优化阻塞队列实现的建议

T BlockingQueue<T>::pop( ) { 
       pthread_mutex_lock(&lock);
       if (list.empty( )) { 
           pthread_cond_wait(&cond) ;
       }
       T temp = list.front( );
       list.pop_front( );
       pthread_mutex_unlock(&lock);
       return temp;
}