axmol/cocos/base/CCRef.cpp

/****************************************************************************
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2013-2014 Chukong Technologies

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#include "base/CCRef.h"
#include "CCAutoreleasePool.h"
#include "2d/ccMacros.h"
#include "2d/CCScriptSupport.h"

NS_CC_BEGIN

Ref::Ref()
: _referenceCount(1) // when the Ref is created, the reference count of it is 1
{
#if CC_ENABLE_SCRIPT_BINDING
    static unsigned int uObjectCount = 0;
    _luaID = 0;
    _ID = ++uObjectCount;
#endif
}

Ref::~Ref()
{
#if CC_ENABLE_SCRIPT_BINDING
    // if the object is referenced by Lua engine, remove it
    if (_luaID)
    {
        ScriptEngineManager::getInstance()->getScriptEngine()->removeScriptObjectByObject(this);
    }
    else
    {
        ScriptEngineProtocol* pEngine = ScriptEngineManager::getInstance()->getScriptEngine();
        if (pEngine != NULL && pEngine->getScriptType() == kScriptTypeJavascript)
        {
            pEngine->removeScriptObjectByObject(this);
        }
    }
#endif
}

void Ref::retain()
{
    CCASSERT(_referenceCount > 0, "reference count should greater than 0");
    ++_referenceCount;
}

void Ref::release()
{
    CCASSERT(_referenceCount > 0, "reference count should greater than 0");
    --_referenceCount;
    
    if (_referenceCount == 0)
    {
#if defined(COCOS2D_DEBUG) && (COCOS2D_DEBUG > 0)
        auto poolManager = PoolManager::getInstance();
        if (!poolManager->getCurrentPool()->isClearing() && poolManager->isObjectInPools(this))
        {
            // Trigger an assert if the reference count is 0 but the Ref is still in autorelease pool.
            // This happens when 'autorelease/release' were not used in pairs with 'new/retain'.
            //
            // Wrong usage (1):
            //
            // auto obj = Node::create();   // Ref = 1, but it's an autorelease Ref which means it was in the autorelease pool.
            // obj->autorelease();   // Wrong: If you wish to invoke autorelease several times, you should retain `obj` first.
            //
            // Wrong usage (2):
            //
            // auto obj = Node::create();
            // obj->release();   // Wrong: obj is an autorelease Ref, it will be released when clearing current pool.
            //
            // Correct usage (1):
            //
            // auto obj = Node::create();
            //                     |-   new Node();     // `new` is the pair of the `autorelease` of next line
            //                     |-   autorelease();  // The pair of `new Node`.
            //
            // obj->retain();
            // obj->autorelease();  // This `autorelease` is the pair of `retain` of previous line.
            //
            // Correct usage (2):
            //
            // auto obj = Node::create();
            // obj->retain();
            // obj->release();   // This `release` is the pair of `retain` of previous line.
            CCASSERT(false, "The reference shouldn't be 0 because it is still in autorelease pool.");
        }
#endif
        delete this;
    }
}

Ref* Ref::autorelease()
{
    PoolManager::getInstance()->getCurrentPool()->addObject(this);
    return this;
}

unsigned int Ref::getReferenceCount() const
{
    return _referenceCount;
}

NS_CC_END