internal IntPtr tpHandle; // PyType *
/// <summary>
/// Given a Python object, return the associated managed object or null.
/// </summary>
internal static ManagedType GetManagedObject(IntPtr ob)
{
if (ob != IntPtr.Zero)
{
IntPtr tp = Runtime.PyObject_TYPE(ob);
if (tp == Runtime.PyTypeType || tp == Runtime.PyCLRMetaType)
{
tp = ob;
}
var flags = Util.ReadCLong(tp, TypeOffset.tp_flags);
if ((flags & TypeFlags.Managed) != 0)
{
IntPtr op = tp == ob
? Marshal.ReadIntPtr(tp, TypeOffset.magic())
: Marshal.ReadIntPtr(ob, ObjectOffset.magic(ob));
if (op == IntPtr.Zero)
{
return(null);
}
var gc = (GCHandle)op;
return((ManagedType)gc.Target);
}
}
return(null);
}
/// <summary>
/// Dealloc implementation. This is called when a Python type generated
/// by this metatype is no longer referenced from the Python runtime.
/// </summary>
public static void tp_dealloc(IntPtr tp)
{
// Fix this when we dont cheat on the handle for subclasses!
var flags = Util.ReadCLong(tp, TypeOffset.tp_flags);
if ((flags & TypeFlags.Subclass) == 0)
{
IntPtr gc = Marshal.ReadIntPtr(tp, TypeOffset.magic());
((GCHandle)gc).Free();
}
IntPtr op = Marshal.ReadIntPtr(tp, TypeOffset.ob_type);
Runtime.XDecref(op);
// Delegate the rest of finalization the Python metatype. Note
// that the PyType_Type implementation of tp_dealloc will call
// tp_free on the type of the type being deallocated - in this
// case our CLR metatype. That is why we implement tp_free.
op = Marshal.ReadIntPtr(Runtime.PyTypeType, TypeOffset.tp_dealloc);
NativeCall.Void_Call_1(op, tp);
}
internal static IntPtr CreateType(ManagedType impl, Type clrType)
{
// Cleanup the type name to get rid of funny nested type names.
string name = "CLR." + clrType.FullName;
int i = name.LastIndexOf('+');
if (i > -1)
{
name = name.Substring(i + 1);
}
i = name.LastIndexOf('.');
if (i > -1)
{
name = name.Substring(i + 1);
}
IntPtr base_ = IntPtr.Zero;
int ob_size = ObjectOffset.Size(Runtime.PyTypeType);
int tp_dictoffset = ObjectOffset.DictOffset(Runtime.PyTypeType);
// XXX Hack, use a different base class for System.Exception
// Python 2.5+ allows new style class exceptions but they *must*
// subclass BaseException (or better Exception).
if (typeof(Exception).IsAssignableFrom(clrType))
{
ob_size = ObjectOffset.Size(Exceptions.Exception);
tp_dictoffset = ObjectOffset.DictOffset(Exceptions.Exception);
}
if (clrType == typeof(Exception))
{
base_ = Exceptions.Exception;
}
else if (clrType.BaseType != null)
{
ClassBase bc = ClassManager.GetClass(clrType.BaseType);
base_ = bc.pyHandle;
}
IntPtr type = AllocateTypeObject(name);
Marshal.WriteIntPtr(type, TypeOffset.ob_type, Runtime.PyCLRMetaType);
Runtime.XIncref(Runtime.PyCLRMetaType);
Marshal.WriteIntPtr(type, TypeOffset.tp_basicsize, (IntPtr)ob_size);
Marshal.WriteIntPtr(type, TypeOffset.tp_itemsize, IntPtr.Zero);
Marshal.WriteIntPtr(type, TypeOffset.tp_dictoffset, (IntPtr)tp_dictoffset);
InitializeSlots(type, impl.GetType());
if (base_ != IntPtr.Zero)
{
Marshal.WriteIntPtr(type, TypeOffset.tp_base, base_);
Runtime.XIncref(base_);
}
int flags = TypeFlags.Default;
flags |= TypeFlags.Managed;
flags |= TypeFlags.HeapType;
flags |= TypeFlags.BaseType;
flags |= TypeFlags.HaveGC;
Util.WriteCLong(type, TypeOffset.tp_flags, flags);
// Leverage followup initialization from the Python runtime. Note
// that the type of the new type must PyType_Type at the time we
// call this, else PyType_Ready will skip some slot initialization.
Runtime.PyType_Ready(type);
IntPtr dict = Marshal.ReadIntPtr(type, TypeOffset.tp_dict);
string mn = clrType.Namespace ?? "";
IntPtr mod = Runtime.PyString_FromString(mn);
Runtime.PyDict_SetItemString(dict, "__module__", mod);
// Hide the gchandle of the implementation in a magic type slot.
GCHandle gc = GCHandle.Alloc(impl);
Marshal.WriteIntPtr(type, TypeOffset.magic(), (IntPtr)gc);
// Set the handle attributes on the implementing instance.
impl.tpHandle = Runtime.PyCLRMetaType;
impl.gcHandle = gc;
impl.pyHandle = type;
//DebugUtil.DumpType(type);
return(type);
}
/// <summary>
/// Metatype __new__ implementation. This is called to create a new
/// class / type when a reflected class is subclassed.
/// </summary>
public static IntPtr tp_new(IntPtr tp, IntPtr args, IntPtr kw)
{
var len = Runtime.PyTuple_Size(args);
if (len < 3)
{
return(Exceptions.RaiseTypeError("invalid argument list"));
}
IntPtr name = Runtime.PyTuple_GetItem(args, 0);
IntPtr bases = Runtime.PyTuple_GetItem(args, 1);
IntPtr dict = Runtime.PyTuple_GetItem(args, 2);
// We do not support multiple inheritance, so the bases argument
// should be a 1-item tuple containing the type we are subtyping.
// That type must itself have a managed implementation. We check
// that by making sure its metatype is the CLR metatype.
if (Runtime.PyTuple_Size(bases) != 1)
{
return(Exceptions.RaiseTypeError("cannot use multiple inheritance with managed classes"));
}
IntPtr base_type = Runtime.PyTuple_GetItem(bases, 0);
IntPtr mt = Runtime.PyObject_TYPE(base_type);
if (!(mt == PyCLRMetaType || mt == Runtime.PyTypeType))
{
return(Exceptions.RaiseTypeError("invalid metatype"));
}
// Ensure that the reflected type is appropriate for subclassing,
// disallowing subclassing of delegates, enums and array types.
var cb = GetManagedObject(base_type) as ClassBase;
if (cb != null)
{
if (!cb.CanSubclass())
{
return(Exceptions.RaiseTypeError("delegates, enums and array types cannot be subclassed"));
}
}
IntPtr slots = Runtime.PyDict_GetItemString(dict, "__slots__");
if (slots != IntPtr.Zero)
{
return(Exceptions.RaiseTypeError("subclasses of managed classes do not support __slots__"));
}
// If __assembly__ or __namespace__ are in the class dictionary then create
// a managed sub type.
// This creates a new managed type that can be used from .net to call back
// into python.
if (IntPtr.Zero != dict)
{
Runtime.XIncref(dict);
using (var clsDict = new PyDict(dict)) {
if (clsDict.HasKey("__assembly__") || clsDict.HasKey("__namespace__"))
{
return(TypeManager.CreateSubType(name, base_type, dict));
}
}
}
// otherwise just create a basic type without reflecting back into the managed side.
IntPtr func = Marshal.ReadIntPtr(Runtime.PyTypeType, TypeOffset.tp_new);
IntPtr type = NativeCall.Call_3(func, tp, args, kw);
if (type == IntPtr.Zero)
{
return(IntPtr.Zero);
}
int flags = TypeFlags.Default;
flags |= TypeFlags.Managed;
flags |= TypeFlags.HeapType;
flags |= TypeFlags.BaseType;
flags |= TypeFlags.Subclass;
flags |= TypeFlags.HaveGC;
Util.WriteCLong(type, TypeOffset.tp_flags, flags);
TypeManager.CopySlot(base_type, type, TypeOffset.tp_dealloc);
// Hmm - the standard subtype_traverse, clear look at ob_size to
// do things, so to allow gc to work correctly we need to move
// our hidden handle out of ob_size. Then, in theory we can
// comment this out and still not crash.
TypeManager.CopySlot(base_type, type, TypeOffset.tp_traverse);
TypeManager.CopySlot(base_type, type, TypeOffset.tp_clear);
// for now, move up hidden handle...
IntPtr gc = Marshal.ReadIntPtr(base_type, TypeOffset.magic());
Marshal.WriteIntPtr(type, TypeOffset.magic(), gc);
return(type);
}
