Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(199)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: src/spaces.cc

Issue 2255004: Cardmarking writebarrier. (Closed)
Patch Set: Created 10 years, 7 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « src/spaces.h ('k') | src/spaces-inl.h » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index 6b6d926e257153f35de2453e9359cb9faf772f0a..1d868e9ac731d32a7c354bf8b8b8c6098ce322ec 100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -41,6 +41,7 @@ namespace internal {
&& (info).top <= (space).high() \
&& (info).limit == (space).high())
+intptr_t Page::watermark_invalidated_mark_ = Page::WATERMARK_INVALIDATED;
// ----------------------------------------------------------------------------
// HeapObjectIterator
@@ -139,13 +140,6 @@ PageIterator::PageIterator(PagedSpace* space, Mode mode) : space_(space) {
// -----------------------------------------------------------------------------
-// Page
-
-#ifdef DEBUG
-Page::RSetState Page::rset_state_ = Page::IN_USE;
-#endif
-
-// -----------------------------------------------------------------------------
// CodeRange
List<CodeRange::FreeBlock> CodeRange::free_list_(0);
@@ -524,7 +518,10 @@ Page* MemoryAllocator::InitializePagesInChunk(int chunk_id, int pages_in_chunk,
for (int i = 0; i < pages_in_chunk; i++) {
Page* p = Page::FromAddress(page_addr);
p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id;
+ p->InvalidateWatermark(true);
p->SetIsLargeObjectPage(false);
+ p->SetAllocationWatermark(p->ObjectAreaStart());
+ p->SetCachedAllocationWatermark(p->ObjectAreaStart());
page_addr += Page::kPageSize;
}
@@ -681,6 +678,7 @@ Page* MemoryAllocator::RelinkPagesInChunk(int chunk_id,
p->opaque_header = OffsetFrom(page_addr + Page::kPageSize) | chunk_id;
page_addr += Page::kPageSize;
+ p->InvalidateWatermark(true);
if (p->WasInUseBeforeMC()) {
*last_page_in_use = p;
}
@@ -744,10 +742,10 @@ bool PagedSpace::Setup(Address start, size_t size) {
accounting_stats_.ExpandSpace(num_pages * Page::kObjectAreaSize);
ASSERT(Capacity() <= max_capacity_);
- // Sequentially initialize remembered sets in the newly allocated
+ // Sequentially clear region marks in the newly allocated
// pages and cache the current last page in the space.
for (Page* p = first_page_; p->is_valid(); p = p->next_page()) {
- p->ClearRSet();
+ p->SetRegionMarks(Page::kAllRegionsCleanMarks);
last_page_ = p;
}
@@ -794,10 +792,10 @@ void PagedSpace::Unprotect() {
#endif
-void PagedSpace::ClearRSet() {
+void PagedSpace::MarkAllPagesClean() {
PageIterator it(this, PageIterator::ALL_PAGES);
while (it.has_next()) {
- it.next()->ClearRSet();
+ it.next()->SetRegionMarks(Page::kAllRegionsCleanMarks);
}
}
@@ -900,7 +898,8 @@ HeapObject* PagedSpace::SlowMCAllocateRaw(int size_in_bytes) {
// of forwarding addresses is as an offset in terms of live bytes, so we
// need quick access to the allocation top of each page to decode
// forwarding addresses.
- current_page->mc_relocation_top = mc_forwarding_info_.top;
+ current_page->SetAllocationWatermark(mc_forwarding_info_.top);
+ current_page->next_page()->InvalidateWatermark(true);
SetAllocationInfo(&mc_forwarding_info_, current_page->next_page());
return AllocateLinearly(&mc_forwarding_info_, size_in_bytes);
}
@@ -928,10 +927,10 @@ bool PagedSpace::Expand(Page* last_page) {
MemoryAllocator::SetNextPage(last_page, p);
- // Sequentially clear remembered set of new pages and and cache the
+ // Sequentially clear region marks of new pages and and cache the
// new last page in the space.
while (p->is_valid()) {
- p->ClearRSet();
+ p->SetRegionMarks(Page::kAllRegionsCleanMarks);
last_page_ = p;
p = p->next_page();
}
@@ -1030,16 +1029,11 @@ void PagedSpace::Verify(ObjectVisitor* visitor) {
if (above_allocation_top) {
// We don't care what's above the allocation top.
} else {
- // Unless this is the last page in the space containing allocated
- // objects, the allocation top should be at a constant offset from the
- // object area end.
Address top = current_page->AllocationTop();
if (current_page == top_page) {
ASSERT(top == allocation_info_.top);
// The next page will be above the allocation top.
above_allocation_top = true;
- } else {
- ASSERT(top == PageAllocationLimit(current_page));
}
// It should be packed with objects from the bottom to the top.
@@ -1060,8 +1054,8 @@ void PagedSpace::Verify(ObjectVisitor* visitor) {
object->Verify();
// All the interior pointers should be contained in the heap and
- // have their remembered set bits set if required as determined
- // by the visitor.
+ // have page regions covering intergenerational references should be
+ // marked dirty.
int size = object->Size();
object->IterateBody(map->instance_type(), size, visitor);
@@ -1120,7 +1114,7 @@ bool NewSpace::Setup(Address start, int size) {
start_ = start;
address_mask_ = ~(size - 1);
- object_mask_ = address_mask_ | kHeapObjectTag;
+ object_mask_ = address_mask_ | kHeapObjectTagMask;
object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag;
allocation_info_.top = to_space_.low();
@@ -1324,7 +1318,7 @@ bool SemiSpace::Setup(Address start,
start_ = start;
address_mask_ = ~(maximum_capacity - 1);
- object_mask_ = address_mask_ | kHeapObjectTag;
+ object_mask_ = address_mask_ | kHeapObjectTagMask;
object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag;
age_mark_ = start_;
@@ -1634,7 +1628,7 @@ void FreeListNode::set_size(int size_in_bytes) {
// If the block is too small (eg, one or two words), to hold both a size
// field and a next pointer, we give it a filler map that gives it the
// correct size.
- if (size_in_bytes > ByteArray::kAlignedSize) {
+ if (size_in_bytes > ByteArray::kHeaderSize) {
set_map(Heap::raw_unchecked_byte_array_map());
// Can't use ByteArray::cast because it fails during deserialization.
ByteArray* this_as_byte_array = reinterpret_cast<ByteArray*>(this);
@@ -1831,7 +1825,7 @@ FixedSizeFreeList::FixedSizeFreeList(AllocationSpace owner, int object_size)
void FixedSizeFreeList::Reset() {
available_ = 0;
- head_ = NULL;
+ head_ = tail_ = NULL;
}
@@ -1843,8 +1837,13 @@ void FixedSizeFreeList::Free(Address start) {
ASSERT(!MarkCompactCollector::IsCompacting());
FreeListNode* node = FreeListNode::FromAddress(start);
node->set_size(object_size_);
- node->set_next(head_);
- head_ = node->address();
+ node->set_next(NULL);
+ if (head_ == NULL) {
+ tail_ = head_ = node->address();
+ } else {
+ FreeListNode::FromAddress(tail_)->set_next(node->address());
+ tail_ = node->address();
+ }
available_ += object_size_;
}
@@ -1907,15 +1906,14 @@ void OldSpace::MCCommitRelocationInfo() {
Page* p = it.next();
// Space below the relocation pointer is allocated.
computed_size +=
- static_cast<int>(p->mc_relocation_top - p->ObjectAreaStart());
+ static_cast<int>(p->AllocationWatermark() - p->ObjectAreaStart());
if (it.has_next()) {
- // Free the space at the top of the page. We cannot use
- // p->mc_relocation_top after the call to Free (because Free will clear
- // remembered set bits).
+ // Free the space at the top of the page.
int extra_size =
- static_cast<int>(p->ObjectAreaEnd() - p->mc_relocation_top);
+ static_cast<int>(p->ObjectAreaEnd() - p->AllocationWatermark());
if (extra_size > 0) {
- int wasted_bytes = free_list_.Free(p->mc_relocation_top, extra_size);
+ int wasted_bytes = free_list_.Free(p->AllocationWatermark(),
+ extra_size);
// The bytes we have just "freed" to add to the free list were
// already accounted as available.
accounting_stats_.WasteBytes(wasted_bytes);
@@ -1963,7 +1961,10 @@ void PagedSpace::FreePages(Page* prev, Page* last) {
// Clean them up.
do {
- first->ClearRSet();
+ first->InvalidateWatermark(true);
+ first->SetAllocationWatermark(first->ObjectAreaStart());
+ first->SetCachedAllocationWatermark(first->ObjectAreaStart());
+ first->SetRegionMarks(Page::kAllRegionsCleanMarks);
first = first->next_page();
} while (first != NULL);
@@ -2003,6 +2004,7 @@ void PagedSpace::PrepareForMarkCompact(bool will_compact) {
// Current allocation top points to a page which is now in the middle
// of page list. We should move allocation top forward to the new last
// used page so various object iterators will continue to work properly.
+ last_in_use->SetAllocationWatermark(last_in_use->AllocationTop());
int size_in_bytes = static_cast<int>(PageAllocationLimit(last_in_use) -
last_in_use->AllocationTop());
@@ -2035,6 +2037,7 @@ void PagedSpace::PrepareForMarkCompact(bool will_compact) {
int size_in_bytes = static_cast<int>(PageAllocationLimit(p) -
p->ObjectAreaStart());
+ p->SetAllocationWatermark(p->ObjectAreaStart());
Heap::CreateFillerObjectAt(p->ObjectAreaStart(), size_in_bytes);
}
}
@@ -2066,6 +2069,7 @@ bool PagedSpace::ReserveSpace(int bytes) {
if (!reserved_page->is_valid()) return false;
}
ASSERT(TopPageOf(allocation_info_)->next_page()->is_valid());
+ TopPageOf(allocation_info_)->next_page()->InvalidateWatermark(true);
SetAllocationInfo(&allocation_info_,
TopPageOf(allocation_info_)->next_page());
return true;
@@ -2100,7 +2104,20 @@ HeapObject* OldSpace::SlowAllocateRaw(int size_in_bytes) {
accounting_stats_.WasteBytes(wasted_bytes);
if (!result->IsFailure()) {
accounting_stats_.AllocateBytes(size_in_bytes);
- return HeapObject::cast(result);
+
+ HeapObject* obj = HeapObject::cast(result);
+ Page* p = Page::FromAddress(obj->address());
+
+ if (obj->address() >= p->AllocationWatermark()) {
+ // There should be no hole between the allocation watermark
+ // and allocated object address.
+ // Memory above the allocation watermark was not swept and
+ // might contain garbage pointers to new space.
+ ASSERT(obj->address() == p->AllocationWatermark());
+ p->SetAllocationWatermark(obj->address() + size_in_bytes);
+ }
+
+ return obj;
}
}
@@ -2123,6 +2140,7 @@ HeapObject* OldSpace::SlowAllocateRaw(int size_in_bytes) {
void OldSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) {
+ current_page->SetAllocationWatermark(allocation_info_.top);
int free_size =
static_cast<int>(current_page->ObjectAreaEnd() - allocation_info_.top);
if (free_size > 0) {
@@ -2133,6 +2151,7 @@ void OldSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) {
void FixedSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) {
+ current_page->SetAllocationWatermark(allocation_info_.top);
int free_size =
static_cast<int>(current_page->ObjectAreaEnd() - allocation_info_.top);
// In the fixed space free list all the free list items have the right size.
@@ -2152,8 +2171,10 @@ void FixedSpace::PutRestOfCurrentPageOnFreeList(Page* current_page) {
HeapObject* OldSpace::AllocateInNextPage(Page* current_page,
int size_in_bytes) {
ASSERT(current_page->next_page()->is_valid());
+ Page* next_page = current_page->next_page();
+ next_page->ClearGCFields();
PutRestOfCurrentPageOnFreeList(current_page);
- SetAllocationInfo(&allocation_info_, current_page->next_page());
+ SetAllocationInfo(&allocation_info_, next_page);
return AllocateLinearly(&allocation_info_, size_in_bytes);
}
@@ -2296,160 +2317,12 @@ void OldSpace::ReportStatistics() {
PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n",
Capacity(), Waste(), Available(), pct);
- // Report remembered set statistics.
- int rset_marked_pointers = 0;
- int rset_marked_arrays = 0;
- int rset_marked_array_elements = 0;
- int cross_gen_pointers = 0;
- int cross_gen_array_elements = 0;
-
- PageIterator page_it(this, PageIterator::PAGES_IN_USE);
- while (page_it.has_next()) {
- Page* p = page_it.next();
-
- for (Address rset_addr = p->RSetStart();
- rset_addr < p->RSetEnd();
- rset_addr += kIntSize) {
- int rset = Memory::int_at(rset_addr);
- if (rset != 0) {
- // Bits were set
- int intoff =
- static_cast<int>(rset_addr - p->address() - Page::kRSetOffset);
- int bitoff = 0;
- for (; bitoff < kBitsPerInt; ++bitoff) {
- if ((rset & (1 << bitoff)) != 0) {
- int bitpos = intoff*kBitsPerByte + bitoff;
- Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits);
- Object** obj = reinterpret_cast<Object**>(slot);
- if (*obj == Heap::raw_unchecked_fixed_array_map()) {
- rset_marked_arrays++;
- FixedArray* fa = FixedArray::cast(HeapObject::FromAddress(slot));
-
- rset_marked_array_elements += fa->length();
- // Manually inline FixedArray::IterateBody
- Address elm_start = slot + FixedArray::kHeaderSize;
- Address elm_stop = elm_start + fa->length() * kPointerSize;
- for (Address elm_addr = elm_start;
- elm_addr < elm_stop; elm_addr += kPointerSize) {
- // Filter non-heap-object pointers
- Object** elm_p = reinterpret_cast<Object**>(elm_addr);
- if (Heap::InNewSpace(*elm_p))
- cross_gen_array_elements++;
- }
- } else {
- rset_marked_pointers++;
- if (Heap::InNewSpace(*obj))
- cross_gen_pointers++;
- }
- }
- }
- }
- }
- }
-
- pct = rset_marked_pointers == 0 ?
- 0 : cross_gen_pointers * 100 / rset_marked_pointers;
- PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n",
- rset_marked_pointers, cross_gen_pointers, pct);
- PrintF(" rset_marked arrays %d, ", rset_marked_arrays);
- PrintF(" elements %d, ", rset_marked_array_elements);
- pct = rset_marked_array_elements == 0 ? 0
- : cross_gen_array_elements * 100 / rset_marked_array_elements;
- PrintF(" pointers to new space %d (%%%d)\n", cross_gen_array_elements, pct);
- PrintF(" total rset-marked bits %d\n",
- (rset_marked_pointers + rset_marked_arrays));
- pct = (rset_marked_pointers + rset_marked_array_elements) == 0 ? 0
- : (cross_gen_pointers + cross_gen_array_elements) * 100 /
- (rset_marked_pointers + rset_marked_array_elements);
- PrintF(" total rset pointers %d, true cross generation ones %d (%%%d)\n",
- (rset_marked_pointers + rset_marked_array_elements),
- (cross_gen_pointers + cross_gen_array_elements),
- pct);
-
ClearHistograms();
HeapObjectIterator obj_it(this);
for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next())
CollectHistogramInfo(obj);
ReportHistogram(true);
}
-
-
-// Dump the range of remembered set words between [start, end) corresponding
-// to the pointers starting at object_p. The allocation_top is an object
-// pointer which should not be read past. This is important for large object
-// pages, where some bits in the remembered set range do not correspond to
-// allocated addresses.
-static void PrintRSetRange(Address start, Address end, Object** object_p,
- Address allocation_top) {
- Address rset_address = start;
-
- // If the range starts on on odd numbered word (eg, for large object extra
- // remembered set ranges), print some spaces.
- if ((reinterpret_cast<uintptr_t>(start) / kIntSize) % 2 == 1) {
- PrintF(" ");
- }
-
- // Loop over all the words in the range.
- while (rset_address < end) {
- uint32_t rset_word = Memory::uint32_at(rset_address);
- int bit_position = 0;
-
- // Loop over all the bits in the word.
- while (bit_position < kBitsPerInt) {
- if (object_p == reinterpret_cast<Object**>(allocation_top)) {
- // Print a bar at the allocation pointer.
- PrintF("|");
- } else if (object_p > reinterpret_cast<Object**>(allocation_top)) {
- // Do not dereference object_p past the allocation pointer.
- PrintF("#");
- } else if ((rset_word & (1 << bit_position)) == 0) {
- // Print a dot for zero bits.
- PrintF(".");
- } else if (Heap::InNewSpace(*object_p)) {
- // Print an X for one bits for pointers to new space.
- PrintF("X");
- } else {
- // Print a circle for one bits for pointers to old space.
- PrintF("o");
- }
-
- // Print a space after every 8th bit except the last.
- if (bit_position % 8 == 7 && bit_position != (kBitsPerInt - 1)) {
- PrintF(" ");
- }
-
- // Advance to next bit.
- bit_position++;
- object_p++;
- }
-
- // Print a newline after every odd numbered word, otherwise a space.
- if ((reinterpret_cast<uintptr_t>(rset_address) / kIntSize) % 2 == 1) {
- PrintF("\n");
- } else {
- PrintF(" ");
- }
-
- // Advance to next remembered set word.
- rset_address += kIntSize;
- }
-}
-
-
-void PagedSpace::DoPrintRSet(const char* space_name) {
- PageIterator it(this, PageIterator::PAGES_IN_USE);
- while (it.has_next()) {
- Page* p = it.next();
- PrintF("%s page 0x%x:\n", space_name, p);
- PrintRSetRange(p->RSetStart(), p->RSetEnd(),
- reinterpret_cast<Object**>(p->ObjectAreaStart()),
- p->AllocationTop());
- PrintF("\n");
- }
-}
-
-
-void OldSpace::PrintRSet() { DoPrintRSet("old"); }
#endif
// -----------------------------------------------------------------------------
@@ -2499,6 +2372,7 @@ void FixedSpace::MCCommitRelocationInfo() {
if (it.has_next()) {
accounting_stats_.WasteBytes(
static_cast<int>(page->ObjectAreaEnd() - page_top));
+ page->SetAllocationWatermark(page_top);
}
}
@@ -2528,7 +2402,19 @@ HeapObject* FixedSpace::SlowAllocateRaw(int size_in_bytes) {
Object* result = free_list_.Allocate();
if (!result->IsFailure()) {
accounting_stats_.AllocateBytes(size_in_bytes);
- return HeapObject::cast(result);
+ HeapObject* obj = HeapObject::cast(result);
+ Page* p = Page::FromAddress(obj->address());
+
+ if (obj->address() >= p->AllocationWatermark()) {
+ // There should be no hole between the allocation watermark
+ // and allocated object address.
+ // Memory above the allocation watermark was not swept and
+ // might contain garbage pointers to new space.
+ ASSERT(obj->address() == p->AllocationWatermark());
+ p->SetAllocationWatermark(obj->address() + size_in_bytes);
+ }
+
+ return obj;
}
}
@@ -2558,8 +2444,11 @@ HeapObject* FixedSpace::AllocateInNextPage(Page* current_page,
ASSERT(current_page->next_page()->is_valid());
ASSERT(allocation_info_.top == PageAllocationLimit(current_page));
ASSERT_EQ(object_size_in_bytes_, size_in_bytes);
+ Page* next_page = current_page->next_page();
+ next_page->ClearGCFields();
+ current_page->SetAllocationWatermark(allocation_info_.top);
accounting_stats_.WasteBytes(page_extra_);
- SetAllocationInfo(&allocation_info_, current_page->next_page());
+ SetAllocationInfo(&allocation_info_, next_page);
return AllocateLinearly(&allocation_info_, size_in_bytes);
}
@@ -2570,51 +2459,12 @@ void FixedSpace::ReportStatistics() {
PrintF(" capacity: %d, waste: %d, available: %d, %%%d\n",
Capacity(), Waste(), Available(), pct);
- // Report remembered set statistics.
- int rset_marked_pointers = 0;
- int cross_gen_pointers = 0;
-
- PageIterator page_it(this, PageIterator::PAGES_IN_USE);
- while (page_it.has_next()) {
- Page* p = page_it.next();
-
- for (Address rset_addr = p->RSetStart();
- rset_addr < p->RSetEnd();
- rset_addr += kIntSize) {
- int rset = Memory::int_at(rset_addr);
- if (rset != 0) {
- // Bits were set
- int intoff =
- static_cast<int>(rset_addr - p->address() - Page::kRSetOffset);
- int bitoff = 0;
- for (; bitoff < kBitsPerInt; ++bitoff) {
- if ((rset & (1 << bitoff)) != 0) {
- int bitpos = intoff*kBitsPerByte + bitoff;
- Address slot = p->OffsetToAddress(bitpos << kObjectAlignmentBits);
- Object** obj = reinterpret_cast<Object**>(slot);
- rset_marked_pointers++;
- if (Heap::InNewSpace(*obj))
- cross_gen_pointers++;
- }
- }
- }
- }
- }
-
- pct = rset_marked_pointers == 0 ?
- 0 : cross_gen_pointers * 100 / rset_marked_pointers;
- PrintF(" rset-marked pointers %d, to-new-space %d (%%%d)\n",
- rset_marked_pointers, cross_gen_pointers, pct);
-
ClearHistograms();
HeapObjectIterator obj_it(this);
for (HeapObject* obj = obj_it.next(); obj != NULL; obj = obj_it.next())
CollectHistogramInfo(obj);
ReportHistogram(false);
}
-
-
-void FixedSpace::PrintRSet() { DoPrintRSet(name_); }
#endif
@@ -2793,8 +2643,7 @@ Object* LargeObjectSpace::AllocateRawInternal(int requested_size,
chunk->set_size(chunk_size);
first_chunk_ = chunk;
- // Set the object address and size in the page header and clear its
- // remembered set.
+ // Initialize page header.
Page* page = Page::FromAddress(RoundUp(chunk->address(), Page::kPageSize));
Address object_address = page->ObjectAreaStart();
// Clear the low order bit of the second word in the page to flag it as a
@@ -2802,13 +2651,7 @@ Object* LargeObjectSpace::AllocateRawInternal(int requested_size,
// low order bit should already be clear.
ASSERT((chunk_size & 0x1) == 0);
page->SetIsLargeObjectPage(true);
- page->ClearRSet();
- int extra_bytes = requested_size - object_size;
- if (extra_bytes > 0) {
- // The extra memory for the remembered set should be cleared.
- memset(object_address + object_size, 0, extra_bytes);
- }
-
+ page->SetRegionMarks(Page::kAllRegionsCleanMarks);
return HeapObject::FromAddress(object_address);
}
@@ -2823,8 +2666,7 @@ Object* LargeObjectSpace::AllocateRawCode(int size_in_bytes) {
Object* LargeObjectSpace::AllocateRawFixedArray(int size_in_bytes) {
ASSERT(0 < size_in_bytes);
- int extra_rset_bytes = ExtraRSetBytesFor(size_in_bytes);
- return AllocateRawInternal(size_in_bytes + extra_rset_bytes,
+ return AllocateRawInternal(size_in_bytes,
size_in_bytes,
NOT_EXECUTABLE);
}
@@ -2851,59 +2693,61 @@ Object* LargeObjectSpace::FindObject(Address a) {
return Failure::Exception();
}
-
-void LargeObjectSpace::ClearRSet() {
- ASSERT(Page::is_rset_in_use());
-
- LargeObjectIterator it(this);
- for (HeapObject* object = it.next(); object != NULL; object = it.next()) {
- // We only have code, sequential strings, or fixed arrays in large
- // object space, and only fixed arrays need remembered set support.
- if (object->IsFixedArray()) {
- // Clear the normal remembered set region of the page;
- Page* page = Page::FromAddress(object->address());
- page->ClearRSet();
-
- // Clear the extra remembered set.
- int size = object->Size();
- int extra_rset_bytes = ExtraRSetBytesFor(size);
- memset(object->address() + size, 0, extra_rset_bytes);
- }
- }
-}
-
-
-void LargeObjectSpace::IterateRSet(ObjectSlotCallback copy_object_func) {
- ASSERT(Page::is_rset_in_use());
-
- static void* lo_rset_histogram = StatsTable::CreateHistogram(
- "V8.RSetLO",
- 0,
- // Keeping this histogram's buckets the same as the paged space histogram.
- Page::kObjectAreaSize / kPointerSize,
- 30);
-
+void LargeObjectSpace::IterateDirtyRegions(ObjectSlotCallback copy_object) {
LargeObjectIterator it(this);
for (HeapObject* object = it.next(); object != NULL; object = it.next()) {
// We only have code, sequential strings, or fixed arrays in large
// object space, and only fixed arrays can possibly contain pointers to
// the young generation.
if (object->IsFixedArray()) {
- // Iterate the normal page remembered set range.
Page* page = Page::FromAddress(object->address());
- Address object_end = object->address() + object->Size();
- int count = Heap::IterateRSetRange(page->ObjectAreaStart(),
- Min(page->ObjectAreaEnd(), object_end),
- page->RSetStart(),
- copy_object_func);
-
- // Iterate the extra array elements.
- if (object_end > page->ObjectAreaEnd()) {
- count += Heap::IterateRSetRange(page->ObjectAreaEnd(), object_end,
- object_end, copy_object_func);
- }
- if (lo_rset_histogram != NULL) {
- StatsTable::AddHistogramSample(lo_rset_histogram, count);
+ uint32_t marks = page->GetRegionMarks();
+ uint32_t newmarks = Page::kAllRegionsCleanMarks;
+
+ if (marks != Page::kAllRegionsCleanMarks) {
+ // For a large page a single dirty mark corresponds to several
+ // regions (modulo 32). So we treat a large page as a sequence of
+ // normal pages of size Page::kPageSize having same dirty marks
+ // and subsequently iterate dirty regions on each of these pages.
+ Address start = object->address();
+ Address end = page->ObjectAreaEnd();
+ Address object_end = start + object->Size();
+
+ // Iterate regions of the first normal page covering object.
+ uint32_t first_region_number = page->GetRegionNumberForAddress(start);
+ newmarks |=
+ Heap::IterateDirtyRegions(marks >> first_region_number,
+ start,
+ end,
+ &Heap::IteratePointersInDirtyRegion,
+ copy_object) << first_region_number;
+
+ start = end;
+ end = start + Page::kPageSize;
+ while (end <= object_end) {
+ // Iterate next 32 regions.
+ newmarks |=
+ Heap::IterateDirtyRegions(marks,
+ start,
+ end,
+ &Heap::IteratePointersInDirtyRegion,
+ copy_object);
+ start = end;
+ end = start + Page::kPageSize;
+ }
+
+ if (start != object_end) {
+ // Iterate the last piece of an object which is less than
+ // Page::kPageSize.
+ newmarks |=
+ Heap::IterateDirtyRegions(marks,
+ start,
+ object_end,
+ &Heap::IteratePointersInDirtyRegion,
+ copy_object);
+ }
+
+ page->SetRegionMarks(newmarks);
}
}
}
@@ -2995,7 +2839,7 @@ void LargeObjectSpace::Verify() {
} else if (object->IsFixedArray()) {
// We loop over fixed arrays ourselves, rather then using the visitor,
// because the visitor doesn't support the start/offset iteration
- // needed for IsRSetSet.
+ // needed for IsRegionDirty.
FixedArray* array = FixedArray::cast(object);
for (int j = 0; j < array->length(); j++) {
Object* element = array->get(j);
@@ -3004,8 +2848,11 @@ void LargeObjectSpace::Verify() {
ASSERT(Heap::Contains(element_object));
ASSERT(element_object->map()->IsMap());
if (Heap::InNewSpace(element_object)) {
- ASSERT(Page::IsRSetSet(object->address(),
- FixedArray::kHeaderSize + j * kPointerSize));
+ Address array_addr = object->address();
+ Address element_addr = array_addr + FixedArray::kHeaderSize +
+ j * kPointerSize;
+
+ ASSERT(Page::FromAddress(array_addr)->IsRegionDirty(element_addr));
}
}
}
@@ -3046,33 +2893,6 @@ void LargeObjectSpace::CollectCodeStatistics() {
}
}
}
-
-
-void LargeObjectSpace::PrintRSet() {
- LargeObjectIterator it(this);
- for (HeapObject* object = it.next(); object != NULL; object = it.next()) {
- if (object->IsFixedArray()) {
- Page* page = Page::FromAddress(object->address());
-
- Address allocation_top = object->address() + object->Size();
- PrintF("large page 0x%x:\n", page);
- PrintRSetRange(page->RSetStart(), page->RSetEnd(),
- reinterpret_cast<Object**>(object->address()),
- allocation_top);
- int extra_array_bytes = object->Size() - Page::kObjectAreaSize;
- int extra_rset_bits = RoundUp(extra_array_bytes / kPointerSize,
- kBitsPerInt);
- PrintF("------------------------------------------------------------"
- "-----------\n");
- PrintRSetRange(allocation_top,
- allocation_top + extra_rset_bits / kBitsPerByte,
- reinterpret_cast<Object**>(object->address()
- + Page::kObjectAreaSize),
- allocation_top);
- PrintF("\n");
- }
- }
-}
#endif // DEBUG
} } // namespace v8::internal
« no previous file with comments | « src/spaces.h ('k') | src/spaces-inl.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698