[heap] Remove LocalStoreBuffer and add slots in parallel

src/heap/remembered-set.h

 // Copyright 2016 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.
 
 #ifndef V8_REMEMBERED_SET_H
 #define V8_REMEMBERED_SET_H
 
 #include "src/heap/heap.h"
 #include "src/heap/slot-set.h"
 #include "src/heap/spaces.h"
@@ skipping 221 matching lines @@
       }
     } else {
       DCHECK(!heap->InNewSpace(object));
     }
     return REMOVE_SLOT;
   }
 
   static bool IsValidSlot(Heap* heap, MemoryChunk* chunk, Object** slot);
 };
 
-// Buffer for keeping thead local migration slots during compaction.
-// TODO(ulan): Remove this once every thread gets local pages in compaction
-// space.
-class LocalSlotsBuffer BASE_EMBEDDED {
- public:
-  LocalSlotsBuffer() : top_(new Node(nullptr)) {}
-
-  ~LocalSlotsBuffer() {
-    Node* current = top_;
-    while (current != nullptr) {
-      Node* tmp = current->next;
-      delete current;
-      current = tmp;
-    }
-  }
-
-  void Record(Address addr) {
-    EnsureSpaceFor(1);
-    uintptr_t entry = reinterpret_cast<uintptr_t>(addr);
-    DCHECK_GE(entry, static_cast<uintptr_t>(NUMBER_OF_SLOT_TYPES));
-    Insert(entry);
-  }
-
-  void Record(SlotType type, Address addr) {
-    EnsureSpaceFor(2);
-    Insert(static_cast<uintptr_t>(type));
-    uintptr_t entry = reinterpret_cast<uintptr_t>(addr);
-    DCHECK_GE(entry, static_cast<uintptr_t>(NUMBER_OF_SLOT_TYPES));
-    Insert(entry);
-  }
-
-  template <typename UntypedCallback, typename TypedCallback>
-  void Iterate(UntypedCallback untyped_callback, TypedCallback typed_callback) {
-    Node* current = top_;
-    bool typed = false;
-    SlotType type;
-    Address addr;
-    while (current != nullptr) {
-      for (int i = 0; i < current->count; i++) {
-        uintptr_t entry = current->buffer[i];
-        if (entry < NUMBER_OF_SLOT_TYPES) {
-          DCHECK(!typed);
-          typed = true;
-          type = static_cast<SlotType>(entry);
-        } else {
-          addr = reinterpret_cast<Address>(entry);
-          if (typed) {
-            typed_callback(type, addr);
-            typed = false;
-          } else {
-            untyped_callback(addr);
-          }
-        }
-      }
-      current = current->next;
-    }
-  }
-
- private:
-  void EnsureSpaceFor(int count) {
-    if (top_->remaining_free_slots() < count) top_ = new Node(top_);
-  }
-
-  void Insert(uintptr_t entry) { top_->buffer[top_->count++] = entry; }
-
-  static const int kBufferSize = 16 * KB;
-
-  struct Node : Malloced {
-    explicit Node(Node* next_node) : next(next_node), count(0) {}
-
-    inline int remaining_free_slots() { return kBufferSize - count; }
-
-    Node* next;
-    uintptr_t buffer[kBufferSize];
-    int count;
-  };
-
-  Node* top_;
-};
-
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REMEMBERED_SET_H