{"id":28254,"date":"2025-04-19T23:31:35","date_gmt":"2025-04-19T15:31:35","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/28254.html"},"modified":"2025-04-19T23:31:35","modified_gmt":"2025-04-19T15:31:35","slug":"%e5%a4%9a%e7%ba%bf%e7%a8%8b%e6%9c%8d%e5%8a%a1%e5%99%a8%e5%88%86%e6%9e%90-reactor%e7%ba%bf%e7%a8%8b%e6%a8%a1%e5%9e%8b%e5%92%8c%e6%80%a7%e8%83%bd%e5%88%86%e6%9e%90%e4%b8%80","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/28254.html","title":{"rendered":"\u591a\u7ebf\u7a0b\u670d\u52a1\u5668\u5206\u6790\u2014\u2014Reactor\u7ebf\u7a0b\u6a21\u578b\u548c\u6027\u80fd\u5206\u6790(\u4e00)"},"content":{"rendered":"

\u4e0a\u63a5\u591a\u7ebf\u7a0b\u670d\u52a1\u5668\u5206\u6790\u2014\u2014Reactor\u7ebf\u7a0b\u6a21\u578b\u548c\u6027\u80fd\u5206\u6790(\u5e8f\u7ae0)<\/p>\n

\u5728\u5e8f\u7ae0\u4e2d\u7684\u6700\u540e\u63d0\u5230\u4e86\u4e24\u4e2a\u670d\u52a1\u5668\u74f6\u9888\u7684\u539f\u56e0： 1\u3001\u80fd\u591f\u6269\u5c55\u7684\u7ebf\u7a0b\u6570\u91cf\u662f\u6709\u9650\u7684 2\u3001\u963b\u585e\u5f0f\u7684\u7b49\u5f85socket\u4f1a\u8ba9\u7ebf\u7a0b\u4e00\u76f4\u5904\u4e8e\u7a7a\u95f2\u72b6\u6001（\u5f53\u7136socket\u53ef\u4ee5\u6362\u6210\u5176\u4ed6\u6587\u4ef6\u63cf\u8ff0\u7b26）<\/p>\n

\u9488\u5bf9\u95ee\u98981，\u65e2\u7136\u7ebf\u7a0b\u7684\u6570\u91cf\u662f\u6709\u9650\u7684，\u90a3\u6211\u4eec\u5c31\u5c3d\u6700\u5927\u7684\u53ef\u80fd\u53bb\u5229\u7528\u5b83，\u69a8\u5e72\u5b83\u7684\u80fd\u529b；\u9488\u5bf9\u95ee\u98982，\u5219\u53ef\u4ee5\u6362\u4e00\u79cd\u601d\u8def，\u5982\u679c\u5f53\u524d\u7684socket\u6ca1\u6709\u6570\u636e\u4f20\u8f93\u8fc7\u6765，\u90a3\u5c31\u7acb\u5373\u8fd4\u56de\u4e00\u4e2a\u9519\u8bef\u4fe1\u606f，\u5904\u7406\u4e0b\u4e00\u4e2a\u5efa\u7acb\u7684\u8fde\u63a5，\u7136\u540e\u5faa\u73af\u8be2\u95ee\u6240\u6709\u5efa\u7acb\u7684\u8fde\u63a5\u7684socket，\u5982\u679c\u67d0\u4e2asocket\u6709\u6570\u636e\u4f20\u8f93\u8fc7\u6765\u5c31\u7acb\u9a6c\u8fdb\u884c\u5904\u7406，\u8fd9\u5c31\u662f\u975e\u963b\u585e(NIO)\u7684\u601d\u60f3\u3002<\/p>\n

3.3 \u975e\u963b\u585e\u5355\u7ebf\u7a0b\u670d\u52a1\u5668<\/h3>\n

\u5728\u4ecb\u7ecd\u975e\u963b\u585e\u7684\u591a\u7ebf\u7a0b\u670d\u52a1\u5668\u4e4b\u524d，\u5148\u4ecb\u7ecd\u51e0\u4e2a\u6982\u5ff5，\u76f8\u4fe1\u8bfb\u8005\u770b\u8fc7\u4e4b\u540e\u4f1a\u5bf9\u6700\u7ec8\u4ecb\u7ecd\u7684\u591a\u7ebf\u7a0b\u670d\u52a1\u5668\u6a21\u578b\u7684\u7406\u89e3\u6709\u5e2e\u52a9\u3002\u8fd9\u91cc\u6211\u4eec\u53c8\u6682\u65f6\u56de\u5230\u4e86\u5355\u7ebf\u7a0b\u670d\u52a1\u5668，\u53ea\u80fd\u5148\u59d4\u5c48\u4e00\u4e0b\u4f60\u7684\u714e\u997c\u679c\u5b50\u644a\u4e86:-)\u3002<\/p>\n

3.3.1 \u975e\u963b\u585eIO<\/h4>\n

\u9644\u8fd1\u7684\u516c\u53f8\u5012\u95ed\u4e86，\u4f60\u53ea\u5f97\u53e6\u8d77\u7089\u7076\u6362\u5730\u65b9，\u4e5f\u96c7\u4e0d\u8d77\u6708\u85aa2\u4e07\u7684\u4f19\u8ba1\u4e86，\u4e0d\u8fc7\u4f60\u6709\u4e86\u4e0a\u6b21\u7684\u7ecf\u9a8c，\u5347\u7ea7\u4e86\u714e\u997c\u679c\u5b50，\u53ef\u4ee5\u52a0\u9e21\u6392\u3001\u52a0\u9e21\u86cb，\u52a0\u8fa3\u6761\u7b49\u7b49\u3002\u4f46\u6e10\u6e10\u7684\u4f60\u53d1\u73b0\u4e86\u4e00\u4e2a\u95ee\u9898，\u9762\u5bf9\u8bf8\u591a\u9009\u62e9\u987e\u5ba2\u4eec\u53cd\u800c\u72b9\u8c6b\u4e0d\u51b3，\u4e0d\u77e5\u9053\u8be5\u52a0\u5565，\u7ad9\u5728\u644a\u4f4d\u524d\u9009\u534a\u5929\u624d\u9009\u597d，\u540e\u9762\u6709\u60f3\u597d\u4e70\u4ec0\u4e48\u7684\u987e\u5ba2\u4e5f\u6ca1\u6cd5\u4e70，\u7b49\u4e86\u534a\u5929\u8d70\u4e86\u3002 \u4e8e\u662f\u4f60\u5c31\u81ea\u5df1\u6328\u4e2a\u95ee\u987e\u5ba2，\u9009\u597d\u7684\u987e\u5ba2\u4f1a\u628a\u714e\u997c\u679c\u5b50\u7684\u8981\u6c42\u544a\u8bc9\u4f60，\u4f60\u518d\u628a\u6c47\u603b\u7684\u4fe1\u606f\u62ff\u56de\u644a\u4f4d\u6328\u4e2a\u53bb\u505a，\u8fd9\u6837\u4e00\u6765\u6548\u7387\u5c31\u9ad8\u591a\u4e86\u3002<\/p>\n

\u4e0d\u7b49\u5f85\u987e\u5ba2\u63d0\u51fa\u8981\u6c42，\u7c7b\u6bd4\u5230\u4ee3\u7801\u4e0a\u5c31\u662f\u4e0d\u7b49\u5f85\u6587\u4ef6\u63cf\u8ff0\u7b26\u51c6\u5907\u597d\u6570\u636e，\u800c\u662f\u6ca1\u51c6\u5907\u597d\u8fd4\u56de\u300e\u6ca1\u51c6\u5907\u597d\u300f，\u51c6\u5907\u597d\u4e86\u5c31\u8bfb\u6570\u636e\u3002\u5177\u8c61\u5316\u5230socket，\u5f53\u8fdb\u884cread\/recv socket\u7684\u64cd\u4f5c\u65f6，\u6240\u8c13\u7684\u300e\u6ca1\u51c6\u5907\u597d\u300f\u7684\u9519\u8bef\u7801\u5c31\u662fEAGAIN \u6216\u8005 EWOULDBLOCK\u3002<\/p>\n

#<\/span>include<\/span> <fcntl.h><\/span><\/span>
\n#<\/span>include<\/span> <sys\/socket.h><\/span><\/span><\/p>\n

int<\/span> sockfd =<\/span> socket<\/span>(<\/span>AF_INET,<\/span> SOCK_STREAM,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ \u521b\u5efa socket<\/span><\/p>\n

\/\/ \u83b7\u53d6 socket \u7684\u5f53\u524d flags<\/span>
\nint<\/span> flags =<\/span> fcntl<\/span>(<\/span>sockfd,<\/span> F_GETFL,<\/span> 0<\/span>)<\/span>;<\/span>
\nif<\/span> (<\/span>flags ==<\/span> –<\/span>1<\/span>)<\/span> {<\/span>
\n \/\/ \u5904\u7406\u9519\u8bef<\/span>
\n}<\/span><\/p>\n

\/\/ \u8bbe\u7f6e socket \u4e3a\u975e\u963b\u585e\u6a21\u5f0f<\/span>
\nif<\/span> (<\/span>fcntl<\/span>(<\/span>sockfd,<\/span> F_SETFL,<\/span> flags |<\/span> O_NONBLOCK)<\/span> ==<\/span> –<\/span>1<\/span>)<\/span> {<\/span>
\n \/\/ \u5904\u7406\u9519\u8bef<\/span>
\n}<\/span><\/p>\n

.<\/span>.<\/span>.<\/span><\/p>\n

ssize_t bytes_read =<\/span> read<\/span>(<\/span>sockfd,<\/span> buffer,<\/span> sizeof<\/span>(<\/span>buffer)<\/span>)<\/span>;<\/span>
\nif<\/span> (<\/span>bytes_read ==<\/span> –<\/span>1<\/span>)<\/span> {<\/span>
\n if<\/span> (<\/span>errno ==<\/span> EAGAIN ||<\/span> errno ==<\/span> EWOULDBLOCK)<\/span> {<\/span>
\n \/\/ \u6ca1\u6709\u6570\u636e\u53ef\u8bfb，\u975e\u963b\u585e\u64cd\u4f5c<\/span>
\n \/\/ \u5728\u8fd9\u91cc\u5904\u7406\u6ca1\u6709\u6570\u636e\u7684\u60c5\u51b5<\/span>
\n }<\/span> else<\/span> {<\/span>
\n \/\/ \u53d1\u751f\u4e86\u5176\u4ed6\u9519\u8bef<\/span>
\n }<\/span>
\n}<\/span><\/p>\n

\u4e0a\u9762\u7684\u4ee3\u7801\u5c31\u662f\u8bbe\u7f6esocket\u975e\u963b\u585e\u4ee5\u53ca\u975e\u963b\u585e\u8bfb\u53d6socket\u7684\u8fc7\u7a0b\u3002\u501f\u52a9\u975e\u963b\u585eIO，\u5c31\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e2a\u7ebf\u7a0b\u76d1\u542c\u6240\u6709\u7684socket\u72b6\u6001，\u54ea\u4e2asocket\u51c6\u5907\u597d\u5c31\u5904\u7406\u54ea\u4e2asocket\u3002<\/p>\n

3.3.2 IO\u591a\u8def\u590d\u7528(IO-Multiplexing)<\/h4>\n

\u4f60\u89c9\u5f97\u6328\u4e2a\u53bb\u6536\u96c6\u987e\u5ba2\u7684\u8981\u6c42\u6709\u70b9\u6162，\u4e8e\u662f\u4f60\u5efa\u4e86\u4e00\u4e2a\u5fae\u4fe1\u7fa4，\u987e\u5ba2\u76f4\u63a5\u628a\u9700\u6c42\u53d1\u5230\u7fa4\u91cc，\u4f60\u6bcf\u8fc7\u4e00\u4f1a\u513f\u5c31\u53bb\u770b\u4e00\u773c\u5fae\u4fe1\u7fa4，\u628a\u6bcf\u4e2a\u5fae\u4fe1\u53f7\u5bf9\u5e94\u7684\u9700\u6c42\u8bb0\u4e0b\u6765\u5199\u5728\u5c0f\u7eb8\u6761\u4e0a，\u7136\u540e\u505a\u8fd9\u4e9b\u5c0f\u7eb8\u6761\u4e0a\u5199\u597d\u7684\u714e\u997c\u679c\u5b50\u9700\u6c42\u3002<\/p>\n

\u6709\u4e86\u975e\u963b\u585eIO，\u670d\u52a1\u5668\u7684\u5904\u7406\u903b\u8f91\u5c31\u53ef\u4ee5\u5c06\u6240\u6709\u5efa\u7acb\u8fde\u63a5\u7684socket\u653e\u5230\u4e00\u4e2a\u5217\u8868\u4e2d，\u63a5\u7740\u5efa\u7acb\u4e00\u4e2a\u5faa\u73af\u904d\u5386\u8fd9\u4e2a\u5217\u8868，\u6bcf\u5f53\u6709socket\u53ef\u8bfb\u65f6\u5c31\u53bb\u5904\u7406；\u4f46\u662f\u5f53\u8bf7\u6c42\u7684\u6570\u91cf\u8d8a\u6765\u8d8a\u591a\u7684\u65f6\u5019，\u7ef4\u62a4\u7684\u5217\u8868\u4e5f\u8d8a\u6765\u8d8a\u957f，\u904d\u5386\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662f <\/p>\n

O <\/p>\n

( <\/p>\n

n <\/p>\n

) <\/p>\n

O(n) <\/p>\n

<\/span><\/span>O<\/span>(<\/span>n<\/span>)<\/span><\/span><\/span><\/span><\/span>， <\/p>\n

n <\/p>\n

n <\/p>\n

<\/span><\/span>n<\/span><\/span><\/span><\/span><\/span>\u5c31\u662f\u5217\u8868\u7684\u957f\u5ea6\u3002Linux\u5219\u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86IO\u591a\u8def\u590d\u7528\u8fd9\u4e00\u673a\u5236，\u53ef\u4ee5\u76f4\u63a5\u8fd4\u56de\u76d1\u542c\u5217\u8868\u4e2d\u6240\u6709\u72b6\u6001\u53d1\u751f\u53d8\u5316\u7684socket(\u6216\u8005\u5176\u4ed6file descriptor，\u4ee5\u4e0b\u7b80\u79f0fd)，\u907f\u514d\u4e86\u904d\u5386\u4e00\u904d\u5374\u53ea\u6709\u5f88\u5c11\u751a\u81f3\u6ca1\u6709fd\u53d1\u751f\u53d8\u5316\u7684\u7a98\u5883，\u63d0\u9ad8\u4e86\u6027\u80fd\u3002\u5c31\u50cf\u672c\u8282\u5f00\u5934\u63d0\u5230\u7684\u714e\u997c\u679c\u5b50\u8001\u677f\u7684\u505a\u6cd5，\u76f4\u63a5\u62ff\u5230\u51c6\u5907\u597d\u4e0b\u5355\u987e\u5ba2\u7684\u9700\u6c42，\u800c\u4e0d\u662f\u6328\u4e2a\u8be2\u95ee\u3002 \u7531\u4e8e\u672c\u6587\u4e0d\u662f\u4e3b\u8981\u4ecb\u7ecdIO\u591a\u8def\u590d\u7528\u7684\u6587\u7ae0，\u5728\u8fd9\u91cc\u4e00\u6b65\u5230\u4f4d\u4f7f\u7528epoll\u8fdb\u884c\u76d1\u542c，\u5bf9\u6b64\u4e0d\u592a\u719f\u6089\u7684\u8bfb\u8005\u53ef\u4ee5\u5148\u4e86\u89e3select\u3001poll\u5230epoll\u7684\u53d1\u5c55\u8fc7\u7a0b\u4ee5\u53ca\u5b83\u4eec\u7684\u4f7f\u7528\u65b9\u6cd5\u3002<\/p>\n

int<\/span> main<\/span>(<\/span>)<\/span> {<\/span>
\n int<\/span> epoll_fd =<\/span> epoll_create1<\/span>(<\/span>0<\/span>)<\/span>;<\/span>
\n if<\/span> (<\/span>epoll_fd ==<\/span> –<\/span>1<\/span>)<\/span> {<\/span>
\n .<\/span>.<\/span>.<\/span>
\n }<\/span><\/p>\n

int<\/span> listen_sock =<\/span> socket<\/span>(<\/span>AF_INET,<\/span> SOCK_STREAM,<\/span> 0<\/span>)<\/span>;<\/span>
\n \/\/ \u8bbe\u7f6e socket \u4e3a\u975e\u963b\u585e\u6a21\u5f0f（\u53ef\u9009）<\/span>
\n fcntl<\/span>(<\/span>listen_sock,<\/span> F_SETFL,<\/span> fcntl<\/span>(<\/span>listen_sock,<\/span> F_GETFL,<\/span> 0<\/span>)<\/span> |<\/span> O_NONBLOCK)<\/span>;<\/span><\/p>\n

\/\/ \u7ed1\u5b9a\u548c\u76d1\u542csocket<\/span>
\n .<\/span>.<\/span>.<\/span><\/p>\n

struct<\/span> epoll_event<\/span> ev,<\/span> events[<\/span>MAX_EVENTS]<\/span>;<\/span>
\n ev.<\/span>events =<\/span> EPOLLIN;<\/span>
\n ev.<\/span>data.<\/span>fd =<\/span> listen_sock;<\/span><\/p>\n

\/\/ \u6dfb\u52a0\u76d1\u542c socket \u5230 epoll \u5b9e\u4f8b<\/span>
\n if<\/span> (<\/span>epoll_ctl<\/span>(<\/span>epoll_fd,<\/span> EPOLL_CTL_ADD,<\/span> listen_sock,<\/span> &<\/span>ev)<\/span> ==<\/span> –<\/span>1<\/span>)<\/span> {<\/span>
\n .<\/span>.<\/span>.<\/span>
\n }<\/span><\/p>\n

for<\/span> (<\/span>;<\/span>;<\/span>)<\/span> {<\/span>
\n \/\/ \u7b49\u5f85\u4e8b\u4ef6<\/span>
\n int<\/span> nfds =<\/span> epoll_wait<\/span>(<\/span>epoll_fd,<\/span> events,<\/span> MAX_EVENTS,<\/span> –<\/span>1<\/span>)<\/span>;<\/span>
\n .<\/span>.<\/span>.<\/span><\/p>\n

\/\/ \u5904\u7406\u4e8b\u4ef6<\/span>
\n for<\/span> (<\/span>int<\/span> n =<\/span> 0<\/span>;<\/span> n <<\/span> nfds;<\/span> ++<\/span>n)<\/span> {<\/span>
\n if<\/span> (<\/span>events[<\/span>n]<\/span>.<\/span>data.<\/span>fd ==<\/span> listen_sock)<\/span> {<\/span>
\n \/\/ \u63a5\u53d7\u65b0\u8fde\u63a5\u5e76\u52a0\u5165\u76d1\u542c<\/span>
\n int<\/span> conn_sock =<\/span> accept<\/span>(<\/span>listen_sock,<\/span> NULL<\/span>,<\/span> NULL<\/span>)<\/span>;<\/span>
\n .<\/span>.<\/span>.<\/span>
\n if<\/span> (<\/span>epoll_ctl<\/span>(<\/span>epoll_fd,<\/span> EPOLL_CTL_ADD,<\/span> conn_sock,<\/span> &<\/span>ev)<\/span> ==<\/span> –<\/span>1<\/span>)<\/span> {<\/span>
\n .<\/span>.<\/span>.<\/span>
\n }<\/span>
\n }<\/span> else<\/span> {<\/span>
\n \/\/ \u5904\u7406socket\u4e0a\u7684\u53ef\u8bfb\u4e8b\u4ef6<1><\/span>
\n char<\/span> buf[<\/span>512<\/span>]<\/span>;<\/span>
\n ssize_t count =<\/span> read<\/span>(<\/span>events[<\/span>n]<\/span>.<\/span>data.<\/span>fd,<\/span> buf,<\/span> sizeof<\/span>(<\/span>buf)<\/span>)<\/span>;<\/span>
\n .<\/span>.<\/span>.<\/span>
\n }<\/span>
\n }<\/span>
\n }<\/span><\/p>\n

return<\/span> 0<\/span>;<\/span>
\n}<\/span><\/p>\n

3.3.3 \u5355\u7ebf\u7a0bReactor\u6a21\u578b<\/h4>\n

\u3010\u4ee3\u7801：reactor\/single_thread_reactor\u3011 \u7ed3\u54083.3.1\u548c3.3.2\u7684\u5185\u5bb9\u5c31\u662f\u4e00\u4e2a\u6700\u57fa\u7840\u7684\u5355\u7ebf\u7a0breactor，\u5176\u672c\u8d28\u5c31\u662fnon-blocking\u548cIO multiplexing\u3002\u5728\u4e00\u4e2a\u6b7b\u5faa\u73af\u4e2d\u8c03\u7528epoll_wait，\u5f97\u5230\u53ef\u8bfb\u7684socket\u5217\u8868，\u5e76\u4f9d\u6b21\u9488\u5bf9\u8fd9\u4e9bsocket\u6267\u884cread\u64cd\u4f5c，\u5c06read\u51fa\u7684\u6570\u636e\u8fdb\u884c\u5904\u7406\u3002\u5c063.3.2\u4e2d\u7684\u4ee3\u7801\u4e2d\u7684<1>\u5904\u7684read\u6362\u6210handle_request(int fd)，handle_request\u8fd9\u4e2a\u51fd\u6570\u53ef\u4ee5\u66ff\u6362\u6210\u4efb\u610f\u9488\u5bf9\u5ba2\u6237\u7aef\u53d1\u6765\u7684\u6570\u636e\u7684\u5904\u7406\u51fd\u6570，\u4f8b\u5982\u5728tcp server\u7684\u57fa\u7840\u4e0a\u6dfb\u52a0\u4e00\u4e2ahttp\u7684\u5e93\u89e3\u6790\u6765\u81ea\u5ba2\u6237\u7aef\u7684http\u8bf7\u6c42\u3002\u5982\u679c\u9700\u8981\u5bf9\u6bd4\u65f6\u95f4\u4e0a\u7684\u5dee\u5f02，\u4e5f\u53ea\u80fd\u4e0e\u591a\u7ebf\u7a0b\u670d\u52a1\u5668\u5206\u6790\u2014\u2014Reactor\u7ebf\u7a0b\u6a21\u578b\u548c\u6027\u80fd\u5206\u6790(\u5e8f\u7ae0)\u4e2d\u7684\u5355\u7ebf\u7a0b\u963b\u585e\u670d\u52a1\u5668\u8fdb\u884c\u5bf9\u6bd4，\u9700\u8981\u8bfb\u8005\u989d\u5916\u505a\u7684\u662f\u5728client.cc\u7684\u8bf7\u6c42\u51fd\u6570\u4e2d\u5728connect\u4e0e\u670d\u52a1\u7aef\u5efa\u7acb\u8fde\u63a5\u4e4b\u540e\u6dfb\u52a0sleep\u6a21\u62df\u7f51\u7edc\u963b\u585e\u5bfc\u81f4\u6570\u636e\u5230\u8fbe\u670d\u52a1\u7aef\u4e0d\u53ca\u65f6，\u8bfb\u8005\u53ef\u4ee5\u81ea\u884c\u5c1d\u8bd5\u3002 \u5355\u7ebf\u7a0b\u7684reactor\u6267\u884c\u8fc7\u7a0b\u5219\u5982\u4e0b\u56fe\u6240\u793a： \"\u8bf7\u6dfb\u52a0\u56fe\u7247\u63cf\u8ff0\" \u5728loop\u5faa\u73af\u4e2d\u62ff\u5230\u53ef\u8bfbsocket\u5e76\u6309socket\u5217\u8868\u987a\u5e8f\u6267\u884chandle_request\u8fdb\u884c\u5904\u7406，\u4e00\u53e5\u8bdd\u5c31\u53ef\u4ee5\u6982\u62ec\u6574\u4e2a\u7684\u6267\u884c\u8fc7\u7a0b\u3002\u5728\u5b9e\u8df5\u4e2d，\u6211\u4eec\u901a\u5e38\u4e0d\u4f1a\u8d64\u88f8\u88f8\u7684\u76f4\u63a5\u5bf9socket\u8fdb\u884c\u5904\u7406，\u800c\u662f\u5c06\u300e\u53ef\u8bfb\u300f\u5305\u88c5\u6210\u4e00\u4e2a\u4e8b\u4ef6(Event)，handle_request\u5219\u88ab\u79f0\u4e3a\u4e8b\u4ef6\u56de\u8c03(Event Callback)，\u800cepoll\u6240\u5728\u7684\u5faa\u73af\u88ab\u79f0\u4e3a\u4e8b\u4ef6\u5faa\u73af，\u4ee5\u4e8b\u4ef6\u9a71\u52a8(Event Driven)\u6574\u4e2a\u6a21\u578b\u5b8c\u6210\u4e1a\u52a1\u903b\u8f91\u3002<\/p>\n

3.3.3.1 \u4e8b\u4ef6\u9a71\u52a8(Event Driven)<\/h5>\n

\u5728\u8fd9\u91cc\u63d0\u5230\u4e86\u4e8b\u4ef6\u9a71\u52a8，\u8fd9\u4e2a\u6982\u5ff5\u4e5f\u662f\u56f0\u6270\u4e86\u6211\u6bd4\u8f83\u4e45，\u4e3b\u8981\u662f\u5b83\u548c\u6d88\u606f\u9a71\u52a8(Message Driven)\u7684\u533a\u522b\u3002\u5728\u7f51\u4e0a\u641c\u4e86\u5f88\u4e45\u4e5f\u6ca1\u6709\u771f\u6b63\u5f04\u61c2，\u5176\u5b9e\u8fd9\u4e24\u8005\u5728\u5b9e\u73b0\u4e0a\u662f\u975e\u5e38\u63a5\u8fd1\u7684，\u90fd\u53ef\u4ee5\u91c7\u7528\u751f\u4ea7\u8005-\u6d88\u8d39\u8005\u6a21\u578b，\u5373\u7ef4\u62a4\u4e00\u4e2a\u961f\u5217\u5411\u91cc\u9762\u586b\u5145\u4e8b\u4ef6\/\u6d88\u606f，\u53e6\u4e00\u8fb9\u7ebf\u7a0b\u6c60\u4e0d\u65ad\u4ece\u961f\u5217\u4e2d\u53d6\u51fa\u4e8b\u4ef6\/\u6d88\u606f\u5e76\u5904\u7406，\u56e0\u6b64\u4e2a\u4eba\u7406\u89e3\u8fd9\u4e8c\u8005\u7684\u533a\u522b\u66f4\u591a\u7684\u662f\u5728\u7f16\u7a0b\u601d\u60f3\u6216\u8005\u8bbe\u8ba1\u6846\u67b6\u65f6\u7684\u533a\u522b\u3002\u6700\u7ec8\u5728stackoverflow\u4e0a\u627e\u5230\u4e86\u4e24\u4e2a\u7b54\u6848：<\/p>\n

A message is an item of data that is sent to a specific destination. An event is a signal emitted by a component upon reaching a given state. In a message-driven system addressable recipients await the arrival of messages and react to them, otherwise lying dormant. In an event-driven system notification listeners are attached to the sources of events such that they are invoked when the event is emitted. This means that an event-driven system focuses on addressable event sources while a message-driven system concentrates on addressable recipients. A message can contain an encoded event as its payload.<\/p>\n

\u8fd9\u4e00\u6bb5\u4e3b\u8981\u7684\u610f\u601d\u662f\u6d88\u606f\u9a71\u52a8\u7684\u7cfb\u7edf\u6709\u4e00\u4e2a\u786e\u5b9a\u7684\u63a5\u6536\u65b9，\u7b49\u5f85\u6d88\u606f\u5230\u6765\u5e76\u5904\u7406\u3001\u8fd4\u56de，\u5982\u679c\u6ca1\u6709\u6d88\u606f\u5219\u5904\u4e8e\u4f11\u7720\u72b6\u6001；\u800c\u4e8b\u4ef6\u9a71\u52a8\u5219\u6709\u4e00\u4e2a\u53d1\u9001\u6e90，\u9488\u5bf9\u53d1\u9001\u6e90\u6709\u591a\u4e2a\u8ba2\u9605\u8005，\u5f53\u53d1\u9001\u6e90\u6709\u4e8b\u4ef6\u53d1\u751f\u65f6\u5c31\u4f1a\u5524\u9192\u8ba2\u9605\u8005\u3002 \u5176\u5b9e\u8fd9\u6bb5\u8bdd\u6211\u7684\u4e2a\u4eba\u611f\u89c9\u770b\u7740\u8fd8\u662f\u6709\u70b9\u61f5\u5708，\u4e0b\u9762\u6709\u4e2a\u7b54\u6848\u4e3e\u4e86\u4e2a\u4f8b\u5b50：<\/p>\n

Let\u2019s say you are building a Payment service for an eCommerce website. When an order is placed, the Order service will ask your Payment service to authorize the customer\u2019s credit card. Only when the credit card has been authorized will the Order service send the order to the warehouse for packing and shipping. You need to agree with the team working on the Order service on how that request for credit card authorization is sent from their service to yours. There are two options. Message-driven: When an order is placed, the Order service sends an authorization request to your Payment service. Your service processes the request and returns success\/failure to the Order service. The initial request and the result could be sent synchronously or asynchronously. Event-driven: When an order is placed, the Order service publishes a NewOrder event. Your Payment service subscribes to that type of event so it is triggered. Your service processes the request and either publishes an AuthorizationAccepted or an AuthorizationDeclined event. The Order service subscribes to those event types. All events are asynchronous.<\/p>\n

\u6709\u4e00\u4e2a\u7f51\u4e0a\u7535\u5546\u7684\u4ed8\u6b3e\u7cfb\u7edf，\u9996\u5148\u8981\u6821\u9a8c\u4f60\u7684\u4fe1\u7528\u5361\u4fe1\u606f\u624d\u80fd\u7ee7\u7eed\u8ba2\u5355\u64cd\u4f5c，\u73b0\u5728\u6839\u636e\u6d88\u606f\u9a71\u52a8\u548c\u4e8b\u4ef6\u9a71\u52a8\u6709\u4e24\u79cd\u5904\u7406\u6821\u9a8c\u7684\u65b9\u5f0f：<\/p>\n