src/v8/src/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_INL_H_
   6 #define V8_HEAP_INL_H_
   7
   8 #include <cmath>
   9
  10 #include "heap.h"
  11 #include "heap-profiler.h"
  12 #include "isolate.h"
  13 #include "list-inl.h"
  14 #include "objects.h"
  15 #include "platform.h"
  16 #include "v8-counters.h"
  17 #include "store-buffer.h"
  18 #include "store-buffer-inl.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     ASSERT(!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     ASSERT(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(
  83         Vector<const uint8_t>::cast(str), hash_field);
  84   }
  85   return AllocateInternalizedStringImpl<false>(str, chars, hash_field);
  86 }
  87
  88
  89 template<typename T>
  90 AllocationResult Heap::AllocateInternalizedStringImpl(
  91     T t, int chars, 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,
 101     uint32_t hash_field) {
 102   if (str.length() > String::kMaxLength) {
 103     return isolate()->ThrowInvalidStringLength();
 104   }
 105   // Compute map and object size.
 106   Map* map = ascii_internalized_string_map();
 107   int size = SeqOneByteString::SizeFor(str.length());
 108   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
 109
 110   // Allocate string.
 111   HeapObject* result;
 112   { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
 113     if (!allocation.To(&result)) return allocation;
 114   }
 115
 116   // String maps are all immortal immovable objects.
 117   result->set_map_no_write_barrier(map);
 118   // Set length and hash fields of the allocated string.
 119   String* answer = String::cast(result);
 120   answer->set_length(str.length());
 121   answer->set_hash_field(hash_field);
 122
 123   ASSERT_EQ(size, answer->Size());
 124
 125   // Fill in the characters.
 126   OS::MemCopy(answer->address() + SeqOneByteString::kHeaderSize,
 127               str.start(), str.length());
 128
 129   return answer;
 130 }
 131
 132
 133 AllocationResult Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
 134                                                          uint32_t hash_field) {
 135   if (str.length() > String::kMaxLength) {
 136     return isolate()->ThrowInvalidStringLength();
 137   }
 138   // Compute map and object size.
 139   Map* map = internalized_string_map();
 140   int size = SeqTwoByteString::SizeFor(str.length());
 141   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
 142
 143   // Allocate string.
 144   HeapObject* result;
 145   { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
 146     if (!allocation.To(&result)) return allocation;
 147   }
 148
 149   result->set_map(map);
 150   // Set length and hash fields of the allocated string.
 151   String* answer = String::cast(result);
 152   answer->set_length(str.length());
 153   answer->set_hash_field(hash_field);
 154
 155   ASSERT_EQ(size, answer->Size());
 156
 157   // Fill in the characters.
 158   OS::MemCopy(answer->address() + SeqTwoByteString::kHeaderSize,
 159               str.start(), str.length() * kUC16Size);
 160
 161   return answer;
 162 }
 163
 164 AllocationResult Heap::CopyFixedArray(FixedArray* src) {
 165   if (src->length() == 0) return src;
 166   return CopyFixedArrayWithMap(src, src->map());
 167 }
 168
 169
 170 AllocationResult Heap::CopyFixedDoubleArray(FixedDoubleArray* src) {
 171   if (src->length() == 0) return src;
 172   return CopyFixedDoubleArrayWithMap(src, src->map());
 173 }
 174
 175
 176 AllocationResult Heap::CopyConstantPoolArray(ConstantPoolArray* src) {
 177   if (src->length() == 0) return src;
 178   return CopyConstantPoolArrayWithMap(src, src->map());
 179 }
 180
 181
 182 AllocationResult Heap::AllocateRaw(int size_in_bytes,
 183                                    AllocationSpace space,
 184                                    AllocationSpace retry_space) {
 185   ASSERT(AllowHandleAllocation::IsAllowed());
 186   ASSERT(AllowHeapAllocation::IsAllowed());
 187   ASSERT(gc_state_ == NOT_IN_GC);
 188   HeapProfiler* profiler = isolate_->heap_profiler();
 189 #ifdef DEBUG
 190   if (FLAG_gc_interval >= 0 &&
 191       AllowAllocationFailure::IsAllowed(isolate_) &&
 192       Heap::allocation_timeout_-- <= 0) {
 193     return AllocationResult::Retry(space);
 194   }
 195   isolate_->counters()->objs_since_last_full()->Increment();
 196   isolate_->counters()->objs_since_last_young()->Increment();
 197 #endif
 198
 199   HeapObject* object;
 200   AllocationResult allocation;
 201   if (NEW_SPACE == space) {
 202     allocation = new_space_.AllocateRaw(size_in_bytes);
 203     if (always_allocate() &&
 204         allocation.IsRetry() &&
 205         retry_space != NEW_SPACE) {
 206       space = retry_space;
 207     } else {
 208       if (profiler->is_tracking_allocations() && allocation.To(&object)) {
 209         profiler->AllocationEvent(object->address(), size_in_bytes);
 210       }
 211       return allocation;
 212     }
 213   }
 214
 215   if (OLD_POINTER_SPACE == space) {
 216     allocation = old_pointer_space_->AllocateRaw(size_in_bytes);
 217   } else if (OLD_DATA_SPACE == space) {
 218     allocation = old_data_space_->AllocateRaw(size_in_bytes);
 219   } else if (CODE_SPACE == space) {
 220     allocation = code_space_->AllocateRaw(size_in_bytes);
 221   } else if (LO_SPACE == space) {
 222     allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
 223   } else if (CELL_SPACE == space) {
 224     allocation = cell_space_->AllocateRaw(size_in_bytes);
 225   } else if (PROPERTY_CELL_SPACE == space) {
 226     allocation = property_cell_space_->AllocateRaw(size_in_bytes);
 227   } else {
 228     ASSERT(MAP_SPACE == space);
 229     allocation = map_space_->AllocateRaw(size_in_bytes);
 230   }
 231   if (allocation.IsRetry()) old_gen_exhausted_ = true;
 232   if (profiler->is_tracking_allocations() && allocation.To(&object)) {
 233     profiler->AllocationEvent(object->address(), size_in_bytes);
 234   }
 235   return allocation;
 236 }
 237
 238
 239 void Heap::FinalizeExternalString(String* string) {
 240   ASSERT(string->IsExternalString());
 241   v8::String::ExternalStringResourceBase** resource_addr =
 242       reinterpret_cast<v8::String::ExternalStringResourceBase**>(
 243           reinterpret_cast<byte*>(string) +
 244           ExternalString::kResourceOffset -
 245           kHeapObjectTag);
 246
 247   // Dispose of the C++ object if it has not already been disposed.
 248   if (*resource_addr != NULL) {
 249     (*resource_addr)->Dispose();
 250     *resource_addr = NULL;
 251   }
 252 }
 253
 254
 255 bool Heap::InNewSpace(Object* object) {
 256   bool result = new_space_.Contains(object);
 257   ASSERT(!result ||                  // Either not in new space
 258          gc_state_ != NOT_IN_GC ||   // ... or in the middle of GC
 259          InToSpace(object));         // ... or in to-space (where we allocate).
 260   return result;
 261 }
 262
 263
 264 bool Heap::InNewSpace(Address address) {
 265   return new_space_.Contains(address);
 266 }
 267
 268
 269 bool Heap::InFromSpace(Object* object) {
 270   return new_space_.FromSpaceContains(object);
 271 }
 272
 273
 274 bool Heap::InToSpace(Object* object) {
 275   return new_space_.ToSpaceContains(object);
 276 }
 277
 278
 279 bool Heap::InOldPointerSpace(Address address) {
 280   return old_pointer_space_->Contains(address);
 281 }
 282
 283
 284 bool Heap::InOldPointerSpace(Object* object) {
 285   return InOldPointerSpace(reinterpret_cast<Address>(object));
 286 }
 287
 288
 289 bool Heap::InOldDataSpace(Address address) {
 290   return old_data_space_->Contains(address);
 291 }
 292
 293
 294 bool Heap::InOldDataSpace(Object* object) {
 295   return InOldDataSpace(reinterpret_cast<Address>(object));
 296 }
 297
 298
 299 bool Heap::OldGenerationAllocationLimitReached() {
 300   if (!incremental_marking()->IsStopped()) return false;
 301   return OldGenerationSpaceAvailable() < 0;
 302 }
 303
 304
 305 bool Heap::ShouldBePromoted(Address old_address, int object_size) {
 306   // An object should be promoted if:
 307   // - the object has survived a scavenge operation or
 308   // - to space is already 25% full.
 309   NewSpacePage* page = NewSpacePage::FromAddress(old_address);
 310   Address age_mark = new_space_.age_mark();
 311   bool below_mark = page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
 312       (!page->ContainsLimit(age_mark) || old_address < age_mark);
 313   return below_mark || (new_space_.Size() + object_size) >=
 314                         (new_space_.EffectiveCapacity() >> 2);
 315 }
 316
 317
 318 void Heap::RecordWrite(Address address, int offset) {
 319   if (!InNewSpace(address)) store_buffer_.Mark(address + offset);
 320 }
 321
 322
 323 void Heap::RecordWrites(Address address, int start, int len) {
 324   if (!InNewSpace(address)) {
 325     for (int i = 0; i < len; i++) {
 326       store_buffer_.Mark(address + start + i * kPointerSize);
 327     }
 328   }
 329 }
 330
 331
 332 OldSpace* Heap::TargetSpace(HeapObject* object) {
 333   InstanceType type = object->map()->instance_type();
 334   AllocationSpace space = TargetSpaceId(type);
 335   return (space == OLD_POINTER_SPACE)
 336       ? old_pointer_space_
 337       : old_data_space_;
 338 }
 339
 340
 341 AllocationSpace Heap::TargetSpaceId(InstanceType type) {
 342   // Heap numbers and sequential strings are promoted to old data space, all
 343   // other object types are promoted to old pointer space.  We do not use
 344   // object->IsHeapNumber() and object->IsSeqString() because we already
 345   // know that object has the heap object tag.
 346
 347   // These objects are never allocated in new space.
 348   ASSERT(type != MAP_TYPE);
 349   ASSERT(type != CODE_TYPE);
 350   ASSERT(type != ODDBALL_TYPE);
 351   ASSERT(type != CELL_TYPE);
 352   ASSERT(type != PROPERTY_CELL_TYPE);
 353
 354   if (type <= LAST_NAME_TYPE) {
 355     if (type == SYMBOL_TYPE) return OLD_POINTER_SPACE;
 356     ASSERT(type < FIRST_NONSTRING_TYPE);
 357     // There are four string representations: sequential strings, external
 358     // strings, cons strings, and sliced strings.
 359     // Only the latter two contain non-map-word pointers to heap objects.
 360     return ((type & kIsIndirectStringMask) == kIsIndirectStringTag)
 361         ? OLD_POINTER_SPACE
 362         : OLD_DATA_SPACE;
 363   } else {
 364     return (type <= LAST_DATA_TYPE) ? OLD_DATA_SPACE : OLD_POINTER_SPACE;
 365   }
 366 }
 367
 368
 369 bool Heap::AllowedToBeMigrated(HeapObject* obj, AllocationSpace dst) {
 370   // Object migration is governed by the following rules:
 371   //
 372   // 1) Objects in new-space can be migrated to one of the old spaces
 373   //    that matches their target space or they stay in new-space.
 374   // 2) Objects in old-space stay in the same space when migrating.
 375   // 3) Fillers (two or more words) can migrate due to left-trimming of
 376   //    fixed arrays in new-space, old-data-space and old-pointer-space.
 377   // 4) Fillers (one word) can never migrate, they are skipped by
 378   //    incremental marking explicitly to prevent invalid pattern.
 379   // 5) Short external strings can end up in old pointer space when a cons
 380   //    string in old pointer space is made external (String::MakeExternal).
 381   //
 382   // Since this function is used for debugging only, we do not place
 383   // asserts here, but check everything explicitly.
 384   if (obj->map() == one_pointer_filler_map()) return false;
 385   InstanceType type = obj->map()->instance_type();
 386   MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
 387   AllocationSpace src = chunk->owner()->identity();
 388   switch (src) {
 389     case NEW_SPACE:
 390       return dst == src || dst == TargetSpaceId(type);
 391     case OLD_POINTER_SPACE:
 392       return dst == src &&
 393           (dst == TargetSpaceId(type) || obj->IsFiller() ||
 394           (obj->IsExternalString() && ExternalString::cast(obj)->is_short()));
 395     case OLD_DATA_SPACE:
 396       return dst == src && dst == TargetSpaceId(type);
 397     case CODE_SPACE:
 398       return dst == src && type == CODE_TYPE;
 399     case MAP_SPACE:
 400     case CELL_SPACE:
 401     case PROPERTY_CELL_SPACE:
 402     case LO_SPACE:
 403       return false;
 404     case INVALID_SPACE:
 405       break;
 406   }
 407   UNREACHABLE();
 408   return false;
 409 }
 410
 411
 412 void Heap::CopyBlock(Address dst, Address src, int byte_size) {
 413   CopyWords(reinterpret_cast<Object**>(dst),
 414             reinterpret_cast<Object**>(src),
 415             static_cast<size_t>(byte_size / kPointerSize));
 416 }
 417
 418
 419 void Heap::MoveBlock(Address dst, Address src, int byte_size) {
 420   ASSERT(IsAligned(byte_size, kPointerSize));
 421
 422   int size_in_words = byte_size / kPointerSize;
 423
 424   if ((dst < src) || (dst >= (src + byte_size))) {
 425     Object** src_slot = reinterpret_cast<Object**>(src);
 426     Object** dst_slot = reinterpret_cast<Object**>(dst);
 427     Object** end_slot = src_slot + size_in_words;
 428
 429     while (src_slot != end_slot) {
 430       *dst_slot++ = *src_slot++;
 431     }
 432   } else {
 433     OS::MemMove(dst, src, static_cast<size_t>(byte_size));
 434   }
 435 }
 436
 437
 438 void Heap::ScavengePointer(HeapObject** p) {
 439   ScavengeObject(p, *p);
 440 }
 441
 442
 443 AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) {
 444   // Check if there is potentially a memento behind the object. If
 445   // the last word of the momento is on another page we return
 446   // immediately.
 447   Address object_address = object->address();
 448   Address memento_address = object_address + object->Size();
 449   Address last_memento_word_address = memento_address + kPointerSize;
 450   if (!NewSpacePage::OnSamePage(object_address,
 451                                 last_memento_word_address)) {
 452     return NULL;
 453   }
 454
 455   HeapObject* candidate = HeapObject::FromAddress(memento_address);
 456   if (candidate->map() != allocation_memento_map()) return NULL;
 457
 458   // Either the object is the last object in the new space, or there is another
 459   // object of at least word size (the header map word) following it, so
 460   // suffices to compare ptr and top here. Note that technically we do not have
 461   // to compare with the current top pointer of the from space page during GC,
 462   // since we always install filler objects above the top pointer of a from
 463   // space page when performing a garbage collection. However, always performing
 464   // the test makes it possible to have a single, unified version of
 465   // FindAllocationMemento that is used both by the GC and the mutator.
 466   Address top = NewSpaceTop();
 467   ASSERT(memento_address == top ||
 468          memento_address + HeapObject::kHeaderSize <= top ||
 469          !NewSpacePage::OnSamePage(memento_address, top));
 470   if (memento_address == top) return NULL;
 471
 472   AllocationMemento* memento = AllocationMemento::cast(candidate);
 473   if (!memento->IsValid()) return NULL;
 474   return memento;
 475 }
 476
 477
 478 void Heap::UpdateAllocationSiteFeedback(HeapObject* object,
 479                                         ScratchpadSlotMode mode) {
 480   Heap* heap = object->GetHeap();
 481   ASSERT(heap->InFromSpace(object));
 482
 483   if (!FLAG_allocation_site_pretenuring ||
 484       !AllocationSite::CanTrack(object->map()->instance_type())) return;
 485
 486   AllocationMemento* memento = heap->FindAllocationMemento(object);
 487   if (memento == NULL) return;
 488
 489   if (memento->GetAllocationSite()->IncrementMementoFoundCount()) {
 490     heap->AddAllocationSiteToScratchpad(memento->GetAllocationSite(), mode);
 491   }
 492 }
 493
 494
 495 void Heap::ScavengeObject(HeapObject** p, HeapObject* object) {
 496   ASSERT(object->GetIsolate()->heap()->InFromSpace(object));
 497
 498   // We use the first word (where the map pointer usually is) of a heap
 499   // object to record the forwarding pointer.  A forwarding pointer can
 500   // point to an old space, the code space, or the to space of the new
 501   // generation.
 502   MapWord first_word = object->map_word();
 503
 504   // If the first word is a forwarding address, the object has already been
 505   // copied.
 506   if (first_word.IsForwardingAddress()) {
 507     HeapObject* dest = first_word.ToForwardingAddress();
 508     ASSERT(object->GetIsolate()->heap()->InFromSpace(*p));
 509     *p = dest;
 510     return;
 511   }
 512
 513   UpdateAllocationSiteFeedback(object, IGNORE_SCRATCHPAD_SLOT);
 514
 515   // AllocationMementos are unrooted and shouldn't survive a scavenge
 516   ASSERT(object->map() != object->GetHeap()->allocation_memento_map());
 517   // Call the slow part of scavenge object.
 518   return ScavengeObjectSlow(p, object);
 519 }
 520
 521
 522 bool Heap::CollectGarbage(AllocationSpace space,
 523                           const char* gc_reason,
 524                           const v8::GCCallbackFlags callbackFlags) {
 525   const char* collector_reason = NULL;
 526   GarbageCollector collector = SelectGarbageCollector(space, &collector_reason);
 527   return CollectGarbage(collector, gc_reason, collector_reason, callbackFlags);
 528 }
 529
 530
 531 int64_t Heap::AdjustAmountOfExternalAllocatedMemory(
 532     int64_t change_in_bytes) {
 533   ASSERT(HasBeenSetUp());
 534   int64_t amount = amount_of_external_allocated_memory_ + change_in_bytes;
 535   if (change_in_bytes > 0) {
 536     // Avoid overflow.
 537     if (amount > amount_of_external_allocated_memory_) {
 538       amount_of_external_allocated_memory_ = amount;
 539     } else {
 540       // Give up and reset the counters in case of an overflow.
 541       amount_of_external_allocated_memory_ = 0;
 542       amount_of_external_allocated_memory_at_last_global_gc_ = 0;
 543     }
 544     int64_t amount_since_last_global_gc = PromotedExternalMemorySize();
 545     if (amount_since_last_global_gc > external_allocation_limit_) {
 546       CollectAllGarbage(kNoGCFlags, "external memory allocation limit reached");
 547     }
 548   } else {
 549     // Avoid underflow.
 550     if (amount >= 0) {
 551       amount_of_external_allocated_memory_ = amount;
 552     } else {
 553       // Give up and reset the counters in case of an underflow.
 554       amount_of_external_allocated_memory_ = 0;
 555       amount_of_external_allocated_memory_at_last_global_gc_ = 0;
 556     }
 557   }
 558   if (FLAG_trace_external_memory) {
 559     PrintPID("%8.0f ms: ", isolate()->time_millis_since_init());
 560     PrintF("Adjust amount of external memory: delta=%6" V8_PTR_PREFIX "d KB, "
 561            "amount=%6" V8_PTR_PREFIX "d KB, since_gc=%6" V8_PTR_PREFIX "d KB, "
 562            "isolate=0x%08" V8PRIxPTR ".\n",
 563            static_cast<intptr_t>(change_in_bytes / KB),
 564            static_cast<intptr_t>(amount_of_external_allocated_memory_ / KB),
 565            static_cast<intptr_t>(PromotedExternalMemorySize() / KB),
 566            reinterpret_cast<intptr_t>(isolate()));
 567   }
 568   ASSERT(amount_of_external_allocated_memory_ >= 0);
 569   return amount_of_external_allocated_memory_;
 570 }
 571
 572
 573 Isolate* Heap::isolate() {
 574   return reinterpret_cast<Isolate*>(reinterpret_cast<intptr_t>(this) -
 575       reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(4)->heap()) + 4);
 576 }
 577
 578
 579 // Calls the FUNCTION_CALL function and retries it up to three times
 580 // to guarantee that any allocations performed during the call will
 581 // succeed if there's enough memory.
 582
 583 // Warning: Do not use the identifiers __object__, __maybe_object__ or
 584 // __scope__ in a call to this macro.
 585
 586 #define RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY)    \
 587   if (!__allocation__.IsRetry()) {                                             \
 588     __object__ = __allocation__.ToObjectChecked();                             \
 589     if (__object__ == (ISOLATE)->heap()->exception()) { RETURN_EMPTY; }        \
 590     RETURN_VALUE;                                                              \
 591   }
 592
 593 #define CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)     \
 594   do {                                                                         \
 595     AllocationResult __allocation__ = FUNCTION_CALL;                           \
 596     Object* __object__ = NULL;                                                 \
 597     RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY)        \
 598     (ISOLATE)->heap()->CollectGarbage(__allocation__.RetrySpace(),             \
 599                                       "allocation failure");                   \
 600     __allocation__ = FUNCTION_CALL;                                            \
 601     RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY)        \
 602     (ISOLATE)->counters()->gc_last_resort_from_handles()->Increment();         \
 603     (ISOLATE)->heap()->CollectAllAvailableGarbage("last resort gc");           \
 604     {                                                                          \
 605       AlwaysAllocateScope __scope__(ISOLATE);                                  \
 606       __allocation__ = FUNCTION_CALL;                                          \
 607     }                                                                          \
 608     RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY)        \
 609       /* TODO(1181417): Fix this. */                                           \
 610     v8::internal::Heap::FatalProcessOutOfMemory("CALL_AND_RETRY_LAST", true);  \
 611     RETURN_EMPTY;                                                              \
 612   } while (false)
 613
 614 #define CALL_AND_RETRY_OR_DIE(                                             \
 615      ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)                   \
 616   CALL_AND_RETRY(                                                          \
 617       ISOLATE,                                                             \
 618       FUNCTION_CALL,                                                       \
 619       RETURN_VALUE,                                                        \
 620       RETURN_EMPTY)
 621
 622 #define CALL_HEAP_FUNCTION(ISOLATE, FUNCTION_CALL, TYPE)                      \
 623   CALL_AND_RETRY_OR_DIE(ISOLATE,                                              \
 624                         FUNCTION_CALL,                                        \
 625                         return Handle<TYPE>(TYPE::cast(__object__), ISOLATE), \
 626                         return Handle<TYPE>())                                \
 627
 628
 629 #define CALL_HEAP_FUNCTION_VOID(ISOLATE, FUNCTION_CALL)  \
 630   CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, return, return)
 631
 632
 633 void ExternalStringTable::AddString(String* string) {
 634   ASSERT(string->IsExternalString());
 635   if (heap_->InNewSpace(string)) {
 636     new_space_strings_.Add(string);
 637   } else {
 638     old_space_strings_.Add(string);
 639   }
 640 }
 641
 642
 643 void ExternalStringTable::Iterate(ObjectVisitor* v) {
 644   if (!new_space_strings_.is_empty()) {
 645     Object** start = &new_space_strings_[0];
 646     v->VisitPointers(start, start + new_space_strings_.length());
 647   }
 648   if (!old_space_strings_.is_empty()) {
 649     Object** start = &old_space_strings_[0];
 650     v->VisitPointers(start, start + old_space_strings_.length());
 651   }
 652 }
 653
 654
 655 // Verify() is inline to avoid ifdef-s around its calls in release
 656 // mode.
 657 void ExternalStringTable::Verify() {
 658 #ifdef DEBUG
 659   for (int i = 0; i < new_space_strings_.length(); ++i) {
 660     Object* obj = Object::cast(new_space_strings_[i]);
 661     ASSERT(heap_->InNewSpace(obj));
 662     ASSERT(obj != heap_->the_hole_value());
 663   }
 664   for (int i = 0; i < old_space_strings_.length(); ++i) {
 665     Object* obj = Object::cast(old_space_strings_[i]);
 666     ASSERT(!heap_->InNewSpace(obj));
 667     ASSERT(obj != heap_->the_hole_value());
 668   }
 669 #endif
 670 }
 671
 672
 673 void ExternalStringTable::AddOldString(String* string) {
 674   ASSERT(string->IsExternalString());
 675   ASSERT(!heap_->InNewSpace(string));
 676   old_space_strings_.Add(string);
 677 }
 678
 679
 680 void ExternalStringTable::ShrinkNewStrings(int position) {
 681   new_space_strings_.Rewind(position);
 682 #ifdef VERIFY_HEAP
 683   if (FLAG_verify_heap) {
 684     Verify();
 685   }
 686 #endif
 687 }
 688
 689
 690 void Heap::ClearInstanceofCache() {
 691   set_instanceof_cache_function(the_hole_value());
 692 }
 693
 694
 695 Object* Heap::ToBoolean(bool condition) {
 696   return condition ? true_value() : false_value();
 697 }
 698
 699
 700 void Heap::CompletelyClearInstanceofCache() {
 701   set_instanceof_cache_map(the_hole_value());
 702   set_instanceof_cache_function(the_hole_value());
 703 }
 704
 705
 706 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
 707     : heap_(isolate->heap()), daf_(isolate) {
 708   // We shouldn't hit any nested scopes, because that requires
 709   // non-handle code to call handle code. The code still works but
 710   // performance will degrade, so we want to catch this situation
 711   // in debug mode.
 712   ASSERT(heap_->always_allocate_scope_depth_ == 0);
 713   heap_->always_allocate_scope_depth_++;
 714 }
 715
 716
 717 AlwaysAllocateScope::~AlwaysAllocateScope() {
 718   heap_->always_allocate_scope_depth_--;
 719   ASSERT(heap_->always_allocate_scope_depth_ == 0);
 720 }
 721
 722
 723 #ifdef VERIFY_HEAP
 724 NoWeakObjectVerificationScope::NoWeakObjectVerificationScope() {
 725   Isolate* isolate = Isolate::Current();
 726   isolate->heap()->no_weak_object_verification_scope_depth_++;
 727 }
 728
 729
 730 NoWeakObjectVerificationScope::~NoWeakObjectVerificationScope() {
 731   Isolate* isolate = Isolate::Current();
 732   isolate->heap()->no_weak_object_verification_scope_depth_--;
 733 }
 734 #endif
 735
 736
 737 GCCallbacksScope::GCCallbacksScope(Heap* heap) : heap_(heap) {
 738   heap_->gc_callbacks_depth_++;
 739 }
 740
 741
 742 GCCallbacksScope::~GCCallbacksScope() {
 743   heap_->gc_callbacks_depth_--;
 744 }
 745
 746
 747 bool GCCallbacksScope::CheckReenter() {
 748   return heap_->gc_callbacks_depth_ == 1;
 749 }
 750
 751
 752 void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
 753   for (Object** current = start; current < end; current++) {
 754     if ((*current)->IsHeapObject()) {
 755       HeapObject* object = HeapObject::cast(*current);
 756       CHECK(object->GetIsolate()->heap()->Contains(object));
 757       CHECK(object->map()->IsMap());
 758     }
 759   }
 760 }
 761
 762
 763 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
 764   for (Object** current = start; current < end; current++) {
 765      CHECK((*current)->IsSmi());
 766   }
 767 }
 768
 769
 770 double GCTracer::SizeOfHeapObjects() {
 771   return (static_cast<double>(heap_->SizeOfObjects())) / MB;
 772 }
 773
 774
 775 } }  // namespace v8::internal
 776
 777 #endif  // V8_HEAP_INL_H_