Simple BlinkGC heap compaction.

third_party/WebKit/Source/platform/heap/HeapCompactTest.cpp

+// Copyright 2016 The Chromium 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 "platform/heap/HeapCompact.h"
+
+#include "platform/heap/Handle.h"
+#include "platform/heap/SparseHeapBitmap.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "wtf/Deque.h"
+#include "wtf/HashMap.h"
+#include "wtf/LinkedHashSet.h"
+#include "wtf/Vector.h"
+
+#include <memory>
+
+namespace blink {
+class IntWrapper;
+}
+
+using IntVector = blink::HeapVector<blink::Member<blink::IntWrapper>>;
+using IntDeque = blink::HeapDeque<blink::Member<blink::IntWrapper>>;
+using IntMap = blink::HeapHashMap<blink::Member<blink::IntWrapper>, int>;
+// TODO(sof): decide if this ought to be a global trait specialization.
+// (i.e., for HeapHash*<T>.)
+WTF_ALLOW_CLEAR_UNUSED_SLOTS_WITH_MEM_FUNCTIONS(IntMap);
+
+namespace blink {
+
+static const size_t chunkRange = SparseHeapBitmap::s_bitmapChunkRange;
+static const size_t unitPointer = 0x1u
+                                  << SparseHeapBitmap::s_pointerAlignmentInBits;
+
+TEST(HeapCompactTest, SparseBitmapBasic) {
+  Address base = reinterpret_cast<Address>(0x10000u);
+  std::unique_ptr<SparseHeapBitmap> bitmap = SparseHeapBitmap::create(base);
+
+  size_t doubleChunk = 2 * chunkRange;
+
+  // 101010... starting at |base|.
+  for (size_t i = 0; i < doubleChunk; i += 2 * unitPointer)
+    bitmap->add(base + i);
+
+  // Check that hasRange() returns a bitmap subtree, if any, for a given
+  // address.
+  EXPECT_TRUE(!!bitmap->hasRange(base, 1));
+  EXPECT_TRUE(!!bitmap->hasRange(base + unitPointer, 1));
+  EXPECT_FALSE(!!bitmap->hasRange(base - unitPointer, 1));
+
+  // Test implementation details.. that each SparseHeapBitmap node maps
+  // |s_bitmapChunkRange| ranges only.
+  EXPECT_EQ(bitmap->hasRange(base + unitPointer, 1),
+            bitmap->hasRange(base + 2 * unitPointer, 1));
+  // Second range will be just past the first.
+  EXPECT_NE(bitmap->hasRange(base, 1), bitmap->hasRange(base + chunkRange, 1));
+
+  // Iterate a range that will encompass more than one 'chunk'.
+  SparseHeapBitmap* start =
+      bitmap->hasRange(base + 2 * unitPointer, doubleChunk);
+  EXPECT_TRUE(!!start);
+  for (size_t i = 2 * unitPointer; i < doubleChunk; i += 2 * unitPointer) {
+    EXPECT_TRUE(start->isSet(base + i));
+    EXPECT_FALSE(start->isSet(base + i + unitPointer));
+  }
+}
+
+TEST(HeapCompactTest, SparseBitmapBuild) {
+  Address base = reinterpret_cast<Address>(0x10000u);
+  std::unique_ptr<SparseHeapBitmap> bitmap = SparseHeapBitmap::create(base);
+
+  size_t doubleChunk = 2 * chunkRange;
+
+  // Create a sparse bitmap containing at least three chunks.
+  bitmap->add(base - doubleChunk);
+  bitmap->add(base + doubleChunk);
+
+  // This is sanity testing internal implementation details of
+  // SparseHeapBitmap; probing |isSet()| outside the bitmap
+  // of the range used in |hasRange()|, is not defined.
+  //
+  // Regardless, the testing here verifies that a |hasRange()| that
+  // straddles multiple internal nodes, returns a bitmap that is
+  // capable of returning correct |isSet()| results.
+  SparseHeapBitmap* start =
+      bitmap->hasRange(base - doubleChunk - 2 * unitPointer, 4 * unitPointer);
+  EXPECT_TRUE(!!start);
+  EXPECT_TRUE(start->isSet(base - doubleChunk));
+  EXPECT_FALSE(start->isSet(base - doubleChunk + unitPointer));
+  EXPECT_FALSE(start->isSet(base));
+  EXPECT_FALSE(start->isSet(base + unitPointer));
+  EXPECT_FALSE(start->isSet(base + doubleChunk));
+  EXPECT_FALSE(start->isSet(base + doubleChunk + unitPointer));
+
+  start = bitmap->hasRange(base - doubleChunk - 2 * unitPointer,
+                           2 * doubleChunk + 2 * unitPointer);
+  EXPECT_TRUE(!!start);
+  EXPECT_TRUE(start->isSet(base - doubleChunk));
+  EXPECT_FALSE(start->isSet(base - doubleChunk + unitPointer));
+  EXPECT_TRUE(start->isSet(base));
+  EXPECT_FALSE(start->isSet(base + unitPointer));
+  EXPECT_TRUE(start->isSet(base + doubleChunk));
+  EXPECT_FALSE(start->isSet(base + doubleChunk + unitPointer));
+
+  start = bitmap->hasRange(base, 20);
+  EXPECT_TRUE(!!start);
+  // Probing for values outside of hasRange() should be considered
+  // undefined, but do it to exercise the (left) tree traversal.
+  EXPECT_TRUE(start->isSet(base - doubleChunk));
+  EXPECT_FALSE(start->isSet(base - doubleChunk + unitPointer));
+  EXPECT_TRUE(start->isSet(base));
+  EXPECT_FALSE(start->isSet(base + unitPointer));
+  EXPECT_TRUE(start->isSet(base + doubleChunk));
+  EXPECT_FALSE(start->isSet(base + doubleChunk + unitPointer));
+
+  start = bitmap->hasRange(base + chunkRange + 2 * unitPointer, 2048);
+  EXPECT_TRUE(!!start);
+  // Probing for values outside of hasRange() should be considered
+  // undefined, but do it to exercise node traversal.
+  EXPECT_FALSE(start->isSet(base - doubleChunk));
+  EXPECT_FALSE(start->isSet(base - doubleChunk + unitPointer));
+  EXPECT_FALSE(start->isSet(base));
+  EXPECT_FALSE(start->isSet(base + unitPointer));
+  EXPECT_FALSE(start->isSet(base + chunkRange));
+  EXPECT_TRUE(start->isSet(base + doubleChunk));
+  EXPECT_FALSE(start->isSet(base + doubleChunk + unitPointer));
+}
+
+TEST(HeapCompactTest, SparseBitmapLeftExtension) {
+  Address base = reinterpret_cast<Address>(0x10000u);
+  std::unique_ptr<SparseHeapBitmap> bitmap = SparseHeapBitmap::create(base);
+
+  SparseHeapBitmap* start = bitmap->hasRange(base, 1);
+  EXPECT_TRUE(start);
+
+  // Verify that re-adding is a no-op.
+  bitmap->add(base);
+  EXPECT_EQ(start, bitmap->hasRange(base, 1));
+
+  // Adding an Address |A| before a single-address SparseHeapBitmap node should
+  // cause that node to  be "left extended" to use |A| as its new base.
+  bitmap->add(base - 2 * unitPointer);
+  EXPECT_EQ(bitmap->hasRange(base, 1),
+            bitmap->hasRange(base - 2 * unitPointer, 1));
+
+  // Reset.
+  bitmap = SparseHeapBitmap::create(base);
+
+  // If attempting same as above, but the Address |A| is outside the
+  // chunk size of a node, a new SparseHeapBitmap node needs to be
+  // created to the left of |bitmap|.
+  bitmap->add(base - chunkRange);
+  EXPECT_NE(bitmap->hasRange(base, 1),
+            bitmap->hasRange(base - 2 * unitPointer, 1));
+
+  bitmap = SparseHeapBitmap::create(base);
+  bitmap->add(base - chunkRange + unitPointer);
+  // This address is just inside the horizon and shouldn't create a new chunk.
+  EXPECT_EQ(bitmap->hasRange(base, 1),
+            bitmap->hasRange(base - 2 * unitPointer, 1));
+  // ..but this one should, like for the sub-test above.
+  bitmap->add(base - chunkRange);
+  EXPECT_EQ(bitmap->hasRange(base, 1),
+            bitmap->hasRange(base - 2 * unitPointer, 1));
+  EXPECT_NE(bitmap->hasRange(base, 1), bitmap->hasRange(base - chunkRange, 1));
+}
+
+static void preciselyCollectGarbage() {
+  ThreadState::current()->collectGarbage(
+      BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithSweep, BlinkGC::ForcedGC);
+}
+
+static void performHeapCompaction() {
+  EXPECT_FALSE(HeapCompact::scheduleCompactionGCForTesting(true));
+  preciselyCollectGarbage();
+  EXPECT_FALSE(HeapCompact::scheduleCompactionGCForTesting(false));
+}
+
+// Do several GCs to make sure that later GCs don't free up old memory from
+// previously run tests in this process.
+static void clearOutOldGarbage() {
+  ThreadHeap& heap = ThreadState::current()->heap();
+  while (true) {
+    size_t used = heap.objectPayloadSizeForTesting();
+    preciselyCollectGarbage();
+    if (heap.objectPayloadSizeForTesting() >= used)
+      break;
+  }
+}
+
+class IntWrapper : public GarbageCollectedFinalized<IntWrapper> {
+ public:
+  static IntWrapper* create(int x) { return new IntWrapper(x); }
+
+  virtual ~IntWrapper() { ++s_destructorCalls; }
+
+  static int s_destructorCalls;
+  DEFINE_INLINE_TRACE() {}
+
+  int value() const { return m_x; }
+
+  bool operator==(const IntWrapper& other) const {
+    return other.value() == value();
+  }
+
+  unsigned hash() { return IntHash<int>::hash(m_x); }
+
+  IntWrapper(int x) : m_x(x) {}
+
+ private:
+  IntWrapper();
+  int m_x;
+};
+static_assert(WTF::IsTraceable<IntWrapper>::value,
+              "IsTraceable<> template failed to recognize trace method.");
+
+TEST(HeapCompactTest, CompactVector) {
+  clearOutOldGarbage();
+
+  IntWrapper* val = IntWrapper::create(1);
+  Persistent<IntVector> vector = new IntVector(10, val);
+  EXPECT_EQ(10u, vector->size());
+
+  for (size_t i = 0; i < vector->size(); ++i)
+    EXPECT_EQ(val, (*vector)[i]);
+
+  performHeapCompaction();
+
+  for (size_t i = 0; i < vector->size(); ++i)
+    EXPECT_EQ(val, (*vector)[i]);
+}
+
+TEST(HeapCompactTest, CompactHashMap) {
+  clearOutOldGarbage();
+
+  Persistent<IntMap> intMap = new IntMap();
+  for (size_t i = 0; i < 100; ++i) {
+    IntWrapper* val = IntWrapper::create(i);
+    intMap->add(val, 100 - i);
+  }
+
+  EXPECT_EQ(100u, intMap->size());
+  for (auto k : *intMap)
+    EXPECT_EQ(k.key->value(), 100 - k.value);
+
+  performHeapCompaction();
+
+  for (auto k : *intMap)
+    EXPECT_EQ(k.key->value(), 100 - k.value);
+}
+
+TEST(HeapCompactTest, CompactVectorPartHashMap) {
+  clearOutOldGarbage();
+
+  using IntMapVector = HeapVector<IntMap>;
+
+  Persistent<IntMapVector> intMapVector = new IntMapVector();
+  for (size_t i = 0; i < 10; ++i) {
+    IntMap map;
+    for (size_t j = 0; j < 10; ++j) {
+      IntWrapper* val = IntWrapper::create(j);
+      map.add(val, 10 - j);
+    }
+    intMapVector->append(map);
+  }
+
+  EXPECT_EQ(10u, intMapVector->size());
+  for (auto map : *intMapVector) {
+    EXPECT_EQ(10u, map.size());
+    for (auto k : map) {
+      EXPECT_EQ(k.key->value(), 10 - k.value);
+    }
+  }
+
+  performHeapCompaction();
+
+  EXPECT_EQ(10u, intMapVector->size());
+  for (auto map : *intMapVector) {
+    EXPECT_EQ(10u, map.size());
+    for (auto k : map) {
+      EXPECT_EQ(k.key->value(), 10 - k.value);
+    }
+  }
+}
+
+TEST(HeapCompactTest, CompactHashPartVector) {
+  clearOutOldGarbage();
+
+  using IntVectorMap = HeapHashMap<int, IntVector>;
+
+  Persistent<IntVectorMap> intVectorMap = new IntVectorMap();
+  for (size_t i = 0; i < 10; ++i) {
+    IntVector vector;
+    for (size_t j = 0; j < 10; ++j) {
+      vector.append(IntWrapper::create(j));
+    }
+    intVectorMap->add(1 + i, vector);
+  }
+
+  EXPECT_EQ(10u, intVectorMap->size());
+  for (const IntVector& intVector : intVectorMap->values()) {
+    EXPECT_EQ(10u, intVector.size());
+    for (size_t i = 0; i < intVector.size(); ++i) {
+      EXPECT_EQ(static_cast<int>(i), intVector[i]->value());
+    }
+  }
+
+  performHeapCompaction();
+
+  EXPECT_EQ(10u, intVectorMap->size());
+  for (const IntVector& intVector : intVectorMap->values()) {
+    EXPECT_EQ(10u, intVector.size());
+    for (size_t i = 0; i < intVector.size(); ++i) {
+      EXPECT_EQ(static_cast<int>(i), intVector[i]->value());
+    }
+  }
+}
+
+TEST(HeapCompactTest, CompactDeques) {
+  Persistent<IntDeque> deque = new IntDeque;
+  for (int i = 0; i < 8; ++i) {
+    deque->prepend(IntWrapper::create(i));
+  }
+  EXPECT_EQ(8u, deque->size());
+
+  for (size_t i = 0; i < deque->size(); ++i)
+    EXPECT_EQ(static_cast<int>(7 - i), deque->at(i)->value());
+
+  performHeapCompaction();
+
+  for (size_t i = 0; i < deque->size(); ++i)
+    EXPECT_EQ(static_cast<int>(7 - i), deque->at(i)->value());
+}
+
+TEST(HeapCompactTest, CompactDequeVectors) {
+  Persistent<HeapDeque<IntVector>> deque = new HeapDeque<IntVector>;
+  for (int i = 0; i < 8; ++i) {
+    IntWrapper* value = IntWrapper::create(i);
+    IntVector vector = IntVector(8, value);
+    deque->prepend(vector);
+  }
+  EXPECT_EQ(8u, deque->size());
+
+  for (size_t i = 0; i < deque->size(); ++i)
+    EXPECT_EQ(static_cast<int>(7 - i), deque->at(i).at(i)->value());
+
+  performHeapCompaction();
+
+  for (size_t i = 0; i < deque->size(); ++i)
+    EXPECT_EQ(static_cast<int>(7 - i), deque->at(i).at(i)->value());
+}
+
+TEST(HeapCompactTest, CompactLinkedHashSet) {
+  using OrderedHashSet = HeapLinkedHashSet<Member<IntWrapper>>;
+  Persistent<OrderedHashSet> set = new OrderedHashSet;
+  for (int i = 0; i < 13; ++i) {
+    IntWrapper* value = IntWrapper::create(i);
+    set->add(value);
+  }
+  EXPECT_EQ(13u, set->size());
+
+  int expected = 0;
+  for (IntWrapper* v : *set) {
+    EXPECT_EQ(expected, v->value());
+    expected++;
+  }
+
+  performHeapCompaction();
+
+  expected = 0;
+  for (IntWrapper* v : *set) {
+    EXPECT_EQ(expected, v->value());
+    expected++;
+  }
+}
+
+TEST(HeapCompactTest, CompactLinkedHashSetVector) {
+  using OrderedHashSet = HeapLinkedHashSet<Member<IntVector>>;
+  Persistent<OrderedHashSet> set = new OrderedHashSet;
+  for (int i = 0; i < 13; ++i) {
+    IntWrapper* value = IntWrapper::create(i);
+    IntVector* vector = new IntVector(19, value);
+    set->add(vector);
+  }
+  EXPECT_EQ(13u, set->size());
+
+  int expected = 0;
+  for (IntVector* v : *set) {
+    EXPECT_EQ(expected, (*v)[0]->value());
+    expected++;
+  }
+
+  performHeapCompaction();
+
+  expected = 0;
+  for (IntVector* v : *set) {
+    EXPECT_EQ(expected, (*v)[0]->value());
+    expected++;
+  }
+}
+
+TEST(HeapCompactTest, CompactLinkedHashSetMap) {
+  using Inner = HeapHashSet<Member<IntWrapper>>;
+  using OrderedHashSet = HeapLinkedHashSet<Member<Inner>>;
+
+  Persistent<OrderedHashSet> set = new OrderedHashSet;
+  for (int i = 0; i < 13; ++i) {
+    IntWrapper* value = IntWrapper::create(i);
+    Inner* inner = new Inner;
+    inner->add(value);
+    set->add(inner);
+  }
+  EXPECT_EQ(13u, set->size());
+
+  int expected = 0;
+  for (const Inner* v : *set) {
+    EXPECT_EQ(1u, v->size());
+    EXPECT_EQ(expected, (*v->begin())->value());
+    expected++;
+  }
+
+  performHeapCompaction();
+
+  expected = 0;
+  for (const Inner* v : *set) {
+    EXPECT_EQ(1u, v->size());
+    EXPECT_EQ(expected, (*v->begin())->value());
+    expected++;
+  }
+}
+
+TEST(HeapCompactTest, CompactLinkedHashSetNested) {
+  using Inner = HeapLinkedHashSet<Member<IntWrapper>>;
+  using OrderedHashSet = HeapLinkedHashSet<Member<Inner>>;
+
+  Persistent<OrderedHashSet> set = new OrderedHashSet;
+  for (int i = 0; i < 13; ++i) {
+    IntWrapper* value = IntWrapper::create(i);
+    Inner* inner = new Inner;
+    inner->add(value);
+    set->add(inner);
+  }
+  EXPECT_EQ(13u, set->size());
+
+  int expected = 0;
+  for (const Inner* v : *set) {
+    EXPECT_EQ(1u, v->size());
+    EXPECT_EQ(expected, (*v->begin())->value());
+    expected++;
+  }
+
+  performHeapCompaction();
+
+  expected = 0;
+  for (const Inner* v : *set) {
+    EXPECT_EQ(1u, v->size());
+    EXPECT_EQ(expected, (*v->begin())->value());
+    expected++;
+  }
+}
+
+}  // namespace blink