还有一种就是定义一个基类.里面实现new,delete操作符,然后以后所有的类从该类派生,自动继承基类的new,delete的实现.这种方法容易产生内存碎片.我的代码实现如下.下面的代码还存在很多问题.暂时先放上去吧.
版本3.
#include<iostream>
#include <list>
#include <algorithm>
using namespace std;
class memorypool//该类的实例只允许出现一次.我用到了singleton模式.
{
public:
static memorypool* Instance()
{
if(_instance == 0)
_instance = new memorypool;
return _instance;
}
void Add( void * p)
{
lpMemlist->push_back(p);
}
void Del(const void* p)
{
list<void*>::iterator ite = find(lpMemlist->begin(),lpMemlist->end(),p);
lpMemlist->erase(ite);
}
void clear()
{
list<void*>::iterator it =lpMemlist->begin();
while(!lpMemList->empty())
delete (*it++);
lpMemlist->clear();
}
protected:
memorypool();
private:
static memorypool* _instance;
static list<void*>* lpMemlist;//作为池的数据结构
};
memorypool* memorypool::_instance = 0;
list<void*>* memorypool::lpMemlist = 0;
memorypool::memorypool()
{
lpMemlist = new list<void*>;
cout<<"list now has : " << lpMemlist->size() << endl;
}
///////////////////////////////////////////////////////////////////////////////////
class CBase
{
public:
CBase() {
memorypool::Instance();
}
void* operator new(size_t size)
{
void *p = malloc(size);
memorypool::Instance()->Add(p);
return p;
}
void operator delete(void* p)
{ delete p;
memorypool::Instance()->Del(p);
}
~CBase() { memorypool::Instance()->clear(); cout<<"base dtor\n";
}
private:
//static memorypool*
//int nLeft;
};
class myclass :public CBase
{
public:
myclass() { cout << "myclass ctor\n";
}
};
class myclass2:public CBase
{
public:
myclass2() { cout<<"myclass2 ctor\n";
}
};
void testfun()
{
myclass* p = new myclass;
myclass2* p2 =new myclass2;
memorypool::Instance()->clear();
}
void main()
{
testfun();
}
上面的几种想法只是我想实现一下所谓的gc,感觉还是智能指针效果最好.其它几个版本我只是想模拟一下,验证我自己的想法而已.代码中肯定有错误的地方.不要被指责得一无是处就好.
