通过重载new和delete实现简单的对象池

通过重载new和delete实现简单的对象池

通过重载new和delete实现简单的对象池

对象池的用途在这里就不介绍了，本例中只是其一个简单的实现。

#include <list>

#include <iostream>

using namespace std;

template<class T>

class object_pool

{

list<void *> data_list;

public:

void* malloc_data()

{

if(!data_list.empty())

{

list<void *>::iterator it = data_list.begin();

void *p = *it;

data_list.pop_front();

return p;

}

else

{

void* p = malloc(sizeof(T));

return p;

}

}

void free_data(void* p)

{

data_list.push_back(p);

}

};

class A

{

public:

int value;

A(int a):value(a){cout<<"A("<<a<<") called"<<endl;}

~A() {cout<<"~A("<<value<<") called"<<endl;}

static object_pool<A> pool_;

void* operator new (size_t size)

{

return pool_.malloc_data();

}

void operator delete(void* p)

{

pool_.free_data(p);

}

};

object_pool<A> A::pool_;

void main()

{

A* a1=new A(1);

delete a1;

A* a2=new A(2);

delete a2;

}