[heap] Temporarily do not use size to iterate live object to investigate Win 10 memory regression.

BUG=chromium:633537

Review-Url: https://codereview.chromium.org/2211893002
Cr-Commit-Position: refs/heads/master@{#38369}

src/heap/mark-compact-inl.h

@@ -168,25 +168,20 @@ HeapObject* LiveObjectIterator<T>::Next() {
         // make sure that we skip all set bits in the black area until the
         // object ends.
         HeapObject* black_object = HeapObject::FromAddress(addr);
-        Address end = addr + black_object->Size() - kPointerSize;
+        Address end = addr + black_object->Size();
         // One word filler objects do not borrow the second mark bit. We have
         // to jump over the advancing and clearing part.
         // Note that we know that we are at a one word filler when
         // object_start + object_size - kPointerSize == object_start.
         if (addr != end) {
-          DCHECK_EQ(chunk_, MemoryChunk::FromAddress(end));
-          uint32_t end_mark_bit_index = chunk_->AddressToMarkbitIndex(end);
-          unsigned int end_cell_index =
-              end_mark_bit_index >> Bitmap::kBitsPerCellLog2;
-          MarkBit::CellType end_index_mask =
-              1u << Bitmap::IndexInCell(end_mark_bit_index);
-          if (it_.Advance(end_cell_index)) {
-            cell_base_ = it_.CurrentCellBase();
-            current_cell_ = *it_.CurrentCell();
-          }
-
-          // Clear all bits in current_cell, including the end index.
-          current_cell_ &= ~(end_index_mask | (end_index_mask - 1));
+          // Clear all bits from second_bit_index.
+          current_cell_ &= ~(second_bit_index | (second_bit_index - 1));
+
+          // Check that all bits corresponding to in object fields after the
+          // two cleared bits in the beginning are indeed zero.
+          CHECK(chunk_->markbits()->AllBitsClearInRange(
+              chunk_->AddressToMarkbitIndex(addr + 2 * kPointerSize),
+              chunk_->AddressToMarkbitIndex(end)));
         }
 
         if (T == kBlackObjects || T == kAllLiveObjects) {

test/cctest/heap/test-heap.cc

@@ -6828,164 +6828,6 @@ TEST(Regress615489) {
   CHECK_LE(size_after, size_before);
 }
 
-TEST(LeftTrimFixedArrayInBlackArea) {
-  FLAG_black_allocation = true;
-  CcTest::InitializeVM();
-  v8::HandleScope scope(CcTest::isolate());
-  Heap* heap = CcTest::heap();
-  Isolate* isolate = heap->isolate();
-  heap->CollectAllGarbage();
-
-  i::MarkCompactCollector* collector = heap->mark_compact_collector();
-  i::IncrementalMarking* marking = heap->incremental_marking();
-  if (collector->sweeping_in_progress()) {
-    collector->EnsureSweepingCompleted();
-  }
-  CHECK(marking->IsMarking() || marking->IsStopped());
-  if (marking->IsStopped()) {
-    heap->StartIncrementalMarking();
-  }
-  CHECK(marking->IsMarking());
-  marking->StartBlackAllocationForTesting();
-
-  // Ensure that we allocate a new page, set up a bump pointer area, and
-  // perform the allocation in a black area.
-  heap::SimulateFullSpace(heap->old_space());
-  isolate->factory()->NewFixedArray(4, TENURED);
-  Handle<FixedArray> array = isolate->factory()->NewFixedArray(50, TENURED);
-  CHECK(heap->old_space()->Contains(*array));
-  CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
-
-  // Now left trim the allocated black area. A filler has to be installed
-  // for the trimmed area and all mark bits of the trimmed area have to be
-  // cleared.
-  FixedArrayBase* trimmed = heap->LeftTrimFixedArray(*array, 10);
-  CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
-
-  heap::GcAndSweep(heap, OLD_SPACE);
-}
-
-TEST(ContinuousLeftTrimFixedArrayInBlackArea) {
-  FLAG_black_allocation = true;
-  CcTest::InitializeVM();
-  v8::HandleScope scope(CcTest::isolate());
-  Heap* heap = CcTest::heap();
-  Isolate* isolate = heap->isolate();
-  heap->CollectAllGarbage();
-
-  i::MarkCompactCollector* collector = heap->mark_compact_collector();
-  i::IncrementalMarking* marking = heap->incremental_marking();
-  if (collector->sweeping_in_progress()) {
-    collector->EnsureSweepingCompleted();
-  }
-  CHECK(marking->IsMarking() || marking->IsStopped());
-  if (marking->IsStopped()) {
-    heap->StartIncrementalMarking();
-  }
-  CHECK(marking->IsMarking());
-  marking->StartBlackAllocationForTesting();
-
-  // Ensure that we allocate a new page, set up a bump pointer area, and
-  // perform the allocation in a black area.
-  heap::SimulateFullSpace(heap->old_space());
-  isolate->factory()->NewFixedArray(10, TENURED);
-
-  // Allocate the fixed array that will be trimmed later.
-  Handle<FixedArray> array = isolate->factory()->NewFixedArray(100, TENURED);
-  Address start_address = array->address();
-  Address end_address = start_address + array->Size();
-  Page* page = Page::FromAddress(start_address);
-  CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
-  CHECK(page->markbits()->AllBitsSetInRange(
-      page->AddressToMarkbitIndex(start_address),
-      page->AddressToMarkbitIndex(end_address)));
-  CHECK(heap->old_space()->Contains(*array));
-
-  FixedArrayBase* previous = *array;
-  FixedArrayBase* trimmed;
-
-  // First trim in one word steps.
-  for (int i = 0; i < 10; i++) {
-    trimmed = heap->LeftTrimFixedArray(previous, 1);
-    HeapObject* filler = HeapObject::FromAddress(previous->address());
-    CHECK(filler->IsFiller());
-    CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
-    CHECK(Marking::IsImpossible(ObjectMarking::MarkBitFrom(previous)));
-    previous = trimmed;
-  }
-
-  // Then trim in two and three word steps.
-  for (int i = 2; i <= 3; i++) {
-    for (int j = 0; j < 10; j++) {
-      trimmed = heap->LeftTrimFixedArray(previous, i);
-      HeapObject* filler = HeapObject::FromAddress(previous->address());
-      CHECK(filler->IsFiller());
-      CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
-      CHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(previous)));
-      previous = trimmed;
-    }
-  }
-
-  heap::GcAndSweep(heap, OLD_SPACE);
-}
-
-TEST(ContinuousRightTrimFixedArrayInBlackArea) {
-  FLAG_black_allocation = true;
-  CcTest::InitializeVM();
-  v8::HandleScope scope(CcTest::isolate());
-  Heap* heap = CcTest::heap();
-  Isolate* isolate = heap->isolate();
-  heap->CollectAllGarbage();
-
-  i::MarkCompactCollector* collector = heap->mark_compact_collector();
-  i::IncrementalMarking* marking = heap->incremental_marking();
-  if (collector->sweeping_in_progress()) {
-    collector->EnsureSweepingCompleted();
-  }
-  CHECK(marking->IsMarking() || marking->IsStopped());
-  if (marking->IsStopped()) {
-    heap->StartIncrementalMarking();
-  }
-  CHECK(marking->IsMarking());
-  marking->StartBlackAllocationForTesting();
-
-  // Ensure that we allocate a new page, set up a bump pointer area, and
-  // perform the allocation in a black area.
-  heap::SimulateFullSpace(heap->old_space());
-  isolate->factory()->NewFixedArray(10, TENURED);
-
-  // Allocate the fixed array that will be trimmed later.
-  Handle<FixedArray> array = isolate->factory()->NewFixedArray(100, TENURED);
-  Address start_address = array->address();
-  Address end_address = start_address + array->Size();
-  Page* page = Page::FromAddress(start_address);
-  CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
-  CHECK(page->markbits()->AllBitsSetInRange(
-      page->AddressToMarkbitIndex(start_address),
-      page->AddressToMarkbitIndex(end_address)));
-  CHECK(heap->old_space()->Contains(*array));
-
-  // Trim it once by one word to make checking for white marking color uniform.
-  Address previous = end_address - kPointerSize;
-  heap->RightTrimFixedArray<Heap::SEQUENTIAL_TO_SWEEPER>(*array, 1);
-  HeapObject* filler = HeapObject::FromAddress(previous);
-  CHECK(filler->IsFiller());
-  CHECK(Marking::IsImpossible(ObjectMarking::MarkBitFrom(previous)));
-
-  // Trim 10 times by one, two, and three word.
-  for (int i = 1; i <= 3; i++) {
-    for (int j = 0; j < 10; j++) {
-      previous -= kPointerSize * i;
-      heap->RightTrimFixedArray<Heap::SEQUENTIAL_TO_SWEEPER>(*array, i);
-      HeapObject* filler = HeapObject::FromAddress(previous);
-      CHECK(filler->IsFiller());
-      CHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(previous)));
-    }
-  }
-
-  heap::GcAndSweep(heap, OLD_SPACE);
-}
-
 TEST(Regress618958) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());