Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

   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
/*
 * Copyright (c) 2016, Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 *
 * @brief Public kernel APIs.
 */

#ifndef ZEPHYR_INCLUDE_KERNEL_H_
#define ZEPHYR_INCLUDE_KERNEL_H_

#if !defined(_ASMLANGUAGE)
#include <kernel_includes.h>
#include <errno.h>
#include <stdbool.h>
#include <toolchain.h>

#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
#include <timing/timing.h>
#endif

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Kernel APIs
 * @defgroup kernel_apis Kernel APIs
 * @{
 * @}
 */

#if defined(CONFIG_COOP_ENABLED) && defined(CONFIG_PREEMPT_ENABLED)
#define _NUM_COOP_PRIO (CONFIG_NUM_COOP_PRIORITIES)
#define _NUM_PREEMPT_PRIO (CONFIG_NUM_PREEMPT_PRIORITIES + 1)
#elif defined(CONFIG_COOP_ENABLED)
#define _NUM_COOP_PRIO (CONFIG_NUM_COOP_PRIORITIES + 1)
#define _NUM_PREEMPT_PRIO (0)
#elif defined(CONFIG_PREEMPT_ENABLED)
#define _NUM_COOP_PRIO (0)
#define _NUM_PREEMPT_PRIO (CONFIG_NUM_PREEMPT_PRIORITIES + 1)
#else
#error "invalid configuration"
#endif

#define K_PRIO_COOP(x) (-(_NUM_COOP_PRIO - (x)))
#define K_PRIO_PREEMPT(x) (x)

#define K_ANY NULL
#define K_END NULL

#if defined(CONFIG_COOP_ENABLED) && defined(CONFIG_PREEMPT_ENABLED)
#define K_HIGHEST_THREAD_PRIO (-CONFIG_NUM_COOP_PRIORITIES)
#elif defined(CONFIG_COOP_ENABLED)
#define K_HIGHEST_THREAD_PRIO (-CONFIG_NUM_COOP_PRIORITIES - 1)
#elif defined(CONFIG_PREEMPT_ENABLED)
#define K_HIGHEST_THREAD_PRIO 0
#else
#error "invalid configuration"
#endif

#ifdef CONFIG_PREEMPT_ENABLED
#define K_LOWEST_THREAD_PRIO CONFIG_NUM_PREEMPT_PRIORITIES
#else
#define K_LOWEST_THREAD_PRIO -1
#endif

#define K_IDLE_PRIO K_LOWEST_THREAD_PRIO

#define K_HIGHEST_APPLICATION_THREAD_PRIO (K_HIGHEST_THREAD_PRIO)
#define K_LOWEST_APPLICATION_THREAD_PRIO (K_LOWEST_THREAD_PRIO - 1)

#ifdef CONFIG_OBJECT_TRACING
#define _OBJECT_TRACING_NEXT_PTR(type) struct type *__next;
#define _OBJECT_TRACING_LINKED_FLAG uint8_t __linked;
#define _OBJECT_TRACING_INIT \
	.__next = NULL,	     \
	.__linked = 0,
#else
#define _OBJECT_TRACING_INIT
#define _OBJECT_TRACING_NEXT_PTR(type)
#define _OBJECT_TRACING_LINKED_FLAG
#endif

#ifdef CONFIG_POLL
#define _POLL_EVENT_OBJ_INIT(obj) \
	.poll_events = SYS_DLIST_STATIC_INIT(&obj.poll_events),
#define _POLL_EVENT sys_dlist_t poll_events
#else
#define _POLL_EVENT_OBJ_INIT(obj)
#define _POLL_EVENT
#endif

struct k_thread;
struct k_mutex;
struct k_sem;
struct k_msgq;
struct k_mbox;
struct k_pipe;
struct k_queue;
struct k_fifo;
struct k_lifo;
struct k_stack;
struct k_mem_slab;
struct k_mem_pool;
struct k_timer;
struct k_poll_event;
struct k_poll_signal;
struct k_mem_domain;
struct k_mem_partition;
struct k_futex;

enum execution_context_types {
	K_ISR = 0,
	K_COOP_THREAD,
	K_PREEMPT_THREAD,
};

/* private, used by k_poll and k_work_poll */
struct k_work_poll;
typedef int (*_poller_cb_t)(struct k_poll_event *event, uint32_t state);

/**
 * @addtogroup thread_apis
 * @{
 */

typedef void (*k_thread_user_cb_t)(const struct k_thread *thread,
				   void *user_data);

/**
 * @brief Iterate over all the threads in the system.
 *
 * This routine iterates over all the threads in the system and
 * calls the user_cb function for each thread.
 *
 * @param user_cb Pointer to the user callback function.
 * @param user_data Pointer to user data.
 *
 * @note @option{CONFIG_THREAD_MONITOR} must be set for this function
 * to be effective.
 * @note This API uses @ref k_spin_lock to protect the _kernel.threads
 * list which means creation of new threads and terminations of existing
 * threads are blocked until this API returns.
 *
 * @return N/A
 */
extern void k_thread_foreach(k_thread_user_cb_t user_cb, void *user_data);

/**
 * @brief Iterate over all the threads in the system without locking.
 *
 * This routine works exactly the same like @ref k_thread_foreach
 * but unlocks interrupts when user_cb is executed.
 *
 * @param user_cb Pointer to the user callback function.
 * @param user_data Pointer to user data.
 *
 * @note @option{CONFIG_THREAD_MONITOR} must be set for this function
 * to be effective.
 * @note This API uses @ref k_spin_lock only when accessing the _kernel.threads
 * queue elements. It unlocks it during user callback function processing.
 * If a new task is created when this @c foreach function is in progress,
 * the added new task would not be included in the enumeration.
 * If a task is aborted during this enumeration, there would be a race here
 * and there is a possibility that this aborted task would be included in the
 * enumeration.
 * @note If the task is aborted and the memory occupied by its @c k_thread
 * structure is reused when this @c k_thread_foreach_unlocked is in progress
 * it might even lead to the system behave unstable.
 * This function may never return, as it would follow some @c next task
 * pointers treating given pointer as a pointer to the k_thread structure
 * while it is something different right now.
 * Do not reuse the memory that was occupied by k_thread structure of aborted
 * task if it was aborted after this function was called in any context.
 */
extern void k_thread_foreach_unlocked(
	k_thread_user_cb_t user_cb, void *user_data);

/** @} */

/**
 * @defgroup thread_apis Thread APIs
 * @ingroup kernel_apis
 * @{
 */

#endif /* !_ASMLANGUAGE */


/*
 * Thread user options. May be needed by assembly code. Common part uses low
 * bits, arch-specific use high bits.
 */

/**
 * @brief system thread that must not abort
 * */
#define K_ESSENTIAL (BIT(0))

#if defined(CONFIG_FPU_SHARING)
/**
 * @brief FPU registers are managed by context switch
 *
 * @details
 * This option indicates that the thread uses the CPU's floating point
 * registers. This instructs the kernel to take additional steps to save
 * and restore the contents of these registers when scheduling the thread.
 * No effect if @option{CONFIG_FPU_SHARING} is not enabled.
 */
#define K_FP_REGS (BIT(1))
#endif

/**
 * @brief user mode thread
 *
 * This thread has dropped from supervisor mode to user mode and consequently
 * has additional restrictions
 */
#define K_USER (BIT(2))

/**
 * @brief Inherit Permissions
 *
 * @details
 * Indicates that the thread being created should inherit all kernel object
 * permissions from the thread that created it. No effect if
 * @option{CONFIG_USERSPACE} is not enabled.
 */
#define K_INHERIT_PERMS (BIT(3))

#ifdef CONFIG_X86
/* x86 Bitmask definitions for threads user options */

#if defined(CONFIG_FPU_SHARING) && defined(CONFIG_SSE)
/* thread uses SSEx (and also FP) registers */
#define K_SSE_REGS (BIT(7))
#endif
#endif

/* end - thread options */

#if !defined(_ASMLANGUAGE)
/**
 * @brief Create a thread.
 *
 * This routine initializes a thread, then schedules it for execution.
 *
 * The new thread may be scheduled for immediate execution or a delayed start.
 * If the newly spawned thread does not have a delayed start the kernel
 * scheduler may preempt the current thread to allow the new thread to
 * execute.
 *
 * Thread options are architecture-specific, and can include K_ESSENTIAL,
 * K_FP_REGS, and K_SSE_REGS. Multiple options may be specified by separating
 * them using "|" (the logical OR operator).
 *
 * Stack objects passed to this function must be originally defined with
 * either of these macros in order to be portable:
 *
 * - K_THREAD_STACK_DEFINE() - For stacks that may support either user or
 *   supervisor threads.
 * - K_KERNEL_STACK_DEFINE() - For stacks that may support supervisor
 *   threads only. These stacks use less memory if CONFIG_USERSPACE is
 *   enabled.
 *
 * The stack_size parameter has constraints. It must either be:
 *
 * - The original size value passed to K_THREAD_STACK_DEFINE() or
 *   K_KERNEL_STACK_DEFINE()
 * - The return value of K_THREAD_STACK_SIZEOF(stack) if the stack was
 *   defined with K_THREAD_STACK_DEFINE()
 * - The return value of K_KERNEL_STACK_SIZEOF(stack) if the stack was
 *   defined with K_KERNEL_STACK_DEFINE().
 *
 * Using other values, or sizeof(stack) may produce undefined behavior.
 *
 * @param new_thread Pointer to uninitialized struct k_thread
 * @param stack Pointer to the stack space.
 * @param stack_size Stack size in bytes.
 * @param entry Thread entry function.
 * @param p1 1st entry point parameter.
 * @param p2 2nd entry point parameter.
 * @param p3 3rd entry point parameter.
 * @param prio Thread priority.
 * @param options Thread options.
 * @param delay Scheduling delay, or K_NO_WAIT (for no delay).
 *
 * @return ID of new thread.
 *
 */
__syscall k_tid_t k_thread_create(struct k_thread *new_thread,
				  k_thread_stack_t *stack,
				  size_t stack_size,
				  k_thread_entry_t entry,
				  void *p1, void *p2, void *p3,
				  int prio, uint32_t options, k_timeout_t delay);

/**
 * @brief Drop a thread's privileges permanently to user mode
 *
 * This allows a supervisor thread to be re-used as a user thread.
 * This function does not return, but control will transfer to the provided
 * entry point as if this was a new user thread.
 *
 * The implementation ensures that the stack buffer contents are erased.
 * Any thread-local storage will be reverted to a pristine state.
 *
 * Memory domain membership, resource pool assignment, kernel object
 * permissions, priority, and thread options are preserved.
 *
 * A common use of this function is to re-use the main thread as a user thread
 * once all supervisor mode-only tasks have been completed.
 *
 * @param entry Function to start executing from
 * @param p1 1st entry point parameter
 * @param p2 2nd entry point parameter
 * @param p3 3rd entry point parameter
 */
extern FUNC_NORETURN void k_thread_user_mode_enter(k_thread_entry_t entry,
						   void *p1, void *p2,
						   void *p3);

/**
 * @brief Grant a thread access to a set of kernel objects
 *
 * This is a convenience function. For the provided thread, grant access to
 * the remaining arguments, which must be pointers to kernel objects.
 *
 * The thread object must be initialized (i.e. running). The objects don't
 * need to be.
 * Note that NULL shouldn't be passed as an argument.
 *
 * @param thread Thread to grant access to objects
 * @param ... list of kernel object pointers
 */
#define k_thread_access_grant(thread, ...) \
	FOR_EACH_FIXED_ARG(k_object_access_grant, (;), thread, __VA_ARGS__)

/**
 * @brief Assign a resource memory pool to a thread
 *
 * By default, threads have no resource pool assigned unless their parent
 * thread has a resource pool, in which case it is inherited. Multiple
 * threads may be assigned to the same memory pool.
 *
 * Changing a thread's resource pool will not migrate allocations from the
 * previous pool.
 *
 * @param thread Target thread to assign a memory pool for resource requests.
 * @param heap Heap object to use for resources,
 *             or NULL if the thread should no longer have a memory pool.
 */
static inline void k_thread_heap_assign(struct k_thread *thread,
					struct k_heap *heap)
{
	thread->resource_pool = heap;
}

#if defined(CONFIG_INIT_STACKS) && defined(CONFIG_THREAD_STACK_INFO)
/**
 * @brief Obtain stack usage information for the specified thread
 *
 * User threads will need to have permission on the target thread object.
 *
 * Some hardware may prevent inspection of a stack buffer currently in use.
 * If this API is called from supervisor mode, on the currently running thread,
 * on a platform which selects @option{CONFIG_NO_UNUSED_STACK_INSPECTION}, an
 * error will be generated.
 *
 * @param thread Thread to inspect stack information
 * @param unused_ptr Output parameter, filled in with the unused stack space
 *	of the target thread in bytes.
 * @return 0 on success
 * @return -EBADF Bad thread object (user mode only)
 * @return -EPERM No permissions on thread object (user mode only)
 * #return -ENOTSUP Forbidden by hardware policy
 * @return -EINVAL Thread is uninitialized or exited (user mode only)
 * @return -EFAULT Bad memory address for unused_ptr (user mode only)
 */
__syscall int k_thread_stack_space_get(const struct k_thread *thread,
				       size_t *unused_ptr);
#endif

#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
/**
 * @brief Assign the system heap as a thread's resource pool
 *
 * Similar to z_thread_resource_pool_assign(), but the thread will use
 * the kernel heap to draw memory.
 *
 * Use with caution, as a malicious thread could perform DoS attacks on the
 * kernel heap.
 *
 * @param thread Target thread to assign the system heap for resource requests
 *
 */
void k_thread_system_pool_assign(struct k_thread *thread);
#endif /* (CONFIG_HEAP_MEM_POOL_SIZE > 0) */

/**
 * @brief Sleep until a thread exits
 *
 * The caller will be put to sleep until the target thread exits, either due
 * to being aborted, self-exiting, or taking a fatal error. This API returns
 * immediately if the thread isn't running.
 *
 * This API may only be called from ISRs with a K_NO_WAIT timeout.
 *
 * @param thread Thread to wait to exit
 * @param timeout upper bound time to wait for the thread to exit.
 * @retval 0 success, target thread has exited or wasn't running
 * @retval -EBUSY returned without waiting
 * @retval -EAGAIN waiting period timed out
 * @retval -EDEADLK target thread is joining on the caller, or target thread
 *                  is the caller
 */
__syscall int k_thread_join(struct k_thread *thread, k_timeout_t timeout);

/**
 * @brief Put the current thread to sleep.
 *
 * This routine puts the current thread to sleep for @a duration,
 * specified as a k_timeout_t object.
 *
 * @note if @a timeout is set to K_FOREVER then the thread is suspended.
 *
 * @param timeout Desired duration of sleep.
 *
 * @return Zero if the requested time has elapsed or the number of milliseconds
 * left to sleep, if thread was woken up by \ref k_wakeup call.
 */
__syscall int32_t k_sleep(k_timeout_t timeout);

/**
 * @brief Put the current thread to sleep.
 *
 * This routine puts the current thread to sleep for @a duration milliseconds.
 *
 * @param ms Number of milliseconds to sleep.
 *
 * @return Zero if the requested time has elapsed or the number of milliseconds
 * left to sleep, if thread was woken up by \ref k_wakeup call.
 */
static inline int32_t k_msleep(int32_t ms)
{
	return k_sleep(Z_TIMEOUT_MS(ms));
}

/**
 * @brief Put the current thread to sleep with microsecond resolution.
 *
 * This function is unlikely to work as expected without kernel tuning.
 * In particular, because the lower bound on the duration of a sleep is
 * the duration of a tick, @option{CONFIG_SYS_CLOCK_TICKS_PER_SEC} must be
 * adjusted to achieve the resolution desired. The implications of doing
 * this must be understood before attempting to use k_usleep(). Use with
 * caution.
 *
 * @param us Number of microseconds to sleep.
 *
 * @return Zero if the requested time has elapsed or the number of microseconds
 * left to sleep, if thread was woken up by \ref k_wakeup call.
 */
__syscall int32_t k_usleep(int32_t us);

/**
 * @brief Cause the current thread to busy wait.
 *
 * This routine causes the current thread to execute a "do nothing" loop for
 * @a usec_to_wait microseconds.
 *
 * @note The clock used for the microsecond-resolution delay here may
 * be skewed relative to the clock used for system timeouts like
 * k_sleep().  For example k_busy_wait(1000) may take slightly more or
 * less time than k_sleep(K_MSEC(1)), with the offset dependent on
 * clock tolerances.
 *
 * @return N/A
 */
__syscall void k_busy_wait(uint32_t usec_to_wait);

/**
 * @brief Yield the current thread.
 *
 * This routine causes the current thread to yield execution to another
 * thread of the same or higher priority. If there are no other ready threads
 * of the same or higher priority, the routine returns immediately.
 *
 * @return N/A
 */
__syscall void k_yield(void);

/**
 * @brief Wake up a sleeping thread.
 *
 * This routine prematurely wakes up @a thread from sleeping.
 *
 * If @a thread is not currently sleeping, the routine has no effect.
 *
 * @param thread ID of thread to wake.
 *
 * @return N/A
 */
__syscall void k_wakeup(k_tid_t thread);

/**
 * @brief Get thread ID of the current thread.
 *
 * @return ID of current thread.
 *
 */
__syscall k_tid_t k_current_get(void);

/**
 * @brief Abort a thread.
 *
 * This routine permanently stops execution of @a thread. The thread is taken
 * off all kernel queues it is part of (i.e. the ready queue, the timeout
 * queue, or a kernel object wait queue). However, any kernel resources the
 * thread might currently own (such as mutexes or memory blocks) are not
 * released. It is the responsibility of the caller of this routine to ensure
 * all necessary cleanup is performed.
 *
 * @param thread ID of thread to abort.
 *
 * @return N/A
 */
__syscall void k_thread_abort(k_tid_t thread);


/**
 * @brief Start an inactive thread
 *
 * If a thread was created with K_FOREVER in the delay parameter, it will
 * not be added to the scheduling queue until this function is called
 * on it.
 *
 * @param thread thread to start
 */
__syscall void k_thread_start(k_tid_t thread);

extern k_ticks_t z_timeout_expires(const struct _timeout *timeout);
extern k_ticks_t z_timeout_remaining(const struct _timeout *timeout);

#ifdef CONFIG_SYS_CLOCK_EXISTS

/**
 * @brief Get time when a thread wakes up, in system ticks
 *
 * This routine computes the system uptime when a waiting thread next
 * executes, in units of system ticks.  If the thread is not waiting,
 * it returns current system time.
 */
__syscall k_ticks_t k_thread_timeout_expires_ticks(const struct k_thread *t);

static inline k_ticks_t z_impl_k_thread_timeout_expires_ticks(
						const struct k_thread *t)
{
	return z_timeout_expires(&t->base.timeout);
}

/**
 * @brief Get time remaining before a thread wakes up, in system ticks
 *
 * This routine computes the time remaining before a waiting thread
 * next executes, in units of system ticks.  If the thread is not
 * waiting, it returns zero.
 */
__syscall k_ticks_t k_thread_timeout_remaining_ticks(const struct k_thread *t);

static inline k_ticks_t z_impl_k_thread_timeout_remaining_ticks(
						const struct k_thread *t)
{
	return z_timeout_remaining(&t->base.timeout);
}

#endif /* CONFIG_SYS_CLOCK_EXISTS */

/**
 * @cond INTERNAL_HIDDEN
 */

/* timeout has timed out and is not on _timeout_q anymore */
#define _EXPIRED (-2)

struct _static_thread_data {
	struct k_thread *init_thread;
	k_thread_stack_t *init_stack;
	unsigned int init_stack_size;
	k_thread_entry_t init_entry;
	void *init_p1;
	void *init_p2;
	void *init_p3;
	int init_prio;
	uint32_t init_options;
	int32_t init_delay;
	void (*init_abort)(void);
	const char *init_name;
};

#define Z_THREAD_INITIALIZER(thread, stack, stack_size,           \
			    entry, p1, p2, p3,                   \
			    prio, options, delay, abort, tname)  \
	{                                                        \
	.init_thread = (thread),				 \
	.init_stack = (stack),					 \
	.init_stack_size = (stack_size),                         \
	.init_entry = (k_thread_entry_t)entry,			 \
	.init_p1 = (void *)p1,                                   \
	.init_p2 = (void *)p2,                                   \
	.init_p3 = (void *)p3,                                   \
	.init_prio = (prio),                                     \
	.init_options = (options),                               \
	.init_delay = (delay),                                   \
	.init_abort = (abort),                                   \
	.init_name = STRINGIFY(tname),                           \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @brief Statically define and initialize a thread.
 *
 * The thread may be scheduled for immediate execution or a delayed start.
 *
 * Thread options are architecture-specific, and can include K_ESSENTIAL,
 * K_FP_REGS, and K_SSE_REGS. Multiple options may be specified by separating
 * them using "|" (the logical OR operator).
 *
 * The ID of the thread can be accessed using:
 *
 * @code extern const k_tid_t <name>; @endcode
 *
 * @param name Name of the thread.
 * @param stack_size Stack size in bytes.
 * @param entry Thread entry function.
 * @param p1 1st entry point parameter.
 * @param p2 2nd entry point parameter.
 * @param p3 3rd entry point parameter.
 * @param prio Thread priority.
 * @param options Thread options.
 * @param delay Scheduling delay (in milliseconds), zero for no delay.
 *
 *
 * @internal It has been observed that the x86 compiler by default aligns
 * these _static_thread_data structures to 32-byte boundaries, thereby
 * wasting space. To work around this, force a 4-byte alignment.
 *
 */
#define K_THREAD_DEFINE(name, stack_size,                                \
			entry, p1, p2, p3,                               \
			prio, options, delay)                            \
	K_THREAD_STACK_DEFINE(_k_thread_stack_##name, stack_size);	 \
	struct k_thread _k_thread_obj_##name;				 \
	Z_STRUCT_SECTION_ITERABLE(_static_thread_data, _k_thread_data_##name) =\
		Z_THREAD_INITIALIZER(&_k_thread_obj_##name,		 \
				    _k_thread_stack_##name, stack_size,  \
				entry, p1, p2, p3, prio, options, delay, \
				NULL, name);				 	 \
	const k_tid_t name = (k_tid_t)&_k_thread_obj_##name

/**
 * @brief Get a thread's priority.
 *
 * This routine gets the priority of @a thread.
 *
 * @param thread ID of thread whose priority is needed.
 *
 * @return Priority of @a thread.
 */
__syscall int k_thread_priority_get(k_tid_t thread);

/**
 * @brief Set a thread's priority.
 *
 * This routine immediately changes the priority of @a thread.
 *
 * Rescheduling can occur immediately depending on the priority @a thread is
 * set to:
 *
 * - If its priority is raised above the priority of the caller of this
 * function, and the caller is preemptible, @a thread will be scheduled in.
 *
 * - If the caller operates on itself, it lowers its priority below that of
 * other threads in the system, and the caller is preemptible, the thread of
 * highest priority will be scheduled in.
 *
 * Priority can be assigned in the range of -CONFIG_NUM_COOP_PRIORITIES to
 * CONFIG_NUM_PREEMPT_PRIORITIES-1, where -CONFIG_NUM_COOP_PRIORITIES is the
 * highest priority.
 *
 * @param thread ID of thread whose priority is to be set.
 * @param prio New priority.
 *
 * @warning Changing the priority of a thread currently involved in mutex
 * priority inheritance may result in undefined behavior.
 *
 * @return N/A
 */
__syscall void k_thread_priority_set(k_tid_t thread, int prio);


#ifdef CONFIG_SCHED_DEADLINE
/**
 * @brief Set deadline expiration time for scheduler
 *
 * This sets the "deadline" expiration as a time delta from the
 * current time, in the same units used by k_cycle_get_32().  The
 * scheduler (when deadline scheduling is enabled) will choose the
 * next expiring thread when selecting between threads at the same
 * static priority.  Threads at different priorities will be scheduled
 * according to their static priority.
 *
 * @note Deadlines are stored internally using 32 bit unsigned
 * integers.  The number of cycles between the "first" deadline in the
 * scheduler queue and the "last" deadline must be less than 2^31 (i.e
 * a signed non-negative quantity).  Failure to adhere to this rule
 * may result in scheduled threads running in an incorrect dealine
 * order.
 *
 * @note Despite the API naming, the scheduler makes no guarantees the
 * the thread WILL be scheduled within that deadline, nor does it take
 * extra metadata (like e.g. the "runtime" and "period" parameters in
 * Linux sched_setattr()) that allows the kernel to validate the
 * scheduling for achievability.  Such features could be implemented
 * above this call, which is simply input to the priority selection
 * logic.
 *
 * @note You should enable @option{CONFIG_SCHED_DEADLINE} in your project
 * configuration.
 *
 * @param thread A thread on which to set the deadline
 * @param deadline A time delta, in cycle units
 *
 */
__syscall void k_thread_deadline_set(k_tid_t thread, int deadline);
#endif

#ifdef CONFIG_SCHED_CPU_MASK
/**
 * @brief Sets all CPU enable masks to zero
 *
 * After this returns, the thread will no longer be schedulable on any
 * CPUs.  The thread must not be currently runnable.
 *
 * @note You should enable @option{CONFIG_SCHED_DEADLINE} in your project
 * configuration.
 *
 * @param thread Thread to operate upon
 * @return Zero on success, otherwise error code
 */
int k_thread_cpu_mask_clear(k_tid_t thread);

/**
 * @brief Sets all CPU enable masks to one
 *
 * After this returns, the thread will be schedulable on any CPU.  The
 * thread must not be currently runnable.
 *
 * @note You should enable @option{CONFIG_SCHED_DEADLINE} in your project
 * configuration.
 *
 * @param thread Thread to operate upon
 * @return Zero on success, otherwise error code
 */
int k_thread_cpu_mask_enable_all(k_tid_t thread);

/**
 * @brief Enable thread to run on specified CPU
 *
 * The thread must not be currently runnable.
 *
 * @note You should enable @option{CONFIG_SCHED_DEADLINE} in your project
 * configuration.
 *
 * @param thread Thread to operate upon
 * @param cpu CPU index
 * @return Zero on success, otherwise error code
 */
int k_thread_cpu_mask_enable(k_tid_t thread, int cpu);

/**
 * @brief Prevent thread to run on specified CPU
 *
 * The thread must not be currently runnable.
 *
 * @note You should enable @option{CONFIG_SCHED_DEADLINE} in your project
 * configuration.
 *
 * @param thread Thread to operate upon
 * @param cpu CPU index
 * @return Zero on success, otherwise error code
 */
int k_thread_cpu_mask_disable(k_tid_t thread, int cpu);
#endif

/**
 * @brief Suspend a thread.
 *
 * This routine prevents the kernel scheduler from making @a thread
 * the current thread. All other internal operations on @a thread are
 * still performed; for example, kernel objects it is waiting on are
 * still handed to it.  Note that any existing timeouts
 * (e.g. k_sleep(), or a timeout argument to k_sem_take() et. al.)
 * will be canceled.  On resume, the thread will begin running
 * immediately and return from the blocked call.
 *
 * If @a thread is already suspended, the routine has no effect.
 *
 * @param thread ID of thread to suspend.
 *
 * @return N/A
 */
__syscall void k_thread_suspend(k_tid_t thread);

/**
 * @brief Resume a suspended thread.
 *
 * This routine allows the kernel scheduler to make @a thread the current
 * thread, when it is next eligible for that role.
 *
 * If @a thread is not currently suspended, the routine has no effect.
 *
 * @param thread ID of thread to resume.
 *
 * @return N/A
 */
__syscall void k_thread_resume(k_tid_t thread);

/**
 * @brief Set time-slicing period and scope.
 *
 * This routine specifies how the scheduler will perform time slicing of
 * preemptible threads.
 *
 * To enable time slicing, @a slice must be non-zero. The scheduler
 * ensures that no thread runs for more than the specified time limit
 * before other threads of that priority are given a chance to execute.
 * Any thread whose priority is higher than @a prio is exempted, and may
 * execute as long as desired without being preempted due to time slicing.
 *
 * Time slicing only limits the maximum amount of time a thread may continuously
 * execute. Once the scheduler selects a thread for execution, there is no
 * minimum guaranteed time the thread will execute before threads of greater or
 * equal priority are scheduled.
 *
 * When the current thread is the only one of that priority eligible
 * for execution, this routine has no effect; the thread is immediately
 * rescheduled after the slice period expires.
 *
 * To disable timeslicing, set both @a slice and @a prio to zero.
 *
 * @param slice Maximum time slice length (in milliseconds).
 * @param prio Highest thread priority level eligible for time slicing.
 *
 * @return N/A
 */
extern void k_sched_time_slice_set(int32_t slice, int prio);

/** @} */

/**
 * @addtogroup isr_apis
 * @{
 */

/**
 * @brief Determine if code is running at interrupt level.
 *
 * This routine allows the caller to customize its actions, depending on
 * whether it is a thread or an ISR.
 *
 * @note Can be called by ISRs.
 *
 * @return false if invoked by a thread.
 * @return true if invoked by an ISR.
 */
extern bool k_is_in_isr(void);

/**
 * @brief Determine if code is running in a preemptible thread.
 *
 * This routine allows the caller to customize its actions, depending on
 * whether it can be preempted by another thread. The routine returns a 'true'
 * value if all of the following conditions are met:
 *
 * - The code is running in a thread, not at ISR.
 * - The thread's priority is in the preemptible range.
 * - The thread has not locked the scheduler.
 *
 * @note Can be called by ISRs.
 *
 * @return 0 if invoked by an ISR or by a cooperative thread.
 * @return Non-zero if invoked by a preemptible thread.
 */
__syscall int k_is_preempt_thread(void);

/**
 * @brief Test whether startup is in the before-main-task phase.
 *
 * This routine allows the caller to customize its actions, depending on
 * whether it being invoked before the kernel is fully active.
 *
 * @note Can be called by ISRs.
 *
 * @return true if invoked before post-kernel initialization
 * @return false if invoked during/after post-kernel initialization
 */
static inline bool k_is_pre_kernel(void)
{
	extern bool z_sys_post_kernel; /* in init.c */

	return !z_sys_post_kernel;
}

/**
 * @}
 */

/**
 * @addtogroup thread_apis
 * @{
 */

/**
 * @brief Lock the scheduler.
 *
 * This routine prevents the current thread from being preempted by another
 * thread by instructing the scheduler to treat it as a cooperative thread.
 * If the thread subsequently performs an operation that makes it unready,
 * it will be context switched out in the normal manner. When the thread
 * again becomes the current thread, its non-preemptible status is maintained.
 *
 * This routine can be called recursively.
 *
 * @note k_sched_lock() and k_sched_unlock() should normally be used
 * when the operation being performed can be safely interrupted by ISRs.
 * However, if the amount of processing involved is very small, better
 * performance may be obtained by using irq_lock() and irq_unlock().
 *
 * @return N/A
 */
extern void k_sched_lock(void);

/**
 * @brief Unlock the scheduler.
 *
 * This routine reverses the effect of a previous call to k_sched_lock().
 * A thread must call the routine once for each time it called k_sched_lock()
 * before the thread becomes preemptible.
 *
 * @return N/A
 */
extern void k_sched_unlock(void);

/**
 * @brief Set current thread's custom data.
 *
 * This routine sets the custom data for the current thread to @ value.
 *
 * Custom data is not used by the kernel itself, and is freely available
 * for a thread to use as it sees fit. It can be used as a framework
 * upon which to build thread-local storage.
 *
 * @param value New custom data value.
 *
 * @return N/A
 *
 */
__syscall void k_thread_custom_data_set(void *value);

/**
 * @brief Get current thread's custom data.
 *
 * This routine returns the custom data for the current thread.
 *
 * @return Current custom data value.
 */
__syscall void *k_thread_custom_data_get(void);

/**
 * @brief Set current thread name
 *
 * Set the name of the thread to be used when @option{CONFIG_THREAD_MONITOR}
 * is enabled for tracing and debugging.
 *
 * @param thread_id Thread to set name, or NULL to set the current thread
 * @param value Name string
 * @retval 0 on success
 * @retval -EFAULT Memory access error with supplied string
 * @retval -ENOSYS Thread name configuration option not enabled
 * @retval -EINVAL Thread name too long
 */
__syscall int k_thread_name_set(k_tid_t thread_id, const char *value);

/**
 * @brief Get thread name
 *
 * Get the name of a thread
 *
 * @param thread_id Thread ID
 * @retval Thread name, or NULL if configuration not enabled
 */
const char *k_thread_name_get(k_tid_t thread_id);

/**
 * @brief Copy the thread name into a supplied buffer
 *
 * @param thread_id Thread to obtain name information
 * @param buf Destination buffer
 * @param size Destination buffer size
 * @retval -ENOSPC Destination buffer too small
 * @retval -EFAULT Memory access error
 * @retval -ENOSYS Thread name feature not enabled
 * @retval 0 Success
 */
__syscall int k_thread_name_copy(k_tid_t thread_id, char *buf,
				 size_t size);

/**
 * @brief Get thread state string
 *
 * Get the human friendly thread state string
 *
 * @param thread_id Thread ID
 * @retval Thread state string, empty if no state flag is set
 */
const char *k_thread_state_str(k_tid_t thread_id);

/**
 * @}
 */

/**
 * @addtogroup clock_apis
 * @{
 */

/**
 * @brief Generate null timeout delay.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * not to wait if the requested operation cannot be performed immediately.
 *
 * @return Timeout delay value.
 */
#define K_NO_WAIT Z_TIMEOUT_NO_WAIT

/**
 * @brief Generate timeout delay from nanoseconds.
 *
 * This macro generates a timeout delay that instructs a kernel API to
 * wait up to @a t nanoseconds to perform the requested operation.
 * Note that timer precision is limited to the tick rate, not the
 * requested value.
 *
 * @param t Duration in nanoseconds.
 *
 * @return Timeout delay value.
 */
#define K_NSEC(t)     Z_TIMEOUT_NS(t)

/**
 * @brief Generate timeout delay from microseconds.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a t microseconds to perform the requested operation.
 * Note that timer precision is limited to the tick rate, not the
 * requested value.
 *
 * @param t Duration in microseconds.
 *
 * @return Timeout delay value.
 */
#define K_USEC(t)     Z_TIMEOUT_US(t)

/**
 * @brief Generate timeout delay from cycles.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a t cycles to perform the requested operation.
 *
 * @param t Duration in cycles.
 *
 * @return Timeout delay value.
 */
#define K_CYC(t)     Z_TIMEOUT_CYC(t)

/**
 * @brief Generate timeout delay from system ticks.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a t ticks to perform the requested operation.
 *
 * @param t Duration in system ticks.
 *
 * @return Timeout delay value.
 */
#define K_TICKS(t)     Z_TIMEOUT_TICKS(t)

/**
 * @brief Generate timeout delay from milliseconds.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a ms milliseconds to perform the requested operation.
 *
 * @param ms Duration in milliseconds.
 *
 * @return Timeout delay value.
 */
#define K_MSEC(ms)     Z_TIMEOUT_MS(ms)

/**
 * @brief Generate timeout delay from seconds.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a s seconds to perform the requested operation.
 *
 * @param s Duration in seconds.
 *
 * @return Timeout delay value.
 */
#define K_SECONDS(s)   K_MSEC((s) * MSEC_PER_SEC)

/**
 * @brief Generate timeout delay from minutes.

 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a m minutes to perform the requested operation.
 *
 * @param m Duration in minutes.
 *
 * @return Timeout delay value.
 */
#define K_MINUTES(m)   K_SECONDS((m) * 60)

/**
 * @brief Generate timeout delay from hours.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait up to @a h hours to perform the requested operation.
 *
 * @param h Duration in hours.
 *
 * @return Timeout delay value.
 */
#define K_HOURS(h)     K_MINUTES((h) * 60)

/**
 * @brief Generate infinite timeout delay.
 *
 * This macro generates a timeout delay that instructs a kernel API
 * to wait as long as necessary to perform the requested operation.
 *
 * @return Timeout delay value.
 */
#define K_FOREVER Z_FOREVER

#ifdef CONFIG_TIMEOUT_64BIT

/**
 * @brief Generates an absolute/uptime timeout value from system ticks
 *
 * This macro generates a timeout delay that represents an expiration
 * at the absolute uptime value specified, in system ticks.  That is, the
 * timeout will expire immediately after the system uptime reaches the
 * specified tick count.
 *
 * @param t Tick uptime value
 * @return Timeout delay value
 */
#define K_TIMEOUT_ABS_TICKS(t) \
	Z_TIMEOUT_TICKS(Z_TICK_ABS((k_ticks_t)MAX(t, 0)))

/**
 * @brief Generates an absolute/uptime timeout value from milliseconds
 *
 * This macro generates a timeout delay that represents an expiration
 * at the absolute uptime value specified, in milliseconds.  That is,
 * the timeout will expire immediately after the system uptime reaches
 * the specified tick count.
 *
 * @param t Millisecond uptime value
 * @return Timeout delay value
 */
#define K_TIMEOUT_ABS_MS(t) K_TIMEOUT_ABS_TICKS(k_ms_to_ticks_ceil64(t))

/**
 * @brief Generates an absolute/uptime timeout value from microseconds
 *
 * This macro generates a timeout delay that represents an expiration
 * at the absolute uptime value specified, in microseconds.  That is,
 * the timeout will expire immediately after the system uptime reaches
 * the specified time.  Note that timer precision is limited by the
 * system tick rate and not the requested timeout value.
 *
 * @param t Microsecond uptime value
 * @return Timeout delay value
 */
#define K_TIMEOUT_ABS_US(t) K_TIMEOUT_ABS_TICKS(k_us_to_ticks_ceil64(t))

/**
 * @brief Generates an absolute/uptime timeout value from nanoseconds
 *
 * This macro generates a timeout delay that represents an expiration
 * at the absolute uptime value specified, in nanoseconds.  That is,
 * the timeout will expire immediately after the system uptime reaches
 * the specified time.  Note that timer precision is limited by the
 * system tick rate and not the requested timeout value.
 *
 * @param t Nanosecond uptime value
 * @return Timeout delay value
 */
#define K_TIMEOUT_ABS_NS(t) K_TIMEOUT_ABS_TICKS(k_ns_to_ticks_ceil64(t))

/**
 * @brief Generates an absolute/uptime timeout value from system cycles
 *
 * This macro generates a timeout delay that represents an expiration
 * at the absolute uptime value specified, in cycles.  That is, the
 * timeout will expire immediately after the system uptime reaches the
 * specified time.  Note that timer precision is limited by the system
 * tick rate and not the requested timeout value.
 *
 * @param t Cycle uptime value
 * @return Timeout delay value
 */
#define K_TIMEOUT_ABS_CYC(t) K_TIMEOUT_ABS_TICKS(k_cyc_to_ticks_ceil64(t))

#endif

/**
 * @}
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_timer {
	/*
	 * _timeout structure must be first here if we want to use
	 * dynamic timer allocation. timeout.node is used in the double-linked
	 * list of free timers
	 */
	struct _timeout timeout;

	/* wait queue for the (single) thread waiting on this timer */
	_wait_q_t wait_q;

	/* runs in ISR context */
	void (*expiry_fn)(struct k_timer *timer);

	/* runs in the context of the thread that calls k_timer_stop() */
	void (*stop_fn)(struct k_timer *timer);

	/* timer period */
	k_timeout_t period;

	/* timer status */
	uint32_t status;

	/* user-specific data, also used to support legacy features */
	void *user_data;

	_OBJECT_TRACING_NEXT_PTR(k_timer)
	_OBJECT_TRACING_LINKED_FLAG
};

#define Z_TIMER_INITIALIZER(obj, expiry, stop) \
	{ \
	.timeout = { \
		.node = {},\
		.fn = z_timer_expiration_handler, \
		.dticks = 0, \
	}, \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q), \
	.expiry_fn = expiry, \
	.stop_fn = stop, \
	.status = 0, \
	.user_data = 0, \
	_OBJECT_TRACING_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup timer_apis Timer APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @typedef k_timer_expiry_t
 * @brief Timer expiry function type.
 *
 * A timer's expiry function is executed by the system clock interrupt handler
 * each time the timer expires. The expiry function is optional, and is only
 * invoked if the timer has been initialized with one.
 *
 * @param timer     Address of timer.
 *
 * @return N/A
 */
typedef void (*k_timer_expiry_t)(struct k_timer *timer);

/**
 * @typedef k_timer_stop_t
 * @brief Timer stop function type.
 *
 * A timer's stop function is executed if the timer is stopped prematurely.
 * The function runs in the context of call that stops the timer.  As
 * k_timer_stop() can be invoked from an ISR, the stop function must be
 * callable from interrupt context (isr-ok).
 *
 * The stop function is optional, and is only invoked if the timer has been
 * initialized with one.
 *
 * @param timer     Address of timer.
 *
 * @return N/A
 */
typedef void (*k_timer_stop_t)(struct k_timer *timer);

/**
 * @brief Statically define and initialize a timer.
 *
 * The timer can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_timer <name>; @endcode
 *
 * @param name Name of the timer variable.
 * @param expiry_fn Function to invoke each time the timer expires.
 * @param stop_fn   Function to invoke if the timer is stopped while running.
 */
#define K_TIMER_DEFINE(name, expiry_fn, stop_fn) \
	Z_STRUCT_SECTION_ITERABLE(k_timer, name) = \
		Z_TIMER_INITIALIZER(name, expiry_fn, stop_fn)

/**
 * @brief Initialize a timer.
 *
 * This routine initializes a timer, prior to its first use.
 *
 * @param timer     Address of timer.
 * @param expiry_fn Function to invoke each time the timer expires.
 * @param stop_fn   Function to invoke if the timer is stopped while running.
 *
 * @return N/A
 */
extern void k_timer_init(struct k_timer *timer,
			 k_timer_expiry_t expiry_fn,
			 k_timer_stop_t stop_fn);

/**
 * @brief Start a timer.
 *
 * This routine starts a timer, and resets its status to zero. The timer
 * begins counting down using the specified duration and period values.
 *
 * Attempting to start a timer that is already running is permitted.
 * The timer's status is reset to zero and the timer begins counting down
 * using the new duration and period values.
 *
 * @param timer     Address of timer.
 * @param duration  Initial timer duration.
 * @param period    Timer period.
 *
 * @return N/A
 */
__syscall void k_timer_start(struct k_timer *timer,
			     k_timeout_t duration, k_timeout_t period);

/**
 * @brief Stop a timer.
 *
 * This routine stops a running timer prematurely. The timer's stop function,
 * if one exists, is invoked by the caller.
 *
 * Attempting to stop a timer that is not running is permitted, but has no
 * effect on the timer.
 *
 * @note Can be called by ISRs.  The stop handler has to be callable from ISRs
 * if @a k_timer_stop is to be called from ISRs.
 *
 * @param timer     Address of timer.
 *
 * @return N/A
 */
__syscall void k_timer_stop(struct k_timer *timer);

/**
 * @brief Read timer status.
 *
 * This routine reads the timer's status, which indicates the number of times
 * it has expired since its status was last read.
 *
 * Calling this routine resets the timer's status to zero.
 *
 * @param timer     Address of timer.
 *
 * @return Timer status.
 */
__syscall uint32_t k_timer_status_get(struct k_timer *timer);

/**
 * @brief Synchronize thread to timer expiration.
 *
 * This routine blocks the calling thread until the timer's status is non-zero
 * (indicating that it has expired at least once since it was last examined)
 * or the timer is stopped. If the timer status is already non-zero,
 * or the timer is already stopped, the caller continues without waiting.
 *
 * Calling this routine resets the timer's status to zero.
 *
 * This routine must not be used by interrupt handlers, since they are not
 * allowed to block.
 *
 * @param timer     Address of timer.
 *
 * @return Timer status.
 */
__syscall uint32_t k_timer_status_sync(struct k_timer *timer);

#ifdef CONFIG_SYS_CLOCK_EXISTS

/**
 * @brief Get next expiration time of a timer, in system ticks
 *
 * This routine returns the future system uptime reached at the next
 * time of expiration of the timer, in units of system ticks.  If the
 * timer is not running, current system time is returned.
 *
 * @param timer The timer object
 * @return Uptime of expiration, in ticks
 */
__syscall k_ticks_t k_timer_expires_ticks(const struct k_timer *timer);

static inline k_ticks_t z_impl_k_timer_expires_ticks(
				       const struct k_timer *timer)
{
	return z_timeout_expires(&timer->timeout);
}

/**
 * @brief Get time remaining before a timer next expires, in system ticks
 *
 * This routine computes the time remaining before a running timer
 * next expires, in units of system ticks.  If the timer is not
 * running, it returns zero.
 */
__syscall k_ticks_t k_timer_remaining_ticks(const struct k_timer *timer);

static inline k_ticks_t z_impl_k_timer_remaining_ticks(
				       const struct k_timer *timer)
{
	return z_timeout_remaining(&timer->timeout);
}

/**
 * @brief Get time remaining before a timer next expires.
 *
 * This routine computes the (approximate) time remaining before a running
 * timer next expires. If the timer is not running, it returns zero.
 *
 * @param timer     Address of timer.
 *
 * @return Remaining time (in milliseconds).
 */
static inline uint32_t k_timer_remaining_get(struct k_timer *timer)
{
	return k_ticks_to_ms_floor32(k_timer_remaining_ticks(timer));
}

#endif /* CONFIG_SYS_CLOCK_EXISTS */

/**
 * @brief Associate user-specific data with a timer.
 *
 * This routine records the @a user_data with the @a timer, to be retrieved
 * later.
 *
 * It can be used e.g. in a timer handler shared across multiple subsystems to
 * retrieve data specific to the subsystem this timer is associated with.
 *
 * @param timer     Address of timer.
 * @param user_data User data to associate with the timer.
 *
 * @return N/A
 */
__syscall void k_timer_user_data_set(struct k_timer *timer, void *user_data);

/**
 * @internal
 */
static inline void z_impl_k_timer_user_data_set(struct k_timer *timer,
					       void *user_data)
{
	timer->user_data = user_data;
}

/**
 * @brief Retrieve the user-specific data from a timer.
 *
 * @param timer     Address of timer.
 *
 * @return The user data.
 */
__syscall void *k_timer_user_data_get(const struct k_timer *timer);

static inline void *z_impl_k_timer_user_data_get(const struct k_timer *timer)
{
	return timer->user_data;
}

/** @} */

/**
 * @addtogroup clock_apis
 * @{
 */

/**
 * @brief Get system uptime, in system ticks.
 *
 * This routine returns the elapsed time since the system booted, in
 * ticks (c.f. @option{CONFIG_SYS_CLOCK_TICKS_PER_SEC}), which is the
 * fundamental unit of resolution of kernel timekeeping.
 *
 * @return Current uptime in ticks.
 */
__syscall int64_t k_uptime_ticks(void);

/**
 * @brief Get system uptime.
 *
 * This routine returns the elapsed time since the system booted,
 * in milliseconds.
 *
 * @note
 *    While this function returns time in milliseconds, it does
 *    not mean it has millisecond resolution. The actual resolution depends on
 *    @option{CONFIG_SYS_CLOCK_TICKS_PER_SEC} config option.
 *
 * @return Current uptime in milliseconds.
 */
static inline int64_t k_uptime_get(void)
{
	return k_ticks_to_ms_floor64(k_uptime_ticks());
}

/**
 * @brief Get system uptime (32-bit version).
 *
 * This routine returns the lower 32 bits of the system uptime in
 * milliseconds.
 *
 * Because correct conversion requires full precision of the system
 * clock there is no benefit to using this over k_uptime_get() unless
 * you know the application will never run long enough for the system
 * clock to approach 2^32 ticks.  Calls to this function may involve
 * interrupt blocking and 64-bit math.
 *
 * @note
 *    While this function returns time in milliseconds, it does
 *    not mean it has millisecond resolution. The actual resolution depends on
 *    @option{CONFIG_SYS_CLOCK_TICKS_PER_SEC} config option
 *
 * @return The low 32 bits of the current uptime, in milliseconds.
 */
static inline uint32_t k_uptime_get_32(void)
{
	return (uint32_t)k_uptime_get();
}

/**
 * @brief Get elapsed time.
 *
 * This routine computes the elapsed time between the current system uptime
 * and an earlier reference time, in milliseconds.
 *
 * @param reftime Pointer to a reference time, which is updated to the current
 *                uptime upon return.
 *
 * @return Elapsed time.
 */
static inline int64_t k_uptime_delta(int64_t *reftime)
{
	int64_t uptime, delta;

	uptime = k_uptime_get();
	delta = uptime - *reftime;
	*reftime = uptime;

	return delta;
}

/**
 * @brief Read the hardware clock.
 *
 * This routine returns the current time, as measured by the system's hardware
 * clock.
 *
 * @return Current hardware clock up-counter (in cycles).
 */
static inline uint32_t k_cycle_get_32(void)
{
	return arch_k_cycle_get_32();
}

/**
 * @}
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_queue {
	sys_sflist_t data_q;
	struct k_spinlock lock;
	_wait_q_t wait_q;

	_POLL_EVENT;
	_OBJECT_TRACING_NEXT_PTR(k_queue)
	_OBJECT_TRACING_LINKED_FLAG
};

#define Z_QUEUE_INITIALIZER(obj) \
	{ \
	.data_q = SYS_SFLIST_STATIC_INIT(&obj.data_q), \
	.lock = { }, \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q),	\
	_POLL_EVENT_OBJ_INIT(obj)		\
	_OBJECT_TRACING_INIT \
	}

extern void *z_queue_node_peek(sys_sfnode_t *node, bool needs_free);

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup queue_apis Queue APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Initialize a queue.
 *
 * This routine initializes a queue object, prior to its first use.
 *
 * @param queue Address of the queue.
 *
 * @return N/A
 */
__syscall void k_queue_init(struct k_queue *queue);

/**
 * @brief Cancel waiting on a queue.
 *
 * This routine causes first thread pending on @a queue, if any, to
 * return from k_queue_get() call with NULL value (as if timeout expired).
 * If the queue is being waited on by k_poll(), it will return with
 * -EINTR and K_POLL_STATE_CANCELLED state (and per above, subsequent
 * k_queue_get() will return NULL).
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 *
 * @return N/A
 */
__syscall void k_queue_cancel_wait(struct k_queue *queue);

/**
 * @brief Append an element to the end of a queue.
 *
 * This routine appends a data item to @a queue. A queue data item must be
 * aligned on a word boundary, and the first word of the item is reserved
 * for the kernel's use.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param data Address of the data item.
 *
 * @return N/A
 */
extern void k_queue_append(struct k_queue *queue, void *data);

/**
 * @brief Append an element to a queue.
 *
 * This routine appends a data item to @a queue. There is an implicit memory
 * allocation to create an additional temporary bookkeeping data structure from
 * the calling thread's resource pool, which is automatically freed when the
 * item is removed. The data itself is not copied.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param data Address of the data item.
 *
 * @retval 0 on success
 * @retval -ENOMEM if there isn't sufficient RAM in the caller's resource pool
 */
__syscall int32_t k_queue_alloc_append(struct k_queue *queue, void *data);

/**
 * @brief Prepend an element to a queue.
 *
 * This routine prepends a data item to @a queue. A queue data item must be
 * aligned on a word boundary, and the first word of the item is reserved
 * for the kernel's use.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param data Address of the data item.
 *
 * @return N/A
 */
extern void k_queue_prepend(struct k_queue *queue, void *data);

/**
 * @brief Prepend an element to a queue.
 *
 * This routine prepends a data item to @a queue. There is an implicit memory
 * allocation to create an additional temporary bookkeeping data structure from
 * the calling thread's resource pool, which is automatically freed when the
 * item is removed. The data itself is not copied.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param data Address of the data item.
 *
 * @retval 0 on success
 * @retval -ENOMEM if there isn't sufficient RAM in the caller's resource pool
 */
__syscall int32_t k_queue_alloc_prepend(struct k_queue *queue, void *data);

/**
 * @brief Inserts an element to a queue.
 *
 * This routine inserts a data item to @a queue after previous item. A queue
 * data item must be aligned on a word boundary, and the first word of
 * the item is reserved for the kernel's use.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param prev Address of the previous data item.
 * @param data Address of the data item.
 *
 * @return N/A
 */
extern void k_queue_insert(struct k_queue *queue, void *prev, void *data);

/**
 * @brief Atomically append a list of elements to a queue.
 *
 * This routine adds a list of data items to @a queue in one operation.
 * The data items must be in a singly-linked list, with the first word
 * in each data item pointing to the next data item; the list must be
 * NULL-terminated.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param head Pointer to first node in singly-linked list.
 * @param tail Pointer to last node in singly-linked list.
 *
 * @retval 0 on success
 * @retval -EINVAL on invalid supplied data
 *
 */
extern int k_queue_append_list(struct k_queue *queue, void *head, void *tail);

/**
 * @brief Atomically add a list of elements to a queue.
 *
 * This routine adds a list of data items to @a queue in one operation.
 * The data items must be in a singly-linked list implemented using a
 * sys_slist_t object. Upon completion, the original list is empty.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 * @param list Pointer to sys_slist_t object.
 *
 * @retval 0 on success
 * @retval -EINVAL on invalid data
 */
extern int k_queue_merge_slist(struct k_queue *queue, sys_slist_t *list);

/**
 * @brief Get an element from a queue.
 *
 * This routine removes first data item from @a queue. The first word of the
 * data item is reserved for the kernel's use.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param queue Address of the queue.
 * @param timeout Non-negative waiting period to obtain a data item
 *                or one of the special values K_NO_WAIT and
 *                K_FOREVER.
 *
 * @return Address of the data item if successful; NULL if returned
 * without waiting, or waiting period timed out.
 */
__syscall void *k_queue_get(struct k_queue *queue, k_timeout_t timeout);

/**
 * @brief Remove an element from a queue.
 *
 * This routine removes data item from @a queue. The first word of the
 * data item is reserved for the kernel's use. Removing elements from k_queue
 * rely on sys_slist_find_and_remove which is not a constant time operation.
 *
 * @note Can be called by ISRs
 *
 * @param queue Address of the queue.
 * @param data Address of the data item.
 *
 * @return true if data item was removed
 */
static inline bool k_queue_remove(struct k_queue *queue, void *data)
{
	return sys_sflist_find_and_remove(&queue->data_q, (sys_sfnode_t *)data);
}

/**
 * @brief Append an element to a queue only if it's not present already.
 *
 * This routine appends data item to @a queue. The first word of the data
 * item is reserved for the kernel's use. Appending elements to k_queue
 * relies on sys_slist_is_node_in_list which is not a constant time operation.
 *
 * @note Can be called by ISRs
 *
 * @param queue Address of the queue.
 * @param data Address of the data item.
 *
 * @return true if data item was added, false if not
 */
static inline bool k_queue_unique_append(struct k_queue *queue, void *data)
{
	sys_sfnode_t *test;

	SYS_SFLIST_FOR_EACH_NODE(&queue->data_q, test) {
		if (test == (sys_sfnode_t *) data) {
			return false;
		}
	}

	k_queue_append(queue, data);
	return true;
}

/**
 * @brief Query a queue to see if it has data available.
 *
 * Note that the data might be already gone by the time this function returns
 * if other threads are also trying to read from the queue.
 *
 * @note Can be called by ISRs.
 *
 * @param queue Address of the queue.
 *
 * @return Non-zero if the queue is empty.
 * @return 0 if data is available.
 */
__syscall int k_queue_is_empty(struct k_queue *queue);

static inline int z_impl_k_queue_is_empty(struct k_queue *queue)
{
	return (int)sys_sflist_is_empty(&queue->data_q);
}

/**
 * @brief Peek element at the head of queue.
 *
 * Return element from the head of queue without removing it.
 *
 * @param queue Address of the queue.
 *
 * @return Head element, or NULL if queue is empty.
 */
__syscall void *k_queue_peek_head(struct k_queue *queue);

static inline void *z_impl_k_queue_peek_head(struct k_queue *queue)
{
	return z_queue_node_peek(sys_sflist_peek_head(&queue->data_q), false);
}

/**
 * @brief Peek element at the tail of queue.
 *
 * Return element from the tail of queue without removing it.
 *
 * @param queue Address of the queue.
 *
 * @return Tail element, or NULL if queue is empty.
 */
__syscall void *k_queue_peek_tail(struct k_queue *queue);

static inline void *z_impl_k_queue_peek_tail(struct k_queue *queue)
{
	return z_queue_node_peek(sys_sflist_peek_tail(&queue->data_q), false);
}

/**
 * @brief Statically define and initialize a queue.
 *
 * The queue can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_queue <name>; @endcode
 *
 * @param name Name of the queue.
 */
#define K_QUEUE_DEFINE(name) \
	Z_STRUCT_SECTION_ITERABLE(k_queue, name) = \
		Z_QUEUE_INITIALIZER(name)

/** @} */

#ifdef CONFIG_USERSPACE
/**
 * @brief futex structure
 *
 * A k_futex is a lightweight mutual exclusion primitive designed
 * to minimize kernel involvement. Uncontended operation relies
 * only on atomic access to shared memory. k_futex are tracked as
 * kernel objects and can live in user memory so any access bypass
 * the kernel object permission management mechanism.
 */
struct k_futex {
	atomic_t val;
};

/**
 * @brief futex kernel data structure
 *
 * z_futex_data are the helper data structure for k_futex to complete
 * futex contended operation on kernel side, structure z_futex_data
 * of every futex object is invisible in user mode.
 */
struct z_futex_data {
	_wait_q_t wait_q;
	struct k_spinlock lock;
};

#define Z_FUTEX_DATA_INITIALIZER(obj) \
	{ \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q) \
	}

/**
 * @defgroup futex_apis FUTEX APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Pend the current thread on a futex
 *
 * Tests that the supplied futex contains the expected value, and if so,
 * goes to sleep until some other thread calls k_futex_wake() on it.
 *
 * @param futex Address of the futex.
 * @param expected Expected value of the futex, if it is different the caller
 *		   will not wait on it.
 * @param timeout Non-negative waiting period on the futex, or
 *		  one of the special values K_NO_WAIT or K_FOREVER.
 * @retval -EACCES Caller does not have read access to futex address.
 * @retval -EAGAIN If the futex value did not match the expected parameter.
 * @retval -EINVAL Futex parameter address not recognized by the kernel.
 * @retval -ETIMEDOUT Thread woke up due to timeout and not a futex wakeup.
 * @retval 0 if the caller went to sleep and was woken up. The caller
 *	     should check the futex's value on wakeup to determine if it needs
 *	     to block again.
 */
__syscall int k_futex_wait(struct k_futex *futex, int expected,
			   k_timeout_t timeout);

/**
 * @brief Wake one/all threads pending on a futex
 *
 * Wake up the highest priority thread pending on the supplied futex, or
 * wakeup all the threads pending on the supplied futex, and the behavior
 * depends on wake_all.
 *
 * @param futex Futex to wake up pending threads.
 * @param wake_all If true, wake up all pending threads; If false,
 *                 wakeup the highest priority thread.
 * @retval -EACCES Caller does not have access to the futex address.
 * @retval -EINVAL Futex parameter address not recognized by the kernel.
 * @retval Number of threads that were woken up.
 */
__syscall int k_futex_wake(struct k_futex *futex, bool wake_all);

/** @} */
#endif

struct k_fifo {
	struct k_queue _queue;
};

/**
 * @cond INTERNAL_HIDDEN
 */
#define Z_FIFO_INITIALIZER(obj) \
	{ \
	._queue = Z_QUEUE_INITIALIZER(obj._queue) \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup fifo_apis FIFO APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Initialize a FIFO queue.
 *
 * This routine initializes a FIFO queue, prior to its first use.
 *
 * @param fifo Address of the FIFO queue.
 *
 * @return N/A
 */
#define k_fifo_init(fifo) \
	k_queue_init(&(fifo)->_queue)

/**
 * @brief Cancel waiting on a FIFO queue.
 *
 * This routine causes first thread pending on @a fifo, if any, to
 * return from k_fifo_get() call with NULL value (as if timeout
 * expired).
 *
 * @note Can be called by ISRs.
 *
 * @param fifo Address of the FIFO queue.
 *
 * @return N/A
 */
#define k_fifo_cancel_wait(fifo) \
	k_queue_cancel_wait(&(fifo)->_queue)

/**
 * @brief Add an element to a FIFO queue.
 *
 * This routine adds a data item to @a fifo. A FIFO data item must be
 * aligned on a word boundary, and the first word of the item is reserved
 * for the kernel's use.
 *
 * @note Can be called by ISRs.
 *
 * @param fifo Address of the FIFO.
 * @param data Address of the data item.
 *
 * @return N/A
 */
#define k_fifo_put(fifo, data) \
	k_queue_append(&(fifo)->_queue, data)

/**
 * @brief Add an element to a FIFO queue.
 *
 * This routine adds a data item to @a fifo. There is an implicit memory
 * allocation to create an additional temporary bookkeeping data structure from
 * the calling thread's resource pool, which is automatically freed when the
 * item is removed. The data itself is not copied.
 *
 * @note Can be called by ISRs.
 *
 * @param fifo Address of the FIFO.
 * @param data Address of the data item.
 *
 * @retval 0 on success
 * @retval -ENOMEM if there isn't sufficient RAM in the caller's resource pool
 */
#define k_fifo_alloc_put(fifo, data) \
	k_queue_alloc_append(&(fifo)->_queue, data)

/**
 * @brief Atomically add a list of elements to a FIFO.
 *
 * This routine adds a list of data items to @a fifo in one operation.
 * The data items must be in a singly-linked list, with the first word of
 * each data item pointing to the next data item; the list must be
 * NULL-terminated.
 *
 * @note Can be called by ISRs.
 *
 * @param fifo Address of the FIFO queue.
 * @param head Pointer to first node in singly-linked list.
 * @param tail Pointer to last node in singly-linked list.
 *
 * @return N/A
 */
#define k_fifo_put_list(fifo, head, tail) \
	k_queue_append_list(&(fifo)->_queue, head, tail)

/**
 * @brief Atomically add a list of elements to a FIFO queue.
 *
 * This routine adds a list of data items to @a fifo in one operation.
 * The data items must be in a singly-linked list implemented using a
 * sys_slist_t object. Upon completion, the sys_slist_t object is invalid
 * and must be re-initialized via sys_slist_init().
 *
 * @note Can be called by ISRs.
 *
 * @param fifo Address of the FIFO queue.
 * @param list Pointer to sys_slist_t object.
 *
 * @return N/A
 */
#define k_fifo_put_slist(fifo, list) \
	k_queue_merge_slist(&(fifo)->_queue, list)

/**
 * @brief Get an element from a FIFO queue.
 *
 * This routine removes a data item from @a fifo in a "first in, first out"
 * manner. The first word of the data item is reserved for the kernel's use.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param fifo Address of the FIFO queue.
 * @param timeout Waiting period to obtain a data item,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @return Address of the data item if successful; NULL if returned
 * without waiting, or waiting period timed out.
 */
#define k_fifo_get(fifo, timeout) \
	k_queue_get(&(fifo)->_queue, timeout)

/**
 * @brief Query a FIFO queue to see if it has data available.
 *
 * Note that the data might be already gone by the time this function returns
 * if other threads is also trying to read from the FIFO.
 *
 * @note Can be called by ISRs.
 *
 * @param fifo Address of the FIFO queue.
 *
 * @return Non-zero if the FIFO queue is empty.
 * @return 0 if data is available.
 */
#define k_fifo_is_empty(fifo) \
	k_queue_is_empty(&(fifo)->_queue)

/**
 * @brief Peek element at the head of a FIFO queue.
 *
 * Return element from the head of FIFO queue without removing it. A usecase
 * for this is if elements of the FIFO object are themselves containers. Then
 * on each iteration of processing, a head container will be peeked,
 * and some data processed out of it, and only if the container is empty,
 * it will be completely remove from the FIFO queue.
 *
 * @param fifo Address of the FIFO queue.
 *
 * @return Head element, or NULL if the FIFO queue is empty.
 */
#define k_fifo_peek_head(fifo) \
	k_queue_peek_head(&(fifo)->_queue)

/**
 * @brief Peek element at the tail of FIFO queue.
 *
 * Return element from the tail of FIFO queue (without removing it). A usecase
 * for this is if elements of the FIFO queue are themselves containers. Then
 * it may be useful to add more data to the last container in a FIFO queue.
 *
 * @param fifo Address of the FIFO queue.
 *
 * @return Tail element, or NULL if a FIFO queue is empty.
 */
#define k_fifo_peek_tail(fifo) \
	k_queue_peek_tail(&(fifo)->_queue)

/**
 * @brief Statically define and initialize a FIFO queue.
 *
 * The FIFO queue can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_fifo <name>; @endcode
 *
 * @param name Name of the FIFO queue.
 */
#define K_FIFO_DEFINE(name) \
	Z_STRUCT_SECTION_ITERABLE_ALTERNATE(k_queue, k_fifo, name) = \
		Z_FIFO_INITIALIZER(name)

/** @} */

struct k_lifo {
	struct k_queue _queue;
};

/**
 * @cond INTERNAL_HIDDEN
 */

#define Z_LIFO_INITIALIZER(obj) \
	{ \
	._queue = Z_QUEUE_INITIALIZER(obj._queue) \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup lifo_apis LIFO APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Initialize a LIFO queue.
 *
 * This routine initializes a LIFO queue object, prior to its first use.
 *
 * @param lifo Address of the LIFO queue.
 *
 * @return N/A
 */
#define k_lifo_init(lifo) \
	k_queue_init(&(lifo)->_queue)

/**
 * @brief Add an element to a LIFO queue.
 *
 * This routine adds a data item to @a lifo. A LIFO queue data item must be
 * aligned on a word boundary, and the first word of the item is
 * reserved for the kernel's use.
 *
 * @note Can be called by ISRs.
 *
 * @param lifo Address of the LIFO queue.
 * @param data Address of the data item.
 *
 * @return N/A
 */
#define k_lifo_put(lifo, data) \
	k_queue_prepend(&(lifo)->_queue, data)

/**
 * @brief Add an element to a LIFO queue.
 *
 * This routine adds a data item to @a lifo. There is an implicit memory
 * allocation to create an additional temporary bookkeeping data structure from
 * the calling thread's resource pool, which is automatically freed when the
 * item is removed. The data itself is not copied.
 *
 * @note Can be called by ISRs.
 *
 * @param lifo Address of the LIFO.
 * @param data Address of the data item.
 *
 * @retval 0 on success
 * @retval -ENOMEM if there isn't sufficient RAM in the caller's resource pool
 */
#define k_lifo_alloc_put(lifo, data) \
	k_queue_alloc_prepend(&(lifo)->_queue, data)

/**
 * @brief Get an element from a LIFO queue.
 *
 * This routine removes a data item from @a LIFO in a "last in, first out"
 * manner. The first word of the data item is reserved for the kernel's use.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param lifo Address of the LIFO queue.
 * @param timeout Waiting period to obtain a data item,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @return Address of the data item if successful; NULL if returned
 * without waiting, or waiting period timed out.
 */
#define k_lifo_get(lifo, timeout) \
	k_queue_get(&(lifo)->_queue, timeout)

/**
 * @brief Statically define and initialize a LIFO queue.
 *
 * The LIFO queue can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_lifo <name>; @endcode
 *
 * @param name Name of the fifo.
 */
#define K_LIFO_DEFINE(name) \
	Z_STRUCT_SECTION_ITERABLE_ALTERNATE(k_queue, k_lifo, name) = \
		Z_LIFO_INITIALIZER(name)

/** @} */

/**
 * @cond INTERNAL_HIDDEN
 */
#define K_STACK_FLAG_ALLOC	((uint8_t)1)	/* Buffer was allocated */

typedef uintptr_t stack_data_t;

struct k_stack {
	_wait_q_t wait_q;
	struct k_spinlock lock;
	stack_data_t *base, *next, *top;

	_OBJECT_TRACING_NEXT_PTR(k_stack)
	_OBJECT_TRACING_LINKED_FLAG
	uint8_t flags;
};

#define Z_STACK_INITIALIZER(obj, stack_buffer, stack_num_entries) \
	{ \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q),	\
	.base = stack_buffer, \
	.next = stack_buffer, \
	.top = stack_buffer + stack_num_entries, \
	_OBJECT_TRACING_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup stack_apis Stack APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Initialize a stack.
 *
 * This routine initializes a stack object, prior to its first use.
 *
 * @param stack Address of the stack.
 * @param buffer Address of array used to hold stacked values.
 * @param num_entries Maximum number of values that can be stacked.
 *
 * @return N/A
 */
void k_stack_init(struct k_stack *stack,
		  stack_data_t *buffer, uint32_t num_entries);


/**
 * @brief Initialize a stack.
 *
 * This routine initializes a stack object, prior to its first use. Internal
 * buffers will be allocated from the calling thread's resource pool.
 * This memory will be released if k_stack_cleanup() is called, or
 * userspace is enabled and the stack object loses all references to it.
 *
 * @param stack Address of the stack.
 * @param num_entries Maximum number of values that can be stacked.
 *
 * @return -ENOMEM if memory couldn't be allocated
 */

__syscall int32_t k_stack_alloc_init(struct k_stack *stack,
				   uint32_t num_entries);

/**
 * @brief Release a stack's allocated buffer
 *
 * If a stack object was given a dynamically allocated buffer via
 * k_stack_alloc_init(), this will free it. This function does nothing
 * if the buffer wasn't dynamically allocated.
 *
 * @param stack Address of the stack.
 * @retval 0 on success
 * @retval -EAGAIN when object is still in use
 */
int k_stack_cleanup(struct k_stack *stack);

/**
 * @brief Push an element onto a stack.
 *
 * This routine adds a stack_data_t value @a data to @a stack.
 *
 * @note Can be called by ISRs.
 *
 * @param stack Address of the stack.
 * @param data Value to push onto the stack.
 *
 * @retval 0 on success
 * @retval -ENOMEM if stack is full
 */
__syscall int k_stack_push(struct k_stack *stack, stack_data_t data);

/**
 * @brief Pop an element from a stack.
 *
 * This routine removes a stack_data_t value from @a stack in a "last in,
 * first out" manner and stores the value in @a data.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param stack Address of the stack.
 * @param data Address of area to hold the value popped from the stack.
 * @param timeout Waiting period to obtain a value,
 *                or one of the special values K_NO_WAIT and
 *                K_FOREVER.
 *
 * @retval 0 Element popped from stack.
 * @retval -EBUSY Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
__syscall int k_stack_pop(struct k_stack *stack, stack_data_t *data,
			  k_timeout_t timeout);

/**
 * @brief Statically define and initialize a stack
 *
 * The stack can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_stack <name>; @endcode
 *
 * @param name Name of the stack.
 * @param stack_num_entries Maximum number of values that can be stacked.
 */
#define K_STACK_DEFINE(name, stack_num_entries)                \
	stack_data_t __noinit                                  \
		_k_stack_buf_##name[stack_num_entries];        \
	Z_STRUCT_SECTION_ITERABLE(k_stack, name) = \
		Z_STACK_INITIALIZER(name, _k_stack_buf_##name, \
				    stack_num_entries)

/** @} */

struct k_work;

/**
 * @addtogroup thread_apis
 * @{
 */

/**
 * @typedef k_work_handler_t
 * @brief Work item handler function type.
 *
 * A work item's handler function is executed by a workqueue's thread
 * when the work item is processed by the workqueue.
 *
 * @param work Address of the work item.
 *
 * @return N/A
 */
typedef void (*k_work_handler_t)(struct k_work *work);

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_work_q {
	struct k_queue queue;
	struct k_thread thread;
};

enum {
	K_WORK_STATE_PENDING,	/* Work item pending state */
};

struct k_work {
	void *_reserved;		/* Used by k_queue implementation. */
	k_work_handler_t handler;
	atomic_t flags[1];
};

struct k_delayed_work {
	struct k_work work;
	struct _timeout timeout;
	struct k_work_q *work_q;
};

struct k_work_poll {
	struct k_work work;
	struct k_work_q *workq;
	struct z_poller poller;
	struct k_poll_event *events;
	int num_events;
	k_work_handler_t real_handler;
	struct _timeout timeout;
	int poll_result;
};

extern struct k_work_q k_sys_work_q;

/**
 * INTERNAL_HIDDEN @endcond
 */

#define Z_WORK_INITIALIZER(work_handler) \
	{ \
	._reserved = NULL, \
	.handler = work_handler, \
	.flags = { 0 } \
	}

/**
 * @brief Initialize a statically-defined work item.
 *
 * This macro can be used to initialize a statically-defined workqueue work
 * item, prior to its first use. For example,
 *
 * @code static K_WORK_DEFINE(<work>, <work_handler>); @endcode
 *
 * @param work Symbol name for work item object
 * @param work_handler Function to invoke each time work item is processed.
 */
#define K_WORK_DEFINE(work, work_handler) \
	struct k_work work = Z_WORK_INITIALIZER(work_handler)

/**
 * @brief Initialize a work item.
 *
 * This routine initializes a workqueue work item, prior to its first use.
 *
 * @param work Address of work item.
 * @param handler Function to invoke each time work item is processed.
 *
 * @return N/A
 */
static inline void k_work_init(struct k_work *work, k_work_handler_t handler)
{
	*work = (struct k_work)Z_WORK_INITIALIZER(handler);
}

/**
 * @brief Submit a work item.
 *
 * This routine submits work item @p work to be processed by workqueue @p
 * work_q. If the work item is already pending in @p work_q or any other
 * workqueue as a result of an earlier submission, this routine has no
 * effect on the work item. If the work item has already been processed, or
 * is currently being processed, its work is considered complete and the
 * work item can be resubmitted.
 *
 * @warning
 * A submitted work item must not be modified until it has been processed
 * by the workqueue.
 *
 * @note Can be called by ISRs.
 *
 * @param work_q Address of workqueue.
 * @param work Address of work item.
 *
 * @return N/A
 */
static inline void k_work_submit_to_queue(struct k_work_q *work_q,
					  struct k_work *work)
{
	if (!atomic_test_and_set_bit(work->flags, K_WORK_STATE_PENDING)) {
		k_queue_append(&work_q->queue, work);
	}
}

/**
 * @brief Submit a work item to a user mode workqueue
 *
 * Submits a work item to a workqueue that runs in user mode. A temporary
 * memory allocation is made from the caller's resource pool which is freed
 * once the worker thread consumes the k_work item. The workqueue
 * thread must have memory access to the k_work item being submitted. The caller
 * must have permission granted on the work_q parameter's queue object.
 *
 * Otherwise this works the same as k_work_submit_to_queue().
 *
 * @note Can be called by ISRs.
 *
 * @param work_q Address of workqueue.
 * @param work Address of work item.
 *
 * @retval -EBUSY if the work item was already in some workqueue
 * @retval -ENOMEM if no memory for thread resource pool allocation
 * @retval 0 Success
 */
static inline int k_work_submit_to_user_queue(struct k_work_q *work_q,
					      struct k_work *work)
{
	int ret = -EBUSY;

	if (!atomic_test_and_set_bit(work->flags, K_WORK_STATE_PENDING)) {
		ret = k_queue_alloc_append(&work_q->queue, work);

		/* Couldn't insert into the queue. Clear the pending bit
		 * so the work item can be submitted again
		 */
		if (ret != 0) {
			atomic_clear_bit(work->flags, K_WORK_STATE_PENDING);
		}
	}

	return ret;
}

/**
 * @brief Check if a work item is pending.
 *
 * This routine indicates if work item @a work is pending in a workqueue's
 * queue.
 *
 * @note Checking if the work is pending gives no guarantee that the
 *       work will still be pending when this information is used. It is up to
 *       the caller to make sure that this information is used in a safe manner.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of work item.
 *
 * @return true if work item is pending, or false if it is not pending.
 */
static inline bool k_work_pending(struct k_work *work)
{
	return atomic_test_bit(work->flags, K_WORK_STATE_PENDING);
}

/**
 * @brief  Check if a delayed work item is pending.
 *
 * This routine indicates if the work item @a work is pending in a workqueue's
 * queue or waiting for the delay timeout.
 *
 * @note Checking if the delayed work is pending gives no guarantee that the
 *       work will still be pending when this information is used. It is up to
 *       the caller to make sure that this information is used in a safe manner.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of delayed work item.
 *
 * @return true if work item is waiting for the delay to expire or pending on a
 *         work queue, or false if it is not pending.
 */
bool k_delayed_work_pending(struct k_delayed_work *work);

/**
 * @brief Start a workqueue.
 *
 * This routine starts workqueue @a work_q. The workqueue spawns its work
 * processing thread, which runs forever.
 *
 * @param work_q Address of workqueue.
 * @param stack Pointer to work queue thread's stack space, as defined by
 *		K_THREAD_STACK_DEFINE()
 * @param stack_size Size of the work queue thread's stack (in bytes), which
 *		should either be the same constant passed to
 *		K_THREAD_STACK_DEFINE() or the value of K_THREAD_STACK_SIZEOF().
 * @param prio Priority of the work queue's thread.
 *
 * @return N/A
 */
extern void k_work_q_start(struct k_work_q *work_q,
			   k_thread_stack_t *stack,
			   size_t stack_size, int prio);

/**
 * @brief Start a workqueue in user mode
 *
 * This works identically to k_work_q_start() except it is callable from user
 * mode, and the worker thread created will run in user mode.
 * The caller must have permissions granted on both the work_q parameter's
 * thread and queue objects, and the same restrictions on priority apply as
 * k_thread_create().
 *
 * @param work_q Address of workqueue.
 * @param stack Pointer to work queue thread's stack space, as defined by
 *		K_THREAD_STACK_DEFINE()
 * @param stack_size Size of the work queue thread's stack (in bytes), which
 *		should either be the same constant passed to
 *		K_THREAD_STACK_DEFINE() or the value of K_THREAD_STACK_SIZEOF().
 * @param prio Priority of the work queue's thread.
 *
 * @return N/A
 */
extern void k_work_q_user_start(struct k_work_q *work_q,
				k_thread_stack_t *stack,
				size_t stack_size, int prio);

#define Z_DELAYED_WORK_INITIALIZER(work_handler) \
	{ \
		.work = Z_WORK_INITIALIZER(work_handler), \
		.timeout = { \
			.node = {},\
			.fn = NULL, \
			.dticks = 0, \
		}, \
		.work_q = NULL, \
	}

/**
 * @brief Initialize a statically-defined delayed work item.
 *
 * This macro can be used to initialize a statically-defined workqueue
 * delayed work item, prior to its first use. For example,
 *
 * @code static K_DELAYED_WORK_DEFINE(<work>, <work_handler>); @endcode
 *
 * @param work Symbol name for delayed work item object
 * @param work_handler Function to invoke each time work item is processed.
 */
#define K_DELAYED_WORK_DEFINE(work, work_handler) \
	struct k_delayed_work work = Z_DELAYED_WORK_INITIALIZER(work_handler)

/**
 * @brief Initialize a delayed work item.
 *
 * This routine initializes a workqueue delayed work item, prior to
 * its first use.
 *
 * @param work Address of delayed work item.
 * @param handler Function to invoke each time work item is processed.
 *
 * @return N/A
 */
static inline void k_delayed_work_init(struct k_delayed_work *work,
				       k_work_handler_t handler)
{
	*work = (struct k_delayed_work)Z_DELAYED_WORK_INITIALIZER(handler);
}

/**
 * @brief Submit a delayed work item.
 *
 * This routine schedules work item @a work to be processed by workqueue
 * @a work_q after a delay of @a delay milliseconds. The routine initiates
 * an asynchronous countdown for the work item and then returns to the caller.
 * Only when the countdown completes is the work item actually submitted to
 * the workqueue and becomes pending.
 *
 * Submitting a previously submitted delayed work item that is still counting
 * down or is pending cancels the existing submission and restarts the
 * countdown using the new delay.  Note that this behavior is inherently
 * subject to race conditions with the pre-existing timeouts and work queue,
 * so care must be taken to synchronize such resubmissions externally.
 *
 * Attempts to submit a work item to a queue after it has been submitted to a
 * different queue will fail with @c -EALREADY until k_delayed_work_cancel()
 * is successfully invoked on the work item to clear its internal state.
 *
 * @warning
 * A delayed work item must not be modified until it has been processed
 * by the workqueue.
 *
 * @note Can be called by ISRs.
 *
 * @param work_q Address of workqueue.
 * @param work Address of delayed work item.
 * @param delay Delay before submitting the work item
 *
 * @retval 0 Work item countdown started.
 * @retval -EINVAL
 *    * if a previously submitted work item had to be cancelled and the
 *      cancellation failed; or
 *    * Work item is being processed or has completed its work.
 * @retval -EADDRINUSE Work item was submitted to a different workqueue.
 */
extern int k_delayed_work_submit_to_queue(struct k_work_q *work_q,
					  struct k_delayed_work *work,
					  k_timeout_t delay);

/**
 * @brief Cancel a delayed work item.
 *
 * This routine cancels the submission of delayed work item @a work.  Whether
 * the work item can be successfully cancelled depends on its state.
 *
 * @note Can be called by ISRs.
 *
 * @note When @c -EALREADY is returned the caller cannot distinguish whether
 * the work item handler is still being invoked by the work queue thread or
 * has completed.
 *
 * @param work Address of delayed work item.
 *
 * @retval 0
 *   * Work item countdown cancelled before the item was submitted to its
 *     queue; or
 *   * Work item was removed from its queue before it was processed.
 * @retval -EINVAL
 *   * Work item has never been submitted; or
 *   * Work item has been successfully cancelled; or
 *   * Timeout handler is in the process of submitting the work item to its
 *     queue; or
 *   * Work queue thread has removed the work item from the queue but has not
 *     called its handler.
 * @retval -EALREADY
 *   * Work queue thread has removed the work item from the queue and cleared
 *     its pending flag; or
 *   * Work queue thread is invoking the item handler; or
 *   * Work item handler has completed.
 */
extern int k_delayed_work_cancel(struct k_delayed_work *work);

/**
 * @brief Submit a work item to the system workqueue.
 *
 * This routine submits work item @a work to be processed by the system
 * workqueue. If the work item is already pending in the system workqueue or
 * any other workqueue as a result of an earlier submission, this routine
 * has no effect on the work item. If the work item has already been
 * processed, or is currently being processed, its work is considered
 * complete and the work item can be resubmitted.
 *
 * @warning
 * Work items submitted to the system workqueue should avoid using handlers
 * that block or yield since this may prevent the system workqueue from
 * processing other work items in a timely manner.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of work item.
 *
 * @return N/A
 */
static inline void k_work_submit(struct k_work *work)
{
	k_work_submit_to_queue(&k_sys_work_q, work);
}

/**
 * @brief Submit a delayed work item to the system workqueue.
 *
 * This routine schedules work item @a work to be processed by the system
 * workqueue after a delay of @a delay milliseconds. The routine initiates
 * an asynchronous countdown for the work item and then returns to the caller.
 * Only when the countdown completes is the work item actually submitted to
 * the workqueue and becomes pending.
 *
 * Submitting a previously submitted delayed work item that is still
 * counting down cancels the existing submission and restarts the countdown
 * using the new delay. If the work item is currently pending on the
 * workqueue's queue because the countdown has completed it is too late to
 * resubmit the item, and resubmission fails without impacting the work item.
 * If the work item has already been processed, or is currently being processed,
 * its work is considered complete and the work item can be resubmitted.
 *
 * Attempts to submit a work item to a queue after it has been submitted to a
 * different queue will fail with @c -EALREADY until k_delayed_work_cancel()
 * is invoked on the work item to clear its internal state.
 *
 * @warning
 * Work items submitted to the system workqueue should avoid using handlers
 * that block or yield since this may prevent the system workqueue from
 * processing other work items in a timely manner.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of delayed work item.
 * @param delay Delay before submitting the work item
 *
 * @retval 0 Work item countdown started.
 * @retval -EINVAL Work item is being processed or has completed its work.
 * @retval -EADDRINUSE Work item was submitted to a different workqueue.
 */
static inline int k_delayed_work_submit(struct k_delayed_work *work,
					k_timeout_t delay)
{
	return k_delayed_work_submit_to_queue(&k_sys_work_q, work, delay);
}

/**
 * @brief Get time when a delayed work will be scheduled
 *
 * This routine computes the system uptime when a delayed work gets
 * executed. If the delayed work is not waiting to be scheduled, it
 * returns current system time.
 *
 * @param work     Delayed work item.
 *
 * @return Uptime of execution (in ticks).
 */
static inline k_ticks_t k_delayed_work_expires_ticks(
				       const struct k_delayed_work *work)
{
	return z_timeout_expires(&work->timeout);
}

/**
 * @brief Get time remaining before a delayed work gets scheduled, in
 * system ticks
 *
 * This routine computes the time remaining before a delayed work gets
 * executed. If the delayed work is not waiting to be scheduled, it
 * returns zero.
 *
 * @param work     Delayed work item.
 *
 * @return Remaining time (in ticks).
 */
static inline k_ticks_t k_delayed_work_remaining_ticks(
				       const struct k_delayed_work *work)
{
	return z_timeout_remaining(&work->timeout);
}

/**
 * @brief Get time remaining before a delayed work gets scheduled.
 *
 * This routine computes the (approximate) time remaining before a
 * delayed work gets executed. If the delayed work is not waiting to be
 * scheduled, it returns zero.
 *
 * @param work     Delayed work item.
 *
 * @return Remaining time (in milliseconds).
 */
static inline int32_t k_delayed_work_remaining_get(const struct k_delayed_work *work)
{
	return k_ticks_to_ms_floor32(z_timeout_remaining(&work->timeout));
}

/**
 * @brief Initialize a triggered work item.
 *
 * This routine initializes a workqueue triggered work item, prior to
 * its first use.
 *
 * @param work Address of triggered work item.
 * @param handler Function to invoke each time work item is processed.
 *
 * @return N/A
 */
extern void k_work_poll_init(struct k_work_poll *work,
			     k_work_handler_t handler);

/**
 * @brief Submit a triggered work item.
 *
 * This routine schedules work item @a work to be processed by workqueue
 * @a work_q when one of the given @a events is signaled. The routine
 * initiates internal poller for the work item and then returns to the caller.
 * Only when one of the watched events happen the work item is actually
 * submitted to the workqueue and becomes pending.
 *
 * Submitting a previously submitted triggered work item that is still
 * waiting for the event cancels the existing submission and reschedules it
 * the using the new event list. Note that this behavior is inherently subject
 * to race conditions with the pre-existing triggered work item and work queue,
 * so care must be taken to synchronize such resubmissions externally.
 *
 * @note Can be called by ISRs.
 *
 * @warning
 * Provided array of events as well as a triggered work item must be placed
 * in persistent memory (valid until work handler execution or work
 * cancellation) and cannot be modified after submission.
 *
 * @param work_q Address of workqueue.
 * @param work Address of delayed work item.
 * @param events An array of events which trigger the work.
 * @param num_events The number of events in the array.
 * @param timeout Timeout after which the work will be scheduled
 *		  for execution even if not triggered.
 *
 *
 * @retval 0 Work item started watching for events.
 * @retval -EINVAL Work item is being processed or has completed its work.
 * @retval -EADDRINUSE Work item is pending on a different workqueue.
 */
extern int k_work_poll_submit_to_queue(struct k_work_q *work_q,
				       struct k_work_poll *work,
				       struct k_poll_event *events,
				       int num_events,
				       k_timeout_t timeout);

/**
 * @brief Submit a triggered work item to the system workqueue.
 *
 * This routine schedules work item @a work to be processed by system
 * workqueue when one of the given @a events is signaled. The routine
 * initiates internal poller for the work item and then returns to the caller.
 * Only when one of the watched events happen the work item is actually
 * submitted to the workqueue and becomes pending.
 *
 * Submitting a previously submitted triggered work item that is still
 * waiting for the event cancels the existing submission and reschedules it
 * the using the new event list. Note that this behavior is inherently subject
 * to race conditions with the pre-existing triggered work item and work queue,
 * so care must be taken to synchronize such resubmissions externally.
 *
 * @note Can be called by ISRs.
 *
 * @warning
 * Provided array of events as well as a triggered work item must not be
 * modified until the item has been processed by the workqueue.
 *
 * @param work Address of delayed work item.
 * @param events An array of events which trigger the work.
 * @param num_events The number of events in the array.
 * @param timeout Timeout after which the work will be scheduled
 *		  for execution even if not triggered.
 *
 * @retval 0 Work item started watching for events.
 * @retval -EINVAL Work item is being processed or has completed its work.
 * @retval -EADDRINUSE Work item is pending on a different workqueue.
 */
static inline int k_work_poll_submit(struct k_work_poll *work,
				     struct k_poll_event *events,
				     int num_events,
				     k_timeout_t timeout)
{
	return k_work_poll_submit_to_queue(&k_sys_work_q, work,
						events, num_events, timeout);
}

/**
 * @brief Cancel a triggered work item.
 *
 * This routine cancels the submission of triggered work item @a work.
 * A triggered work item can only be canceled if no event triggered work
 * submission.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of delayed work item.
 *
 * @retval 0 Work item canceled.
 * @retval -EINVAL Work item is being processed or has completed its work.
 */
extern int k_work_poll_cancel(struct k_work_poll *work);

/** @} */
/**
 * @defgroup mutex_apis Mutex APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * Mutex Structure
 * @ingroup mutex_apis
 */
struct k_mutex {
	/** Mutex wait queue */
	_wait_q_t wait_q;
	/** Mutex owner */
	struct k_thread *owner;

	/** Current lock count */
	uint32_t lock_count;

	/** Original thread priority */
	int owner_orig_prio;

	_OBJECT_TRACING_NEXT_PTR(k_mutex)
	_OBJECT_TRACING_LINKED_FLAG
};

/**
 * @cond INTERNAL_HIDDEN
 */
#define Z_MUTEX_INITIALIZER(obj) \
	{ \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q), \
	.owner = NULL, \
	.lock_count = 0, \
	.owner_orig_prio = K_LOWEST_THREAD_PRIO, \
	_OBJECT_TRACING_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @brief Statically define and initialize a mutex.
 *
 * The mutex can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_mutex <name>; @endcode
 *
 * @param name Name of the mutex.
 */
#define K_MUTEX_DEFINE(name) \
	Z_STRUCT_SECTION_ITERABLE(k_mutex, name) = \
		Z_MUTEX_INITIALIZER(name)

/**
 * @brief Initialize a mutex.
 *
 * This routine initializes a mutex object, prior to its first use.
 *
 * Upon completion, the mutex is available and does not have an owner.
 *
 * @param mutex Address of the mutex.
 *
 * @retval 0 Mutex object created
 *
 */
__syscall int k_mutex_init(struct k_mutex *mutex);


/**
 * @brief Lock a mutex.
 *
 * This routine locks @a mutex. If the mutex is locked by another thread,
 * the calling thread waits until the mutex becomes available or until
 * a timeout occurs.
 *
 * A thread is permitted to lock a mutex it has already locked. The operation
 * completes immediately and the lock count is increased by 1.
 *
 * Mutexes may not be locked in ISRs.
 *
 * @param mutex Address of the mutex.
 * @param timeout Waiting period to lock the mutex,
 *                or one of the special values K_NO_WAIT and
 *                K_FOREVER.
 *
 * @retval 0 Mutex locked.
 * @retval -EBUSY Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
__syscall int k_mutex_lock(struct k_mutex *mutex, k_timeout_t timeout);

/**
 * @brief Unlock a mutex.
 *
 * This routine unlocks @a mutex. The mutex must already be locked by the
 * calling thread.
 *
 * The mutex cannot be claimed by another thread until it has been unlocked by
 * the calling thread as many times as it was previously locked by that
 * thread.
 *
 * Mutexes may not be unlocked in ISRs, as mutexes must only be manipulated
 * in thread context due to ownership and priority inheritance semantics.
 *
 * @param mutex Address of the mutex.
 *
 * @retval 0 Mutex unlocked.
 * @retval -EPERM The current thread does not own the mutex
 * @retval -EINVAL The mutex is not locked
 *
 */
__syscall int k_mutex_unlock(struct k_mutex *mutex);

/**
 * @}
 */


struct k_condvar {
	_wait_q_t wait_q;
};

#define Z_CONDVAR_INITIALIZER(obj)                                             \
	{                                                                      \
		.wait_q = Z_WAIT_Q_INIT(&obj.wait_q),                          \
	}

/**
 * @defgroup condvar_apis Condition Variables APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Initialize a condition variable
 *
 * @param condvar pointer to a @p k_condvar structure
 * @retval 0 Condition variable created successfully
 */
__syscall int k_condvar_init(struct k_condvar *condvar);

/**
 * @brief Signals one thread that is pending on the condition variable
 *
 * @param condvar pointer to a @p k_condvar structure
 * @retval 0 On success
 */
__syscall int k_condvar_signal(struct k_condvar *condvar);

/**
 * @brief Unblock all threads that are pending on the condition
 * variable
 *
 * @param condvar pointer to a @p k_condvar structure
 * @return An integer with number of woken threads on success
 */
__syscall int k_condvar_broadcast(struct k_condvar *condvar);

/**
 * @brief Waits on the condition variable releasing the mutex lock
 *
 * Automically releases the currently owned mutex, blocks the current thread
 * waiting on the condition variable specified by @a condvar,
 * and finally acquires the mutex again.
 *
 * The waiting thread unblocks only after another thread calls
 * k_condvar_signal, or k_condvar_broadcast with the same condition variable.
 *
 * @param condvar pointer to a @p k_condvar structure
 * @param mutex Address of the mutex.
 * @param timeout Waiting period for the condition variable
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 * @retval 0 On success
 * @retval -EAGAIN Waiting period timed out.
 */
__syscall int k_condvar_wait(struct k_condvar *condvar, struct k_mutex *mutex,
			     k_timeout_t timeout);

/**
 * @brief Statically define and initialize a condition variable.
 *
 * The condition variable can be accessed outside the module where it is
 * defined using:
 *
 * @code extern struct k_condvar <name>; @endcode
 *
 * @param name Name of the condition variable.
 */
#define K_CONDVAR_DEFINE(name)                                                 \
	Z_STRUCT_SECTION_ITERABLE(k_condvar, name) =                           \
		Z_CONDVAR_INITIALIZER(name)
/**
 * @}
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_sem {
	_wait_q_t wait_q;
	uint32_t count;
	uint32_t limit;
	_POLL_EVENT;

	_OBJECT_TRACING_NEXT_PTR(k_sem)
	_OBJECT_TRACING_LINKED_FLAG
};

#define Z_SEM_INITIALIZER(obj, initial_count, count_limit) \
	{ \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q), \
	.count = initial_count, \
	.limit = count_limit, \
	_POLL_EVENT_OBJ_INIT(obj) \
	_OBJECT_TRACING_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup semaphore_apis Semaphore APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Initialize a semaphore.
 *
 * This routine initializes a semaphore object, prior to its first use.
 *
 * @param sem Address of the semaphore.
 * @param initial_count Initial semaphore count.
 * @param limit Maximum permitted semaphore count.
 *
 * @retval 0 Semaphore created successfully
 * @retval -EINVAL Invalid values
 *
 */
__syscall int k_sem_init(struct k_sem *sem, unsigned int initial_count,
			  unsigned int limit);

/**
 * @brief Take a semaphore.
 *
 * This routine takes @a sem.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param sem Address of the semaphore.
 * @param timeout Waiting period to take the semaphore,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @retval 0 Semaphore taken.
 * @retval -EBUSY Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
__syscall int k_sem_take(struct k_sem *sem, k_timeout_t timeout);

/**
 * @brief Give a semaphore.
 *
 * This routine gives @a sem, unless the semaphore is already at its maximum
 * permitted count.
 *
 * @note Can be called by ISRs.
 *
 * @param sem Address of the semaphore.
 *
 * @return N/A
 */
__syscall void k_sem_give(struct k_sem *sem);

/**
 * @brief Reset a semaphore's count to zero.
 *
 * This routine sets the count of @a sem to zero.
 *
 * @param sem Address of the semaphore.
 *
 * @return N/A
 */
__syscall void k_sem_reset(struct k_sem *sem);

/**
 * @internal
 */
static inline void z_impl_k_sem_reset(struct k_sem *sem)
{
	sem->count = 0U;
}

/**
 * @brief Get a semaphore's count.
 *
 * This routine returns the current count of @a sem.
 *
 * @param sem Address of the semaphore.
 *
 * @return Current semaphore count.
 */
__syscall unsigned int k_sem_count_get(struct k_sem *sem);

/**
 * @internal
 */
static inline unsigned int z_impl_k_sem_count_get(struct k_sem *sem)
{
	return sem->count;
}

/**
 * @brief Statically define and initialize a semaphore.
 *
 * The semaphore can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_sem <name>; @endcode
 *
 * @param name Name of the semaphore.
 * @param initial_count Initial semaphore count.
 * @param count_limit Maximum permitted semaphore count.
 */
#define K_SEM_DEFINE(name, initial_count, count_limit) \
	Z_STRUCT_SECTION_ITERABLE(k_sem, name) = \
		Z_SEM_INITIALIZER(name, initial_count, count_limit); \
	BUILD_ASSERT(((count_limit) != 0) && \
		     ((initial_count) <= (count_limit)));

/** @} */

/**
 * @defgroup msgq_apis Message Queue APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Message Queue Structure
 */
struct k_msgq {
	/** Message queue wait queue */
	_wait_q_t wait_q;
	/** Lock */
	struct k_spinlock lock;
	/** Message size */
	size_t msg_size;
	/** Maximal number of messages */
	uint32_t max_msgs;
	/** Start of message buffer */
	char *buffer_start;
	/** End of message buffer */
	char *buffer_end;
	/** Read pointer */
	char *read_ptr;
	/** Write pointer */
	char *write_ptr;
	/** Number of used messages */
	uint32_t used_msgs;

	_OBJECT_TRACING_NEXT_PTR(k_msgq)
	_OBJECT_TRACING_LINKED_FLAG

	/** Message queue */
	uint8_t flags;
};
/**
 * @cond INTERNAL_HIDDEN
 */


#define Z_MSGQ_INITIALIZER(obj, q_buffer, q_msg_size, q_max_msgs) \
	{ \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q), \
	.msg_size = q_msg_size, \
	.max_msgs = q_max_msgs, \
	.buffer_start = q_buffer, \
	.buffer_end = q_buffer + (q_max_msgs * q_msg_size), \
	.read_ptr = q_buffer, \
	.write_ptr = q_buffer, \
	.used_msgs = 0, \
	_OBJECT_TRACING_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */


#define K_MSGQ_FLAG_ALLOC	BIT(0)

/**
 * @brief Message Queue Attributes
 */
struct k_msgq_attrs {
	/** Message Size */
	size_t msg_size;
	/** Maximal number of messages */
	uint32_t max_msgs;
	/** Used messages */
	uint32_t used_msgs;
};


/**
 * @brief Statically define and initialize a message queue.
 *
 * The message queue's ring buffer contains space for @a q_max_msgs messages,
 * each of which is @a q_msg_size bytes long. The buffer is aligned to a
 * @a q_align -byte boundary, which must be a power of 2. To ensure that each
 * message is similarly aligned to this boundary, @a q_msg_size must also be
 * a multiple of @a q_align.
 *
 * The message queue can be accessed outside the module where it is defined
 * using:
 *
 * @code extern struct k_msgq <name>; @endcode
 *
 * @param q_name Name of the message queue.
 * @param q_msg_size Message size (in bytes).
 * @param q_max_msgs Maximum number of messages that can be queued.
 * @param q_align Alignment of the message queue's ring buffer.
 *
 */
#define K_MSGQ_DEFINE(q_name, q_msg_size, q_max_msgs, q_align)		\
	static char __noinit __aligned(q_align)				\
		_k_fifo_buf_##q_name[(q_max_msgs) * (q_msg_size)];	\
	Z_STRUCT_SECTION_ITERABLE(k_msgq, q_name) =			\
	       Z_MSGQ_INITIALIZER(q_name, _k_fifo_buf_##q_name,	\
				  q_msg_size, q_max_msgs)

/**
 * @brief Initialize a message queue.
 *
 * This routine initializes a message queue object, prior to its first use.
 *
 * The message queue's ring buffer must contain space for @a max_msgs messages,
 * each of which is @a msg_size bytes long. The buffer must be aligned to an
 * N-byte boundary, where N is a power of 2 (i.e. 1, 2, 4, ...). To ensure
 * that each message is similarly aligned to this boundary, @a q_msg_size
 * must also be a multiple of N.
 *
 * @param q Address of the message queue.
 * @param buffer Pointer to ring buffer that holds queued messages.
 * @param msg_size Message size (in bytes).
 * @param max_msgs Maximum number of messages that can be queued.
 *
 * @return N/A
 */
void k_msgq_init(struct k_msgq *q, char *buffer, size_t msg_size,
		 uint32_t max_msgs);

/**
 * @brief Initialize a message queue.
 *
 * This routine initializes a message queue object, prior to its first use,
 * allocating its internal ring buffer from the calling thread's resource
 * pool.
 *
 * Memory allocated for the ring buffer can be released by calling
 * k_msgq_cleanup(), or if userspace is enabled and the msgq object loses
 * all of its references.
 *
 * @param msgq Address of the message queue.
 * @param msg_size Message size (in bytes).
 * @param max_msgs Maximum number of messages that can be queued.
 *
 * @return 0 on success, -ENOMEM if there was insufficient memory in the
 *	thread's resource pool, or -EINVAL if the size parameters cause
 *	an integer overflow.
 */
__syscall int k_msgq_alloc_init(struct k_msgq *msgq, size_t msg_size,
				uint32_t max_msgs);

/**
 * @brief Release allocated buffer for a queue
 *
 * Releases memory allocated for the ring buffer.
 *
 * @param msgq message queue to cleanup
 *
 * @retval 0 on success
 * @retval -EBUSY Queue not empty
 */
int k_msgq_cleanup(struct k_msgq *msgq);

/**
 * @brief Send a message to a message queue.
 *
 * This routine sends a message to message queue @a q.
 *
 * @note Can be called by ISRs.
 * @note The message content is copied from @a data into @a msgq and the @a data
 * pointer is not retained, so the message content will not be modified
 * by this function.
 *
 * @param msgq Address of the message queue.
 * @param data Pointer to the message.
 * @param timeout Non-negative waiting period to add the message,
 *                or one of the special values K_NO_WAIT and
 *                K_FOREVER.
 *
 * @retval 0 Message sent.
 * @retval -ENOMSG Returned without waiting or queue purged.
 * @retval -EAGAIN Waiting period timed out.
 */
__syscall int k_msgq_put(struct k_msgq *msgq, const void *data, k_timeout_t timeout);

/**
 * @brief Receive a message from a message queue.
 *
 * This routine receives a message from message queue @a q in a "first in,
 * first out" manner.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param msgq Address of the message queue.
 * @param data Address of area to hold the received message.
 * @param timeout Waiting period to receive the message,
 *                or one of the special values K_NO_WAIT and
 *                K_FOREVER.
 *
 * @retval 0 Message received.
 * @retval -ENOMSG Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
__syscall int k_msgq_get(struct k_msgq *msgq, void *data, k_timeout_t timeout);

/**
 * @brief Peek/read a message from a message queue.
 *
 * This routine reads a message from message queue @a q in a "first in,
 * first out" manner and leaves the message in the queue.
 *
 * @note Can be called by ISRs.
 *
 * @param msgq Address of the message queue.
 * @param data Address of area to hold the message read from the queue.
 *
 * @retval 0 Message read.
 * @retval -ENOMSG Returned when the queue has no message.
 */
__syscall int k_msgq_peek(struct k_msgq *msgq, void *data);

/**
 * @brief Purge a message queue.
 *
 * This routine discards all unreceived messages in a message queue's ring
 * buffer. Any threads that are blocked waiting to send a message to the
 * message queue are unblocked and see an -ENOMSG error code.
 *
 * @param msgq Address of the message queue.
 *
 * @return N/A
 */
__syscall void k_msgq_purge(struct k_msgq *msgq);

/**
 * @brief Get the amount of free space in a message queue.
 *
 * This routine returns the number of unused entries in a message queue's
 * ring buffer.
 *
 * @param msgq Address of the message queue.
 *
 * @return Number of unused ring buffer entries.
 */
__syscall uint32_t k_msgq_num_free_get(struct k_msgq *msgq);

/**
 * @brief Get basic attributes of a message queue.
 *
 * This routine fetches basic attributes of message queue into attr argument.
 *
 * @param msgq Address of the message queue.
 * @param attrs pointer to message queue attribute structure.
 *
 * @return N/A
 */
__syscall void  k_msgq_get_attrs(struct k_msgq *msgq,
				 struct k_msgq_attrs *attrs);


static inline uint32_t z_impl_k_msgq_num_free_get(struct k_msgq *msgq)
{
	return msgq->max_msgs - msgq->used_msgs;
}

/**
 * @brief Get the number of messages in a message queue.
 *
 * This routine returns the number of messages in a message queue's ring buffer.
 *
 * @param msgq Address of the message queue.
 *
 * @return Number of messages.
 */
__syscall uint32_t k_msgq_num_used_get(struct k_msgq *msgq);

static inline uint32_t z_impl_k_msgq_num_used_get(struct k_msgq *msgq)
{
	return msgq->used_msgs;
}

/** @} */

/**
 * @defgroup mailbox_apis Mailbox APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Mailbox Message Structure
 *
 */
struct k_mbox_msg {
	/** internal use only - needed for legacy API support */
	uint32_t _mailbox;
	/** size of message (in bytes) */
	size_t size;
	/** application-defined information value */
	uint32_t info;
	/** sender's message data buffer */
	void *tx_data;
	/** internal use only - needed for legacy API support */
	void *_rx_data;
	/** message data block descriptor */
	struct k_mem_block tx_block;
	/** source thread id */
	k_tid_t rx_source_thread;
	/** target thread id */
	k_tid_t tx_target_thread;
	/** internal use only - thread waiting on send (may be a dummy) */
	k_tid_t _syncing_thread;
#if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0)
	/** internal use only - semaphore used during asynchronous send */
	struct k_sem *_async_sem;
#endif
};
/**
 * @brief Mailbox Structure
 *
 */
struct k_mbox {
	/** Transmit messages queue */
	_wait_q_t tx_msg_queue;
	/** Receive message queue */
	_wait_q_t rx_msg_queue;
	struct k_spinlock lock;

	_OBJECT_TRACING_NEXT_PTR(k_mbox)
	_OBJECT_TRACING_LINKED_FLAG
};
/**
 * @cond INTERNAL_HIDDEN
 */

#define Z_MBOX_INITIALIZER(obj) \
	{ \
	.tx_msg_queue = Z_WAIT_Q_INIT(&obj.tx_msg_queue), \
	.rx_msg_queue = Z_WAIT_Q_INIT(&obj.rx_msg_queue), \
	_OBJECT_TRACING_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @brief Statically define and initialize a mailbox.
 *
 * The mailbox is to be accessed outside the module where it is defined using:
 *
 * @code extern struct k_mbox <name>; @endcode
 *
 * @param name Name of the mailbox.
 */
#define K_MBOX_DEFINE(name) \
	Z_STRUCT_SECTION_ITERABLE(k_mbox, name) = \
		Z_MBOX_INITIALIZER(name) \

/**
 * @brief Initialize a mailbox.
 *
 * This routine initializes a mailbox object, prior to its first use.
 *
 * @param mbox Address of the mailbox.
 *
 * @return N/A
 */
extern void k_mbox_init(struct k_mbox *mbox);

/**
 * @brief Send a mailbox message in a synchronous manner.
 *
 * This routine sends a message to @a mbox and waits for a receiver to both
 * receive and process it. The message data may be in a buffer, in a memory
 * pool block, or non-existent (i.e. an empty message).
 *
 * @param mbox Address of the mailbox.
 * @param tx_msg Address of the transmit message descriptor.
 * @param timeout Waiting period for the message to be received,
 *                or one of the special values K_NO_WAIT
 *                and K_FOREVER. Once the message has been received,
 *                this routine waits as long as necessary for the message
 *                to be completely processed.
 *
 * @retval 0 Message sent.
 * @retval -ENOMSG Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
extern int k_mbox_put(struct k_mbox *mbox, struct k_mbox_msg *tx_msg,
		      k_timeout_t timeout);

/**
 * @brief Send a mailbox message in an asynchronous manner.
 *
 * This routine sends a message to @a mbox without waiting for a receiver
 * to process it. The message data may be in a buffer, in a memory pool block,
 * or non-existent (i.e. an empty message). Optionally, the semaphore @a sem
 * will be given when the message has been both received and completely
 * processed by the receiver.
 *
 * @param mbox Address of the mailbox.
 * @param tx_msg Address of the transmit message descriptor.
 * @param sem Address of a semaphore, or NULL if none is needed.
 *
 * @return N/A
 */
extern void k_mbox_async_put(struct k_mbox *mbox, struct k_mbox_msg *tx_msg,
			     struct k_sem *sem);

/**
 * @brief Receive a mailbox message.
 *
 * This routine receives a message from @a mbox, then optionally retrieves
 * its data and disposes of the message.
 *
 * @param mbox Address of the mailbox.
 * @param rx_msg Address of the receive message descriptor.
 * @param buffer Address of the buffer to receive data, or NULL to defer data
 *               retrieval and message disposal until later.
 * @param timeout Waiting period for a message to be received,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @retval 0 Message received.
 * @retval -ENOMSG Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
extern int k_mbox_get(struct k_mbox *mbox, struct k_mbox_msg *rx_msg,
		      void *buffer, k_timeout_t timeout);

/**
 * @brief Retrieve mailbox message data into a buffer.
 *
 * This routine completes the processing of a received message by retrieving
 * its data into a buffer, then disposing of the message.
 *
 * Alternatively, this routine can be used to dispose of a received message
 * without retrieving its data.
 *
 * @param rx_msg Address of the receive message descriptor.
 * @param buffer Address of the buffer to receive data, or NULL to discard
 *               the data.
 *
 * @return N/A
 */
extern void k_mbox_data_get(struct k_mbox_msg *rx_msg, void *buffer);

/** @} */

/**
 * @defgroup pipe_apis Pipe APIs
 * @ingroup kernel_apis
 * @{
 */

/** Pipe Structure */
struct k_pipe {
	unsigned char *buffer;          /**< Pipe buffer: may be NULL */
	size_t         size;            /**< Buffer size */
	size_t         bytes_used;      /**< # bytes used in buffer */
	size_t         read_index;      /**< Where in buffer to read from */
	size_t         write_index;     /**< Where in buffer to write */
	struct k_spinlock lock;		/**< Synchronization lock */

	struct {
		_wait_q_t      readers; /**< Reader wait queue */
		_wait_q_t      writers; /**< Writer wait queue */
	} wait_q;			/** Wait queue */

	_OBJECT_TRACING_NEXT_PTR(k_pipe)
	_OBJECT_TRACING_LINKED_FLAG
	uint8_t	       flags;		/**< Flags */
};

/**
 * @cond INTERNAL_HIDDEN
 */
#define K_PIPE_FLAG_ALLOC	BIT(0)	/** Buffer was allocated */

#define Z_PIPE_INITIALIZER(obj, pipe_buffer, pipe_buffer_size)     \
	{                                                           \
	.buffer = pipe_buffer,                                      \
	.size = pipe_buffer_size,                                   \
	.bytes_used = 0,                                            \
	.read_index = 0,                                            \
	.write_index = 0,                                           \
	.lock = {},                                                 \
	.wait_q = {                                                 \
		.readers = Z_WAIT_Q_INIT(&obj.wait_q.readers),       \
		.writers = Z_WAIT_Q_INIT(&obj.wait_q.writers)        \
	},                                                          \
	_OBJECT_TRACING_INIT                                        \
	.flags = 0                                                  \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @brief Statically define and initialize a pipe.
 *
 * The pipe can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_pipe <name>; @endcode
 *
 * @param name Name of the pipe.
 * @param pipe_buffer_size Size of the pipe's ring buffer (in bytes),
 *                         or zero if no ring buffer is used.
 * @param pipe_align Alignment of the pipe's ring buffer (power of 2).
 *
 */
#define K_PIPE_DEFINE(name, pipe_buffer_size, pipe_align)		\
	static unsigned char __noinit __aligned(pipe_align)	\
		_k_pipe_buf_##name[pipe_buffer_size];			\
	Z_STRUCT_SECTION_ITERABLE(k_pipe, name) = \
		Z_PIPE_INITIALIZER(name, _k_pipe_buf_##name, pipe_buffer_size)

/**
 * @brief Initialize a pipe.
 *
 * This routine initializes a pipe object, prior to its first use.
 *
 * @param pipe Address of the pipe.
 * @param buffer Address of the pipe's ring buffer, or NULL if no ring buffer
 *               is used.
 * @param size Size of the pipe's ring buffer (in bytes), or zero if no ring
 *             buffer is used.
 *
 * @return N/A
 */
void k_pipe_init(struct k_pipe *pipe, unsigned char *buffer, size_t size);

/**
 * @brief Release a pipe's allocated buffer
 *
 * If a pipe object was given a dynamically allocated buffer via
 * k_pipe_alloc_init(), this will free it. This function does nothing
 * if the buffer wasn't dynamically allocated.
 *
 * @param pipe Address of the pipe.
 * @retval 0 on success
 * @retval -EAGAIN nothing to cleanup
 */
int k_pipe_cleanup(struct k_pipe *pipe);

/**
 * @brief Initialize a pipe and allocate a buffer for it
 *
 * Storage for the buffer region will be allocated from the calling thread's
 * resource pool. This memory will be released if k_pipe_cleanup() is called,
 * or userspace is enabled and the pipe object loses all references to it.
 *
 * This function should only be called on uninitialized pipe objects.
 *
 * @param pipe Address of the pipe.
 * @param size Size of the pipe's ring buffer (in bytes), or zero if no ring
 *             buffer is used.
 * @retval 0 on success
 * @retval -ENOMEM if memory couldn't be allocated
 */
__syscall int k_pipe_alloc_init(struct k_pipe *pipe, size_t size);

/**
 * @brief Write data to a pipe.
 *
 * This routine writes up to @a bytes_to_write bytes of data to @a pipe.
 *
 * @param pipe Address of the pipe.
 * @param data Address of data to write.
 * @param bytes_to_write Size of data (in bytes).
 * @param bytes_written Address of area to hold the number of bytes written.
 * @param min_xfer Minimum number of bytes to write.
 * @param timeout Waiting period to wait for the data to be written,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @retval 0 At least @a min_xfer bytes of data were written.
 * @retval -EIO Returned without waiting; zero data bytes were written.
 * @retval -EAGAIN Waiting period timed out; between zero and @a min_xfer
 *                 minus one data bytes were written.
 */
__syscall int k_pipe_put(struct k_pipe *pipe, void *data,
			 size_t bytes_to_write, size_t *bytes_written,
			 size_t min_xfer, k_timeout_t timeout);

/**
 * @brief Read data from a pipe.
 *
 * This routine reads up to @a bytes_to_read bytes of data from @a pipe.
 *
 * @param pipe Address of the pipe.
 * @param data Address to place the data read from pipe.
 * @param bytes_to_read Maximum number of data bytes to read.
 * @param bytes_read Address of area to hold the number of bytes read.
 * @param min_xfer Minimum number of data bytes to read.
 * @param timeout Waiting period to wait for the data to be read,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @retval 0 At least @a min_xfer bytes of data were read.
 * @retval -EINVAL invalid parameters supplied
 * @retval -EIO Returned without waiting; zero data bytes were read.
 * @retval -EAGAIN Waiting period timed out; between zero and @a min_xfer
 *                 minus one data bytes were read.
 */
__syscall int k_pipe_get(struct k_pipe *pipe, void *data,
			 size_t bytes_to_read, size_t *bytes_read,
			 size_t min_xfer, k_timeout_t timeout);

/**
 * @brief Write memory block to a pipe.
 *
 * This routine writes the data contained in a memory block to @a pipe.
 * Once all of the data in the block has been written to the pipe, it will
 * free the memory block @a block and give the semaphore @a sem (if specified).
 *
 * @param pipe Address of the pipe.
 * @param block Memory block containing data to send
 * @param size Number of data bytes in memory block to send
 * @param sem Semaphore to signal upon completion (else NULL)
 *
 * @return N/A
 */
extern void k_pipe_block_put(struct k_pipe *pipe, struct k_mem_block *block,
			     size_t size, struct k_sem *sem);

/**
 * @brief Query the number of bytes that may be read from @a pipe.
 *
 * @param pipe Address of the pipe.
 *
 * @retval a number n such that 0 <= n <= @ref k_pipe.size; the
 *         result is zero for unbuffered pipes.
 */
__syscall size_t k_pipe_read_avail(struct k_pipe *pipe);

/**
 * @brief Query the number of bytes that may be written to @a pipe
 *
 * @param pipe Address of the pipe.
 *
 * @retval a number n such that 0 <= n <= @ref k_pipe.size; the
 *         result is zero for unbuffered pipes.
 */
__syscall size_t k_pipe_write_avail(struct k_pipe *pipe);

/** @} */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_mem_slab {
	_wait_q_t wait_q;
	uint32_t num_blocks;
	size_t block_size;
	char *buffer;
	char *free_list;
	uint32_t num_used;
#ifdef CONFIG_MEM_SLAB_TRACE_MAX_UTILIZATION
	uint32_t max_used;
#endif

	_OBJECT_TRACING_NEXT_PTR(k_mem_slab)
	_OBJECT_TRACING_LINKED_FLAG
};

#define Z_MEM_SLAB_INITIALIZER(obj, slab_buffer, slab_block_size, \
			       slab_num_blocks) \
	{ \
	.wait_q = Z_WAIT_Q_INIT(&obj.wait_q), \
	.num_blocks = slab_num_blocks, \
	.block_size = slab_block_size, \
	.buffer = slab_buffer, \
	.free_list = NULL, \
	.num_used = 0, \
	_OBJECT_TRACING_INIT \
	}


/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @defgroup mem_slab_apis Memory Slab APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Statically define and initialize a memory slab.
 *
 * The memory slab's buffer contains @a slab_num_blocks memory blocks
 * that are @a slab_block_size bytes long. The buffer is aligned to a
 * @a slab_align -byte boundary. To ensure that each memory block is similarly
 * aligned to this boundary, @a slab_block_size must also be a multiple of
 * @a slab_align.
 *
 * The memory slab can be accessed outside the module where it is defined
 * using:
 *
 * @code extern struct k_mem_slab <name>; @endcode
 *
 * @param name Name of the memory slab.
 * @param slab_block_size Size of each memory block (in bytes).
 * @param slab_num_blocks Number memory blocks.
 * @param slab_align Alignment of the memory slab's buffer (power of 2).
 */
#define K_MEM_SLAB_DEFINE(name, slab_block_size, slab_num_blocks, slab_align) \
	char __noinit __aligned(WB_UP(slab_align)) \
	   _k_mem_slab_buf_##name[(slab_num_blocks) * WB_UP(slab_block_size)]; \
	Z_STRUCT_SECTION_ITERABLE(k_mem_slab, name) = \
		Z_MEM_SLAB_INITIALIZER(name, _k_mem_slab_buf_##name, \
					WB_UP(slab_block_size), slab_num_blocks)

/**
 * @brief Initialize a memory slab.
 *
 * Initializes a memory slab, prior to its first use.
 *
 * The memory slab's buffer contains @a slab_num_blocks memory blocks
 * that are @a slab_block_size bytes long. The buffer must be aligned to an
 * N-byte boundary matching a word boundary, where N is a power of 2
 * (i.e. 4 on 32-bit systems, 8, 16, ...).
 * To ensure that each memory block is similarly aligned to this boundary,
 * @a slab_block_size must also be a multiple of N.
 *
 * @param slab Address of the memory slab.
 * @param buffer Pointer to buffer used for the memory blocks.
 * @param block_size Size of each memory block (in bytes).
 * @param num_blocks Number of memory blocks.
 *
 * @retval 0 on success
 * @retval -EINVAL invalid data supplied
 *
 */
extern int k_mem_slab_init(struct k_mem_slab *slab, void *buffer,
			   size_t block_size, uint32_t num_blocks);

/**
 * @brief Allocate memory from a memory slab.
 *
 * This routine allocates a memory block from a memory slab.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param slab Address of the memory slab.
 * @param mem Pointer to block address area.
 * @param timeout Non-negative waiting period to wait for operation to complete.
 *        Use K_NO_WAIT to return without waiting,
 *        or K_FOREVER to wait as long as necessary.
 *
 * @retval 0 Memory allocated. The block address area pointed at by @a mem
 *         is set to the starting address of the memory block.
 * @retval -ENOMEM Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 * @retval -EINVAL Invalid data supplied
 */
extern int k_mem_slab_alloc(struct k_mem_slab *slab, void **mem,
			    k_timeout_t timeout);

/**
 * @brief Free memory allocated from a memory slab.
 *
 * This routine releases a previously allocated memory block back to its
 * associated memory slab.
 *
 * @param slab Address of the memory slab.
 * @param mem Pointer to block address area (as set by k_mem_slab_alloc()).
 *
 * @return N/A
 */
extern void k_mem_slab_free(struct k_mem_slab *slab, void **mem);

/**
 * @brief Get the number of used blocks in a memory slab.
 *
 * This routine gets the number of memory blocks that are currently
 * allocated in @a slab.
 *
 * @param slab Address of the memory slab.
 *
 * @return Number of allocated memory blocks.
 */
static inline uint32_t k_mem_slab_num_used_get(struct k_mem_slab *slab)
{
	return slab->num_used;
}

/**
 * @brief Get the number of maximum used blocks so far in a memory slab.
 *
 * This routine gets the maximum number of memory blocks that were
 * allocated in @a slab.
 *
 * @param slab Address of the memory slab.
 *
 * @return Maximum number of allocated memory blocks.
 */
static inline uint32_t k_mem_slab_max_used_get(struct k_mem_slab *slab)
{
#ifdef CONFIG_MEM_SLAB_TRACE_MAX_UTILIZATION
	return slab->max_used;
#else
	ARG_UNUSED(slab);
	return 0;
#endif
}

/**
 * @brief Get the number of unused blocks in a memory slab.
 *
 * This routine gets the number of memory blocks that are currently
 * unallocated in @a slab.
 *
 * @param slab Address of the memory slab.
 *
 * @return Number of unallocated memory blocks.
 */
static inline uint32_t k_mem_slab_num_free_get(struct k_mem_slab *slab)
{
	return slab->num_blocks - slab->num_used;
}

/** @} */

/**
 * @addtogroup heap_apis
 * @{
 */

/* kernel synchronized heap struct */

struct k_heap {
	struct sys_heap heap;
	_wait_q_t wait_q;
	struct k_spinlock lock;
};

/**
 * @brief Initialize a k_heap
 *
 * This constructs a synchronized k_heap object over a memory region
 * specified by the user.  Note that while any alignment and size can
 * be passed as valid parameters, internal alignment restrictions
 * inside the inner sys_heap mean that not all bytes may be usable as
 * allocated memory.
 *
 * @param h Heap struct to initialize
 * @param mem Pointer to memory.
 * @param bytes Size of memory region, in bytes
 */
void k_heap_init(struct k_heap *h, void *mem, size_t bytes);

/** @brief Allocate aligned memory from a k_heap
 *
 * Behaves in all ways like k_heap_alloc(), except that the returned
 * memory (if available) will have a starting address in memory which
 * is a multiple of the specified power-of-two alignment value in
 * bytes.  The resulting memory can be returned to the heap using
 * k_heap_free().
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param h Heap from which to allocate
 * @param align Alignment in bytes, must be a power of two
 * @param bytes Number of bytes requested
 * @param timeout How long to wait, or K_NO_WAIT
 * @return Pointer to memory the caller can now use
 */
void *k_heap_aligned_alloc(struct k_heap *h, size_t align, size_t bytes,
			k_timeout_t timeout);

/**
 * @brief Allocate memory from a k_heap
 *
 * Allocates and returns a memory buffer from the memory region owned
 * by the heap.  If no memory is available immediately, the call will
 * block for the specified timeout (constructed via the standard
 * timeout API, or K_NO_WAIT or K_FOREVER) waiting for memory to be
 * freed.  If the allocation cannot be performed by the expiration of
 * the timeout, NULL will be returned.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param h Heap from which to allocate
 * @param bytes Desired size of block to allocate
 * @param timeout How long to wait, or K_NO_WAIT
 * @return A pointer to valid heap memory, or NULL
 */
static inline void *k_heap_alloc(struct k_heap *h, size_t bytes,
				 k_timeout_t timeout)
{
	return k_heap_aligned_alloc(h, sizeof(void *), bytes, timeout);
}

/**
 * @brief Free memory allocated by k_heap_alloc()
 *
 * Returns the specified memory block, which must have been returned
 * from k_heap_alloc(), to the heap for use by other callers.  Passing
 * a NULL block is legal, and has no effect.
 *
 * @param h Heap to which to return the memory
 * @param mem A valid memory block, or NULL
 */
void k_heap_free(struct k_heap *h, void *mem);

/**
 * @brief Define a static k_heap
 *
 * This macro defines and initializes a static memory region and
 * k_heap of the requested size.  After kernel start, &name can be
 * used as if k_heap_init() had been called.
 *
 * @param name Symbol name for the struct k_heap object
 * @param bytes Size of memory region, in bytes
 */
#define K_HEAP_DEFINE(name, bytes)				\
	char __aligned(sizeof(void *)) kheap_##name[bytes];	\
	Z_STRUCT_SECTION_ITERABLE(k_heap, name) = {		\
		.heap = {					\
			.init_mem = kheap_##name,		\
			.init_bytes = (bytes),			\
		 },						\
	}

extern int z_mem_pool_alloc(struct k_mem_pool *pool, struct k_mem_block *block,
			    size_t size, k_timeout_t timeout);
extern void *z_mem_pool_malloc(struct k_mem_pool *pool, size_t size);
extern void z_mem_pool_free(struct k_mem_block *block);
extern void z_mem_pool_free_id(struct k_mem_block_id *id);

/**
 * @}
 */

/**
 * @defgroup heap_apis Heap APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @brief Allocate memory from the heap with a specified alignment.
 *
 * This routine provides semantics similar to aligned_alloc(); memory is
 * allocated from the heap with a specified alignment. However, one minor
 * difference is that k_aligned_alloc() accepts any non-zero @p size,
 * wherase aligned_alloc() only accepts a @p size that is an integral
 * multiple of @p align.
 *
 * Above, aligned_alloc() refers to:
 * C11 standard (ISO/IEC 9899:2011): 7.22.3.1
 * The aligned_alloc function (p: 347-348)
 *
 * @param align Alignment of memory requested (in bytes).
 * @param size Amount of memory requested (in bytes).
 *
 * @return Address of the allocated memory if successful; otherwise NULL.
 */
extern void *k_aligned_alloc(size_t align, size_t size);

/**
 * @brief Allocate memory from the heap.
 *
 * This routine provides traditional malloc() semantics. Memory is
 * allocated from the heap memory pool.
 *
 * @param size Amount of memory requested (in bytes).
 *
 * @return Address of the allocated memory if successful; otherwise NULL.
 */
static inline void *k_malloc(size_t size)
{
	return k_aligned_alloc(sizeof(void *), size);
}

/**
 * @brief Free memory allocated from heap.
 *
 * This routine provides traditional free() semantics. The memory being
 * returned must have been allocated from the heap memory pool or
 * k_mem_pool_malloc().
 *
 * If @a ptr is NULL, no operation is performed.
 *
 * @param ptr Pointer to previously allocated memory.
 *
 * @return N/A
 */
extern void k_free(void *ptr);

/**
 * @brief Allocate memory from heap, array style
 *
 * This routine provides traditional calloc() semantics. Memory is
 * allocated from the heap memory pool and zeroed.
 *
 * @param nmemb Number of elements in the requested array
 * @param size Size of each array element (in bytes).
 *
 * @return Address of the allocated memory if successful; otherwise NULL.
 */
extern void *k_calloc(size_t nmemb, size_t size);

/** @} */

/* polling API - PRIVATE */

#ifdef CONFIG_POLL
#define _INIT_OBJ_POLL_EVENT(obj) do { (obj)->poll_event = NULL; } while (false)
#else
#define _INIT_OBJ_POLL_EVENT(obj) do { } while (false)
#endif

/* private - types bit positions */
enum _poll_types_bits {
	/* can be used to ignore an event */
	_POLL_TYPE_IGNORE,

	/* to be signaled by k_poll_signal_raise() */
	_POLL_TYPE_SIGNAL,

	/* semaphore availability */
	_POLL_TYPE_SEM_AVAILABLE,

	/* queue/FIFO/LIFO data availability */
	_POLL_TYPE_DATA_AVAILABLE,

	_POLL_NUM_TYPES
};

#define Z_POLL_TYPE_BIT(type) (1U << ((type) - 1U))

/* private - states bit positions */
enum _poll_states_bits {
	/* default state when creating event */
	_POLL_STATE_NOT_READY,

	/* signaled by k_poll_signal_raise() */
	_POLL_STATE_SIGNALED,

	/* semaphore is available */
	_POLL_STATE_SEM_AVAILABLE,

	/* data is available to read on queue/FIFO/LIFO */
	_POLL_STATE_DATA_AVAILABLE,

	/* queue/FIFO/LIFO wait was cancelled */
	_POLL_STATE_CANCELLED,

	_POLL_NUM_STATES
};

#define Z_POLL_STATE_BIT(state) (1U << ((state) - 1U))

#define _POLL_EVENT_NUM_UNUSED_BITS \
	(32 - (0 \
	       + 8 /* tag */ \
	       + _POLL_NUM_TYPES \
	       + _POLL_NUM_STATES \
	       + 1 /* modes */ \
	      ))

/* end of polling API - PRIVATE */


/**
 * @defgroup poll_apis Async polling APIs
 * @ingroup kernel_apis
 * @{
 */

/* Public polling API */

/* public - values for k_poll_event.type bitfield */
#define K_POLL_TYPE_IGNORE 0
#define K_POLL_TYPE_SIGNAL Z_POLL_TYPE_BIT(_POLL_TYPE_SIGNAL)
#define K_POLL_TYPE_SEM_AVAILABLE Z_POLL_TYPE_BIT(_POLL_TYPE_SEM_AVAILABLE)
#define K_POLL_TYPE_DATA_AVAILABLE Z_POLL_TYPE_BIT(_POLL_TYPE_DATA_AVAILABLE)
#define K_POLL_TYPE_FIFO_DATA_AVAILABLE K_POLL_TYPE_DATA_AVAILABLE

/* public - polling modes */
enum k_poll_modes {
	/* polling thread does not take ownership of objects when available */
	K_POLL_MODE_NOTIFY_ONLY = 0,

	K_POLL_NUM_MODES
};

/* public - values for k_poll_event.state bitfield */
#define K_POLL_STATE_NOT_READY 0
#define K_POLL_STATE_SIGNALED Z_POLL_STATE_BIT(_POLL_STATE_SIGNALED)
#define K_POLL_STATE_SEM_AVAILABLE Z_POLL_STATE_BIT(_POLL_STATE_SEM_AVAILABLE)
#define K_POLL_STATE_DATA_AVAILABLE Z_POLL_STATE_BIT(_POLL_STATE_DATA_AVAILABLE)
#define K_POLL_STATE_FIFO_DATA_AVAILABLE K_POLL_STATE_DATA_AVAILABLE
#define K_POLL_STATE_CANCELLED Z_POLL_STATE_BIT(_POLL_STATE_CANCELLED)

/* public - poll signal object */
struct k_poll_signal {
	/** PRIVATE - DO NOT TOUCH */
	sys_dlist_t poll_events;

	/**
	 * 1 if the event has been signaled, 0 otherwise. Stays set to 1 until
	 * user resets it to 0.
	 */
	unsigned int signaled;

	/** custom result value passed to k_poll_signal_raise() if needed */
	int result;
};

#define K_POLL_SIGNAL_INITIALIZER(obj) \
	{ \
	.poll_events = SYS_DLIST_STATIC_INIT(&obj.poll_events), \
	.signaled = 0, \
	.result = 0, \
	}
/**
 * @brief Poll Event
 *
 */
struct k_poll_event {
	/** PRIVATE - DO NOT TOUCH */
	sys_dnode_t _node;

	/** PRIVATE - DO NOT TOUCH */
	struct z_poller *poller;

	/** optional user-specified tag, opaque, untouched by the API */
	uint32_t tag:8;

	/** bitfield of event types (bitwise-ORed K_POLL_TYPE_xxx values) */
	uint32_t type:_POLL_NUM_TYPES;

	/** bitfield of event states (bitwise-ORed K_POLL_STATE_xxx values) */
	uint32_t state:_POLL_NUM_STATES;

	/** mode of operation, from enum k_poll_modes */
	uint32_t mode:1;

	/** unused bits in 32-bit word */
	uint32_t unused:_POLL_EVENT_NUM_UNUSED_BITS;

	/** per-type data */
	union {
		void *obj;
		struct k_poll_signal *signal;
		struct k_sem *sem;
		struct k_fifo *fifo;
		struct k_queue *queue;
	};
};

#define K_POLL_EVENT_INITIALIZER(_event_type, _event_mode, _event_obj) \
	{ \
	.poller = NULL, \
	.type = _event_type, \
	.state = K_POLL_STATE_NOT_READY, \
	.mode = _event_mode, \
	.unused = 0, \
	.obj = _event_obj, \
	}

#define K_POLL_EVENT_STATIC_INITIALIZER(_event_type, _event_mode, _event_obj, \
					event_tag) \
	{ \
	.tag = event_tag, \
	.type = _event_type, \
	.state = K_POLL_STATE_NOT_READY, \
	.mode = _event_mode, \
	.unused = 0, \
	.obj = _event_obj, \
	}

/**
 * @brief Initialize one struct k_poll_event instance
 *
 * After this routine is called on a poll event, the event it ready to be
 * placed in an event array to be passed to k_poll().
 *
 * @param event The event to initialize.
 * @param type A bitfield of the types of event, from the K_POLL_TYPE_xxx
 *             values. Only values that apply to the same object being polled
 *             can be used together. Choosing K_POLL_TYPE_IGNORE disables the
 *             event.
 * @param mode Future. Use K_POLL_MODE_NOTIFY_ONLY.
 * @param obj Kernel object or poll signal.
 *
 * @return N/A
 */

extern void k_poll_event_init(struct k_poll_event *event, uint32_t type,
			      int mode, void *obj);

/**
 * @brief Wait for one or many of multiple poll events to occur
 *
 * This routine allows a thread to wait concurrently for one or many of
 * multiple poll events to have occurred. Such events can be a kernel object
 * being available, like a semaphore, or a poll signal event.
 *
 * When an event notifies that a kernel object is available, the kernel object
 * is not "given" to the thread calling k_poll(): it merely signals the fact
 * that the object was available when the k_poll() call was in effect. Also,
 * all threads trying to acquire an object the regular way, i.e. by pending on
 * the object, have precedence over the thread polling on the object. This
 * means that the polling thread will never get the poll event on an object
 * until the object becomes available and its pend queue is empty. For this
 * reason, the k_poll() call is more effective when the objects being polled
 * only have one thread, the polling thread, trying to acquire them.
 *
 * When k_poll() returns 0, the caller should loop on all the events that were
 * passed to k_poll() and check the state field for the values that were
 * expected and take the associated actions.
 *
 * Before being reused for another call to k_poll(), the user has to reset the
 * state field to K_POLL_STATE_NOT_READY.
 *
 * When called from user mode, a temporary memory allocation is required from
 * the caller's resource pool.
 *
 * @param events An array of events to be polled for.
 * @param num_events The number of events in the array.
 * @param timeout Waiting period for an event to be ready,
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @retval 0 One or more events are ready.
 * @retval -EAGAIN Waiting period timed out.
 * @retval -EINTR Polling has been interrupted, e.g. with
 *         k_queue_cancel_wait(). All output events are still set and valid,
 *         cancelled event(s) will be set to K_POLL_STATE_CANCELLED. In other
 *         words, -EINTR status means that at least one of output events is
 *         K_POLL_STATE_CANCELLED.
 * @retval -ENOMEM Thread resource pool insufficient memory (user mode only)
 * @retval -EINVAL Bad parameters (user mode only)
 */

__syscall int k_poll(struct k_poll_event *events, int num_events,
		     k_timeout_t timeout);

/**
 * @brief Initialize a poll signal object.
 *
 * Ready a poll signal object to be signaled via k_poll_signal_raise().
 *
 * @param signal A poll signal.
 *
 * @return N/A
 */

__syscall void k_poll_signal_init(struct k_poll_signal *signal);

/*
 * @brief Reset a poll signal object's state to unsignaled.
 *
 * @param signal A poll signal object
 */
__syscall void k_poll_signal_reset(struct k_poll_signal *signal);

static inline void z_impl_k_poll_signal_reset(struct k_poll_signal *signal)
{
	signal->signaled = 0U;
}

/**
 * @brief Fetch the signaled state and result value of a poll signal
 *
 * @param signal A poll signal object
 * @param signaled An integer buffer which will be written nonzero if the
 *		   object was signaled
 * @param result An integer destination buffer which will be written with the
 *		   result value if the object was signaled, or an undefined
 *		   value if it was not.
 */
__syscall void k_poll_signal_check(struct k_poll_signal *signal,
				   unsigned int *signaled, int *result);

/**
 * @brief Signal a poll signal object.
 *
 * This routine makes ready a poll signal, which is basically a poll event of
 * type K_POLL_TYPE_SIGNAL. If a thread was polling on that event, it will be
 * made ready to run. A @a result value can be specified.
 *
 * The poll signal contains a 'signaled' field that, when set by
 * k_poll_signal_raise(), stays set until the user sets it back to 0 with
 * k_poll_signal_reset(). It thus has to be reset by the user before being
 * passed again to k_poll() or k_poll() will consider it being signaled, and
 * will return immediately.
 *
 * @note The result is stored and the 'signaled' field is set even if
 * this function returns an error indicating that an expiring poll was
 * not notified.  The next k_poll() will detect the missed raise.
 *
 * @param signal A poll signal.
 * @param result The value to store in the result field of the signal.
 *
 * @retval 0 The signal was delivered successfully.
 * @retval -EAGAIN The polling thread's timeout is in the process of expiring.
 */

__syscall int k_poll_signal_raise(struct k_poll_signal *signal, int result);

/**
 * @internal
 */
extern void z_handle_obj_poll_events(sys_dlist_t *events, uint32_t state);

/** @} */

/**
 * @defgroup cpu_idle_apis CPU Idling APIs
 * @ingroup kernel_apis
 * @{
 */
/**
 * @brief Make the CPU idle.
 *
 * This function makes the CPU idle until an event wakes it up.
 *
 * In a regular system, the idle thread should be the only thread responsible
 * for making the CPU idle and triggering any type of power management.
 * However, in some more constrained systems, such as a single-threaded system,
 * the only thread would be responsible for this if needed.
 *
 * @note In some architectures, before returning, the function unmasks interrupts
 * unconditionally.
 *
 * @return N/A
 */
static inline void k_cpu_idle(void)
{
	arch_cpu_idle();
}

/**
 * @brief Make the CPU idle in an atomic fashion.
 *
 * Similar to k_cpu_idle(), but must be called with interrupts locked.
 *
 * Enabling interrupts and entering a low-power mode will be atomic,
 * i.e. there will be no period of time where interrupts are enabled before
 * the processor enters a low-power mode.
 *
 * After waking up from the low-power mode, the interrupt lockout state will
 * be restored as if by irq_unlock(key).
 *
 * @param key Interrupt locking key obtained from irq_lock().
 *
 * @return N/A
 */
static inline void k_cpu_atomic_idle(unsigned int key)
{
	arch_cpu_atomic_idle(key);
}

/**
 * @}
 */

/**
 * @internal
 */
#ifdef ARCH_EXCEPT
/* This architecture has direct support for triggering a CPU exception */
#define z_except_reason(reason)	ARCH_EXCEPT(reason)
#else

#if !defined(CONFIG_ASSERT_NO_FILE_INFO)
#define __EXCEPT_LOC() __ASSERT_PRINT("@ %s:%d\n", __FILE__, __LINE__)
#else
#define __EXCEPT_LOC()
#endif

/* NOTE: This is the implementation for arches that do not implement
 * ARCH_EXCEPT() to generate a real CPU exception.
 *
 * We won't have a real exception frame to determine the PC value when
 * the oops occurred, so print file and line number before we jump into
 * the fatal error handler.
 */
#define z_except_reason(reason) do { \
		__EXCEPT_LOC();              \
		z_fatal_error(reason, NULL); \
	} while (false)

#endif /* _ARCH__EXCEPT */

/**
 * @brief Fatally terminate a thread
 *
 * This should be called when a thread has encountered an unrecoverable
 * runtime condition and needs to terminate. What this ultimately
 * means is determined by the _fatal_error_handler() implementation, which
 * will be called will reason code K_ERR_KERNEL_OOPS.
 *
 * If this is called from ISR context, the default system fatal error handler
 * will treat it as an unrecoverable system error, just like k_panic().
 */
#define k_oops()	z_except_reason(K_ERR_KERNEL_OOPS)

/**
 * @brief Fatally terminate the system
 *
 * This should be called when the Zephyr kernel has encountered an
 * unrecoverable runtime condition and needs to terminate. What this ultimately
 * means is determined by the _fatal_error_handler() implementation, which
 * will be called will reason code K_ERR_KERNEL_PANIC.
 */
#define k_panic()	z_except_reason(K_ERR_KERNEL_PANIC)

/*
 * private APIs that are utilized by one or more public APIs
 */

/**
 * @internal
 */
extern void z_init_thread_base(struct _thread_base *thread_base,
			      int priority, uint32_t initial_state,
			      unsigned int options);

#ifdef CONFIG_MULTITHREADING
/**
 * @internal
 */
extern void z_init_static_threads(void);
#else
/**
 * @internal
 */
#define z_init_static_threads() do { } while (false)
#endif

/**
 * @internal
 */
extern bool z_is_thread_essential(void);
/**
 * @internal
 */
extern void z_timer_expiration_handler(struct _timeout *t);

#ifdef CONFIG_PRINTK
/**
 * @brief Emit a character buffer to the console device
 *
 * @param c String of characters to print
 * @param n The length of the string
 *
 */
__syscall void k_str_out(char *c, size_t n);
#endif

/**
 * @brief Disable preservation of floating point context information.
 *
 * This routine informs the kernel that the specified thread
 * will no longer be using the floating point registers.
 *
 * @warning
 * Some architectures apply restrictions on how the disabling of floating
 * point preservation may be requested, see arch_float_disable.
 *
 * @warning
 * This routine should only be used to disable floating point support for
 * a thread that currently has such support enabled.
 *
 * @param thread ID of thread.
 *
 * @retval 0       On success.
 * @retval -ENOSYS If the floating point disabling is not implemented.
 *         -EINVAL If the floating point disabling could not be performed.
 */
__syscall int k_float_disable(struct k_thread *thread);

#ifdef CONFIG_THREAD_RUNTIME_STATS

/**
 * @brief Get the runtime statistics of a thread
 *
 * @param thread ID of thread.
 * @param stats Pointer to struct to copy statistics into.
 * @return -EINVAL if null pointers, otherwise 0
 */
int k_thread_runtime_stats_get(k_tid_t thread,
			       k_thread_runtime_stats_t *stats);

/**
 * @brief Get the runtime statistics of all threads
 *
 * @param stats Pointer to struct to copy statistics into.
 * @return -EINVAL if null pointers, otherwise 0
 */
int k_thread_runtime_stats_all_get(k_thread_runtime_stats_t *stats);

#endif

#ifdef __cplusplus
}
#endif

#include <tracing/tracing.h>
#include <syscalls/kernel.h>

#endif /* !_ASMLANGUAGE */

#endif /* ZEPHYR_INCLUDE_KERNEL_H_ */