Directly remove slot buffer entries in deoptimized code objects.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5997 matching lines @@
   size_t counter2 = 2000;
   tracer->SampleAllocation(time2, counter2, counter2);
   size_t throughput = tracer->AllocationThroughputInBytesPerMillisecond(100);
   CHECK_EQ(2 * (counter2 - counter1) / (time2 - time1), throughput);
   int time3 = 1000;
   size_t counter3 = 30000;
   tracer->SampleAllocation(time3, counter3, counter3);
   throughput = tracer->AllocationThroughputInBytesPerMillisecond(100);
   CHECK_EQ(2 * (counter3 - counter1) / (time3 - time1), throughput);
 }
+
+
+TEST(SlotsBufferObjectSlotsRemoval) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  Factory* factory = isolate->factory();
+
+  SlotsBuffer* buffer = new SlotsBuffer(NULL);
+  void* fake_object[1];
+
+  Handle<FixedArray> array = factory->NewFixedArray(2, TENURED);
+  CHECK(heap->old_space()->Contains(*array));
+  array->set(0, reinterpret_cast<Object*>(fake_object), SKIP_WRITE_BARRIER);
+
+  // Firstly, let's test the regular slots buffer entry.
+  buffer->Add(HeapObject::RawField(*array, FixedArray::kHeaderSize));
+  DCHECK(reinterpret_cast<void*>(buffer->Get(0)) ==
+         HeapObject::RawField(*array, FixedArray::kHeaderSize));
+  SlotsBuffer::RemoveObjectSlots(CcTest::i_isolate()->heap(), buffer, *array);
+  DCHECK(reinterpret_cast<void*>(buffer->Get(0)) ==
+         HeapObject::RawField(heap->empty_fixed_array(),
+                              FixedArrayBase::kLengthOffset));
+
+  // Secondly, let's test the typed slots buffer entry.
+  SlotsBuffer::AddTo(NULL, &buffer, SlotsBuffer::EMBEDDED_OBJECT_SLOT,
+                     array->address() + FixedArray::kHeaderSize,
+                     SlotsBuffer::FAIL_ON_OVERFLOW);
+  DCHECK(reinterpret_cast<void*>(buffer->Get(1)) ==
+         reinterpret_cast<Object**>(SlotsBuffer::EMBEDDED_OBJECT_SLOT));
+  DCHECK(reinterpret_cast<void*>(buffer->Get(2)) ==
+         HeapObject::RawField(*array, FixedArray::kHeaderSize));
+  SlotsBuffer::RemoveObjectSlots(CcTest::i_isolate()->heap(), buffer, *array);
+  DCHECK(reinterpret_cast<void*>(buffer->Get(1)) ==
+         HeapObject::RawField(heap->empty_fixed_array(),
+                              FixedArrayBase::kLengthOffset));
+  DCHECK(reinterpret_cast<void*>(buffer->Get(2)) ==
+         HeapObject::RawField(heap->empty_fixed_array(),
+                              FixedArrayBase::kLengthOffset));
+  delete buffer;
+}