code: public void writeAndFlush(ResponseWrapper... responses) {
          synchronized (this) {
              for (ResponseWrapper response : responses) {
                  msgId_response.put(response.getRequest().getMsgId(), response);
              }
              toContinue();
              if (isTooMany()) {
                  processTooMany();
              }
          }
      }
docs: 增加并发安全机制,日后如遇到长连接处理速度极限可以考虑去掉synchronized关键字,但需要仔细验证并发安全问题