//
// RefCountedObject.h
//
// $Id: //poco/1.3/Foundation/include/Poco/RefCountedObject.h#2 $
//
// Library: Foundation
// Package: Core
// Module:  RefCountedObject
//
// Definition of the RefCountedObject class.
//
// Copyright (c) 2004-2009, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Foundation_RefCountedObject_INCLUDED
#define Foundation_RefCountedObject_INCLUDED


#include "Poco/Foundation.h"
#include "Poco/AtomicCounter.h"


namespace Poco {


class Foundation_API RefCountedObject
	/// A base class for objects that employ
	/// reference counting based garbage collection.
	///
	/// Reference-counted objects inhibit construction
	/// by copying and assignment.
{
public:
	RefCountedObject();
		/// Creates the RefCountedObject.
		/// The initial reference count is one.

	void duplicate() const;
		/// Increments the object's reference count.
		
	void release() const;
		/// Decrements the object's reference count
		/// and deletes the object if the count
		/// reaches zero.
		
	int referenceCount() const;
		/// Returns the reference count.

protected:
	virtual ~RefCountedObject();
		/// Destroys the RefCountedObject.

private:
	RefCountedObject(const RefCountedObject&);
	RefCountedObject& operator = (const RefCountedObject&);

	mutable AtomicCounter _counter;
};


//
// inlines
//
inline int RefCountedObject::referenceCount() const
{
	return _counter.value();
}


inline void RefCountedObject::duplicate() const
{
	++_counter;
}


inline void RefCountedObject::release() const
{
	if (--_counter == 0) delete this;
}


} // namespace Poco


#endif // Foundation_RefCountedObject_INCLUDED
