实现方式一:
#include <pthread.h>
template<typename T>
class Singleton : boost::noncopyable {
public:
static T& instance() {
pthread_once(&ponce_, &Singleton::init);
return *value_;
}
static void init() {
value_ = new T();
}
private:
static pthread_once_t ponce_;
static T* value_;
};
template<typename T>
pthread_once_t Singleton<T>::ponce_ = PTHREAD_ONCE_INIT;
template<typename T>
T* Singleton<T>::value_ = NULL;
实现方式二:
#ifndef LOCKER_H_
#define LOCKER_H_
#include "pthread.h"
class locker
{
public:
inline locker(){ pthread_mutex_init(&mutex,NULL);}
inline ~locker(){ pthread_mutex_destroy(&mutex);}
inline void lock(){ pthread_mutex_lock(&mutex);}
inline void unlock(){ pthread_mutex_unlock(&mutex);}
private:
pthread_mutex_t mutex;
};
#endif /* LOCKER_H_ */
#ifndef __SINGLETON_H__
#define __SINGLETON_H__
template <typename T>
class Singleton
{
public:
inline static T* getInstance();
inline static void release();
private:
static T* t;
static locker llocker;
};
template <typename T>
inline T* Singleton<T>::getInstance()
{
llocker.lock();
if (!t)
{
t = new T;
}
llocker.unlock();
return t;
}
template<typename T>
inline void Singleton<T>::release()
{
llocker.lock();
if (t)
{
delete t;
t = 0;
}
llocker.unlock();
}
template <typename T>
T* Singleton<T>::t = 0;
locker Singleton<T>::llocker
#endif // __SINGLE_H__