SmartObject.h

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#ifndef TIL_SMARTOBJECT_H
#define TIL_SMARTOBJECT_H

#include <iostream>

#include "til/til_common.h"


// SmartObject is a base class used for garbage collection.
// A class should derive from SmartObject if garbage collection is needed
// for this class.
// SmartObject contains nothing but a number that counts the number of 
// pointers pointing to this object. It provided also method for the pointers
// to increase and decrease this number.

// Ptr and ConstPtr classes implements this functionality.


// Namespace 

namespace til {

class TIL_API SmartObject
{

public: // Constructors and destructor

        SmartObject(void)
        {
#ifdef SMARTOBJ_DEBUG
                std::cout << "SmartObj constr" << std::endl;
#endif
                m_refCount = 0;
                m_lock = false;
        }

        virtual ~SmartObject()
        {
#ifdef SMARTOBJ_DEBUG
                std::cout << "SmartObj destr" << std::endl;
#endif
        }

public: // functions

        void subscribe(void)
        {
                ++m_refCount;
#ifdef SMARTOBJ_DEBUG
                std::cout << "Increase to " << m_refCount << std::endl;
#endif
        }

        void unsubscribe(void)
        {
#ifdef SMARTOBJ_DEBUG
                std::cout << "Decrease to " << m_refCount - 1 << std::endl;
#endif
                if ((--m_refCount == 0) && (!m_lock)) delete this;
        }

        int getReferenceCount(void)
        {
                return m_refCount;
        }

        void lock() { m_lock = true; }

        void unlock()
        {
                m_lock = false;
                if (m_refCount==0) delete this;
        }

private: // data
        
        int m_refCount;
        bool m_lock;
};


} // namespace


#endif