Revert "[heap] Make SlotSet allocation thread-safe and refactor code."

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 5202200bf75874621776337c2e89824a9382de6c..d322916a5dc0a9cbc2957f961f407f11976d32b2 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -527,10 +527,10 @@ MemoryChunk* MemoryChunk::Initialize(Heap* heap, Address base, size_t size,
   chunk->flags_ = Flags(NO_FLAGS);
   chunk->set_owner(owner);
   chunk->InitializeReservedMemory();
-  chunk->slot_set_[OLD_TO_NEW].SetValue(nullptr);
-  chunk->slot_set_[OLD_TO_OLD].SetValue(nullptr);
-  chunk->typed_slot_set_[OLD_TO_NEW].SetValue(nullptr);
-  chunk->typed_slot_set_[OLD_TO_OLD].SetValue(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->progress_bar_ = 0;
   chunk->high_water_mark_.SetValue(static_cast<intptr_t>(area_start - base));
@@ -1114,15 +1114,15 @@ void MemoryChunk::ReleaseAllocatedMemory() {
     delete mutex_;
     mutex_ = nullptr;
   }
-  ReleaseSlotSet<OLD_TO_NEW>();
-  ReleaseSlotSet<OLD_TO_OLD>();
-  ReleaseTypedSlotSet<OLD_TO_NEW>();
-  ReleaseTypedSlotSet<OLD_TO_OLD>();
+  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();
   if (young_generation_bitmap_ != nullptr) ReleaseYoungGenerationBitmap();
 }
 
-static SlotSet* AllocateAndInitializeSlotSet(size_t size, Address page_start) {
+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];
@@ -1132,58 +1132,46 @@ static SlotSet* AllocateAndInitializeSlotSet(size_t size, Address page_start) {
   return slot_set;
 }
 
-template SlotSet* MemoryChunk::AllocateSlotSet<OLD_TO_NEW>();
-template SlotSet* MemoryChunk::AllocateSlotSet<OLD_TO_OLD>();
+void MemoryChunk::AllocateOldToNewSlots() {
+  DCHECK(nullptr == old_to_new_slots_.Value());
+  old_to_new_slots_.SetValue(AllocateSlotSet(size_, address()));
+}
 
-template <RememberedSetType type>
-SlotSet* MemoryChunk::AllocateSlotSet() {
-  SlotSet* slot_set = AllocateAndInitializeSlotSet(size_, address());
-  if (!slot_set_[type].TrySetValue(nullptr, slot_set)) {
-    delete[] slot_set;
-    slot_set = slot_set_[type].Value();
-    DCHECK(slot_set);
-    return slot_set;
-  }
-  return slot_set;
+void MemoryChunk::ReleaseOldToNewSlots() {
+  SlotSet* old_to_new_slots = old_to_new_slots_.Value();
+  delete[] old_to_new_slots;
+  old_to_new_slots_.SetValue(nullptr);
 }
 
-template void MemoryChunk::ReleaseSlotSet<OLD_TO_NEW>();
-template void MemoryChunk::ReleaseSlotSet<OLD_TO_OLD>();
+void MemoryChunk::AllocateOldToOldSlots() {
+  DCHECK(nullptr == old_to_old_slots_);
+  old_to_old_slots_ = AllocateSlotSet(size_, address());
+}
 
-template <RememberedSetType type>
-void MemoryChunk::ReleaseSlotSet() {
-  SlotSet* slot_set = slot_set_[type].Value();
-  if (slot_set) {
-    delete[] slot_set;
-    slot_set_[type].SetValue(nullptr);
-  }
+void MemoryChunk::ReleaseOldToOldSlots() {
+  delete[] old_to_old_slots_;
+  old_to_old_slots_ = nullptr;
 }
 
-template TypedSlotSet* MemoryChunk::AllocateTypedSlotSet<OLD_TO_NEW>();
-template TypedSlotSet* MemoryChunk::AllocateTypedSlotSet<OLD_TO_OLD>();
+void MemoryChunk::AllocateTypedOldToNewSlots() {
+  DCHECK(nullptr == typed_old_to_new_slots_.Value());
+  typed_old_to_new_slots_.SetValue(new TypedSlotSet(address()));
+}
 
-template <RememberedSetType type>
-TypedSlotSet* MemoryChunk::AllocateTypedSlotSet() {
-  TypedSlotSet* slot_set = new TypedSlotSet(address());
-  if (!typed_slot_set_[type].TrySetValue(nullptr, slot_set)) {
-    delete slot_set;
-    slot_set = typed_slot_set_[type].Value();
-    DCHECK(slot_set);
-    return slot_set;
-  }
-  return slot_set;
+void MemoryChunk::ReleaseTypedOldToNewSlots() {
+  TypedSlotSet* typed_old_to_new_slots = typed_old_to_new_slots_.Value();
+  delete typed_old_to_new_slots;
+  typed_old_to_new_slots_.SetValue(nullptr);
 }
 
-template void MemoryChunk::ReleaseTypedSlotSet<OLD_TO_NEW>();
-template void MemoryChunk::ReleaseTypedSlotSet<OLD_TO_OLD>();
+void MemoryChunk::AllocateTypedOldToOldSlots() {
+  DCHECK(nullptr == typed_old_to_old_slots_);
+  typed_old_to_old_slots_ = new TypedSlotSet(address());
+}
 
-template <RememberedSetType type>
-void MemoryChunk::ReleaseTypedSlotSet() {
-  TypedSlotSet* typed_slot_set = typed_slot_set_[type].Value();
-  if (typed_slot_set) {
-    delete typed_slot_set;
-    typed_slot_set_[type].SetValue(nullptr);
-  }
+void MemoryChunk::ReleaseTypedOldToOldSlots() {
+  delete typed_old_to_old_slots_;
+  typed_old_to_old_slots_ = nullptr;
 }
 
 void MemoryChunk::AllocateLocalTracker() {