动态内存管理

//LIst.hpp 

#ifndef _LIST_H_
#define _LIST_H_

#include<iostream>
using namespace std;

template<class T>
struct Node
{
	T _value;
	Node<T>* _next;
	Node<T>(const T& value)
		: _value(value)
		, _next(NULL)
	{}
};

template<class T>
class List
{
public:
	List()
		:_head(NULL)
	{}
	void PushBack(const T&data);
	Node<T>* Find(const T&data);
	void Remove(Node<T>*del);
	void Print();
private:
	Node<T>*_head;
};

template<class T>
void List<T>::PushBack(const T&data)
{
	Node<T>*tmp = new Node<T>(data);
	if (_head == NULL)
	{
		_head = tmp;
		return;
	}
	Node<T>*begin = _head;
	while (begin->_next)
	{
		begin = begin->_next;
	}
	begin->_next = tmp;
}
template<class T>
Node<T>* List<T>::Find(const T&data)
{
	if (_head == NULL)
	{
		return NULL;
	}
	Node<T>*begin = _head;
	while (begin)
	{
		if (begin->_value== data)
		{
			return begin;
		}
		begin = begin->_next;
	}
	return NULL;
}

template<class T>
void List<T>::Remove(Node<T>*del)
{
	if (_head == NULL)
	{
		return;
	}
	Node<T>*begin = _head;
	Node<T>*prev = _head;
	while (begin)
	{
		if (del == begin)
		{
			if (del == _head)
			{
				_head = _head->_next;
			}
			else
			{
				prev->_next = begin->_next;
			}
			delete del;
			return;
		}
		prev = begin;
		begin = begin->_next;
	}
}

template<class T>
void List<T>::Print()
{
	Node<T>*begin = _head;
	while (begin)
	{
		cout << begin->_value<<" ";
		begin = begin->_next;
	}
}

#endif //_LIST_H

//MemoryBlockInfo.h

#ifndef _MEM_H_
#define _MEM_H_

#include"List.hpp"
#include<string>

struct MemoryBlockInfo//内存块信息
{
	void* _ptr;
	string _filename;
	int _line;
	MemoryBlockInfo(void*ptr = NULL, string filename = "", int line = 0);
	bool operator==(const MemoryBlockInfo&m);
	friend ostream& operator<<(ostream& out, MemoryBlockInfo&m);
};

class MemoryManage//单例模式，管理链表
{
public:
	static MemoryManage* GetInStance()
	{
		if (_InStance == NULL)
		{
			_InStance = new MemoryManage();
		}
		return _InStance;
	}
	void* __NEW(size_t size, string filename, int line);//申请空间
	void __DELETE(void*ptr);//释放空间
	void PPrint()
	{
		_infos.Print();
	}
private:
	MemoryManage()
	{}
	static MemoryManage* _InStance;
	List<MemoryBlockInfo>_infos;
};

/*****************************************************************************************************/
//对于单个对象
template<class T>
inline T* _NEW(size_t size, string filename, int line)
{
	//对于自定义类型，会调用构造函数；但在这里对象已经产生，所以需要用new的定位表达式来调构造函数
	return new((T*)MemoryManage::GetInStance()->__NEW(size, filename, line))T;
}
template<class T>
inline void _DELETE(T*ptr)//释放空间
{
	ptr->~T();//对于自定义类型，会调用析构函数
	MemoryManage::GetInStance()->__DELETE(ptr);
}
#define NEW(type) _NEW<type>(sizeof(type), __FILE__, __LINE__)
#define DELETE(ptr) _DELETE(ptr)
/****************************************************************************************************/
//对于对象数组
template<class T>
inline T* _NEW_ARRAY(size_t num, string filename, int line)
{
	//对于对象数组，在申请空间时，需多申请4个字节的空间，存储数组元素的个数，即有多少个对象
	T*ptr = (T*)(MemoryManage::GetInStance()->__NEW(sizeof(T)*num + 4, filename, line));
	*(int*)ptr = num;
	T*Retptr = (T*)((int*)ptr + 1);
	for (int i = 0; i <(int) num; i++)
	{
		new(&Retptr[i])T;//调用构造函数
	}
	return ptr;
}
template<class T>
inline void _DELETE_ARRAY(T*ptr)
{
	int num = *(int*)ptr;
	T*Retptr = (T*)((int*)ptr + 1);
	for (int i = 0; i < num; i++)
	{
		Retptr[i].~T();//调用析构函数
	}
	MemoryManage::GetInStance()->__DELETE(ptr);
}

#define NEW_ARRAY(type,num) _NEW_ARRAY<type>(num,__FILE__,__LINE__)
#define DELETE_ARRAY(ptr) _DELETE_ARRAY(ptr)
#endif //_MEM_H_
/****************************************************************************************************/

//MemoryBlockInfo.cpp

#include"MemoryBlockInfo.h"

MemoryBlockInfo::MemoryBlockInfo(void*ptr, string filename, int line)
:_ptr(ptr)
, _filename(filename)
, _line(line)
{}

bool MemoryBlockInfo::operator==(const MemoryBlockInfo&m)
{
	return _ptr == m._ptr;
}

ostream& operator<<(ostream& out, MemoryBlockInfo&m)
{
	out << "ptr:" << m._ptr << endl;
	out << "filename:" << m._filename << endl;
	out << "line:" << m._line << endl;
	return out;
}



void* MemoryManage::__NEW(size_t size, string filename, int line)
{
	void*ptr = malloc(size);
	if (ptr)
	{
		_infos.PushBack(MemoryBlockInfo(ptr, filename, line));
	}
	return ptr;
}

void MemoryManage::__DELETE(void*ptr)
{
	if (ptr)
	{
		Node<MemoryBlockInfo>*del = _infos.Find(MemoryBlockInfo(ptr));
		_infos.Remove(del);
	}
	free(ptr);
}

//main.cpp

#define _CRT_SECURE_NO_WARNINGS
#include"MemoryBlockInfo.h"

class String//自定义String类
{
public:
	String(char* ptr = "")
		:_ptr(new char[strlen(ptr) + 1])
	{
		cout << "String()" << endl;
		strcpy(_ptr, ptr);
	}
	~String()
	{
		if (_ptr)
		{
			delete []_ptr;
		}
		cout << "~String()" << endl;
	}
private:
	char* _ptr;
};
void Test()
{
	int*p1 = NEW(int);
	String*p2 = NEW(String);
	DELETE(p1);
	DELETE(p2);
	String*p3 = NEW_ARRAY(String,3);
	DELETE_ARRAY(p3);
	MemoryManage::GetInStance()->PPrint();
}
MemoryManage* MemoryManage::_InStance = NULL;//初始化静态数据
int main()
{
	
	Test();
	system("pause");
	return 0;
}