summaryrefslogtreecommitdiff
path: root/glib/gmain.c
blob: b994b59b1e030fd353b93c732afc1c77fe9f0f13 (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
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * gmain.c: Main loop abstraction, timeouts, and idle functions
 * Copyright 1998 Owen Taylor
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GLib Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GLib at ftp://ftp.gtk.org/pub/gtk/.
 */

/*
 * MT safe
 */

#include "config.h"
#include "glibconfig.h"
#include "glib_trace.h"

/* Uncomment the next line (and the corresponding line in gpoll.c) to
 * enable debugging printouts if the environment variable
 * G_MAIN_POLL_DEBUG is set to some value.
 */
/* #define G_MAIN_POLL_DEBUG */

#ifdef _WIN32
/* Always enable debugging printout on Windows, as it is more often
 * needed there...
 */
#define G_MAIN_POLL_DEBUG
#endif

#ifdef G_OS_UNIX
#include "glib-unix.h"
#include <pthread.h>
#ifdef HAVE_EVENTFD
#include <sys/eventfd.h>
#endif
#endif

#include <signal.h>
#include <sys/types.h>
#include <time.h>
#include <stdlib.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif /* HAVE_SYS_TIME_H */
#ifdef G_OS_UNIX
#include <unistd.h>
#endif /* G_OS_UNIX */
#include <errno.h>
#include <string.h>

#ifdef HAVE_PIDFD
#include <sys/syscall.h>
#include <sys/wait.h>
#include <linux/wait.h>  /* P_PIDFD */
#ifndef W_EXITCODE
#define W_EXITCODE(ret, sig) ((ret) << 8 | (sig))
#endif
#ifndef W_STOPCODE
#define W_STOPCODE(sig)      ((sig) << 8 | 0x7f)
#endif
#ifndef WCOREFLAG
/* musl doesn’t define WCOREFLAG while glibc does. Unfortunately, there’s no way
 * to detect we’re building against musl, so just define it and hope.
 * See https://git.musl-libc.org/cgit/musl/tree/include/sys/wait.h#n51 */
#define WCOREFLAG 0x80
#endif
#ifndef __W_CONTINUED
/* Same as above, for musl */
#define __W_CONTINUED 0xffff
#endif
#endif  /* HAVE_PIDFD */

#ifdef G_OS_WIN32
#define STRICT
#include <windows.h>
#endif /* G_OS_WIN32 */

#ifdef HAVE_MACH_MACH_TIME_H
#include <mach/mach_time.h>
#endif

#include "glib_trace.h"

#include "gmain.h"

#include "garray.h"
#include "giochannel.h"
#include "ghash.h"
#include "ghook.h"
#include "gqueue.h"
#include "gstrfuncs.h"
#include "gtestutils.h"
#include "gthreadprivate.h"
#include "gtrace-private.h"

#ifdef G_OS_WIN32
#include "gwin32.h"
#endif

#ifdef  G_MAIN_POLL_DEBUG
#include "gtimer.h"
#endif

#include "gwakeup.h"
#include "gmain-internal.h"
#include "glib-init.h"
#include "glib-private.h"

/**
 * SECTION:main
 * @title: The Main Event Loop
 * @short_description: manages all available sources of events
 *
 * The main event loop manages all the available sources of events for
 * GLib and GTK+ applications. These events can come from any number of
 * different types of sources such as file descriptors (plain files,
 * pipes or sockets) and timeouts. New types of event sources can also
 * be added using g_source_attach().
 *
 * To allow multiple independent sets of sources to be handled in
 * different threads, each source is associated with a #GMainContext.
 * A #GMainContext can only be running in a single thread, but
 * sources can be added to it and removed from it from other threads. All
 * functions which operate on a #GMainContext or a built-in #GSource are
 * thread-safe.
 *
 * Each event source is assigned a priority. The default priority,
 * %G_PRIORITY_DEFAULT, is 0. Values less than 0 denote higher priorities.
 * Values greater than 0 denote lower priorities. Events from high priority
 * sources are always processed before events from lower priority sources: if
 * several sources are ready to dispatch, the ones with equal-highest priority
 * will be dispatched on the current #GMainContext iteration, and the rest wait
 * until a subsequent #GMainContext iteration when they have the highest
 * priority of the sources which are ready for dispatch.
 *
 * Idle functions can also be added, and assigned a priority. These will
 * be run whenever no events with a higher priority are ready to be dispatched.
 *
 * The #GMainLoop data type represents a main event loop. A GMainLoop is
 * created with g_main_loop_new(). After adding the initial event sources,
 * g_main_loop_run() is called. This continuously checks for new events from
 * each of the event sources and dispatches them. Finally, the processing of
 * an event from one of the sources leads to a call to g_main_loop_quit() to
 * exit the main loop, and g_main_loop_run() returns.
 *
 * It is possible to create new instances of #GMainLoop recursively.
 * This is often used in GTK+ applications when showing modal dialog
 * boxes. Note that event sources are associated with a particular
 * #GMainContext, and will be checked and dispatched for all main
 * loops associated with that GMainContext.
 *
 * GTK+ contains wrappers of some of these functions, e.g. gtk_main(),
 * gtk_main_quit() and gtk_events_pending().
 *
 * ## Creating new source types
 *
 * One of the unusual features of the #GMainLoop functionality
 * is that new types of event source can be created and used in
 * addition to the builtin type of event source. A new event source
 * type is used for handling GDK events. A new source type is created
 * by "deriving" from the #GSource structure. The derived type of
 * source is represented by a structure that has the #GSource structure
 * as a first element, and other elements specific to the new source
 * type. To create an instance of the new source type, call
 * g_source_new() passing in the size of the derived structure and
 * a table of functions. These #GSourceFuncs determine the behavior of
 * the new source type.
 *
 * New source types basically interact with the main context
 * in two ways. Their prepare function in #GSourceFuncs can set a timeout
 * to determine the maximum amount of time that the main loop will sleep
 * before checking the source again. In addition, or as well, the source
 * can add file descriptors to the set that the main context checks using
 * g_source_add_poll().
 *
 * ## Customizing the main loop iteration
 *
 * Single iterations of a #GMainContext can be run with
 * g_main_context_iteration(). In some cases, more detailed control
 * of exactly how the details of the main loop work is desired, for
 * instance, when integrating the #GMainLoop with an external main loop.
 * In such cases, you can call the component functions of
 * g_main_context_iteration() directly. These functions are
 * g_main_context_prepare(), g_main_context_query(),
 * g_main_context_check() and g_main_context_dispatch().
 *
 * If the event loop thread releases #GMainContext ownership until the results
 * required by g_main_context_check() are ready you must create a context with
 * the flag %G_MAIN_CONTEXT_FLAGS_OWNERLESS_POLLING or else you'll lose
 * g_source_attach() notifications. This happens for instance when you integrate
 * the GLib event loop into implementations that follow the proactor pattern
 * (i.e. in these contexts the `poll()` implementation will reclaim the thread for
 * other tasks until the results are ready). One example of the proactor pattern
 * is the Boost.Asio library.
 *
 * ## State of a Main Context # {#mainloop-states}
 *
 * The operation of these functions can best be seen in terms
 * of a state diagram, as shown in this image.
 *
 * ![](mainloop-states.gif)
 *
 * On UNIX, the GLib mainloop is incompatible with fork(). Any program
 * using the mainloop must either exec() or exit() from the child
 * without returning to the mainloop.
 *
 * ## Memory management of sources # {#mainloop-memory-management}
 *
 * There are two options for memory management of the user data passed to a
 * #GSource to be passed to its callback on invocation. This data is provided
 * in calls to g_timeout_add(), g_timeout_add_full(), g_idle_add(), etc. and
 * more generally, using g_source_set_callback(). This data is typically an
 * object which ‘owns’ the timeout or idle callback, such as a widget or a
 * network protocol implementation. In many cases, it is an error for the
 * callback to be invoked after this owning object has been destroyed, as that
 * results in use of freed memory.
 *
 * The first, and preferred, option is to store the source ID returned by
 * functions such as g_timeout_add() or g_source_attach(), and explicitly
 * remove that source from the main context using g_source_remove() when the
 * owning object is finalized. This ensures that the callback can only be
 * invoked while the object is still alive.
 *
 * The second option is to hold a strong reference to the object in the
 * callback, and to release it in the callback’s #GDestroyNotify. This ensures
 * that the object is kept alive until after the source is finalized, which is
 * guaranteed to be after it is invoked for the final time. The #GDestroyNotify
 * is another callback passed to the ‘full’ variants of #GSource functions (for
 * example, g_timeout_add_full()). It is called when the source is finalized,
 * and is designed for releasing references like this.
 *
 * One important caveat of this second approach is that it will keep the object
 * alive indefinitely if the main loop is stopped before the #GSource is
 * invoked, which may be undesirable.
 */

/* Types */

typedef struct _GIdleSource GIdleSource;
typedef struct _GTimeoutSource GTimeoutSource;
typedef struct _GChildWatchSource GChildWatchSource;
typedef struct _GUnixSignalWatchSource GUnixSignalWatchSource;
typedef struct _GPollRec GPollRec;
typedef struct _GSourceCallback GSourceCallback;

typedef enum
{
  G_SOURCE_READY = 1 << G_HOOK_FLAG_USER_SHIFT,
  G_SOURCE_CAN_RECURSE = 1 << (G_HOOK_FLAG_USER_SHIFT + 1),
  G_SOURCE_BLOCKED = 1 << (G_HOOK_FLAG_USER_SHIFT + 2)
} GSourceFlags;

typedef struct _GSourceList GSourceList;

struct _GSourceList
{
  GSource *head, *tail;
  gint priority;
};

typedef struct _GMainWaiter GMainWaiter;

struct _GMainWaiter
{
  GCond *cond;
  GMutex *mutex;
};

typedef struct _GMainDispatch GMainDispatch;

struct _GMainDispatch
{
  gint depth;
  GSource *source;
};

#ifdef G_MAIN_POLL_DEBUG
gboolean _g_main_poll_debug = FALSE;
#endif

struct _GMainContext
{
  /* The following lock is used for both the list of sources
   * and the list of poll records
   */
  GMutex mutex;
  GCond cond;
  GThread *owner;
  guint owner_count;
  GMainContextFlags flags;
  GSList *waiters;

  gint ref_count;  /* (atomic) */

  GHashTable *sources;              /* guint -> GSource */

  GPtrArray *pending_dispatches;
  gint timeout;			/* Timeout for current iteration */

  guint next_id;
  GList *source_lists;
  gint in_check_or_prepare;

  GPollRec *poll_records;
  guint n_poll_records;
  GPollFD *cached_poll_array;
  guint cached_poll_array_size;

  GWakeup *wakeup;

  GPollFD wake_up_rec;

/* Flag indicating whether the set of fd's changed during a poll */
  gboolean poll_changed;

  GPollFunc poll_func;

  gint64   time;
  gboolean time_is_fresh;
};

struct _GSourceCallback
{
  gint ref_count;  /* (atomic) */
  GSourceFunc func;
  gpointer    data;
  GDestroyNotify notify;
};

struct _GMainLoop
{
  GMainContext *context;
  gboolean is_running; /* (atomic) */
  gint ref_count;  /* (atomic) */
};

struct _GIdleSource
{
  GSource  source;
  gboolean one_shot;
};

struct _GTimeoutSource
{
  GSource     source;
  /* Measured in seconds if 'seconds' is TRUE, or milliseconds otherwise. */
  guint       interval;
  gboolean    seconds;
  gboolean    one_shot;
};

struct _GChildWatchSource
{
  GSource     source;
  GPid        pid;
  /* On Unix this is a wait status, which is the thing you pass to WEXITSTATUS()
   * to get the status returned from the process’ main() or passed to exit(): */
  gint        child_status;
  /* @poll is always used on Windows, and used on Unix iff @using_pidfd is set: */
  GPollFD     poll;
#ifndef G_OS_WIN32
  gboolean    child_exited; /* (atomic); not used iff @using_pidfd is set */
  gboolean    using_pidfd;
#endif /* G_OS_WIN32 */
};

struct _GUnixSignalWatchSource
{
  GSource     source;
  int         signum;
  gboolean    pending; /* (atomic) */
};

struct _GPollRec
{
  GPollFD *fd;
  GPollRec *prev;
  GPollRec *next;
  gint priority;
};

struct _GSourcePrivate
{
  GSList *child_sources;
  GSource *parent_source;

  gint64 ready_time;

  /* This is currently only used on UNIX, but we always declare it (and
   * let it remain empty on Windows) to avoid #ifdef all over the place.
   */
  GSList *fds;

  GSourceDisposeFunc dispose;

  gboolean static_name;
};

typedef struct _GSourceIter
{
  GMainContext *context;
  gboolean may_modify;
  GList *current_list;
  GSource *source;
} GSourceIter;

#define LOCK_CONTEXT(context) g_mutex_lock (&context->mutex)
#define UNLOCK_CONTEXT(context) g_mutex_unlock (&context->mutex)
#define G_THREAD_SELF g_thread_self ()

#define SOURCE_DESTROYED(source) (((source)->flags & G_HOOK_FLAG_ACTIVE) == 0)
#define SOURCE_BLOCKED(source) (((source)->flags & G_SOURCE_BLOCKED) != 0)

/* Forward declarations */

static void g_source_unref_internal             (GSource      *source,
						 GMainContext *context,
						 gboolean      have_lock);
static void g_source_destroy_internal           (GSource      *source,
						 GMainContext *context,
						 gboolean      have_lock);
static void g_source_set_priority_unlocked      (GSource      *source,
						 GMainContext *context,
						 gint          priority);
static void g_child_source_remove_internal      (GSource      *child_source,
                                                 GMainContext *context);

static gboolean g_main_context_acquire_unlocked (GMainContext *context);
static void g_main_context_release_unlocked     (GMainContext *context);
static gboolean g_main_context_prepare_unlocked (GMainContext *context,
                                                 gint         *priority);
static gint g_main_context_query_unlocked       (GMainContext *context,
                                                 gint          max_priority,
                                                 gint         *timeout,
                                                 GPollFD      *fds,
                                                 gint          n_fds);
static gboolean g_main_context_check_unlocked   (GMainContext *context,
                                                 gint          max_priority,
                                                 GPollFD      *fds,
                                                 gint          n_fds);
static void g_main_context_dispatch_unlocked    (GMainContext *context);
static void g_main_context_poll_unlocked        (GMainContext *context,
                                                 int           timeout,
                                                 int           priority,
                                                 GPollFD      *fds,
                                                 int           n_fds);
static void g_main_context_add_poll_unlocked    (GMainContext *context,
						 gint          priority,
						 GPollFD      *fd);
static void g_main_context_remove_poll_unlocked (GMainContext *context,
						 GPollFD      *fd);

static void     g_source_iter_init  (GSourceIter   *iter,
				     GMainContext  *context,
				     gboolean       may_modify);
static gboolean g_source_iter_next  (GSourceIter   *iter,
				     GSource      **source);
static void     g_source_iter_clear (GSourceIter   *iter);

static gboolean g_timeout_dispatch (GSource     *source,
				    GSourceFunc  callback,
				    gpointer     user_data);
static gboolean g_child_watch_prepare  (GSource     *source,
				        gint        *timeout);
static gboolean g_child_watch_check    (GSource     *source);
static gboolean g_child_watch_dispatch (GSource     *source,
					GSourceFunc  callback,
					gpointer     user_data);
static void     g_child_watch_finalize (GSource     *source);
#ifdef G_OS_UNIX
static void g_unix_signal_handler (int signum);
static gboolean g_unix_signal_watch_prepare  (GSource     *source,
					      gint        *timeout);
static gboolean g_unix_signal_watch_check    (GSource     *source);
static gboolean g_unix_signal_watch_dispatch (GSource     *source,
					      GSourceFunc  callback,
					      gpointer     user_data);
static void     g_unix_signal_watch_finalize  (GSource     *source);
#endif
static gboolean g_idle_prepare     (GSource     *source,
				    gint        *timeout);
static gboolean g_idle_check       (GSource     *source);
static gboolean g_idle_dispatch    (GSource     *source,
				    GSourceFunc  callback,
				    gpointer     user_data);

static void block_source (GSource *source);

static GMainContext *glib_worker_context;

#ifndef G_OS_WIN32


/* UNIX signals work by marking one of these variables then waking the
 * worker context to check on them and dispatch accordingly.
 *
 * Both variables must be accessed using atomic primitives, unless those atomic
 * primitives are implemented using fallback mutexes (as those aren’t safe in
 * an interrupt context).
 *
 * If using atomic primitives, the variables must be of type `int` (so they’re
 * the right size for the atomic primitives). Otherwise, use `sig_atomic_t` if
 * it’s available, which is guaranteed to be async-signal-safe (but it’s *not*
 * guaranteed to be thread-safe, which is why we use atomic primitives if
 * possible).
 *
 * Typically, `sig_atomic_t` is a typedef to `int`, but that’s not the case on
 * FreeBSD, so we can’t use it unconditionally if it’s defined.
 */
#if (defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)) || !defined(HAVE_SIG_ATOMIC_T)
static volatile int unix_signal_pending[NSIG];
static volatile int any_unix_signal_pending;
#else
static volatile sig_atomic_t unix_signal_pending[NSIG];
static volatile sig_atomic_t any_unix_signal_pending;
#endif

/* Guards all the data below */
G_LOCK_DEFINE_STATIC (unix_signal_lock);
static guint unix_signal_refcount[NSIG];
static GSList *unix_signal_watches;
static GSList *unix_child_watches;

GSourceFuncs g_unix_signal_funcs =
{
  g_unix_signal_watch_prepare,
  g_unix_signal_watch_check,
  g_unix_signal_watch_dispatch,
  g_unix_signal_watch_finalize,
  NULL, NULL
};
#endif /* !G_OS_WIN32 */
G_LOCK_DEFINE_STATIC (main_context_list);
static GSList *main_context_list = NULL;

GSourceFuncs g_timeout_funcs =
{
  NULL, /* prepare */
  NULL, /* check */
  g_timeout_dispatch,
  NULL, NULL, NULL
};

GSourceFuncs g_child_watch_funcs =
{
  g_child_watch_prepare,
  g_child_watch_check,
  g_child_watch_dispatch,
  g_child_watch_finalize,
  NULL, NULL
};

GSourceFuncs g_idle_funcs =
{
  g_idle_prepare,
  g_idle_check,
  g_idle_dispatch,
  NULL, NULL, NULL
};

/**
 * g_main_context_ref:
 * @context: (not nullable): a #GMainContext
 * 
 * Increases the reference count on a #GMainContext object by one.
 *
 * Returns: the @context that was passed in (since 2.6)
 **/
GMainContext *
g_main_context_ref (GMainContext *context)
{
  int old_ref_count;

  g_return_val_if_fail (context != NULL, NULL);

  old_ref_count = g_atomic_int_add (&context->ref_count, 1);
  g_return_val_if_fail (old_ref_count > 0, NULL);

  return context;
}

static inline void
poll_rec_list_free (GMainContext *context,
		    GPollRec     *list)
{
  g_slice_free_chain (GPollRec, list, next);
}

/**
 * g_main_context_unref:
 * @context: (not nullable): a #GMainContext
 * 
 * Decreases the reference count on a #GMainContext object by one. If
 * the result is zero, free the context and free all associated memory.
 **/
void
g_main_context_unref (GMainContext *context)
{
  GSourceIter iter;
  GSource *source;
  GList *sl_iter;
  GSList *s_iter, *remaining_sources = NULL;
  GSourceList *list;
  guint i;

  g_return_if_fail (context != NULL);
  g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0); 

  if (!g_atomic_int_dec_and_test (&context->ref_count))
    return;

  G_LOCK (main_context_list);
  main_context_list = g_slist_remove (main_context_list, context);
  G_UNLOCK (main_context_list);

  /* Free pending dispatches */
  for (i = 0; i < context->pending_dispatches->len; i++)
    g_source_unref_internal (context->pending_dispatches->pdata[i], context, FALSE);

  /* g_source_iter_next() assumes the context is locked. */
  LOCK_CONTEXT (context);

  /* First collect all remaining sources from the sources lists and store a
   * new reference in a separate list. Also set the context of the sources
   * to NULL so that they can't access a partially destroyed context anymore.
   *
   * We have to do this first so that we have a strong reference to all
   * sources and destroying them below does not also free them, and so that
   * none of the sources can access the context from their finalize/dispose
   * functions. */
  g_source_iter_init (&iter, context, FALSE);
  while (g_source_iter_next (&iter, &source))
    {
      source->context = NULL;
      remaining_sources = g_slist_prepend (remaining_sources, g_source_ref (source));
    }
  g_source_iter_clear (&iter);

  /* Next destroy all sources. As we still hold a reference to all of them,
   * this won't cause any of them to be freed yet and especially prevents any
   * source that unrefs another source from its finalize function to be freed.
   */
  for (s_iter = remaining_sources; s_iter; s_iter = s_iter->next)
    {
      source = s_iter->data;
      g_source_destroy_internal (source, context, TRUE);
    }

  for (sl_iter = context->source_lists; sl_iter; sl_iter = sl_iter->next)
    {
      list = sl_iter->data;
      g_slice_free (GSourceList, list);
    }
  g_list_free (context->source_lists);

  g_hash_table_destroy (context->sources);

  UNLOCK_CONTEXT (context);
  g_mutex_clear (&context->mutex);

  g_ptr_array_free (context->pending_dispatches, TRUE);
  g_free (context->cached_poll_array);

  poll_rec_list_free (context, context->poll_records);

  g_wakeup_free (context->wakeup);
  g_cond_clear (&context->cond);

  g_free (context);

  /* And now finally get rid of our references to the sources. This will cause
   * them to be freed unless something else still has a reference to them. Due
   * to setting the context pointers in the sources to NULL above, this won't
   * ever access the context or the internal linked list inside the GSource.
   * We already removed the sources completely from the context above. */
  for (s_iter = remaining_sources; s_iter; s_iter = s_iter->next)
    {
      source = s_iter->data;
      g_source_unref_internal (source, NULL, FALSE);
    }
  g_slist_free (remaining_sources);
}

/* Helper function used by mainloop/overflow test.
 */
GMainContext *
g_main_context_new_with_next_id (guint next_id)
{
  GMainContext *ret = g_main_context_new ();
  
  ret->next_id = next_id;
  
  return ret;
}

/**
 * g_main_context_new:
 * 
 * Creates a new #GMainContext structure.
 * 
 * Returns: the new #GMainContext
 **/
GMainContext *
g_main_context_new (void)
{
  return g_main_context_new_with_flags (G_MAIN_CONTEXT_FLAGS_NONE);
}

/**
 * g_main_context_new_with_flags:
 * @flags: a bitwise-OR combination of #GMainContextFlags flags that can only be
 *         set at creation time.
 *
 * Creates a new #GMainContext structure.
 *
 * Returns: (transfer full): the new #GMainContext
 *
 * Since: 2.72
 */
GMainContext *
g_main_context_new_with_flags (GMainContextFlags flags)
{
  static gsize initialised;
  GMainContext *context;

  if (g_once_init_enter (&initialised))
    {
#ifdef G_MAIN_POLL_DEBUG
      if (g_getenv ("G_MAIN_POLL_DEBUG") != NULL)
        _g_main_poll_debug = TRUE;
#endif

      g_once_init_leave (&initialised, TRUE);
    }

  context = g_new0 (GMainContext, 1);

  TRACE (GLIB_MAIN_CONTEXT_NEW (context));

  g_mutex_init (&context->mutex);
  g_cond_init (&context->cond);

  context->sources = g_hash_table_new (NULL, NULL);
  context->owner = NULL;
  context->flags = flags;
  context->waiters = NULL;

  context->ref_count = 1;

  context->next_id = 1;
  
  context->source_lists = NULL;
  
  context->poll_func = g_poll;
  
  context->cached_poll_array = NULL;
  context->cached_poll_array_size = 0;
  
  context->pending_dispatches = g_ptr_array_new ();
  
  context->time_is_fresh = FALSE;
  
  context->wakeup = g_wakeup_new ();
  g_wakeup_get_pollfd (context->wakeup, &context->wake_up_rec);
  g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);

  G_LOCK (main_context_list);
  main_context_list = g_slist_append (main_context_list, context);

#ifdef G_MAIN_POLL_DEBUG
  if (_g_main_poll_debug)
    g_print ("created context=%p\n", context);
#endif

  G_UNLOCK (main_context_list);

  return context;
}

/**
 * g_main_context_default:
 *
 * Returns the global-default main context. This is the main context
 * used for main loop functions when a main loop is not explicitly
 * specified, and corresponds to the "main" main loop. See also
 * g_main_context_get_thread_default().
 *
 * Returns: (transfer none): the global-default main context.
 **/
GMainContext *
g_main_context_default (void)
{
  static GMainContext *default_main_context = NULL;

  if (g_once_init_enter (&default_main_context))
    {
      GMainContext *context;

      context = g_main_context_new ();

      TRACE (GLIB_MAIN_CONTEXT_DEFAULT (context));

#ifdef G_MAIN_POLL_DEBUG
      if (_g_main_poll_debug)
        g_print ("global-default main context=%p\n", context);
#endif

      g_once_init_leave (&default_main_context, context);
    }

  return default_main_context;
}

static void
free_context (gpointer data)
{
  GMainContext *context = data;

  TRACE (GLIB_MAIN_CONTEXT_FREE (context));

  g_main_context_release (context);
  if (context)
    g_main_context_unref (context);
}

static void
free_context_stack (gpointer data)
{
  g_queue_free_full((GQueue *) data, (GDestroyNotify) free_context);
}

static GPrivate thread_context_stack = G_PRIVATE_INIT (free_context_stack);

/**
 * g_main_context_push_thread_default:
 * @context: (nullable): a #GMainContext, or %NULL for the global-default
 *   main context
 *
 * Acquires @context and sets it as the thread-default context for the
 * current thread. This will cause certain asynchronous operations
 * (such as most [gio][gio]-based I/O) which are
 * started in this thread to run under @context and deliver their
 * results to its main loop, rather than running under the global
 * default main context in the main thread. Note that calling this function
 * changes the context returned by g_main_context_get_thread_default(),
 * not the one returned by g_main_context_default(), so it does not affect
 * the context used by functions like g_idle_add().
 *
 * Normally you would call this function shortly after creating a new
 * thread, passing it a #GMainContext which will be run by a
 * #GMainLoop in that thread, to set a new default context for all
 * async operations in that thread. In this case you may not need to
 * ever call g_main_context_pop_thread_default(), assuming you want the
 * new #GMainContext to be the default for the whole lifecycle of the
 * thread.
 *
 * If you don't have control over how the new thread was created (e.g.
 * in the new thread isn't newly created, or if the thread life
 * cycle is managed by a #GThreadPool), it is always suggested to wrap
 * the logic that needs to use the new #GMainContext inside a
 * g_main_context_push_thread_default() / g_main_context_pop_thread_default()
 * pair, otherwise threads that are re-used will end up never explicitly
 * releasing the #GMainContext reference they hold.
 *
 * In some cases you may want to schedule a single operation in a
 * non-default context, or temporarily use a non-default context in
 * the main thread. In that case, you can wrap the call to the
 * asynchronous operation inside a
 * g_main_context_push_thread_default() /
 * g_main_context_pop_thread_default() pair, but it is up to you to
 * ensure that no other asynchronous operations accidentally get
 * started while the non-default context is active.
 *
 * Beware that libraries that predate this function may not correctly
 * handle being used from a thread with a thread-default context. Eg,
 * see g_file_supports_thread_contexts().
 *
 * Since: 2.22
 **/
void
g_main_context_push_thread_default (GMainContext *context)
{
  GQueue *stack;
  gboolean acquired_context;

  acquired_context = g_main_context_acquire (context);
  g_return_if_fail (acquired_context);

  if (context == g_main_context_default ())
    context = NULL;
  else if (context)
    g_main_context_ref (context);

  stack = g_private_get (&thread_context_stack);
  if (!stack)
    {
      stack = g_queue_new ();
      g_private_set (&thread_context_stack, stack);
    }

  g_queue_push_head (stack, context);

  TRACE (GLIB_MAIN_CONTEXT_PUSH_THREAD_DEFAULT (context));
}

/**
 * g_main_context_pop_thread_default:
 * @context: (nullable): a #GMainContext, or %NULL for the global-default
 *   main context
 *
 * Pops @context off the thread-default context stack (verifying that
 * it was on the top of the stack).
 *
 * Since: 2.22
 **/
void
g_main_context_pop_thread_default (GMainContext *context)
{
  GQueue *stack;

  if (context == g_main_context_default ())
    context = NULL;

  stack = g_private_get (&thread_context_stack);

  g_return_if_fail (stack != NULL);
  g_return_if_fail (g_queue_peek_head (stack) == context);

  TRACE (GLIB_MAIN_CONTEXT_POP_THREAD_DEFAULT (context));

  g_queue_pop_head (stack);

  g_main_context_release (context);
  if (context)
    g_main_context_unref (context);
}

/**
 * g_main_context_get_thread_default:
 *
 * Gets the thread-default #GMainContext for this thread. Asynchronous
 * operations that want to be able to be run in contexts other than
 * the default one should call this method or
 * g_main_context_ref_thread_default() to get a #GMainContext to add
 * their #GSources to. (Note that even in single-threaded
 * programs applications may sometimes want to temporarily push a
 * non-default context, so it is not safe to assume that this will
 * always return %NULL if you are running in the default thread.)
 *
 * If you need to hold a reference on the context, use
 * g_main_context_ref_thread_default() instead.
 *
 * Returns: (transfer none) (nullable): the thread-default #GMainContext, or
 * %NULL if the thread-default context is the global-default main context.
 *
 * Since: 2.22
 **/
GMainContext *
g_main_context_get_thread_default (void)
{
  GQueue *stack;

  stack = g_private_get (&thread_context_stack);
  if (stack)
    return g_queue_peek_head (stack);
  else
    return NULL;
}

/**
 * g_main_context_ref_thread_default:
 *
 * Gets the thread-default #GMainContext for this thread, as with
 * g_main_context_get_thread_default(), but also adds a reference to
 * it with g_main_context_ref(). In addition, unlike
 * g_main_context_get_thread_default(), if the thread-default context
 * is the global-default context, this will return that #GMainContext
 * (with a ref added to it) rather than returning %NULL.
 *
 * Returns: (transfer full): the thread-default #GMainContext. Unref
 *     with g_main_context_unref() when you are done with it.
 *
 * Since: 2.32
 */
GMainContext *
g_main_context_ref_thread_default (void)
{
  GMainContext *context;

  context = g_main_context_get_thread_default ();
  if (!context)
    context = g_main_context_default ();
  return g_main_context_ref (context);
}

/* Hooks for adding to the main loop */

/**
 * g_source_new:
 * @source_funcs: structure containing functions that implement
 *                the sources behavior.
 * @struct_size: size of the #GSource structure to create.
 * 
 * Creates a new #GSource structure. The size is specified to
 * allow creating structures derived from #GSource that contain
 * additional data. The size passed in must be at least
 * `sizeof (GSource)`.
 * 
 * The source will not initially be associated with any #GMainContext
 * and must be added to one with g_source_attach() before it will be
 * executed.
 * 
 * Returns: the newly-created #GSource.
 **/
GSource *
g_source_new (GSourceFuncs *source_funcs,
	      guint         struct_size)
{
  GSource *source;

  g_return_val_if_fail (source_funcs != NULL, NULL);
  g_return_val_if_fail (struct_size >= sizeof (GSource), NULL);
  
  source = (GSource*) g_malloc0 (struct_size);
  source->priv = g_slice_new0 (GSourcePrivate);
  source->source_funcs = source_funcs;
  source->ref_count = 1;
  
  source->priority = G_PRIORITY_DEFAULT;

  source->flags = G_HOOK_FLAG_ACTIVE;

  source->priv->ready_time = -1;

  /* NULL/0 initialization for all other fields */

  TRACE (GLIB_SOURCE_NEW (source, source_funcs->prepare, source_funcs->check,
                          source_funcs->dispatch, source_funcs->finalize,
                          struct_size));

  return source;
}

/**
 * g_source_set_dispose_function:
 * @source: A #GSource to set the dispose function on
 * @dispose: #GSourceDisposeFunc to set on the source
 *
 * Set @dispose as dispose function on @source. @dispose will be called once
 * the reference count of @source reaches 0 but before any of the state of the
 * source is freed, especially before the finalize function is called.
 *
 * This means that at this point @source is still a valid #GSource and it is
 * allow for the reference count to increase again until @dispose returns.
 *
 * The dispose function can be used to clear any "weak" references to the
 * @source in other data structures in a thread-safe way where it is possible
 * for another thread to increase the reference count of @source again while
 * it is being freed.
 *
 * The finalize function can not be used for this purpose as at that point
 * @source is already partially freed and not valid anymore.
 *
 * This should only ever be called from #GSource implementations.
 *
 * Since: 2.64
 **/
void
g_source_set_dispose_function (GSource            *source,
			       GSourceDisposeFunc  dispose)
{
  g_return_if_fail (source != NULL);
  g_return_if_fail (source->priv->dispose == NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  source->priv->dispose = dispose;
}

/* Holds context's lock */
static void
g_source_iter_init (GSourceIter  *iter,
		    GMainContext *context,
		    gboolean      may_modify)
{
  iter->context = context;
  iter->current_list = NULL;
  iter->source = NULL;
  iter->may_modify = may_modify;
}

/* Holds context's lock */
static gboolean
g_source_iter_next (GSourceIter *iter, GSource **source)
{
  GSource *next_source;

  if (iter->source)
    next_source = iter->source->next;
  else
    next_source = NULL;

  if (!next_source)
    {
      if (iter->current_list)
	iter->current_list = iter->current_list->next;
      else
	iter->current_list = iter->context->source_lists;

      if (iter->current_list)
	{
	  GSourceList *source_list = iter->current_list->data;

	  next_source = source_list->head;
	}
    }

  /* Note: unreffing iter->source could potentially cause its
   * GSourceList to be removed from source_lists (if iter->source is
   * the only source in its list, and it is destroyed), so we have to
   * keep it reffed until after we advance iter->current_list, above.
   *
   * Also we first have to ref the next source before unreffing the
   * previous one as unreffing the previous source can potentially
   * free the next one.
   */
  if (next_source && iter->may_modify)
    g_source_ref (next_source);

  if (iter->source && iter->may_modify)
    g_source_unref_internal (iter->source, iter->context, TRUE);
  iter->source = next_source;

  *source = iter->source;
  return *source != NULL;
}

/* Holds context's lock. Only necessary to call if you broke out of
 * the g_source_iter_next() loop early.
 */
static void
g_source_iter_clear (GSourceIter *iter)
{
  if (iter->source && iter->may_modify)
    {
      g_source_unref_internal (iter->source, iter->context, TRUE);
      iter->source = NULL;
    }
}

/* Holds context's lock
 */
static GSourceList *
find_source_list_for_priority (GMainContext *context,
			       gint          priority,
			       gboolean      create)
{
  GList *iter, *last;
  GSourceList *source_list;

  last = NULL;
  for (iter = context->source_lists; iter != NULL; last = iter, iter = iter->next)
    {
      source_list = iter->data;

      if (source_list->priority == priority)
	return source_list;

      if (source_list->priority > priority)
	{
	  if (!create)
	    return NULL;

	  source_list = g_slice_new0 (GSourceList);
	  source_list->priority = priority;
	  context->source_lists = g_list_insert_before (context->source_lists,
							iter,
							source_list);
	  return source_list;
	}
    }

  if (!create)
    return NULL;

  source_list = g_slice_new0 (GSourceList);
  source_list->priority = priority;

  if (!last)
    context->source_lists = g_list_append (NULL, source_list);
  else
    {
      /* This just appends source_list to the end of
       * context->source_lists without having to walk the list again.
       */
      last = g_list_append (last, source_list);
      (void) last;
    }
  return source_list;
}

/* Holds context's lock
 */
static void
source_add_to_context (GSource      *source,
		       GMainContext *context)
{
  GSourceList *source_list;
  GSource *prev, *next;

  source_list = find_source_list_for_priority (context, source->priority, TRUE);

  if (source->priv->parent_source)
    {
      g_assert (source_list->head != NULL);

      /* Put the source immediately before its parent */
      prev = source->priv->parent_source->prev;
      next = source->priv->parent_source;
    }
  else
    {
      prev = source_list->tail;
      next = NULL;
    }

  source->next = next;
  if (next)
    next->prev = source;
  else
    source_list->tail = source;
  
  source->prev = prev;
  if (prev)
    prev->next = source;
  else
    source_list->head = source;
}

/* Holds context's lock
 */
static void
source_remove_from_context (GSource      *source,
			    GMainContext *context)
{
  GSourceList *source_list;

  source_list = find_source_list_for_priority (context, source->priority, FALSE);
  g_return_if_fail (source_list != NULL);

  if (source->prev)
    source->prev->next = source->next;
  else
    source_list->head = source->next;

  if (source->next)
    source->next->prev = source->prev;
  else
    source_list->tail = source->prev;

  source->prev = NULL;
  source->next = NULL;

  if (source_list->head == NULL)
    {
      context->source_lists = g_list_remove (context->source_lists, source_list);
      g_slice_free (GSourceList, source_list);
    }
}

static guint
g_source_attach_unlocked (GSource      *source,
                          GMainContext *context,
                          gboolean      do_wakeup)
{
  GSList *tmp_list;
  guint id;

  /* The counter may have wrapped, so we must ensure that we do not
   * reuse the source id of an existing source.
   */
  do
    id = context->next_id++;
  while (id == 0 || g_hash_table_contains (context->sources, GUINT_TO_POINTER (id)));

  source->context = context;
  source->source_id = id;
  g_source_ref (source);

  g_hash_table_insert (context->sources, GUINT_TO_POINTER (id), source);

  source_add_to_context (source, context);

  if (!SOURCE_BLOCKED (source))
    {
      tmp_list = source->poll_fds;
      while (tmp_list)
        {
          g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
          tmp_list = tmp_list->next;
        }

      for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
        g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
    }

  tmp_list = source->priv->child_sources;
  while (tmp_list)
    {
      g_source_attach_unlocked (tmp_list->data, context, FALSE);
      tmp_list = tmp_list->next;
    }

  /* If another thread has acquired the context, wake it up since it
   * might be in poll() right now.
   */
  if (do_wakeup &&
      (context->flags & G_MAIN_CONTEXT_FLAGS_OWNERLESS_POLLING ||
       (context->owner && context->owner != G_THREAD_SELF)))
    {
      g_wakeup_signal (context->wakeup);
    }

  g_trace_mark (G_TRACE_CURRENT_TIME, 0,
                "GLib", "g_source_attach",
                "%s to context %p",
                (g_source_get_name (source) != NULL) ? g_source_get_name (source) : "(unnamed)",
                context);

  return source->source_id;
}

/**
 * g_source_attach:
 * @source: a #GSource
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * 
 * Adds a #GSource to a @context so that it will be executed within
 * that context. Remove it by calling g_source_destroy().
 *
 * This function is safe to call from any thread, regardless of which thread
 * the @context is running in.
 *
 * Returns: the ID (greater than 0) for the source within the 
 *   #GMainContext. 
 **/
guint
g_source_attach (GSource      *source,
		 GMainContext *context)
{
  guint result = 0;

  g_return_val_if_fail (source != NULL, 0);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, 0);
  g_return_val_if_fail (source->context == NULL, 0);
  g_return_val_if_fail (!SOURCE_DESTROYED (source), 0);
  
  if (!context)
    context = g_main_context_default ();

  LOCK_CONTEXT (context);

  result = g_source_attach_unlocked (source, context, TRUE);

  TRACE (GLIB_MAIN_SOURCE_ATTACH (g_source_get_name (source), source, context,
                                  result));

  UNLOCK_CONTEXT (context);

  return result;
}

static void
g_source_destroy_internal (GSource      *source,
			   GMainContext *context,
			   gboolean      have_lock)
{
  TRACE (GLIB_MAIN_SOURCE_DESTROY (g_source_get_name (source), source,
                                   context));

  if (!have_lock)
    LOCK_CONTEXT (context);
  
  if (!SOURCE_DESTROYED (source))
    {
      GSList *tmp_list;
      gpointer old_cb_data;
      GSourceCallbackFuncs *old_cb_funcs;
      
      source->flags &= ~G_HOOK_FLAG_ACTIVE;

      old_cb_data = source->callback_data;
      old_cb_funcs = source->callback_funcs;

      source->callback_data = NULL;
      source->callback_funcs = NULL;

      if (old_cb_funcs)
	{
	  UNLOCK_CONTEXT (context);
	  old_cb_funcs->unref (old_cb_data);
	  LOCK_CONTEXT (context);
	}

      if (!SOURCE_BLOCKED (source))
	{
	  tmp_list = source->poll_fds;
	  while (tmp_list)
	    {
	      g_main_context_remove_poll_unlocked (context, tmp_list->data);
	      tmp_list = tmp_list->next;
	    }

          for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
            g_main_context_remove_poll_unlocked (context, tmp_list->data);
	}

      while (source->priv->child_sources)
        g_child_source_remove_internal (source->priv->child_sources->data, context);

      if (source->priv->parent_source)
        g_child_source_remove_internal (source, context);
	  
      g_source_unref_internal (source, context, TRUE);
    }

  if (!have_lock)
    UNLOCK_CONTEXT (context);
}

/**
 * g_source_destroy:
 * @source: a #GSource
 * 
 * Removes a source from its #GMainContext, if any, and mark it as
 * destroyed.  The source cannot be subsequently added to another
 * context. It is safe to call this on sources which have already been
 * removed from their context.
 *
 * This does not unref the #GSource: if you still hold a reference, use
 * g_source_unref() to drop it.
 *
 * This function is safe to call from any thread, regardless of which thread
 * the #GMainContext is running in.
 *
 * If the source is currently attached to a #GMainContext, destroying it
 * will effectively unset the callback similar to calling g_source_set_callback().
 * This can mean, that the data's #GDestroyNotify gets called right away.
 */
void
g_source_destroy (GSource *source)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  
  context = source->context;
  
  if (context)
    g_source_destroy_internal (source, context, FALSE);
  else
    source->flags &= ~G_HOOK_FLAG_ACTIVE;
}

/**
 * g_source_get_id:
 * @source: a #GSource
 * 
 * Returns the numeric ID for a particular source. The ID of a source
 * is a positive integer which is unique within a particular main loop 
 * context. The reverse
 * mapping from ID to source is done by g_main_context_find_source_by_id().
 *
 * You can only call this function while the source is associated to a
 * #GMainContext instance; calling this function before g_source_attach()
 * or after g_source_destroy() yields undefined behavior. The ID returned
 * is unique within the #GMainContext instance passed to g_source_attach().
 *
 * Returns: the ID (greater than 0) for the source
 **/
guint
g_source_get_id (GSource *source)
{
  guint result;
  
  g_return_val_if_fail (source != NULL, 0);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, 0);
  g_return_val_if_fail (source->context != NULL, 0);

  LOCK_CONTEXT (source->context);
  result = source->source_id;
  UNLOCK_CONTEXT (source->context);
  
  return result;
}

/**
 * g_source_get_context:
 * @source: a #GSource
 * 
 * Gets the #GMainContext with which the source is associated.
 *
 * You can call this on a source that has been destroyed, provided
 * that the #GMainContext it was attached to still exists (in which
 * case it will return that #GMainContext). In particular, you can
 * always call this function on the source returned from
 * g_main_current_source(). But calling this function on a source
 * whose #GMainContext has been destroyed is an error.
 * 
 * Returns: (transfer none) (nullable): the #GMainContext with which the
 *               source is associated, or %NULL if the context has not
 *               yet been added to a source.
 **/
GMainContext *
g_source_get_context (GSource *source)
{
  g_return_val_if_fail (source != NULL, NULL);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, NULL);
  g_return_val_if_fail (source->context != NULL || !SOURCE_DESTROYED (source), NULL);

  return source->context;
}

/**
 * g_source_add_poll:
 * @source:a #GSource 
 * @fd: a #GPollFD structure holding information about a file
 *      descriptor to watch.
 *
 * Adds a file descriptor to the set of file descriptors polled for
 * this source. This is usually combined with g_source_new() to add an
 * event source. The event source's check function will typically test
 * the @revents field in the #GPollFD struct and return %TRUE if events need
 * to be processed.
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * Using this API forces the linear scanning of event sources on each
 * main loop iteration.  Newly-written event sources should try to use
 * g_source_add_unix_fd() instead of this API.
 **/
void
g_source_add_poll (GSource *source,
		   GPollFD *fd)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (fd != NULL);
  g_return_if_fail (!SOURCE_DESTROYED (source));
  
  context = source->context;

  if (context)
    LOCK_CONTEXT (context);
  
  source->poll_fds = g_slist_prepend (source->poll_fds, fd);

  if (context)
    {
      if (!SOURCE_BLOCKED (source))
	g_main_context_add_poll_unlocked (context, source->priority, fd);
      UNLOCK_CONTEXT (context);
    }
}

/**
 * g_source_remove_poll:
 * @source:a #GSource 
 * @fd: a #GPollFD structure previously passed to g_source_add_poll().
 * 
 * Removes a file descriptor from the set of file descriptors polled for
 * this source. 
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 **/
void
g_source_remove_poll (GSource *source,
		      GPollFD *fd)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (fd != NULL);
  g_return_if_fail (!SOURCE_DESTROYED (source));
  
  context = source->context;

  if (context)
    LOCK_CONTEXT (context);
  
  source->poll_fds = g_slist_remove (source->poll_fds, fd);

  if (context)
    {
      if (!SOURCE_BLOCKED (source))
	g_main_context_remove_poll_unlocked (context, fd);
      UNLOCK_CONTEXT (context);
    }
}

/**
 * g_source_add_child_source:
 * @source:a #GSource
 * @child_source: a second #GSource that @source should "poll"
 *
 * Adds @child_source to @source as a "polled" source; when @source is
 * added to a #GMainContext, @child_source will be automatically added
 * with the same priority, when @child_source is triggered, it will
 * cause @source to dispatch (in addition to calling its own
 * callback), and when @source is destroyed, it will destroy
 * @child_source as well. (@source will also still be dispatched if
 * its own prepare/check functions indicate that it is ready.)
 *
 * If you don't need @child_source to do anything on its own when it
 * triggers, you can call g_source_set_dummy_callback() on it to set a
 * callback that does nothing (except return %TRUE if appropriate).
 *
 * @source will hold a reference on @child_source while @child_source
 * is attached to it.
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * Since: 2.28
 **/
void
g_source_add_child_source (GSource *source,
			   GSource *child_source)
{
  GMainContext *context;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (child_source != NULL);
  g_return_if_fail (g_atomic_int_get (&child_source->ref_count) > 0);
  g_return_if_fail (!SOURCE_DESTROYED (source));
  g_return_if_fail (!SOURCE_DESTROYED (child_source));
  g_return_if_fail (child_source->context == NULL);
  g_return_if_fail (child_source->priv->parent_source == NULL);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  TRACE (GLIB_SOURCE_ADD_CHILD_SOURCE (source, child_source));

  source->priv->child_sources = g_slist_prepend (source->priv->child_sources,
						 g_source_ref (child_source));
  child_source->priv->parent_source = source;
  g_source_set_priority_unlocked (child_source, NULL, source->priority);
  if (SOURCE_BLOCKED (source))
    block_source (child_source);

  if (context)
    {
      g_source_attach_unlocked (child_source, context, TRUE);
      UNLOCK_CONTEXT (context);
    }
}

static void
g_child_source_remove_internal (GSource *child_source,
                                GMainContext *context)
{
  GSource *parent_source = child_source->priv->parent_source;

  parent_source->priv->child_sources =
    g_slist_remove (parent_source->priv->child_sources, child_source);
  child_source->priv->parent_source = NULL;

  g_source_destroy_internal (child_source, context, TRUE);
  g_source_unref_internal (child_source, context, TRUE);
}

/**
 * g_source_remove_child_source:
 * @source:a #GSource
 * @child_source: a #GSource previously passed to
 *     g_source_add_child_source().
 *
 * Detaches @child_source from @source and destroys it.
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * Since: 2.28
 **/
void
g_source_remove_child_source (GSource *source,
			      GSource *child_source)
{
  GMainContext *context;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (child_source != NULL);
  g_return_if_fail (g_atomic_int_get (&child_source->ref_count) > 0);
  g_return_if_fail (child_source->priv->parent_source == source);
  g_return_if_fail (!SOURCE_DESTROYED (source));
  g_return_if_fail (!SOURCE_DESTROYED (child_source));

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  g_child_source_remove_internal (child_source, context);

  if (context)
    UNLOCK_CONTEXT (context);
}

static void
g_source_callback_ref (gpointer cb_data)
{
  GSourceCallback *callback = cb_data;

  g_atomic_int_inc (&callback->ref_count);
}

static void
g_source_callback_unref (gpointer cb_data)
{
  GSourceCallback *callback = cb_data;

  if (g_atomic_int_dec_and_test (&callback->ref_count))
    {
      if (callback->notify)
        callback->notify (callback->data);
      g_free (callback);
    }
}

static void
g_source_callback_get (gpointer     cb_data,
		       GSource     *source, 
		       GSourceFunc *func,
		       gpointer    *data)
{
  GSourceCallback *callback = cb_data;

  *func = callback->func;
  *data = callback->data;
}

static GSourceCallbackFuncs g_source_callback_funcs = {
  g_source_callback_ref,
  g_source_callback_unref,
  g_source_callback_get,
};

/**
 * g_source_set_callback_indirect:
 * @source: the source
 * @callback_data: pointer to callback data "object"
 * @callback_funcs: functions for reference counting @callback_data
 *                  and getting the callback and data
 * 
 * Sets the callback function storing the data as a refcounted callback
 * "object". This is used internally. Note that calling 
 * g_source_set_callback_indirect() assumes
 * an initial reference count on @callback_data, and thus
 * @callback_funcs->unref will eventually be called once more
 * than @callback_funcs->ref.
 *
 * It is safe to call this function multiple times on a source which has already
 * been attached to a context. The changes will take effect for the next time
 * the source is dispatched after this call returns.
 **/
void
g_source_set_callback_indirect (GSource              *source,
				gpointer              callback_data,
				GSourceCallbackFuncs *callback_funcs)
{
  GMainContext *context;
  gpointer old_cb_data;
  GSourceCallbackFuncs *old_cb_funcs;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (callback_funcs != NULL || callback_data == NULL);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  if (callback_funcs != &g_source_callback_funcs)
    {
      TRACE (GLIB_SOURCE_SET_CALLBACK_INDIRECT (source, callback_data,
                                                callback_funcs->ref,
                                                callback_funcs->unref,
                                                callback_funcs->get));
    }

  old_cb_data = source->callback_data;
  old_cb_funcs = source->callback_funcs;

  source->callback_data = callback_data;
  source->callback_funcs = callback_funcs;
  
  if (context)
    UNLOCK_CONTEXT (context);
  
  if (old_cb_funcs)
    old_cb_funcs->unref (old_cb_data);
}

/**
 * g_source_set_callback:
 * @source: the source
 * @func: a callback function
 * @data: the data to pass to callback function
 * @notify: (nullable): a function to call when @data is no longer in use, or %NULL.
 * 
 * Sets the callback function for a source. The callback for a source is
 * called from the source's dispatch function.
 *
 * The exact type of @func depends on the type of source; ie. you
 * should not count on @func being called with @data as its first
 * parameter. Cast @func with G_SOURCE_FUNC() to avoid warnings about
 * incompatible function types.
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle memory management of @data.
 * 
 * Typically, you won't use this function. Instead use functions specific
 * to the type of source you are using, such as g_idle_add() or g_timeout_add().
 *
 * It is safe to call this function multiple times on a source which has already
 * been attached to a context. The changes will take effect for the next time
 * the source is dispatched after this call returns.
 *
 * Note that g_source_destroy() for a currently attached source has the effect
 * of also unsetting the callback.
 **/
void
g_source_set_callback (GSource        *source,
		       GSourceFunc     func,
		       gpointer        data,
		       GDestroyNotify  notify)
{
  GSourceCallback *new_callback;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);

  TRACE (GLIB_SOURCE_SET_CALLBACK (source, func, data, notify));

  new_callback = g_new (GSourceCallback, 1);

  new_callback->ref_count = 1;
  new_callback->func = func;
  new_callback->data = data;
  new_callback->notify = notify;

  g_source_set_callback_indirect (source, new_callback, &g_source_callback_funcs);
}


/**
 * g_source_set_funcs:
 * @source: a #GSource
 * @funcs: the new #GSourceFuncs
 * 
 * Sets the source functions (can be used to override 
 * default implementations) of an unattached source.
 * 
 * Since: 2.12
 */
void
g_source_set_funcs (GSource     *source,
	           GSourceFuncs *funcs)
{
  g_return_if_fail (source != NULL);
  g_return_if_fail (source->context == NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (funcs != NULL);

  source->source_funcs = funcs;
}

static void
g_source_set_priority_unlocked (GSource      *source,
				GMainContext *context,
				gint          priority)
{
  GSList *tmp_list;
  
  g_return_if_fail (source->priv->parent_source == NULL ||
		    source->priv->parent_source->priority == priority);

  TRACE (GLIB_SOURCE_SET_PRIORITY (source, context, priority));

  if (context)
    {
      /* Remove the source from the context's source and then
       * add it back after so it is sorted in the correct place
       */
      source_remove_from_context (source, source->context);
    }

  source->priority = priority;

  if (context)
    {
      source_add_to_context (source, source->context);

      if (!SOURCE_BLOCKED (source))
	{
	  tmp_list = source->poll_fds;
	  while (tmp_list)
	    {
	      g_main_context_remove_poll_unlocked (context, tmp_list->data);
	      g_main_context_add_poll_unlocked (context, priority, tmp_list->data);
	      
	      tmp_list = tmp_list->next;
	    }

          for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
            {
              g_main_context_remove_poll_unlocked (context, tmp_list->data);
              g_main_context_add_poll_unlocked (context, priority, tmp_list->data);
            }
	}
    }

  if (source->priv->child_sources)
    {
      tmp_list = source->priv->child_sources;
      while (tmp_list)
	{
	  g_source_set_priority_unlocked (tmp_list->data, context, priority);
	  tmp_list = tmp_list->next;
	}
    }
}

/**
 * g_source_set_priority:
 * @source: a #GSource
 * @priority: the new priority.
 *
 * Sets the priority of a source. While the main loop is being run, a
 * source will be dispatched if it is ready to be dispatched and no
 * sources at a higher (numerically smaller) priority are ready to be
 * dispatched.
 *
 * A child source always has the same priority as its parent.  It is not
 * permitted to change the priority of a source once it has been added
 * as a child of another source.
 **/
void
g_source_set_priority (GSource  *source,
		       gint      priority)
{
  GMainContext *context;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (source->priv->parent_source == NULL);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);
  g_source_set_priority_unlocked (source, context, priority);
  if (context)
    UNLOCK_CONTEXT (context);
}

/**
 * g_source_get_priority:
 * @source: a #GSource
 * 
 * Gets the priority of a source.
 * 
 * Returns: the priority of the source
 **/
gint
g_source_get_priority (GSource *source)
{
  g_return_val_if_fail (source != NULL, 0);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, 0);

  return source->priority;
}

/**
 * g_source_set_ready_time:
 * @source: a #GSource
 * @ready_time: the monotonic time at which the source will be ready,
 *              0 for "immediately", -1 for "never"
 *
 * Sets a #GSource to be dispatched when the given monotonic time is
 * reached (or passed).  If the monotonic time is in the past (as it
 * always will be if @ready_time is 0) then the source will be
 * dispatched immediately.
 *
 * If @ready_time is -1 then the source is never woken up on the basis
 * of the passage of time.
 *
 * Dispatching the source does not reset the ready time.  You should do
 * so yourself, from the source dispatch function.
 *
 * Note that if you have a pair of sources where the ready time of one
 * suggests that it will be delivered first but the priority for the
 * other suggests that it would be delivered first, and the ready time
 * for both sources is reached during the same main context iteration,
 * then the order of dispatch is undefined.
 *
 * It is a no-op to call this function on a #GSource which has already been
 * destroyed with g_source_destroy().
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * Since: 2.36
 **/
void
g_source_set_ready_time (GSource *source,
                         gint64   ready_time)
{
  GMainContext *context;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  if (source->priv->ready_time == ready_time)
    {
      if (context)
        UNLOCK_CONTEXT (context);

      return;
    }

  source->priv->ready_time = ready_time;

  TRACE (GLIB_SOURCE_SET_READY_TIME (source, ready_time));

  if (context)
    {
      /* Quite likely that we need to change the timeout on the poll */
      if (!SOURCE_BLOCKED (source))
        g_wakeup_signal (context->wakeup);
      UNLOCK_CONTEXT (context);
    }
}

/**
 * g_source_get_ready_time:
 * @source: a #GSource
 *
 * Gets the "ready time" of @source, as set by
 * g_source_set_ready_time().
 *
 * Any time before the current monotonic time (including 0) is an
 * indication that the source will fire immediately.
 *
 * Returns: the monotonic ready time, -1 for "never"
 **/
gint64
g_source_get_ready_time (GSource *source)
{
  g_return_val_if_fail (source != NULL, -1);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, -1);

  return source->priv->ready_time;
}

/**
 * g_source_set_can_recurse:
 * @source: a #GSource
 * @can_recurse: whether recursion is allowed for this source
 * 
 * Sets whether a source can be called recursively. If @can_recurse is
 * %TRUE, then while the source is being dispatched then this source
 * will be processed normally. Otherwise, all processing of this
 * source is blocked until the dispatch function returns.
 **/
void
g_source_set_can_recurse (GSource  *source,
			  gboolean  can_recurse)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);
  
  if (can_recurse)
    source->flags |= G_SOURCE_CAN_RECURSE;
  else
    source->flags &= ~G_SOURCE_CAN_RECURSE;

  if (context)
    UNLOCK_CONTEXT (context);
}

/**
 * g_source_get_can_recurse:
 * @source: a #GSource
 * 
 * Checks whether a source is allowed to be called recursively.
 * see g_source_set_can_recurse().
 * 
 * Returns: whether recursion is allowed.
 **/
gboolean
g_source_get_can_recurse (GSource  *source)
{
  g_return_val_if_fail (source != NULL, FALSE);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, FALSE);
  
  return (source->flags & G_SOURCE_CAN_RECURSE) != 0;
}

static void
g_source_set_name_full (GSource    *source,
                        const char *name,
                        gboolean    is_static)
{
  GMainContext *context;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  TRACE (GLIB_SOURCE_SET_NAME (source, name));

  /* setting back to NULL is allowed, just because it's
   * weird if get_name can return NULL but you can't
   * set that.
   */

  if (!source->priv->static_name)
    g_free (source->name);

  if (is_static)
    source->name = (char *)name;
  else
    source->name = g_strdup (name);

  source->priv->static_name = is_static;

  if (context)
    UNLOCK_CONTEXT (context);
}

/**
 * g_source_set_name:
 * @source: a #GSource
 * @name: debug name for the source
 *
 * Sets a name for the source, used in debugging and profiling.
 * The name defaults to #NULL.
 *
 * The source name should describe in a human-readable way
 * what the source does. For example, "X11 event queue"
 * or "GTK+ repaint idle handler" or whatever it is.
 *
 * It is permitted to call this function multiple times, but is not
 * recommended due to the potential performance impact.  For example,
 * one could change the name in the "check" function of a #GSourceFuncs
 * to include details like the event type in the source name.
 *
 * Use caution if changing the name while another thread may be
 * accessing it with g_source_get_name(); that function does not copy
 * the value, and changing the value will free it while the other thread
 * may be attempting to use it.
 *
 * Also see g_source_set_static_name().
 *
 * Since: 2.26
 **/
void
g_source_set_name (GSource    *source,
                   const char *name)
{
  g_source_set_name_full (source, name, FALSE);
}

/**
 * g_source_set_static_name:
 * @source: a #GSource
 * @name: debug name for the source
 *
 * A variant of g_source_set_name() that does not
 * duplicate the @name, and can only be used with
 * string literals.
 *
 * Since: 2.70
 */
void
g_source_set_static_name (GSource    *source,
                          const char *name)
{
  g_source_set_name_full (source, name, TRUE);
}

/**
 * g_source_get_name:
 * @source: a #GSource
 *
 * Gets a name for the source, used in debugging and profiling.  The
 * name may be #NULL if it has never been set with g_source_set_name().
 *
 * Returns: (nullable): the name of the source
 *
 * Since: 2.26
 **/
const char *
g_source_get_name (GSource *source)
{
  g_return_val_if_fail (source != NULL, NULL);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, NULL);

  return source->name;
}

/**
 * g_source_set_name_by_id:
 * @tag: a #GSource ID
 * @name: debug name for the source
 *
 * Sets the name of a source using its ID.
 *
 * This is a convenience utility to set source names from the return
 * value of g_idle_add(), g_timeout_add(), etc.
 *
 * It is a programmer error to attempt to set the name of a non-existent
 * source.
 *
 * More specifically: source IDs can be reissued after a source has been
 * destroyed and therefore it is never valid to use this function with a
 * source ID which may have already been removed.  An example is when
 * scheduling an idle to run in another thread with g_idle_add(): the
 * idle may already have run and been removed by the time this function
 * is called on its (now invalid) source ID.  This source ID may have
 * been reissued, leading to the operation being performed against the
 * wrong source.
 *
 * Since: 2.26
 **/
void
g_source_set_name_by_id (guint           tag,
                         const char     *name)
{
  GSource *source;

  g_return_if_fail (tag > 0);

  source = g_main_context_find_source_by_id (NULL, tag);
  if (source == NULL)
    return;

  g_source_set_name (source, name);
}


/**
 * g_source_ref:
 * @source: a #GSource
 * 
 * Increases the reference count on a source by one.
 * 
 * Returns: @source
 **/
GSource *
g_source_ref (GSource *source)
{
  g_return_val_if_fail (source != NULL, NULL);
  /* We allow ref_count == 0 here to allow the dispose function to resurrect
   * the GSource if needed */
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) >= 0, NULL);

  g_atomic_int_inc (&source->ref_count);

  return source;
}

/* g_source_unref() but possible to call within context lock
 */
static void
g_source_unref_internal (GSource      *source,
			 GMainContext *context,
			 gboolean      have_lock)
{
  gpointer old_cb_data = NULL;
  GSourceCallbackFuncs *old_cb_funcs = NULL;

  g_return_if_fail (source != NULL);

  if (!have_lock && context)
    LOCK_CONTEXT (context);

  if (g_atomic_int_dec_and_test (&source->ref_count))
    {
      /* If there's a dispose function, call this first */
      if (source->priv->dispose)
        {
          /* Temporarily increase the ref count again so that GSource methods
           * can be called from dispose(). */
          g_atomic_int_inc (&source->ref_count);
          if (context)
            UNLOCK_CONTEXT (context);
          source->priv->dispose (source);
          if (context)
            LOCK_CONTEXT (context);

          /* Now the reference count might be bigger than 0 again, in which
           * case we simply return from here before freeing the source */
          if (!g_atomic_int_dec_and_test (&source->ref_count))
            {
              if (!have_lock && context)
                UNLOCK_CONTEXT (context);
              return;
            }
        }

      TRACE (GLIB_SOURCE_BEFORE_FREE (source, context,
                                      source->source_funcs->finalize));

      old_cb_data = source->callback_data;
      old_cb_funcs = source->callback_funcs;

      source->callback_data = NULL;
      source->callback_funcs = NULL;

      if (context)
	{
	  if (!SOURCE_DESTROYED (source))
	    g_warning (G_STRLOC ": ref_count == 0, but source was still attached to a context!");
	  source_remove_from_context (source, context);

          g_hash_table_remove (context->sources, GUINT_TO_POINTER (source->source_id));
	}

      if (source->source_funcs->finalize)
	{
          gint old_ref_count;

          /* Temporarily increase the ref count again so that GSource methods
           * can be called from finalize(). */
          g_atomic_int_inc (&source->ref_count);
	  if (context)
	    UNLOCK_CONTEXT (context);
	  source->source_funcs->finalize (source);
	  if (context)
	    LOCK_CONTEXT (context);
          old_ref_count = g_atomic_int_add (&source->ref_count, -1);
          g_warn_if_fail (old_ref_count == 1);
	}

      if (old_cb_funcs)
        {
          gint old_ref_count;

          /* Temporarily increase the ref count again so that GSource methods
           * can be called from callback_funcs.unref(). */
          g_atomic_int_inc (&source->ref_count);
          if (context)
            UNLOCK_CONTEXT (context);

          old_cb_funcs->unref (old_cb_data);

          if (context)
            LOCK_CONTEXT (context);
          old_ref_count = g_atomic_int_add (&source->ref_count, -1);
          g_warn_if_fail (old_ref_count == 1);
        }

      if (!source->priv->static_name)
        g_free (source->name);
      source->name = NULL;

      g_slist_free (source->poll_fds);
      source->poll_fds = NULL;

      g_slist_free_full (source->priv->fds, g_free);

      while (source->priv->child_sources)
        {
          GSource *child_source = source->priv->child_sources->data;

          source->priv->child_sources =
            g_slist_remove (source->priv->child_sources, child_source);
          child_source->priv->parent_source = NULL;

          g_source_unref_internal (child_source, context, TRUE);
        }

      g_slice_free (GSourcePrivate, source->priv);
      source->priv = NULL;

      g_free (source);
    }

  if (!have_lock && context)
    UNLOCK_CONTEXT (context);
}

/**
 * g_source_unref:
 * @source: a #GSource
 * 
 * Decreases the reference count of a source by one. If the
 * resulting reference count is zero the source and associated
 * memory will be destroyed. 
 **/
void
g_source_unref (GSource *source)
{
  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);

  g_source_unref_internal (source, source->context, FALSE);
}

/**
 * g_main_context_find_source_by_id:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @source_id: the source ID, as returned by g_source_get_id().
 *
 * Finds a #GSource given a pair of context and ID.
 *
 * It is a programmer error to attempt to look up a non-existent source.
 *
 * More specifically: source IDs can be reissued after a source has been
 * destroyed and therefore it is never valid to use this function with a
 * source ID which may have already been removed.  An example is when
 * scheduling an idle to run in another thread with g_idle_add(): the
 * idle may already have run and been removed by the time this function
 * is called on its (now invalid) source ID.  This source ID may have
 * been reissued, leading to the operation being performed against the
 * wrong source.
 *
 * Returns: (transfer none): the #GSource
 **/
GSource *
g_main_context_find_source_by_id (GMainContext *context,
                                  guint         source_id)
{
  GSource *source;

  g_return_val_if_fail (source_id > 0, NULL);

  if (context == NULL)
    context = g_main_context_default ();

  LOCK_CONTEXT (context);
  source = g_hash_table_lookup (context->sources, GUINT_TO_POINTER (source_id));
  UNLOCK_CONTEXT (context);

  if (source && SOURCE_DESTROYED (source))
    source = NULL;

  return source;
}

/**
 * g_main_context_find_source_by_funcs_user_data:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used).
 * @funcs: the @source_funcs passed to g_source_new().
 * @user_data: the user data from the callback.
 * 
 * Finds a source with the given source functions and user data.  If
 * multiple sources exist with the same source function and user data,
 * the first one found will be returned.
 * 
 * Returns: (transfer none): the source, if one was found, otherwise %NULL
 **/
GSource *
g_main_context_find_source_by_funcs_user_data (GMainContext *context,
					       GSourceFuncs *funcs,
					       gpointer      user_data)
{
  GSourceIter iter;
  GSource *source;
  
  g_return_val_if_fail (funcs != NULL, NULL);

  if (context == NULL)
    context = g_main_context_default ();
  
  LOCK_CONTEXT (context);

  g_source_iter_init (&iter, context, FALSE);
  while (g_source_iter_next (&iter, &source))
    {
      if (!SOURCE_DESTROYED (source) &&
	  source->source_funcs == funcs &&
	  source->callback_funcs)
	{
	  GSourceFunc callback;
	  gpointer callback_data;

	  source->callback_funcs->get (source->callback_data, source, &callback, &callback_data);
	  
	  if (callback_data == user_data)
	    break;
	}
    }
  g_source_iter_clear (&iter);

  UNLOCK_CONTEXT (context);

  return source;
}

/**
 * g_main_context_find_source_by_user_data:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @user_data: the user_data for the callback.
 * 
 * Finds a source with the given user data for the callback.  If
 * multiple sources exist with the same user data, the first
 * one found will be returned.
 * 
 * Returns: (transfer none): the source, if one was found, otherwise %NULL
 **/
GSource *
g_main_context_find_source_by_user_data (GMainContext *context,
					 gpointer      user_data)
{
  GSourceIter iter;
  GSource *source;
  
  if (context == NULL)
    context = g_main_context_default ();
  
  LOCK_CONTEXT (context);

  g_source_iter_init (&iter, context, FALSE);
  while (g_source_iter_next (&iter, &source))
    {
      if (!SOURCE_DESTROYED (source) &&
	  source->callback_funcs)
	{
	  GSourceFunc callback;
	  gpointer callback_data = NULL;

	  source->callback_funcs->get (source->callback_data, source, &callback, &callback_data);

	  if (callback_data == user_data)
	    break;
	}
    }
  g_source_iter_clear (&iter);

  UNLOCK_CONTEXT (context);

  return source;
}

/**
 * g_source_remove:
 * @tag: the ID of the source to remove.
 *
 * Removes the source with the given ID from the default main context. You must
 * use g_source_destroy() for sources added to a non-default main context.
 *
 * The ID of a #GSource is given by g_source_get_id(), or will be
 * returned by the functions g_source_attach(), g_idle_add(),
 * g_idle_add_full(), g_timeout_add(), g_timeout_add_full(),
 * g_child_watch_add(), g_child_watch_add_full(), g_io_add_watch(), and
 * g_io_add_watch_full().
 *
 * It is a programmer error to attempt to remove a non-existent source.
 *
 * More specifically: source IDs can be reissued after a source has been
 * destroyed and therefore it is never valid to use this function with a
 * source ID which may have already been removed.  An example is when
 * scheduling an idle to run in another thread with g_idle_add(): the
 * idle may already have run and been removed by the time this function
 * is called on its (now invalid) source ID.  This source ID may have
 * been reissued, leading to the operation being performed against the
 * wrong source.
 *
 * Returns: %TRUE if the source was found and removed.
 **/
gboolean
g_source_remove (guint tag)
{
  GSource *source;

  g_return_val_if_fail (tag > 0, FALSE);

  source = g_main_context_find_source_by_id (NULL, tag);
  if (source)
    g_source_destroy (source);
  else
    g_critical ("Source ID %u was not found when attempting to remove it", tag);

  return source != NULL;
}

/**
 * g_source_remove_by_user_data:
 * @user_data: the user_data for the callback.
 * 
 * Removes a source from the default main loop context given the user
 * data for the callback. If multiple sources exist with the same user
 * data, only one will be destroyed.
 * 
 * Returns: %TRUE if a source was found and removed. 
 **/
gboolean
g_source_remove_by_user_data (gpointer user_data)
{
  GSource *source;
  
  source = g_main_context_find_source_by_user_data (NULL, user_data);
  if (source)
    {
      g_source_destroy (source);
      return TRUE;
    }
  else
    return FALSE;
}

/**
 * g_source_remove_by_funcs_user_data:
 * @funcs: The @source_funcs passed to g_source_new()
 * @user_data: the user data for the callback
 * 
 * Removes a source from the default main loop context given the
 * source functions and user data. If multiple sources exist with the
 * same source functions and user data, only one will be destroyed.
 * 
 * Returns: %TRUE if a source was found and removed. 
 **/
gboolean
g_source_remove_by_funcs_user_data (GSourceFuncs *funcs,
				    gpointer      user_data)
{
  GSource *source;

  g_return_val_if_fail (funcs != NULL, FALSE);

  source = g_main_context_find_source_by_funcs_user_data (NULL, funcs, user_data);
  if (source)
    {
      g_source_destroy (source);
      return TRUE;
    }
  else
    return FALSE;
}

/**
 * g_clear_handle_id: (skip)
 * @tag_ptr: (not nullable): a pointer to the handler ID
 * @clear_func: (not nullable): the function to call to clear the handler
 *
 * Clears a numeric handler, such as a #GSource ID.
 *
 * @tag_ptr must be a valid pointer to the variable holding the handler.
 *
 * If the ID is zero then this function does nothing.
 * Otherwise, clear_func() is called with the ID as a parameter, and the tag is
 * set to zero.
 *
 * A macro is also included that allows this function to be used without
 * pointer casts.
 *
 * Since: 2.56
 */
#undef g_clear_handle_id
void
g_clear_handle_id (guint            *tag_ptr,
                   GClearHandleFunc  clear_func)
{
  guint _handle_id;

  _handle_id = *tag_ptr;
  if (_handle_id > 0)
    {
      *tag_ptr = 0;
      clear_func (_handle_id);
    }
}

#ifdef G_OS_UNIX
/**
 * g_source_add_unix_fd:
 * @source: a #GSource
 * @fd: the fd to monitor
 * @events: an event mask
 *
 * Monitors @fd for the IO events in @events.
 *
 * The tag returned by this function can be used to remove or modify the
 * monitoring of the fd using g_source_remove_unix_fd() or
 * g_source_modify_unix_fd().
 *
 * It is not necessary to remove the fd before destroying the source; it
 * will be cleaned up automatically.
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * As the name suggests, this function is not available on Windows.
 *
 * Returns: (not nullable): an opaque tag
 *
 * Since: 2.36
 **/
gpointer
g_source_add_unix_fd (GSource      *source,
                      gint          fd,
                      GIOCondition  events)
{
  GMainContext *context;
  GPollFD *poll_fd;

  g_return_val_if_fail (source != NULL, NULL);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, NULL);
  g_return_val_if_fail (!SOURCE_DESTROYED (source), NULL);

  poll_fd = g_new (GPollFD, 1);
  poll_fd->fd = fd;
  poll_fd->events = events;
  poll_fd->revents = 0;

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  source->priv->fds = g_slist_prepend (source->priv->fds, poll_fd);

  if (context)
    {
      if (!SOURCE_BLOCKED (source))
        g_main_context_add_poll_unlocked (context, source->priority, poll_fd);
      UNLOCK_CONTEXT (context);
    }

  return poll_fd;
}

/**
 * g_source_modify_unix_fd:
 * @source: a #GSource
 * @tag: (not nullable): the tag from g_source_add_unix_fd()
 * @new_events: the new event mask to watch
 *
 * Updates the event mask to watch for the fd identified by @tag.
 *
 * @tag is the tag returned from g_source_add_unix_fd().
 *
 * If you want to remove a fd, don't set its event mask to zero.
 * Instead, call g_source_remove_unix_fd().
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * As the name suggests, this function is not available on Windows.
 *
 * Since: 2.36
 **/
void
g_source_modify_unix_fd (GSource      *source,
                         gpointer      tag,
                         GIOCondition  new_events)
{
  GMainContext *context;
  GPollFD *poll_fd;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (g_slist_find (source->priv->fds, tag));

  context = source->context;
  poll_fd = tag;

  poll_fd->events = new_events;

  if (context)
    g_main_context_wakeup (context);
}

/**
 * g_source_remove_unix_fd:
 * @source: a #GSource
 * @tag: (not nullable): the tag from g_source_add_unix_fd()
 *
 * Reverses the effect of a previous call to g_source_add_unix_fd().
 *
 * You only need to call this if you want to remove an fd from being
 * watched while keeping the same source around.  In the normal case you
 * will just want to destroy the source.
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * As the name suggests, this function is not available on Windows.
 *
 * Since: 2.36
 **/
void
g_source_remove_unix_fd (GSource  *source,
                         gpointer  tag)
{
  GMainContext *context;
  GPollFD *poll_fd;

  g_return_if_fail (source != NULL);
  g_return_if_fail (g_atomic_int_get (&source->ref_count) > 0);
  g_return_if_fail (g_slist_find (source->priv->fds, tag));

  context = source->context;
  poll_fd = tag;

  if (context)
    LOCK_CONTEXT (context);

  source->priv->fds = g_slist_remove (source->priv->fds, poll_fd);

  if (context)
    {
      if (!SOURCE_BLOCKED (source))
        g_main_context_remove_poll_unlocked (context, poll_fd);

      UNLOCK_CONTEXT (context);
    }

  g_free (poll_fd);
}

/**
 * g_source_query_unix_fd:
 * @source: a #GSource
 * @tag: (not nullable): the tag from g_source_add_unix_fd()
 *
 * Queries the events reported for the fd corresponding to @tag on
 * @source during the last poll.
 *
 * The return value of this function is only defined when the function
 * is called from the check or dispatch functions for @source.
 *
 * This API is only intended to be used by implementations of #GSource.
 * Do not call this API on a #GSource that you did not create.
 *
 * As the name suggests, this function is not available on Windows.
 *
 * Returns: the conditions reported on the fd
 *
 * Since: 2.36
 **/
GIOCondition
g_source_query_unix_fd (GSource  *source,
                        gpointer  tag)
{
  GPollFD *poll_fd;

  g_return_val_if_fail (source != NULL, 0);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, 0);
  g_return_val_if_fail (g_slist_find (source->priv->fds, tag), 0);

  poll_fd = tag;

  return poll_fd->revents;
}
#endif /* G_OS_UNIX */

/**
 * g_get_current_time:
 * @result: #GTimeVal structure in which to store current time.
 *
 * Equivalent to the UNIX gettimeofday() function, but portable.
 *
 * You may find g_get_real_time() to be more convenient.
 *
 * Deprecated: 2.62: #GTimeVal is not year-2038-safe. Use g_get_real_time()
 *    instead.
 **/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
void
g_get_current_time (GTimeVal *result)
{
  gint64 tv;

  g_return_if_fail (result != NULL);

  tv = g_get_real_time ();

  result->tv_sec = tv / 1000000;
  result->tv_usec = tv % 1000000;
}
G_GNUC_END_IGNORE_DEPRECATIONS

/**
 * g_get_real_time:
 *
 * Queries the system wall-clock time.
 *
 * This call is functionally equivalent to g_get_current_time() except
 * that the return value is often more convenient than dealing with a
 * #GTimeVal.
 *
 * You should only use this call if you are actually interested in the real
 * wall-clock time.  g_get_monotonic_time() is probably more useful for
 * measuring intervals.
 *
 * Returns: the number of microseconds since January 1, 1970 UTC.
 *
 * Since: 2.28
 **/
gint64
g_get_real_time (void)
{
#ifndef G_OS_WIN32
  struct timeval r;

  /* this is required on alpha, there the timeval structs are ints
   * not longs and a cast only would fail horribly */
  gettimeofday (&r, NULL);

  return (((gint64) r.tv_sec) * 1000000) + r.tv_usec;
#else
  FILETIME ft;
  guint64 time64;

  GetSystemTimeAsFileTime (&ft);
  memmove (&time64, &ft, sizeof (FILETIME));

  /* Convert from 100s of nanoseconds since 1601-01-01
   * to Unix epoch. This is Y2038 safe.
   */
  time64 -= G_GINT64_CONSTANT (116444736000000000);
  time64 /= 10;

  return time64;
#endif
}

/**
 * g_get_monotonic_time:
 *
 * Queries the system monotonic time.
 *
 * The monotonic clock will always increase and doesn't suffer
 * discontinuities when the user (or NTP) changes the system time.  It
 * may or may not continue to tick during times where the machine is
 * suspended.
 *
 * We try to use the clock that corresponds as closely as possible to
 * the passage of time as measured by system calls such as poll() but it
 * may not always be possible to do this.
 *
 * Returns: the monotonic time, in microseconds
 *
 * Since: 2.28
 **/
#if defined (G_OS_WIN32)
/* NOTE:
 * time_usec = ticks_since_boot * usec_per_sec / ticks_per_sec
 *
 * Doing (ticks_since_boot * usec_per_sec) before the division can overflow 64 bits
 * (ticks_since_boot  / ticks_per_sec) and then multiply would not be accurate enough.
 * So for now we calculate (usec_per_sec / ticks_per_sec) and use floating point
 */
static gdouble g_monotonic_usec_per_tick = 0;

void
g_clock_win32_init (void)
{
  LARGE_INTEGER freq;

  if (!QueryPerformanceFrequency (&freq) || freq.QuadPart == 0)
    {
      /* The documentation says that this should never happen */
      g_assert_not_reached ();
      return;
    }

  g_monotonic_usec_per_tick = (gdouble)G_USEC_PER_SEC / freq.QuadPart;
}

gint64
g_get_monotonic_time (void)
{
  if (G_LIKELY (g_monotonic_usec_per_tick != 0))
    {
      LARGE_INTEGER ticks;

      if (QueryPerformanceCounter (&ticks))
        return (gint64)(ticks.QuadPart * g_monotonic_usec_per_tick);

      g_warning ("QueryPerformanceCounter Failed (%lu)", GetLastError ());
      g_monotonic_usec_per_tick = 0;
    }

  return 0;
}
#elif defined(HAVE_MACH_MACH_TIME_H) /* Mac OS */
gint64
g_get_monotonic_time (void)
{
  mach_timebase_info_data_t timebase_info;
  guint64 val;

  /* we get nanoseconds from mach_absolute_time() using timebase_info */
  mach_timebase_info (&timebase_info);
  val = mach_absolute_time ();

  if (timebase_info.numer != timebase_info.denom)
    {
#ifdef HAVE_UINT128_T
      val = ((__uint128_t) val * (__uint128_t) timebase_info.numer) / timebase_info.denom / 1000;
#else
      guint64 t_high, t_low;
      guint64 result_high, result_low;

      /* 64 bit x 32 bit / 32 bit with 96-bit intermediate 
       * algorithm lifted from qemu */
      t_low = (val & 0xffffffffLL) * (guint64) timebase_info.numer;
      t_high = (val >> 32) * (guint64) timebase_info.numer;
      t_high += (t_low >> 32);
      result_high = t_high / (guint64) timebase_info.denom;
      result_low = (((t_high % (guint64) timebase_info.denom) << 32) +
                    (t_low & 0xffffffff)) /
                   (guint64) timebase_info.denom;
      val = ((result_high << 32) | result_low) / 1000;
#endif
    }
  else
    {
      /* nanoseconds to microseconds */
      val = val / 1000;
    }

  return val;
}
#else
gint64
g_get_monotonic_time (void)
{
  struct timespec ts;
  gint result;

  result = clock_gettime (CLOCK_MONOTONIC, &ts);

  if G_UNLIKELY (result != 0)
    g_error ("GLib requires working CLOCK_MONOTONIC");

  return (((gint64) ts.tv_sec) * 1000000) + (ts.tv_nsec / 1000);
}
#endif

static void
g_main_dispatch_free (gpointer dispatch)
{
  g_free (dispatch);
}

/* Running the main loop */

static GMainDispatch *
get_dispatch (void)
{
  static GPrivate depth_private = G_PRIVATE_INIT (g_main_dispatch_free);
  GMainDispatch *dispatch;

  dispatch = g_private_get (&depth_private);

  if (!dispatch)
    dispatch = g_private_set_alloc0 (&depth_private, sizeof (GMainDispatch));

  return dispatch;
}

/**
 * g_main_depth:
 *
 * Returns the depth of the stack of calls to
 * g_main_context_dispatch() on any #GMainContext in the current thread.
 * That is, when called from the toplevel, it gives 0. When
 * called from within a callback from g_main_context_iteration()
 * (or g_main_loop_run(), etc.) it returns 1. When called from within 
 * a callback to a recursive call to g_main_context_iteration(),
 * it returns 2. And so forth.
 *
 * This function is useful in a situation like the following:
 * Imagine an extremely simple "garbage collected" system.
 *
 * |[<!-- language="C" --> 
 * static GList *free_list;
 * 
 * gpointer
 * allocate_memory (gsize size)
 * { 
 *   gpointer result = g_malloc (size);
 *   free_list = g_list_prepend (free_list, result);
 *   return result;
 * }
 * 
 * void
 * free_allocated_memory (void)
 * {
 *   GList *l;
 *   for (l = free_list; l; l = l->next);
 *     g_free (l->data);
 *   g_list_free (free_list);
 *   free_list = NULL;
 *  }
 * 
 * [...]
 * 
 * while (TRUE); 
 *  {
 *    g_main_context_iteration (NULL, TRUE);
 *    free_allocated_memory();
 *   }
 * ]|
 *
 * This works from an application, however, if you want to do the same
 * thing from a library, it gets more difficult, since you no longer
 * control the main loop. You might think you can simply use an idle
 * function to make the call to free_allocated_memory(), but that
 * doesn't work, since the idle function could be called from a
 * recursive callback. This can be fixed by using g_main_depth()
 *
 * |[<!-- language="C" --> 
 * gpointer
 * allocate_memory (gsize size)
 * { 
 *   FreeListBlock *block = g_new (FreeListBlock, 1);
 *   block->mem = g_malloc (size);
 *   block->depth = g_main_depth ();   
 *   free_list = g_list_prepend (free_list, block);
 *   return block->mem;
 * }
 * 
 * void
 * free_allocated_memory (void)
 * {
 *   GList *l;
 *   
 *   int depth = g_main_depth ();
 *   for (l = free_list; l; );
 *     {
 *       GList *next = l->next;
 *       FreeListBlock *block = l->data;
 *       if (block->depth > depth)
 *         {
 *           g_free (block->mem);
 *           g_free (block);
 *           free_list = g_list_delete_link (free_list, l);
 *         }
 *               
 *       l = next;
 *     }
 *   }
 * ]|
 *
 * There is a temptation to use g_main_depth() to solve
 * problems with reentrancy. For instance, while waiting for data
 * to be received from the network in response to a menu item,
 * the menu item might be selected again. It might seem that
 * one could make the menu item's callback return immediately
 * and do nothing if g_main_depth() returns a value greater than 1.
 * However, this should be avoided since the user then sees selecting
 * the menu item do nothing. Furthermore, you'll find yourself adding
 * these checks all over your code, since there are doubtless many,
 * many things that the user could do. Instead, you can use the
 * following techniques:
 *
 * 1. Use gtk_widget_set_sensitive() or modal dialogs to prevent
 *    the user from interacting with elements while the main
 *    loop is recursing.
 * 
 * 2. Avoid main loop recursion in situations where you can't handle
 *    arbitrary  callbacks. Instead, structure your code so that you
 *    simply return to the main loop and then get called again when
 *    there is more work to do.
 * 
 * Returns: The main loop recursion level in the current thread
 */
int
g_main_depth (void)
{
  GMainDispatch *dispatch = get_dispatch ();
  return dispatch->depth;
}

/**
 * g_main_current_source:
 *
 * Returns the currently firing source for this thread.
 * 
 * Returns: (transfer none) (nullable): The currently firing source or %NULL.
 *
 * Since: 2.12
 */
GSource *
g_main_current_source (void)
{
  GMainDispatch *dispatch = get_dispatch ();
  return dispatch->source;
}

/**
 * g_source_is_destroyed:
 * @source: a #GSource
 *
 * Returns whether @source has been destroyed.
 *
 * This is important when you operate upon your objects 
 * from within idle handlers, but may have freed the object 
 * before the dispatch of your idle handler.
 *
 * |[<!-- language="C" --> 
 * static gboolean 
 * idle_callback (gpointer data)
 * {
 *   SomeWidget *self = data;
 *    
 *   g_mutex_lock (&self->idle_id_mutex);
 *   // do stuff with self
 *   self->idle_id = 0;
 *   g_mutex_unlock (&self->idle_id_mutex);
 *    
 *   return G_SOURCE_REMOVE;
 * }
 *  
 * static void 
 * some_widget_do_stuff_later (SomeWidget *self)
 * {
 *   g_mutex_lock (&self->idle_id_mutex);
 *   self->idle_id = g_idle_add (idle_callback, self);
 *   g_mutex_unlock (&self->idle_id_mutex);
 * }
 *  
 * static void
 * some_widget_init (SomeWidget *self)
 * {
 *   g_mutex_init (&self->idle_id_mutex);
 *
 *   // ...
 * }
 *
 * static void 
 * some_widget_finalize (GObject *object)
 * {
 *   SomeWidget *self = SOME_WIDGET (object);
 *    
 *   if (self->idle_id)
 *     g_source_remove (self->idle_id);
 *    
 *   g_mutex_clear (&self->idle_id_mutex);
 *
 *   G_OBJECT_CLASS (parent_class)->finalize (object);
 * }
 * ]|
 *
 * This will fail in a multi-threaded application if the 
 * widget is destroyed before the idle handler fires due 
 * to the use after free in the callback. A solution, to 
 * this particular problem, is to check to if the source
 * has already been destroy within the callback.
 *
 * |[<!-- language="C" --> 
 * static gboolean 
 * idle_callback (gpointer data)
 * {
 *   SomeWidget *self = data;
 *   
 *   g_mutex_lock (&self->idle_id_mutex);
 *   if (!g_source_is_destroyed (g_main_current_source ()))
 *     {
 *       // do stuff with self
 *     }
 *   g_mutex_unlock (&self->idle_id_mutex);
 *   
 *   return FALSE;
 * }
 * ]|
 *
 * Calls to this function from a thread other than the one acquired by the
 * #GMainContext the #GSource is attached to are typically redundant, as the
 * source could be destroyed immediately after this function returns. However,
 * once a source is destroyed it cannot be un-destroyed, so this function can be
 * used for opportunistic checks from any thread.
 *
 * Returns: %TRUE if the source has been destroyed
 *
 * Since: 2.12
 */
gboolean
g_source_is_destroyed (GSource *source)
{
  g_return_val_if_fail (source != NULL, TRUE);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, TRUE);
  return SOURCE_DESTROYED (source);
}

/* Temporarily remove all this source's file descriptors from the
 * poll(), so that if data comes available for one of the file descriptors
 * we don't continually spin in the poll()
 */
/* HOLDS: source->context's lock */
static void
block_source (GSource *source)
{
  GSList *tmp_list;

  g_return_if_fail (!SOURCE_BLOCKED (source));

  source->flags |= G_SOURCE_BLOCKED;

  if (source->context)
    {
      tmp_list = source->poll_fds;
      while (tmp_list)
        {
          g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
          tmp_list = tmp_list->next;
        }

      for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
        g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
    }

  if (source->priv && source->priv->child_sources)
    {
      tmp_list = source->priv->child_sources;
      while (tmp_list)
	{
	  block_source (tmp_list->data);
	  tmp_list = tmp_list->next;
	}
    }
}

/* HOLDS: source->context's lock */
static void
unblock_source (GSource *source)
{
  GSList *tmp_list;

  g_return_if_fail (SOURCE_BLOCKED (source)); /* Source already unblocked */
  g_return_if_fail (!SOURCE_DESTROYED (source));
  
  source->flags &= ~G_SOURCE_BLOCKED;

  tmp_list = source->poll_fds;
  while (tmp_list)
    {
      g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data);
      tmp_list = tmp_list->next;
    }

  for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
    g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data);

  if (source->priv && source->priv->child_sources)
    {
      tmp_list = source->priv->child_sources;
      while (tmp_list)
	{
	  unblock_source (tmp_list->data);
	  tmp_list = tmp_list->next;
	}
    }
}

/* HOLDS: context's lock */
static void
g_main_dispatch (GMainContext *context)
{
  GMainDispatch *current = get_dispatch ();
  guint i;

  for (i = 0; i < context->pending_dispatches->len; i++)
    {
      GSource *source = context->pending_dispatches->pdata[i];

      context->pending_dispatches->pdata[i] = NULL;
      g_assert (source);

      source->flags &= ~G_SOURCE_READY;

      if (!SOURCE_DESTROYED (source))
	{
	  gboolean was_in_call;
	  gpointer user_data = NULL;
	  GSourceFunc callback = NULL;
	  GSourceCallbackFuncs *cb_funcs;
	  gpointer cb_data;
	  gboolean need_destroy;

	  gboolean (*dispatch) (GSource *,
				GSourceFunc,
				gpointer);
          GSource *prev_source;
          gint64 begin_time_nsec G_GNUC_UNUSED;

	  dispatch = source->source_funcs->dispatch;
	  cb_funcs = source->callback_funcs;
	  cb_data = source->callback_data;

	  if (cb_funcs)
	    cb_funcs->ref (cb_data);
	  
	  if ((source->flags & G_SOURCE_CAN_RECURSE) == 0)
	    block_source (source);
	  
	  was_in_call = source->flags & G_HOOK_FLAG_IN_CALL;
	  source->flags |= G_HOOK_FLAG_IN_CALL;

	  if (cb_funcs)
	    cb_funcs->get (cb_data, source, &callback, &user_data);

	  UNLOCK_CONTEXT (context);

          /* These operations are safe because 'current' is thread-local
           * and not modified from anywhere but this function.
           */
          prev_source = current->source;
          current->source = source;
          current->depth++;

          begin_time_nsec = G_TRACE_CURRENT_TIME;

          TRACE (GLIB_MAIN_BEFORE_DISPATCH (g_source_get_name (source), source,
                                            dispatch, callback, user_data));
          need_destroy = !(* dispatch) (source, callback, user_data);
          TRACE (GLIB_MAIN_AFTER_DISPATCH (g_source_get_name (source), source,
                                           dispatch, need_destroy));

          g_trace_mark (begin_time_nsec, G_TRACE_CURRENT_TIME - begin_time_nsec,
                        "GLib", "GSource.dispatch",
                        "%s ⇒ %s",
                        (g_source_get_name (source) != NULL) ? g_source_get_name (source) : "(unnamed)",
                        need_destroy ? "destroy" : "keep");

          current->source = prev_source;
          current->depth--;

	  if (cb_funcs)
	    cb_funcs->unref (cb_data);

 	  LOCK_CONTEXT (context);
	  
	  if (!was_in_call)
	    source->flags &= ~G_HOOK_FLAG_IN_CALL;

	  if (SOURCE_BLOCKED (source) && !SOURCE_DESTROYED (source))
	    unblock_source (source);
	  
	  /* Note: this depends on the fact that we can't switch
	   * sources from one main context to another
	   */
	  if (need_destroy && !SOURCE_DESTROYED (source))
	    {
	      g_assert (source->context == context);
	      g_source_destroy_internal (source, context, TRUE);
	    }
	}
      
      g_source_unref_internal (source, context, TRUE);
    }

  g_ptr_array_set_size (context->pending_dispatches, 0);
}

/**
 * g_main_context_acquire:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * 
 * Tries to become the owner of the specified context.
 * If some other thread is the owner of the context,
 * returns %FALSE immediately. Ownership is properly
 * recursive: the owner can require ownership again
 * and will release ownership when g_main_context_release()
 * is called as many times as g_main_context_acquire().
 *
 * You must be the owner of a context before you
 * can call g_main_context_prepare(), g_main_context_query(),
 * g_main_context_check(), g_main_context_dispatch(), g_main_context_release().
 *
 * Since 2.76 @context can be %NULL to use the global-default
 * main context.
 * 
 * Returns: %TRUE if the operation succeeded, and
 *   this thread is now the owner of @context.
 **/
gboolean 
g_main_context_acquire (GMainContext *context)
{
  gboolean result = FALSE;

  if (context == NULL)
    context = g_main_context_default ();
  
  LOCK_CONTEXT (context);

  result = g_main_context_acquire_unlocked (context);

  UNLOCK_CONTEXT (context); 

  return result;
}

static gboolean
g_main_context_acquire_unlocked (GMainContext *context)
{
  GThread *self = G_THREAD_SELF;

  if (!context->owner)
    {
      context->owner = self;
      g_assert (context->owner_count == 0);
      TRACE (GLIB_MAIN_CONTEXT_ACQUIRE (context, TRUE  /* success */));
    }

  if (context->owner == self)
    {
      context->owner_count++;
      return TRUE;
    }
  else
    {
      TRACE (GLIB_MAIN_CONTEXT_ACQUIRE (context, FALSE  /* failure */));
      return FALSE;
    }
}

/**
 * g_main_context_release:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * 
 * Releases ownership of a context previously acquired by this thread
 * with g_main_context_acquire(). If the context was acquired multiple
 * times, the ownership will be released only when g_main_context_release()
 * is called as many times as it was acquired.
 *
 * You must have successfully acquired the context with
 * g_main_context_acquire() before you may call this function.
 **/
void
g_main_context_release (GMainContext *context)
{
  if (context == NULL)
    context = g_main_context_default ();

  LOCK_CONTEXT (context);

#ifndef G_DISABLE_CHECKS
  if (G_UNLIKELY (context->owner != G_THREAD_SELF || context->owner_count == 0))
    {
      GThread *context_owner = context->owner;
      guint context_owner_count = context->owner_count;

      UNLOCK_CONTEXT (context);

      g_critical ("g_main_context_release() called on a context (%p, owner %p, "
                  "owner count %u) which is not acquired by the current thread",
                  context, context_owner, context_owner_count);
    }
#endif  /* !G_DISABLE_CHECKS */

  g_main_context_release_unlocked (context);

  UNLOCK_CONTEXT (context);
}

static void
g_main_context_release_unlocked (GMainContext *context)
{
  context->owner_count--;
  if (context->owner_count == 0)
    {
      TRACE (GLIB_MAIN_CONTEXT_RELEASE (context));

      context->owner = NULL;

      if (context->waiters)
	{
	  GMainWaiter *waiter = context->waiters->data;
	  gboolean loop_internal_waiter = (waiter->mutex == &context->mutex);
	  context->waiters = g_slist_delete_link (context->waiters,
						  context->waiters);
	  if (!loop_internal_waiter)
	    g_mutex_lock (waiter->mutex);
	  
	  g_cond_signal (waiter->cond);
	  
	  if (!loop_internal_waiter)
	    g_mutex_unlock (waiter->mutex);
	}
    }
}

static gboolean
g_main_context_wait_internal (GMainContext *context,
                              GCond        *cond,
                              GMutex       *mutex)
{
  gboolean result = FALSE;
  GThread *self = G_THREAD_SELF;
  gboolean loop_internal_waiter;
  
  loop_internal_waiter = (mutex == &context->mutex);
  
  if (!loop_internal_waiter)
    LOCK_CONTEXT (context);

  if (context->owner && context->owner != self)
    {
      GMainWaiter waiter;

      waiter.cond = cond;
      waiter.mutex = mutex;

      context->waiters = g_slist_append (context->waiters, &waiter);
      
      if (!loop_internal_waiter)
        UNLOCK_CONTEXT (context);
      g_cond_wait (cond, mutex);
      if (!loop_internal_waiter)
        LOCK_CONTEXT (context);

      context->waiters = g_slist_remove (context->waiters, &waiter);
    }

  if (!context->owner)
    {
      context->owner = self;
      g_assert (context->owner_count == 0);
    }

  if (context->owner == self)
    {
      context->owner_count++;
      result = TRUE;
    }

  if (!loop_internal_waiter)
    UNLOCK_CONTEXT (context); 
  
  return result;
}

/**
 * g_main_context_wait:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @cond: a condition variable
 * @mutex: a mutex, currently held
 *
 * Tries to become the owner of the specified context,
 * as with g_main_context_acquire(). But if another thread
 * is the owner, atomically drop @mutex and wait on @cond until
 * that owner releases ownership or until @cond is signaled, then
 * try again (once) to become the owner.
 *
 * Returns: %TRUE if the operation succeeded, and
 *   this thread is now the owner of @context.
 * Deprecated: 2.58: Use g_main_context_is_owner() and separate locking instead.
 */
gboolean
g_main_context_wait (GMainContext *context,
                     GCond        *cond,
                     GMutex       *mutex)
{
  if (context == NULL)
    context = g_main_context_default ();

  if (G_UNLIKELY (cond != &context->cond || mutex != &context->mutex))
    {
      static gboolean warned;

      if (!warned)
        {
          g_critical ("WARNING!! g_main_context_wait() will be removed in a future release.  "
                      "If you see this message, please file a bug immediately.");
          warned = TRUE;
        }
    }

  return g_main_context_wait_internal (context, cond, mutex);
}

/**
 * g_main_context_prepare:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @priority: (out) (optional): location to store priority of highest priority
 *            source already ready.
 *
 * Prepares to poll sources within a main loop. The resulting information
 * for polling is determined by calling g_main_context_query ().
 *
 * You must have successfully acquired the context with
 * g_main_context_acquire() before you may call this function.
 *
 * Returns: %TRUE if some source is ready to be dispatched
 *               prior to polling.
 **/
gboolean
g_main_context_prepare (GMainContext *context,
			gint         *priority)
{
  gboolean ready;

  if (context == NULL)
    context = g_main_context_default ();
  
  LOCK_CONTEXT (context);

  ready = g_main_context_prepare_unlocked (context, priority);

  UNLOCK_CONTEXT (context);
  
  return ready;
}

static gboolean
g_main_context_prepare_unlocked (GMainContext *context,
                                 gint         *priority)
{
  guint i;
  gint n_ready = 0;
  gint current_priority = G_MAXINT;
  GSource *source;
  GSourceIter iter;

  context->time_is_fresh = FALSE;

  if (context->in_check_or_prepare)
    {
      g_warning ("g_main_context_prepare() called recursively from within a source's check() or "
		 "prepare() member.");
      return FALSE;
    }

  TRACE (GLIB_MAIN_CONTEXT_BEFORE_PREPARE (context));

#if 0
  /* If recursing, finish up current dispatch, before starting over */
  if (context->pending_dispatches)
    {
      if (dispatch)
	g_main_dispatch (context, &current_time);
      
      return TRUE;
    }
#endif

  /* If recursing, clear list of pending dispatches */

  for (i = 0; i < context->pending_dispatches->len; i++)
    {
      if (context->pending_dispatches->pdata[i])
        g_source_unref_internal ((GSource *)context->pending_dispatches->pdata[i], context, TRUE);
    }
  g_ptr_array_set_size (context->pending_dispatches, 0);
  
  /* Prepare all sources */

  context->timeout = -1;
  
  g_source_iter_init (&iter, context, TRUE);
  while (g_source_iter_next (&iter, &source))
    {
      gint source_timeout = -1;

      if (SOURCE_DESTROYED (source) || SOURCE_BLOCKED (source))
	continue;
      if ((n_ready > 0) && (source->priority > current_priority))
	break;

      if (!(source->flags & G_SOURCE_READY))
	{
	  gboolean result;
	  gboolean (* prepare) (GSource  *source,
                                gint     *timeout);

          prepare = source->source_funcs->prepare;

          if (prepare)
            {
              gint64 begin_time_nsec G_GNUC_UNUSED;

              context->in_check_or_prepare++;
              UNLOCK_CONTEXT (context);

              begin_time_nsec = G_TRACE_CURRENT_TIME;

              result = (* prepare) (source, &source_timeout);
              TRACE (GLIB_MAIN_AFTER_PREPARE (source, prepare, source_timeout));

              g_trace_mark (begin_time_nsec, G_TRACE_CURRENT_TIME - begin_time_nsec,
                            "GLib", "GSource.prepare",
                            "%s ⇒ %s",
                            (g_source_get_name (source) != NULL) ? g_source_get_name (source) : "(unnamed)",
                            result ? "ready" : "unready");

              LOCK_CONTEXT (context);
              context->in_check_or_prepare--;
            }
          else
            {
              source_timeout = -1;
              result = FALSE;
            }

          if (result == FALSE && source->priv->ready_time != -1)
            {
              if (!context->time_is_fresh)
                {
                  context->time = g_get_monotonic_time ();
                  context->time_is_fresh = TRUE;
                }

              if (source->priv->ready_time <= context->time)
                {
                  source_timeout = 0;
                  result = TRUE;
                }
              else
                {
                  gint64 timeout;

                  /* rounding down will lead to spinning, so always round up */
                  timeout = (source->priv->ready_time - context->time + 999) / 1000;

                  if (source_timeout < 0 || timeout < source_timeout)
                    source_timeout = MIN (timeout, G_MAXINT);
                }
            }

	  if (result)
	    {
	      GSource *ready_source = source;

	      while (ready_source)
		{
		  ready_source->flags |= G_SOURCE_READY;
		  ready_source = ready_source->priv->parent_source;
		}
	    }
	}

      if (source->flags & G_SOURCE_READY)
	{
	  n_ready++;
	  current_priority = source->priority;
	  context->timeout = 0;
	}
      
      if (source_timeout >= 0)
	{
	  if (context->timeout < 0)
	    context->timeout = source_timeout;
	  else
	    context->timeout = MIN (context->timeout, source_timeout);
	}
    }
  g_source_iter_clear (&iter);

  TRACE (GLIB_MAIN_CONTEXT_AFTER_PREPARE (context, current_priority, n_ready));
  
  if (priority)
    *priority = current_priority;
  
  return (n_ready > 0);
}

/**
 * g_main_context_query:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @max_priority: maximum priority source to check
 * @timeout_: (out): location to store timeout to be used in polling
 * @fds: (out caller-allocates) (array length=n_fds): location to
 *       store #GPollFD records that need to be polled.
 * @n_fds: (in): length of @fds.
 *
 * Determines information necessary to poll this main loop. You should
 * be careful to pass the resulting @fds array and its length @n_fds
 * as is when calling g_main_context_check(), as this function relies
 * on assumptions made when the array is filled.
 *
 * You must have successfully acquired the context with
 * g_main_context_acquire() before you may call this function.
 *
 * Returns: the number of records actually stored in @fds,
 *   or, if more than @n_fds records need to be stored, the number
 *   of records that need to be stored.
 **/
gint
g_main_context_query (GMainContext *context,
		      gint          max_priority,
		      gint         *timeout,
		      GPollFD      *fds,
		      gint          n_fds)
{
  gint n_poll;

  if (context == NULL)
    context = g_main_context_default ();
  
  LOCK_CONTEXT (context);

  n_poll = g_main_context_query_unlocked (context, max_priority, timeout, fds, n_fds);

  UNLOCK_CONTEXT (context);

  return n_poll;
}

static gint
g_main_context_query_unlocked (GMainContext *context,
                               gint          max_priority,
                               gint         *timeout,
                               GPollFD      *fds,
                               gint          n_fds)
{
  gint n_poll;
  GPollRec *pollrec, *lastpollrec;
  gushort events;
  
  TRACE (GLIB_MAIN_CONTEXT_BEFORE_QUERY (context, max_priority));

  /* fds is filled sequentially from poll_records. Since poll_records
   * are incrementally sorted by file descriptor identifier, fds will
   * also be incrementally sorted.
   */
  n_poll = 0;
  lastpollrec = NULL;
  for (pollrec = context->poll_records; pollrec; pollrec = pollrec->next)
    {
      if (pollrec->priority > max_priority)
        continue;

      /* In direct contradiction to the Unix98 spec, IRIX runs into
       * difficulty if you pass in POLLERR, POLLHUP or POLLNVAL
       * flags in the events field of the pollfd while it should
       * just ignoring them. So we mask them out here.
       */
      events = pollrec->fd->events & ~(G_IO_ERR|G_IO_HUP|G_IO_NVAL);

      /* This optimization --using the same GPollFD to poll for more
       * than one poll record-- relies on the poll records being
       * incrementally sorted.
       */
      if (lastpollrec && pollrec->fd->fd == lastpollrec->fd->fd)
        {
          if (n_poll - 1 < n_fds)
            fds[n_poll - 1].events |= events;
        }
      else
        {
          if (n_poll < n_fds)
            {
              fds[n_poll].fd = pollrec->fd->fd;
              fds[n_poll].events = events;
              fds[n_poll].revents = 0;
            }

          n_poll++;
        }

      lastpollrec = pollrec;
    }

  context->poll_changed = FALSE;
  
  if (timeout)
    {
      *timeout = context->timeout;
      if (*timeout != 0)
        context->time_is_fresh = FALSE;
    }

  TRACE (GLIB_MAIN_CONTEXT_AFTER_QUERY (context, context->timeout,
                                        fds, n_poll));

  return n_poll;
}

/**
 * g_main_context_check:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @max_priority: the maximum numerical priority of sources to check
 * @fds: (array length=n_fds): array of #GPollFD's that was passed to
 *       the last call to g_main_context_query()
 * @n_fds: return value of g_main_context_query()
 *
 * Passes the results of polling back to the main loop. You should be
 * careful to pass @fds and its length @n_fds as received from
 * g_main_context_query(), as this functions relies on assumptions
 * on how @fds is filled.
 *
 * You must have successfully acquired the context with
 * g_main_context_acquire() before you may call this function.
 *
 * Since 2.76 @context can be %NULL to use the global-default
 * main context.
 *
 * Returns: %TRUE if some sources are ready to be dispatched.
 **/
gboolean
g_main_context_check (GMainContext *context,
		      gint          max_priority,
		      GPollFD      *fds,
		      gint          n_fds)
{
  gboolean ready;
   
  LOCK_CONTEXT (context);

  ready = g_main_context_check_unlocked (context, max_priority, fds, n_fds);

  UNLOCK_CONTEXT (context);

  return ready;
}

static gboolean
g_main_context_check_unlocked (GMainContext *context,
                               gint          max_priority,
                               GPollFD      *fds,
                               gint          n_fds)
{
  GSource *source;
  GSourceIter iter;
  GPollRec *pollrec;
  gint n_ready = 0;
  gint i;

  if (context == NULL)
    context = g_main_context_default ();
   
  if (context->in_check_or_prepare)
    {
      g_warning ("g_main_context_check() called recursively from within a source's check() or "
		 "prepare() member.");
      return FALSE;
    }

  TRACE (GLIB_MAIN_CONTEXT_BEFORE_CHECK (context, max_priority, fds, n_fds));

  for (i = 0; i < n_fds; i++)
    {
      if (fds[i].fd == context->wake_up_rec.fd)
        {
          if (fds[i].revents)
            {
              TRACE (GLIB_MAIN_CONTEXT_WAKEUP_ACKNOWLEDGE (context));
              g_wakeup_acknowledge (context->wakeup);
            }
          break;
        }
    }

  /* If the set of poll file descriptors changed, bail out
   * and let the main loop rerun
   */
  if (context->poll_changed)
    {
      TRACE (GLIB_MAIN_CONTEXT_AFTER_CHECK (context, 0));

      return FALSE;
    }

  /* The linear iteration below relies on the assumption that both
   * poll records and the fds array are incrementally sorted by file
   * descriptor identifier.
   */
  pollrec = context->poll_records;
  i = 0;
  while (pollrec && i < n_fds)
    {
      /* Make sure that fds is sorted by file descriptor identifier. */
      g_assert (i <= 0 || fds[i - 1].fd < fds[i].fd);

      /* Skip until finding the first GPollRec matching the current GPollFD. */
      while (pollrec && pollrec->fd->fd != fds[i].fd)
        pollrec = pollrec->next;

      /* Update all consecutive GPollRecs that match. */
      while (pollrec && pollrec->fd->fd == fds[i].fd)
        {
          if (pollrec->priority <= max_priority)
            {
              pollrec->fd->revents =
                fds[i].revents & (pollrec->fd->events | G_IO_ERR | G_IO_HUP | G_IO_NVAL);
            }
          pollrec = pollrec->next;
        }

      /* Iterate to next GPollFD. */
      i++;
    }

  g_source_iter_init (&iter, context, TRUE);
  while (g_source_iter_next (&iter, &source))
    {
      if (SOURCE_DESTROYED (source) || SOURCE_BLOCKED (source))
	continue;
      if ((n_ready > 0) && (source->priority > max_priority))
	break;

      if (!(source->flags & G_SOURCE_READY))
	{
          gboolean result;
          gboolean (* check) (GSource *source);

          check = source->source_funcs->check;

          if (check)
            {
              gint64 begin_time_nsec G_GNUC_UNUSED;

              /* If the check function is set, call it. */
              context->in_check_or_prepare++;
              UNLOCK_CONTEXT (context);

              begin_time_nsec = G_TRACE_CURRENT_TIME;

              result = (* check) (source);

              TRACE (GLIB_MAIN_AFTER_CHECK (source, check, result));

              g_trace_mark (begin_time_nsec, G_TRACE_CURRENT_TIME - begin_time_nsec,
                            "GLib", "GSource.check",
                            "%s ⇒ %s",
                            (g_source_get_name (source) != NULL) ? g_source_get_name (source) : "(unnamed)",
                            result ? "dispatch" : "ignore");

              LOCK_CONTEXT (context);
              context->in_check_or_prepare--;
            }
          else
            result = FALSE;

          if (result == FALSE)
            {
              GSList *tmp_list;

              /* If not already explicitly flagged ready by ->check()
               * (or if we have no check) then we can still be ready if
               * any of our fds poll as ready.
               */
              for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
                {
                  GPollFD *pollfd = tmp_list->data;

                  if (pollfd->revents)
                    {
                      result = TRUE;
                      break;
                    }
                }
            }

          if (result == FALSE && source->priv->ready_time != -1)
            {
              if (!context->time_is_fresh)
                {
                  context->time = g_get_monotonic_time ();
                  context->time_is_fresh = TRUE;
                }

              if (source->priv->ready_time <= context->time)
                result = TRUE;
            }

	  if (result)
	    {
	      GSource *ready_source = source;

	      while (ready_source)
		{
		  ready_source->flags |= G_SOURCE_READY;
		  ready_source = ready_source->priv->parent_source;
		}
	    }
	}

      if (source->flags & G_SOURCE_READY)
	{
          g_source_ref (source);
	  g_ptr_array_add (context->pending_dispatches, source);

	  n_ready++;

          /* never dispatch sources with less priority than the first
           * one we choose to dispatch
           */
          max_priority = source->priority;
	}
    }
  g_source_iter_clear (&iter);

  TRACE (GLIB_MAIN_CONTEXT_AFTER_CHECK (context, n_ready));

  return n_ready > 0;
}

/**
 * g_main_context_dispatch:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 *
 * Dispatches all pending sources.
 *
 * You must have successfully acquired the context with
 * g_main_context_acquire() before you may call this function.
 *
 * Since 2.76 @context can be %NULL to use the global-default
 * main context.
 **/
void
g_main_context_dispatch (GMainContext *context)
{
  if (context == NULL)
    context = g_main_context_default ();

  LOCK_CONTEXT (context);

  g_main_context_dispatch_unlocked (context);

  UNLOCK_CONTEXT (context);
}

static void
g_main_context_dispatch_unlocked (GMainContext *context)
{
  TRACE (GLIB_MAIN_CONTEXT_BEFORE_DISPATCH (context));

  if (context->pending_dispatches->len > 0)
    {
      g_main_dispatch (context);
    }

  TRACE (GLIB_MAIN_CONTEXT_AFTER_DISPATCH (context));
}

/* HOLDS context lock */
static gboolean
g_main_context_iterate_unlocked (GMainContext *context,
                                 gboolean      block,
                                 gboolean      dispatch,
                                 GThread      *self)
{
  gint max_priority = 0;
  gint timeout;
  gboolean some_ready;
  gint nfds, allocated_nfds;
  GPollFD *fds = NULL;
  gint64 begin_time_nsec G_GNUC_UNUSED;

  begin_time_nsec = G_TRACE_CURRENT_TIME;

  if (!g_main_context_acquire_unlocked (context))
    {
      gboolean got_ownership;

      if (!block)
	return FALSE;

      got_ownership = g_main_context_wait_internal (context,
                                                    &context->cond,
                                                    &context->mutex);

      if (!got_ownership)
	return FALSE;
    }
  
  if (!context->cached_poll_array)
    {
      context->cached_poll_array_size = context->n_poll_records;
      context->cached_poll_array = g_new (GPollFD, context->n_poll_records);
    }

  allocated_nfds = context->cached_poll_array_size;
  fds = context->cached_poll_array;
  
  g_main_context_prepare_unlocked (context, &max_priority);
  
  while ((nfds = g_main_context_query_unlocked (
            context, max_priority, &timeout, fds,
            allocated_nfds)) > allocated_nfds)
    {
      g_free (fds);
      context->cached_poll_array_size = allocated_nfds = nfds;
      context->cached_poll_array = fds = g_new (GPollFD, nfds);
    }

  if (!block)
    timeout = 0;
  
  g_main_context_poll_unlocked (context, timeout, max_priority, fds, nfds);
  
  some_ready = g_main_context_check_unlocked (context, max_priority, fds, nfds);
  
  if (dispatch)
    g_main_context_dispatch_unlocked (context);
  
  g_main_context_release_unlocked (context);

  g_trace_mark (begin_time_nsec, G_TRACE_CURRENT_TIME - begin_time_nsec,
                "GLib", "g_main_context_iterate",
                "Context %p, %s ⇒ %s", context, block ? "blocking" : "non-blocking", some_ready ? "dispatched" : "nothing");

  return some_ready;
}

/**
 * g_main_context_pending:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 *
 * Checks if any sources have pending events for the given context.
 * 
 * Returns: %TRUE if events are pending.
 **/
gboolean 
g_main_context_pending (GMainContext *context)
{
  gboolean retval;

  if (!context)
    context = g_main_context_default();

  LOCK_CONTEXT (context);
  retval = g_main_context_iterate_unlocked (context, FALSE, FALSE, G_THREAD_SELF);
  UNLOCK_CONTEXT (context);
  
  return retval;
}

/**
 * g_main_context_iteration:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @may_block: whether the call may block.
 *
 * Runs a single iteration for the given main loop. This involves
 * checking to see if any event sources are ready to be processed,
 * then if no events sources are ready and @may_block is %TRUE, waiting
 * for a source to become ready, then dispatching the highest priority
 * events sources that are ready. Otherwise, if @may_block is %FALSE
 * sources are not waited to become ready, only those highest priority
 * events sources will be dispatched (if any), that are ready at this
 * given moment without further waiting.
 *
 * Note that even when @may_block is %TRUE, it is still possible for
 * g_main_context_iteration() to return %FALSE, since the wait may
 * be interrupted for other reasons than an event source becoming ready.
 *
 * Returns: %TRUE if events were dispatched.
 **/
gboolean
g_main_context_iteration (GMainContext *context, gboolean may_block)
{
  gboolean retval;

  if (!context)
    context = g_main_context_default();
  
  LOCK_CONTEXT (context);
  retval = g_main_context_iterate_unlocked (context, may_block, TRUE, G_THREAD_SELF);
  UNLOCK_CONTEXT (context);
  
  return retval;
}

/**
 * g_main_loop_new:
 * @context: (nullable): a #GMainContext  (if %NULL, the global-default
 *   main context will be used).
 * @is_running: set to %TRUE to indicate that the loop is running. This
 * is not very important since calling g_main_loop_run() will set this to
 * %TRUE anyway.
 * 
 * Creates a new #GMainLoop structure.
 * 
 * Returns: a new #GMainLoop.
 **/
GMainLoop *
g_main_loop_new (GMainContext *context,
		 gboolean      is_running)
{
  GMainLoop *loop;

  if (!context)
    context = g_main_context_default();
  
  g_main_context_ref (context);

  loop = g_new0 (GMainLoop, 1);
  loop->context = context;
  loop->is_running = is_running != FALSE;
  loop->ref_count = 1;

  TRACE (GLIB_MAIN_LOOP_NEW (loop, context));

  return loop;
}

/**
 * g_main_loop_ref:
 * @loop: a #GMainLoop
 * 
 * Increases the reference count on a #GMainLoop object by one.
 * 
 * Returns: @loop
 **/
GMainLoop *
g_main_loop_ref (GMainLoop *loop)
{
  g_return_val_if_fail (loop != NULL, NULL);
  g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL);

  g_atomic_int_inc (&loop->ref_count);

  return loop;
}

/**
 * g_main_loop_unref:
 * @loop: a #GMainLoop
 * 
 * Decreases the reference count on a #GMainLoop object by one. If
 * the result is zero, free the loop and free all associated memory.
 **/
void
g_main_loop_unref (GMainLoop *loop)
{
  g_return_if_fail (loop != NULL);
  g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);

  if (!g_atomic_int_dec_and_test (&loop->ref_count))
    return;

  g_main_context_unref (loop->context);
  g_free (loop);
}

/**
 * g_main_loop_run:
 * @loop: a #GMainLoop
 * 
 * Runs a main loop until g_main_loop_quit() is called on the loop.
 * If this is called for the thread of the loop's #GMainContext,
 * it will process events from the loop, otherwise it will
 * simply wait.
 **/
void 
g_main_loop_run (GMainLoop *loop)
{
  GThread *self = G_THREAD_SELF;

  g_return_if_fail (loop != NULL);
  g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);

  /* Hold a reference in case the loop is unreffed from a callback function */
  g_atomic_int_inc (&loop->ref_count);

  LOCK_CONTEXT (loop->context);

  if (!g_main_context_acquire_unlocked (loop->context))
    {
      gboolean got_ownership = FALSE;
      
      /* Another thread owns this context */
      g_atomic_int_set (&loop->is_running, TRUE);

      while (g_atomic_int_get (&loop->is_running) && !got_ownership)
        got_ownership = g_main_context_wait_internal (loop->context,
                                                      &loop->context->cond,
                                                      &loop->context->mutex);
      
      if (!g_atomic_int_get (&loop->is_running))
	{
	  if (got_ownership)
	    g_main_context_release_unlocked (loop->context);

	  UNLOCK_CONTEXT (loop->context);
	  g_main_loop_unref (loop);
	  return;
	}

      g_assert (got_ownership);
    }

  if G_UNLIKELY (loop->context->in_check_or_prepare)
    {
      g_warning ("g_main_loop_run(): called recursively from within a source's "
		 "check() or prepare() member, iteration not possible.");
      g_main_context_release_unlocked (loop->context);
      UNLOCK_CONTEXT (loop->context);
      g_main_loop_unref (loop);
      return;
    }

  g_atomic_int_set (&loop->is_running, TRUE);
  while (g_atomic_int_get (&loop->is_running))
    g_main_context_iterate_unlocked (loop->context, TRUE, TRUE, self);

  g_main_context_release_unlocked (loop->context);

  UNLOCK_CONTEXT (loop->context);
  
  g_main_loop_unref (loop);
}

/**
 * g_main_loop_quit:
 * @loop: a #GMainLoop
 * 
 * Stops a #GMainLoop from running. Any calls to g_main_loop_run()
 * for the loop will return. 
 *
 * Note that sources that have already been dispatched when 
 * g_main_loop_quit() is called will still be executed.
 **/
void 
g_main_loop_quit (GMainLoop *loop)
{
  g_return_if_fail (loop != NULL);
  g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);

  LOCK_CONTEXT (loop->context);
  g_atomic_int_set (&loop->is_running, FALSE);
  g_wakeup_signal (loop->context->wakeup);

  g_cond_broadcast (&loop->context->cond);

  UNLOCK_CONTEXT (loop->context);

  TRACE (GLIB_MAIN_LOOP_QUIT (loop));
}

/**
 * g_main_loop_is_running:
 * @loop: a #GMainLoop.
 * 
 * Checks to see if the main loop is currently being run via g_main_loop_run().
 * 
 * Returns: %TRUE if the mainloop is currently being run.
 **/
gboolean
g_main_loop_is_running (GMainLoop *loop)
{
  g_return_val_if_fail (loop != NULL, FALSE);
  g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, FALSE);

  return g_atomic_int_get (&loop->is_running);
}

/**
 * g_main_loop_get_context:
 * @loop: a #GMainLoop.
 * 
 * Returns the #GMainContext of @loop.
 * 
 * Returns: (transfer none): the #GMainContext of @loop
 **/
GMainContext *
g_main_loop_get_context (GMainLoop *loop)
{
  g_return_val_if_fail (loop != NULL, NULL);
  g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL);
 
  return loop->context;
}

/* HOLDS: context's lock */
static void
g_main_context_poll_unlocked (GMainContext *context,
                              int           timeout,
                              int           priority,
                              GPollFD      *fds,
                              int           n_fds)
{
#ifdef  G_MAIN_POLL_DEBUG
  GTimer *poll_timer;
  GPollRec *pollrec;
  gint i;
#endif

  GPollFunc poll_func;

  if (n_fds || timeout != 0)
    {
      int ret, errsv;

#ifdef	G_MAIN_POLL_DEBUG
      poll_timer = NULL;
      if (_g_main_poll_debug)
	{
	  g_print ("polling context=%p n=%d timeout=%d\n",
		   context, n_fds, timeout);
	  poll_timer = g_timer_new ();
	}
#endif
      poll_func = context->poll_func;

      UNLOCK_CONTEXT (context);
      ret = (*poll_func) (fds, n_fds, timeout);
      LOCK_CONTEXT (context);

      errsv = errno;
      if (ret < 0 && errsv != EINTR)
	{
#ifndef G_OS_WIN32
	  g_warning ("poll(2) failed due to: %s.",
		     g_strerror (errsv));
#else
	  /* If g_poll () returns -1, it has already called g_warning() */
#endif
	}
      
#ifdef	G_MAIN_POLL_DEBUG
      if (_g_main_poll_debug)
	{
	  g_print ("g_main_poll(%d) timeout: %d - elapsed %12.10f seconds",
		   n_fds,
		   timeout,
		   g_timer_elapsed (poll_timer, NULL));
	  g_timer_destroy (poll_timer);
	  pollrec = context->poll_records;

	  while (pollrec != NULL)
	    {
	      i = 0;
	      while (i < n_fds)
		{
		  if (fds[i].fd == pollrec->fd->fd &&
		      pollrec->fd->events &&
		      fds[i].revents)
		    {
		      g_print (" [" G_POLLFD_FORMAT " :", fds[i].fd);
		      if (fds[i].revents & G_IO_IN)
			g_print ("i");
		      if (fds[i].revents & G_IO_OUT)
			g_print ("o");
		      if (fds[i].revents & G_IO_PRI)
			g_print ("p");
		      if (fds[i].revents & G_IO_ERR)
			g_print ("e");
		      if (fds[i].revents & G_IO_HUP)
			g_print ("h");
		      if (fds[i].revents & G_IO_NVAL)
			g_print ("n");
		      g_print ("]");
		    }
		  i++;
		}
	      pollrec = pollrec->next;
	    }
	  g_print ("\n");
	}
#endif
    } /* if (n_fds || timeout != 0) */
}

/**
 * g_main_context_add_poll:
 * @context: (nullable): a #GMainContext (or %NULL for the global-default
 *   main context)
 * @fd: a #GPollFD structure holding information about a file
 *      descriptor to watch.
 * @priority: the priority for this file descriptor which should be
 *      the same as the priority used for g_source_attach() to ensure that the
 *      file descriptor is polled whenever the results may be needed.
 *
 * Adds a file descriptor to the set of file descriptors polled for
 * this context. This will very seldom be used directly. Instead
 * a typical event source will use g_source_add_unix_fd() instead.
 **/
void
g_main_context_add_poll (GMainContext *context,
			 GPollFD      *fd,
			 gint          priority)
{
  if (!context)
    context = g_main_context_default ();
  
  g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
  g_return_if_fail (fd);

  LOCK_CONTEXT (context);
  g_main_context_add_poll_unlocked (context, priority, fd);
  UNLOCK_CONTEXT (context);
}

/* HOLDS: main_loop_lock */
static void 
g_main_context_add_poll_unlocked (GMainContext *context,
				  gint          priority,
				  GPollFD      *fd)
{
  GPollRec *prevrec, *nextrec;
  GPollRec *newrec = g_slice_new (GPollRec);

  /* This file descriptor may be checked before we ever poll */
  fd->revents = 0;
  newrec->fd = fd;
  newrec->priority = priority;

  /* Poll records are incrementally sorted by file descriptor identifier. */
  prevrec = NULL;
  nextrec = context->poll_records;
  while (nextrec)
    {
      if (nextrec->fd->fd > fd->fd)
        break;
      prevrec = nextrec;
      nextrec = nextrec->next;
    }

  if (prevrec)
    prevrec->next = newrec;
  else
    context->poll_records = newrec;

  newrec->prev = prevrec;
  newrec->next = nextrec;

  if (nextrec)
    nextrec->prev = newrec;

  context->n_poll_records++;

  context->poll_changed = TRUE;

  /* Now wake up the main loop if it is waiting in the poll() */
  if (fd != &context->wake_up_rec)
    g_wakeup_signal (context->wakeup);
}

/**
 * g_main_context_remove_poll:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @fd: a #GPollFD descriptor previously added with g_main_context_add_poll()
 * 
 * Removes file descriptor from the set of file descriptors to be
 * polled for a particular context.
 **/
void
g_main_context_remove_poll (GMainContext *context,
			    GPollFD      *fd)
{
  if (!context)
    context = g_main_context_default ();
  
  g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
  g_return_if_fail (fd);

  LOCK_CONTEXT (context);
  g_main_context_remove_poll_unlocked (context, fd);
  UNLOCK_CONTEXT (context);
}

static void
g_main_context_remove_poll_unlocked (GMainContext *context,
				     GPollFD      *fd)
{
  GPollRec *pollrec, *prevrec, *nextrec;

  prevrec = NULL;
  pollrec = context->poll_records;

  while (pollrec)
    {
      nextrec = pollrec->next;
      if (pollrec->fd == fd)
	{
	  if (prevrec != NULL)
	    prevrec->next = nextrec;
	  else
	    context->poll_records = nextrec;

	  if (nextrec != NULL)
	    nextrec->prev = prevrec;

	  g_slice_free (GPollRec, pollrec);

	  context->n_poll_records--;
	  break;
	}
      prevrec = pollrec;
      pollrec = nextrec;
    }

  context->poll_changed = TRUE;

  /* Now wake up the main loop if it is waiting in the poll() */
  g_wakeup_signal (context->wakeup);
}

/**
 * g_source_get_current_time:
 * @source:  a #GSource
 * @timeval: #GTimeVal structure in which to store current time.
 *
 * This function ignores @source and is otherwise the same as
 * g_get_current_time().
 *
 * Deprecated: 2.28: use g_source_get_time() instead
 **/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
void
g_source_get_current_time (GSource  *source,
			   GTimeVal *timeval)
{
  g_get_current_time (timeval);
}
G_GNUC_END_IGNORE_DEPRECATIONS

/**
 * g_source_get_time:
 * @source: a #GSource
 *
 * Gets the time to be used when checking this source. The advantage of
 * calling this function over calling g_get_monotonic_time() directly is
 * that when checking multiple sources, GLib can cache a single value
 * instead of having to repeatedly get the system monotonic time.
 *
 * The time here is the system monotonic time, if available, or some
 * other reasonable alternative otherwise.  See g_get_monotonic_time().
 *
 * Returns: the monotonic time in microseconds
 *
 * Since: 2.28
 **/
gint64
g_source_get_time (GSource *source)
{
  GMainContext *context;
  gint64 result;

  g_return_val_if_fail (source != NULL, 0);
  g_return_val_if_fail (g_atomic_int_get (&source->ref_count) > 0, 0);
  g_return_val_if_fail (source->context != NULL, 0);

  context = source->context;

  LOCK_CONTEXT (context);

  if (!context->time_is_fresh)
    {
      context->time = g_get_monotonic_time ();
      context->time_is_fresh = TRUE;
    }

  result = context->time;

  UNLOCK_CONTEXT (context);

  return result;
}

/**
 * g_main_context_set_poll_func:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * @func: the function to call to poll all file descriptors
 * 
 * Sets the function to use to handle polling of file descriptors. It
 * will be used instead of the poll() system call 
 * (or GLib's replacement function, which is used where 
 * poll() isn't available).
 *
 * This function could possibly be used to integrate the GLib event
 * loop with an external event loop.
 **/
void
g_main_context_set_poll_func (GMainContext *context,
			      GPollFunc     func)
{
  if (!context)
    context = g_main_context_default ();
  
  g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);

  LOCK_CONTEXT (context);
  
  if (func)
    context->poll_func = func;
  else
    context->poll_func = g_poll;

  UNLOCK_CONTEXT (context);
}

/**
 * g_main_context_get_poll_func:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * 
 * Gets the poll function set by g_main_context_set_poll_func().
 * 
 * Returns: the poll function
 **/
GPollFunc
g_main_context_get_poll_func (GMainContext *context)
{
  GPollFunc result;
  
  if (!context)
    context = g_main_context_default ();
  
  g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL);

  LOCK_CONTEXT (context);
  result = context->poll_func;
  UNLOCK_CONTEXT (context);

  return result;
}

/**
 * g_main_context_wakeup:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * 
 * If @context is currently blocking in g_main_context_iteration()
 * waiting for a source to become ready, cause it to stop blocking
 * and return.  Otherwise, cause the next invocation of
 * g_main_context_iteration() to return without blocking.
 *
 * This API is useful for low-level control over #GMainContext; for
 * example, integrating it with main loop implementations such as
 * #GMainLoop.
 *
 * Another related use for this function is when implementing a main
 * loop with a termination condition, computed from multiple threads:
 *
 * |[<!-- language="C" --> 
 *   #define NUM_TASKS 10
 *   static gint tasks_remaining = NUM_TASKS;  // (atomic)
 *   ...
 *  
 *   while (g_atomic_int_get (&tasks_remaining) != 0)
 *     g_main_context_iteration (NULL, TRUE);
 * ]|
 *  
 * Then in a thread:
 * |[<!-- language="C" --> 
 *   perform_work();
 *
 *   if (g_atomic_int_dec_and_test (&tasks_remaining))
 *     g_main_context_wakeup (NULL);
 * ]|
 **/
void
g_main_context_wakeup (GMainContext *context)
{
  if (!context)
    context = g_main_context_default ();

  g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);

  TRACE (GLIB_MAIN_CONTEXT_WAKEUP (context));

  g_wakeup_signal (context->wakeup);
}

/**
 * g_main_context_is_owner:
 * @context: (nullable): a #GMainContext (if %NULL, the global-default
 *   main context will be used)
 * 
 * Determines whether this thread holds the (recursive)
 * ownership of this #GMainContext. This is useful to
 * know before waiting on another thread that may be
 * blocking to get ownership of @context.
 *
 * Returns: %TRUE if current thread is owner of @context.
 *
 * Since: 2.10
 **/
gboolean
g_main_context_is_owner (GMainContext *context)
{
  gboolean is_owner;

  if (!context)
    context = g_main_context_default ();

  LOCK_CONTEXT (context);
  is_owner = context->owner == G_THREAD_SELF;
  UNLOCK_CONTEXT (context);

  return is_owner;
}

/* Timeouts */

static void
g_timeout_set_expiration (GTimeoutSource *timeout_source,
                          gint64          current_time)
{
  gint64 expiration;

  if (timeout_source->seconds)
    {
      gint64 remainder;
      static gint timer_perturb = -1;

      if (timer_perturb == -1)
        {
          /*
           * we want a per machine/session unique 'random' value; try the dbus
           * address first, that has a UUID in it. If there is no dbus, use the
           * hostname for hashing.
           */
          const char *session_bus_address = g_getenv ("DBUS_SESSION_BUS_ADDRESS");
          if (!session_bus_address)
            session_bus_address = g_getenv ("HOSTNAME");
          if (session_bus_address)
            timer_perturb = ABS ((gint) g_str_hash (session_bus_address)) % 1000000;
          else
            timer_perturb = 0;
        }

      expiration = current_time + (guint64) timeout_source->interval * 1000 * 1000;

      /* We want the microseconds part of the timeout to land on the
       * 'timer_perturb' mark, but we need to make sure we don't try to
       * set the timeout in the past.  We do this by ensuring that we
       * always only *increase* the expiration time by adding a full
       * second in the case that the microsecond portion decreases.
       */
      expiration -= timer_perturb;

      remainder = expiration % 1000000;
      if (remainder >= 1000000/4)
        expiration += 1000000;

      expiration -= remainder;
      expiration += timer_perturb;
    }
  else
    {
      expiration = current_time + (guint64) timeout_source->interval * 1000;
    }

  g_source_set_ready_time ((GSource *) timeout_source, expiration);
}

static gboolean
g_timeout_dispatch (GSource     *source,
                    GSourceFunc  callback,
                    gpointer     user_data)
{
  GTimeoutSource *timeout_source = (GTimeoutSource *)source;
  gboolean again;

  if (!callback)
    {
      g_warning ("Timeout source dispatched without callback. "
                 "You must call g_source_set_callback().");
      return FALSE;
    }

  if (timeout_source->one_shot)
    {
      GSourceOnceFunc once_callback = (GSourceOnceFunc) callback;
      once_callback (user_data);
      again = G_SOURCE_REMOVE;
    }
  else
    {
      again = callback (user_data);
    }

  TRACE (GLIB_TIMEOUT_DISPATCH (source, source->context, callback, user_data, again));

  if (again)
    g_timeout_set_expiration (timeout_source, g_source_get_time (source));

  return again;
}

static GSource *
timeout_source_new (guint    interval,
                    gboolean seconds,
                    gboolean one_shot)
{
  GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource));
  GTimeoutSource *timeout_source = (GTimeoutSource *)source;

  timeout_source->interval = interval;
  timeout_source->seconds = seconds;
  timeout_source->one_shot = one_shot;

  g_timeout_set_expiration (timeout_source, g_get_monotonic_time ());

  return source;
}

/**
 * g_timeout_source_new:
 * @interval: the timeout interval in milliseconds.
 * 
 * Creates a new timeout source.
 *
 * The source will not initially be associated with any #GMainContext
 * and must be added to one with g_source_attach() before it will be
 * executed.
 *
 * The interval given is in terms of monotonic time, not wall clock
 * time.  See g_get_monotonic_time().
 * 
 * Returns: the newly-created timeout source
 **/
GSource *
g_timeout_source_new (guint interval)
{
  return timeout_source_new (interval, FALSE, FALSE);
}

/**
 * g_timeout_source_new_seconds:
 * @interval: the timeout interval in seconds
 *
 * Creates a new timeout source.
 *
 * The source will not initially be associated with any #GMainContext
 * and must be added to one with g_source_attach() before it will be
 * executed.
 *
 * The scheduling granularity/accuracy of this timeout source will be
 * in seconds.
 *
 * The interval given is in terms of monotonic time, not wall clock time.
 * See g_get_monotonic_time().
 *
 * Returns: the newly-created timeout source
 *
 * Since: 2.14	
 **/
GSource *
g_timeout_source_new_seconds (guint interval)
{
  return timeout_source_new (interval, TRUE, FALSE);
}

static guint
timeout_add_full (gint           priority,
                  guint          interval,
                  gboolean       seconds,
                  gboolean       one_shot,
                  GSourceFunc    function,
                  gpointer       data,
                  GDestroyNotify notify)
{
  GSource *source;
  guint id;

  g_return_val_if_fail (function != NULL, 0);

  source = timeout_source_new (interval, seconds, one_shot);

  if (priority != G_PRIORITY_DEFAULT)
    g_source_set_priority (source, priority);

  g_source_set_callback (source, function, data, notify);
  id = g_source_attach (source, NULL);

  TRACE (GLIB_TIMEOUT_ADD (source, g_main_context_default (), id, priority, interval, function, data));

  g_source_unref (source);

  return id;
}

/**
 * g_timeout_add_full: (rename-to g_timeout_add)
 * @priority: the priority of the timeout source. Typically this will be in
 *   the range between %G_PRIORITY_DEFAULT and %G_PRIORITY_HIGH.
 * @interval: the time between calls to the function, in milliseconds
 *   (1/1000ths of a second)
 * @function: function to call
 * @data: data to pass to @function
 * @notify: (nullable): function to call when the timeout is removed, or %NULL
 * 
 * Sets a function to be called at regular intervals, with the given
 * priority.  The function is called repeatedly until it returns
 * %FALSE, at which point the timeout is automatically destroyed and
 * the function will not be called again.  The @notify function is
 * called when the timeout is destroyed.  The first call to the
 * function will be at the end of the first @interval.
 *
 * Note that timeout functions may be delayed, due to the processing of other
 * event sources. Thus they should not be relied on for precise timing.
 * After each call to the timeout function, the time of the next
 * timeout is recalculated based on the current time and the given interval
 * (it does not try to 'catch up' time lost in delays).
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle the return value and memory management of @data.
 *
 * This internally creates a main loop source using g_timeout_source_new()
 * and attaches it to the global #GMainContext using g_source_attach(), so
 * the callback will be invoked in whichever thread is running that main
 * context. You can do these steps manually if you need greater control or to
 * use a custom main context.
 *
 * The interval given is in terms of monotonic time, not wall clock time.
 * See g_get_monotonic_time().
 * 
 * Returns: the ID (greater than 0) of the event source.
 **/
guint
g_timeout_add_full (gint           priority,
		    guint          interval,
		    GSourceFunc    function,
		    gpointer       data,
		    GDestroyNotify notify)
{
  return timeout_add_full (priority, interval, FALSE, FALSE, function, data, notify);
}

/**
 * g_timeout_add:
 * @interval: the time between calls to the function, in milliseconds
 *    (1/1000ths of a second)
 * @function: function to call
 * @data: data to pass to @function
 * 
 * Sets a function to be called at regular intervals, with the default
 * priority, %G_PRIORITY_DEFAULT.
 *
 * The given @function is called repeatedly until it returns %G_SOURCE_REMOVE
 * or %FALSE, at which point the timeout is automatically destroyed and the
 * function will not be called again. The first call to the function will be
 * at the end of the first @interval.
 *
 * Note that timeout functions may be delayed, due to the processing of other
 * event sources. Thus they should not be relied on for precise timing.
 * After each call to the timeout function, the time of the next
 * timeout is recalculated based on the current time and the given interval
 * (it does not try to 'catch up' time lost in delays).
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle the return value and memory management of @data.
 *
 * If you want to have a timer in the "seconds" range and do not care
 * about the exact time of the first call of the timer, use the
 * g_timeout_add_seconds() function; this function allows for more
 * optimizations and more efficient system power usage.
 *
 * This internally creates a main loop source using g_timeout_source_new()
 * and attaches it to the global #GMainContext using g_source_attach(), so
 * the callback will be invoked in whichever thread is running that main
 * context. You can do these steps manually if you need greater control or to
 * use a custom main context.
 * 
 * It is safe to call this function from any thread.
 *
 * The interval given is in terms of monotonic time, not wall clock
 * time.  See g_get_monotonic_time().
 * 
 * Returns: the ID (greater than 0) of the event source.
 **/
guint
g_timeout_add (guint32        interval,
	       GSourceFunc    function,
	       gpointer       data)
{
  return g_timeout_add_full (G_PRIORITY_DEFAULT, 
			     interval, function, data, NULL);
}

/**
 * g_timeout_add_once:
 * @interval: the time after which the function will be called, in
 *   milliseconds (1/1000ths of a second)
 * @function: function to call
 * @data: data to pass to @function
 *
 * Sets a function to be called after @interval milliseconds have elapsed,
 * with the default priority, %G_PRIORITY_DEFAULT.
 *
 * The given @function is called once and then the source will be automatically
 * removed from the main context.
 *
 * This function otherwise behaves like g_timeout_add().
 *
 * Returns: the ID (greater than 0) of the event source
 *
 * Since: 2.74
 */
guint
g_timeout_add_once (guint32         interval,
                    GSourceOnceFunc function,
                    gpointer        data)
{
  return timeout_add_full (G_PRIORITY_DEFAULT, interval, FALSE, TRUE, (GSourceFunc) function, data, NULL);
}

/**
 * g_timeout_add_seconds_full: (rename-to g_timeout_add_seconds)
 * @priority: the priority of the timeout source. Typically this will be in
 *   the range between %G_PRIORITY_DEFAULT and %G_PRIORITY_HIGH.
 * @interval: the time between calls to the function, in seconds
 * @function: function to call
 * @data: data to pass to @function
 * @notify: (nullable): function to call when the timeout is removed, or %NULL
 *
 * Sets a function to be called at regular intervals, with @priority.
 *
 * The function is called repeatedly until it returns %G_SOURCE_REMOVE
 * or %FALSE, at which point the timeout is automatically destroyed and
 * the function will not be called again.
 *
 * Unlike g_timeout_add(), this function operates at whole second granularity.
 * The initial starting point of the timer is determined by the implementation
 * and the implementation is expected to group multiple timers together so that
 * they fire all at the same time. To allow this grouping, the @interval to the
 * first timer is rounded and can deviate up to one second from the specified
 * interval. Subsequent timer iterations will generally run at the specified
 * interval.
 *
 * Note that timeout functions may be delayed, due to the processing of other
 * event sources. Thus they should not be relied on for precise timing.
 * After each call to the timeout function, the time of the next
 * timeout is recalculated based on the current time and the given @interval
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle the return value and memory management of @data.
 *
 * If you want timing more precise than whole seconds, use g_timeout_add()
 * instead.
 *
 * The grouping of timers to fire at the same time results in a more power
 * and CPU efficient behavior so if your timer is in multiples of seconds
 * and you don't require the first timer exactly one second from now, the
 * use of g_timeout_add_seconds() is preferred over g_timeout_add().
 *
 * This internally creates a main loop source using 
 * g_timeout_source_new_seconds() and attaches it to the main loop context 
 * using g_source_attach(). You can do these steps manually if you need 
 * greater control.
 *
 * It is safe to call this function from any thread.
 *
 * The interval given is in terms of monotonic time, not wall clock
 * time.  See g_get_monotonic_time().
 * 
 * Returns: the ID (greater than 0) of the event source.
 *
 * Since: 2.14
 **/
guint
g_timeout_add_seconds_full (gint           priority,
                            guint32        interval,
                            GSourceFunc    function,
                            gpointer       data,
                            GDestroyNotify notify)
{
  return timeout_add_full (priority, interval, TRUE, FALSE, function, data, notify);
}

/**
 * g_timeout_add_seconds:
 * @interval: the time between calls to the function, in seconds
 * @function: function to call
 * @data: data to pass to @function
 *
 * Sets a function to be called at regular intervals with the default
 * priority, %G_PRIORITY_DEFAULT.
 *
 * The function is called repeatedly until it returns %G_SOURCE_REMOVE
 * or %FALSE, at which point the timeout is automatically destroyed
 * and the function will not be called again.
 *
 * This internally creates a main loop source using
 * g_timeout_source_new_seconds() and attaches it to the main loop context
 * using g_source_attach(). You can do these steps manually if you need
 * greater control. Also see g_timeout_add_seconds_full().
 *
 * It is safe to call this function from any thread.
 *
 * Note that the first call of the timer may not be precise for timeouts
 * of one second. If you need finer precision and have such a timeout,
 * you may want to use g_timeout_add() instead.
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle the return value and memory management of @data.
 *
 * The interval given is in terms of monotonic time, not wall clock
 * time.  See g_get_monotonic_time().
 * 
 * Returns: the ID (greater than 0) of the event source.
 *
 * Since: 2.14
 **/
guint
g_timeout_add_seconds (guint       interval,
                       GSourceFunc function,
                       gpointer    data)
{
  g_return_val_if_fail (function != NULL, 0);

  return g_timeout_add_seconds_full (G_PRIORITY_DEFAULT, interval, function, data, NULL);
}

/**
 * g_timeout_add_seconds_once:
 * @interval: the time after which the function will be called, in seconds
 * @function: function to call
 * @data: data to pass to @function
 *
 * This function behaves like g_timeout_add_once() but with a range in seconds.
 *
 * Returns: the ID (greater than 0) of the event source
 *
 * Since: 2.78
 */
guint
g_timeout_add_seconds_once (guint           interval,
                            GSourceOnceFunc function,
                            gpointer        data)
{
  return timeout_add_full (G_PRIORITY_DEFAULT, interval, TRUE, TRUE, (GSourceFunc) function, data, NULL);
}

/* Child watch functions */

#ifdef G_OS_WIN32

static gboolean
g_child_watch_prepare (GSource *source,
		       gint    *timeout)
{
  *timeout = -1;
  return FALSE;
}

static gboolean 
g_child_watch_check (GSource  *source)
{
  GChildWatchSource *child_watch_source;
  gboolean child_exited;

  child_watch_source = (GChildWatchSource *) source;

  child_exited = child_watch_source->poll.revents & G_IO_IN;

  if (child_exited)
    {
      DWORD child_status;

      /*
       * Note: We do _not_ check for the special value of STILL_ACTIVE
       * since we know that the process has exited and doing so runs into
       * problems if the child process "happens to return STILL_ACTIVE(259)"
       * as Microsoft's Platform SDK puts it.
       */
      if (!GetExitCodeProcess (child_watch_source->pid, &child_status))
        {
	  gchar *emsg = g_win32_error_message (GetLastError ());
	  g_warning (G_STRLOC ": GetExitCodeProcess() failed: %s", emsg);
	  g_free (emsg);

	  child_watch_source->child_status = -1;
	}
      else
	child_watch_source->child_status = child_status;
    }

  return child_exited;
}

static void
g_child_watch_finalize (GSource *source)
{
}

#else /* G_OS_WIN32 */

static void
wake_source (GSource *source)
{
  GMainContext *context;

  /* This should be thread-safe:
   *
   *  - if the source is currently being added to a context, that
   *    context will be woken up anyway
   *
   *  - if the source is currently being destroyed, we simply need not
   *    to crash:
   *
   *    - the memory for the source will remain valid until after the
   *      source finalize function was called (which would remove the
   *      source from the global list which we are currently holding the
   *      lock for)
   *
   *    - the GMainContext will either be NULL or point to a live
   *      GMainContext
   *
   *    - the GMainContext will remain valid since we hold the
   *      main_context_list lock
   *
   *  Since we are holding a lot of locks here, don't try to enter any
   *  more GMainContext functions for fear of dealock -- just hit the
   *  GWakeup and run.  Even if that's safe now, it could easily become
   *  unsafe with some very minor changes in the future, and signal
   *  handling is not the most well-tested codepath.
   */
  G_LOCK(main_context_list);
  context = source->context;
  if (context)
    g_wakeup_signal (context->wakeup);
  G_UNLOCK(main_context_list);
}

static void
dispatch_unix_signals_unlocked (void)
{
  gboolean pending[NSIG];
  GSList *node;
  gint i;

  /* clear this first in case another one arrives while we're processing */
  g_atomic_int_set (&any_unix_signal_pending, 0);

  /* We atomically test/clear the bit from the global array in case
   * other signals arrive while we are dispatching.
   *
   * We then can safely use our own array below without worrying about
   * races.
   */
  for (i = 0; i < NSIG; i++)
    {
      /* Be very careful with (the volatile) unix_signal_pending.
       *
       * We must ensure that it's not possible that we clear it without
       * handling the signal.  We therefore must ensure that our pending
       * array has a field set (ie: we will do something about the
       * signal) before we clear the item in unix_signal_pending.
       *
       * Note specifically: we must check _our_ array.
       */
      pending[i] = g_atomic_int_compare_and_exchange (&unix_signal_pending[i], 1, 0);
    }

  /* handle GChildWatchSource instances */
  if (pending[SIGCHLD])
    {
      /* The only way we can do this is to scan all of the children.
       *
       * The docs promise that we will not reap children that we are not
       * explicitly watching, so that ties our hands from calling
       * waitpid(-1).  We also can't use siginfo's si_pid field since if
       * multiple SIGCHLD arrive at the same time, one of them can be
       * dropped (since a given UNIX signal can only be pending once).
       */
      for (node = unix_child_watches; node; node = node->next)
        {
          GChildWatchSource *source = node->data;

          if (!source->using_pidfd &&
              !g_atomic_int_get (&source->child_exited))
            {
              pid_t pid;
              do
                {
                  g_assert (source->pid > 0);

                  pid = waitpid (source->pid, &source->child_status, WNOHANG);
                  if (pid > 0)
                    {
                      g_atomic_int_set (&source->child_exited, TRUE);
                      wake_source ((GSource *) source);
                    }
                  else if (pid == -1 && errno == ECHILD)
                    {
                      g_warning ("GChildWatchSource: Exit status of a child process was requested but ECHILD was received by waitpid(). See the documentation of g_child_watch_source_new() for possible causes.");
                      source->child_status = 0;
                      g_atomic_int_set (&source->child_exited, TRUE);
                      wake_source ((GSource *) source);
                    }
                }
              while (pid == -1 && errno == EINTR);
            }
        }
    }

  /* handle GUnixSignalWatchSource instances */
  for (node = unix_signal_watches; node; node = node->next)
    {
      GUnixSignalWatchSource *source = node->data;

      if (pending[source->signum] &&
          g_atomic_int_compare_and_exchange (&source->pending, FALSE, TRUE))
        {
          wake_source ((GSource *) source);
        }
    }

}

static void
dispatch_unix_signals (void)
{
  G_LOCK(unix_signal_lock);
  dispatch_unix_signals_unlocked ();
  G_UNLOCK(unix_signal_lock);
}

static gboolean
g_child_watch_prepare (GSource *source,
		       gint    *timeout)
{
  GChildWatchSource *child_watch_source;

  child_watch_source = (GChildWatchSource *) source;

  return g_atomic_int_get (&child_watch_source->child_exited);
}

#ifdef HAVE_PIDFD
static int
siginfo_t_to_wait_status (const siginfo_t *info)
{
  /* Each of these returns is essentially the inverse of WIFEXITED(),
   * WIFSIGNALED(), etc. */
  switch (info->si_code)
    {
    case CLD_EXITED:
      return W_EXITCODE (info->si_status, 0);
    case CLD_KILLED:
      return W_EXITCODE (0, info->si_status);
    case CLD_DUMPED:
      return W_EXITCODE (0, info->si_status | WCOREFLAG);
    case CLD_CONTINUED:
      return __W_CONTINUED;
    case CLD_STOPPED:
    case CLD_TRAPPED:
    default:
      return W_STOPCODE (info->si_status);
    }
}
#endif  /* HAVE_PIDFD */

static gboolean
g_child_watch_check (GSource *source)
{
  GChildWatchSource *child_watch_source;

  child_watch_source = (GChildWatchSource *) source;

#ifdef HAVE_PIDFD
  if (child_watch_source->using_pidfd)
    {
      gboolean child_exited = child_watch_source->poll.revents & G_IO_IN;

      if (child_exited)
        {
          siginfo_t child_info = { 0, };

          /* Get the exit status */
          if (waitid (P_PIDFD, child_watch_source->poll.fd, &child_info, WEXITED | WNOHANG) >= 0 &&
              child_info.si_pid != 0)
            {
              /* waitid() helpfully provides the wait status in a decomposed
               * form which is quite useful. Unfortunately we have to report it
               * to the #GChildWatchFunc as a waitpid()-style platform-specific
               * wait status, so that the user code in #GChildWatchFunc can then
               * call WIFEXITED() (etc.) on it. That means re-composing the
               * status information. */
              child_watch_source->child_status = siginfo_t_to_wait_status (&child_info);
              child_watch_source->child_exited = TRUE;
            }
        }

      return child_exited;
    }
#endif  /* HAVE_PIDFD */

  return g_atomic_int_get (&child_watch_source->child_exited);
}

static gboolean
g_unix_signal_watch_prepare (GSource *source,
			     gint    *timeout)
{
  GUnixSignalWatchSource *unix_signal_source;

  unix_signal_source = (GUnixSignalWatchSource *) source;

  return g_atomic_int_get (&unix_signal_source->pending);
}

static gboolean
g_unix_signal_watch_check (GSource  *source)
{
  GUnixSignalWatchSource *unix_signal_source;

  unix_signal_source = (GUnixSignalWatchSource *) source;

  return g_atomic_int_get (&unix_signal_source->pending);
}

static gboolean
g_unix_signal_watch_dispatch (GSource    *source, 
			      GSourceFunc callback,
			      gpointer    user_data)
{
  GUnixSignalWatchSource *unix_signal_source;
  gboolean again;

  unix_signal_source = (GUnixSignalWatchSource *) source;

  if (!callback)
    {
      g_warning ("Unix signal source dispatched without callback. "
		 "You must call g_source_set_callback().");
      return FALSE;
    }

  g_atomic_int_set (&unix_signal_source->pending, FALSE);

  again = (callback) (user_data);

  return again;
}

static void
ref_unix_signal_handler_unlocked (int signum)
{
  /* Ensure we have the worker context */
  g_get_worker_context ();
  unix_signal_refcount[signum]++;
  if (unix_signal_refcount[signum] == 1)
    {
      struct sigaction action;
      action.sa_handler = g_unix_signal_handler;
      sigemptyset (&action.sa_mask);
#ifdef SA_RESTART
      action.sa_flags = SA_RESTART | SA_NOCLDSTOP;
#else
      action.sa_flags = SA_NOCLDSTOP;
#endif
      sigaction (signum, &action, NULL);
    }
}

static void
unref_unix_signal_handler_unlocked (int signum)
{
  unix_signal_refcount[signum]--;
  if (unix_signal_refcount[signum] == 0)
    {
      struct sigaction action;
      memset (&action, 0, sizeof (action));
      action.sa_handler = SIG_DFL;
      sigemptyset (&action.sa_mask);
      sigaction (signum, &action, NULL);
    }
}

/* Return a const string to avoid allocations. We lose precision in the case the
 * @signum is unrecognised, but that’ll do. */
static const gchar *
signum_to_string (int signum)
{
  /* See `man 0P signal.h` */
#define SIGNAL(s) \
    case (s): \
      return ("GUnixSignalSource: " #s);
  switch (signum)
    {
    /* These signals are guaranteed to exist by POSIX. */
    SIGNAL (SIGABRT)
    SIGNAL (SIGFPE)
    SIGNAL (SIGILL)
    SIGNAL (SIGINT)
    SIGNAL (SIGSEGV)
    SIGNAL (SIGTERM)
    /* Frustratingly, these are not, and hence for brevity the list is
     * incomplete. */
#ifdef SIGALRM
    SIGNAL (SIGALRM)
#endif
#ifdef SIGCHLD
    SIGNAL (SIGCHLD)
#endif
#ifdef SIGHUP
    SIGNAL (SIGHUP)
#endif
#ifdef SIGKILL
    SIGNAL (SIGKILL)
#endif
#ifdef SIGPIPE
    SIGNAL (SIGPIPE)
#endif
#ifdef SIGQUIT
    SIGNAL (SIGQUIT)
#endif
#ifdef SIGSTOP
    SIGNAL (SIGSTOP)
#endif
#ifdef SIGUSR1
    SIGNAL (SIGUSR1)
#endif
#ifdef SIGUSR2
    SIGNAL (SIGUSR2)
#endif
#ifdef SIGPOLL
    SIGNAL (SIGPOLL)
#endif
#ifdef SIGPROF
    SIGNAL (SIGPROF)
#endif
#ifdef SIGTRAP
    SIGNAL (SIGTRAP)
#endif
    default:
      return "GUnixSignalSource: Unrecognized signal";
    }
#undef SIGNAL
}

GSource *
_g_main_create_unix_signal_watch (int signum)
{
  GSource *source;
  GUnixSignalWatchSource *unix_signal_source;

  source = g_source_new (&g_unix_signal_funcs, sizeof (GUnixSignalWatchSource));
  unix_signal_source = (GUnixSignalWatchSource *) source;

  unix_signal_source->signum = signum;
  unix_signal_source->pending = FALSE;

  /* Set a default name on the source, just in case the caller does not. */
  g_source_set_static_name (source, signum_to_string (signum));

  G_LOCK (unix_signal_lock);
  ref_unix_signal_handler_unlocked (signum);
  unix_signal_watches = g_slist_prepend (unix_signal_watches, unix_signal_source);
  dispatch_unix_signals_unlocked ();
  G_UNLOCK (unix_signal_lock);

  return source;
}

static void
g_unix_signal_watch_finalize (GSource    *source)
{
  GUnixSignalWatchSource *unix_signal_source;

  unix_signal_source = (GUnixSignalWatchSource *) source;

  G_LOCK (unix_signal_lock);
  unref_unix_signal_handler_unlocked (unix_signal_source->signum);
  unix_signal_watches = g_slist_remove (unix_signal_watches, source);
  G_UNLOCK (unix_signal_lock);
}

static void
g_child_watch_finalize (GSource *source)
{
  GChildWatchSource *child_watch_source = (GChildWatchSource *) source;

  if (child_watch_source->using_pidfd)
    {
      if (child_watch_source->poll.fd >= 0)
        close (child_watch_source->poll.fd);
      return;
    }

  G_LOCK (unix_signal_lock);
  unix_child_watches = g_slist_remove (unix_child_watches, source);
  unref_unix_signal_handler_unlocked (SIGCHLD);
  G_UNLOCK (unix_signal_lock);
}

#endif /* G_OS_WIN32 */

static gboolean
g_child_watch_dispatch (GSource    *source, 
			GSourceFunc callback,
			gpointer    user_data)
{
  GChildWatchSource *child_watch_source;
  GChildWatchFunc child_watch_callback = (GChildWatchFunc) callback;

  child_watch_source = (GChildWatchSource *) source;

  if (!callback)
    {
      g_warning ("Child watch source dispatched without callback. "
		 "You must call g_source_set_callback().");
      return FALSE;
    }

  (child_watch_callback) (child_watch_source->pid, child_watch_source->child_status, user_data);

  /* We never keep a child watch source around as the child is gone */
  return FALSE;
}

#ifndef G_OS_WIN32

static void
g_unix_signal_handler (int signum)
{
  gint saved_errno = errno;

#if defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
  g_atomic_int_set (&unix_signal_pending[signum], 1);
  g_atomic_int_set (&any_unix_signal_pending, 1);
#else
#warning "Can't use atomics in g_unix_signal_handler(): Unix signal handling will be racy"
  unix_signal_pending[signum] = 1;
  any_unix_signal_pending = 1;
#endif

  g_wakeup_signal (glib_worker_context->wakeup);

  errno = saved_errno;
}

#endif /* !G_OS_WIN32 */

/**
 * g_child_watch_source_new:
 * @pid: process to watch. On POSIX the positive pid of a child process. On
 * Windows a handle for a process (which doesn't have to be a child).
 * 
 * Creates a new child_watch source.
 *
 * The source will not initially be associated with any #GMainContext
 * and must be added to one with g_source_attach() before it will be
 * executed.
 * 
 * Note that child watch sources can only be used in conjunction with
 * `g_spawn...` when the %G_SPAWN_DO_NOT_REAP_CHILD flag is used.
 *
 * Note that on platforms where #GPid must be explicitly closed
 * (see g_spawn_close_pid()) @pid must not be closed while the
 * source is still active. Typically, you will want to call
 * g_spawn_close_pid() in the callback function for the source.
 *
 * On POSIX platforms, the following restrictions apply to this API
 * due to limitations in POSIX process interfaces:
 *
 * * @pid must be a child of this process
 * * @pid must be positive
 * * the application must not call `waitpid` with a non-positive
 *   first argument, for instance in another thread
 * * the application must not wait for @pid to exit by any other
 *   mechanism, including `waitpid(pid, ...)` or a second child-watch
 *   source for the same @pid
 * * the application must not ignore `SIGCHLD`
 *
 * If any of those conditions are not met, this and related APIs will
 * not work correctly. This can often be diagnosed via a GLib warning
 * stating that `ECHILD` was received by `waitpid`.
 *
 * Calling `waitpid` for specific processes other than @pid remains a
 * valid thing to do.
 *
 * Returns: the newly-created child watch source
 *
 * Since: 2.4
 **/
GSource *
g_child_watch_source_new (GPid pid)
{
  GSource *source;
  GChildWatchSource *child_watch_source;
#ifdef HAVE_PIDFD
  int errsv;
#endif

#ifndef G_OS_WIN32
  g_return_val_if_fail (pid > 0, NULL);
#endif

  source = g_source_new (&g_child_watch_funcs, sizeof (GChildWatchSource));
  child_watch_source = (GChildWatchSource *)source;

  /* Set a default name on the source, just in case the caller does not. */
  g_source_set_static_name (source, "GChildWatchSource");

  child_watch_source->pid = pid;

#ifdef G_OS_WIN32
  child_watch_source->poll.fd = (gintptr) pid;
  child_watch_source->poll.events = G_IO_IN;

  g_source_add_poll (source, &child_watch_source->poll);
#else /* !G_OS_WIN32 */

#ifdef HAVE_PIDFD
  /* Use a pidfd, if possible, to avoid having to install a global SIGCHLD
   * handler and potentially competing with any other library/code which wants
   * to install one.
   *
   * Unfortunately this use of pidfd isn’t race-free (the PID could be recycled
   * between the caller calling g_child_watch_source_new() and here), but it’s
   * better than SIGCHLD.
   */
  child_watch_source->poll.fd = (int) syscall (SYS_pidfd_open, pid, 0);
  errsv = errno;

  if (child_watch_source->poll.fd >= 0)
    {
      child_watch_source->using_pidfd = TRUE;
      child_watch_source->poll.events = G_IO_IN;
      g_source_add_poll (source, &child_watch_source->poll);

      return source;
    }
  else
    {
      g_debug ("pidfd_open(%" G_PID_FORMAT ") failed with error: %s",
               pid, g_strerror (errsv));
      /* Fall through; likely the kernel isn’t new enough to support pidfd_open() */
    }
#endif  /* HAVE_PIDFD */

  G_LOCK (unix_signal_lock);
  ref_unix_signal_handler_unlocked (SIGCHLD);
  unix_child_watches = g_slist_prepend (unix_child_watches, child_watch_source);
  if (waitpid (pid, &child_watch_source->child_status, WNOHANG) > 0)
    child_watch_source->child_exited = TRUE;
  G_UNLOCK (unix_signal_lock);
#endif /* !G_OS_WIN32 */

  return source;
}

/**
 * g_child_watch_add_full: (rename-to g_child_watch_add)
 * @priority: the priority of the idle source. Typically this will be in the
 *   range between %G_PRIORITY_DEFAULT_IDLE and %G_PRIORITY_HIGH_IDLE.
 * @pid: process to watch. On POSIX the positive pid of a child process. On
 * Windows a handle for a process (which doesn't have to be a child).
 * @function: function to call
 * @data: data to pass to @function
 * @notify: (nullable): function to call when the idle is removed, or %NULL
 * 
 * Sets a function to be called when the child indicated by @pid 
 * exits, at the priority @priority.
 *
 * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes() 
 * you will need to pass %G_SPAWN_DO_NOT_REAP_CHILD as flag to 
 * the spawn function for the child watching to work.
 *
 * In many programs, you will want to call g_spawn_check_wait_status()
 * in the callback to determine whether or not the child exited
 * successfully.
 * 
 * Also, note that on platforms where #GPid must be explicitly closed
 * (see g_spawn_close_pid()) @pid must not be closed while the source
 * is still active.  Typically, you should invoke g_spawn_close_pid()
 * in the callback function for the source.
 * 
 * GLib supports only a single callback per process id.
 * On POSIX platforms, the same restrictions mentioned for
 * g_child_watch_source_new() apply to this function.
 *
 * This internally creates a main loop source using 
 * g_child_watch_source_new() and attaches it to the main loop context 
 * using g_source_attach(). You can do these steps manually if you 
 * need greater control.
 *
 * Returns: the ID (greater than 0) of the event source.
 *
 * Since: 2.4
 **/
guint
g_child_watch_add_full (gint            priority,
			GPid            pid,
			GChildWatchFunc function,
			gpointer        data,
			GDestroyNotify  notify)
{
  GSource *source;
  guint id;
  
  g_return_val_if_fail (function != NULL, 0);
#ifndef G_OS_WIN32
  g_return_val_if_fail (pid > 0, 0);
#endif

  source = g_child_watch_source_new (pid);

  if (priority != G_PRIORITY_DEFAULT)
    g_source_set_priority (source, priority);

  g_source_set_callback (source, (GSourceFunc) function, data, notify);
  id = g_source_attach (source, NULL);
  g_source_unref (source);

  return id;
}

/**
 * g_child_watch_add:
 * @pid: process id to watch. On POSIX the positive pid of a child
 *   process. On Windows a handle for a process (which doesn't have
 *   to be a child).
 * @function: function to call
 * @data: data to pass to @function
 * 
 * Sets a function to be called when the child indicated by @pid 
 * exits, at a default priority, %G_PRIORITY_DEFAULT.
 * 
 * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes() 
 * you will need to pass %G_SPAWN_DO_NOT_REAP_CHILD as flag to 
 * the spawn function for the child watching to work.
 * 
 * Note that on platforms where #GPid must be explicitly closed
 * (see g_spawn_close_pid()) @pid must not be closed while the
 * source is still active. Typically, you will want to call
 * g_spawn_close_pid() in the callback function for the source.
 *
 * GLib supports only a single callback per process id.
 * On POSIX platforms, the same restrictions mentioned for
 * g_child_watch_source_new() apply to this function.
 *
 * This internally creates a main loop source using 
 * g_child_watch_source_new() and attaches it to the main loop context 
 * using g_source_attach(). You can do these steps manually if you 
 * need greater control.
 *
 * Returns: the ID (greater than 0) of the event source.
 *
 * Since: 2.4
 **/
guint 
g_child_watch_add (GPid            pid,
		   GChildWatchFunc function,
		   gpointer        data)
{
  return g_child_watch_add_full (G_PRIORITY_DEFAULT, pid, function, data, NULL);
}


/* Idle functions */

static gboolean 
g_idle_prepare  (GSource  *source,
		 gint     *timeout)
{
  *timeout = 0;

  return TRUE;
}

static gboolean 
g_idle_check    (GSource  *source)
{
  return TRUE;
}

static gboolean
g_idle_dispatch (GSource    *source, 
		 GSourceFunc callback,
		 gpointer    user_data)
{
  GIdleSource *idle_source = (GIdleSource *)source;
  gboolean again;

  if (!callback)
    {
      g_warning ("Idle source dispatched without callback. "
		 "You must call g_source_set_callback().");
      return FALSE;
    }

  if (idle_source->one_shot)
    {
      GSourceOnceFunc once_callback = (GSourceOnceFunc) callback;
      once_callback (user_data);
      again = G_SOURCE_REMOVE;
    }
  else
    {
      again = callback (user_data);
    }

  TRACE (GLIB_IDLE_DISPATCH (source, source->context, callback, user_data, again));

  return again;
}

static GSource *
idle_source_new (gboolean one_shot)
{
  GSource *source;
  GIdleSource *idle_source;

  source = g_source_new (&g_idle_funcs, sizeof (GIdleSource));
  idle_source = (GIdleSource *) source;

  idle_source->one_shot = one_shot;

  g_source_set_priority (source, G_PRIORITY_DEFAULT_IDLE);

  /* Set a default name on the source, just in case the caller does not. */
  g_source_set_static_name (source, "GIdleSource");

  return source;
}

/**
 * g_idle_source_new:
 * 
 * Creates a new idle source.
 *
 * The source will not initially be associated with any #GMainContext
 * and must be added to one with g_source_attach() before it will be
 * executed. Note that the default priority for idle sources is
 * %G_PRIORITY_DEFAULT_IDLE, as compared to other sources which
 * have a default priority of %G_PRIORITY_DEFAULT.
 * 
 * Returns: the newly-created idle source
 **/
GSource *
g_idle_source_new (void)
{
  return idle_source_new (FALSE);
}

static guint
idle_add_full (gint           priority,
               gboolean       one_shot,
               GSourceFunc    function,
               gpointer       data,
               GDestroyNotify notify)
{
  GSource *source;
  guint id;

  g_return_val_if_fail (function != NULL, 0);

  source = idle_source_new (one_shot);

  if (priority != G_PRIORITY_DEFAULT_IDLE)
    g_source_set_priority (source, priority);

  g_source_set_callback (source, function, data, notify);
  id = g_source_attach (source, NULL);

  TRACE (GLIB_IDLE_ADD (source, g_main_context_default (), id, priority, function, data));

  g_source_unref (source);

  return id;
}

/**
 * g_idle_add_full: (rename-to g_idle_add)
 * @priority: the priority of the idle source. Typically this will be in the
 *   range between %G_PRIORITY_DEFAULT_IDLE and %G_PRIORITY_HIGH_IDLE.
 * @function: function to call
 * @data: data to pass to @function
 * @notify: (nullable): function to call when the idle is removed, or %NULL
 * 
 * Adds a function to be called whenever there are no higher priority
 * events pending.
 *
 * If the function returns %G_SOURCE_REMOVE or %FALSE it is automatically
 * removed from the list of event sources and will not be called again.
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle the return value and memory management of @data.
 * 
 * This internally creates a main loop source using g_idle_source_new()
 * and attaches it to the global #GMainContext using g_source_attach(), so
 * the callback will be invoked in whichever thread is running that main
 * context. You can do these steps manually if you need greater control or to
 * use a custom main context.
 * 
 * Returns: the ID (greater than 0) of the event source.
 **/
guint 
g_idle_add_full (gint           priority,
		 GSourceFunc    function,
		 gpointer       data,
		 GDestroyNotify notify)
{
  return idle_add_full (priority, FALSE, function, data, notify);
}

/**
 * g_idle_add:
 * @function: function to call 
 * @data: data to pass to @function.
 * 
 * Adds a function to be called whenever there are no higher priority
 * events pending to the default main loop. The function is given the
 * default idle priority, %G_PRIORITY_DEFAULT_IDLE.  If the function
 * returns %FALSE it is automatically removed from the list of event
 * sources and will not be called again.
 *
 * See [memory management of sources][mainloop-memory-management] for details
 * on how to handle the return value and memory management of @data.
 * 
 * This internally creates a main loop source using g_idle_source_new()
 * and attaches it to the global #GMainContext using g_source_attach(), so
 * the callback will be invoked in whichever thread is running that main
 * context. You can do these steps manually if you need greater control or to
 * use a custom main context.
 * 
 * Returns: the ID (greater than 0) of the event source.
 **/
guint 
g_idle_add (GSourceFunc    function,
	    gpointer       data)
{
  return g_idle_add_full (G_PRIORITY_DEFAULT_IDLE, function, data, NULL);
}

/**
 * g_idle_add_once:
 * @function: function to call
 * @data: data to pass to @function
 *
 * Adds a function to be called whenever there are no higher priority
 * events pending to the default main loop. The function is given the
 * default idle priority, %G_PRIORITY_DEFAULT_IDLE.
 *
 * The function will only be called once and then the source will be
 * automatically removed from the main context.
 *
 * This function otherwise behaves like g_idle_add().
 *
 * Returns: the ID (greater than 0) of the event source
 *
 * Since: 2.74
 */
guint
g_idle_add_once (GSourceOnceFunc function,
                 gpointer        data)
{
  return idle_add_full (G_PRIORITY_DEFAULT_IDLE, TRUE, (GSourceFunc) function, data, NULL);
}

/**
 * g_idle_remove_by_data:
 * @data: the data for the idle source's callback.
 * 
 * Removes the idle function with the given data.
 * 
 * Returns: %TRUE if an idle source was found and removed.
 **/
gboolean
g_idle_remove_by_data (gpointer data)
{
  return g_source_remove_by_funcs_user_data (&g_idle_funcs, data);
}

/**
 * g_main_context_invoke:
 * @context: (nullable): a #GMainContext, or %NULL for the global-default
 *   main context
 * @function: function to call
 * @data: data to pass to @function
 *
 * Invokes a function in such a way that @context is owned during the
 * invocation of @function.
 *
 * If @context is %NULL then the global-default main context — as
 * returned by g_main_context_default() — is used.
 *
 * If @context is owned by the current thread, @function is called
 * directly.  Otherwise, if @context is the thread-default main context
 * of the current thread and g_main_context_acquire() succeeds, then
 * @function is called and g_main_context_release() is called
 * afterwards.
 *
 * In any other case, an idle source is created to call @function and
 * that source is attached to @context (presumably to be run in another
 * thread).  The idle source is attached with %G_PRIORITY_DEFAULT
 * priority.  If you want a different priority, use
 * g_main_context_invoke_full().
 *
 * Note that, as with normal idle functions, @function should probably
 * return %FALSE.  If it returns %TRUE, it will be continuously run in a
 * loop (and may prevent this call from returning).
 *
 * Since: 2.28
 **/
void
g_main_context_invoke (GMainContext *context,
                       GSourceFunc   function,
                       gpointer      data)
{
  g_main_context_invoke_full (context,
                              G_PRIORITY_DEFAULT,
                              function, data, NULL);
}

/**
 * g_main_context_invoke_full:
 * @context: (nullable): a #GMainContext, or %NULL for the global-default
 *   main context
 * @priority: the priority at which to run @function
 * @function: function to call
 * @data: data to pass to @function
 * @notify: (nullable): a function to call when @data is no longer in use, or %NULL.
 *
 * Invokes a function in such a way that @context is owned during the
 * invocation of @function.
 *
 * This function is the same as g_main_context_invoke() except that it
 * lets you specify the priority in case @function ends up being
 * scheduled as an idle and also lets you give a #GDestroyNotify for @data.
 *
 * @notify should not assume that it is called from any particular
 * thread or with any particular context acquired.
 *
 * Since: 2.28
 **/
void
g_main_context_invoke_full (GMainContext   *context,
                            gint            priority,
                            GSourceFunc     function,
                            gpointer        data,
                            GDestroyNotify  notify)
{
  g_return_if_fail (function != NULL);

  if (!context)
    context = g_main_context_default ();

  if (g_main_context_is_owner (context))
    {
      while (function (data));
      if (notify != NULL)
        notify (data);
    }

  else
    {
      GMainContext *thread_default;

      thread_default = g_main_context_get_thread_default ();

      if (!thread_default)
        thread_default = g_main_context_default ();

      if (thread_default == context && g_main_context_acquire (context))
        {
          while (function (data));

          g_main_context_release (context);

          if (notify != NULL)
            notify (data);
        }
      else
        {
          GSource *source;

          source = g_idle_source_new ();
          g_source_set_priority (source, priority);
          g_source_set_callback (source, function, data, notify);
          g_source_attach (source, context);
          g_source_unref (source);
        }
    }
}

static gpointer
glib_worker_main (gpointer data)
{
  while (TRUE)
    {
      g_main_context_iteration (glib_worker_context, TRUE);

#ifdef G_OS_UNIX
      if (g_atomic_int_get (&any_unix_signal_pending))
        dispatch_unix_signals ();
#endif
    }

  return NULL; /* worst GCC warning message ever... */
}

GMainContext *
g_get_worker_context (void)
{
  static gsize initialised;

  if (g_once_init_enter (&initialised))
    {
      /* mask all signals in the worker thread */
#ifdef G_OS_UNIX
      sigset_t prev_mask;
      sigset_t all;

      sigfillset (&all);
      pthread_sigmask (SIG_SETMASK, &all, &prev_mask);
#endif
      glib_worker_context = g_main_context_new ();
      g_thread_new ("gmain", glib_worker_main, NULL);
#ifdef G_OS_UNIX
      pthread_sigmask (SIG_SETMASK, &prev_mask, NULL);
#endif
      g_once_init_leave (&initialised, TRUE);
    }

  return glib_worker_context;
}

/**
 * g_steal_fd:
 * @fd_ptr: (not optional) (inout): A pointer to a file descriptor
 *
 * Sets @fd_ptr to `-1`, returning the value that was there before.
 *
 * Conceptually, this transfers the ownership of the file descriptor
 * from the referenced variable to the caller of the function (i.e.
 * ‘steals’ the reference). This is very similar to g_steal_pointer(),
 * but for file descriptors.
 *
 * On POSIX platforms, this function is async-signal safe
 * (see [`signal(7)`](man:signal(7)) and
 * [`signal-safety(7)`](man:signal-safety(7))), making it safe to call from a
 * signal handler or a #GSpawnChildSetupFunc.
 *
 * Returns: the value that @fd_ptr previously had
 * Since: 2.70
 */