C++再论单例模式

#include <iostream>
#include <windows.h>
#include <mutex>
std::mutex gmutex;
using namespace std;

template<typename Type>
class Singleton
{
public:
    static Type* GetSingleton()
    {
        if (siglen == NULL)
        {
            unique_lock<std::mutex> lock(gmutex);//C++11加锁。
            if (siglen == NULL)
            {
                siglen = new Type();
                Type *temp = new Type();
                MemoryBarrier();
                siglen = temp;
            }
        }
        return siglen;
    }
private:
    static Type* siglen;
};

template<typename Type>
Type* Singleton<Type>::siglen = NULL;

class Text
{
public:
    Text()
    {
        data = 100;
        //由于是单例模式。所以唯一会出现申请内存。调用构造
        //函数。赋值三个步骤混乱的机会仅仅有在前面的1-2次
        //的时候。可惜速度太快了。这样的情况发生的概率及其低
        //，可是我们的心理要始终明确。

}
    void Printf()
    {
        cout << "data="<<data << endl;
    }
    static DWORD WINAPI ThreadFunc(LPVOID arg)
    {
        Singleton<Text>::GetSingleton()->Printf();
        return DWORD(0);
    }
private:
    int data;
};

int main()
{
    HANDLE hThread;
    DWORD threadId;

    for (int i = 0; i < 10; i++)
    {
        hThread = CreateThread(NULL, 0, &(Text::ThreadFunc), (void *)"123",0, &threadId);
    }
    Sleep(5);
    cout << "ThreadFunc is running!!!" << endl;
    return 0;
}

#include <iostream>
using namespace std;
//引用计数的智能指针。
template<typename Type>
class my_auto_ptr
{
public:
    my_auto_ptr(Type* p = NULL) :ptr(p)
    {
        count = new int[1];
        count[0] = 1;
    }
    my_auto_ptr(const my_auto_ptr &ma)
    {
        count = ma.count;
        count[0]++;
    }
    my_auto_ptr& operator=(const my_auto_ptr &ma)
    {
        if (this != &ma)
        {
            this->~my_auto_ptr();
            count = ma.count;
            count[0]++;
            ptr = ma.ptr;
        }
        return *this;
    }
    ~my_auto_ptr()
    {
        if (count!=NULL &&count[0]-- == 1)
        {
            cout << "~my_auto_ptr()" << endl;
            delete ptr;
            ptr = NULL;
            delete[] count;
            count = NULL;
        }
    }
    Type* operator->()
    {
        return ptr;
    }
    Type& operator*()
    {
        return *ptr;
    }
private:
    Type *ptr;
    int *count;
};
int main()
{
    my_auto_ptr<int> ps(new int(100));
    my_auto_ptr<int> pb(ps);
    my_auto_ptr<int> pd;
    pd = pb;
    return 0;
}