src/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/objects.h"
  19
  20 namespace v8 {
  21 namespace internal {
  22
  23 void PromotionQueue::insert(HeapObject* target, int size) {
  24   if (emergency_stack_ != NULL) {
  25     emergency_stack_->Add(Entry(target, size));
  26     return;
  27   }
  28
  29   if (NewSpacePage::IsAtStart(reinterpret_cast<Address>(rear_))) {
  30     NewSpacePage* rear_page =
  31         NewSpacePage::FromAddress(reinterpret_cast<Address>(rear_));
  32     DCHECK(!rear_page->prev_page()->is_anchor());
  33     rear_ = reinterpret_cast<intptr_t*>(rear_page->prev_page()->area_end());
  34     ActivateGuardIfOnTheSamePage();
  35   }
  36
  37   if (guard_) {
  38     DCHECK(GetHeadPage() ==
  39            Page::FromAllocationTop(reinterpret_cast<Address>(limit_)));
  40
  41     if ((rear_ - 2) < limit_) {
  42       RelocateQueueHead();
  43       emergency_stack_->Add(Entry(target, size));
  44       return;
  45     }
  46   }
  47
  48   *(--rear_) = reinterpret_cast<intptr_t>(target);
  49   *(--rear_) = size;
  50 // Assert no overflow into live objects.
  51 #ifdef DEBUG
  52   SemiSpace::AssertValidRange(target->GetIsolate()->heap()->new_space()->top(),
  53                               reinterpret_cast<Address>(rear_));
  54 #endif
  55 }
  56
  57
  58 void PromotionQueue::ActivateGuardIfOnTheSamePage() {
  59   guard_ = guard_ ||
  60            heap_->new_space()->active_space()->current_page()->address() ==
  61                GetHeadPage()->address();
  62 }
  63
  64
  65 template <>
  66 bool inline Heap::IsOneByte(Vector<const char> str, int chars) {
  67   // TODO(dcarney): incorporate Latin-1 check when Latin-1 is supported?
  68   // ASCII only check.
  69   return chars == str.length();
  70 }
  71
  72
  73 template <>
  74 bool inline Heap::IsOneByte(String* str, int chars) {
  75   return str->IsOneByteRepresentation();
  76 }
  77
  78
  79 AllocationResult Heap::AllocateInternalizedStringFromUtf8(
  80     Vector<const char> str, int chars, uint32_t hash_field) {
  81   if (IsOneByte(str, chars)) {
  82     return AllocateOneByteInternalizedString(Vector<const uint8_t>::cast(str),
  83                                              hash_field);
  84   }
  85   return AllocateInternalizedStringImpl<false>(str, chars, hash_field);
  86 }
  87
  88
  89 template <typename T>
  90 AllocationResult Heap::AllocateInternalizedStringImpl(T t, int chars,
  91                                                       uint32_t hash_field) {
  92   if (IsOneByte(t, chars)) {
  93     return AllocateInternalizedStringImpl<true>(t, chars, hash_field);
  94   }
  95   return AllocateInternalizedStringImpl<false>(t, chars, hash_field);
  96 }
  97
  98
  99 AllocationResult Heap::AllocateOneByteInternalizedString(
 100     Vector<const uint8_t> str, uint32_t hash_field) {
 101   CHECK_GE(String::kMaxLength, str.length());
 102   // Compute map and object size.
 103   Map* map = ascii_internalized_string_map();
 104   int size = SeqOneByteString::SizeFor(str.length());
 105   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
 106
 107   // Allocate string.
 108   HeapObject* result;
 109   {
 110     AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
 111     if (!allocation.To(&result)) return allocation;
 112   }
 113
 114   // String maps are all immortal immovable objects.
 115   result->set_map_no_write_barrier(map);
 116   // Set length and hash fields of the allocated string.
 117   String* answer = String::cast(result);
 118   answer->set_length(str.length());
 119   answer->set_hash_field(hash_field);
 120
 121   DCHECK_EQ(size, answer->Size());
 122
 123   // Fill in the characters.
 124   MemCopy(answer->address() + SeqOneByteString::kHeaderSize, str.start(),
 125           str.length());
 126
 127   return answer;
 128 }
 129
 130
 131 AllocationResult Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
 132                                                          uint32_t hash_field) {
 133   CHECK_GE(String::kMaxLength, str.length());
 134   // Compute map and object size.
 135   Map* map = internalized_string_map();
 136   int size = SeqTwoByteString::SizeFor(str.length());
 137   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
 138
 139   // Allocate string.
 140   HeapObject* result;
 141   {
 142     AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
 143     if (!allocation.To(&result)) return allocation;
 144   }
 145
 146   result->set_map(map);
 147   // Set length and hash fields of the allocated string.
 148   String* answer = String::cast(result);
 149   answer->set_length(str.length());
 150   answer->set_hash_field(hash_field);
 151
 152   DCHECK_EQ(size, answer->Size());
 153
 154   // Fill in the characters.
 155   MemCopy(answer->address() + SeqTwoByteString::kHeaderSize, str.start(),
 156           str.length() * kUC16Size);
 157
 158   return answer;
 159 }
 160
 161 AllocationResult Heap::CopyFixedArray(FixedArray* src) {
 162   if (src->length() == 0) return src;
 163   return CopyFixedArrayWithMap(src, src->map());
 164 }
 165
 166
 167 AllocationResult Heap::CopyFixedDoubleArray(FixedDoubleArray* src) {
 168   if (src->length() == 0) return src;
 169   return CopyFixedDoubleArrayWithMap(src, src->map());
 170 }
 171
 172
 173 AllocationResult Heap::CopyConstantPoolArray(ConstantPoolArray* src) {
 174   if (src->length() == 0) return src;
 175   return CopyConstantPoolArrayWithMap(src, src->map());
 176 }
 177
 178
 179 AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
 180                                    AllocationSpace retry_space) {
 181   DCHECK(AllowHandleAllocation::IsAllowed());
 182   DCHECK(AllowHeapAllocation::IsAllowed());
 183   DCHECK(gc_state_ == NOT_IN_GC);
 184 #ifdef DEBUG
 185   if (FLAG_gc_interval >= 0 && AllowAllocationFailure::IsAllowed(isolate_) &&
 186       Heap::allocation_timeout_-- <= 0) {
 187     return AllocationResult::Retry(space);
 188   }
 189   isolate_->counters()->objs_since_last_full()->Increment();
 190   isolate_->counters()->objs_since_last_young()->Increment();
 191 #endif
 192
 193   HeapObject* object;
 194   AllocationResult allocation;
 195   if (NEW_SPACE == space) {
 196     allocation = new_space_.AllocateRaw(size_in_bytes);
 197     if (always_allocate() && allocation.IsRetry() && retry_space != NEW_SPACE) {
 198       space = retry_space;
 199     } else {
 200       if (allocation.To(&object)) {
 201         OnAllocationEvent(object, size_in_bytes);
 202       }
 203       return allocation;
 204     }
 205   }
 206
 207   if (OLD_POINTER_SPACE == space) {
 208     allocation = old_pointer_space_->AllocateRaw(size_in_bytes);
 209   } else if (OLD_DATA_SPACE == space) {
 210     allocation = old_data_space_->AllocateRaw(size_in_bytes);
 211   } else if (CODE_SPACE == space) {
 212     if (size_in_bytes <= code_space()->AreaSize()) {
 213       allocation = code_space_->AllocateRaw(size_in_bytes);
 214     } else {
 215       // Large code objects are allocated in large object space.
 216       allocation = lo_space_->AllocateRaw(size_in_bytes, EXECUTABLE);
 217     }
 218   } else if (LO_SPACE == space) {
 219     allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
 220   } else if (CELL_SPACE == space) {
 221     allocation = cell_space_->AllocateRaw(size_in_bytes);
 222   } else if (PROPERTY_CELL_SPACE == space) {
 223     allocation = property_cell_space_->AllocateRaw(size_in_bytes);
 224   } else {
 225     DCHECK(MAP_SPACE == space);
 226     allocation = map_space_->AllocateRaw(size_in_bytes);
 227   }
 228   if (allocation.To(&object)) {
 229     OnAllocationEvent(object, size_in_bytes);
 230   } else {
 231     old_gen_exhausted_ = true;
 232   }
 233   return allocation;
 234 }
 235
 236
 237 void Heap::OnAllocationEvent(HeapObject* object, int size_in_bytes) {
 238   HeapProfiler* profiler = isolate_->heap_profiler();
 239   if (profiler->is_tracking_allocations()) {
 240     profiler->AllocationEvent(object->address(), size_in_bytes);
 241   }
 242
 243   if (FLAG_verify_predictable) {
 244     ++allocations_count_;
 245
 246     UpdateAllocationsHash(object);
 247     UpdateAllocationsHash(size_in_bytes);
 248
 249     if ((FLAG_dump_allocations_digest_at_alloc > 0) &&
 250         (--dump_allocations_hash_countdown_ == 0)) {
 251       dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc;
 252       PrintAlloctionsHash();
 253     }
 254   }
 255 }
 256
 257
 258 void Heap::OnMoveEvent(HeapObject* target, HeapObject* source,
 259                        int size_in_bytes) {
 260   HeapProfiler* heap_profiler = isolate_->heap_profiler();
 261   if (heap_profiler->is_tracking_object_moves()) {
 262     heap_profiler->ObjectMoveEvent(source->address(), target->address(),
 263                                    size_in_bytes);
 264   }
 265
 266   if (isolate_->logger()->is_logging_code_events() ||
 267       isolate_->cpu_profiler()->is_profiling()) {
 268     if (target->IsSharedFunctionInfo()) {
 269       PROFILE(isolate_, SharedFunctionInfoMoveEvent(source->address(),
 270                                                     target->address()));
 271     }
 272   }
 273
 274   if (FLAG_verify_predictable) {
 275     ++allocations_count_;
 276
 277     UpdateAllocationsHash(source);
 278     UpdateAllocationsHash(target);
 279     UpdateAllocationsHash(size_in_bytes);
 280
 281     if ((FLAG_dump_allocations_digest_at_alloc > 0) &&
 282         (--dump_allocations_hash_countdown_ == 0)) {
 283       dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc;
 284       PrintAlloctionsHash();
 285     }
 286   }
 287 }
 288
 289
 290 void Heap::UpdateAllocationsHash(HeapObject* object) {
 291   Address object_address = object->address();
 292   MemoryChunk* memory_chunk = MemoryChunk::FromAddress(object_address);
 293   AllocationSpace allocation_space = memory_chunk->owner()->identity();
 294
 295   STATIC_ASSERT(kSpaceTagSize + kPageSizeBits <= 32);
 296   uint32_t value =
 297       static_cast<uint32_t>(object_address - memory_chunk->address()) |
 298       (static_cast<uint32_t>(allocation_space) << kPageSizeBits);
 299
 300   UpdateAllocationsHash(value);
 301 }
 302
 303
 304 void Heap::UpdateAllocationsHash(uint32_t value) {
 305   uint16_t c1 = static_cast<uint16_t>(value);
 306   uint16_t c2 = static_cast<uint16_t>(value >> 16);
 307   raw_allocations_hash_ =
 308       StringHasher::AddCharacterCore(raw_allocations_hash_, c1);
 309   raw_allocations_hash_ =
 310       StringHasher::AddCharacterCore(raw_allocations_hash_, c2);
 311 }
 312
 313
 314 void Heap::PrintAlloctionsHash() {
 315   uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_);
 316   PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count_, hash);
 317 }
 318
 319
 320 void Heap::FinalizeExternalString(String* string) {
 321   DCHECK(string->IsExternalString());
 322   v8::String::ExternalStringResourceBase** resource_addr =
 323       reinterpret_cast<v8::String::ExternalStringResourceBase**>(
 324           reinterpret_cast<byte*>(string) + ExternalString::kResourceOffset -
 325           kHeapObjectTag);
 326
 327   // Dispose of the C++ object if it has not already been disposed.
 328   if (*resource_addr != NULL) {
 329     (*resource_addr)->Dispose();
 330     *resource_addr = NULL;
 331   }
 332 }
 333
 334
 335 bool Heap::InNewSpace(Object* object) {
 336   bool result = new_space_.Contains(object);
 337   DCHECK(!result ||                 // Either not in new space
 338          gc_state_ != NOT_IN_GC ||  // ... or in the middle of GC
 339          InToSpace(object));        // ... or in to-space (where we allocate).
 340   return result;
 341 }
 342
 343
 344 bool Heap::InNewSpace(Address address) { return new_space_.Contains(address); }
 345
 346
 347 bool Heap::InFromSpace(Object* object) {
 348   return new_space_.FromSpaceContains(object);
 349 }
 350
 351
 352 bool Heap::InToSpace(Object* object) {
 353   return new_space_.ToSpaceContains(object);
 354 }
 355
 356
 357 bool Heap::InOldPointerSpace(Address address) {
 358   return old_pointer_space_->Contains(address);
 359 }
 360
 361
 362 bool Heap::InOldPointerSpace(Object* object) {
 363   return InOldPointerSpace(reinterpret_cast<Address>(object));
 364 }
 365
 366
 367 bool Heap::InOldDataSpace(Address address) {
 368   return old_data_space_->Contains(address);
 369 }
 370
 371
 372 bool Heap::InOldDataSpace(Object* object) {
 373   return InOldDataSpace(reinterpret_cast<Address>(object));
 374 }
 375
 376
 377 bool Heap::OldGenerationAllocationLimitReached() {
 378   if (!incremental_marking()->IsStopped()) return false;
 379   return OldGenerationSpaceAvailable() < 0;
 380 }
 381
 382
 383 bool Heap::ShouldBePromoted(Address old_address, int object_size) {
 384   NewSpacePage* page = NewSpacePage::FromAddress(old_address);
 385   Address age_mark = new_space_.age_mark();
 386   return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
 387          (!page->ContainsLimit(age_mark) || old_address < age_mark);
 388 }
 389
 390
 391 void Heap::RecordWrite(Address address, int offset) {
 392   if (!InNewSpace(address)) store_buffer_.Mark(address + offset);
 393 }
 394
 395
 396 void Heap::RecordWrites(Address address, int start, int len) {
 397   if (!InNewSpace(address)) {
 398     for (int i = 0; i < len; i++) {
 399       store_buffer_.Mark(address + start + i * kPointerSize);
 400     }
 401   }
 402 }
 403
 404
 405 OldSpace* Heap::TargetSpace(HeapObject* object) {
 406   InstanceType type = object->map()->instance_type();
 407   AllocationSpace space = TargetSpaceId(type);
 408   return (space == OLD_POINTER_SPACE) ? old_pointer_space_ : old_data_space_;
 409 }
 410
 411
 412 AllocationSpace Heap::TargetSpaceId(InstanceType type) {
 413   // Heap numbers and sequential strings are promoted to old data space, all
 414   // other object types are promoted to old pointer space.  We do not use
 415   // object->IsHeapNumber() and object->IsSeqString() because we already
 416   // know that object has the heap object tag.
 417
 418   // These objects are never allocated in new space.
 419   DCHECK(type != MAP_TYPE);
 420   DCHECK(type != CODE_TYPE);
 421   DCHECK(type != ODDBALL_TYPE);
 422   DCHECK(type != CELL_TYPE);
 423   DCHECK(type != PROPERTY_CELL_TYPE);
 424
 425   if (type <= LAST_NAME_TYPE) {
 426     if (type == SYMBOL_TYPE) return OLD_POINTER_SPACE;
 427     DCHECK(type < FIRST_NONSTRING_TYPE);
 428     // There are four string representations: sequential strings, external
 429     // strings, cons strings, and sliced strings.
 430     // Only the latter two contain non-map-word pointers to heap objects.
 431     return ((type & kIsIndirectStringMask) == kIsIndirectStringTag)
 432                ? OLD_POINTER_SPACE
 433                : OLD_DATA_SPACE;
 434   } else {
 435     return (type <= LAST_DATA_TYPE) ? OLD_DATA_SPACE : OLD_POINTER_SPACE;
 436   }
 437 }
 438
 439
 440 bool Heap::AllowedToBeMigrated(HeapObject* obj, AllocationSpace dst) {
 441   // Object migration is governed by the following rules:
 442   //
 443   // 1) Objects in new-space can be migrated to one of the old spaces
 444   //    that matches their target space or they stay in new-space.
 445   // 2) Objects in old-space stay in the same space when migrating.
 446   // 3) Fillers (two or more words) can migrate due to left-trimming of
 447   //    fixed arrays in new-space, old-data-space and old-pointer-space.
 448   // 4) Fillers (one word) can never migrate, they are skipped by
 449   //    incremental marking explicitly to prevent invalid pattern.
 450   // 5) Short external strings can end up in old pointer space when a cons
 451   //    string in old pointer space is made external (String::MakeExternal).
 452   //
 453   // Since this function is used for debugging only, we do not place
 454   // asserts here, but check everything explicitly.
 455   if (obj->map() == one_pointer_filler_map()) return false;
 456   InstanceType type = obj->map()->instance_type();
 457   MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
 458   AllocationSpace src = chunk->owner()->identity();
 459   switch (src) {
 460     case NEW_SPACE:
 461       return dst == src || dst == TargetSpaceId(type);
 462     case OLD_POINTER_SPACE:
 463       return dst == src && (dst == TargetSpaceId(type) || obj->IsFiller() ||
 464                             (obj->IsExternalString() &&
 465                              ExternalString::cast(obj)->is_short()));
 466     case OLD_DATA_SPACE:
 467       return dst == src && dst == TargetSpaceId(type);
 468     case CODE_SPACE:
 469       return dst == src && type == CODE_TYPE;
 470     case MAP_SPACE:
 471     case CELL_SPACE:
 472     case PROPERTY_CELL_SPACE:
 473     case LO_SPACE:
 474       return false;
 475     case INVALID_SPACE:
 476       break;
 477   }
 478   UNREACHABLE();
 479   return false;
 480 }
 481
 482
 483 void Heap::CopyBlock(Address dst, Address src, int byte_size) {
 484   CopyWords(reinterpret_cast<Object**>(dst), reinterpret_cast<Object**>(src),
 485             static_cast<size_t>(byte_size / kPointerSize));
 486 }
 487
 488
 489 void Heap::MoveBlock(Address dst, Address src, int byte_size) {
 490   DCHECK(IsAligned(byte_size, kPointerSize));
 491
 492   int size_in_words = byte_size / kPointerSize;
 493
 494   if ((dst < src) || (dst >= (src + byte_size))) {
 495     Object** src_slot = reinterpret_cast<Object**>(src);
 496     Object** dst_slot = reinterpret_cast<Object**>(dst);
 497     Object** end_slot = src_slot + size_in_words;
 498
 499     while (src_slot != end_slot) {
 500       *dst_slot++ = *src_slot++;
 501     }
 502   } else {
 503     MemMove(dst, src, static_cast<size_t>(byte_size));
 504   }
 505 }
 506
 507
 508 void Heap::ScavengePointer(HeapObject** p) { ScavengeObject(p, *p); }
 509
 510
 511 AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) {
 512   // Check if there is potentially a memento behind the object. If
 513   // the last word of the momento is on another page we return
 514   // immediately.
 515   Address object_address = object->address();
 516   Address memento_address = object_address + object->Size();
 517   Address last_memento_word_address = memento_address + kPointerSize;
 518   if (!NewSpacePage::OnSamePage(object_address, last_memento_word_address)) {
 519     return NULL;
 520   }
 521
 522   HeapObject* candidate = HeapObject::FromAddress(memento_address);
 523   if (candidate->map() != allocation_memento_map()) return NULL;
 524
 525   // Either the object is the last object in the new space, or there is another
 526   // object of at least word size (the header map word) following it, so
 527   // suffices to compare ptr and top here. Note that technically we do not have
 528   // to compare with the current top pointer of the from space page during GC,
 529   // since we always install filler objects above the top pointer of a from
 530   // space page when performing a garbage collection. However, always performing
 531   // the test makes it possible to have a single, unified version of
 532   // FindAllocationMemento that is used both by the GC and the mutator.
 533   Address top = NewSpaceTop();
 534   DCHECK(memento_address == top ||
 535          memento_address + HeapObject::kHeaderSize <= top ||
 536          !NewSpacePage::OnSamePage(memento_address, top));
 537   if (memento_address == top) return NULL;
 538
 539   AllocationMemento* memento = AllocationMemento::cast(candidate);
 540   if (!memento->IsValid()) return NULL;
 541   return memento;
 542 }
 543
 544
 545 void Heap::UpdateAllocationSiteFeedback(HeapObject* object,
 546                                         ScratchpadSlotMode mode) {
 547   Heap* heap = object->GetHeap();
 548   DCHECK(heap->InFromSpace(object));
 549
 550   if (!FLAG_allocation_site_pretenuring ||
 551       !AllocationSite::CanTrack(object->map()->instance_type()))
 552     return;
 553
 554   AllocationMemento* memento = heap->FindAllocationMemento(object);
 555   if (memento == NULL) return;
 556
 557   if (memento->GetAllocationSite()->IncrementMementoFoundCount()) {
 558     heap->AddAllocationSiteToScratchpad(memento->GetAllocationSite(), mode);
 559   }
 560 }
 561
 562
 563 void Heap::ScavengeObject(HeapObject** p, HeapObject* object) {
 564   DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
 565
 566   // We use the first word (where the map pointer usually is) of a heap
 567   // object to record the forwarding pointer.  A forwarding pointer can
 568   // point to an old space, the code space, or the to space of the new
 569   // generation.
 570   MapWord first_word = object->map_word();
 571
 572   // If the first word is a forwarding address, the object has already been
 573   // copied.
 574   if (first_word.IsForwardingAddress()) {
 575     HeapObject* dest = first_word.ToForwardingAddress();
 576     DCHECK(object->GetIsolate()->heap()->InFromSpace(*p));
 577     *p = dest;
 578     return;
 579   }
 580
 581   UpdateAllocationSiteFeedback(object, IGNORE_SCRATCHPAD_SLOT);
 582
 583   // AllocationMementos are unrooted and shouldn't survive a scavenge
 584   DCHECK(object->map() != object->GetHeap()->allocation_memento_map());
 585   // Call the slow part of scavenge object.
 586   return ScavengeObjectSlow(p, object);
 587 }
 588
 589
 590 bool Heap::CollectGarbage(AllocationSpace space, const char* gc_reason,
 591                           const v8::GCCallbackFlags callbackFlags) {
 592   const char* collector_reason = NULL;
 593   GarbageCollector collector = SelectGarbageCollector(space, &collector_reason);
 594   return CollectGarbage(collector, gc_reason, collector_reason, callbackFlags);
 595 }
 596
 597
 598 Isolate* Heap::isolate() {
 599   return reinterpret_cast<Isolate*>(
 600       reinterpret_cast<intptr_t>(this) -
 601       reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(4)->heap()) + 4);
 602 }
 603
 604
 605 // Calls the FUNCTION_CALL function and retries it up to three times
 606 // to guarantee that any allocations performed during the call will
 607 // succeed if there's enough memory.
 608
 609 // Warning: Do not use the identifiers __object__, __maybe_object__ or
 610 // __scope__ in a call to this macro.
 611
 612 #define RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \
 613   if (__allocation__.To(&__object__)) {                   \
 614     DCHECK(__object__ != (ISOLATE)->heap()->exception()); \
 615     RETURN_VALUE;                                         \
 616   }
 617
 618 #define CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)    \
 619   do {                                                                        \
 620     AllocationResult __allocation__ = FUNCTION_CALL;                          \
 621     Object* __object__ = NULL;                                                \
 622     RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
 623     (ISOLATE)->heap()->CollectGarbage(__allocation__.RetrySpace(),            \
 624                                       "allocation failure");                  \
 625     __allocation__ = FUNCTION_CALL;                                           \
 626     RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
 627     (ISOLATE)->counters()->gc_last_resort_from_handles()->Increment();        \
 628     (ISOLATE)->heap()->CollectAllAvailableGarbage("last resort gc");          \
 629     {                                                                         \
 630       AlwaysAllocateScope __scope__(ISOLATE);                                 \
 631       __allocation__ = FUNCTION_CALL;                                         \
 632     }                                                                         \
 633     RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
 634     /* TODO(1181417): Fix this. */                                            \
 635     v8::internal::Heap::FatalProcessOutOfMemory("CALL_AND_RETRY_LAST", true); \
 636     RETURN_EMPTY;                                                             \
 637   } while (false)
 638
 639 #define CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, RETURN_VALUE, \
 640                               RETURN_EMPTY)                         \
 641   CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)
 642
 643 #define CALL_HEAP_FUNCTION(ISOLATE, FUNCTION_CALL, TYPE)                      \
 644   CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL,                               \
 645                         return Handle<TYPE>(TYPE::cast(__object__), ISOLATE), \
 646                         return Handle<TYPE>())
 647
 648
 649 #define CALL_HEAP_FUNCTION_VOID(ISOLATE, FUNCTION_CALL) \
 650   CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, return, return)
 651
 652
 653 void ExternalStringTable::AddString(String* string) {
 654   DCHECK(string->IsExternalString());
 655   if (heap_->InNewSpace(string)) {
 656     new_space_strings_.Add(string);
 657   } else {
 658     old_space_strings_.Add(string);
 659   }
 660 }
 661
 662
 663 void ExternalStringTable::Iterate(ObjectVisitor* v) {
 664   if (!new_space_strings_.is_empty()) {
 665     Object** start = &new_space_strings_[0];
 666     v->VisitPointers(start, start + new_space_strings_.length());
 667   }
 668   if (!old_space_strings_.is_empty()) {
 669     Object** start = &old_space_strings_[0];
 670     v->VisitPointers(start, start + old_space_strings_.length());
 671   }
 672 }
 673
 674
 675 // Verify() is inline to avoid ifdef-s around its calls in release
 676 // mode.
 677 void ExternalStringTable::Verify() {
 678 #ifdef DEBUG
 679   for (int i = 0; i < new_space_strings_.length(); ++i) {
 680     Object* obj = Object::cast(new_space_strings_[i]);
 681     DCHECK(heap_->InNewSpace(obj));
 682     DCHECK(obj != heap_->the_hole_value());
 683   }
 684   for (int i = 0; i < old_space_strings_.length(); ++i) {
 685     Object* obj = Object::cast(old_space_strings_[i]);
 686     DCHECK(!heap_->InNewSpace(obj));
 687     DCHECK(obj != heap_->the_hole_value());
 688   }
 689 #endif
 690 }
 691
 692
 693 void ExternalStringTable::AddOldString(String* string) {
 694   DCHECK(string->IsExternalString());
 695   DCHECK(!heap_->InNewSpace(string));
 696   old_space_strings_.Add(string);
 697 }
 698
 699
 700 void ExternalStringTable::ShrinkNewStrings(int position) {
 701   new_space_strings_.Rewind(position);
 702 #ifdef VERIFY_HEAP
 703   if (FLAG_verify_heap) {
 704     Verify();
 705   }
 706 #endif
 707 }
 708
 709
 710 void Heap::ClearInstanceofCache() {
 711   set_instanceof_cache_function(the_hole_value());
 712 }
 713
 714
 715 Object* Heap::ToBoolean(bool condition) {
 716   return condition ? true_value() : false_value();
 717 }
 718
 719
 720 void Heap::CompletelyClearInstanceofCache() {
 721   set_instanceof_cache_map(the_hole_value());
 722   set_instanceof_cache_function(the_hole_value());
 723 }
 724
 725
 726 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
 727     : heap_(isolate->heap()), daf_(isolate) {
 728   // We shouldn't hit any nested scopes, because that requires
 729   // non-handle code to call handle code. The code still works but
 730   // performance will degrade, so we want to catch this situation
 731   // in debug mode.
 732   DCHECK(heap_->always_allocate_scope_depth_ == 0);
 733   heap_->always_allocate_scope_depth_++;
 734 }
 735
 736
 737 AlwaysAllocateScope::~AlwaysAllocateScope() {
 738   heap_->always_allocate_scope_depth_--;
 739   DCHECK(heap_->always_allocate_scope_depth_ == 0);
 740 }
 741
 742
 743 #ifdef VERIFY_HEAP
 744 NoWeakObjectVerificationScope::NoWeakObjectVerificationScope() {
 745   Isolate* isolate = Isolate::Current();
 746   isolate->heap()->no_weak_object_verification_scope_depth_++;
 747 }
 748
 749
 750 NoWeakObjectVerificationScope::~NoWeakObjectVerificationScope() {
 751   Isolate* isolate = Isolate::Current();
 752   isolate->heap()->no_weak_object_verification_scope_depth_--;
 753 }
 754 #endif
 755
 756
 757 GCCallbacksScope::GCCallbacksScope(Heap* heap) : heap_(heap) {
 758   heap_->gc_callbacks_depth_++;
 759 }
 760
 761
 762 GCCallbacksScope::~GCCallbacksScope() { heap_->gc_callbacks_depth_--; }
 763
 764
 765 bool GCCallbacksScope::CheckReenter() {
 766   return heap_->gc_callbacks_depth_ == 1;
 767 }
 768
 769
 770 void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
 771   for (Object** current = start; current < end; current++) {
 772     if ((*current)->IsHeapObject()) {
 773       HeapObject* object = HeapObject::cast(*current);
 774       CHECK(object->GetIsolate()->heap()->Contains(object));
 775       CHECK(object->map()->IsMap());
 776     }
 777   }
 778 }
 779
 780
 781 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
 782   for (Object** current = start; current < end; current++) {
 783     CHECK((*current)->IsSmi());
 784   }
 785 }
 786 }
 787 }  // namespace v8::internal
 788
 789 #endif  // V8_HEAP_HEAP_INL_H_