1// Copyright 2012 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_HEAP_HEAP_INL_H_
6#define V8_HEAP_HEAP_INL_H_
7
8#include <cmath>
9
10#include "src/base/platform/platform.h"
11#include "src/counters-inl.h"
12#include "src/feedback-vector-inl.h"
13#include "src/heap/heap.h"
14#include "src/heap/incremental-marking-inl.h"
15#include "src/heap/mark-compact.h"
16#include "src/heap/object-stats.h"
17#include "src/heap/remembered-set.h"
18#include "src/heap/spaces-inl.h"
19#include "src/heap/store-buffer.h"
20#include "src/isolate.h"
21#include "src/list-inl.h"
22#include "src/log.h"
23#include "src/msan.h"
24#include "src/objects-inl.h"
25#include "src/objects/scope-info.h"
26
27namespace v8 {
28namespace internal {
29
30AllocationSpace AllocationResult::RetrySpace() {
31  DCHECK(IsRetry());
32  return static_cast<AllocationSpace>(Smi::cast(object_)->value());
33}
34
35HeapObject* AllocationResult::ToObjectChecked() {
36  CHECK(!IsRetry());
37  return HeapObject::cast(object_);
38}
39
40void PromotionQueue::insert(HeapObject* target, int32_t size,
41                            bool was_marked_black) {
42  if (emergency_stack_ != NULL) {
43    emergency_stack_->Add(Entry(target, size, was_marked_black));
44    return;
45  }
46
47  if ((rear_ - 1) < limit_) {
48    RelocateQueueHead();
49    emergency_stack_->Add(Entry(target, size, was_marked_black));
50    return;
51  }
52
53  struct Entry* entry = reinterpret_cast<struct Entry*>(--rear_);
54  entry->obj_ = target;
55  entry->size_ = size;
56  entry->was_marked_black_ = was_marked_black;
57
58// Assert no overflow into live objects.
59#ifdef DEBUG
60  SemiSpace::AssertValidRange(target->GetIsolate()->heap()->new_space()->top(),
61                              reinterpret_cast<Address>(rear_));
62#endif
63}
64
65void PromotionQueue::remove(HeapObject** target, int32_t* size,
66                            bool* was_marked_black) {
67  DCHECK(!is_empty());
68  if (front_ == rear_) {
69    Entry e = emergency_stack_->RemoveLast();
70    *target = e.obj_;
71    *size = e.size_;
72    *was_marked_black = e.was_marked_black_;
73    return;
74  }
75
76  struct Entry* entry = reinterpret_cast<struct Entry*>(--front_);
77  *target = entry->obj_;
78  *size = entry->size_;
79  *was_marked_black = entry->was_marked_black_;
80
81  // Assert no underflow.
82  SemiSpace::AssertValidRange(reinterpret_cast<Address>(rear_),
83                              reinterpret_cast<Address>(front_));
84}
85
86Page* PromotionQueue::GetHeadPage() {
87  return Page::FromAllocationAreaAddress(reinterpret_cast<Address>(rear_));
88}
89
90void PromotionQueue::SetNewLimit(Address limit) {
91  // If we are already using an emergency stack, we can ignore it.
92  if (emergency_stack_) return;
93
94  // If the limit is not on the same page, we can ignore it.
95  if (Page::FromAllocationAreaAddress(limit) != GetHeadPage()) return;
96
97  limit_ = reinterpret_cast<struct Entry*>(limit);
98
99  if (limit_ <= rear_) {
100    return;
101  }
102
103  RelocateQueueHead();
104}
105
106bool PromotionQueue::IsBelowPromotionQueue(Address to_space_top) {
107  // If an emergency stack is used, the to-space address cannot interfere
108  // with the promotion queue.
109  if (emergency_stack_) return true;
110
111  // If the given to-space top pointer and the head of the promotion queue
112  // are not on the same page, then the to-space objects are below the
113  // promotion queue.
114  if (GetHeadPage() != Page::FromAddress(to_space_top)) {
115    return true;
116  }
117  // If the to space top pointer is smaller or equal than the promotion
118  // queue head, then the to-space objects are below the promotion queue.
119  return reinterpret_cast<struct Entry*>(to_space_top) <= rear_;
120}
121
122#define ROOT_ACCESSOR(type, name, camel_name) \
123  type* Heap::name() { return type::cast(roots_[k##camel_name##RootIndex]); }
124ROOT_LIST(ROOT_ACCESSOR)
125#undef ROOT_ACCESSOR
126
127#define STRUCT_MAP_ACCESSOR(NAME, Name, name) \
128  Map* Heap::name##_map() { return Map::cast(roots_[k##Name##MapRootIndex]); }
129STRUCT_LIST(STRUCT_MAP_ACCESSOR)
130#undef STRUCT_MAP_ACCESSOR
131
132#define STRING_ACCESSOR(name, str) \
133  String* Heap::name() { return String::cast(roots_[k##name##RootIndex]); }
134INTERNALIZED_STRING_LIST(STRING_ACCESSOR)
135#undef STRING_ACCESSOR
136
137#define SYMBOL_ACCESSOR(name) \
138  Symbol* Heap::name() { return Symbol::cast(roots_[k##name##RootIndex]); }
139PRIVATE_SYMBOL_LIST(SYMBOL_ACCESSOR)
140#undef SYMBOL_ACCESSOR
141
142#define SYMBOL_ACCESSOR(name, description) \
143  Symbol* Heap::name() { return Symbol::cast(roots_[k##name##RootIndex]); }
144PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR)
145WELL_KNOWN_SYMBOL_LIST(SYMBOL_ACCESSOR)
146#undef SYMBOL_ACCESSOR
147
148#define ROOT_ACCESSOR(type, name, camel_name)                                 \
149  void Heap::set_##name(type* value) {                                        \
150    /* The deserializer makes use of the fact that these common roots are */  \
151    /* never in new space and never on a page that is being compacted.    */  \
152    DCHECK(!deserialization_complete() ||                                     \
153           RootCanBeWrittenAfterInitialization(k##camel_name##RootIndex));    \
154    DCHECK(k##camel_name##RootIndex >= kOldSpaceRoots || !InNewSpace(value)); \
155    roots_[k##camel_name##RootIndex] = value;                                 \
156  }
157ROOT_LIST(ROOT_ACCESSOR)
158#undef ROOT_ACCESSOR
159
160PagedSpace* Heap::paged_space(int idx) {
161  DCHECK_NE(idx, LO_SPACE);
162  DCHECK_NE(idx, NEW_SPACE);
163  return static_cast<PagedSpace*>(space_[idx]);
164}
165
166Space* Heap::space(int idx) { return space_[idx]; }
167
168Address* Heap::NewSpaceAllocationTopAddress() {
169  return new_space_->allocation_top_address();
170}
171
172Address* Heap::NewSpaceAllocationLimitAddress() {
173  return new_space_->allocation_limit_address();
174}
175
176Address* Heap::OldSpaceAllocationTopAddress() {
177  return old_space_->allocation_top_address();
178}
179
180Address* Heap::OldSpaceAllocationLimitAddress() {
181  return old_space_->allocation_limit_address();
182}
183
184void Heap::UpdateNewSpaceAllocationCounter() {
185  new_space_allocation_counter_ = NewSpaceAllocationCounter();
186}
187
188size_t Heap::NewSpaceAllocationCounter() {
189  return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC();
190}
191
192template <>
193bool inline Heap::IsOneByte(Vector<const char> str, int chars) {
194  // TODO(dcarney): incorporate Latin-1 check when Latin-1 is supported?
195  return chars == str.length();
196}
197
198
199template <>
200bool inline Heap::IsOneByte(String* str, int chars) {
201  return str->IsOneByteRepresentation();
202}
203
204
205AllocationResult Heap::AllocateInternalizedStringFromUtf8(
206    Vector<const char> str, int chars, uint32_t hash_field) {
207  if (IsOneByte(str, chars)) {
208    return AllocateOneByteInternalizedString(Vector<const uint8_t>::cast(str),
209                                             hash_field);
210  }
211  return AllocateInternalizedStringImpl<false>(str, chars, hash_field);
212}
213
214
215template <typename T>
216AllocationResult Heap::AllocateInternalizedStringImpl(T t, int chars,
217                                                      uint32_t hash_field) {
218  if (IsOneByte(t, chars)) {
219    return AllocateInternalizedStringImpl<true>(t, chars, hash_field);
220  }
221  return AllocateInternalizedStringImpl<false>(t, chars, hash_field);
222}
223
224
225AllocationResult Heap::AllocateOneByteInternalizedString(
226    Vector<const uint8_t> str, uint32_t hash_field) {
227  CHECK_GE(String::kMaxLength, str.length());
228  // The canonical empty_string is the only zero-length string we allow.
229  DCHECK_IMPLIES(str.length() == 0, roots_[kempty_stringRootIndex] == nullptr);
230  // Compute map and object size.
231  Map* map = one_byte_internalized_string_map();
232  int size = SeqOneByteString::SizeFor(str.length());
233
234  // Allocate string.
235  HeapObject* result = nullptr;
236  {
237    AllocationResult allocation = AllocateRaw(size, OLD_SPACE);
238    if (!allocation.To(&result)) return allocation;
239  }
240
241  // String maps are all immortal immovable objects.
242  result->set_map_no_write_barrier(map);
243  // Set length and hash fields of the allocated string.
244  String* answer = String::cast(result);
245  answer->set_length(str.length());
246  answer->set_hash_field(hash_field);
247
248  DCHECK_EQ(size, answer->Size());
249
250  // Fill in the characters.
251  MemCopy(answer->address() + SeqOneByteString::kHeaderSize, str.start(),
252          str.length());
253
254  return answer;
255}
256
257
258AllocationResult Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
259                                                         uint32_t hash_field) {
260  CHECK_GE(String::kMaxLength, str.length());
261  DCHECK_NE(0, str.length());  // Use Heap::empty_string() instead.
262  // Compute map and object size.
263  Map* map = internalized_string_map();
264  int size = SeqTwoByteString::SizeFor(str.length());
265
266  // Allocate string.
267  HeapObject* result = nullptr;
268  {
269    AllocationResult allocation = AllocateRaw(size, OLD_SPACE);
270    if (!allocation.To(&result)) return allocation;
271  }
272
273  result->set_map(map);
274  // Set length and hash fields of the allocated string.
275  String* answer = String::cast(result);
276  answer->set_length(str.length());
277  answer->set_hash_field(hash_field);
278
279  DCHECK_EQ(size, answer->Size());
280
281  // Fill in the characters.
282  MemCopy(answer->address() + SeqTwoByteString::kHeaderSize, str.start(),
283          str.length() * kUC16Size);
284
285  return answer;
286}
287
288AllocationResult Heap::CopyFixedArray(FixedArray* src) {
289  if (src->length() == 0) return src;
290  return CopyFixedArrayWithMap(src, src->map());
291}
292
293
294AllocationResult Heap::CopyFixedDoubleArray(FixedDoubleArray* src) {
295  if (src->length() == 0) return src;
296  return CopyFixedDoubleArrayWithMap(src, src->map());
297}
298
299
300AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
301                                   AllocationAlignment alignment) {
302  DCHECK(AllowHandleAllocation::IsAllowed());
303  DCHECK(AllowHeapAllocation::IsAllowed());
304  DCHECK(gc_state_ == NOT_IN_GC);
305#ifdef DEBUG
306  if (FLAG_gc_interval >= 0 && !always_allocate() &&
307      Heap::allocation_timeout_-- <= 0) {
308    return AllocationResult::Retry(space);
309  }
310  isolate_->counters()->objs_since_last_full()->Increment();
311  isolate_->counters()->objs_since_last_young()->Increment();
312#endif
313
314  bool large_object = size_in_bytes > kMaxRegularHeapObjectSize;
315  HeapObject* object = nullptr;
316  AllocationResult allocation;
317  if (NEW_SPACE == space) {
318    if (large_object) {
319      space = LO_SPACE;
320    } else {
321      allocation = new_space_->AllocateRaw(size_in_bytes, alignment);
322      if (allocation.To(&object)) {
323        OnAllocationEvent(object, size_in_bytes);
324      }
325      return allocation;
326    }
327  }
328
329  // Here we only allocate in the old generation.
330  if (OLD_SPACE == space) {
331    if (large_object) {
332      allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
333    } else {
334      allocation = old_space_->AllocateRaw(size_in_bytes, alignment);
335    }
336  } else if (CODE_SPACE == space) {
337    if (size_in_bytes <= code_space()->AreaSize()) {
338      allocation = code_space_->AllocateRawUnaligned(size_in_bytes);
339    } else {
340      allocation = lo_space_->AllocateRaw(size_in_bytes, EXECUTABLE);
341    }
342  } else if (LO_SPACE == space) {
343    DCHECK(large_object);
344    allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
345  } else if (MAP_SPACE == space) {
346    allocation = map_space_->AllocateRawUnaligned(size_in_bytes);
347  } else {
348    // NEW_SPACE is not allowed here.
349    UNREACHABLE();
350  }
351  if (allocation.To(&object)) {
352    OnAllocationEvent(object, size_in_bytes);
353  }
354
355  return allocation;
356}
357
358
359void Heap::OnAllocationEvent(HeapObject* object, int size_in_bytes) {
360  HeapProfiler* profiler = isolate_->heap_profiler();
361  if (profiler->is_tracking_allocations()) {
362    profiler->AllocationEvent(object->address(), size_in_bytes);
363  }
364
365  if (FLAG_verify_predictable) {
366    ++allocations_count_;
367    // Advance synthetic time by making a time request.
368    MonotonicallyIncreasingTimeInMs();
369
370    UpdateAllocationsHash(object);
371    UpdateAllocationsHash(size_in_bytes);
372
373    if (allocations_count_ % FLAG_dump_allocations_digest_at_alloc == 0) {
374      PrintAlloctionsHash();
375    }
376  }
377
378  if (FLAG_trace_allocation_stack_interval > 0) {
379    if (!FLAG_verify_predictable) ++allocations_count_;
380    if (allocations_count_ % FLAG_trace_allocation_stack_interval == 0) {
381      isolate()->PrintStack(stdout, Isolate::kPrintStackConcise);
382    }
383  }
384}
385
386
387void Heap::OnMoveEvent(HeapObject* target, HeapObject* source,
388                       int size_in_bytes) {
389  HeapProfiler* heap_profiler = isolate_->heap_profiler();
390  if (heap_profiler->is_tracking_object_moves()) {
391    heap_profiler->ObjectMoveEvent(source->address(), target->address(),
392                                   size_in_bytes);
393  }
394  if (target->IsSharedFunctionInfo()) {
395    LOG_CODE_EVENT(isolate_, SharedFunctionInfoMoveEvent(source->address(),
396                                                         target->address()));
397  }
398
399  if (FLAG_verify_predictable) {
400    ++allocations_count_;
401    // Advance synthetic time by making a time request.
402    MonotonicallyIncreasingTimeInMs();
403
404    UpdateAllocationsHash(source);
405    UpdateAllocationsHash(target);
406    UpdateAllocationsHash(size_in_bytes);
407
408    if (allocations_count_ % FLAG_dump_allocations_digest_at_alloc == 0) {
409      PrintAlloctionsHash();
410    }
411  }
412}
413
414
415void Heap::UpdateAllocationsHash(HeapObject* object) {
416  Address object_address = object->address();
417  MemoryChunk* memory_chunk = MemoryChunk::FromAddress(object_address);
418  AllocationSpace allocation_space = memory_chunk->owner()->identity();
419
420  STATIC_ASSERT(kSpaceTagSize + kPageSizeBits <= 32);
421  uint32_t value =
422      static_cast<uint32_t>(object_address - memory_chunk->address()) |
423      (static_cast<uint32_t>(allocation_space) << kPageSizeBits);
424
425  UpdateAllocationsHash(value);
426}
427
428
429void Heap::UpdateAllocationsHash(uint32_t value) {
430  uint16_t c1 = static_cast<uint16_t>(value);
431  uint16_t c2 = static_cast<uint16_t>(value >> 16);
432  raw_allocations_hash_ =
433      StringHasher::AddCharacterCore(raw_allocations_hash_, c1);
434  raw_allocations_hash_ =
435      StringHasher::AddCharacterCore(raw_allocations_hash_, c2);
436}
437
438
439void Heap::RegisterExternalString(String* string) {
440  external_string_table_.AddString(string);
441}
442
443
444void Heap::FinalizeExternalString(String* string) {
445  DCHECK(string->IsExternalString());
446  v8::String::ExternalStringResourceBase** resource_addr =
447      reinterpret_cast<v8::String::ExternalStringResourceBase**>(
448          reinterpret_cast<byte*>(string) + ExternalString::kResourceOffset -
449          kHeapObjectTag);
450
451  // Dispose of the C++ object if it has not already been disposed.
452  if (*resource_addr != NULL) {
453    (*resource_addr)->Dispose();
454    *resource_addr = NULL;
455  }
456}
457
458Address Heap::NewSpaceTop() { return new_space_->top(); }
459
460bool Heap::DeoptMaybeTenuredAllocationSites() {
461  return new_space_->IsAtMaximumCapacity() && maximum_size_scavenges_ == 0;
462}
463
464bool Heap::InNewSpace(Object* object) {
465  // Inlined check from NewSpace::Contains.
466  bool result =
467      object->IsHeapObject() &&
468      Page::FromAddress(HeapObject::cast(object)->address())->InNewSpace();
469  DCHECK(!result ||                 // Either not in new space
470         gc_state_ != NOT_IN_GC ||  // ... or in the middle of GC
471         InToSpace(object));        // ... or in to-space (where we allocate).
472  return result;
473}
474
475bool Heap::InFromSpace(Object* object) {
476  return object->IsHeapObject() &&
477         MemoryChunk::FromAddress(HeapObject::cast(object)->address())
478             ->IsFlagSet(Page::IN_FROM_SPACE);
479}
480
481
482bool Heap::InToSpace(Object* object) {
483  return object->IsHeapObject() &&
484         MemoryChunk::FromAddress(HeapObject::cast(object)->address())
485             ->IsFlagSet(Page::IN_TO_SPACE);
486}
487
488bool Heap::InOldSpace(Object* object) { return old_space_->Contains(object); }
489
490bool Heap::InNewSpaceSlow(Address address) {
491  return new_space_->ContainsSlow(address);
492}
493
494bool Heap::InOldSpaceSlow(Address address) {
495  return old_space_->ContainsSlow(address);
496}
497
498bool Heap::ShouldBePromoted(Address old_address, int object_size) {
499  Page* page = Page::FromAddress(old_address);
500  Address age_mark = new_space_->age_mark();
501  return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
502         (!page->ContainsLimit(age_mark) || old_address < age_mark);
503}
504
505void Heap::RecordWrite(Object* object, int offset, Object* o) {
506  if (!InNewSpace(o) || !object->IsHeapObject() || InNewSpace(object)) {
507    return;
508  }
509  store_buffer()->InsertEntry(HeapObject::cast(object)->address() + offset);
510}
511
512void Heap::RecordWriteIntoCode(Code* host, RelocInfo* rinfo, Object* value) {
513  if (InNewSpace(value)) {
514    RecordWriteIntoCodeSlow(host, rinfo, value);
515  }
516}
517
518void Heap::RecordFixedArrayElements(FixedArray* array, int offset, int length) {
519  if (InNewSpace(array)) return;
520  for (int i = 0; i < length; i++) {
521    if (!InNewSpace(array->get(offset + i))) continue;
522    store_buffer()->InsertEntry(
523        reinterpret_cast<Address>(array->RawFieldOfElementAt(offset + i)));
524  }
525}
526
527Address* Heap::store_buffer_top_address() {
528  return store_buffer()->top_address();
529}
530
531bool Heap::AllowedToBeMigrated(HeapObject* obj, AllocationSpace dst) {
532  // Object migration is governed by the following rules:
533  //
534  // 1) Objects in new-space can be migrated to the old space
535  //    that matches their target space or they stay in new-space.
536  // 2) Objects in old-space stay in the same space when migrating.
537  // 3) Fillers (two or more words) can migrate due to left-trimming of
538  //    fixed arrays in new-space or old space.
539  // 4) Fillers (one word) can never migrate, they are skipped by
540  //    incremental marking explicitly to prevent invalid pattern.
541  //
542  // Since this function is used for debugging only, we do not place
543  // asserts here, but check everything explicitly.
544  if (obj->map() == one_pointer_filler_map()) return false;
545  InstanceType type = obj->map()->instance_type();
546  MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
547  AllocationSpace src = chunk->owner()->identity();
548  switch (src) {
549    case NEW_SPACE:
550      return dst == src || dst == OLD_SPACE;
551    case OLD_SPACE:
552      return dst == src &&
553             (dst == OLD_SPACE || obj->IsFiller() || obj->IsExternalString());
554    case CODE_SPACE:
555      return dst == src && type == CODE_TYPE;
556    case MAP_SPACE:
557    case LO_SPACE:
558      return false;
559  }
560  UNREACHABLE();
561  return false;
562}
563
564void Heap::CopyBlock(Address dst, Address src, int byte_size) {
565  CopyWords(reinterpret_cast<Object**>(dst), reinterpret_cast<Object**>(src),
566            static_cast<size_t>(byte_size / kPointerSize));
567}
568
569template <Heap::FindMementoMode mode>
570AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) {
571  Address object_address = object->address();
572  Address memento_address = object_address + object->Size();
573  Address last_memento_word_address = memento_address + kPointerSize;
574  // If the memento would be on another page, bail out immediately.
575  if (!Page::OnSamePage(object_address, last_memento_word_address)) {
576    return nullptr;
577  }
578  HeapObject* candidate = HeapObject::FromAddress(memento_address);
579  Map* candidate_map = candidate->map();
580  // This fast check may peek at an uninitialized word. However, the slow check
581  // below (memento_address == top) ensures that this is safe. Mark the word as
582  // initialized to silence MemorySanitizer warnings.
583  MSAN_MEMORY_IS_INITIALIZED(&candidate_map, sizeof(candidate_map));
584  if (candidate_map != allocation_memento_map()) {
585    return nullptr;
586  }
587
588  // Bail out if the memento is below the age mark, which can happen when
589  // mementos survived because a page got moved within new space.
590  Page* object_page = Page::FromAddress(object_address);
591  if (object_page->IsFlagSet(Page::NEW_SPACE_BELOW_AGE_MARK)) {
592    Address age_mark =
593        reinterpret_cast<SemiSpace*>(object_page->owner())->age_mark();
594    if (!object_page->Contains(age_mark)) {
595      return nullptr;
596    }
597    // Do an exact check in the case where the age mark is on the same page.
598    if (object_address < age_mark) {
599      return nullptr;
600    }
601  }
602
603  AllocationMemento* memento_candidate = AllocationMemento::cast(candidate);
604
605  // Depending on what the memento is used for, we might need to perform
606  // additional checks.
607  Address top;
608  switch (mode) {
609    case Heap::kForGC:
610      return memento_candidate;
611    case Heap::kForRuntime:
612      if (memento_candidate == nullptr) return nullptr;
613      // Either the object is the last object in the new space, or there is
614      // another object of at least word size (the header map word) following
615      // it, so suffices to compare ptr and top here.
616      top = NewSpaceTop();
617      DCHECK(memento_address == top ||
618             memento_address + HeapObject::kHeaderSize <= top ||
619             !Page::OnSamePage(memento_address, top - 1));
620      if ((memento_address != top) && memento_candidate->IsValid()) {
621        return memento_candidate;
622      }
623      return nullptr;
624    default:
625      UNREACHABLE();
626  }
627  UNREACHABLE();
628  return nullptr;
629}
630
631template <Heap::UpdateAllocationSiteMode mode>
632void Heap::UpdateAllocationSite(HeapObject* object,
633                                base::HashMap* pretenuring_feedback) {
634  DCHECK(InFromSpace(object) ||
635         (InToSpace(object) &&
636          Page::FromAddress(object->address())
637              ->IsFlagSet(Page::PAGE_NEW_NEW_PROMOTION)) ||
638         (!InNewSpace(object) &&
639          Page::FromAddress(object->address())
640              ->IsFlagSet(Page::PAGE_NEW_OLD_PROMOTION)));
641  if (!FLAG_allocation_site_pretenuring ||
642      !AllocationSite::CanTrack(object->map()->instance_type()))
643    return;
644  AllocationMemento* memento_candidate = FindAllocationMemento<kForGC>(object);
645  if (memento_candidate == nullptr) return;
646
647  if (mode == kGlobal) {
648    DCHECK_EQ(pretenuring_feedback, global_pretenuring_feedback_);
649    // Entering global pretenuring feedback is only used in the scavenger, where
650    // we are allowed to actually touch the allocation site.
651    if (!memento_candidate->IsValid()) return;
652    AllocationSite* site = memento_candidate->GetAllocationSite();
653    DCHECK(!site->IsZombie());
654    // For inserting in the global pretenuring storage we need to first
655    // increment the memento found count on the allocation site.
656    if (site->IncrementMementoFoundCount()) {
657      global_pretenuring_feedback_->LookupOrInsert(site,
658                                                   ObjectHash(site->address()));
659    }
660  } else {
661    DCHECK_EQ(mode, kCached);
662    DCHECK_NE(pretenuring_feedback, global_pretenuring_feedback_);
663    // Entering cached feedback is used in the parallel case. We are not allowed
664    // to dereference the allocation site and rather have to postpone all checks
665    // till actually merging the data.
666    Address key = memento_candidate->GetAllocationSiteUnchecked();
667    base::HashMap::Entry* e =
668        pretenuring_feedback->LookupOrInsert(key, ObjectHash(key));
669    DCHECK(e != nullptr);
670    (*bit_cast<intptr_t*>(&e->value))++;
671  }
672}
673
674
675void Heap::RemoveAllocationSitePretenuringFeedback(AllocationSite* site) {
676  global_pretenuring_feedback_->Remove(
677      site, static_cast<uint32_t>(bit_cast<uintptr_t>(site)));
678}
679
680bool Heap::CollectGarbage(AllocationSpace space,
681                          GarbageCollectionReason gc_reason,
682                          const v8::GCCallbackFlags callbackFlags) {
683  const char* collector_reason = NULL;
684  GarbageCollector collector = SelectGarbageCollector(space, &collector_reason);
685  return CollectGarbage(collector, gc_reason, collector_reason, callbackFlags);
686}
687
688
689Isolate* Heap::isolate() {
690  return reinterpret_cast<Isolate*>(
691      reinterpret_cast<intptr_t>(this) -
692      reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(16)->heap()) + 16);
693}
694
695void Heap::ExternalStringTable::PromoteAllNewSpaceStrings() {
696  old_space_strings_.AddAll(new_space_strings_);
697  new_space_strings_.Clear();
698}
699
700void Heap::ExternalStringTable::AddString(String* string) {
701  DCHECK(string->IsExternalString());
702  if (heap_->InNewSpace(string)) {
703    new_space_strings_.Add(string);
704  } else {
705    old_space_strings_.Add(string);
706  }
707}
708
709void Heap::ExternalStringTable::IterateNewSpaceStrings(ObjectVisitor* v) {
710  if (!new_space_strings_.is_empty()) {
711    Object** start = &new_space_strings_[0];
712    v->VisitPointers(start, start + new_space_strings_.length());
713  }
714}
715
716void Heap::ExternalStringTable::IterateAll(ObjectVisitor* v) {
717  IterateNewSpaceStrings(v);
718  if (!old_space_strings_.is_empty()) {
719    Object** start = &old_space_strings_[0];
720    v->VisitPointers(start, start + old_space_strings_.length());
721  }
722}
723
724
725// Verify() is inline to avoid ifdef-s around its calls in release
726// mode.
727void Heap::ExternalStringTable::Verify() {
728#ifdef DEBUG
729  for (int i = 0; i < new_space_strings_.length(); ++i) {
730    Object* obj = Object::cast(new_space_strings_[i]);
731    DCHECK(heap_->InNewSpace(obj));
732    DCHECK(!obj->IsTheHole(heap_->isolate()));
733  }
734  for (int i = 0; i < old_space_strings_.length(); ++i) {
735    Object* obj = Object::cast(old_space_strings_[i]);
736    DCHECK(!heap_->InNewSpace(obj));
737    DCHECK(!obj->IsTheHole(heap_->isolate()));
738  }
739#endif
740}
741
742
743void Heap::ExternalStringTable::AddOldString(String* string) {
744  DCHECK(string->IsExternalString());
745  DCHECK(!heap_->InNewSpace(string));
746  old_space_strings_.Add(string);
747}
748
749
750void Heap::ExternalStringTable::ShrinkNewStrings(int position) {
751  new_space_strings_.Rewind(position);
752#ifdef VERIFY_HEAP
753  if (FLAG_verify_heap) {
754    Verify();
755  }
756#endif
757}
758
759void Heap::ClearInstanceofCache() { set_instanceof_cache_function(Smi::kZero); }
760
761Oddball* Heap::ToBoolean(bool condition) {
762  return condition ? true_value() : false_value();
763}
764
765
766void Heap::CompletelyClearInstanceofCache() {
767  set_instanceof_cache_map(Smi::kZero);
768  set_instanceof_cache_function(Smi::kZero);
769}
770
771
772uint32_t Heap::HashSeed() {
773  uint32_t seed = static_cast<uint32_t>(hash_seed()->value());
774  DCHECK(FLAG_randomize_hashes || seed == 0);
775  return seed;
776}
777
778
779int Heap::NextScriptId() {
780  int last_id = last_script_id()->value();
781  if (last_id == Smi::kMaxValue) {
782    last_id = 1;
783  } else {
784    last_id++;
785  }
786  set_last_script_id(Smi::FromInt(last_id));
787  return last_id;
788}
789
790void Heap::SetArgumentsAdaptorDeoptPCOffset(int pc_offset) {
791  DCHECK(arguments_adaptor_deopt_pc_offset() == Smi::kZero);
792  set_arguments_adaptor_deopt_pc_offset(Smi::FromInt(pc_offset));
793}
794
795void Heap::SetConstructStubCreateDeoptPCOffset(int pc_offset) {
796  DCHECK(construct_stub_create_deopt_pc_offset() == Smi::kZero);
797  set_construct_stub_create_deopt_pc_offset(Smi::FromInt(pc_offset));
798}
799
800void Heap::SetConstructStubInvokeDeoptPCOffset(int pc_offset) {
801  DCHECK(construct_stub_invoke_deopt_pc_offset() == Smi::kZero);
802  set_construct_stub_invoke_deopt_pc_offset(Smi::FromInt(pc_offset));
803}
804
805void Heap::SetGetterStubDeoptPCOffset(int pc_offset) {
806  DCHECK(getter_stub_deopt_pc_offset() == Smi::kZero);
807  set_getter_stub_deopt_pc_offset(Smi::FromInt(pc_offset));
808}
809
810void Heap::SetSetterStubDeoptPCOffset(int pc_offset) {
811  DCHECK(setter_stub_deopt_pc_offset() == Smi::kZero);
812  set_setter_stub_deopt_pc_offset(Smi::FromInt(pc_offset));
813}
814
815void Heap::SetInterpreterEntryReturnPCOffset(int pc_offset) {
816  DCHECK(interpreter_entry_return_pc_offset() == Smi::kZero);
817  set_interpreter_entry_return_pc_offset(Smi::FromInt(pc_offset));
818}
819
820int Heap::GetNextTemplateSerialNumber() {
821  int next_serial_number = next_template_serial_number()->value() + 1;
822  set_next_template_serial_number(Smi::FromInt(next_serial_number));
823  return next_serial_number;
824}
825
826void Heap::SetSerializedTemplates(FixedArray* templates) {
827  DCHECK_EQ(empty_fixed_array(), serialized_templates());
828  DCHECK(isolate()->serializer_enabled());
829  set_serialized_templates(templates);
830}
831
832void Heap::SetSerializedGlobalProxySizes(FixedArray* sizes) {
833  DCHECK_EQ(empty_fixed_array(), serialized_global_proxy_sizes());
834  DCHECK(isolate()->serializer_enabled());
835  set_serialized_global_proxy_sizes(sizes);
836}
837
838void Heap::CreateObjectStats() {
839  if (V8_LIKELY(FLAG_gc_stats == 0)) return;
840  if (!live_object_stats_) {
841    live_object_stats_ = new ObjectStats(this);
842  }
843  if (!dead_object_stats_) {
844    dead_object_stats_ = new ObjectStats(this);
845  }
846}
847
848AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
849    : heap_(isolate->heap()) {
850  heap_->always_allocate_scope_count_.Increment(1);
851}
852
853
854AlwaysAllocateScope::~AlwaysAllocateScope() {
855  heap_->always_allocate_scope_count_.Increment(-1);
856}
857
858
859void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
860  for (Object** current = start; current < end; current++) {
861    if ((*current)->IsHeapObject()) {
862      HeapObject* object = HeapObject::cast(*current);
863      CHECK(object->GetIsolate()->heap()->Contains(object));
864      CHECK(object->map()->IsMap());
865    } else {
866      CHECK((*current)->IsSmi());
867    }
868  }
869}
870
871
872void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
873  for (Object** current = start; current < end; current++) {
874    CHECK((*current)->IsSmi());
875  }
876}
877}  // namespace internal
878}  // namespace v8
879
880#endif  // V8_HEAP_HEAP_INL_H_
881