curl_easy_opt throws EXE_BAD_Access or malloc pointer being freed was not allocated error

I have following run time error sometimes (not all the times)

malloc: * error for object 0x14: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug

else

EXE_BAD_ACCESS

on the same line of code.

Please help me to solve this trouble.

I have following structure for curl based server connector. in curlBasedServerConnector.cpp see the place where >>>ERROR POINTED HERE line appear.

curlBasedServerConnector.hpp

 class curlBasedServerConnector  : public webServiceConnectorInterfaceA
{

private:
    CURLcode curlCode;
    CURL* curlHandle;        
    char* messagePtr;
    std::string message = "";        
    static std::atomic<int> totalNumOfCurlProcesses;
    static std::atomic<bool> isGlobalInitCalledAlready;
    static std::mutex curlGlobalInitKey;   
    static size_t writeContents_s(char *buf, size_t size, size_t nmemb, void *up)
    {
        curlBasedServerConnector* pThis = static_cast<curlBasedServerConnector*>(up);
        return pThis->writeContents(buf, size, nmemb);
    }    
    // member version
    size_t writeContents(char* buf, size_t size, size_t nmemb)
    {
        std::copy(buf, buf+(size*nmemb), std::back_inserter(message));
        return size*nmemb;
    }

public:

    bool executeOperation()override ;

    bool openConnection() override;

    bool setHttpHeader(const char* contentType, const char* charSet)override;

    bool setServerUrl(const char* url)override;

    void setRequest(const char* request)override;

    void closeConnection() override;
    std::string getResponseAsString()override;

    bool listenToNotification()override;

    void setTrace(bool trace);

    int getNumberofCurlProcessesInitialized();

    curlBasedServerConnector()
    {       
        curlGlobalInitKey.lock();
        {
            if(!isGlobalInitCalledAlready)
            {
                curlCode = curl_global_init(CURL_GLOBAL_ALL);
                cout<<" Server Connector GLOBAL_INIT CALLED "<<endl;
                isGlobalInitCalledAlready = true;
                totalNumOfCurlProcesses++;
            }
            else
            {
                totalNumOfCurlProcesses++;            
            }            
        }
        curlGlobalInitKey.unlock();       
        openConnection();        
    }

    virtual ~curlBasedServerConnector(){

        curlGlobalInitKey.lock();        
        totalNumOfCurlProcesses--;        
        if(totalNumOfCurlProcesses == 0)
        {          
            curl_global_cleanup();      
        }        
        curlGlobalInitKey.unlock();      
    }  

};

curlBasedServerConnector.cpp

bool curlBasedServerConnector::openConnection(){
    bool successStatus = false;

    if(curlHandle )
    {
        cout<<"curl hanlde --"<<curlHandle<<endl;
        successStatus = true;            
    }
    else
    {
        curlHandle = curl_easy_init();

        if(curlHandle != NULL){

            successStatus = true;
        }
    }

    cout<<"openConnection() CURL CODE "<<curlCode<<endl;

    return successStatus;
}

void curlBasedServerConnector::closeConnection(){
     curl_easy_cleanup(curlHandle);
}


bool curlBasedServerConnector::setServerUrl(const char *url){

    cout<<"curl handle at setting url "<<curlHandle<<endl;

  curlCode = curl_easy_setopt(curlHandle, CURLOPT_URL,  url);  >>>ERROR POINTED HERE

    bool successStatus = false;

    if(curlCode == 0 | curlCode == CURLE_OK)
    {
        successStatus = true;
    }
    else if (curlCode == 27 | curlCode == CURLE_OUT_OF_MEMORY){

        exit(8);
    }        
    return successStatus;
}

webServiceConnectorInterfaceA.hpp

class webServiceConnectorInterfaceA
{

public:   

    virtual bool openConnection() = 0;
    virtual bool executeOperation()= 0; //
    virtual bool setHttpHeader(const char* contentType, const char* charSet) = 0;

    virtual bool setServerUrl(const char* url)=0;
    virtual void setRequest(const char* request)=0;
    virtual void closeConnection() = 0;
    virtual bool listenToNotification() = 0;

    virtual std::string getResponseAsString()=0;

    webServiceConnectorInterfaceA(){ };

     ~webServiceConnectorInterfaceA(){   };

};

I have accessor class which compose this class as following

class webServiceAccessor{
private:       
    const char* serverAddress = "http://localhost:2000";        
    std::shared_ptr<sharedQueue> gmsListenerQueue;
    std::shared_ptr<webServiceConnectorInterfaceA> webServiceConnectorInterface;

webServiceAccessor(){}
~webServiceAccessor(){} 

}

Why it throws such error on the same line ? Who cause this error curlBasedServerConnector class or class webServiceAccessor ? How to solve this or debug this? I am using C++11 in Xcode IDE. Thanks