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/*
Copyright (C) 2002 Simon Hausmann <simon@lst.de>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
#ifndef SINGLETON_H
#define SINGLETON_H
#include "threadutil.h"
template <class Product>
struct DefaultSingletonCreator
{
static Product *create() { return new Product; }
};
template <class Product>
struct NullSingletonCreator
{
static Product *create() { return 0; }
};
template
<
class T,
template <class> class Creator = DefaultSingletonCreator
>
class Singleton
{
public:
static T &self()
{
if ( !s_self ) {
ThreadUtil::AutoLock lock( s_guard );
if ( !s_self )
s_self = Creator<T>::create();
}
return *s_self;
}
protected:
Singleton()
{ s_self = static_cast<T *>( this ); }
~Singleton()
{ s_self = 0; }
private:
Singleton( const Singleton<T, Creator> &rhs );
Singleton<T, Creator> &operator=( const Singleton<T, Creator> &rhs );
static T *s_self;
static ThreadUtil::Mutex s_guard;
};
template <class T, template <class> class Creator>
T *Singleton<T, Creator>::s_self = 0;
template <class T, template <class> class Creator>
ThreadUtil::Mutex Singleton<T, Creator>::s_guard;
#endif // SINGLETON_H
/* vim: et sw=4 ts=4
*/
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