BIO

优点 可以接收更多连接 缺点 线程内存消耗 cpu调度消耗

NIO

优点 规避多线程问题 缺点 C10K，弊端: 假设 1万个连接 只有一个发来数据每循环一次 必须向内核发送1万次recv的系统调用 那么这里有9999次是无意义的，浪费的，消耗时间和资源的(用户空间向内核空间的循环遍历，复杂度在系统调用上)

多路复用器

select 1024限制 ，poll 无限制
epoll
jdk1.5及以上 epoll_create 内核中开辟空间FD,红黑树 epoll_ctl add(accept) epoll_wait 阻塞(timeout) 等待文件描述符上的事件
AIO JDK1.7中，这部分内容被称作NIO.2 AsynchronousSocketChannel read/write方法都是异步的，完成后会主动调用回调函数 异步非阻塞，服务器实现模式为一个有效请求一个线程，客户端的I/O请求都是由OS先完成了再通知服务器应用去启动线程进行处理，

三者应用场景

BIO 连接数目比较小且固定的架构，对服务器资源要求比较高，并发局限于应用中，JDK1.4以前的唯一选择，但程序直观简单易理解。
NIO 连接数目多且连接比较短（轻操作）的架构，比如聊天服务器，并发局限于应用中，编程比较复杂，JDK1.4开始支持。
AIO连接数目多且连接比较长（重操作）的架构，比如相册服务器，充分调用OS参与并发操作，编程比较复杂，JDK7开始支持。

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On March 8, according to the Science and Technology Daily, the second "Minister's Channel" of the Fifth Session of the 13th National People's Congress opened today. Minister of Science and Technology Wang Zhigang brought you good news about new crown drugs and vaccines.

Wang Zhigang revealed that broad-spectrum drugs against coronavirus or new coronavirus are being actively developed; vaccination through nasal spray and inhalation is also under study, and there is good progress now.

Wang Zhigang said that China has always adhered to five major directions to carry out scientific research, including vaccines, drugs, testing, animal models and scientific traceability.

In terms of vaccines, there were 3 inactivated vaccines and 1 adenovirus vector vaccine with conditions, and this year, another recombinant protein vaccine was listed with conditions. There are also two technical routes that have made positive progress. One is mRNA vaccines, which have entered Phase III clinical trials; the other is DNA vaccines, which have also entered Phase III clinical trials. This is an important achievement achieved by the majority of scientific researchers with their level, integrity, dedication and perseverance.

In terms of drug research and development, 1 neutralizing antibody drug has been marketed with conditions, and 3 small molecule drugs have entered Phase III clinical trials. In addition, there are some neutralizing antibody drugs, small molecule drugs, and traditional Chinese medicines, which are all under active research and development, showing good prospects.

In terms of detection, sample detection can be completed in as little as 30 minutes, and an integrated detection system can detect 200,000 samples a day, greatly improving the capability.

腾讯音乐娱乐集团（TME）对短暂下架后的旧版“音兔”进行了重新设计和升级，现已重新上架 App Store。

腾讯音兔 App 是由全民 K 歌推出的一款年轻新潮的音乐短视频 App，最初于 2018 年上架，除了最新的一次更新外，曾于 2021 年进行过一次更新，再之前就是 2019 年，不过都是修复 bug。

此次上架后，腾讯音兔 App 版本号直接从 2.9.6 跨越到了 3.1.6，更新内容显示为：

【短视频 k 歌】音兔新升级支持 k 歌啦！海量曲库、新潮音效、沉浸画面，让你嗨唱爽翻天！
【百变舞台】丰富的短视频模板，让你随时成为最亮眼的 Super Vocal！
【清新曲风】想唱当下最火的热歌吉他版、钢琴版？音兔应有尽有！
据介绍，腾讯音兔 App 支持一键制作音乐短片，而且此次还新增了 K 歌功能，用户可以将翻唱的歌曲进行二次创作，目前支持清唱创作和视频创作两种方式，制作好的音乐视频可以发布到首页中，供其他用户点赞和评论。