Cocos2dx对象池的一个实现

//
//  ObjectPool.h
//  DragonBall
//
//  Created by user on 13-8-22.
//
//

#ifndef __DragonBall__ObjectPool__
#define __DragonBall__ObjectPool__

#include <iostream>
#include <vector>
#include "cocos2d.h"
#include <algorithm>
using namespace std;
using namespace cocos2d;

template <typename T>
class ObjectPool{

public:

ObjectPool(int initSize):m_initSize(initSize)
{
CCAssert(m_initSize >= 4, "m_initSize should >= 4");
allocate(initSize);
};

virtual ~ObjectPool()
{
for_each(m_usedList.begin(), m_usedList.end(), freeObject);
for_each(m_freeList.begin(), m_freeList.end(), freeObject);
}

// 请求一个对象
T* request(){

//先检查空闲里面是否为空
if (m_freeList.size() == 0) {
allocate(m_initSize/2);
}

T* t = m_freeList[0];
m_freeList.erase(m_freeList.begin());
m_usedList.push_back(t);
return t;
};

// 放回一个对象到池里面
void putback(T* t)
{
for (int i = 0; i < m_usedList.size(); ++i) {
if (t == m_usedList[i]) {
//找到此对象
m_usedList.erase(m_usedList.begin() + i);
m_freeList.push_back(t);return;
}
}
}

//为了避免内存的不断增长，需要保持空间
void garbage()
{
//打印下大小
CCLog("m_usedList.size:%d",m_usedList.size());
CCLog("m_freeList.size:%d",m_freeList.size());

//如果空余的多余20则删除到初始化个数
if (m_freeList.size() > m_initSize) {

typename vector<T*>::iterator it = m_freeList.begin();
int pIndex = 0;
while (it != m_freeList.end()) {

if (pIndex > m_initSize) {
T* t = (*it);
m_freeList.erase(it);
freeObject(t);
--it;
}

++pIndex;
++it;
}
}
}

private:

// 分配size个空间
void allocate(int size)
{
for (int i = 0; i < size; ++i) {
T* t = new T;
m_freeList.push_back(t);
}
}

static void freeObject(void* p)
{
T* t = (T*)p;
CCObject* temp = (CCObject*)t;
CCLog("temp.ref : %d",temp->retainCount());
delete t;
}
private:

// 使用两个list一个用来放已经使用的,一个用来放未使用的
vector<T*> m_freeList;
vector<T*> m_usedList;

// 初始容量
int m_initSize;

};

#endif /* defined(__DragonBall__ObjectPool__) */

／／初始化里面，参数为默认池的大小

当需要请求一个对象的时候：

 CCSprite* sp = m_objectPool->request();当对象使用完毕后， 先从屏幕上移除.,然后再放回池中        firstSprite->removeFromParentAndCleanup(true); m_objectPool->putback(firstSprite);
注意garbage方法，

为了避免内存的无限增长，需要定时检查空余内存