Reviewers: Benedikt Meurer,
Message:
Committed patchset #1 manually as r22270 (presubmit successful).
Description:
Reland "Precisely sweep scan on scavenge pages and use heap iterator to
iterate
over them."
BUG=
[email protected]
Committed: https://code.google.com/p/v8/source/detail?r=22270
Please review this at https://codereview.chromium.org/377863003/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+58, -27 lines):
M src/mark-compact.cc
M src/objects.h
M src/objects-inl.h
M src/spaces.cc
M src/store-buffer.cc
Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index
fafc9e1faebf192641e04bea34529d28f8ca786d..9192c5882036c3a2fe3eed8cd9c24f7023d05228
100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -4146,12 +4146,23 @@ void MarkCompactCollector::SweepSpace(PagedSpace*
space, SweeperType sweeper) {
pages_swept++;
parallel_sweeping_active = true;
} else {
- if (FLAG_gc_verbose) {
- PrintF("Sweeping 0x%" V8PRIxPTR " conservatively in
parallel.\n",
- reinterpret_cast<intptr_t>(p));
+ if (p->scan_on_scavenge()) {
+ SweepPrecisely<SWEEP_ONLY, IGNORE_SKIP_LIST,
IGNORE_FREE_SPACE>(
+ space, p, NULL);
+ pages_swept++;
+ if (FLAG_gc_verbose) {
+ PrintF("Sweeping 0x%" V8PRIxPTR
+ " scan on scavenge page precisely.\n",
+ reinterpret_cast<intptr_t>(p));
+ }
+ } else {
+ if (FLAG_gc_verbose) {
+ PrintF("Sweeping 0x%" V8PRIxPTR " conservatively in
parallel.\n",
+ reinterpret_cast<intptr_t>(p));
+ }
+
p->set_parallel_sweeping(MemoryChunk::PARALLEL_SWEEPING_PENDING);
+ space->IncreaseUnsweptFreeBytes(p);
}
- p->set_parallel_sweeping(MemoryChunk::PARALLEL_SWEEPING_PENDING);
- space->IncreaseUnsweptFreeBytes(p);
}
space->set_end_of_unswept_pages(p);
break;
Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index
0b500089c4a9879a04bb33b0a61aed7ecdf7e225..434ae95ac65e47f92f3af6c1973a66c4d6fa9c95
100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1480,6 +1480,22 @@ int HeapObject::Size() {
}
+bool HeapObject::ContainsPointers() {
+ InstanceType type = map()->instance_type();
+ if (type <= LAST_NAME_TYPE) {
+ if (type == SYMBOL_TYPE) {
+ return true;
+ }
+ ASSERT(type < FIRST_NONSTRING_TYPE);
+ // There are four string representations: sequential strings, external
+ // strings, cons strings, and sliced strings.
+ // Only the latter two contain non-map-word pointers to heap objects.
+ return ((type & kIsIndirectStringMask) == kIsIndirectStringTag);
+ }
+ return (type > LAST_DATA_TYPE);
+}
+
+
void HeapObject::IteratePointers(ObjectVisitor* v, int start, int end) {
v->VisitPointers(reinterpret_cast<Object**>(FIELD_ADDR(this, start)),
reinterpret_cast<Object**>(FIELD_ADDR(this, end)));
Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index
d49e365e59e51823655a71dee8046452551c8040..3cdd70bf9d86222e7fbd5d726a457e62260bb44c
100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -714,6 +714,7 @@ enum InstanceType {
FIXED_UINT8_CLAMPED_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE
FIXED_DOUBLE_ARRAY_TYPE,
+ CONSTANT_POOL_ARRAY_TYPE,
FILLER_TYPE, // LAST_DATA_TYPE
// Structs.
@@ -740,7 +741,6 @@ enum InstanceType {
BREAK_POINT_INFO_TYPE,
FIXED_ARRAY_TYPE,
- CONSTANT_POOL_ARRAY_TYPE,
SHARED_FUNCTION_INFO_TYPE,
// All the following types are subtypes of JSReceiver, which corresponds
to
@@ -1716,6 +1716,10 @@ class HeapObject: public Object {
// Returns the heap object's size in bytes
inline int Size();
+ // Returns true if this heap object contains only references to other
+ // heap objects.
+ inline bool ContainsPointers();
+
// Given a heap object's map pointer, returns the heap size in bytes
// Useful when the map pointer field is used for other purposes.
// GC internal.
Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index
560c7d87188e052ec5941f56cceb8a78cee7d7b9..12613c7cb0fc4898d9a5ca172deda517d56a2922
100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -18,6 +18,9 @@ namespace internal {
// HeapObjectIterator
HeapObjectIterator::HeapObjectIterator(PagedSpace* space) {
+ // Check that we actually can iterate this space.
+ ASSERT(space->is_iterable());
+
// You can't actually iterate over the anchor page. It is not a real
page,
// just an anchor for the double linked page list. Initialize as if we
have
// reached the end of the anchor page, then the first iteration will
move on
@@ -32,6 +35,9 @@ HeapObjectIterator::HeapObjectIterator(PagedSpace* space)
{
HeapObjectIterator::HeapObjectIterator(PagedSpace* space,
HeapObjectCallback size_func) {
+ // Check that we actually can iterate this space.
+ ASSERT(space->is_iterable());
+
// You can't actually iterate over the anchor page. It is not a real
page,
// just an anchor for the double linked page list. Initialize the
current
// address and end as NULL, then the first iteration will move on
@@ -66,9 +72,6 @@ void HeapObjectIterator::Initialize(PagedSpace* space,
Address cur, Address end,
HeapObjectIterator::PageMode mode,
HeapObjectCallback size_f) {
- // Check that we actually can iterate this space.
- ASSERT(space->is_iterable());
-
space_ = space;
cur_addr_ = cur;
cur_end_ = end;
Index: src/store-buffer.cc
diff --git a/src/store-buffer.cc b/src/store-buffer.cc
index
7ee4fa2d4000ed4529476a427505194d579e443a..a7575ae32822344c7c626e81daa9a122a4e614f4
100644
--- a/src/store-buffer.cc
+++ b/src/store-buffer.cc
@@ -519,25 +519,22 @@ void
StoreBuffer::IteratePointersToNewSpace(ObjectSlotCallback slot_callback,
FindPointersToNewSpaceInRegion(start, end, slot_callback,
clear_maps);
} else {
Page* page = reinterpret_cast<Page*>(chunk);
- PagedSpace* owner = reinterpret_cast<PagedSpace*>(page->owner());
- Address start = page->area_start();
- Address end = page->area_end();
- if (owner == heap_->map_space()) {
- ASSERT(page->WasSweptPrecisely());
- HeapObjectIterator iterator(page, NULL);
- for (HeapObject* heap_object = iterator.Next(); heap_object !=
NULL;
- heap_object = iterator.Next()) {
- // We skip free space objects.
- if (!heap_object->IsFiller()) {
- FindPointersToNewSpaceInRegion(
- heap_object->address() + HeapObject::kHeaderSize,
- heap_object->address() + heap_object->Size(),
slot_callback,
- clear_maps);
- }
+ ASSERT(page->owner() == heap_->map_space() ||
+ page->owner() == heap_->old_pointer_space());
+ CHECK(page->WasSweptPrecisely());
+
+ HeapObjectIterator iterator(page, NULL);
+ for (HeapObject* heap_object = iterator.Next();
+ heap_object != NULL;
+ heap_object = iterator.Next()) {
+ // We iterate over objects that contain pointers only.
+ if (heap_object->ContainsPointers()) {
+ FindPointersToNewSpaceInRegion(
+ heap_object->address() + HeapObject::kHeaderSize,
+ heap_object->address() + heap_object->Size(),
+ slot_callback,
+ clear_maps);
}
- } else {
- FindPointersToNewSpaceInRegion(
- start, end, slot_callback, clear_maps);
}
}
}
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