Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
#ifndef KMP_DISPATCH_HIER_H
#define KMP_DISPATCH_HIER_H
#include "kmp.h"
#include "kmp_dispatch.h"

// Layer type for scheduling hierarchy
enum kmp_hier_layer_e {
  LAYER_THREAD = -1,
  LAYER_L1,
  LAYER_L2,
  LAYER_L3,
  LAYER_NUMA,
  LAYER_LOOP,
  LAYER_LAST
};

// Convert hierarchy type (LAYER_L1, LAYER_L2, etc.) to C-style string
static inline const char *__kmp_get_hier_str(kmp_hier_layer_e type) {
  switch (type) {
  case kmp_hier_layer_e::LAYER_THREAD:
    return "THREAD";
  case kmp_hier_layer_e::LAYER_L1:
    return "L1";
  case kmp_hier_layer_e::LAYER_L2:
    return "L2";
  case kmp_hier_layer_e::LAYER_L3:
    return "L3";
  case kmp_hier_layer_e::LAYER_NUMA:
    return "NUMA";
  case kmp_hier_layer_e::LAYER_LOOP:
    return "WHOLE_LOOP";
  case kmp_hier_layer_e::LAYER_LAST:
    return "LAST";
  }
  KMP_ASSERT(0);
  // Appease compilers, should never get here
  return "ERROR";
}

// Structure to store values parsed from OMP_SCHEDULE for scheduling hierarchy
typedef struct kmp_hier_sched_env_t {
  int size;
  int capacity;
  enum sched_type *scheds;
  kmp_int32 *small_chunks;
  kmp_int64 *large_chunks;
  kmp_hier_layer_e *layers;
  // Append a level of the hierarchy
  void append(enum sched_type sched, kmp_int32 chunk, kmp_hier_layer_e layer) {
    if (capacity == 0) {
      scheds = (enum sched_type *)__kmp_allocate(sizeof(enum sched_type) *
                                                 kmp_hier_layer_e::LAYER_LAST);
      small_chunks = (kmp_int32 *)__kmp_allocate(sizeof(kmp_int32) *
                                                 kmp_hier_layer_e::LAYER_LAST);
      large_chunks = (kmp_int64 *)__kmp_allocate(sizeof(kmp_int64) *
                                                 kmp_hier_layer_e::LAYER_LAST);
      layers = (kmp_hier_layer_e *)__kmp_allocate(sizeof(kmp_hier_layer_e) *
                                                  kmp_hier_layer_e::LAYER_LAST);
      capacity = kmp_hier_layer_e::LAYER_LAST;
    }
    int current_size = size;
    KMP_DEBUG_ASSERT(current_size < kmp_hier_layer_e::LAYER_LAST);
    scheds[current_size] = sched;
    layers[current_size] = layer;
    small_chunks[current_size] = chunk;
    large_chunks[current_size] = (kmp_int64)chunk;
    size++;
  }
  // Sort the hierarchy using selection sort, size will always be small
  // (less than LAYER_LAST) so it is not necessary to use an nlog(n) algorithm
  void sort() {
    if (size <= 1)
      return;
    for (int i = 0; i < size; ++i) {
      int switch_index = i;
      for (int j = i + 1; j < size; ++j) {
        if (layers[j] < layers[switch_index])
          switch_index = j;
      }
      if (switch_index != i) {
        kmp_hier_layer_e temp1 = layers[i];
        enum sched_type temp2 = scheds[i];
        kmp_int32 temp3 = small_chunks[i];
        kmp_int64 temp4 = large_chunks[i];
        layers[i] = layers[switch_index];
        scheds[i] = scheds[switch_index];
        small_chunks[i] = small_chunks[switch_index];
        large_chunks[i] = large_chunks[switch_index];
        layers[switch_index] = temp1;
        scheds[switch_index] = temp2;
        small_chunks[switch_index] = temp3;
        large_chunks[switch_index] = temp4;
      }
    }
  }
  // Free all memory
  void deallocate() {
    if (capacity > 0) {
      __kmp_free(scheds);
      __kmp_free(layers);
      __kmp_free(small_chunks);
      __kmp_free(large_chunks);
      scheds = NULL;
      layers = NULL;
      small_chunks = NULL;
      large_chunks = NULL;
    }
    size = 0;
    capacity = 0;
  }
} kmp_hier_sched_env_t;

extern int __kmp_dispatch_hand_threading;
extern kmp_hier_sched_env_t __kmp_hier_scheds;

// Sizes of layer arrays bounded by max number of detected L1s, L2s, etc.
extern int __kmp_hier_max_units[kmp_hier_layer_e::LAYER_LAST + 1];
extern int __kmp_hier_threads_per[kmp_hier_layer_e::LAYER_LAST + 1];

extern int __kmp_dispatch_get_index(int tid, kmp_hier_layer_e type);
extern int __kmp_dispatch_get_id(int gtid, kmp_hier_layer_e type);
extern int __kmp_dispatch_get_t1_per_t2(kmp_hier_layer_e t1,
                                        kmp_hier_layer_e t2);
extern void __kmp_dispatch_free_hierarchies(kmp_team_t *team);

template <typename T> struct kmp_hier_shared_bdata_t {
  typedef typename traits_t<T>::signed_t ST;
  volatile kmp_uint64 val[2];
  kmp_int32 status[2];
  T lb[2];
  T ub[2];
  ST st[2];
  dispatch_shared_info_template<T> sh[2];
  void zero() {
    val[0] = val[1] = 0;
    status[0] = status[1] = 0;
    lb[0] = lb[1] = 0;
    ub[0] = ub[1] = 0;
    st[0] = st[1] = 0;
    sh[0].u.s.iteration = sh[1].u.s.iteration = 0;
  }
  void set_next_hand_thread(T nlb, T nub, ST nst, kmp_int32 nstatus,
                            kmp_uint64 index) {
    lb[1 - index] = nlb;
    ub[1 - index] = nub;
    st[1 - index] = nst;
    status[1 - index] = nstatus;
  }
  void set_next(T nlb, T nub, ST nst, kmp_int32 nstatus, kmp_uint64 index) {
    lb[1 - index] = nlb;
    ub[1 - index] = nub;
    st[1 - index] = nst;
    status[1 - index] = nstatus;
    sh[1 - index].u.s.iteration = 0;
  }

  kmp_int32 get_next_status(kmp_uint64 index) const {
    return status[1 - index];
  }
  T get_next_lb(kmp_uint64 index) const { return lb[1 - index]; }
  T get_next_ub(kmp_uint64 index) const { return ub[1 - index]; }
  ST get_next_st(kmp_uint64 index) const { return st[1 - index]; }
  dispatch_shared_info_template<T> volatile *get_next_sh(kmp_uint64 index) {
    return &(sh[1 - index]);
  }

  kmp_int32 get_curr_status(kmp_uint64 index) const { return status[index]; }
  T get_curr_lb(kmp_uint64 index) const { return lb[index]; }
  T get_curr_ub(kmp_uint64 index) const { return ub[index]; }
  ST get_curr_st(kmp_uint64 index) const { return st[index]; }
  dispatch_shared_info_template<T> volatile *get_curr_sh(kmp_uint64 index) {
    return &(sh[index]);
  }
};

/*
 * In the barrier implementations, num_active is the number of threads that are
 * attached to the kmp_hier_top_unit_t structure in the scheduling hierarchy.
 * bdata is the shared barrier data that resides on the kmp_hier_top_unit_t
 * structure. tdata is the thread private data that resides on the thread
 * data structure.
 *
 * The reset_shared() method is used to initialize the barrier data on the
 * kmp_hier_top_unit_t hierarchy structure
 *
 * The reset_private() method is used to initialize the barrier data on the
 * thread's private dispatch buffer structure
 *
 * The barrier() method takes an id, which is that thread's id for the
 * kmp_hier_top_unit_t structure, and implements the barrier.  All threads wait
 * inside barrier() until all fellow threads who are attached to that
 * kmp_hier_top_unit_t structure have arrived.
 */

// Core barrier implementation
// Can be used in a unit with between 2 to 8 threads
template <typename T> class core_barrier_impl {
  static inline kmp_uint64 get_wait_val(int num_active) {
    kmp_uint64 wait_val;
    switch (num_active) {
    case 2:
      wait_val = 0x0101LL;
      break;
    case 3:
      wait_val = 0x010101LL;
      break;
    case 4:
      wait_val = 0x01010101LL;
      break;
    case 5:
      wait_val = 0x0101010101LL;
      break;
    case 6:
      wait_val = 0x010101010101LL;
      break;
    case 7:
      wait_val = 0x01010101010101LL;
      break;
    case 8:
      wait_val = 0x0101010101010101LL;
      break;
    default:
      // don't use the core_barrier_impl for more than 8 threads
      KMP_ASSERT(0);
    }
    return wait_val;
  }

public:
  static void reset_private(kmp_int32 num_active,
                            kmp_hier_private_bdata_t *tdata);
  static void reset_shared(kmp_int32 num_active,
                           kmp_hier_shared_bdata_t<T> *bdata);
  static void barrier(kmp_int32 id, kmp_hier_shared_bdata_t<T> *bdata,
                      kmp_hier_private_bdata_t *tdata);
};

template <typename T>
void core_barrier_impl<T>::reset_private(kmp_int32 num_active,
                                         kmp_hier_private_bdata_t *tdata) {
  tdata->num_active = num_active;
  tdata->index = 0;
  tdata->wait_val[0] = tdata->wait_val[1] = get_wait_val(num_active);
}
template <typename T>
void core_barrier_impl<T>::reset_shared(kmp_int32 num_active,
                                        kmp_hier_shared_bdata_t<T> *bdata) {
  bdata->val[0] = bdata->val[1] = 0LL;
  bdata->status[0] = bdata->status[1] = 0LL;
}
template <typename T>
void core_barrier_impl<T>::barrier(kmp_int32 id,
                                   kmp_hier_shared_bdata_t<T> *bdata,
                                   kmp_hier_private_bdata_t *tdata) {
  kmp_uint64 current_index = tdata->index;
  kmp_uint64 next_index = 1 - current_index;
  kmp_uint64 current_wait_value = tdata->wait_val[current_index];
  kmp_uint64 next_wait_value =
      (current_wait_value ? 0 : get_wait_val(tdata->num_active));
  KD_TRACE(10, ("core_barrier_impl::barrier(): T#%d current_index:%llu "
                "next_index:%llu curr_wait:%llu next_wait:%llu\n",
                __kmp_get_gtid(), current_index, next_index, current_wait_value,
                next_wait_value));
  char v = (current_wait_value ? 0x1 : 0x0);
  (RCAST(volatile char *, &(bdata->val[current_index])))[id] = v;
  __kmp_wait_yield<kmp_uint64>(&(bdata->val[current_index]), current_wait_value,
                               __kmp_eq<kmp_uint64> USE_ITT_BUILD_ARG(NULL));
  tdata->wait_val[current_index] = next_wait_value;
  tdata->index = next_index;
}

// Counter barrier implementation
// Can be used in a unit with arbitrary number of active threads
template <typename T> class counter_barrier_impl {
public:
  static void reset_private(kmp_int32 num_active,
                            kmp_hier_private_bdata_t *tdata);
  static void reset_shared(kmp_int32 num_active,
                           kmp_hier_shared_bdata_t<T> *bdata);
  static void barrier(kmp_int32 id, kmp_hier_shared_bdata_t<T> *bdata,
                      kmp_hier_private_bdata_t *tdata);
};

template <typename T>
void counter_barrier_impl<T>::reset_private(kmp_int32 num_active,
                                            kmp_hier_private_bdata_t *tdata) {
  tdata->num_active = num_active;
  tdata->index = 0;
  tdata->wait_val[0] = tdata->wait_val[1] = (kmp_uint64)num_active;
}
template <typename T>
void counter_barrier_impl<T>::reset_shared(kmp_int32 num_active,
                                           kmp_hier_shared_bdata_t<T> *bdata) {
  bdata->val[0] = bdata->val[1] = 0LL;
  bdata->status[0] = bdata->status[1] = 0LL;
}
template <typename T>
void counter_barrier_impl<T>::barrier(kmp_int32 id,
                                      kmp_hier_shared_bdata_t<T> *bdata,
                                      kmp_hier_private_bdata_t *tdata) {
  volatile kmp_int64 *val;
  kmp_uint64 current_index = tdata->index;
  kmp_uint64 next_index = 1 - current_index;
  kmp_uint64 current_wait_value = tdata->wait_val[current_index];
  kmp_uint64 next_wait_value = current_wait_value + tdata->num_active;

  KD_TRACE(10, ("counter_barrier_impl::barrier(): T#%d current_index:%llu "
                "next_index:%llu curr_wait:%llu next_wait:%llu\n",
                __kmp_get_gtid(), current_index, next_index, current_wait_value,
                next_wait_value));
  val = RCAST(volatile kmp_int64 *, &(bdata->val[current_index]));
  KMP_TEST_THEN_INC64(val);
  __kmp_wait_yield<kmp_uint64>(&(bdata->val[current_index]), current_wait_value,
                               __kmp_ge<kmp_uint64> USE_ITT_BUILD_ARG(NULL));
  tdata->wait_val[current_index] = next_wait_value;
  tdata->index = next_index;
}

// Data associated with topology unit within a layer
// For example, one kmp_hier_top_unit_t corresponds to one L1 cache
template <typename T> struct kmp_hier_top_unit_t {
  typedef typename traits_t<T>::signed_t ST;
  typedef typename traits_t<T>::unsigned_t UT;
  kmp_int32 active; // number of topology units that communicate with this unit
  // chunk information (lower/upper bound, stride, etc.)
  dispatch_private_info_template<T> hier_pr;
  kmp_hier_top_unit_t<T> *hier_parent; // pointer to parent unit
  kmp_hier_shared_bdata_t<T> hier_barrier; // shared barrier data for this unit

  kmp_int32 get_hier_id() const { return hier_pr.hier_id; }
  void reset_shared_barrier() {
    KMP_DEBUG_ASSERT(active > 0);
    if (active == 1)
      return;
    hier_barrier.zero();
    if (active >= 2 && active <= 8) {
      core_barrier_impl<T>::reset_shared(active, &hier_barrier);
    } else {
      counter_barrier_impl<T>::reset_shared(active, &hier_barrier);
    }
  }
  void reset_private_barrier(kmp_hier_private_bdata_t *tdata) {
    KMP_DEBUG_ASSERT(tdata);
    KMP_DEBUG_ASSERT(active > 0);
    if (active == 1)
      return;
    if (active >= 2 && active <= 8) {
      core_barrier_impl<T>::reset_private(active, tdata);
    } else {
      counter_barrier_impl<T>::reset_private(active, tdata);
    }
  }
  void barrier(kmp_int32 id, kmp_hier_private_bdata_t *tdata) {
    KMP_DEBUG_ASSERT(tdata);
    KMP_DEBUG_ASSERT(active > 0);
    KMP_DEBUG_ASSERT(id >= 0 && id < active);
    if (active == 1) {
      tdata->index = 1 - tdata->index;
      return;
    }
    if (active >= 2 && active <= 8) {
      core_barrier_impl<T>::barrier(id, &hier_barrier, tdata);
    } else {
      counter_barrier_impl<T>::barrier(id, &hier_barrier, tdata);
    }
  }

  kmp_int32 get_next_status(kmp_uint64 index) const {
    return hier_barrier.get_next_status(index);
  }
  T get_next_lb(kmp_uint64 index) const {
    return hier_barrier.get_next_lb(index);
  }
  T get_next_ub(kmp_uint64 index) const {
    return hier_barrier.get_next_ub(index);
  }
  ST get_next_st(kmp_uint64 index) const {
    return hier_barrier.get_next_st(index);
  }
  dispatch_shared_info_template<T> volatile *get_next_sh(kmp_uint64 index) {
    return hier_barrier.get_next_sh(index);
  }

  kmp_int32 get_curr_status(kmp_uint64 index) const {
    return hier_barrier.get_curr_status(index);
  }
  T get_curr_lb(kmp_uint64 index) const {
    return hier_barrier.get_curr_lb(index);
  }
  T get_curr_ub(kmp_uint64 index) const {
    return hier_barrier.get_curr_ub(index);
  }
  ST get_curr_st(kmp_uint64 index) const {
    return hier_barrier.get_curr_st(index);
  }
  dispatch_shared_info_template<T> volatile *get_curr_sh(kmp_uint64 index) {
    return hier_barrier.get_curr_sh(index);
  }

  void set_next_hand_thread(T lb, T ub, ST st, kmp_int32 status,
                            kmp_uint64 index) {
    hier_barrier.set_next_hand_thread(lb, ub, st, status, index);
  }
  void set_next(T lb, T ub, ST st, kmp_int32 status, kmp_uint64 index) {
    hier_barrier.set_next(lb, ub, st, status, index);
  }
  dispatch_private_info_template<T> *get_my_pr() { return &hier_pr; }
  kmp_hier_top_unit_t<T> *get_parent() { return hier_parent; }
  dispatch_private_info_template<T> *get_parent_pr() {
    return &(hier_parent->hier_pr);
  }

  kmp_int32 is_active() const { return active; }
  kmp_int32 get_num_active() const { return active; }
  void print() {
    KD_TRACE(
        10,
        ("    kmp_hier_top_unit_t: active:%d pr:%p lb:%d ub:%d st:%d tc:%d\n",
         active, &hier_pr, hier_pr.u.p.lb, hier_pr.u.p.ub, hier_pr.u.p.st,
         hier_pr.u.p.tc));
  }
};

// Information regarding a single layer within the scheduling hierarchy
template <typename T> struct kmp_hier_layer_info_t {
  int num_active; // number of threads active in this level
  kmp_hier_layer_e type; // LAYER_L1, LAYER_L2, etc.
  enum sched_type sched; // static, dynamic, guided, etc.
  typename traits_t<T>::signed_t chunk; // chunk size associated with schedule
  int length; // length of the kmp_hier_top_unit_t array

  // Print this layer's information
  void print() {
    const char *t = __kmp_get_hier_str(type);
    KD_TRACE(
        10,
        ("    kmp_hier_layer_info_t: num_active:%d type:%s sched:%d chunk:%d "
         "length:%d\n",
         num_active, t, sched, chunk, length));
  }
};

/*
 * Structure to implement entire hierarchy
 *
 * The hierarchy is kept as an array of arrays to represent the different
 * layers.  Layer 0 is the lowest layer to layer num_layers - 1 which is the
 * highest layer.
 * Example:
 * [ 2 ] -> [ L3 | L3 ]
 * [ 1 ] -> [ L2 | L2 | L2 | L2 ]
 * [ 0 ] -> [ L1 | L1 | L1 | L1 | L1 | L1 | L1 | L1 ]
 * There is also an array of layer_info_t which has information regarding
 * each layer
 */
template <typename T> struct kmp_hier_t {
public:
  typedef typename traits_t<T>::unsigned_t UT;
  typedef typename traits_t<T>::signed_t ST;

private:
  int next_recurse(ident_t *loc, int gtid, kmp_hier_top_unit_t<T> *current,
                   kmp_int32 *p_last, T *p_lb, T *p_ub, ST *p_st,
                   kmp_int32 previous_id, int hier_level) {
    int status;
    kmp_info_t *th = __kmp_threads[gtid];
    auto parent = current->get_parent();
    bool last_layer = (hier_level == get_num_layers() - 1);
    KMP_DEBUG_ASSERT(th);
    kmp_hier_private_bdata_t *tdata = &(th->th.th_hier_bar_data[hier_level]);
    KMP_DEBUG_ASSERT(current);
    KMP_DEBUG_ASSERT(hier_level >= 0);
    KMP_DEBUG_ASSERT(hier_level < get_num_layers());
    KMP_DEBUG_ASSERT(tdata);
    KMP_DEBUG_ASSERT(parent || last_layer);

    KD_TRACE(
        1, ("kmp_hier_t.next_recurse(): T#%d (%d) called\n", gtid, hier_level));

    T hier_id = (T)current->get_hier_id();
    // Attempt to grab next iteration range for this level
    if (previous_id == 0) {
      KD_TRACE(1, ("kmp_hier_t.next_recurse(): T#%d (%d) is master of unit\n",
                   gtid, hier_level));
      kmp_int32 contains_last;
      T my_lb, my_ub;
      ST my_st;
      T nproc;
      dispatch_shared_info_template<T> volatile *my_sh;
      dispatch_private_info_template<T> *my_pr;
      if (last_layer) {
        // last layer below the very top uses the single shared buffer
        // from the team struct.
        KD_TRACE(10,
                 ("kmp_hier_t.next_recurse(): T#%d (%d) using top level sh\n",
                  gtid, hier_level));
        my_sh = reinterpret_cast<dispatch_shared_info_template<T> volatile *>(
            th->th.th_dispatch->th_dispatch_sh_current);
        nproc = (T)get_top_level_nproc();
      } else {
        // middle layers use the shared buffer inside the kmp_hier_top_unit_t
        // structure
        KD_TRACE(10, ("kmp_hier_t.next_recurse(): T#%d (%d) using hier sh\n",
                      gtid, hier_level));
        my_sh =
            parent->get_curr_sh(th->th.th_hier_bar_data[hier_level + 1].index);
        nproc = (T)parent->get_num_active();
      }
      my_pr = current->get_my_pr();
      KMP_DEBUG_ASSERT(my_sh);
      KMP_DEBUG_ASSERT(my_pr);
      enum sched_type schedule = get_sched(hier_level);
      ST chunk = (ST)get_chunk(hier_level);
      status = __kmp_dispatch_next_algorithm<T>(gtid, my_pr, my_sh,
                                                &contains_last, &my_lb, &my_ub,
                                                &my_st, nproc, hier_id);
      KD_TRACE(
          10,
          ("kmp_hier_t.next_recurse(): T#%d (%d) next_pr_sh() returned %d\n",
           gtid, hier_level, status));
      // When no iterations are found (status == 0) and this is not the last
      // layer, attempt to go up the hierarchy for more iterations
      if (status == 0 && !last_layer) {
        status = next_recurse(loc, gtid, parent, &contains_last, &my_lb, &my_ub,
                              &my_st, hier_id, hier_level + 1);
        KD_TRACE(
            10,
            ("kmp_hier_t.next_recurse(): T#%d (%d) hier_next() returned %d\n",
             gtid, hier_level, status));
        if (status == 1) {
          kmp_hier_private_bdata_t *upper_tdata =
              &(th->th.th_hier_bar_data[hier_level + 1]);
          my_sh = parent->get_curr_sh(upper_tdata->index);
          KD_TRACE(10, ("kmp_hier_t.next_recurse(): T#%d (%d) about to init\n",
                        gtid, hier_level));
          __kmp_dispatch_init_algorithm(loc, gtid, my_pr, schedule,
                                        parent->get_curr_lb(upper_tdata->index),
                                        parent->get_curr_ub(upper_tdata->index),
                                        parent->get_curr_st(upper_tdata->index),
#if USE_ITT_BUILD
                                        NULL,
#endif
                                        chunk, nproc, hier_id);
          status = __kmp_dispatch_next_algorithm<T>(
              gtid, my_pr, my_sh, &contains_last, &my_lb, &my_ub, &my_st, nproc,
              hier_id);
          if (!status) {
            KD_TRACE(10, ("kmp_hier_t.next_recurse(): T#%d (%d) status not 1 "
                          "setting to 2!\n",
                          gtid, hier_level));
            status = 2;
          }
        }
      }
      current->set_next(my_lb, my_ub, my_st, status, tdata->index);
      // Propagate whether a unit holds the actual global last iteration
      // The contains_last attribute is sent downwards from the top to the
      // bottom of the hierarchy via the contains_last flag inside the
      // private dispatch buffers in the hierarchy's middle layers
      if (contains_last) {
        // If the next_algorithm() method returns 1 for p_last and it is the
        // last layer or our parent contains the last serial chunk, then the
        // chunk must contain the last serial iteration.
        if (last_layer || parent->hier_pr.flags.contains_last) {
          KD_TRACE(10, ("kmp_hier_t.next_recurse(): T#%d (%d) Setting this pr "
                        "to contain last.\n",
                        gtid, hier_level));
          current->hier_pr.flags.contains_last = contains_last;
        }
        if (!current->hier_pr.flags.contains_last)
          contains_last = FALSE;
      }
      if (p_last)
        *p_last = contains_last;
    } // if master thread of this unit
    if (hier_level > 0 || !__kmp_dispatch_hand_threading) {
      KD_TRACE(10,
               ("kmp_hier_t.next_recurse(): T#%d (%d) going into barrier.\n",
                gtid, hier_level));
      current->barrier(previous_id, tdata);
      KD_TRACE(10,
               ("kmp_hier_t.next_recurse(): T#%d (%d) released and exit %d\n",
                gtid, hier_level, current->get_curr_status(tdata->index)));
    } else {
      KMP_DEBUG_ASSERT(previous_id == 0);
      return status;
    }
    return current->get_curr_status(tdata->index);
  }

public:
  int top_level_nproc;
  int num_layers;
  bool valid;
  int type_size;
  kmp_hier_layer_info_t<T> *info;
  kmp_hier_top_unit_t<T> **layers;
  // Deallocate all memory from this hierarchy
  void deallocate() {
    for (int i = 0; i < num_layers; ++i)
      if (layers[i] != NULL) {
        __kmp_free(layers[i]);
      }
    if (layers != NULL) {
      __kmp_free(layers);
      layers = NULL;
    }
    if (info != NULL) {
      __kmp_free(info);
      info = NULL;
    }
    num_layers = 0;
    valid = false;
  }
  // Returns true if reallocation is needed else false
  bool need_to_reallocate(int n, const kmp_hier_layer_e *new_layers,
                          const enum sched_type *new_scheds,
                          const ST *new_chunks) const {
    if (!valid || layers == NULL || info == NULL ||
        traits_t<T>::type_size != type_size || n != num_layers)
      return true;
    for (int i = 0; i < n; ++i) {
      if (info[i].type != new_layers[i])
        return true;
      if (info[i].sched != new_scheds[i])
        return true;
      if (info[i].chunk != new_chunks[i])
        return true;
    }
    return false;
  }
  // A single thread should call this function while the other threads wait
  // create a new scheduling hierarchy consisting of new_layers, new_scheds
  // and new_chunks.  These should come pre-sorted according to
  // kmp_hier_layer_e value.  This function will try to avoid reallocation
  // if it can
  void allocate_hier(int n, const kmp_hier_layer_e *new_layers,
                     const enum sched_type *new_scheds, const ST *new_chunks) {
    top_level_nproc = 0;
    if (!need_to_reallocate(n, new_layers, new_scheds, new_chunks)) {
      KD_TRACE(
          10,
          ("kmp_hier_t<T>::allocate_hier: T#0 do not need to reallocate\n"));
      for (int i = 0; i < n; ++i) {
        info[i].num_active = 0;
        for (int j = 0; j < get_length(i); ++j)
          layers[i][j].active = 0;
      }
      return;
    }
    KD_TRACE(10, ("kmp_hier_t<T>::allocate_hier: T#0 full alloc\n"));
    deallocate();
    type_size = traits_t<T>::type_size;
    num_layers = n;
    info = (kmp_hier_layer_info_t<T> *)__kmp_allocate(
        sizeof(kmp_hier_layer_info_t<T>) * n);
    layers = (kmp_hier_top_unit_t<T> **)__kmp_allocate(
        sizeof(kmp_hier_top_unit_t<T> *) * n);
    for (int i = 0; i < n; ++i) {
      int max = 0;
      kmp_hier_layer_e layer = new_layers[i];
      info[i].num_active = 0;
      info[i].type = layer;
      info[i].sched = new_scheds[i];
      info[i].chunk = new_chunks[i];
      max = __kmp_hier_max_units[layer + 1];
      if (max == 0) {
        valid = false;
        KMP_WARNING(HierSchedInvalid, __kmp_get_hier_str(layer));
        deallocate();
        return;
      }
      info[i].length = max;
      layers[i] = (kmp_hier_top_unit_t<T> *)__kmp_allocate(
          sizeof(kmp_hier_top_unit_t<T>) * max);
      for (int j = 0; j < max; ++j) {
        layers[i][j].active = 0;
      }
    }
    valid = true;
  }
  // loc - source file location
  // gtid - global thread identifier
  // pr - this thread's private dispatch buffer (corresponding with gtid)
  // p_last (return value) - pointer to flag indicating this set of iterations
  // contains last
  //          iteration
  // p_lb (return value) - lower bound for this chunk of iterations
  // p_ub (return value) - upper bound for this chunk of iterations
  // p_st (return value) - stride for this chunk of iterations
  //
  // Returns 1 if there are more iterations to perform, 0 otherwise
  int next(ident_t *loc, int gtid, dispatch_private_info_template<T> *pr,
           kmp_int32 *p_last, T *p_lb, T *p_ub, ST *p_st) {
    int status;
    kmp_int32 contains_last = 0;
    kmp_info_t *th = __kmp_threads[gtid];
    kmp_hier_private_bdata_t *tdata = &(th->th.th_hier_bar_data[0]);
    auto parent = pr->get_parent();
    KMP_DEBUG_ASSERT(parent);
    KMP_DEBUG_ASSERT(th);
    KMP_DEBUG_ASSERT(tdata);
    KMP_DEBUG_ASSERT(parent);
    T nproc = (T)parent->get_num_active();
    T unit_id = (T)pr->get_hier_id();
    KD_TRACE(
        10,
        ("kmp_hier_t.next(): T#%d THREAD LEVEL nproc:%d unit_id:%d called\n",
         gtid, nproc, unit_id));
    // Handthreading implementation
    // Each iteration is performed by all threads on last unit (typically
    // cores/tiles)
    // e.g., threads 0,1,2,3 all execute iteration 0
    //       threads 0,1,2,3 all execute iteration 1
    //       threads 4,5,6,7 all execute iteration 2
    //       threads 4,5,6,7 all execute iteration 3
    //       ... etc.
    if (__kmp_dispatch_hand_threading) {
      KD_TRACE(10,
               ("kmp_hier_t.next(): T#%d THREAD LEVEL using hand threading\n",
                gtid));
      if (unit_id == 0) {
        // For hand threading, the sh buffer on the lowest level is only ever
        // modified and read by the master thread on that level.  Because of
        // this, we can always use the first sh buffer.
        auto sh = &(parent->hier_barrier.sh[0]);
        KMP_DEBUG_ASSERT(sh);
        status = __kmp_dispatch_next_algorithm<T>(
            gtid, pr, sh, &contains_last, p_lb, p_ub, p_st, nproc, unit_id);
        if (!status) {
          bool done = false;
          while (!done) {
            done = true;
            status = next_recurse(loc, gtid, parent, &contains_last, p_lb, p_ub,
                                  p_st, unit_id, 0);
            if (status == 1) {
              __kmp_dispatch_init_algorithm(loc, gtid, pr, pr->schedule,
                                            parent->get_next_lb(tdata->index),
                                            parent->get_next_ub(tdata->index),
                                            parent->get_next_st(tdata->index),
#if USE_ITT_BUILD
                                            NULL,
#endif
                                            pr->u.p.parm1, nproc, unit_id);
              sh->u.s.iteration = 0;
              status = __kmp_dispatch_next_algorithm<T>(
                  gtid, pr, sh, &contains_last, p_lb, p_ub, p_st, nproc,
                  unit_id);
              if (!status) {
                KD_TRACE(10,
                         ("kmp_hier_t.next(): T#%d THREAD LEVEL status == 0 "
                          "after next_pr_sh()"
                          "trying again.\n",
                          gtid));
                done = false;
              }
            } else if (status == 2) {
              KD_TRACE(10, ("kmp_hier_t.next(): T#%d THREAD LEVEL status == 2 "
                            "trying again.\n",
                            gtid));
              done = false;
            }
          }
        }
        parent->set_next_hand_thread(*p_lb, *p_ub, *p_st, status, tdata->index);
      } // if master thread of lowest unit level
      parent->barrier(pr->get_hier_id(), tdata);
      if (unit_id != 0) {
        *p_lb = parent->get_curr_lb(tdata->index);
        *p_ub = parent->get_curr_ub(tdata->index);
        *p_st = parent->get_curr_st(tdata->index);
        status = parent->get_curr_status(tdata->index);
      }
    } else {
      // Normal implementation
      // Each thread grabs an iteration chunk and executes it (no cooperation)
      auto sh = parent->get_curr_sh(tdata->index);
      KMP_DEBUG_ASSERT(sh);
      status = __kmp_dispatch_next_algorithm<T>(
          gtid, pr, sh, &contains_last, p_lb, p_ub, p_st, nproc, unit_id);
      KD_TRACE(10,
               ("kmp_hier_t.next(): T#%d THREAD LEVEL next_algorithm status:%d "
                "contains_last:%d p_lb:%d p_ub:%d p_st:%d\n",
                gtid, status, contains_last, *p_lb, *p_ub, *p_st));
      if (!status) {
        bool done = false;
        while (!done) {
          done = true;
          status = next_recurse(loc, gtid, parent, &contains_last, p_lb, p_ub,
                                p_st, unit_id, 0);
          if (status == 1) {
            sh = parent->get_curr_sh(tdata->index);
            __kmp_dispatch_init_algorithm(loc, gtid, pr, pr->schedule,
                                          parent->get_curr_lb(tdata->index),
                                          parent->get_curr_ub(tdata->index),
                                          parent->get_curr_st(tdata->index),
#if USE_ITT_BUILD
                                          NULL,
#endif
                                          pr->u.p.parm1, nproc, unit_id);
            status = __kmp_dispatch_next_algorithm<T>(
                gtid, pr, sh, &contains_last, p_lb, p_ub, p_st, nproc, unit_id);
            if (!status) {
              KD_TRACE(10, ("kmp_hier_t.next(): T#%d THREAD LEVEL status == 0 "
                            "after next_pr_sh()"
                            "trying again.\n",
                            gtid));
              done = false;
            }
          } else if (status == 2) {
            KD_TRACE(10, ("kmp_hier_t.next(): T#%d THREAD LEVEL status == 2 "
                          "trying again.\n",
                          gtid));
            done = false;
          }
        }
      }
    }
    if (contains_last && !parent->hier_pr.flags.contains_last) {
      KD_TRACE(10, ("kmp_hier_t.next(): T#%d THREAD LEVEL resetting "
                    "contains_last to FALSE\n",
                    gtid));
      contains_last = FALSE;
    }
    if (p_last)
      *p_last = contains_last;
    KD_TRACE(10, ("kmp_hier_t.next(): T#%d THREAD LEVEL exit status %d\n", gtid,
                  status));
    return status;
  }
  // These functions probe the layer info structure
  // Returns the type of topology unit given level
  kmp_hier_layer_e get_type(int level) const {
    KMP_DEBUG_ASSERT(level >= 0);
    KMP_DEBUG_ASSERT(level < num_layers);
    return info[level].type;
  }
  // Returns the schedule type at given level
  enum sched_type get_sched(int level) const {
    KMP_DEBUG_ASSERT(level >= 0);
    KMP_DEBUG_ASSERT(level < num_layers);
    return info[level].sched;
  }
  // Returns the chunk size at given level
  ST get_chunk(int level) const {
    KMP_DEBUG_ASSERT(level >= 0);
    KMP_DEBUG_ASSERT(level < num_layers);
    return info[level].chunk;
  }
  // Returns the number of active threads at given level
  int get_num_active(int level) const {
    KMP_DEBUG_ASSERT(level >= 0);
    KMP_DEBUG_ASSERT(level < num_layers);
    return info[level].num_active;
  }
  // Returns the length of topology unit array at given level
  int get_length(int level) const {
    KMP_DEBUG_ASSERT(level >= 0);
    KMP_DEBUG_ASSERT(level < num_layers);
    return info[level].length;
  }
  // Returns the topology unit given the level and index
  kmp_hier_top_unit_t<T> *get_unit(int level, int index) {
    KMP_DEBUG_ASSERT(level >= 0);
    KMP_DEBUG_ASSERT(level < num_layers);
    KMP_DEBUG_ASSERT(index >= 0);
    KMP_DEBUG_ASSERT(index < get_length(level));
    return &(layers[level][index]);
  }
  // Returns the number of layers in the hierarchy
  int get_num_layers() const { return num_layers; }
  // Returns the number of threads in the top layer
  // This is necessary because we don't store a topology unit as
  // the very top level and the scheduling algorithms need this information
  int get_top_level_nproc() const { return top_level_nproc; }
  // Return whether this hierarchy is valid or not
  bool is_valid() const { return valid; }
  // Print the hierarchy
  void print() {
    KD_TRACE(10, ("kmp_hier_t:\n"));
    for (int i = num_layers - 1; i >= 0; --i) {
      KD_TRACE(10, ("Info[%d] = ", i));
      info[i].print();
    }
    for (int i = num_layers - 1; i >= 0; --i) {
      KD_TRACE(10, ("Layer[%d] =\n", i));
      for (int j = 0; j < info[i].length; ++j) {
        layers[i][j].print();
      }
    }
  }
};

template <typename T>
void __kmp_dispatch_init_hierarchy(ident_t *loc, int n,
                                   kmp_hier_layer_e *new_layers,
                                   enum sched_type *new_scheds,
                                   typename traits_t<T>::signed_t *new_chunks,
                                   T lb, T ub,
                                   typename traits_t<T>::signed_t st) {
  typedef typename traits_t<T>::signed_t ST;
  typedef typename traits_t<T>::unsigned_t UT;
  int tid, gtid, num_hw_threads, num_threads_per_layer1, active;
  int my_buffer_index;
  kmp_info_t *th;
  kmp_team_t *team;
  dispatch_private_info_template<T> *pr;
  dispatch_shared_info_template<T> volatile *sh;
  gtid = __kmp_entry_gtid();
  tid = __kmp_tid_from_gtid(gtid);
#ifdef KMP_DEBUG
  KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d called: %d layer(s)\n",
                gtid, n));
  for (int i = 0; i < n; ++i) {
    const char *layer = __kmp_get_hier_str(new_layers[i]);
    KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d: new_layers[%d] = %s, "
                  "new_scheds[%d] = %d, new_chunks[%d] = %u\n",
                  gtid, i, layer, i, (int)new_scheds[i], i, new_chunks[i]));
  }
#endif // KMP_DEBUG
  KMP_DEBUG_ASSERT(n > 0);
  KMP_DEBUG_ASSERT(new_layers);
  KMP_DEBUG_ASSERT(new_scheds);
  KMP_DEBUG_ASSERT(new_chunks);
  if (!TCR_4(__kmp_init_parallel))
    __kmp_parallel_initialize();
  th = __kmp_threads[gtid];
  team = th->th.th_team;
  active = !team->t.t_serialized;
  th->th.th_ident = loc;
  num_hw_threads = __kmp_hier_max_units[kmp_hier_layer_e::LAYER_THREAD + 1];
  if (!active) {
    KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d not active parallel. "
                  "Using normal dispatch functions.\n",
                  gtid));
    pr = reinterpret_cast<dispatch_private_info_template<T> *>(
        th->th.th_dispatch->th_disp_buffer);
    KMP_DEBUG_ASSERT(pr);
    pr->flags.use_hier = FALSE;
    pr->flags.contains_last = FALSE;
    return;
  }
  KMP_DEBUG_ASSERT(th->th.th_dispatch ==
                   &th->th.th_team->t.t_dispatch[th->th.th_info.ds.ds_tid]);

  my_buffer_index = th->th.th_dispatch->th_disp_index;
  pr = reinterpret_cast<dispatch_private_info_template<T> *>(
      &th->th.th_dispatch
           ->th_disp_buffer[my_buffer_index % __kmp_dispatch_num_buffers]);
  sh = reinterpret_cast<dispatch_shared_info_template<T> volatile *>(
      &team->t.t_disp_buffer[my_buffer_index % __kmp_dispatch_num_buffers]);
  KMP_DEBUG_ASSERT(pr);
  KMP_DEBUG_ASSERT(sh);
  pr->flags.use_hier = TRUE;
  pr->u.p.tc = 0;
  // Have master allocate the hierarchy
  if (__kmp_tid_from_gtid(gtid) == 0) {
    KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d pr:%p sh:%p allocating "
                  "hierarchy\n",
                  gtid, pr, sh));
    if (sh->hier == NULL) {
      sh->hier = (kmp_hier_t<T> *)__kmp_allocate(sizeof(kmp_hier_t<T>));
    }
    sh->hier->allocate_hier(n, new_layers, new_scheds, new_chunks);
    sh->u.s.iteration = 0;
  }
  __kmp_barrier(bs_plain_barrier, gtid, FALSE, 0, NULL, NULL);
  // Check to make sure the hierarchy is valid
  kmp_hier_t<T> *hier = sh->hier;
  if (!sh->hier->is_valid()) {
    pr->flags.use_hier = FALSE;
    return;
  }
  // Have threads allocate their thread-private barrier data if it hasn't
  // already been allocated
  if (th->th.th_hier_bar_data == NULL) {
    th->th.th_hier_bar_data = (kmp_hier_private_bdata_t *)__kmp_allocate(
        sizeof(kmp_hier_private_bdata_t) * kmp_hier_layer_e::LAYER_LAST);
  }
  // Have threads "register" themselves by modifiying the active count for each
  // level they are involved in. The active count will act as nthreads for that
  // level regarding the scheduling algorithms
  for (int i = 0; i < n; ++i) {
    int index = __kmp_dispatch_get_index(tid, hier->get_type(i));
    kmp_hier_top_unit_t<T> *my_unit = hier->get_unit(i, index);
    // Setup the thread's private dispatch buffer's hierarchy pointers
    if (i == 0)
      pr->hier_parent = my_unit;
    // If this unit is already active, then increment active count and wait
    if (my_unit->is_active()) {
      KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d my_unit (%p) "
                    "is already active (%d)\n",
                    gtid, my_unit, my_unit->active));
      KMP_TEST_THEN_INC32(&(my_unit->active));
      break;
    }
    // Flag that this unit is active
    if (KMP_COMPARE_AND_STORE_ACQ32(&(my_unit->active), 0, 1)) {
      // Do not setup parent pointer for top level unit since it has no parent
      if (i < n - 1) {
        // Setup middle layer pointers to parents
        my_unit->get_my_pr()->hier_id =
            index % __kmp_dispatch_get_t1_per_t2(hier->get_type(i),
                                                 hier->get_type(i + 1));
        int parent_index = __kmp_dispatch_get_index(tid, hier->get_type(i + 1));
        my_unit->hier_parent = hier->get_unit(i + 1, parent_index);
      } else {
        // Setup top layer information (no parent pointers are set)
        my_unit->get_my_pr()->hier_id =
            index % __kmp_dispatch_get_t1_per_t2(hier->get_type(i),
                                                 kmp_hier_layer_e::LAYER_LOOP);
        KMP_TEST_THEN_INC32(&(hier->top_level_nproc));
        my_unit->hier_parent = nullptr;
      }
      // Set trip count to 0 so that next() operation will initially climb up
      // the hierarchy to get more iterations (early exit in next() for tc == 0)
      my_unit->get_my_pr()->u.p.tc = 0;
      // Increment this layer's number of active units
      KMP_TEST_THEN_INC32(&(hier->info[i].num_active));
      KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d my_unit (%p) "
                    "incrementing num_active\n",
                    gtid, my_unit));
    } else {
      KMP_TEST_THEN_INC32(&(my_unit->active));
      break;
    }
  }
  // Set this thread's id
  num_threads_per_layer1 = __kmp_dispatch_get_t1_per_t2(
      kmp_hier_layer_e::LAYER_THREAD, hier->get_type(0));
  pr->hier_id = tid % num_threads_per_layer1;
  // For oversubscribed threads, increment their index within the lowest unit
  // This is done to prevent having two or more threads with id 0, id 1, etc.
  if (tid >= num_hw_threads)
    pr->hier_id += ((tid / num_hw_threads) * num_threads_per_layer1);
  KD_TRACE(
      10, ("__kmp_dispatch_init_hierarchy: T#%d setting lowest hier_id to %d\n",
           gtid, pr->hier_id));

  pr->flags.contains_last = FALSE;
  __kmp_barrier(bs_plain_barrier, gtid, FALSE, 0, NULL, NULL);

  // Now that the number of active threads at each level is determined,
  // the barrier data for each unit can be initialized and the last layer's
  // loop information can be initialized.
  int prev_id = pr->get_hier_id();
  for (int i = 0; i < n; ++i) {
    if (prev_id != 0)
      break;
    int index = __kmp_dispatch_get_index(tid, hier->get_type(i));
    kmp_hier_top_unit_t<T> *my_unit = hier->get_unit(i, index);
    // Only master threads of this unit within the hierarchy do initialization
    KD_TRACE(10, ("__kmp_dispatch_init_hierarchy: T#%d (%d) prev_id is 0\n",
                  gtid, i));
    my_unit->reset_shared_barrier();
    my_unit->hier_pr.flags.contains_last = FALSE;
    // Last layer, initialize the private buffers with entire loop information
    // Now the next next_algorithim() call will get the first chunk of
    // iterations properly
    if (i == n - 1) {
      __kmp_dispatch_init_algorithm<T>(
          loc, gtid, my_unit->get_my_pr(), hier->get_sched(i), lb, ub, st,
#if USE_ITT_BUILD
          NULL,
#endif
          hier->get_chunk(i), hier->get_num_active(i), my_unit->get_hier_id());
    }
    prev_id = my_unit->get_hier_id();
  }
  // Initialize each layer of the thread's private barrier data
  kmp_hier_top_unit_t<T> *unit = pr->hier_parent;
  for (int i = 0; i < n && unit; ++i, unit = unit->get_parent()) {
    kmp_hier_private_bdata_t *tdata = &(th->th.th_hier_bar_data[i]);
    unit->reset_private_barrier(tdata);
  }
  __kmp_barrier(bs_plain_barrier, gtid, FALSE, 0, NULL, NULL);

#ifdef KMP_DEBUG
  if (__kmp_tid_from_gtid(gtid) == 0) {
    for (int i = 0; i < n; ++i) {
      KD_TRACE(10,
               ("__kmp_dispatch_init_hierarchy: T#%d active count[%d] = %d\n",
                gtid, i, hier->get_num_active(i)));
    }
    hier->print();
  }
  __kmp_barrier(bs_plain_barrier, gtid, FALSE, 0, NULL, NULL);
#endif // KMP_DEBUG
}
#endif