src/v8/src/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_SPACES_INL_H_
   6 #define V8_SPACES_INL_H_
   7
   8 #include "heap-profiler.h"
   9 #include "isolate.h"
  10 #include "spaces.h"
  11 #include "v8memory.h"
  12
  13 namespace v8 {
  14 namespace internal {
  15
  16
  17 // -----------------------------------------------------------------------------
  18 // Bitmap
  19
  20 void Bitmap::Clear(MemoryChunk* chunk) {
  21   Bitmap* bitmap = chunk->markbits();
  22   for (int i = 0; i < bitmap->CellsCount(); i++) bitmap->cells()[i] = 0;
  23   chunk->ResetLiveBytes();
  24 }
  25
  26
  27 // -----------------------------------------------------------------------------
  28 // PageIterator
  29
  30
  31 PageIterator::PageIterator(PagedSpace* space)
  32     : space_(space),
  33       prev_page_(&space->anchor_),
  34       next_page_(prev_page_->next_page()) { }
  35
  36
  37 bool PageIterator::has_next() {
  38   return next_page_ != &space_->anchor_;
  39 }
  40
  41
  42 Page* PageIterator::next() {
  43   ASSERT(has_next());
  44   prev_page_ = next_page_;
  45   next_page_ = next_page_->next_page();
  46   return prev_page_;
  47 }
  48
  49
  50 // -----------------------------------------------------------------------------
  51 // NewSpacePageIterator
  52
  53
  54 NewSpacePageIterator::NewSpacePageIterator(NewSpace* space)
  55     : prev_page_(NewSpacePage::FromAddress(space->ToSpaceStart())->prev_page()),
  56       next_page_(NewSpacePage::FromAddress(space->ToSpaceStart())),
  57       last_page_(NewSpacePage::FromLimit(space->ToSpaceEnd())) { }
  58
  59 NewSpacePageIterator::NewSpacePageIterator(SemiSpace* space)
  60     : prev_page_(space->anchor()),
  61       next_page_(prev_page_->next_page()),
  62       last_page_(prev_page_->prev_page()) { }
  63
  64 NewSpacePageIterator::NewSpacePageIterator(Address start, Address limit)
  65     : prev_page_(NewSpacePage::FromAddress(start)->prev_page()),
  66       next_page_(NewSpacePage::FromAddress(start)),
  67       last_page_(NewSpacePage::FromLimit(limit)) {
  68   SemiSpace::AssertValidRange(start, limit);
  69 }
  70
  71
  72 bool NewSpacePageIterator::has_next() {
  73   return prev_page_ != last_page_;
  74 }
  75
  76
  77 NewSpacePage* NewSpacePageIterator::next() {
  78   ASSERT(has_next());
  79   prev_page_ = next_page_;
  80   next_page_ = next_page_->next_page();
  81   return prev_page_;
  82 }
  83
  84
  85 // -----------------------------------------------------------------------------
  86 // HeapObjectIterator
  87 HeapObject* HeapObjectIterator::FromCurrentPage() {
  88   while (cur_addr_ != cur_end_) {
  89     if (cur_addr_ == space_->top() && cur_addr_ != space_->limit()) {
  90       cur_addr_ = space_->limit();
  91       continue;
  92     }
  93     HeapObject* obj = HeapObject::FromAddress(cur_addr_);
  94     int obj_size = (size_func_ == NULL) ? obj->Size() : size_func_(obj);
  95     cur_addr_ += obj_size;
  96     ASSERT(cur_addr_ <= cur_end_);
  97     if (!obj->IsFiller()) {
  98       ASSERT_OBJECT_SIZE(obj_size);
  99       return obj;
 100     }
 101   }
 102   return NULL;
 103 }
 104
 105
 106 // -----------------------------------------------------------------------------
 107 // MemoryAllocator
 108
 109 #ifdef ENABLE_HEAP_PROTECTION
 110
 111 void MemoryAllocator::Protect(Address start, size_t size) {
 112   OS::Protect(start, size);
 113 }
 114
 115
 116 void MemoryAllocator::Unprotect(Address start,
 117                                 size_t size,
 118                                 Executability executable) {
 119   OS::Unprotect(start, size, executable);
 120 }
 121
 122
 123 void MemoryAllocator::ProtectChunkFromPage(Page* page) {
 124   int id = GetChunkId(page);
 125   OS::Protect(chunks_[id].address(), chunks_[id].size());
 126 }
 127
 128
 129 void MemoryAllocator::UnprotectChunkFromPage(Page* page) {
 130   int id = GetChunkId(page);
 131   OS::Unprotect(chunks_[id].address(), chunks_[id].size(),
 132                 chunks_[id].owner()->executable() == EXECUTABLE);
 133 }
 134
 135 #endif
 136
 137
 138 // --------------------------------------------------------------------------
 139 // PagedSpace
 140 Page* Page::Initialize(Heap* heap,
 141                        MemoryChunk* chunk,
 142                        Executability executable,
 143                        PagedSpace* owner) {
 144   Page* page = reinterpret_cast<Page*>(chunk);
 145   ASSERT(page->area_size() <= kMaxRegularHeapObjectSize);
 146   ASSERT(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 (!p->is_valid()) 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_(kOldPointerState),
 210       old_pointer_iterator_(heap->old_pointer_space()),
 211       map_iterator_(heap->map_space()),
 212       lo_iterator_(heap->lo_space()) { }
 213
 214
 215 Page* Page::next_page() {
 216   ASSERT(next_chunk()->owner() == owner());
 217   return static_cast<Page*>(next_chunk());
 218 }
 219
 220
 221 Page* Page::prev_page() {
 222   ASSERT(prev_chunk()->owner() == owner());
 223   return static_cast<Page*>(prev_chunk());
 224 }
 225
 226
 227 void Page::set_next_page(Page* page) {
 228   ASSERT(page->owner() == owner());
 229   set_next_chunk(page);
 230 }
 231
 232
 233 void Page::set_prev_page(Page* page) {
 234   ASSERT(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 // Raw allocation.
 254 AllocationResult PagedSpace::AllocateRaw(int size_in_bytes) {
 255   HeapObject* object = AllocateLinearly(size_in_bytes);
 256   if (object != NULL) {
 257     if (identity() == CODE_SPACE) {
 258       SkipList::Update(object->address(), size_in_bytes);
 259     }
 260     return object;
 261   }
 262
 263   ASSERT(!heap()->linear_allocation() ||
 264          (anchor_.next_chunk() == &anchor_ &&
 265           anchor_.prev_chunk() == &anchor_));
 266
 267   object = free_list_.Allocate(size_in_bytes);
 268   if (object != NULL) {
 269     if (identity() == CODE_SPACE) {
 270       SkipList::Update(object->address(), size_in_bytes);
 271     }
 272     return object;
 273   }
 274
 275   object = SlowAllocateRaw(size_in_bytes);
 276   if (object != NULL) {
 277     if (identity() == CODE_SPACE) {
 278       SkipList::Update(object->address(), size_in_bytes);
 279     }
 280     return object;
 281   }
 282
 283   return AllocationResult::Retry(identity());
 284 }
 285
 286
 287 // -----------------------------------------------------------------------------
 288 // NewSpace
 289
 290
 291 AllocationResult NewSpace::AllocateRaw(int size_in_bytes) {
 292   Address old_top = allocation_info_.top();
 293 #ifdef DEBUG
 294   // If we are stressing compaction we waste some memory in new space
 295   // in order to get more frequent GCs.
 296   if (FLAG_stress_compaction && !heap()->linear_allocation()) {
 297     if (allocation_info_.limit() - old_top >= size_in_bytes * 4) {
 298       int filler_size = size_in_bytes * 4;
 299       for (int i = 0; i < filler_size; i += kPointerSize) {
 300         *(reinterpret_cast<Object**>(old_top + i)) =
 301             heap()->one_pointer_filler_map();
 302       }
 303       old_top += filler_size;
 304       allocation_info_.set_top(allocation_info_.top() + filler_size);
 305     }
 306   }
 307 #endif
 308
 309   if (allocation_info_.limit() - old_top < size_in_bytes) {
 310     return SlowAllocateRaw(size_in_bytes);
 311   }
 312
 313   HeapObject* obj = HeapObject::FromAddress(old_top);
 314   allocation_info_.set_top(allocation_info_.top() + size_in_bytes);
 315   ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
 316
 317   return obj;
 318 }
 319
 320
 321 LargePage* LargePage::Initialize(Heap* heap, MemoryChunk* chunk) {
 322   heap->incremental_marking()->SetOldSpacePageFlags(chunk);
 323   return static_cast<LargePage*>(chunk);
 324 }
 325
 326
 327 intptr_t LargeObjectSpace::Available() {
 328   return ObjectSizeFor(heap()->isolate()->memory_allocator()->Available());
 329 }
 330
 331
 332 bool FreeListNode::IsFreeListNode(HeapObject* object) {
 333   Map* map = object->map();
 334   Heap* heap = object->GetHeap();
 335   return map == heap->raw_unchecked_free_space_map()
 336       || map == heap->raw_unchecked_one_pointer_filler_map()
 337       || map == heap->raw_unchecked_two_pointer_filler_map();
 338 }
 339
 340 } }  // namespace v8::internal
 341
 342 #endif  // V8_SPACES_INL_H_