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
/*
 * Copyright (c) 2016, Wind River Systems, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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

#ifndef _kernel__h_
#define _kernel__h_

#include <stddef.h>
#include <stdint.h>
#include <toolchain.h>
#include <sections.h>
#include <atomic.h>
#include <errno.h>
#include <misc/__assert.h>
#include <misc/dlist.h>
#include <misc/slist.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifdef CONFIG_KERNEL_DEBUG
#include <misc/printk.h>
#define K_DEBUG(fmt, ...) printk("[%s]  " fmt, __func__, ##__VA_ARGS__)
#else
#define K_DEBUG(fmt, ...)
#endif

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

#define K_ANY NULL
#define K_END NULL

#if CONFIG_NUM_COOP_PRIORITIES > 0
#define K_HIGHEST_THREAD_PRIO (-CONFIG_NUM_COOP_PRIORITIES)
#else
#define K_HIGHEST_THREAD_PRIO 0
#endif

#if CONFIG_NUM_PREEMPT_PRIORITIES > 0
#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)

typedef sys_dlist_t _wait_q_t;

#ifdef CONFIG_DEBUG_TRACING_KERNEL_OBJECTS
#define _DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(type) struct type *__next
#define _DEBUG_TRACING_KERNEL_OBJECTS_INIT .__next = NULL,
#else
#define _DEBUG_TRACING_KERNEL_OBJECTS_INIT
#define _DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(type)
#endif

#define tcs k_thread
struct k_thread;
struct k_mutex;
struct k_sem;
struct k_alert;
struct k_msgq;
struct k_mbox;
struct k_pipe;
struct k_fifo;
struct k_lifo;
struct k_stack;
struct k_mem_slab;
struct k_mem_pool;
struct k_timer;

typedef struct k_thread *k_tid_t;

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

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

/**
 * @typedef k_thread_entry_t
 * @brief Thread entry point function type.
 *
 * A thread's entry point function is invoked when the thread starts executing.
 * Up to 3 argument values can be passed to the function.
 *
 * The thread terminates execution permanently if the entry point function
 * returns. The thread is responsible for releasing any shared resources
 * it may own (such as mutexes and dynamically allocated memory), prior to
 * returning.
 *
 * @param p1 First argument.
 * @param p2 Second argument.
 * @param p3 Third argument.
 *
 * @return N/A
 */
typedef void (*k_thread_entry_t)(void *p1, void *p2, void *p3);

/**
 * @brief Spawn 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).
 *
 * @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 (in milliseconds), or K_NO_WAIT (for no delay).
 *
 * @return ID of new thread.
 */
extern k_tid_t k_thread_spawn(char *stack, size_t stack_size,
			      k_thread_entry_t entry,
			      void *p1, void *p2, void *p3,
			      int prio, uint32_t options, int32_t delay);

/**
 * @brief Put the current thread to sleep.
 *
 * This routine puts the current thread to sleep for @a duration
 * milliseconds.
 *
 * @param duration Number of milliseconds to sleep.
 *
 * @return N/A
 */
extern void k_sleep(int32_t duration);

/**
 * @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.
 *
 * @return N/A
 */
extern 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
 */
extern 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
 */
extern void k_wakeup(k_tid_t thread);

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

/**
 * @brief Cancel thread performing a delayed start.
 *
 * This routine prevents @a thread from executing if it has not yet started
 * execution. The thread must be re-spawned before it will execute.
 *
 * @param thread ID of thread to cancel.
 *
 * @retval 0 Thread spawning cancelled.
 * @retval -EINVAL Thread has already started executing.
 */
extern int k_thread_cancel(k_tid_t thread);

/**
 * @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
 */
extern void k_thread_abort(k_tid_t thread);

/**
 * @cond INTERNAL_HIDDEN
 */

#ifdef CONFIG_SYS_CLOCK_EXISTS
#define _THREAD_TIMEOUT_INIT(obj) \
	(obj).nano_timeout = { \
	.node = { {0}, {0} }, \
	.thread = NULL, \
	.wait_q = NULL, \
	.delta_ticks_from_prev = -1, \
	},
#else
#define _THREAD_TIMEOUT_INIT(obj)
#endif

#ifdef CONFIG_ERRNO
#define _THREAD_ERRNO_INIT(obj) (obj).errno_var = 0,
#else
#define _THREAD_ERRNO_INIT(obj)
#endif

struct _static_thread_data {
	union {
		char *init_stack;
		struct k_thread *thread;
	};
	unsigned int init_stack_size;
	void (*init_entry)(void *, void *, void *);
	void *init_p1;
	void *init_p2;
	void *init_p3;
	int init_prio;
	uint32_t init_options;
	int32_t init_delay;
	void (*init_abort)(void);
	uint32_t init_groups;
};

#define _THREAD_INITIALIZER(stack, stack_size,                   \
			    entry, p1, p2, p3,                   \
			    prio, options, delay, abort, groups) \
	{                                                        \
	.init_stack = (stack),                                   \
	.init_stack_size = (stack_size),                         \
	.init_entry = (void (*)(void *, void *, void *))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_groups = (groups),                                 \
	}

/**
 * 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), or K_NO_WAIT (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)                            \
	char __noinit __stack _k_thread_obj_##name[stack_size];          \
	struct _static_thread_data _k_thread_data_##name __aligned(4)    \
		__in_section(_static_thread_data, static, name) =        \
		_THREAD_INITIALIZER(_k_thread_obj_##name, stack_size,    \
				entry, p1, p2, p3, prio, options, delay, \
				NULL, 0); \
	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.
 */
extern 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
 */
extern void k_thread_priority_set(k_tid_t thread, int prio);

/**
 * @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, any timeout it is waiting on keeps ticking,
 * kernel objects it is waiting on are still handed to it, etc.
 *
 * If @a thread is already suspended, the routine has no effect.
 *
 * @param thread ID of thread to suspend.
 *
 * @return N/A
 */
extern 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
 */
extern 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 pre-empted 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);

/**
 * @} end defgroup thread_apis
 */

/**
 * @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 0 if invoked by a thread.
 * @return Non-zero if invoked by an ISR.
 */
extern int 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.
 */
extern int k_is_preempt_thread(void);

/**
 * @} end addtogroup isr_apis
 */

/**
 * @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
 */
extern 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.
 */
extern void *k_thread_custom_data_get(void);

/**
 * @} end addtogroup thread_apis
 */

#include <sys_clock.h>

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

/**
 * @brief Generate null timeout delay.
 *
 * This macro generates a timeout delay that that instructs a kernel API
 * not to wait if the requested operation cannot be performed immediately.
 *
 * @return Timeout delay value.
 */
#define K_NO_WAIT 0

/**
 * @brief Generate timeout delay from milliseconds.
 *
 * This macro generates a timeout delay that 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)     (ms)

/**
 * @brief Generate timeout delay from seconds.
 *
 * This macro generates a timeout delay that 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 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 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 that instructs a kernel API
 * to wait as long as necessary to perform the requested operation.
 *
 * @return Timeout delay value.
 */
#define K_FOREVER (-1)

/**
 * @} end addtogroup clock_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

/* added tick needed to account for tick in progress */
#define _TICK_ALIGN 1

static int64_t __ticks_to_ms(int64_t ticks)
{
#if CONFIG_SYS_CLOCK_EXISTS
	return (MSEC_PER_SEC * (uint64_t)ticks) / sys_clock_ticks_per_sec;
#else
	__ASSERT(ticks == 0, "");
	return 0;
#endif
}

/* timeouts */

struct _timeout;
typedef void (*_timeout_func_t)(struct _timeout *t);

struct _timeout {
	sys_dlist_t node;
	struct k_thread *thread;
	sys_dlist_t *wait_q;
	int32_t delta_ticks_from_prev;
	_timeout_func_t func;
};

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @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 *);

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

	/* timer period */
	int32_t period;

	/* timer status */
	uint32_t status;

	/* used to support legacy timer APIs */
	void *_legacy_data;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_timer);
};

#define K_TIMER_INITIALIZER(obj, expiry, stop) \
	{ \
	.timeout.delta_ticks_from_prev = -1, \
	.timeout.wait_q = NULL, \
	.timeout.thread = NULL, \
	.timeout.func = _timer_expiration_handler, \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.expiry_fn = expiry, \
	.stop_fn = stop, \
	.status = 0, \
	._legacy_data = NULL, \
	_DEBUG_TRACING_KERNEL_OBJECTS_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 the thread that stops the timer.
 * 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) \
	struct k_timer name \
		__in_section(_k_timer, static, name) = \
		K_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 (in milliseconds).
 * @param period    Timer period (in milliseconds).
 *
 * @return N/A
 */
extern void k_timer_start(struct k_timer *timer,
			  int32_t duration, int32_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.
 *
 * @param timer     Address of timer.
 *
 * @return N/A
 */
extern 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.
 */
extern 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.
 */
extern uint32_t k_timer_status_sync(struct k_timer *timer);

/**
 * @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).
 */
extern int32_t k_timer_remaining_get(struct k_timer *timer);

/**
 * @} end defgroup timer_apis
 */

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

/**
 * @brief Get system uptime.
 *
 * This routine returns the elapsed time since the system booted,
 * in milliseconds.
 *
 * @return Current uptime.
 */
extern int64_t k_uptime_get(void);

/**
 * @brief Get system uptime (32-bit version).
 *
 * This routine returns the lower 32-bits of the elapsed time since the system
 * booted, in milliseconds.
 *
 * This routine can be more efficient than k_uptime_get(), as it reduces the
 * need for interrupt locking and 64-bit math. However, the 32-bit result
 * cannot hold a system uptime time larger than approximately 50 days, so the
 * caller must handle possible rollovers.
 *
 * @return Current uptime.
 */
extern uint32_t k_uptime_get_32(void);

/**
 * @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.
 */
extern int64_t k_uptime_delta(int64_t *reftime);

/**
 * @brief Get elapsed time (32-bit version).
 *
 * This routine computes the elapsed time between the current system uptime
 * and an earlier reference time, in milliseconds.
 *
 * This routine can be more efficient than k_uptime_delta(), as it reduces the
 * need for interrupt locking and 64-bit math. However, the 32-bit result
 * cannot hold an elapsed time larger than approximately 50 days, so the
 * caller must handle possible rollovers.
 *
 * @param reftime Pointer to a reference time, which is updated to the current
 *                uptime upon return.
 *
 * @return Elapsed time.
 */
extern uint32_t k_uptime_delta_32(int64_t *reftime);

/**
 * @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).
 */
extern uint32_t k_cycle_get_32(void);

/**
 * @} end addtogroup clock_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_fifo {
	_wait_q_t wait_q;
	sys_slist_t data_q;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_fifo);
};

#define K_FIFO_INITIALIZER(obj) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.data_q = SYS_SLIST_STATIC_INIT(&obj.data_q), \
	_DEBUG_TRACING_KERNEL_OBJECTS_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

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

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

/**
 * @brief Add an element to a fifo.
 *
 * This routine adds a data item to @a fifo. A fifo data item must be
 * aligned on a 4-byte boundary, and the first 32 bits of the item are
 * 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
 */
extern void k_fifo_put(struct k_fifo *fifo, void *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 32 bits
 * 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.
 * @param head Pointer to first node in singly-linked list.
 * @param tail Pointer to last node in singly-linked list.
 *
 * @return N/A
 */
extern void k_fifo_put_list(struct k_fifo *fifo, void *head, void *tail);

/**
 * @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 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.
 * @param list Pointer to sys_slist_t object.
 *
 * @return N/A
 */
extern void k_fifo_put_slist(struct k_fifo *fifo, sys_slist_t *list);

/**
 * @brief Get an element from a fifo.
 *
 * This routine removes a data item from @a fifo in a "first in, first out"
 * manner. The first 32 bits of the data item are 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.
 * @param timeout Waiting period to obtain a data item (in milliseconds),
 *                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.
 */
extern void *k_fifo_get(struct k_fifo *fifo, int32_t timeout);

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

/**
 * @} end defgroup fifo_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_lifo {
	_wait_q_t wait_q;
	void *list;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_lifo);
};

#define K_LIFO_INITIALIZER(obj) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.list = NULL, \
	_DEBUG_TRACING_KERNEL_OBJECTS_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

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

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

/**
 * @brief Add an element to a lifo.
 *
 * This routine adds a data item to @a lifo. A lifo data item must be
 * aligned on a 4-byte boundary, and the first 32 bits of the item are
 * reserved for the kernel's use.
 *
 * @note Can be called by ISRs.
 *
 * @param lifo Address of the lifo.
 * @param data Address of the data item.
 *
 * @return N/A
 */
extern void k_lifo_put(struct k_lifo *lifo, void *data);

/**
 * @brief Get an element from a lifo.
 *
 * This routine removes a data item from @a lifo in a "last in, first out"
 * manner. The first 32 bits of the data item are 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.
 * @param timeout Waiting period to obtain a data item (in milliseconds),
 *                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.
 */
extern void *k_lifo_get(struct k_lifo *lifo, int32_t timeout);

/**
 * @brief Statically define and initialize a lifo.
 *
 * The lifo 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) \
	struct k_lifo name \
		__in_section(_k_lifo, static, name) = \
		K_LIFO_INITIALIZER(name)

/**
 * @} end defgroup lifo_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_stack {
	_wait_q_t wait_q;
	uint32_t *base, *next, *top;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_stack);
};

#define K_STACK_INITIALIZER(obj, stack_buffer, stack_num_entries) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.base = stack_buffer, \
	.next = stack_buffer, \
	.top = stack_buffer + stack_num_entries, \
	_DEBUG_TRACING_KERNEL_OBJECTS_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
 */
extern void k_stack_init(struct k_stack *stack,
			 uint32_t *buffer, int num_entries);

/**
 * @brief Push an element onto a stack.
 *
 * This routine adds a 32-bit 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.
 *
 * @return N/A
 */
extern void k_stack_push(struct k_stack *stack, uint32_t data);

/**
 * @brief Pop an element from a stack.
 *
 * This routine removes a 32-bit 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 (in milliseconds),
 *                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.
 */
extern int k_stack_pop(struct k_stack *stack, uint32_t *data, int32_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)                \
	uint32_t __noinit                                      \
		_k_stack_buf_##name[stack_num_entries];        \
	struct k_stack name                                    \
		__in_section(_k_stack, static, name) =    \
		K_STACK_INITIALIZER(name, _k_stack_buf_##name, \
				    stack_num_entries)

/**
 * @} end defgroup stack_apis
 */

struct k_work;

/**
 * @defgroup workqueue_apis Workqueue Thread APIs
 * @ingroup kernel_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_fifo fifo;
};

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

struct k_work {
	void *_reserved;		/* Used by k_fifo 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;
};

extern struct k_work_q k_sys_work_q;

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @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 struct k_work <work> = K_WORK_INITIALIZER(<work_handler>); @endcode
 *
 * @param work_handler Function to invoke each time work item is processed.
 */
#define K_WORK_INITIALIZER(work_handler) \
	{ \
	._reserved = NULL, \
	.handler = work_handler, \
	.flags = { 0 } \
	}

/**
 * @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)
{
	atomic_clear_bit(work->flags, K_WORK_STATE_PENDING);
	work->handler = handler;
}

/**
 * @brief Submit a work item.
 *
 * This routine submits work item @a work to be processed by workqueue
 * @a work_q. If the work item is already pending in the workqueue's queue
 * 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_fifo_put(&work_q->fifo, work);
	}
}

/**
 * @brief Check if a work item is pending.
 *
 * This routine indicates if work item @a work is pending in a workqueue's
 * queue.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of work item.
 *
 * @return 1 if work item is pending, or 0 if it is not pending.
 */
static inline int k_work_pending(struct k_work *work)
{
	return atomic_test_bit(work->flags, K_WORK_STATE_PENDING);
}

/**
 * @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.
 * @param stack_size Size of the work queue thread's stack (in bytes).
 * @param prio Priority of the work queue's thread.
 *
 * @return N/A
 */
extern void k_work_q_start(struct k_work_q *work_q, char *stack,
			   size_t stack_size, int prio);

/**
 * @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
 */
extern void k_delayed_work_init(struct k_delayed_work *work,
				k_work_handler_t 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 asychronous 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.
 *
 * @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 (in milliseconds).
 *
 * @retval 0 Work item countdown started.
 * @retval -EINPROGRESS Work item is already pending.
 * @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_delayed_work_submit_to_queue(struct k_work_q *work_q,
					  struct k_delayed_work *work,
					  int32_t delay);

/**
 * @brief Cancel a delayed work item.
 *
 * This routine cancels the submission of delayed work item @a work.
 * A delayed work item can only be cancelled while its countdown is still
 * underway.
 *
 * @note Can be called by ISRs.
 *
 * @param work Address of delayed work item.
 *
 * @retval 0 Work item countdown cancelled.
 * @retval -EINPROGRESS Work item is already pending.
 * @retval -EINVAL Work item is being processed or has completed its work.
 */
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 workqueue's queue
 * 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 asychronous 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.
 *
 * @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 (in milliseconds).
 *
 * @retval 0 Work item countdown started.
 * @retval -EINPROGRESS Work item is already pending.
 * @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_delayed_work_submit(struct k_delayed_work *work,
					int32_t delay)
{
	return k_delayed_work_submit_to_queue(&k_sys_work_q, work, delay);
}

/**
 * @} end defgroup workqueue_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_mutex {
	_wait_q_t wait_q;
	struct k_thread *owner;
	uint32_t lock_count;
	int owner_orig_prio;
#ifdef CONFIG_OBJECT_MONITOR
	int num_lock_state_changes;
	int num_conflicts;
#endif

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_mutex);
};

#ifdef CONFIG_OBJECT_MONITOR
#define _MUTEX_INIT_OBJECT_MONITOR \
	.num_lock_state_changes = 0, .num_conflicts = 0,
#else
#define _MUTEX_INIT_OBJECT_MONITOR
#endif

#define K_MUTEX_INITIALIZER(obj) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.owner = NULL, \
	.lock_count = 0, \
	.owner_orig_prio = K_LOWEST_THREAD_PRIO, \
	_MUTEX_INIT_OBJECT_MONITOR \
	_DEBUG_TRACING_KERNEL_OBJECTS_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

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

/**
 * @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) \
	struct k_mutex name \
		__in_section(_k_mutex, static, name) = \
		K_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.
 *
 * @return N/A
 */
extern void 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.
 *
 * @param mutex Address of the mutex.
 * @param timeout Waiting period to lock the mutex (in milliseconds),
 *                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.
 */
extern int k_mutex_lock(struct k_mutex *mutex, int32_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.
 *
 * @param mutex Address of the mutex.
 *
 * @return N/A
 */
extern void k_mutex_unlock(struct k_mutex *mutex);

/**
 * @} end defgroup mutex_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_sem {
	_wait_q_t wait_q;
	unsigned int count;
	unsigned int limit;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_sem);
};

#define K_SEM_INITIALIZER(obj, initial_count, count_limit) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.count = initial_count, \
	.limit = count_limit, \
	_DEBUG_TRACING_KERNEL_OBJECTS_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.
 *
 * @return N/A
 */
extern void 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 (in milliseconds),
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @note When porting code from the nanokernel legacy API to the new API, be
 * careful with the return value of this function. The return value is the
 * reverse of the one of nano_sem_take family of APIs: 0 means success, and
 * non-zero means failure, while the nano_sem_take family returns 1 for success
 * and 0 for failure.
 *
 * @retval 0 Semaphore taken.
 * @retval -EBUSY Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
extern int k_sem_take(struct k_sem *sem, int32_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
 */
extern 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
 */
static inline void k_sem_reset(struct k_sem *sem)
{
	sem->count = 0;
}

/**
 * @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.
 */
static inline unsigned int 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) \
	struct k_sem name \
		__in_section(_k_sem, static, name) = \
		K_SEM_INITIALIZER(name, initial_count, count_limit)

/**
 * @} end defgroup semaphore_apis
 */

/**
 * @defgroup alert_apis Alert APIs
 * @ingroup kernel_apis
 * @{
 */

/**
 * @typedef k_alert_handler_t
 * @brief Alert handler function type.
 *
 * An alert's alert handler function is invoked by the system workqueue
 * when the alert is signalled. The alert handler function is optional,
 * and is only invoked if the alert has been initialized with one.
 *
 * @param alert Address of the alert.
 *
 * @return 0 if alert has been consumed; non-zero if alert should pend.
 */
typedef int (*k_alert_handler_t)(struct k_alert *alert);

/**
 * @} end defgroup alert_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

#define K_ALERT_DEFAULT NULL
#define K_ALERT_IGNORE ((void *)(-1))

struct k_alert {
	k_alert_handler_t handler;
	atomic_t send_count;
	struct k_work work_item;
	struct k_sem sem;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_alert);
};

extern void _alert_deliver(struct k_work *work);

#define K_ALERT_INITIALIZER(obj, alert_handler, max_num_pending_alerts) \
	{ \
	.handler = (k_alert_handler_t)alert_handler, \
	.send_count = ATOMIC_INIT(0), \
	.work_item = K_WORK_INITIALIZER(_alert_deliver), \
	.sem = K_SEM_INITIALIZER(obj.sem, 0, max_num_pending_alerts), \
	_DEBUG_TRACING_KERNEL_OBJECTS_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @addtogroup alert_apis
 * @{
 */

/**
 * @brief Statically define and initialize an alert.
 *
 * The alert can be accessed outside the module where it is defined using:
 *
 * @code extern struct k_alert <name>; @endcode
 *
 * @param name Name of the alert.
 * @param alert_handler Action to take when alert is sent. Specify either
 *        the address of a function to be invoked by the system workqueue
 *        thread, K_ALERT_IGNORE (which causes the alert to be ignored), or
 *        K_ALERT_DEFAULT (which causes the alert to pend).
 * @param max_num_pending_alerts Maximum number of pending alerts.
 */
#define K_ALERT_DEFINE(name, alert_handler, max_num_pending_alerts) \
	struct k_alert name \
		__in_section(_k_alert, static, name) = \
		K_ALERT_INITIALIZER(name, alert_handler, \
				    max_num_pending_alerts)

/**
 * @brief Initialize an alert.
 *
 * This routine initializes an alert object, prior to its first use.
 *
 * @param alert Address of the alert.
 * @param handler Action to take when alert is sent. Specify either the address
 *                of a function to be invoked by the system workqueue thread,
 *                K_ALERT_IGNORE (which causes the alert to be ignored), or
 *                K_ALERT_DEFAULT (which causes the alert to pend).
 * @param max_num_pending_alerts Maximum number of pending alerts.
 *
 * @return N/A
 */
extern void k_alert_init(struct k_alert *alert, k_alert_handler_t handler,
			 unsigned int max_num_pending_alerts);

/**
 * @brief Receive an alert.
 *
 * This routine receives a pending alert for @a alert.
 *
 * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
 *
 * @param alert Address of the alert.
 * @param timeout Waiting period to receive the alert (in milliseconds),
 *                or one of the special values K_NO_WAIT and K_FOREVER.
 *
 * @retval 0 Alert received.
 * @retval -EBUSY Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
extern int k_alert_recv(struct k_alert *alert, int32_t timeout);

/**
 * @brief Signal an alert.
 *
 * This routine signals @a alert. The action specified for @a alert will
 * be taken, which may trigger the execution of an alert handler function
 * and/or cause the alert to pend (assuming the alert has not reached its
 * maximum number of pending alerts).
 *
 * @note Can be called by ISRs.
 *
 * @param alert Address of the alert.
 *
 * @return N/A
 */
extern void k_alert_send(struct k_alert *alert);

/**
 * @} end addtogroup alert_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_msgq {
	_wait_q_t wait_q;
	size_t msg_size;
	uint32_t max_msgs;
	char *buffer_start;
	char *buffer_end;
	char *read_ptr;
	char *write_ptr;
	uint32_t used_msgs;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_msgq);
};

#define K_MSGQ_INITIALIZER(obj, q_buffer, q_msg_size, q_max_msgs) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.max_msgs = q_max_msgs, \
	.msg_size = q_msg_size, \
	.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, \
	_DEBUG_TRACING_KERNEL_OBJECTS_INIT \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

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

/**
 * @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)];  \
	struct k_msgq q_name                                        \
		__in_section(_k_msgq, static, q_name) =        \
	       K_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
 */
extern void k_msgq_init(struct k_msgq *q, char *buffer,
			size_t msg_size, uint32_t max_msgs);

/**
 * @brief Send a message to a message queue.
 *
 * This routine sends a message to message queue @a q.
 *
 * @note Can be called by ISRs.
 *
 * @param q Address of the message queue.
 * @param data Pointer to the message.
 * @param timeout Waiting period to add the message (in milliseconds),
 *                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.
 */
extern int k_msgq_put(struct k_msgq *q, void *data, int32_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 q Address of the message queue.
 * @param data Address of area to hold the received message.
 * @param timeout Waiting period to receive the message (in milliseconds),
 *                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_msgq_get(struct k_msgq *q, void *data, int32_t timeout);

/**
 * @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 q Address of the message queue.
 *
 * @return N/A
 */
extern void k_msgq_purge(struct k_msgq *q);

/**
 * @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 q Address of the message queue.
 *
 * @return Number of unused ring buffer entries.
 */
static inline uint32_t k_msgq_num_free_get(struct k_msgq *q)
{
	return q->max_msgs - q->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 q Address of the message queue.
 *
 * @return Number of messages.
 */
static inline uint32_t k_msgq_num_used_get(struct k_msgq *q)
{
	return q->used_msgs;
}

/**
 * @} end defgroup msgq_apis
 */

/**
 * @defgroup mem_pool_apis Memory Pool APIs
 * @ingroup kernel_apis
 * @{
 */

struct k_mem_block {
	struct k_mem_pool *pool_id;
	void *addr_in_pool;
	void *data;
	size_t req_size;
};

/**
 * @} end defgroup mem_pool_apis
 */

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

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
};

/**
 * @cond INTERNAL_HIDDEN
 */

struct k_mbox {
	_wait_q_t tx_msg_queue;
	_wait_q_t rx_msg_queue;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_mbox);
};

#define K_MBOX_INITIALIZER(obj) \
	{ \
	.tx_msg_queue = SYS_DLIST_STATIC_INIT(&obj.tx_msg_queue), \
	.rx_msg_queue = SYS_DLIST_STATIC_INIT(&obj.rx_msg_queue), \
	_DEBUG_TRACING_KERNEL_OBJECTS_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) \
	struct k_mbox name \
		__in_section(_k_mbox, static, name) = \
		K_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 (in
 *                milliseconds), 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,
		      int32_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 (in
 *                milliseconds), 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, int32_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);

/**
 * @brief Retrieve mailbox message data into a memory pool block.
 *
 * This routine completes the processing of a received message by retrieving
 * its data into a memory pool block, then disposing of the message.
 * The memory pool block that results from successful retrieval must be
 * returned to the pool once the data has been processed, even in cases
 * where zero bytes of data are retrieved.
 *
 * Alternatively, this routine can be used to dispose of a received message
 * without retrieving its data. In this case there is no need to return a
 * memory pool block to the pool.
 *
 * This routine allocates a new memory pool block for the data only if the
 * data is not already in one. If a new block cannot be allocated, the routine
 * returns a failure code and the received message is left unchanged. This
 * permits the caller to reattempt data retrieval at a later time or to dispose
 * of the received message without retrieving its data.
 *
 * @param rx_msg Address of a receive message descriptor.
 * @param pool Address of memory pool, or NULL to discard data.
 * @param block Address of the area to hold memory pool block info.
 * @param timeout Waiting period to wait for a memory pool block (in
 *                milliseconds), or one of the special values K_NO_WAIT
 *                and K_FOREVER.
 *
 * @retval 0 Data retrieved.
 * @retval -ENOMEM Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
extern int k_mbox_data_block_get(struct k_mbox_msg *rx_msg,
				 struct k_mem_pool *pool,
				 struct k_mem_block *block, int32_t timeout);

/**
 * @} end defgroup mailbox_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

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

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_pipe);
};

#define K_PIPE_INITIALIZER(obj, pipe_buffer, pipe_buffer_size)        \
	{                                                             \
	.buffer = pipe_buffer,                                        \
	.size = pipe_buffer_size,                                     \
	.bytes_used = 0,                                              \
	.read_index = 0,                                              \
	.write_index = 0,                                             \
	.wait_q.writers = SYS_DLIST_STATIC_INIT(&obj.wait_q.writers), \
	.wait_q.readers = SYS_DLIST_STATIC_INIT(&obj.wait_q.readers), \
	_DEBUG_TRACING_KERNEL_OBJECTS_INIT                            \
	}

/**
 * INTERNAL_HIDDEN @endcond
 */

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

/**
 * @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];         \
	struct k_pipe name                                    \
		__in_section(_k_pipe, static, name) =    \
		K_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
 */
extern void k_pipe_init(struct k_pipe *pipe, unsigned char *buffer,
			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 (in
 *                milliseconds), 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.
 */
extern int k_pipe_put(struct k_pipe *pipe, void *data,
		      size_t bytes_to_write, size_t *bytes_written,
		      size_t min_xfer, int32_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 (in
 *                milliseconds), 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 -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.
 */
extern int k_pipe_get(struct k_pipe *pipe, void *data,
		      size_t bytes_to_read, size_t *bytes_read,
		      size_t min_xfer, int32_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);

/**
 * @} end defgroup pipe_apis
 */

/**
 * @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;

	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_mem_slab);
};

#define K_MEM_SLAB_INITIALIZER(obj, slab_buffer, slab_block_size, \
			       slab_num_blocks) \
	{ \
	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
	.num_blocks = slab_num_blocks, \
	.block_size = slab_block_size, \
	.buffer = slab_buffer, \
	.free_list = NULL, \
	.num_used = 0, \
	_DEBUG_TRACING_KERNEL_OBJECTS_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(slab_align) \
		_k_mem_slab_buf_##name[(slab_num_blocks) * (slab_block_size)]; \
	struct k_mem_slab name \
		__in_section(_k_mem_slab, static, name) = \
		K_MEM_SLAB_INITIALIZER(name, _k_mem_slab_buf_##name, \
				      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, where N is a power of 2 larger than 2 (i.e. 4, 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.
 *
 * @return N/A
 */
extern void 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.
 *
 * @param slab Address of the memory slab.
 * @param mem Pointer to block address area.
 * @param timeout Maximum time to wait for operation to complete
 *        (in milliseconds). 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.
 */
extern int k_mem_slab_alloc(struct k_mem_slab *slab, void **mem,
			    int32_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 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;
}

/**
 * @} end defgroup mem_slab_apis
 */

/**
 * @cond INTERNAL_HIDDEN
 */

/*
 * Memory pool requires a buffer and two arrays of structures for the
 * memory block accounting:
 * A set of arrays of k_mem_pool_quad_block structures where each keeps a
 * status of four blocks of memory.
 */
struct k_mem_pool_quad_block {
	char *mem_blocks; /* pointer to the first of four memory blocks */
	uint32_t mem_status; /* four bits. If bit is set, memory block is
				allocated */
};
/*
 * Memory pool mechanism uses one array of k_mem_pool_quad_block for accounting
 * blocks of one size. Block sizes go from maximal to minimal. Next memory
 * block size is 4 times less than the previous one and thus requires 4 times
 * bigger array of k_mem_pool_quad_block structures to keep track of the
 * memory blocks.
 */

/*
 * The array of k_mem_pool_block_set keeps the information of each array of
 * k_mem_pool_quad_block structures
 */
struct k_mem_pool_block_set {
	size_t block_size; /* memory block size */
	uint32_t nr_of_entries; /* nr of quad block structures in the array */
	struct k_mem_pool_quad_block *quad_block;
	int count;
};

/* Memory pool descriptor */
struct k_mem_pool {
	size_t max_block_size;
	size_t min_block_size;
	uint32_t nr_of_maxblocks;
	uint32_t nr_of_block_sets;
	struct k_mem_pool_block_set *block_set;
	char *bufblock;
	_wait_q_t wait_q;
	_DEBUG_TRACING_KERNEL_OBJECTS_NEXT_PTR(k_mem_pool);
};

#ifdef CONFIG_ARM
#define _SECTION_TYPE_SIGN "%"
#else
#define _SECTION_TYPE_SIGN "@"
#endif

/*
 * Static memory pool initialization
 */

/*
 * Use .altmacro to be able to recalculate values and pass them as string
 * arguments when calling assembler macros resursively
 */
__asm__(".altmacro\n\t");

/*
 * Recursively calls a macro
 * The followig global symbols need to be initialized:
 * __memory_pool_max_block_size - maximal size of the memory block
 * __memory_pool_min_block_size - minimal size of the memory block
 * Notes:
 * Global symbols are used due the fact that assembler macro allows only
 * one argument be passed with the % conversion
 * Some assemblers do not get division operation ("/"). To avoid it >> 2
 * is used instead of / 4.
 * n_max argument needs to go first in the invoked macro, as some
 * assemblers concatenate \name and %(\n_max * 4) arguments
 * if \name goes first
 */
__asm__(".macro __do_recurse macro_name, name, n_max\n\t"
	".ifge __memory_pool_max_block_size >> 2 -"
	" __memory_pool_min_block_size\n\t\t"
	"__memory_pool_max_block_size = __memory_pool_max_block_size >> 2\n\t\t"
	"\\macro_name %(\\n_max * 4) \\name\n\t"
	".endif\n\t"
	".endm\n");

/*
 * Build quad blocks
 * Macro allocates space in memory for the array of k_mem_pool_quad_block
 * structures and recursively calls itself for the next array, 4 times
 * larger.
 * The followig global symbols need to be initialized:
 * __memory_pool_max_block_size - maximal size of the memory block
 * __memory_pool_min_block_size - minimal size of the memory block
 * __memory_pool_quad_block_size - sizeof(struct k_mem_pool_quad_block)
 */
__asm__(".macro _build_quad_blocks n_max, name\n\t"
	".balign 4\n\t"
	"_mem_pool_quad_blocks_\\name\\()_\\n_max:\n\t"
	".skip __memory_pool_quad_block_size * \\n_max >> 2\n\t"
	".if \\n_max % 4\n\t\t"
	".skip __memory_pool_quad_block_size\n\t"
	".endif\n\t"
	"__do_recurse _build_quad_blocks \\name \\n_max\n\t"
	".endm\n");

/*
 * Build block sets and initialize them
 * Macro initializes the k_mem_pool_block_set structure and
 * recursively calls itself for the next one.
 * The followig global symbols need to be initialized:
 * __memory_pool_max_block_size - maximal size of the memory block
 * __memory_pool_min_block_size - minimal size of the memory block
 * __memory_pool_block_set_count, the number of the elements in the
 * block set array must be set to 0. Macro calculates it's real
 * value.
 * Since the macro initializes pointers to an array of k_mem_pool_quad_block
 * structures, _build_quad_blocks must be called prior it.
 */
__asm__(".macro _build_block_set n_max, name\n\t"
	".int __memory_pool_max_block_size\n\t" /* block_size */
	".if \\n_max % 4\n\t\t"
	".int \\n_max >> 2 + 1\n\t" /* nr_of_entries */
	".else\n\t\t"
	".int \\n_max >> 2\n\t"
	".endif\n\t"
	".int _mem_pool_quad_blocks_\\name\\()_\\n_max\n\t" /* quad_block */
	".int 0\n\t" /* count */
	"__memory_pool_block_set_count = __memory_pool_block_set_count + 1\n\t"
	"__do_recurse _build_block_set \\name \\n_max\n\t"
	".endm\n");

/*
 * Build a memory pool structure and initialize it
 * Macro uses __memory_pool_block_set_count global symbol,
 * block set addresses and buffer address, it may be called only after
 * _build_block_set
 */
__asm__(".macro _build_mem_pool name, min_size, max_size, n_max\n\t"
	".pushsection ._k_mem_pool.static.\\name,\"aw\","
	_SECTION_TYPE_SIGN "progbits\n\t"
	".globl \\name\n\t"
	"\\name:\n\t"
	".int \\max_size\n\t" /* max_block_size */
	".int \\min_size\n\t" /* min_block_size */
	".int \\n_max\n\t" /* nr_of_maxblocks */
	".int __memory_pool_block_set_count\n\t" /* nr_of_block_sets */
	".int _mem_pool_block_sets_\\name\n\t" /* block_set */
	".int _mem_pool_buffer_\\name\n\t" /* bufblock */
	".int 0\n\t" /* wait_q->head */
	".int 0\n\t" /* wait_q->next */
	".popsection\n\t"
	".endm\n");

#define _MEMORY_POOL_QUAD_BLOCK_DEFINE(name, min_size, max_size, n_max) \
	__asm__(".pushsection ._k_memory_pool.struct,\"aw\","		\
		_SECTION_TYPE_SIGN "progbits\n\t");			\
	__asm__("__memory_pool_min_block_size = " STRINGIFY(min_size) "\n\t"); \
	__asm__("__memory_pool_max_block_size = " STRINGIFY(max_size) "\n\t"); \
	__asm__("_build_quad_blocks " STRINGIFY(n_max) " "		\
		STRINGIFY(name) "\n\t");				\
	__asm__(".popsection\n\t")

#define _MEMORY_POOL_BLOCK_SETS_DEFINE(name, min_size, max_size, n_max) \
	__asm__("__memory_pool_block_set_count = 0\n\t");		\
	__asm__("__memory_pool_max_block_size = " STRINGIFY(max_size) "\n\t"); \
	__asm__(".pushsection ._k_memory_pool.struct,\"aw\","		\
		_SECTION_TYPE_SIGN "progbits\n\t");			\
	__asm__(".balign 4\n\t");			\
	__asm__("_mem_pool_block_sets_" STRINGIFY(name) ":\n\t");	\
	__asm__("_build_block_set " STRINGIFY(n_max) " "		\
		STRINGIFY(name) "\n\t");				\
	__asm__("_mem_pool_block_set_count_" STRINGIFY(name) ":\n\t");	\
	__asm__(".int __memory_pool_block_set_count\n\t");		\
	__asm__(".popsection\n\t");					\
	extern uint32_t _mem_pool_block_set_count_##name;		\
	extern struct k_mem_pool_block_set _mem_pool_block_sets_##name[]

#define _MEMORY_POOL_BUFFER_DEFINE(name, max_size, n_max, align)	\
	char __noinit __aligned(align)                                  \
		_mem_pool_buffer_##name[(max_size) * (n_max)]

/*
 * Dummy function that assigns the value of sizeof(struct k_mem_pool_quad_block)
 * to __memory_pool_quad_block_size absolute symbol.
 * This function does not get called, but compiler calculates the value and
 * assigns it to the absolute symbol, that, in turn is used by assembler macros.
 */
static void __attribute__ ((used)) __k_mem_pool_quad_block_size_define(void)
{
	__asm__(".globl __memory_pool_quad_block_size\n\t"
#ifdef CONFIG_NIOS2
	    "__memory_pool_quad_block_size = %0\n\t"
#else
	    "__memory_pool_quad_block_size = %c0\n\t"
#endif
	    :
	    : "n"(sizeof(struct k_mem_pool_quad_block)));
}

/**
 * INTERNAL_HIDDEN @endcond
 */

/**
 * @addtogroup mem_pool_apis
 * @{
 */

/**
 * @brief Statically define and initialize a memory pool.
 *
 * The memory pool's buffer contains @a n_max blocks that are @a max_size bytes
 * long. The memory pool allows blocks to be repeatedly partitioned into
 * quarters, down to blocks of @a min_size bytes long. The buffer is aligned
 * to a @a align -byte boundary. To ensure that the minimum sized blocks are
 * similarly aligned to this boundary, @a min_size must also be a multiple of
 * @a align.
 *
 * If the pool is to be accessed outside the module where it is defined, it
 * can be declared via
 *
 * @code extern struct k_mem_pool <name>; @endcode
 *
 * @param name Name of the memory pool.
 * @param min_size Size of the smallest blocks in the pool (in bytes).
 * @param max_size Size of the largest blocks in the pool (in bytes).
 * @param n_max Number of maximum sized blocks in the pool.
 * @param align Alignment of the pool's buffer (power of 2).
 */
#define K_MEM_POOL_DEFINE(name, min_size, max_size, n_max, align)     \
	_MEMORY_POOL_QUAD_BLOCK_DEFINE(name, min_size, max_size, n_max); \
	_MEMORY_POOL_BLOCK_SETS_DEFINE(name, min_size, max_size, n_max); \
	_MEMORY_POOL_BUFFER_DEFINE(name, max_size, n_max, align);        \
	__asm__("_build_mem_pool " STRINGIFY(name) " " STRINGIFY(min_size) " " \
	       STRINGIFY(max_size) " " STRINGIFY(n_max) "\n\t");	\
	extern struct k_mem_pool name

/**
 * @brief Allocate memory from a memory pool.
 *
 * This routine allocates a memory block from a memory pool.
 *
 * @param pool Address of the memory pool.
 * @param block Pointer to block descriptor for the allocated memory.
 * @param size Amount of memory to allocate (in bytes).
 * @param timeout Maximum time to wait for operation to complete
 *        (in milliseconds). Use K_NO_WAIT to return without waiting,
 *        or K_FOREVER to wait as long as necessary.
 *
 * @retval 0 Memory allocated. The @a data field of the block descriptor
 *         is set to the starting address of the memory block.
 * @retval -ENOMEM Returned without waiting.
 * @retval -EAGAIN Waiting period timed out.
 */
extern int k_mem_pool_alloc(struct k_mem_pool *pool, struct k_mem_block *block,
			    size_t size, int32_t timeout);

/**
 * @brief Free memory allocated from a memory pool.
 *
 * This routine releases a previously allocated memory block back to its
 * memory pool.
 *
 * @param block Pointer to block descriptor for the allocated memory.
 *
 * @return N/A
 */
extern void k_mem_pool_free(struct k_mem_block *block);

/**
 * @brief Defragment a memory pool.
 *
 * This routine instructs a memory pool to concatenate unused memory blocks
 * into larger blocks wherever possible. Manually defragmenting the memory
 * pool may speed up future allocations of memory blocks by eliminating the
 * need for the memory pool to perform an automatic partial defragmentation.
 *
 * @param pool Address of the memory pool.
 *
 * @return N/A
 */
extern void k_mem_pool_defrag(struct k_mem_pool *pool);

/**
 * @} end addtogroup mem_pool_apis
 */

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

/**
 * @brief Allocate memory from 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.
 */
extern void *k_malloc(size_t 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.
 *
 * @param ptr Pointer to previously allocated memory.
 *
 * @return N/A
 */
extern void k_free(void *ptr);

/**
 * @} end defgroup heap_apis
 */

/*
 * legacy.h must be before arch/cpu.h to allow the ioapic/loapic drivers to
 * hook into the device subsystem, which itself uses nanokernel semaphores,
 * and thus currently requires the definition of nano_sem.
 */
#include <legacy.h>
#include <arch/cpu.h>

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

extern int _is_thread_essential(void);
extern void _init_static_threads(void);
extern void _timer_expiration_handler(struct _timeout *t);

#ifdef __cplusplus
}
#endif

#if defined(CONFIG_CPLUSPLUS) && defined(__cplusplus)
/*
 * Define new and delete operators.
 * At this moment, the operators do nothing since objects are supposed
 * to be statically allocated.
 */
inline void operator delete(void *ptr)
{
	(void)ptr;
}

inline void operator delete[](void *ptr)
{
	(void)ptr;
}

inline void *operator new(size_t size)
{
	(void)size;
	return NULL;
}

inline void *operator new[](size_t size)
{
	(void)size;
	return NULL;
}

/* Placement versions of operator new and delete */
inline void operator delete(void *ptr1, void *ptr2)
{
	(void)ptr1;
	(void)ptr2;
}

inline void operator delete[](void *ptr1, void *ptr2)
{
	(void)ptr1;
	(void)ptr2;
}

inline void *operator new(size_t size, void *ptr)
{
	(void)size;
	return ptr;
}

inline void *operator new[](size_t size, void *ptr)
{
	(void)size;
	return ptr;
}

#endif /* defined(CONFIG_CPLUSPLUS) && defined(__cplusplus) */

#endif /* _kernel__h_ */