“坑爹的LIST容器--删除操作千倍消耗CPU”一文有误，在VC2010里是STL完胜
下面是STL的测试情况：
every 3 seconds add/del element number is 40000
stl list has 40000 elements
add cost time too much: 109
stl list has 0 elements
delete cost time too much: 4992
***************************************************
stl list has 40000 elements
add cost time too much: 499
stl list has 0 elements
delete cost time too much: 4961
***************************************************
stl list has 40000 elements
add cost time too much: 499
stl list has 0 elements
delete cost time too much: 4961
***************************************************
stl list has 40000 elements
add cost time too much: 499
stl list has 0 elements
delete cost time too much: 4961
***************************************************
stl list has 40000 elements
add cost time too much: 483
stl list has 0 elements
delete cost time too much: 4945
***************************************************
下面使用自己写的链表：
every 3 seconds add/del element number is 40000
my list has 40000 elements
add cost time too much: 110
my list has 0 elements
delete cost time too much: 10218
***************************************************
my list has 40000 elements
add cost time too much: 578
my list has 0 elements
delete cost time too much: 10920
***************************************************
my list has 40000 elements
add cost time too much: 452
my list has 0 elements
delete cost time too much: 11232
***************************************************
my list has 40000 elements
add cost time too much: 2496
my list has 0 elements
delete cost time too much: 12043
***************************************************
my list has 40000 elements
add cost time too much: 577
my list has 0 elements
delete cost time too much: 11295
***************************************************
my list has 40000 elements
add cost time too much: 468
my list has 0 elements
delete cost time too much: 11716
***************************************************
my list has 40000 elements
add cost time too much: 2449
my list has 0 elements
delete cost time too much: 12059
***************************************************
my list has 40000 elements
add cost time too much: 437
my list has 0 elements
delete cost time too much: 12090
***************************************************
my list has 40000 elements
add cost time too much: 436
my list has 0 elements
delete cost time too much: 12527
***************************************************
my list has 40000 elements
add cost time too much: 499
my list has 0 elements
delete cost time too much: 12792
***************************************************
my list has 40000 elements
add cost time too much: 452
my list has 0 elements
delete cost time too much: 12215
***************************************************
my list has 40000 elements
add cost time too much: 421
my list has 0 elements
delete cost time too much: 11981
***************************************************
my list has 40000 elements
add cost time too much: 468
my list has 0 elements
delete cost time too much: 12261
***************************************************
my list has 40000 elements
add cost time too much: 453
完整代码如下：
// TestList.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <Windows.h>
#include <list>
#include<algorithm>
#include <time.h>
#include <iostream>
using namespace std;
//待测试的对象，链表中的每个元素就是对象A的指针
class A {};
//每3秒钟插入链表末尾/从链表首部取出的元素个数
int testPressureNum = 40000;
//测试的STL链表
list<A*> testList;
//自己写的链表
typedef struct
{
A* p;
void* prev;
void* next;
} SelfListElement;
SelfListElement* myListHead;
SelfListElement* myListTail;
int myListSize;
//向自己写的链表首部添加元素
bool add(A* packet)
{
SelfListElement* ele = new SelfListElement;
ele->p = packet;
myListSize++;
if (myListHead == NULL)
{
myListHead = myListTail = ele;
ele->prev = NULL;
ele->next = NULL;
return true;
}
ele->next = myListHead;
myListHead->prev = ele;
ele->prev = NULL;
myListHead = ele;
return true;
}
// 从自己写的链表尾部取出元素
SelfListElement* get()
{
if (myListTail == NULL)
return NULL;
myListSize--;
SelfListElement* p = myListTail;
if (myListTail->prev == NULL)
{
myListHead = myListTail = NULL;
}
else
{
myListTail = (SelfListElement*)myListTail->prev;
myListTail->next = NULL;
}
return p;
}
//从STL链表中取出元素并删除
struct DeletePointer
{
template<typename T> void operator()( T* ptr ) const { delete ptr; }
};
void testDelete1()
{
/* while (testList.size() > 0)
{
A* p = testList.back();
testList.pop_back();
delete p;
p = NULL;
} */
std::for_each(testList.begin(),testList.end(),DeletePointer());
testList.resize(0);
}
//从简单链表中取出元素并删除
void testDelete2()
{
do {
SelfListElement* packet = myListTail;
if (packet == NULL)
break;
packet = get();
delete packet->p;
delete packet;
packet = NULL;
} while (true);
}
//向Stl链表中添加元素
void testAdd1()
{
for (int i = 0; i < testPressureNum; ++i)
{
testList.push_back(new A());
}
}
//向简单链表中添加元素
void testAdd2()
{
for (int i = 0; i < testPressureNum; i++)
{
A* p = new A();
add(p);
}
}
void printUsage(int argc, _TCHAR* argv[])
{
cout<<"usage: "<<argv[0]<<" [1|2] [oneRoundPressueNum]"<<endl
<<"1 means STL, 2 means simple list\noneRoundPressueNum means in 3 seconds how many elements add/del in list"<<endl;
}
int _tmain(int argc, _TCHAR* argv[])
{
//为方便测试可使用2个参数
if (argc < 2)
{
printUsage(argc, argv);
return -1;
}
int type = _wtoi(argv[1]);
if (type != 1 && type != 2)
{
printUsage(argc, argv);
return -2;
}
if (argc > 2)
testPressureNum = _wtoi(argv[2]);
cout<<"every 3 seconds add/del element number is "<<testPressureNum<<endl;
time_t tStart = time(NULL);
while (true)
{
DWORD dwAdd = GetTickCount();
if (type == 1)
{
testAdd1();
cout<<"stl list has "<<testList.size()<<" elements"<<endl;
}
else
{
testAdd2();
cout<<"my list has "<<myListSize<<" elements"<<endl;
}
dwAdd = GetTickCount() - dwAdd;
cout<<"add cost time too much: "<<dwAdd<<endl;
DWORD dwDel = GetTickCount();
if (type == 1)
{
testDelete1();
cout<<"stl list has "<<testList.size()<<" elements"<<endl;
}
else
{
testDelete2();
cout<<"my list has "<<myListSize<<" elements"<<endl;
}
dwDel = GetTickCount() - dwDel;
cout<<"delete cost time too much: "<<dwDel<<endl;
cout<<endl;
cout<<"***************************************************"<<endl;
cout<<endl;
//每3秒一个周期
Sleep(3000);
}
return 0;
}