[heap] Scalable slots buffer for parallel compaction.

src/heap/slots-buffer.cc

 // Copyright 2015 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/slots-buffer.h"
 
 #include "src/assembler.h"
 #include "src/heap/heap.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 bool SlotsBuffer::IsTypedSlot(ObjectSlot slot) {
   return reinterpret_cast<uintptr_t>(slot) < NUMBER_OF_SLOT_TYPES;
 }
 
 
-bool SlotsBuffer::AddToSynchronized(SlotsBufferAllocator* allocator,
-                                    SlotsBuffer** buffer_address,
-                                    base::Mutex* buffer_mutex, SlotType type,
-                                    Address addr, AdditionMode mode) {
-  base::LockGuard<base::Mutex> lock_guard(buffer_mutex);
-  return AddTo(allocator, buffer_address, type, addr, mode);
-}
-
-
 bool SlotsBuffer::AddTo(SlotsBufferAllocator* allocator,
                         SlotsBuffer** buffer_address, SlotType type,
                         Address addr, AdditionMode mode) {
   SlotsBuffer* buffer = *buffer_address;
   if (buffer == NULL || !buffer->HasSpaceForTypedSlot()) {
     if (mode == FAIL_ON_OVERFLOW && ChainLengthThresholdReached(buffer)) {
       allocator->DeallocateChain(buffer_address);
       return false;
     }
     buffer = allocator->AllocateBuffer(buffer);
@@ skipping 123 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 }  // namespace internal
 }  // namespace v8