cocos2dx CCHttpRequest里面的内存引用计数的故事
CCHttpRequest 本身是一个CCObject 对象, 用于lua的create函数 默认会retain request对象一次,因此需要在lua的callback函数里面处理结束request之后,需要release对象否则会内存泄露。
实际的引用计数变化的过程如下:
new 引用计数 = 1
autorelease 引用计数先变成2 再变成1 , 将对象加入自动释放池子里面之后,对象引用计数会+1, 接着会调用对象的release方法,对象引用计数又减去1
retain 引用计数变成 2
start 开始http请求,对象加入schedule 的列表里面 引用计数+1 引用计数变成3
update 过程中,到下一个update循环的时候,对象的引用计数会减去1,因为自动释放池子release了这个对象,这时候引用计数变成2
http请求处理结束,update函数里面检测结束,取消schedule 更新,但是因为当前在函数体内,所以不会立即release掉request对象,而是等待本次回合结束的时候再release对象
http请求结束,在callback函数里面release 掉对象,引用计数-1 变成 1
在本次更新回合结束,schedule模块,将标记删除的对象的引用计数-1, 引用计数 = 0 对象被删除掉。
#include "network/CCHttpRequest.h"#include "network/CCHttpRequest_impl.h"#include "cocos2d.h"#include "CCLuaEngine.h"using namespace cocos2d;NS_CC_EXT_BEGINCCHttpRequest* CCHttpRequest::createWithUrl(CCHttpRequestDelegate* delegate, const char* url, CCHttpRequestMethod method, bool isAutoReleaseOnFinish){ CCHttpRequest* request = new CCHttpRequest(delegate, url, method, isAutoReleaseOnFinish); request->initHttpRequest(); request->autorelease(); if (isAutoReleaseOnFinish) { request->retain(); } return request;}CCHttpRequest* CCHttpRequest::createWithUrlLua(int nHandler, const char* url, bool isGet){ CCHttpRequest* request = new CCHttpRequest(NULL, url, isGet?CCHttpRequestMethodGET:CCHttpRequestMethodPOST, true); request->m_luaHandler = nHandler; request->initHttpRequest(); request->autorelease(); request->retain(); CCLog("request count is? %d", request->retainCount()); return request;}bool CCHttpRequest::initHttpRequest(void){ m_request = new CCHttpRequest_impl(m_url.c_str(), m_method); return true;}CCHttpRequest::~CCHttpRequest(void){ delete (CCHttpRequest_impl*)m_request;}void CCHttpRequest::addRequestHeader(const char* key, const char* value){ if (key && value) { ((CCHttpRequest_impl*)m_request)->addRequestHeader(key, value); }}void CCHttpRequest::addPostValue(const char* key, const char* value){ if (key && value) { ((CCHttpRequest_impl*)m_request)->addPostValue(key, value); }}void CCHttpRequest::setPostData(const char* data){ if (data) { ((CCHttpRequest_impl*)m_request)->setPostData(data); }}void CCHttpRequest::setTimeout(float timeout){ ((CCHttpRequest_impl*)m_request)->setTimeout(timeout);}bool CCHttpRequest::getIsInProgress(void){ return ((CCHttpRequest_impl*)m_request)->getIsInProgress();}void CCHttpRequest::start(bool isCached){ CCDirector::sharedDirector()->getScheduler()->unscheduleUpdateForTarget(this); if (((CCHttpRequest_impl*)m_request)->start()) { CCDirector::sharedDirector()->getScheduler()->scheduleUpdateForTarget(this, 0, false); }}void CCHttpRequest::cancel(void){ CCDirector::sharedDirector()->getScheduler()->unscheduleUpdateForTarget(this); ((CCHttpRequest_impl*)m_request)->cancel();}void CCHttpRequest::clearDelegatesAndCancel(void){ m_delegate = NULL; cancel();}int CCHttpRequest::getResponseStatusCode(void) { return ((CCHttpRequest_impl*)m_request)->getResponseStatusCode();}const char* CCHttpRequest::getResponseString(void){ return ((CCHttpRequest_impl*)m_request)->getResposeString().c_str();}const void* CCHttpRequest::getResponseData(int* dataLength){ return ((CCHttpRequest_impl*)m_request)->getResponseData();}int CCHttpRequest::getResponseDataLength(){ return ((CCHttpRequest_impl*)m_request)->getResponseDataLength();}CCHttpRequestError CCHttpRequest::getErrorCode(void){ return ((CCHttpRequest_impl*)m_request)->getErrorCode();}const char* CCHttpRequest::getErrorMessage(void){ return ((CCHttpRequest_impl*)m_request)->getErrorMessage();}void CCHttpRequest::update(float dt){ CCLog("update Request state %d", retainCount()); CCHttpRequest_impl* request = (CCHttpRequest_impl*)m_request; if (!request || !request->getIsInProgress()) { CCDirector::sharedDirector()->getScheduler()->unscheduleUpdateForTarget(this); } if (request->getIsCompleted()) { if (m_delegate) m_delegate->requestFinished(this); if (m_luaHandler) {bool isSuc = (request->getErrorCode()==CCHttpRequestErrorNone);CCLuaEngine* engine = CCLuaEngine::defaultEngine();engine->getLuaStack()->clean();engine->getLuaStack()->pushBoolean(isSuc);engine->getLuaStack()->executeFunctionByHandler(m_luaHandler, 1); CCLog("afterHandler retainCount %d", retainCount());/* cocos2d::CCLuaValueDict dict; dict["name"] = cocos2d::CCLuaValue::stringValue("completed"); dict["request"] = cocos2d::CCLuaValue::ccobjectValue(this, "CCHttpRequest"); cocos2d::CCLuaEngine* engine = cocos2d::CCLuaEngine::defaultEngine(); engine->cleanStack(); engine->pushCCLuaValueDict(dict); engine->executeFunctionByHandler(m_luaHandler, 1);*/ } } else if (request->getIsCancelled()) { if (m_delegate) m_delegate->requestFailed(this); if (m_luaHandler) {CCLuaEngine* engine = CCLuaEngine::defaultEngine();engine->getLuaStack()->clean();engine->getLuaStack()->pushBoolean(false);engine->getLuaStack()->executeFunctionByHandler(m_luaHandler, 1);/* cocos2d::CCLuaValueDict dict; dict["name"] = cocos2d::CCLuaValue::stringValue("failed"); dict["request"] = cocos2d::CCLuaValue::ccobjectValue(this, "CCHttpRequest"); cocos2d::CCLuaEngine* engine = cocos2d::CCLuaEngine::defaultEngine(); engine->cleanStack(); engine->pushCCLuaValueDict(dict); engine->executeFunctionByHandler(m_luaHandler, 1);*/ } }}NS_CC_EXT_END