Singleton template (一)

共享一个Singleton template的实现：

Singleton.hpp如下

************************************************************************
* Template of Singleton, threads safe.
* by xiuleili 2013-7-5
************************************************************************/ 
#pragma once  
#include   
 
#ifdef WIN32  
#include "ResGuard.hpp"  
#else  
#include "ResGuard_linux.hpp"  
#endif   
 
template  
class Singleton 
{ 
public: 
    // return instance of the singleton  
    static inline T* instance(){ 
        if( 0 == _instance.get() ) 
        { 
            ResGuard::Lock gd(_rs); 
            if( 0== _instance.get()) 
            { 
                _instance.reset ( new T); 
            } 
        } 
        return _instance.get(); 
    } 
 
private: 
    Singleton(void){} 
    ~Singleton(void){} 
    Singleton(const Singleton&){} 
    Singleton & operator= (const Singleton &){} 
 
    static std::auto_ptr _instance; // auto_ptr used for release the resource.  
    static ResGuard _rs;               //   
}; 
 
template  
std::auto_ptr Singleton::_instance; 
 
template  
ResGuard Singleton::_rs; 
 
// use this macro to declare a singleton  
#define DECLARE_SINGLETON_CLASS( type ) \  
    friend class std::auto_ptr< type >;\ 
    friend class Singleton< type >; 
 
// How to use:  
// class A{  
// private:  
//     A(){}  
//     A(const A &){}  
//     ~A(){}  
//     A & operator=(const A &){}  
//     DECLARE_SINGLETON_CLASS(A);  
// };  
//  
// declare the singleton:  
// typedef Singleton theA;  
 
//  
// call it somewhere like this:  
// theA::instance()->foo(); 

/************************************************************************
* Template of Singleton, threads safe.
* by xiuleili 2013-7-5
************************************************************************/
#pragma once
#include 

#ifdef WIN32
#include "ResGuard.hpp"
#else
#include "ResGuard_linux.hpp"
#endif

template 
class Singleton
{
public:
    // return instance of the singleton
    static inline T* instance(){
        if( 0 == _instance.get() )
        {
            ResGuard::Lock gd(_rs);
            if( 0== _instance.get())
            {
                _instance.reset ( new T);
            }
        }
        return _instance.get();
    }

private:
 Singleton(void){}
 ~Singleton(void){}
 Singleton(const Singleton&){}
 Singleton & operator= (const Singleton &){}

 static std::auto_ptr _instance; // auto_ptr used for release the resource.
 static ResGuard _rs;               //
};

template 
std::auto_ptr Singleton::_instance;

template 
ResGuard Singleton::_rs;

// use this macro to declare a singleton
#define DECLARE_SINGLETON_CLASS( type ) \
 friend class std::auto_ptr< type >;\
 friend class Singleton< type >;

// How to use:
// class A{
// private:
//     A(){}
//     A(const A &){}
//     ~A(){}
//     A & operator=(const A &){}
//     DECLARE_SINGLETON_CLASS(A);
// };
//
// declare the singleton:
// typedef Singleton theA;

//
// call it somewhere like this:
// theA::instance()->foo();

Resguard.hpp

* Implementation of ResGuard on Windows.
* see <<windows kernal var cpp>>
* by xiuleili 2013-7-5
*/ 
 
#pragma once  
#ifndef _UNIX  
#include   
///////////////////////////////////////////////////////////////////////////////  
 
// Instances of this class will be accessed by multiple threads. So,  
// all members of this class (except the constructor and destructor)  
// must be thread-safe.  
class ResGuard { 
public: 
    ResGuard()  { m_guardcount = 0; InitializeCriticalSection(&m_cs); } 
    ~ResGuard() { DeleteCriticalSection(&m_