Cross thread calls in native C++

/************************************************************************
** Copyright 2007 Einar Otto Stangvik
** 
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** 
**    http://www.apache.org/licenses/LICENSE-2.0
** 
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/

/*
** This is a stub class which will be included multiple times in 
** ExceptionExpecter.h. Expansions of preprocessor parameters and
** variables comes from the boost preprocessor helpers used in said
** header.
*/

template<typename E>
class ExceptionExpecter<E, BOOST_PP_ITERATION()>
{
public:
    ExceptionExpecter(boost::function<void(details::CaughtExceptionType)> onCompleteFunctor)
        : m_onCompleteFunctor(onCompleteFunctor),
          m_caughtExceptionType(details::CaughtExceptionType_None)
    {}
    
    ~ExceptionExpecter() {}
    
    // Generate functions to throw an exception of the iterated type,
    // from the expected exceptions type vector
    BOOST_PP_REPEAT_2ND(BOOST_PP_ITERATION(), THROWEX, throwEx)

    void execute(boost::function<void()> functor)
    {
        try
        {
            functor();
        }
        // Generate blocks to catch an exception of the iterated type,
        // from the expected exceptions type vector
        BOOST_PP_REPEAT_2ND(BOOST_PP_ITERATION(), CATCH, 0)
        // Catch other exceptions
        catch(...)
        {
            m_caughtExceptionType = details::CaughtExceptionType_Unknown;
            m_rethrowFunctor = boost::bind(throwExUnexpected, _1);
            m_onCompleteFunctor(m_caughtExceptionType);
            return;
        }

        // No exceptions caught, call the completion functor
        m_onCompleteFunctor(m_caughtExceptionType);
    }

    void rethrow(boost::function<void()> onDestroyException)
    {
        if(m_caughtExceptionType == details::CaughtExceptionType_Expected ||
           m_caughtExceptionType == details::CaughtExceptionType_Unknown)
        {
            m_rethrowFunctor(onDestroyException);
        }
    }

    /*! 
    ** @brief releases any resources currently held by an ExceptionExpecter
    **   instance, and deletes the instance itself.
    */
    inline void free()
    { delete this; }

private:
    static void throwExUnexpected(boost::function<void()>& onExceptionDestroyed)
    {
        details::throwHooked(UnexpectedException(), onExceptionDestroyed);
    }

    boost::function<void(details::CaughtExceptionType)> m_onCompleteFunctor;
    boost::function<void(boost::function<void()>&)> m_rethrowFunctor;
    details::CaughtExceptionType m_caughtExceptionType;
};