Reland "Remove the weak list of views from array buffers"

src/heap/objects-visiting.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/v8.h"
 
 #include "src/heap/objects-visiting.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 225 matching lines @@
 
   // Terminate the list if there is one or more elements.
   if (tail != NULL) {
     WeakListVisitor<T>::SetWeakNext(tail, undefined);
     if (list_tail) *list_tail = tail;
   }
   return head;
 }
 
 
-Object* VisitNewArrayBufferViewsWeakList(Heap* heap, Object* list,
-                                         WeakObjectRetainer* retainer) {
-  Object* undefined = heap->undefined_value();
-  Object* previous = undefined;
-  Object* head = undefined;
-  Object* next;
-  MarkCompactCollector* collector = heap->mark_compact_collector();
-  bool record_slots = MustRecordSlots(heap);
-
-  for (Object* o = list; o != undefined;) {
-    JSArrayBufferView* view = JSArrayBufferView::cast(o);
-    next = view->weak_next();
-    if (!heap->InNewSpace(view)) {
-      if (previous != undefined) {
-        // We are in the middle of the list, skip the old space element.
-        JSArrayBufferView* previous_view = JSArrayBufferView::cast(previous);
-        previous_view->set_weak_next(next);
-        if (record_slots) {
-          Object** next_slot = HeapObject::RawField(
-              previous_view, JSArrayBufferView::kWeakNextOffset);
-          collector->RecordSlot(next_slot, next_slot, next);
-        }
-      }
-      JSArrayBuffer* buffer = JSArrayBuffer::cast(view->buffer());
-      view->set_weak_next(buffer->weak_first_view());
-      if (record_slots) {
-        Object** next_slot =
-            HeapObject::RawField(view, JSArrayBufferView::kWeakNextOffset);
-        collector->RecordSlot(next_slot, next_slot, buffer->weak_first_view());
-      }
-      buffer->set_weak_first_view(view);
-      if (record_slots) {
-        Object** slot =
-            HeapObject::RawField(buffer, JSArrayBuffer::kWeakFirstViewOffset);
-        heap->mark_compact_collector()->RecordSlot(slot, slot, view);
-      }
-    } else {
-      // We found a valid new space view, remember it.
-      previous = view;
-      if (head == undefined) {
-        // We are at the list head.
-        head = view;
-      }
-    }
-    o = next;
-  }
-  return head;
-}
-
-
 template <class T>
 static void ClearWeakList(Heap* heap, Object* list) {
   Object* undefined = heap->undefined_value();
   while (list != undefined) {
     T* candidate = reinterpret_cast<T*>(list);
     list = WeakListVisitor<T>::WeakNext(candidate);
     WeakListVisitor<T>::SetWeakNext(candidate, undefined);
   }
 }
 
@@ skipping 82 matching lines @@
   static void VisitPhantomObject(Heap* heap, Context* context) {
     ClearWeakList<JSFunction>(heap,
                               context->get(Context::OPTIMIZED_FUNCTIONS_LIST));
     ClearWeakList<Code>(heap, context->get(Context::OPTIMIZED_CODE_LIST));
     ClearWeakList<Code>(heap, context->get(Context::DEOPTIMIZED_CODE_LIST));
   }
 };
 
 
 template <>
-struct WeakListVisitor<JSArrayBufferView> {
-  static void SetWeakNext(JSArrayBufferView* obj, Object* next) {
-    obj->set_weak_next(next);
-  }
-
-  static Object* WeakNext(JSArrayBufferView* obj) { return obj->weak_next(); }
-
-  static int WeakNextOffset() { return JSArrayBufferView::kWeakNextOffset; }
-
-  static void VisitLiveObject(Heap*, JSArrayBufferView*, WeakObjectRetainer*) {}
-
-  static void VisitPhantomObject(Heap*, JSArrayBufferView*) {}
-};
-
-
-template <>
 struct WeakListVisitor<JSArrayBuffer> {
   static void SetWeakNext(JSArrayBuffer* obj, Object* next) {
     obj->set_weak_next(next);
   }
 
   static Object* WeakNext(JSArrayBuffer* obj) { return obj->weak_next(); }
 
   static int WeakNextOffset() { return JSArrayBuffer::kWeakNextOffset; }
 
   static void VisitLiveObject(Heap* heap, JSArrayBuffer* array_buffer,
                               WeakObjectRetainer* retainer) {
-    Object* typed_array_obj = VisitWeakList<JSArrayBufferView>(
-        heap, array_buffer->weak_first_view(), retainer, false, NULL);
-    array_buffer->set_weak_first_view(typed_array_obj);
-    if (typed_array_obj != heap->undefined_value() && MustRecordSlots(heap)) {
-      Object** slot = HeapObject::RawField(array_buffer,
-                                           JSArrayBuffer::kWeakFirstViewOffset);
-      heap->mark_compact_collector()->RecordSlot(slot, slot, typed_array_obj);
-    }
   }
 
   static void VisitPhantomObject(Heap* heap, JSArrayBuffer* phantom) {
     Runtime::FreeArrayBuffer(heap->isolate(), phantom);
   }
 };
 
 
 template <>
 struct WeakListVisitor<AllocationSite> {
@@ skipping 15 matching lines @@
                                         WeakObjectRetainer* retainer,
                                         bool stop_after_young,
                                         Object** list_tail);
 
 
 template Object* VisitWeakList<JSArrayBuffer>(Heap* heap, Object* list,
                                               WeakObjectRetainer* retainer,
                                               bool stop_after_young,
                                               Object** list_tail);
 
-template Object* VisitWeakList<JSArrayBufferView>(Heap* heap, Object* list,
-                                                  WeakObjectRetainer* retainer,
-                                                  bool stop_after_young,
-                                                  Object** list_tail);
-
 template Object* VisitWeakList<AllocationSite>(Heap* heap, Object* list,
                                                WeakObjectRetainer* retainer,
                                                bool stop_after_young,
                                                Object** list_tail);
 }
 }  // namespace v8::internal