pthread使用barrier栅栏方式同步
https://langzi989.github.io/2018/07/05/pthread%E4%BD%BF%E7%94%A8barrier%E6%A0%85%E6%A0%8F%E6%96%B9%E5%BC%8F%E5%90%8C%E6%AD%A5/
https://langzi989.github.io/2018/07/05/pthread%E4%BD%BF%E7%94%A8barrier%E6%A0%85%E6%A0%8F%E6%96%B9%E5%BC%8F%E5%90%8C%E6%AD%A5/