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Clear SMI and non-evacuation candidate entries when filtering the slots buffer.

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BUG=

Review URL: https://codereview.chromium.org/1313383005

Cr-Commit-Position: refs/heads/master@{#30415}
This commit is contained in:
hpayer 2015-08-27 07:30:44 -07:00 committed by Commit bot
parent f481316b14
commit d4e372b41b
2 changed files with 88 additions and 2 deletions
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15
src/heap/mark-compact.cc
View File

@ -4524,9 +4524,18 @@ 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
// - are not within a live heap object on a valid pointer slot
// - point to a heap object not on an evacuation candidate
if (!object->IsHeapObject() || heap->InNewSpace(object) ||
!heap->mark_compact_collector()->IsSlotInLiveObject(
reinterpret_cast<Address>(slot))) {
reinterpret_cast<Address>(slot)) ||
!Page::FromAddress(reinterpret_cast<Address>(object))
->IsEvacuationCandidate()) {
// TODO(hpayer): Instead of replacing slots with kRemovedEntry we
// could shrink the slots buffer in-place.
slots[slot_idx] = kRemovedEntry;
}
} else {
@ -4558,6 +4567,8 @@ 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;

75
test/cctest/test-heap.cc
View File

@ -6502,6 +6502,81 @@ TEST(SlotsBufferObjectSlotsRemoval) {
}
TEST(FilterInvalidSlotsBufferEntries) {
FLAG_manual_evacuation_candidates_selection = true;
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 an old space reference into field 3 which points to an object 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);
// Write an old space reference into field 4 which points to an object on an
// evacuation candidate.
SimulateFullSpace(heap->old_space());
Handle<FixedArray> valid_object =
isolate->factory()->NewFixedArray(23, TENURED);
Page* page = Page::FromAddress(valid_object->address());
page->SetFlag(MemoryChunk::EVACUATION_CANDIDATE);
Object** valid_field = fake_object->RawFieldOfElementAt(3);
*valid_field = *valid_object;
buffer->Add(valid_field);
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);
CHECK_EQ(buffer->Get(3), valid_field);
// 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);
delete buffer;
}
TEST(ContextMeasure) {
CcTest::InitializeVM();
v8::HandleScope scope(CcTest::isolate());