what is the memory management in cocos2dx 3.10?

问题

In class MainLayer init() function, I use a static vector to store the pointer of class block which extend Node. And then, after 5 seconds (I use a schedule to trigger run the function of runBlock()), I try to get data which are stored in static vector.

However, the data that I got was wrong. From the debug, I understand it is the memory error. the data which I initialize looks like be deleted.

I don't konw why the data was deleted. Please help me, Thanks!

Here is my key code:

MainLayer.cpp

std::vector<block*> MainLayer::block_array = std::vector<block*>();
bool MainLayer::init(){
   Layer::init();
   ...
   //the schedule 
   schedule(schedule_selector(MainLayer::runBlock), 5.0f, CC_REPEAT_FOREVER, 0.0f);

   //initialization the data
   block* b1 = block1::create();
   block* b2 = block2::create();
   block* b3 = block3::create();
   block_array.push_back(b1);
   block_array.push_back(b2);
   block_array.push_back(b3);
   this->addChild(b1->node); 
   this->addChild(b2->node);
   this->addChild(b3->node);

   return true;
}

void MainLayer::runBlock(float dt){
   Size size = Director::getInstance()->getVisibleSize();
   int len = block_array.size();
   int rand = floor(CCRANDOM_0_1()*len);
   if (rand == len){
       rand -= 1;
   }

   //here is the problem, the memory which "bb" point is not be allocated
   //by the way, the value of bb equals b1 when initialize the data (I mean the memory address is equal, but the data in memory is different)
   block* bb = block_array[0];   

   bb->come();         //this is function in class block
 }

回答1:

I'm foolish !!!

Although b1->node is added Layer, b1 is not added. So in the next frame, b1 will be recycled.

JUST in MainLayer::init() add code

b1->retain();
b2->retain();
b3->retain();

everything will be normal

来源：https://stackoverflow.com/questions/37066542/what-is-the-memory-management-in-cocos2dx-3-10

标签

c++

cocos2d-x