private void ParseObjectHeader(StartIndices startIndices, MemorySection[] heap, ulong originalHeapAddress, out ulong typeInfoAddress, out int indexOfObject, out bool wasAlreadyCrawled, List <PackedManagedObject> outManagedObjects)
{
BytesAndOffset bo = heap.Find(originalHeapAddress, _virtualMachineInformation);
UInt64 pointer1 = bo.ReadPointer();
BytesAndOffset pointer2 = bo.NextPointer();
if (HasMarkBit(pointer1) == 0)
{
TypeDescription typeDescription = GetTypeDescription(heap, pointer1);
wasAlreadyCrawled = false;
indexOfObject = outManagedObjects.Count + startIndices.OfFirstManagedObject;
typeInfoAddress = typeDescription.typeInfoAddress;
int size = SizeOfObjectInBytes(typeDescription, bo, heap, originalHeapAddress);
outManagedObjects.Add(new PackedManagedObject()
{
address = originalHeapAddress, size = size, typeIndex = typeDescription.typeIndex
});
//okay, we gathered all information, now lets set the mark bit, and store the index for this object in the 2nd pointer of the header, which is rarely used.
bo.WritePointer(pointer1 | 1);
pointer2.WritePointer((ulong)indexOfObject);
return;
}
//give typeinfo address back without the markbit
typeInfoAddress = ClearMarkBit(pointer1);
wasAlreadyCrawled = true;
//read the index for this object that we stored in the 2ndpointer field of the header
indexOfObject = (int)pointer2.ReadPointer();
}
private TypeDescription RestoreObjectHeader(MemorySection[] heaps, ulong address, int managedObjectIndex)
{
BytesAndOffset bo = heaps.Find(address, _virtualMachineInformation);
UInt64 mask = this._virtualMachineInformation.pointerSize == 8 ? System.UInt64.MaxValue - 1 : System.UInt32.MaxValue - 1;
UInt64 pointer = bo.ReadPointer();
UInt64 typeInfoAddress = pointer & mask;
bo.WritePointer(typeInfoAddress);
UInt64 restoreValue = 0;
_pointer2Backups.TryGetValue(managedObjectIndex, out restoreValue);
bo.NextPointer().WritePointer(restoreValue);
return(GetTypeDescription(heaps, typeInfoAddress));
}