ClickHouse/base/poco/Foundation/include/Poco/RefCountedObject.h

//
// RefCountedObject.h
//
// Library: Foundation
// Package: Core
// Module:  RefCountedObject
//
// Definition of the RefCountedObject class.
//
// Copyright (c) 2004-2009, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_RefCountedObject_INCLUDED
#define Foundation_RefCountedObject_INCLUDED


#include "Poco/AtomicCounter.h"
#include "Poco/Foundation.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 throw();
    /// 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 throw()
{
    try
    {
        if (--_counter == 0)
            delete this;
    }
    catch (...)
    {
        poco_unexpected();
    }
}


} // namespace Poco


#endif // Foundation_RefCountedObject_INCLUDED