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Revert "[heap, runtime] Avoid redundant clearing of slots outside an object."

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This reverts commit 3f820ebb0b.

Revert "[heap, runtime] Avoid redundant clearing of slots in a trimmed array."

This reverts commit ed76f17b15.

Reason: canary crashes.

Bug: chromium:752750, chromium:694255
TBR: mlippautz@chromium.org
Change-Id: I57c533e8a3db5f28e7659c5f326fa343627a3ff7
Reviewed-on: https://chromium-review.googlesource.com/607868
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47300}
This commit is contained in:
Ulan Degenbaev 2017-08-09 10:10:20 +02:00 committed by Commit Bot
parent 0410e7e850
commit 1e182fd446
2 changed files with 5 additions and 14 deletions
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8
src/heap/heap.cc
View File

@ -3325,7 +3325,7 @@ HeapObject* Heap::CreateFillerObjectAt(Address addr, int size,
FreeSpace::cast(filler)->relaxed_write_size(size);
}
if (mode == ClearRecordedSlots::kYes) {
UNREACHABLE();
ClearRecordedSlotRange(addr, addr + size);
}
// At this point, we may be deserializing the heap from a snapshot, and
@ -3407,8 +3407,7 @@ FixedArrayBase* Heap::LeftTrimFixedArray(FixedArrayBase* object,
// Technically in new space this write might be omitted (except for
// debug mode which iterates through the heap), but to play safer
// we still do it.
// Recorded slots will be cleared by the sweeper.
CreateFillerObjectAt(old_start, bytes_to_trim, ClearRecordedSlots::kNo);
CreateFillerObjectAt(old_start, bytes_to_trim, ClearRecordedSlots::kYes);
// Initialize header of the trimmed array. Since left trimming is only
// performed on pages which are not concurrently swept creating a filler
@ -3477,9 +3476,8 @@ void Heap::RightTrimFixedArray(FixedArrayBase* object, int elements_to_trim) {
// TODO(hpayer): We should shrink the large object page if the size
// of the object changed significantly.
if (!lo_space()->Contains(object)) {
// Recorded slots will be cleared by the sweeper.
HeapObject* filler =
CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kNo);
CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes);
DCHECK_NOT_NULL(filler);
// Clear the mark bits of the black area that belongs now to the filler.
// This is an optimization. The sweeper will release black fillers anyway.

11
src/objects.cc
View File

@ -4030,11 +4030,8 @@ void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map) {
if (instance_size_delta > 0) {
Address address = object->address();
// The object has shrunk and is not going to use these slots again.
// Since there will be no untagged stores in these slots,
// we can just let the sweeper remove slots in the filler.
heap->CreateFillerObjectAt(address + new_instance_size, instance_size_delta,
ClearRecordedSlots::kNo);
ClearRecordedSlots::kYes);
heap->AdjustLiveBytes(*object, -instance_size_delta);
}
@ -4116,11 +4113,8 @@ void MigrateFastToSlow(Handle<JSObject> object, Handle<Map> new_map,
DCHECK(instance_size_delta >= 0);
if (instance_size_delta > 0) {
// The object has shrunk and is not going to use these slots again.
// Since there will be no untagged stores in these slots,
// we can just let the sweeper remove slots in the filler.
heap->CreateFillerObjectAt(object->address() + new_instance_size,
instance_size_delta, ClearRecordedSlots::kNo);
instance_size_delta, ClearRecordedSlots::kYes);
heap->AdjustLiveBytes(*object, -instance_size_delta);
}
@ -4161,7 +4155,6 @@ void MigrateFastToSlow(Handle<JSObject> object, Handle<Map> new_map,
// static
void JSObject::NotifyMapChange(Handle<Map> old_map, Handle<Map> new_map,
Isolate* isolate) {
DCHECK_LE(new_map->instance_size(), old_map->instance_size());
if (!old_map->is_prototype_map()) return;
InvalidatePrototypeChains(*old_map);