deps/v8/src/heap/heap-inl.h

   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/cpu-profiler.h"
  12 #include "src/heap/heap.h"
  13 #include "src/heap/store-buffer.h"
  14 #include "src/heap/store-buffer-inl.h"
  15 #include "src/heap-profiler.h"
  16 #include "src/isolate.h"
  17 #include "src/list-inl.h"
  18 #include "src/msan.h"
  19 #include "src/objects.h"
  20
  21 namespace v8 {
  22 namespace internal {
  23
  24 void PromotionQueue::insert(HeapObject* target, int size) {
  25   if (emergency_stack_ != NULL) {
  26     emergency_stack_->Add(Entry(target, size));
  27     return;
  28   }
  29
  30   if ((rear_ - 2) < limit_) {
  31     RelocateQueueHead();
  32     emergency_stack_->Add(Entry(target, size));
  33     return;
  34   }
  35
  36   *(--rear_) = reinterpret_cast<intptr_t>(target);
  37   *(--rear_) = size;
  38 // Assert no overflow into live objects.
  39 #ifdef DEBUG
  40   SemiSpace::AssertValidRange(target->GetIsolate()->heap()->new_space()->top(),
  41                               reinterpret_cast<Address>(rear_));
  42 #endif
  43 }
  44
  45
  46 template <>
  47 bool inline Heap::IsOneByte(Vector<const char> str, int chars) {
  48   // TODO(dcarney): incorporate Latin-1 check when Latin-1 is supported?
  49   return chars == str.length();
  50 }
  51
  52
  53 template <>
  54 bool inline Heap::IsOneByte(String* str, int chars) {
  55   return str->IsOneByteRepresentation();
  56 }
  57
  58
  59 AllocationResult Heap::AllocateInternalizedStringFromUtf8(
  60     Vector<const char> str, int chars, uint32_t hash_field) {
  61   if (IsOneByte(str, chars)) {
  62     return AllocateOneByteInternalizedString(Vector<const uint8_t>::cast(str),
  63                                              hash_field);
  64   }
  65   return AllocateInternalizedStringImpl<false>(str, chars, hash_field);
  66 }
  67
  68
  69 template <typename T>
  70 AllocationResult Heap::AllocateInternalizedStringImpl(T t, int chars,
  71                                                       uint32_t hash_field) {
  72   if (IsOneByte(t, chars)) {
  73     return AllocateInternalizedStringImpl<true>(t, chars, hash_field);
  74   }
  75   return AllocateInternalizedStringImpl<false>(t, chars, hash_field);
  76 }
  77
  78
  79 AllocationResult Heap::AllocateOneByteInternalizedString(
  80     Vector<const uint8_t> str, uint32_t hash_field) {
  81   CHECK_GE(String::kMaxLength, str.length());
  82   // Compute map and object size.
  83   Map* map = one_byte_internalized_string_map();
  84   int size = SeqOneByteString::SizeFor(str.length());
  85   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
  86
  87   // Allocate string.
  88   HeapObject* result;
  89   {
  90     AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
  91     if (!allocation.To(&result)) return allocation;
  92   }
  93
  94   // String maps are all immortal immovable objects.
  95   result->set_map_no_write_barrier(map);
  96   // Set length and hash fields of the allocated string.
  97   String* answer = String::cast(result);
  98   answer->set_length(str.length());
  99   answer->set_hash_field(hash_field);
 100
 101   DCHECK_EQ(size, answer->Size());
 102
 103   // Fill in the characters.
 104   MemCopy(answer->address() + SeqOneByteString::kHeaderSize, str.start(),
 105           str.length());
 106
 107   return answer;
 108 }
 109
 110
 111 AllocationResult Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
 112                                                          uint32_t hash_field) {
 113   CHECK_GE(String::kMaxLength, str.length());
 114   // Compute map and object size.
 115   Map* map = internalized_string_map();
 116   int size = SeqTwoByteString::SizeFor(str.length());
 117   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
 118
 119   // Allocate string.
 120   HeapObject* result;
 121   {
 122     AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
 123     if (!allocation.To(&result)) return allocation;
 124   }
 125
 126   result->set_map(map);
 127   // Set length and hash fields of the allocated string.
 128   String* answer = String::cast(result);
 129   answer->set_length(str.length());
 130   answer->set_hash_field(hash_field);
 131
 132   DCHECK_EQ(size, answer->Size());
 133
 134   // Fill in the characters.
 135   MemCopy(answer->address() + SeqTwoByteString::kHeaderSize, str.start(),
 136           str.length() * kUC16Size);
 137
 138   return answer;
 139 }
 140
 141 AllocationResult Heap::CopyFixedArray(FixedArray* src) {
 142   if (src->length() == 0) return src;
 143   return CopyFixedArrayWithMap(src, src->map());
 144 }
 145
 146
 147 AllocationResult Heap::CopyFixedDoubleArray(FixedDoubleArray* src) {
 148   if (src->length() == 0) return src;
 149   return CopyFixedDoubleArrayWithMap(src, src->map());
 150 }
 151
 152
 153 AllocationResult Heap::CopyConstantPoolArray(ConstantPoolArray* src) {
 154   if (src->length() == 0) return src;
 155   return CopyConstantPoolArrayWithMap(src, src->map());
 156 }
 157
 158
 159 AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
 160                                    AllocationSpace retry_space) {
 161   DCHECK(AllowHandleAllocation::IsAllowed());
 162   DCHECK(AllowHeapAllocation::IsAllowed());
 163   DCHECK(gc_state_ == NOT_IN_GC);
 164 #ifdef DEBUG
 165   if (FLAG_gc_interval >= 0 && AllowAllocationFailure::IsAllowed(isolate_) &&
 166       Heap::allocation_timeout_-- <= 0) {
 167     return AllocationResult::Retry(space);
 168   }
 169   isolate_->counters()->objs_since_last_full()->Increment();
 170   isolate_->counters()->objs_since_last_young()->Increment();
 171 #endif
 172
 173   HeapObject* object;
 174   AllocationResult allocation;
 175   if (NEW_SPACE == space) {
 176     allocation = new_space_.AllocateRaw(size_in_bytes);
 177     if (always_allocate() && allocation.IsRetry() && retry_space != NEW_SPACE) {
 178       space = retry_space;
 179     } else {
 180       if (allocation.To(&object)) {
 181         OnAllocationEvent(object, size_in_bytes);
 182       }
 183       return allocation;
 184     }
 185   }
 186
 187   if (OLD_POINTER_SPACE == space) {
 188     allocation = old_pointer_space_->AllocateRaw(size_in_bytes);
 189   } else if (OLD_DATA_SPACE == space) {
 190     allocation = old_data_space_->AllocateRaw(size_in_bytes);
 191   } else if (CODE_SPACE == space) {
 192     if (size_in_bytes <= code_space()->AreaSize()) {
 193       allocation = code_space_->AllocateRaw(size_in_bytes);
 194     } else {
 195       // Large code objects are allocated in large object space.
 196       allocation = lo_space_->AllocateRaw(size_in_bytes, EXECUTABLE);
 197     }
 198   } else if (LO_SPACE == space) {
 199     allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
 200   } else if (CELL_SPACE == space) {
 201     allocation = cell_space_->AllocateRaw(size_in_bytes);
 202   } else if (PROPERTY_CELL_SPACE == space) {
 203     allocation = property_cell_space_->AllocateRaw(size_in_bytes);
 204   } else {
 205     DCHECK(MAP_SPACE == space);
 206     allocation = map_space_->AllocateRaw(size_in_bytes);
 207   }
 208   if (allocation.To(&object)) {
 209     OnAllocationEvent(object, size_in_bytes);
 210   } else {
 211     old_gen_exhausted_ = true;
 212   }
 213   return allocation;
 214 }
 215
 216
 217 void Heap::OnAllocationEvent(HeapObject* object, int size_in_bytes) {
 218   HeapProfiler* profiler = isolate_->heap_profiler();
 219   if (profiler->is_tracking_allocations()) {
 220     profiler->AllocationEvent(object->address(), size_in_bytes);
 221   }
 222
 223   if (FLAG_verify_predictable) {
 224     ++allocations_count_;
 225
 226     UpdateAllocationsHash(object);
 227     UpdateAllocationsHash(size_in_bytes);
 228
 229     if ((FLAG_dump_allocations_digest_at_alloc > 0) &&
 230         (--dump_allocations_hash_countdown_ == 0)) {
 231       dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc;
 232       PrintAlloctionsHash();
 233     }
 234   }
 235 }
 236
 237
 238 void Heap::OnMoveEvent(HeapObject* target, HeapObject* source,
 239                        int size_in_bytes) {
 240   HeapProfiler* heap_profiler = isolate_->heap_profiler();
 241   if (heap_profiler->is_tracking_object_moves()) {
 242     heap_profiler->ObjectMoveEvent(source->address(), target->address(),
 243                                    size_in_bytes);
 244   }
 245
 246   if (isolate_->logger()->is_logging_code_events() ||
 247       isolate_->cpu_profiler()->is_profiling()) {
 248     if (target->IsSharedFunctionInfo()) {
 249       PROFILE(isolate_, SharedFunctionInfoMoveEvent(source->address(),
 250                                                     target->address()));
 251     }
 252   }
 253
 254   if (FLAG_verify_predictable) {
 255     ++allocations_count_;
 256
 257     UpdateAllocationsHash(source);
 258     UpdateAllocationsHash(target);
 259     UpdateAllocationsHash(size_in_bytes);
 260
 261     if ((FLAG_dump_allocations_digest_at_alloc > 0) &&
 262         (--dump_allocations_hash_countdown_ == 0)) {
 263       dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc;
 264       PrintAlloctionsHash();
 265     }
 266   }
 267 }
 268
 269
 270 void Heap::UpdateAllocationsHash(HeapObject* object) {
 271   Address object_address = object->address();
 272   MemoryChunk* memory_chunk = MemoryChunk::FromAddress(object_address);
 273   AllocationSpace allocation_space = memory_chunk->owner()->identity();
 274
 275   STATIC_ASSERT(kSpaceTagSize + kPageSizeBits <= 32);
 276   uint32_t value =
 277       static_cast<uint32_t>(object_address - memory_chunk->address()) |
 278       (static_cast<uint32_t>(allocation_space) << kPageSizeBits);
 279
 280   UpdateAllocationsHash(value);
 281 }
 282
 283
 284 void Heap::UpdateAllocationsHash(uint32_t value) {
 285   uint16_t c1 = static_cast<uint16_t>(value);
 286   uint16_t c2 = static_cast<uint16_t>(value >> 16);
 287   raw_allocations_hash_ =
 288       StringHasher::AddCharacterCore(raw_allocations_hash_, c1);
 289   raw_allocations_hash_ =
 290       StringHasher::AddCharacterCore(raw_allocations_hash_, c2);
 291 }
 292
 293
 294 void Heap::PrintAlloctionsHash() {
 295   uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_);
 296   PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count_, hash);
 297 }
 298
 299
 300 void Heap::FinalizeExternalString(String* string) {
 301   DCHECK(string->IsExternalString());
 302   v8::String::ExternalStringResourceBase** resource_addr =
 303       reinterpret_cast<v8::String::ExternalStringResourceBase**>(
 304           reinterpret_cast<byte*>(string) + ExternalString::kResourceOffset -
 305           kHeapObjectTag);
 306
 307   // Dispose of the C++ object if it has not already been disposed.
 308   if (*resource_addr != NULL) {
 309     (*resource_addr)->Dispose();
 310     *resource_addr = NULL;
 311   }
 312 }
 313
 314
 315 bool Heap::InNewSpace(Object* object) {
 316   bool result = new_space_.Contains(object);
 317   DCHECK(!result ||                 // Either not in new space
 318          gc_state_ != NOT_IN_GC ||  // ... or in the middle of GC
 319          InToSpace(object));        // ... or in to-space (where we allocate).
 320   return result;
 321 }
 322
 323
 324 bool Heap::InNewSpace(Address address) { return new_space_.Contains(address); }
 325
 326
 327 bool Heap::InFromSpace(Object* object) {
 328   return new_space_.FromSpaceContains(object);
 329 }
 330
 331
 332 bool Heap::InToSpace(Object* object) {
 333   return new_space_.ToSpaceContains(object);
 334 }
 335
 336
 337 bool Heap::InOldPointerSpace(Address address) {
 338   return old_pointer_space_->Contains(address);
 339 }
 340
 341
 342 bool Heap::InOldPointerSpace(Object* object) {
 343   return InOldPointerSpace(reinterpret_cast<Address>(object));
 344 }
 345
 346
 347 bool Heap::InOldDataSpace(Address address) {
 348   return old_data_space_->Contains(address);
 349 }
 350
 351
 352 bool Heap::InOldDataSpace(Object* object) {
 353   return InOldDataSpace(reinterpret_cast<Address>(object));
 354 }
 355
 356
 357 bool Heap::OldGenerationAllocationLimitReached() {
 358   if (!incremental_marking()->IsStopped()) return false;
 359   return OldGenerationSpaceAvailable() < 0;
 360 }
 361
 362
 363 bool Heap::ShouldBePromoted(Address old_address, int object_size) {
 364   NewSpacePage* page = NewSpacePage::FromAddress(old_address);
 365   Address age_mark = new_space_.age_mark();
 366   return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
 367          (!page->ContainsLimit(age_mark) || old_address < age_mark);
 368 }
 369
 370
 371 void Heap::RecordWrite(Address address, int offset) {
 372   if (!InNewSpace(address)) store_buffer_.Mark(address + offset);
 373 }
 374
 375
 376 void Heap::RecordWrites(Address address, int start, int len) {
 377   if (!InNewSpace(address)) {
 378     for (int i = 0; i < len; i++) {
 379       store_buffer_.Mark(address + start + i * kPointerSize);
 380     }
 381   }
 382 }
 383
 384
 385 OldSpace* Heap::TargetSpace(HeapObject* object) {
 386   InstanceType type = object->map()->instance_type();
 387   AllocationSpace space = TargetSpaceId(type);
 388   return (space == OLD_POINTER_SPACE) ? old_pointer_space_ : old_data_space_;
 389 }
 390
 391
 392 AllocationSpace Heap::TargetSpaceId(InstanceType type) {
 393   // Heap numbers and sequential strings are promoted to old data space, all
 394   // other object types are promoted to old pointer space.  We do not use
 395   // object->IsHeapNumber() and object->IsSeqString() because we already
 396   // know that object has the heap object tag.
 397
 398   // These objects are never allocated in new space.
 399   DCHECK(type != MAP_TYPE);
 400   DCHECK(type != CODE_TYPE);
 401   DCHECK(type != ODDBALL_TYPE);
 402   DCHECK(type != CELL_TYPE);
 403   DCHECK(type != PROPERTY_CELL_TYPE);
 404
 405   if (type <= LAST_NAME_TYPE) {
 406     if (type == SYMBOL_TYPE) return OLD_POINTER_SPACE;
 407     DCHECK(type < FIRST_NONSTRING_TYPE);
 408     // There are four string representations: sequential strings, external
 409     // strings, cons strings, and sliced strings.
 410     // Only the latter two contain non-map-word pointers to heap objects.
 411     return ((type & kIsIndirectStringMask) == kIsIndirectStringTag)
 412                ? OLD_POINTER_SPACE
 413                : OLD_DATA_SPACE;
 414   } else {
 415     return (type <= LAST_DATA_TYPE) ? OLD_DATA_SPACE : OLD_POINTER_SPACE;
 416   }
 417 }
 418
 419
 420 bool Heap::AllowedToBeMigrated(HeapObject* obj, AllocationSpace dst) {
 421   // Object migration is governed by the following rules:
 422   //
 423   // 1) Objects in new-space can be migrated to one of the old spaces
 424   //    that matches their target space or they stay in new-space.
 425   // 2) Objects in old-space stay in the same space when migrating.
 426   // 3) Fillers (two or more words) can migrate due to left-trimming of
 427   //    fixed arrays in new-space, old-data-space and old-pointer-space.
 428   // 4) Fillers (one word) can never migrate, they are skipped by
 429   //    incremental marking explicitly to prevent invalid pattern.
 430   // 5) Short external strings can end up in old pointer space when a cons
 431   //    string in old pointer space is made external (String::MakeExternal).
 432   //
 433   // Since this function is used for debugging only, we do not place
 434   // asserts here, but check everything explicitly.
 435   if (obj->map() == one_pointer_filler_map()) return false;
 436   InstanceType type = obj->map()->instance_type();
 437   MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
 438   AllocationSpace src = chunk->owner()->identity();
 439   switch (src) {
 440     case NEW_SPACE:
 441       return dst == src || dst == TargetSpaceId(type);
 442     case OLD_POINTER_SPACE:
 443       return dst == src && (dst == TargetSpaceId(type) || obj->IsFiller() ||
 444                             obj->IsExternalString());
 445     case OLD_DATA_SPACE:
 446       return dst == src && dst == TargetSpaceId(type);
 447     case CODE_SPACE:
 448       return dst == src && type == CODE_TYPE;
 449     case MAP_SPACE:
 450     case CELL_SPACE:
 451     case PROPERTY_CELL_SPACE:
 452     case LO_SPACE:
 453       return false;
 454   }
 455   UNREACHABLE();
 456   return false;
 457 }
 458
 459
 460 void Heap::CopyBlock(Address dst, Address src, int byte_size) {
 461   CopyWords(reinterpret_cast<Object**>(dst), reinterpret_cast<Object**>(src),
 462             static_cast<size_t>(byte_size / kPointerSize));
 463 }
 464
 465
 466 void Heap::MoveBlock(Address dst, Address src, int byte_size) {
 467   DCHECK(IsAligned(byte_size, kPointerSize));
 468
 469   int size_in_words = byte_size / kPointerSize;
 470
 471   if ((dst < src) || (dst >= (src + byte_size))) {
 472     Object** src_slot = reinterpret_cast<Object**>(src);
 473     Object** dst_slot = reinterpret_cast<Object**>(dst);
 474     Object** end_slot = src_slot + size_in_words;
 475
 476     while (src_slot != end_slot) {
 477       *dst_slot++ = *src_slot++;
 478     }
 479   } else {
 480     MemMove(dst, src, static_cast<size_t>(byte_size));
 481   }
 482 }
 483
 484
 485 void Heap::ScavengePointer(HeapObject** p) { ScavengeObject(p, *p); }
 486
 487
 488 AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) {
 489   // Check if there is potentially a memento behind the object. If
 490   // the last word of the memento is on another page we return
 491   // immediately.
 492   Address object_address = object->address();
 493   Address memento_address = object_address + object->Size();
 494   Address last_memento_word_address = memento_address + kPointerSize;
 495   if (!NewSpacePage::OnSamePage(object_address, last_memento_word_address)) {
 496     return NULL;
 497   }
 498
 499   HeapObject* candidate = HeapObject::FromAddress(memento_address);
 500   Map* candidate_map = candidate->map();
 501   // This fast check may peek at an uninitialized word. However, the slow check
 502   // below (memento_address == top) ensures that this is safe. Mark the word as
 503   // initialized to silence MemorySanitizer warnings.
 504   MSAN_MEMORY_IS_INITIALIZED(&candidate_map, sizeof(candidate_map));
 505   if (candidate_map != allocation_memento_map()) return NULL;
 506
 507   // Either the object is the last object in the new space, or there is another
 508   // object of at least word size (the header map word) following it, so
 509   // suffices to compare ptr and top here. Note that technically we do not have
 510   // to compare with the current top pointer of the from space page during GC,
 511   // since we always install filler objects above the top pointer of a from
 512   // space page when performing a garbage collection. However, always performing
 513   // the test makes it possible to have a single, unified version of
 514   // FindAllocationMemento that is used both by the GC and the mutator.
 515   Address top = NewSpaceTop();
 516   DCHECK(memento_address == top ||
 517          memento_address + HeapObject::kHeaderSize <= top ||
 518          !NewSpacePage::OnSamePage(memento_address, top));
 519   if (memento_address == top) return NULL;
 520
 521   AllocationMemento* memento = AllocationMemento::cast(candidate);
 522   if (!memento->IsValid()) return NULL;
 523   return memento;
 524 }
 525
 526
 527 void Heap::UpdateAllocationSiteFeedback(HeapObject* object,
 528                                         ScratchpadSlotMode mode) {
 529   Heap* heap = object->GetHeap();
 530   DCHECK(heap->InFromSpace(object));
 531
 532   if (!FLAG_allocation_site_pretenuring ||
 533       !AllocationSite::CanTrack(object->map()->instance_type()))
 534     return;
 535
 536   AllocationMemento* memento = heap->FindAllocationMemento(object);
 537   if (memento == NULL) return;
 538
 539   if (memento->GetAllocationSite()->IncrementMementoFoundCount()) {
 540     heap->AddAllocationSiteToScratchpad(memento->GetAllocationSite(), mode);
 541   }
 542 }
 543
 544
 545 void Heap::ScavengeObject(HeapObject** p, HeapObject* object) {
 546   DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
 547
 548   // We use the first word (where the map pointer usually is) of a heap
 549   // object to record the forwarding pointer.  A forwarding pointer can
 550   // point to an old space, the code space, or the to space of the new
 551   // generation.
 552   MapWord first_word = object->map_word();
 553
 554   // If the first word is a forwarding address, the object has already been
 555   // copied.
 556   if (first_word.IsForwardingAddress()) {
 557     HeapObject* dest = first_word.ToForwardingAddress();
 558     DCHECK(object->GetIsolate()->heap()->InFromSpace(*p));
 559     *p = dest;
 560     return;
 561   }
 562
 563   UpdateAllocationSiteFeedback(object, IGNORE_SCRATCHPAD_SLOT);
 564
 565   // AllocationMementos are unrooted and shouldn't survive a scavenge
 566   DCHECK(object->map() != object->GetHeap()->allocation_memento_map());
 567   // Call the slow part of scavenge object.
 568   return ScavengeObjectSlow(p, object);
 569 }
 570
 571
 572 bool Heap::CollectGarbage(AllocationSpace space, const char* gc_reason,
 573                           const v8::GCCallbackFlags callbackFlags) {
 574   const char* collector_reason = NULL;
 575   GarbageCollector collector = SelectGarbageCollector(space, &collector_reason);
 576   return CollectGarbage(collector, gc_reason, collector_reason, callbackFlags);
 577 }
 578
 579
 580 Isolate* Heap::isolate() {
 581   return reinterpret_cast<Isolate*>(
 582       reinterpret_cast<intptr_t>(this) -
 583       reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(16)->heap()) + 16);
 584 }
 585
 586
 587 // Calls the FUNCTION_CALL function and retries it up to three times
 588 // to guarantee that any allocations performed during the call will
 589 // succeed if there's enough memory.
 590
 591 // Warning: Do not use the identifiers __object__, __maybe_object__ or
 592 // __scope__ in a call to this macro.
 593
 594 #define RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \
 595   if (__allocation__.To(&__object__)) {                   \
 596     DCHECK(__object__ != (ISOLATE)->heap()->exception()); \
 597     RETURN_VALUE;                                         \
 598   }
 599
 600 #define CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)    \
 601   do {                                                                        \
 602     AllocationResult __allocation__ = FUNCTION_CALL;                          \
 603     Object* __object__ = NULL;                                                \
 604     RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
 605     (ISOLATE)->heap()->CollectGarbage(__allocation__.RetrySpace(),            \
 606                                       "allocation failure");                  \
 607     __allocation__ = FUNCTION_CALL;                                           \
 608     RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
 609     (ISOLATE)->counters()->gc_last_resort_from_handles()->Increment();        \
 610     (ISOLATE)->heap()->CollectAllAvailableGarbage("last resort gc");          \
 611     {                                                                         \
 612       AlwaysAllocateScope __scope__(ISOLATE);                                 \
 613       __allocation__ = FUNCTION_CALL;                                         \
 614     }                                                                         \
 615     RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
 616     /* TODO(1181417): Fix this. */                                            \
 617     v8::internal::Heap::FatalProcessOutOfMemory("CALL_AND_RETRY_LAST", true); \
 618     RETURN_EMPTY;                                                             \
 619   } while (false)
 620
 621 #define CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, RETURN_VALUE, \
 622                               RETURN_EMPTY)                         \
 623   CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)
 624
 625 #define CALL_HEAP_FUNCTION(ISOLATE, FUNCTION_CALL, TYPE)                      \
 626   CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL,                               \
 627                         return Handle<TYPE>(TYPE::cast(__object__), ISOLATE), \
 628                         return Handle<TYPE>())
 629
 630
 631 #define CALL_HEAP_FUNCTION_VOID(ISOLATE, FUNCTION_CALL) \
 632   CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, return, return)
 633
 634
 635 void ExternalStringTable::AddString(String* string) {
 636   DCHECK(string->IsExternalString());
 637   if (heap_->InNewSpace(string)) {
 638     new_space_strings_.Add(string);
 639   } else {
 640     old_space_strings_.Add(string);
 641   }
 642 }
 643
 644
 645 void ExternalStringTable::Iterate(ObjectVisitor* v) {
 646   if (!new_space_strings_.is_empty()) {
 647     Object** start = &new_space_strings_[0];
 648     v->VisitPointers(start, start + new_space_strings_.length());
 649   }
 650   if (!old_space_strings_.is_empty()) {
 651     Object** start = &old_space_strings_[0];
 652     v->VisitPointers(start, start + old_space_strings_.length());
 653   }
 654 }
 655
 656
 657 // Verify() is inline to avoid ifdef-s around its calls in release
 658 // mode.
 659 void ExternalStringTable::Verify() {
 660 #ifdef DEBUG
 661   for (int i = 0; i < new_space_strings_.length(); ++i) {
 662     Object* obj = Object::cast(new_space_strings_[i]);
 663     DCHECK(heap_->InNewSpace(obj));
 664     DCHECK(obj != heap_->the_hole_value());
 665   }
 666   for (int i = 0; i < old_space_strings_.length(); ++i) {
 667     Object* obj = Object::cast(old_space_strings_[i]);
 668     DCHECK(!heap_->InNewSpace(obj));
 669     DCHECK(obj != heap_->the_hole_value());
 670   }
 671 #endif
 672 }
 673
 674
 675 void ExternalStringTable::AddOldString(String* string) {
 676   DCHECK(string->IsExternalString());
 677   DCHECK(!heap_->InNewSpace(string));
 678   old_space_strings_.Add(string);
 679 }
 680
 681
 682 void ExternalStringTable::ShrinkNewStrings(int position) {
 683   new_space_strings_.Rewind(position);
 684 #ifdef VERIFY_HEAP
 685   if (FLAG_verify_heap) {
 686     Verify();
 687   }
 688 #endif
 689 }
 690
 691
 692 void Heap::ClearInstanceofCache() {
 693   set_instanceof_cache_function(Smi::FromInt(0));
 694 }
 695
 696
 697 Object* Heap::ToBoolean(bool condition) {
 698   return condition ? true_value() : false_value();
 699 }
 700
 701
 702 void Heap::CompletelyClearInstanceofCache() {
 703   set_instanceof_cache_map(Smi::FromInt(0));
 704   set_instanceof_cache_function(Smi::FromInt(0));
 705 }
 706
 707
 708 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
 709     : heap_(isolate->heap()), daf_(isolate) {
 710   // We shouldn't hit any nested scopes, because that requires
 711   // non-handle code to call handle code. The code still works but
 712   // performance will degrade, so we want to catch this situation
 713   // in debug mode.
 714   DCHECK(heap_->always_allocate_scope_depth_ == 0);
 715   heap_->always_allocate_scope_depth_++;
 716 }
 717
 718
 719 AlwaysAllocateScope::~AlwaysAllocateScope() {
 720   heap_->always_allocate_scope_depth_--;
 721   DCHECK(heap_->always_allocate_scope_depth_ == 0);
 722 }
 723
 724
 725 GCCallbacksScope::GCCallbacksScope(Heap* heap) : heap_(heap) {
 726   heap_->gc_callbacks_depth_++;
 727 }
 728
 729
 730 GCCallbacksScope::~GCCallbacksScope() { heap_->gc_callbacks_depth_--; }
 731
 732
 733 bool GCCallbacksScope::CheckReenter() {
 734   return heap_->gc_callbacks_depth_ == 1;
 735 }
 736
 737
 738 void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
 739   for (Object** current = start; current < end; current++) {
 740     if ((*current)->IsHeapObject()) {
 741       HeapObject* object = HeapObject::cast(*current);
 742       CHECK(object->GetIsolate()->heap()->Contains(object));
 743       CHECK(object->map()->IsMap());
 744     }
 745   }
 746 }
 747
 748
 749 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
 750   for (Object** current = start; current < end; current++) {
 751     CHECK((*current)->IsSmi());
 752   }
 753 }
 754 }
 755 }  // namespace v8::internal
 756
 757 #endif  // V8_HEAP_HEAP_INL_H_