Reviewers: Igor Sheludko,
Description:
Clear SMI entries when filtering the slots buffer.
BUG=
Please review this at https://codereview.chromium.org/1313383005/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+73, -1 lines):
M src/heap/mark-compact.cc
M test/cctest/test-heap.cc
Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index
dc93a5a9a746549ce548a478a56b623dc34bc423..c8ef4146f92c7570abd8668b1b54170b920a0d9a
100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -4501,9 +4501,19 @@ void SlotsBuffer::RemoveInvalidSlots(Heap* heap,
SlotsBuffer* buffer) {
ObjectSlot slot = slots[slot_idx];
if (!IsTypedSlot(slot)) {
Object* object = *slot;
- if ((object->IsHeapObject() && heap->InNewSpace(object)) ||
+ // Slots are invalid when they currently:
+ // - do not point to a heap object (SMI)
+ // - point to a heap object in new space
+ // - point to a heap object not on an evacuation candidate
+ // - are not within a live heap object
+ if (!object->IsHeapObject() ||
+ (object->IsHeapObject() && heap->InNewSpace(object)) ||
+ !Page::FromAddress(reinterpret_cast<Address>(object))
+ ->IsEvacuationCandidate() ||
!heap->mark_compact_collector()->IsSlotInLiveObject(
reinterpret_cast<Address>(slot))) {
+ // TODO(hpayer): Instead of replacing slots with kRemovedEntry we
+ // could shrink the slots buffer in-place.
slots[slot_idx] = kRemovedEntry;
}
} else {
@@ -4535,6 +4545,8 @@ void SlotsBuffer::RemoveObjectSlots(Heap* heap,
SlotsBuffer* buffer,
if (!IsTypedSlot(slot)) {
Address slot_address = reinterpret_cast<Address>(slot);
if (slot_address >= start_slot && slot_address < end_slot) {
+ // TODO(hpayer): Instead of replacing slots with kRemovedEntry we
+ // could shrink the slots buffer in-place.
slots[slot_idx] = kRemovedEntry;
if (is_typed_slot) {
slots[slot_idx - 1] = kRemovedEntry;
Index: test/cctest/test-heap.cc
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index
4d210317efc7e521a6701310de89da11eb913ba2..41d380e32629b3cff14ed3b702120b6952f68796
100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -6483,6 +6483,66 @@ TEST(SlotsBufferObjectSlotsRemoval) {
}
+TEST(FilterInvalidSlotsBufferEntries) {
+ 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);
+
+ // Set up a fake black object that will contain a recorded SMI, a
recorded
+ // pointer to a new space object, and a recorded pointer to a
non-evacuation
+ // candidate object. These object should be filtered out. Additionally,
+ // we point to an evacuation candidate object which should not be
filtered
+ // out.
+
+ // Create fake object and mark it black.
+ Handle<FixedArray> fake_object = factory->NewFixedArray(23, TENURED);
+ MarkBit mark_bit = Marking::MarkBitFrom(*fake_object);
+ Marking::MarkBlack(mark_bit);
+
+ // Write a SMI into field one and record its address;
+ Object** field_smi = fake_object->RawFieldOfElementAt(0);
+ *field_smi = Smi::FromInt(100);
+ buffer->Add(field_smi);
+
+ // Write a new space reference into field 2 and record its address;
+ Handle<FixedArray> new_space_object = factory->NewFixedArray(23);
+ mark_bit = Marking::MarkBitFrom(*new_space_object);
+ Marking::MarkBlack(mark_bit);
+ Object** field_new_space = fake_object->RawFieldOfElementAt(1);
+ *field_new_space = *new_space_object;
+ buffer->Add(field_new_space);
+
+ // Write a old space reference into field 3 which is not on an evacuation
+ // candidate.
+ Handle<FixedArray> old_space_object_non_evacuation =
+ factory->NewFixedArray(23, TENURED);
+ mark_bit = Marking::MarkBitFrom(*old_space_object_non_evacuation);
+ Marking::MarkBlack(mark_bit);
+ Object** field_old_space_object_non_evacuation =
+ fake_object->RawFieldOfElementAt(2);
+ *field_old_space_object_non_evacuation =
*old_space_object_non_evacuation;
+ buffer->Add(field_old_space_object_non_evacuation);
+
+ SlotsBuffer::RemoveInvalidSlots(heap, buffer);
+ Object** kRemovedEntry = HeapObject::RawField(heap->empty_fixed_array(),
+
FixedArrayBase::kLengthOffset);
+ CHECK_EQ(buffer->Get(0), kRemovedEntry);
+ CHECK_EQ(buffer->Get(1), kRemovedEntry);
+ CHECK_EQ(buffer->Get(2), kRemovedEntry);
+
+ // Clean-up to make verify heap happy.
+ mark_bit = Marking::MarkBitFrom(*fake_object);
+ Marking::MarkWhite(mark_bit);
+ mark_bit = Marking::MarkBitFrom(*new_space_object);
+ Marking::MarkWhite(mark_bit);
+ mark_bit = Marking::MarkBitFrom(*old_space_object_non_evacuation);
+ Marking::MarkWhite(mark_bit);
+}
+
+
TEST(ContextMeasure) {
CcTest::InitializeVM();
v8::HandleScope scope(CcTest::isolate());
--
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