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| 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 "src/base/platform/platform.h" | |
| 11 #include "src/cpu-profiler.h" | |
| 12 #include "src/heap.h" | |
| 13 #include "src/heap-profiler.h" | |
| 14 #include "src/isolate.h" | |
| 15 #include "src/list-inl.h" | |
| 16 #include "src/objects.h" | |
| 17 #include "src/store-buffer.h" | |
| 18 #include "src/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 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( | |
| 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 CHECK_GE(String::kMaxLength, str.length()); | |
| 103 // Compute map and object size. | |
| 104 Map* map = ascii_internalized_string_map(); | |
| 105 int size = SeqOneByteString::SizeFor(str.length()); | |
| 106 AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED); | |
| 107 | |
| 108 // Allocate string. | |
| 109 HeapObject* result; | |
| 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 { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE); | |
| 142 if (!allocation.To(&result)) return allocation; | |
| 143 } | |
| 144 | |
| 145 result->set_map(map); | |
| 146 // Set length and hash fields of the allocated string. | |
| 147 String* answer = String::cast(result); | |
| 148 answer->set_length(str.length()); | |
| 149 answer->set_hash_field(hash_field); | |
| 150 | |
| 151 DCHECK_EQ(size, answer->Size()); | |
| 152 | |
| 153 // Fill in the characters. | |
| 154 MemCopy(answer->address() + SeqTwoByteString::kHeaderSize, str.start(), | |
| 155 str.length() * kUC16Size); | |
| 156 | |
| 157 return answer; | |
| 158 } | |
| 159 | |
| 160 AllocationResult Heap::CopyFixedArray(FixedArray* src) { | |
| 161 if (src->length() == 0) return src; | |
| 162 return CopyFixedArrayWithMap(src, src->map()); | |
| 163 } | |
| 164 | |
| 165 | |
| 166 AllocationResult Heap::CopyFixedDoubleArray(FixedDoubleArray* src) { | |
| 167 if (src->length() == 0) return src; | |
| 168 return CopyFixedDoubleArrayWithMap(src, src->map()); | |
| 169 } | |
| 170 | |
| 171 | |
| 172 AllocationResult Heap::CopyConstantPoolArray(ConstantPoolArray* src) { | |
| 173 if (src->length() == 0) return src; | |
| 174 return CopyConstantPoolArrayWithMap(src, src->map()); | |
| 175 } | |
| 176 | |
| 177 | |
| 178 AllocationResult Heap::AllocateRaw(int size_in_bytes, | |
| 179 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 && | |
| 186 AllowAllocationFailure::IsAllowed(isolate_) && | |
| 187 Heap::allocation_timeout_-- <= 0) { | |
| 188 return AllocationResult::Retry(space); | |
| 189 } | |
| 190 isolate_->counters()->objs_since_last_full()->Increment(); | |
| 191 isolate_->counters()->objs_since_last_young()->Increment(); | |
| 192 #endif | |
| 193 | |
| 194 HeapObject* object; | |
| 195 AllocationResult allocation; | |
| 196 if (NEW_SPACE == space) { | |
| 197 allocation = new_space_.AllocateRaw(size_in_bytes); | |
| 198 if (always_allocate() && | |
| 199 allocation.IsRetry() && | |
| 200 retry_space != NEW_SPACE) { | |
| 201 space = retry_space; | |
| 202 } else { | |
| 203 if (allocation.To(&object)) { | |
| 204 OnAllocationEvent(object, size_in_bytes); | |
| 205 } | |
| 206 return allocation; | |
| 207 } | |
| 208 } | |
| 209 | |
| 210 if (OLD_POINTER_SPACE == space) { | |
| 211 allocation = old_pointer_space_->AllocateRaw(size_in_bytes); | |
| 212 } else if (OLD_DATA_SPACE == space) { | |
| 213 allocation = old_data_space_->AllocateRaw(size_in_bytes); | |
| 214 } else if (CODE_SPACE == space) { | |
| 215 if (size_in_bytes <= code_space()->AreaSize()) { | |
| 216 allocation = code_space_->AllocateRaw(size_in_bytes); | |
| 217 } else { | |
| 218 // Large code objects are allocated in large object space. | |
| 219 allocation = lo_space_->AllocateRaw(size_in_bytes, EXECUTABLE); | |
| 220 } | |
| 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 DCHECK(MAP_SPACE == space); | |
| 229 allocation = map_space_->AllocateRaw(size_in_bytes); | |
| 230 } | |
| 231 if (allocation.To(&object)) { | |
| 232 OnAllocationEvent(object, size_in_bytes); | |
| 233 } else { | |
| 234 old_gen_exhausted_ = true; | |
| 235 } | |
| 236 return allocation; | |
| 237 } | |
| 238 | |
| 239 | |
| 240 void Heap::OnAllocationEvent(HeapObject* object, int size_in_bytes) { | |
| 241 HeapProfiler* profiler = isolate_->heap_profiler(); | |
| 242 if (profiler->is_tracking_allocations()) { | |
| 243 profiler->AllocationEvent(object->address(), size_in_bytes); | |
| 244 } | |
| 245 | |
| 246 if (FLAG_verify_predictable) { | |
| 247 ++allocations_count_; | |
| 248 | |
| 249 UpdateAllocationsHash(object); | |
| 250 UpdateAllocationsHash(size_in_bytes); | |
| 251 | |
| 252 if ((FLAG_dump_allocations_digest_at_alloc > 0) && | |
| 253 (--dump_allocations_hash_countdown_ == 0)) { | |
| 254 dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc; | |
| 255 PrintAlloctionsHash(); | |
| 256 } | |
| 257 } | |
| 258 } | |
| 259 | |
| 260 | |
| 261 void Heap::OnMoveEvent(HeapObject* target, | |
| 262 HeapObject* source, | |
| 263 int size_in_bytes) { | |
| 264 HeapProfiler* heap_profiler = isolate_->heap_profiler(); | |
| 265 if (heap_profiler->is_tracking_object_moves()) { | |
| 266 heap_profiler->ObjectMoveEvent(source->address(), target->address(), | |
| 267 size_in_bytes); | |
| 268 } | |
| 269 | |
| 270 if (isolate_->logger()->is_logging_code_events() || | |
| 271 isolate_->cpu_profiler()->is_profiling()) { | |
| 272 if (target->IsSharedFunctionInfo()) { | |
| 273 PROFILE(isolate_, SharedFunctionInfoMoveEvent( | |
| 274 source->address(), target->address())); | |
| 275 } | |
| 276 } | |
| 277 | |
| 278 if (FLAG_verify_predictable) { | |
| 279 ++allocations_count_; | |
| 280 | |
| 281 UpdateAllocationsHash(source); | |
| 282 UpdateAllocationsHash(target); | |
| 283 UpdateAllocationsHash(size_in_bytes); | |
| 284 | |
| 285 if ((FLAG_dump_allocations_digest_at_alloc > 0) && | |
| 286 (--dump_allocations_hash_countdown_ == 0)) { | |
| 287 dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc; | |
| 288 PrintAlloctionsHash(); | |
| 289 } | |
| 290 } | |
| 291 } | |
| 292 | |
| 293 | |
| 294 void Heap::UpdateAllocationsHash(HeapObject* object) { | |
| 295 Address object_address = object->address(); | |
| 296 MemoryChunk* memory_chunk = MemoryChunk::FromAddress(object_address); | |
| 297 AllocationSpace allocation_space = memory_chunk->owner()->identity(); | |
| 298 | |
| 299 STATIC_ASSERT(kSpaceTagSize + kPageSizeBits <= 32); | |
| 300 uint32_t value = | |
| 301 static_cast<uint32_t>(object_address - memory_chunk->address()) | | |
| 302 (static_cast<uint32_t>(allocation_space) << kPageSizeBits); | |
| 303 | |
| 304 UpdateAllocationsHash(value); | |
| 305 } | |
| 306 | |
| 307 | |
| 308 void Heap::UpdateAllocationsHash(uint32_t value) { | |
| 309 uint16_t c1 = static_cast<uint16_t>(value); | |
| 310 uint16_t c2 = static_cast<uint16_t>(value >> 16); | |
| 311 raw_allocations_hash_ = | |
| 312 StringHasher::AddCharacterCore(raw_allocations_hash_, c1); | |
| 313 raw_allocations_hash_ = | |
| 314 StringHasher::AddCharacterCore(raw_allocations_hash_, c2); | |
| 315 } | |
| 316 | |
| 317 | |
| 318 void Heap::PrintAlloctionsHash() { | |
| 319 uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_); | |
| 320 PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count_, hash); | |
| 321 } | |
| 322 | |
| 323 | |
| 324 void Heap::FinalizeExternalString(String* string) { | |
| 325 DCHECK(string->IsExternalString()); | |
| 326 v8::String::ExternalStringResourceBase** resource_addr = | |
| 327 reinterpret_cast<v8::String::ExternalStringResourceBase**>( | |
| 328 reinterpret_cast<byte*>(string) + | |
| 329 ExternalString::kResourceOffset - | |
| 330 kHeapObjectTag); | |
| 331 | |
| 332 // Dispose of the C++ object if it has not already been disposed. | |
| 333 if (*resource_addr != NULL) { | |
| 334 (*resource_addr)->Dispose(); | |
| 335 *resource_addr = NULL; | |
| 336 } | |
| 337 } | |
| 338 | |
| 339 | |
| 340 bool Heap::InNewSpace(Object* object) { | |
| 341 bool result = new_space_.Contains(object); | |
| 342 DCHECK(!result || // Either not in new space | |
| 343 gc_state_ != NOT_IN_GC || // ... or in the middle of GC | |
| 344 InToSpace(object)); // ... or in to-space (where we allocate). | |
| 345 return result; | |
| 346 } | |
| 347 | |
| 348 | |
| 349 bool Heap::InNewSpace(Address address) { | |
| 350 return new_space_.Contains(address); | |
| 351 } | |
| 352 | |
| 353 | |
| 354 bool Heap::InFromSpace(Object* object) { | |
| 355 return new_space_.FromSpaceContains(object); | |
| 356 } | |
| 357 | |
| 358 | |
| 359 bool Heap::InToSpace(Object* object) { | |
| 360 return new_space_.ToSpaceContains(object); | |
| 361 } | |
| 362 | |
| 363 | |
| 364 bool Heap::InOldPointerSpace(Address address) { | |
| 365 return old_pointer_space_->Contains(address); | |
| 366 } | |
| 367 | |
| 368 | |
| 369 bool Heap::InOldPointerSpace(Object* object) { | |
| 370 return InOldPointerSpace(reinterpret_cast<Address>(object)); | |
| 371 } | |
| 372 | |
| 373 | |
| 374 bool Heap::InOldDataSpace(Address address) { | |
| 375 return old_data_space_->Contains(address); | |
| 376 } | |
| 377 | |
| 378 | |
| 379 bool Heap::InOldDataSpace(Object* object) { | |
| 380 return InOldDataSpace(reinterpret_cast<Address>(object)); | |
| 381 } | |
| 382 | |
| 383 | |
| 384 bool Heap::OldGenerationAllocationLimitReached() { | |
| 385 if (!incremental_marking()->IsStopped()) return false; | |
| 386 return OldGenerationSpaceAvailable() < 0; | |
| 387 } | |
| 388 | |
| 389 | |
| 390 bool Heap::ShouldBePromoted(Address old_address, int object_size) { | |
| 391 NewSpacePage* page = NewSpacePage::FromAddress(old_address); | |
| 392 Address age_mark = new_space_.age_mark(); | |
| 393 return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) && | |
| 394 (!page->ContainsLimit(age_mark) || old_address < age_mark); | |
| 395 } | |
| 396 | |
| 397 | |
| 398 void Heap::RecordWrite(Address address, int offset) { | |
| 399 if (!InNewSpace(address)) store_buffer_.Mark(address + offset); | |
| 400 } | |
| 401 | |
| 402 | |
| 403 void Heap::RecordWrites(Address address, int start, int len) { | |
| 404 if (!InNewSpace(address)) { | |
| 405 for (int i = 0; i < len; i++) { | |
| 406 store_buffer_.Mark(address + start + i * kPointerSize); | |
| 407 } | |
| 408 } | |
| 409 } | |
| 410 | |
| 411 | |
| 412 OldSpace* Heap::TargetSpace(HeapObject* object) { | |
| 413 InstanceType type = object->map()->instance_type(); | |
| 414 AllocationSpace space = TargetSpaceId(type); | |
| 415 return (space == OLD_POINTER_SPACE) | |
| 416 ? old_pointer_space_ | |
| 417 : old_data_space_; | |
| 418 } | |
| 419 | |
| 420 | |
| 421 AllocationSpace Heap::TargetSpaceId(InstanceType type) { | |
| 422 // Heap numbers and sequential strings are promoted to old data space, all | |
| 423 // other object types are promoted to old pointer space. We do not use | |
| 424 // object->IsHeapNumber() and object->IsSeqString() because we already | |
| 425 // know that object has the heap object tag. | |
| 426 | |
| 427 // These objects are never allocated in new space. | |
| 428 DCHECK(type != MAP_TYPE); | |
| 429 DCHECK(type != CODE_TYPE); | |
| 430 DCHECK(type != ODDBALL_TYPE); | |
| 431 DCHECK(type != CELL_TYPE); | |
| 432 DCHECK(type != PROPERTY_CELL_TYPE); | |
| 433 | |
| 434 if (type <= LAST_NAME_TYPE) { | |
| 435 if (type == SYMBOL_TYPE) return OLD_POINTER_SPACE; | |
| 436 DCHECK(type < FIRST_NONSTRING_TYPE); | |
| 437 // There are four string representations: sequential strings, external | |
| 438 // strings, cons strings, and sliced strings. | |
| 439 // Only the latter two contain non-map-word pointers to heap objects. | |
| 440 return ((type & kIsIndirectStringMask) == kIsIndirectStringTag) | |
| 441 ? OLD_POINTER_SPACE | |
| 442 : OLD_DATA_SPACE; | |
| 443 } else { | |
| 444 return (type <= LAST_DATA_TYPE) ? OLD_DATA_SPACE : OLD_POINTER_SPACE; | |
| 445 } | |
| 446 } | |
| 447 | |
| 448 | |
| 449 bool Heap::AllowedToBeMigrated(HeapObject* obj, AllocationSpace dst) { | |
| 450 // Object migration is governed by the following rules: | |
| 451 // | |
| 452 // 1) Objects in new-space can be migrated to one of the old spaces | |
| 453 // that matches their target space or they stay in new-space. | |
| 454 // 2) Objects in old-space stay in the same space when migrating. | |
| 455 // 3) Fillers (two or more words) can migrate due to left-trimming of | |
| 456 // fixed arrays in new-space, old-data-space and old-pointer-space. | |
| 457 // 4) Fillers (one word) can never migrate, they are skipped by | |
| 458 // incremental marking explicitly to prevent invalid pattern. | |
| 459 // 5) Short external strings can end up in old pointer space when a cons | |
| 460 // string in old pointer space is made external (String::MakeExternal). | |
| 461 // | |
| 462 // Since this function is used for debugging only, we do not place | |
| 463 // asserts here, but check everything explicitly. | |
| 464 if (obj->map() == one_pointer_filler_map()) return false; | |
| 465 InstanceType type = obj->map()->instance_type(); | |
| 466 MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address()); | |
| 467 AllocationSpace src = chunk->owner()->identity(); | |
| 468 switch (src) { | |
| 469 case NEW_SPACE: | |
| 470 return dst == src || dst == TargetSpaceId(type); | |
| 471 case OLD_POINTER_SPACE: | |
| 472 return dst == src && (dst == TargetSpaceId(type) || obj->IsFiller() || | |
| 473 (obj->IsExternalString() && | |
| 474 ExternalString::cast(obj)->is_short())); | |
| 475 case OLD_DATA_SPACE: | |
| 476 return dst == src && dst == TargetSpaceId(type); | |
| 477 case CODE_SPACE: | |
| 478 return dst == src && type == CODE_TYPE; | |
| 479 case MAP_SPACE: | |
| 480 case CELL_SPACE: | |
| 481 case PROPERTY_CELL_SPACE: | |
| 482 case LO_SPACE: | |
| 483 return false; | |
| 484 case INVALID_SPACE: | |
| 485 break; | |
| 486 } | |
| 487 UNREACHABLE(); | |
| 488 return false; | |
| 489 } | |
| 490 | |
| 491 | |
| 492 void Heap::CopyBlock(Address dst, Address src, int byte_size) { | |
| 493 CopyWords(reinterpret_cast<Object**>(dst), | |
| 494 reinterpret_cast<Object**>(src), | |
| 495 static_cast<size_t>(byte_size / kPointerSize)); | |
| 496 } | |
| 497 | |
| 498 | |
| 499 void Heap::MoveBlock(Address dst, Address src, int byte_size) { | |
| 500 DCHECK(IsAligned(byte_size, kPointerSize)); | |
| 501 | |
| 502 int size_in_words = byte_size / kPointerSize; | |
| 503 | |
| 504 if ((dst < src) || (dst >= (src + byte_size))) { | |
| 505 Object** src_slot = reinterpret_cast<Object**>(src); | |
| 506 Object** dst_slot = reinterpret_cast<Object**>(dst); | |
| 507 Object** end_slot = src_slot + size_in_words; | |
| 508 | |
| 509 while (src_slot != end_slot) { | |
| 510 *dst_slot++ = *src_slot++; | |
| 511 } | |
| 512 } else { | |
| 513 MemMove(dst, src, static_cast<size_t>(byte_size)); | |
| 514 } | |
| 515 } | |
| 516 | |
| 517 | |
| 518 void Heap::ScavengePointer(HeapObject** p) { | |
| 519 ScavengeObject(p, *p); | |
| 520 } | |
| 521 | |
| 522 | |
| 523 AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) { | |
| 524 // Check if there is potentially a memento behind the object. If | |
| 525 // the last word of the momento is on another page we return | |
| 526 // immediately. | |
| 527 Address object_address = object->address(); | |
| 528 Address memento_address = object_address + object->Size(); | |
| 529 Address last_memento_word_address = memento_address + kPointerSize; | |
| 530 if (!NewSpacePage::OnSamePage(object_address, | |
| 531 last_memento_word_address)) { | |
| 532 return NULL; | |
| 533 } | |
| 534 | |
| 535 HeapObject* candidate = HeapObject::FromAddress(memento_address); | |
| 536 if (candidate->map() != allocation_memento_map()) return NULL; | |
| 537 | |
| 538 // Either the object is the last object in the new space, or there is another | |
| 539 // object of at least word size (the header map word) following it, so | |
| 540 // suffices to compare ptr and top here. Note that technically we do not have | |
| 541 // to compare with the current top pointer of the from space page during GC, | |
| 542 // since we always install filler objects above the top pointer of a from | |
| 543 // space page when performing a garbage collection. However, always performing | |
| 544 // the test makes it possible to have a single, unified version of | |
| 545 // FindAllocationMemento that is used both by the GC and the mutator. | |
| 546 Address top = NewSpaceTop(); | |
| 547 DCHECK(memento_address == top || | |
| 548 memento_address + HeapObject::kHeaderSize <= top || | |
| 549 !NewSpacePage::OnSamePage(memento_address, top)); | |
| 550 if (memento_address == top) return NULL; | |
| 551 | |
| 552 AllocationMemento* memento = AllocationMemento::cast(candidate); | |
| 553 if (!memento->IsValid()) return NULL; | |
| 554 return memento; | |
| 555 } | |
| 556 | |
| 557 | |
| 558 void Heap::UpdateAllocationSiteFeedback(HeapObject* object, | |
| 559 ScratchpadSlotMode mode) { | |
| 560 Heap* heap = object->GetHeap(); | |
| 561 DCHECK(heap->InFromSpace(object)); | |
| 562 | |
| 563 if (!FLAG_allocation_site_pretenuring || | |
| 564 !AllocationSite::CanTrack(object->map()->instance_type())) return; | |
| 565 | |
| 566 AllocationMemento* memento = heap->FindAllocationMemento(object); | |
| 567 if (memento == NULL) return; | |
| 568 | |
| 569 if (memento->GetAllocationSite()->IncrementMementoFoundCount()) { | |
| 570 heap->AddAllocationSiteToScratchpad(memento->GetAllocationSite(), mode); | |
| 571 } | |
| 572 } | |
| 573 | |
| 574 | |
| 575 void Heap::ScavengeObject(HeapObject** p, HeapObject* object) { | |
| 576 DCHECK(object->GetIsolate()->heap()->InFromSpace(object)); | |
| 577 | |
| 578 // We use the first word (where the map pointer usually is) of a heap | |
| 579 // object to record the forwarding pointer. A forwarding pointer can | |
| 580 // point to an old space, the code space, or the to space of the new | |
| 581 // generation. | |
| 582 MapWord first_word = object->map_word(); | |
| 583 | |
| 584 // If the first word is a forwarding address, the object has already been | |
| 585 // copied. | |
| 586 if (first_word.IsForwardingAddress()) { | |
| 587 HeapObject* dest = first_word.ToForwardingAddress(); | |
| 588 DCHECK(object->GetIsolate()->heap()->InFromSpace(*p)); | |
| 589 *p = dest; | |
| 590 return; | |
| 591 } | |
| 592 | |
| 593 UpdateAllocationSiteFeedback(object, IGNORE_SCRATCHPAD_SLOT); | |
| 594 | |
| 595 // AllocationMementos are unrooted and shouldn't survive a scavenge | |
| 596 DCHECK(object->map() != object->GetHeap()->allocation_memento_map()); | |
| 597 // Call the slow part of scavenge object. | |
| 598 return ScavengeObjectSlow(p, object); | |
| 599 } | |
| 600 | |
| 601 | |
| 602 bool Heap::CollectGarbage(AllocationSpace space, | |
| 603 const char* gc_reason, | |
| 604 const v8::GCCallbackFlags callbackFlags) { | |
| 605 const char* collector_reason = NULL; | |
| 606 GarbageCollector collector = SelectGarbageCollector(space, &collector_reason); | |
| 607 return CollectGarbage(collector, gc_reason, collector_reason, callbackFlags); | |
| 608 } | |
| 609 | |
| 610 | |
| 611 Isolate* Heap::isolate() { | |
| 612 return reinterpret_cast<Isolate*>(reinterpret_cast<intptr_t>(this) - | |
| 613 reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(4)->heap()) + 4); | |
| 614 } | |
| 615 | |
| 616 | |
| 617 // Calls the FUNCTION_CALL function and retries it up to three times | |
| 618 // to guarantee that any allocations performed during the call will | |
| 619 // succeed if there's enough memory. | |
| 620 | |
| 621 // Warning: Do not use the identifiers __object__, __maybe_object__ or | |
| 622 // __scope__ in a call to this macro. | |
| 623 | |
| 624 #define RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \ | |
| 625 if (__allocation__.To(&__object__)) { \ | |
| 626 DCHECK(__object__ != (ISOLATE)->heap()->exception()); \ | |
| 627 RETURN_VALUE; \ | |
| 628 } | |
| 629 | |
| 630 #define CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY) \ | |
| 631 do { \ | |
| 632 AllocationResult __allocation__ = FUNCTION_CALL; \ | |
| 633 Object* __object__ = NULL; \ | |
| 634 RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \ | |
| 635 (ISOLATE)->heap()->CollectGarbage(__allocation__.RetrySpace(), \ | |
| 636 "allocation failure"); \ | |
| 637 __allocation__ = FUNCTION_CALL; \ | |
| 638 RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \ | |
| 639 (ISOLATE)->counters()->gc_last_resort_from_handles()->Increment(); \ | |
| 640 (ISOLATE)->heap()->CollectAllAvailableGarbage("last resort gc"); \ | |
| 641 { \ | |
| 642 AlwaysAllocateScope __scope__(ISOLATE); \ | |
| 643 __allocation__ = FUNCTION_CALL; \ | |
| 644 } \ | |
| 645 RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \ | |
| 646 /* TODO(1181417): Fix this. */ \ | |
| 647 v8::internal::Heap::FatalProcessOutOfMemory("CALL_AND_RETRY_LAST", true); \ | |
| 648 RETURN_EMPTY; \ | |
| 649 } while (false) | |
| 650 | |
| 651 #define CALL_AND_RETRY_OR_DIE( \ | |
| 652 ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY) \ | |
| 653 CALL_AND_RETRY( \ | |
| 654 ISOLATE, \ | |
| 655 FUNCTION_CALL, \ | |
| 656 RETURN_VALUE, \ | |
| 657 RETURN_EMPTY) | |
| 658 | |
| 659 #define CALL_HEAP_FUNCTION(ISOLATE, FUNCTION_CALL, TYPE) \ | |
| 660 CALL_AND_RETRY_OR_DIE(ISOLATE, \ | |
| 661 FUNCTION_CALL, \ | |
| 662 return Handle<TYPE>(TYPE::cast(__object__), ISOLATE), \ | |
| 663 return Handle<TYPE>()) \ | |
| 664 | |
| 665 | |
| 666 #define CALL_HEAP_FUNCTION_VOID(ISOLATE, FUNCTION_CALL) \ | |
| 667 CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, return, return) | |
| 668 | |
| 669 | |
| 670 void ExternalStringTable::AddString(String* string) { | |
| 671 DCHECK(string->IsExternalString()); | |
| 672 if (heap_->InNewSpace(string)) { | |
| 673 new_space_strings_.Add(string); | |
| 674 } else { | |
| 675 old_space_strings_.Add(string); | |
| 676 } | |
| 677 } | |
| 678 | |
| 679 | |
| 680 void ExternalStringTable::Iterate(ObjectVisitor* v) { | |
| 681 if (!new_space_strings_.is_empty()) { | |
| 682 Object** start = &new_space_strings_[0]; | |
| 683 v->VisitPointers(start, start + new_space_strings_.length()); | |
| 684 } | |
| 685 if (!old_space_strings_.is_empty()) { | |
| 686 Object** start = &old_space_strings_[0]; | |
| 687 v->VisitPointers(start, start + old_space_strings_.length()); | |
| 688 } | |
| 689 } | |
| 690 | |
| 691 | |
| 692 // Verify() is inline to avoid ifdef-s around its calls in release | |
| 693 // mode. | |
| 694 void ExternalStringTable::Verify() { | |
| 695 #ifdef DEBUG | |
| 696 for (int i = 0; i < new_space_strings_.length(); ++i) { | |
| 697 Object* obj = Object::cast(new_space_strings_[i]); | |
| 698 DCHECK(heap_->InNewSpace(obj)); | |
| 699 DCHECK(obj != heap_->the_hole_value()); | |
| 700 } | |
| 701 for (int i = 0; i < old_space_strings_.length(); ++i) { | |
| 702 Object* obj = Object::cast(old_space_strings_[i]); | |
| 703 DCHECK(!heap_->InNewSpace(obj)); | |
| 704 DCHECK(obj != heap_->the_hole_value()); | |
| 705 } | |
| 706 #endif | |
| 707 } | |
| 708 | |
| 709 | |
| 710 void ExternalStringTable::AddOldString(String* string) { | |
| 711 DCHECK(string->IsExternalString()); | |
| 712 DCHECK(!heap_->InNewSpace(string)); | |
| 713 old_space_strings_.Add(string); | |
| 714 } | |
| 715 | |
| 716 | |
| 717 void ExternalStringTable::ShrinkNewStrings(int position) { | |
| 718 new_space_strings_.Rewind(position); | |
| 719 #ifdef VERIFY_HEAP | |
| 720 if (FLAG_verify_heap) { | |
| 721 Verify(); | |
| 722 } | |
| 723 #endif | |
| 724 } | |
| 725 | |
| 726 | |
| 727 void Heap::ClearInstanceofCache() { | |
| 728 set_instanceof_cache_function(the_hole_value()); | |
| 729 } | |
| 730 | |
| 731 | |
| 732 Object* Heap::ToBoolean(bool condition) { | |
| 733 return condition ? true_value() : false_value(); | |
| 734 } | |
| 735 | |
| 736 | |
| 737 void Heap::CompletelyClearInstanceofCache() { | |
| 738 set_instanceof_cache_map(the_hole_value()); | |
| 739 set_instanceof_cache_function(the_hole_value()); | |
| 740 } | |
| 741 | |
| 742 | |
| 743 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate) | |
| 744 : heap_(isolate->heap()), daf_(isolate) { | |
| 745 // We shouldn't hit any nested scopes, because that requires | |
| 746 // non-handle code to call handle code. The code still works but | |
| 747 // performance will degrade, so we want to catch this situation | |
| 748 // in debug mode. | |
| 749 DCHECK(heap_->always_allocate_scope_depth_ == 0); | |
| 750 heap_->always_allocate_scope_depth_++; | |
| 751 } | |
| 752 | |
| 753 | |
| 754 AlwaysAllocateScope::~AlwaysAllocateScope() { | |
| 755 heap_->always_allocate_scope_depth_--; | |
| 756 DCHECK(heap_->always_allocate_scope_depth_ == 0); | |
| 757 } | |
| 758 | |
| 759 | |
| 760 #ifdef VERIFY_HEAP | |
| 761 NoWeakObjectVerificationScope::NoWeakObjectVerificationScope() { | |
| 762 Isolate* isolate = Isolate::Current(); | |
| 763 isolate->heap()->no_weak_object_verification_scope_depth_++; | |
| 764 } | |
| 765 | |
| 766 | |
| 767 NoWeakObjectVerificationScope::~NoWeakObjectVerificationScope() { | |
| 768 Isolate* isolate = Isolate::Current(); | |
| 769 isolate->heap()->no_weak_object_verification_scope_depth_--; | |
| 770 } | |
| 771 #endif | |
| 772 | |
| 773 | |
| 774 GCCallbacksScope::GCCallbacksScope(Heap* heap) : heap_(heap) { | |
| 775 heap_->gc_callbacks_depth_++; | |
| 776 } | |
| 777 | |
| 778 | |
| 779 GCCallbacksScope::~GCCallbacksScope() { | |
| 780 heap_->gc_callbacks_depth_--; | |
| 781 } | |
| 782 | |
| 783 | |
| 784 bool GCCallbacksScope::CheckReenter() { | |
| 785 return heap_->gc_callbacks_depth_ == 1; | |
| 786 } | |
| 787 | |
| 788 | |
| 789 void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) { | |
| 790 for (Object** current = start; current < end; current++) { | |
| 791 if ((*current)->IsHeapObject()) { | |
| 792 HeapObject* object = HeapObject::cast(*current); | |
| 793 CHECK(object->GetIsolate()->heap()->Contains(object)); | |
| 794 CHECK(object->map()->IsMap()); | |
| 795 } | |
| 796 } | |
| 797 } | |
| 798 | |
| 799 | |
| 800 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) { | |
| 801 for (Object** current = start; current < end; current++) { | |
| 802 CHECK((*current)->IsSmi()); | |
| 803 } | |
| 804 } | |
| 805 | |
| 806 | |
| 807 } } // namespace v8::internal | |
| 808 | |
| 809 #endif // V8_HEAP_INL_H_ | |
| OLD | NEW |
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Chromium Code Reviews
Issue 437993003:
Move a bunch of GC related files to heap/ subdirectory (Closed)
Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge