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

   1 // Copyright 2011 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_SPACES_INL_H_
   6 #define V8_HEAP_SPACES_INL_H_
   7
   8 #include "src/heap/spaces.h"
   9 #include "src/heap-profiler.h"
  10 #include "src/isolate.h"
  11 #include "src/msan.h"
  12 #include "src/v8memory.h"
  13
  14 namespace v8 {
  15 namespace internal {
  16
  17
  18 // -----------------------------------------------------------------------------
  19 // Bitmap
  20
  21 void Bitmap::Clear(MemoryChunk* chunk) {
  22   Bitmap* bitmap = chunk->markbits();
  23   for (int i = 0; i < bitmap->CellsCount(); i++) bitmap->cells()[i] = 0;
  24   chunk->ResetLiveBytes();
  25 }
  26
  27
  28 // -----------------------------------------------------------------------------
  29 // PageIterator
  30
  31
  32 PageIterator::PageIterator(PagedSpace* space)
  33     : space_(space),
  34       prev_page_(&space->anchor_),
  35       next_page_(prev_page_->next_page()) {}
  36
  37
  38 bool PageIterator::has_next() { return next_page_ != &space_->anchor_; }
  39
  40
  41 Page* PageIterator::next() {
  42   DCHECK(has_next());
  43   prev_page_ = next_page_;
  44   next_page_ = next_page_->next_page();
  45   return prev_page_;
  46 }
  47
  48
  49 // -----------------------------------------------------------------------------
  50 // NewSpacePageIterator
  51
  52
  53 NewSpacePageIterator::NewSpacePageIterator(NewSpace* space)
  54     : prev_page_(NewSpacePage::FromAddress(space->ToSpaceStart())->prev_page()),
  55       next_page_(NewSpacePage::FromAddress(space->ToSpaceStart())),
  56       last_page_(NewSpacePage::FromLimit(space->ToSpaceEnd())) {}
  57
  58 NewSpacePageIterator::NewSpacePageIterator(SemiSpace* space)
  59     : prev_page_(space->anchor()),
  60       next_page_(prev_page_->next_page()),
  61       last_page_(prev_page_->prev_page()) {}
  62
  63 NewSpacePageIterator::NewSpacePageIterator(Address start, Address limit)
  64     : prev_page_(NewSpacePage::FromAddress(start)->prev_page()),
  65       next_page_(NewSpacePage::FromAddress(start)),
  66       last_page_(NewSpacePage::FromLimit(limit)) {
  67   SemiSpace::AssertValidRange(start, limit);
  68 }
  69
  70
  71 bool NewSpacePageIterator::has_next() { return prev_page_ != last_page_; }
  72
  73
  74 NewSpacePage* NewSpacePageIterator::next() {
  75   DCHECK(has_next());
  76   prev_page_ = next_page_;
  77   next_page_ = next_page_->next_page();
  78   return prev_page_;
  79 }
  80
  81
  82 // -----------------------------------------------------------------------------
  83 // HeapObjectIterator
  84 HeapObject* HeapObjectIterator::FromCurrentPage() {
  85   while (cur_addr_ != cur_end_) {
  86     if (cur_addr_ == space_->top() && cur_addr_ != space_->limit()) {
  87       cur_addr_ = space_->limit();
  88       continue;
  89     }
  90     HeapObject* obj = HeapObject::FromAddress(cur_addr_);
  91     int obj_size = (size_func_ == NULL) ? obj->Size() : size_func_(obj);
  92     cur_addr_ += obj_size;
  93     DCHECK(cur_addr_ <= cur_end_);
  94     // TODO(hpayer): Remove the debugging code.
  95     if (cur_addr_ > cur_end_) {
  96       space_->heap()->isolate()->PushStackTraceAndDie(0xaaaaaaaa, obj, NULL,
  97                                                       obj_size);
  98     }
  99
 100     if (!obj->IsFiller()) {
 101       DCHECK_OBJECT_SIZE(obj_size);
 102       return obj;
 103     }
 104   }
 105   return NULL;
 106 }
 107
 108
 109 // -----------------------------------------------------------------------------
 110 // MemoryAllocator
 111
 112 #ifdef ENABLE_HEAP_PROTECTION
 113
 114 void MemoryAllocator::Protect(Address start, size_t size) {
 115   base::OS::Protect(start, size);
 116 }
 117
 118
 119 void MemoryAllocator::Unprotect(Address start, size_t size,
 120                                 Executability executable) {
 121   base::OS::Unprotect(start, size, executable);
 122 }
 123
 124
 125 void MemoryAllocator::ProtectChunkFromPage(Page* page) {
 126   int id = GetChunkId(page);
 127   base::OS::Protect(chunks_[id].address(), chunks_[id].size());
 128 }
 129
 130
 131 void MemoryAllocator::UnprotectChunkFromPage(Page* page) {
 132   int id = GetChunkId(page);
 133   base::OS::Unprotect(chunks_[id].address(), chunks_[id].size(),
 134                       chunks_[id].owner()->executable() == EXECUTABLE);
 135 }
 136
 137 #endif
 138
 139
 140 // --------------------------------------------------------------------------
 141 // PagedSpace
 142 Page* Page::Initialize(Heap* heap, MemoryChunk* chunk, Executability executable,
 143                        PagedSpace* owner) {
 144   Page* page = reinterpret_cast<Page*>(chunk);
 145   DCHECK(page->area_size() <= kMaxRegularHeapObjectSize);
 146   DCHECK(chunk->owner() == owner);
 147   owner->IncreaseCapacity(page->area_size());
 148   owner->Free(page->area_start(), page->area_size());
 149
 150   heap->incremental_marking()->SetOldSpacePageFlags(chunk);
 151
 152   return page;
 153 }
 154
 155
 156 bool PagedSpace::Contains(Address addr) {
 157   Page* p = Page::FromAddress(addr);
 158   if (!Page::IsValid(p)) return false;
 159   return p->owner() == this;
 160 }
 161
 162
 163 void MemoryChunk::set_scan_on_scavenge(bool scan) {
 164   if (scan) {
 165     if (!scan_on_scavenge()) heap_->increment_scan_on_scavenge_pages();
 166     SetFlag(SCAN_ON_SCAVENGE);
 167   } else {
 168     if (scan_on_scavenge()) heap_->decrement_scan_on_scavenge_pages();
 169     ClearFlag(SCAN_ON_SCAVENGE);
 170   }
 171   heap_->incremental_marking()->SetOldSpacePageFlags(this);
 172 }
 173
 174
 175 MemoryChunk* MemoryChunk::FromAnyPointerAddress(Heap* heap, Address addr) {
 176   MemoryChunk* maybe = reinterpret_cast<MemoryChunk*>(
 177       OffsetFrom(addr) & ~Page::kPageAlignmentMask);
 178   if (maybe->owner() != NULL) return maybe;
 179   LargeObjectIterator iterator(heap->lo_space());
 180   for (HeapObject* o = iterator.Next(); o != NULL; o = iterator.Next()) {
 181     // Fixed arrays are the only pointer-containing objects in large object
 182     // space.
 183     if (o->IsFixedArray()) {
 184       MemoryChunk* chunk = MemoryChunk::FromAddress(o->address());
 185       if (chunk->Contains(addr)) {
 186         return chunk;
 187       }
 188     }
 189   }
 190   UNREACHABLE();
 191   return NULL;
 192 }
 193
 194
 195 void MemoryChunk::UpdateHighWaterMark(Address mark) {
 196   if (mark == NULL) return;
 197   // Need to subtract one from the mark because when a chunk is full the
 198   // top points to the next address after the chunk, which effectively belongs
 199   // to another chunk. See the comment to Page::FromAllocationTop.
 200   MemoryChunk* chunk = MemoryChunk::FromAddress(mark - 1);
 201   int new_mark = static_cast<int>(mark - chunk->address());
 202   if (new_mark > chunk->high_water_mark_) {
 203     chunk->high_water_mark_ = new_mark;
 204   }
 205 }
 206
 207
 208 PointerChunkIterator::PointerChunkIterator(Heap* heap)
 209     : state_(kOldSpaceState),
 210       old_iterator_(heap->old_space()),
 211       map_iterator_(heap->map_space()),
 212       lo_iterator_(heap->lo_space()) {}
 213
 214
 215 Page* Page::next_page() {
 216   DCHECK(next_chunk()->owner() == owner());
 217   return static_cast<Page*>(next_chunk());
 218 }
 219
 220
 221 Page* Page::prev_page() {
 222   DCHECK(prev_chunk()->owner() == owner());
 223   return static_cast<Page*>(prev_chunk());
 224 }
 225
 226
 227 void Page::set_next_page(Page* page) {
 228   DCHECK(page->owner() == owner());
 229   set_next_chunk(page);
 230 }
 231
 232
 233 void Page::set_prev_page(Page* page) {
 234   DCHECK(page->owner() == owner());
 235   set_prev_chunk(page);
 236 }
 237
 238
 239 // Try linear allocation in the page of alloc_info's allocation top.  Does
 240 // not contain slow case logic (e.g. move to the next page or try free list
 241 // allocation) so it can be used by all the allocation functions and for all
 242 // the paged spaces.
 243 HeapObject* PagedSpace::AllocateLinearly(int size_in_bytes) {
 244   Address current_top = allocation_info_.top();
 245   Address new_top = current_top + size_in_bytes;
 246   if (new_top > allocation_info_.limit()) return NULL;
 247
 248   allocation_info_.set_top(new_top);
 249   return HeapObject::FromAddress(current_top);
 250 }
 251
 252
 253 HeapObject* PagedSpace::AllocateLinearlyAligned(int* size_in_bytes,
 254                                                 AllocationAlignment alignment) {
 255   Address current_top = allocation_info_.top();
 256   int filler_size = Heap::GetFillToAlign(current_top, alignment);
 257
 258   Address new_top = current_top + filler_size + *size_in_bytes;
 259   if (new_top > allocation_info_.limit()) return NULL;
 260
 261   allocation_info_.set_top(new_top);
 262   if (filler_size > 0) {
 263     *size_in_bytes += filler_size;
 264     return heap()->PrecedeWithFiller(HeapObject::FromAddress(current_top),
 265                                      filler_size);
 266   }
 267
 268   return HeapObject::FromAddress(current_top);
 269 }
 270
 271
 272 // Raw allocation.
 273 AllocationResult PagedSpace::AllocateRawUnaligned(int size_in_bytes) {
 274   HeapObject* object = AllocateLinearly(size_in_bytes);
 275
 276   if (object == NULL) {
 277     object = free_list_.Allocate(size_in_bytes);
 278     if (object == NULL) {
 279       object = SlowAllocateRaw(size_in_bytes);
 280     }
 281   }
 282
 283   if (object != NULL) {
 284     if (identity() == CODE_SPACE) {
 285       SkipList::Update(object->address(), size_in_bytes);
 286     }
 287     MSAN_ALLOCATED_UNINITIALIZED_MEMORY(object->address(), size_in_bytes);
 288     return object;
 289   }
 290
 291   return AllocationResult::Retry(identity());
 292 }
 293
 294
 295 // Raw allocation.
 296 AllocationResult PagedSpace::AllocateRawAligned(int size_in_bytes,
 297                                                 AllocationAlignment alignment) {
 298   DCHECK(identity() == OLD_SPACE);
 299   int allocation_size = size_in_bytes;
 300   HeapObject* object = AllocateLinearlyAligned(&allocation_size, alignment);
 301
 302   if (object == NULL) {
 303     // We don't know exactly how much filler we need to align until space is
 304     // allocated, so assume the worst case.
 305     int filler_size = Heap::GetMaximumFillToAlign(alignment);
 306     allocation_size += filler_size;
 307     object = free_list_.Allocate(allocation_size);
 308     if (object == NULL) {
 309       object = SlowAllocateRaw(allocation_size);
 310     }
 311     if (object != NULL && filler_size != 0) {
 312       object = heap()->AlignWithFiller(object, size_in_bytes, allocation_size,
 313                                        alignment);
 314       // Filler objects are initialized, so mark only the aligned object memory
 315       // as uninitialized.
 316       allocation_size = size_in_bytes;
 317     }
 318   }
 319
 320   if (object != NULL) {
 321     MSAN_ALLOCATED_UNINITIALIZED_MEMORY(object->address(), allocation_size);
 322     return object;
 323   }
 324
 325   return AllocationResult::Retry(identity());
 326 }
 327
 328
 329 AllocationResult PagedSpace::AllocateRaw(int size_in_bytes,
 330                                          AllocationAlignment alignment) {
 331 #ifdef V8_HOST_ARCH_32_BIT
 332   return alignment == kDoubleAligned
 333              ? AllocateRawAligned(size_in_bytes, kDoubleAligned)
 334              : AllocateRawUnaligned(size_in_bytes);
 335 #else
 336   return AllocateRawUnaligned(size_in_bytes);
 337 #endif
 338 }
 339
 340
 341 // -----------------------------------------------------------------------------
 342 // NewSpace
 343
 344
 345 AllocationResult NewSpace::AllocateRawAligned(int size_in_bytes,
 346                                               AllocationAlignment alignment) {
 347   Address old_top = allocation_info_.top();
 348   int filler_size = Heap::GetFillToAlign(old_top, alignment);
 349   int aligned_size_in_bytes = size_in_bytes + filler_size;
 350
 351   if (allocation_info_.limit() - old_top < aligned_size_in_bytes) {
 352     return SlowAllocateRaw(size_in_bytes, alignment);
 353   }
 354
 355   HeapObject* obj = HeapObject::FromAddress(old_top);
 356   allocation_info_.set_top(allocation_info_.top() + aligned_size_in_bytes);
 357   DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
 358
 359   if (filler_size > 0) {
 360     obj = heap()->PrecedeWithFiller(obj, filler_size);
 361   }
 362
 363   // The slow path above ultimately goes through AllocateRaw, so this suffices.
 364   MSAN_ALLOCATED_UNINITIALIZED_MEMORY(obj->address(), size_in_bytes);
 365
 366   return obj;
 367 }
 368
 369
 370 AllocationResult NewSpace::AllocateRawUnaligned(int size_in_bytes) {
 371   Address old_top = allocation_info_.top();
 372
 373   if (allocation_info_.limit() - old_top < size_in_bytes) {
 374     return SlowAllocateRaw(size_in_bytes, kWordAligned);
 375   }
 376
 377   HeapObject* obj = HeapObject::FromAddress(old_top);
 378   allocation_info_.set_top(allocation_info_.top() + size_in_bytes);
 379   DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
 380
 381   // The slow path above ultimately goes through AllocateRaw, so this suffices.
 382   MSAN_ALLOCATED_UNINITIALIZED_MEMORY(obj->address(), size_in_bytes);
 383
 384   return obj;
 385 }
 386
 387
 388 AllocationResult NewSpace::AllocateRaw(int size_in_bytes,
 389                                        AllocationAlignment alignment) {
 390 #ifdef V8_HOST_ARCH_32_BIT
 391   return alignment == kDoubleAligned
 392              ? AllocateRawAligned(size_in_bytes, kDoubleAligned)
 393              : AllocateRawUnaligned(size_in_bytes);
 394 #else
 395   return AllocateRawUnaligned(size_in_bytes);
 396 #endif
 397 }
 398
 399
 400 LargePage* LargePage::Initialize(Heap* heap, MemoryChunk* chunk) {
 401   heap->incremental_marking()->SetOldSpacePageFlags(chunk);
 402   return static_cast<LargePage*>(chunk);
 403 }
 404
 405
 406 intptr_t LargeObjectSpace::Available() {
 407   return ObjectSizeFor(heap()->isolate()->memory_allocator()->Available());
 408 }
 409
 410 }
 411 }  // namespace v8::internal
 412
 413 #endif  // V8_HEAP_SPACES_INL_H_