Revert of "[heap] Divide available memory upon compaction tasks"

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 520a4060ca4c8280bc324f1c17228254e0c0a06b..ea41b43a766e881a519ba93678d819ee36f65fef 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -982,101 +982,6 @@
 }
 
 
-void PagedSpace::AddMemory(Address start, intptr_t size) {
-  accounting_stats_.ExpandSpace(static_cast<int>(size));
-  Free(start, static_cast<int>(size));
-}
-
-
-FreeSpace* PagedSpace::TryRemoveMemory(intptr_t size_in_bytes) {
-  FreeSpace* free_space = free_list()->TryRemoveMemory(size_in_bytes);
-  if (free_space != nullptr) {
-    accounting_stats_.DecreaseCapacity(free_space->size());
-  }
-  return free_space;
-}
-
-
-void PagedSpace::DivideUponCompactionSpaces(CompactionSpaceCollection** other,
-                                            int num, intptr_t limit) {
-  DCHECK_GT(num, 0);
-  DCHECK(other != nullptr);
-
-  if (limit == 0) limit = std::numeric_limits<intptr_t>::max();
-
-  EmptyAllocationInfo();
-
-  bool memory_available = true;
-  bool spaces_need_memory = true;
-  FreeSpace* node = nullptr;
-  CompactionSpace* current_space = nullptr;
-  // Iterate over spaces and memory as long as we have memory and there are
-  // spaces in need of some.
-  while (memory_available && spaces_need_memory) {
-    spaces_need_memory = false;
-    // Round-robin over all spaces.
-    for (int i = 0; i < num; i++) {
-      current_space = other[i]->Get(identity());
-      if (current_space->free_list()->Available() < limit) {
-        // Space has not reached its limit. Try to get some memory.
-        spaces_need_memory = true;
-        node = TryRemoveMemory(limit - current_space->free_list()->Available());
-        if (node != nullptr) {
-          CHECK(current_space->identity() == identity());
-          current_space->AddMemory(node->address(), node->size());
-        } else {
-          memory_available = false;
-          break;
-        }
-      }
-    }
-  }
-}
-
-
-void PagedSpace::RefillFreeList() {
-  MarkCompactCollector* collector = heap()->mark_compact_collector();
-  FreeList* free_list = nullptr;
-  if (this == heap()->old_space()) {
-    free_list = collector->free_list_old_space().get();
-  } else if (this == heap()->code_space()) {
-    free_list = collector->free_list_code_space().get();
-  } else if (this == heap()->map_space()) {
-    free_list = collector->free_list_map_space().get();
-  } else {
-    // Any PagedSpace might invoke RefillFreeList. We filter all but our old
-    // generation spaces out.
-    return;
-  }
-  DCHECK(free_list != nullptr);
-  intptr_t added = free_list_.Concatenate(free_list);
-  accounting_stats_.IncreaseCapacity(added);
-}
-
-
-void CompactionSpace::RefillFreeList() {
-  MarkCompactCollector* collector = heap()->mark_compact_collector();
-  FreeList* free_list = nullptr;
-  if (identity() == OLD_SPACE) {
-    free_list = collector->free_list_old_space().get();
-  } else if (identity() == CODE_SPACE) {
-    free_list = collector->free_list_code_space().get();
-  } else {
-    // Compaction spaces only represent old or code space.
-    UNREACHABLE();
-  }
-  DCHECK(free_list != nullptr);
-  intptr_t refilled = 0;
-  while (refilled < kCompactionMemoryWanted) {
-    FreeSpace* node =
-        free_list->TryRemoveMemory(kCompactionMemoryWanted - refilled);
-    if (node == nullptr) return;
-    refilled += node->size();
-    AddMemory(node->address(), node->size());
-  }
-}
-
-
 void PagedSpace::MoveOverFreeMemory(PagedSpace* other) {
   DCHECK(identity() == other->identity());
   // Destroy the linear allocation space of {other}. This is needed to
@@ -1089,7 +994,8 @@
   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.
+  // 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(added);
   accounting_stats_.IncreaseCapacity(added);
 }
@@ -1098,19 +1004,16 @@
 void PagedSpace::MergeCompactionSpace(CompactionSpace* other) {
   // Unmerged fields:
   //   area_size_
+  //   allocation_info_
+  //   end_of_unswept_pages_
+  //   unswept_free_bytes_
   //   anchor_
 
   MoveOverFreeMemory(other);
 
   // Update and clear accounting statistics.
   accounting_stats_.Merge(other->accounting_stats_);
-  other->accounting_stats_.Clear();
-
-  // The linear allocation area of {other} should be destroyed now.
-  DCHECK(other->top() == nullptr);
-  DCHECK(other->limit() == nullptr);
-
-  DCHECK(other->end_of_unswept_pages_ == nullptr);
+  other->accounting_stats_.Reset();
 
   AccountCommitted(other->CommittedMemory());
 
@@ -2477,37 +2380,6 @@
 }
 
 
-FreeSpace* FreeList::TryRemoveMemory(intptr_t hint_size_in_bytes) {
-  hint_size_in_bytes = RoundDown(hint_size_in_bytes, kPointerSize);
-  base::LockGuard<base::Mutex> guard(&mutex_);
-  FreeSpace* node = nullptr;
-  int node_size = 0;
-  // Try to find a node that fits exactly.
-  node = FindNodeFor(static_cast<int>(hint_size_in_bytes), &node_size);
-  // If no node could be found get as much memory as possible.
-  if (node == nullptr) node = FindNodeIn(kHuge, &node_size);
-  if (node == nullptr) node = FindNodeIn(kLarge, &node_size);
-  if (node != nullptr) {
-    // We round up the size to (kSmallListMin + 1) to (a) have a size larger
-    // then the minimum size required for FreeSpace, and (b) to get a block
-    // that can actually be freed into some FreeList later on.
-    if (hint_size_in_bytes <= kSmallListMin) {
-      hint_size_in_bytes = kSmallListMin + 1;
-    }
-    // Give back left overs that were not required by {size_in_bytes}.
-    intptr_t left_over = node_size - hint_size_in_bytes;
-
-    // Do not bother to return anything below {kSmallListMin} as it would be
-    // immediately discarded anyways.
-    if (left_over > kSmallListMin) {
-      Free(node->address() + hint_size_in_bytes, static_cast<int>(left_over));
-      node->set_size(static_cast<int>(hint_size_in_bytes));
-    }
-  }
-  return node;
-}
-
-
 // Allocation on the old space free list.  If it succeeds then a new linear
 // allocation space has been set up with the top and limit of the space.  If
 // the allocation fails then NULL is returned, and the caller can perform a GC
@@ -2736,7 +2608,7 @@
   if (collector->sweeping_in_progress()) {
     // First try to refill the free-list, concurrent sweeper threads
     // may have freed some objects in the meantime.
-    RefillFreeList();
+    collector->RefillFreeList(this);
 
     // Retry the free list allocation.
     HeapObject* object = free_list_.Allocate(size_in_bytes);
@@ -2744,7 +2616,7 @@
 
     // If sweeping is still in progress try to sweep pages on the main thread.
     int free_chunk = collector->SweepInParallel(this, size_in_bytes);
-    RefillFreeList();
+    collector->RefillFreeList(this);
     if (free_chunk >= size_in_bytes) {
       HeapObject* object = free_list_.Allocate(size_in_bytes);
       // We should be able to allocate an object here since we just freed that