void Heap::markRoots()
{
SamplingRegion samplingRegion("Garbage Collection: Tracing");
GCPHASE(MarkRoots);
ASSERT(isValidThreadState(m_vm));
#if ENABLE(OBJECT_MARK_LOGGING)
double gcStartTime = WTF::monotonicallyIncreasingTime();
#endif
void* dummy;
// We gather conservative roots before clearing mark bits because conservative
// gathering uses the mark bits to determine whether a reference is valid.
ConservativeRoots machineThreadRoots(&m_objectSpace.blocks(), &m_storageSpace);
m_jitStubRoutines.clearMarks();
{
GCPHASE(GatherConservativeRoots);
m_machineThreads.gatherConservativeRoots(machineThreadRoots, &dummy);
}
ConservativeRoots stackRoots(&m_objectSpace.blocks(), &m_storageSpace);
m_codeBlocks.clearMarks();
{
GCPHASE(GatherStackRoots);
stack().gatherConservativeRoots(stackRoots, m_jitStubRoutines, m_codeBlocks);
stack().sanitizeStack();
}
#if ENABLE(DFG_JIT)
ConservativeRoots scratchBufferRoots(&m_objectSpace.blocks(), &m_storageSpace);
{
GCPHASE(GatherScratchBufferRoots);
m_vm->gatherConservativeRoots(scratchBufferRoots);
}
#endif
{
GCPHASE(ClearLivenessData);
m_objectSpace.clearNewlyAllocated();
m_objectSpace.clearMarks();
}
m_sharedData.didStartMarking();
SlotVisitor& visitor = m_slotVisitor;
visitor.setup();
HeapRootVisitor heapRootVisitor(visitor);
{
ParallelModeEnabler enabler(visitor);
m_vm->smallStrings.visitStrongReferences(visitor);
{
GCPHASE(VisitMachineRoots);
MARK_LOG_ROOT(visitor, "C++ Stack");
visitor.append(machineThreadRoots);
visitor.donateAndDrain();
}
{
GCPHASE(VisitStackRoots);
MARK_LOG_ROOT(visitor, "Stack");
visitor.append(stackRoots);
visitor.donateAndDrain();
}
#if ENABLE(DFG_JIT)
{
GCPHASE(VisitScratchBufferRoots);
MARK_LOG_ROOT(visitor, "Scratch Buffers");
visitor.append(scratchBufferRoots);
visitor.donateAndDrain();
}
#endif
{
GCPHASE(VisitProtectedObjects);
MARK_LOG_ROOT(visitor, "Protected Objects");
markProtectedObjects(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(VisitTempSortVectors);
MARK_LOG_ROOT(visitor, "Temp Sort Vectors");
markTempSortVectors(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(MarkingArgumentBuffers);
if (m_markListSet && m_markListSet->size()) {
MARK_LOG_ROOT(visitor, "Argument Buffers");
MarkedArgumentBuffer::markLists(heapRootVisitor, *m_markListSet);
visitor.donateAndDrain();
}
}
if (m_vm->exception()) {
GCPHASE(MarkingException);
MARK_LOG_ROOT(visitor, "Exceptions");
heapRootVisitor.visit(m_vm->addressOfException());
visitor.donateAndDrain();
}
{
GCPHASE(VisitStrongHandles);
MARK_LOG_ROOT(visitor, "Strong Handles");
m_handleSet.visitStrongHandles(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(HandleStack);
MARK_LOG_ROOT(visitor, "Handle Stack");
m_handleStack.visit(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(TraceCodeBlocksAndJITStubRoutines);
MARK_LOG_ROOT(visitor, "Trace Code Blocks and JIT Stub Routines");
m_codeBlocks.traceMarked(visitor);
m_jitStubRoutines.traceMarkedStubRoutines(visitor);
visitor.donateAndDrain();
}
#if ENABLE(PARALLEL_GC)
{
GCPHASE(Convergence);
visitor.drainFromShared(SlotVisitor::MasterDrain);
}
#endif
}
// Weak references must be marked last because their liveness depends on
// the liveness of the rest of the object graph.
{
GCPHASE(VisitingLiveWeakHandles);
MARK_LOG_ROOT(visitor, "Live Weak Handles");
while (true) {
m_objectSpace.visitWeakSets(heapRootVisitor);
harvestWeakReferences();
if (visitor.isEmpty())
break;
{
ParallelModeEnabler enabler(visitor);
visitor.donateAndDrain();
#if ENABLE(PARALLEL_GC)
visitor.drainFromShared(SlotVisitor::MasterDrain);
#endif
}
}
}
GCCOUNTER(VisitedValueCount, visitor.visitCount());
m_sharedData.didFinishMarking();
#if ENABLE(OBJECT_MARK_LOGGING)
size_t visitCount = visitor.visitCount();
#if ENABLE(PARALLEL_GC)
visitCount += m_sharedData.childVisitCount();
#endif
MARK_LOG_MESSAGE2("\nNumber of live Objects after full GC %lu, took %.6f secs\n", visitCount, WTF::monotonicallyIncreasingTime() - gcStartTime);
#endif
m_totalBytesVisited = visitor.bytesVisited();
m_totalBytesCopied = visitor.bytesCopied();
#if ENABLE(PARALLEL_GC)
m_totalBytesVisited += m_sharedData.childBytesVisited();
m_totalBytesCopied += m_sharedData.childBytesCopied();
#endif
visitor.reset();
#if ENABLE(PARALLEL_GC)
m_sharedData.resetChildren();
#endif
m_sharedData.reset();
}
void Heap::markRoots(bool fullGC)
{
SamplingRegion samplingRegion("Garbage Collection: Tracing");
COND_GCPHASE(fullGC, MarkFullRoots, MarkYoungRoots);
UNUSED_PARAM(fullGC);
ASSERT(isValidThreadState(m_globalData));
#if ENABLE(OBJECT_MARK_LOGGING)
double gcStartTime = WTF::currentTime();
#endif
void* dummy;
// We gather conservative roots before clearing mark bits because conservative
// gathering uses the mark bits to determine whether a reference is valid.
ConservativeRoots machineThreadRoots(&m_objectSpace.blocks(), &m_storageSpace);
m_jitStubRoutines.clearMarks();
{
GCPHASE(GatherConservativeRoots);
m_machineThreads.gatherConservativeRoots(machineThreadRoots, &dummy);
}
ConservativeRoots stackRoots(&m_objectSpace.blocks(), &m_storageSpace);
m_dfgCodeBlocks.clearMarks();
{
GCPHASE(GatherStackRoots);
stack().gatherConservativeRoots(
stackRoots, m_jitStubRoutines, m_dfgCodeBlocks);
}
#if ENABLE(DFG_JIT)
ConservativeRoots scratchBufferRoots(&m_objectSpace.blocks(), &m_storageSpace);
{
GCPHASE(GatherScratchBufferRoots);
m_globalData->gatherConservativeRoots(scratchBufferRoots);
}
#endif
#if ENABLE(GGC)
MarkedBlock::DirtyCellVector dirtyCells;
if (!fullGC) {
GCPHASE(GatheringDirtyCells);
m_objectSpace.gatherDirtyCells(dirtyCells);
} else
#endif
{
GCPHASE(clearMarks);
m_objectSpace.clearMarks();
}
m_sharedData.didStartMarking();
SlotVisitor& visitor = m_slotVisitor;
visitor.setup();
HeapRootVisitor heapRootVisitor(visitor);
{
ParallelModeEnabler enabler(visitor);
#if ENABLE(GGC)
{
size_t dirtyCellCount = dirtyCells.size();
GCPHASE(VisitDirtyCells);
GCCOUNTER(DirtyCellCount, dirtyCellCount);
for (size_t i = 0; i < dirtyCellCount; i++) {
heapRootVisitor.visitChildren(dirtyCells[i]);
visitor.donateAndDrain();
}
}
#endif
if (m_globalData->codeBlocksBeingCompiled.size()) {
GCPHASE(VisitActiveCodeBlock);
for (size_t i = 0; i < m_globalData->codeBlocksBeingCompiled.size(); i++)
m_globalData->codeBlocksBeingCompiled[i]->visitAggregate(visitor);
}
{
GCPHASE(VisitMachineRoots);
MARK_LOG_ROOT(visitor, "C++ Stack");
visitor.append(machineThreadRoots);
visitor.donateAndDrain();
}
{
GCPHASE(VisitStackRoots);
MARK_LOG_ROOT(visitor, "Stack");
visitor.append(stackRoots);
visitor.donateAndDrain();
}
#if ENABLE(DFG_JIT)
{
GCPHASE(VisitScratchBufferRoots);
MARK_LOG_ROOT(visitor, "Scratch Buffers");
visitor.append(scratchBufferRoots);
visitor.donateAndDrain();
}
#endif
{
GCPHASE(VisitProtectedObjects);
MARK_LOG_ROOT(visitor, "Protected Objects");
markProtectedObjects(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(VisitTempSortVectors);
MARK_LOG_ROOT(visitor, "Temp Sort Vectors");
markTempSortVectors(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(MarkingArgumentBuffers);
if (m_markListSet && m_markListSet->size()) {
MARK_LOG_ROOT(visitor, "Argument Buffers");
MarkedArgumentBuffer::markLists(heapRootVisitor, *m_markListSet);
visitor.donateAndDrain();
}
}
if (m_globalData->exception) {
GCPHASE(MarkingException);
MARK_LOG_ROOT(visitor, "Exceptions");
heapRootVisitor.visit(&m_globalData->exception);
visitor.donateAndDrain();
}
{
GCPHASE(VisitStrongHandles);
MARK_LOG_ROOT(visitor, "Strong Handles");
m_handleSet.visitStrongHandles(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(HandleStack);
MARK_LOG_ROOT(visitor, "Handle Stack");
m_handleStack.visit(heapRootVisitor);
visitor.donateAndDrain();
}
{
GCPHASE(TraceCodeBlocksAndJITStubRoutines);
MARK_LOG_ROOT(visitor, "Trace Code Blocks and JIT Stub Routines");
m_dfgCodeBlocks.traceMarkedCodeBlocks(visitor);
m_jitStubRoutines.traceMarkedStubRoutines(visitor);
visitor.donateAndDrain();
}
#if ENABLE(PARALLEL_GC)
{
GCPHASE(Convergence);
visitor.drainFromShared(SlotVisitor::MasterDrain);
}
#endif
}
// Weak references must be marked last because their liveness depends on
// the liveness of the rest of the object graph.
{
GCPHASE(VisitingLiveWeakHandles);
MARK_LOG_ROOT(visitor, "Live Weak Handles");
while (true) {
m_objectSpace.visitWeakSets(heapRootVisitor);
harvestWeakReferences();
if (visitor.isEmpty())
break;
{
ParallelModeEnabler enabler(visitor);
visitor.donateAndDrain();
#if ENABLE(PARALLEL_GC)
visitor.drainFromShared(SlotVisitor::MasterDrain);
#endif
}
}
}
GCCOUNTER(VisitedValueCount, visitor.visitCount());
m_sharedData.didFinishMarking();
#if ENABLE(OBJECT_MARK_LOGGING)
size_t visitCount = visitor.visitCount();
#if ENABLE(PARALLEL_GC)
visitCount += m_sharedData.childVisitCount();
#endif
MARK_LOG_MESSAGE2("\nNumber of live Objects after full GC %lu, took %.6f secs\n", visitCount, WTF::currentTime() - gcStartTime);
#endif
visitor.reset();
#if ENABLE(PARALLEL_GC)
m_sharedData.resetChildren();
#endif
m_sharedData.reset();
}