c++在类的两个对象之间使用blockingqueue

为了在类的两个对象之间发送消息！我暗示了这一点

BlockingQueue sentQueue = BlockingQueue();
BlockingQueue receivedQueue = BlockingQueue();


class User
{
public:

    
    
     virtual void run()
    {
        while (true)
        {
            string receivedMessage = receiveMessage();
            sendMessage(receivedMessage);
        }
    }

    
     virtual void sendMessage(string message)
    {
        sentQueue.push(reply);
    };

    
     virtual string receiveMessage()
    {
        string receivedMessage;
        receivedMessage = receivedQueue.pop();
        return receivedMessage;
    };
private:
    
};

我现在要问的是，在哪里实例化这个阻塞队列，以便在两个对象（用户1和用户2）之间使用它，以便在它们之间交换消息