{"id":16349,"date":"2024-09-12T16:10:20","date_gmt":"2024-09-12T08:10:20","guid":{"rendered":"https:\/\/92it.top\/?p=16349"},"modified":"2024-09-12T16:20:00","modified_gmt":"2024-09-12T08:20:00","slug":"%e4%b8%80%e6%96%87%e8%ae%a9%e4%bd%a0%e5%bd%bb%e5%ba%95%e6%98%8e%e7%99%bd%ef%bc%8c%e7%90%86%e8%a7%a3i-o%e5%a4%9a%e8%b7%af%e5%a4%8d%e7%94%a8","status":"publish","type":"post","link":"https:\/\/92it.top\/?p=16349","title":{"rendered":"\u4e00\u6587\u8ba9\u4f60\u5f7b\u5e95\u660e\u767d\uff0c\u7406\u89e3I\/O\u591a\u8def\u590d\u7528"},"content":{"rendered":"\n<p>\u5728\u8bb2\u89e3\u8be5\u6280\u672f\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u9884\u4e60\u4e00\u4e0b\u6587\u4ef6\u4ee5\u53ca\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/p>\n\n\n\n<p><strong>\u4ec0\u4e48\u662f\u6587\u4ef6<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u7a0b\u5e8f\u5458\u4f7f\u7528I\/O\u6700\u7ec8\u90fd\u9003\u4e0d\u8fc7\u6587\u4ef6\u8fd9\u4e2a\u6982\u5ff5\u3002<\/p>\n\n\n\n<p>\u5728Linux\u4e16\u754c\u4e2d\u6587\u4ef6\u662f\u4e00\u4e2a\u5f88\u7b80\u5355\u7684\u6982\u5ff5\uff0c\u4f5c\u4e3a\u7a0b\u5e8f\u5458\u6211\u4eec\u53ea\u9700\u8981\u5c06\u5176\u7406\u89e3\u4e3a\u4e00\u4e2aN byte\u7684<strong>\u5e8f\u5217<\/strong>\u5c31\u53ef\u4ee5\u4e86\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">b1, b2, b3, b4, ....... bN<\/pre>\n\n\n\n<p>\u5b9e\u9645\u4e0a\u6240\u6709\u7684I\/O\u8bbe\u5907\u90fd\u88ab\u62bd\u8c61\u4e3a\u4e86\u6587\u4ef6\u8fd9\u4e2a\u6982\u5ff5\uff0c\u4e00\u5207\u7686\u6587\u4ef6\uff0cEverything is File\uff0c\u78c1\u76d8\u3001\u7f51\u7edc\u6570\u636e\u3001\u7ec8\u7aef\uff0c\u751a\u81f3\u8fdb\u7a0b\u95f4\u901a\u4fe1\u5de5\u5177\u7ba1\u9053pipe\u7b49\u90fd\u88ab\u5f53\u505a\u6587\u4ef6\u5bf9\u5f85\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"490\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-1024x490.png\" alt=\"\" class=\"wp-image-16350\" style=\"width:534px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-1024x490.png 1024w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-300x144.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-768x368.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-830x397.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-230x110.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-350x168.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111-480x230.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-111.png 1416w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<p>\u6240\u6709\u7684I\/O\u64cd\u4f5c\u4e5f\u90fd\u53ef\u4ee5\u901a\u8fc7\u6587\u4ef6\u8bfb\u5199\u6765\u5b9e\u73b0\uff0c<strong>\u8fd9\u4e00\u975e\u5e38\u4f18\u96c5\u7684\u62bd\u8c61\u53ef\u4ee5\u8ba9\u7a0b\u5e8f\u5458\u4f7f\u7528\u4e00\u5957\u63a5\u53e3\u5c31\u80fd\u5bf9\u6240\u6709\u5916\u8bbeI\/O\u64cd\u4f5c<\/strong>\u3002<\/p>\n\n\n\n<p>\u5e38\u7528\u7684I\/O\u64cd\u4f5c\u63a5\u53e3\u4e00\u822c\u6709\u4ee5\u4e0b\u51e0\u7c7b\uff1a<\/p>\n\n\n\n<ul>\n<li>\u6253\u5f00\u6587\u4ef6\uff0copen<\/li>\n\n\n\n<li>\u6539\u53d8\u8bfb\u5199\u4f4d\u7f6e\uff0cseek<\/li>\n\n\n\n<li>\u6587\u4ef6\u8bfb\u5199\uff0cread\u3001write<\/li>\n\n\n\n<li>\u5173\u95ed\u6587\u4ef6\uff0cclose<\/li>\n<\/ul>\n\n\n\n<p>\u7a0b\u5e8f\u5458\u901a\u8fc7\u8fd9\u51e0\u4e2a\u63a5\u53e3\u51e0\u4e4e\u53ef\u4ee5\u5b9e\u73b0\u6240\u6709I\/O\u64cd\u4f5c\uff0c\u8fd9\u5c31\u662f\u6587\u4ef6\u8fd9\u4e2a\u6982\u5ff5\u7684\u5f3a\u5927\u4e4b\u5904\u3002<\/p>\n\n\n\n<p><strong>\u6587\u4ef6\u63cf\u8ff0\u7b26<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u8981\u60f3\u8fdb\u884cI\/O\u8bfb\u64cd\u4f5c\uff0c\u50cf\u78c1\u76d8\u6570\u636e\uff0c\u6211\u4eec\u9700\u8981\u6307\u5b9a\u4e00\u4e2abuff\u7528\u6765\u88c5\u5165\u6570\u636e\uff0c\u4e00\u822c\u90fd\u662f\u8fd9\u6837\u5199\u7684\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">read(buff);<\/pre>\n\n\n\n<p>\u4f46\u662f\u8fd9\u91cc\u6211\u4eec\u5ffd\u7565\u4e86\u4e00\u4e2a\u5173\u952e\u95ee\u9898\uff0c\u90a3\u5c31\u662f\u867d\u7136\u6211\u4eec\u6307\u5b9a\u4e86\u5f80\u54ea\u91cc\u5199\u6570\u636e\uff0c\u4f46\u662f\u6211\u4eec\u8be5\u4ece\u54ea\u91cc\u8bfb\u6570\u636e\u5462\uff1f\u4ece\u4e0a\u4e00\u8282\u4e2d\u6211\u4eec\u77e5\u9053\uff0c\u901a\u8fc7\u6587\u4ef6\u8fd9\u4e2a\u6982\u5ff5\u6211\u4eec\u80fd\u5b9e\u73b0\u51e0\u4e4e\u6240\u6709I\/O\u64cd\u4f5c\uff0c<strong>\u56e0\u6b64\u8fd9\u91cc\u5c11\u7684\u4e00\u4e2a\u4e3b\u89d2\u5c31\u662f\u6587\u4ef6<\/strong>\u3002<\/p>\n\n\n\n<p>\u90a3\u4e48\u6211\u4eec\u4e00\u822c\u90fd\u600e\u6837\u4f7f\u7528\u6587\u4ef6\u5462\uff1f<\/p>\n\n\n\n<p>\u5982\u679c\u5468\u672b\u4f60\u53bb\u6bd4\u8f83\u706b\u7684\u9910\u5385\u5403\u996d\u5e94\u8be5\u4f1a\u6709\u4f53\u4f1a\uff0c\u4e00\u822c\u5468\u672b\u4eba\u6c14\u9ad8\u7684\u9910\u5385\u90fd\u4f1a\u6392\u961f\uff0c\u7136\u540e\u670d\u52a1\u5458\u4f1a\u7ed9\u4f60\u4e00\u4e2a\u6392\u961f\u5e8f\u53f7\uff0c\u901a\u8fc7\u8fd9\u4e2a\u5e8f\u53f7\u670d\u52a1\u5458\u5c31\u80fd\u627e\u5230\u4f60\uff0c\u8fd9\u91cc\u7684\u597d\u5904\u5c31\u662f\u670d\u52a1\u5458\u65e0\u9700\u8bb0\u4f4f\u4f60\u662f\u8c01\u3001\u4f60\u7684\u540d\u5b57\u662f\u4ec0\u4e48\u3001\u6765\u81ea\u54ea\u91cc\u3001\u559c\u597d\u662f\u4ec0\u4e48\u3001\u662f\u4e0d\u662f\u4fdd\u62a4\u73af\u5883\u7231\u62a4\u5c0f\u52a8\u7269\u7b49\u7b49\uff0c\u8fd9\u91cc\u7684\u5173\u952e\u70b9\u5c31\u662f<strong>\u670d\u52a1\u5458\u5bf9\u4f60\u4e00\u65e0\u6240\u77e5\uff0c\u4f46\u4f9d\u7136\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e2a\u53f7\u7801\u5c31\u80fd\u627e\u5230\u4f60<\/strong>\u3002<\/p>\n\n\n\n<p>\u540c\u6837\u7684\uff0c\u5728Linux\u4e16\u754c\u8981\u60f3\u4f7f\u7528\u6587\u4ef6\uff0c\u6211\u4eec\u4e5f\u9700\u8981\u501f\u52a9\u4e00\u4e2a\u53f7\u7801\uff0c\u8fd9\u4e2a\u53f7\u7801\u5c31\u88ab\u79f0\u4e3a\u4e86\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c<strong>file descriptors<\/strong>\uff0c\u5728Linux\u4e16\u754c\u4e2d\u9f0e\u9f0e\u5927\u540d\uff0c\u5176\u9053\u7406\u548c\u4e0a\u9762\u90a3\u4e2a\u6392\u961f\u53f7\u7801\u4e00\u6837\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\uff0c\u6587\u4ef6\u63cf\u8ff0\u4ec5\u4ec5\u5c31\u662f\u4e00\u4e2a\u6570\u5b57\u800c\u5df2\uff0c\u4f46\u662f\u901a\u8fc7\u8fd9\u4e2a\u6570\u5b57\u6211\u4eec\u53ef\u4ee5\u64cd\u4f5c\u4e00\u4e2a\u6253\u5f00\u7684\u6587\u4ef6\uff0c\u8fd9\u4e00\u70b9\u8981\u8bb0\u4f4f\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"941\" height=\"1024\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-941x1024.png\" alt=\"\" class=\"wp-image-16352\" style=\"width:466px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-941x1024.png 941w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-276x300.png 276w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-768x835.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-830x903.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-230x250.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-350x381.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113-480x522.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-113.png 1232w\" sizes=\"(max-width: 941px) 100vw, 941px\" \/><\/figure><\/div>\n\n\n<p><strong>\u6709\u4e86\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u8fdb\u7a0b\u53ef\u4ee5\u5bf9\u6587\u4ef6\u4e00\u65e0\u6240\u77e5<\/strong>\uff0c\u6bd4\u5982\u6587\u4ef6\u5728\u78c1\u76d8\u7684\u4ec0\u4e48\u4f4d\u7f6e\u3001\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d\u53c8\u662f\u600e\u6837\u7ba1\u7406\u7684\u7b49\u7b49\uff0c\u8fd9\u4e9b\u4fe1\u606f\u7edf\u7edf\u4ea4\u7531\u64cd\u4f5c\u7cfb\u7edf\u6253\u7406\uff0c\u8fdb\u7a0b\u65e0\u9700\u5173\u5fc3\uff0c\u64cd\u4f5c\u7cfb\u7edf\u53ea\u9700\u8981\u7ed9\u8fdb\u7a0b\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u5c31\u8db3\u591f\u4e86\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\u6211\u4eec\u6765\u5b8c\u5584\u4e0a\u8ff0\u7a0b\u5e8f\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">int fd = open(file_name); \/\/ \u83b7\u53d6\u6587\u4ef6\u63cf\u8ff0\u7b26\nread(fd, buff);<\/pre>\n\n\n\n<p>\u600e\u4e48\u6837\uff0c\u662f\u4e0d\u662f\u975e\u5e38\u7b80\u5355\u3002<\/p>\n\n\n\n<p><strong>\u6587\u4ef6\u63cf\u8ff0\u7b26\u592a\u591a\u4e86\u600e\u4e48\u529e<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u7ecf\u8fc7\u4e86\u8fd9\u4e48\u591a\u7684\u94fa\u57ab\uff0c\u7ec8\u4e8e\u8981\u5230\u9ad8\u6027\u80fd\u3001\u9ad8\u5e76\u53d1\u8fd9\u4e00\u4e3b\u9898\u4e86\u3002<\/p>\n\n\n\n<p>\u4ece\u524d\u51e0\u8282\u6211\u4eec\u77e5\u9053\uff0c\u6240\u6709I\/O\u64cd\u4f5c\u90fd\u53ef\u4ee5\u901a\u8fc7\u6587\u4ef6\u6837\u7684\u6982\u5ff5\u6765\u8fdb\u884c\uff0c\u8fd9\u5f53\u7136\u5305\u62ec\u7f51\u7edc\u901a\u4fe1\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u4f60\u6709\u4e00\u4e2aweb\u670d\u52a1\u5668\uff0c\u5f53\u4e09\u6b21\u63e1\u624b\u6210\u529f\u4ee5\u540e\uff0c\u6211\u4eec\u4f1a\u8c03\u7528accept\u6765\u83b7\u53d6\u4e00\u4e2a\u94fe\u63a5\uff0c\u8c03\u7528\u8be5\u51fd\u6570\u6211\u4eec\u540c\u6837\u4f1a\u5f97\u5230\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u901a\u8fc7\u8fd9\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u5c31\u53ef\u4ee5\u5904\u7406\u5ba2\u6237\u7aef\u53d1\u9001\u7684\u8bf7\u6c42\u5e76\u4e14\u628a\u5904\u7406\u7ed3\u679c\u53d1\u9001\u56de\u53bb\u3002\u4e5f\u5c31\u662f\u8bf4\u901a\u8fc7\u8fd9\u4e2a\u63cf\u8ff0\u7b26\u6211\u4eec\u5c31\u53ef\u4ee5\u548c\u5ba2\u6237\u7aef\u8fdb\u884c\u901a\u4fe1\u4e86\u3002<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u901a\u8fc7accept\u83b7\u53d6\u5ba2\u6237\u7aef\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\nint conn_fd = accept(...);<\/pre>\n\n\n\n<p>server\u7684\u5904\u7406\u903b\u8f91\u901a\u5e38\u662f\u8bfb\u53d6\u5ba2\u6237\u7aef\u8bf7\u6c42\u6570\u636e\uff0c\u7136\u540e\u6267\u884c\u67d0\u4e9b\u7279\u5b9a\u903b\u8f91\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">if(read(conn_fd, request_buff) > 0) {\n    do_something(request_buff);\n}<\/pre>\n\n\n\n<p>\u662f\u4e0d\u662f\u975e\u5e38\u7b80\u5355\uff0c\u7136\u800c\u4e16\u754c\u7ec8\u5f52\u662f\u590d\u6742\u7684\uff0c\u5f53\u7136\u4e5f\u4e0d\u662f\u8fd9\u4e48\u7b80\u5355\u7684\u3002<\/p>\n\n\n\n<p>\u63a5\u4e0b\u6765\u5c31\u662f\u6bd4\u8f83\u590d\u6742\u7684\u4e86\u3002<\/p>\n\n\n\n<p>\u65e2\u7136\u6211\u4eec\u7684\u4e3b\u9898\u662f\u9ad8\u5e76\u53d1\uff0c\u90a3\u4e48<strong>server\u5c31\u4e0d\u53ef\u80fd\u53ea\u548c\u4e00\u4e2a\u5ba2\u6237\u7aef\u901a\u4fe1<\/strong>\uff0c\u800c\u662f\u53ef\u80fd\u4f1a\u540c\u65f6\u548c\u6210\u5343\u4e0a\u4e07\u4e2a\u5ba2\u6237\u7aef\u8fdb\u884c\u901a\u4fe1\u3002<strong>\u8fd9\u65f6\u4f60\u9700\u8981\u5904\u7406\u4e0d\u518d\u662f\u4e00\u4e2a\u63cf\u8ff0\u7b26\u8fd9\u4e48\u7b80\u5355\uff0c\u800c\u662f\u6709\u53ef\u80fd\u8981\u5904\u7406\u6210\u5343\u4e0a\u4e07\u4e2a\u63cf\u8ff0\u7b26<\/strong>\u3002<\/p>\n\n\n\n<p>\u4e3a\u4e86\u4e0d\u8ba9\u95ee\u9898\u4e00\u4e0a\u6765\u5c31\u8fc7\u4e8e\u590d\u6742\uff0c\u6211\u4eec\u5148\u7b80\u5355\u5316\uff0c\u5047\u8bbe\u53ea\u540c\u65f6\u5904\u7406\u4e24\u4e2a\u5ba2\u6237\u7aef\u7684\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p>\u6709\u7684\u540c\u5b66\u53ef\u80fd\u4f1a\u8bf4\uff0c\u8fd9\u8fd8\u4e0d\u7b80\u5355\uff0c\u8fd9\u6837\u5199\u4e0d\u5c31\u884c\u4e86\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">if(read(socket_fd1, buff) > 0) { \/\/ \u5904\u7406\u7b2c\u4e00\u4e2a\n    do_something();\n}\nif(read(socket_fd2, buff) > 0) { \/\/ \u5904\u7406\u7b2c\u4e8c\u4e2a\n    do_something();<\/pre>\n\n\n\n<p>\u8fd9\u662f\u975e\u5e38\u5178\u578b\u7684\u963b\u585e\u5f0fI\/O\uff0c\u5982\u679c\u6b64\u65f6\u6ca1\u6709\u6570\u636e\u53ef\u8bfb\u90a3\u4e48\u8fdb\u7a0b\u4f1a\u88ab\u963b\u585e\u800c\u6682\u505c\u8fd0\u884c\uff0c\u8fd9\u65f6\u6211\u4eec\u5c31\u65e0\u6cd5\u5904\u7406\u7b2c\u4e8c\u4e2a\u8bf7\u6c42\u4e86\uff0c\u5373\u4f7f\u7b2c\u4e8c\u4e2a\u8bf7\u6c42\u7684\u6570\u636e\u5df2\u7ecf\u5c31\u4f4d\uff0c\u8fd9\u4e5f\u5c31\u610f\u5473\u7740\u5904\u7406\u67d0\u4e00\u4e2a\u5ba2\u6237\u7aef\u65f6\u7531\u4e8e\u8fdb\u7a0b\u88ab\u963b\u585e\u5bfc\u81f4\u5269\u4e0b\u7684\u6240\u6709\u5176\u5b83\u5ba2\u6237\u7aef\u5fc5\u987b<strong>\u7b49\u5f85<\/strong>\uff0c\u5728\u540c\u65f6\u5904\u7406\u51e0\u4e07\u5ba2\u6237\u7aef\u7684server\u4e0a\uff0c\u8fd9\u663e\u7136\u662f\u4e0d\u80fd\u5bb9\u5fcd\u7684\u3002<\/p>\n\n\n\n<p>\u806a\u660e\u7684\u4f60\u4e00\u5b9a\u4f1a\u60f3\u5230\u4f7f\u7528\u591a\u7ebf\u7a0b\uff0c\u4e3a\u6bcf\u4e2a\u5ba2\u6237\u7aef\u8bf7\u6c42\u5f00\u542f\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u8fd9\u6837\u4e00\u4e2a\u5ba2\u6237\u7aef\u88ab\u963b\u585e\u5c31\u4e0d\u4f1a\u5f71\u54cd\u5230\u5904\u7406\u5176\u5b83\u5ba2\u6237\u7aef\u7684\u7ebf\u7a0b\u4e86\uff0c\u6ce8\u610f\uff0c\u65e2\u7136\u662f\u9ad8\u5e76\u53d1\uff0c\u90a3\u4e48\u6211\u4eec\u8981\u4e3a\u6210\u5343\u4e0a\u4e07\u4e2a\u8bf7\u6c42\u5f00\u542f\u6210\u5343\u4e0a\u4e07\u4e2a\u7ebf\u7a0b\u5417\uff0c\u5927\u91cf\u521b\u5efa\u9500\u6bc1\u7ebf\u7a0b\u4f1a\u4e25\u91cd\u5f71\u54cd\u7cfb\u7edf\u6027\u80fd\u3002<\/p>\n\n\n\n<p>\u90a3\u4e48\u8fd9\u4e2a\u95ee\u9898\u8be5\u600e\u4e48\u89e3\u51b3\u5462\uff1f<\/p>\n\n\n\n<p><strong>\u8fd9\u91cc\u7684\u5173\u952e\u70b9\u5728\u4e8e\uff0c\u6211\u4eec\u4e8b\u5148\u5e76\u4e0d\u77e5\u9053\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u5bf9\u5e94\u7684I\/O\u8bbe\u5907\u662f\u5426\u662f\u53ef\u8bfb\u7684\u3001\u662f\u5426\u662f\u53ef\u5199\u7684<\/strong>\uff0c\u5728\u5916\u8bbe\u7684\u4e0d\u53ef\u8bfb\u6216\u4e0d\u53ef\u5199\u7684\u72b6\u6001\u4e0b\u8fdb\u884cI\/O\u53ea\u4f1a\u5bfc\u81f4\u8fdb\u7a0b\u963b\u585e\u88ab\u6682\u505c\u8fd0\u884c\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\u8981\u4f18\u96c5\u7684\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u5c31\u8981\u4ece\u5176\u5b83\u89d2\u5ea6\u6765\u601d\u8003\u8fd9\u4e2a\u95ee\u9898\u4e86<\/p>\n\n\n\n<p><strong>\u4e0d\u8981\u6253\u7535\u8bdd\u7ed9\u6211\uff0c\u6709\u9700\u8981\u6211\u4f1a\u6253\u7ed9\u4f60<\/strong><\/p>\n\n\n\n<p>\u5927\u5bb6\u751f\u6d3b\u4e2d\u80af\u5b9a\u4f1a\u63a5\u5230\u8fc7\u63a8\u9500\u7535\u8bdd\uff0c\u800c\u4e14\u4e0d\u6b62\u4e00\u4e2a\uff0c\u4e00\u5929\u4e0b\u6765\u63a5\u4e0a\u5341\u4e2a\u516b\u4e2a\u63a8\u9500\u7535\u8bdd\u4f60\u7684\u8eab\u4f53\u4f1a\u88ab\u638f\u7a7a\u7684\u3002<\/p>\n\n\n\n<p>\u8fd9\u4e2a\u573a\u666f\u7684\u5173\u952e\u70b9\u5728\u4e8e\u6253\u7535\u8bdd\u7684\u4eba\u5e76\u4e0d\u77e5\u9053\u4f60\u662f\u4e0d\u662f\u8981\u4e70\u4e1c\u897f\uff0c\u53ea\u80fd\u6765\u4e00\u904d\u904d\u95ee\u4f60\uff0c\u56e0\u6b64\u4e00\u79cd\u66f4\u597d\u7684\u7b56\u7565\u662f\u4e0d\u8981\u8ba9\u4ed6\u4eec\u6253\u7535\u8bdd\u7ed9\u4f60\uff0c\u8bb0\u4e0b\u4ed6\u4eec\u7684\u7535\u8bdd\uff0c\u6709\u9700\u8981\u7684\u8bdd\u6253\u7ed9\u4ed6\u4eec\uff0c\u8fd9\u6837\u63a8\u9500\u5458\u5c31\u4e0d\u4f1a\u4e00\u904d\u4e00\u904d\u7684\u6765\u70e6\u4f60\u4e86(\u867d\u7136\u73b0\u5b9e\u751f\u6d3b\u4e2d\u8fd9\u5e76\u4e0d\u53ef\u80fd)\u3002<\/p>\n\n\n\n<p>\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f60\uff0c\u5c31\u597d\u6bd4\u5185\u6838\uff0c\u63a8\u9500\u8005\u5c31\u597d\u6bd4\u5e94\u7528\u7a0b\u5e8f\uff0c\u7535\u8bdd\u53f7\u7801\u5c31\u597d\u6bd4\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u548c\u4f60\u7528\u7535\u8bdd\u6c9f\u901a\u5c31\u597d\u6bd4I\/O\u3002<\/p>\n\n\n\n<p>\u73b0\u5728\u4f60\u5e94\u8be5\u660e\u767d\u4e86\u5427\uff0c\u5904\u7406\u591a\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u66f4\u597d\u65b9\u6cd5\u5176\u5b9e\u5c31\u5b58\u5728\u4e8e\u63a8\u9500\u7535\u8bdd\u4e2d\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\u76f8\u6bd4\u4e0a\u4e00\u8282\u4e2d\u6211\u4eec\u901a\u8fc7I\/O\u63a5\u53e3<strong>\u4e3b\u52a8<\/strong>\u95ee\u5185\u6838\u8fd9\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u5bf9\u5e94\u7684\u5916\u8bbe\u662f\u4e0d\u662f\u5df2\u7ecf\u5c31\u7eea\u4e86\uff0c\u4e00\u79cd\u66f4\u597d\u7684\u65b9\u6cd5\u662f\uff0c\u6211\u4eec\u628a\u8fd9\u4e9b\u611f\u5174\u8da3\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e00\u80a1\u8111\u6254\u7ed9\u5185\u6838\uff0c\u5e76\u9738\u6c14\u7684\u544a\u8bc9\u5185\u6838\uff1a\u201c<strong>\u6211\u8fd9\u91cc\u67091\u4e07\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u4f60\u66ff\u6211\u76d1\u89c6\u7740\u5b83\u4eec\uff0c\u6709\u53ef\u4ee5\u8bfb\u5199\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u65f6\u4f60\u5c31\u544a\u8bc9\u6211\uff0c\u6211\u597d\u5904\u7406<\/strong>\u201d\u3002\u800c\u4e0d\u662f\u5f31\u5f31\u7684\u95ee\u5185\u6838\uff1a\u201c\u7b2c\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u53ef\u4ee5\u8bfb\u5199\u4e86\u5417\uff1f\u7b2c\u4e8c\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u5199\u5417\uff1f\u7b2c\u4e09\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u5199\u4e86\u5417\uff1f\u3002\u3002\u3002\u201d<\/p>\n\n\n\n<p>\u8fd9\u6837\u5e94\u7528\u7a0b\u5e8f\u5c31<strong>\u4ece\u201c\u7e41\u5fd9\u201d\u7684\u4e3b\u52a8\u53d8\u4e3a\u4e86\u6e05\u95f2\u7684\u88ab\u52a8<\/strong>\uff0c<strong>\u53cd\u6b63\u6587\u4ef6\u63cf\u8ff0\u53ef\u8bfb\u53ef\u5199\u4e86\u5185\u6838\u4f1a\u901a\u77e5\u6211<\/strong>\uff0c\u80fd\u5077\u61d2\u6211\u624d\u4e0d\u8981\u90a3\u4e48\u52e4\u594b\u3002<\/p>\n\n\n\n<p>\u8fd9\u662f\u4e00\u79cd\u66f4\u52a0\u9ad8\u6548\u7684I\/O\u5904\u7406\u673a\u5236\uff0c<strong>\u73b0\u5728\u6211\u4eec\u53ef\u4ee5\u4e00\u6b21\u5904\u7406\u591a\u8defI\/O\u4e86<\/strong>\uff0c\u4e3a\u8fd9\u79cd\u673a\u5236\u8d77\u4e00\u4e2a\u540d\u5b57\u5427\uff0c\u5c31\u53ebI\/O\u591a\u8def\u590d\u7528\u5427\uff0c\u8fd9\u5c31\u662f I\/O multiplexing\u3002<\/p>\n\n\n\n<p><strong>I\/O\u591a\u8def\u590d\u7528\uff0cI\/O multiplexing<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>multiplexing\u4e00\u8bcd\u5176\u5b9e\u591a\u7528\u4e8e\u901a\u4fe1\u9886\u57df\uff0c\u4e3a\u4e86\u5145\u5206\u5229\u7528\u901a\u4fe1\u7ebf\u8def\uff0c\u5e0c\u671b\u5728\u4e00\u4e2a\u4fe1\u9053\u4e2d\u4f20\u8f93\u591a\u8def\u4fe1\u53f7\uff0c\u8981\u60f3\u5728\u4e00\u4e2a\u4fe1\u9053\u4e2d\u4f20\u8f93\u591a\u8def\u4fe1\u53f7\u5c31\u9700\u8981\u628a\u8fd9\u591a\u8def\u4fe1\u53f7\u7ed3\u5408\u4e3a\u4e00\u8def\uff0c\u5c06\u591a\u8def\u4fe1\u53f7\u7ec4\u5408\u6210\u4e00\u4e2a\u4fe1\u53f7\u7684\u8bbe\u5907\u88ab\u79f0\u4e3amultiplexer\uff0c\u663e\u7136\u63a5\u6536\u65b9\u63a5\u6536\u5230\u8fd9\u4e00\u8def\u7ec4\u5408\u540e\u7684\u4fe1\u53f7\u540e\u8981\u6062\u590d\u539f\u5148\u7684\u591a\u8def\u4fe1\u53f7\uff0c\u8fd9\u4e2a\u8bbe\u5907\u88ab\u79f0\u4e3ademultiplexer\uff0c\u5982\u56fe\u6240\u793a\uff1a<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"392\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-1024x392.png\" alt=\"\" class=\"wp-image-16355\" style=\"width:516px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-1024x392.png 1024w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-300x115.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-768x294.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-830x318.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-230x88.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-350x134.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116-480x184.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-116.png 1148w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<p>\u56de\u5230\u6211\u4eec\u7684\u4e3b\u9898\u3002<\/p>\n\n\n\n<p>\u6240\u8c13I\/O\u591a\u8def\u590d\u7528\u6307\u7684\u662f\u8fd9\u6837\u4e00\u4e2a\u8fc7\u7a0b\uff1a<\/p>\n\n\n\n<p>1. \u6211\u4eec\u62ff\u5230\u4e86\u4e00\u5806\u6587\u4ef6\u63cf\u8ff0\u7b26(\u4e0d\u7ba1\u662f\u7f51\u7edc\u76f8\u5173\u7684\u3001\u8fd8\u662f\u78c1\u76d8\u6587\u4ef6\u76f8\u5173\u7b49\u7b49\uff0c\u4efb\u4f55\u6587\u4ef6\u63cf\u8ff0\u7b26\u90fd\u53ef\u4ee5)<\/p>\n\n\n\n<p>2. \u901a\u8fc7\u8c03\u7528<strong>\u67d0\u4e2a\u51fd\u6570<\/strong>\u544a\u8bc9\u5185\u6838\uff1a\u201c<strong>\u8fd9\u4e2a\u51fd\u6570\u4f60\u5148\u4e0d\u8981\u8fd4\u56de\uff0c\u4f60\u66ff\u6211\u76d1\u89c6\u7740\u8fd9\u4e9b\u63cf\u8ff0\u7b26\uff0c\u5f53\u8fd9\u5806\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e2d\u6709\u53ef\u4ee5\u8fdb\u884cI\/O\u8bfb\u5199\u64cd\u4f5c\u7684\u65f6\u5019\u4f60\u518d\u8fd4\u56de<\/strong>\u201d<\/p>\n\n\n\n<p>3. \u5f53\u8c03\u7528\u7684\u8fd9\u4e2a\u51fd\u6570\u8fd4\u56de\u540e\u6211\u4eec\u5c31\u80fd\u77e5\u9053\u54ea\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8fdb\u884cI\/O\u64cd\u4f5c\u4e86\u3002<\/p>\n\n\n\n<p>\u4e5f\u5c31\u662f\u8bf4<strong>\u901a\u8fc7I\/O\u591a\u8def\u590d\u7528\u6211\u4eec\u53ef\u4ee5\u540c\u65f6\u5904\u7406\u591a\u8defI\/O<\/strong>\u3002\u90a3\u4e48\u6709\u54ea\u4e9b\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u8fdb\u884cI\/O\u591a\u8def\u590d\u7528\u5462\uff1f<\/p>\n\n\n\n<p>\u5728Linux\u4e16\u754c\u4e2d\u6709\u8fd9\u6837\u4e09\u79cd\u673a\u5236\u53ef\u4ee5\u7528\u6765\u8fdb\u884cI\/O\u591a\u8def\u590d\u7528\uff1a<\/p>\n\n\n\n<ul>\n<li>select<\/li>\n\n\n\n<li>poll<\/li>\n\n\n\n<li>epoll<\/li>\n<\/ul>\n\n\n\n<p>\u63a5\u4e0b\u6765\u6211\u4eec\u5c31\u6765\u4ecb\u7ecd\u4e00\u4e0b\u725b\u63b0\u7684I\/O\u591a\u8def\u590d\u7528\u4e09\u5251\u5ba2\u3002<\/p>\n\n\n\n<p><strong>I\/O\u591a\u8def\u590d\u7528\u4e09\u5251\u5ba2<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u672c\u8d28\u4e0aselect\u3001poll\u3001epoll\u90fd\u662f\u963b\u585e\u5f0fI\/O\uff0c\u4e5f\u5c31\u662f\u6211\u4eec\u5e38\u8bf4\u7684\u540c\u6b65I\/O\uff0c\u539f\u56e0\u5728\u4e8e\u8c03\u7528\u8fd9\u4e9bI\/O\u591a\u8def\u590d\u7528\u51fd\u6570\u65f6\u5982\u679c\u4efb\u4f55\u4e00\u4e2a\u9700\u8981\u76d1\u89c6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u90fd\u4e0d\u53ef\u8bfb\u6216\u8005\u53ef\u5199\u90a3\u4e48\u8fdb\u7a0b\u4f1a\u88ab\u963b\u585e\u6682\u505c\u6267\u884c\uff0c\u76f4\u5230\u6709\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u8bfb\u6216\u8005\u53ef\u5199\u624d\u7ee7\u7eed\u8fd0\u884c\u3002<\/p>\n\n\n\n<p><strong>1 select\uff1a\u521d\u51fa\u8305\u5e90<\/strong><\/p>\n\n\n\n<p>\u5728select\u8fd9\u79cdI\/O\u591a\u8def\u590d\u7528\u673a\u5236\u4e0b\uff0c\u6211\u4eec\u9700\u8981\u628a\u60f3\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u96c6\u5408\u901a\u8fc7\u51fd\u6570\u53c2\u6570\u7684\u5f62\u5f0f\u544a\u8bc9select\uff0c\u7136\u540eselect\u4f1a\u5c06\u8fd9\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408<strong>\u62f7\u8d1d<\/strong>\u5230\u5185\u6838\u4e2d\uff0c\u6211\u4eec\u77e5\u9053\u6570\u636e\u62f7\u8d1d\u662f\u6709\u6027\u80fd\u635f\u8017\u7684\uff0c\u56e0\u6b64\u4e3a\u4e86\u51cf\u5c11\u8fd9\u79cd\u6570\u636e\u62f7\u8d1d\u5e26\u6765\u7684\u6027\u80fd\u635f\u8017\uff0cLinux\u5185\u6838\u5bf9\u96c6\u5408\u7684\u5927\u5c0f\u505a\u4e86\u9650\u5236\uff0c\u5e76\u89c4\u5b9a\u7528\u6237\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u96c6\u5408\u4e0d\u80fd\u8d85\u8fc71024\u4e2a\uff0c\u540c\u65f6\u5f53select\u8fd4\u56de\u540e<strong>\u6211\u4eec\u4ec5\u4ec5\u80fd\u77e5\u9053\u6709\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u5199\u4e86\uff0c\u4f46\u662f\u6211\u4eec\u4e0d\u77e5\u9053\u662f\u54ea\u4e00\u4e2a<\/strong>\uff0c\u56e0\u6b64\u7a0b\u5e8f\u5458\u5fc5\u987b\u518d\u904d\u5386\u4e00\u8fb9\u627e\u5230\u5177\u4f53\u662f\u54ea\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u5199\u4e86\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\uff0c\u603b\u7ed3\u4e0b\u6765select\u6709\u8fd9\u6837\u51e0\u4e2a\u7279\u70b9\uff1a<\/p>\n\n\n\n<ul>\n<li>\u6211\u80fd\u7167\u770b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\u6709\u9650\uff0c\u4e0d\u80fd\u8d85\u8fc71024\u4e2a<\/li>\n\n\n\n<li>\u7528\u6237\u7ed9\u6211\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u9700\u8981\u62f7\u8d1d\u7684\u5185\u6838\u4e2d<\/li>\n\n\n\n<li>\u6211\u53ea\u80fd\u544a\u8bc9\u4f60\u6709\u6587\u4ef6\u63cf\u8ff0\u7b26\u6ee1\u8db3\u8981\u6c42\u4e86\uff0c\u4f46\u662f\u6211\u4e0d\u77e5\u9053\u662f\u54ea\u4e2a\uff0c\u4f60\u81ea\u5df1\u4e00\u4e2a\u4e00\u4e2a\u53bb\u627e\u5427(\u904d\u5386\uff09<\/li>\n<\/ul>\n\n\n\n<p>\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u770b\u5230\uff0cselect\u673a\u5236\u7684\u8fd9\u4e9b\u7279\u6027\u5728\u9ad8\u5e76\u53d1\u7f51\u7edc\u670d\u52a1\u5668\u52a8\u8f84\u51e0\u4e07\u51e0\u5341\u4e07\u5e76\u53d1\u94fe\u63a5\u7684\u573a\u666f\u4e0b\u65e0\u7591\u662f\u4f4e\u6548\u7684\u3002<\/p>\n\n\n\n<p><strong>2 poll\uff1a\u5c0f\u6709\u6240\u6210<\/strong><\/p>\n\n\n\n<p>poll\u548cselect\u662f\u975e\u5e38\u76f8\u4f3c\u7684\uff0cpoll\u76f8\u5bf9\u4e8eselect\u7684\u4f18\u5316\u4ec5\u4ec5\u5728\u4e8e\u89e3\u51b3\u4e86\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0d\u80fd\u8d85\u8fc71024\u4e2a\u7684\u9650\u5236\uff0cselect\u548cpoll\u90fd\u4f1a\u968f\u7740\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u6570\u91cf\u589e\u52a0\u800c\u6027\u80fd\u4e0b\u964d\uff0c\u56e0\u6b64\u4e0d\u9002\u5408\u9ad8\u5e76\u53d1\u573a\u666f\u3002<\/p>\n\n\n\n<p><strong>3 epoll\uff1a\u72ec\u6b65\u5929\u4e0b<\/strong><\/p>\n\n\n\n<p>\u5728select\u9762\u4e34\u7684\u4e09\u4e2a\u95ee\u9898\u4e2d\uff0c\u6587\u4ef6\u63cf\u8ff0\u6570\u91cf\u9650\u5236\u5df2\u7ecf\u5728poll\u4e2d\u89e3\u51b3\u4e86\uff0c\u5269\u4e0b\u7684\u4e24\u4e2a\u95ee\u9898\u5462\uff1f<\/p>\n\n\n\n<p>\u9488\u5bf9\u62f7\u8d1d\u95ee\u9898\uff0cepoll\u4f7f\u7528\u7684\u7b56\u7565\u662f<strong>\u5404\u4e2a\u51fb\u7834<\/strong>\u4e0e<strong>\u5171\u4eab\u5185\u5b58<\/strong>\u3002<\/p>\n\n\n\n<p>\u5b9e\u9645\u4e0a\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u7684\u53d8\u5316\u9891\u7387\u6bd4\u8f83\u4f4e\uff0cselect\u548cpoll\u9891\u7e41\u7684\u62f7\u8d1d\u6574\u4e2a\u96c6\u5408\uff0c\u5185\u6838\u90fd\u5feb\u88ab\u70e6\u6b7b\u4e86\uff0cepoll\u901a\u8fc7\u5f15\u5165epoll_ctl\u5f88\u4f53\u8d34\u7684\u505a\u5230\u4e86\u53ea\u64cd\u4f5c\u90a3\u4e9b\u6709\u53d8\u5316\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u540c\u65f6epoll\u548c\u5185\u6838\u8fd8\u6210\u4e3a\u4e86\u597d\u670b\u53cb\uff0c\u5171\u4eab\u4e86\u540c\u4e00\u5757\u5185\u5b58\uff0c\u8fd9\u5757\u5185\u5b58\u4e2d\u4fdd\u5b58\u7684\u5c31\u662f\u90a3\u4e9b\u5df2\u7ecf\u53ef\u8bfb\u6216\u8005\u53ef\u5199\u7684\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\uff0c\u8fd9\u6837\u5c31\u51cf\u5c11\u4e86\u5185\u6838\u548c\u7a0b\u5e8f\u7684\u62f7\u8d1d\u5f00\u9500\u3002<\/p>\n\n\n\n<p>\u9488\u5bf9\u9700\u8981\u904d\u5386\u6587\u4ef6\u63cf\u8ff0\u7b26\u624d\u80fd\u77e5\u9053\u54ea\u4e2a\u53ef\u8bfb\u53ef\u5199\u8fd9\u4e00\u95ee\u9898\uff0cepoll\u4f7f\u7528\u7684\u7b56\u7565\u662f\u201c\u5f53\u5c0f\u5f1f\u201d\u3002<\/p>\n\n\n\n<p>\u5728select\u548cpoll\u673a\u5236\u4e0b\uff0c<strong>\u8fdb\u7a0b\u8981\u4eb2\u81ea\u4e0b\u573a\u53bb\u5404\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u7b49\u5f85<\/strong>\uff0c\u4efb\u4f55\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u53ef\u8bfb\u6216\u8005\u53ef\u5199\u5c31\u5524\u9192\u8fdb\u7a0b\uff0c\u4f46\u662f\u8fdb\u7a0b\u88ab\u5524\u9192\u540e\u4e5f\u662f\u4e00\u8138\u61f5\u903c\u5e76\u4e0d\u77e5\u9053\u5230\u5e95\u662f\u54ea\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u8bfb\u6216\u53ef\u5199\uff0c\u8fd8\u8981\u518d\u4ece\u5934\u5230\u5c3e\u68c0\u67e5\u4e00\u904d\u3002<\/p>\n\n\n\n<p>\u4f46epoll\u5c31\u61c2\u4e8b\u591a\u4e86\uff0c\u4e3b\u52a8\u627e\u5230\u8fdb\u7a0b\u8981\u5f53\u5c0f\u5f1f\u66ff\u5927\u54e5\u51fa\u5934\u3002<\/p>\n\n\n\n<p>\u5728\u8fd9\u79cd\u673a\u5236\u4e0b\uff0c\u8fdb\u7a0b\u4e0d\u9700\u8981\u4eb2\u81ea\u4e0b\u573a\u4e86\uff0c\u8fdb\u7a0b\u53ea\u8981\u7b49\u5f85\u5728epoll\u4e0a\uff0cepoll\u4ee3\u66ff\u8fdb\u7a0b\u53bb\u5404\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u7b49\u5f85\uff0c\u5f53\u54ea\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u8bfb\u6216\u8005\u53ef\u5199\u7684\u65f6\u5019\u5c31\u544a\u8bc9epoll\uff0cepoll\u7528\u5c0f\u672c\u672c\u8ba4\u771f\u8bb0\u5f55\u4e0b\u6765\u7136\u540e\u5524\u9192\u5927\u54e5\uff1a\u201c\u8fdb\u7a0b\u5927\u54e5\uff0c\u5feb\u9192\u9192\uff0c\u4f60\u8981\u5904\u7406\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6211\u90fd\u8bb0\u4e0b\u6765\u4e86\u201d\uff0c\u8fd9\u6837\u8fdb\u7a0b\u88ab\u5524\u9192\u540e\u5c31\u65e0\u9700\u81ea\u5df1\u4ece\u5934\u5230\u5c3e\u68c0\u67e5\u4e00\u904d\uff0c\u56e0\u4e3aepoll\u5c0f\u5f1f\u90fd\u5df2\u7ecf\u8bb0\u4e0b\u6765\u4e86\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u770b\u5230\uff0c\u5728epoll\u8fd9\u79cd\u673a\u5236\u4e0b\uff0c\u5b9e\u9645\u4e0a\u5229\u7528\u7684\u5c31\u662f\u201c\u4e0d\u8981\u6253\u7535\u8bdd\u7ed9\u6211\uff0c\u6709\u9700\u8981\u6211\u4f1a\u6253\u7ed9\u4f60\u201d\u8fd9\u79cd\u7b56\u7565\uff0c\u8fdb\u7a0b\u4e0d\u9700\u8981\u4e00\u904d\u4e00\u904d\u9ebb\u70e6\u7684\u95ee\u5404\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u800c\u662f\u7ffb\u8eab\u505a\u4e3b\u4eba\u4e86\uff0c\u201c\u4f60\u4eec\u8fd9\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u6709\u54ea\u4e2a\u53ef\u8bfb\u6216\u8005\u53ef\u5199\u4e86\u4e3b\u52a8\u62a5\u4e0a\u6765\u201d\uff0c\u8fd9\u79cd\u673a\u5236\u5b9e\u9645\u4e0a\u5c31\u662f\u5927\u540d\u9f0e\u9f0e\u7684\u4e8b\u4ef6\u9a71\u52a8\uff0cEvent-driven\uff0c\u8fd9\u4e5f\u662f\u6211\u4eec\u4e0b\u4e00\u7bc7\u7684\u4e3b\u9898\u3002<\/p>\n\n\n\n<p>\u5b9e\u9645\u4e0a\u5728Linux\u5e73\u53f0\uff0c<strong>epoll\u57fa\u672c\u4e0a\u5c31\u662f\u9ad8\u5e76\u53d1\u7684\u4ee3\u540d\u8bcd<\/strong>\u3002<\/p>\n\n\n\n<p><strong>\u4ece\u4e00\u6b21\u7f51\u7edc\u8c03\u7528\u8bf4\u8d77<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"879\" height=\"1024\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-879x1024.png\" alt=\"\" class=\"wp-image-16357\" style=\"width:456px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-879x1024.png 879w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-257x300.png 257w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-768x895.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-830x967.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-230x268.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-350x408.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118-480x559.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-118.png 1102w\" sizes=\"(max-width: 879px) 100vw, 879px\" \/><\/figure><\/div>\n\n\n<p>\u5047\u8bbe\u5e94\u7528A\u60f3\u8981\u8bf7\u6c42\u5e94\u7528B\u83b7\u53d6\u6570\u636e\uff0c\u90a3\u4e48\u4ed6\u4f1a\u7ecf\u5386\u4ee5\u4e0b\u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ol>\n<li>\u5e94\u7528A\u5c06\u8bf7\u6c42\u62a5\u6587\u5199\u5165\u81ea\u5df1\u7684TCP\u5199\u7f13\u51b2\u533a<\/li>\n\n\n\n<li>\u5e94\u7528A\u7684\u8bf7\u6c42\u62a5\u6587\u7ecf\u8fc7\u7f51\u7ebf\u5230\u8fbe\u5e94\u7528B\u7684TCP\u8bfb\u7f13\u51b2\u533a<\/li>\n\n\n\n<li>\u5e94\u7528B\u83b7\u5f97\u8bf7\u6c42\u62a5\u6587\u540e\uff0c\u8fdb\u884c\u4e1a\u52a1\u903b\u8f91\u5904\u7406<\/li>\n\n\n\n<li>\u5e94\u7528B\u4e1a\u52a1\u903b\u8f91\u5904\u7406\u5b8c\u6210\u540e\uff0c\u5c06\u54cd\u5e94\u62a5\u6587\u5199\u5165\u81ea\u5df1\u7684TCP\u5199\u7f13\u51b2\u533a\uff0c\u7136\u540e\u7ecf\u8fc7\u7f51\u7ebf\u8fbe\u5230\u5e94\u7528A\u7684TCP\u8bfb\u7f13\u51b2\u533a<\/li>\n<\/ol>\n\n\n\n<p>\u73b0\u5728\u6211\u4eec\u5c06\u6ce8\u610f\u529b\u653e\u5230\u5e94\u7528A\u4e0a\uff0c\u5e94\u7528A\u5c06\u8bf7\u6c42\u53d1\u9001\u51fa\u53bb\u540e\uff0c\u5c31\u4f1a\u5f00\u59cb\u8c03\u7528\u7cfb\u7edf\u8c03\u7528\u4eceTCP\u8bfb\u7f13\u51b2\u533a\u8bfb\u53d6\u6570\u636e\uff0c\u7531\u4e8e\u65e0\u6cd5\u77e5\u9053\u5e94\u7528B\u4ec0\u4e48\u65f6\u5019\u4f1a\u628a\u54cd\u5e94\u6570\u636e\u8fd4\u56de\uff0c\u90a3\u4e48\u5c31\u4f1a\u4e24\u79cd\u60c5\u51b5\uff1a<\/p>\n\n\n\n<ol>\n<li>\u5e94\u7528B\u54cd\u5e94\u901f\u5ea6\u5f88\u5feb\uff0c\u5728\u5e94\u7528A\u8bfb\u53d6TCP\u7f13\u51b2\u533a\u65f6\uff0c\u5c31\u5df2\u7ecf\u628a\u54cd\u5e94\u6570\u636e\u8fd4\u56de\u4e86\u3002\u90a3\u4e48\u5e94\u7528A\u5c31\u53ef\u4ee5\u987a\u5229\u83b7\u53d6\u5230\u6570\u636e\uff0c\u7686\u5927\u6b22\u559c\u3002<\/li>\n\n\n\n<li>\u5e94\u7528B\u54cd\u5e94\u6bd4\u8f83\u6162\uff0c\u5728\u5e94\u7528A\u8bfb\u53d6TCP\u7f13\u51b2\u533a\u65f6\uff0c\u8fd8\u6ca1\u6709\u5c06\u54cd\u5e94\u6570\u636e\u8fd4\u56de\u4e86\u3002\u8fd9\u4e2a\u65f6\u5019\u64cd\u4f5c\u7cfb\u7edf\u5c31\u9762\u4e34\u4e24\u79cd\u9009\u62e9\uff1a \u9009\u62e9\u4e00\uff1a\u628a\u5e94\u7528A\u7684\u672c\u6b21\u8c03\u7528\u963b\u585e\u5728\u8fd9\uff0c\u7b49\u5230\u5e94\u7528B\u7684\u6570\u636e\u8fbe\u5230\u4e86\u7f13\u51b2\u533a\u518d\u91cd\u65b0\u5524\u9192\u5e94\u7528A\u3002 \u2002\u2002\u2002\u2002\u2002\u2002\u9009\u62e9\u4e8c\uff1a\u544a\u8bc9\u5e94\u7528A\u4f60\u8981\u7684\u6570\u636e\u8fd8\u6ca1\u6765\uff0c\u4f60\u7b49\u4f1a\u518d\u6765\u95ee\u3002<\/li>\n<\/ol>\n\n\n\n<p><strong>\u963b\u585eIO<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u5bf9\u4e8e\u9009\u62e9\u4e00\uff0c\u5c31\u662f\u6211\u4eec\u5e38\u8bf4\u7684\u963b\u585e\u5f0fIO\u3002<br>\u5b66\u672f\u70b9\u7684\u8bf4\u6cd5\uff1a\u5f53\u7528\u6237\u8fdb\u7a0b\u53d1\u8d77read\u8c03\u7528\u65f6\uff0c\u5982\u679c\u5185\u6838\u7684\u6570\u636e\u6ca1\u6709\u51c6\u5907\u597d\uff0c\u90a3\u4e48\u64cd\u4f5c\u7cfb\u7edf\u5c31\u4f1a\u628a\u8be5\u8fdb\u7a0b\u6302\u8d77\u6765\uff0c\u8fdb\u5165\u7b49\u5f85\u72b6\u6001(\u4e0d\u6d88\u8017CPU)\u3002\u76f4\u5230\u6570\u636e\u51c6\u5907\u597d\u4e86\u6216\u8005\u53d1\u751f\u4e86\u9519\u8bef\uff0c\u8be5\u8fdb\u7a0b\u624d\u4f1a\u88ab\u5524\u9192\u3002<br>\u6574\u4f53\u6d41\u7a0b\u5982\u56fe\uff1a<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"884\" height=\"530\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119.png\" alt=\"\" class=\"wp-image-16358\" style=\"width:400px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119.png 884w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119-300x180.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119-768x460.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119-830x498.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119-230x138.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119-350x210.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-119-480x288.png 480w\" sizes=\"(max-width: 884px) 100vw, 884px\" \/><\/figure><\/div>\n\n\n<p><strong>\u975e\u963b\u585eIO<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u5bf9\u4e8e\u9009\u62e9\u4e8c\uff0c\u5c31\u662f\u6211\u4eec\u5e38\u8bf4\u7684\u975e\u963b\u585e\u5f0fIO\u3002<br>\u5b66\u672f\u70b9\u7684\u8bf4\u6cd5\uff1a\u5f53\u7528\u6237\u8fdb\u7a0b\u53d1\u8d77read\u8c03\u7528\u65f6\uff0c\u5982\u679c\u5185\u6838\u7684\u6570\u636e\u6ca1\u6709\u51c6\u5907\u597d\uff0c\u90a3\u4e48\u64cd\u4f5c\u7cfb\u7edf\u4f1a\u8fd4\u56de\u4e00\u4e2aEAGAIN error\uff0c\u7528\u6237\u8fdb\u7a0b\u53ef\u4ee5\u6839\u636e\u8be5error\u5224\u65ad\u51fa\u662f\u6570\u636e\u672a\u51c6\u5907\u597d\uff0c\u53ef\u4ee5\u7b49\u4f1a\u518d\u6765\u95ee\u3002\u5982\u679c\u5728\u8f6e\u8be2\u671f\u95f4\uff0c\u5185\u6838\u51c6\u5907\u597d\u6570\u636e\u4e86\uff0c\u7528\u6237\u8fdb\u7a0b\u5c31\u53ef\u4ee5\u628a\u6570\u636e\u62f7\u8d1d\u5230\u7528\u6237\u6001\u7a7a\u95f4\u4e86\u3002<br>\u6574\u4f53\u6d41\u7a0b\u5982\u56fe\uff1a<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"940\" height=\"624\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120.png\" alt=\"\" class=\"wp-image-16359\" style=\"width:460px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120.png 940w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120-300x199.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120-768x510.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120-830x551.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120-230x153.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120-350x232.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-120-480x319.png 480w\" sizes=\"(max-width: 940px) 100vw, 940px\" \/><\/figure><\/div>\n\n\n<p><strong>IO\u591a\u8def\u590d\u7528<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u963b\u585eIO\u548c\u975e\u963b\u585eIO\u90fd\u662f\u65e9\u671f\u6700\u5e38\u89c1\u7684\u7f51\u7edc\u7f16\u7a0b\u6a21\u578b\uff0c\u4f46\u662f\u4ed6\u4eec\u6709\u7740\u81f4\u547d\u7684\u7f3a\u70b9\u3002\u8003\u8651\u5982\u4e0b\u573a\u666f\uff1a<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"492\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-1024x492.png\" alt=\"\" class=\"wp-image-16361\" style=\"width:520px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-1024x492.png 1024w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-300x144.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-768x369.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-830x399.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-230x111.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-350x168.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122-480x231.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-122.png 1348w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<ol>\n<li>\u6bcf\u4e2a\u7528\u6237\u8bf7\u6c42\u90fd\u9700\u8981\u4f7f\u7528\u4e00\u4e2a\u5355\u72ec\u7684\u7ebf\u7a0b\u8fdb\u884c\u670d\u52a1\uff0c\u540c\u65f6\u8fd8\u8981\u8bf7\u6c42\u5e94\u7528B\u624d\u80fd\u5b8c\u6210\u4e1a\u52a1\u903b\u8f91\u3002<\/li>\n\n\n\n<li>\u7531\u4e8e\u4e0d\u77e5\u9053\u5e94\u7528B\u7684\u54cd\u5e94\u6570\u636e\u4f55\u65f6\u4f1a\u8fd4\u56de\uff0c\u90a3\u4e48\u53ea\u80fd\u9009\u62e9\u963b\u585eIO\u6216\u8005\u975e\u963b\u585eIO\u8fdb\u884c\u8f6e\u8be2\u3002<\/li>\n<\/ol>\n\n\n\n<p>\u7136\u800c\u963b\u585eIO\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u88ab\u6302\u8d77\uff0c\u975e\u963b\u585eIO\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u4e00\u76f4\u5904\u4e8e\u8f6e\u8be2\u72b6\u6001\u3002\u8fd9\u4e24\u79cd\u60c5\u51b5\u90fd\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u65e0\u6cd5\u88ab\u91ca\u653e\u6216\u8005\u590d\u7528\u3002\u968f\u7740\u7528\u6237\u8bf7\u6c42\u6570\u7684\u589e\u591a\uff0c\u5e94\u7528A\u4e0d\u5f97\u4e0d\u521b\u5efa\u66f4\u591a\u7684\u7ebf\u7a0b\u3002 \u7136\u800c\u5bf9\u4e8e\u64cd\u4f5c\u7cfb\u7edf\u6765\u8bf4\uff0c\u53ef\u4ee5\u521b\u5efa\u7684\u7ebf\u7a0b\u662f\u6709\u4e0a\u9650\u7684\uff0c\u5e76\u4e14\u8fc7\u591a\u7684\u7ebf\u7a0b\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u5207\u6362\u7684\u65f6\u95f4\u53d8\u591a\uff0c\u4e25\u91cd\u65f6\u53ef\u80fd\u5bfc\u81f4\u7cfb\u7edf\u5361\u6b7b\uff0c\u65e0\u6cd5\u5bf9\u5916\u63d0\u4f9b\u670d\u52a1\u3002\u8fd9\u4e5f\u662f\u8457\u540d\u7684C10K\u95ee\u9898\u3002<\/p>\n\n\n\n<p>\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u4e8e\u662f\u4eba\u4eec\u5c31\u63d0\u51fa\u4e86\u65b9\u6848\uff1a\u7531\u4e00\u4e2a\u6216\u8005\u51e0\u4e2a\u7ebf\u7a0b\u53bb\u76d1\u63a7\u591a\u4e2a\u7f51\u7edc\u8bf7\u6c42\uff0c\u7531\u4ed6\u4eec\u53bb\u5b8c\u6210\u6570\u636e\u51c6\u5907\u9636\u6bb5\u7684\u64cd\u4f5c\u3002\u5f53\u6709\u6570\u636e\u51c6\u5907\u5c31\u7eea\u4e4b\u540e\u518d\u5206\u914d\u5bf9\u5e94\u7684\u7ebf\u7a0b\u53bb\u8bfb\u53d6\u6570\u636e\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u4f7f\u7528\u5c11\u91cf\u7684\u7ebf\u7a0b\u7ef4\u62a4\u5927\u91cf\u7684\u7f51\u7edc\u8bf7\u6c42\uff0c\u8fd9\u5c31\u662fIO\u591a\u8def\u590d\u7528\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\"> IO \u591a\u8def\u590d\u7528\u7684\u590d\u7528\u6307\u7684\u662f\u590d\u7528\u7ebf\u7a0b\uff0c\u800c\u4e0d\u662fIO\u8fde\u63a5\uff1b\u76ee\u7684\u662f\u8ba9\u5c11\u91cf\u7ebf\u7a0b\u80fd\u591f\u5904\u7406\u591a\u4e2aIO\u8fde\u63a5\u3002<\/pre>\n\n\n\n<p>IO\u591a\u8def\u590d\u7528\u53c8\u4e3b\u8981\u7531\u4ee5\u4e0b\u51fd\u6570\u5206\u522b\u5b9e\u73b0\uff0c\u5206\u522b\u662fselect\u3001poll\u3001epoll\u3002<\/p>\n\n\n\n<p><strong>select<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>select\u662fLinux\u6700\u65e9\u652f\u6301IO\u591a\u8def\u590d\u7528\u7684\u51fd\u6570\u3002<\/p>\n\n\n\n<p><strong>select\u539f\u7406<\/strong><\/p>\n\n\n\n<p>\u901a\u8fc7select\u51fd\u6570\u53ef\u4ee5\u5b8c\u6210\u591a\u4e2aIO\u4e8b\u4ef6\u7684\u76d1\u542c\u3002<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">#define __FD_SETSIZE 1024\n\ntypedef struct {\nunsigned long fds_bits[__FD_SETSIZE \/ (8 * sizeof(long))];\n} __kernel_fd_set;\n\nstruct timeval {\ntime_t      tv_sec;         \/* seconds *\/\nsuseconds_t tv_usec;        \/* microseconds *\/\n};\n\n\/\/\u51fd\u6570\u58f0\u660e\nint select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);<\/pre>\n\n\n\n<p>\u51fd\u6570\u53c2\u6570\uff1a<\/p>\n\n\n\n<ul>\n<li>readfds\uff1a\u5185\u6838\u68c0\u6d4b\u8be5\u96c6\u5408\u4e2d\u7684IO\u662f\u5426\u53ef\u8bfb\u3002\u5982\u679c\u60f3\u8ba9\u5185\u6838\u5e2e\u5fd9\u68c0\u6d4b\u67d0\u4e2aIO\u662f\u5426\u53ef\u8bfb\uff0c\u9700\u8981\u624b\u52a8\u628a\u6587\u4ef6\u63cf\u8ff0\u7b26\u52a0\u5165\u8be5\u96c6\u5408\u3002<\/li>\n\n\n\n<li>writefds\uff1a\u5185\u6838\u68c0\u6d4b\u8be5\u96c6\u5408\u4e2d\u7684IO\u662f\u5426\u53ef\u5199\u3002\u540creadfds\uff0c\u9700\u8981\u624b\u52a8\u52a0\u5165<\/li>\n\n\n\n<li>exceptfds\uff1a\u5185\u6838\u68c0\u6d4b\u8be5\u96c6\u5408\u4e2d\u7684IO\u662f\u5426\u5f02\u5e38\u3002\u540creadfds\uff0c\u9700\u8981\u624b\u52a8\u52a0\u5165<\/li>\n\n\n\n<li>nfds\uff1a\u4ee5\u4e0a\u4e09\u4e2a\u96c6\u5408\u4e2d\u6700\u5927\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u503c + 1\uff0c\u4f8b\u5982\u96c6\u5408\u662f{0,1,4}\uff0c\u90a3\u4e48 maxfd \u5c31\u662f 5<\/li>\n\n\n\n<li>timeout\uff1a\u7528\u6237\u7ebf\u7a0b\u8c03\u7528select\u7684\u8d85\u65f6\u65f6\u957f\u3002\n<ul>\n<li>\u8bbe\u7f6e\u6210NULL\uff0c\u8868\u793a\u5982\u679c\u6ca1\u6709 I\/O \u4e8b\u4ef6\u53d1\u751f\uff0c\u5219 select \u4e00\u76f4\u7b49\u5f85\u4e0b\u53bb\u3002<\/li>\n\n\n\n<li>\u8bbe\u7f6e\u4e3a\u975e0\u7684\u503c\uff0c\u8fd9\u4e2a\u8868\u793a\u7b49\u5f85\u56fa\u5b9a\u7684\u4e00\u6bb5\u65f6\u95f4\u540e\u4ece select \u963b\u585e\u8c03\u7528\u4e2d\u8fd4\u56de\u3002<\/li>\n\n\n\n<li>\u8bbe\u7f6e\u6210 0\uff0c\u8868\u793a\u6839\u672c\u4e0d\u7b49\u5f85\uff0c\u68c0\u6d4b\u5b8c\u6bd5\u7acb\u5373\u8fd4\u56de\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u51fd\u6570\u8fd4\u56de\u503c\uff1a<\/p>\n\n\n\n<ul>\n<li>\u5927\u4e8e0\uff1a\u6210\u529f\uff0c\u8fd4\u56de\u96c6\u5408\u4e2d\u5df2\u5c31\u7eea\u7684IO\u603b\u4e2a\u6570<\/li>\n\n\n\n<li>\u7b49\u4e8e-1\uff1a\u8c03\u7528\u5931\u8d25<\/li>\n\n\n\n<li>\u7b49\u4e8e0\uff1a\u6ca1\u6709\u5c31\u7eea\u7684IO<\/li>\n<\/ul>\n\n\n\n<p>\u4ece\u4e0a\u8ff0\u7684select\u51fd\u6570\u58f0\u660e\u53ef\u4ee5\u770b\u51fa\uff0cfd_set\u672c\u8d28\u662f\u4e00\u4e2a\u6570\u7ec4\uff0c\u4e3a\u4e86\u65b9\u4fbf\u6211\u4eec\u64cd\u4f5c\u8be5\u6570\u7ec4\uff0c\u64cd\u4f5c\u7cfb\u7edf\u63d0\u4f9b\u4e86\u4ee5\u4e0b\u51fd\u6570\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26fd\u4eceset\u96c6\u5408\u4e2d\u5220\u9664 \nvoid FD_CLR(int fd, fd_set *set); \n\n\/\/ \u5224\u65ad\u6587\u4ef6\u63cf\u8ff0\u7b26fd\u662f\u5426\u5728set\u96c6\u5408\u4e2d \nint  FD_ISSET(int fd, fd_set *set); \n\n\/\/ \u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26fd\u6dfb\u52a0\u5230set\u96c6\u5408\u4e2d \nvoid FD_SET(int fd, fd_set *set); \n\n\/\/ \u5c06set\u96c6\u5408\u4e2d, \u6240\u6709\u6587\u4ef6\u63cf\u8ff0\u7b26\u5bf9\u5e94\u7684\u6807\u5fd7\u4f4d\u8bbe\u7f6e\u4e3a0\nvoid FD_ZERO(fd_set *set); <\/pre>\n\n\n\n<p><strong>select\u7f3a\u70b9<\/strong><\/p>\n\n\n\n<ol>\n<li>fd_set\u957f\u5ea6\u9650\u5236\uff1a\u7531\u4e8efd_set\u672c\u8d28\u662f\u4e00\u4e2a\u6570\u7ec4\uff0c\u540c\u65f6\u64cd\u4f5c\u7cfb\u7edf\u9650\u5236\u4e86\u5176\u957f\u5ea6\uff0c\u5bfc\u81f4\u5176\u53ea\u80fd\u63a5\u53d7\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u503c\u57281024\u4ee5\u5185\u7684\u3002<\/li>\n\n\n\n<li>select\u51fd\u6570\u7684\u8fd4\u56de\u503c\u662fint\uff0c\u5bfc\u81f4\u6bcf\u6b21\u8fd4\u56de\u540e\uff0c\u7528\u6237\u5f97\u624b\u52a8\u68c0\u6d4b\u96c6\u5408\u4e2d\u54ea\u4e9b\u503c\u88ab\u6539\u4e3a1\u4e86(\u88ab\u6539\u4e3a1\u7684\u8868\u793a\u4ea7\u751f\u4e86IO\u5c31\u7eea\u4e8b\u4ef6)<\/li>\n\n\n\n<li>\u6bcf\u6b21\u8c03\u7528 select\uff0c\u90fd\u9700\u8981\u628a fd \u96c6\u5408\u4ece\u7528\u6237\u6001\u62f7\u8d1d\u5230\u5185\u6838\u6001\uff0c\u5f53fd\u5f88\u591a\u65f6\uff0c\u5f00\u9500\u5f88\u5927\u3002<\/li>\n\n\n\n<li>\u7531\u4e8efd_set\u672c\u8d28\u662f\u6570\u7ec4\uff0c\u6240\u4ee5\u6bcf\u6b21\u5185\u6838\u90fd\u662f\u7ebf\u6027\u626b\u63cf\u6574\u4e2a fd_set\uff0c\u5224\u65ad\u662f\u5426\u6709IO\u5c31\u7eea\u4e8b\u4ef6\uff0c\u5bfc\u81f4\u968f\u7740\u76d1\u63a7\u7684\u63cf\u8ff0\u7b26 fd \u6570\u91cf\u589e\u957f\uff0c\u5176\u6027\u80fd\u4f1a\u7ebf\u6027\u4e0b\u964d<\/li>\n<\/ol>\n\n\n\n<p><strong>poll<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>poll\u662f\u5728select\u4e4b\u540e\u51fa\u73b0\u7684\u53e6\u4e00\u79cdI\/O \u591a\u8def\u590d\u7528\u6280\u672f\u3002\u548c select \u76f8\u6bd4\uff0c\u5b83\u4f7f\u7528\u4e86\u4e0d\u540c\u7684\u65b9\u5f0f\u5b58\u50a8\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u4e5f\u89e3\u51b3\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u4e2a\u6570\u9650\u5236\u3002<\/p>\n\n\n\n<p><strong>poll\u539f\u7406<\/strong><\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">struct pollfd {\n    int fd; \/* file descriptor *\/\n    short events; \/* events to look for *\/\n    short revents; \/* events returned *\/\n};\n\nint poll(struct pollfd *fds, unsigned long nfds, int timeout);    <\/pre>\n\n\n\n<p>\u51fd\u6570\u53c2\u6570\uff1a<\/p>\n\n\n\n<ul>\n<li>fds\uff1astruct pollfd\u7c7b\u578b\u7684\u6570\u7ec4, \u5b58\u50a8\u4e86\u5f85\u68c0\u6d4b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0cstruct pollfd\u6709\u4e09\u4e2a\u6210\u5458\uff1a\n<ul>\n<li>fd\uff1a\u59d4\u6258\u5185\u6838\u68c0\u6d4b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26<\/li>\n\n\n\n<li>events\uff1a\u59d4\u6258\u5185\u6838\u68c0\u6d4b\u7684fd\u4e8b\u4ef6\uff08\u8f93\u5165\u3001\u8f93\u51fa\u3001\u9519\u8bef\uff09\uff0c\u6bcf\u4e00\u4e2a\u4e8b\u4ef6\u6709\u591a\u4e2a\u53d6\u503c<\/li>\n\n\n\n<li>revents\uff1a\u8fd9\u662f\u4e00\u4e2a\u4f20\u51fa\u53c2\u6570\uff0c\u6570\u636e\u7531\u5185\u6838\u5199\u5165\uff0c\u5b58\u50a8\u5185\u6838\u68c0\u6d4b\u4e4b\u540e\u7684\u7ed3\u679c<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>nfds\uff1a\u63cf\u8ff0\u7684\u662f\u6570\u7ec4 fds \u7684\u5927\u5c0f<\/li>\n\n\n\n<li>timeout: \u6307\u5b9apoll\u51fd\u6570\u7684\u963b\u585e\u65f6\u957f\n<ul>\n<li>-1\uff1a\u4e00\u76f4\u963b\u585e\uff0c\u76f4\u5230\u68c0\u6d4b\u7684\u96c6\u5408\u4e2d\u6709\u5c31\u7eea\u7684IO\u4e8b\u4ef6\uff0c\u7136\u540e\u89e3\u9664\u963b\u585e\u51fd\u6570\u8fd4\u56de<\/li>\n\n\n\n<li>0\uff1a\u4e0d\u963b\u585e\uff0c\u4e0d\u7ba1\u68c0\u6d4b\u96c6\u5408\u4e2d\u6709\u6ca1\u6709\u5df2\u5c31\u7eea\u7684IO\u4e8b\u4ef6\uff0c\u51fd\u6570\u9a6c\u4e0a\u8fd4\u56de<\/li>\n\n\n\n<li>\u5927\u4e8e0\uff1a\u8868\u793a poll \u8c03\u7528\u65b9\u7b49\u5f85\u6307\u5b9a\u7684\u6beb\u79d2\u6570\u540e\u8fd4\u56de<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u51fd\u6570\u8fd4\u56de\u503c\uff1a<\/p>\n\n\n\n<ul>\n<li>-1\uff1a\u5931\u8d25<\/li>\n\n\n\n<li>\u5927\u4e8e0\uff1a\u8868\u793a\u68c0\u6d4b\u7684\u96c6\u5408\u4e2d\u5df2\u5c31\u7eea\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u603b\u4e2a\u6570<\/li>\n<\/ul>\n\n\n\n<p>\u5728 select \u91cc\u9762\uff0c\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u4e2a\u6570\u5df2\u7ecf\u968f\u7740 fd_set \u7684\u5b9e\u73b0\u800c\u56fa\u5b9a\uff0c\u6ca1\u6709\u529e\u6cd5\u5bf9\u6b64\u8fdb\u884c\u914d\u7f6e\uff1b\u800c\u5728 poll \u51fd\u6570\u91cc\uff0c\u6211\u4eec\u53ef\u4ee5\u81ea\u7531\u63a7\u5236 pollfd \u7ed3\u6784\u7684\u6570\u7ec4\u5927\u5c0f\uff0c\u4ece\u800c\u7a81\u7834select\u4e2d\u9762\u4e34\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e2a\u6570\u7684\u9650\u5236\u3002<\/p>\n\n\n\n<p><strong>poll\u7f3a\u70b9<\/strong><\/p>\n\n\n\n<p>poll \u7684\u5b9e\u73b0\u548c select \u975e\u5e38\u76f8\u4f3c\uff0c\u53ea\u662fpoll \u4f7f\u7528 pollfd \u7ed3\u6784\uff0c\u800c select \u4f7f\u7528fd_set \u7ed3\u6784\uff0cpoll \u89e3\u51b3\u4e86\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\u9650\u5236\u7684\u95ee\u9898\uff0c\u4f46\u662f\u540c\u6837\u9700\u8981\u4ece\u7528\u6237\u6001\u62f7\u8d1d\u6240\u6709\u7684 fd \u5230\u5185\u6838\u6001\uff0c\u4e5f\u9700\u8981\u7ebf\u6027\u904d\u5386\u6240\u6709\u7684 fd \u96c6\u5408\uff0c\u6240\u4ee5\u5b83\u548c select \u5e76\u6ca1\u6709\u672c\u8d28\u4e0a\u7684\u533a\u522b\u3002<\/p>\n\n\n\n<p><strong>epoll<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>epoll \u662f Linux kernel 2.6 \u4e4b\u540e\u5f15\u5165\u7684\u65b0 I\/O \u4e8b\u4ef6\u9a71\u52a8\u6280\u672f\uff0c\u5b83\u89e3\u51b3\u4e86select\u3001poll\u5728\u6027\u80fd\u4e0a\u7684\u7f3a\u70b9\uff0c\u662f\u76ee\u524dIO\u591a\u8def\u590d\u7528\u7684\u4e3b\u6d41\u89e3\u51b3\u65b9\u6848\u3002 \u300aThe Linux Programming Interface\u300b\u4e2d\u7528\u4e86\u4e00\u5f20\u56fe\u76f4\u89c2\u7684\u5c55\u793a\u4e86 select\u3001poll\u3001epoll\u5728\u4e0d\u540c\u6570\u91cf\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0b\u7684\u6027\u80fd\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"970\" height=\"262\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123.png\" alt=\"\" class=\"wp-image-16362\" style=\"width:448px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123.png 970w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123-300x81.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123-768x207.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123-830x224.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123-230x62.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123-350x95.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-123-480x130.png 480w\" sizes=\"(max-width: 970px) 100vw, 970px\" \/><\/figure><\/div>\n\n\n<p>\u4ece\u4e0a\u56fe\u53ef\u4ee5\u660e\u663e\u5730\u770b\u5230\uff0c\u968f\u7740\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\u7684\u4e0a\u6da8\uff0cepoll \u7684\u6027\u80fd\u8fd8\u662f\u5f88\u4f18\u5f02\u3002\u800cselect\u3001poll\u5219\u968f\u7740\u63cf\u8ff0\u7b26\u6570\u91cf\u7684\u4e0a\u6da8\u6027\u80fd\u9010\u6e10\u53d8\u5dee\u3002<\/p>\n\n\n\n<p><strong>epoll \u539f\u7406<\/strong><\/p>\n\n\n\n<p>epoll \u7684 API \u975e\u5e38\u7b80\u6d01\uff0c\u75313\u4e2a\u7cfb\u7edf\u51fd\u6570\u7ec4\u6210\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">int epoll_create(int size);  \nint epoll_create1(int flags);\n\nint epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);\nint epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout);\n\nstruct epoll_event {\n    __uint32_t events;\n    epoll_data_t data;\n};\n\nunion epoll_data {\n void     *ptr;\n int       fd;\n uint32_t  u32;\n uint64_t  u64;\n};\ntypedef union epoll_data  epoll_data_t;<\/pre>\n\n\n\n<ol>\n<li>epoll_creare\u3001epoll_create1\uff1a\u8fd9\u4e24\u4e2a\u51fd\u6570\u7684\u4f5c\u7528\u662f\u4e00\u6837\u7684\uff0c\u90fd\u662f\u521b\u5efa\u4e00\u4e2aepoll\u5b9e\u4f8b\u3002<\/li>\n\n\n\n<li>epoll_ctl\uff1a\u5728\u521b\u5efa\u5b8c epoll \u5b9e\u4f8b\u4e4b\u540e\uff0c\u53ef\u4ee5\u901a\u8fc7\u8c03\u7528 epoll_ctl \u5f80 epoll \u5b9e\u4f8b\u589e\u52a0\u6216\u5220\u9664\u9700\u8981\u76d1\u63a7\u7684IO\u4e8b\u4ef6\u3002\n<ul>\n<li>epfd\uff1a\u8c03\u7528 epoll_create \u521b\u5efa\u7684 epoll \u83b7\u5f97\u7684\u8fd4\u56de\u503c\uff0c\u53ef\u4ee5\u7b80\u5355\u7406\u89e3\u6210\u662f epoll \u5b9e\u4f8b\u7684\u552f\u4e00\u6807\u8bc6\u3002<\/li>\n\n\n\n<li>op\uff1a\u8868\u793a\u662f\u589e\u52a0\u8fd8\u662f\u5220\u9664\u4e00\u4e2a\u76d1\u63a7\u4e8b\u4ef6\uff0c\u5b83\u6709\u4e09\u4e2a\u9009\u9879\u53ef\u4f9b\u9009\u62e9\uff1a\n<ul>\n<li>EPOLL_CTL_ADD\uff1a \u5411 epoll \u5b9e\u4f8b\u6ce8\u518c\u6587\u4ef6\u63cf\u8ff0\u7b26\u5bf9\u5e94\u7684\u4e8b\u4ef6\uff1b<\/li>\n\n\n\n<li>EPOLL_CTL_DEL\uff1a\u5411 epoll \u5b9e\u4f8b\u5220\u9664\u6587\u4ef6\u63cf\u8ff0\u7b26\u5bf9\u5e94\u7684\u4e8b\u4ef6\uff1b<\/li>\n\n\n\n<li>EPOLL_CTL_MOD\uff1a \u4fee\u6539\u6587\u4ef6\u63cf\u8ff0\u7b26\u5bf9\u5e94\u7684\u4e8b\u4ef6\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>fd\uff1a\u9700\u8981\u6ce8\u518c\u7684\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li>epoll_event\uff1a\u8868\u793a\u9700\u8981\u6ce8\u518c\u7684\u4e8b\u4ef6\u7c7b\u578b\uff0c\u5e76\u4e14\u53ef\u4ee5\u5728\u8fd9\u4e2a\u7ed3\u6784\u4f53\u91cc\u8bbe\u7f6e\u7528\u6237\u9700\u8981\u7684\u6570\u636e\u3002\n<ul>\n<li>events\uff1a\u8868\u793a\u9700\u8981\u6ce8\u518c\u7684\u4e8b\u4ef6\u7c7b\u578b\uff0c\u53ef\u9009\u503c\u5728\u4e0b\u6587\u7684 Linux \u5e38\u89c1\u7f51\u7edcIO\u4e8b\u4ef6\u5b9a\u4e49\u4e2d\u5217\u51fa<\/li>\n\n\n\n<li>data\uff1a\u53ef\u4ee5\u5b58\u653e\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6570\u636e\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>epoll_wait\uff1a\u8c03\u7528\u8005\u8fdb\u7a0b\u8c03\u7528\u8be5\u51fd\u6570\u7b49\u5f85I\/O \u4e8b\u4ef6\u5c31\u7eea\u3002\n<ul>\n<li>epfd\uff1a epoll \u5b9e\u4f8b\u7684\u552f\u4e00\u6807\u8bc6\u3002<\/li>\n\n\n\n<li>epoll_event\uff1a\u540c2.4<\/li>\n\n\n\n<li>maxevents\uff1a\u4e00\u4e2a\u5927\u4e8e 0 \u7684\u6574\u6570\uff0c\u8868\u793a epoll_wait \u53ef\u4ee5\u8fd4\u56de\u7684\u6700\u5927\u4e8b\u4ef6\u503c\u3002<\/li>\n\n\n\n<li>timeout\uff1a\n<ul>\n<li>-1\uff1a\u4e00\u76f4\u963b\u585e\uff0c\u76f4\u5230\u68c0\u6d4b\u7684\u96c6\u5408\u4e2d\u6709\u5c31\u7eea\u7684IO\u4e8b\u4ef6\uff0c\u7136\u540e\u89e3\u9664\u963b\u585e\u51fd\u6570\u8fd4\u56de<\/li>\n\n\n\n<li>0\uff1a\u4e0d\u963b\u585e\uff0c\u4e0d\u7ba1\u68c0\u6d4b\u96c6\u5408\u4e2d\u6709\u6ca1\u6709\u5df2\u5c31\u7eea\u7684IO\u4e8b\u4ef6\uff0c\u51fd\u6570\u9a6c\u4e0a\u8fd4\u56de<\/li>\n\n\n\n<li>\u5927\u4e8e0\uff1a\u8868\u793a epoll \u8c03\u7528\u65b9\u7b49\u5f85\u6307\u5b9a\u7684\u6beb\u79d2\u6570\u540e\u8fd4\u56de<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<p><strong>epoll \u5de5\u4f5c\u6d41\u7a0b<\/strong><\/p>\n\n\n\n<p>epoll \u4e3b\u8981\u7684\u7ed3\u6784\u5bf9\u8c61\u4e3aeventpoll\uff0c\u5176\u4e3b\u8981\u5305\u542b\u51e0\u4e2a\u91cd\u8981\u5c5e\u6027\u6210\u5458\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">struct eventpoll {\n   \/* Wait queue used by sys_epoll_wait() *\/\n wait_queue_head_t wq;\n\n \/* List of ready file descriptors *\/\n struct list_head rdllist;\n\n    \/* RB tree root used to store monitored fd structs *\/\n struct rb_root_cached rbr;\n}<\/pre>\n\n\n\n<ul>\n<li>wq\uff1a\u5f53\u7528\u6237\u8fdb\u7a0b\u6267\u884c\u4e86epoll_wait\u5bfc\u81f4\u4e86\u963b\u585e\u540e\uff0c\u7528\u6237\u8fdb\u7a0b\u5c31\u4f1a\u5b58\u50a8\u5230\u8fd9\uff0c\u7b49\u5f85\u540e\u7eed\u6570\u636e\u51c6\u5907\u5b8c\u6210\u540e\u5524\u9192\u3002<\/li>\n\n\n\n<li>rdllist\uff1a\u5f53\u67d0\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u5c31\u7eea\u4e86\u540e\uff0c\u5c31\u4f1a\u4ecerbr\u79fb\u52a8\u5230\u8fd9\u3002\u5176\u672c\u8d28\u662f\u4e00\u4e2a\u94fe\u8868\u3002<\/li>\n\n\n\n<li>rbr\uff1a\u7528\u6237\u8c03\u7528epoll_ctl\u589e\u52a0\u7684\u6587\u4ef6\u63cf\u8ff0\u90fd\u5b58\u50a8\u5728\u8fd9\uff0c\u5176\u672c\u8d28\u662f\u4e00\u9897\u7ea2\u9ed1\u6811\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5176\u5de5\u4f5c\u6d41\u7a0b\u4e3b\u8981\u5982\u56fe\u6240\u793a\uff1a<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"725\" src=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-1024x725.png\" alt=\"\" class=\"wp-image-16364\" style=\"width:486px;height:auto\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-1024x725.png 1024w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-300x212.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-768x543.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-830x587.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-230x163.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-350x248.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125-480x340.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2024\/09\/\u56fe\u7247-125.png 1450w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<p><strong>epoll \u76f8\u6bd4select\u3001poll\u4e3a\u4ec0\u4e48\u9ad8\u6548\uff1f<\/strong><\/p>\n\n\n\n<ol>\n<li>epoll \u91c7\u7528\u7ea2\u9ed1\u6811\u7ba1\u7406\u6587\u4ef6\u63cf\u8ff0\u7b26 \u4ece\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fa\uff0cepoll\u4f7f\u7528\u7ea2\u9ed1\u6811\u7ba1\u7406\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u7ea2\u9ed1\u6811\u63d2\u5165\u548c\u5220\u9664\u7684\u90fd\u662f\u65f6\u95f4\u590d\u6742\u5ea6 O(logN)\uff0c\u4e0d\u4f1a\u968f\u7740\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\u589e\u52a0\u800c\u6539\u53d8\u3002 select\u3001poll\u91c7\u7528\u6570\u7ec4\u6216\u8005\u94fe\u8868\u7684\u5f62\u5f0f\u7ba1\u7406\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u90a3\u4e48\u5728\u904d\u5386\u6587\u4ef6\u63cf\u8ff0\u7b26\u65f6\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u4f1a\u968f\u7740\u6587\u4ef6\u63cf\u8ff0\u7684\u589e\u52a0\u800c\u589e\u52a0\u3002<\/li>\n\n\n\n<li>epoll \u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u6dfb\u52a0\u548c\u68c0\u6d4b\u5206\u79bb\uff0c\u51cf\u5c11\u4e86\u6587\u4ef6\u63cf\u8ff0\u7b26\u62f7\u8d1d\u7684\u6d88\u8017 select&amp;poll \u8c03\u7528\u65f6\u4f1a\u5c06\u5168\u90e8\u76d1\u542c\u7684 fd \u4ece\u7528\u6237\u6001\u7a7a\u95f4\u62f7\u8d1d\u81f3\u5185\u6838\u6001\u7a7a\u95f4\u5e76\u7ebf\u6027\u626b\u63cf\u4e00\u904d\u627e\u51fa\u5c31\u7eea\u7684 fd \u518d\u8fd4\u56de\u5230\u7528\u6237\u6001\u3002\u4e0b\u6b21\u9700\u8981\u76d1\u542c\u65f6\uff0c\u53c8\u9700\u8981\u628a\u4e4b\u524d\u5df2\u7ecf\u4f20\u9012\u8fc7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u518d\u8bfb\u4f20\u9012\u8fdb\u53bb\uff0c\u589e\u52a0\u4e86\u62f7\u8d1d\u6587\u4ef6\u7684\u65e0\u6548\u6d88\u8017\uff0c\u5f53\u6587\u4ef6\u63cf\u8ff0\u5f88\u591a\u65f6\uff0c\u6027\u80fd\u74f6\u9888\u66f4\u52a0\u660e\u663e\u3002 \u800cepoll\u53ea\u9700\u8981\u4f7f\u7528epoll_ctl\u6dfb\u52a0\u4e00\u6b21\uff0c\u540e\u7eed\u7684\u68c0\u67e5\u4f7f\u7528epoll_wait\uff0c\u51cf\u5c11\u4e86\u6587\u4ef6\u62f7\u8d1d\u7684\u6d88\u8017\u3002<\/li>\n<\/ol>\n\n\n\n<p><strong>\u603b\u7ed3<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>I\/O \uff1a\u7f51\u7edc I\/O<\/p>\n\n\n\n<p>\u591a\u8def \uff1a\u591a\u4e2a\u7f51\u7edc\u8fde\u63a5<\/p>\n\n\n\n<p>\u590d\u7528\uff1a\u590d\u7528\u540c\u4e00\u4e2a\u7ebf\u7a0b\u3002<\/p>\n\n\n\n<p>IO\u591a\u8def\u590d\u7528\u5176\u5b9e\u5c31\u662f\u4e00\u79cd\u540c\u6b65IO\u6a21\u578b\uff0c\u5b83\u5b9e\u73b0\u4e86\u4e00\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u76d1\u89c6\u591a\u4e2a\u6587\u4ef6\u53e5\u67c4\uff1b\u4e00\u65e6\u67d0\u4e2a\u6587\u4ef6\u53e5\u67c4\u5c31\u7eea\uff0c\u5c31\u80fd\u591f\u901a\u77e5\u5e94\u7528\u7a0b\u5e8f\u8fdb\u884c\u76f8\u5e94\u7684\u8bfb\u5199\u64cd\u4f5c\uff1b\u800c\u6ca1\u6709\u6587\u4ef6\u53e5\u67c4\u5c31\u7eea\u65f6,\u5c31\u4f1a\u963b\u585e\u5e94\u7528\u7a0b\u5e8f\uff0c\u4ea4\u51facpu<\/p>\n\n\n\n<p>\u662f\u5229\u7528\u5355\u4e2a\u7ebf\u7a0b\u6765\u540c\u65f6\u76d1\u542c\u591a\u4e2aSocket\uff0c\u5e76\u5728\u67d0\u4e2aSocket\u53ef\u8bfb\u3001\u53ef\u5199\u65f6\u5f97\u5230\u901a\u77e5\uff0c\u4ece\u800c\u907f\u514d\u65e0\u6548\u7684\u7b49\u5f85\uff0c\u5145\u5206\u5229\u7528CPU\u8d44\u6e90\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u8bb2\u89e3\u8be5\u6280\u672f\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u9884\u4e60\u4e00\u4e0b\u6587\u4ef6\u4ee5\u53ca\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002 \u4ec0\u4e48\u662f\u6587\u4ef6 \u7a0b\u5e8f\u5458\u4f7f\u7528I\/O\u6700\u7ec8\u90fd\u9003\u4e0d\u8fc7\u6587\u4ef6\u8fd9\u4e2a\u6982\u5ff5\u3002 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[],"_links":{"self":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/16349"}],"collection":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=16349"}],"version-history":[{"count":4,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/16349\/revisions"}],"predecessor-version":[{"id":16368,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/16349\/revisions\/16368"}],"wp:attachment":[{"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=16349"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=16349"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=16349"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}