Member variable is corrupted in iOS, but works fine on Android

@Kreacher wrote:

In my game, I have a custom class, Hero, that is derived from Node, and has a custom class, StateMachine to manage its state.

The StateMachine is derived from cocos2d::Ref, so that I can use Cocos' automatic ref counting to manage its memory.

At the end of the Hero's init function, its StateMachine is correctly initialized and has a _refCount of 2, which reduces to 1 at the end of the first frame, which makes sense because the AutoReleasePool gets cleared then.

However, I'm finding that when the Hero's move function is invoked, its StateMachine variable points to a random new memory address, in which XCode debugger tells me has empty variables etc.

Here are some relevant code snippets:

// GameScene.hpp
class GameScene : public cocos2d::Layer {
private:
    // ...
    Hero* m_hero;
public:
    // ...
}

// GameScene.cpp
bool GameScene::init(const ValueMap& configuration) {
    // ... other config

    m_hero = Hero::create(refNode, heroConfig);
    if(!m_hero) {
        FATAL("Could not create a Hero!");
        return false;
    }
    m_hero->retain();

    // other stuff

    return true;
}

GameScene::onExit() {
    // ...
    CC_SAFE_RELEASE(m_hero);
    // ...
}

// Hero.hpp
class Hero : public Node {
private:
    // ...
    StateMachine* m_stateMachine;
public:
    static Hero* create(Node* heroNode, const ValueMap& configuration);
    // ...
}

// Hero.cpp
Hero* Hero::create(Node* heroNode, const ValueMap& configuration) {
    Hero* hero = static_cast<Hero*>(heroNode);

    if(hero && hero->init(configuration)) {
        hero->autorelease();

    } else {
        CC_SAFE_DELETE(hero);

    }

    return hero;
}

bool Hero::init(const ValueMap& configuration) {
    // ...

    m_stateMachine = StateMachine::create("HeroState");
    if(!m_stateMachine) {
        FATAL("Could not create a StateMachine!");
        return false;
    }
    m_stateMachine->retain();

    // ...

    // breakpoint here reveals:
    // m_stateMachine->_ID == 1042
    // m_stateMachine->_referenceCount == 2

    return true;
}

void Hero::moveToPosition(const Vec2& targetPosition) {

    // breakpoint here reveals:
    // m_stateMachine points to a different memory address
    // m_stateMachine->_ID == some random number
    // m_stateMachine->_referenceCount == some random number, but usually 256

    // never goes here because `isInState` returns false always, since this StateMachine
    // hasn't been initialized
    if(m_stateMachine->isInState(IDLE)) {...}
}

Also, using XCode debugger, during the Hero's init function, if I use expr m_stateMachine to get a reference to the StateMachine, and then later check this reference, it still exists, but its _ID and _referenceCount are also similarly changed, and the instance of Hero has lost the reference to it.

Here's a screenshot of that flow, the this that is referenced is the instance of Hero:

I have other modules that contain StateMachines but they don't seem to have any of these issues.

Any idea what is going on here? Or do you have any suggestions to point me in the right direction?

---

Sidenote:

Also, I noticed that XCode thinks of the Hero object pointer as a Node* in the debugger variables view. Additionally, I've noticed that even though I have overriden Node's virtual void update(float delta) method, invoking m_hero->update(...) in GameScene calls Node's update. Which is wierd, because m_hero is a Hero* pointer. I got around that by creating an update function of a different name and using that, but I'm wondering if that's related to this issue

Posts: 4

Participants: 3

Read full topic