Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (96371 => 96372)
--- trunk/Source/_javascript_Core/ChangeLog 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/ChangeLog 2011-09-29 22:52:45 UTC (rev 96372)
@@ -1,3 +1,46 @@
+2011-09-29 Oliver Hunt <oli...@apple.com>
+
+ Add logic to collect dirty objects as roots
+ https://bugs.webkit.org/show_bug.cgi?id=69100
+
+ Reviewed by Geoff Garen.
+
+ This gives us the ability to walk all the MarkedBlocks in an
+ AllocationSpace and collect the dirty objects, and then use
+ them as GC roots.
+
+ I also rearranged the order of these instructions because it
+ makes them smaller on some platforms with some card sizes.
+
+ * dfg/DFGJITCodeGenerator.cpp:
+ (JSC::DFG::JITCodeGenerator::markCellCard):
+ * dfg/DFGJITCodeGenerator32_64.cpp:
+ (JSC::DFG::JITCodeGenerator::markCellCard):
+ * heap/AllocationSpace.cpp:
+ Tidy up the write barrier logic a bit.
+ (JSC::MarkedBlock::gatherDirtyObjects):
+ (JSC::TakeIfDirty::returnValue):
+ (JSC::TakeIfDirty::TakeIfDirty):
+ (JSC::TakeIfDirty::operator()):
+ (JSC::AllocationSpace::gatherDirtyObjects):
+ * heap/AllocationSpace.h:
+ * heap/CardSet.h:
+ (JSC::::isCardMarked):
+ (JSC::::clearCard):
+ * heap/Heap.cpp:
+ (JSC::Heap::markRoots):
+ * heap/Heap.h:
+ (JSC::Heap::writeBarrier):
+ * heap/MarkStack.cpp:
+ (JSC::SlotVisitor::visitChildren):
+ * heap/MarkedBlock.h:
+ (JSC::MarkedBlock::setDirtyObject):
+ (JSC::MarkedBlock::addressOfCardFor):
+ * heap/SlotVisitor.h:
+ * jit/JITPropertyAccess.cpp:
+ (JSC::JIT::emitWriteBarrier):
+ Tidy the write barrier a bit.
+
2011-09-29 Gavin Barraclough <barraclo...@apple.com>
Unreviewed windows build fix.
Modified: trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator.cpp (96371 => 96372)
--- trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator.cpp 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator.cpp 2011-09-29 22:52:45 UTC (rev 96372)
@@ -1205,8 +1205,8 @@
jit.move(owner, scratch1);
jit.andPtr(TrustedImm32(static_cast<int32_t>(MarkedBlock::blockMask)), scratch1);
jit.move(owner, scratch2);
- jit.andPtr(TrustedImm32(static_cast<int32_t>(~MarkedBlock::blockMask)), scratch2);
- jit.rshift32(TrustedImm32(MarkedBlock::log2CardSize), scratch2);
+ jit.rshift32(TrustedImm32(MarkedBlock::cardShift), scratch2);
+ jit.andPtr(TrustedImm32(MarkedBlock::cardMask), scratch2);
jit.store8(TrustedImm32(1), MacroAssembler::BaseIndex(scratch1, scratch2, MacroAssembler::TimesOne, MarkedBlock::offsetOfCards()));
#endif
}
Modified: trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator32_64.cpp (96371 => 96372)
--- trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator32_64.cpp 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/dfg/DFGJITCodeGenerator32_64.cpp 2011-09-29 22:52:45 UTC (rev 96372)
@@ -1255,8 +1255,8 @@
jit.move(owner, scratch1);
jit.andPtr(TrustedImm32(static_cast<int32_t>(MarkedBlock::blockMask)), scratch1);
jit.move(owner, scratch2);
- jit.andPtr(TrustedImm32(static_cast<int32_t>(~MarkedBlock::blockMask)), scratch2);
- jit.rshift32(TrustedImm32(MarkedBlock::log2CardSize), scratch2);
+ jit.rshift32(TrustedImm32(MarkedBlock::cardShift), scratch2);
+ jit.andPtr(TrustedImm32(MarkedBlock::cardMask), scratch2);
jit.store8(TrustedImm32(1), MacroAssembler::BaseIndex(scratch1, scratch2, MacroAssembler::TimesOne, MarkedBlock::offsetOfCards()));
#endif
}
Modified: trunk/Source/_javascript_Core/heap/AllocationSpace.cpp (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/AllocationSpace.cpp 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/AllocationSpace.cpp 2011-09-29 22:52:45 UTC (rev 96372)
@@ -162,4 +162,35 @@
freeBlocks(forEachBlock(takeIfUnmarked));
}
+#if ENABLE(GGC)
+class GatherDirtyCells {
+ WTF_MAKE_NONCOPYABLE(GatherDirtyCells);
+public:
+ typedef void* ReturnType;
+
+ explicit GatherDirtyCells(MarkedBlock::DirtyCellVector*);
+ void operator()(MarkedBlock*);
+ ReturnType returnValue() { return 0; }
+
+private:
+ MarkedBlock::DirtyCellVector* m_dirtyCells;
+};
+
+inline GatherDirtyCells::GatherDirtyCells(MarkedBlock::DirtyCellVector* dirtyCells)
+ : m_dirtyCells(dirtyCells)
+{
}
+
+inline void GatherDirtyCells::operator()(MarkedBlock* block)
+{
+ block->gatherDirtyCells(*m_dirtyCells);
+}
+
+void AllocationSpace::gatherDirtyCells(MarkedBlock::DirtyCellVector& dirtyCells)
+{
+ GatherDirtyCells gatherDirtyCells(&dirtyCells);
+ forEachBlock(gatherDirtyCells);
+}
+#endif
+
+}
Modified: trunk/Source/_javascript_Core/heap/AllocationSpace.h (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/AllocationSpace.h 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/AllocationSpace.h 2011-09-29 22:52:45 UTC (rev 96372)
@@ -50,7 +50,9 @@
MarkedSpace::SizeClass& sizeClassFor(size_t bytes) { return m_markedSpace.sizeClassFor(bytes); }
void setHighWaterMark(size_t bytes) { m_markedSpace.setHighWaterMark(bytes); }
size_t highWaterMark() { return m_markedSpace.highWaterMark(); }
-
+
+ void gatherDirtyCells(MarkedBlock::DirtyCellVector&);
+
template<typename Functor> typename Functor::ReturnType forEachCell(Functor&);
template<typename Functor> typename Functor::ReturnType forEachCell();
template<typename Functor> typename Functor::ReturnType forEachBlock(Functor&);
Modified: trunk/Source/_javascript_Core/heap/CardSet.h (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/CardSet.h 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/CardSet.h 2011-09-29 22:52:45 UTC (rev 96372)
@@ -34,9 +34,10 @@
template <size_t cardSize, size_t blockSize> class CardSet {
WTF_MAKE_NONCOPYABLE(CardSet);
+
+public:
static const size_t cardCount = (blockSize + cardSize - 1) / cardSize;
-public:
CardSet()
{
memset(m_cards, 0, cardCount);
@@ -45,6 +46,8 @@
bool isCardMarkedForAtom(const void*);
void markCardForAtom(const void*);
uint8_t& cardForAtom(const void*);
+ bool isCardMarked(size_t);
+ void clearCard(size_t);
private:
uint8_t m_cards[cardCount];
@@ -69,6 +72,18 @@
cardForAtom(ptr) = 1;
}
+template <size_t cardSize, size_t blockSize> bool CardSet<cardSize, blockSize>::isCardMarked(size_t i)
+{
+ ASSERT(i < cardCount);
+ return m_cards[i];
}
+template <size_t cardSize, size_t blockSize> void CardSet<cardSize, blockSize>::clearCard(size_t i)
+{
+ ASSERT(i < cardCount);
+ m_cards[i] = 0;
+}
+
+}
+
#endif
Modified: trunk/Source/_javascript_Core/heap/Heap.cpp (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/Heap.cpp 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/Heap.cpp 2011-09-29 22:52:45 UTC (rev 96372)
@@ -471,12 +471,27 @@
m_jettisonedCodeBlocks.clearMarks();
registerFile().gatherConservativeRoots(registerFileRoots, m_jettisonedCodeBlocks);
m_jettisonedCodeBlocks.deleteUnmarkedCodeBlocks();
+#if ENABLE(GGC)
+ MarkedBlock::DirtyCellVector dirtyCells;
+ // Until we have a sensible policy we just random choose to perform
+ // young generation collections 90% of the time.
+ if (WTF::randomNumber() > 0.1)
+ m_objectSpace.gatherDirtyCells(dirtyCells);
+ else
+#endif
+ clearMarks();
- clearMarks();
SlotVisitor& visitor = m_slotVisitor;
HeapRootVisitor heapRootVisitor(visitor);
-
+
+#if ENABLE(GGC)
+ for (size_t i = 0; i < dirtyObjectCount; i++) {
+ heapRootVisitor.visitChildren(dirtyCells[i]);
+ visitor.drain();
+ }
+#endif
+
visitor.append(machineThreadRoots);
visitor.drain();
Modified: trunk/Source/_javascript_Core/heap/Heap.h (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/Heap.h 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/Heap.h 2011-09-29 22:52:45 UTC (rev 96372)
@@ -240,7 +240,9 @@
inline void Heap::writeBarrier(const JSCell* owner, JSCell*)
{
WriteBarrierCounters::countWriteBarrier();
- MarkedBlock::blockFor(owner)->setDirtyObject(owner);
+ MarkedBlock* block = MarkedBlock::blockFor(owner);
+ if (block->isMarked(owner))
+ block->setDirtyObject(owner);
}
inline void Heap::writeBarrier(const JSCell* owner, JSValue value)
Modified: trunk/Source/_javascript_Core/heap/HeapRootVisitor.h (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/HeapRootVisitor.h 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/HeapRootVisitor.h 2011-09-29 22:52:45 UTC (rev 96372)
@@ -43,7 +43,8 @@
void visit(JSValue*, size_t);
void visit(JSString**);
void visit(JSCell**);
-
+ void visitChildren(JSCell*);
+
SlotVisitor& visitor();
private:
@@ -75,6 +76,11 @@
m_visitor.append(slot);
}
+ inline void HeapRootVisitor::visitChildren(JSCell* cell)
+ {
+ m_visitor.visitChildren(cell);
+ }
+
inline SlotVisitor& HeapRootVisitor::visitor()
{
return m_visitor;
Modified: trunk/Source/_javascript_Core/heap/MarkStack.cpp (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/MarkStack.cpp 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/MarkStack.cpp 2011-09-29 22:52:45 UTC (rev 96372)
@@ -51,7 +51,7 @@
internalAppend(roots[i]);
}
-inline void SlotVisitor::visitChildren(JSCell* cell)
+void SlotVisitor::visitChildren(JSCell* cell)
{
#if ENABLE(SIMPLE_HEAP_PROFILING)
m_visitedTypeCounts.count(cell);
Modified: trunk/Source/_javascript_Core/heap/MarkedBlock.h (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/MarkedBlock.h 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/MarkedBlock.h 2011-09-29 22:52:45 UTC (rev 96372)
@@ -29,6 +29,7 @@
#include <wtf/HashFunctions.h>
#include <wtf/PageAllocationAligned.h>
#include <wtf/StdLibExtras.h>
+#include <wtf/Vector.h>
// Set to log state transitions of blocks.
#define HEAP_LOG_BLOCK_STATE_TRANSITIONS 0
@@ -72,8 +73,10 @@
static const size_t blockMask = ~(blockSize - 1); // blockSize must be a power of two.
static const size_t atomsPerBlock = blockSize / atomSize; // ~0.4% overhead
- static const size_t bytesPerCard = 512; // 1.6% overhead
- static const int log2CardSize = 9;
+ static const int cardShift = 10; // This is log2 of bytes per card.
+ static const size_t bytesPerCard = 1 << cardShift;
+ static const int cardCount = blockSize / bytesPerCard;
+ static const int cardMask = cardCount - 1;
struct FreeCell {
FreeCell* next;
@@ -123,11 +126,13 @@
#if ENABLE(GGC)
void setDirtyObject(const void* atom)
{
+ ASSERT(MarkedBlock::blockFor(atom) == this);
m_cards.markCardForAtom(atom);
}
uint8_t* addressOfCardFor(const void* atom)
{
+ ASSERT(MarkedBlock::blockFor(atom) == this);
return &m_cards.cardForAtom(atom);
}
@@ -135,6 +140,9 @@
{
return OBJECT_OFFSETOF(MarkedBlock, m_cards);
}
+
+ typedef Vector<JSCell*, 32> DirtyCellVector;
+ inline void gatherDirtyCells(DirtyCellVector&);
#endif
template <typename Functor> void forEachCell(Functor&);
@@ -300,6 +308,45 @@
}
}
+#if ENABLE(GGC)
+void MarkedBlock::gatherDirtyCells(DirtyCellVector& dirtyCells)
+{
+ COMPILE_ASSERT(m_cards.cardCount == cardCount, MarkedBlockCardCountsMatch);
+
+ ASSERT(m_state != New && m_state != FreeListed);
+
+ // This is an optimisation to avoid having to walk the set of marked
+ // blocks twice during GC.
+ m_state = Marked;
+
+ if (markCountIsZero())
+ return;
+
+ size_t cellSize = this->cellSize();
+ const size_t firstCellOffset = firstAtom() * atomSize % cellSize;
+
+ for (size_t i = 0; i < m_cards.cardCount; i++) {
+ if (!m_cards.isCardMarked(i))
+ continue;
+ char* ptr = reinterpret_cast<char*>(this);
+ if (i)
+ ptr += firstCellOffset + cellSize * ((i * bytesPerCard + cellSize - 1 - firstCellOffset) / cellSize);
+ else
+ ptr += firstAtom() * atomSize;
+ char* end = reinterpret_cast<char*>(this) + std::min((i + 1) * bytesPerCard, m_endAtom * atomSize);
+
+ while (ptr < end) {
+ JSCell* cell = reinterpret_cast<JSCell*>(ptr);
+ ASSERT(*addressOfCardFor(cell));
+ if (isMarked(cell))
+ dirtyCells.append(cell);
+ ptr += cellSize;
+ }
+ m_cards.clearCard(i);
+ }
+}
+#endif
+
} // namespace JSC
namespace WTF {
Modified: trunk/Source/_javascript_Core/heap/SlotVisitor.h (96371 => 96372)
--- trunk/Source/_javascript_Core/heap/SlotVisitor.h 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/heap/SlotVisitor.h 2011-09-29 22:52:45 UTC (rev 96372)
@@ -31,6 +31,7 @@
namespace JSC {
class SlotVisitor : public MarkStack {
+ friend class HeapRootVisitor;
public:
SlotVisitor(void* jsArrayVPtr);
Modified: trunk/Source/_javascript_Core/jit/JITPropertyAccess.cpp (96371 => 96372)
--- trunk/Source/_javascript_Core/jit/JITPropertyAccess.cpp 2011-09-29 22:42:03 UTC (rev 96371)
+++ trunk/Source/_javascript_Core/jit/JITPropertyAccess.cpp 2011-09-29 22:52:45 UTC (rev 96372)
@@ -1044,8 +1044,8 @@
move(owner, scratch);
andPtr(TrustedImm32(static_cast<int32_t>(MarkedBlock::blockMask)), scratch);
move(owner, scratch2);
- andPtr(TrustedImm32(static_cast<int32_t>(~MarkedBlock::blockMask)), scratch2);
- rshift32(TrustedImm32(MarkedBlock::log2CardSize), scratch2);
+ rshift32(TrustedImm32(MarkedBlock::cardShift), scratch2);
+ andPtr(TrustedImm32(MarkedBlock::cardMask), scratch2);
store8(TrustedImm32(1), BaseIndex(scratch, scratch2, TimesOne, MarkedBlock::offsetOfCards()));
if (mode == ShouldFilterImmediates)
filterCells.link(this);
