// **********************************************************************
//
// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************

#ifdef _WIN32
#   include <IceUtil/Config.h>
#endif
#include <Operation.h>
#include <Current.h>
#include <Proxy.h>
#include <Types.h>
#include <Util.h>
#include <Ice/Communicator.h>
#include <Ice/IncomingAsync.h>
#include <Ice/Initialize.h>
#include <Ice/LocalException.h>
#include <Ice/Logger.h>
#include <Ice/ObjectAdapter.h>
#include <Ice/OutgoingAsync.h>
#include <Ice/Properties.h>
#include <Ice/Proxy.h>
#include <Slice/PythonUtil.h>

using namespace std;
using namespace IcePy;
using namespace Slice::Python;

namespace IcePy
{

//
// Information about an operation's parameter.
//
class ParamInfo : public UnmarshalCallback
{
public:

    virtual void unmarshaled(PyObject*, PyObject*, void*);

    Ice::StringSeq metaData;
    TypeInfoPtr type;
};
typedef IceUtil::Handle<ParamInfo> ParamInfoPtr;
typedef vector<ParamInfoPtr> ParamInfoList;

//
// Encapsulates attributes of an operation.
//
class Operation : public IceUtil::Shared
{
public:

    Operation(const char*, PyObject*, PyObject*, int, PyObject*, PyObject*, PyObject*, PyObject*, PyObject*);

    void deprecate(const string&);

    string name;
    Ice::OperationMode mode;
    Ice::OperationMode sendMode;
    bool amd;
    Ice::StringSeq metaData;
    ParamInfoList inParams;
    ParamInfoList outParams;
    ParamInfoPtr returnType;
    ExceptionInfoList exceptions;
    string dispatchName;
    bool sendsClasses;
    bool returnsClasses;

private:

    string _deprecateMessage;

    static void convertParams(PyObject*, ParamInfoList&, bool&);
};
typedef IceUtil::Handle<Operation> OperationPtr;

//
// The base class for client-side invocations.
//
class Invocation : virtual public IceUtil::Shared
{
public:

    Invocation(const Ice::ObjectPrx&);

    virtual PyObject* invoke(PyObject*) = 0;

protected:

    Ice::ObjectPrx _prx;
};
typedef IceUtil::Handle<Invocation> InvocationPtr;

//
// TypedInvocation uses the information in the given Operation to validate, marshal, and unmarshal
// parameters and exceptions.
//
class TypedInvocation : virtual public Invocation
{
public:

    TypedInvocation(const Ice::ObjectPrx&, const OperationPtr&);

protected:

    OperationPtr _op;
    Ice::CommunicatorPtr _communicator;

    bool prepareRequest(PyObject*, bool, vector<Ice::Byte>&);
    PyObject* unmarshalResults(const pair<const Ice::Byte*, const Ice::Byte*>&);
    PyObject* unmarshalException(const pair<const Ice::Byte*, const Ice::Byte*>&);
    bool validateException(PyObject*) const;
    void checkTwowayOnly(const Ice::ObjectPrx&) const;
};

//
// A synchronous typed invocation.
//
class SyncTypedInvocation : virtual public TypedInvocation
{
public:

    SyncTypedInvocation(const Ice::ObjectPrx&, const OperationPtr&);

    virtual PyObject* invoke(PyObject*);
};

//
// An asynchronous typed invocation.
//
class AsyncTypedInvocation : virtual public TypedInvocation, virtual public Ice::AMI_Array_Object_ice_invoke
{
public:

    AsyncTypedInvocation(const Ice::ObjectPrx&, const OperationPtr&);
    ~AsyncTypedInvocation();

    virtual PyObject* invoke(PyObject*);

    virtual void ice_response(bool, const pair<const Ice::Byte*, const Ice::Byte*>&);
    virtual void ice_exception(const Ice::Exception&);

protected:

    void handleException(PyObject*);

    PyObject* _callback;
};

//
// An asynchronous typed invocation with support for ice_sent.
//
class AsyncSentTypedInvocation : virtual public AsyncTypedInvocation, virtual public Ice::AMISentCallback
{
public:

    AsyncSentTypedInvocation(const Ice::ObjectPrx&, const OperationPtr&);

    virtual void ice_sent();
};

//
// A synchronous blobject invocation.
//
class SyncBlobjectInvocation : virtual public Invocation
{
public:

    SyncBlobjectInvocation(const Ice::ObjectPrx&);

    virtual PyObject* invoke(PyObject*);
};

//
// An asynchronous blobject invocation.
//
class AsyncBlobjectInvocation : virtual public Invocation, virtual public Ice::AMI_Array_Object_ice_invoke
{
public:

    AsyncBlobjectInvocation(const Ice::ObjectPrx&);
    ~AsyncBlobjectInvocation();

    virtual PyObject* invoke(PyObject*);

    virtual void ice_response(bool, const pair<const Ice::Byte*, const Ice::Byte*>&);
    virtual void ice_exception(const Ice::Exception&);

protected:

    string _op;
    PyObject* _callback;

    void handleException(PyObject*);
};

//
// An asynchronous blobject invocation with support for ice_sent.
//
class AsyncSentBlobjectInvocation : virtual public AsyncBlobjectInvocation, virtual public Ice::AMISentCallback
{
public:

    AsyncSentBlobjectInvocation(const Ice::ObjectPrx&);

    virtual void ice_sent();
};

//
// The base class for server-side upcalls.
//
class Upcall : virtual public IceUtil::Shared
{
public:

    virtual void dispatch(PyObject*, const pair<const Ice::Byte*, const Ice::Byte*>&, const Ice::Current&) = 0;
    virtual void response(PyObject*) = 0;
    virtual void exception(PyException&) = 0;
};
typedef IceUtil::Handle<Upcall> UpcallPtr;

//
// TypedInvocation uses the information in the given Operation to validate, marshal, and unmarshal
// parameters and exceptions.
//
class TypedUpcall : virtual public Upcall
{
public:

    TypedUpcall(const OperationPtr&, const Ice::AMD_Array_Object_ice_invokePtr&, const Ice::CommunicatorPtr&);

    virtual void dispatch(PyObject*, const pair<const Ice::Byte*, const Ice::Byte*>&, const Ice::Current&);
    virtual void response(PyObject*);
    virtual void exception(PyException&);

private:

    bool validateException(PyObject*) const;

    OperationPtr _op;
    Ice::AMD_Array_Object_ice_invokePtr _callback;
    Ice::CommunicatorPtr _communicator;
};

//
// Upcall for blobject servants.
//
class BlobjectUpcall : virtual public Upcall
{
public:

    BlobjectUpcall(bool, const Ice::AMD_Array_Object_ice_invokePtr&);

    virtual void dispatch(PyObject*, const pair<const Ice::Byte*, const Ice::Byte*>&, const Ice::Current&);
    virtual void response(PyObject*);
    virtual void exception(PyException&);

private:

    bool _amd;
    Ice::AMD_Array_Object_ice_invokePtr _callback;
};

//
// TypedServantWrapper uses the information in Operation to validate, marshal, and unmarshal
// parameters and exceptions.
//
class TypedServantWrapper : public ServantWrapper
{
public:

    TypedServantWrapper(PyObject*);

    virtual void ice_invoke_async(const Ice::AMD_Array_Object_ice_invokePtr&,
                                  const pair<const Ice::Byte*, const Ice::Byte*>&,
                                  const Ice::Current&);

private:

    typedef map<string, OperationPtr> OperationMap;
    OperationMap _operationMap;
    OperationMap::iterator _lastOp;
};

//
// Encapsulates a blobject servant.
//
class BlobjectServantWrapper : public ServantWrapper
{
public:

    BlobjectServantWrapper(PyObject*, bool);

    virtual void ice_invoke_async(const Ice::AMD_Array_Object_ice_invokePtr&,
                                  const pair<const Ice::Byte*, const Ice::Byte*>&,
                                  const Ice::Current&);

private:

    bool _amd;
};

struct OperationObject
{
    PyObject_HEAD
    OperationPtr* op;
};

struct AMDCallbackObject
{
    PyObject_HEAD
    UpcallPtr* upcall;
};

extern PyTypeObject OperationType;
extern PyTypeObject AMDCallbackType;

}

static OperationPtr
getOperation(PyObject* p)
{
    assert(PyObject_IsInstance(p, reinterpret_cast<PyObject*>(&OperationType)) == 1);
    OperationObject* obj = reinterpret_cast<OperationObject*>(p);
    return *obj->op;
}

#ifdef WIN32
extern "C"
#endif
static OperationObject*
operationNew(PyObject* /*arg*/)
{
    OperationObject* self = PyObject_New(OperationObject, &OperationType);
    if(!self)
    {
        return 0;
    }
    self->op = 0;
    return self;
}

#ifdef WIN32
extern "C"
#endif
static int
operationInit(OperationObject* self, PyObject* args, PyObject* /*kwds*/)
{
    char* name;
    PyObject* modeType = lookupType("Ice.OperationMode");
    assert(modeType);
    PyObject* mode;
    PyObject* sendMode;
    int amd;
    PyObject* meta;
    PyObject* inParams;
    PyObject* outParams;
    PyObject* returnType;
    PyObject* exceptions;
    if(!PyArg_ParseTuple(args, STRCAST("sO!O!iO!O!O!OO!"), &name, modeType, &mode, modeType, &sendMode, &amd,
                         &PyTuple_Type, &meta, &PyTuple_Type, &inParams, &PyTuple_Type, &outParams, &returnType,
                         &PyTuple_Type, &exceptions))
    {
        return -1;
    }

    OperationPtr op = new Operation(name, mode, sendMode, amd, meta, inParams, outParams, returnType, exceptions);
    self->op = new OperationPtr(op);

    return 0;
}

#ifdef WIN32
extern "C"
#endif
static void
operationDealloc(OperationObject* self)
{
    delete self->op;
    PyObject_Del(self);
}

#ifdef WIN32
extern "C"
#endif
static PyObject*
operationInvoke(OperationObject* self, PyObject* args)
{
    PyObject* pyProxy;
    PyObject* opArgs;
    if(!PyArg_ParseTuple(args, STRCAST("O!O!"), &ProxyType, &pyProxy, &PyTuple_Type, &opArgs))
    {
        return 0;
    }

    Ice::ObjectPrx prx = getProxy(pyProxy);
    assert(self->op);

    InvocationPtr i = new SyncTypedInvocation(prx, *self->op);
    return i->invoke(opArgs);
}

#ifdef WIN32
extern "C"
#endif
static PyObject*
operationInvokeAsync(OperationObject* self, PyObject* args)
{
    PyObject* pyProxy;
    PyObject* opArgs;
    if(!PyArg_ParseTuple(args, STRCAST("O!O!"), &ProxyType, &pyProxy, &PyTuple_Type, &opArgs))
    {
        return 0;
    }

    Ice::ObjectPrx prx = getProxy(pyProxy);
    assert(self->op);

    //
    // If the callback implements an ice_sent method, we create a wrapper that derives
    // from AMISentCallback.
    //
    assert(PyTuple_GET_SIZE(opArgs) > 0);
    PyObject* callback = PyTuple_GET_ITEM(opArgs, 0);
    if(PyObject_HasAttrString(callback, STRCAST("ice_sent")))
    {
        InvocationPtr i = new AsyncSentTypedInvocation(prx, *self->op);
        return i->invoke(opArgs);
    }
    else
    {
        InvocationPtr i = new AsyncTypedInvocation(prx, *self->op);
        return i->invoke(opArgs);
    }
}

#ifdef WIN32
extern "C"
#endif
static PyObject*
operationDeprecate(OperationObject* self, PyObject* args)
{
    char* msg;
    if(!PyArg_ParseTuple(args, STRCAST("s"), &msg))
    {
        return 0;
    }

    assert(self->op);
    (*self->op)->deprecate(msg);

    Py_INCREF(Py_None);
    return Py_None;
}

#ifdef WIN32
extern "C"
#endif
static AMDCallbackObject*
amdCallbackNew(PyObject* /*arg*/)
{
    AMDCallbackObject* self = PyObject_New(AMDCallbackObject, &AMDCallbackType);
    if(!self)
    {
        return 0;
    }
    self->upcall = 0;
    return self;
}

#ifdef WIN32
extern "C"
#endif
static void
amdCallbackDealloc(AMDCallbackObject* self)
{
    delete self->upcall;
    PyObject_Del(self);
}

#ifdef WIN32
extern "C"
#endif
static PyObject*
amdCallbackIceResponse(AMDCallbackObject* self, PyObject* args)
{
    try
    {
        assert(self->upcall);
        (*self->upcall)->response(args);
    }
    catch(...)
    {
        //
        // No exceptions should propagate to Python.
        //
        assert(false);
    }

    Py_INCREF(Py_None);
    return Py_None;
}

#ifdef WIN32
extern "C"
#endif
static PyObject*
amdCallbackIceException(AMDCallbackObject* self, PyObject* args)
{
    PyObject* ex;
    if(!PyArg_ParseTuple(args, STRCAST("O"), &ex))
    {
        return 0;
    }

    try
    {
        assert(self->upcall);
        PyException pye(ex); // No traceback information available.
        (*self->upcall)->exception(pye);
    }
    catch(...)
    {
        //
        // No exceptions should propagate to Python.
        //
        assert(false);
    }

    Py_INCREF(Py_None);
    return Py_None;
}

//
// ParamInfo implementation.
//
void
IcePy::ParamInfo::unmarshaled(PyObject* val, PyObject* target, void* closure)
{
    assert(PyTuple_Check(target));
    long i = reinterpret_cast<long>(closure);
    PyTuple_SET_ITEM(target, i, val);
    Py_INCREF(val); // PyTuple_SET_ITEM steals a reference.
}

//
// Operation implementation.
//
IcePy::Operation::Operation(const char* n, PyObject* m, PyObject* sm, int amdFlag, PyObject* meta,
                            PyObject* in, PyObject* out, PyObject* ret, PyObject* ex)
{
    name = n;

    //
    // mode
    //
    PyObjectHandle modeValue = PyObject_GetAttrString(m, STRCAST("value"));
    assert(PyInt_Check(modeValue.get()));
    mode = (Ice::OperationMode)static_cast<int>(PyInt_AS_LONG(modeValue.get()));

    //
    // sendMode
    //
    PyObjectHandle sendModeValue = PyObject_GetAttrString(sm, STRCAST("value"));
    assert(PyInt_Check(sendModeValue.get()));
    sendMode = (Ice::OperationMode)static_cast<int>(PyInt_AS_LONG(sendModeValue.get()));

    //
    // amd
    //
    amd = amdFlag ? true : false;
    if(amd)
    {
        dispatchName = fixIdent(name) + "_async";
    }
    else
    {
        dispatchName = fixIdent(name);
    }

    //
    // metaData
    //
#ifndef NDEBUG
    bool b =
#endif
    tupleToStringSeq(meta, metaData);
    assert(b);

    Py_ssize_t i, sz;

    //
    // inParams
    //
    convertParams(in, inParams, sendsClasses);

    //
    // outParams
    //
    convertParams(out, outParams, returnsClasses);

    //
    // returnType
    //
    if(ret != Py_None)
    {
        returnType = new ParamInfo;
        returnType->type = getType(ret);
        if(!returnsClasses)
        {
            returnsClasses = returnType->type->usesClasses();
        }
    }

    //
    // exceptions
    //
    sz = PyTuple_GET_SIZE(ex);
    for(i = 0; i < sz; ++i)
    {
        exceptions.push_back(getException(PyTuple_GET_ITEM(ex, i)));
    }
}

void
IcePy::Operation::deprecate(const string& msg)
{
    if(!msg.empty())
    {
        _deprecateMessage = msg;
    }
    else
    {
        _deprecateMessage = "operation " + name + " is deprecated";
    }
}

void
IcePy::Operation::convertParams(PyObject* p, ParamInfoList& params, bool& usesClasses)
{
    usesClasses = false;
    int sz = static_cast<int>(PyTuple_GET_SIZE(p));
    for(int i = 0; i < sz; ++i)
    {
        PyObject* item = PyTuple_GET_ITEM(p, i);
        assert(PyTuple_Check(item));
        assert(PyTuple_GET_SIZE(item) == 2);

        ParamInfoPtr param = new ParamInfo;

        //
        // metaData
        //
        PyObject* meta = PyTuple_GET_ITEM(item, 0);
        assert(PyTuple_Check(meta));
#ifndef NDEBUG
        bool b =
#endif
        tupleToStringSeq(meta, param->metaData);
        assert(b);

        //
        // type
        //
        param->type = getType(PyTuple_GET_ITEM(item, 1));
        params.push_back(param);
        if(!usesClasses)
        {
            usesClasses = param->type->usesClasses();
        }
    }
}

static PyMethodDef OperationMethods[] =
{
    { STRCAST("invoke"), reinterpret_cast<PyCFunction>(operationInvoke), METH_VARARGS,
      PyDoc_STR(STRCAST("internal function")) },
    { STRCAST("invokeAsync"), reinterpret_cast<PyCFunction>(operationInvokeAsync), METH_VARARGS,
      PyDoc_STR(STRCAST("internal function")) },
    { STRCAST("deprecate"), reinterpret_cast<PyCFunction>(operationDeprecate), METH_VARARGS,
      PyDoc_STR(STRCAST("internal function")) },
    { 0, 0 } /* sentinel */
};

static PyMethodDef AMDCallbackMethods[] =
{
    { STRCAST("ice_response"), reinterpret_cast<PyCFunction>(amdCallbackIceResponse), METH_VARARGS,
      PyDoc_STR(STRCAST("internal function")) },
    { STRCAST("ice_exception"), reinterpret_cast<PyCFunction>(amdCallbackIceException), METH_VARARGS,
      PyDoc_STR(STRCAST("internal function")) },
    { 0, 0 } /* sentinel */
};

namespace IcePy
{

PyTypeObject OperationType =
{
    /* The ob_type field must be initialized in the module init function
     * to be portable to Windows without using C++. */
    PyObject_HEAD_INIT(0)
    0,                               /* ob_size */
    STRCAST("IcePy.Operation"),      /* tp_name */
    sizeof(OperationObject),         /* tp_basicsize */
    0,                               /* tp_itemsize */
    /* methods */
    reinterpret_cast<destructor>(operationDealloc), /* tp_dealloc */
    0,                               /* tp_print */
    0,                               /* tp_getattr */
    0,                               /* tp_setattr */
    0,                               /* tp_compare */
    0,                               /* tp_repr */
    0,                               /* tp_as_number */
    0,                               /* tp_as_sequence */
    0,                               /* tp_as_mapping */
    0,                               /* tp_hash */
    0,                               /* tp_call */
    0,                               /* tp_str */
    0,                               /* tp_getattro */
    0,                               /* tp_setattro */
    0,                               /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT,              /* tp_flags */
    0,                               /* tp_doc */
    0,                               /* tp_traverse */
    0,                               /* tp_clear */
    0,                               /* tp_richcompare */
    0,                               /* tp_weaklistoffset */
    0,                               /* tp_iter */
    0,                               /* tp_iternext */
    OperationMethods,                /* tp_methods */
    0,                               /* tp_members */
    0,                               /* tp_getset */
    0,                               /* tp_base */
    0,                               /* tp_dict */
    0,                               /* tp_descr_get */
    0,                               /* tp_descr_set */
    0,                               /* tp_dictoffset */
    reinterpret_cast<initproc>(operationInit), /* tp_init */
    0,                               /* tp_alloc */
    reinterpret_cast<newfunc>(operationNew), /* tp_new */
    0,                               /* tp_free */
    0,                               /* tp_is_gc */
};

PyTypeObject AMDCallbackType =
{
    /* The ob_type field must be initialized in the module init function
     * to be portable to Windows without using C++. */
    PyObject_HEAD_INIT(0)
    0,                               /* ob_size */
    STRCAST("IcePy.AMDCallback"),    /* tp_name */
    sizeof(AMDCallbackObject),       /* tp_basicsize */
    0,                               /* tp_itemsize */
    /* methods */
    reinterpret_cast<destructor>(amdCallbackDealloc), /* tp_dealloc */
    0,                               /* tp_print */
    0,                               /* tp_getattr */
    0,                               /* tp_setattr */
    0,                               /* tp_compare */
    0,                               /* tp_repr */
    0,                               /* tp_as_number */
    0,                               /* tp_as_sequence */
    0,                               /* tp_as_mapping */
    0,                               /* tp_hash */
    0,                               /* tp_call */
    0,                               /* tp_str */
    0,                               /* tp_getattro */
    0,                               /* tp_setattro */
    0,                               /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT,              /* tp_flags */
    0,                               /* tp_doc */
    0,                               /* tp_traverse */
    0,                               /* tp_clear */
    0,                               /* tp_richcompare */
    0,                               /* tp_weaklistoffset */
    0,                               /* tp_iter */
    0,                               /* tp_iternext */
    AMDCallbackMethods,              /* tp_methods */
    0,                               /* tp_members */
    0,                               /* tp_getset */
    0,                               /* tp_base */
    0,                               /* tp_dict */
    0,                               /* tp_descr_get */
    0,                               /* tp_descr_set */
    0,                               /* tp_dictoffset */
    0,                               /* tp_init */
    0,                               /* tp_alloc */
    reinterpret_cast<newfunc>(amdCallbackNew), /* tp_new */
    0,                               /* tp_free */
    0,                               /* tp_is_gc */
};

}

bool
IcePy::initOperation(PyObject* module)
{
    if(PyType_Ready(&OperationType) < 0)
    {
        return false;
    }
    PyTypeObject* opType = &OperationType; // Necessary to prevent GCC's strict-alias warnings.
    if(PyModule_AddObject(module, STRCAST("Operation"), reinterpret_cast<PyObject*>(opType)) < 0)
    {
        return false;
    }

    if(PyType_Ready(&AMDCallbackType) < 0)
    {
        return false;
    }
    PyTypeObject* cbType = &AMDCallbackType; // Necessary to prevent GCC's strict-alias warnings.
    if(PyModule_AddObject(module, STRCAST("AMDCallback"), reinterpret_cast<PyObject*>(cbType)) < 0)
    {
        return false;
    }

    return true;
}

//
// Invocation
//
IcePy::Invocation::Invocation(const Ice::ObjectPrx& prx) :
    _prx(prx)
{
}

//
// TypedInvocation
//
IcePy::TypedInvocation::TypedInvocation(const Ice::ObjectPrx& prx, const OperationPtr& op) :
    Invocation(prx), _op(op), _communicator(prx->ice_getCommunicator())
{
}

bool
IcePy::TypedInvocation::prepareRequest(PyObject* args, bool async, vector<Ice::Byte>& bytes)
{
    assert(PyTuple_Check(args));

    //
    // Validate the number of arguments.
    //
    Py_ssize_t argc = PyTuple_GET_SIZE(args);
    Py_ssize_t paramCount = static_cast<Py_ssize_t>(_op->inParams.size());
    if(argc != paramCount)
    {
        string fixedName = fixIdent(_op->name);
        if(async)
        {
            fixedName += "_async";
        }
        PyErr_Format(PyExc_RuntimeError, STRCAST("%s expects %d in parameters"), fixedName.c_str(),
                     static_cast<int>(paramCount));
        return false;
    }

    if(!_op->inParams.empty())
    {
        try
        {
            //
            // Marshal the in parameters.
            //
            Ice::OutputStreamPtr os = Ice::createOutputStream(_communicator);

            ObjectMap objectMap;
            int i = 0;
            for(ParamInfoList::iterator p = _op->inParams.begin(); p != _op->inParams.end(); ++p, ++i)
            {
                PyObject* arg = PyTuple_GET_ITEM(args, i);
                if(!(*p)->type->validate(arg))
                {
                    string opName;
                    if(async)
                    {
                        opName = fixIdent(_op->name) + "_async";
                    }
                    else
                    {
                        opName = fixIdent(_op->name);
                    }
                    PyErr_Format(PyExc_ValueError, STRCAST("invalid value for argument %d in operation `%s'"),
                                 async ? i + 2 : i + 1, const_cast<char*>(opName.c_str()));
                    return false;
                }
                (*p)->type->marshal(arg, os, &objectMap, &(*p)->metaData);
            }

            if(_op->sendsClasses)
            {
                os->writePendingObjects();
            }

            os->finished(bytes);
        }
        catch(const AbortMarshaling&)
        {
            assert(PyErr_Occurred());
            return false;
        }
        catch(const Ice::Exception& ex)
        {
            setPythonException(ex);
            return false;
        }
    }

    return true;
}

PyObject*
IcePy::TypedInvocation::unmarshalResults(const pair<const Ice::Byte*, const Ice::Byte*>& bytes)
{
    Py_ssize_t i = _op->returnType ? 1 : 0;
    Py_ssize_t numResults = static_cast<Py_ssize_t>(_op->outParams.size()) + i;

    PyObjectHandle results = PyTuple_New(numResults);
    if(results.get() && numResults > 0)
    {
        //
        // Unmarshal the results. If there is more than one value to be returned, then return them
        // in a tuple of the form (result, outParam1, ...). Otherwise just return the value.
        //
        Ice::InputStreamPtr is = Ice::createInputStream(_communicator, bytes);
        for(ParamInfoList::iterator p = _op->outParams.begin(); p != _op->outParams.end(); ++p, ++i)
        {
            void* closure = reinterpret_cast<void*>(i);
            (*p)->type->unmarshal(is, *p, results.get(), closure, &(*p)->metaData);
        }

        if(_op->returnType)
        {
            _op->returnType->type->unmarshal(is, _op->returnType, results.get(), 0, &_op->metaData);
        }

        if(_op->returnsClasses)
        {
            is->readPendingObjects();
        }
    }

    return results.release();
}

PyObject*
IcePy::TypedInvocation::unmarshalException(const pair<const Ice::Byte*, const Ice::Byte*>& bytes)
{
    int traceSlicing = -1;

    Ice::InputStreamPtr is = Ice::createInputStream(_communicator, bytes);

    is->readBool(); // usesClasses

    string id = is->readString();
    const string origId = id;

    while(!id.empty())
    {
        ExceptionInfoPtr info = lookupExceptionInfo(id);
        if(info)
        {
            PyObjectHandle ex = info->unmarshal(is);
            if(info->usesClasses)
            {
                is->readPendingObjects();
            }

            if(validateException(ex.get()))
            {
                return ex.release();
            }
            else
            {
                PyException pye(ex.get()); // No traceback information available.
                pye.raise();
            }
        }
        else
        {
            if(traceSlicing == -1)
            {
                traceSlicing = _communicator->getProperties()->getPropertyAsInt("Ice.Trace.Slicing") > 0;
            }

            if(traceSlicing > 0)
            {
                _communicator->getLogger()->trace("Slicing", "unknown exception type `" + id + "'");
            }

            is->skipSlice(); // Slice off what we don't understand.

            try
            {
                id = is->readString(); // Read type id for next slice.
            }
            catch(Ice::UnmarshalOutOfBoundsException& ex)
            {
                //
                // When readString raises this exception it means we've seen the last slice,
                // so we set the reason member to a more helpful message.
                //
                ex.reason = "unknown exception type `" + origId + "'";
                throw;
            }
        }
    }

    //
    // Getting here should be impossible: we can get here only if the
    // sender has marshaled a sequence of type IDs, none of which we
    // have a factory for. This means that sender and receiver disagree
    // about the Slice definitions they use.
    //
    throw Ice::UnknownUserException(__FILE__, __LINE__, "unknown exception type `" + origId + "'");
}

bool
IcePy::TypedInvocation::validateException(PyObject* ex) const
{
    for(ExceptionInfoList::const_iterator p = _op->exceptions.begin(); p != _op->exceptions.end(); ++p)
    {
        if(PyObject_IsInstance(ex, (*p)->pythonType.get()))
        {
            return true;
        }
    }

    return false;
}

void
IcePy::TypedInvocation::checkTwowayOnly(const Ice::ObjectPrx& proxy) const
{
    if((_op->returnType != 0 || !_op->outParams.empty()) && !proxy->ice_isTwoway())
    {
        Ice::TwowayOnlyException ex(__FILE__, __LINE__);
        ex.operation = _op->name;
        throw ex;
    }
}

//
// SyncTypedInvocation
//
IcePy::SyncTypedInvocation::SyncTypedInvocation(const Ice::ObjectPrx& prx, const OperationPtr& op) :
    Invocation(prx), TypedInvocation(prx, op)
{
}

PyObject*
IcePy::SyncTypedInvocation::invoke(PyObject* args)
{
    assert(PyTuple_Check(args));
    assert(PyTuple_GET_SIZE(args) == 2); // Format is ((params...), context|None)
    PyObject* pyparams = PyTuple_GET_ITEM(args, 0);
    assert(PyTuple_Check(pyparams));
    PyObject* pyctx = PyTuple_GET_ITEM(args, 1);

    //
    // Marshal the input parameters to a byte sequence.
    //
    Ice::ByteSeq params;
    if(!prepareRequest(pyparams, false, params))
    {
        return 0;
    }

    try
    {
        checkTwowayOnly(_prx);

        //
        // Invoke the operation.
        //
        vector<Ice::Byte> result;
        bool status;
        {
            if(pyctx != Py_None)
            {
                Ice::Context ctx;

                if(!PyDict_Check(pyctx))
                {
                    PyErr_Format(PyExc_ValueError, STRCAST("context argument must be None or a dictionary"));
                    return 0;
                }

                if(!dictionaryToContext(pyctx, ctx))
                {
                    return 0;
                }

                AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
                status = _prx->ice_invoke(_op->name, _op->sendMode, params, result, ctx);
            }
            else
            {
                AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
                status = _prx->ice_invoke(_op->name, _op->sendMode, params, result);
            }
        }

        //
        // Process the reply.
        //
        if(_prx->ice_isTwoway())
        {
            if(!status)
            {
                //
                // Unmarshal a user exception.
                //
                pair<const Ice::Byte*, const Ice::Byte*> rb(0, 0);
                if(!result.empty())
                {
                    rb.first = &result[0];
                    rb.second = &result[0] + result.size();
                }
                PyObjectHandle ex = unmarshalException(rb);

                //
                // Set the Python exception.
                //
                setPythonException(ex.get());
                return 0;
            }
            else if(_op->outParams.size() > 0 || _op->returnType)
            {
                //
                // Unmarshal the results. If there is more than one value to be returned, then return them
                // in a tuple of the form (result, outParam1, ...). Otherwise just return the value.
                //
                pair<const Ice::Byte*, const Ice::Byte*> rb(0, 0);
                if(!result.empty())
                {
                    rb.first = &result[0];
                    rb.second = &result[0] + result.size();
                }
                PyObjectHandle results = unmarshalResults(rb);
                if(!results.get())
                {
                    return 0;
                }

                if(PyTuple_GET_SIZE(results.get()) > 1)
                {
                    return results.release();
                }
                else
                {
                    PyObject* ret = PyTuple_GET_ITEM(results.get(), 0);
                    if(!ret)
                    {
                        return 0;
                    }
                    else
                    {
                        Py_INCREF(ret);
                        return ret;
                    }
                }
            }
        }
    }
    catch(const AbortMarshaling&)
    {
        assert(PyErr_Occurred());
        return 0;
    }
    catch(const Ice::Exception& ex)
    {
        setPythonException(ex);
        return 0;
    }

    Py_INCREF(Py_None);
    return Py_None;
}

//
// AsyncTypedInvocation
//
IcePy::AsyncTypedInvocation::AsyncTypedInvocation(const Ice::ObjectPrx& prx, const OperationPtr& op)
    : Invocation(prx), TypedInvocation(prx, op), _callback(0)
{
}

IcePy::AsyncTypedInvocation::~AsyncTypedInvocation()
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    Py_XDECREF(_callback);
}

PyObject*
IcePy::AsyncTypedInvocation::invoke(PyObject* args)
{
    assert(PyTuple_Check(args));
    assert(PyTuple_GET_SIZE(args) == 3); // Format is (callback, (params...), context|None)
    _callback = PyTuple_GET_ITEM(args, 0);
    Py_INCREF(_callback);
    PyObject* pyparams = PyTuple_GET_ITEM(args, 1);
    assert(PyTuple_Check(pyparams));
    PyObject* pyctx = PyTuple_GET_ITEM(args, 2);

    //
    // Marshal the input parameters to a byte sequence.
    //
    Ice::ByteSeq params;
    if(!prepareRequest(pyparams, true, params))
    {
        return 0;
    }

    bool result = false;
    try
    {
        checkTwowayOnly(_prx);
        pair<const Ice::Byte*, const Ice::Byte*> pparams(0, 0);
        if(!params.empty())
        {
            pparams.first = &params[0];
            pparams.second = &params[0] + params.size();
        }

        //
        // Invoke the operation asynchronously.
        //
        if(pyctx != Py_None)
        {
            Ice::Context ctx;

            if(!PyDict_Check(pyctx))
            {
                PyErr_Format(PyExc_ValueError, STRCAST("context argument must be None or a dictionary"));
                return 0;
            }

            if(!dictionaryToContext(pyctx, ctx))
            {
                return 0;
            }

            AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
            result = _prx->ice_invoke_async(this, _op->name, _op->sendMode, pparams, ctx);
        }
        else
        {
            AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
            result = _prx->ice_invoke_async(this, _op->name, _op->sendMode, pparams);
        }
    }
    catch(const Ice::CommunicatorDestroyedException& ex)
    {
        //
        // CommunicatorDestroyedException is the only exception that can propagate directly.
        //
        setPythonException(ex);
        return 0;
    }
    catch(const Ice::Exception& ex)
    {
        PyObjectHandle exh = convertException(ex);
        assert(exh.get());
        handleException(exh.get());
    }

    PyRETURN_BOOL(result);
}

void
IcePy::AsyncTypedInvocation::ice_response(bool ok, const pair<const Ice::Byte*, const Ice::Byte*>& results)
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    try
    {
        if(ok)
        {
            //
            // Unmarshal the results.
            //
            PyObjectHandle args;
            try
            {
                args = unmarshalResults(results);
                if(!args.get())
                {
                    assert(PyErr_Occurred());
                    PyErr_Print();
                    return;
                }
            }
            catch(const Ice::Exception& ex)
            {
                PyObjectHandle h = convertException(ex);
                handleException(h.get());
                return;
            }

            PyObjectHandle method = PyObject_GetAttrString(_callback, STRCAST("ice_response"));
            if(!method.get())
            {
                ostringstream ostr;
                ostr << "AMI callback object for operation `" << _op->name << "' does not define ice_response()";
                string str = ostr.str();
                PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
            }
            else
            {
                PyObjectHandle tmp = PyObject_Call(method.get(), args.get(), 0);
                if(PyErr_Occurred())
                {
                    PyErr_Print();
                }
            }
        }
        else
        {
            PyObjectHandle ex = unmarshalException(results);
            handleException(ex.get());
        }
    }
    catch(const AbortMarshaling&)
    {
        assert(PyErr_Occurred());
        PyErr_Print();
    }
    catch(const Ice::Exception& ex)
    {
        ostringstream ostr;
        ostr << "Exception raised by AMI callback for operation `" << _op->name << "':" << ex;
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
    }
}

void
IcePy::AsyncTypedInvocation::ice_exception(const Ice::Exception& ex)
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    PyObjectHandle exh = convertException(ex);
    assert(exh.get());

    handleException(exh.get());
}

void
IcePy::AsyncTypedInvocation::handleException(PyObject* ex)
{
    PyObjectHandle method = PyObject_GetAttrString(_callback, STRCAST("ice_exception"));
    if(!method.get())
    {
        ostringstream ostr;
        ostr << "AMI callback object for operation `" << _op->name << "' does not define ice_exception()";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
    }
    else
    {
        PyObjectHandle args = Py_BuildValue(STRCAST("(O)"), ex);
        PyObjectHandle tmp = PyObject_Call(method.get(), args.get(), 0);
        if(PyErr_Occurred())
        {
            PyErr_Print();
        }
    }
}

//
// AsyncSentTypedInvocation
//
IcePy::AsyncSentTypedInvocation::AsyncSentTypedInvocation(const Ice::ObjectPrx& prx, const OperationPtr& op)
    : Invocation(prx), TypedInvocation(prx, op), AsyncTypedInvocation(prx, op)
{
}

void
IcePy::AsyncSentTypedInvocation::ice_sent()
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    PyObjectHandle method = PyObject_GetAttrString(_callback, STRCAST("ice_sent"));
    if(!method.get())
    {
        ostringstream ostr;
        ostr << "AMI callback object for operation `" << _op->name << "' does not define ice_sent()";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
    }
    else
    {
        PyObjectHandle args = PyTuple_New(0);
        PyObjectHandle tmp = PyObject_Call(method.get(), args.get(), 0);
        if(PyErr_Occurred())
        {
            PyErr_Print();
        }
    }
}

//
// SyncBlobjectInvocation
//
IcePy::SyncBlobjectInvocation::SyncBlobjectInvocation(const Ice::ObjectPrx& prx)
    : Invocation(prx)
{
}

PyObject*
IcePy::SyncBlobjectInvocation::invoke(PyObject* args)
{
    char* operation;
    PyObject* mode;
    PyObject* inParams;
    PyObject* operationModeType = lookupType("Ice.OperationMode");
    PyObject* ctx = 0;
    if(!PyArg_ParseTuple(args, STRCAST("sO!O!|O"), &operation, operationModeType, &mode, &PyBuffer_Type, &inParams,
                         &ctx))
    {
        return 0;
    }

    PyObjectHandle modeValue = PyObject_GetAttrString(mode, STRCAST("value"));
    Ice::OperationMode sendMode = (Ice::OperationMode)static_cast<int>(PyInt_AS_LONG(modeValue.get()));

    //
    // Use the array API to avoid copying the data.
    //
#if PY_VERSION_HEX < 0x02050000
    const char* charBuf = 0;
#else
    char* charBuf = 0;
#endif
    Py_ssize_t sz = inParams->ob_type->tp_as_buffer->bf_getcharbuffer(inParams, 0, &charBuf);
    const Ice::Byte* mem = reinterpret_cast<const Ice::Byte*>(charBuf);
    pair<const ::Ice::Byte*, const ::Ice::Byte*> in(0, 0);
    if(sz > 0)
    {
        in.first = mem;
        in.second = mem + sz;
    }

    try
    {
        vector<Ice::Byte> out;

        bool ok;
        if(ctx == 0 || ctx == Py_None)
        {
            AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
            ok = _prx->ice_invoke(operation, sendMode, in, out);
        }
        else
        {
            Ice::Context context;
            if(!dictionaryToContext(ctx, context))
            {
                return 0;
            }

            AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
            ok = _prx->ice_invoke(operation, sendMode, in, out, context);
        }

        //
        // Prepare the result as a tuple of the bool and out param buffer.
        //
        PyObjectHandle result = PyTuple_New(2);
        if(!result.get())
        {
            throwPythonException();
        }

        if(PyTuple_SET_ITEM(result.get(), 0, ok ? getTrue() : getFalse()) < 0)
        {
            throwPythonException();
        }

        //
        // Create the output buffer and copy in the outParams.
        //
        PyObjectHandle ip = PyBuffer_New(out.size());
        if(!ip.get())
        {
            throwPythonException();
        }
        if(!out.empty())
        {
            void* buf;
            Py_ssize_t sz;
            if(PyObject_AsWriteBuffer(ip.get(), &buf, &sz))
            {
                throwPythonException();
            }
            memcpy(buf, &out[0], sz);
        }
        
        if(PyTuple_SET_ITEM(result.get(), 1, ip.get()) < 0)
        {
            throwPythonException();
        }
        ip.release(); // PyTuple_SET_ITEM steals a reference.

        return result.release();
    }
    catch(const Ice::Exception& ex)
    {
        setPythonException(ex);
        return 0;
    }
}

//
// AsyncBlobjectInvocation
//
IcePy::AsyncBlobjectInvocation::AsyncBlobjectInvocation(const Ice::ObjectPrx& prx)
    : Invocation(prx), _callback(0)
{
}

IcePy::AsyncBlobjectInvocation::~AsyncBlobjectInvocation()
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    Py_XDECREF(_callback);
}

PyObject*
IcePy::AsyncBlobjectInvocation::invoke(PyObject* args)
{
    char* operation;
    PyObject* mode;
    PyObject* inParams;
    PyObject* operationModeType = lookupType("Ice.OperationMode");
    PyObject* ctx = 0;
    if(!PyArg_ParseTuple(args, STRCAST("OsO!O!|O"), &_callback, &operation, operationModeType, &mode,
                         &PyBuffer_Type, &inParams, &ctx))
    {
        return 0;
    }

    Py_INCREF(_callback);
    _op = operation;

    PyObjectHandle modeValue = PyObject_GetAttrString(mode, STRCAST("value"));
    Ice::OperationMode sendMode = (Ice::OperationMode)static_cast<int>(PyInt_AS_LONG(modeValue.get()));

    //
    // Use the array API to avoid copying the data.
    //
#if PY_VERSION_HEX < 0x02050000
    const char* charBuf = 0;
#else
    char* charBuf = 0;
#endif
    Py_ssize_t sz = inParams->ob_type->tp_as_buffer->bf_getcharbuffer(inParams, 0, &charBuf);
    const Ice::Byte* mem = reinterpret_cast<const Ice::Byte*>(charBuf);
    pair<const ::Ice::Byte*, const ::Ice::Byte*> in(0, 0);
    if(sz > 0)
    {
        in.first = mem;
        in.second = mem + sz;
    }

    bool result = false;
    try
    {
        if(ctx == 0 || ctx == Py_None)
        {
            AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
            result = _prx->ice_invoke_async(this, operation, sendMode, in);
        }
        else
        {
            Ice::Context context;
            if(!dictionaryToContext(ctx, context))
            {
                return 0;
            }

            AllowThreads allowThreads; // Release Python's global interpreter lock during remote invocations.
            result = _prx->ice_invoke_async(this, operation, sendMode, in, context);
        }
    }
    catch(const Ice::CommunicatorDestroyedException& ex)
    {
        //
        // CommunicatorDestroyedException is the only exception that can propagate directly.
        //
        setPythonException(ex);
        return 0;
    }
    catch(const Ice::Exception& ex)
    {
        PyObjectHandle exh = convertException(ex);
        assert(exh.get());
        handleException(exh.get());
    }

    PyRETURN_BOOL(result);
}

void
IcePy::AsyncBlobjectInvocation::ice_response(bool ok, const pair<const Ice::Byte*, const Ice::Byte*>& results)
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    try
    {
        //
        // Prepare the args as a tuple of the bool and out param buffer.
        //
        PyObjectHandle args = PyTuple_New(2);
        if(!args.get())
        {
            assert(PyErr_Occurred());
            PyErr_Print();
            return;
        }

        if(PyTuple_SET_ITEM(args.get(), 0, ok ? getTrue() : getFalse()) < 0)
        {
            assert(PyErr_Occurred());
            PyErr_Print();
            return;
        }

        //
        // Create the output buffer and copy in the outParams.
        //
        PyObjectHandle ip = PyBuffer_New(results.second - results.first);
        if(!ip.get())
        {
            assert(PyErr_Occurred());
            PyErr_Print();
            return;
        }

        void* buf;
        Py_ssize_t sz;
        if(PyObject_AsWriteBuffer(ip.get(), &buf, &sz))
        {
            assert(PyErr_Occurred());
            PyErr_Print();
            return;
        }
        assert(sz == results.second - results.first);
        memcpy(buf, results.first, sz);

        if(PyTuple_SET_ITEM(args.get(), 1, ip.get()) < 0)
        {
            assert(PyErr_Occurred());
            PyErr_Print();
            return;
        }
        ip.release(); // PyTuple_SET_ITEM steals a reference.

        PyObjectHandle method = PyObject_GetAttrString(_callback, STRCAST("ice_response"));
        if(!method.get())
        {
            ostringstream ostr;
            ostr << "AMI callback object for operation `ice_invoke_async' does not define ice_response()";
            string str = ostr.str();
            PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
        }
        else
        {
            PyObjectHandle tmp = PyObject_Call(method.get(), args.get(), 0);
            if(PyErr_Occurred())
            {
                PyErr_Print();
            }
        }
    }
    catch(const Ice::Exception& ex)
    {
        ostringstream ostr;
        ostr << "Exception raised by AMI callback for operation `ice_invoke_async':" << ex;
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
    }
}

void
IcePy::AsyncBlobjectInvocation::ice_exception(const Ice::Exception& ex)
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    PyObjectHandle exh = convertException(ex);
    assert(exh.get());

    handleException(exh.get());
}

void
IcePy::AsyncBlobjectInvocation::handleException(PyObject* ex)
{
    PyObjectHandle method = PyObject_GetAttrString(_callback, STRCAST("ice_exception"));
    if(!method.get())
    {
        ostringstream ostr;
        ostr << "AMI callback object for operation `" << _op << "' does not define ice_exception()";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
    }
    else
    {
        PyObjectHandle args = Py_BuildValue(STRCAST("(O)"), ex);
        PyObjectHandle tmp = PyObject_Call(method.get(), args.get(), 0);
        if(PyErr_Occurred())
        {
            PyErr_Print();
        }
    }
}

//
// AsyncSentBlobjectInvocation
//
IcePy::AsyncSentBlobjectInvocation::AsyncSentBlobjectInvocation(const Ice::ObjectPrx& prx)
    : Invocation(prx), AsyncBlobjectInvocation(prx)
{
}

void
IcePy::AsyncSentBlobjectInvocation::ice_sent()
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    PyObjectHandle method = PyObject_GetAttrString(_callback, STRCAST("ice_sent"));
    if(!method.get())
    {
        ostringstream ostr;
        ostr << "AMI callback object for ice_invoke_async does not define ice_sent()";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
    }
    else
    {
        PyObjectHandle args = PyTuple_New(0);
        PyObjectHandle tmp = PyObject_Call(method.get(), args.get(), 0);
        if(PyErr_Occurred())
        {
            PyErr_Print();
        }
    }
}

//
// TypedUpcall
//
IcePy::TypedUpcall::TypedUpcall(const OperationPtr& op, const Ice::AMD_Array_Object_ice_invokePtr& callback,
                                const Ice::CommunicatorPtr& communicator) :
    _op(op), _callback(callback), _communicator(communicator)
{
}

void
IcePy::TypedUpcall::dispatch(PyObject* servant, const pair<const Ice::Byte*, const Ice::Byte*>& inBytes,
                             const Ice::Current& current)
{
    //
    // Unmarshal the in parameters. We have to leave room in the arguments for a trailing
    // Ice::Current object.
    //
    Py_ssize_t count = static_cast<Py_ssize_t>(_op->inParams.size()) + 1;

    Py_ssize_t start = 0;
    if(_op->amd)
    {
        ++count; // Leave room for a leading AMD callback argument.
        start = 1;
    }

    PyObjectHandle args = PyTuple_New(count);
    if(!args.get())
    {
        throwPythonException();
    }

    if(!_op->inParams.empty())
    {
        Ice::InputStreamPtr is = Ice::createInputStream(_communicator, inBytes);
        try
        {
            Py_ssize_t i = start;
            for(ParamInfoList::iterator p = _op->inParams.begin(); p != _op->inParams.end(); ++p, ++i)
            {
                void* closure = reinterpret_cast<void*>(i);
                (*p)->type->unmarshal(is, *p, args.get(), closure, &(*p)->metaData);
            }
            if(_op->sendsClasses)
            {
                is->readPendingObjects();
            }
        }
        catch(const AbortMarshaling&)
        {
            throwPythonException();
        }
    }

    //
    // Create an object to represent Ice::Current. We need to append this to the argument tuple.
    //
    PyObjectHandle curr = createCurrent(current);
    if(PyTuple_SET_ITEM(args.get(), PyTuple_GET_SIZE(args.get()) - 1, curr.get()) < 0)
    {
        throwPythonException();
    }
    curr.release(); // PyTuple_SET_ITEM steals a reference.

    if(_op->amd)
    {
        //
        // Create the callback object and pass it as the first argument.
        //
        AMDCallbackObject* obj = amdCallbackNew(0);
        if(!obj)
        {
            throwPythonException();
        }
        obj->upcall = new UpcallPtr(this);
        if(PyTuple_SET_ITEM(args.get(), 0, (PyObject*)obj) < 0) // PyTuple_SET_ITEM steals a reference.
        {
            Py_DECREF(obj);
            throwPythonException();
        }
    }

    //
    // Dispatch the operation. Use _dispatchName here, not current.operation.
    //
    PyObjectHandle method = PyObject_GetAttrString(servant, const_cast<char*>(_op->dispatchName.c_str()));
    if(!method.get())
    {
        ostringstream ostr;
        ostr << "servant for identity " << _communicator->identityToString(current.id)
             << " does not define operation `" << _op->dispatchName << "'";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
        Ice::UnknownException ex(__FILE__, __LINE__);
        ex.unknown = str;
        throw ex;
    }

    PyObjectHandle result = PyObject_Call(method.get(), args.get(), 0);

    //
    // Check for exceptions.
    //
    if(PyErr_Occurred())
    {
        PyException ex; // Retrieve it before another Python API call clears it.
        exception(ex);
        return;
    }

    if(!_op->amd)
    {
        response(result.get());
    }
}

void
IcePy::TypedUpcall::response(PyObject* args)
{
    try
    {
        //
        // Marshal the results. If there is more than one value to be returned, then they must be
        // returned in a tuple of the form (result, outParam1, ...).
        //
        Ice::OutputStreamPtr os = Ice::createOutputStream(_communicator);
        try
        {
            Py_ssize_t i = _op->returnType ? 1 : 0;
            Py_ssize_t numResults = static_cast<Py_ssize_t>(_op->outParams.size()) + i;
            if(numResults > 1)
            {
                if(!PyTuple_Check(args) || PyTuple_GET_SIZE(args) != numResults)
                {
                    ostringstream ostr;
                    ostr << "operation `" << fixIdent(_op->name) << "' should return a tuple of length " << numResults;
                    string str = ostr.str();
                    PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
                    throw Ice::MarshalException(__FILE__, __LINE__);
                }
            }

            ObjectMap objectMap;

            for(ParamInfoList::iterator p = _op->outParams.begin(); p != _op->outParams.end(); ++p, ++i)
            {
                PyObject* arg;
                if(_op->amd || numResults > 1)
                {
                    arg = PyTuple_GET_ITEM(args, i);
                }
                else
                {
                    arg = args;
                    assert(_op->outParams.size() == 1);
                }

                if(!(*p)->type->validate(arg))
                {
                    // TODO: Provide the parameter name instead?
                    ostringstream ostr;
                    ostr << "invalid value for out argument " << (i + 1) << " in operation `" << fixIdent(_op->name)
                         << (_op->amd ? "_async" : "") << "'";
                    string str = ostr.str();
                    PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
                    throw Ice::MarshalException(__FILE__, __LINE__);
                }
                (*p)->type->marshal(arg, os, &objectMap, &(*p)->metaData);
            }

            if(_op->returnType)
            {
                PyObject* res;
                if(_op->amd || numResults > 1)
                {
                    res = PyTuple_GET_ITEM(args, 0);
                }
                else
                {
                    assert(_op->outParams.size() == 0);
                    res = args;
                }
                if(!_op->returnType->type->validate(res))
                {
                    ostringstream ostr;
                    ostr << "invalid return value for operation `" << fixIdent(_op->name) << "'";
                    string str = ostr.str();
                    PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
                    throw Ice::MarshalException(__FILE__, __LINE__);
                }
                _op->returnType->type->marshal(res, os, &objectMap, &_op->metaData);
            }

            if(_op->returnsClasses)
            {
                os->writePendingObjects();
            }

            Ice::ByteSeq bytes;
            os->finished(bytes);
            pair<const Ice::Byte*, const Ice::Byte*> ob(0, 0);
            if(!bytes.empty())
            {
                ob.first = &bytes[0];
                ob.second = &bytes[0] + bytes.size();
            }

            AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
            _callback->ice_response(true, ob);
        }
        catch(const AbortMarshaling&)
        {
            throwPythonException();
        }
    }
    catch(const Ice::Exception& ex)
    {
        AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
        _callback->ice_exception(ex);
    }
}

void
IcePy::TypedUpcall::exception(PyException& ex)
{
    try
    {
        try
        {
            //
            // A servant that calls sys.exit() will raise the SystemExit exception.
            // This is normally caught by the interpreter, causing it to exit.
            // However, we have no way to pass this exception to the interpreter,
            // so we act on it directly.
            //
            ex.checkSystemExit();

            PyObject* userExceptionType = lookupType("Ice.UserException");

            if(PyObject_IsInstance(ex.ex.get(), userExceptionType))
            {
                //
                // Get the exception's type and verify that it is legal to be thrown from this operation.
                //
                PyObjectHandle iceType = PyObject_GetAttrString(ex.ex.get(), STRCAST("ice_type"));
                assert(iceType.get());
                ExceptionInfoPtr info = ExceptionInfoPtr::dynamicCast(getException(iceType.get()));
                assert(info);
                if(!validateException(ex.ex.get()))
                {
                    ex.raise(); // Raises UnknownUserException.
                }
                else
                {
                    Ice::OutputStreamPtr os = Ice::createOutputStream(_communicator);

                    os->writeBool(info->usesClasses);

                    ObjectMap objectMap;
                    info->marshal(ex.ex.get(), os, &objectMap);

                    if(info->usesClasses)
                    {
                        os->writePendingObjects();
                    }

                    Ice::ByteSeq bytes;
                    os->finished(bytes);
                    pair<const Ice::Byte*, const Ice::Byte*> ob(0, 0);
                    if(!bytes.empty())
                    {
                        ob.first = &bytes[0];
                        ob.second = &bytes[0] + bytes.size();
                    }

                    AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
                    _callback->ice_response(false, ob);
                }
            }
            else
            {
                ex.raise();
            }
        }
        catch(const AbortMarshaling&)
        {
            throwPythonException();
        }
    }
    catch(const Ice::Exception& ex)
    {
        AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
        _callback->ice_exception(ex);
    }
}

bool
IcePy::TypedUpcall::validateException(PyObject* ex) const
{
    for(ExceptionInfoList::const_iterator p = _op->exceptions.begin(); p != _op->exceptions.end(); ++p)
    {
        if(PyObject_IsInstance(ex, (*p)->pythonType.get()))
        {
            return true;
        }
    }

    return false;
}

//
// BlobjectUpcall
//
IcePy::BlobjectUpcall::BlobjectUpcall(bool amd, const Ice::AMD_Array_Object_ice_invokePtr& callback) :
    _amd(amd), _callback(callback)
{
}

void
IcePy::BlobjectUpcall::dispatch(PyObject* servant, const pair<const Ice::Byte*, const Ice::Byte*>& inBytes,
                                const Ice::Current& current)
{
    Ice::CommunicatorPtr communicator = current.adapter->getCommunicator();

    Py_ssize_t count = 2; // First is the inParams, second is the Ice::Current object.

    Py_ssize_t start = 0;
    if(_amd)
    {
        ++count; // Leave room for a leading AMD callback argument.
        start = 1;
    }

    PyObjectHandle args = PyTuple_New(count);
    if(!args.get())
    {
        throwPythonException();
    }
 
    //
    // If using AMD we need to copy the bytes since the bytes may be
    // accessed after this method is over, otherwise
    // PyBuffer_FromMemory can be used which doesn't do a copy.
    //
    PyObjectHandle ip;
    if(!_amd)
    {
        ip = PyBuffer_FromMemory((void*)inBytes.first, inBytes.second - inBytes.first);
        if(!ip.get())
        {
            throwPythonException();
        }
    }
    else
    {
        ip = PyBuffer_New(inBytes.second - inBytes.first);
        if(!ip.get())
        {
            throwPythonException();
        }
        void* buf;
        Py_ssize_t sz;
        if(PyObject_AsWriteBuffer(ip.get(), &buf, &sz))
        {
            throwPythonException();
        }
        assert(sz == inBytes.second - inBytes.first);
        memcpy(buf, inBytes.first, sz);
    }

    if(PyTuple_SET_ITEM(args.get(), start, ip.get()) < 0)
    {
        throwPythonException();
    }
    ++start;
    ip.release(); // PyTuple_SET_ITEM steals a reference.

    //
    // Create an object to represent Ice::Current. We need to append
    // this to the argument tuple.
    //
    PyObjectHandle curr = createCurrent(current);
    if(PyTuple_SET_ITEM(args.get(), start, curr.get()) < 0)
    {
        throwPythonException();
    }
    curr.release(); // PyTuple_SET_ITEM steals a reference.

    string dispatchName = "ice_invoke";
    if(_amd)
    {
        dispatchName += "_async";
        //
        // Create the callback object and pass it as the first argument.
        //
        AMDCallbackObject* obj = amdCallbackNew(0);
        if(!obj)
        {
            throwPythonException();
        }
        obj->upcall = new UpcallPtr(this);
        if(PyTuple_SET_ITEM(args.get(), 0, (PyObject*)obj) < 0) // PyTuple_SET_ITEM steals a reference.
        {
            Py_DECREF(obj);
            throwPythonException();
        }
    }

    //
    // Dispatch the operation.
    //
    PyObjectHandle method = PyObject_GetAttrString(servant, const_cast<char*>(dispatchName.c_str()));
    if(!method.get())
    {
        ostringstream ostr;
        ostr << "servant for identity " << communicator->identityToString(current.id)
             << " does not define operation `" << dispatchName << "'";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
        Ice::UnknownException ex(__FILE__, __LINE__);
        ex.unknown = str;
        throw ex;
    }

    PyObjectHandle result = PyObject_Call(method.get(), args.get(), 0);

    //
    // Check for exceptions.
    //
    if(PyErr_Occurred())
    {
        PyException ex; // Retrieve it before another Python API call clears it.
        exception(ex);
        return;
    }

    if(!_amd)
    {
        response(result.get());
    }
}

void
IcePy::BlobjectUpcall::response(PyObject* args)
{
    //
    // The return value is a tuple of (bool, PyBuffer).
    //
    if(!PyTuple_Check(args) || PyTuple_GET_SIZE(args) != 2)
    {
        ostringstream ostr;
        string name = "ice_invoke";
        if(_amd)
        {
            name += "_async";
        }
        ostr << "operation `" << name << "' should return a tuple of length 2";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
        throw Ice::MarshalException(__FILE__, __LINE__);
    }

    PyObject* arg = PyTuple_GET_ITEM(args, 0);
    int isTrue = PyObject_IsTrue(arg);

    arg = PyTuple_GET_ITEM(args, 1);
    if(!PyBuffer_Check(arg))
    {
        ostringstream ostr;
        ostr << "invalid return value for operation `ice_invoke'";
        string str = ostr.str();
        PyErr_Warn(PyExc_RuntimeWarning, const_cast<char*>(str.c_str()));
        throw Ice::MarshalException(__FILE__, __LINE__);
    }

#if PY_VERSION_HEX < 0x02050000
    const char* charBuf = 0;
#else
    char* charBuf = 0;
#endif
    Py_ssize_t sz = arg->ob_type->tp_as_buffer->bf_getcharbuffer(arg, 0, &charBuf);
    const Ice::Byte* mem = reinterpret_cast<const Ice::Byte*>(charBuf);
    const pair<const ::Ice::Byte*, const ::Ice::Byte*> bytes(mem, mem + sz);

    AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
    _callback->ice_response(isTrue, bytes);
}

void
IcePy::BlobjectUpcall::exception(PyException& ex)
{
    try
    {
        //
        // A servant that calls sys.exit() will raise the SystemExit exception.
        // This is normally caught by the interpreter, causing it to exit.
        // However, we have no way to pass this exception to the interpreter,
        // so we act on it directly.
        //
        ex.checkSystemExit();

        ex.raise();
    }
    catch(const Ice::Exception& ex)
    {
        AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
        _callback->ice_exception(ex);
    }
}

PyObject*
IcePy::iceIsA(const Ice::ObjectPrx& prx, PyObject* args)
{
    PyObject* objectType = lookupType("Ice.Object");
    assert(objectType);
    PyObjectHandle obj = PyObject_GetAttrString(objectType, "_op_ice_isA");
    assert(obj.get());

    OperationPtr op = getOperation(obj.get());
    assert(op);

    InvocationPtr i = new SyncTypedInvocation(prx, op);
    return i->invoke(args);
}

PyObject*
IcePy::icePing(const Ice::ObjectPrx& prx, PyObject* args)
{
    PyObject* objectType = lookupType("Ice.Object");
    assert(objectType);
    PyObjectHandle obj = PyObject_GetAttrString(objectType, "_op_ice_ping");
    assert(obj.get());

    OperationPtr op = getOperation(obj.get());
    assert(op);

    InvocationPtr i = new SyncTypedInvocation(prx, op);
    return i->invoke(args);
}

PyObject*
IcePy::iceIds(const Ice::ObjectPrx& prx, PyObject* args)
{
    PyObject* objectType = lookupType("Ice.Object");
    assert(objectType);
    PyObjectHandle obj = PyObject_GetAttrString(objectType, "_op_ice_ids");
    assert(obj.get());

    OperationPtr op = getOperation(obj.get());
    assert(op);

    InvocationPtr i = new SyncTypedInvocation(prx, op);
    return i->invoke(args);
}

PyObject*
IcePy::iceId(const Ice::ObjectPrx& prx, PyObject* args)
{
    PyObject* objectType = lookupType("Ice.Object");
    assert(objectType);
    PyObjectHandle obj = PyObject_GetAttrString(objectType, "_op_ice_id");
    assert(obj.get());

    OperationPtr op = getOperation(obj.get());
    assert(op);

    InvocationPtr i = new SyncTypedInvocation(prx, op);
    return i->invoke(args);
}

PyObject*
IcePy::iceInvoke(const Ice::ObjectPrx& prx, PyObject* args)
{
    InvocationPtr i = new SyncBlobjectInvocation(prx);
    return i->invoke(args);
}

PyObject*
IcePy::iceInvokeAsync(const Ice::ObjectPrx& prx, PyObject* args)
{
    //
    // If the callback implements an ice_sent method, we create a wrapper that derives
    // from AMISentCallback.
    //
    assert(PyTuple_GET_SIZE(args) > 0);
    PyObject* callback = PyTuple_GET_ITEM(args, 0);
    if(PyObject_HasAttrString(callback, STRCAST("ice_sent")))
    {
        InvocationPtr i = new AsyncSentBlobjectInvocation(prx);
        return i->invoke(args);
    }
    else
    {
        InvocationPtr i = new AsyncBlobjectInvocation(prx);
        return i->invoke(args);
    }
}

//
// ServantWrapper implementation.
//
IcePy::ServantWrapper::ServantWrapper(PyObject* servant) :
    _servant(servant)
{
    Py_INCREF(_servant);
}

IcePy::ServantWrapper::~ServantWrapper()
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    Py_DECREF(_servant);
}

PyObject*
IcePy::ServantWrapper::getObject()
{
    Py_INCREF(_servant);
    return _servant;
}

//
// TypedServantWrapper implementation.
//
IcePy::TypedServantWrapper::TypedServantWrapper(PyObject* servant) :
    ServantWrapper(servant), _lastOp(_operationMap.end())
{
}

void
IcePy::TypedServantWrapper::ice_invoke_async(const Ice::AMD_Array_Object_ice_invokePtr& cb,
                                             const pair<const Ice::Byte*, const Ice::Byte*>& inParams,
                                             const Ice::Current& current)
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    try
    {
        //
        // Locate the Operation object. As an optimization we keep a reference
        // to the most recent operation we've dispatched, so check that first.
        //
        OperationPtr op;
        if(_lastOp != _operationMap.end() && _lastOp->first == current.operation)
        {
            op = _lastOp->second;
        }
        else
        {
            //
            // Next check our cache of operations.
            //
            _lastOp = _operationMap.find(current.operation);
            if(_lastOp == _operationMap.end())
            {
                //
                // Look for the Operation object in the servant's type.
                //
                string attrName = "_op_" + current.operation;
                PyObjectHandle h = PyObject_GetAttrString((PyObject*)_servant->ob_type,
                                                          const_cast<char*>(attrName.c_str()));
                if(!h.get())
                {
                    PyErr_Clear();
                    Ice::OperationNotExistException ex(__FILE__, __LINE__);
                    ex.id = current.id;
                    ex.facet = current.facet;
                    ex.operation = current.operation;
                    throw ex;
                }

                assert(PyObject_IsInstance(h.get(), reinterpret_cast<PyObject*>(&OperationType)) == 1);
                OperationObject* obj = reinterpret_cast<OperationObject*>(h.get());
                op = *obj->op;
                _lastOp = _operationMap.insert(OperationMap::value_type(current.operation, op)).first;
            }
            else
            {
                op = _lastOp->second;
            }
        }

        __checkMode(op->mode, current.mode);

        UpcallPtr up = new TypedUpcall(op, cb, current.adapter->getCommunicator());
        up->dispatch(_servant, inParams, current);
    }
    catch(const Ice::Exception& ex)
    {
        AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
        cb->ice_exception(ex);
    }
}

//
// BlobjectServantWrapper implementation.
//
IcePy::BlobjectServantWrapper::BlobjectServantWrapper(PyObject* servant, bool amd) :
    ServantWrapper(servant), _amd(amd)
{
}

void
IcePy::BlobjectServantWrapper::ice_invoke_async(const Ice::AMD_Array_Object_ice_invokePtr& cb,
                                                const pair<const Ice::Byte*, const Ice::Byte*>& inParams,
                                                const Ice::Current& current)
{
    AdoptThread adoptThread; // Ensure the current thread is able to call into Python.

    try
    {
        UpcallPtr up = new BlobjectUpcall(_amd, cb);
        up->dispatch(_servant, inParams, current);
    }
    catch(const Ice::Exception& ex)
    {
        AllowThreads allowThreads; // Release Python's global interpreter lock during blocking calls.
        cb->ice_exception(ex);
    }
}

IcePy::ServantWrapperPtr
IcePy::createServantWrapper(PyObject* servant)
{
    ServantWrapperPtr wrapper;
    PyObject* blobjectType = lookupType("Ice.Blobject");
    PyObject* blobjectAsyncType = lookupType("Ice.BlobjectAsync");
    if(PyObject_IsInstance(servant, blobjectType))
    {
        return new BlobjectServantWrapper(servant, false);
    }
    else if(PyObject_IsInstance(servant, blobjectAsyncType))
    {
        return new BlobjectServantWrapper(servant, true);
    }

    return new TypedServantWrapper(servant);
}