#pragma once
namespace JSC {
class HeapUtil {
public:
template<typename Func>
static void findGCObjectPointersForMarking(
Heap& heap, HeapVersion markingVersion, HeapVersion newlyAllocatedVersion, TinyBloomFilter filter,
void* passedPointer, const Func& func)
{
const HashSet<MarkedBlock*>& set = heap.objectSpace().blocks().set();
ASSERT(heap.objectSpace().isMarking());
static constexpr bool isMarking = true;
char* pointer = static_cast<char*>(passedPointer);
if (heap.objectSpace().preciseAllocationsForThisCollectionSize()) {
if (heap.objectSpace().preciseAllocationsForThisCollectionBegin()[0]->aboveLowerBound(pointer)
&& heap.objectSpace().preciseAllocationsForThisCollectionEnd()[-1]->belowUpperBound(pointer)) {
PreciseAllocation** result = approximateBinarySearch<PreciseAllocation*>(
heap.objectSpace().preciseAllocationsForThisCollectionBegin(),
heap.objectSpace().preciseAllocationsForThisCollectionSize(),
PreciseAllocation::fromCell(pointer),
[] (PreciseAllocation** ptr) -> PreciseAllocation* { return *ptr; });
if (result) {
auto attemptLarge = [&] (PreciseAllocation* allocation) {
if (allocation->contains(pointer) && allocation->hasValidCell())
func(allocation->cell(), allocation->attributes().cellKind);
};
if (result > heap.objectSpace().preciseAllocationsForThisCollectionBegin())
attemptLarge(result[-1]);
attemptLarge(result[0]);
if (result + 1 < heap.objectSpace().preciseAllocationsForThisCollectionEnd())
attemptLarge(result[1]);
}
}
}
MarkedBlock* candidate = MarkedBlock::blockFor(pointer);
if (pointer <= bitwise_cast<char*>(candidate) + sizeof(IndexingHeader)) {
char* previousPointer = bitwise_cast<char*>(bitwise_cast<uintptr_t>(pointer) - sizeof(IndexingHeader) - 1);
MarkedBlock* previousCandidate = MarkedBlock::blockFor(previousPointer);
if (!filter.ruleOut(bitwise_cast<Bits>(previousCandidate))
&& set.contains(previousCandidate)
&& hasInteriorPointers(previousCandidate->handle().cellKind())) {
previousPointer = static_cast<char*>(previousCandidate->handle().cellAlign(previousPointer));
if (previousCandidate->handle().isLiveCell(markingVersion, newlyAllocatedVersion, isMarking, previousPointer))
func(previousPointer, previousCandidate->handle().cellKind());
}
}
if (filter.ruleOut(bitwise_cast<Bits>(candidate))) {
ASSERT(!candidate || !set.contains(candidate));
return;
}
if (!set.contains(candidate))
return;
HeapCell::Kind cellKind = candidate->handle().cellKind();
auto tryPointer = [&] (void* pointer) {
if (candidate->handle().isLiveCell(markingVersion, newlyAllocatedVersion, isMarking, pointer))
func(pointer, cellKind);
};
if (isJSCellKind(cellKind)) {
if (MarkedBlock::isAtomAligned(pointer))
tryPointer(pointer);
if (!hasInteriorPointers(cellKind))
return;
}
char* alignedPointer = static_cast<char*>(candidate->handle().cellAlign(pointer));
tryPointer(alignedPointer);
if (candidate->candidateAtomNumber(alignedPointer) > 0
&& pointer <= alignedPointer + sizeof(IndexingHeader))
tryPointer(alignedPointer - candidate->cellSize());
}
static bool isPointerGCObjectJSCell(Heap& heap, TinyBloomFilter filter, JSCell* pointer)
{
if (pointer->isPreciseAllocation()) {
auto* set = heap.objectSpace().preciseAllocationSet();
ASSERT(set);
if (set->isEmpty())
return false;
return set->contains(pointer);
}
const HashSet<MarkedBlock*>& set = heap.objectSpace().blocks().set();
MarkedBlock* candidate = MarkedBlock::blockFor(pointer);
if (filter.ruleOut(bitwise_cast<Bits>(candidate))) {
ASSERT(!candidate || !set.contains(candidate));
return false;
}
if (!MarkedBlock::isAtomAligned(pointer))
return false;
if (!set.contains(candidate))
return false;
if (candidate->handle().cellKind() != HeapCell::JSCell)
return false;
if (!candidate->handle().isLiveCell(pointer))
return false;
return true;
}
static bool isValueGCObject(
Heap& heap, TinyBloomFilter filter, JSValue value)
{
ASSERT(heap.objectSpace().preciseAllocationSet());
if (!value.isCell())
return false;
return isPointerGCObjectJSCell(heap, filter, value.asCell());
}
};
}