result) &&
                easy->easy_conn->bits.reuse) {
          /*
           * In this situation, a connection that we were trying to use
           * may have unexpectedly died.  If possible, send the connection
           * back to the CONNECT phase so we can try again.
           */
          char *newurl = NULL;
          followtype follow=FOLLOW_NONE;
          CURLcode drc;
          bool retry = FALSE;

          drc = Curl_retry_request(easy->easy_conn, &newurl);
          if(drc) {
            /* a failure here pretty much implies an out of memory */
            easy->result = drc;
            disconnect_conn = TRUE;
          }
          else
            retry = (newurl)?TRUE:FALSE;

          Curl_posttransfer(data);
          drc = Curl_done(&easy->easy_conn, easy->result, FALSE);

          /* When set to retry the connection, we must to go back to
           * the CONNECT state */
          if(retry) {
            if((drc == CURLE_OK) || (drc == CURLE_SEND_ERROR)) {
              follow = FOLLOW_RETRY;
              drc = Curl_follow(data, newurl, follow);
              if(drc == CURLE_OK) {
                multistate(easy, CURLM_STATE_CONNECT);
                result = CURLM_CALL_MULTI_PERFORM;
                easy->result = CURLE_OK;
              }
              else {
                /* Follow failed */
                easy->result = drc;
                free(newurl);
              }
            }
            else {
              /* done didn't return OK or SEND_ERROR */
              easy->result = drc;
              free(newurl);
            }
          }
          else {
            /* Have error handler disconnect conn if we can't retry */
            disconnect_conn = TRUE;
          }
        }
        else {
          /* failure detected */
          Curl_posttransfer(data);
          if(easy->easy_conn)
            Curl_done(&easy->easy_conn, easy->result, FALSE);
          disconnect_conn = TRUE;
        }
      }
      break;

    case CURLM_STATE_DOING:
      /* we continue DOING until the DO phase is complete */
      easy->result = Curl_protocol_doing(easy->easy_conn,
                                         &dophase_done);
      if(CURLE_OK == easy->result) {
        if(dophase_done) {
          /* after DO, go DO_DONE or DO_MORE */
          multistate(easy, easy->easy_conn->bits.do_more?
                     CURLM_STATE_DO_MORE:
                     CURLM_STATE_DO_DONE);
          result = CURLM_CALL_MULTI_PERFORM;
        } /* dophase_done */
      }
      else {
        /* failure detected */
        Curl_posttransfer(data);
        Curl_done(&easy->easy_conn, easy->result, FALSE);
        disconnect_conn = TRUE;
      }
      break;

    case CURLM_STATE_DO_MORE:
      /*
       * When we are connected, DO MORE and then go DO_DONE
       */
      easy->result = Curl_do_more(easy->easy_conn, &control);

      /* No need to remove this handle from the send pipeline here since that
         is done in Curl_done() */
      if(CURLE_OK == easy->result) {
        if(control) {
          /* if positive, advance to DO_DONE
             if negative, go back to DOING */
          multistate(easy, control==1?
                     CURLM_STATE_DO_DONE:
                     CURLM_STATE_DOING);
          result = CURLM_CALL_MULTI_PERFORM;
        }
        else
          /* stay in DO_MORE */
          result = CURLM_OK;
      }
      else {
        /* failure detected */
        Curl_posttransfer(data);
        Curl_done(&easy->easy_conn, easy->result, FALSE);
        disconnect_conn = TRUE;
      }
      break;

    case CURLM_STATE_DO_DONE:
      /* Move ourselves from the send to recv pipeline */
      Curl_move_handle_from_send_to_recv_pipe(data, easy->easy_conn);
      /* Check if we can move pending requests to send pipe */
      Curl_multi_process_pending_handles(multi);
      multistate(easy, CURLM_STATE_WAITPERFORM);
      result = CURLM_CALL_MULTI_PERFORM;
      break;

    case CURLM_STATE_WAITPERFORM:
      /* Wait for our turn to PERFORM */
      if(!easy->easy_conn->readchannel_inuse &&
         isHandleAtHead(data,
                        easy->easy_conn->recv_pipe)) {
        /* Grab the channel */
        easy->easy_conn->readchannel_inuse = TRUE;
        multistate(easy, CURLM_STATE_PERFORM);
        result = CURLM_CALL_MULTI_PERFORM;
      }
#ifdef DEBUGBUILD
      else {
        infof(data, "WAITPERFORM: Conn %ld recv pipe %zu inuse %s athead %s\n",
              easy->easy_conn->connection_id,
              easy->easy_conn->recv_pipe->size,
              easy->easy_conn->readchannel_inuse?"TRUE":"FALSE",
              isHandleAtHead(data,
                             easy->easy_conn->recv_pipe)?"TRUE":"FALSE");
      }
#endif
      break;

    case CURLM_STATE_TOOFAST: /* limit-rate exceeded in either direction */
      /* if both rates are within spec, resume transfer */
      if(Curl_pgrsUpdate(easy->easy_conn))
        easy->result = CURLE_ABORTED_BY_CALLBACK;
      else
        easy->result = Curl_speedcheck(data, now);

      if(( (data->set.max_send_speed == 0) ||
           (data->progress.ulspeed < data->set.max_send_speed ))  &&
         ( (data->set.max_recv_speed == 0) ||
           (data->progress.dlspeed < data->set.max_recv_speed)))
        multistate(easy, CURLM_STATE_PERFORM);
      break;

    case CURLM_STATE_PERFORM:
      {
      char *newurl = NULL;
      bool retry = FALSE;

      /* check if over send speed */
      if((data->set.max_send_speed > 0) &&
         (data->progress.ulspeed > data->set.max_send_speed)) {
        int buffersize;

        multistate(easy, CURLM_STATE_TOOFAST);

        /* calculate upload rate-limitation timeout. */
        buffersize = (int)(data->set.buffer_size ?
                           data->set.buffer_size : BUFSIZE);
        timeout_ms = Curl_sleep_time(data->set.max_send_speed,
                                     data->progress.ulspeed, buffersize);
        Curl_expire(data, timeout_ms);
        break;
      }

      /* check if over recv speed */
      if((data->set.max_recv_speed > 0) &&
         (data->progress.dlspeed > data->set.max_recv_speed)) {
        int buffersize;

        multistate(easy, CURLM_STATE_TOOFAST);

         /* Calculate download rate-limitation timeout. */
        buffersize = (int)(data->set.buffer_size ?
                           data->set.buffer_size : BUFSIZE);
        timeout_ms = Curl_sleep_time(data->set.max_recv_speed,
                                     data->progress.dlspeed, buffersize);
        Curl_expire(data, timeout_ms);
        break;
      }

      /* read/write data if it is ready to do so */
      easy->result = Curl_readwrite(easy->easy_conn, &done);

      k = &data->req;

      if(!(k->keepon & KEEP_RECV)) {
        /* We're done receiving */
        easy->easy_conn->readchannel_inuse = FALSE;
      }

      if(!(k->keepon & KEEP_SEND)) {
        /* We're done sending */
        easy->easy_conn->writechannel_inuse = FALSE;
      }

      if(done || (easy->result == CURLE_RECV_ERROR)) {
        /* If CURLE_RECV_ERROR happens early enough, we assume it was a race
         * condition and the server closed the re-used connection exactly when
         * we wanted to use it, so figure out if that is indeed the case.
         */
        CURLcode ret = Curl_retry_request(easy->easy_conn, &newurl);
        if(!ret)
          retry = (newurl)?TRUE:FALSE;

        if(retry) {
          /* if we are to retry, set the result to OK and consider the
             request as done */
          easy->result = CURLE_OK;
          done = TRUE;
        }
      }

      if(easy->result) {
        /*
         * The transfer phase returned error, we mark the connection to get
         * closed to prevent being re-used. This is because we can't possibly
         * know if the connection is in a good shape or not now.  Unless it is
         * a protocol which uses two "channels" like FTP, as then the error
         * happened in the data connection.
         */

        if(!(easy->easy_conn->handler->flags & PROTOPT_DUAL))
          easy->easy_conn->bits.close = TRUE;

        Curl_posttransfer(data);
        Curl_done(&easy->easy_conn, easy->result, FALSE);
      }
      else if(done) {
        followtype follow=FOLLOW_NONE;

        /* call this even if the readwrite function returned error */
        Curl_posttransfer(data);

        /* we're no longer receiving */
        Curl_removeHandleFromPipeline(data, easy->easy_conn->recv_pipe);

        /* expire the new receiving pipeline head */
        if(easy->easy_conn->recv_pipe->head)
          Curl_expire(easy->easy_conn->recv_pipe->head->ptr, 1);

        /* Check if we can move pending requests to send pipe */
        Curl_multi_process_pending_handles(multi);

        /* When we follow redirects or is set to retry the connection, we must
           to go back to the CONNECT state */
        if(data->req.newurl || retry) {
          if(!retry) {
            /* if the URL is a follow-location and not just a retried request
               then figure out the URL here */
            newurl = data->req.newurl;
            data->req.newurl = NULL;
            follow = FOLLOW_REDIR;
          }
          else
            follow = FOLLOW_RETRY;
          easy->result = Curl_done(&easy->easy_conn, CURLE_OK, FALSE);
          if(CURLE_OK == easy->result) {
            easy->result = Curl_follow(data, newurl, follow);
            if(CURLE_OK == easy->result) {
              multistate(easy, CURLM_STATE_CONNECT);
              result = CURLM_CALL_MULTI_PERFORM;
              newurl = NULL; /* handed over the memory ownership to
                                Curl_follow(), make sure we don't free() it
                                here */
            }
          }
        }
        else {
          /* after the transfer is done, go DONE */

          /* but first check to see if we got a location info even though we're
             not following redirects */
          if(data->req.location) {
            if(newurl)
              free(newurl);
            newurl = data->req.location;
            data->req.location = NULL;
            easy->result = Curl_follow(data, newurl, FOLLOW_FAKE);
            if(CURLE_OK == easy->result)
              newurl = NULL; /* allocation was handed over Curl_follow() */
            else
              disconnect_conn = TRUE;
          }

          multistate(easy, CURLM_STATE_DONE);
          result = CURLM_CALL_MULTI_PERFORM;
        }
      }

      if(newurl)
        free(newurl);
      break;
      }

    case CURLM_STATE_DONE:

      if(easy->easy_conn) {
        /* Remove ourselves from the receive pipeline, if we are there. */
        Curl_removeHandleFromPipeline(data,
                                      easy->easy_conn->recv_pipe);
        /* Check if we can move pending requests to send pipe */
        Curl_multi_process_pending_handles(multi);

        if(easy->easy_conn->bits.stream_was_rewound) {
          /* This request read past its response boundary so we quickly let
             the other requests consume those bytes since there is no
             guarantee that the socket will become active again */
          result = CURLM_CALL_MULTI_PERFORM;
        }

        /* post-transfer command */
        easy->result = Curl_done(&easy->easy_conn, CURLE_OK, FALSE);
        /*
         * If there are other handles on the pipeline, Curl_done won't set
         * easy_conn to NULL.  In such a case, curl_multi_remove_handle() can
         * access free'd data, if the connection is free'd and the handle
         * removed before we perform the processing in CURLM_STATE_COMPLETED
         */
        if(easy->easy_conn)
          easy->easy_conn = NULL;
      }

      if(data->set.wildcardmatch) {
        if(data->wildcard.state != CURLWC_DONE) {
          /* if a wildcard is set and we are not ending -> lets start again
             with CURLM_STATE_INIT */
          result = CURLM_CALL_MULTI_PERFORM;
          multistate(easy, CURLM_STATE_INIT);
          break;
        }
      }

      /* after we have DONE what we're supposed to do, go COMPLETED, and
         it doesn't matter what the Curl_done() returned! */
      multistate(easy, CURLM_STATE_COMPLETED);

      break;

    case CURLM_STATE_COMPLETED:
      /* this is a completed transfer, it is likely to still be connected */

      /* This node should be delinked from the list now and we should post
         an information message that we are complete. */

      /* Important: reset the conn pointer so that we don't point to memory
         that could be freed anytime */
      easy->easy_conn = NULL;

      Curl_expire(data, 0); /* stop all timers */
      break;

    case CURLM_STATE_MSGSENT:
      return CURLM_OK; /* do nothing */

    default:
      return CURLM_INTERNAL_ERROR;
    }

    if(easy->mstate < CURLM_STATE_COMPLETED) {
      if(CURLE_OK != easy->result) {
        /*
         * If an error was returned, and we aren't in completed state now,
         * then we go to completed and consider this transfer aborted.
         */

        /* NOTE: no attempt to disconnect connections must be made
           in the case blocks above - cleanup happens only here */

        data->state.pipe_broke = FALSE;

        if(easy->easy_conn) {
          /* if this has a connection, unsubscribe from the pipelines */
          easy->easy_conn->writechannel_inuse = FALSE;
          easy->easy_conn->readchannel_inuse = FALSE;
          Curl_removeHandleFromPipeline(data,
                                        easy->easy_conn->send_pipe);
          Curl_removeHandleFromPipeline(data,
                                        easy->easy_conn->recv_pipe);
          /* Check if we can move pending requests to send pipe */
          Curl_multi_process_pending_handles(multi);

          if(disconnect_conn) {
            /* disconnect properly */
            Curl_disconnect(easy->easy_conn, /* dead_connection */ FALSE);

            /* This is where we make sure that the easy_conn pointer is reset.
               We don't have to do this in every case block above where a
               failure is detected */
            easy->easy_conn = NULL;
          }
        }
        else if(easy->mstate == CURLM_STATE_CONNECT) {
          /* Curl_connect() failed */
          (void)Curl_posttransfer(data);
        }

        multistate(easy, CURLM_STATE_COMPLETED);
      }
      /* if there's still a connection to use, call the progress function */
      else if(easy->easy_conn && Curl_pgrsUpdate(easy->easy_conn)) {
        /* aborted due to progress callback return code must close the
           connection */
        easy->easy_conn->bits.close = TRUE;

        /* if not yet in DONE state, go there, otherwise COMPLETED */
        multistate(easy, (easy->mstate < CURLM_STATE_DONE)?
                   CURLM_STATE_DONE: CURLM_STATE_COMPLETED);
        result = CURLM_CALL_MULTI_PERFORM;
      }
    }
  } WHILE_FALSE; /* just to break out from! */

  if(CURLM_STATE_COMPLETED == easy->mstate) {
    /* now fill in the Curl_message with this info */
    msg = &easy->msg;

    msg->extmsg.msg = CURLMSG_DONE;
    msg->extmsg.easy_handle = data;
    msg->extmsg.data.result = easy->result;

    result = multi_addmsg(multi, msg);

    multistate(easy, CURLM_STATE_MSGSENT);
  }

  return result;
}


CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct SessionHandle *easy;
  CURLMcode returncode=CURLM_OK;
  struct Curl_tree *t;
  struct timeval now = Curl_tvnow();

  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  easy=multi->easyp;
  while(easy) {
    CURLMcode result;
    struct WildcardData *wc = &easy->wildcard;

    if(easy->set.wildcardmatch) {
      if(!wc->filelist) {
        CURLcode ret = Curl_wildcard_init(wc); /* init wildcard structures */
        if(ret)
          return CURLM_OUT_OF_MEMORY;
      }
    }

    do
      result = multi_runsingle(multi, now, easy);
    while(CURLM_CALL_MULTI_PERFORM == result);

    if(easy->set.wildcardmatch) {
      /* destruct wildcard structures if it is needed */
      if(wc->state == CURLWC_DONE || result)
        Curl_wildcard_dtor(wc);
    }

    if(result)
      returncode = result;

    easy = easy->next; /* operate on next handle */
  }

  /*
   * Simply remove all expired timers from the splay since handles are dealt
   * with unconditionally by this function and curl_multi_timeout() requires
   * that already passed/handled expire times are removed from the splay.
   *
   * It is important that the 'now' value is set at the entry of this function
   * and not for the current time as it may have ticked a little while since
   * then and then we risk this loop to remove timers that actually have not
   * been handled!
   */
  do {
    multi->timetree = Curl_splaygetbest(now, multi->timetree, &t);
    if(t)
      /* the removed may have another timeout in queue */
      (void)add_next_timeout(now, multi, t->payload);

  } while(t);

  *running_handles = multi->num_alive;

  if(CURLM_OK >= returncode)
    update_timer(multi);

  return returncode;
}

static void close_all_connections(struct Curl_multi *multi)
{
  struct connectdata *conn;

  conn = Curl_conncache_find_first_connection(multi->conn_cache);
  while(conn) {
    conn->data = multi->closure_handle;

    /* This will remove the connection from the cache */
    (void)Curl_disconnect(conn, FALSE);

    conn = Curl_conncache_find_first_connection(multi->conn_cache);
  }
}

CURLMcode curl_multi_cleanup(CURLM *multi_handle)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct SessionHandle *easy;
  struct SessionHandle *nexteasy;

  if(GOOD_MULTI_HANDLE(multi)) {
    multi->type = 0; /* not good anymore */

    /* Close all the connections in the connection cache */
    close_all_connections(multi);

    if(multi->closure_handle) {
      multi->closure_handle->dns.hostcache = multi->hostcache;
      Curl_hostcache_clean(multi->closure_handle,
                           multi->closure_handle->dns.hostcache);

      Curl_close(multi->closure_handle);
      multi->closure_handle = NULL;
    }

    Curl_hash_destroy(multi->sockhash);
    multi->sockhash = NULL;

    Curl_conncache_destroy(multi->conn_cache);
    multi->conn_cache = NULL;

    /* remove the pending list of messages */
    Curl_llist_destroy(multi->msglist, NULL);
    multi->msglist = NULL;

    /* remove all easy handles */
    easy = multi->easyp;
    while(easy) {
      nexteasy=easy->next;
      if(easy->dns.hostcachetype == HCACHE_MULTI) {
        /* clear out the usage of the shared DNS cache */
        Curl_hostcache_clean(easy, easy->dns.hostcache);
        easy->dns.hostcache = NULL;
        easy->dns.hostcachetype = HCACHE_NONE;
      }

      /* Clear the pointer to the connection cache */
      easy->state.conn_cache = NULL;

      Curl_easy_addmulti(easy, NULL); /* clear the association */

      easy = nexteasy;
    }

    Curl_hash_destroy(multi->hostcache);
    multi->hostcache = NULL;

    /* Free the blacklists by setting them to NULL */
    Curl_pipeline_set_site_blacklist(NULL, &multi->pipelining_site_bl);
    Curl_pipeline_set_server_blacklist(NULL, &multi->pipelining_server_bl);

    free(multi);

    return CURLM_OK;
  }
  else
    return CURLM_BAD_HANDLE;
}

/*
 * curl_multi_info_read()
 *
 * This function is the primary way for a multi/multi_socket application to
 * figure out if a transfer has ended. We MUST make this function as fast as
 * possible as it will be polled frequently and we MUST NOT scan any lists in
 * here to figure out things. We must scale fine to thousands of handles and
 * beyond. The current design is fully O(1).
 */

CURLMsg *curl_multi_info_read(CURLM *multi_handle, int *msgs_in_queue)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct Curl_message *msg;

  *msgs_in_queue = 0; /* default to none */

  if(GOOD_MULTI_HANDLE(multi) && Curl_llist_count(multi->msglist)) {
    /* there is one or more messages in the list */
    struct curl_llist_element *e;

    /* extract the head of the list to return */
    e = multi->msglist->head;

    msg = e->ptr;

    /* remove the extracted entry */
    Curl_llist_remove(multi->msglist, e, NULL);

    *msgs_in_queue = curlx_uztosi(Curl_llist_count(multi->msglist));

    return &msg->extmsg;
  }
  else
    return NULL;
}

/*
 * singlesocket() checks what sockets we deal with and their "action state"
 * and if we have a different state in any of those sockets from last time we
 * call the callback accordingly.
 */
static void singlesocket(struct Curl_multi *multi,
                         struct SessionHandle *easy)
{
  curl_socket_t socks[MAX_SOCKSPEREASYHANDLE];
  int i;
  struct Curl_sh_entry *entry;
  curl_socket_t s;
  int num;
  unsigned int curraction;
  bool remove_sock_from_hash;

  for(i=0; i< MAX_SOCKSPEREASYHANDLE; i++)
    socks[i] = CURL_SOCKET_BAD;

  /* Fill in the 'current' struct with the state as it is now: what sockets to
     supervise and for what actions */
  curraction = multi_getsock(easy, socks, MAX_SOCKSPEREASYHANDLE);

  /* We have 0 .. N sockets already and we get to know about the 0 .. M
     sockets we should have from now on. Detect the differences, remove no
     longer supervised ones and add new ones */

  /* walk over the sockets we got right now */
  for(i=0; (i< MAX_SOCKSPEREASYHANDLE) &&
        (curraction & (GETSOCK_READSOCK(i) | GETSOCK_WRITESOCK(i)));
      i++) {
    int action = CURL_POLL_NONE;

    s = socks[i];

    /* get it from the hash */
    entry = Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));

    if(curraction & GETSOCK_READSOCK(i))
      action |= CURL_POLL_IN;
    if(curraction & GETSOCK_WRITESOCK(i))
      action |= CURL_POLL_OUT;

    if(entry) {
      /* yeps, already present so check if it has the same action set */
      if(entry->action == action)
        /* same, continue */
        continue;
    }
    else {
      /* this is a socket we didn't have before, add it! */
      entry = sh_addentry(multi->sockhash, s, easy);
      if(!entry)
        /* fatal */
        return;
    }

    /* we know (entry != NULL) at this point, see the logic above */
    if(multi->socket_cb)
      multi->socket_cb(easy,
                       s,
                       action,
                       multi->socket_userp,
                       entry->socketp);

    entry->action = action; /* store the current action state */
  }

  num = i; /* number of sockets */

  /* when we've walked over all the sockets we should have right now, we must
     make sure to detect sockets that are removed */
  for(i=0; i< easy->numsocks; i++) {
    int j;
    s = easy->sockets[i];
    for(j=0; j<num; j++) {
      if(s == socks[j]) {
        /* this is still supervised */
        s = CURL_SOCKET_BAD;
        break;
      }
    }
    if(s != CURL_SOCKET_BAD) {

      /* this socket has been removed. Tell the app to remove it */
      remove_sock_from_hash = TRUE;

      entry = Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));
      if(entry) {
        /* check if the socket to be removed serves a connection which has
           other easy-s in a pipeline. In this case the socket should not be
           removed. */
        struct connectdata *easy_conn = easy->easy_conn;
        if(easy_conn) {
          if(easy_conn->recv_pipe && easy_conn->recv_pipe->size > 1) {
            /* the handle should not be removed from the pipe yet */
            remove_sock_from_hash = FALSE;

            /* Update the sockhash entry to instead point to the next in line
               for the recv_pipe, or the first (in case this particular easy
               isn't already) */
            if(entry->easy == easy) {
              if(isHandleAtHead(easy, easy_conn->recv_pipe))
                entry->easy = easy_conn->recv_pipe->head->next->ptr;
              else
                entry->easy = easy_conn->recv_pipe->head->ptr;
            }
          }
          if(easy_conn->send_pipe  && easy_conn->send_pipe->size > 1) {
            /* the handle should not be removed from the pipe yet */
            remove_sock_from_hash = FALSE;

            /* Update the sockhash entry to instead point to the next in line
               for the send_pipe, or the first (in case this particular easy
               isn't already) */
            if(entry->easy == easy) {
              if(isHandleAtHead(easy, easy_conn->send_pipe))
                entry->easy = easy_conn->send_pipe->head->next->ptr;
              else
                entry->easy = easy_conn->send_pipe->head->ptr;
            }
          }
          /* Don't worry about overwriting recv_pipe head with send_pipe_head,
             when action will be asked on the socket (see multi_socket()), the
             head of the correct pipe will be taken according to the
             action. */
        }
      }
      else
        /* just a precaution, this socket really SHOULD be in the hash already
           but in case it isn't, we don't have to tell the app to remove it
           either since it never got to know about it */
        remove_sock_from_hash = FALSE;

      if(remove_sock_from_hash) {
        /* in this case 'entry' is always non-NULL */
        if(multi->socket_cb)
          multi->socket_cb(easy,
                           s,
                           CURL_POLL_REMOVE,
                           multi->socket_userp,
                           entry->socketp);
        sh_delentry(multi->sockhash, s);
      }

    }
  }

  memcpy(easy->sockets, socks, num*sizeof(curl_socket_t));
  easy->numsocks = num;
}

/*
 * Curl_multi_closed()
 *
 * Used by the connect code to tell the multi_socket code that one of the
 * sockets we were using have just been closed.  This function will then
 * remove it from the sockethash for this handle to make the multi_socket API
 * behave properly, especially for the case when libcurl will create another
 * socket again and it gets the same file descriptor number.
 */

void Curl_multi_closed(struct connectdata *conn, curl_socket_t s)
{
  struct Curl_multi *multi = conn->data->multi;
  if(multi) {
    /* this is set if this connection is part of a handle that is added to
       a multi handle, and only then this is necessary */
    struct Curl_sh_entry *entry =
      Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));

    if(entry) {
      if(multi->socket_cb)
        multi->socket_cb(conn->data, s, CURL_POLL_REMOVE,
                         multi->socket_userp,
                         entry->socketp);

      /* now remove it from the socket hash */
      sh_delentry(multi->sockhash, s);
    }
  }
}



/*
 * add_next_timeout()
 *
 * Each SessionHandle has a list of timeouts. The add_next_timeout() is called
 * when it has just been removed from the splay tree because the timeout has
 * expired. This function is then to advance in the list to pick the next
 * timeout to use (skip the already expired ones) and add this node back to
 * the splay tree again.
 *
 * The splay tree only has each sessionhandle as a single node and the nearest
 * timeout is used to sort it on.
 */
static CURLMcode add_next_timeout(struct timeval now,
                                  struct Curl_multi *multi,
                                  struct SessionHandle *d)
{
  struct timeval *tv = &d->state.expiretime;
  struct curl_llist *list = d->state.timeoutlist;
  struct curl_llist_element *e;

  /* move over the timeout list for this specific handle and remove all
     timeouts that are now passed tense and store the next pending
     timeout in *tv */
  for(e = list->head; e; ) {
    struct curl_llist_element *n = e->next;
    long diff = curlx_tvdiff(*(struct timeval *)e->ptr, now);
    if(diff <= 0)
      /* remove outdated entry */
      Curl_llist_remove(list, e, NULL);
    else
      /* the list is sorted so get out on the first mismatch */
      break;
    e = n;
  }
  e = list->head;
  if(!e) {
    /* clear the expire times within the handles that we remove from the
       splay tree */
    tv->tv_sec = 0;
    tv->tv_usec = 0;
  }
  else {
    /* copy the first entry to 'tv' */
    memcpy(tv, e->ptr, sizeof(*tv));

    /* remove first entry from list */
    Curl_llist_remove(list, e, NULL);

    /* insert this node again into the splay */
    multi->timetree = Curl_splayinsert(*tv, multi->timetree,
                                       &d->state.timenode);
  }
  return CURLM_OK;
}

#ifdef WIN32
#define TIMEOUT_INACCURACY 40000
#else
#define TIMEOUT_INACCURACY 3000
#endif

static CURLMcode multi_socket(struct Curl_multi *multi,
                              bool checkall,
                              curl_socket_t s,
                              int ev_bitmask,
                              int *running_handles)
{
  CURLMcode result = CURLM_OK;
  struct SessionHandle *data = NULL;
  struct Curl_tree *t;
  struct timeval now = Curl_tvnow();

  if(checkall) {
    struct SessionHandle *easy;
    /* *perform() deals with running_handles on its own */
    result = curl_multi_perform(multi, running_handles);

    /* walk through each easy handle and do the socket state change magic
       and callbacks */
    easy=multi->easyp;
    while(easy) {
      singlesocket(multi, easy);
      easy = easy->next;
    }

    /* or should we fall-through and do the timer-based stuff? */
    return result;
  }
  else if(s != CURL_SOCKET_TIMEOUT) {

    struct Curl_sh_entry *entry =
      Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));

    if(!entry)
      /* Unmatched socket, we can't act on it but we ignore this fact.  In
         real-world tests it has been proved that libevent can in fact give
         the application actions even though the socket was just previously
         asked to get removed, so thus we better survive stray socket actions
         and just move on. */
      ;
    else {
      data = entry->easy;

      if(data->magic != CURLEASY_MAGIC_NUMBER)
        /* bad bad bad bad bad bad bad */
        return CURLM_INTERNAL_ERROR;

      /* If the pipeline is enabled, take the handle which is in the head of
         the pipeline. If we should write into the socket, take the send_pipe
         head.  If we should read from the socket, take the recv_pipe head. */
      if(data->easy_conn) {
        if((ev_bitmask & CURL_POLL_OUT) &&
           data->easy_conn->send_pipe &&
           data->easy_conn->send_pipe->head)
          data = data->easy_conn->send_pipe->head->ptr;
        else if((ev_bitmask & CURL_POLL_IN) &&
                data->easy_conn->recv_pipe &&
                data->easy_conn->recv_pipe->head)
          data = data->easy_conn->recv_pipe->head->ptr;
      }

      if(data->easy_conn &&
         !(data->easy_conn->handler->flags & PROTOPT_DIRLOCK))
        /* set socket event bitmask if they're not locked */
        data->easy_conn->cselect_bits = ev_bitmask;

      do
        result = multi_runsingle(multi, now, data);
      while(CURLM_CALL_MULTI_PERFORM == result);

      if(data->easy_conn &&
         !(data->easy_conn->handler->flags & PROTOPT_DIRLOCK))
        /* clear the bitmask only if not locked */
        data->easy_conn->cselect_bits = 0;

      if(CURLM_OK >= result)
        /* get the socket(s) and check if the state has been changed since
           last */
        singlesocket(multi, data);

      /* Now we fall-through and do the timer-based stuff, since we don't want
         to force the user to have to deal with timeouts as long as at least
         one connection in fact has traffic. */

      data = NULL; /* set data to NULL again to avoid calling
                      multi_runsingle() in case there's no need to */
    }
  }

  /* Compensate for bad precision timers that might've triggered too early.

     This precaution was added in commit 2c72732ebf3da5e as a result of bad
     resolution in the windows function use(d).

     The problematic case here is when using the multi_socket API and libcurl
     has told the application about a timeout, and that timeout is what fires
     off a bit early. As we don't have any IDs associated with the timeout we
     can't tell which timeout that fired off but we only have the times to use
     to check what to do. If it fires off too early, we don't run the correct
     actions and we don't tell the application again about the same timeout as
     was already first in the queue...

     Originally we made the timeouts run 40 milliseconds early on all systems,
     but now we have an #ifdef setup to provide a decent precaution inaccuracy
     margin.
  */

  now.tv_usec += TIMEOUT_INACCURACY;
  if(now.tv_usec >= 1000000) {
    now.tv_sec++;
    now.tv_usec -= 1000000;
  }

  /*
   * The loop following here will go on as long as there are expire-times left
   * to process in the splay and 'data' will be re-assigned for every expired
   * handle we deal with.
   */
  do {
    /* the first loop lap 'data' can be NULL */
    if(data) {
      do
        result = multi_runsingle(multi, now, data);
      while(CURLM_CALL_MULTI_PERFORM == result);

      if(CURLM_OK >= result)
        /* get the socket(s) and check if the state has been changed since
           last */
        singlesocket(multi, data);
    }

    /* Check if there's one (more) expired timer to deal with! This function
       extracts a matching node if there is one */

    multi->timetree = Curl_splaygetbest(now, multi->timetree, &t);
    if(t) {
      data = t->payload; /* assign this for next loop */
      (void)add_next_timeout(now, multi, t->payload);
    }

  } while(t);

  *running_handles = multi->num_alive;
  return result;
}

#undef curl_multi_setopt
CURLMcode curl_multi_setopt(CURLM *multi_handle,
                            CURLMoption option, ...)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  CURLMcode res = CURLM_OK;
  va_list param;

  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  va_start(param, option);

  switch(option) {
  case CURLMOPT_SOCKETFUNCTION:
    multi->socket_cb = va_arg(param, curl_socket_callback);
    break;
  case CURLMOPT_SOCKETDATA:
    multi->socket_userp = va_arg(param, void *);
    break;
  case CURLMOPT_PIPELINING:
    multi->pipelining_enabled = (0 != va_arg(param, long)) ? TRUE : FALSE;
    break;
  case CURLMOPT_TIMERFUNCTION:
    multi->timer_cb = va_arg(param, curl_multi_timer_callback);
    break;
  case CURLMOPT_TIMERDATA:
    multi->timer_userp = va_arg(param, void *);
    break;
  case CURLMOPT_MAXCONNECTS:
    multi->maxconnects = va_arg(param, long);
    break;
  case CURLMOPT_MAX_HOST_CONNECTIONS:
    multi->max_host_connections = va_arg(param, long);
    break;
  case CURLMOPT_MAX_PIPELINE_LENGTH:
    multi->max_pipeline_length = va_arg(param, long);
    break;
  case CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE:
    multi->content_length_penalty_size = va_arg(param, long);
    break;
  case CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE:
    multi->chunk_length_penalty_size = va_arg(param, long);
    break;
  case CURLMOPT_PIPELINING_SITE_BL:
    res = Curl_pipeline_set_site_blacklist(va_arg(param, char **),
                                           &multi->pipelining_site_bl);
    break;
  case CURLMOPT_PIPELINING_SERVER_BL:
    res = Curl_pipeline_set_server_blacklist(va_arg(param, char **),
                                             &multi->pipelining_server_bl);
    break;
  case CURLMOPT_MAX_TOTAL_CONNECTIONS:
    multi->max_total_connections = va_arg(param, long);
    break;
  default:
    res = CURLM_UNKNOWN_OPTION;
    break;
  }
  va_end(param);
  return res;
}

/* we define curl_multi_socket() in the public multi.h header */
#undef curl_multi_socket

CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
                            int *running_handles)
{
  CURLMcode result = multi_socket((struct Curl_multi *)multi_handle, FALSE, s,
                                  0, running_handles);
  if(CURLM_OK >= result)
    update_timer((struct Curl_multi *)multi_handle);
  return result;
}

CURLMcode curl_multi_socket_action(CURLM *multi_handle, curl_socket_t s,
                                   int ev_bitmask, int *running_handles)
{
  CURLMcode result = multi_socket((struct Curl_multi *)multi_handle, FALSE, s,
                                  ev_bitmask, running_handles);
  if(CURLM_OK >= result)
    update_timer((struct Curl_multi *)multi_handle);
  return result;
}

CURLMcode curl_multi_socket_all(CURLM *multi_handle, int *running_handles)

{
  CURLMcode result = multi_socket((struct Curl_multi *)multi_handle,
                                  TRUE, CURL_SOCKET_BAD, 0, running_handles);
  if(CURLM_OK >= result)
    update_timer((struct Curl_multi *)multi_handle);
  return result;
}

static CURLMcode multi_timeout(struct Curl_multi *multi,
                               long *timeout_ms)
{
  static struct timeval tv_zero = {0,0};

  if(multi->timetree) {
    /* we have a tree of expire times */
    struct timeval now = Curl_tvnow();

    /* splay the lowest to the bottom */
    multi->timetree = Curl_splay(tv_zero, multi->timetree);

    if(Curl_splaycomparekeys(multi->timetree->key, now) > 0) {
      /* some time left before expiration */
      *timeout_ms = curlx_tvdiff(multi->timetree->key, now);
      if(!*timeout_ms)
        /*
         * Since we only provide millisecond resolution on the returned value
         * and the diff might be less than one millisecond here, we don't
         * return zero as that may cause short bursts of busyloops on fast
         * processors while the diff is still present but less than one
         * millisecond! instead we return 1 until the time is ripe.
         */
        *timeout_ms=1;
    }
    else
      /* 0 means immediately */
      *timeout_ms = 0;
  }
  else
    *timeout_ms = -1;

  return CURLM_OK;
}

CURLMcode curl_multi_timeout(CURLM *multi_handle,
                             long *timeout_ms)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;

  /* First, make some basic checks that the CURLM handle is a good handle */
  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  return multi_timeout(multi, timeout_ms);
}

/*
 * Tell the application it should update its timers, if it subscribes to the
 * update timer callback.
 */
static int update_timer(struct Curl_multi *multi)
{
  long timeout_ms;

  if(!multi->timer_cb)
    return 0;
  if(multi_timeout(multi, &timeout_ms)) {
    return -1;
  }
  if(timeout_ms < 0) {
    static const struct timeval none={0,0};
    if(Curl_splaycomparekeys(none, multi->timer_lastcall)) {
      multi->timer_lastcall = none;
      /* there's no timeout now but there was one previously, tell the app to
         disable it */
      return multi->timer_cb((CURLM*)multi, -1, multi->timer_userp);
    }
    return 0;
  }

  /* When multi_timeout() is done, multi->timetree points to the node with the
   * timeout we got the (relative) time-out time for. We can thus easily check
   * if this is the same (fixed) time as we got in a previous call and then
   * avoid calling the callback again. */
  if(Curl_splaycomparekeys(multi->timetree->key, multi->timer_lastcall) == 0)
    return 0;

  multi->timer_lastcall = multi->timetree->key;

  return multi->timer_cb((CURLM*)multi, timeout_ms, multi->timer_userp);
}

void Curl_multi_set_easy_connection(struct SessionHandle *handle,
                                    struct connectdata *conn)
{
  handle->easy_conn = conn;
}

static bool isHandleAtHead(struct SessionHandle *handle,
                           struct curl_llist *pipeline)
{
  struct curl_llist_element *curr = pipeline->head;
  if(curr)
    return (curr->ptr == handle) ? TRUE : FALSE;

  return FALSE;
}

/*
 * multi_freetimeout()
 *
 * Callback used by the llist system when a single timeout list entry is
 * destroyed.
 */
static void multi_freetimeout(void *user, void *entryptr)
{
  (void)user;

  /* the entry was plain malloc()'ed */
  free(entryptr);
}

/*
 * multi_addtimeout()
 *
 * Add a timestamp to the list of timeouts. Keep the list sorted so that head
 * of list is always the timeout nearest in time.
 *
 */
static CURLMcode
multi_addtimeout(struct curl_llist *timeoutlist,
                 struct timeval *stamp)
{
  struct curl_llist_element *e;
  struct timeval *timedup;
  struct curl_llist_element *prev = NULL;

  timedup = malloc(sizeof(*timedup));
  if(!timedup)
    return CURLM_OUT_OF_MEMORY;

  /* copy the timestamp */
  memcpy(timedup, stamp, sizeof(*timedup));

  if(Curl_llist_count(timeoutlist)) {
    /* find the correct spot in the list */
    for(e = timeoutlist->head; e; e = e->next) {
      struct timeval *checktime = e->ptr;
      long diff = curlx_tvdiff(*checktime, *timedup);
      if(diff > 0)
        break;
      prev = e;
    }

  }
  /* else
     this is the first timeout on the list */

  if(!Curl_llist_insert_next(timeoutlist, prev, timedup)) {
    free(timedup);
    return CURLM_OUT_OF_MEMORY;
  }

  return CURLM_OK;
}

/*
 * Curl_expire()
 *
 * given a number of milliseconds from now to use to set the 'act before
 * this'-time for the transfer, to be extracted by curl_multi_timeout()
 *
 * Note that the timeout will be added to a queue of timeouts if it defines a
 * moment in time that is later than the current head of queue.
 *
 * Pass zero to clear all timeout values for this handle.
*/
void Curl_expire(struct SessionHandle *data, long milli)
{
  struct Curl_multi *multi = data->multi;
  struct timeval *nowp = &data->state.expiretime;
  int rc;

  /* this is only interesting while there is still an associated multi struct
     remaining! */
  if(!multi)
    return;

  if(!milli) {
    /* No timeout, clear the time data. */
    if(nowp->tv_sec || nowp->tv_usec) {
      /* Since this is an cleared time, we must remove the previous entry from
         the splay tree */
      struct curl_llist *list = data->state.timeoutlist;

      rc = Curl_splayremovebyaddr(multi->timetree,
                                  &data->state.timenode,
                                  &multi->timetree);
      if(rc)
        infof(data, "Internal error clearing splay node = %d\n", rc);

      /* flush the timeout list too */
      while(list->size > 0)
        Curl_llist_remove(list, list->tail, NULL);

#ifdef DEBUGBUILD
      infof(data, "Expire cleared\n");
#endif
      nowp->tv_sec = 0;
      nowp->tv_usec = 0;
    }
  }
  else {
    struct timeval set;

    set = Curl_tvnow();
    set.tv_sec += milli/1000;
    set.tv_usec += (milli%1000)*1000;

    if(set.tv_usec >= 1000000) {
      set.tv_sec++;
      set.tv_usec -= 1000000;
    }

    if(nowp->tv_sec || nowp->tv_usec) {
      /* This means that the struct is added as a node in the splay tree.
         Compare if the new time is earlier, and only remove-old/add-new if it
         is. */
      long diff = curlx_tvdiff(set, *nowp);
      if(diff > 0) {
        /* the new expire time was later so just add it to the queue
           and get out */
        multi_addtimeout(data->state.timeoutlist, &set);
        return;
      }

      /* the new time is newer than the presently set one, so add the current
         to the queue and update the head */
      multi_addtimeout(data->state.timeoutlist, nowp);

      /* Since this is an updated time, we must remove the previous entry from
         the splay tree first and then re-add the new value */
      rc = Curl_splayremovebyaddr(multi->timetree,
                                  &data->state.timenode,
                                  &multi->timetree);
      if(rc)
        infof(data, "Internal error removing splay node = %d\n", rc);
    }

    *nowp = set;
    data->state.timenode.payload = data;
    multi->timetree = Curl_splayinsert(*nowp,
                                       multi->timetree,
                                       &data->state.timenode);
  }
#if 0
  Curl_splayprint(multi->timetree, 0, TRUE);
#endif
}

CURLMcode curl_multi_assign(CURLM *multi_handle,
                            curl_socket_t s, void *hashp)
{
  struct Curl_sh_entry *there = NULL;
  struct Curl_multi *multi = (struct Curl_multi *)multi_handle;

  if(s != CURL_SOCKET_BAD)
    there = Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(curl_socket_t));

  if(!there)
    return CURLM_BAD_SOCKET;

  there->socketp = hashp;

  return CURLM_OK;
}

size_t Curl_multi_max_host_connections(struct Curl_multi *multi)
{
  return multi ? multi->max_host_connections : 0;
}

size_t Curl_multi_max_total_connections(struct Curl_multi *multi)
{
  return multi ? multi->max_total_connections : 0;
}

size_t Curl_multi_max_pipeline_length(struct Curl_multi *multi)
{
  return multi ? multi->max_pipeline_length : 0;
}

curl_off_t Curl_multi_content_length_penalty_size(struct Curl_multi *multi)
{
  return multi ? multi->content_length_penalty_size : 0;
}

curl_off_t Curl_multi_chunk_length_penalty_size(struct Curl_multi *multi)
{
  return multi ? multi->chunk_length_penalty_size : 0;
}

struct curl_llist *Curl_multi_pipelining_site_bl(struct Curl_multi *multi)
{
  return multi->pipelining_site_bl;
}

struct curl_llist *Curl_multi_pipelining_server_bl(struct Curl_multi *multi)
{
  return multi->pipelining_server_bl;
}

void Curl_multi_process_pending_handles(struct Curl_multi *multi)
{
  struct SessionHandle *easy;

  easy=multi->easyp;
  while(easy) {
    if(easy->mstate == CURLM_STATE_CONNECT_PEND) {
      multistate(easy, CURLM_STATE_CONNECT);
      /* Make sure that the handle will be processed soonish. */
      Curl_expire(easy, 1);
    }
    easy = easy->next; /* operate on next handle */
  }
}

#ifdef DEBUGBUILD
void Curl_multi_dump(const struct Curl_multi *multi_handle)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct SessionHandle *easy;
  int i;
  fprintf(stderr, "* Multi status: %d handles, %d alive\n",
          multi->num_easy, multi->num_alive);
  for(easy=multi->easyp; easy; easy = easy->next) {
    if(easy->mstate < CURLM_STATE_COMPLETED) {
      /* only display handles that are not completed */
      fprintf(stderr, "handle %p, state %s, %d sockets\n",
              (void *)easy,
              statename[easy->mstate], easy->numsocks);
      for(i=0; i < easy->numsocks; i++) {
        curl_socket_t s = easy->sockets[i];
        struct Curl_sh_entry *entry =
          Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));

        fprintf(stderr, "%d ", (int)s);
        if(!entry) {
          fprintf(stderr, "INTERNAL CONFUSION\n");
          continue;
        }
        fprintf(stderr, "[%s %s] ",
                entry->action&CURL_POLL_IN?"RECVING":"",
                entry->action&CURL_POLL_OUT?"SENDING":"");
      }
      if(easy->numsocks)
        fprintf(stderr, "\n");
    }
  }
}
#endif