[heap] Concurrently free empty slot set buckets.

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 <utility>
 
 #include "src/base/bits.h"
 #include "src/base/platform/platform.h"
@@ skipping 490 matching lines @@
 
   DCHECK(base == chunk->address());
 
   chunk->heap_ = heap;
   chunk->size_ = size;
   chunk->area_start_ = area_start;
   chunk->area_end_ = area_end;
   chunk->flags_ = Flags(NO_FLAGS);
   chunk->set_owner(owner);
   chunk->InitializeReservedMemory();
-  chunk->old_to_new_slots_ = nullptr;
+  chunk->old_to_new_slots_.SetValue(nullptr);
   chunk->old_to_old_slots_ = nullptr;
   chunk->typed_old_to_new_slots_.SetValue(nullptr);
   chunk->typed_old_to_old_slots_ = nullptr;
   chunk->skip_list_ = nullptr;
   chunk->write_barrier_counter_ = kWriteBarrierCounterGranularity;
   chunk->progress_bar_ = 0;
   chunk->high_water_mark_.SetValue(static_cast<intptr_t>(area_start - base));
   chunk->concurrent_sweeping_state().SetValue(kSweepingDone);
   chunk->mutex_ = new base::Mutex();
   chunk->available_in_free_list_ = 0;
@@ skipping 546 matching lines @@
 
 void MemoryChunk::ReleaseAllocatedMemory() {
   if (skip_list_ != nullptr) {
     delete skip_list_;
     skip_list_ = nullptr;
   }
   if (mutex_ != nullptr) {
     delete mutex_;
     mutex_ = nullptr;
   }
-  if (old_to_new_slots_ != nullptr) ReleaseOldToNewSlots();
+  if (old_to_new_slots_.Value() != nullptr) ReleaseOldToNewSlots();
   if (old_to_old_slots_ != nullptr) ReleaseOldToOldSlots();
   if (typed_old_to_new_slots_.Value() != nullptr) ReleaseTypedOldToNewSlots();
   if (typed_old_to_old_slots_ != nullptr) ReleaseTypedOldToOldSlots();
   if (local_tracker_ != nullptr) ReleaseLocalTracker();
 }
 
 static SlotSet* AllocateSlotSet(size_t size, Address page_start) {
   size_t pages = (size + Page::kPageSize - 1) / Page::kPageSize;
   DCHECK(pages > 0);
   SlotSet* slot_set = new SlotSet[pages];
   for (size_t i = 0; i < pages; i++) {
     slot_set[i].SetPageStart(page_start + i * Page::kPageSize);
   }
   return slot_set;
 }
 
 void MemoryChunk::AllocateOldToNewSlots() {
-  DCHECK(nullptr == old_to_new_slots_);
-  old_to_new_slots_ = AllocateSlotSet(size_, address());
+  DCHECK(nullptr == old_to_new_slots_.Value());
+  old_to_new_slots_.SetValue(AllocateSlotSet(size_, address()));
 }
 
 void MemoryChunk::ReleaseOldToNewSlots() {
-  delete[] old_to_new_slots_;
-  old_to_new_slots_ = nullptr;
+  SlotSet* old_to_new_slots = old_to_new_slots_.Value();
+  delete[] old_to_new_slots;
+  old_to_new_slots_.SetValue(nullptr);
 }
 
 void MemoryChunk::AllocateOldToOldSlots() {
   DCHECK(nullptr == old_to_old_slots_);
   old_to_old_slots_ = AllocateSlotSet(size_, address());
 }
 
 void MemoryChunk::ReleaseOldToOldSlots() {
   delete[] old_to_old_slots_;
   old_to_old_slots_ = nullptr;
@@ skipping 2126 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 }  // namespace internal
 }  // namespace v8