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| #include<iostream>
#include<thread>
#include<mutex>
#include"stdlib.h"
using namespace std;
std::mutex m;
class Singleton{
private:
Singleton(){};
static Singleton* instance;
public:
int data = 1;
static Singleton* getInstance();
private:
class Deletor {
public:
~Deletor() {
cout<<"now in the Deletor function"<<endl;
if(Singleton::instance != NULL)
delete Singleton::instance;
}
};
static Deletor deletor;
};
Singleton::Deletor Singleton::deletor;
Singleton* Singleton::instance = NULL;
Singleton* Singleton::getInstance()
{
cout<<"DEBUG: now in getInstance "<<endl;
if(instance == NULL){
m.lock();
if(instance == NULL){
instance = new Singleton;
}
m.unlock();
}
cout <<"the address of instance " << Singleton::instance<<endl;
return instance;
}
void test(){
cout<<"Hello world"<<endl;
}
Singleton* GetInstance(){
return Singleton::getInstance();
}
int main()
{
for(int i = 0 ;i<500 ; i++)
{
thread th(GetInstance);
th.join();
}
cout<<"LOG: end of main"<<endl;
}
|