Add a generic remembered set class.

src/heap/spaces-inl.h

 // 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.
 
 #ifndef V8_HEAP_SPACES_INL_H_
 #define V8_HEAP_SPACES_INL_H_
 
 #include "src/heap/incremental-marking.h"
 #include "src/heap/spaces.h"
 #include "src/isolate.h"
@@ skipping 278 matching lines @@
 }
 
 bool PagedSpace::Contains(Object* o) {
   if (!o->IsHeapObject()) return false;
   Page* p = Page::FromAddress(HeapObject::cast(o)->address());
   if (!p->is_valid()) return false;
   return p->owner() == this;
 }
 
 MemoryChunk* MemoryChunk::FromAnyPointerAddress(Heap* heap, Address addr) {
-  MemoryChunk* maybe = reinterpret_cast<MemoryChunk*>(
-      OffsetFrom(addr) & ~Page::kPageAlignmentMask);
-  if (maybe->owner() != NULL) return maybe;
-  LargeObjectIterator iterator(heap->lo_space());
-  for (HeapObject* o = iterator.Next(); o != NULL; o = iterator.Next()) {
-    // Fixed arrays are the only pointer-containing objects in large object
-    // space.
-    if (o->IsFixedArray()) {
-      MemoryChunk* chunk = MemoryChunk::FromAddress(o->address());
-      if (chunk->Contains(addr)) {
-        return chunk;
-      }
-    }
+  MemoryChunk* chunk = MemoryChunk::FromAddress(addr);
+  uintptr_t offset = addr - chunk->address();
+  if (offset < MemoryChunk::kHeaderSize || chunk->owner() == nullptr) {

[Hannes Payer (out of office), 2016/02/15 16:53:39]

We already check somewhere else for LO page with owner() == heap->lo_space(). I
think we should add a static check function to large pages that tells us if a
chunk* is a large page.

[ulan, 2016/02/16 10:24:52]

I added HasPageHeader predicate to chunk, which is what we want to test for in
this case.

+    chunk = heap->lo_space()->FindPage(addr);
   }
-  UNREACHABLE();
-  return NULL;
+  return chunk;
+}
+
+Page* Page::FromAnyPointerAddress(Heap* heap, Address addr) {
+  return static_cast<Page*>(MemoryChunk::FromAnyPointerAddress(heap, addr));
 }
 
 
 PointerChunkIterator::PointerChunkIterator(Heap* heap)
     : state_(kOldSpaceState),
       old_iterator_(heap->old_space()),
       map_iterator_(heap->map_space()),
       lo_iterator_(heap->lo_space()) {}
 
 
@@ skipping 286 matching lines @@
     other->allocation_info_.Reset(nullptr, nullptr);
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_INL_H_