jdk

1
/*
2
 * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
3
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4
 *
5
 * This code is free software; you can redistribute it and/or modify it
6
 * under the terms of the GNU General Public License version 2 only, as
7
 * published by the Free Software Foundation.
8
 *
9
 * This code is distributed in the hope that it will be useful, but WITHOUT
10
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12
 * version 2 for more details (a copy is included in the LICENSE file that
13
 * accompanied this code).
14
 *
15
 * You should have received a copy of the GNU General Public License version
16
 * 2 along with this work; if not, write to the Free Software Foundation,
17
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18
 *
19
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20
 * or visit www.oracle.com if you need additional information or have any
21
 * questions.
22
 *
23
 */
24

25
#include "precompiled.hpp"
26
#include "classfile/classFileParser.hpp"
27
#include "classfile/fieldLayoutBuilder.hpp"
28
#include "jvm.h"
29
#include "memory/resourceArea.hpp"
30
#include "oops/array.hpp"
31
#include "oops/fieldStreams.inline.hpp"
32
#include "oops/instanceMirrorKlass.hpp"
33
#include "oops/instanceKlass.inline.hpp"
34
#include "oops/klass.inline.hpp"
35
#include "runtime/fieldDescriptor.inline.hpp"
36

37

38
LayoutRawBlock::LayoutRawBlock(Kind kind, int size) :
39
  _next_block(nullptr),
40
  _prev_block(nullptr),
41
  _kind(kind),
42
  _offset(-1),
43
  _alignment(1),
44
  _size(size),
45
  _field_index(-1),
46
  _is_reference(false) {
47
  assert(kind == EMPTY || kind == RESERVED || kind == PADDING || kind == INHERITED,
48
         "Otherwise, should use the constructor with a field index argument");
49
  assert(size > 0, "Sanity check");
50
}
51

52

53
LayoutRawBlock::LayoutRawBlock(int index, Kind kind, int size, int alignment, bool is_reference) :
54
 _next_block(nullptr),
55
 _prev_block(nullptr),
56
 _kind(kind),
57
 _offset(-1),
58
 _alignment(alignment),
59
 _size(size),
60
 _field_index(index),
61
 _is_reference(is_reference) {
62
  assert(kind == REGULAR || kind == FLATTENED || kind == INHERITED,
63
         "Other kind do not have a field index");
64
  assert(size > 0, "Sanity check");
65
  assert(alignment > 0, "Sanity check");
66
}
67

68
bool LayoutRawBlock::fit(int size, int alignment) {
69
  int adjustment = 0;
70
  if ((_offset % alignment) != 0) {
71
    adjustment = alignment - (_offset % alignment);
72
  }
73
  return _size >= size + adjustment;
74
}
75

76
FieldGroup::FieldGroup(int contended_group) :
77
  _next(nullptr),
78
  _primitive_fields(nullptr),
79
  _oop_fields(nullptr),
80
  _contended_group(contended_group),  // -1 means no contended group, 0 means default contended group
81
  _oop_count(0) {}
82

83
void FieldGroup::add_primitive_field(int idx, BasicType type) {
84
  int size = type2aelembytes(type);
85
  LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::REGULAR, size, size /* alignment == size for primitive types */, false);
86
  if (_primitive_fields == nullptr) {
87
    _primitive_fields = new GrowableArray<LayoutRawBlock*>(INITIAL_LIST_SIZE);
88
  }
89
  _primitive_fields->append(block);
90
}
91

92
void FieldGroup::add_oop_field(int idx) {
93
  int size = type2aelembytes(T_OBJECT);
94
  LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::REGULAR, size, size /* alignment == size for oops */, true);
95
  if (_oop_fields == nullptr) {
96
    _oop_fields = new GrowableArray<LayoutRawBlock*>(INITIAL_LIST_SIZE);
97
  }
98
  _oop_fields->append(block);
99
  _oop_count++;
100
}
101

102
void FieldGroup::sort_by_size() {
103
  if (_primitive_fields != nullptr) {
104
    _primitive_fields->sort(LayoutRawBlock::compare_size_inverted);
105
  }
106
}
107

108
FieldLayout::FieldLayout(GrowableArray<FieldInfo>* field_info, ConstantPool* cp) :
109
  _field_info(field_info),
110
  _cp(cp),
111
  _blocks(nullptr),
112
  _start(_blocks),
113
  _last(_blocks) {}
114

115
void FieldLayout::initialize_static_layout() {
116
  _blocks = new LayoutRawBlock(LayoutRawBlock::EMPTY, INT_MAX);
117
  _blocks->set_offset(0);
118
  _last = _blocks;
119
  _start = _blocks;
120
  // Note: at this stage, InstanceMirrorKlass::offset_of_static_fields() could be zero, because
121
  // during bootstrapping, the size of the java.lang.Class is still not known when layout
122
  // of static field is computed. Field offsets are fixed later when the size is known
123
  // (see java_lang_Class::fixup_mirror())
124
  if (InstanceMirrorKlass::offset_of_static_fields() > 0) {
125
    insert(first_empty_block(), new LayoutRawBlock(LayoutRawBlock::RESERVED, InstanceMirrorKlass::offset_of_static_fields()));
126
    _blocks->set_offset(0);
127
  }
128
}
129

130
void FieldLayout::initialize_instance_layout(const InstanceKlass* super_klass) {
131
  if (super_klass == nullptr) {
132
    _blocks = new LayoutRawBlock(LayoutRawBlock::EMPTY, INT_MAX);
133
    _blocks->set_offset(0);
134
    _last = _blocks;
135
    _start = _blocks;
136
    insert(first_empty_block(), new LayoutRawBlock(LayoutRawBlock::RESERVED, instanceOopDesc::base_offset_in_bytes()));
137
  } else {
138
    bool has_fields = reconstruct_layout(super_klass);
139
    fill_holes(super_klass);
140
    if (!super_klass->has_contended_annotations() || !has_fields) {
141
      _start = _blocks;  // start allocating fields from the first empty block
142
    } else {
143
      _start = _last;    // append fields at the end of the reconstructed layout
144
    }
145
  }
146
}
147

148
LayoutRawBlock* FieldLayout::first_field_block() {
149
  LayoutRawBlock* block = _start;
150
  while (block->kind() != LayoutRawBlock::INHERITED && block->kind() != LayoutRawBlock::REGULAR
151
      && block->kind() != LayoutRawBlock::FLATTENED && block->kind() != LayoutRawBlock::PADDING) {
152
    block = block->next_block();
153
  }
154
  return block;
155
}
156

157

158
// Insert a set of fields into a layout using a best-fit strategy.
159
// For each field, search for the smallest empty slot able to fit the field
160
// (satisfying both size and alignment requirements), if none is found,
161
// add the field at the end of the layout.
162
// Fields cannot be inserted before the block specified in the "start" argument
163
void FieldLayout::add(GrowableArray<LayoutRawBlock*>* list, LayoutRawBlock* start) {
164
  if (list == nullptr) return;
165
  if (start == nullptr) start = this->_start;
166
  bool last_search_success = false;
167
  int last_size = 0;
168
  int last_alignment = 0;
169
  for (int i = 0; i < list->length(); i ++) {
170
    LayoutRawBlock* b = list->at(i);
171
    LayoutRawBlock* cursor = nullptr;
172
    LayoutRawBlock* candidate = nullptr;
173

174
    // if start is the last block, just append the field
175
    if (start == last_block()) {
176
      candidate = last_block();
177
    }
178
    // Before iterating over the layout to find an empty slot fitting the field's requirements,
179
    // check if the previous field had the same requirements and if the search for a fitting slot
180
    // was successful. If the requirements were the same but the search failed, a new search will
181
    // fail the same way, so just append the field at the of the layout.
182
    else  if (b->size() == last_size && b->alignment() == last_alignment && !last_search_success) {
183
      candidate = last_block();
184
    } else {
185
      // Iterate over the layout to find an empty slot fitting the field's requirements
186
      last_size = b->size();
187
      last_alignment = b->alignment();
188
      cursor = last_block()->prev_block();
189
      assert(cursor != nullptr, "Sanity check");
190
      last_search_success = true;
191
      while (cursor != start) {
192
        if (cursor->kind() == LayoutRawBlock::EMPTY && cursor->fit(b->size(), b->alignment())) {
193
          if (candidate == nullptr || cursor->size() < candidate->size()) {
194
            candidate = cursor;
195
          }
196
        }
197
        cursor = cursor->prev_block();
198
      }
199
      if (candidate == nullptr) {
200
        candidate = last_block();
201
        last_search_success = false;
202
      }
203
      assert(candidate != nullptr, "Candidate must not be null");
204
      assert(candidate->kind() == LayoutRawBlock::EMPTY, "Candidate must be an empty block");
205
      assert(candidate->fit(b->size(), b->alignment()), "Candidate must be able to store the block");
206
    }
207

208
    insert_field_block(candidate, b);
209
  }
210
}
211

212
// Used for classes with hard coded field offsets, insert a field at the specified offset */
213
void FieldLayout::add_field_at_offset(LayoutRawBlock* block, int offset, LayoutRawBlock* start) {
214
  assert(block != nullptr, "Sanity check");
215
  block->set_offset(offset);
216
  if (start == nullptr) {
217
    start = this->_start;
218
  }
219
  LayoutRawBlock* slot = start;
220
  while (slot != nullptr) {
221
    if ((slot->offset() <= block->offset() && (slot->offset() + slot->size()) > block->offset()) ||
222
        slot == _last){
223
      assert(slot->kind() == LayoutRawBlock::EMPTY, "Matching slot must be an empty slot");
224
      assert(slot->size() >= block->offset() + block->size() ,"Matching slot must be big enough");
225
      if (slot->offset() < block->offset()) {
226
        int adjustment = block->offset() - slot->offset();
227
        LayoutRawBlock* adj = new LayoutRawBlock(LayoutRawBlock::EMPTY, adjustment);
228
        insert(slot, adj);
229
      }
230
      insert(slot, block);
231
      if (slot->size() == 0) {
232
        remove(slot);
233
      }
234
      _field_info->adr_at(block->field_index())->set_offset(block->offset());
235
      return;
236
    }
237
    slot = slot->next_block();
238
  }
239
  fatal("Should have found a matching slot above, corrupted layout or invalid offset");
240
}
241

242
// The allocation logic uses a best fit strategy: the set of fields is allocated
243
// in the first empty slot big enough to contain the whole set ((including padding
244
// to fit alignment constraints).
245
void FieldLayout::add_contiguously(GrowableArray<LayoutRawBlock*>* list, LayoutRawBlock* start) {
246
  if (list == nullptr) return;
247
  if (start == nullptr) {
248
    start = _start;
249
  }
250
  // This code assumes that if the first block is well aligned, the following
251
  // blocks would naturally be well aligned (no need for adjustment)
252
  int size = 0;
253
  for (int i = 0; i < list->length(); i++) {
254
    size += list->at(i)->size();
255
  }
256

257
  LayoutRawBlock* candidate = nullptr;
258
  if (start == last_block()) {
259
    candidate = last_block();
260
  } else {
261
    LayoutRawBlock* first = list->at(0);
262
    candidate = last_block()->prev_block();
263
    while (candidate->kind() != LayoutRawBlock::EMPTY || !candidate->fit(size, first->alignment())) {
264
      if (candidate == start) {
265
        candidate = last_block();
266
        break;
267
      }
268
      candidate = candidate->prev_block();
269
    }
270
    assert(candidate != nullptr, "Candidate must not be null");
271
    assert(candidate->kind() == LayoutRawBlock::EMPTY, "Candidate must be an empty block");
272
    assert(candidate->fit(size, first->alignment()), "Candidate must be able to store the whole contiguous block");
273
  }
274

275
  for (int i = 0; i < list->length(); i++) {
276
    LayoutRawBlock* b = list->at(i);
277
    insert_field_block(candidate, b);
278
    assert((candidate->offset() % b->alignment() == 0), "Contiguous blocks must be naturally well aligned");
279
  }
280
}
281

282
LayoutRawBlock* FieldLayout::insert_field_block(LayoutRawBlock* slot, LayoutRawBlock* block) {
283
  assert(slot->kind() == LayoutRawBlock::EMPTY, "Blocks can only be inserted in empty blocks");
284
  if (slot->offset() % block->alignment() != 0) {
285
    int adjustment = block->alignment() - (slot->offset() % block->alignment());
286
    LayoutRawBlock* adj = new LayoutRawBlock(LayoutRawBlock::EMPTY, adjustment);
287
    insert(slot, adj);
288
  }
289
  insert(slot, block);
290
  if (slot->size() == 0) {
291
    remove(slot);
292
  }
293
  _field_info->adr_at(block->field_index())->set_offset(block->offset());
294
  return block;
295
}
296

297
bool FieldLayout::reconstruct_layout(const InstanceKlass* ik) {
298
  bool has_instance_fields = false;
299
  GrowableArray<LayoutRawBlock*>* all_fields = new GrowableArray<LayoutRawBlock*>(32);
300
  while (ik != nullptr) {
301
    for (AllFieldStream fs(ik->fieldinfo_stream(), ik->constants()); !fs.done(); fs.next()) {
302
      BasicType type = Signature::basic_type(fs.signature());
303
      // distinction between static and non-static fields is missing
304
      if (fs.access_flags().is_static()) continue;
305
      has_instance_fields = true;
306
      int size = type2aelembytes(type);
307
      // INHERITED blocks are marked as non-reference because oop_maps are handled by their holder class
308
      LayoutRawBlock* block = new LayoutRawBlock(fs.index(), LayoutRawBlock::INHERITED, size, size, false);
309
      block->set_offset(fs.offset());
310
      all_fields->append(block);
311
    }
312
    ik = ik->super() == nullptr ? nullptr : InstanceKlass::cast(ik->super());
313
  }
314

315
  all_fields->sort(LayoutRawBlock::compare_offset);
316
  _blocks = new LayoutRawBlock(LayoutRawBlock::RESERVED, instanceOopDesc::base_offset_in_bytes());
317
  _blocks->set_offset(0);
318
  _last = _blocks;
319

320
  for(int i = 0; i < all_fields->length(); i++) {
321
    LayoutRawBlock* b = all_fields->at(i);
322
    _last->set_next_block(b);
323
    b->set_prev_block(_last);
324
    _last = b;
325
  }
326
  _start = _blocks;
327
  return has_instance_fields;
328
}
329

330
// Called during the reconstruction of a layout, after fields from super
331
// classes have been inserted. It fills unused slots between inserted fields
332
// with EMPTY blocks, so the regular field insertion methods would work.
333
// This method handles classes with @Contended annotations differently
334
// by inserting PADDING blocks instead of EMPTY block to prevent subclasses'
335
// fields to interfere with contended fields/classes.
336
void FieldLayout::fill_holes(const InstanceKlass* super_klass) {
337
  assert(_blocks != nullptr, "Sanity check");
338
  assert(_blocks->offset() == 0, "first block must be at offset zero");
339
  LayoutRawBlock::Kind filling_type = super_klass->has_contended_annotations() ? LayoutRawBlock::PADDING: LayoutRawBlock::EMPTY;
340
  LayoutRawBlock* b = _blocks;
341
  while (b->next_block() != nullptr) {
342
    if (b->next_block()->offset() > (b->offset() + b->size())) {
343
      int size = b->next_block()->offset() - (b->offset() + b->size());
344
      LayoutRawBlock* empty = new LayoutRawBlock(filling_type, size);
345
      empty->set_offset(b->offset() + b->size());
346
      empty->set_next_block(b->next_block());
347
      b->next_block()->set_prev_block(empty);
348
      b->set_next_block(empty);
349
      empty->set_prev_block(b);
350
    }
351
    b = b->next_block();
352
  }
353
  assert(b->next_block() == nullptr, "Invariant at this point");
354
  assert(b->kind() != LayoutRawBlock::EMPTY, "Sanity check");
355

356
  // If the super class has @Contended annotation, a padding block is
357
  // inserted at the end to ensure that fields from the subclasses won't share
358
  // the cache line of the last field of the contended class
359
  if (super_klass->has_contended_annotations() && ContendedPaddingWidth > 0) {
360
    LayoutRawBlock* p = new LayoutRawBlock(LayoutRawBlock::PADDING, ContendedPaddingWidth);
361
    p->set_offset(b->offset() + b->size());
362
    b->set_next_block(p);
363
    p->set_prev_block(b);
364
    b = p;
365
  }
366

367
  LayoutRawBlock* last = new LayoutRawBlock(LayoutRawBlock::EMPTY, INT_MAX);
368
  last->set_offset(b->offset() + b->size());
369
  assert(last->offset() > 0, "Sanity check");
370
  b->set_next_block(last);
371
  last->set_prev_block(b);
372
  _last = last;
373
}
374

375
LayoutRawBlock* FieldLayout::insert(LayoutRawBlock* slot, LayoutRawBlock* block) {
376
  assert(slot->kind() == LayoutRawBlock::EMPTY, "Blocks can only be inserted in empty blocks");
377
  assert(slot->offset() % block->alignment() == 0, "Incompatible alignment");
378
  block->set_offset(slot->offset());
379
  slot->set_offset(slot->offset() + block->size());
380
  assert((slot->size() - block->size()) < slot->size(), "underflow checking");
381
  assert(slot->size() - block->size() >= 0, "no negative size allowed");
382
  slot->set_size(slot->size() - block->size());
383
  block->set_prev_block(slot->prev_block());
384
  block->set_next_block(slot);
385
  slot->set_prev_block(block);
386
  if (block->prev_block() != nullptr) {
387
    block->prev_block()->set_next_block(block);
388
  }
389
  if (_blocks == slot) {
390
    _blocks = block;
391
  }
392
  return block;
393
}
394

395
void FieldLayout::remove(LayoutRawBlock* block) {
396
  assert(block != nullptr, "Sanity check");
397
  assert(block != _last, "Sanity check");
398
  if (_blocks == block) {
399
    _blocks = block->next_block();
400
    if (_blocks != nullptr) {
401
      _blocks->set_prev_block(nullptr);
402
    }
403
  } else {
404
    assert(block->prev_block() != nullptr, "_prev should be set for non-head blocks");
405
    block->prev_block()->set_next_block(block->next_block());
406
    block->next_block()->set_prev_block(block->prev_block());
407
  }
408
  if (block == _start) {
409
    _start = block->prev_block();
410
  }
411
}
412

413
void FieldLayout::print(outputStream* output, bool is_static, const InstanceKlass* super) {
414
  ResourceMark rm;
415
  LayoutRawBlock* b = _blocks;
416
  while(b != _last) {
417
    switch(b->kind()) {
418
      case LayoutRawBlock::REGULAR: {
419
        FieldInfo* fi = _field_info->adr_at(b->field_index());
420
        output->print_cr(" @%d \"%s\" %s %d/%d %s",
421
                         b->offset(),
422
                         fi->name(_cp)->as_C_string(),
423
                         fi->signature(_cp)->as_C_string(),
424
                         b->size(),
425
                         b->alignment(),
426
                         "REGULAR");
427
        break;
428
      }
429
      case LayoutRawBlock::FLATTENED: {
430
        FieldInfo* fi = _field_info->adr_at(b->field_index());
431
        output->print_cr(" @%d \"%s\" %s %d/%d %s",
432
                         b->offset(),
433
                         fi->name(_cp)->as_C_string(),
434
                         fi->signature(_cp)->as_C_string(),
435
                         b->size(),
436
                         b->alignment(),
437
                         "FLATTENED");
438
        break;
439
      }
440
      case LayoutRawBlock::RESERVED: {
441
        output->print_cr(" @%d %d/- %s",
442
                         b->offset(),
443
                         b->size(),
444
                         "RESERVED");
445
        break;
446
      }
447
      case LayoutRawBlock::INHERITED: {
448
        assert(!is_static, "Static fields are not inherited in layouts");
449
        assert(super != nullptr, "super klass must be provided to retrieve inherited fields info");
450
        bool found = false;
451
        const InstanceKlass* ik = super;
452
        while (!found && ik != nullptr) {
453
          for (AllFieldStream fs(ik->fieldinfo_stream(), ik->constants()); !fs.done(); fs.next()) {
454
            if (fs.offset() == b->offset()) {
455
              output->print_cr(" @%d \"%s\" %s %d/%d %s",
456
                  b->offset(),
457
                  fs.name()->as_C_string(),
458
                  fs.signature()->as_C_string(),
459
                  b->size(),
460
                  b->size(), // so far, alignment constraint == size, will change with Valhalla
461
                  "INHERITED");
462
              found = true;
463
              break;
464
            }
465
          }
466
          ik = ik->java_super();
467
        }
468
        break;
469
      }
470
      case LayoutRawBlock::EMPTY:
471
        output->print_cr(" @%d %d/1 %s",
472
                         b->offset(),
473
                         b->size(),
474
                        "EMPTY");
475
        break;
476
      case LayoutRawBlock::PADDING:
477
        output->print_cr(" @%d %d/1 %s",
478
                         b->offset(),
479
                         b->size(),
480
                        "PADDING");
481
        break;
482
    }
483
    b = b->next_block();
484
  }
485
}
486

487
FieldLayoutBuilder::FieldLayoutBuilder(const Symbol* classname, const InstanceKlass* super_klass, ConstantPool* constant_pool,
488
      GrowableArray<FieldInfo>* field_info, bool is_contended, FieldLayoutInfo* info) :
489
  _classname(classname),
490
  _super_klass(super_klass),
491
  _constant_pool(constant_pool),
492
  _field_info(field_info),
493
  _info(info),
494
  _root_group(nullptr),
495
  _contended_groups(GrowableArray<FieldGroup*>(8)),
496
  _static_fields(nullptr),
497
  _layout(nullptr),
498
  _static_layout(nullptr),
499
  _nonstatic_oopmap_count(0),
500
  _alignment(-1),
501
  _has_nonstatic_fields(false),
502
  _is_contended(is_contended) {}
503

504

505
FieldGroup* FieldLayoutBuilder::get_or_create_contended_group(int g) {
506
  assert(g > 0, "must only be called for named contended groups");
507
  FieldGroup* fg = nullptr;
508
  for (int i = 0; i < _contended_groups.length(); i++) {
509
    fg = _contended_groups.at(i);
510
    if (fg->contended_group() == g) return fg;
511
  }
512
  fg = new FieldGroup(g);
513
  _contended_groups.append(fg);
514
  return fg;
515
}
516

517
void FieldLayoutBuilder::prologue() {
518
  _layout = new FieldLayout(_field_info, _constant_pool);
519
  const InstanceKlass* super_klass = _super_klass;
520
  _layout->initialize_instance_layout(super_klass);
521
  if (super_klass != nullptr) {
522
    _has_nonstatic_fields = super_klass->has_nonstatic_fields();
523
  }
524
  _static_layout = new FieldLayout(_field_info, _constant_pool);
525
  _static_layout->initialize_static_layout();
526
  _static_fields = new FieldGroup();
527
  _root_group = new FieldGroup();
528
}
529

530
// Field sorting for regular classes:
531
//   - fields are sorted in static and non-static fields
532
//   - non-static fields are also sorted according to their contention group
533
//     (support of the @Contended annotation)
534
//   - @Contended annotation is ignored for static fields
535
void FieldLayoutBuilder::regular_field_sorting() {
536
  int idx = 0;
537
  for (GrowableArrayIterator<FieldInfo> it = _field_info->begin(); it != _field_info->end(); ++it, ++idx) {
538
    FieldInfo ctrl = _field_info->at(0);
539
    FieldGroup* group = nullptr;
540
    FieldInfo fieldinfo = *it;
541
    if (fieldinfo.access_flags().is_static()) {
542
      group = _static_fields;
543
    } else {
544
      _has_nonstatic_fields = true;
545
      if (fieldinfo.field_flags().is_contended()) {
546
        int g = fieldinfo.contended_group();
547
        if (g == 0) {
548
          group = new FieldGroup(true);
549
          _contended_groups.append(group);
550
        } else {
551
          group = get_or_create_contended_group(g);
552
        }
553
      } else {
554
        group = _root_group;
555
      }
556
    }
557
    assert(group != nullptr, "invariant");
558
    BasicType type = Signature::basic_type(fieldinfo.signature(_constant_pool));
559
    switch(type) {
560
      case T_BYTE:
561
      case T_CHAR:
562
      case T_DOUBLE:
563
      case T_FLOAT:
564
      case T_INT:
565
      case T_LONG:
566
      case T_SHORT:
567
      case T_BOOLEAN:
568
        group->add_primitive_field(idx, type);
569
        break;
570
      case T_OBJECT:
571
      case T_ARRAY:
572
        if (group != _static_fields) _nonstatic_oopmap_count++;
573
        group->add_oop_field(idx);
574
        break;
575
      default:
576
        fatal("Something wrong?");
577
    }
578
  }
579
  _root_group->sort_by_size();
580
  _static_fields->sort_by_size();
581
  if (!_contended_groups.is_empty()) {
582
    for (int i = 0; i < _contended_groups.length(); i++) {
583
      _contended_groups.at(i)->sort_by_size();
584
    }
585
  }
586
}
587

588
void FieldLayoutBuilder::insert_contended_padding(LayoutRawBlock* slot) {
589
  if (ContendedPaddingWidth > 0) {
590
    LayoutRawBlock* padding = new LayoutRawBlock(LayoutRawBlock::PADDING, ContendedPaddingWidth);
591
    _layout->insert(slot, padding);
592
  }
593
}
594

595
// Computation of regular classes layout is an evolution of the previous default layout
596
// (FieldAllocationStyle 1):
597
//   - primitive fields are allocated first (from the biggest to the smallest)
598
//   - then oop fields are allocated, either in existing gaps or at the end of
599
//     the layout
600
void FieldLayoutBuilder::compute_regular_layout() {
601
  bool need_tail_padding = false;
602
  prologue();
603
  regular_field_sorting();
604

605
  if (_is_contended) {
606
    _layout->set_start(_layout->last_block());
607
    // insertion is currently easy because the current strategy doesn't try to fill holes
608
    // in super classes layouts => the _start block is by consequence the _last_block
609
    insert_contended_padding(_layout->start());
610
    need_tail_padding = true;
611
  }
612
  _layout->add(_root_group->primitive_fields());
613
  _layout->add(_root_group->oop_fields());
614

615
  if (!_contended_groups.is_empty()) {
616
    for (int i = 0; i < _contended_groups.length(); i++) {
617
      FieldGroup* cg = _contended_groups.at(i);
618
      LayoutRawBlock* start = _layout->last_block();
619
      insert_contended_padding(start);
620
      _layout->add(cg->primitive_fields(), start);
621
      _layout->add(cg->oop_fields(), start);
622
      need_tail_padding = true;
623
    }
624
  }
625

626
  if (need_tail_padding) {
627
    insert_contended_padding(_layout->last_block());
628
  }
629

630
  _static_layout->add_contiguously(this->_static_fields->oop_fields());
631
  _static_layout->add(this->_static_fields->primitive_fields());
632

633
  epilogue();
634
}
635

636
void FieldLayoutBuilder::epilogue() {
637
  // Computing oopmaps
638
  int super_oop_map_count = (_super_klass == nullptr) ? 0 :_super_klass->nonstatic_oop_map_count();
639
  int max_oop_map_count = super_oop_map_count + _nonstatic_oopmap_count;
640

641
  OopMapBlocksBuilder* nonstatic_oop_maps =
642
      new OopMapBlocksBuilder(max_oop_map_count);
643
  if (super_oop_map_count > 0) {
644
    nonstatic_oop_maps->initialize_inherited_blocks(_super_klass->start_of_nonstatic_oop_maps(),
645
    _super_klass->nonstatic_oop_map_count());
646
  }
647

648
  if (_root_group->oop_fields() != nullptr) {
649
    for (int i = 0; i < _root_group->oop_fields()->length(); i++) {
650
      LayoutRawBlock* b = _root_group->oop_fields()->at(i);
651
      nonstatic_oop_maps->add(b->offset(), 1);
652
    }
653
  }
654

655
  if (!_contended_groups.is_empty()) {
656
    for (int i = 0; i < _contended_groups.length(); i++) {
657
      FieldGroup* cg = _contended_groups.at(i);
658
      if (cg->oop_count() > 0) {
659
        assert(cg->oop_fields() != nullptr && cg->oop_fields()->at(0) != nullptr, "oop_count > 0 but no oop fields found");
660
        nonstatic_oop_maps->add(cg->oop_fields()->at(0)->offset(), cg->oop_count());
661
      }
662
    }
663
  }
664

665
  nonstatic_oop_maps->compact();
666

667
  int instance_end = align_up(_layout->last_block()->offset(), wordSize);
668
  int static_fields_end = align_up(_static_layout->last_block()->offset(), wordSize);
669
  int static_fields_size = (static_fields_end -
670
      InstanceMirrorKlass::offset_of_static_fields()) / wordSize;
671
  int nonstatic_field_end = align_up(_layout->last_block()->offset(), heapOopSize);
672

673
  // Pass back information needed for InstanceKlass creation
674

675
  _info->oop_map_blocks = nonstatic_oop_maps;
676
  _info->_instance_size = align_object_size(instance_end / wordSize);
677
  _info->_static_field_size = static_fields_size;
678
  _info->_nonstatic_field_size = (nonstatic_field_end - instanceOopDesc::base_offset_in_bytes()) / heapOopSize;
679
  _info->_has_nonstatic_fields = _has_nonstatic_fields;
680

681
  if (PrintFieldLayout) {
682
    ResourceMark rm;
683
    tty->print_cr("Layout of class %s", _classname->as_C_string());
684
    tty->print_cr("Instance fields:");
685
    _layout->print(tty, false, _super_klass);
686
    tty->print_cr("Static fields:");
687
    _static_layout->print(tty, true, nullptr);
688
    tty->print_cr("Instance size = %d bytes", _info->_instance_size * wordSize);
689
    tty->print_cr("---");
690
  }
691
}
692

693
void FieldLayoutBuilder::build_layout() {
694
  compute_regular_layout();
695
}
696