[heap] Remove unswept bytes counter

src/heap/spaces.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/spaces.h"
 
 #include "src/base/bits.h"
 #include "src/base/platform/platform.h"
 #include "src/full-codegen/full-codegen.h"
 #include "src/heap/slots-buffer.h"
@@ skipping 906 matching lines @@
   return false;
 }
 
 
 // -----------------------------------------------------------------------------
 // MemoryChunk implementation
 
 void MemoryChunk::IncrementLiveBytesFromMutator(HeapObject* object, int by) {
   MemoryChunk* chunk = MemoryChunk::FromAddress(object->address());
   if (!chunk->InNewSpace() && !static_cast<Page*>(chunk)->WasSwept()) {
-    static_cast<PagedSpace*>(chunk->owner())->IncrementUnsweptFreeBytes(-by);
+    static_cast<PagedSpace*>(chunk->owner())->Allocate(by);
   }
   chunk->IncrementLiveBytes(by);
 }
 
 
 void MemoryChunk::ReleaseAllocatedMemory() {
   delete slots_buffer_;
   delete skip_list_;
   delete mutex_;
 }
 
 
 // -----------------------------------------------------------------------------
 // PagedSpace implementation
 
 STATIC_ASSERT(static_cast<ObjectSpace>(1 << AllocationSpace::NEW_SPACE) ==
               ObjectSpace::kObjectSpaceNewSpace);
 STATIC_ASSERT(static_cast<ObjectSpace>(1 << AllocationSpace::OLD_SPACE) ==
               ObjectSpace::kObjectSpaceOldSpace);
 STATIC_ASSERT(static_cast<ObjectSpace>(1 << AllocationSpace::CODE_SPACE) ==
               ObjectSpace::kObjectSpaceCodeSpace);
 STATIC_ASSERT(static_cast<ObjectSpace>(1 << AllocationSpace::MAP_SPACE) ==
               ObjectSpace::kObjectSpaceMapSpace);
 
 
 PagedSpace::PagedSpace(Heap* heap, AllocationSpace space,
                        Executability executable)
     : Space(heap, space, executable),
       free_list_(this),
-      unswept_free_bytes_(0),
       end_of_unswept_pages_(NULL) {
   area_size_ = MemoryAllocator::PageAreaSize(space);
   accounting_stats_.Clear();
 
   allocation_info_.set_top(NULL);
   allocation_info_.set_limit(NULL);
 
   anchor_.InitializeAsAnchor(this);
 }
 
@@ skipping 17 matching lines @@
 
 void PagedSpace::MoveOverFreeMemory(PagedSpace* other) {
   DCHECK(identity() == other->identity());
   // Destroy the linear allocation space of {other}. This is needed to
   //   (a) not waste the memory and
   //   (b) keep the rest of the chunk in an iterable state (filler is needed).
   other->EmptyAllocationInfo();
 
   // Move over the free list. Concatenate makes sure that the source free list
   // gets properly reset after moving over all nodes.
-  intptr_t freed_bytes = free_list_.Concatenate(other->free_list());
+  intptr_t added = free_list_.Concatenate(other->free_list());
 
   // Moved memory is not recorded as allocated memory, but rather increases and
   // decreases capacity of the corresponding spaces. Used size and waste size
   // are maintained by the receiving space upon allocating and freeing blocks.
-  other->accounting_stats_.DecreaseCapacity(freed_bytes);
-  accounting_stats_.IncreaseCapacity(freed_bytes);
+  other->accounting_stats_.DecreaseCapacity(added);
+  accounting_stats_.IncreaseCapacity(added);
 }
 
 
 void PagedSpace::MergeCompactionSpace(CompactionSpace* other) {
   // Unmerged fields:
   //   area_size_
   //   allocation_info_
   //   end_of_unswept_pages_
   //   unswept_free_bytes_
   //   anchor_
@@ skipping 123 matching lines @@
 
 
 void PagedSpace::ReleasePage(Page* page) {
   DCHECK(page->LiveBytes() == 0);
   DCHECK(AreaSize() == page->area_size());
 
   if (page->WasSwept()) {
     intptr_t size = free_list_.EvictFreeListItems(page);
     accounting_stats_.AllocateBytes(size);
     DCHECK_EQ(AreaSize(), static_cast<int>(size));
-  } else {
-    DecreaseUnsweptFreeBytes(page);
   }
 
   if (page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE)) {
     heap()->decrement_scan_on_scavenge_pages();
     page->ClearFlag(MemoryChunk::SCAN_ON_SCAVENGE);
   }
 
   DCHECK(!free_list_.ContainsPageFreeListItems(page));
 
   if (Page::FromAllocationTop(allocation_info_.top()) == page) {
@@ skipping 1087 matching lines @@
       wasted_bytes_(0),
       small_list_(this, kSmall),
       medium_list_(this, kMedium),
       large_list_(this, kLarge),
       huge_list_(this, kHuge) {
   Reset();
 }
 
 
 intptr_t FreeList::Concatenate(FreeList* other) {
-  intptr_t free_bytes = 0;
+  intptr_t usable_bytes = 0;
+  intptr_t wasted_bytes = 0;
 
   // This is safe (not going to deadlock) since Concatenate operations
   // are never performed on the same free lists at the same time in
   // reverse order. Furthermore, we only lock if the PagedSpace containing
   // the free list is know to be globally available, i.e., not local.
   if (!owner()->is_local()) mutex_.Lock();
   if (!other->owner()->is_local()) other->mutex()->Lock();
 
-  wasted_bytes_ += other->wasted_bytes_;
+  wasted_bytes = other->wasted_bytes_;
+  wasted_bytes_ += wasted_bytes;
   other->wasted_bytes_ = 0;
 
-  free_bytes += small_list_.Concatenate(other->small_list());
-  free_bytes += medium_list_.Concatenate(other->medium_list());
-  free_bytes += large_list_.Concatenate(other->large_list());
-  free_bytes += huge_list_.Concatenate(other->huge_list());
+  usable_bytes += small_list_.Concatenate(other->small_list());
+  usable_bytes += medium_list_.Concatenate(other->medium_list());
+  usable_bytes += large_list_.Concatenate(other->large_list());
+  usable_bytes += huge_list_.Concatenate(other->huge_list());
 
   if (!other->owner()->is_local()) other->mutex()->Unlock();
   if (!owner()->is_local()) mutex_.Unlock();
-  return free_bytes;
+  return usable_bytes + wasted_bytes;
 }
 
 
 void FreeList::Reset() {
   small_list_.Reset();
   medium_list_.Reset();
   large_list_.Reset();
   huge_list_.Reset();
   ResetStats();
 }
@@ skipping 264 matching lines @@
 
 
 // -----------------------------------------------------------------------------
 // OldSpace implementation
 
 void PagedSpace::PrepareForMarkCompact() {
   // We don't have a linear allocation area while sweeping.  It will be restored
   // on the first allocation after the sweep.
   EmptyAllocationInfo();
 
-  // This counter will be increased for pages which will be swept by the
-  // sweeper threads.
-  unswept_free_bytes_ = 0;
-
   // Clear the free list before a full GC---it will be rebuilt afterward.
   free_list_.Reset();
 }
 
 
 intptr_t PagedSpace::SizeOfObjects() {
-  DCHECK(!FLAG_concurrent_sweeping ||
-         heap()->mark_compact_collector()->sweeping_in_progress() ||
-         (unswept_free_bytes_ == 0));
-  const intptr_t size = Size() - unswept_free_bytes_ - (limit() - top());
+  const intptr_t size = Size() - (limit() - top());
   DCHECK_GE(size, 0);
   USE(size);
   return size;
 }
 
 
 // After we have booted, we have created a map which represents free space
 // on the heap.  If there was already a free list then the elements on it
 // were created with the wrong FreeSpaceMap (normally NULL), so we need to
 // fix them.
@@ skipping 582 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 }  // namespace internal
 }  // namespace v8