{"id":6501,"date":"2024-08-21T16:35:06","date_gmt":"2024-08-21T08:35:06","guid":{"rendered":"https:\/\/t.n-years.com\/?p=6501"},"modified":"2024-08-21T16:35:06","modified_gmt":"2024-08-21T08:35:06","slug":"epoll-%e4%ba%8b%e4%bb%b6%e9%a9%b1%e5%8a%a8%e6%9c%ba%e5%88%b6%e7%9a%84%e4%bc%98%e7%82%b9","status":"publish","type":"post","link":"https:\/\/t.n-years.com\/?p=6501","title":{"rendered":"epoll \u4e8b\u4ef6\u9a71\u52a8\u673a\u5236\u7684\u4f18\u70b9"},"content":{"rendered":"<blockquote>\n<p>\u975e\u539f\u521b\u3001ChatGPT \u95ee\u7b54\u751f\u6210<\/p>\n<\/blockquote>\n<p><code>epoll<\/code> \u662f Linux \u63d0\u4f9b\u7684\u4e00\u79cd\u9ad8\u6548\u7684 I\/O \u4e8b\u4ef6\u901a\u77e5\u673a\u5236\uff0c\u4e0e\u65e9\u671f\u7684 <code>select<\/code> \u548c <code>poll<\/code> \u7cfb\u7edf\u8c03\u7528\u76f8\u6bd4\uff0c<code>epoll<\/code> \u5728\u6027\u80fd\u548c\u8d44\u6e90\u5229\u7528\u4e0a\u6709\u663e\u8457\u4f18\u52bf\uff0c\u7279\u522b\u662f\u5728\u9ad8\u5e76\u53d1\u7684\u573a\u666f\u4e2d\u3002\u4ee5\u4e0b\u662f <code>epoll<\/code> \u7684\u4e3b\u8981\u4f18\u70b9\uff1a<\/p>\n<h3>1. <strong>\u9ad8\u6548\u7684\u4e8b\u4ef6\u901a\u77e5\u673a\u5236<\/strong><\/h3>\n<ul>\n<li><strong>\u8fb9\u7f18\u89e6\u53d1\uff08Edge-Triggered\uff09\u548c\u6c34\u5e73\u89e6\u53d1\uff08Level-Triggered\uff09<\/strong>\uff1a<code>epoll<\/code> \u652f\u6301\u4e24\u79cd\u89e6\u53d1\u6a21\u5f0f\uff0c\u5176\u4e2d\u8fb9\u7f18\u89e6\u53d1\u53ea\u5728\u72b6\u6001\u53d1\u751f\u53d8\u5316\u65f6\u901a\u77e5\uff0c\u8fd9\u51cf\u5c11\u4e86\u91cd\u590d\u5904\u7406\u76f8\u540c\u4e8b\u4ef6\u7684\u5f00\u9500\uff0c\u975e\u5e38\u9002\u5408\u9ad8\u5e76\u53d1\u5e94\u7528\u3002<\/li>\n<\/ul>\n<h3>2. <strong>O(1) \u590d\u6742\u5ea6<\/strong><\/h3>\n<ul>\n<li>\u4e0e <code>select<\/code> \u548c <code>poll<\/code> \u4e0d\u540c\uff0c<code>epoll<\/code> \u7684\u6027\u80fd\u4e0d\u4f1a\u968f\u7740\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\u589e\u52a0\u800c\u4e0b\u964d\u3002<code>select<\/code> \u548c <code>poll<\/code> \u90fd\u9700\u8981\u5728\u6bcf\u6b21\u8c03\u7528\u65f6\u904d\u5386\u6574\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\uff0c\u5bfc\u81f4 O(n) \u7684\u65f6\u95f4\u590d\u6742\u5ea6\uff0c\u800c <code>epoll<\/code> \u901a\u8fc7\u5185\u6838\u7ef4\u62a4\u7684\u9ad8\u6548\u6570\u636e\u7ed3\u6784\uff08\u5982\u7ea2\u9ed1\u6811\uff09\u5b9e\u73b0\u4e86 O(1) \u7684\u4e8b\u4ef6\u901a\u77e5\u590d\u6742\u5ea6\u3002<\/li>\n<\/ul>\n<h3>3. <strong>\u652f\u6301\u5927\u91cf\u6587\u4ef6\u63cf\u8ff0\u7b26<\/strong><\/h3>\n<ul>\n<li><code>select<\/code> \u901a\u5e38\u6709\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\u7684\u9650\u5236\uff08\u4e00\u822c\u4e3a 1024\uff09\uff0c\u800c <code>epoll<\/code> \u6ca1\u6709\u8fd9\u79cd\u9650\u5236\uff0c\u53ef\u4ee5\u8f7b\u677e\u7ba1\u7406\u6210\u5343\u4e0a\u4e07\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u9002\u7528\u4e8e\u9ad8\u5e76\u53d1\u670d\u52a1\u5668\u7684\u9700\u6c42\u3002<\/li>\n<\/ul>\n<h3>4. <strong>\u6301\u4e45\u7684\u4e8b\u4ef6\u76d1\u63a7<\/strong><\/h3>\n<ul>\n<li>\u4f7f\u7528 <code>select<\/code> \u6216 <code>poll<\/code> \u65f6\uff0c\u6bcf\u6b21\u8c03\u7528\u90fd\u9700\u8981\u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u5217\u8868\u4f20\u9012\u7ed9\u5185\u6838\uff0c\u91cd\u65b0\u8fdb\u884c\u76d1\u63a7\u3002\u800c <code>epoll<\/code> \u901a\u8fc7 <code>epoll_ctl<\/code> \u8fdb\u884c\u4e00\u6b21\u6ce8\u518c\u540e\uff0c\u5c31\u53ef\u4ee5\u6301\u4e45\u76d1\u63a7\u8fd9\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u65e0\u9700\u91cd\u590d\u4f20\u9012\uff0c\u51cf\u5c11\u4e86\u7cfb\u7edf\u8c03\u7528\u5f00\u9500\u3002<\/li>\n<\/ul>\n<h3>5. <strong>\u5185\u5b58\u590d\u5236\u5f00\u9500\u4f4e<\/strong><\/h3>\n<ul>\n<li><code>select<\/code> \u548c <code>poll<\/code> \u90fd\u9700\u8981\u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u4ece\u7528\u6237\u6001\u590d\u5236\u5230\u5185\u6838\u6001\uff0c\u5e76\u5728\u8c03\u7528\u7ed3\u675f\u540e\u518d\u590d\u5236\u56de\u7528\u6237\u6001\uff0c\u8fd9\u5728\u5927\u91cf\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u60c5\u51b5\u4e0b\u9020\u6210\u8f83\u5927\u5f00\u9500\u3002<code>epoll<\/code> \u4f7f\u7528\u4e8b\u4ef6\u901a\u77e5\u7684\u65b9\u5f0f\uff0c\u51cf\u5c11\u4e86\u8fd9\u79cd\u9891\u7e41\u7684\u5185\u5b58\u590d\u5236\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<h3>6. <strong>\u826f\u597d\u7684\u6269\u5c55\u6027<\/strong><\/h3>\n<ul>\n<li><code>epoll<\/code> \u7684\u8bbe\u8ba1\u4f7f\u5176\u5728\u5904\u7406\u5927\u91cf I\/O \u4e8b\u4ef6\u65f6\u5177\u6709\u826f\u597d\u7684\u6269\u5c55\u6027\uff0c\u8fd9\u5bf9\u4e8e\u9700\u8981\u652f\u6301\u9ad8\u5e76\u53d1\u8fde\u63a5\u7684\u7f51\u7edc\u670d\u52a1\u5668\uff08\u5982 Nginx\u3001Redis\uff09\u81f3\u5173\u91cd\u8981\u3002\u5b83\u901a\u8fc7\u4f7f\u7528\u56de\u8c03\u548c\u5185\u6838\u4f18\u5316\uff0c\u5b9e\u73b0\u4e86\u9ad8\u5e76\u53d1\u4e0b\u7684\u4f4e\u5ef6\u8fdf\u3002<\/li>\n<\/ul>\n<h3>7. <strong>\u5185\u6838\u652f\u6301\u7684\u4e8b\u4ef6\u961f\u5217<\/strong><\/h3>\n<ul>\n<li><code>epoll<\/code> \u4f7f\u7528\u4e00\u4e2a\u7531\u5185\u6838\u7ba1\u7406\u7684\u4e8b\u4ef6\u961f\u5217\uff0c\u7528\u6237\u7a0b\u5e8f\u53ea\u9700\u8bfb\u53d6\u8fd9\u4e2a\u961f\u5217\u4e2d\u7684\u4e8b\u4ef6\u5373\u53ef\u3002\u4e8b\u4ef6\u53d1\u751f\u65f6\uff0c\u5185\u6838\u4f1a\u5c06\u4e8b\u4ef6\u52a0\u5165\u961f\u5217\uff0c\u800c\u7528\u6237\u6001\u53ea\u9700\u8c03\u7528 <code>epoll_wait<\/code> \u7b49\u5f85\u5373\u53ef\u3002\u8fd9\u79cd\u673a\u5236\u51cf\u5c11\u4e86\u7528\u6237\u6001\u4e0e\u5185\u6838\u6001\u7684\u9891\u7e41\u4ea4\u4e92\uff0c\u63d0\u9ad8\u4e86\u6548\u7387\u3002<\/li>\n<\/ul>\n<h3>8. <strong>\u9002\u7528\u957f\u8fde\u63a5\u573a\u666f<\/strong><\/h3>\n<ul>\n<li>\u5728\u9ad8\u5e76\u53d1\u7684\u957f\u8fde\u63a5\uff08\u5982 WebSocket\u3001\u804a\u5929\u670d\u52a1\u5668\uff09\u573a\u666f\u4e2d\uff0c<code>epoll<\/code> \u7684\u6301\u4e45\u76d1\u63a7\u548c\u4e8b\u4ef6\u901a\u77e5\u673a\u5236\u975e\u5e38\u9ad8\u6548\uff0c\u53ef\u4ee5\u5e94\u5bf9\u5927\u91cf\u7684\u7a7a\u95f2\u8fde\u63a5\u800c\u4e0d\u9020\u6210\u6027\u80fd\u4e0b\u964d\u3002<\/li>\n<\/ul>\n<h3>\u603b\u7ed3<\/h3>\n<p><code>epoll<\/code> \u7684\u4f18\u52bf\u4e3b\u8981\u4f53\u73b0\u5728\u9ad8\u6548\u7684\u4e8b\u4ef6\u5904\u7406\u3001\u4f18\u826f\u7684\u6269\u5c55\u6027\u3001\u4f4e\u7cfb\u7edf\u8c03\u7528\u5f00\u9500\u3001\u652f\u6301\u5927\u89c4\u6a21\u5e76\u53d1\u8fde\u63a5\u7b49\u65b9\u9762\u3002\u4e0e <code>select<\/code> \u548c <code>poll<\/code> \u76f8\u6bd4\uff0c<code>epoll<\/code> \u66f4\u9002\u5408\u5728 Linux \u7cfb\u7edf\u4e0b\u6784\u5efa\u9ad8\u5e76\u53d1\u7684\u7f51\u7edc\u670d\u52a1\uff0c\u662f Nginx\u3001Redis \u7b49\u77e5\u540d\u9ad8\u6027\u80fd\u670d\u52a1\u5668\u7684\u91cd\u8981\u6280\u672f\u652f\u6491\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u975e\u539f\u521b\u3001ChatGPT \u95ee\u7b54\u751f\u6210 epoll \u662f Linux \u63d0\u4f9b\u7684\u4e00\u79cd\u9ad8\u6548\u7684 I\/O \u4e8b\u4ef6\u901a\u77e5\u673a\u5236\uff0c\u4e0e\u65e9\u671f\u7684&#8230; <\/p>\n<div class=\"read-more navbutton\"><a href=\"https:\/\/t.n-years.com\/?p=6501\">\u9605\u8bfb\u66f4\u591a<i class=\"fa fa-angle-double-right\"><\/i><\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[123],"tags":[],"class_list":["post-6501","post","type-post","status-publish","format-standard","hentry","category-123"],"_links":{"self":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6501","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6501"}],"version-history":[{"count":1,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6501\/revisions"}],"predecessor-version":[{"id":6502,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6501\/revisions\/6502"}],"wp:attachment":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6501"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6501"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6501"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}