summaryrefslogtreecommitdiff
path: root/rtos/FreeRTOS/Source/include/task.h
blob: f2c0e1728555cc739eff6a9fb451ba470c72abaf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
/*
    FreeRTOS V8.2.3 - Copyright (C) 2015 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.

    ***************************************************************************
    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<
    ***************************************************************************

    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
     *                                                                       *
     *    Help yourself get started quickly while simultaneously helping     *
     *    to support the FreeRTOS project by purchasing a FreeRTOS           *
     *    tutorial book, reference manual, or both:                          *
     *    http://www.FreeRTOS.org/Documentation                              *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading
    the FAQ page "My application does not run, what could be wrong?".  Have you
    defined configASSERT()?

    http://www.FreeRTOS.org/support - In return for receiving this top quality
    embedded software for free we request you assist our global community by
    participating in the support forum.

    http://www.FreeRTOS.org/training - Investing in training allows your team to
    be as productive as possible as early as possible.  Now you can receive
    FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
    Ltd, and the world's leading authority on the world's leading RTOS.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/


#ifndef INC_TASK_H
#define INC_TASK_H

#ifndef INC_FREERTOS_H
	#error "include FreeRTOS.h must appear in source files before include task.h"
#endif

#include "list.h"

#ifdef __cplusplus
extern "C" {
#endif

/*-----------------------------------------------------------
 * MACROS AND DEFINITIONS
 *----------------------------------------------------------*/

#define tskKERNEL_VERSION_NUMBER "V8.2.3"
#define tskKERNEL_VERSION_MAJOR 8
#define tskKERNEL_VERSION_MINOR 2
#define tskKERNEL_VERSION_BUILD 3

/**
 * task. h
 *
 * Type by which tasks are referenced.  For example, a call to xTaskCreate
 * returns (via a pointer parameter) an TaskHandle_t variable that can then
 * be used as a parameter to vTaskDelete to delete the task.
 *
 * \defgroup TaskHandle_t TaskHandle_t
 * \ingroup Tasks
 */
typedef void * TaskHandle_t;

/*
 * Defines the prototype to which the application task hook function must
 * conform.
 */
typedef BaseType_t (*TaskHookFunction_t)( void * );

/* Task states returned by eTaskGetState. */
typedef enum
{
	eRunning = 0,	/* A task is querying the state of itself, so must be running. */
	eReady,			/* The task being queried is in a read or pending ready list. */
	eBlocked,		/* The task being queried is in the Blocked state. */
	eSuspended,		/* The task being queried is in the Suspended state, or is in the Blocked state with an infinite time out. */
	eDeleted		/* The task being queried has been deleted, but its TCB has not yet been freed. */
} eTaskState;

/* Actions that can be performed when vTaskNotify() is called. */
typedef enum
{
	eNoAction = 0,				/* Notify the task without updating its notify value. */
	eSetBits,					/* Set bits in the task's notification value. */
	eIncrement,					/* Increment the task's notification value. */
	eSetValueWithOverwrite,		/* Set the task's notification value to a specific value even if the previous value has not yet been read by the task. */
	eSetValueWithoutOverwrite	/* Set the task's notification value if the previous value has been read by the task. */
} eNotifyAction;

/*
 * Used internally only.
 */
typedef struct xTIME_OUT
{
	BaseType_t xOverflowCount;
	TickType_t xTimeOnEntering;
} TimeOut_t;

/*
 * Defines the memory ranges allocated to the task when an MPU is used.
 */
typedef struct xMEMORY_REGION
{
	void *pvBaseAddress;
	uint32_t ulLengthInBytes;
	uint32_t ulParameters;
} MemoryRegion_t;

/*
 * Parameters required to create an MPU protected task.
 */
typedef struct xTASK_PARAMETERS
{
	TaskFunction_t pvTaskCode;
	const char * const pcName;	/*lint !e971 Unqualified char types are allowed for strings and single characters only. */
	uint16_t usStackDepth;
	void *pvParameters;
	UBaseType_t uxPriority;
	StackType_t *puxStackBuffer;
	MemoryRegion_t xRegions[ portNUM_CONFIGURABLE_REGIONS ];
} TaskParameters_t;

/* Used with the uxTaskGetSystemState() function to return the state of each task
in the system. */
typedef struct xTASK_STATUS
{
	TaskHandle_t xHandle;			/* The handle of the task to which the rest of the information in the structure relates. */
	const char *pcTaskName;			/* A pointer to the task's name.  This value will be invalid if the task was deleted since the structure was populated! */ /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
	UBaseType_t xTaskNumber;		/* A number unique to the task. */
	eTaskState eCurrentState;		/* The state in which the task existed when the structure was populated. */
	UBaseType_t uxCurrentPriority;	/* The priority at which the task was running (may be inherited) when the structure was populated. */
	UBaseType_t uxBasePriority;		/* The priority to which the task will return if the task's current priority has been inherited to avoid unbounded priority inversion when obtaining a mutex.  Only valid if configUSE_MUTEXES is defined as 1 in FreeRTOSConfig.h. */
	uint32_t ulRunTimeCounter;		/* The total run time allocated to the task so far, as defined by the run time stats clock.  See http://www.freertos.org/rtos-run-time-stats.html.  Only valid when configGENERATE_RUN_TIME_STATS is defined as 1 in FreeRTOSConfig.h. */
	uint16_t usStackHighWaterMark;	/* The minimum amount of stack space that has remained for the task since the task was created.  The closer this value is to zero the closer the task has come to overflowing its stack. */
} TaskStatus_t;

/* Possible return values for eTaskConfirmSleepModeStatus(). */
typedef enum
{
	eAbortSleep = 0,		/* A task has been made ready or a context switch pended since portSUPPORESS_TICKS_AND_SLEEP() was called - abort entering a sleep mode. */
	eStandardSleep,			/* Enter a sleep mode that will not last any longer than the expected idle time. */
	eNoTasksWaitingTimeout	/* No tasks are waiting for a timeout so it is safe to enter a sleep mode that can only be exited by an external interrupt. */
} eSleepModeStatus;


/**
 * Defines the priority used by the idle task.  This must not be modified.
 *
 * \ingroup TaskUtils
 */
#define tskIDLE_PRIORITY			( ( UBaseType_t ) 0U )

/**
 * task. h
 *
 * Macro for forcing a context switch.
 *
 * \defgroup taskYIELD taskYIELD
 * \ingroup SchedulerControl
 */
#define taskYIELD()					portYIELD()

/**
 * task. h
 *
 * Macro to mark the start of a critical code region.  Preemptive context
 * switches cannot occur when in a critical region.
 *
 * NOTE: This may alter the stack (depending on the portable implementation)
 * so must be used with care!
 *
 * \defgroup taskENTER_CRITICAL taskENTER_CRITICAL
 * \ingroup SchedulerControl
 */
#define taskENTER_CRITICAL()		portENTER_CRITICAL()
#define taskENTER_CRITICAL_FROM_ISR() portSET_INTERRUPT_MASK_FROM_ISR()

/**
 * task. h
 *
 * Macro to mark the end of a critical code region.  Preemptive context
 * switches cannot occur when in a critical region.
 *
 * NOTE: This may alter the stack (depending on the portable implementation)
 * so must be used with care!
 *
 * \defgroup taskEXIT_CRITICAL taskEXIT_CRITICAL
 * \ingroup SchedulerControl
 */
#define taskEXIT_CRITICAL()			portEXIT_CRITICAL()
#define taskEXIT_CRITICAL_FROM_ISR( x ) portCLEAR_INTERRUPT_MASK_FROM_ISR( x )
/**
 * task. h
 *
 * Macro to disable all maskable interrupts.
 *
 * \defgroup taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS
 * \ingroup SchedulerControl
 */
#define taskDISABLE_INTERRUPTS()	portDISABLE_INTERRUPTS()

/**
 * task. h
 *
 * Macro to enable microcontroller interrupts.
 *
 * \defgroup taskENABLE_INTERRUPTS taskENABLE_INTERRUPTS
 * \ingroup SchedulerControl
 */
#define taskENABLE_INTERRUPTS()		portENABLE_INTERRUPTS()

/* Definitions returned by xTaskGetSchedulerState().  taskSCHEDULER_SUSPENDED is
0 to generate more optimal code when configASSERT() is defined as the constant
is used in assert() statements. */
#define taskSCHEDULER_SUSPENDED		( ( BaseType_t ) 0 )
#define taskSCHEDULER_NOT_STARTED	( ( BaseType_t ) 1 )
#define taskSCHEDULER_RUNNING		( ( BaseType_t ) 2 )


/*-----------------------------------------------------------
 * TASK CREATION API
 *----------------------------------------------------------*/

/**
 * task. h
 *<pre>
 BaseType_t xTaskCreate(
							  TaskFunction_t pvTaskCode,
							  const char * const pcName,
							  uint16_t usStackDepth,
							  void *pvParameters,
							  UBaseType_t uxPriority,
							  TaskHandle_t *pvCreatedTask
						  );</pre>
 *
 * Create a new task and add it to the list of tasks that are ready to run.
 *
 * xTaskCreate() can only be used to create a task that has unrestricted
 * access to the entire microcontroller memory map.  Systems that include MPU
 * support can alternatively create an MPU constrained task using
 * xTaskCreateRestricted().
 *
 * @param pvTaskCode Pointer to the task entry function.  Tasks
 * must be implemented to never return (i.e. continuous loop).
 *
 * @param pcName A descriptive name for the task.  This is mainly used to
 * facilitate debugging.  Max length defined by configMAX_TASK_NAME_LEN - default
 * is 16.
 *
 * @param usStackDepth The size of the task stack specified as the number of
 * variables the stack can hold - not the number of bytes.  For example, if
 * the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes
 * will be allocated for stack storage.
 *
 * @param pvParameters Pointer that will be used as the parameter for the task
 * being created.
 *
 * @param uxPriority The priority at which the task should run.  Systems that
 * include MPU support can optionally create tasks in a privileged (system)
 * mode by setting bit portPRIVILEGE_BIT of the priority parameter.  For
 * example, to create a privileged task at priority 2 the uxPriority parameter
 * should be set to ( 2 | portPRIVILEGE_BIT ).
 *
 * @param pvCreatedTask Used to pass back a handle by which the created task
 * can be referenced.
 *
 * @return pdPASS if the task was successfully created and added to a ready
 * list, otherwise an error code defined in the file projdefs.h
 *
 * Example usage:
   <pre>
 // Task to be created.
 void vTaskCode( void * pvParameters )
 {
	 for( ;; )
	 {
		 // Task code goes here.
	 }
 }

 // Function that creates a task.
 void vOtherFunction( void )
 {
 static uint8_t ucParameterToPass;
 TaskHandle_t xHandle = NULL;

	 // Create the task, storing the handle.  Note that the passed parameter ucParameterToPass
	 // must exist for the lifetime of the task, so in this case is declared static.  If it was just an
	 // an automatic stack variable it might no longer exist, or at least have been corrupted, by the time
	 // the new task attempts to access it.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
     configASSERT( xHandle );

	 // Use the handle to delete the task.
     if( xHandle != NULL )
     {
	     vTaskDelete( xHandle );
     }
 }
   </pre>
 * \defgroup xTaskCreate xTaskCreate
 * \ingroup Tasks
 */
#define xTaskCreate( pvTaskCode, pcName, usStackDepth, pvParameters, uxPriority, pxCreatedTask ) xTaskGenericCreate( ( pvTaskCode ), ( pcName ), ( usStackDepth ), ( pvParameters ), ( uxPriority ), ( pxCreatedTask ), ( NULL ), ( NULL ) )

/**
 * task. h
 *<pre>
 BaseType_t xTaskCreateRestricted( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );</pre>
 *
 * xTaskCreateRestricted() should only be used in systems that include an MPU
 * implementation.
 *
 * Create a new task and add it to the list of tasks that are ready to run.
 * The function parameters define the memory regions and associated access
 * permissions allocated to the task.
 *
 * @param pxTaskDefinition Pointer to a structure that contains a member
 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
 * documentation) plus an optional stack buffer and the memory region
 * definitions.
 *
 * @param pxCreatedTask Used to pass back a handle by which the created task
 * can be referenced.
 *
 * @return pdPASS if the task was successfully created and added to a ready
 * list, otherwise an error code defined in the file projdefs.h
 *
 * Example usage:
   <pre>
// Create an TaskParameters_t structure that defines the task to be created.
static const TaskParameters_t xCheckTaskParameters =
{
	vATask,		// pvTaskCode - the function that implements the task.
	"ATask",	// pcName - just a text name for the task to assist debugging.
	100,		// usStackDepth	- the stack size DEFINED IN WORDS.
	NULL,		// pvParameters - passed into the task function as the function parameters.
	( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
	cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.

	// xRegions - Allocate up to three separate memory regions for access by
	// the task, with appropriate access permissions.  Different processors have
	// different memory alignment requirements - refer to the FreeRTOS documentation
	// for full information.
	{
		// Base address					Length	Parameters
        { cReadWriteArray,				32,		portMPU_REGION_READ_WRITE },
        { cReadOnlyArray,				32,		portMPU_REGION_READ_ONLY },
        { cPrivilegedOnlyAccessArray,	128,	portMPU_REGION_PRIVILEGED_READ_WRITE }
	}
};

int main( void )
{
TaskHandle_t xHandle;

	// Create a task from the const structure defined above.  The task handle
	// is requested (the second parameter is not NULL) but in this case just for
	// demonstration purposes as its not actually used.
	xTaskCreateRestricted( &xRegTest1Parameters, &xHandle );

	// Start the scheduler.
	vTaskStartScheduler();

	// Will only get here if there was insufficient memory to create the idle
	// and/or timer task.
	for( ;; );
}
   </pre>
 * \defgroup xTaskCreateRestricted xTaskCreateRestricted
 * \ingroup Tasks
 */
#define xTaskCreateRestricted( x, pxCreatedTask ) xTaskGenericCreate( ((x)->pvTaskCode), ((x)->pcName), ((x)->usStackDepth), ((x)->pvParameters), ((x)->uxPriority), (pxCreatedTask), ((x)->puxStackBuffer), ((x)->xRegions) )

/**
 * task. h
 *<pre>
 void vTaskAllocateMPURegions( TaskHandle_t xTask, const MemoryRegion_t * const pxRegions );</pre>
 *
 * Memory regions are assigned to a restricted task when the task is created by
 * a call to xTaskCreateRestricted().  These regions can be redefined using
 * vTaskAllocateMPURegions().
 *
 * @param xTask The handle of the task being updated.
 *
 * @param xRegions A pointer to an MemoryRegion_t structure that contains the
 * new memory region definitions.
 *
 * Example usage:
   <pre>
// Define an array of MemoryRegion_t structures that configures an MPU region
// allowing read/write access for 1024 bytes starting at the beginning of the
// ucOneKByte array.  The other two of the maximum 3 definable regions are
// unused so set to zero.
static const MemoryRegion_t xAltRegions[ portNUM_CONFIGURABLE_REGIONS ] =
{
	// Base address		Length		Parameters
	{ ucOneKByte,		1024,		portMPU_REGION_READ_WRITE },
	{ 0,				0,			0 },
	{ 0,				0,			0 }
};

void vATask( void *pvParameters )
{
	// This task was created such that it has access to certain regions of
	// memory as defined by the MPU configuration.  At some point it is
	// desired that these MPU regions are replaced with that defined in the
	// xAltRegions const struct above.  Use a call to vTaskAllocateMPURegions()
	// for this purpose.  NULL is used as the task handle to indicate that this
	// function should modify the MPU regions of the calling task.
	vTaskAllocateMPURegions( NULL, xAltRegions );

	// Now the task can continue its function, but from this point on can only
	// access its stack and the ucOneKByte array (unless any other statically
	// defined or shared regions have been declared elsewhere).
}
   </pre>
 * \defgroup xTaskCreateRestricted xTaskCreateRestricted
 * \ingroup Tasks
 */
void vTaskAllocateMPURegions( TaskHandle_t xTask, const MemoryRegion_t * const pxRegions ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskDelete( TaskHandle_t xTask );</pre>
 *
 * INCLUDE_vTaskDelete must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Remove a task from the RTOS real time kernel's management.  The task being
 * deleted will be removed from all ready, blocked, suspended and event lists.
 *
 * NOTE:  The idle task is responsible for freeing the kernel allocated
 * memory from tasks that have been deleted.  It is therefore important that
 * the idle task is not starved of microcontroller processing time if your
 * application makes any calls to vTaskDelete ().  Memory allocated by the
 * task code is not automatically freed, and should be freed before the task
 * is deleted.
 *
 * See the demo application file death.c for sample code that utilises
 * vTaskDelete ().
 *
 * @param xTask The handle of the task to be deleted.  Passing NULL will
 * cause the calling task to be deleted.
 *
 * Example usage:
   <pre>
 void vOtherFunction( void )
 {
 TaskHandle_t xHandle;

	 // Create the task, storing the handle.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );

	 // Use the handle to delete the task.
	 vTaskDelete( xHandle );
 }
   </pre>
 * \defgroup vTaskDelete vTaskDelete
 * \ingroup Tasks
 */
void vTaskDelete( TaskHandle_t xTaskToDelete ) PRIVILEGED_FUNCTION;

/*-----------------------------------------------------------
 * TASK CONTROL API
 *----------------------------------------------------------*/

/**
 * task. h
 * <pre>void vTaskDelay( const TickType_t xTicksToDelay );</pre>
 *
 * Delay a task for a given number of ticks.  The actual time that the
 * task remains blocked depends on the tick rate.  The constant
 * portTICK_PERIOD_MS can be used to calculate real time from the tick
 * rate - with the resolution of one tick period.
 *
 * INCLUDE_vTaskDelay must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 *
 * vTaskDelay() specifies a time at which the task wishes to unblock relative to
 * the time at which vTaskDelay() is called.  For example, specifying a block
 * period of 100 ticks will cause the task to unblock 100 ticks after
 * vTaskDelay() is called.  vTaskDelay() does not therefore provide a good method
 * of controlling the frequency of a periodic task as the path taken through the
 * code, as well as other task and interrupt activity, will effect the frequency
 * at which vTaskDelay() gets called and therefore the time at which the task
 * next executes.  See vTaskDelayUntil() for an alternative API function designed
 * to facilitate fixed frequency execution.  It does this by specifying an
 * absolute time (rather than a relative time) at which the calling task should
 * unblock.
 *
 * @param xTicksToDelay The amount of time, in tick periods, that
 * the calling task should block.
 *
 * Example usage:

 void vTaskFunction( void * pvParameters )
 {
 // Block for 500ms.
 const TickType_t xDelay = 500 / portTICK_PERIOD_MS;

	 for( ;; )
	 {
		 // Simply toggle the LED every 500ms, blocking between each toggle.
		 vToggleLED();
		 vTaskDelay( xDelay );
	 }
 }

 * \defgroup vTaskDelay vTaskDelay
 * \ingroup TaskCtrl
 */
void vTaskDelay( const TickType_t xTicksToDelay ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskDelayUntil( TickType_t *pxPreviousWakeTime, const TickType_t xTimeIncrement );</pre>
 *
 * INCLUDE_vTaskDelayUntil must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Delay a task until a specified time.  This function can be used by periodic
 * tasks to ensure a constant execution frequency.
 *
 * This function differs from vTaskDelay () in one important aspect:  vTaskDelay () will
 * cause a task to block for the specified number of ticks from the time vTaskDelay () is
 * called.  It is therefore difficult to use vTaskDelay () by itself to generate a fixed
 * execution frequency as the time between a task starting to execute and that task
 * calling vTaskDelay () may not be fixed [the task may take a different path though the
 * code between calls, or may get interrupted or preempted a different number of times
 * each time it executes].
 *
 * Whereas vTaskDelay () specifies a wake time relative to the time at which the function
 * is called, vTaskDelayUntil () specifies the absolute (exact) time at which it wishes to
 * unblock.
 *
 * The constant portTICK_PERIOD_MS can be used to calculate real time from the tick
 * rate - with the resolution of one tick period.
 *
 * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the
 * task was last unblocked.  The variable must be initialised with the current time
 * prior to its first use (see the example below).  Following this the variable is
 * automatically updated within vTaskDelayUntil ().
 *
 * @param xTimeIncrement The cycle time period.  The task will be unblocked at
 * time *pxPreviousWakeTime + xTimeIncrement.  Calling vTaskDelayUntil with the
 * same xTimeIncrement parameter value will cause the task to execute with
 * a fixed interface period.
 *
 * Example usage:
   <pre>
 // Perform an action every 10 ticks.
 void vTaskFunction( void * pvParameters )
 {
 TickType_t xLastWakeTime;
 const TickType_t xFrequency = 10;

	 // Initialise the xLastWakeTime variable with the current time.
	 xLastWakeTime = xTaskGetTickCount ();
	 for( ;; )
	 {
		 // Wait for the next cycle.
		 vTaskDelayUntil( &xLastWakeTime, xFrequency );

		 // Perform action here.
	 }
 }
   </pre>
 * \defgroup vTaskDelayUntil vTaskDelayUntil
 * \ingroup TaskCtrl
 */
void vTaskDelayUntil( TickType_t * const pxPreviousWakeTime, const TickType_t xTimeIncrement ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>UBaseType_t uxTaskPriorityGet( TaskHandle_t xTask );</pre>
 *
 * INCLUDE_uxTaskPriorityGet must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Obtain the priority of any task.
 *
 * @param xTask Handle of the task to be queried.  Passing a NULL
 * handle results in the priority of the calling task being returned.
 *
 * @return The priority of xTask.
 *
 * Example usage:
   <pre>
 void vAFunction( void )
 {
 TaskHandle_t xHandle;

	 // Create a task, storing the handle.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );

	 // ...

	 // Use the handle to obtain the priority of the created task.
	 // It was created with tskIDLE_PRIORITY, but may have changed
	 // it itself.
	 if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
	 {
		 // The task has changed it's priority.
	 }

	 // ...

	 // Is our priority higher than the created task?
	 if( uxTaskPriorityGet( xHandle ) < uxTaskPriorityGet( NULL ) )
	 {
		 // Our priority (obtained using NULL handle) is higher.
	 }
 }
   </pre>
 * \defgroup uxTaskPriorityGet uxTaskPriorityGet
 * \ingroup TaskCtrl
 */
UBaseType_t uxTaskPriorityGet( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>UBaseType_t uxTaskPriorityGetFromISR( TaskHandle_t xTask );</pre>
 *
 * A version of uxTaskPriorityGet() that can be used from an ISR.
 */
UBaseType_t uxTaskPriorityGetFromISR( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>eTaskState eTaskGetState( TaskHandle_t xTask );</pre>
 *
 * INCLUDE_eTaskGetState must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Obtain the state of any task.  States are encoded by the eTaskState
 * enumerated type.
 *
 * @param xTask Handle of the task to be queried.
 *
 * @return The state of xTask at the time the function was called.  Note the
 * state of the task might change between the function being called, and the
 * functions return value being tested by the calling task.
 */
eTaskState eTaskGetState( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskPrioritySet( TaskHandle_t xTask, UBaseType_t uxNewPriority );</pre>
 *
 * INCLUDE_vTaskPrioritySet must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Set the priority of any task.
 *
 * A context switch will occur before the function returns if the priority
 * being set is higher than the currently executing task.
 *
 * @param xTask Handle to the task for which the priority is being set.
 * Passing a NULL handle results in the priority of the calling task being set.
 *
 * @param uxNewPriority The priority to which the task will be set.
 *
 * Example usage:
   <pre>
 void vAFunction( void )
 {
 TaskHandle_t xHandle;

	 // Create a task, storing the handle.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );

	 // ...

	 // Use the handle to raise the priority of the created task.
	 vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 );

	 // ...

	 // Use a NULL handle to raise our priority to the same value.
	 vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 );
 }
   </pre>
 * \defgroup vTaskPrioritySet vTaskPrioritySet
 * \ingroup TaskCtrl
 */
void vTaskPrioritySet( TaskHandle_t xTask, UBaseType_t uxNewPriority ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskSuspend( TaskHandle_t xTaskToSuspend );</pre>
 *
 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Suspend any task.  When suspended a task will never get any microcontroller
 * processing time, no matter what its priority.
 *
 * Calls to vTaskSuspend are not accumulative -
 * i.e. calling vTaskSuspend () twice on the same task still only requires one
 * call to vTaskResume () to ready the suspended task.
 *
 * @param xTaskToSuspend Handle to the task being suspended.  Passing a NULL
 * handle will cause the calling task to be suspended.
 *
 * Example usage:
   <pre>
 void vAFunction( void )
 {
 TaskHandle_t xHandle;

	 // Create a task, storing the handle.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );

	 // ...

	 // Use the handle to suspend the created task.
	 vTaskSuspend( xHandle );

	 // ...

	 // The created task will not run during this period, unless
	 // another task calls vTaskResume( xHandle ).

	 //...


	 // Suspend ourselves.
	 vTaskSuspend( NULL );

	 // We cannot get here unless another task calls vTaskResume
	 // with our handle as the parameter.
 }
   </pre>
 * \defgroup vTaskSuspend vTaskSuspend
 * \ingroup TaskCtrl
 */
void vTaskSuspend( TaskHandle_t xTaskToSuspend ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskResume( TaskHandle_t xTaskToResume );</pre>
 *
 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
 * See the configuration section for more information.
 *
 * Resumes a suspended task.
 *
 * A task that has been suspended by one or more calls to vTaskSuspend ()
 * will be made available for running again by a single call to
 * vTaskResume ().
 *
 * @param xTaskToResume Handle to the task being readied.
 *
 * Example usage:
   <pre>
 void vAFunction( void )
 {
 TaskHandle_t xHandle;

	 // Create a task, storing the handle.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );

	 // ...

	 // Use the handle to suspend the created task.
	 vTaskSuspend( xHandle );

	 // ...

	 // The created task will not run during this period, unless
	 // another task calls vTaskResume( xHandle ).

	 //...


	 // Resume the suspended task ourselves.
	 vTaskResume( xHandle );

	 // The created task will once again get microcontroller processing
	 // time in accordance with its priority within the system.
 }
   </pre>
 * \defgroup vTaskResume vTaskResume
 * \ingroup TaskCtrl
 */
void vTaskResume( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void xTaskResumeFromISR( TaskHandle_t xTaskToResume );</pre>
 *
 * INCLUDE_xTaskResumeFromISR must be defined as 1 for this function to be
 * available.  See the configuration section for more information.
 *
 * An implementation of vTaskResume() that can be called from within an ISR.
 *
 * A task that has been suspended by one or more calls to vTaskSuspend ()
 * will be made available for running again by a single call to
 * xTaskResumeFromISR ().
 *
 * xTaskResumeFromISR() should not be used to synchronise a task with an
 * interrupt if there is a chance that the interrupt could arrive prior to the
 * task being suspended - as this can lead to interrupts being missed. Use of a
 * semaphore as a synchronisation mechanism would avoid this eventuality.
 *
 * @param xTaskToResume Handle to the task being readied.
 *
 * @return pdTRUE if resuming the task should result in a context switch,
 * otherwise pdFALSE. This is used by the ISR to determine if a context switch
 * may be required following the ISR.
 *
 * \defgroup vTaskResumeFromISR vTaskResumeFromISR
 * \ingroup TaskCtrl
 */
BaseType_t xTaskResumeFromISR( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;

/*-----------------------------------------------------------
 * SCHEDULER CONTROL
 *----------------------------------------------------------*/

/**
 * task. h
 * <pre>void vTaskStartScheduler( void );</pre>
 *
 * Starts the real time kernel tick processing.  After calling the kernel
 * has control over which tasks are executed and when.
 *
 * See the demo application file main.c for an example of creating
 * tasks and starting the kernel.
 *
 * Example usage:
   <pre>
 void vAFunction( void )
 {
	 // Create at least one task before starting the kernel.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );

	 // Start the real time kernel with preemption.
	 vTaskStartScheduler ();

	 // Will not get here unless a task calls vTaskEndScheduler ()
 }
   </pre>
 *
 * \defgroup vTaskStartScheduler vTaskStartScheduler
 * \ingroup SchedulerControl
 */
void vTaskStartScheduler( void ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskEndScheduler( void );</pre>
 *
 * NOTE:  At the time of writing only the x86 real mode port, which runs on a PC
 * in place of DOS, implements this function.
 *
 * Stops the real time kernel tick.  All created tasks will be automatically
 * deleted and multitasking (either preemptive or cooperative) will
 * stop.  Execution then resumes from the point where vTaskStartScheduler ()
 * was called, as if vTaskStartScheduler () had just returned.
 *
 * See the demo application file main. c in the demo/PC directory for an
 * example that uses vTaskEndScheduler ().
 *
 * vTaskEndScheduler () requires an exit function to be defined within the
 * portable layer (see vPortEndScheduler () in port. c for the PC port).  This
 * performs hardware specific operations such as stopping the kernel tick.
 *
 * vTaskEndScheduler () will cause all of the resources allocated by the
 * kernel to be freed - but will not free resources allocated by application
 * tasks.
 *
 * Example usage:
   <pre>
 void vTaskCode( void * pvParameters )
 {
	 for( ;; )
	 {
		 // Task code goes here.

		 // At some point we want to end the real time kernel processing
		 // so call ...
		 vTaskEndScheduler ();
	 }
 }

 void vAFunction( void )
 {
	 // Create at least one task before starting the kernel.
	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );

	 // Start the real time kernel with preemption.
	 vTaskStartScheduler ();

	 // Will only get here when the vTaskCode () task has called
	 // vTaskEndScheduler ().  When we get here we are back to single task
	 // execution.
 }
   </pre>
 *
 * \defgroup vTaskEndScheduler vTaskEndScheduler
 * \ingroup SchedulerControl
 */
void vTaskEndScheduler( void ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>void vTaskSuspendAll( void );</pre>
 *
 * Suspends the scheduler without disabling interrupts.  Context switches will
 * not occur while the scheduler is suspended.
 *
 * After calling vTaskSuspendAll () the calling task will continue to execute
 * without risk of being swapped out until a call to xTaskResumeAll () has been
 * made.
 *
 * API functions that have the potential to cause a context switch (for example,
 * vTaskDelayUntil(), xQueueSend(), etc.) must not be called while the scheduler
 * is suspended.
 *
 * Example usage:
   <pre>
 void vTask1( void * pvParameters )
 {
	 for( ;; )
	 {
		 // Task code goes here.

		 // ...

		 // At some point the task wants to perform a long operation during
		 // which it does not want to get swapped out.  It cannot use
		 // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
		 // operation may cause interrupts to be missed - including the
		 // ticks.

		 // Prevent the real time kernel swapping out the task.
		 vTaskSuspendAll ();

		 // Perform the operation here.  There is no need to use critical
		 // sections as we have all the microcontroller processing time.
		 // During this time interrupts will still operate and the kernel
		 // tick count will be maintained.

		 // ...

		 // The operation is complete.  Restart the kernel.
		 xTaskResumeAll ();
	 }
 }
   </pre>
 * \defgroup vTaskSuspendAll vTaskSuspendAll
 * \ingroup SchedulerControl
 */
void vTaskSuspendAll( void ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <pre>BaseType_t xTaskResumeAll( void );</pre>
 *
 * Resumes scheduler activity after it was suspended by a call to
 * vTaskSuspendAll().
 *
 * xTaskResumeAll() only resumes the scheduler.  It does not unsuspend tasks
 * that were previously suspended by a call to vTaskSuspend().
 *
 * @return If resuming the scheduler caused a context switch then pdTRUE is
 *		  returned, otherwise pdFALSE is returned.
 *
 * Example usage:
   <pre>
 void vTask1( void * pvParameters )
 {
	 for( ;; )
	 {
		 // Task code goes here.

		 // ...

		 // At some point the task wants to perform a long operation during
		 // which it does not want to get swapped out.  It cannot use
		 // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
		 // operation may cause interrupts to be missed - including the
		 // ticks.

		 // Prevent the real time kernel swapping out the task.
		 vTaskSuspendAll ();

		 // Perform the operation here.  There is no need to use critical
		 // sections as we have all the microcontroller processing time.
		 // During this time interrupts will still operate and the real
		 // time kernel tick count will be maintained.

		 // ...

		 // The operation is complete.  Restart the kernel.  We want to force
		 // a context switch - but there is no point if resuming the scheduler
		 // caused a context switch already.
		 if( !xTaskResumeAll () )
		 {
			  taskYIELD ();
		 }
	 }
 }
   </pre>
 * \defgroup xTaskResumeAll xTaskResumeAll
 * \ingroup SchedulerControl
 */
BaseType_t xTaskResumeAll( void ) PRIVILEGED_FUNCTION;

/*-----------------------------------------------------------
 * TASK UTILITIES
 *----------------------------------------------------------*/

/**
 * task. h
 * <PRE>TickType_t xTaskGetTickCount( void );</PRE>
 *
 * @return The count of ticks since vTaskStartScheduler was called.
 *
 * \defgroup xTaskGetTickCount xTaskGetTickCount
 * \ingroup TaskUtils
 */
TickType_t xTaskGetTickCount( void ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>TickType_t xTaskGetTickCountFromISR( void );</PRE>
 *
 * @return The count of ticks since vTaskStartScheduler was called.
 *
 * This is a version of xTaskGetTickCount() that is safe to be called from an
 * ISR - provided that TickType_t is the natural word size of the
 * microcontroller being used or interrupt nesting is either not supported or
 * not being used.
 *
 * \defgroup xTaskGetTickCountFromISR xTaskGetTickCountFromISR
 * \ingroup TaskUtils
 */
TickType_t xTaskGetTickCountFromISR( void ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>uint16_t uxTaskGetNumberOfTasks( void );</PRE>
 *
 * @return The number of tasks that the real time kernel is currently managing.
 * This includes all ready, blocked and suspended tasks.  A task that
 * has been deleted but not yet freed by the idle task will also be
 * included in the count.
 *
 * \defgroup uxTaskGetNumberOfTasks uxTaskGetNumberOfTasks
 * \ingroup TaskUtils
 */
UBaseType_t uxTaskGetNumberOfTasks( void ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>char *pcTaskGetTaskName( TaskHandle_t xTaskToQuery );</PRE>
 *
 * @return The text (human readable) name of the task referenced by the handle
 * xTaskToQuery.  A task can query its own name by either passing in its own
 * handle, or by setting xTaskToQuery to NULL.  INCLUDE_pcTaskGetTaskName must be
 * set to 1 in FreeRTOSConfig.h for pcTaskGetTaskName() to be available.
 *
 * \defgroup pcTaskGetTaskName pcTaskGetTaskName
 * \ingroup TaskUtils
 */
char *pcTaskGetTaskName( TaskHandle_t xTaskToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */

/**
 * task.h
 * <PRE>UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask );</PRE>
 *
 * INCLUDE_uxTaskGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for
 * this function to be available.
 *
 * Returns the high water mark of the stack associated with xTask.  That is,
 * the minimum free stack space there has been (in words, so on a 32 bit machine
 * a value of 1 means 4 bytes) since the task started.  The smaller the returned
 * number the closer the task has come to overflowing its stack.
 *
 * @param xTask Handle of the task associated with the stack to be checked.
 * Set xTask to NULL to check the stack of the calling task.
 *
 * @return The smallest amount of free stack space there has been (in words, so
 * actual spaces on the stack rather than bytes) since the task referenced by
 * xTask was created.
 */
UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;

/* When using trace macros it is sometimes necessary to include task.h before
FreeRTOS.h.  When this is done TaskHookFunction_t will not yet have been defined,
so the following two prototypes will cause a compilation error.  This can be
fixed by simply guarding against the inclusion of these two prototypes unless
they are explicitly required by the configUSE_APPLICATION_TASK_TAG configuration
constant. */
#ifdef configUSE_APPLICATION_TASK_TAG
	#if configUSE_APPLICATION_TASK_TAG == 1
		/**
		 * task.h
		 * <pre>void vTaskSetApplicationTaskTag( TaskHandle_t xTask, TaskHookFunction_t pxHookFunction );</pre>
		 *
		 * Sets pxHookFunction to be the task hook function used by the task xTask.
		 * Passing xTask as NULL has the effect of setting the calling tasks hook
		 * function.
		 */
		void vTaskSetApplicationTaskTag( TaskHandle_t xTask, TaskHookFunction_t pxHookFunction ) PRIVILEGED_FUNCTION;

		/**
		 * task.h
		 * <pre>void xTaskGetApplicationTaskTag( TaskHandle_t xTask );</pre>
		 *
		 * Returns the pxHookFunction value assigned to the task xTask.
		 */
		TaskHookFunction_t xTaskGetApplicationTaskTag( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
	#endif /* configUSE_APPLICATION_TASK_TAG ==1 */
#endif /* ifdef configUSE_APPLICATION_TASK_TAG */

#if( configNUM_THREAD_LOCAL_STORAGE_POINTERS > 0 )

	/* Each task contains an array of pointers that is dimensioned by the
	configNUM_THREAD_LOCAL_STORAGE_POINTERS setting in FreeRTOSConfig.h.  The
	kernel does not use the pointers itself, so the application writer can use
	the pointers for any purpose they wish.  The following two functions are
	used to set and query a pointer respectively. */
	void vTaskSetThreadLocalStoragePointer( TaskHandle_t xTaskToSet, BaseType_t xIndex, void *pvValue ) PRIVILEGED_FUNCTION;
	void *pvTaskGetThreadLocalStoragePointer( TaskHandle_t xTaskToQuery, BaseType_t xIndex ) PRIVILEGED_FUNCTION;

#endif

/**
 * task.h
 * <pre>BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask, void *pvParameter );</pre>
 *
 * Calls the hook function associated with xTask.  Passing xTask as NULL has
 * the effect of calling the Running tasks (the calling task) hook function.
 *
 * pvParameter is passed to the hook function for the task to interpret as it
 * wants.  The return value is the value returned by the task hook function
 * registered by the user.
 */
BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask, void *pvParameter ) PRIVILEGED_FUNCTION;

/**
 * xTaskGetIdleTaskHandle() is only available if
 * INCLUDE_xTaskGetIdleTaskHandle is set to 1 in FreeRTOSConfig.h.
 *
 * Simply returns the handle of the idle task.  It is not valid to call
 * xTaskGetIdleTaskHandle() before the scheduler has been started.
 */
TaskHandle_t xTaskGetIdleTaskHandle( void ) PRIVILEGED_FUNCTION;

/**
 * configUSE_TRACE_FACILITY must be defined as 1 in FreeRTOSConfig.h for
 * uxTaskGetSystemState() to be available.
 *
 * uxTaskGetSystemState() populates an TaskStatus_t structure for each task in
 * the system.  TaskStatus_t structures contain, among other things, members
 * for the task handle, task name, task priority, task state, and total amount
 * of run time consumed by the task.  See the TaskStatus_t structure
 * definition in this file for the full member list.
 *
 * NOTE:  This function is intended for debugging use only as its use results in
 * the scheduler remaining suspended for an extended period.
 *
 * @param pxTaskStatusArray A pointer to an array of TaskStatus_t structures.
 * The array must contain at least one TaskStatus_t structure for each task
 * that is under the control of the RTOS.  The number of tasks under the control
 * of the RTOS can be determined using the uxTaskGetNumberOfTasks() API function.
 *
 * @param uxArraySize The size of the array pointed to by the pxTaskStatusArray
 * parameter.  The size is specified as the number of indexes in the array, or
 * the number of TaskStatus_t structures contained in the array, not by the
 * number of bytes in the array.
 *
 * @param pulTotalRunTime If configGENERATE_RUN_TIME_STATS is set to 1 in
 * FreeRTOSConfig.h then *pulTotalRunTime is set by uxTaskGetSystemState() to the
 * total run time (as defined by the run time stats clock, see
 * http://www.freertos.org/rtos-run-time-stats.html) since the target booted.
 * pulTotalRunTime can be set to NULL to omit the total run time information.
 *
 * @return The number of TaskStatus_t structures that were populated by
 * uxTaskGetSystemState().  This should equal the number returned by the
 * uxTaskGetNumberOfTasks() API function, but will be zero if the value passed
 * in the uxArraySize parameter was too small.
 *
 * Example usage:
   <pre>
    // This example demonstrates how a human readable table of run time stats
	// information is generated from raw data provided by uxTaskGetSystemState().
	// The human readable table is written to pcWriteBuffer
	void vTaskGetRunTimeStats( char *pcWriteBuffer )
	{
	TaskStatus_t *pxTaskStatusArray;
	volatile UBaseType_t uxArraySize, x;
	uint32_t ulTotalRunTime, ulStatsAsPercentage;

		// Make sure the write buffer does not contain a string.
		*pcWriteBuffer = 0x00;

		// Take a snapshot of the number of tasks in case it changes while this
		// function is executing.
		uxArraySize = uxTaskGetNumberOfTasks();

		// Allocate a TaskStatus_t structure for each task.  An array could be
		// allocated statically at compile time.
		pxTaskStatusArray = pvPortMalloc( uxArraySize * sizeof( TaskStatus_t ) );

		if( pxTaskStatusArray != NULL )
		{
			// Generate raw status information about each task.
			uxArraySize = uxTaskGetSystemState( pxTaskStatusArray, uxArraySize, &ulTotalRunTime );

			// For percentage calculations.
			ulTotalRunTime /= 100UL;

			// Avoid divide by zero errors.
			if( ulTotalRunTime > 0 )
			{
				// For each populated position in the pxTaskStatusArray array,
				// format the raw data as human readable ASCII data
				for( x = 0; x < uxArraySize; x++ )
				{
					// What percentage of the total run time has the task used?
					// This will always be rounded down to the nearest integer.
					// ulTotalRunTimeDiv100 has already been divided by 100.
					ulStatsAsPercentage = pxTaskStatusArray[ x ].ulRunTimeCounter / ulTotalRunTime;

					if( ulStatsAsPercentage > 0UL )
					{
						sprintf( pcWriteBuffer, "%s\t\t%lu\t\t%lu%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter, ulStatsAsPercentage );
					}
					else
					{
						// If the percentage is zero here then the task has
						// consumed less than 1% of the total run time.
						sprintf( pcWriteBuffer, "%s\t\t%lu\t\t<1%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter );
					}

					pcWriteBuffer += strlen( ( char * ) pcWriteBuffer );
				}
			}

			// The array is no longer needed, free the memory it consumes.
			vPortFree( pxTaskStatusArray );
		}
	}
	</pre>
 */
UBaseType_t uxTaskGetSystemState( TaskStatus_t * const pxTaskStatusArray, const UBaseType_t uxArraySize, uint32_t * const pulTotalRunTime ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>void vTaskList( char *pcWriteBuffer );</PRE>
 *
 * configUSE_TRACE_FACILITY and configUSE_STATS_FORMATTING_FUNCTIONS must
 * both be defined as 1 for this function to be available.  See the
 * configuration section of the FreeRTOS.org website for more information.
 *
 * NOTE 1: This function will disable interrupts for its duration.  It is
 * not intended for normal application runtime use but as a debug aid.
 *
 * Lists all the current tasks, along with their current state and stack
 * usage high water mark.
 *
 * Tasks are reported as blocked ('B'), ready ('R'), deleted ('D') or
 * suspended ('S').
 *
 * PLEASE NOTE:
 *
 * This function is provided for convenience only, and is used by many of the
 * demo applications.  Do not consider it to be part of the scheduler.
 *
 * vTaskList() calls uxTaskGetSystemState(), then formats part of the
 * uxTaskGetSystemState() output into a human readable table that displays task
 * names, states and stack usage.
 *
 * vTaskList() has a dependency on the sprintf() C library function that might
 * bloat the code size, use a lot of stack, and provide different results on
 * different platforms.  An alternative, tiny, third party, and limited
 * functionality implementation of sprintf() is provided in many of the
 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
 * printf-stdarg.c does not provide a full snprintf() implementation!).
 *
 * It is recommended that production systems call uxTaskGetSystemState()
 * directly to get access to raw stats data, rather than indirectly through a
 * call to vTaskList().
 *
 * @param pcWriteBuffer A buffer into which the above mentioned details
 * will be written, in ASCII form.  This buffer is assumed to be large
 * enough to contain the generated report.  Approximately 40 bytes per
 * task should be sufficient.
 *
 * \defgroup vTaskList vTaskList
 * \ingroup TaskUtils
 */
void vTaskList( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */

/**
 * task. h
 * <PRE>void vTaskGetRunTimeStats( char *pcWriteBuffer );</PRE>
 *
 * configGENERATE_RUN_TIME_STATS and configUSE_STATS_FORMATTING_FUNCTIONS
 * must both be defined as 1 for this function to be available.  The application
 * must also then provide definitions for
 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE()
 * to configure a peripheral timer/counter and return the timers current count
 * value respectively.  The counter should be at least 10 times the frequency of
 * the tick count.
 *
 * NOTE 1: This function will disable interrupts for its duration.  It is
 * not intended for normal application runtime use but as a debug aid.
 *
 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
 * accumulated execution time being stored for each task.  The resolution
 * of the accumulated time value depends on the frequency of the timer
 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
 * Calling vTaskGetRunTimeStats() writes the total execution time of each
 * task into a buffer, both as an absolute count value and as a percentage
 * of the total system execution time.
 *
 * NOTE 2:
 *
 * This function is provided for convenience only, and is used by many of the
 * demo applications.  Do not consider it to be part of the scheduler.
 *
 * vTaskGetRunTimeStats() calls uxTaskGetSystemState(), then formats part of the
 * uxTaskGetSystemState() output into a human readable table that displays the
 * amount of time each task has spent in the Running state in both absolute and
 * percentage terms.
 *
 * vTaskGetRunTimeStats() has a dependency on the sprintf() C library function
 * that might bloat the code size, use a lot of stack, and provide different
 * results on different platforms.  An alternative, tiny, third party, and
 * limited functionality implementation of sprintf() is provided in many of the
 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
 * printf-stdarg.c does not provide a full snprintf() implementation!).
 *
 * It is recommended that production systems call uxTaskGetSystemState() directly
 * to get access to raw stats data, rather than indirectly through a call to
 * vTaskGetRunTimeStats().
 *
 * @param pcWriteBuffer A buffer into which the execution times will be
 * written, in ASCII form.  This buffer is assumed to be large enough to
 * contain the generated report.  Approximately 40 bytes per task should
 * be sufficient.
 *
 * \defgroup vTaskGetRunTimeStats vTaskGetRunTimeStats
 * \ingroup TaskUtils
 */
void vTaskGetRunTimeStats( char *pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */

/**
 * task. h
 * <PRE>BaseType_t xTaskNotify( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction );</PRE>
 *
 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
 * function to be available.
 *
 * When configUSE_TASK_NOTIFICATIONS is set to one each task has its own private
 * "notification value", which is a 32-bit unsigned integer (uint32_t).
 *
 * Events can be sent to a task using an intermediary object.  Examples of such
 * objects are queues, semaphores, mutexes and event groups.  Task notifications
 * are a method of sending an event directly to a task without the need for such
 * an intermediary object.
 *
 * A notification sent to a task can optionally perform an action, such as
 * update, overwrite or increment the task's notification value.  In that way
 * task notifications can be used to send data to a task, or be used as light
 * weight and fast binary or counting semaphores.
 *
 * A notification sent to a task will remain pending until it is cleared by the
 * task calling xTaskNotifyWait() or ulTaskNotifyTake().  If the task was
 * already in the Blocked state to wait for a notification when the notification
 * arrives then the task will automatically be removed from the Blocked state
 * (unblocked) and the notification cleared.
 *
 * A task can use xTaskNotifyWait() to [optionally] block to wait for a
 * notification to be pending, or ulTaskNotifyTake() to [optionally] block
 * to wait for its notification value to have a non-zero value.  The task does
 * not consume any CPU time while it is in the Blocked state.
 *
 * See http://www.FreeRTOS.org/RTOS-task-notifications.html for details.
 *
 * @param xTaskToNotify The handle of the task being notified.  The handle to a
 * task can be returned from the xTaskCreate() API function used to create the
 * task, and the handle of the currently running task can be obtained by calling
 * xTaskGetCurrentTaskHandle().
 *
 * @param ulValue Data that can be sent with the notification.  How the data is
 * used depends on the value of the eAction parameter.
 *
 * @param eAction Specifies how the notification updates the task's notification
 * value, if at all.  Valid values for eAction are as follows:
 *
 * eSetBits -
 * The task's notification value is bitwise ORed with ulValue.  xTaskNofify()
 * always returns pdPASS in this case.
 *
 * eIncrement -
 * The task's notification value is incremented.  ulValue is not used and
 * xTaskNotify() always returns pdPASS in this case.
 *
 * eSetValueWithOverwrite -
 * The task's notification value is set to the value of ulValue, even if the
 * task being notified had not yet processed the previous notification (the
 * task already had a notification pending).  xTaskNotify() always returns
 * pdPASS in this case.
 *
 * eSetValueWithoutOverwrite -
 * If the task being notified did not already have a notification pending then
 * the task's notification value is set to ulValue and xTaskNotify() will
 * return pdPASS.  If the task being notified already had a notification
 * pending then no action is performed and pdFAIL is returned.
 *
 * eNoAction -
 * The task receives a notification without its notification value being
 * updated.  ulValue is not used and xTaskNotify() always returns pdPASS in
 * this case.
 *
 *  pulPreviousNotificationValue -
 *  Can be used to pass out the subject task's notification value before any
 *  bits are modified by the notify function.
 *
 * @return Dependent on the value of eAction.  See the description of the
 * eAction parameter.
 *
 * \defgroup xTaskNotify xTaskNotify
 * \ingroup TaskNotifications
 */
BaseType_t xTaskGenericNotify( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue ) PRIVILEGED_FUNCTION;
#define xTaskNotify( xTaskToNotify, ulValue, eAction ) xTaskGenericNotify( ( xTaskToNotify ), ( ulValue ), ( eAction ), NULL )
#define xTaskNotifyAndQuery( xTaskToNotify, ulValue, eAction, pulPreviousNotifyValue ) xTaskGenericNotify( ( xTaskToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )

/**
 * task. h
 * <PRE>BaseType_t xTaskNotifyFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
 *
 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
 * function to be available.
 *
 * When configUSE_TASK_NOTIFICATIONS is set to one each task has its own private
 * "notification value", which is a 32-bit unsigned integer (uint32_t).
 *
 * A version of xTaskNotify() that can be used from an interrupt service routine
 * (ISR).
 *
 * Events can be sent to a task using an intermediary object.  Examples of such
 * objects are queues, semaphores, mutexes and event groups.  Task notifications
 * are a method of sending an event directly to a task without the need for such
 * an intermediary object.
 *
 * A notification sent to a task can optionally perform an action, such as
 * update, overwrite or increment the task's notification value.  In that way
 * task notifications can be used to send data to a task, or be used as light
 * weight and fast binary or counting semaphores.
 *
 * A notification sent to a task will remain pending until it is cleared by the
 * task calling xTaskNotifyWait() or ulTaskNotifyTake().  If the task was
 * already in the Blocked state to wait for a notification when the notification
 * arrives then the task will automatically be removed from the Blocked state
 * (unblocked) and the notification cleared.
 *
 * A task can use xTaskNotifyWait() to [optionally] block to wait for a
 * notification to be pending, or ulTaskNotifyTake() to [optionally] block
 * to wait for its notification value to have a non-zero value.  The task does
 * not consume any CPU time while it is in the Blocked state.
 *
 * See http://www.FreeRTOS.org/RTOS-task-notifications.html for details.
 *
 * @param xTaskToNotify The handle of the task being notified.  The handle to a
 * task can be returned from the xTaskCreate() API function used to create the
 * task, and the handle of the currently running task can be obtained by calling
 * xTaskGetCurrentTaskHandle().
 *
 * @param ulValue Data that can be sent with the notification.  How the data is
 * used depends on the value of the eAction parameter.
 *
 * @param eAction Specifies how the notification updates the task's notification
 * value, if at all.  Valid values for eAction are as follows:
 *
 * eSetBits -
 * The task's notification value is bitwise ORed with ulValue.  xTaskNofify()
 * always returns pdPASS in this case.
 *
 * eIncrement -
 * The task's notification value is incremented.  ulValue is not used and
 * xTaskNotify() always returns pdPASS in this case.
 *
 * eSetValueWithOverwrite -
 * The task's notification value is set to the value of ulValue, even if the
 * task being notified had not yet processed the previous notification (the
 * task already had a notification pending).  xTaskNotify() always returns
 * pdPASS in this case.
 *
 * eSetValueWithoutOverwrite -
 * If the task being notified did not already have a notification pending then
 * the task's notification value is set to ulValue and xTaskNotify() will
 * return pdPASS.  If the task being notified already had a notification
 * pending then no action is performed and pdFAIL is returned.
 *
 * eNoAction -
 * The task receives a notification without its notification value being
 * updated.  ulValue is not used and xTaskNotify() always returns pdPASS in
 * this case.
 *
 * @param pxHigherPriorityTaskWoken  xTaskNotifyFromISR() will set
 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
 * task to which the notification was sent to leave the Blocked state, and the
 * unblocked task has a priority higher than the currently running task.  If
 * xTaskNotifyFromISR() sets this value to pdTRUE then a context switch should
 * be requested before the interrupt is exited.  How a context switch is
 * requested from an ISR is dependent on the port - see the documentation page
 * for the port in use.
 *
 * @return Dependent on the value of eAction.  See the description of the
 * eAction parameter.
 *
 * \defgroup xTaskNotify xTaskNotify
 * \ingroup TaskNotifications
 */
BaseType_t xTaskGenericNotifyFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
#define xTaskNotifyFromISR( xTaskToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
#define xTaskNotifyAndQueryFromISR( xTaskToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )

/**
 * task. h
 * <PRE>BaseType_t xTaskNotifyWait( uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );</pre>
 *
 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
 * function to be available.
 *
 * When configUSE_TASK_NOTIFICATIONS is set to one each task has its own private
 * "notification value", which is a 32-bit unsigned integer (uint32_t).
 *
 * Events can be sent to a task using an intermediary object.  Examples of such
 * objects are queues, semaphores, mutexes and event groups.  Task notifications
 * are a method of sending an event directly to a task without the need for such
 * an intermediary object.
 *
 * A notification sent to a task can optionally perform an action, such as
 * update, overwrite or increment the task's notification value.  In that way
 * task notifications can be used to send data to a task, or be used as light
 * weight and fast binary or counting semaphores.
 *
 * A notification sent to a task will remain pending until it is cleared by the
 * task calling xTaskNotifyWait() or ulTaskNotifyTake().  If the task was
 * already in the Blocked state to wait for a notification when the notification
 * arrives then the task will automatically be removed from the Blocked state
 * (unblocked) and the notification cleared.
 *
 * A task can use xTaskNotifyWait() to [optionally] block to wait for a
 * notification to be pending, or ulTaskNotifyTake() to [optionally] block
 * to wait for its notification value to have a non-zero value.  The task does
 * not consume any CPU time while it is in the Blocked state.
 *
 * See http://www.FreeRTOS.org/RTOS-task-notifications.html for details.
 *
 * @param ulBitsToClearOnEntry Bits that are set in ulBitsToClearOnEntry value
 * will be cleared in the calling task's notification value before the task
 * checks to see if any notifications are pending, and optionally blocks if no
 * notifications are pending.  Setting ulBitsToClearOnEntry to ULONG_MAX (if
 * limits.h is included) or 0xffffffffUL (if limits.h is not included) will have
 * the effect of resetting the task's notification value to 0.  Setting
 * ulBitsToClearOnEntry to 0 will leave the task's notification value unchanged.
 *
 * @param ulBitsToClearOnExit If a notification is pending or received before
 * the calling task exits the xTaskNotifyWait() function then the task's
 * notification value (see the xTaskNotify() API function) is passed out using
 * the pulNotificationValue parameter.  Then any bits that are set in
 * ulBitsToClearOnExit will be cleared in the task's notification value (note
 * *pulNotificationValue is set before any bits are cleared).  Setting
 * ulBitsToClearOnExit to ULONG_MAX (if limits.h is included) or 0xffffffffUL
 * (if limits.h is not included) will have the effect of resetting the task's
 * notification value to 0 before the function exits.  Setting
 * ulBitsToClearOnExit to 0 will leave the task's notification value unchanged
 * when the function exits (in which case the value passed out in
 * pulNotificationValue will match the task's notification value).
 *
 * @param pulNotificationValue Used to pass the task's notification value out
 * of the function.  Note the value passed out will not be effected by the
 * clearing of any bits caused by ulBitsToClearOnExit being non-zero.
 *
 * @param xTicksToWait The maximum amount of time that the task should wait in
 * the Blocked state for a notification to be received, should a notification
 * not already be pending when xTaskNotifyWait() was called.  The task
 * will not consume any processing time while it is in the Blocked state.  This
 * is specified in kernel ticks, the macro pdMS_TO_TICSK( value_in_ms ) can be
 * used to convert a time specified in milliseconds to a time specified in
 * ticks.
 *
 * @return If a notification was received (including notifications that were
 * already pending when xTaskNotifyWait was called) then pdPASS is
 * returned.  Otherwise pdFAIL is returned.
 *
 * \defgroup xTaskNotifyWait xTaskNotifyWait
 * \ingroup TaskNotifications
 */
BaseType_t xTaskNotifyWait( uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>BaseType_t xTaskNotifyGive( TaskHandle_t xTaskToNotify );</PRE>
 *
 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this macro
 * to be available.
 *
 * When configUSE_TASK_NOTIFICATIONS is set to one each task has its own private
 * "notification value", which is a 32-bit unsigned integer (uint32_t).
 *
 * Events can be sent to a task using an intermediary object.  Examples of such
 * objects are queues, semaphores, mutexes and event groups.  Task notifications
 * are a method of sending an event directly to a task without the need for such
 * an intermediary object.
 *
 * A notification sent to a task can optionally perform an action, such as
 * update, overwrite or increment the task's notification value.  In that way
 * task notifications can be used to send data to a task, or be used as light
 * weight and fast binary or counting semaphores.
 *
 * xTaskNotifyGive() is a helper macro intended for use when task notifications
 * are used as light weight and faster binary or counting semaphore equivalents.
 * Actual FreeRTOS semaphores are given using the xSemaphoreGive() API function,
 * the equivalent action that instead uses a task notification is
 * xTaskNotifyGive().
 *
 * When task notifications are being used as a binary or counting semaphore
 * equivalent then the task being notified should wait for the notification
 * using the ulTaskNotificationTake() API function rather than the
 * xTaskNotifyWait() API function.
 *
 * See http://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
 *
 * @param xTaskToNotify The handle of the task being notified.  The handle to a
 * task can be returned from the xTaskCreate() API function used to create the
 * task, and the handle of the currently running task can be obtained by calling
 * xTaskGetCurrentTaskHandle().
 *
 * @return xTaskNotifyGive() is a macro that calls xTaskNotify() with the
 * eAction parameter set to eIncrement - so pdPASS is always returned.
 *
 * \defgroup xTaskNotifyGive xTaskNotifyGive
 * \ingroup TaskNotifications
 */
#define xTaskNotifyGive( xTaskToNotify ) xTaskGenericNotify( ( xTaskToNotify ), ( 0 ), eIncrement, NULL )

/**
 * task. h
 * <PRE>void vTaskNotifyGiveFromISR( TaskHandle_t xTaskHandle, BaseType_t *pxHigherPriorityTaskWoken );
 *
 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this macro
 * to be available.
 *
 * When configUSE_TASK_NOTIFICATIONS is set to one each task has its own private
 * "notification value", which is a 32-bit unsigned integer (uint32_t).
 *
 * A version of xTaskNotifyGive() that can be called from an interrupt service
 * routine (ISR).
 *
 * Events can be sent to a task using an intermediary object.  Examples of such
 * objects are queues, semaphores, mutexes and event groups.  Task notifications
 * are a method of sending an event directly to a task without the need for such
 * an intermediary object.
 *
 * A notification sent to a task can optionally perform an action, such as
 * update, overwrite or increment the task's notification value.  In that way
 * task notifications can be used to send data to a task, or be used as light
 * weight and fast binary or counting semaphores.
 *
 * vTaskNotifyGiveFromISR() is intended for use when task notifications are
 * used as light weight and faster binary or counting semaphore equivalents.
 * Actual FreeRTOS semaphores are given from an ISR using the
 * xSemaphoreGiveFromISR() API function, the equivalent action that instead uses
 * a task notification is vTaskNotifyGiveFromISR().
 *
 * When task notifications are being used as a binary or counting semaphore
 * equivalent then the task being notified should wait for the notification
 * using the ulTaskNotificationTake() API function rather than the
 * xTaskNotifyWait() API function.
 *
 * See http://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
 *
 * @param xTaskToNotify The handle of the task being notified.  The handle to a
 * task can be returned from the xTaskCreate() API function used to create the
 * task, and the handle of the currently running task can be obtained by calling
 * xTaskGetCurrentTaskHandle().
 *
 * @param pxHigherPriorityTaskWoken  vTaskNotifyGiveFromISR() will set
 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
 * task to which the notification was sent to leave the Blocked state, and the
 * unblocked task has a priority higher than the currently running task.  If
 * vTaskNotifyGiveFromISR() sets this value to pdTRUE then a context switch
 * should be requested before the interrupt is exited.  How a context switch is
 * requested from an ISR is dependent on the port - see the documentation page
 * for the port in use.
 *
 * \defgroup xTaskNotifyWait xTaskNotifyWait
 * \ingroup TaskNotifications
 */
void vTaskNotifyGiveFromISR( TaskHandle_t xTaskToNotify, BaseType_t *pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>uint32_t ulTaskNotifyTake( BaseType_t xClearCountOnExit, TickType_t xTicksToWait );</pre>
 *
 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
 * function to be available.
 *
 * When configUSE_TASK_NOTIFICATIONS is set to one each task has its own private
 * "notification value", which is a 32-bit unsigned integer (uint32_t).
 *
 * Events can be sent to a task using an intermediary object.  Examples of such
 * objects are queues, semaphores, mutexes and event groups.  Task notifications
 * are a method of sending an event directly to a task without the need for such
 * an intermediary object.
 *
 * A notification sent to a task can optionally perform an action, such as
 * update, overwrite or increment the task's notification value.  In that way
 * task notifications can be used to send data to a task, or be used as light
 * weight and fast binary or counting semaphores.
 *
 * ulTaskNotifyTake() is intended for use when a task notification is used as a
 * faster and lighter weight binary or counting semaphore alternative.  Actual
 * FreeRTOS semaphores are taken using the xSemaphoreTake() API function, the
 * equivalent action that instead uses a task notification is
 * ulTaskNotifyTake().
 *
 * When a task is using its notification value as a binary or counting semaphore
 * other tasks should send notifications to it using the xTaskNotifyGive()
 * macro, or xTaskNotify() function with the eAction parameter set to
 * eIncrement.
 *
 * ulTaskNotifyTake() can either clear the task's notification value to
 * zero on exit, in which case the notification value acts like a binary
 * semaphore, or decrement the task's notification value on exit, in which case
 * the notification value acts like a counting semaphore.
 *
 * A task can use ulTaskNotifyTake() to [optionally] block to wait for a
 * the task's notification value to be non-zero.  The task does not consume any
 * CPU time while it is in the Blocked state.
 *
 * Where as xTaskNotifyWait() will return when a notification is pending,
 * ulTaskNotifyTake() will return when the task's notification value is
 * not zero.
 *
 * See http://www.FreeRTOS.org/RTOS-task-notifications.html for details.
 *
 * @param xClearCountOnExit if xClearCountOnExit is pdFALSE then the task's
 * notification value is decremented when the function exits.  In this way the
 * notification value acts like a counting semaphore.  If xClearCountOnExit is
 * not pdFALSE then the task's notification value is cleared to zero when the
 * function exits.  In this way the notification value acts like a binary
 * semaphore.
 *
 * @param xTicksToWait The maximum amount of time that the task should wait in
 * the Blocked state for the task's notification value to be greater than zero,
 * should the count not already be greater than zero when
 * ulTaskNotifyTake() was called.  The task will not consume any processing
 * time while it is in the Blocked state.  This is specified in kernel ticks,
 * the macro pdMS_TO_TICSK( value_in_ms ) can be used to convert a time
 * specified in milliseconds to a time specified in ticks.
 *
 * @return The task's notification count before it is either cleared to zero or
 * decremented (see the xClearCountOnExit parameter).
 *
 * \defgroup ulTaskNotifyTake ulTaskNotifyTake
 * \ingroup TaskNotifications
 */
uint32_t ulTaskNotifyTake( BaseType_t xClearCountOnExit, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;

/**
 * task. h
 * <PRE>BaseType_t xTaskNotifyStateClear( TaskHandle_t xTask );</pre>
 *
 * If the notification state of the task referenced by the handle xTask is
 * eNotified, then set the task's notification state to eNotWaitingNotification.
 * The task's notification value is not altered.  Set xTask to NULL to clear the
 * notification state of the calling task.
 *
 * @return pdTRUE if the task's notification state was set to
 * eNotWaitingNotification, otherwise pdFALSE.
 * \defgroup xTaskNotifyStateClear xTaskNotifyStateClear
 * \ingroup TaskNotifications
 */
BaseType_t xTaskNotifyStateClear( TaskHandle_t xTask );

/*-----------------------------------------------------------
 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
 *----------------------------------------------------------*/

/*
 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE.  IT IS ONLY
 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
 *
 * Called from the real time kernel tick (either preemptive or cooperative),
 * this increments the tick count and checks if any tasks that are blocked
 * for a finite period required removing from a blocked list and placing on
 * a ready list.  If a non-zero value is returned then a context switch is
 * required because either:
 *   + A task was removed from a blocked list because its timeout had expired,
 *     or
 *   + Time slicing is in use and there is a task of equal priority to the
 *     currently running task.
 */
BaseType_t xTaskIncrementTick( void ) PRIVILEGED_FUNCTION;

/*
 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE.  IT IS AN
 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
 *
 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
 *
 * Removes the calling task from the ready list and places it both
 * on the list of tasks waiting for a particular event, and the
 * list of delayed tasks.  The task will be removed from both lists
 * and replaced on the ready list should either the event occur (and
 * there be no higher priority tasks waiting on the same event) or
 * the delay period expires.
 *
 * The 'unordered' version replaces the event list item value with the
 * xItemValue value, and inserts the list item at the end of the list.
 *
 * The 'ordered' version uses the existing event list item value (which is the
 * owning tasks priority) to insert the list item into the event list is task
 * priority order.
 *
 * @param pxEventList The list containing tasks that are blocked waiting
 * for the event to occur.
 *
 * @param xItemValue The item value to use for the event list item when the
 * event list is not ordered by task priority.
 *
 * @param xTicksToWait The maximum amount of time that the task should wait
 * for the event to occur.  This is specified in kernel ticks,the constant
 * portTICK_PERIOD_MS can be used to convert kernel ticks into a real time
 * period.
 */
void vTaskPlaceOnEventList( List_t * const pxEventList, const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
void vTaskPlaceOnUnorderedEventList( List_t * pxEventList, const TickType_t xItemValue, const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;

/*
 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE.  IT IS AN
 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
 *
 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
 *
 * This function performs nearly the same function as vTaskPlaceOnEventList().
 * The difference being that this function does not permit tasks to block
 * indefinitely, whereas vTaskPlaceOnEventList() does.
 *
 */
void vTaskPlaceOnEventListRestricted( List_t * const pxEventList, const TickType_t xTicksToWait, const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;

/*
 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE.  IT IS AN
 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
 *
 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
 *
 * Removes a task from both the specified event list and the list of blocked
 * tasks, and places it on a ready queue.
 *
 * xTaskRemoveFromEventList()/xTaskRemoveFromUnorderedEventList() will be called
 * if either an event occurs to unblock a task, or the block timeout period
 * expires.
 *
 * xTaskRemoveFromEventList() is used when the event list is in task priority
 * order.  It removes the list item from the head of the event list as that will
 * have the highest priority owning task of all the tasks on the event list.
 * xTaskRemoveFromUnorderedEventList() is used when the event list is not
 * ordered and the event list items hold something other than the owning tasks
 * priority.  In this case the event list item value is updated to the value
 * passed in the xItemValue parameter.
 *
 * @return pdTRUE if the task being removed has a higher priority than the task
 * making the call, otherwise pdFALSE.
 */
BaseType_t xTaskRemoveFromEventList( const List_t * const pxEventList ) PRIVILEGED_FUNCTION;
BaseType_t xTaskRemoveFromUnorderedEventList( ListItem_t * pxEventListItem, const TickType_t xItemValue ) PRIVILEGED_FUNCTION;

/*
 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE.  IT IS ONLY
 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
 *
 * Sets the pointer to the current TCB to the TCB of the highest priority task
 * that is ready to run.
 */
void vTaskSwitchContext( void ) PRIVILEGED_FUNCTION;

/*
 * THESE FUNCTIONS MUST NOT BE USED FROM APPLICATION CODE.  THEY ARE USED BY
 * THE EVENT BITS MODULE.
 */
TickType_t uxTaskResetEventItemValue( void ) PRIVILEGED_FUNCTION;

/*
 * Return the handle of the calling task.
 */
TaskHandle_t xTaskGetCurrentTaskHandle( void ) PRIVILEGED_FUNCTION;

/*
 * Capture the current time status for future reference.
 */
void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;

/*
 * Compare the time status now with that previously captured to see if the
 * timeout has expired.
 */
BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut, TickType_t * const pxTicksToWait ) PRIVILEGED_FUNCTION;

/*
 * Shortcut used by the queue implementation to prevent unnecessary call to
 * taskYIELD();
 */
void vTaskMissedYield( void ) PRIVILEGED_FUNCTION;

/*
 * Returns the scheduler state as taskSCHEDULER_RUNNING,
 * taskSCHEDULER_NOT_STARTED or taskSCHEDULER_SUSPENDED.
 */
BaseType_t xTaskGetSchedulerState( void ) PRIVILEGED_FUNCTION;

/*
 * Raises the priority of the mutex holder to that of the calling task should
 * the mutex holder have a priority less than the calling task.
 */
void vTaskPriorityInherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;

/*
 * Set the priority of a task back to its proper priority in the case that it
 * inherited a higher priority while it was holding a semaphore.
 */
BaseType_t xTaskPriorityDisinherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;

/*
 * Generic version of the task creation function which is in turn called by the
 * xTaskCreate() and xTaskCreateRestricted() macros.
 */
BaseType_t xTaskGenericCreate( TaskFunction_t pxTaskCode, const char * const pcName, const uint16_t usStackDepth, void * const pvParameters, UBaseType_t uxPriority, TaskHandle_t * const pxCreatedTask, StackType_t * const puxStackBuffer, const MemoryRegion_t * const xRegions ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */

/*
 * Get the uxTCBNumber assigned to the task referenced by the xTask parameter.
 */
UBaseType_t uxTaskGetTaskNumber( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;

/*
 * Set the uxTaskNumber of the task referenced by the xTask parameter to
 * uxHandle.
 */
void vTaskSetTaskNumber( TaskHandle_t xTask, const UBaseType_t uxHandle ) PRIVILEGED_FUNCTION;

/*
 * Only available when configUSE_TICKLESS_IDLE is set to 1.
 * If tickless mode is being used, or a low power mode is implemented, then
 * the tick interrupt will not execute during idle periods.  When this is the
 * case, the tick count value maintained by the scheduler needs to be kept up
 * to date with the actual execution time by being skipped forward by a time
 * equal to the idle period.
 */
void vTaskStepTick( const TickType_t xTicksToJump ) PRIVILEGED_FUNCTION;

/*
 * Only avilable when configUSE_TICKLESS_IDLE is set to 1.
 * Provided for use within portSUPPRESS_TICKS_AND_SLEEP() to allow the port
 * specific sleep function to determine if it is ok to proceed with the sleep,
 * and if it is ok to proceed, if it is ok to sleep indefinitely.
 *
 * This function is necessary because portSUPPRESS_TICKS_AND_SLEEP() is only
 * called with the scheduler suspended, not from within a critical section.  It
 * is therefore possible for an interrupt to request a context switch between
 * portSUPPRESS_TICKS_AND_SLEEP() and the low power mode actually being
 * entered.  eTaskConfirmSleepModeStatus() should be called from a short
 * critical section between the timer being stopped and the sleep mode being
 * entered to ensure it is ok to proceed into the sleep mode.
 */
eSleepModeStatus eTaskConfirmSleepModeStatus( void ) PRIVILEGED_FUNCTION;

/*
 * For internal use only.  Increment the mutex held count when a mutex is
 * taken and return the handle of the task that has taken the mutex.
 */
void *pvTaskIncrementMutexHeldCount( void ) PRIVILEGED_FUNCTION;

#ifdef __cplusplus
}
#endif
#endif /* INC_TASK_H */