Replace slots buffer with remembered set.

test/unittests/heap/slot-set-unittest.cc

 // 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.
 
 #include <limits>
 
 #include "src/globals.h"
 #include "src/heap/slot-set.h"
 #include "src/heap/spaces.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 37 matching lines @@
   set.SetPageStart(0);
   for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
     if (i % 7 == 0) {
       set.Insert(i);
     }
   }
 
   set.Iterate([](Address slot_address) {
     uintptr_t intaddr = reinterpret_cast<uintptr_t>(slot_address);
     if (intaddr % 3 == 0) {
-      return SlotSet::KEEP_SLOT;
+      return KEEP_SLOT;
     } else {
-      return SlotSet::REMOVE_SLOT;
+      return REMOVE_SLOT;
     }
   });
 
   for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
     if (i % 21 == 0) {
       EXPECT_TRUE(set.Lookup(i));
     } else {
       EXPECT_FALSE(set.Lookup(i));
     }
   }
@@ skipping 61 matching lines @@
   }
   SlotSet set;
   set.SetPageStart(0);
   set.Insert(Page::kPageSize / 2);
   set.RemoveRange(0, Page::kPageSize);
   for (uint32_t i = 0; i < Page::kPageSize; i += kPointerSize) {
     EXPECT_FALSE(set.Lookup(i));
   }
 }
 
+TEST(TypedSlotSet, Iterate) {
+  TypedSlotSet set(0);
+  const int kDelta = 10000001;
+  int added = 0;
+  for (uint32_t i = 0; i < TypedSlotSet::kMaxOffset; i += kDelta) {
+    SlotType type = static_cast<SlotType>(i % NUMBER_OF_SLOT_TYPES);
+    set.Insert(type, i);
+    ++added;
+  }
+  int iterated = 0;
+  set.Iterate([&iterated, kDelta](SlotType type, Address addr) {
+    uint32_t i = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(addr));
+    EXPECT_EQ(i % NUMBER_OF_SLOT_TYPES, static_cast<uint32_t>(type));
+    EXPECT_EQ(0, i % kDelta);
+    ++iterated;
+    return i % 2 == 0 ? KEEP_SLOT : REMOVE_SLOT;
+  });
+  EXPECT_EQ(added, iterated);
+  iterated = 0;
+  set.Iterate([&iterated](SlotType type, Address addr) {
+    uint32_t i = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(addr));
+    EXPECT_EQ(0, i % 2);
+    ++iterated;
+    return KEEP_SLOT;
+  });
+  EXPECT_EQ(added / 2, iterated);
+}
+
 }  // namespace internal
 }  // namespace v8