[heap] Fix mark bits for partially compacted pages.

test/unittests/heap/bitmap-unittest.cc

+// Copyright 2015 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/heap/spaces.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using v8::internal::Bitmap;
+
+class BitmapTest : public ::testing::Test {
+ public:
+  static const uint32_t kBlackCell;
+  static const uint32_t kWhiteCell;
+  static const uint32_t kBlackByte;
+  static const uint32_t kWhiteByte;
+
+  BitmapTest() : memory_(new uint8_t[Bitmap::kSize]) {
+    memset(memory_, 0, Bitmap::kSize);
+  }
+
+  virtual ~BitmapTest() { delete[] memory_; }
+
+  Bitmap* bitmap() { return reinterpret_cast<Bitmap*>(memory_); }
+  uint8_t* raw_bitmap() { return memory_; }
+
+ private:
+  uint8_t* memory_;
+};
+
+
+const uint32_t BitmapTest::kBlackCell = 0xAAAAAAAA;
+const uint32_t BitmapTest::kWhiteCell = 0x00000000;
+const uint32_t BitmapTest::kBlackByte = 0xAA;
+const uint32_t BitmapTest::kWhiteByte = 0x00;
+
+
+TEST_F(BitmapTest, IsZeroInitialized) {
+  // We require all tests to start from a zero-initialized bitmap. Manually
+  // verify this invariant here.
+  for (size_t i = 0; i < Bitmap::kSize; i++) {
+    EXPECT_EQ(raw_bitmap()[i], kWhiteByte);
+  }
+}
+
+
+TEST_F(BitmapTest, Cells) {
+  Bitmap* bm = bitmap();
+  bm->cells()[1] = kBlackCell;
+  uint8_t* raw = raw_bitmap();
+  int second_cell_base = Bitmap::kBytesPerCell;
+  for (size_t i = 0; i < Bitmap::kBytesPerCell; i++) {
+    EXPECT_EQ(raw[second_cell_base + i], kBlackByte);
+  }
+}
+
+
+TEST_F(BitmapTest, CellsCount) {
+  int last_cell_index = bitmap()->CellsCount() - 1;
+  bitmap()->cells()[last_cell_index] = kBlackCell;
+  // Manually verify on raw memory.
+  uint8_t* raw = raw_bitmap();
+  for (size_t i = 0; i < Bitmap::kSize; i++) {
+    // Last cell should be set.
+    if (i >= (Bitmap::kSize - Bitmap::kBytesPerCell)) {
+      EXPECT_EQ(raw[i], kBlackByte);
+    } else {
+      EXPECT_EQ(raw[i], kWhiteByte);
+    }
+  }
+}
+
+
+TEST_F(BitmapTest, IsClean) {
+  Bitmap* bm = bitmap();
+  EXPECT_TRUE(bm->IsClean());
+  bm->cells()[0] = kBlackCell;
+  EXPECT_FALSE(bm->IsClean());
+}
+
+
+TEST_F(BitmapTest, ClearRange1) {
+  Bitmap* bm = bitmap();
+  bm->cells()[0] = kBlackCell;
+  bm->cells()[1] = kBlackCell;
+  bm->cells()[2] = kBlackCell;
+  bm->ClearRange(0, Bitmap::kBitsPerCell + Bitmap::kBitsPerCell / 2);
+  EXPECT_EQ(bm->cells()[0], kWhiteCell);
+  EXPECT_EQ(bm->cells()[1], 0xAAAA0000);
+  EXPECT_EQ(bm->cells()[2], kBlackCell);
+}
+
+
+TEST_F(BitmapTest, ClearRange2) {
+  Bitmap* bm = bitmap();
+  bm->cells()[0] = kBlackCell;
+  bm->cells()[1] = kBlackCell;
+  bm->cells()[2] = kBlackCell;
+  bm->ClearRange(Bitmap::kBitsPerCell,
+                 Bitmap::kBitsPerCell + Bitmap::kBitsPerCell / 2);
+  EXPECT_EQ(bm->cells()[0], kBlackCell);
+  EXPECT_EQ(bm->cells()[1], 0xAAAA0000);
+  EXPECT_EQ(bm->cells()[2], kBlackCell);
+}
+
+}  // namespace