Reland of Remove slots that point to unboxed doubles from the StoreBuffer/SlotsBuffer.

test/cctest/test-unboxed-doubles.cc

 // Copyright 2014 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 <stdlib.h>
 #include <utility>
 
 #include "src/v8.h"
 
 #include "src/compilation-cache.h"
@@ skipping 30 matching lines @@
 }
 
 
 static Handle<String> MakeName(const char* str, int suffix) {
   EmbeddedVector<char, 128> buffer;
   SNPrintF(buffer, "%s%d", str, suffix);
   return MakeString(buffer.start());
 }
 
 
+Handle<JSObject> GetObject(const char* name) {
+  return v8::Utils::OpenHandle(
+      *v8::Handle<v8::Object>::Cast(CcTest::global()->Get(v8_str(name))));
+}
+
+
 static double GetDoubleFieldValue(JSObject* obj, FieldIndex field_index) {
   if (obj->IsUnboxedDoubleField(field_index)) {
     return obj->RawFastDoublePropertyAt(field_index);
   } else {
     Object* value = obj->RawFastPropertyAt(field_index);
     DCHECK(value->IsMutableHeapNumber());
     return HeapNumber::cast(value)->value();
   }
 }
 
@@ skipping 1237 matching lines @@
   Object* clone_obj = heap->CopyJSObject(jsobject).ToObjectChecked();
   Handle<JSObject> clone(JSObject::cast(clone_obj));
   CHECK(heap->old_pointer_space()->Contains(clone->address()));
 
   CcTest::heap()->CollectGarbage(NEW_SPACE, "boom");
 
   // The value in cloned object should not be corrupted by GC.
   CHECK_EQ(boom_value, clone->RawFastDoublePropertyAt(index));
 }
 
+
+static void TestWriteBarrier(Handle<Map> map, Handle<Map> new_map,
+                             int tagged_descriptor, int double_descriptor,
+                             bool check_tagged_value = true) {
+  FLAG_stress_compaction = true;
+  FLAG_manual_evacuation_candidates_selection = true;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  Heap* heap = CcTest::heap();
+  PagedSpace* old_pointer_space = heap->old_pointer_space();
+
+  // The plan: create |obj| by |map| in old space, create |obj_value| in
+  // new space and ensure that write barrier is triggered when |obj_value| is
+  // written to property |tagged_descriptor| of |obj|.
+  // Then migrate object to |new_map| and set proper value for property
+  // |double_descriptor|. Call GC and ensure that it did not crash during
+  // store buffer entries updating.
+
+  Handle<JSObject> obj;
+  Handle<HeapObject> obj_value;
+  {
+    AlwaysAllocateScope always_allocate(isolate);
+    obj = factory->NewJSObjectFromMap(map, TENURED, false);
+    CHECK(old_pointer_space->Contains(*obj));
+
+    obj_value = factory->NewJSArray(32 * KB, FAST_HOLEY_ELEMENTS);
+  }
+
+  CHECK(heap->InNewSpace(*obj_value));
+
+  StoreBuffer* store_buffer = heap->store_buffer();
+  USE(store_buffer);
+  Address slot;
+  {
+    FieldIndex index = FieldIndex::ForDescriptor(*map, tagged_descriptor);
+    int offset = index.offset();
+    slot = reinterpret_cast<Address>(HeapObject::RawField(*obj, offset));
+    USE(slot);
+    DCHECK(!store_buffer->CellIsInStoreBuffer(slot));
+
+    const int n = 153;
+    for (int i = 0; i < n; i++) {
+      obj->FastPropertyAtPut(index, *obj_value);
+    }
+    // Ensure that the slot was actually added to the store buffer.
+    DCHECK(store_buffer->CellIsInStoreBuffer(slot));
+  }
+
+  // Migrate |obj| to |new_map| which should shift fields and put the
+  // |boom_value| to the slot that was earlier recorded by write barrier.
+  JSObject::MigrateToMap(obj, new_map);
+
+  // Ensure that invalid entries were removed from the store buffer.
+  DCHECK(!store_buffer->CellIsInStoreBuffer(slot));
+
+  Address fake_object = reinterpret_cast<Address>(*obj_value) + kPointerSize;
+  double boom_value = bit_cast<double>(fake_object);
+
+  FieldIndex double_field_index =
+      FieldIndex::ForDescriptor(*new_map, double_descriptor);
+  CHECK(obj->IsUnboxedDoubleField(double_field_index));
+  obj->RawFastDoublePropertyAtPut(double_field_index, boom_value);
+
+  // Trigger GC to evacuate all candidates.
+  CcTest::heap()->CollectGarbage(NEW_SPACE, "boom");
+
+  if (check_tagged_value) {
+    FieldIndex tagged_field_index =
+        FieldIndex::ForDescriptor(*new_map, tagged_descriptor);
+    CHECK_EQ(*obj_value, obj->RawFastPropertyAt(tagged_field_index));
+  }
+  CHECK_EQ(boom_value, obj->RawFastDoublePropertyAt(double_field_index));
+}
+
+
+static void TestIncrementalWriteBarrier(Handle<Map> map, Handle<Map> new_map,
+                                        int tagged_descriptor,
+                                        int double_descriptor,
+                                        bool check_tagged_value = true) {
+  if (FLAG_never_compact || !FLAG_incremental_marking) return;
+  FLAG_stress_compaction = true;
+  FLAG_manual_evacuation_candidates_selection = true;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  Heap* heap = CcTest::heap();
+  PagedSpace* old_pointer_space = heap->old_pointer_space();
+
+  // The plan: create |obj| by |map| in old space, create |obj_value| in
+  // old space and ensure it end up in evacuation candidate page. Start
+  // incremental marking and ensure that incremental write barrier is triggered
+  // when |obj_value| is written to property |tagged_descriptor| of |obj|.
+  // Then migrate object to |new_map| and set proper value for property
+  // |double_descriptor|. Call GC and ensure that it did not crash during
+  // slots buffer entries updating.
+
+  Handle<JSObject> obj;
+  Handle<HeapObject> obj_value;
+  Page* ec_page;
+  {
+    AlwaysAllocateScope always_allocate(isolate);
+    obj = factory->NewJSObjectFromMap(map, TENURED, false);
+    CHECK(old_pointer_space->Contains(*obj));
+
+    // Make sure |obj_value| is placed on an old-space evacuation candidate.
+    SimulateFullSpace(old_pointer_space);
+    obj_value = factory->NewJSArray(32 * KB, FAST_HOLEY_ELEMENTS, TENURED);
+    ec_page = Page::FromAddress(obj_value->address());
+    CHECK_NE(ec_page, Page::FromAddress(obj->address()));
+  }
+
+  // Heap is ready, force |ec_page| to become an evacuation candidate and
+  // simulate incremental marking.
+  ec_page->SetFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
+  SimulateIncrementalMarking(heap);
+
+  // Check that everything is ready for triggering incremental write barrier
+  // (i.e. that both |obj| and |obj_value| are black and the marking phase is
+  // still active and |obj_value|'s page is indeed an evacuation candidate).
+  IncrementalMarking* marking = heap->incremental_marking();
+  CHECK(marking->IsMarking());
+  CHECK(Marking::IsBlack(Marking::MarkBitFrom(*obj)));
+  CHECK(Marking::IsBlack(Marking::MarkBitFrom(*obj_value)));
+  CHECK(MarkCompactCollector::IsOnEvacuationCandidate(*obj_value));
+
+  // Trigger incremental write barrier, which should add a slot to |ec_page|'s
+  // slots buffer.
+  {
+    int slots_buffer_len = SlotsBuffer::SizeOfChain(ec_page->slots_buffer());
+    FieldIndex index = FieldIndex::ForDescriptor(*map, tagged_descriptor);
+    const int n = SlotsBuffer::kNumberOfElements + 10;
+    for (int i = 0; i < n; i++) {
+      obj->FastPropertyAtPut(index, *obj_value);
+    }
+    // Ensure that the slot was actually added to the |ec_page|'s slots buffer.
+    CHECK_EQ(slots_buffer_len + n,
+             SlotsBuffer::SizeOfChain(ec_page->slots_buffer()));
+  }
+
+  // Migrate |obj| to |new_map| which should shift fields and put the
+  // |boom_value| to the slot that was earlier recorded by incremental write
+  // barrier.
+  JSObject::MigrateToMap(obj, new_map);
+
+  double boom_value = bit_cast<double>(UINT64_C(0xbaad0176a37c28e1));
+
+  FieldIndex double_field_index =
+      FieldIndex::ForDescriptor(*new_map, double_descriptor);
+  CHECK(obj->IsUnboxedDoubleField(double_field_index));
+  obj->RawFastDoublePropertyAtPut(double_field_index, boom_value);
+
+  // Trigger GC to evacuate all candidates.
+  CcTest::heap()->CollectGarbage(OLD_POINTER_SPACE, "boom");
+
+  // Ensure that the values are still there and correct.
+  CHECK(!MarkCompactCollector::IsOnEvacuationCandidate(*obj_value));
+
+  if (check_tagged_value) {
+    FieldIndex tagged_field_index =
+        FieldIndex::ForDescriptor(*new_map, tagged_descriptor);
+    CHECK_EQ(*obj_value, obj->RawFastPropertyAt(tagged_field_index));
+  }
+  CHECK_EQ(boom_value, obj->RawFastDoublePropertyAt(double_field_index));
+}
+
+
+enum WriteBarrierKind { OLD_TO_OLD_WRITE_BARRIER, OLD_TO_NEW_WRITE_BARRIER };
+static void TestWriteBarrierObjectShiftFieldsRight(
+    WriteBarrierKind write_barrier_kind) {
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  v8::HandleScope scope(CcTest::isolate());
+
+  Handle<HeapType> any_type = HeapType::Any(isolate);
+
+  CompileRun("function func() { return 1; }");
+
+  Handle<JSObject> func = GetObject("func");
+
+  Handle<Map> map = Map::Create(isolate, 10);
+  map = Map::CopyWithConstant(map, MakeName("prop", 0), func, NONE,
+                              INSERT_TRANSITION).ToHandleChecked();
+  map = Map::CopyWithField(map, MakeName("prop", 1), any_type, NONE,
+                           Representation::Double(),
+                           INSERT_TRANSITION).ToHandleChecked();
+  map = Map::CopyWithField(map, MakeName("prop", 2), any_type, NONE,
+                           Representation::Tagged(),
+                           INSERT_TRANSITION).ToHandleChecked();
+
+  // Shift fields right by turning constant property to a field.
+  Handle<Map> new_map = Map::ReconfigureProperty(
+      map, 0, kData, NONE, Representation::Tagged(), any_type, FORCE_FIELD);
+
+  if (write_barrier_kind == OLD_TO_NEW_WRITE_BARRIER) {
+    TestWriteBarrier(map, new_map, 2, 1);
+  } else {
+    CHECK_EQ(OLD_TO_OLD_WRITE_BARRIER, write_barrier_kind);
+    TestIncrementalWriteBarrier(map, new_map, 2, 1);
+  }
+}
+
+
+TEST(WriteBarrierObjectShiftFieldsRight) {
+  TestWriteBarrierObjectShiftFieldsRight(OLD_TO_NEW_WRITE_BARRIER);
+}
+
+
+TEST(IncrementalWriteBarrierObjectShiftFieldsRight) {
+  TestWriteBarrierObjectShiftFieldsRight(OLD_TO_OLD_WRITE_BARRIER);
+}
+
+
+// TODO(ishell): add respective tests for property kind reconfiguring from
+// accessor field to double, once accessor fields are supported by
+// Map::ReconfigureProperty().
+
+
+// TODO(ishell): add respective tests for fast property removal case once
+// Map::ReconfigureProperty() supports that.
+
 #endif