{"id":128,"date":"2017-06-25T00:19:29","date_gmt":"2017-06-24T16:19:29","guid":{"rendered":"http:\/\/49.232.131.197\/?p=128"},"modified":"2017-06-25T00:21:30","modified_gmt":"2017-06-24T16:21:30","slug":"linux_epoll","status":"publish","type":"post","link":"http:\/\/www.sourcecool.com\/index.php\/2017\/06\/25\/linux_epoll\/","title":{"rendered":"linux\u4e0b\u7684epoll\u8be6\u6790"},"content":{"rendered":"<p>\u5728Linux\u7684\u7f51\u7edc\u7f16\u7a0b\u4e2d\uff0c\u5f88\u957f\u7684\u65f6\u95f4\u90fd\u5728\u4f7f\u7528select\u6765\u505a\u4e8b\u4ef6\u89e6\u53d1\u3002\u5728linux\u65b0\u7684\u5185\u6838\u4e2d\uff0c\u6709\u4e86\u4e00\u79cd\u66ff\u6362\u5b83\u7684\u673a\u5236\uff0c\u5c31\u662fepoll\u3002\u76f8\u6bd4\u4e8eselect\uff0cepoll\u6700\u5927\u7684\u597d\u5904\u5728\u4e8e\u5b83\u4e0d\u4f1a\u968f\u7740\u76d1\u542cfd\u6570\u76ee\u7684\u589e\u957f\u800c\u964d\u4f4e\u6548\u7387\u3002\u56e0\u4e3a\u5728\u5185\u6838\u4e2d\u7684select\u5b9e\u73b0\u4e2d\uff0c\u5b83\u662f\u91c7\u7528\u8f6e\u8be2\u6765\u5904\u7406\u7684\uff0c\u8f6e\u8be2\u7684fd\u6570\u76ee\u8d8a\u591a\uff0c\u81ea\u7136\u8017\u65f6\u8d8a\u591a\u3002\u5e76\u4e14\uff0clinux\/posix_types.h\u5934\u6587\u4ef6\u6709\u8fd9\u6837\u7684\u58f0\u660e\uff1a<br \/>\n#define__FD_SETSIZE\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>1024<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><strong>\u8868\u793aselect\u6700\u591a\u540c\u65f6\u76d1\u542c1024\u4e2afd\uff0c\u5f53\u7136\uff0c\u53ef\u4ee5\u901a\u8fc7\u4fee\u6539\u5934\u6587\u4ef6\u518d\u91cd\u7f16\u8bd1\u5185\u6838\u6765\u6269\u5927\u8fd9\u4e2a\u6570\u76ee\uff0c\u4f46\u8fd9\u4f3c\u4e4e\u5e76\u4e0d\u6cbb\u672c\u3002<\/strong><\/p>\n<p align=\"center\">\u00a0<wbr \/><\/p>\n<p><strong>epoll\u7684\u63a5\u53e3\u975e\u5e38\u7b80\u5355\uff0c\u4e00\u5171\u5c31\u4e09\u4e2a\u51fd\u6570\uff1a<\/strong><br \/>\n1.<strong>\u521b\u5efaepoll\u53e5\u67c4<\/strong><br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>int\u00a0<wbr \/>epfd = epoll_create(intsize);\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><strong>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><\/strong>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><\/p>\n<p><wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u521b\u5efa\u4e00\u4e2aepoll\u7684\u53e5\u67c4\uff0c<strong>size\u7528\u6765\u544a\u8bc9\u5185\u6838\u8fd9\u4e2a\u76d1\u542c\u7684\u6570\u76ee\u4e00\u5171\u6709\u591a\u5927<\/strong>\u3002<strong>\u8fd9\u4e2a\u53c2\u6570\u4e0d\u540c\u4e8eselect()\u4e2d\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u7ed9\u51fa\u6700\u5927\u76d1\u542c\u7684fd+1\u7684\u503c<\/strong>\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5f53\u521b\u5efa\u597depoll\u53e5\u67c4\u540e\uff0c\u5b83\u5c31\u662f\u4f1a\u5360\u7528\u4e00\u4e2afd\u503c\uff0c\u5728linux\u4e0b\u5982\u679c\u67e5\u770b\/proc\/\u8fdb\u7a0bid\/fd\/\uff0c\u662f\u80fd\u591f\u770b\u5230\u8fd9\u4e2afd\u7684\uff0c<strong>\u6240\u4ee5\u5728\u4f7f\u7528\u5b8cepoll\u540e\uff0c\u5fc5\u987b\u8c03\u7528close()\u5173\u95ed\uff0c\u5426\u5219\u53ef\u80fd\u5bfc\u81f4fd\u88ab\u8017\u5c3d\u3002<br \/>\n<\/strong>\u51fd\u6570\u58f0\u660e\uff1aint epoll_create(int size)<br \/>\n\u8be5 \u51fd\u6570\u751f\u6210\u4e00\u4e2aepoll\u4e13\u7528\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\u5b83\u5176\u5b9e\u662f\u5728\u5185\u6838\u7533\u8bf7\u4e00\u7a7a\u95f4\uff0c\u7528\u6765\u5b58\u653e\u4f60\u60f3\u5173\u6ce8\u7684socket fd\u4e0a\u662f\u5426\u53d1\u751f\u4ee5\u53ca\u53d1\u751f\u4e86\u4ec0\u4e48\u4e8b\u4ef6\u3002size\u5c31\u662f\u4f60\u5728\u8fd9\u4e2aepoll fd\u4e0a\u80fd\u5173\u6ce8\u7684\u6700\u5927socket fd\u6570\u3002\u968f\u4f60\u5b9a\u597d\u4e86\u3002\u53ea\u8981\u4f60\u6709\u7a7a\u95f4\u3002\u53ef\u53c2\u89c1\u4e0a\u9762\u4e0eselect\u4e4b\u4e0d\u540c<br \/>\n2.<strong>\u5c06\u88ab\u76d1\u542c\u7684\u63cf\u8ff0\u7b26\u6dfb\u52a0\u5230epoll\u53e5\u67c4\u6216\u4eceepool\u53e5\u67c4\u4e2d\u5220\u9664\u6216\u8005\u5bf9\u76d1\u542c\u4e8b\u4ef6\u8fdb\u884c\u4fee\u6539\u3002<\/strong><\/p>\n<p><strong>\u51fd\u6570\u58f0\u660e\uff1aint epoll_ctl(int epfd, int op, int fd, struct epoll_event *event)<br \/>\n\u8be5\u51fd\u6570\u7528\u4e8e\u63a7\u5236\u67d0\u4e2aepoll\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u7684\u4e8b\u4ef6\uff0c\u53ef\u4ee5\u6ce8\u518c\u4e8b\u4ef6\uff0c\u4fee\u6539\u4e8b\u4ef6\uff0c\u5220\u9664\u4e8b\u4ef6\u3002<br \/>\n\u53c2\u6570\uff1a<br \/>\nepfd\uff1a\u7531 epoll_create \u751f\u6210\u7684epoll\u4e13\u7528\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff1b<br \/>\nop\uff1a\u8981\u8fdb\u884c\u7684\u64cd\u4f5c\u4f8b\u5982\u6ce8\u518c\u4e8b\u4ef6\uff0c\u53ef\u80fd\u7684\u53d6\u503cEPOLL_CTL_ADD \u6ce8\u518c\u3001EPOLL_CTL_MOD \u4fee \u6539\u3001EPOLL_CTL_DEL \u5220\u9664<\/strong><\/p>\n<p>fd\uff1a\u5173\u8054\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff1b<br \/>\nevent\uff1a\u6307\u5411epoll_event\u7684\u6307\u9488\uff1b<br \/>\n\u5982\u679c\u8c03\u7528\u6210\u529f\u8fd4\u56de0,\u4e0d\u6210\u529f\u8fd4\u56de-1<\/p>\n<p><wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>int epoll_ctl(int epfd, int<strong>op<\/strong>, int fd, struct epoll_event*event);\u00a0<wbr \/><\/p>\n<p><wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>epoll\u7684\u4e8b\u4ef6\u6ce8\u518c\u51fd\u6570\uff0c\u5b83\u4e0d\u540c\u4e0eselect()\u662f\u5728\u76d1\u542c\u4e8b\u4ef6\u65f6\u544a\u8bc9\u5185\u6838\u8981\u76d1\u542c\u4ec0\u4e48\u7c7b\u578b\u7684\u4e8b\u4ef6\uff0c\u800c\u662f\u5728\u8fd9\u91cc\u5148\u6ce8\u518c\u8981\u76d1\u542c\u7684\u4e8b\u4ef6\u7c7b\u578b\u3002<\/p>\n<div>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u7b2c\u4e00\u4e2a\u53c2\u6570\u662fepoll_create()\u7684\u8fd4\u56de\u503c\uff0c<\/div>\n<div>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u7b2c\u4e8c\u4e2a\u53c2\u6570\u8868\u793a\u52a8\u4f5c\uff0c\u7528\u4e09\u4e2a\u5b8f\u6765\u8868\u793a\uff1a<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLL_CTL_ADD\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u6ce8\u518c\u65b0\u7684fd\u5230epfd\u4e2d\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLL_CTL_MOD\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u4fee\u6539\u5df2\u7ecf\u6ce8\u518c\u7684fd\u7684\u76d1\u542c\u4e8b\u4ef6\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLL_CTL_DEL\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u4eceepfd\u4e2d\u5220\u9664\u4e00\u4e2afd\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u7b2c\u4e09\u4e2a\u53c2\u6570\u662f\u9700\u8981\u76d1\u542c\u7684fd\uff0c<\/div>\n<div>\n<p>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u7b2c\u56db\u4e2a\u53c2\u6570\u662f\u544a\u8bc9\u5185\u6838\u9700\u8981\u76d1\u542c\u4ec0\u4e48\u4e8b\u4ef6\uff0cstructepoll_event\u7ed3\u6784\u5982\u4e0b\uff1a<\/p>\n<div class=\"dp-highlighter bg_cpp\">\n<div class=\"bar\"><\/div>\n<ol class=\"dp-cpp\" start=\"1\">\n<li class=\"alt\">\n<pre class=\"lang:c++ decode:true \">typedef\u00a0union\u00a0epoll_data\u00a0{\u00a0\u00a0\r\nvoid\u00a0*ptr;\u00a0\u00a0\r\nint\u00a0fd;\u00a0\u00a0\r\n__uint32_t\u00a0u32;\u00a0\u00a0\r\n__uint64_t\u00a0u64;\u00a0\u00a0\r\n}\u00a0epoll_data_t;\u00a0\u00a0\r\n\u00a0\u00a0\r\nstruct\u00a0epoll_event\u00a0{\u00a0\u00a0\r\n__uint32_t\u00a0events;\u00a0\/*\u00a0Epoll\u00a0events\u00a0*\/\u00a0\u00a0\r\nepoll_data_t\u00a0data;\u00a0\/*\u00a0User\u00a0data\u00a0variable\u00a0*\/\u00a0\u00a0\r\n};<\/pre>\n<p>&nbsp;<\/li>\n<\/ol>\n<\/div>\n<p><wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>events\u53ef\u4ee5\u662f\u4ee5\u4e0b\u51e0\u4e2a\u5b8f\u7684\u96c6\u5408\uff1a<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLIN\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u89e6\u53d1\u8be5\u4e8b\u4ef6\uff0c\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u6709\u53ef\u8bfb\u6570\u636e\u3002(\u5305\u62ec\u5bf9\u7aefSOCKET\u6b63\u5e38\u5173\u95ed)\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLOUT\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u89e6\u53d1\u8be5\u4e8b\u4ef6\uff0c\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u53ef\u4ee5\u5199\u6570\u636e\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLPRI\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6709\u7d27\u6025\u7684\u6570\u636e\u53ef\u8bfb\uff08\u8fd9\u91cc\u5e94\u8be5\u8868\u793a\u6709\u5e26\u5916\u6570\u636e\u5230\u6765\uff09\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLERR\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u53d1\u751f\u9519\u8bef\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLHUP\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u88ab\u6302\u65ad\uff1b<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLET\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u5c06EPOLL\u8bbe\u4e3a\u8fb9\u7f18\u89e6\u53d1(Edge Triggered)\u6a21\u5f0f\uff0c\u8fd9\u662f\u76f8\u5bf9\u4e8e\u6c34\u5e73\u89e6\u53d1(Level Triggered)\u6765\u8bf4\u7684\u3002<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>EPOLLONESHOT\uff1a\u00a0<wbr \/>\u00a0<wbr \/>\u53ea\u76d1\u542c\u4e00\u6b21\u4e8b\u4ef6\uff0c\u5f53\u76d1\u542c\u5b8c\u8fd9\u6b21\u4e8b\u4ef6\u4e4b\u540e\uff0c\u5982\u679c\u8fd8\u9700\u8981\u7ee7\u7eed\u76d1\u542c\u8fd9\u4e2asocket\u7684\u8bdd\uff0c\u9700\u8981\u518d\u6b21\u628a\u8fd9\u4e2asocket\u52a0\u5165\u5230EPOLL\u961f\u5217\u91cc\u3002<br \/>\n\u5982\uff1a<br \/>\nstruct epoll_event ev;<br \/>\n\/\/\u8bbe\u7f6e\u4e0e\u8981\u5904\u7406\u7684\u4e8b\u4ef6\u76f8\u5173\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26<br \/>\nev.data.fd=listenfd;<br \/>\n\/\/\u8bbe\u7f6e\u8981\u5904\u7406\u7684\u4e8b\u4ef6\u7c7b\u578b<br \/>\nev.events=EPOLLIN|EPOLLET;<br \/>\n\/\/\u6ce8\u518cepoll\u4e8b\u4ef6<br \/>\nepoll_ctl(epfd,EPOLL_CTL_ADD,listenfd,&amp;ev);<br \/>\n<strong>3.\u7b49\u5f85\u4e8b\u4ef6\u89e6\u53d1\uff0c\u5f53\u8d85\u8fc7timeout\u8fd8\u6ca1\u6709\u4e8b\u4ef6\u89e6\u53d1\u65f6\uff0c\u5c31\u8d85\u65f6\u3002<\/strong><\/p>\n<\/div>\n<div><strong>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>int epoll_wait(int epfd, struct epoll_event * events, intmaxevents, int timeout);<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><\/strong>\u7b49\u5f85\u4e8b\u4ef6\u7684\u4ea7\u751f\uff0c\u7c7b\u4f3c\u4e8eselect()\u8c03\u7528\u3002\u53c2\u6570events\u7528\u6765\u4ece\u5185\u6838\u5f97\u5230\u4e8b\u4ef6\u7684\u96c6\u5408\uff0cmaxevents\u544a\u4e4b\u5185\u6838\u8fd9\u4e2aevents\u6709\u591a\u5927(\u6570\u7ec4\u6210\u5458\u7684\u4e2a\u6570)\uff0c\u8fd9\u4e2amaxevents\u7684\u503c\u4e0d\u80fd\u5927\u4e8e\u521b\u5efaepoll_create()\u65f6\u7684size\uff0c\u53c2\u6570timeout\u662f\u8d85\u65f6\u65f6\u95f4\uff08\u6beb\u79d2\uff0c0\u4f1a\u7acb\u5373\u8fd4\u56de\uff0c-1\u5c06\u4e0d\u786e\u5b9a\uff0c\u4e5f\u6709\u8bf4\u6cd5\u8bf4\u662f\u6c38\u4e45\u963b\u585e\uff09\u3002<\/div>\n<div>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8be5\u51fd\u6570\u8fd4\u56de\u9700\u8981\u5904\u7406\u7684\u4e8b\u4ef6\u6570\u76ee\uff0c\u5982\u8fd4\u56de0\u8868\u793a\u5df2\u8d85\u65f6\u3002<\/div>\n<div>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8fd4\u56de\u7684\u4e8b\u4ef6\u96c6\u5408\u5728events\u6570\u7ec4\u4e2d\uff0c\u6570\u7ec4\u4e2d\u5b9e\u9645\u5b58\u653e\u7684\u6210\u5458\u4e2a\u6570\u662f\u51fd\u6570\u7684\u8fd4\u56de\u503c\u3002\u8fd4\u56de0\u8868\u793a\u5df2\u7ecf\u8d85\u65f6\u3002<br \/>\n\u51fd\u6570\u58f0\u660e:int epoll_wait(int epfd,struct epoll_event * events,int maxevents,int timeout)<br \/>\n\u8be5\u51fd\u6570\u7528\u4e8e\u8f6e\u8be2I\/O\u4e8b\u4ef6\u7684\u53d1\u751f\uff1b<br \/>\n\u53c2\u6570\uff1a<br \/>\nepfd:\u7531epoll_create \u751f\u6210\u7684epoll\u4e13\u7528\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff1b<br \/>\nepoll_event:\u7528\u4e8e\u56de\u4f20\u4ee3\u5904\u7406\u4e8b\u4ef6\u7684\u6570\u7ec4\uff1b<br \/>\nmaxevents:\u6bcf\u6b21\u80fd\u5904\u7406\u7684\u4e8b\u4ef6\u6570\uff1b<br \/>\ntimeout:\u7b49\u5f85I\/O\u4e8b\u4ef6\u53d1\u751f\u7684\u8d85\u65f6\u503c(\u5355\u4f4d\u6211\u4e5f\u4e0d\u592a\u6e05\u695a)\uff1b-1\u76f8\u5f53\u4e8e\u963b\u585e\uff0c0\u76f8\u5f53\u4e8e\u975e\u963b\u585e\u3002\u4e00\u822c\u7528-1\u5373\u53ef<br \/>\n\u8fd4\u56de\u53d1\u751f\u4e8b\u4ef6\u6570\u3002<br \/>\nepoll_wait\u8fd0\u884c\u7684\u539f\u7406\u662f<br \/>\n\u7b49\u4f8d\u6ce8\u518c\u5728epfd\u4e0a\u7684socket fd\u7684\u4e8b\u4ef6\u7684\u53d1\u751f\uff0c\u5982\u679c\u53d1\u751f\u5219\u5c06\u53d1\u751f\u7684sokct fd\u548c\u4e8b\u4ef6\u7c7b\u578b\u653e\u5165\u5230events\u6570\u7ec4\u4e2d\u3002<br \/>\n<strong>\u5e76 \u4e14\u5c06\u6ce8\u518c\u5728epfd\u4e0a\u7684socket fd\u7684\u4e8b\u4ef6\u7c7b\u578b\u7ed9\u6e05\u7a7a<\/strong>\uff0c\u6240\u4ee5\u5982\u679c\u4e0b\u4e00\u4e2a\u5faa\u73af\u4f60\u8fd8\u8981\u5173\u6ce8\u8fd9\u4e2asocket fd\u7684\u8bdd\uff0c\u5219\u9700\u8981\u7528epoll_ctl(epfd,EPOLL_CTL_MOD,listenfd,&amp;ev)\u6765\u91cd\u65b0\u8bbe\u7f6esocket fd\u7684\u4e8b\u4ef6\u7c7b\u578b\u3002\u8fd9\u65f6\u4e0d\u7528EPOLL_CTL_ADD,\u56e0\u4e3asocket fd\u5e76\u672a\u6e05\u7a7a\uff0c\u53ea\u662f\u4e8b\u4ef6\u7c7b\u578b\u6e05\u7a7a\u3002\u8fd9\u4e00\u6b65\u975e\u5e38\u91cd\u8981\u3002<\/div>\n<div><\/div>\n<div>\u4eceman\u624b\u518c\u4e2d\uff0c\u5f97\u5230ET\u548cLT\u7684\u5177\u4f53\u63cf\u8ff0\u5982\u4e0b<br \/>\nEPOLL\u4e8b\u4ef6\u6709\u4e24\u79cd\u6a21\u578b\uff1a<br \/>\nEdge Triggered(ET)\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\/\/<strong>\u9ad8\u901f\u5de5\u4f5c\u65b9\u5f0f\uff0c\u9519\u8bef\u7387\u6bd4\u8f83\u5927\uff0c\u53ea\u652f\u6301no_block socket\u00a0<wbr \/>(\u975e\u963b\u585esocket)<br \/>\n<\/strong>LevelTriggered(LT)\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\/\/<strong>\u7f3a\u7701\u5de5\u4f5c\u65b9\u5f0f\uff0c\u5373\u9ed8\u8ba4\u7684\u5de5\u4f5c\u65b9\u5f0f,\u652f\u6301blocksocket\u548cno_blocksocket\uff0c\u9519\u8bef\u7387\u6bd4\u8f83\u5c0f\u3002<br \/>\n<\/strong><br \/>\n\u5047\u5982\u6709\u8fd9\u6837\u4e00\u4e2a\u4f8b\u5b50\uff1a(LT\u65b9\u5f0f\uff0c\u5373\u9ed8\u8ba4\u65b9\u5f0f\u4e0b\uff0c\u5185\u6838\u4f1a\u7ee7\u7eed\u901a\u77e5\uff0c\u53ef\u4ee5\u8bfb\u6570\u636e\uff0cET\u65b9\u5f0f\uff0c\u5185\u6838\u4e0d\u4f1a\u518d\u901a\u77e5\uff0c\u53ef\u4ee5\u8bfb\u6570\u636e)<br \/>\n1.\u6211\u4eec\u5df2\u7ecf\u628a\u4e00\u4e2a\u7528\u6765\u4ece\u7ba1\u9053\u4e2d\u8bfb\u53d6\u6570\u636e\u7684\u6587\u4ef6\u53e5\u67c4(RFD)\u6dfb\u52a0\u5230epoll\u63cf\u8ff0\u7b26<br \/>\n2. \u8fd9\u4e2a\u65f6\u5019\u4ece\u7ba1\u9053\u7684\u53e6\u4e00\u7aef\u88ab\u5199\u5165\u4e862KB\u7684\u6570\u636e<br \/>\n3. \u8c03\u7528epoll_wait(2)\uff0c\u5e76\u4e14\u5b83\u4f1a\u8fd4\u56deRFD\uff0c\u8bf4\u660e\u5b83\u5df2\u7ecf\u51c6\u5907\u597d\u8bfb\u53d6\u64cd\u4f5c<br \/>\n4. \u7136\u540e\u6211\u4eec\u8bfb\u53d6\u4e861KB\u7684\u6570\u636e<br \/>\n5. \u8c03\u7528epoll_wait(2)&#8230;&#8230;<strong>Edge Triggered\u5de5\u4f5c\u6a21\u5f0f\uff1a<\/strong><br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u5982\u679c\u6211\u4eec\u5728\u7b2c1\u6b65\u5c06RFD\u6dfb\u52a0\u5230epoll\u63cf\u8ff0\u7b26\u7684\u65f6\u5019\u4f7f\u7528\u4e86EPOLLET\u6807\u5fd7\uff0c\u90a3\u4e48\u5728\u7b2c5\u6b65\u8c03\u7528epoll_wait(2)\u4e4b\u540e\u5c06\u6709\u53ef\u80fd\u4f1a\u6302\u8d77\uff0c\u56e0\u4e3a\u5269\u4f59\u7684\u6570\u636e\u8fd8\u5b58\u5728\u4e8e\u6587\u4ef6\u7684\u8f93\u5165\u7f13\u51b2\u533a\u5185\uff0c\u800c\u4e14\u6570\u636e\u53d1\u51fa\u7aef\u8fd8\u5728\u7b49\u5f85\u4e00\u4e2a\u9488\u5bf9\u5df2\u7ecf\u53d1\u51fa\u6570\u636e\u7684\u53cd\u9988\u4fe1\u606f\u3002\u53ea\u6709\u5728\u76d1\u89c6\u7684\u6587\u4ef6\u53e5\u67c4\u4e0a\u53d1\u751f\u4e86\u67d0\u4e2a\u4e8b\u4ef6\u7684\u65f6\u5019ET\u5de5\u4f5c\u6a21\u5f0f\u624d\u4f1a\u6c47\u62a5\u4e8b\u4ef6\u3002\u56e0\u6b64\u5728\u7b2c5\u6b65\u7684\u65f6\u5019\uff0c\u8c03\u7528\u8005\u53ef\u80fd\u4f1a\u653e\u5f03\u7b49\u5f85\u4ecd\u5728\u5b58\u5728\u4e8e\u6587\u4ef6\u8f93\u5165\u7f13\u51b2\u533a\u5185\u7684\u5269\u4f59\u6570\u636e\u3002\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u4f1a\u6709\u4e00\u4e2a\u4e8b\u4ef6\u4ea7\u751f\u5728RFD\u53e5\u67c4\u4e0a\uff0c\u56e0\u4e3a\u5728\u7b2c2\u6b65\u6267\u884c\u4e86\u4e00\u4e2a\u5199\u64cd\u4f5c\uff0c\u7136\u540e\uff0c\u4e8b\u4ef6\u5c06\u4f1a\u5728\u7b2c3\u6b65\u88ab\u9500\u6bc1\u3002\u56e0\u4e3a\u7b2c4\u6b65\u7684\u8bfb\u53d6\u64cd\u4f5c\u6ca1\u6709\u8bfb\u7a7a\u6587\u4ef6\u8f93\u5165\u7f13\u51b2\u533a\u5185\u7684\u6570\u636e\uff0c\u56e0\u6b64\u6211\u4eec\u5728\u7b2c5\u6b65\u8c03\u7528epoll_wait(2)\u5b8c\u6210\u540e\uff0c\u662f\u5426\u6302\u8d77\u662f\u4e0d\u786e\u5b9a\u7684\u3002epoll\u5de5\u4f5c\u5728ET\u6a21\u5f0f\u7684\u65f6\u5019\uff0c\u5fc5\u987b\u4f7f\u7528\u975e\u963b\u585e\u5957\u63a5\u53e3\uff0c\u4ee5\u907f\u514d\u7531\u4e8e\u4e00\u4e2a\u6587\u4ef6\u53e5\u67c4\u7684\u963b\u585e\u8bfb\/\u963b\u585e\u5199\u64cd\u4f5c\u628a\u5904\u7406\u591a\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u4efb\u52a1\u997f\u6b7b\u3002\u6700\u597d\u4ee5\u4e0b\u9762\u7684\u65b9\u5f0f\u8c03\u7528ET\u6a21\u5f0f\u7684epoll\u63a5\u53e3\uff0c<strong>\u5728\u540e\u9762\u4f1a\u4ecb\u7ecd\u907f\u514d\u53ef\u80fd\u7684\u7f3a\u9677\u3002(LT\u65b9\u5f0f\u53ef\u4ee5\u89e3\u51b3\u8fd9\u79cd\u7f3a\u9677)<br \/>\n<\/strong>\u00a0<wbr \/>\u00a0<wbr \/>i\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u57fa\u4e8e\u975e\u963b\u585e\u6587\u4ef6\u53e5\u67c4<br \/>\n<wbr \/>\u00a0<wbr \/>ii\u00a0<wbr \/>\u00a0<wbr \/>\u53ea\u6709\u5f53read(2)\u6216\u8005write(2)\u8fd4\u56deEAGAIN\u65f6(\u8ba4\u4e3a\u8bfb\u5b8c)\u624d\u9700\u8981\u6302\u8d77\uff0c\u7b49\u5f85\u3002\u4f46\u8fd9\u5e76\u4e0d\u662f\u8bf4\u6bcf\u6b21read()\u65f6\u90fd\u9700\u8981\u5faa\u73af\u8bfb\uff0c\u76f4\u5230\u8bfb\u5230\u4ea7\u751f\u4e00\u4e2aEAGAIN\u624d\u8ba4\u4e3a\u6b64\u6b21\u4e8b\u4ef6\u5904\u7406\u5b8c\u6210\uff0c\u5f53read()\u8fd4\u56de\u7684\u8bfb\u5230\u7684\u6570\u636e\u957f\u5ea6\u5c0f\u4e8e\u8bf7\u6c42\u7684\u6570\u636e\u957f\u5ea6\u65f6(\u5373\u5c0f\u4e8esizeof(buf))\uff0c\u5c31\u53ef\u4ee5\u786e\u5b9a\u6b64\u65f6\u7f13\u51b2\u4e2d\u5df2\u6ca1\u6709\u6570\u636e\u4e86\uff0c\u4e5f\u5c31\u53ef\u4ee5\u8ba4\u4e3a\u6b64\u4e8b\u8bfb\u4e8b\u4ef6\u5df2\u5904\u7406\u5b8c\u6210\u3002<strong>Level Triggered\u5de5\u4f5c\u6a21\u5f0f\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>(\u9ed8\u8ba4\u7684\u5de5\u4f5c\u65b9\u5f0f)<\/strong><br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u76f8\u53cd\u7684\uff0c\u4ee5LT\u65b9\u5f0f\u8c03\u7528epoll\u63a5\u53e3\u7684\u65f6\u5019\uff0c\u5b83\u5c31\u76f8\u5f53\u4e8e\u4e00\u4e2a\u901f\u5ea6\u6bd4\u8f83\u5feb\u7684poll(2)\uff0c\u5e76\u4e14\u65e0\u8bba\u540e\u9762\u7684\u6570\u636e\u662f\u5426\u88ab\u4f7f\u7528\uff0c\u56e0\u6b64\u4ed6\u4eec\u5177\u6709\u540c\u6837\u7684\u804c\u80fd\u3002\u56e0\u4e3a\u5373\u4f7f\u4f7f\u7528ET\u6a21\u5f0f\u7684epoll\uff0c\u5728\u6536\u5230\u591a\u4e2achunk\u7684\u6570\u636e\u7684\u65f6\u5019\u4ecd\u7136\u4f1a\u4ea7\u751f\u591a\u4e2a\u4e8b\u4ef6\u3002\u8c03\u7528\u8005\u53ef\u4ee5\u8bbe\u5b9aEPOLLONESHOT\u6807\u5fd7\uff0c\u5728epoll_wait(2)\u6536\u5230\u4e8b\u4ef6\u540eepoll\u4f1a\u4e0e\u4e8b\u4ef6\u5173\u8054\u7684\u6587\u4ef6\u53e5\u67c4\u4eceepoll\u63cf\u8ff0\u7b26\u4e2d\u7981\u6b62\u6389\u3002\u56e0\u6b64\u5f53EPOLLONESHOT\u8bbe\u5b9a\u540e\uff0c\u4f7f\u7528\u5e26\u6709EPOLL_CTL_MOD\u6807\u5fd7\u7684epoll_ctl(2)\u5904\u7406\u6587\u4ef6\u53e5\u67c4\u5c31\u6210\u4e3a\u8c03\u7528\u8005\u5fc5\u987b\u4f5c\u7684\u4e8b\u60c5\u3002<strong>\u7136\u540e\u8be6\u7ec6\u89e3\u91caET, LT:<\/strong><br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><strong>\u00a0<wbr \/>\/\/\u6ca1\u6709\u5bf9\u5c31\u7eea\u7684fd\u8fdb\u884cIO\u64cd\u4f5c\uff0c\u5185\u6838\u4f1a\u4e0d\u65ad\u7684\u901a\u77e5\u3002<br \/>\n<\/strong>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>LT(leveltriggered)\u662f\u7f3a\u7701\u7684\u5de5\u4f5c\u65b9\u5f0f\uff0c\u5e76\u4e14\u540c\u65f6\u652f\u6301block\u548cno-blocksocket\u3002\u5728\u8fd9\u79cd\u505a\u6cd5\u4e2d\uff0c\u5185\u6838\u544a\u8bc9\u4f60\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u5426\u5c31\u7eea\u4e86\uff0c\u7136\u540e\u4f60\u53ef\u4ee5\u5bf9\u8fd9\u4e2a\u5c31\u7eea\u7684fd\u8fdb\u884cIO\u64cd\u4f5c\u3002\u5982\u679c\u4f60\u4e0d\u4f5c\u4efb\u4f55\u64cd\u4f5c\uff0c<strong>\u5185\u6838\u8fd8\u662f\u4f1a\u7ee7\u7eed\u901a\u77e5\u4f60\u7684<\/strong>\uff0c\u6240\u4ee5\uff0c\u8fd9\u79cd\u6a21\u5f0f\u7f16\u7a0b\u51fa\u9519\u8bef\u53ef\u80fd\u6027\u8981\u5c0f\u4e00\u70b9\u3002\u4f20\u7edf\u7684select\/poll\u90fd\u662f\u8fd9\u79cd\u6a21\u578b\u7684\u4ee3\u8868\u3002<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/><strong>\u00a0<wbr \/>\/\/\u6ca1\u6709\u5bf9\u5c31\u7eea\u7684fd\u8fdb\u884cIO\u64cd\u4f5c\uff0c\u5185\u6838\u4e0d\u4f1a\u518d\u8fdb\u884c\u901a\u77e5\u3002<\/strong><br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>ET(edge-triggered)\u662f\u9ad8\u901f\u5de5\u4f5c\u65b9\u5f0f\uff0c\u53ea\u652f\u6301no-blocksocket\u3002\u5728\u8fd9\u79cd\u6a21\u5f0f\u4e0b\uff0c\u5f53\u63cf\u8ff0\u7b26\u4ece\u672a\u5c31\u7eea\u53d8\u4e3a\u5c31\u7eea\u65f6\uff0c\u5185\u6838\u901a\u8fc7epoll\u544a\u8bc9\u4f60\u3002\u7136\u540e\u5b83\u4f1a\u5047\u8bbe\u4f60\u77e5\u9053\u6587\u4ef6\u63cf\u8ff0\u7b26\u5df2\u7ecf\u5c31\u7eea\uff0c\u5e76\u4e14\u4e0d\u4f1a\u518d\u4e3a\u90a3\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53d1\u9001\u66f4\u591a\u7684\u5c31\u7eea\u901a\u77e5\uff0c\u76f4\u5230\u4f60\u505a\u4e86\u67d0\u4e9b\u64cd\u4f5c\u5bfc\u81f4\u90a3\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0d\u518d\u4e3a\u5c31\u7eea\u72b6\u6001\u4e86(<strong>\u6bd4\u5982\uff0c\u4f60\u5728\u53d1\u9001\uff0c\u63a5\u6536\u6216\u8005\u63a5\u6536\u8bf7\u6c42\uff0c\u6216\u8005\u53d1\u9001\u63a5\u6536\u7684\u6570\u636e\u5c11\u4e8e\u4e00\u5b9a\u91cf\u65f6\u5bfc\u81f4\u4e86\u4e00\u4e2aEWOULDBLOCK\u9519\u8bef\uff09\u3002\u4f46\u662f\u8bf7\u6ce8\u610f\uff0c\u5982\u679c\u4e00\u76f4\u4e0d<\/strong>\u5bf9\u8fd9\u4e2afd\u4f5cIO\u64cd\u4f5c(\u4ece\u800c\u5bfc\u81f4\u5b83\u518d\u6b21\u53d8\u6210\u672a\u5c31\u7eea)\uff0c\u5185\u6838\u4e0d\u4f1a\u53d1\u9001\u66f4\u591a\u7684\u901a\u77e5(only once),\u4e0d\u8fc7\u5728TCP\u534f\u8bae\u4e2d\uff0cET\u6a21\u5f0f\u7684\u52a0\u901f\u6548\u7528\u4ecd\u9700\u8981\u66f4\u591a\u7684benchmark\u786e\u8ba4\uff08\u8fd9\u53e5\u8bdd\u4e0d\u7406\u89e3\uff09\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u5f53\u4f7f\u7528epoll\u7684ET\u6a21\u578b(epoll\u7684\u975e\u9ed8\u8ba4\u5de5\u4f5c\u65b9\u5f0f)\u6765\u5de5\u4f5c\u65f6\uff0c\u5f53\u4ea7\u751f\u4e86\u4e00\u4e2aEPOLLIN\u4e8b\u4ef6\u540e\uff0c<br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8bfb\u6570\u636e\u7684\u65f6\u5019\u9700\u8981\u8003\u8651\u7684\u662f\u5f53recv()\u8fd4\u56de\u7684\u5927\u5c0f\u5982\u679c\u7b49\u4e8e\u8981\u6c42\u7684\u5927\u5c0f\uff0c\u5373sizeof(buf)\uff0c\u90a3\u4e48\u5f88\u6709\u53ef\u80fd\u662f\u7f13\u51b2\u533a\u8fd8\u6709\u6570\u636e\u672a\u8bfb\u5b8c\uff0c\u4e5f\u610f\u5473\u7740\u8be5\u6b21\u4e8b\u4ef6\u8fd8\u6ca1\u6709\u5904\u7406\u5b8c\uff0c\u6240\u4ee5\u8fd8\u9700\u8981\u518d\u6b21\u8bfb\u53d6\uff1a<\/p>\n<pre class=\"lang:c++ decode:true \">while(rs)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ET\u6a21\u578b\r\n{\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0buflen = recv(activeevents[i].data.fd, buf, sizeof(buf), 0);\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if(buflen &lt; 0)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0{\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u7531\u4e8e\u662f\u975e\u963b\u585e\u7684\u6a21\u5f0f,\u6240\u4ee5\u5f53errno\u4e3aEAGAIN\u65f6,\u8868\u793a\u5f53\u524d\u7f13\u51b2\u533a\u5df2\u65e0\u6570\u636e\u53ef\u8bfb\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u5728\u8fd9\u91cc\u5c31\u5f53\u4f5c\u662f\u8be5\u6b21\u4e8b\u4ef6\u5df2\u5904\u7406\u5904.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if(errno== EAGAIN || errno == EINT) \u00a0\/\/\u5373\u5f53buflen&lt;0\u4e14errno=EAGAIN\u65f6\uff0c\u8868\u793a\u6ca1\u6709\u6570\u636e\u4e86\u3002(\u8bfb\/\u5199\u90fd\u662f\u8fd9\u6837)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0break;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0else\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u771f\u7684\u5931\u8d25\u4e86\u3002\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0elseif(buflen == 0)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0{\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u8fd9\u91cc\u8868\u793a\u5bf9\u7aef\u7684socket\u5df2\u6b63\u5e38\u5173\u95ed.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if(buflen== sizeof(buf)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0rs = 1;\u00a0\u00a0\u00a0 \/\/\u9700\u8981\u518d\u6b21\u8bfb\u53d6(\u6709\u53ef\u80fd\u662f\u56e0\u4e3a\u6570\u636e\u7f13\u51b2\u533abuf\u592a\u5c0f\uff0c\u6240\u4ee5\u6570\u636e\u6ca1\u6709\u8bfb\u5b8c)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0else\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0rs =0;\u00a0\u00a0\u00a0\u00a0\/\/\u4e0d\u9700\u8981\u518d\u6b21\u8bfb\u53d6(\u5f53buflen\r\n}<\/pre>\n<p>&nbsp;<\/p>\n<\/div>\n<div>\u00a0<wbr \/><\/div>\n<div>\u00a0<wbr \/><\/div>\n<div><strong>\u975e\u5e38\u91cd\u8981::<\/strong><br \/>\n<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u8fd8\u6709\uff0c\u5047\u5982\u53d1\u9001\u7aef\u6d41\u91cf\u5927\u4e8e\u63a5\u6536\u7aef\u7684\u6d41\u91cf(\u610f\u601d\u662fepoll\u6240\u5728\u7684\u7a0b\u5e8f\u8bfb\u6bd4\u8f6c\u53d1\u7684socket\u8981\u5feb),\u7531\u4e8e\u662f\u975e\u963b\u585e\u7684socket,\u90a3\u4e48send()\u51fd\u6570\u867d\u7136\u8fd4\u56de,\u4f46\u5b9e\u9645\u7f13\u51b2\u533a\u7684\u6570\u636e\u5e76\u672a\u771f\u6b63\u53d1\u7ed9\u63a5\u6536\u7aef,\u8fd9\u6837\u4e0d\u65ad\u7684\u8bfb\u548c\u53d1\uff0c\u5f53\u7f13\u51b2\u533a\u6ee1\u540e\u4f1a\u4ea7\u751fEAGAIN\u9519\u8bef(\u53c2\u8003mansend),\u540c\u65f6,\u4e0d\u7406\u4f1a\u8fd9\u6b21\u8bf7\u6c42\u53d1\u9001\u7684\u6570\u636e.\u6240\u4ee5,<\/div>\n<div>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u00a0<wbr \/>\u9700\u8981\u5c01\u88c5socket_send()\u7684\u51fd\u6570\u7528\u6765\u5904\u7406\u8fd9\u79cd\u60c5\u51b5,\u8be5\u51fd\u6570\u4f1a\u5c3d\u91cf\u5c06\u6570\u636e\u5199\u5b8c\u518d\u8fd4\u56de\uff0c\u8fd4\u56de-1\u8868\u793a\u51fa\u9519\u3002\u5728socket_send()\u5185\u90e8,\u5f53\u5199\u7f13\u51b2\u5df2\u6ee1(send()\u8fd4\u56de-1,\u4e14errno\u4e3aEAGAIN),\u90a3\u4e48\u4f1a\u7b49\u5f85\u540e\u518d\u91cd\u8bd5.\u8fd9\u79cd\u65b9\u5f0f\u5e76\u4e0d\u5f88\u5b8c\u7f8e,\u5728\u7406\u8bba\u4e0a\u53ef\u80fd\u4f1a\u957f\u65f6\u95f4\u7684\u963b\u585e\u5728socket_send()\u5185\u90e8,\u4f46\u6682\u6ca1\u6709\u66f4\u597d\u7684\u529e\u6cd5.<\/div>\n<div>\n<p>\u8fd9\u79cd\u65b9\u6cd5\u7c7b\u4f3c\u4e8ereadn\u548cwriten\u7684\u5c01\u88c5(\u81ea\u5df1\u5199\u8fc7\uff0c\u5728\u300aUNIX\u73af\u5883\u9ad8\u7ea7\u7f16\u7a0b\u300b\u4e2d\u4e5f\u6709\u4ecb\u7ecd)<\/p>\n<pre class=\"lang:c++ decode:true \">ssize_t socket_send(int sockfd, const char* buffer, size_tbuflen)\r\n{\r\n\u00a0\u00a0 ssize_t tmp;\r\n\u00a0 size_t total = buflen;\r\n\u00a0 const char *p = buffer;\r\n\r\n\u00a0 while(1)\r\n\u00a0 {\r\n\u00a0\u00a0\u00a0 tmp =send(sockfd, p, total, 0);\r\n\u00a0\u00a0\u00a0 if(tmp &lt;0)\r\n\u00a0\u00a0\u00a0 {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ \u5f53send\u6536\u5230\u4fe1\u53f7\u65f6,\u53ef\u4ee5\u7ee7\u7eed\u5199,\u4f46\u8fd9\u91cc\u8fd4\u56de-1.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0if(errno == EINTR)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return -1;\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u5f53socket\u662f\u975e\u963b\u585e\u65f6,\u5982\u8fd4\u56de\u6b64\u9519\u8bef,\u8868\u793a\u5199\u7f13\u51b2\u961f\u5217\u5df2\u6ee1,\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u5728\u8fd9\u91cc\u505a\u5ef6\u65f6\u540e\u518d\u91cd\u8bd5.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0if(errno == EAGAIN)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0{\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0usleep(1000);\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0continue;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0}\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0return -1;\r\n\u00a0\u00a0\u00a0 }\r\n\r\n\u00a0\u00a0\u00a0if((size_t)tmp == total)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0return buflen;\r\n\r\n\u00a0\u00a0\u00a0 total -=tmp;\r\n\u00a0\u00a0\u00a0 p +=tmp;\r\n\u00a0 }\r\n\r\n\u00a0 return tmp;\r\n}<\/pre>\n<p>\u603b\u7ed3\uff1a<\/p>\n<div class=\"dp-highlighter bg_cpp\">\n<div class=\"bar\"><\/div>\n<ol class=\"dp-cpp\" start=\"1\">\n<li class=\"alt\">man\u4e2d\u7ed9\u51fa\u4e86epoll\u7684\u7528\u6cd5\uff0cexample\u7a0b\u5e8f\u5982\u4e0b\uff1a<\/li>\n<li class=\"\">\n<pre class=\"lang:c++ decode:true \">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0for(;;)\u00a0{\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0nfds\u00a0=\u00a0epoll_wait(kdpfd,\u00a0events,\u00a0maxevents,\u00a0-1);\u00a0\u00a0\r\n\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0for(n\u00a0=\u00a00;\u00a0n\u00a0&lt;\u00a0nfds;\u00a0++n)\u00a0{\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if(events[n].data.fd\u00a0==\u00a0listener)\u00a0{\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0client\u00a0=\u00a0accept(listener,\u00a0(struct\u00a0sockaddr\u00a0*)\u00a0&amp;local,\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0&amp;addrlen);\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if(client\u00a0&lt;\u00a00){\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0perror(\"accept\");\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0continue;\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0setnonblocking(client);\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ev.events\u00a0=\u00a0EPOLLIN\u00a0|\u00a0EPOLLET;\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ev.data.fd\u00a0=\u00a0client;\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(epoll_ctl(kdpfd,\u00a0EPOLL_CTL_ADD,\u00a0client,\u00a0&amp;ev)\u00a0&lt;\u00a00)\u00a0{\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0fprintf(stderr,\u00a0\"epoll\u00a0set\u00a0insertion\u00a0error:\u00a0fd=%d\\n\",\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0client);\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return\u00a0-1;\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0else\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0do_use_fd(events[n].data.fd);\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/pre>\n<p>&nbsp;<\/li>\n<\/ol>\n<div><embed src=\"http:\/\/static.blog.csdn.net\/scripts\/ZeroClipboard\/ZeroClipboard.swf\" type=\"application\/x-shockwave-flash\" width=\"0\" height=\"0\" data-mce-fragment=\"1\"><\/embed><\/div>\n<\/div>\n<p>\u6b64\u65f6\u4f7f\u7528\u7684\u662fET\u6a21\u5f0f\uff0c\u5373\uff0c\u8fb9\u6cbf\u89e6\u53d1\uff0c\u7c7b\u4f3c\u4e8e\u7535\u5e73\u89e6\u53d1\uff0cepoll\u4e2d\u7684\u8fb9\u6cbf\u89e6\u53d1\u7684\u610f\u601d\u662f\u53ea\u5bf9\u65b0\u5230\u7684\u6570\u636e\u8fdb\u884c\u901a\u77e5\uff0c\u800c\u5185\u6838\u7f13\u51b2\u533a\u4e2d\u5982\u679c\u662f\u65e7\u6570\u636e\u5219\u4e0d\u8fdb\u884c\u901a\u77e5\uff0c\u6240\u4ee5\u5728do_use_fd\u51fd\u6570\u4e2d\u5e94\u8be5\u4f7f\u7528\u5982\u4e0b\u5faa\u73af\uff0c\u624d\u80fd\u5c06\u5185\u6838\u7f13\u51b2\u533a\u4e2d\u7684\u6570\u636e\u8bfb\u5b8c\u3002<\/p>\n<div class=\"dp-highlighter bg_cpp\">\n<div class=\"bar\"><\/div>\n<ol class=\"dp-cpp\" start=\"1\">\n<li class=\"alt\">\n<pre class=\"lang:c++ decode:true \">while\u00a0(1)\u00a0{\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0len\u00a0=\u00a0recv(*******);\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(len\u00a0==\u00a0-1)\u00a0{\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if(errno\u00a0==\u00a0EAGAIN)\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0break;\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0perror(\"recv\");\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0break;\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0do\u00a0something\u00a0with\u00a0the\u00a0recved\u00a0data........\u00a0\u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/pre>\n<p>&nbsp;<\/li>\n<\/ol>\n<\/div>\n<p>\u5728\u4e0a\u9762\u4f8b\u5b50\u4e2d\u6ca1\u6709\u8bf4\u660e\u5bf9\u4e8elisten socket fd\u8be5\u5982\u4f55\u5904\u7406\uff0c\u6709\u7684\u65f6\u5019\u4f1a\u4f7f\u7528\u4e24\u4e2a\u7ebf\u7a0b\uff0c\u4e00\u4e2a\u7528\u6765\u76d1\u542caccept\u53e6\u4e00\u4e2a\u7528\u6765\u76d1\u542cepoll_wait\uff0c\u5982\u679c\u662f\u8fd9\u6837\u4f7f\u7528\u7684\u8bdd\uff0c\u5219listen socket fd\u4f7f\u7528\u9ed8\u8ba4\u7684\u963b\u585e\u65b9\u5f0f\u5c31\u884c\u4e86\uff0c\u800c\u5982\u679cepoll_wait\u548caccept\u5904\u4e8e\u4e00\u4e2a\u7ebf\u7a0b\u4e2d\uff0c\u5373\uff0c\u5168\u90e8\u7531epoll_wait\u8fdb\u884c\u76d1\u542c\uff0c\u5219\uff0c\u9700\u5c06listen socket fd\u4e5f\u8bbe\u7f6e\u6210\u975e\u963b\u585e\u7684\uff0c\u8fd9\u6837\uff0c\u5bf9accept\u4e5f\u5e94\u8be5\u4f7f\u7528while\u5305\u8d77\u6765\uff08\u7c7b\u4f3c\u4e8e\u4e0a\u9762\u7684recv\uff09\uff0c\u56e0\u4e3a\uff0cepoll_wait\u8fd4\u56de\u65f6\u53ea\u662f\u8bf4\u6709\u8fde\u63a5\u5230\u6765\u4e86\uff0c\u5e76\u6ca1\u6709\u8bf4\u6709\u51e0\u4e2a\u8fde\u63a5\uff0c\u800c\u4e14\u5728ET\u6a21\u5f0f\u4e0bepoll_wait\u4e0d\u4f1a\u518d\u56e0\u4e3a\u4e0a\u4e00\u6b21\u7684\u8fde\u63a5\u8fd8\u6ca1\u8bfb\u5b8c\u800c\u8fd4\u56de\uff0c\u8fd9\u79cd\u60c5\u51b5\u786e\u5b9e\u5b58\u5728\uff0c\u6211\u56e0\u4e3a\u8fd9\u4e2a\u95ee\u9898\u800c\u8017\u8d39\u4e86\u4e00\u5929\u591a\u7684\u65f6\u95f4\uff0c\u8fd9\u91cc\u9700\u8981\u8bf4\u660e\u7684\u662f\uff0c\u6bcf\u8c03\u7528\u4e00\u6b21accept\u5c06\u4ece\u5185\u6838\u4e2d\u7684\u5df2\u8fde\u63a5\u961f\u5217\u4e2d\u7684\u961f\u5934\u8bfb\u53d6\u4e00\u4e2a\u8fde\u63a5\uff0c\u56e0\u4e3a\u5728\u5e76\u53d1\u8bbf\u95ee\u7684\u73af\u5883\u4e0b\uff0c\u6709\u53ef\u80fd\u6709\u591a\u4e2a\u8fde\u63a5\u201c\u540c\u65f6\u201d\u5230\u8fbe\uff0c\u800cepoll_wait\u53ea\u8fd4\u56de\u4e86\u4e00\u6b21\u3002<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u5728Linux\u7684\u7f51\u7edc\u7f16\u7a0b\u4e2d\uff0c\u5f88\u957f&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[7,9],"tags":[],"_links":{"self":[{"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/posts\/128"}],"collection":[{"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/comments?post=128"}],"version-history":[{"count":9,"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/posts\/128\/revisions"}],"predecessor-version":[{"id":137,"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/posts\/128\/revisions\/137"}],"wp:attachment":[{"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/media?parent=128"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/categories?post=128"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.sourcecool.com\/index.php\/wp-json\/wp\/v2\/tags?post=128"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}