MCThreadGlobal.h

#if !defined(__MCTHREADGLOBAL_H_)
#define __MCTHREADGLOBAL_H_

#ident "@(#)$Id: MCThreadGlobal.h,v 1.3 2004/12/02 07:05:20 mike Exp $"

/*
 * Copyright Miba Consulting Ltd. (c) 2000-2003
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "mcllib/MCThreadData.h"
#include "mcllib/MCThrow.h"

namespace mcllib
{
    template<typename T>
    class MCThreadSingleton
    {
    private:
        class Inner : public MCThreadData
        { 
        public:
            Inner()
            {
                m_pInstance = new T();
            }
            ~Inner()
            {
                if (m_pInstance)
                    delete m_pInstance;
            }
            inline T* ptr()
            {
                return(m_pInstance);
            }
        private:
            T* m_pInstance;
        };

        void initialize()
        {
            if (m_key == 0) {
                MCThrow("MCThreadSingleton: key not initialized");
            }
            // won't go away whilst the thread is still alive
            MCThreadData* pData = MCThread::getData(m_key);
            if (!pData) {
                m_pInner = new Inner();
                pData = m_pInner;
                MCThread::setData(m_key, (MCThreadData*)m_pInner);
            } else {
                m_pInner = static_cast<Inner*>(pData);
            }
        }

    public:
        MCThreadSingleton(const MCString& key)
        {
            if (m_key == 0) {
                // don't have a key - create one
                // otherwise key is ignored
                m_key = MCThread::getDataIndex(key);
            }
            initialize();
        }
        MCThreadSingleton()
        {
            initialize();
        }
        inline T* operator->()
        {
            return(m_pInner->ptr());
        }
        inline T& operator*()
        {
            return(*(m_pInner->ptr()));
        }
    
        static mcthreaddatakey_t m_key;

        MCRefPtr<Inner, MCThreadModel::THRMODELSINGLE> m_pInner;
    };

    template<typename T>
    void MCThreadSingletonMaker(T* /*unused*/, const MCString& key)
    {
        MCThreadSingleton<T> t(key);
        (void)t.m_pInner;
    }

};

#endif

---