【cocos2d-x 3.x 学习笔记】对象内存管理

class CC_DLL Ref
{
public:
    // 将引用计数加1 
    void retain()
    {
        ++_referenceCount;
    }

    // 将引用技术减1，如果引用计数为0，释放当前对象
    void release()
    {
        --_referenceCount;
        if (_referenceCount == 0)
        {
            delete this;
        }
    }


    // 将当前对象加入到当前的自动回收池中
    Ref* autorelease()
    {
        PoolManager::getInstance()->getCurrentPool()->addObject(this);
        return this;
    }


    unsigned int getReferenceCount() const
    {
        return _referenceCount;
    }


protected:
    Ref()
    : _referenceCount(1) // when the Ref is created, the reference count of it is 1
    {}


public:
    virtual ~Ref();

protected:
    /// count of references
    unsigned int _referenceCount;

    friend class AutoreleasePool;
};

1）auto sprite = new Sprite;
2）auto sprite = Sprite::create();
Object *Object::create()
{
    Object *obj = new Object;
    if (obj && obj->init())
    {
         obj->autorelease();
    }
    else
    {
         delete obj;
         obj = nullptr;
    }
    return obj;

}

// main.cpp
return Application::getInstance()->run();

// Appdelegate.cpp
int Application::run()
{
     ...
    while(!glview->windowShouldClose())
    {
        QueryPerformanceCounter(&nNow);
        if (nNow.QuadPart - nLast.QuadPart > _animationInterval.QuadPart)
        {
            nLast.QuadPart = nNow.QuadPart;
            // Enter loop
            director->mainLoop();
            glview->pollEvents();
        }
        else
        {
            Sleep(0);
        }
    }
     ...
}

// CCDirector.cpp
void DisplayLinkDirector::mainLoop()
{
    if (_purgeDirectorInNextLoop)
    {
        _purgeDirectorInNextLoop = false;
        purgeDirector();
    }
    else if (! _invalid)
    {
        drawScene();
    
        // release the objects 
        PoolManager::getInstance()->getCurrentPool()->clear();
    }
}

// CCAutoReleasePool.cpp
void AutoreleasePool::clear()
{
    for (const auto &obj : _managedObjectArray)
    {
        obj->release();
    }
    _managedObjectArray.clear();          // std::vector<cocos2d::Ref *> 类型的数组
}