{"id":1111,"date":"2024-08-13T12:38:46","date_gmt":"2024-08-13T04:38:46","guid":{"rendered":"http:\/\/blog.chxzking.cn\/?p=1111"},"modified":"2024-08-13T12:38:46","modified_gmt":"2024-08-13T04:38:46","slug":"linux%e7%bd%91%e7%bb%9c%e7%bc%96%e7%a8%8b","status":"publish","type":"post","link":"http:\/\/blog.chxzking.cn\/index.php\/2024\/08\/13\/linux%e7%bd%91%e7%bb%9c%e7%bc%96%e7%a8%8b\/","title":{"rendered":"Linux\u7f51\u7edc\u7f16\u7a0b"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u6e29\u99a8\u63d0\u793a\uff0c\u5728\u5b66\u4e60\u672c\u7bc7\u4e4b\u524d\uff0c\u60a8\u9700\u8981\u5bf9\u7f51\u7edc\u6a21\u578b\u3001TCP\\UDP\u6709\u521d\u6b65\u4e86\u89e3<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><strong><kbd>\u7f51\u7edc\u57fa\u7840\u77e5\u8bc6<\/kbd><\/strong><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u7f51\u7edc\u5b57\u8282\u5e8f\u548c\u4e3b\u673a\u5b57\u8282\u5e8f<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e3b\u673a\u5b57\u8282\u5e8f\uff08Host Byte Order\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3b\u673a\u5b57\u8282\u5e8f\u662f\u6307\u8ba1\u7b97\u673a\u7cfb\u7edf\u5728\u5185\u5b58\u4e2d\u5b58\u50a8\u591a\u5b57\u8282\u6570\u636e\uff08\u5982\u6574\u6570\u3001\u6d6e\u70b9\u6570\u7b49\uff09\u65f6\u7684\u5b57\u8282\u6392\u5217\u987a\u5e8f\u3002\u4e0d\u540c\u7684\u8ba1\u7b97\u673a\u4f53\u7cfb\u7ed3\u6784\u53ef\u80fd\u4f7f\u7528\u4e0d\u540c\u7684\u5b57\u8282\u5e8f\uff0c\u4e3b\u8981\u6709\u4e24\u79cd\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5927\u7aef\u5b57\u8282\u5e8f\uff08Big-endian\uff09<\/strong>\uff1a\u9ad8\u4f4d\u5b57\u8282\u5b58\u50a8\u5728\u4f4e\u5730\u5740\u5904\uff0c\u4f4e\u4f4d\u5b57\u8282\u5b58\u50a8\u5728\u9ad8\u5730\u5740\u5904\u3002\u4f8b\u5982\uff0c\u6574\u65700x12345678\u5728\u5927\u7aef\u5b57\u8282\u5e8f\u4e2d\u5b58\u50a8\u4e3a\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u5730\u5740:  0x00  0x01  0x02  0x03\n\u6570\u636e:  0x12  0x34  0x56  0x78<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5c0f\u7aef\u5b57\u8282\u5e8f\uff08Little-endian\uff09<\/strong>\uff1a\u4f4e\u4f4d\u5b57\u8282\u5b58\u50a8\u5728\u4f4e\u5730\u5740\u5904\uff0c\u9ad8\u4f4d\u5b57\u8282\u5b58\u50a8\u5728\u9ad8\u5730\u5740\u5904\u3002\u4f8b\u5982\uff0c\u6574\u65700x12345678\u5728\u5c0f\u7aef\u5b57\u8282\u5e8f\u4e2d\u5b58\u50a8\u4e3a\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u5730\u5740:  0x00  0x01  0x02  0x03\n\u6570\u636e:  0x78  0x56  0x34  0x12<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u867d\u7136\u5927\u7aef\u5b57\u8282\u5e8f\u5bf9\u4e8e\u4eba\u7c7b\u7684\u9605\u8bfb\u4e0a\u66f4\u52a0\u53cb\u597d\uff0c<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u4f46\u662f\u5728\u5927\u90e8\u5206\u5e73\u53f0\uff0c\u90fd\u662f\u4f7f\u7528\u7684\u5c0f\u7aef\u5b57\u8282\u5e8f<\/mark>\uff0c\u8fd9\u4e2a\u4e3b\u8981\u662f\u5386\u53f2\u539f\u56e0\u5bfc\u81f4\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8ba1\u7b97\u673a\u53d1\u5c55\u65e9\u671f\uff0c\u7535\u5b50\u8bbe\u5907\u7684\u5904\u7406\u80fd\u529b\u5e76\u4e0d\u5f3a\uff0c\u800c\u4f7f\u7528\u5927\u6bb5\u5b57\u8282\u5e8f\u610f\u5473\u7740\u8bfb\u53d6\u6570\u636e\u7684\u65f6\u5019\uff0c\u9700\u8981\u4e0d\u65ad\u8df3\u8dc3\u5730\u5740\uff0c\u7136\u540e\u9006\u5411\u8bfb\u53d6\uff0c\u624d\u80fd\u6b63\u786e\u89e3\u6790\u6570\u636e\uff0c\u5bf9\u4e8e\u6027\u80fd\u5b71\u5f31\u7684\u7535\u5b50\u8bbe\u5907\u65e0\u7591\u589e\u52a0\u4e86\u4e0d\u5fc5\u8981\u7684\u8ba1\u7b97\u91cf\uff0c\u5bf9\u6548\u7387\u4f4e\u5f71\u54cd\u5f88\u591a\u3002\u800c\u4e14\u5185\u5b58\u4e2d\u7684\u6570\u636e\u662f\u7ed9\u8ba1\u7b97\u673a\u8bfb\u7684\uff0c\u53c8\u4e0d\u662f\u7ed9\u4eba\u8bfb\u7684\uff0c\u6240\u4ee5\u4e5f\u6ca1\u6709\u5fc5\u8981\u6309\u7167\u4eba\u7c7b\u9605\u8bfb\u4e60\u60ef\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u73b0\u5728\u7684\u786c\u4ef6\u6027\u80fd\u5bf9\u4e8e\u8fd9\u79cd\u64cd\u4f5c\u5e26\u6765\u7684\u5f00\u9500\u5df2\u7ecf\u5b8c\u5168\u53ef\u4ee5\u5ffd\u7565\u4e0d\u8ba1\uff0c\u4f46\u662f\u7531\u4e8e\u5386\u53f2\u9057\u7559\u7684\u4e60\u60ef\u4ee5\u53ca\u517c\u5bb9\u6027\u95ee\u9898\uff0c\u6240\u4ee5\u4f9d\u65e7\u666e\u904d\u91c7\u7528\u5c0f\u7aef\u5b57\u8282\u5e8f\uff0c\u4f46\u662f\u5e76\u4e0d\u610f\u5473\u7740\u5927\u7aef\u5b57\u8282\u5e8f\u5c31\u5b8c\u5168\u6ca1\u6709\u4f5c\u7528\uff0c\u5b83\u5728\u7f51\u7edc\u901a\u4fe1\u4e2d\u8fd0\u7528\u7684\u6bd4\u8f83\u5e7f\u6cdb\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u7f51\u7edc\u5b57\u8282\u5e8f\uff08Network Byte Order\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7f51\u7edc\u5b57\u8282\u5e8f\u662f\u6307\u5728\u7f51\u7edc\u4f20\u8f93\u4e2d\u4f7f\u7528\u7684\u6807\u51c6\u5b57\u8282\u6392\u5217\u987a\u5e8f\u3002\u4e3a\u4e86\u786e\u4fdd\u4e0d\u540c\u8ba1\u7b97\u673a\u7cfb\u7edf\u4e4b\u95f4\u7684\u6570\u636e\u4f20\u8f93\u4e00\u81f4\u6027\uff0c\u7f51\u7edc\u534f\u8bae\uff08\u5982TCP\/IP\uff09\u89c4\u5b9a\u4f7f\u7528\u5927\u7aef\u5b57\u8282\u5e8f\u4f5c\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\u3002\u8fd9\u610f\u5473\u7740\u5728\u7f51\u7edc\u4f20\u8f93\u4e2d\uff0c\u9ad8\u4f4d\u5b57\u8282\u603b\u662f\u5148\u4f20\u8f93\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7531\u4e8e\u4e0d\u540c\u8ba1\u7b97\u673a\u7cfb\u7edf\u53ef\u80fd\u4f7f\u7528\u4e0d\u540c\u7684\u4e3b\u673a\u5b57\u8282\u5e8f\uff0c\u5728\u8fdb\u884c\u7f51\u7edc\u901a\u4fe1\u65f6\uff0c\u9700\u8981\u5c06\u4e3b\u673a\u5b57\u8282\u5e8f\u8f6c\u6362\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\uff0c\u53cd\u4e4b\u4ea6\u7136\u3002\u5e38\u7528\u7684\u8f6c\u6362\u51fd\u6570\u5305\u62ec\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>htonl()<\/code>\uff1a\u5c0632\u4f4d\u6574\u6570\u4ece\u4e3b\u673a\u5b57\u8282\u5e8f\u8f6c\u6362\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\uff08Host to Network Long\uff09\u3002<\/li>\n\n\n\n<li><code>htons()<\/code>\uff1a\u5c0616\u4f4d\u6574\u6570\u4ece\u4e3b\u673a\u5b57\u8282\u5e8f\u8f6c\u6362\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\uff08Host to Network Short\uff09\u3002<\/li>\n\n\n\n<li><code>ntohl()<\/code>\uff1a\u5c0632\u4f4d\u6574\u6570\u4ece\u7f51\u7edc\u5b57\u8282\u5e8f\u8f6c\u6362\u4e3a\u4e3b\u673a\u5b57\u8282\u5e8f\uff08Network to Host Long\uff09\u3002<\/li>\n\n\n\n<li><code>ntohs()<\/code>\uff1a\u5c0616\u4f4d\u6574\u6570\u4ece\u7f51\u7edc\u5b57\u8282\u5e8f\u8f6c\u6362\u4e3a\u4e3b\u673a\u5b57\u8282\u5e8f\uff08Network to Host Short\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b83\u4eec\u901a\u5e38\u88ab\u5305\u542b\u5728\u5934\u6587\u4ef6<code> #include &lt;arpa\/inet.h&gt;<\/code> \u4e2d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b83\u4eec\u7684\u51fd\u6570\u539f\u578b\u5206\u522b\u662f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>uint32_t htonl(uint32_t hostlong);\n\nuint16_t htons(uint16_t hostshort);\n\nuint32_t ntohl(uint32_t netlong);\n\nuint16_t ntohs(uint16_t netshort);<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u7f51\u7edc\u5730\u5740\u548c\u7aef\u53e3<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u7f51\u7edc\u5730\u5740<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u7f51\u7edc\u5730\u5740\u901a\u5e38\u662f\u6307IP\u5730\u5740\uff0c\u7528\u4e8e\u6807\u8bc6\u7f51\u7edc\u4e2d\u7684\u8bbe\u5907\u3002IP\u5730\u5740\u6709\u4e24\u79cd\u7248\u672c\uff1aIPv4\u548cIPv6\u3002\n<ul class=\"wp-block-list\">\n<li><strong>IPv4\u5730\u5740<\/strong>\uff1a\u7531\u56db\u4e2a8\u4f4d\u5b57\u8282\u7ec4\u6210\uff0c\u901a\u5e38\u8868\u793a\u4e3a\u70b9\u5206\u5341\u8fdb\u5236\u683c\u5f0f\uff08\u4f8b\u5982\uff0c192.168.1.1\uff09\u3002<\/li>\n\n\n\n<li><strong>IPv6\u5730\u5740<\/strong>\uff1a\u7531128\u4f4d\u7ec4\u6210\uff0c\u901a\u5e38\u8868\u793a\u4e3a\u5192\u53f7\u5206\u9694\u7684\u5341\u516d\u8fdb\u5236\u683c\u5f0f\uff08\u4f8b\u5982\uff0c2001:0db8:85a3:0000:0000:8a2e:0370:7334\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u7aef\u53e3<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u7aef\u53e3\u662f\u7528\u4e8e\u6807\u8bc6\u7279\u5b9a\u8fdb\u7a0b\u6216\u670d\u52a1\u7684\u6570\u5b57\u3002\u7aef\u53e3\u53f7\u8303\u56f4\u4ece0\u523065535\uff0c\u5176\u4e2d0\u52301023\u662f\u4fdd\u7559\u7aef\u53e3\uff0c\u901a\u5e38\u7528\u4e8e\u7cfb\u7edf\u670d\u52a1\u548c\u7279\u6743\u670d\u52a1\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728IPV4\u65f6\u671f\u6709\u4e00\u4e2a\u51fd\u6570\u53ef\u4ee5\u8f6c\u6362\u70b9\u5206\u5341\u8fdb\u5236\u7684ipv4\u5b57\u7b26\u4e32\u7c7b\u578b\u7684\u5730\u5740\u8f6c\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\u7684\u4e8c\u8fdb\u5236\u5f62\u5f0f\uff0c\u4e0d\u8fc7\u8fd9\u4e2a\u51fd\u6570\u5df2\u7ecf\u8fc7\u65f6\u4e86\uff0c\u6240\u4ee5\u5e76\u4e0d\u63a8\u8350\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>in_addr_t inet_addr(const char *cp);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u73b0\u4ee3\u7f51\u7edc\u7f16\u7a0b\u4e2d\uff0c<code>inet_pton()<\/code>\u548c<code>inet_ntop()<\/code>\u662f\u66f4\u52a0\u4e3b\u6d41\u548c\u63a8\u8350\u7684\u5730\u5740\u8f6c\u6362\u51fd\u6570\u3002\u5b83\u4eec\u6bd4<code>inet_addr()<\/code>\u548c<code>inet_ntoa()<\/code>\u66f4\u5065\u58ee\uff0c\u5e76\u4e14\u652f\u6301IPv4\u548cIPv6\u5730\u5740\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><code>inet_pton()<\/code>\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>inet_pton()<\/code>\u51fd\u6570\u7528\u4e8e\u5c06\u6587\u672c\u5f62\u5f0f\u7684IP\u5730\u5740\u8f6c\u6362\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\u7684\u4e8c\u8fdb\u5236\u5f62\u5f0f\u3002\u5b83\u652f\u6301IPv4\u548cIPv6\u5730\u5740\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;arpa\/inet.h&gt;\n\nint inet_pton(int af, const char *src, void *dst);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>af<\/code>\uff1a\u5730\u5740\u65cf\uff0c\u53ef\u4ee5\u662f<code>AF_INET<\/code>\uff08\u7528\u4e8eIPv4\uff09\u6216<code>AF_INET6<\/code>\uff08\u7528\u4e8eIPv6\uff09\u3002<\/li>\n\n\n\n<li><code>src<\/code>\uff1a\u6307\u5411\u4e00\u4e2a\u4ee5\u6587\u672c\u5f62\u5f0f\u8868\u793a\u7684IP\u5730\u5740\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n\n\n\n<li><code>dst<\/code>\uff1a\u6307\u5411\u4e00\u4e2a\u7f13\u51b2\u533a\uff0c\u7528\u4e8e\u5b58\u50a8\u8f6c\u6362\u540e\u7684\u4e8c\u8fdb\u5236\u5f62\u5f0f\u7684IP\u5730\u5740\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de1\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de0\uff08\u8868\u793a\u8f93\u5165\u7684\u5b57\u7b26\u4e32\u4e0d\u662f\u6709\u6548\u7684IP\u5730\u5740\uff09\u6216-1\uff08\u8868\u793a\u53d1\u751f\u4e86\u9519\u8bef\uff0c\u5e76\u8bbe\u7f6e<code>errno<\/code>\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h&gt;\n#include &lt;arpa\/inet.h&gt;\n\nint main() {\n    const char *ip_str = \"192.168.1.1\";\n    struct in_addr ip_addr;\n\n    if (inet_pton(AF_INET, ip_str, &amp;ip_addr) == 1) {\n        printf(\"IP address in network byte order: %u\\n\", ip_addr.s_addr);\n    } else {\n        printf(\"Invalid IP address\\n\");\n    }\n\n    return 0;\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><code>inet_ntop()<\/code>\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>inet_ntop()<\/code>\u51fd\u6570\u7528\u4e8e\u5c06\u7f51\u7edc\u5b57\u8282\u5e8f\u7684\u4e8c\u8fdb\u5236\u5f62\u5f0f\u7684IP\u5730\u5740\u8f6c\u6362\u4e3a\u6587\u672c\u5f62\u5f0f\u3002\u5b83\u652f\u6301IPv4\u548cIPv6\u5730\u5740\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;arpa\/inet.h&gt;\n\nconst char *inet_ntop(int af, const void *src,char *dst, socklen_t size);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>af<\/code>\uff1a\u5730\u5740\u65cf\uff0c\u53ef\u4ee5\u662f<code>AF_INET<\/code>\uff08\u7528\u4e8eIPv4\uff09\u6216<code>AF_INET6<\/code>\uff08\u7528\u4e8eIPv6\uff09\u3002<\/li>\n\n\n\n<li><code>src<\/code>\uff1a\u6307\u5411\u4e00\u4e2a\u4ee5\u4e8c\u8fdb\u5236\u5f62\u5f0f\u8868\u793a\u7684IP\u5730\u5740\u3002<\/li>\n\n\n\n<li><code>dst<\/code>\uff1a\u6307\u5411\u4e00\u4e2a\u7f13\u51b2\u533a\uff0c\u7528\u4e8e\u5b58\u50a8\u8f6c\u6362\u540e\u7684\u6587\u672c\u5f62\u5f0f\u7684IP\u5730\u5740\u3002<\/li>\n\n\n\n<li><code>size<\/code>\uff1a\u7f13\u51b2\u533a\u7684\u5927\u5c0f\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de\u6307\u5411\u6587\u672c\u5f62\u5f0fIP\u5730\u5740\u7684\u6307\u9488\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de<code>NULL<\/code>\uff0c\u5e76\u8bbe\u7f6e<code>errno<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h&gt;\n#include &lt;arpa\/inet.h&gt;\n\nint main() {\n    struct in_addr ip_addr;\n    char ip_str&#91;INET_ADDRSTRLEN];\n\n    ip_addr.s_addr = htonl(0xC0A80101); \/\/ 192.168.1.1 in network byte order\n\n    if (inet_ntop(AF_INET, &amp;ip_addr, ip_str, INET_ADDRSTRLEN) != NULL) {\n        printf(\"IP address in text form: %s\\n\", ip_str);\n    } else {\n        printf(\"Conversion failed\\n\");\n    }\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n<h1 class=\"wp-block-heading\"><strong><kbd>\u5957\u63a5\u5b57\u7f16\u7a0b\u57fa\u7840<\/kbd><\/strong><\/h1>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4ec0\u4e48\u662f\u5957\u63a5\u5b57\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u8d28\u4e0a\u6765\u8bb2\uff0c\u5957\u63a5\u5b57\u662f\u4e00\u4e2a\u62bd\u8c61\u7684\u4e1c\u897f\uff0c\u53ef\u4ee5\u5c06\u5176\u7406\u89e3\u4e3a\u901a\u4fe1\u63a5\u53e3\uff0c\u4e8b\u5b9e\u4e0a\u5b83\u662f\u4e00\u4e2a\u5904\u4e8e\u5e94\u7528\u5c42\u4e0e\u4e0e\u7f51\u7edc\u5c42\uff08\u4e5f\u53ef\u4ee5\u8bf4\u662f\u7f51\u7edc\u5c42\u53ca\u4ee5\u4e0b\u5c42\u6b21\uff09\u4e4b\u95f4\u7684\u62bd\u8c61\u5c42\uff0c\u5b83\u4e3a\u5e94\u7528\u5c42\u63d0\u4f9b\u4e00\u4e2a\u63a5\u53e3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5957\u63a5\u5b57\u53ef\u4ee5\u770b\u4f5c\u662f\u4e00\u79cd\u201c\u6253\u5305\u201d\u673a\u5236\uff0c\u5b83\u5c06\u7f51\u7edc\u901a\u4fe1\u7684\u5404\u79cd\u5143\u7d20\uff08\u5982IP\u5730\u5740\u3001\u7aef\u53e3\u53f7\u3001\u534f\u8bae\u7c7b\u578b\u7b49\uff09\u6253\u5305\u5728\u4e00\u8d77\u3002\u7136\u540e\uff0c\u5e94\u7528\u7a0b\u5e8f\u53ef\u4ee5\u901a\u8fc7\u8fd9\u4e2a\u5957\u63a5\u5b57\u6765\u53d1\u9001\u548c\u63a5\u6536\u6570\u636e\uff0c\u5c31\u50cf\u901a\u8fc7\u4e00\u4e2a\u201c\u901a\u4fe1\u7aef\u53e3\u201d\u8fdb\u884c\u901a\u4fe1\u4e00\u6837\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f46\u662f\uff0c\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u5957\u63a5\u5b57\u672c\u8eab\u5e76\u4e0d\u5305\u542b\u8981\u53d1\u9001\u7684\u6d88\u606f\u6570\u636e<\/mark>\u3002\u6d88\u606f\u6570\u636e\u662f\u901a\u8fc7\u5957\u63a5\u5b57\u53d1\u9001\u548c\u63a5\u6536\u7684\uff0c\u4f46\u662f\u6570\u636e\u672c\u8eab\u662f\u72ec\u7acb\u4e8e\u5957\u63a5\u5b57\u7684\u3002\u4f60\u53ef\u4ee5\u628a\u5957\u63a5\u5b57\u60f3\u8c61\u6210\u4e00\u4e2a\u90ae\u5c40\u7684\u4fe1\u7bb1\uff0c\u4f60\u53ef\u4ee5\u901a\u8fc7\u4fe1\u7bb1\u6765\u53d1\u9001\u548c\u63a5\u6536\u4fe1\u4ef6\uff0c\u4f46\u662f\u4fe1\u4ef6\uff08\u5373\u6d88\u606f\u6570\u636e\uff09\u662f\u72ec\u7acb\u4e8e\u4fe1\u7bb1\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u800c\u6211\u4eec\u5728\u5b9e\u9645\u4ea4\u6d41\u4e2d\u8bf4\u7684\u5957\u63a5\u5b57\u662f\u4ec0\u4e48\u5462\uff1f\u6bd4\u5982\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5957\u63a5\u5b57\u3002<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u53e3\u8bed\u4e2d\u63d0\u5230\u7684\u5957\u63a5\u5b57\u5f80\u5f80\u662f\u6307\u4e00\u4e2a\u5957\u63a5\u5b57\u5bf9\u8c61\uff0c\u6216\u8005\u8bf4\u662f\u4e00\u4e2a\u6570\u636e\u7ed3\u6784\uff0c\u56e0\u4e3a\u5957\u63a5\u5b57\u672c\u8d28\u662f\u4e00\u4e2aAPI\u5c42\uff0c\u521b\u5efaAPI\u8fd9\u79cd\u8bf4\u6cd5\u663e\u7136\u662f\u4e0d\u5408\u7406\u7684\u3002\u800c\u5728\u53e3\u8bed\u4e2d\u5e76\u6ca1\u6709\u5206\u5f97\u5f88\u7ec6\u3002\u800c\u662f\u901a\u8fc7API\u521b\u5efa\u4e00\u4e2a\u5957\u63a5\u5b57\u5bf9\u8c61\u5e76\u83b7\u53d6\u8fd9\u4e2a\u5bf9\u8c61\u7684\u63cf\u8ff0\u7b26\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>\u5957\u63a5\u5b57\u521b\u5efa\u4e0e\u5173\u95ed<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">socket\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8be5\u51fd\u6570\u7684\u4f5c\u7528\u662f\u521b\u5efa\u4e00\u4e2a\u5957\u63a5\u5b57\uff0c\u5957\u63a5\u5b57\u901a\u8fc7\u6587\u4ef6\u63cf\u8ff0\u7b26\u64cd\u4f5c\u3002\u4f46\u662f\u8fd9\u4e2a\u5e76\u4e0d\u662f\u751f\u6210\u4e86\u4e00\u4e2a\u5957\u63a5\u5b57\u7684\u7269\u7406\u6587\u4ef6\uff0c<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u800c\u662f\u88ab\u62bd\u8c61\u6210\u4e86\u4e00\u79cd\u53ea\u5b58\u5728\u4e8e\u5185\u5b58\u4e2d\u7684\u865a\u62df\u6587\u4ef6<\/mark>\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u79cd\u6807\u51c6\u7684\u63a5\u53e3\uff0c\u4f7f\u5f97\u5e94\u7528\u7a0b\u5e8f\u53ef\u4ee5\u4f7f\u7528\u7c7b\u4f3c\u4e8e\u8bfb\u5199\u6587\u4ef6\u7684\u65b9\u5f0f\u6765\u8fdb\u884c\u7f51\u7edc\u901a\u4fe1\u3002\u8fd9\u4e2a\u51fd\u6570\u7684\u76f8\u5f53\u4e8e\u5728\u65b0\u5f00\u7684\u90ae\u5c40\u5b89\u88c5\u4e00\u4e2a\u65b0\u7684\u7a7a\u90ae\u7bb1\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6545\u800c\u5957\u63a5\u5b57\u7684\u5173\u95ed\u540c\u6837\u6309\u7167\u6587\u4ef6\u7684\u903b\u8f91\u8fdb\u884c\u64cd\u4f5c\uff0c\u4f7f\u7528close\u8fdb\u884c\u5173\u95ed\uff0c\u4f20\u5165\u7684\u53c2\u6570\u5c31\u662fsocket\u4ea7\u751f\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u53f7<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;          \/* See NOTES *\/\n#include &lt;sys\/socket.h&gt;\n\nint socket(int domain, int type, int protocol);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong><code>int domain<\/code><\/strong>\uff1a\u8fd9\u4e2a\u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u7f51\u7edc\u534f\u8bae\u7684\u7c7b\u578b\u3002\u5e38\u89c1\u7684\u503c\u6709\uff1a\n<ul class=\"wp-block-list\">\n<li><code>AF_INET<\/code>\uff1aIPv4\u7f51\u7edc\u534f\u8bae<\/li>\n\n\n\n<li><code>AF_INET6<\/code>\uff1aIPv6\u7f51\u7edc\u534f\u8bae<\/li>\n\n\n\n<li><code>AF_UNIX<\/code>\uff1aUNIX\u57df\u534f\u8bae\uff08\u7528\u4e8e\u540c\u4e00\u53f0\u673a\u5668\u4e0a\u7684\u8fdb\u7a0b\u95f4\u901a\u4fe1\uff09<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong><code>int type<\/code><\/strong>\uff1a\u8fd9\u4e2a\u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u5957\u63a5\u5b57\u7684\u7c7b\u578b\u3002\u5e38\u89c1\u7684\u503c\u6709\uff1a\n<ul class=\"wp-block-list\">\n<li><code>SOCK_STREAM<\/code>\uff1a\u63d0\u4f9b\u9762\u5411\u8fde\u63a5\u7684\u3001\u53ef\u9760\u7684\u6570\u636e\u6d41\u3002\u901a\u5e38\u7528\u4e8eTCP\u534f\u8bae\u3002<\/li>\n\n\n\n<li><code>SOCK_DGRAM<\/code>\uff1a\u63d0\u4f9b\u65e0\u8fde\u63a5\u7684\u3001\u4e0d\u53ef\u9760\u7684\u6570\u636e\u62a5\u670d\u52a1\u3002\u901a\u5e38\u7528\u4e8eUDP\u534f\u8bae\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong><code>int protocol<\/code><\/strong>\uff1a\u8fd9\u4e2a\u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u5177\u4f53\u7684\u534f\u8bae\u3002\u901a\u5e38\u6211\u4eec\u8bbe\u7f6e\u4e3a0\uff0c\u8ba9\u7cfb\u7edf\u81ea\u52a8\u9009\u62e9\u534f\u8bae\u3002\u4f8b\u5982\uff0c\u5f53<code>domain<\/code>\u53c2\u6570\u4e3a<code>AF_INET<\/code>\uff0c<code>type<\/code>\u53c2\u6570\u4e3a<code>SOCK_STREAM<\/code>\u65f6\uff0c<code>protocol<\/code>\u4f1a\u88ab\u8bbe\u7f6e\u4e3aTCP\u534f\u8bae\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5982\u679c<code>socket()<\/code>\u51fd\u6570\u6210\u529f\uff0c\u5b83\u4f1a\u8fd4\u56de\u4e00\u4e2a\u975e\u8d1f\u6574\u6570\uff0c\u8fd9\u4e2a\u6574\u6570\u5c31\u662f\u65b0\u521b\u5efa\u7684\u5957\u63a5\u5b57\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u5931\u8d25\uff0c\u5b83\u4f1a\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6e\u5168\u5c40\u53d8\u91cf<code>errno<\/code>\u6765\u8868\u793a\u9519\u8bef\u539f\u56e0\u3002<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>\u7ed1\u5b9a\u5957\u63a5\u5b57<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">bind\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>bind()<\/code>\u51fd\u6570\u662f\u5957\u63a5\u5b57\u7f16\u7a0b\u4e2d\u975e\u5e38\u91cd\u8981\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u4e3b\u8981\u7528\u4e8e\u5c06\u5957\u63a5\u5b57\u7ed1\u5b9a\u5230\u4e00\u4e2a\u7279\u5b9a\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u53f7\u3002\u800c<code>bind()<\/code>\u51fd\u6570\u5219\u76f8\u5f53\u4e8e\u7ed9\u8fd9\u4e2a\u90ae\u7bb1\u5206\u914d\u4e86\u4e00\u4e2a\u5177\u4f53\u7684\u5730\u5740\u3002\u8fd9\u4e2a\u5730\u5740\u5c31\u50cf\u662f\u90ae\u5c40\u7684\u95e8\u724c\u53f7\uff0c\u4f7f\u5f97\u5176\u4ed6\u4eba\uff08\u5373\u5176\u4ed6\u7684\u7f51\u7edc\u4e3b\u673a\u6216\u8fdb\u7a0b\uff09\u53ef\u4ee5\u627e\u5230\u8fd9\u4e2a\u90ae\u7bb1\uff0c\u5e76\u5411\u5176\u4e2d\u53d1\u9001\u6216\u4ece\u4e2d\u63a5\u6536\u90ae\u4ef6\uff08\u5373\u7f51\u7edc\u6570\u636e\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;          \/* See NOTES *\/\n#include &lt;sys\/socket.h&gt;\n\nint bind(int sockfd, const struct sockaddr *addr,socklen_t addrlen);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong><code>int sockfd<\/code><\/strong>\uff1a\u8fd9\u662f\u7531<code>socket()<\/code>\u51fd\u6570\u8fd4\u56de\u7684\u5957\u63a5\u5b57\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\u5b83\u662f<code>bind()<\/code>\u51fd\u6570\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u7528\u4e8e\u6307\u5b9a\u9700\u8981\u7ed1\u5b9a\u7684\u5957\u63a5\u5b57\u3002<\/li>\n\n\n\n<li><strong><code>const struct sockaddr *addr<\/code><\/strong>\uff1a\u8fd9\u662f\u4e00\u4e2a\u6307\u5411\u7ed3\u6784\u4f53<code>sockaddr<\/code>\u7684\u6307\u9488\uff0c\u8be5\u7ed3\u6784\u4f53\u4e2d\u5305\u542b\u4e86\u4f60\u5e0c\u671b\u5957\u63a5\u5b57\u7ed1\u5b9a\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u53f7\u3002\u6ce8\u610f\uff0c\u6211\u4eec\u901a\u5e38\u4e0d\u76f4\u63a5\u4f7f\u7528\u8be5\u7ed3\u6784\u4f53\u3002<\/li>\n\n\n\n<li><strong><code>socklen_t addrlen<\/code><\/strong>\uff1a\u8fd9\u662f<code>sockaddr<\/code>\u7ed3\u6784\u4f53\u7684\u5927\u5c0f\uff0c\u901a\u5e38\u662f<code>sizeof(struct sockaddr)<\/code>\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u7b2c\u4e8c\u4e2a\u53c2\u6570<strong><code>struct sockaddr<\/code><\/strong>\u6765\u8bf4\uff0c\u6211\u4eec\u901a\u5e38\u60c5\u51b5\u4e0b\u5e76\u4e0d\u4f1a\u4f7f\u7528\u8fd9\u4e2a\u7ed3\u6784\u4f53\uff0c\u56e0\u4e3a<code>struct sockaddr<\/code>\u662f\u4e00\u4e2a\u901a\u7528\u7684\u5957\u63a5\u5b57\u5730\u5740\u7ed3\u6784\uff0c\u5b83\u88ab\u8bbe\u8ba1\u4e3a\u53ef\u4ee5\u5904\u7406\u4efb\u4f55\u7c7b\u578b\u7684\u7f51\u7edc\u5730\u5740\uff0c\u5305\u62ecIPv4\u3001IPv6\u7b49\u3002\u6240\u4ee5\u4f7f\u7528\u8d77\u6765\u4e0d\u6e05\u6670\u800c\u4e14\u64cd\u4f5c\u9ebb\u70e6\uff0c\u6240\u4ee5\u5f80\u5f80\u4f1a\u4f7f\u7528\u66f4\u52a0\u7ec6\u5316\u7684\u7ed3\u6784\u4f53\u3002<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u88ab\u7ec6\u5316\u7684\u7ed3\u6784\u4f53\u662f\u4e0e<strong><code>struct sockaddr<\/code><\/strong>\u7684\u8bbe\u8ba1\u517c\u5bb9\uff0c\u6240\u4ee5\u5728\u4f20\u53c2\u7684\u65f6\u5019\u5f3a\u8f6c\u5c31\u53ef\u4ee5\u4e86<\/mark>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u5728ipv4\u7f51\u7edc\u4e0b\uff0c\u6211\u4eec\u4f7f\u7528<code>struct sockaddr_in<\/code>\u7ed3\u6784\u4f53<\/mark>\uff0c\u5b83\u662f\u4e13\u95e8\u7528\u4e8e\u5904\u7406IPv4\u5730\u5740\u7684\u3002\u5b83\u7684\u7ed3\u6784\u6bd4<code>struct sockaddr<\/code>\u66f4\u6e05\u6670\uff0c\u66f4\u5bb9\u6613\u4f7f\u7528\u3002\u5b83\u7684\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;netinet\/in.h&gt;\n\nstruct sockaddr_in {\n    short            sin_family;   \/\/ \u5730\u5740\u65cf\uff08Address Family\uff09\uff0c\u4e5f\u5c31\u662f\u5730\u5740\u7c7b\u578b\uff0c\u8be5\u7ed3\u6784\u4f53\u5e94\u8be5\u586b\u5199\u4e3aAF_INET\n    unsigned short   sin_port;     \/\/ \u7aef\u53e3\u53f7\uff0c\u4f7f\u7528\u7f51\u7edc\u5b57\u8282\u5e8f\n    struct in_addr   sin_addr;     \/\/ IPv4\u5730\u5740\u7ed3\u6784\u4f53\n    char             sin_zero&#91;8];  \/\/ \u672a\u4f7f\u7528\uff0c\u4e00\u822c\u586b\u5145\u4e3a0\uff0c\u5176\u5b58\u5728\u7684\u4e3b\u8981\u539f\u56e0\u662f\u4e3a\u4e86\u8ba9sockaddr_in\u548csockaddr\u4fdd\u6301\u5927\u5c0f\u76f8\u540c\n};\n\/\/\u5176\u4e2d\uff0cstruct in_addr\u662f\u4e00\u4e2a\u7528\u4e8e\u8868\u793aIPv4\u5730\u5740\u7684\u7ed3\u6784\u4f53\uff0c\u5b83\u53ea\u6709\u4e00\u4e2a\u6210\u5458\uff1a\nstruct in_addr {\n    unsigned long s_addr;  \/\/ IPv4\u5730\u5740\uff0c\u4f7f\u7528\u7f51\u7edc\u5b57\u8282\u5e8f\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u5728ipv4\u7f51\u7edc\u4e0b\uff0c\u6211\u4eec\u4f7f\u7528<code>struct sockaddr_in6<\/code>\u7ed3\u6784\u4f53\uff1a<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct sockaddr_in6 {\n    sa_family_t     sin6_family;   \/\/ AF_INET6\n    in_port_t       sin6_port;     \/\/ \u7aef\u53e3\u53f7\n    uint32_t        sin6_flowinfo; \/\/ IPv6\u6d41\u4fe1\u606f\n    struct in6_addr sin6_addr;     \/\/ IPv6\u5730\u5740\n    uint32_t        sin6_scope_id; \/\/ Scope ID\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3e\u4f8b\uff1a\uff08ipv4\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h&gt;\n#include &lt;stdlib.h&gt;\n#include &lt;string.h&gt;\n#include &lt;unistd.h&gt;\n#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n#include &lt;netinet\/in.h&gt;\n#include &lt;arpa\/inet.h&gt;\n\nint main() {\n    int sockfd;\n    struct sockaddr_in addr;\n\n    \/\/ \u521b\u5efa\u5957\u63a5\u5b57\n    sockfd = socket(AF_INET, SOCK_STREAM, 0);\n    if (sockfd == -1) {\n        perror(\"Failed to create socket\");\n        return 1;\n    }\n\n    \/\/ \u8bbe\u7f6e\u5730\u5740\u7ed3\u6784\u4f53\n    memset(&amp;addr, 0, sizeof(addr));\n    addr.sin_family = AF_INET; \/\/ \u4f7f\u7528IPv4\u5730\u5740\n    addr.sin_port = htons(12345); \/\/ \u8bbe\u7f6e\u7aef\u53e3\u53f7\uff08\u6ce8\u610f\u7f51\u7edc\u5b57\u8282\u5e8f\uff09\n    addr.sin_addr.s_addr = inet_addr(\"192.168.1.1\"); \/\/ \u8bbe\u7f6eIP\u5730\u5740\n\n    \/\/ \u7ed1\u5b9a\u5957\u63a5\u5b57\n    if (bind(sockfd, (struct sockaddr *)&amp;addr, sizeof(addr)) == -1) {\n        perror(\"Failed to bind socket\");\n        return 1;\n    }\n\n    \/\/ \u73b0\u5728\uff0c\u5957\u63a5\u5b57\u5df2\u7ecf\u7ed1\u5b9a\u5230\u4e86\u6307\u5b9a\u7684\u5730\u5740\u548c\u7aef\u53e3\u4e0a\n    printf(\"Socket bound to %s:%d\\n\", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));\n\n    \/\/ \u5173\u95ed\u5957\u63a5\u5b57\n    close(sockfd);\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5982\u679c<code>bind()<\/code>\u51fd\u6570\u8c03\u7528\u6210\u529f\uff0c\u5b83\u4f1a\u8fd4\u56de0\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u8c03\u7528\u5931\u8d25\uff0c\u5b83\u4f1a\u8fd4\u56de-1\uff0c\u5e76\u901a\u8fc7<code>errno<\/code>\u53d8\u91cf\u63d0\u4f9b\u9519\u8bef\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\"><strong><kbd>TCP\u7f16\u7a0b<\/kbd><\/strong><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e09\u6b21\u63e1\u624b\u4e0e\u56db\u6b21\u6325\u624b<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e09\u6b21\u63e1\u624b<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5ba2\u6237\u7aef<\/strong>\uff1a\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u5e76\u542f\u7528\u62a5\u6587\u7684SYN\u540c\u6b65\u6807\u8bc6\u8bf7\u6c42\u8fde\u63a5\uff0c\u540c\u65f6\u968f\u673a\u751f\u6210\u4e00\u4e2a\u521d\u59cb\u5e8f\u5217\u53f7<code>a<\/code>\u3002<\/li>\n\n\n\n<li><strong>\u670d\u52a1\u7aef<\/strong>\uff1a\u63a5\u6536\u5230\u8bf7\u6c42\u540e\uff0c\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u542f\u7528\u62a5\u6587\u7684SYN\u540c\u6b65\u6807\u8bc6\u4e0eACK\u786e\u8ba4\u6807\u8bc6\uff0c\u786e\u8ba4\u8fde\u63a5\u8bf7\u6c42\uff0c\u5e76\u968f\u673a\u751f\u6210\u4e00\u4e2a\u521d\u59cb\u5e8f\u5217\u53f7<code>b<\/code>\u3002\u540c\u65f6\uff0c\u5c06\u5ba2\u6237\u7aef\u53d1\u9001\u6765\u7684\u5e8f\u5217\u53f7<code>a<\/code>\u52a01\uff08\u5373<code>a+1<\/code>\uff09\u4f5c\u4e3a\u786e\u8ba4\u53f7\u8fd4\u56de\u3002<\/li>\n\n\n\n<li><strong>\u5ba2\u6237\u7aef<\/strong>\uff1a\u63a5\u6536\u5230\u670d\u52a1\u7aef\u7684SYN-ACK\u62a5\u6587\u540e\uff0c\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u542f\u7528ACK\u786e\u8ba4\u6807\u8bc6\uff0c\u786e\u8ba4\u670d\u52a1\u7aef\u7684\u5e8f\u5217\u53f7<code>b<\/code>\uff0c\u5e76\u5c06\u5176\u52a01\uff08\u5373<code>b+1<\/code>\uff09\u4f5c\u4e3a\u786e\u8ba4\u53f7\uff0c\u540c\u65f6\u53d1\u9001\u81ea\u5df1\u7684\u5e8f\u5217\u53f7<code>a+1<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6838\u5fc3\u70b91\uff1a\u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528\u5e8f\u5217\u53f7\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9996\u5148\u7f51\u7edc\u4e16\u754c\u5b58\u5728\u5927\u91cf\u4e0d\u53ef\u9884\u4f30\u7684\u5e72\u6270\uff0c\u5b83\u4eec\u53ef\u80fd\u9020\u6210\u6570\u636e\u5305\u7684\u5ef6\u8fdf\u6216\u8005\u4e22\u5931\uff0c\u751a\u81f3\u6570\u636e\u5305\u53d1\u9001\u987a\u5e8f\u548c\u63a5\u6536\u987a\u5e8f\u76f8\u53cd\u3002\u800c\u63a5\u6536\u65b9\u4e5f\u53ef\u80fd\u4f1a\u56e0\u4e3a\u4e24\u4e2a\u5b8c\u5168\u76f8\u540c\u7684\u5305\u800c\u4e0d\u77e5\u9053\u5982\u4f55\u5904\u7406\u3002\u6bd4\u5982\uff0c\u5ba2\u6237\u7aef\u53d1\u9001\u4e86\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\uff0c\u670d\u52a1\u7aef\u63a5\u6536\u540e\u56de\u5e94\uff0c\u4f46\u662f\u56e0\u4e3a\u67d0\u79cd\u5ef6\u8fdf\uff0c\u5ba2\u6237\u7aef\u8fdf\u8fdf\u6ca1\u6709\u6536\u5230\uff0c\u4e8e\u662f\u5b83\u518d\u6b21\u53d1\u9001\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\uff0c\u7ed3\u679c\u524d\u811a\u53d1\u5b8c\u540e\u811a\u6536\u5230\u4e86\u56de\u590d\u3002\u800c\u670d\u52a1\u7aef\u8fd9\u91cc\u5374\u53c8\u6536\u5230\u4e86\u8fde\u63a5\u8bf7\u6c42\uff0c\u90a3\u4e48\u5b83\u4e0d\u77e5\u9053\u5ba2\u6237\u7aef\u662f\u4ec0\u4e48\u610f\u601d\uff0c\u662f\u6ca1\u6709\u6536\u5230\u81ea\u5df1\u7684\u56de\u590d\u5305\u8fd8\u662f\u60f3\u5efa\u7acb\u4e24\u4e2a\u8fde\u63a5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u5fc5\u987b\u8981\u5b58\u5728\u67d0\u79cd\u673a\u5236\u80fd\u63a7\u5236\u63a5\u6536\u5faa\u5e8f\uff0c\u8fd8\u80fd\u662f\u5305\u7684\u4e00\u4e2a\u6807\u8bc6\uff0c\u90a3\u4e48\u5e8f\u5217\u53f7\u5c31\u53ef\u4ee5\u5b8c\u7f8e\u89e3\u51b3\u8fd9\u79cd\u95ee\u9898\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5ba2\u6237\u7aef\u4e0e\u670d\u52a1\u5668\u662f\u968f\u673a\u751f\u6210\u7684\u4e00\u4e2a\u503c\u800c\u4e0d\u662f\u56fa\u5b9a\u503c\uff0c\u662f\u4e3a\u4e86\u4ee5\u589e\u52a0\u5b89\u5168\u6027\uff0c\u9632\u6b62\u9884\u6d4b\u653b\u51fb\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u8fc7\uff0c\u6709\u8bf4\u6cd5\u8ba4\u4e3a\u670d\u52a1\u5668\u4e3a\u4e86\u8282\u7ea6\u5185\u5b58\uff0c\u9009\u62e9\u4e0d\u5b58\u50a8\u81ea\u5df1\u7684\u5e8f\u5217\u53f7\uff0c\u800c\u662f\u91c7\u7528\u67d0\u79cd\u4f9d\u8d56\u4e3a\u5ba2\u6237\u7aef\u4fe1\u606f\u751f\u6210\u7684\u53ef\u9884\u6d4b\u5e8f\u5217\u53f7\uff0c\u8fd9\u79cd\u8bf4\u6cd5\u6211\u6ca1\u6709\u627e\u5230\u5f3a\u6709\u529b\u8bc1\u636e\uff0c\u4f46\u6211\u5e76\u4e0d\u80fd\u5426\u5b9a\u8fd9\u79cd\u8bf4\u6cd5\u662f\u9519\u8bef\u7684\uff0c\u6240\u4ee5\u8fd8\u662f\u5c06\u8fd9\u79cd\u8bf4\u6cd5\u653e\u4e86\u4e0a\u6765\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6838\u5fc3\u70b92\uff1a\u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528+1\u4f5c\u4e3a\u786e\u8ba4\u53f7\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b9e\u9645\u4e0a\uff0c\u4f7f\u7528<code>+1<\/code>\u4f5c\u4e3a\u786e\u8ba4\u53f7\u786e\u5b9e\u662fTCP\u534f\u8bae\u4e2d\u7684\u4e00\u4e2a\u89c4\u5b9a\uff0c\u76ee\u7684\u662f\u4e3a\u4e86\u786e\u4fdd\u6570\u636e\u5305\u7684\u987a\u5e8f\u548c\u5b8c\u6574\u6027\u3002\u5982\u679c\u53ea\u4ece\u5b9e\u73b0\u7684\u7406\u8bba\u4e0a\u8bb2\uff0c\u4efb\u4f55\u80fd\u591f\u552f\u4e00\u6807\u8bc6\u5e76\u9a8c\u8bc1\u6570\u636e\u5305\u987a\u5e8f\u7684\u673a\u5236\u90fd\u53ef\u4ee5\u4f7f\u7528\uff0c\u6bd4\u5982<code>+5<\/code>\u3001<code>+10<\/code>\u7b49\uff0c\u751a\u81f3\u53ef\u4ee5\u4f7f\u7528\u590d\u6742\u7684\u7b97\u6cd5\u751f\u6210\u786e\u8ba4\u53f7\uff0c\u4f46\u662f\u53ea\u8981\u4fdd\u8bc1\u8be5\u786e\u8ba4\u53f7\u662f\u53ef\u4ee5\u88ab\u7edf\u4e00\u7ea6\u5b9a\u4e0b\u9a8c\u8bc1\u4fe1\u606f\u88ab\u63a5\u6536\u5c31\u884c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7136\u800c\uff0c\u4f7f\u7528<code>+1<\/code>\u6709\u5176\u7b80\u6d01\u548c\u9ad8\u6548\u7684\u4f18\u70b9\uff0c\u4fbf\u4e8e\u5b9e\u73b0\u548c\u7406\u89e3\u3002\u5b83\u786e\u4fdd\u6bcf\u4e2a\u6570\u636e\u5305\u90fd\u80fd\u88ab\u6b63\u786e\u786e\u8ba4\uff0c\u5e76\u4e14\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u5df2\u7ecf\u88ab\u5e7f\u6cdb\u9a8c\u8bc1\u4e3a\u6709\u6548\u7684\u673a\u5236\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6838\u5fc3\u70b93\uff1a\u4e3a\u4ec0\u4e48\u662f3\u6b21\u63e1\u624b\uff1f\u4e0d\u80fd2\u6b21\uff0c5\u6b21\u5417\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e09\u6b21\u63e1\u624b\u7684\u539f\u56e0\u5982\u6b64\uff0c\u6bd4\u8f83\u5f62\u8c61\u7684\u8bb2\u5c31\u662f\u4e24\u4e2a\u5728\u4fe1\u53f7\u4e0d\u597d\u7684\u5730\u65b9\u6253\u7535\u8bdd<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f20\u4e09\uff1a\u4eca\u5929\u665a\u4e0a6\u70b9\u5230\u6211\u5bb6\u5403\u996d\uff0c\u542c\u5230\u4e86\u5417\uff1f<\/li>\n\n\n\n<li>\u674e\u56db\uff1a\u6211\u6709\u70b9\u4e8b\uff0c7:30\u53ef\u4ee5\u5417\uff1f<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u6ca1\u95ee\u9898\uff01<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ece\u8fd9\u4e2a\u60c5\u666f\u4e2d\u53ef\u4ee5\u77e5\u9053\uff0c\u53cc\u65b9\u4ea4\u6362\u4fe1\u606f\u81f3\u5c11\u89813\u6b21\uff0c\u5982\u679c\u5f20\u4e09\u6ca1\u6709\u56de\u7b54\u201c\u6ca1\u95ee\u9898\u201d,\u90a3\u4e48\u674e\u56db\u5c31\u4e0d\u77e5\u9053\u5f20\u4e09\u662f\u5426\u77e5\u9053\u81ea\u5df1\u6709\u4e8b\uff0c\u90a3\u4e48\u7ed3\u679c\u4f1a\u5bfc\u81f4\u5f20\u4e096\u70b9\u51c6\u5907\u4e86\u996d\u83dc\uff0c\u7ed3\u679c\u674e\u56db7:30\u8fc7\u6765\u996d\u90fd\u51c9\u4e86\uff0c\u641e\u5f97\u4e24\u4eba\u90fd\u4e0d\u5f00\u5fc3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u662f\u5426\u53ef\u4ee5\u5927\u4e8e3\u6b21\u5462\uff1f\u4e8b\u5b9e\u4e0a\u4e5f\u6ca1\u95ee\u9898\uff0c\u6bd4\u5982\u5728\u4e4b\u540e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f20\u4e09\uff1a\u4eca\u5929\u665a\u4e0a6\u70b9\u5230\u6211\u5bb6\u5403\u996d\uff0c\u542c\u5230\u4e86\u5417\uff1f<\/li>\n\n\n\n<li>\u674e\u56db\uff1a\u6211\u6709\u70b9\u4e8b\uff0c7:30\u53ef\u4ee5\u5417\uff1f<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u6ca1\u95ee\u9898\uff01<\/li>\n\n\n\n<li>\u674e\u56db\uff1a\u6536\u5230\u4f60\u8bf4\u7684\u201c\u6ca1\u95ee\u9898\u201d\u4e86\u3002<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u6536\u5230\u4f60\u8bf4 \u4f60\u6536\u5230\u4e86\u6211\u8bf4\u7684\u6ca1\u95ee\u9898\u4e86<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7136\u540e\u53ef\u4ee5\u65e0\u9650\u5957\u5a03\u3002\u4f46\u662f\u6709\u4ec0\u4e48\u610f\u4e49\u5462\uff1f\u53cc\u65b9\u90fd\u786e\u8ba4\u4e86\u6d88\u606f\uff0c\u4e4b\u540e\u5c31\u662f\u767d\u767d\u6d6a\u8d39\u8bdd\u8d39\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u5f88\u6e05\u695a\u7684\u77e5\u9053\uff0c\u5728\u7b2c\u4e09\u6b21\u5f20\u4e09\u8bf4\u6ca1\u95ee\u9898\u540e\uff0c\u674e\u56db\u6536\u5230\u4e86\u6d88\u606f\u3002\u90a3\u4e48\u5f20\u4e09\u77e5\u9053\u996d\u5c40\u63a8\u8fdf\uff0c\u674e\u56db\u672c\u6765\u5c31\u4e3b\u52a8\u63a8\u8fdf\u996d\u5c40\uff0c\u5b83\u5f53\u7136\u77e5\u9053\u8fd9\u4e2a\u4e8b\uff0c\u6240\u4ee5\u5c31\u4e0d\u9700\u8981\u674e\u56db\u7684\u56de\u590d\u3002\u674e\u56db\u53ea\u9700\u8981\u77e5\u9053\u5f20\u4e09\u77e5\u9053\u8fd9\u4e2a\u6d88\u606f\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u540c\u6837\u7684\uff0c\u7406\u8bba\u4e0atcp\u4e09\u6b21\u63e1\u624b\uff0c\u4e5f\u53ef\u4ee5\u4f7f\u7528\u4e94\u6b21\u63e1\u624b\uff0c\u4f46\u662f\u8fd9\u4e0d\u8fc7\u662f\u767d\u767d\u6d6a\u8d39\u670d\u52a1\u5668\u8d44\u6e90\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u8fc7\u53ef\u80fd\u6709\u8bfb\u8005\u5bf9\u4e8e\u6700\u540e\u4e00\u6b21\u63e1\u624b\u6709\u7591\u95ee\uff1a\u674e\u56db\u6ca1\u6709\u56de\u590d\uff0c\u90a3\u4e48\u5f20\u4e09\u4e5f\u5c31\u4e0d\u77e5\u9053\u81ea\u5df1\u56de\u590d\u7684\u201c\u6ca1\u95ee\u9898\u201d\u662f\u5426\u88ab\u674e\u56db\u6536\u5230\uff0c\u90a3\u4e48\u6309\u9053\u7406\u6765\u8bf4\u5e94\u8be5\u6709\u7b2c\u56db\u6b21\u63e1\u624b\u3002\u90a3\u4e48\u5982\u4f55\u89e3\u51b3\u8fd9\u4e00\u4e2a\u95ee\u9898\u5462\uff1f\u63a5\u4e0b\u6765\u4f9d\u65e7\u662f\u60c5\u8282\u6a21\u62df<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f20\u4e09\uff1a\u4eca\u5929\u665a\u4e0a6\u70b9\u5230\u6211\u5bb6\u5403\u996d\uff0c\u542c\u5230\u4e86\u5417\uff1f<\/li>\n\n\n\n<li>\u674e\u56db\uff1a\u6211\u6709\u70b9\u4e8b\uff0c7:30\u53ef\u4ee5\u5417\uff1f<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u6ecb\u6ecb\u6ecb\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u674e\u56db\u6ca1\u6709\u542c\u5230\u5f20\u4e09\u8bf4\u4e86\u5565\uff0c\u53ea\u542c\u5230\u4e86\u566a\u58f0\uff0c\u90a3\u4e48\u674e\u56db\u4f1a\u600e\u4e48\u505a\uff1f\u5b83\u4f1a\u9694\u51e0\u79d2\u91cd\u65b0\u95ee\u4e00\u6b21\uff0c\u76f4\u5230\u5f20\u4e09\u56de\u590d\u6210\u529f\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u674e\u56db\uff1a\u6211\u6709\u70b9\u4e8b\uff0c7:30\u53ef\u4ee5\u5417\uff1f<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u6ecb\u6ecb\u6ecb\u3002<\/li>\n\n\n\n<li>\u674e\u56db\uff1a\u6211\u6709\u70b9\u4e8b\uff0c7:30\u53ef\u4ee5\u5417\uff1f<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u6ecb\u6ecb\u6ecb\u3002<\/li>\n\n\n\n<li>\u674e\u56db\uff1a\u6211\u6709\u70b9\u4e8b\uff0c7:30\u53ef\u4ee5\u5417\uff1f<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u77e5\u9053\u4e86\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u8fc7\u7a0b\u662f\u53cd\u590d\u6267\u884c\u7b2c\u4e8c\u6b21\u63e1\u624b\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u56db\u6b21\u6325\u624b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5ba2\u6237\u7aef\u548c\u670d\u52a1\u5668\u90fd\u80fd\u5efa\u7acb\u56db\u6b21\u6325\u624b\uff0c\u8fd9\u91cc\u4f7f\u7528\u5ba2\u6237\u7aef\u7533\u8bf7\u65ad\u5f00\u8fde\u63a5\u4e3a\u4f8b\u5b50<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5ba2\u6237\u7aef\u53d1\u9001FIN\u62a5\u6587<\/strong>\uff1a\u5ba2\u6237\u7aef\u7533\u8bf7\u65ad\u5f00\u8fde\u63a5\uff0c\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u5e76\u5728\u8fd9\u4e2a\u62a5\u6587\u4e2d\u542f\u7528FIN\u7ed3\u675f\u6807\u5fd7\uff0c\u751f\u6210\u4e00\u4e2a\u5e8f\u5217\u53f7\u4e3a<code>a<\/code>\u5199\u5165\u3002<\/li>\n\n\n\n<li><strong>\u670d\u52a1\u7aef\u53d1\u9001ACK\u62a5\u6587<\/strong>\uff1a\u670d\u52a1\u7aef\u6536\u5230FIN\u62a5\u6587\u540e\uff0c\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u5e76\u5728\u8fd9\u4e2a\u62a5\u6587\u4e2d\u542f\u7528ACK\u786e\u8ba4\u6807\u5fd7\uff0c\u751f\u6210\u4e00\u4e2a\u5e8f\u5217\u53f7<code>k<\/code>\uff0c\u548c\u5ba2\u6237\u7aef\u7684\u5e8f\u5217\u53f7<code>a+1<\/code>\u4f5c\u4e3a\u786e\u8ba4\u53f7\u3002<\/li>\n\n\n\n<li><strong>\u670d\u52a1\u7aef\u53d1\u9001FIN\u62a5\u6587<\/strong>\uff1a\u670d\u52a1\u7aef\u518d\u6b21\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u5e76\u5728\u8fd9\u4e2a\u62a5\u6587\u4e2d\u542f\u7528FIN\u7ed3\u675f\u6807\u5fd7\u548cACK\u786e\u8ba4\u6807\u5fd7\uff0c\u751f\u6210\u4e00\u4e2a\u81ea\u5df1\u7684\u5e8f\u5217\u53f7<code>w<\/code>\uff0c\u548c\u5ba2\u6237\u7aef\u7684\u5e8f\u5217\u53f7<code>a+1<\/code>\u4f5c\u4e3a\u786e\u8ba4\u53f7\u3002<\/li>\n\n\n\n<li><strong>\u5ba2\u6237\u7aef\u53d1\u9001ACK\u62a5\u6587<\/strong>\uff1a\u5ba2\u6237\u7aef\u6536\u5230\u670d\u52a1\u7aef\u7684FIN\u62a5\u6587\u540e\uff0c\u751f\u6210\u4e00\u4e2a\u62a5\u6587\uff0c\u5e76\u5728\u8fd9\u4e2a\u62a5\u6587\u4e2d\u542f\u7528ACK\u786e\u8ba4\u6807\u5fd7\uff0c\u53d1\u9001\u5e8f\u5217\u53f7<code>a+1<\/code>\u548c\u786e\u8ba4\u53f7<code>w+1<\/code>\u3002\u7b49\u5f85\u4e00\u6bb5\u65f6\u95f4\u540e\u5173\u95ed\uff08<strong>2MSL<\/strong>\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6838\u5fc3\u70b91\uff1a\u5e8f\u5217\u53f7\u548c\u4e09\u6b21\u6325\u624b\u4e00\u6837\u662f\u968f\u673a\u751f\u6210\u7684\u5417\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5e76\u4e0d\u662f\uff0c\u4e8b\u5b9e\u4e0a\uff0c\u5728\u5ba2\u6237\u7aef\u548c\u670d\u52a1\u7aef\u5206\u522b\u72ec\u81ea\u7ef4\u62a4\u4e00\u4e2a\u62a5\u6587\u5e8f\u5217\u3002\u5bf9\u4e8e\u5ba2\u6237\u7aef\u6765\u8bf4\uff0c\u5728\u7b2c\u4e00\u6b21\u6325\u624b\u65f6\u5b83\u7684\u5e8f\u5217\u53f7\u662f\u57fa\u4e8e\u6700\u540e\u4e00\u4e2a\u6570\u636e\u5305\u7684\u5e8f\u5217\u53f7\u751f\u6210\u7684\uff0c\u901a\u5e38\u60c5\u51b5\u4e0b\u662f\u6700\u540e\u4e00\u4e2a\u5df2\u53d1\u9001\u6570\u636e\u5305\u7684\u5e8f\u5217\u53f7\u52a0\u4e0a\u6570\u636e\u5305\u7684\u957f\u5ea6\u751f\u6210\u7684\u4e00\u4e2a\u6570\u3002\u800c\u670d\u52a1\u7aef\u4e5f\u662f\u5982\u6b64\uff0c\u7b2c\u4e8c\u6b21\u6325\u624b\u7684\u5e8f\u5217\u53f7\u662f\u57fa\u4e8e\u670d\u52a1\u7aef\u7684\u6700\u540e\u4e00\u4e2a\u5df2\u53d1\u9001\u6570\u636e\u5305\u7684\u5e8f\u5217\u53f7\u52a0\u4e0a\u6570\u636e\u5305\u7684\u957f\u5ea6\u751f\u6210\uff0c\u800c\u7b2c\u4e09\u6b21\u6325\u624b\u7684\u5e8f\u5217\u53f7\u662f\u57fa\u4e8e\u7b2c\u4e8c\u6b21\u6325\u624b\u7684\u6570\u636e\u5305\u7684\u5e8f\u5217\u53f7\u52a0\u4e0a\u6570\u636e\u5305\u7684\u957f\u5ea6\u751f\u6210\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5148\u524d\u5728\u4e09\u6b21\u63e1\u624b\u7684\u65f6\u5019\u8bb2\u89e3\u8fc7\u5e8f\u5217\u53f7\u7684\u4f5c\u7528\u3002\u800c\u540c\u6837\u786e\u8ba4\u4fe1\u53f7\u4e5f\u662f\u57fa\u4e8e\u4e0a\u4e00\u6b21\u6325\u624b\u7684\u5e8f\u5217\u53f7+1\uff0c\u4f46\u662f\u4e3a\u4ec0\u4e48\u5b83\u4e0d\u50cf\u4e09\u6b21\u6325\u624b\u4e00\u6837\u4f7f\u7528\u968f\u673a\u6570\u4f5c\u4e3a\u5e8f\u5217\u53f7\u5462\uff1f\u56e0\u4e3a\u4e09\u6b21\u6325\u624b\u53cc\u65b9\u5e76\u6ca1\u6709\u6570\u636e\u9700\u8981\u53d1\u9001\uff0c\u6240\u6709\u6240\u6709\u7684\u5e8f\u5217\u53f7\u5747\u53ef\u7528\uff0c\u800c\u56db\u6b21\u6325\u624b\u7684\u65f6\u5019\uff0c\u6709\u53ef\u80fd\u5b58\u5728\u5f85\u53d1\u9001\u6570\u636e\uff0c\u4ee5\u53ca\u6570\u636e\u5728\u53d1\u9001\u4e2d\u8fd8\u6ca1\u6709\u5230\u8fbe\u3002\u5982\u679c\u4f7f\u7528\u968f\u673a\u6570\u53ef\u80fd\u5bfc\u81f4\u51b2\u7a81\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6838\u5fc3\u70b92\uff1a\u4e3a\u4ec0\u4e48\u8981\u56db\u6b21\u6325\u624b\u800c\u4e0d\u662f\u4e09\u6b21\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u56e0\u4e3a\u4e0e\u5efa\u7acb\u8fde\u63a5\u4e0d\u540c\uff0c\u6325\u624b\u7684\u65f6\u5019\uff0c\u4e0d\u80fd\u786e\u4fdd\u6240\u6709\u7684\u6570\u636e\u90fd\u5df2\u7ecf\u4f20\u8f93\u5b8c\u6210\uff0c\u6240\u4ee5\u5728\u7b2c\u4e8c\u6b21\u4e0e\u7b2c\u4e09\u6b21\u6325\u624b\u4e4b\u95f4\u662f\u4e3a\u4e86\u5904\u7406\u8fd9\u4e9b\u6570\u636e\u3002\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff0c\u5988\u5988\u5728\u5fd9\u5bb6\u52a1\u7684\u5988\u5988\u60f3\u8ba9\u5728\u5ba2\u5385\u6253\u6e38\u620f\u7684\u5f20\u4e09\u53bb\u62ff\u4e2a\u5feb\u9012\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5988\u5988\uff1a\u5f20\u4e09\uff0c\u5e2e\u6211\u62ff\u4e2a\u5feb\u9012\u3002<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u597d\uff0c\u7b49\u6211\u6253\u5b8c\u8fd9\u4e00\u5c40\u3002<\/li>\n\n\n\n<li>\u5f20\u4e09\uff1a\u5988\u5988\u6211\u6253\u5b8c\u4e86\uff0c\u8bf7\u544a\u8bc9\u6211\u53d6\u4ef6\u7801\uff1f<\/li>\n\n\n\n<li>\u5988\u5988\uff1a\u597d\uff0c\u53d6\u4ef6\u7801\u662f1234\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u53ef\u4ee5\u770b\u5230\uff0c\u5f20\u4e09\u7684\u6e38\u620f\u6ca1\u6709\u6253\u5b8c\uff0c\u4ed6\u9700\u8981\u4e00\u70b9\u70b9\u65f6\u95f4\u7ed3\u675f\u8fd9\u4e00\u53e5\u6e38\u620f\u3002\u6240\u4ee5\u8fd9\u4e24\u6b21\u6325\u624b\u4e0d\u80fd\u5408\u5e76\u6210\u4e00\u6b21\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u4e3a\u4ec0\u4e48\u4e0d\u9700\u8981\u7b2c\u4e94\u6b21\u6325\u624b\u8ba9\u5988\u5988\u77e5\u9053\u5f20\u4e09\u62ff\u5230\u4e86\u53d6\u4ef6\u7801\u5462\uff1f\u4f9d\u65e7\u662f\u573a\u666f\u6a21\u62df\uff0c\u6bd4\u5982\u5988\u5988\u53ef\u80fd\u5728\u6253\u626b\u53a8\u623f\uff0c\u6ca1\u6709\u542c\u5230\u5f20\u4e09\u6253\u5b8c\u6e38\u620f\u4e86\u3002\u6216\u8005\u5988\u5988\u8bf4\u5b8c\u540e\u5f20\u4e09\u6ca1\u6709\u542c\u6e05\u3002\u90a3\u4e48\u5f20\u4e09\u4f1a\u9694\u51e0\u79d2\u540e\u91cd\u65b0\u95ee\u4e00\u6b21\u53d6\u4ef6\u7801\u662f\u4ec0\u4e48\u3002\u76f4\u5230\u81ea\u5df1\u542c\u6e05\u540e\uff0c\u5f20\u4e09\u5c31\u76f4\u63a5\u51fa\u95e8\u4e86\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6838\u5fc3\u70b93\uff1a\u4e3a\u4ec0\u4e48\u5ba2\u6237\u7aef\u56db\u6b21\u6325\u624b\u5b8c\u6210\u540e\u8981\u7b49\u5f85\u4e00\u6bb5\u65f6\u95f4\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u65f6\u95f4<strong>2MSL<\/strong>\uff0cMSL\u662fMaximum Segment Lifetime\u82f1\u6587\u7684\u7f29\u5199\uff0c\u4e2d\u6587\u53ef\u4ee5\u8bd1\u4e3a\u201c\u62a5\u6587\u6700\u5927\u751f\u5b58\u65f6\u95f4\u201d\uff0c\u4ed6\u662f\u4efb\u4f55\u62a5\u6587\u5728\u7f51\u7edc\u4e0a\u5b58\u6d3b\u7684\u6700\u957f\u65f6\u95f4\uff0c\u8d85\u8fc7\u8fd9\u4e2a\u65f6\u95f4\u62a5\u6587\u5c06\u88ab\u4e22\u5f03\u3002\u7b49\u5f852\u500d\u8fd9\u4e2a\u65f6\u95f4\uff0c\u5c31\u662f\u907f\u514d\u7b2c\u4e09\u6b21\u6325\u624b\u6ca1\u6709\u542c\u6e05\uff0c\u800c\u7b49\u5f85\u4e00\u6bb5\u65f6\u95f4\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u60c5\u666f\u6a21\u62df\uff1a\u5f20\u4e09\u6253\u5b8c\u6e38\u620f\u540e\u95ee\u53d6\u4ef6\u7801\uff0c\u5988\u5988\u56de\u590d\u4e861234.\u4f46\u662f\u8fd9\u4e2a\u65f6\u5019\u5988\u5988\u4ee5\u9632\u5f20\u4e09\u6ca1\u6709\u542c\u6e05\uff0c\u505c\u4e0b\u6765\u624b\u4e2d\u7684\u6d3b\uff0c\u7b49\u51e0\u79d2\u770b\u770b\u5f20\u4e09\u662f\u4e0d\u662f\u4f1a\u518d\u95ee\u4e00\u904d\u3002\u5982\u679c\u5f20\u4e09\u6ca1\u6709\u95ee\u90a3\u4e48\u5c31\u662f\u6536\u5230\u4e86\u6d88\u606f\u51fa\u95e8\u4e86\uff0c\u5988\u5988\u8fc7\u51e0\u79d2\u5c31\u4f1a\u7ee7\u7eed\u505a\u5bb6\u52a1\uff0c\u5982\u679c\u5f20\u4e09\u6ca1\u542c\u6e05\uff0c\u5c31\u4f1a\u518d\u95ee\u4e00\u904d\uff0c\u5988\u5988\u5c31\u4f1a\u5c06\u53d6\u4ef6\u7801\u518d\u544a\u8bc9\u4ed6\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u5efa\u7acbTCP\u8fde\u63a5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">listen\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>listen()<\/code>\u51fd\u6570\u7684\u4e3b\u8981\u4f5c\u7528\u662f\u5c06\u4e00\u4e2a\u4e3b\u52a8\u5957\u63a5\u5b57\uff08active socket\uff09\u8f6c\u6362\u4e3a\u4e00\u4e2a\u88ab\u52a8\u5957\u63a5\u5b57\uff08passive socket\uff09\u3002\u8fd9\u6837\u505a\u7684\u76ee\u7684\u662f\u4e3a\u4e86\u8ba9\u5957\u63a5\u5b57\u80fd\u591f\u63a5\u53d7\u6765\u81ea\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u7f51\u7edc\u7f16\u7a0b\u4e2d\uff0c\u4e3b\u52a8\u5957\u63a5\u5b57\u548c\u88ab\u52a8\u5957\u63a5\u5b57\u7684\u6982\u5ff5\u662f\u975e\u5e38\u91cd\u8981\u7684\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4e3b\u52a8\u5957\u63a5\u5b57<\/strong>\uff1a\u662f\u6307\u90a3\u4e9b\u7528\u4e8e\u53d1\u8d77\u8fde\u63a5\u8bf7\u6c42\u7684\u5957\u63a5\u5b57\u3002\u5728\u5ba2\u6237\u7aef\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u6211\u4eec\u901a\u5e38\u4f1a\u521b\u5efa\u4e00\u4e2a\u4e3b\u52a8\u5957\u63a5\u5b57\uff0c\u7136\u540e\u4f7f\u7528<code>connect()<\/code>\u51fd\u6570\u6765\u53d1\u8d77\u5bf9\u670d\u52a1\u5668\u7684\u8fde\u63a5\u8bf7\u6c42\u3002<\/li>\n\n\n\n<li><strong>\u88ab\u52a8\u5957\u63a5\u5b57<\/strong>\uff1a\u662f\u6307\u90a3\u4e9b\u7528\u4e8e\u63a5\u53d7\u8fde\u63a5\u8bf7\u6c42\u7684\u5957\u63a5\u5b57\u3002\u5728\u670d\u52a1\u5668\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u6211\u4eec\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u88ab\u52a8\u5957\u63a5\u5b57\uff0c\u7136\u540e\u4f7f\u7528<code>listen()<\/code>\u51fd\u6570\u6765\u76d1\u542c\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u6211\u4eec\u5728\u670d\u52a1\u5668\u7aef\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5957\u63a5\u5b57\u65f6\uff0c\u8fd9\u4e2a\u5957\u63a5\u5b57\u9ed8\u8ba4\u662f\u4e00\u4e2a\u4e3b\u52a8\u5957\u63a5\u5b57\u3002\u4f46\u662f\uff0c\u670d\u52a1\u5668\u901a\u5e38\u4e0d\u4f1a\u4e3b\u52a8\u53bb\u8fde\u63a5\u5ba2\u6237\u7aef\uff0c\u800c\u662f\u7b49\u5f85\u5ba2\u6237\u7aef\u6765\u8fde\u63a5\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u9700\u8981\u8c03\u7528<code>listen()<\/code>\u51fd\u6570\u5c06\u8fd9\u4e2a\u4e3b\u52a8\u5957\u63a5\u5b57\u8f6c\u6362\u4e3a\u88ab\u52a8\u5957\u63a5\u5b57\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u65e6\u5957\u63a5\u5b57\u53d8\u4e3a\u88ab\u52a8\u5957\u63a5\u5b57\uff0c\u5b83\u5c31\u53ef\u4ee5\u63a5\u53d7\u6765\u81ea\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u4e86\u3002\u5f53\u4e00\u4e2a\u5ba2\u6237\u7aef\u8fde\u63a5\u8bf7\u6c42\u5230\u8fbe\u65f6\uff0c\u670d\u52a1\u5668\u53ef\u4ee5\u4f7f\u7528<code>accept()<\/code>\u51fd\u6570\u6765\u63a5\u53d7\u8fd9\u4e2a\u8fde\u63a5\u8bf7\u6c42\uff0c\u5e76\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5957\u63a5\u5b57\u6765\u4e0e\u5ba2\u6237\u7aef\u8fdb\u884c\u901a\u4fe1\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u8fd9\u4e2a\u51fd\u6570\u5e76\u4e0d\u662f\u76f4\u63a5\u54cd\u5e94\u8fde\u63a5\u8bf7\u6c42\uff0c\u5b83\u7684\u4f5c\u7528\u4ec5\u4ec5\u662f\u5c06\u4e00\u4e2a\u5957\u63a5\u5b57\u7531\u4e3b\u52a8\u72b6\u6001\u8f6c\u6362\u4e3a\u88ab\u52a8\u72b6\u6001\uff0c\u6240\u4ee5\u901a\u5e38\u88ab<strong>\u670d\u52a1\u5668\u7aef<\/strong>\u4f7f\u7528\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u7b80\u5355\u6765\u8bf4\uff0c\u5c31\u662f\u8fd9\u4e2a\u51fd\u6570\u5c06\u670d\u52a1\u5668\u5957\u63a5\u5b57\u8f6c\u6362\u4e3a\u4e86\u76d1\u542c\u5957\u63a5\u5b57\uff08<strong>Listening Socket<\/strong>\uff09\u3002\u5728\u6b64\u4e4b\u540e\uff0c\u8fd9\u4e2a\u5957\u63a5\u5b57\u5c06\u4e0d\u662f\u518d\u5904\u7406\u6570\u636e\u4fe1\u606f\uff0c\u5b83\u7684\u4f5c\u7528\u662f\u8d1f\u8d23\u76d1\u542c\u6765\u81ea\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u800c\u4e0d\u662f\u6570\u636e\u5904\u7406\u8bf7\u6c42<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;          \/* See NOTES *\/\n#include &lt;sys\/socket.h&gt;\n\nint listen(int sockfd, int backlog);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>sockfd<\/code>\uff1a<\/strong>\u8fd9\u662f\u7531<code>socket()<\/code>\u51fd\u6570\u8fd4\u56de\u7684\u5957\u63a5\u5b57\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li><code><strong>backlog<\/strong><\/code>\uff1a\u8fd9\u662f\u5728\u5957\u63a5\u5b57\u5b8c\u6210\u4e09\u6b21\u63e1\u624b\u5e76\u51c6\u5907\u597d\u88ab\u63a5\u53d7\u7684\u8fde\u63a5\u961f\u5217\u4e2d\u5141\u8bb8\u7684\u6700\u5927\u6570\u91cf\u3002\u5982\u679c\u5230\u8fbe\u7684\u8fde\u63a5\u8bf7\u6c42\u8d85\u8fc7\u4e86\u961f\u5217\u7684\u5927\u5c0f\uff0c\u5ba2\u6237\u7aef\u53ef\u80fd\u4f1a\u6536\u5230ECONNREFUSED\u9519\u8bef\uff0c\u6216\u8005\uff0c\u5982\u679c\u5185\u6838\u652f\u6301\u7684\u8bdd\uff0c\u8bf7\u6c42\u53ef\u80fd\u4f1a\u88ab\u5ffd\u7565\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">backlog\u53c2\u6570\u6307\u5b9a\u7684\u662f\u7b49\u5f85\u961f\u5217\u7684\u5927\u5c0f<\/mark>\uff0c\u4e5f\u5c31\u662f\u5728\u670d\u52a1\u5668\u8fd8\u6ca1\u6709\u8c03\u7528accept\u51fd\u6570\u63a5\u53d7\u8fde\u63a5\u65f6\uff0c\u53ef\u4ee5\u5728\u961f\u5217\u4e2d\u7b49\u5f85\u7684\u8fde\u63a5\u8bf7\u6c42\u7684\u6700\u5927\u6570\u91cf\u3002\u5982\u679c\u670d\u52a1\u5668\u5904\u7406\u901f\u5ea6\u5c0f\u4e8e\u5ba2\u6237\u7aef\u7533\u8bf7\u901f\u5ea6\uff0c\u90a3\u4e48\u7b49\u5f85\u961f\u5217\u4e2d\u7684\u8fde\u63a5\u8bf7\u6c42\u4f1a\u9010\u6e10\u589e\u591a\u3002\u5982\u679c\u8fde\u63a5\u8bf7\u6c42\u7684\u6570\u91cf\u8d85\u8fc7\u4e86backlog\u6307\u5b9a\u7684\u5927\u5c0f\uff0c\u90a3\u4e48\u989d\u5916\u7684\u8fde\u63a5\u8bf7\u6c42\u53ef\u80fd\u4f1a\u88ab\u5ffd\u7565\uff0c\u6216\u8005\u5ba2\u6237\u7aef\u53ef\u80fd\u4f1a\u6536\u5230ECONNREFUSED\u9519\u8bef\u3002\u540c\u65f6\uff0c<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u670d\u52a1\u5668\u5b9e\u9645\u4e0a\u6b63\u5728\u8fde\u63a5\u7684\u5ba2\u6237\u7aef\u7684\u6570\u91cf\u5e76\u4e0d\u53d7backlog\u53c2\u6570\u7684\u9650\u5236\uff0c\u800c\u662f\u53d6\u51b3\u4e8e\u670d\u52a1\u5668\u7684\u786c\u4ef6\u6027\u80fd\u548c\u64cd\u4f5c\u7cfb\u7edf\u914d\u7f6e\u3002<\/mark>\u6240\u4ee5\uff0c\u670d\u52a1\u5668\u53ef\u80fd\u6b63\u5728\u4e0e100\u53f0\u5ba2\u6237\u7aef\u4ea4\u4e92\uff0c\u4f46\u662f\u5b83\u53ea\u652f\u6301\u6700\u591a5\u4e2a\u5ba2\u6237\u7aef\u7b49\u5f85\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>listen()<\/code>\u51fd\u6570\u7684\u8fd4\u56de\u503c\u662f\u4e00\u4e2a\u6574\u6570\u3002\u5982\u679c\u51fd\u6570\u6210\u529f\uff0c\u5b83\u5c06\u8fd4\u56de0\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u53d1\u751f\u9519\u8bef\uff0c\u5b83\u5c06\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6e\u5168\u5c40\u53d8\u91cf<code>errno<\/code>\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b\u3002<code>listen()<\/code>\u51fd\u6570\u53ef\u80fd\u4f1a\u5728\u4ee5\u4e0b\u51e0\u79cd\u60c5\u51b5\u4e0b\u8fd4\u56de\u9519\u8bef\uff1a\n<ul class=\"wp-block-list\">\n<li><strong>\u5957\u63a5\u5b57\u672a\u7ed1\u5b9a<\/strong>\uff1a\u5982\u679c\u4f60\u5728\u8c03\u7528<code>listen()<\/code>\u51fd\u6570\u4e4b\u524d\u6ca1\u6709\u4f7f\u7528<code>bind()<\/code>\u51fd\u6570\u5c06\u5957\u63a5\u5b57\u7ed1\u5b9a\u5230\u4e00\u4e2a\u5730\u5740\uff0c\u90a3\u4e48<code>listen()<\/code>\u51fd\u6570\u4f1a\u8fd4\u56de\u9519\u8bef\u3002<\/li>\n\n\n\n<li><strong>\u5957\u63a5\u5b57\u4e0d\u662f\u4e00\u4e2a\u6d41\u5957\u63a5\u5b57<\/strong>\uff1a<code>listen()<\/code>\u51fd\u6570\u53ea\u80fd\u7528\u4e8e\u6d41\u5957\u63a5\u5b57\uff08\u5373SOCK_STREAM\u7c7b\u578b\u7684\u5957\u63a5\u5b57\uff09\u3002\u5982\u679c\u4f60\u5c1d\u8bd5\u5728\u4e00\u4e2a\u6570\u636e\u62a5\u5957\u63a5\u5b57\uff08\u5373SOCK_DGRAM\u7c7b\u578b\u7684\u5957\u63a5\u5b57\uff09\u4e0a\u8c03\u7528<code>listen()<\/code>\u51fd\u6570\uff0c\u5b83\u4f1a\u8fd4\u56de\u9519\u8bef\u3002<\/li>\n\n\n\n<li><strong>\u6587\u4ef6\u63cf\u8ff0\u7b26\u65e0\u6548<\/strong>\uff1a\u5982\u679c\u63d0\u4f9b\u7ed9<code>listen()<\/code>\u51fd\u6570\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0d\u662f\u4e00\u4e2a\u6709\u6548\u7684\u5957\u63a5\u5b57\u63cf\u8ff0\u7b26\uff0c\u90a3\u4e48\u5b83\u4f1a\u8fd4\u56de\u9519\u8bef\u3002<\/li>\n\n\n\n<li><strong>\u5957\u63a5\u5b57\u5df2\u8fde\u63a5<\/strong>\uff1a\u5982\u679c\u5957\u63a5\u5b57\u5df2\u7ecf\u8fde\u63a5\u5230\u53e6\u4e00\u4e2a\u5957\u63a5\u5b57\uff0c\u90a3\u4e48\u5728\u8fd9\u4e2a\u5957\u63a5\u5b57\u4e0a\u8c03\u7528<code>listen()<\/code>\u51fd\u6570\u4f1a\u8fd4\u56de\u9519\u8bef\u3002<\/li>\n\n\n\n<li><strong>\u5185\u5b58\u4e0d\u8db3<\/strong>\uff1a\u5982\u679c\u7cfb\u7edf\u6ca1\u6709\u8db3\u591f\u7684\u5185\u5b58\u6765\u5904\u7406\u65b0\u7684\u8fde\u63a5\uff0c\u90a3\u4e48<code>listen()<\/code>\u51fd\u6570\u53ef\u80fd\u4f1a\u8fd4\u56de\u9519\u8bef\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">accept\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">accept\u51fd\u6570\u662fLinux\u7f51\u7edc\u7f16\u7a0b\u4e2d\u7684\u4e00\u4e2a\u91cd\u8981\u51fd\u6570\uff0c\u4e3b\u8981\u7528\u4e8e\u5904\u7406\u57fa\u4e8e\u8fde\u63a5\u7684\u5957\u63a5\u5b57\uff08\u5982SOCK_STREAM\u548cSOCK_SEQPACKET\uff09\u7684\u8fde\u63a5\u8bf7\u6c42\u3002\u5f53\u670d\u52a1\u5668\u7aef\u76d1\u542c\u5230\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u65f6\uff0caccept\u51fd\u6570\u4f1a\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5957\u63a5\u5b57\uff0c\u7528\u4e8e\u4e0e\u5ba2\u6237\u7aef\u8fdb\u884c\u901a\u4fe1\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u51fd\u6570\u7684\u5e94\u7528\u573a\u666f\u901a\u5e38\u4e3a<strong>\u670d\u52a1\u5668\u7aef<\/strong>\uff0c\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u8fd9\u4e2a\u51fd\u6570\u5982\u679c\u6ca1\u6709\u63a5\u6536\u5230\u8fde\u63a5\u8bf7\u6c42\u4f1a\u5904\u4e8e\u963b\u585e\u72b6\u6001\uff0c\u4e0d\u8fc7\u8fd9\u4e2a\u53ef\u4ee5\u8fdb\u884c\u8bbe\u7f6e\uff0c\u8c03\u6574\u4e3a\u4e0d\u963b\u585e\u6a21\u5f0f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u8865\u5145\u2014\u2014\u4e3a\u4ec0\u4e48\u9700\u8981\u5efa\u7acb\u65b0\u7684\u5957\u63a5\u5b57\uff08\u5373\u8fde\u63a5\u5957\u63a5\u5b57 Connected Socket\uff09<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u5148\u5047\u8bbe\u4e00\u4e2a\u60c5\u51b5\uff0c\u670d\u52a1\u5668\u53ea\u6709\u76d1\u542c\u5957\u63a5\u5b57\u4f1a\u600e\u4e48\u6837\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u73b0\u5728\u6709\u4e24\u53f0\u5ba2\u6237\u7aef\u8fde\u63a5\u4e00\u4e2a\u670d\u52a1\u5668\uff0c\u90a3\u4e48\u670d\u52a1\u7aef\u7684\u76d1\u542c\u5957\u63a5\u5b57\u540c\u65f6\u4e0e\u4e24\u4e2a\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u76f8\u8fde\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u4e24\u4e2a\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u540c\u4eab\u4e00\u4e2a\u76d1\u542c\u5957\u63a5\u5b57\u7f13\u51b2\u533a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6b64\u65f6\u4f1a\u51fa\u73b0\u4e00\u79cd\u60c5\u51b5\uff0c\u5982\u679c\u6211\u7684\u5ba2\u6237\u7aef1\u53d1\u9001\u6d88\u606f\uff0c\u76d1\u542c\u5957\u63a5\u5b57\u7f13\u51b2\u533a\u521a\u521a\u5199\u5165\u4e00\u534a\u6d88\u606f\uff0c\u5ba2\u6237\u7aef2\u53d1\u9001\u4e86\u6d88\u606f\uff0c\u4e8e\u662f\uff0c\u5ba2\u6237\u7aef2\u7684\u6d88\u606f\u4e5f\u88ab\u5199\u5165\u4e86\u4e00\u90e8\u5206\u8fdb\u5165\u4e86\u7f13\u51b2\u533a\uff0c\u90a3\u4e48\u4e24\u8005\u7684\u6570\u636e\u53d1\u9001\u4e86\u51b2\u7a81\uff0c\u610f\u5473\u7740\u8fd9\u4e2a\u6d88\u606f\u5df2\u7ecf\u4f5c\u5e9f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u65f6\u5019\u6709\u4eba\u8981\u95ee\u4e86\uff0c\u90a3\u4e48\u6211\u53ef\u4ee5\u8ba9\u4e00\u4e2a\u6d88\u606f\u5199\u5b8c\u518d\u5199\u53e6\u5916\u4e00\u4e2a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u5047\u8bbe\u67091000000\u53f0\u5ba2\u670d\u7aef\u540c\u65f6\u8bbf\u95ee\u4e00\u4e2a\u670d\u52a1\u7aef\uff0c\u5047\u8bbe\u670d\u52a1\u5668\u6027\u80fd\u8db3\u591f\u7684\u60c5\u51b5\u4e0b\uff0c\u56fa\u5b9a\u5904\u7406\u4e00\u4e2a\u6d88\u606f\u8017\u65f61\u79d2\uff0c\u90a3\u4e48\u4e5f\u5c31\u610f\u5473\u7740\uff0c\u5f53\u5ba2\u6237\u7aef\u4f1a\u6392\u51fa\u957f\u961f\uff0c\u6700\u540e\u4e00\u4e2a\u5ba2\u6237\u7aef\u7684\u8bf7\u6c42\u9700\u8981\u7b49\u52301000000\u79d2\u540e\u54cd\u5e94\uff0c\u5dee\u4e0d\u591a11\u5929\u534a\u3002\u90a3\u4e48\u89e3\u51b3\u65b9\u6848\u662f\u4ec0\u4e48\u5462\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u670d\u52a1\u5668\u4e2d\u5efa\u7acb\u4e00\u4e2a\u4e13\u5c5e\u7684\u5957\u63a5\u5b57\u4e0e\u4e00\u4e2a\u5ba2\u6237\u7aef\u4e00\u5bf9\u4e00\u8fdb\u884c\u5904\u7406\uff0c\u5728\u8fd9\u4e2a\u60c5\u51b5\u4e0b\uff0c\u4f9d\u65e7\u5047\u8bbe\u670d\u52a1\u5668\u6027\u80fd\u8db3\u591f\u7684\u60c5\u51b5\u4e0b\uff0c\u5c31\u53d8\u6210\u6240\u6709\u7684\u5ba2\u6237\u7aef\u8bf7\u6c42\u5e76\u884c\u8ba1\u7b97\uff0c\u90a3\u4e48\u6700\u7ec8\u53ea\u9700\u89811\u79d2\u89e3\u51b3\u6240\u6709\u5ba2\u6237\u7684\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5c3d\u7ba1\u5728\u5b9e\u9645\u4e0a\uff0c\u670d\u52a1\u5668\u7684\u6027\u80fd\u6709\u9650\uff0c\u90a3\u4e48\u4e5f\u4f9d\u65e7\u6548\u7387\u6bd4\u9010\u4e00\u5904\u7406\u9ad8\u51fa\u51e0\u4f55\u500d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;          \/* See NOTES *\/\n#include &lt;sys\/socket.h&gt;\n\nint accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>sockfd<\/code>\uff1a\u7528\u6765\u6807\u8bc6\u670d\u52a1\u7aef\u5957\u63a5\u5b57\uff0c\u4e5f\u5c31\u662flisten\u51fd\u6570\u4e2d\u8bbe\u7f6e\u4e3a\u76d1\u542c\u72b6\u6001\u7684\u5957\u63a5\u5b57\u3002<\/li>\n\n\n\n<li><code>addr<\/code>\uff1a\u662f\u4e00\u4e2a\u4f20\u51fa\u53c2\u6570\uff0c\u7528\u6765\u4fdd\u5b58\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u5bf9\u5e94\u7684\u5185\u5b58\u7a7a\u95f4\u53d8\u91cf\uff08\u5305\u62ec\u5ba2\u6237\u7aefIP\u548c\u7aef\u53e3\u4fe1\u606f\u7b49\uff09\u3002\u5982\u679c\u5e94\u7528\u5c42\u4e0d\u9700\u8981\u8bb0\u5f55\u5ba2\u6237\u7aef\u7684IP\u548c\u7aef\u53e3\u53f7\uff0c\u5219\u53ef\u4ee5\u8bbe\u7f6e\u4e3aNULL\u3002<\/li>\n\n\n\n<li><code>addrlen<\/code>\uff1a\u8fd9\u662f\u4e00\u4e2a\u4f20\u5165\u4f20\u51fa\u53c2\u6570\uff0c\u4f20\u5165\u65f6\u4e3a\u51fd\u6570\u8c03\u7528\u65f6\u63d0\u4f9b\u53c2\u6570addr\u7684\u957f\u5ea6\uff0c\u4f20\u51fa\u65f6\u4e3a\u5ba2\u6237\u7aef\u5730\u5740\u7ed3\u6784\u4f53\u7684\u5b9e\u9645\u957f\u5ea6\u3002\u5982\u679c<code>addr<\/code>\u4e3a<code>NULL<\/code>\uff0c\u90a3\u4e48\u8fd9\u4e2a\u503c\u4e5f\u4e3a<code>NULL<\/code><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u9996\u5148\u9700\u8981\u4e86\u89e3\u7684\u4e00\u70b9\u662f\uff0c<strong>sockfd\u662f\u7c7b\u4f3c\u4e8e\u4e00\u4e2a\u201d\u6307\u9488\u201c<\/strong>\uff0c\u5b83\u6307\u5411<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u751f\u6210\u7684\u4e00\u4e2a\u7528\u6765\u6807\u8bc6\u670d\u52a1\u5668\u7aef\u7684\u5957\u63a5\u5b57<\/mark>\uff0c\u8fd9\u4e2a\u5957\u63a5\u5b57\u7528\u4e8e\u76d1\u542c\u548c\u63a5\u53d7\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u3002\u800c\u51fd\u6570\u7684\u8fd4\u56de\u503c\u662f\u4e00\u4e2a\u901a\u4fe1\u63cf\u8ff0\u7b26\uff08\u901a\u5e38\u79f0\u4e3a<code>acceptfd<\/code>\uff09\uff0c\u8fd9\u4e2a<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u63cf\u8ff0\u7b26\u662f\u4ecesockfd\u6d3e\u751f\u51fa\u6765\u7684<\/mark>\uff0c\u5b83\u6307\u5411\u4e8e\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u751f\u6210\u4e00\u4e2a\u6709\u5173\u5ba2\u6237\u7aef\u7684\u5957\u63a5\u5b57\uff0c<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u800c<code>addr<\/code>\u53c2\u6570\u5219\u66f4\u50cf\u662f\u4e00\u4e2a\u5907\u5fd8\u5f55<\/mark>\uff0c\u5982\u679c\u4f60\u60f3\u5c06\u8fd9\u4e2a\u6709\u5173\u5ba2\u6237\u7aef\u7684\u5957\u63a5\u5b57\u8bb0\u5f55\u4e0b\u6765\uff0c\u4f60\u53ef\u4ee5\u4f20\u5165\u4e00\u4e2a\u7a7a\u5957\u63a5\u5b57\u5730\u5740\uff0c\u90a3\u4e48\u51fd\u6570\u4f1a\u590d\u5236\u4e00\u4e2a\u526f\u672c\u5230\u4f20\u5165\u7684\u5730\u5740\u4e2d\uff0c\u5982\u679c\u4e0d\u9700\u8981\u5219\u586b\u5199<code>NULL<\/code>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\uff1a\u8fd4\u56de\u4e00\u4e2a\u670d\u52a1\u5668\u7528\u4e8e\u4ee5\u540e\u901a\u4fe1\u7684\u201c\u901a\u4fe1\u63cf\u8ff0\u7b26\u201d\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\uff1a\u8fd4\u56de-1<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">connect\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u51fd\u6570\u4e3b\u8981\u7528\u4e8e\u5ba2\u6237\u7aef\u5411\u670d\u52a1\u7aef\u53d1\u9001\u8fde\u63a5\u7533\u8bf7\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;          \/* See NOTES *\/\n#include &lt;sys\/socket.h&gt;\n\nint connect(int sockfd, struct sockaddr *serv_addr, int addrlen);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>sockfd<\/strong>\uff1a\u901a\u8fc7\u8c03\u7528socket()\u51fd\u6570\u83b7\u5f97\u7684\u5957\u63a5\u5b57\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li><strong>serv_addr<\/strong>\uff1a\u6307\u5411\u4e00\u4e2a\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u8be5\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u6211\u4eec\u60f3\u8981\u8fde\u63a5\u7684\u670d\u52a1\u7aef\u7684\u5730\u5740\u548c\u7aef\u53e3\u4fe1\u606f\u3002\u8fd9\u4e2a\u7ed3\u6784\u4f53\u53ef\u4ee5\u662fsockaddr_in\uff08\u7528\u4e8eIPv4\uff09\u6216sockaddr_in6\uff08\u7528\u4e8eIPv6\uff09\u3002<\/li>\n\n\n\n<li><strong>addrlen<\/strong>\uff1aserv_addr\u6307\u5411\u7684\u7ed3\u6784\u4f53\u7684\u5927\u5c0f\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u4e2d\u7684\u53c2\u6570<strong>sockfd\u662f\u7c7b\u4f3c\u4e8e\u4e00\u4e2a\u201d\u6307\u9488\u201c<\/strong>\uff0c\u5b83\u6307\u5411<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u751f\u6210\u7684\u4e00\u4e2a\u7528\u6765\u6807\u8bc6\u5ba2\u6237\u7aef\u7684\u5957\u63a5\u5b57<\/mark>\uff0c\u8be5\u5957\u63a5\u5b57\u7528\u4e8e\u4e0e\u670d\u52a1\u5668\u5efa\u7acb\u8fde\u63a5\u3002<strong>\u800cserv_addr\u662f\u5bf9\u670d\u52a1\u5668\u7684\u4e00\u4e2a\u5957\u63a5\u5b57\u63cf\u8ff0<\/strong>\uff0c\u800c\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u5b58\u5728\u4e00\u4e2a\u8fde\u63a5\u8868\uff08CCB\uff09\uff0c\u8fd9\u4e2a\u8868\u4e2d\u8bb0\u5f55\u4e86\u5173\u4e8e\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u548c\u670d\u52a1\u7aef\u5730\u5740\u7684\u4fe1\u606f\uff0cserv_addr\u4f20\u5165\u7684\u4fe1\u606f\u4f1a\u88ab<strong>\u590d\u5236<\/strong>\u5230\u8fd9\u4e2a\u8fde\u63a5\u8868\u4e2d\uff0c<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u6ce8\u610f\u5e76\u4e0d\u662f\u76f4\u63a5\u4f7f\u7528serv_addr\u7684\u5730\u5740\uff0c\u800c\u662f\u8fd9\u4e2a\u5730\u5740\u4e2d\u7684\u503c\u7684\u526f\u672c\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u5373\u4fbf\u5728serv_addr\u5728\u51fd\u6570\u6267\u884c\u5b8c\u6210\u540e\u9500\u6bc1\u4e86\uff0c\u4e5f\u4e0d\u4f1a\u5f71\u54cd\u5230\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u7684\u6570\u636e\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\uff1a\u8fd4\u56de0\uff0c\u8868\u793a\u8fde\u63a5\u5df2\u7ecf\u6210\u529f\u5efa\u7acb\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\uff1a\u8fd4\u56de-1\uff0c\u5e76\u4f1a\u8bbe\u7f6e\u5168\u5c40\u9519\u8bef\u53d8\u91cferrno\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">TCP\u534f\u8bae\u4e0b\u7684\u5ba2\u6237\u7aef\u4e0e\u670d\u52a1\u7aef\u5de5\u4f5c\u6d41\u7a0b\uff1a<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u5957\u63a5\u5b57\u51c6\u5907\uff1a<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e8c\u5143\u7ec4\u5957\u63a5\u5b57\u2014\u2014\u76d1\u542c\u5957\u63a5\u5b57\uff08<strong>Client Socket<\/strong>\uff09\uff1a\u5305\u542b\u5ba2\u6237\u7aef\u7684 IP \u5730\u5740\u548c\u7aef\u53e3\u53f7<\/li>\n\n\n\n<li>\u4e8c\u5143\u7ec4\u5957\u63a5\u5b57\u2014\u2014\u5ba2\u6237\u7aef\u5957\u63a5\u5b57<strong>\uff08Listening Socket\uff09<\/strong>\uff1a\u5305\u542b\u670d\u52a1\u5668\u7684 IP \u5730\u5740\u548c\u7aef\u53e3\u53f7<\/li>\n\n\n\n<li>\u56db\u5143\u7ec4\u5957\u63a5\u5b57\u2014\u2014\u8fde\u63a5\u5957\u63a5\u5b57 \uff08<strong>Connected Socket<\/strong>\uff09\uff1a\u5305\u542b\u5ba2\u6237\u7aef\u7684 IP \u5730\u5740\u3001\u5ba2\u6237\u7aef\u7684\u7aef\u53e3\u53f7\u3001\u670d\u52a1\u5668\u7684 IP \u5730\u5740\u548c\u670d\u52a1\u5668\u7684\u7aef\u53e3\u53f7<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u8fc7\u7a0b\uff1a<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u5ba2\u6237\u7aef\uff1a<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5ba2\u6237\u7aef\u751f\u6210\u4e8c\u5143\u7ec4\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\uff0c\u901a\u8fc7\u4f7f\u7528connect\u51fd\u6570\uff0c\u5c06\u4f20\u5165\u7684\u670d\u52a1\u7aef\u7684<strong>\u5957\u63a5\u5b57\u5730\u5740\u7ed3\u6784\u4f53<\/strong>\u7684\u4fe1\u606f\u5199\u5165\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u8d1f\u8d23\u7ef4\u62a4\u7684<strong>\u8fde\u63a5\u8868<\/strong>\u4e2d\uff0c\u5e76\u901a\u8fc7\u8fde\u63a5\u8868\u4fe1\u606f\u548c\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u4fe1\u606f\u7ec4\u5408\uff0c\u5411\u670d\u52a1\u5668\u53d1\u9001\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u670d\u52a1\u7aef\uff1a<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u670d\u52a1\u7aef\u751f\u6210\u4e8c\u5143\u7ec4\u76d1\u542c\u5957\u63a5\u5b57\uff0c\u5e76\u4f7f\u7528bind\u7ed1\u5b9a\u4e86\u670d\u52a1\u5668\u7aef\u53e3\u548cip\uff0c<strong>\u4f7f\u7528listen\u5c06\u5957\u63a5\u5b57\u8f6c\u5316\u4e3a\u88ab\u52a8\u8bf7\u6c42\u7c7b\u578b<\/strong>\uff0c\u901a\u8fc7accpet\u7b49\u5f85\u8fde\u63a5\u3002\u5f53\u6570\u636e\u4fe1\u606f\u88ab\u670d\u52a1\u7aef\u63a5\u6536\u5230\u540e\uff0c\u670d\u52a1\u5668\u7684\u7f51\u7edc\u6808\u4f1a\u5224\u65ad\u6d88\u606f\u7c7b\u578b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u4e3a\u8fde\u63a5\u8bf7\u6c42\uff0c\u5219\u7acb\u5373\u5c06\u6d88\u606f\u8f6c\u79fb\u5230\u76d1\u542c\u5957\u63a5\u5b57\u4e2d\uff0c\u76d1\u542c\u5957\u63a5\u5b57\u6536\u5230\u8fde\u63a5\u8bf7\u6c42\uff0c\u6fc0\u6d3baccept\u51fd\u6570\uff0c\u751f\u6210\u4e00\u4e2a\u5305\u542b\u5ba2\u6237\u7aef\u4fe1\u606f\u4e0e\u670d\u52a1\u7aef\u4fe1\u606f\u7684\u56db\u5143\u8fde\u63a5\u5957\u63a5\u5b57\uff0c\u5e76\u5199\u5165\u64cd\u4f5c\u7cfb\u7edf\u5185\u90e8\u7ef4\u62a4\u7684\u4e00\u5f20<strong>hash\u8868<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u7f51\u7edc\u6808\u5224\u65ad\u6d88\u606f\u4e3a\u6570\u636e\u5305\uff0c\u90a3\u4e48\u5c31\u4f1a<strong>\u901a\u8fc7hash\u8868\u67e5\u627e\u5bf9\u5e94\u7684\u8fde\u63a5\u5957\u63a5\u5b57<\/strong>\uff0c\u4e4b\u540e\u5c06\u6570\u636e\u5305\u8f6c\u79fb\u5230\u8be5\u8fde\u63a5\u5957\u63a5\u5b57\u4e2d\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u6570\u636e\u7684\u53d1\u9001\u548c\u63a5\u6536<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">send\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u51fd\u6570\u662f\u53d1\u9001\u51fd\u6570\uff0c\u5b83\u80fd\u5c06\u7f13\u51b2\u533a\u7684\u6d88\u606f\u53d1\u9001\u51fa\u53bb\u3002\u4f46\u662f\u5b58\u5728\u4e00\u4e2a\u9700\u8981\u6ce8\u610f\u7684\u70b9\uff1asend\u51fd\u6570\u5b58\u5728\u53d1\u9001\u9650\u5236\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u5b83\u4e0d\u4e00\u5b9a\u4f1a\u5c06\u7f13\u51b2\u533a\u5168\u90e8\u53d1\u9001\u51fa\u53bb\uff0c\u4f46\u662f\u5b83\u4f1a\u8fd4\u56de\u4e00\u4e2a\u53d1\u9001\u5b57\u8282\u603b\u6570\u3002\u53d1\u9001\u4e0a\u9650\u901a\u5e38\u53d6\u51b3\u4e8e\u591a\u4e2a\u56e0\u7d20\uff0c\u5305\u62ec\u7f51\u7edc\u72b6\u51b5\u3001\u5957\u63a5\u5b57\u7f13\u51b2\u533a\u7684\u5927\u5c0f\u4ee5\u53ca\u64cd\u4f5c\u7cfb\u7edf\u7684\u5b9e\u73b0\u7b49\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5927\u591a\u6570\u7cfb\u7edf\u4e0a\uff0c\u9ed8\u8ba4\u7684\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u901a\u5e38\u5728\u51e0\u5343\u5b57\u8282\u5230\u51e0\u5341\u5343\u5b57\u8282\u4e4b\u95f4\u3002\u4f8b\u5982\uff0cLinux\u7cfb\u7edf\u4e0a\u7684\u9ed8\u8ba4\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u901a\u5e38\u662f16KB\u621664KB\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n\nssize_t send(int sockfd, const void *buf, size_t len, int flags);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>sockfd<\/code><\/strong>\uff1a\u5957\u63a5\u5b57\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u6807\u8bc6\u4e00\u4e2a\u5df2\u8fde\u63a5\u7684\u5957\u63a5\u5b57\u3002<\/li>\n\n\n\n<li><strong><code>buf<\/code><\/strong>\uff1a\u6307\u5411\u8981\u53d1\u9001\u7684\u6570\u636e\u7f13\u51b2\u533a\u7684\u6307\u9488\u3002<\/li>\n\n\n\n<li><strong><code>len<\/code><\/strong>\uff1a\u8981\u53d1\u9001\u7684\u6570\u636e\u957f\u5ea6\uff0c\u4ee5\u5b57\u8282\u4e3a\u5355\u4f4d\u3002<\/li>\n\n\n\n<li><strong><code>flags<\/code><\/strong>\uff1a\u53d1\u9001\u6570\u636e\u65f6\u7684\u6807\u5fd7\uff0c\u53ef\u4ee5\u662f\u4ee5\u4e0b\u503c\u7684\u7ec4\u5408\uff1a\n<ul class=\"wp-block-list\">\n<li><code>0<\/code>\uff1a\u9ed8\u8ba4\u503c\uff0c\u6ca1\u6709\u7279\u6b8a\u6807\u5fd7\u3002<\/li>\n\n\n\n<li><code>MSG_DONTROUTE<\/code>\uff1a\u6570\u636e\u5305\u4e0d\u7ecf\u8fc7\u8def\u7531\u8868\uff0c\u76f4\u63a5\u53d1\u9001\u5230\u672c\u5730\u7f51\u7edc\u3002<\/li>\n\n\n\n<li><code>MSG_OOB<\/code>\uff1a\u53d1\u9001\u5e26\u5916\u6570\u636e\u3002<\/li>\n\n\n\n<li><code>MSG_DONTWAIT<\/code>\uff1a\u975e\u963b\u585e\u53d1\u9001\uff0c\u5982\u679c\u5957\u63a5\u5b57\u4e0d\u53ef\u5199\uff0c\u7acb\u5373\u8fd4\u56de\u3002<\/li>\n\n\n\n<li><code>MSG_NOSIGNAL<\/code>\uff1a\u53d1\u9001\u65f6\u4e0d\u4ea7\u751f&nbsp;<code>SIGPIPE<\/code>&nbsp;\u4fe1\u53f7\u3002\u5b83\u901a\u5e38\u5728\u4ee5\u4e0b\u60c5\u51b5\u4e0b\u4ea7\u751f\uff1a\u5f53\u4f60\u5c1d\u8bd5\u5411\u4e00\u4e2a\u5df2\u7ecf\u5173\u95ed\u7684\u5957\u63a5\u5b57\u53d1\u9001\u6570\u636e\u65f6\uff0c\u7cfb\u7edf\u4f1a\u5411\u8fdb\u7a0b\u53d1\u9001\u4e00\u4e2a&nbsp;<code>SIGPIPE<\/code>&nbsp;\u4fe1\u53f7\u3002\u800c\u8fd9\u4e2a\u4fe1\u53f7\u4f1a\u5bfc\u81f4\u8fdb\u7a0b\u5f02\u5e38\u7ec8\u6b62\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de\u5b9e\u9645\u53d1\u9001\u7684\u5b57\u8282\u6570\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de -1\uff0c\u5e76\u8bbe\u7f6e&nbsp;<code>errno<\/code>&nbsp;\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b\uff1a<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>size_t total_bytes_sent = 0;\/\/\u5df2\u53d1\u9001\u7684\u6570\u636e\nsize_t bytes_to_send = strlen(buffer);\/\/\u603b\u6570\u636e\n\n \/\/ \u5faa\u73af\u53d1\u9001\u6d88\u606f\uff0c\u76f4\u5230\u6240\u6709\u6570\u636e\u90fd\u88ab\u53d1\u9001\nwhile (total_bytes_sent &lt; bytes_to_send) {\n        \/\/\u53d1\u9001\u6570\u636e\uff0c\u5e76\u8bb0\u5f55\u5f53\u524d\u6210\u529f\u53d1\u9001\u7684\u5b57\u8282\u6570\n        ssize_t bytes_sent = send(sockfd, buffer + total_bytes_sent, bytes_to_send - total_bytes_sent, 0);\n        \/\/\u53d1\u9001\u5931\u8d25\u5224\u65ad\n        if (bytes_sent == -1) {\n            perror(\"send failed\");\n            break;\n        }\n        \/\/\u66f4\u65b0\u5f53\u524d\u53d1\u9001\u7684\u6570\u636e\u603b\u6570\n        total_bytes_sent += bytes_sent;\n}<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">recv\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u63a5\u6536\u51fd\u6570\u548c\u53d1\u9001\u51fd\u6570\u4e00\u6837\uff0c\u5b83\u53ef\u80fd\u4e0d\u4f1a\u4e00\u6b21\u6027\u63a5\u53d7\u6240\u6709\u7684\u6570\u636e\uff0c\u8fd4\u56de\u503c\u8868\u793a\u5b9e\u9645\u63a5\u6536\u7684\u5b57\u8282\u6570\u3002\u9700\u8981\u5728\u5faa\u73af\u4e2d\u8c03\u7528&nbsp;<code>recv<\/code>&nbsp;\u76f4\u5230\u6240\u6709\u6570\u636e\u63a5\u6536\u5b8c\u6bd5\u3002\u5b83\u7684\u63a5\u6536\u4e0a\u9650\u5f80\u5f80\u548c\u53d1\u9001\u4e0a\u9650\u4e00\u81f4<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n\nssize_t recv(int sockfd, void *buf, size_t len, int flags);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>sockfd<\/code><\/strong>\uff1a\u5957\u63a5\u5b57\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u6807\u8bc6\u4e00\u4e2a\u5df2\u8fde\u63a5\u7684\u5957\u63a5\u5b57\u3002<\/li>\n\n\n\n<li><strong><code>buf<\/code><\/strong>\uff1a\u6307\u5411\u63a5\u6536\u6570\u636e\u7f13\u51b2\u533a\u7684\u6307\u9488\u3002<\/li>\n\n\n\n<li><strong><code>len<\/code><\/strong>\uff1a\u7f13\u51b2\u533a\u7684\u957f\u5ea6\uff0c\u4ee5\u5b57\u8282\u4e3a\u5355\u4f4d\u3002<\/li>\n\n\n\n<li><strong><code>flags<\/code><\/strong>\uff1a\u63a5\u6536\u6570\u636e\u65f6\u7684\u6807\u5fd7\uff0c\u53ef\u4ee5\u662f\u4ee5\u4e0b\u503c\u7684\u7ec4\u5408\uff1a\n<ul class=\"wp-block-list\">\n<li><code>0<\/code>\uff1a\u9ed8\u8ba4\u503c\uff0c\u6ca1\u6709\u7279\u6b8a\u6807\u5fd7\u3002<\/li>\n\n\n\n<li><code>MSG_PEEK<\/code>\uff1a\u67e5\u770b\u6570\u636e\u4f46\u4e0d\u4ece\u7f13\u51b2\u533a\u4e2d\u79fb\u9664\u3002<\/li>\n\n\n\n<li><code>MSG_WAITALL<\/code>\uff1a\u7b49\u5f85\u6240\u6709\u6570\u636e\u5230\u8fbe\u540e\u518d\u8fd4\u56de\u3002<\/li>\n\n\n\n<li><code>MSG_DONTWAIT<\/code>\uff1a\u975e\u963b\u585e\u63a5\u6536\uff0c\u5982\u679c\u6ca1\u6709\u6570\u636e\u53ef\u8bfb\uff0c\u7acb\u5373\u8fd4\u56de\u3002<\/li>\n\n\n\n<li><code>MSG_OOB<\/code>\uff1a\u63a5\u6536\u5e26\u5916\u6570\u636e\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de\u5b9e\u9645\u63a5\u6536\u7684\u5b57\u8282\u6570\u3002<\/li>\n\n\n\n<li>\u8fde\u63a5\u5173\u95ed\u65f6\uff0c\u8fd4\u56de 0\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de -1\uff0c\u5e76\u8bbe\u7f6e&nbsp;<code>errno<\/code>&nbsp;\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u8fde\u63a5\u7684\u5173\u95ed<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5957\u63a5\u5b57\u5728Linux\u7cfb\u7edf\u4e2d\u5df2\u7ecf\u88ab\u62bd\u8c61\u6210\u4e3a\u6587\u4ef6\uff0c\u6240\u4ee5\u53ef\u4ee5\u4f7f\u7528close(\u6587\u4ef6\u63cf\u8ff0\u7b26)\u7684\u65b9\u5f0f\u65ad\u5f00\u8fde\u63a5\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u7531\u5ba2\u6237\u7aef\u8fdb\u884c\u8fde\u63a5\u7684\u65ad\u5f00\uff0c\u5f53\u5ba2\u6237\u7aef\u8fdb\u884cclose\u64cd\u4f5c\u540e\uff0c\u4f1a\u6fc0\u6d3b\u56db\u6b21\u6325\u624b\u64cd\u4f5c\uff0c\u670d\u52a1\u7aef\u7684\u8bfb\u5199\u51fd\u6570\u4f1a\u8fd4\u56de\u54cd\u5e94\u7684\u9519\u8bef\u503c\uff0c\u7528\u4e8e\u5224\u65ad\u5ba2\u6237\u7aef\u5df2\u7ecf\u65ad\u5f00\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u63a8\u8350\u670d\u52a1\u7aef\u63a5\u6536\u5230\u6d88\u606f\u540e\u663e\u5f0f\u8c03\u7528close\u5173\u95ed\u8fde\u63a5\u5957\u63a5\u5b57\uff0c\u56e0\u4e3a\u8fd9\u4f1a\u663e\u5f0f\u56de\u6536\u8d44\u6e90\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><strong><kbd>UDP\u7f16\u7a0b<\/kbd><\/strong><\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">UDP\uff08\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae\uff09\u662f\u4e00\u79cd\u7b80\u5355\u7684\u4f20\u8f93\u5c42\u534f\u8bae\uff0c\u5b83\u7684\u8bbe\u8ba1\u521d\u8877\u662f\u7b80\u5355\u9ad8\u6548\uff0c\u4e3b\u8981\u7279\u70b9\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u65e0\u8fde\u63a5<\/strong>\uff1aUDP\u662f\u65e0\u8fde\u63a5\u7684\u534f\u8bae\uff0c\u8fd9\u610f\u5473\u7740\u5728\u53d1\u9001\u6570\u636e\u4e4b\u524d\u4e0d\u9700\u8981\u5efa\u7acb\u8fde\u63a5\u3002\u6bcf\u4e2a\u6570\u636e\u5305\uff08\u79f0\u4e3a\u6570\u636e\u62a5\uff09\u90fd\u662f\u72ec\u7acb\u7684\u3002<\/li>\n\n\n\n<li><strong>\u4e0d\u53ef\u9760\u4f20\u8f93<\/strong>\uff1aUDP\u4e0d\u4fdd\u8bc1\u6570\u636e\u5305\u7684\u9001\u8fbe\u987a\u5e8f\uff0c\u4e5f\u4e0d\u4fdd\u8bc1\u6570\u636e\u5305\u7684\u9001\u8fbe\u3002\u6570\u636e\u5305\u53ef\u80fd\u4f1a\u4e22\u5931\u3001\u91cd\u590d\u6216\u4e71\u5e8f\u3002<\/li>\n\n\n\n<li><strong>\u8f7b\u91cf\u7ea7<\/strong>\uff1a\u7531\u4e8eUDP\u4e0d\u9700\u8981\u5efa\u7acb\u548c\u7ef4\u62a4\u8fde\u63a5\uff0c\u5b83\u7684\u5f00\u9500\u6bd4TCP\u5c0f\uff0c\u9002\u7528\u4e8e\u9700\u8981\u5feb\u901f\u4f20\u8f93\u6570\u636e\u7684\u573a\u666f\u3002<\/li>\n\n\n\n<li><strong>\u65e0\u6d41\u91cf\u63a7\u5236\u548c\u62e5\u585e\u63a7\u5236<\/strong>\uff1aUDP\u6ca1\u6709TCP\u90a3\u6837\u7684\u6d41\u91cf\u63a7\u5236\u548c\u62e5\u585e\u63a7\u5236\u673a\u5236\uff0c\u56e0\u6b64\u5728\u7f51\u7edc\u62e5\u585e\u65f6\uff0cUDP\u7684\u6570\u636e\u5305\u53ef\u80fd\u4f1a\u88ab\u4e22\u5f03\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">UDP\u9002\u7528\u4e8e\u4ee5\u4e0b\u573a\u666f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5b9e\u65f6\u5e94\u7528<\/strong>\uff1a\u5982\u89c6\u9891\u4f1a\u8bae\u3001\u5728\u7ebf\u6e38\u620f\u548c\u5b9e\u65f6\u97f3\u9891\u4f20\u8f93\u3002<\/li>\n\n\n\n<li><strong>\u7b80\u5355\u67e5\u8be2<\/strong>\uff1a\u5982DNS\u67e5\u8be2\u3002<\/li>\n\n\n\n<li><strong>\u5e7f\u64ad\u548c\u591a\u64ad<\/strong>\uff1a\u5982\u7f51\u7edc\u53d1\u73b0\u534f\u8bae\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5c3d\u7ba1UDP\u6709\u5176\u5c40\u9650\u6027\uff0c\u4f46\u5728\u9700\u8981\u5feb\u901f\u4f20\u8f93\u4e14\u5bf9\u53ef\u9760\u6027\u8981\u6c42\u4e0d\u9ad8\u7684\u573a\u666f\u4e2d\uff0c\u5b83\u662f\u4e00\u4e2a\u975e\u5e38\u6709\u6548\u7684\u9009\u62e9\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u8fde\u63a5\u4e0e\u5173\u95ed<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">UDP\u4e0d\u9700\u8981\u7ecf\u5386TCP\u7684\u4e09\u6b21\u63e1\u624b\u548c\u6325\u624b\uff0c\u5b83\u53ea\u9700\u8981\u5728\u5957\u63a5\u5b57\u5bf9\u8c61\u751f\u6210\u540e\uff0c\u4f7f\u7528\u53d1\u9001\u6570\u636e\u5373\u53ef\u3002\u540c\u7406\u5173\u95ed\u4e5f\u4e0d\u9700\u8981\u7ecf\u5386\u56db\u6b21\u6325\u624b\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u6570\u636e\u53d1\u9001\u4e0e\u63a5\u6536<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">sendto\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n\nssize_t sendto(int sockfd, const void *buf, size_t len, int flags,const struct sockaddr *dest_addr, socklen_t addrlen);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>sockfd<\/code>\uff1a\u5957\u63a5\u5b57\u63cf\u8ff0\u7b26\uff0c\u8868\u793a\u8981\u53d1\u9001\u6570\u636e\u7684\u5957\u63a5\u5b57\u3002<\/li>\n\n\n\n<li><code>msg<\/code>\uff1a\u6307\u5411\u8981\u53d1\u9001\u7684\u6570\u636e\u7684\u6307\u9488\u3002<\/li>\n\n\n\n<li><code>len<\/code>\uff1a\u8981\u53d1\u9001\u7684\u6570\u636e\u7684\u957f\u5ea6\uff08\u5b57\u8282\u6570\uff09\u3002<\/li>\n\n\n\n<li><code>flags<\/code>\uff1a\u53d1\u9001\u6807\u5fd7\uff0c\u901a\u5e38\u8bbe\u7f6e\u4e3a0\u3002<\/li>\n\n\n\n<li><code>to<\/code>\uff1a\u6307\u5411\u76ee\u6807\u5730\u5740\u7684\u6307\u9488\uff0c\u5305\u542b\u76ee\u6807IP\u5730\u5740\u548c\u7aef\u53e3\u53f7\u3002<\/li>\n\n\n\n<li><code>tolen<\/code>\uff1a\u76ee\u6807\u5730\u5740\u7684\u957f\u5ea6\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u53d1\u9001\u6210\u529f\u8fd4\u56de\u5b9e\u9645\u53d1\u9001\u51fa\u53bb\u7684\u5b57\u8282\u6570\u91cf\u3002<\/li>\n\n\n\n<li>\u53d1\u9001\u5931\u8d25\u8fd4\u56de-1\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n#include &lt;netinet\/in.h&gt;\n#include &lt;arpa\/inet.h&gt;\n#include &lt;unistd.h&gt;\n#include &lt;stdio.h&gt;\n#include &lt;string.h&gt;\n\nint main() {\n    int sockfd;\n    struct sockaddr_in servaddr;\n\n    \/\/ \u521b\u5efaUDP\u5957\u63a5\u5b57\n    sockfd = socket(AF_INET, SOCK_DGRAM, 0);\n\n    \/\/ \u8bbe\u7f6e\u76ee\u6807\u5730\u5740\n    memset(&amp;servaddr, 0, sizeof(servaddr));\n    servaddr.sin_family = AF_INET;\n    servaddr.sin_port = htons(8080);\n    inet_pton(AF_INET, \"127.0.0.1\", &amp;servaddr.sin_addr);\n\n    \/\/ \u8981\u53d1\u9001\u7684\u6570\u636e\n    const char *message = \"Hello, UDP!\";\n\n    \/\/ \u53d1\u9001\u6570\u636e\n    sendto(sockfd, message, strlen(message), 0, (const struct sockaddr *)&amp;servaddr, sizeof(servaddr));\n\n    \/\/ \u5173\u95ed\u5957\u63a5\u5b57\n    close(sockfd);\n\n    return 0;\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">recvfrom\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n\nssize_t recvfrom(int sockfd, void *buf, size_t len, int flags,struct sockaddr *src_addr, socklen_t *addrlen);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>sockfd<\/code>\uff1a\u5957\u63a5\u5b57\u63cf\u8ff0\u7b26\uff0c\u8868\u793a\u8981\u63a5\u6536\u6570\u636e\u7684\u5957\u63a5\u5b57\u3002<\/li>\n\n\n\n<li><code>buf<\/code>\uff1a\u6307\u5411\u7528\u4e8e\u5b58\u653e\u63a5\u6536\u5230\u7684\u6570\u636e\u7684\u7f13\u51b2\u533a\u7684\u6307\u9488\u3002<\/li>\n\n\n\n<li><code>len<\/code>\uff1a\u7f13\u51b2\u533a\u7684\u5927\u5c0f\uff08\u4ee5\u5b57\u8282\u4e3a\u5355\u4f4d\uff09\u3002<\/li>\n\n\n\n<li><code>flags<\/code>\uff1a\u63a7\u5236\u63a5\u6536\u884c\u4e3a\u7684\u6807\u5fd7\uff0c\u901a\u5e38\u8bbe\u7f6e\u4e3a0\u3002<\/li>\n\n\n\n<li><code>src_addr<\/code>\uff1a\u6307\u5411<code>sockaddr<\/code>\u7ed3\u6784\u7684\u6307\u9488\uff0c\u7528\u4e8e\u4fdd\u5b58\u53d1\u9001\u6570\u636e\u7684\u6e90\u5730\u5740\u3002<\/li>\n\n\n\n<li><code>addrlen<\/code>\uff1a\u4e00\u4e2a\u503c-\u7ed3\u679c\u53c2\u6570\uff0c\u5f00\u59cb\u65f6\u5e94\u8bbe\u7f6e\u4e3a<code>src_addr<\/code>\u7f13\u51b2\u533a\u7684\u5927\u5c0f\uff0c\u8fd4\u56de\u65f6\u4f1a\u88ab\u4fee\u6539\u4e3a\u5b9e\u9645\u5730\u5740\u7684\u957f\u5ea6\uff08\u4ee5\u5b57\u8282\u4e3a\u5355\u4f4d\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>recvfrom\u51fd\u6570\u7684\u8fd4\u56de\u503c\u662f\u63a5\u6536\u5230\u7684\u5b57\u8282\u6570\u3002\u5982\u679c\u63a5\u6536\u6210\u529f\uff0c\u51fd\u6570\u8fd4\u56de\u63a5\u6536\u5230\u7684\u5b57\u8282\u6570\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u63a5\u6536\u5931\u8d25\uff0c\u51fd\u6570\u8fd4\u56de-1\uff0c\u5e76\u4e14\u9519\u8bef\u539f\u56e0\u4f1a\u5b58\u50a8\u5728errno\u4e2d\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/types.h&gt;\n#include &lt;sys\/socket.h&gt;\n#include &lt;netinet\/in.h&gt;\n#include &lt;arpa\/inet.h&gt;\n#include &lt;unistd.h&gt;\n#include &lt;stdio.h&gt;\n#include &lt;string.h&gt;\n\nint main() {\n    int sockfd;\n    struct sockaddr_in servaddr, cliaddr;\n    char buffer&#91;1024];\n    socklen_t len;\n    int n;\n\n    \/\/ \u521b\u5efaUDP\u5957\u63a5\u5b57\n    sockfd = socket(AF_INET, SOCK_DGRAM, 0);\n\n    \/\/ \u8bbe\u7f6e\u670d\u52a1\u5668\u5730\u5740\n    memset(&amp;servaddr, 0, sizeof(servaddr));\n    servaddr.sin_family = AF_INET;\n    servaddr.sin_addr.s_addr = INADDR_ANY;\n    servaddr.sin_port = htons(8080);\n\n    \/\/ \u7ed1\u5b9a\u5957\u63a5\u5b57\n    bind(sockfd, (const struct sockaddr *)&amp;servaddr, sizeof(servaddr));\n\n    \/\/ \u63a5\u6536\u6570\u636e\n    len = sizeof(cliaddr);\n    n = recvfrom(sockfd, (char *)buffer, 1024, 0, (struct sockaddr *)&amp;cliaddr, &amp;len);\n    buffer&#91;n] = '\\0';\n    printf(\"Client : %s\\n\", buffer);\n\n    \/\/ \u5173\u95ed\u5957\u63a5\u5b57\n    close(sockfd);\n\n    return 0;\n}\n<\/code><\/pre>\n\n\n\n<h1 class=\"wp-block-heading\"><kbd>\u9ad8\u7ea7\u4e3b\u9898<\/kbd><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">IO\u591a\u8def\u590d\u7528<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u524d\u7f6e<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5b9e\u9645\u7684\u670d\u52a1\u5668\u5f00\u53d1\u4e2d\uff0c\u5f80\u5f80\u9700\u8981\u8003\u8651\u5e76\u53d1\u60c5\u51b5\u3002\u4e3a\u4e86\u5e94\u5bf9\u8fd9\u4e2a\u60c5\u51b5\uff0c\u4e0d\u65ad\u8fed\u4ee3\u51fa\u4e86\u65b0\u7684\u6280\u672f\uff0c\u6240\u6709\u7684\u65b0\u6280\u672f\u5e76\u4e0d\u662f\u4e00\u8e74\u800c\u5c31\u7684\uff0c\u800c\u662f\u5728\u524d\u4eba\u7684\u57fa\u7840\u4e0a\u4e0d\u65ad\u521b\u65b0\u3002\u6211\u7684\u98ce\u683c\u662f\u77e5\u5176\u7136\u8981\u77e5\u5176\u6240\u4ee5\u7136\uff0c\u77e5\u8bc6\u4e0d\u80fd\u786c\u704c\uff0c\u6240\u4ee5\u8fd9\u4e2a\u677f\u5757\u4f9d\u65e7\u91c7\u7528\u8ddf\u968f\u6280\u672f\u8fed\u4ee3\u7684\u65b9\u5f0f\u8bb2\u89e3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e86\u89e3IO\u590d\u7528\u4e4b\u524d\uff0c\u9700\u8981\u9996\u5148\u63a2\u8ba8\u6700\u521d\u7684\u60f3\u6cd5\u3002\u5047\u8bbe\u4f60\u9700\u8981\u505a\u4e00\u4e2a\u9ad8\u5e76\u53d1\u7684\u670d\u52a1\u5668\u3002\u90a3\u4e48\u9996\u5148\u600e\u4e48\u60f3\u5462\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u7ed9\u6bcf\u4e00\u4e2a\u5ba2\u6237\u7aef\u521b\u5efa\u4e00\u4e2a\u8fdb\u7a0b\uff0c\u4e00\u5bf9\u4e00VIP\u670d\u52a1\uff0c\u5b8c\u7f8e\u7ed3\u5c40\u4e86\u5e76\u53d1\u95ee\u9898\u3002\u8fd9\u786e\u5b9e\u662f\u4e00\u4e2a\u597d\u65b9\u6cd5\uff0c\u4f46\u662f\u95ee\u9898\u662f\u670d\u52a1\u5668\u7684\u8d44\u6e90\u662f\u6709\u9650\u7684\uff0c\u8fdb\u7a0b\u7684\u5f00\u8f9f\u4e0e\u5207\u6362\u9700\u8981\u6d88\u8017\u5f88\u5927\u7684\u8d44\u6e90\u3002\u5982\u679c\u7528\u6237\u4e00\u591a\uff0c\u670d\u52a1\u5668\u76f4\u63a5\u5361\u6b7b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e8e\u662f\u4f60\u5f00\u59cb\u5bfb\u627e\u66f4\u597d\u7684\u60f3\u6cd5\uff0c\u5982\u679c\u8fdb\u7a0b\u5207\u6362\u7684\u8d44\u6e90\u5f00\u9500\u5927\uff0c\u90a3\u4e48\u8bd5\u8bd5\u7ebf\u7a0b\u5982\u4f55\u5462\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e8e\u662f\u8bd5\u7740\u7ed9\u6bcf\u4e00\u4e2a\u5ba2\u6237\u7aef\u5f00\u8f9f\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u76f8\u5f53\u4e8e\u7528\u5c065\u661f\u670d\u52a1\u5458\u6362\u6210\u4e862\u661f\u670d\u52a1\u5458\uff0c\u4f46\u662f\u8fd8\u662f\u5b8c\u7f8e\u7684\u89e3\u51b3\u4e86\u95ee\u9898\uff0c\u4f46\u662f\u968f\u7740\u670d\u52a1\u5668\u5ba2\u6237\u7aef\u8bbf\u95ee\u4eba\u6570\u7684\u589e\u591a\uff0c\u7ec8\u4e8e\u7528\u6237\u5e76\u53d1\u5230\u8fbe\u4e86\u5341\u4e07\u7ea7\u522b\uff0c\u7ec8\u4e8e\u8d44\u6e90\u518d\u6b21\u8017\u5c3d\uff0c\u670d\u52a1\u5668\u8fd8\u662f\u5361\u6b7b\u4e86\uff0c\u56e0\u4e3a\u5373\u4fbf\u7ebf\u7a0b\u7684\u8d44\u6e90\u8fdc\u8fdc\u5c0f\u4e8e\u8fdb\u7a0b\uff0c\u6d77\u91cf\u7684\u7ebf\u7a0b\u7d2f\u52a0\u7684\u8d44\u6e90\u4f9d\u65e7\u662f\u4e0d\u53ef\u5c0f\u89d1\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u65e0\u8111\u6269\u5c55\u7ebf\u7a0b\u7684\u65b9\u6cd5\u4e0d\u80fd\u89e3\u51b3\uff0c\u90a3\u4e48\u6362\u4e2a\u89d2\u5ea6\u60f3\uff0c\u63d0\u9ad8\u7ebf\u7a0b\u8d28\u91cf\u800c\u4e0d\u662f\u63d0\u9ad8\u7ebf\u7a0b\u6570\u91cf\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e8e\u662f\u4f60\u4ed4\u7ec6\u7684\u5206\u6790\u4e86\u5355\u7ebf\u7a0b\u4e2d\u5f71\u54cd\u6548\u7387\u7684\u65b9\u9762\uff0c\u7136\u540e\u4f60\u53d1\u73b0\u5f53\u4f60\u4f7f\u7528<code>recv<\/code>\u51fd\u6570\u7684\u65f6\u5019\uff0c\u7531\u4e8e\u6307\u5b9a\u5ba2\u6237\u7aef\u6ca1\u6709\u53d1\u9001\u6d88\u606f\uff0c\u90a3\u4e48\u7ebf\u7a0b\u4f1a\u5728\u8fd9\u91cc\u963b\u585e\u3002\u90a3\u4e48\u6211\u662f\u5426\u53ef\u4ee5\u4f7f\u7528\u975e\u963b\u585e\u7684<code>recv<\/code>\u5462\uff1f\u4f46\u662f\u5728\u5c1d\u8bd5\u4e4b\u540e\uff0c\u4f60\u53d1\u73b0\u9ad8\u9891\u7387\u7684<code>recv<\/code>\u9020\u6210\u4e86\u9ad8\u8d1f\u62c5\u7684\u7cfb\u7edf\u8c03\u7528\uff0c\u5c24\u5176\u5728\u7528\u6237\u6570\u91cf\u5f00\u59cb\u589e\u591a\u540e\uff0c\u9ad8\u8d1f\u62c5\u7684\u7cfb\u7edf\u8c03\u7528\u6781\u5927\u589e\u52a0\u4e86CPU\u7684\u8d1f\u62c5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u662f\u5426\u6709\u529e\u6cd5\u8ba9\u5ba2\u6237\u7aef\u51fa\u73b0\u8bf7\u6c42\u7684\u65f6\u5019\uff0c\u901a\u77e5\u6211\u8fdb\u884c<code>recv<\/code>\u5462\uff1f\u8fd9\u6837\u6781\u5927\u51cf\u5c11\u4e86\u7cfb\u7edf\u8c03\u7528\u7684\u8d1f\u62c5\uff0c\u6781\u5927\u63d0\u9ad8\u7ebf\u7a0b\u5229\u7528\u6548\u7387\uff0c\u5e76\u4e14\u53ef\u4ee5\u66f4\u597d\u5e94\u5bf9\u9ad8\u5e76\u53d1\u573a\u666f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e8e\u662f\u4f60\u60f3\u5230\u4e86\u5c06\u6240\u6709\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u90fd\u7ed9\u5185\u6838\uff0c\u8ba9\u5185\u6838\u5e2e\u52a9\u4f60\u76d1\u542c\uff0c\u5f53\u54ea\u4e2a\u5ba2\u6237\u7aef\u51fa\u73b0\u6d88\u606f\uff0c\u90a3\u4e48\u5c31\u544a\u8bc9\u4f60\u5904\u7406\u54ea\u4e2a\u5ba2\u6237\u7aef\uff0c\u7531\u6b64\uff0c\u4ee5<code>select<\/code>\u3001<code>poll<\/code>\u3001<code>epoll<\/code>\u8fd9\u6837\u7684API\u51fd\u6570\u8bde\u751f\u4e86\u3002\u5728\u4fdd\u8bc1\u5904\u7406\u65f6\u95f4\u4e0d\u8981\u8fc7\u957f\u7684\u524d\u63d0\u4e0b\uff0c\u5bf9\u7ebf\u7a0b\u7684\u5229\u7528\u5230\u8fbe\u4e86\u6781\u81f4\uff0c\u6709\u6548\u63d0\u9ad8\u4e86\u670d\u52a1\u5668\u7684\u5e76\u53d1\u80fd\u529b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u60c5\u666f\u6a21\u62df\u5728\u8fd9\u91cc\u5c31\u505c\u6b62\u4e86\uff0c\u4e8b\u5b9e\u4e0a\u540e\u7eed\u8fd8\u6709\u6280\u672f\u8fed\u4ee3\uff0c\u6bd4\u5982\u591a\u7ebf\u7a0b\u4e0eIO\u591a\u8def\u590d\u7528\u6280\u672f\u7ed3\u5408\uff0c\u8fd9\u662f\u4e3a\u4e86\u5e94\u5bf9\u65b0\u7684\u95ee\u9898\u2014\u2014\u6240\u6709\u7684\u5e76\u53d1\u90fd\u538b\u5728\u4e00\u4e2a\u7ebf\u7a0b\u8eab\u4e0a\uff0c\u4f60\u768432\u6838\u5904\u7406\u5668\u4e2d\uff0c\u4e00\u4e2a\u6838\u5fc3\u5feb\u8981\u7b97\u70b8\u4e86\uff0c\u53e6\u591631\u4e2a\u6838\u8fd8\u5728\u6478\u9c7c\uff0c\u6240\u8c13&#8221;\u4e00\u6838\u6709\u96be\uff0c\u591a\u6838\u56f4\u89c2&#8221;\u3002\u4e0d\u8fc7\u8fd9\u4e2a\u4e0d\u5728\u672c\u6587\u7ae0\u7684\u8ba8\u8bba\u8303\u56f4\u5185\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u90a3\u4e48\u63a5\u4e0b\u6765\u5c31\u5f00\u59cb\u8bb2\u89e3\u63d0\u9ad8\u7ebf\u7a0b\u5229\u7528\u7387\u7684IO\u590d\u7528\u6280\u672f\uff0c\u4ee5\u4e0b\u63d0\u5230\u7684\u7b56\u7565\u4e3b\u8981\u6709<strong>select\u51fd\u6570\u3001poll\u51fd\u6570\u4ee5\u53caepoll\u51fd\u6570\u96c6\u5408<\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">select\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>select<\/code>\u8bed\u53e5\u7528\u4e8e\u5728\u4e00\u7ec4\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u8fdb\u884c\u591a\u8def\u590d\u7528\uff0c\u4ee5\u4fbf\u80fd\u591f\u540c\u65f6\u76d1\u89c6\u591a\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u5426\u6709\u6570\u636e\u53ef\u8bfb\u3001\u53ef\u5199\u6216\u5f02\u5e38\u7b49\u4e8b\u4ef6\u53d1\u751f\u3002\u867d\u7136\u8be5\u51fd\u6570\u7684\u4f5c\u7528\u5bf9\u8c61\u662f\u6587\u4ef6\uff0c\u4f46\u662f\u901a\u5e38\u4f7f\u7528\u5728\u7f51\u7edc\u4e2d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u800c\u7f51\u7edc\u4e0a\u5e38\u89c1\u7684\u5f02\u5e38\u4e8b\u4ef6\u6bd4\u5982<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6570\u636e\u5916\u5e26<\/strong>\uff1a\u5e26\u5916\u6570\u636e\uff08Out-of-band data\uff09 \u662f\u6307\u5728TCP\u8fde\u63a5\u4e2d\u4f20\u8f93\u7684\u7d27\u6025\u6570\u636e\u3002\u5b83\u901a\u5e38\u7528\u4e8e\u4f20\u9012\u91cd\u8981\u7684\u3001\u9700\u8981\u4f18\u5148\u5904\u7406\u7684\u4fe1\u606f\u3002\u5e26\u5916\u6570\u636e\u901a\u8fc7\u73b0\u6709\u7684\u8fde\u63a5\u4f20\u8f93\uff0c\u4f46\u5177\u6709\u66f4\u9ad8\u7684\u4f18\u5148\u7ea7\u3002TCP\u534f\u8bae\u901a\u8fc7\u8bbe\u7f6eURG\uff08\u7d27\u6025\uff09\u6807\u5fd7\u548c\u7d27\u6025\u6307\u9488\u6765\u6807\u8bc6\u5e26\u5916\u6570\u636e<\/li>\n\n\n\n<li><strong>\u6761\u4ef6\u9519\u8bef<\/strong>\uff1a\u6307\u5728\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u53d1\u751f\u7684\u5404\u79cd\u9519\u8bef\u60c5\u51b5\u3002\u4f8b\u5982\uff1a\n<ul class=\"wp-block-list\">\n<li><strong>\u8fde\u63a5\u91cd\u7f6e\uff08Connection reset\uff09<\/strong>\uff1a\u5f53\u5bf9\u7aef\u5173\u95ed\u8fde\u63a5\u65f6\uff0c\u53ef\u80fd\u4f1a\u89e6\u53d1\u9519\u8bef\u6761\u4ef6\u3002<\/li>\n\n\n\n<li><strong>\u8fde\u63a5\u62d2\u7edd\uff08Connection refused\uff09<\/strong>\uff1a\u5f53\u5c1d\u8bd5\u8fde\u63a5\u5230\u4e00\u4e2a\u6ca1\u6709\u76d1\u542c\u7684\u7aef\u53e3\u65f6\uff0c\u53ef\u80fd\u4f1a\u89e6\u53d1\u9519\u8bef\u6761\u4ef6\u3002<\/li>\n\n\n\n<li><strong>\u7f51\u7edc\u4e0d\u53ef\u8fbe\uff08Network unreachable\uff09<\/strong>\uff1a\u5f53\u7f51\u7edc\u4e0d\u53ef\u8fbe\u65f6\uff0c\u53ef\u80fd\u4f1a\u89e6\u53d1\u9519\u8bef\u6761\u4ef6\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b83\u53ef\u4ee5\u8bbe\u7f6e\u4e00\u4e2a\u7b49\u5f85\u65f6\u95f4\uff0c\u5728\u6307\u5b9a\u65f6\u95f4\u5bf9\u6587\u4ef6\u4e8b\u4ef6\u8fdb\u884c\u76d1\u542c\uff0c\u5982\u679c\u8d85\u65f6\u6ca1\u6709\u4efb\u4f55\u4e8b\u4ef6\u53d1\u751f\uff0c\u51fd\u6570\u4f1a\u7acb\u5373\u8fd4\u56de\uff0c\u5982\u679c\u5728\u6307\u5b9a\u65f6\u95f4\u5185\u6709\u4e8b\u4ef6\u53d1\u751f\uff0c\u5219\u7acb\u523b\u8fd4\u56de\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7b80\u5355\u6765\u8bf4\uff0c<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">select\u53ef\u4ee5\u5728\u6307\u5b9a\u65f6\u95f4\u91cc\uff08\u4e5f\u53ef\u4ee5\u8bbe\u7f6e\u4e3a\u6c38\u4e45\u963b\u585e\uff09\u76d1\u542c\u4e00\u4e2a\u6587\u4ef6\u96c6\u5408\u7684\u662f\u5426\u6709\u88ab\u5176\u4ed6\u7a0b\u5e8f\u7533\u8bf7\u5bf9\u67d0\u4e00\u4e2a\u6216\u8005\u591a\u4e2a\u6587\u4ef6\u8fdb\u884c\u8bfb\u5199\uff0c\u6216\u8005\u6587\u4ef6\u51fa\u73b0\u5f02\u5e38\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u8fc7select\u51fd\u6570\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u6700\u591a\u80fd\u540c\u65f6\u76d1\u542c1024\u4e2a\u6587\u4ef6\uff08\u5982\u679c\u60f3\u4fee\u6539\u8fd9\u4e2a\u9650\u5236\uff0c\u5fc5\u987b\u8981\u53bbLinux\u6e90\u4ee3\u7801\u4fee\u6539<code>#define FD_SETSIZE 1024<\/code> \u8fd9\u4e2a\u4ee3\u7801\uff0c\u5c06\u540e\u9762\u7684\u503c\u4fee\u6539\u81ea\u5df1\u60f3\u8981\u7684\u503c\u540e\u8fdb\u884c\u6e90\u4ee3\u7801\u7f16\u8bd1\uff09\uff0c\u6ce8\u610f\uff0cLinux\u4f7f\u7528\u4f4d\u56fe\u6620\u5c04\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u8fd91024\u4e2a\u6587\u4ef6\u5b9e\u9645\u4e0a\u662f\u4e00\u4e2a\u603b\u6570\u4e3a128\u4e2a\u5b57\u8282\u7684\u6570\u636e\uff0c\u5f53\u8fd9\u4e9b\u5b57\u8282\u6a2a\u5411\u6392\u5217\u6210\u4e00\u884c\uff0c\u90a3\u4e48\u4ece\u5de6\u5f80\u53f3\u6570\uff0c\u5206\u522b\u662f\u7b2c0\u4e2a\u4f4d\uff0c\u7b2c1\u4e2a\u4f4d\uff0c\u7b2c2\u4e2a\u4f4d&#8230; \u90a3\u4e48\u5c31\u610f\u5473\u7740\u53ef\u4ee5\u4f7f\u7528\u8fd9\u79cd\u65b9\u6cd5\u4ee3\u8868\u6587\u4ef6\uff0c\u6bd4\u5982\u6587\u4ef6\u63cf\u8ff0\u7b260\uff0c\u6587\u4ef6\u63cf\u8ff0\u7b261\uff0c\u6587\u4ef6\u63cf\u8ff0\u7b262\u3002\u8fd9\u79cd\u65b9\u6848\u5927\u91cf\u8282\u7701\u4e86\u5185\u5b58\uff0c\u5e76\u4e14\u5c06\u9009\u4e2d\u4e00\u4f4d\u5c31\u80fd\u4ee3\u8868\u4e00\u4e2a\u6587\u4ef6\uff0c\u901f\u5ea6\u4e5f\u80fd\u66f4\u5feb\u3002\u4f46\u662f0 \u30011\u30012\u5206\u522b\u5bf9\u5e94\u6807\u51c6\u8f93\u5165\uff08stdin\uff09\u3001\u6807\u51c6\u8f93\u51fa\uff08stdout\uff09\u548c\u6807\u51c6\u9519\u8bef\uff08stderr\uff09\uff0c\u8fd9\u4e9b\u662f\u7531\u7cfb\u7edf\u4fdd\u7559\u548c\u4f7f\u7528\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/select.h&gt;\n\nint select(int nfds, fd_set *readfds, fd_set *writefds,fd_set *exceptfds, struct timeval *timeout);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>nfds<\/code>\uff1a\u76d1\u89c6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u91cf\uff0c\u901a\u5e38\u662f\u6240\u6709\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e2d\u6700\u5927\u503c\u52a0\u4e00\u3002\u8fd9\u4e2a\u5f88\u597d\u7406\u89e3\uff0c\u56e0\u4e3a\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u4ece0\u5f00\u59cb\u7684\uff0c\u90a3\u4e48\u603b\u6570\u5c31\u662f\u63cf\u8ff0\u7b26\u52a01\uff0c\u4e0d\u8fc7\u4e0d\u8981\u8d85\u8fc7\u6700\u5927\u76d1\u89c6\u6570\u91cf\uff0c\u5426\u5219\u53ef\u80fd\u4f1a\u5f15\u53d1\u672a\u5b9a\u4e49\u7684\u95ee\u9898\u3002<\/li>\n\n\n\n<li><code>readfds<\/code>\uff1a\u76d1\u89c6\u53ef\u8bfb\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u3002<\/li>\n\n\n\n<li><code>writefds<\/code>\uff1a\u76d1\u89c6\u53ef\u5199\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u3002<\/li>\n\n\n\n<li><code>exceptfds<\/code>\uff1a\u76d1\u89c6\u5f02\u5e38\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u3002<\/li>\n\n\n\n<li><code>timeout<\/code>\uff1a\u8d85\u65f6\u65f6\u95f4\uff0c\u53ef\u4ee5\u6307\u5b9a&nbsp;<code>NULL<\/code>&nbsp;\u8868\u793a\u65e0\u9650\u7b49\u5f85\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5148\u8c08\u4e00\u8c08fd_set,\u5b83\u662f\u4e00\u4e2a\u5de8\u5927\u7684\u8fde\u7eed\u7684\u6570\u7ec4\uff0c\u6240\u4ee5\u5bf9\u6570\u7ec4\u4e2d\u6307\u5b9a\u7684\u4f4d\u64cd\u4f5c\u6709\u70b9\u9ebb\u70e6\uff0c\u6240\u4ee5\u7cfb\u7edf\u63d0\u4f9b\u4e86\u4e00\u4e9b\u5b8f\u6765\u64cd\u4f5c<code>fd_set<\/code>\uff0c\u5305\u62ec\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>FD_ZERO(fd_set *set):<\/code><\/strong>\uff1a\u5c06<code>fd_set<\/code>\u53d8\u91cf\u6e05\u96f6\uff0c\u4f7f\u96c6\u5408\u4e2d\u4e0d\u542b\u4efb\u4f55\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li><strong><code>FD_SET(int fd, fd_set *set)<\/code><\/strong>\uff1a\u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26<code>fd<\/code>\u52a0\u5165\u5230<code>fd_set<\/code>\u96c6\u5408\u4e2d\u3002<\/li>\n\n\n\n<li><strong><code>FD_CLR(int fd, fd_set *set)<\/code><\/strong>\uff1a\u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26<code>fd<\/code>\u4ece<code>fd_set<\/code>\u96c6\u5408\u4e2d\u79fb\u9664\u3002<\/li>\n\n\n\n<li><strong><code>FD_ISSET(int fd, fd_set *set)<\/code><\/strong>\uff1a\u68c0\u67e5\u6587\u4ef6\u63cf\u8ff0\u7b26<code>fd<\/code>\u662f\u5426\u5728<code>fd_set<\/code>\u96c6\u5408\u4e2d\uff0c\u5982\u679c\u5728\u5219\u8fd4\u56de\u975e\u96f6\u503c\uff0c\u53ea\u6709\u8fd9\u4e2a\u5b8f\u51fd\u6570\u6709\u8fd4\u56de\u503c\uff0c\u4e0a\u8ff0\u4e09\u4e2a\u662f\u6ca1\u6709\u7684\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b83\u7684\u4f7f\u7528\u65b9\u6cd5\u6bd4\u8f83\u7279\u522b\uff0c\u62ff<code>readfds<\/code>\u4e3e\u4f8b\uff0c\u8fd9\u4e2a\u4f20\u5165\u53c2\u6570\u662f\u901a\u77e5\u5185\u6838\u54ea\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u9700\u8981\u88ab\u76d1\u63a7\u7684\uff0c\u7136\u540e\u4f60\u8981\u5c06\u8fd9\u4e2a\u53c2\u6570\u4e2d\u5bf9\u5e94\u7684\u4f4d\u7f6e\u8bbe\u7f6e\u4e3a1\uff0c\u6ce8\u610f\uff0c\u53ef\u4ee5\u4e00\u6b21\u6027\u5199\u5165\u591a\u4e2a\u9700\u8981\u76d1\u63a7\u7684\u6587\u4ef6\u3002\u800c\u5185\u6838\u53d1\u73b0\u8bfb\u53d6\u4fe1\u53f7\u540e\uff0c\u5b83\u4f1a\u7acb\u5373\u8fd4\u56de\uff0c<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u800c\u4f20\u5165\u7684\u53c2\u6570\u4f1a\u88ab\u4fee\u6539\uff0c\u5728\u4fe1\u53f7\u53d1\u751f\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u4f4d\u7f6e\u7f6e1\uff0c\u4f46\u662f\u4f1a\u5b8c\u5168\u8986\u76d6\u4e4b\u524d\u7684\u503c\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7b80\u5355\u6765\u8bf4\uff0c\u5c31\u662f\u5185\u6838\u8bb0\u4f4f\u4e86\u4f60\u8981\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u8fd4\u56de\u7684\u7ed3\u679c\u6807\u8bb0\u4e86\u54ea\u4e9b\u4fe1\u53f7\u88ab\u89e6\u53d1\u3002<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u81f3\u4e8e\u4e3a\u4ec0\u4e48\u8981\u5185\u6838\u76d1\u542c\uff0c\u662f\u56e0\u4e3a\u907f\u514d\u9891\u7e41\u7684\u7cfb\u7edf\u8c03\u7528\u4f1a\u9020\u6210\u5f88\u5927\u7684\u8d44\u6e90\u5f00\u9500\uff0c\u4e00\u6b21\u6027\u4ea4\u7ed9\u5185\u6838\uff0c\u5c31\u907f\u514d\u4e86\u7cfb\u7edf\u5728\u5185\u6838\u6001\u4e0e\u7528\u6237\u6001\u4e4b\u95f4\u53cd\u5207\u6362\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff1a\u4e3a\u4e86\u65b9\u4fbf\u5c31\u75281\u4e2a\u5b57\u8282\u4f5c\u4e3a\u6f14\u793a\uff08\u5b9e\u9645\u4e0a\u9ed8\u8ba4\u60c5\u51b5\u67091024\u4e2a\u5b57\u8282\uff09\u3002\u521d\u59cb\u7684\u53c2\u6570<code>readfd<\/code> \u662f<code>00000000<\/code>\uff0c\u73b0\u5728\u4f60\u5e0c\u671b\u68c0\u67e5<code>\u6587\u4ef6\u63cf\u8ff0\u7b263<\/code>\u548c<code>\u6587\u4ef6\u63cf\u8ff0\u7b266<\/code> \u662f\u5426\u51fa\u73b0\u4e86\u53ef\u8bfb\u4fe1\u53f7\uff0c\u4e8e\u662f\u8fd9\u4e2a\u5b57\u8282\u88ab\u8bbe\u7f6e\u4e3a\u4e86<code>00010010<\/code>\u3002\u7136\u540e\u5c06\u8fd9\u4e2a\u53c2\u6570\u653e\u5165\u4e86\u51fd\u6570\u4e2d\uff0c\u6b64\u65f6<code>\u6587\u4ef6\u63cf\u8ff0\u7b263<\/code>\u51fa\u73b0\u4e86\u53ef\u8bfb\u4fe1\u53f7\uff0c\u4f46\u662f<code>\u6587\u4ef6\u63cf\u8ff0\u7b266<\/code>\u6ca1\u6709\u51fa\u73b0\u53ef\u8bfb\u4fe1\u53f7\uff0c\u51fd\u6570\u7acb\u5373\u8fd4\u56de\uff0c\u800c\u4f60\u4f20\u5165\u7684\u53c2\u6570<code>readfd<\/code>\u4f1a\u88ab\u4fee\u6539\u4e3a<code>00010000<\/code>\u3002\u6b64\u65f6\u4f60\u53ea\u9700\u8981\u5224\u65ad\u81ea\u5df1\u8f93\u5165\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4f4d\u7f6e\u662f\u4e0d\u662f1\uff0c\u5c31\u53ef\u4ee5\u77e5\u9053\u662f\u5426\u53d1\u751f\u4e86\u53ef\u8bfb\u4fe1\u53f7\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7136\u540e\u4f60\u5206\u6790\u4e86<code>\u6587\u4ef6\u63cf\u8ff0\u7b263<\/code>\u548c<code>\u6587\u4ef6\u63cf\u8ff0\u7b266<\/code>\u5bf9\u5e94\u7684\u4f4d\u7f6e\uff0c\u5f97\u51fa\u7ed3\u8bba\uff0c<code>\u6587\u4ef6\u63cf\u8ff0\u7b263<\/code>\u53d1\u751f\u4e86\u4fe1\u53f7\uff0c\u800c<code>\u6587\u4ef6\u63cf\u8ff0\u7b266<\/code>\u6ca1\u6709\u3002\u4f46\u662f\u6b64\u65f6\u8fd8\u6709\u53e6\u5916\u4e00\u4e2a\u95ee\u9898\uff0c\u90a3\u5c31\u662f\u4f60\u7684\u539f\u53c2\u6570\u5df2\u7ecf\u88ab\u6539\u53d8\u4e86\uff0c\u6240\u4ee5\u4e0b\u4e00\u6b21\u8fdb\u884c<code>select\u51fd\u6570<\/code>\u4e4b\u524d\uff0c\u5fc5\u987b\u8981\u5bf9\u53c2\u6570\u8fdb\u884c\u91cd\u65b0\u8bbe\u7f6e\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u63a5\u4e0b\u6765\u8bb2\u8bb2<code>timeout<\/code>\u53c2\u6570\uff0c\u5b9e\u9645\u4e0a\u5b83\u662f\u4e00\u4e2a\u7ed3\u6784\u4f53\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct timeval {\n    long tv_sec;  \/\/ \u79d2\n    long tv_usec; \/\/ \u5fae\u79d2\n};\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f60\u53ef\u4ee5\u901a\u8fc7\u8fd9\u4e2a\u53c2\u6570\u8bbe\u7f6e\u7b49\u5f85\u65f6\u95f4\uff0c\u4e0d\u8fc7\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5fc5\u8981\u521d\u59cb\u5316\uff0c\u5426\u5219\u968f\u673a\u7684\u521d\u503c\u53ef\u80fd\u5f15\u53d1\u65f6\u95f4\u7684\u5e72\u6270\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8fd4\u56de\u503c\u4e3a\u6b63\u6570<\/strong>\uff1a\u8868\u793a\u6709\u591a\u5c11\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u5df2\u7ecf\u5c31\u7eea\uff0c\u53ef\u4ee5\u8fdb\u884c\u8bfb\u3001\u5199\u6216\u6709\u5f02\u5e38\u4e8b\u4ef6\u3002<\/li>\n\n\n\n<li><strong>\u8fd4\u56de\u503c\u4e3a 0<\/strong>\uff1a\u8868\u793a\u5728\u6307\u5b9a\u7684\u8d85\u65f6\u65f6\u95f4\u5185\u6ca1\u6709\u4efb\u4f55\u6587\u4ef6\u63cf\u8ff0\u7b26\u5c31\u7eea\u3002<\/li>\n\n\n\n<li><strong>\u8fd4\u56de\u503c\u4e3a -1<\/strong>\uff1a\u8868\u793a\u53d1\u751f\u4e86\u9519\u8bef\uff0c\u6b64\u65f6\u53ef\u4ee5\u901a\u8fc7&nbsp;<code>errno<\/code>&nbsp;\u6765\u83b7\u53d6\u5177\u4f53\u7684\u9519\u8bef\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u89e3\u6790<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9700\u8981\u8865\u5145\u7684\u662f\uff0c\u5185\u6838\u5e76\u4e0d\u4f1a\u76f4\u63a5\u4f7f\u7528\u4f60\u4f20\u5165\u7684fd_set\u53c2\u6570\uff0c\u5b83\u4f1a\u5b8c\u6574\u7684\u590d\u5236\u4e00\u4efd\u8fd9\u4e2a\u53c2\u6570\uff0c\u5373\u4fbf\u4f60\u6ca1\u6709\u4f7f\u7528\u5230\u5b83\u7684\u4e0a\u9650\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u63a5\u4e0b\u6765\u5185\u6838\u4f1a\u8fdb\u884c\u76d1\u63a7\uff0c\u5e76\u4e14\u6839\u636e\u5b9e\u9645\u60c5\u51b5\u6309\u7167\u5f53\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u51fa\u73b0\u6307\u5b9a\u4fe1\u53f7\uff0c\u5c31\u4f1a\u5bf9fd_set\u53c2\u6570\u4fee\u6539\uff0c\u8fd9\u4e2a\u65f6\u5019\u4fee\u6539\u662f\u5185\u6838\u4e2d\u7684\u53c2\u6570\uff0c\u7136\u540e\u4fee\u6539\u5b8c\u6210\u4e4b\u540e\uff0c\u5185\u6838\u4f1a\u5c06\u65b0\u7684\u53c2\u6570\u4ece\u5185\u6838\u4e2d\u590d\u5236\u5230\u4f20\u5165\u7684fd_set\u53c2\u6570\u4e2d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u77e5\u9053\u54ea\u4e9b\u6587\u4ef6\u51fa\u73b0\u4e86\u4fe1\u53f7\uff0c\u5f00\u53d1\u8005\u9700\u8981\u904d\u5386\u81ea\u5df1\u6240\u6709\u5f55\u5165\u8fc7\u7684\u6587\u4ef6\uff0c\u7136\u540e\u786e\u5b9a\u662f\u5426\u4ea7\u751f\u4e86\u4fe1\u53f7\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u670d\u52a1\u5668\u4f1a\u5c06<code>select\u51fd\u6570<\/code>\u653e\u5728<code>while<\/code>\u4e2d\u3002\u90a3\u4e48\u7eb5\u89c2\u5168\u5c40\uff0c\u6574\u4e2a\u64cd\u4f5c\u5c31\u4f1a\u6d89\u53ca\u5230\u4e86\u591a\u6b21\u521d\u59cb\u5316\u3001\u5185\u6838\u4e0e\u7528\u6237\u6001\u76f4\u63a5\u5230\u6570\u636e\u590d\u5236\uff0c\u4ee5\u53ca\u4e3a\u4e86\u83b7\u53d6\u4fe1\u53f7\uff0c\u5f00\u53d1\u8005\u4e0d\u5f97\u4e0d\u5728\u6240\u6709\u6587\u4ef6\u4e2d\u53cd\u590d\u904d\u5386\u3002\u800c\u4e14select\u7684\u76d1\u63a7\u5b58\u5728\u4e0a\u9650\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u6240\u4ee5\u53ef\u4ee5\u5f97\u51fa\u7ed3\u8bba\uff1a\u8fd9\u4e2a\u51fd\u6570\u9002\u7528\u4e8e\u6587\u4ef6\u8f83\u5c11\u7684\u60c5\u51b5\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#9b51e0\" class=\"has-inline-color\">\u6574\u4f53\u603b\u7ed3select\u51fd\u6570\u7684\u6267\u884c\u8fc7\u7a0b<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7528\u6237\u5c06\u5e0c\u671b\u5173\u6ce8\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u8bbe\u7f6e\u8fdb\u5165<code>fd_set<\/code>\u53c2\u6570\u4e2d\u3002<\/li>\n\n\n\n<li>\u5185\u6838\u5c06\u53c2\u6570\u5b8c\u6574\u7684\u590d\u5236\u5230\u5185\u6838\u4e2d\uff0c\u5e76\u963b\u585e<code>select<\/code>\u51fd\u6570\uff0c\u6b64\u65f6\u5185\u6838\u5c06\u76d1\u542c\u5bf9\u5e94\u7f13\u51b2\u533a\u662f\u5426\u51fa\u73b0\u4fe1\u53f7\uff0c\u5185\u6838\u91c7\u7528\u7684\u662f\u65e0\u5dee\u522b\u9ad8\u901f\u904d\u5386\u6240\u6709\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u76f4\u5230\u6700\u5927\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u800c\u4e14\u4e0d\u7ba1\u8fd9\u4e2a\u63cf\u8ff0\u7b26\u662f\u5426\u5e0c\u671b\u88ab\u5f00\u53d1\u8005\u76d1\u542c\u3002\u6bd4\u5982\u53ea\u5e0c\u671b\u76d1\u542c3\u548c9\uff0c\u4f46\u662f\u5185\u6838\u5b9e\u9645\u4e0a\u4f1a\u76d1\u542c0-9\u7684\u6240\u6709\u6587\u4ef6\u63cf\u8ff0\u3002<\/li>\n\n\n\n<li>\u51fa\u73b0\u4fe1\u53f7\u540e\uff0c\u5185\u6838\u5c06\u7ed3\u679c\u4ece\u5185\u6838\u62f7\u8d1d\u5230\u53c2\u6570\u4e2d\uff0c\u5e76\u8fd4\u56de\u51fa\u73b0\u4e86\u5c31\u7eea\u4fe1\u53f7\u7684\u603b\u6570\u3002<\/li>\n\n\n\n<li>\u7528\u6237\u6839\u636e\u8fd4\u56de\u7ed3\u679c\u8fdb\u884c\u8f6e\u8be2\uff0c\u786e\u8ba4\u54ea\u4e9b\u6587\u4ef6\u63cf\u8ff0\u7b26\u51fa\u73b0\u4e86\u4fe1\u53f7\u3002\u7136\u540e\u91cd\u65b0\u8bbe\u7f6e\u6587\u4ef6\u63cf\u8ff0\u7b26\u5e76\u5728\u6b64\u8c03\u7528<code>select<\/code>\uff0c\u56e0\u4e3a<code>fd_set<\/code>\u53c2\u6570\u65e0\u6cd5\u91cd\u7528<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h&gt;\n#include &lt;sys\/types.h&gt;          \n#include &lt;sys\/socket.h&gt;\n#include &lt;string.h&gt;\n#include &lt;netinet\/in.h&gt;\n#include &lt;arpa\/inet.h&gt;\n#include &lt;sys\/select.h&gt;\nint main(){\n    int sock_id = socket(AF_INET, SOCK_STREAM, 0);\n    if(sock_id == -1){\n        perror(\"\u5957\u63a5\u5b57\u751f\u6210\u51fa\u9519\");\n        return 0;\n    }\n    struct sockaddr_in addr;\n    memset(&amp;addr,0,sizeof(struct sockaddr_in));\n    addr.sin_family = AF_INET;\n    addr.sin_port = htons(8888);\n    addr.sin_addr.s_addr = inet_addr(\"127.0.0.1\");\n    \n    if(bind(sock_id,(struct sockaddr*)&amp;addr,sizeof(addr))){\n        perror(\"\u5957\u63a5\u5b57\u7ed1\u5b9a\u51fa\u9519\");\n        return 0;\n    }\n\n    if(listen(sock_id,5)){\n        perror(\"\u8f6c\u5316\u4e3a\u76d1\u542c\u5957\u63a5\u5b57\u5931\u8d25\");\n        return 0;\n    }\n\n    \/\/\u5b9a\u4e49\u4e00\u4e2a\u7f13\u51b2\u533a\n    char text&#91;50];\n\n    \/\/\u5b9a\u4e49\u4e00\u4e2afd_set\u5e76\u5c06\u76d1\u542c\u5957\u63a5\u5b57\u653e\u5165\u5176\u4e2d\n    fd_set readfds;\n    FD_ZERO(&amp;readfds);\n    FD_SET(sock_id, &amp;readfds);\n    \/\/\u5b9a\u4e49\u4e00\u4e2a\u6700\u5927\u6587\u4ef6\u63cf\u8ff0\u7b26\n    int max_fd = sock_id;\n    \/\/\u5b9a\u4e49\u4e00\u4e2a\u526f\u672c\uff0c\u4f5c\u4e3a\u6bcf\u6b21\u8c03\u7528\u540e\u6062\u590d\u7684\u53c2\u8003\n    fd_set readfds_source = readfds;\n    while(1){\n        printf(\"\u6b63\u5728\u76d1\u542c\u5ba2\u6237\u7aef\u8bf7\u6c42\\n\");\n        \/\/select\u51fd\u6570\u963b\u585e\uff0c\u83b7\u53d6\u51fa\u73b0\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u51fa\u73b0\u4fe1\u53f7\u7684\u4e2a\u6570\n        int r_count = select(max_fd + 1,&amp;readfds,NULL,NULL,NULL);\n        \/\/\u5224\u65ad\u76d1\u542c\u5957\u63a5\u5b57\u662f\u5426\u51fa\u73b0\u53ef\u8bfb\n        if(FD_ISSET(sock_id,&amp;readfds)){\n            \/\/\u5982\u679c\u53ef\u8bfb\u5c31\u610f\u5473\u7740\u51fa\u73b0\u4e86\u8fde\u63a5\u8bf7\u6c42\n            \/\/\u8fdb\u884c\u8fde\u63a5\n            int afd = accept(sock_id,NULL,NULL);\n            if(afd != -1){\n                FD_SET(afd, &amp;readfds_source);\n                max_fd = (afd &gt; max_fd ? afd : max_fd);\n            }\n        }\n        \/\/\u68c0\u67e5\u8fde\u63a5\u5957\u63a5\u5b57\n        for(int i = 0;i &lt; max_fd + 1;i++){\n            \/\/\u5982\u679c\u8fd9\u4e2a\u503c\u4e0d\u662f\u76d1\u542c\u5957\u63a5\u5b57\uff0c\u5e76\u4e14\u5b83\u88abselect\u68c0\u6d4b\u5230\n            if( i != sock_id &amp;&amp; FD_ISSET(i,&amp;readfds)){\n                int r_recv =  recv(i,text,sizeof(text),MSG_NOSIGNAL);\n                if(r_recv == -1){\n                    perror(\"recv\u51fd\u6570\u51fa\u73b0\u9519\u8bef\");\n                    return 0;\n                }\n                if( r_recv == 0){\n                    \/\/\u5982\u679c\u8fd9\u4e2a\u8fde\u63a5\u5957\u63a5\u5b57\u65ad\u5f00\u8fde\u63a5\uff0c\u90a3\u4e48\u5c31\u4ece\u53c2\u6570\u4e2d\u5254\u9664\n                    FD_CLR(i, &amp;readfds_source);\n                }\n                if( r_recv &gt; 0){\n                    printf(\"        &gt;&gt;&gt;\u5ba2\u6237\u7aef\u53d1\u9001\u4fe1\u606f:%s\\n\",text);\n                }\n            }\n        }\n        \/\/\u6062\u590dreadfds\u53c2\u6570\n        readfds = readfds_source;\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u8fd0\u884c\u7ed3\u679c<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5ba2\u6237\u7aef\u8fde\u63a5\u540e\u53d1\u9001\u4e86\u4e00\u4e2a[ hello ]<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6b63\u5728\u76d1\u542c\u5ba2\u6237\u7aef\u8bf7\u6c42\n        &gt;&gt;&gt;\u5ba2\u6237\u7aef\u53d1\u9001\u4fe1\u606f:hello<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">poll\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>pool<\/code>\u51fd\u6570\u4e0e<code>select<\/code>\u51fd\u6570\u7c7b\u4f3c\uff0c\u90fd\u662f\u7528\u4e8e\u5728\u4e00\u7ec4\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u8fdb\u884c\u591a\u8def\u590d\u7528\uff0c\u4ee5\u4fbf\u80fd\u591f\u540c\u65f6\u76d1\u89c6\u591a\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u5426\u6709\u6570\u636e\u53ef\u8bfb\u3001\u53ef\u5199\u6216\u5f02\u5e38\u7b49\u4e8b\u4ef6\u53d1\u751f\u3002\u540c\u65f6\u4e5f\u5e7f\u6cdb\u8fd0\u7528\u5728\u7f51\u7edc\u7f16\u7a0b\u4e2d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f9d\u65e7\u4f7f\u7528\u4f18\u5316\u7684\u601d\u60f3\uff0c\u5728select\u51fd\u6570\u4e2d\uff0c\u9047\u5230\u4e86\u6700\u4e3b\u8981\u7684\u95ee\u9898\u5c31\u662f\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u9650\u7684\u9650\u5236\uff0c\u5982\u679c\u8981\u66f4\u6539\u4e0a\u9650\u5fc5\u987b\u8981\u91cd\u65b0\u4fee\u6539\u6e90\u4ee3\u7801\u5e76\u4e14\u91cd\u65b0\u7f16\u8bd1\uff0c\u663e\u7136\u662f\u4e00\u4e2a\u975e\u5e38\u7cdf\u7cd5\u7684\u51b3\u5b9a\uff0c\u4e8e\u662fpoll\u51fd\u6570\u6539\u8fdb\u4e86\u8fd9\u4e00\u70b9\uff0c\u6d88\u9664\u4e86\u4e0a\u9650\u9650\u5236\uff0c\u76f4\u63a5\u4f7f\u7528\u6587\u4ef6\u63cf\u8ff0\u7b26\u672c\u8eab\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u5e94\u5bf9\u8bbe\u7f6e\u7684\u63cf\u8ff0\u7b26\u4f1a\u88ab\u91cd\u7f6e\uff0c\u6240\u4ee5\u5c06\u8fd9\u4e2a\u53c2\u6570\u8bbe\u8ba1\u4e3a\u4e86\u7ed3\u6784\u4f53\uff0c\u5e76\u4e14\u8fd4\u56de\u503c\u548c\u9884\u671f\u503c\u5206\u5f00\uff0c\u907f\u514d\u4e86\u53cd\u590d\u590d\u5236\u6d88\u8017\u7684\u65f6\u95f4\u548c\u5197\u4f59\u7684\u4ee3\u7801\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;poll.h&gt;\n\n int poll(struct pollfd *fds, nfds_t nfds, int timeout);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>fds<\/code>: \u6307\u5411\u4e00\u4e2a<code>pollfd<\/code>\u7ed3\u6784\u4f53\u6570\u7ec4\u7684\u6307\u9488\uff0c\u6bcf\u4e2a\u6570\u7ec4\u5143\u7d20\u90fd\u662f\u4e00\u4e2a<code>struct pollfd<\/code>\u7ed3\u6784\uff0c\u7528\u4e8e\u6307\u5b9a\u6d4b\u8bd5\u67d0\u4e2a\u7ed9\u5b9a\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u6761\u4ef6\u3002<\/li>\n\n\n\n<li><code>nfds<\/code>: \u6570\u7ec4<code>fds<\/code>\u7684\u6700\u5927\u6709\u6548\u6570\u7684\u4e0b\u6807\u7684\u7f16\u53f7+1\u3002<\/li>\n\n\n\n<li><code>timeout<\/code>: \u7b49\u5f85\u7684\u6beb\u79d2\u6570\u3002\u5982\u679c\u4e3a\u8d1f\u503c\uff0c<code>poll<\/code>\u5c06\u65e0\u9650\u671f\u5730\u7b49\u5f85\u3002\u5982\u679c\u4e3a0\uff0c\u5219\u8868\u793a\u4e0d\u7b49\u5f85<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u53c2\u6570fds\u7ed3\u6784\u4f53<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct pollfd {\n    int fd;         \/\/ \u6587\u4ef6\u63cf\u8ff0\u7b26\n    short events;   \/\/ \u7b49\u5f85\u7684\u4e8b\u4ef6\n    short revents;  \/\/ \u5b9e\u9645\u53d1\u751f\u7684\u4e8b\u4ef6\n};\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>fd<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8fd9\u662f\u4f60\u60f3\u8981\u76d1\u89c6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u662f\u4e00\u4e2a\u5957\u63a5\u5b57\u3001\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u6216\u6807\u51c6\u8f93\u5165\u8f93\u51fa\u7b49\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u4f60\u4e0d\u60f3\u76d1\u89c6\u67d0\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u53ef\u4ee5\u5c06\u5176\u8bbe\u7f6e\u4e3a\u8d1f\u503c\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>events<\/strong>: \u8fd9\u662f\u4e00\u4e2a\u4f4d\u63a9\u7801\uff0c\u7528\u4e8e\u6307\u5b9a\u4f60\u60f3\u8981\u76d1\u89c6\u7684\u4e8b\u4ef6\u7c7b\u578b\u3002\u4f60\u53ef\u4ee5\u901a\u8fc7\u6309\u4f4d\u6216\u64cd\u4f5c\u7b26\uff08<code>|<\/code>\uff09\u7ec4\u5408\u591a\u4e2a\u4e8b\u4ef6\u7c7b\u578b\uff0c\u5e38\u7528\u7684\u4e8b\u4ef6\u7c7b\u578b\u5305\u62ec\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>POLLIN<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u53d6\u6570\u636e\uff08\u5305\u62ec\u666e\u901a\u6570\u636e\u548c\u4f18\u5148\u6570\u636e\uff09\u3002<\/li>\n\n\n\n<li><strong>POLLRDNORM<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u53d6\u666e\u901a\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLRDBAND<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u53d6\u4f18\u5148\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLPRI<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u6709\u7d27\u6025\u6570\u636e\u53ef\u8bfb\u3002<\/li>\n\n\n\n<li><strong>POLLOUT<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u5165\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLWRNORM<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u5165\u666e\u901a\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLWRBAND<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u5165\u4f18\u5148\u6570\u636e\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee5\u4e0a\u6700\u5e38\u7528\u7684\u662f<strong><code>POLLIN<\/code><\/strong>\u3001<strong><code>POLLOUT<\/code><\/strong>\u4e24\u79cd<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>revents<\/strong>: \u8fd9\u662f\u4e00\u4e2a\u4f4d\u63a9\u7801\uff0c\u7528\u4e8e\u8fd4\u56de\u5b9e\u9645\u53d1\u751f\u7684\u4e8b\u4ef6\u7c7b\u578b\uff0c<code>poll<\/code>\u51fd\u6570\u5728\u8fd4\u56de\u65f6\u4f1a\u8bbe\u7f6e\u8fd9\u4e2a\u5b57\u6bb5\uff0c\u4ee5\u6307\u793a\u54ea\u4e9b\u4e8b\u4ef6\u5b9e\u9645\u53d1\u751f\u4e86\uff0c\u4f60\u53ef\u4ee5\u68c0\u67e5\u8fd9\u4e2a\u5b57\u6bb5\u6765\u786e\u5b9a\u54ea\u4e9b\u4e8b\u4ef6\u53d1\u751f\u4e86\u3002\u5e38\u7528\u7684\u8fd4\u56de\u4e8b\u4ef6\u7c7b\u578b\u5305\u62ec<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>POLLIN<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u53d6\u6570\u636e\uff08\u5305\u62ec\u666e\u901a\u6570\u636e\u548c\u4f18\u5148\u6570\u636e\uff09\u3002<\/li>\n\n\n\n<li><strong>POLLRDNORM<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u53d6\u666e\u901a\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLRDBAND<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\u53d6\u4f18\u5148\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLPRI<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u6709\u7d27\u6025\u6570\u636e\u53ef\u8bfb\u3002<\/li>\n\n\n\n<li><strong>POLLOUT<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u5165\u6570\u636e\u3002\uff08\u6ce8\u610f\u662f\u68c0\u67e5\u662f\u5426\u53ef\u5199\uff0c\u5c31\u662f\u5199\u7f13\u51b2\u533a\u662f\u5426\u6ee1\u4e86\uff0c\u800c\u4e0d\u662f\u662f\u5426\u5199\u5165\uff09<\/li>\n\n\n\n<li><strong>POLLWRNORM<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u5165\u666e\u901a\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLWRBAND<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u5165\u4f18\u5148\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>POLLERR<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u53d1\u751f\u9519\u8bef\u3002<\/li>\n\n\n\n<li><strong>POLLHUP<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u6302\u8d77\u3002<\/li>\n\n\n\n<li><strong>POLLNVAL<\/strong>: \u8868\u793a\u6587\u4ef6\u63cf\u8ff0\u7b26\u65e0\u6548\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de<code>revents<\/code>\u57df\u4e0d\u4e3a0\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e2a\u6570\u3002<\/li>\n\n\n\n<li>\u8d85\u65f6\u6216\u65e0\u4e8b\u4ef6\u53d1\u751f\u65f6\uff0c\u8fd4\u56de0\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6e<code>errno<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u89e3\u6790<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u51fd\u6570\u7684\u8bde\u751f\u5728\u5f88\u5927\u7a0b\u5ea6\u4e0a\u4fee\u6539\u4e86select\u51fd\u6570\u7684\u4e0d\u8db3\u4e4b\u5904\uff0c\u4f46\u662f\u5374\u51fa\u73b0\u4e86\u4e00\u4e9b\u5176\u4ed6\u7684\u95ee\u9898\uff0c\u9996\u5f53\u5176\u51b2\u5c31\u662f\u8fd9\u4e2a\u51fd\u6570\u4e0d\u652f\u6301windows\u7cfb\u7edf\uff0c\u8de8\u5e73\u53f0\u6027\u964d\u4f4e\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5168\u5c40\u89c6\u89d2\u4e0b\uff0c\u8fd9\u4e2a\u51fd\u6570\u5728\u4f9d\u65e7\u5b58\u5728\u5c40\u9650\u6027\uff0c\u5b83\u540c\u6837\u9700\u8981\u5185\u6838\u5b8c\u6574\u590d\u5236\u9700\u8981\u4f7f\u7528\u5230\u7684\u7ed3\u6784\u4f53\u6570\u7ec4\uff0c\u867d\u7136\u4e0d\u662f\u5c06\u6240\u6709\u7684\u7ed3\u6784\u4f53\u590d\u5236\uff0c\u4f46\u662f\u5728\u7ed3\u6784\u4f53\u672c\u4f53\u7684\u7a7a\u95f4\u8f83\u5927\uff0c\u800c\u4e14\u5728\u8fd4\u56de\u7684\u65f6\u5019\u4e5f\u9700\u8981\u7ecf\u5386\u4e00\u8f6e\u590d\u5236\uff0c\u4ece\u5185\u6838\u6001\u8f6c\u79fb\u5230\u7528\u6237\u6001\u3002epoll\u7684\u672c\u8d28\u662f\u4e00\u4e2a\u94fe\u8868\uff0c\u5b83\u4f9d\u65e7\u65e0\u6cd5\u62dc\u6258\u7ebf\u6027\u904d\u5386\u7684\u8bc5\u5492\uff0c\u5f00\u53d1\u8005\u9700\u8981\u5bf9\u6574\u4e2a\u6709\u6548\u7684\u90e8\u5206\u7684\u7ed3\u6784\u4f53\u8fdb\u884c\u5b8c\u6574\u7684\u904d\u5386\uff0c\u83b7\u53d6\u5230\u54ea\u4e9b\u503c\u88ab\u6fc0\u6d3b\uff0c\u5bf9\u4e8e\u7ed3\u679c\u904d\u5386\u4f9d\u65e7\u9700\u8981\u5927\u91cf\u7684\u65f6\u95f4\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e8b\u5b9e\u4e0a\u8fd9\u4e2a\u51fd\u6570\u7528\u7684\u6bd4\u8f83\u5c11\uff0c\u56e0\u4e3a\u5b83\u50cf\u662f\u53d1\u5c55\u8fc7\u7a0b\u4e2d\u4e00\u4e2a\u8fdb\u5316\u4e0d\u5168\u7684\u4ea7\u7269\uff0c\u800c\u4e14\u65e0\u6cd5\u8de8winodws\u8fd9\u6837\u7684\u4e3b\u6d41\u5e73\u53f0\uff0c\u4f7f\u7528\u66f4\u5e7f\u9614\u7684\u662f\u540e\u7eed\u7684<code>epoll<\/code>\u51fd\u6570<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u603b\u5f97\u6765\u8bf4\uff0c<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u8fd9\u4e2a\u51fd\u6570\u5bf9select\u51fd\u6570\u7684\u90e8\u5206\u7f3a\u70b9\u8fdb\u884c\u4e86\u6539\u8fdb\uff0c\u76f8\u5bf9select\u5728\u5904\u7406\u89c4\u6a21\u66f4\u5927\u7684\u5e76\u53d1\u4e0b\u6709\u826f\u597d\u7684\u9002\u5e94\uff0c\u4f46\u662f\u5728\u5de8\u5927\u89c4\u6a21\u7684\u5e76\u53d1\u4e0b\uff0c\u4f9d\u65e7\u548cselect\u4e00\u6837\u6548\u7387\u4f1a\u53d8\u5f97\u5e95\u4e0b\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#9b51e0\" class=\"has-inline-color\">\u6574\u4f53\u603b\u7ed3poll\u51fd\u6570\u7684\u6267\u884c\u8fc7\u7a0b<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7528\u6237\u8bbe\u7f6e\u7ed3\u6784\u4f53\u6570\u7ec4\uff0c\u5e76\u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u5199\u5165\u5176\u4e2d<\/li>\n\n\n\n<li>\u5185\u6838\u4f1a\u5c06\u7528\u6237\u8bbe\u7f6e\u7684\u6709\u6548\u7ed3\u6784\u4f53\u6570\u7ec4\u5b8c\u6574\u590d\u5236\u5230\u5185\u6838\u4e2d\uff0c\u4f46\u662f\u5728\u5185\u6838\u4e2d\u4ee5\u94fe\u8868\u7684\u5f62\u5f0f\u5b58\u50a8\u3002\u7136\u540e\u8ba9poll\u51fd\u6570\u963b\u585e\u3002<\/li>\n\n\n\n<li>\u5185\u6838\u4ee5\u8f6e\u8be2\u7684\u65b9\u5f0f\u76d1\u542c\u7ed3\u6784\u4f53\u8868\uff0c\u5f53\u53d1\u751f\u4fe1\u53f7\u65f6\uff0c\u5b83\u5c06\u6574\u4e2a\u8868\u4ece\u5185\u6838\u6001\u5b8c\u6574\u7684\u590d\u5236\u5230\u7528\u6237\u6001\uff0c\u8fd4\u56de\u51fa\u73b0\u4fe1\u53f7\u7684\u6570\u91cf\uff0c\u5e76\u89e3\u9664\u963b\u585e\u3002<\/li>\n\n\n\n<li>\u7528\u6237\u9700\u8981\u4f7f\u7528\u8f6e\u8be2\u7684\u65b9\u5f0f\u5bfb\u627e\u89e6\u53d1\u4fe1\u53f7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h&gt;\n#include &lt;sys\/types.h&gt;          \n#include &lt;sys\/socket.h&gt;\n#include &lt;string.h&gt;\n#include &lt;netinet\/in.h&gt;\n#include &lt;arpa\/inet.h&gt;\n#include &lt;poll.h&gt;\nint main(){\n    int sock_id = socket(AF_INET, SOCK_STREAM, 0);\n    if(sock_id == -1){\n        perror(\"\u5957\u63a5\u5b57\u751f\u6210\u51fa\u9519\");\n        return 0;\n    }\n    struct sockaddr_in addr;\n    memset(&amp;addr,0,sizeof(struct sockaddr_in));\n    addr.sin_family = AF_INET;\n    addr.sin_port = htons(8888);\n    addr.sin_addr.s_addr = inet_addr(\"127.0.0.1\");\n    \n    if(bind(sock_id,(struct sockaddr*)&amp;addr,sizeof(addr))){\n        perror(\"\u5957\u63a5\u5b57\u7ed1\u5b9a\u51fa\u9519\");\n        return 0;\n    }\n\n    if(listen(sock_id,5)){\n        perror(\"\u8f6c\u5316\u4e3a\u76d1\u542c\u5957\u63a5\u5b57\u5931\u8d25\");\n        return 0;\n    }\n\n    \/\/\u5b9a\u4e49\u4e00\u4e2a\u7f13\u51b2\u533a\n    char text&#91;50];\n    \/\/\u5b9a\u4e49\u63cf\u8ff0\u7b26\u6570\u7ec4\n    struct pollfd fds&#91;1024];\n    \/\/\u521d\u59cb\u5316\u6240\u6709\u7684\u63cf\u8ff0\u7b26\n    for(int i = 0;i&lt;1024;i++){\n        fds&#91;i].fd = -1;\/\/\u521d\u59cb\u5316\u4e3a\u8fd9\u4e2a\u503c\u662f\u56e0\u4e3a\u8d1f\u6570\u5c5e\u4e8e\u4e0d\u5408\u6cd5\u6587\u4ef6\u63cf\u8ff0\u7b26\n        fds&#91;i].events = POLLIN;\/\/\u8bbe\u7f6e\u76d1\u542c\u8f93\u5165\u60c5\u51b5\n    }\n    \/\/\u5c06\u76d1\u542c\u5957\u63a5\u5b57\u5199\u5165\n    fds&#91;0].fd = sock_id;\n    \/\/\u521d\u59cb\u5316\u6700\u5927\u4e0b\u6807\n    int max_id = 0;\n    while(1){\n        printf(\"\u6b63\u5728\u76d1\u542c\u5ba2\u6237\u7aef\u8bf7\u6c42\\n\");\n        \/\/poll\u51fd\u6570\u963b\u585e\uff0c\u83b7\u53d6\u51fa\u73b0\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u51fa\u73b0\u4fe1\u53f7\u7684\u4e2a\u6570\n        int r_count = poll(fds,max_id+1,-1);\n        if(r_count == -1 ){\n            perror(\"poll\u51fd\u6570\u51fa\u9519\");\n            return 0;\n        }\n        printf(\"\u6b63\u5728\u68c0\u67e5\u662f\u5426\u51fa\u73b0\u65b0\u8fde\u63a5\u8bf7\u6c42\\n\");\n        \/\/\u68c0\u67e5\u662f\u5426\u51fa\u73b0\u4e86\u65b0\u7684\u8fde\u63a5\u8bf7\u6c42\n        if(fds&#91;0].revents &amp; POLLIN){\n            int afd = accept(sock_id,NULL,NULL);\n            if(afd != -1){\n                \/\/\u627e\u4e00\u4e2a\u7a7a\u4f4d\u5199\u5165\n                for(int i = 1;i&lt;1024;i++){\n                    if(fds&#91;i].fd == -1){\n                        fds&#91;i].fd = afd;\n                        max_id = (i &gt; max_id ? i : max_id);\n                        break;\n                    }\n                } \n            }\n            printf(\"maxid = %d fds = %d\\n\",max_id,fds&#91;max_id].fd);\n        }\n        printf(\"\u6b63\u5728\u68c0\u67e5\u662f\u5426\u6709\u5ba2\u6237\u7aef\u53d1\u9001\u6d88\u606f\\n\");\n        \/\/\u68c0\u67e5\u8fde\u63a5\u5957\u63a5\u5b57\n        for(int i = 1;i &lt; max_id + 1;i++){\n            \/\/\u5982\u679c\u8fd9\u4e2a\u503c\u4e0d\u662f\u76d1\u542c\u5957\u63a5\u5b57\uff0c\u5e76\u4e14\u5b83\u88abselect\u68c0\u6d4b\u5230\n            if(fds&#91;i].fd != -1 &amp;&amp; (fds&#91;i].revents &amp; POLLIN)){\n                int r_recv =  recv(fds&#91;i].fd,text,sizeof(text),MSG_NOSIGNAL);\n                if(r_recv == -1){\n                    perror(\"recv\u51fd\u6570\u51fa\u73b0\u9519\u8bef\");\n                    return 0;\n                }\n                if( r_recv == 0){\n                    \/\/\u5982\u679c\u8fd9\u4e2a\u8fde\u63a5\u5957\u63a5\u5b57\u65ad\u5f00\u8fde\u63a5\uff0c\u90a3\u4e48\u5c31\u4ece\u53c2\u6570\u4e2d\u5254\u9664\n                    fds&#91;i].fd = -1;\n                }\n                if( r_recv &gt; 0){\n                    printf(\"        &gt;&gt;&gt;\u5ba2\u6237\u7aef\u53d1\u9001\u4fe1\u606f:%s\\n\",text);\n                }\n            }\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u6267\u884c\u7ed3\u679c<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5ba2\u6237\u7aef\u8fde\u63a5\u540e\u53d1\u9001\u4e86\u4e00\u4e2a[ hello ]<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6b63\u5728\u76d1\u542c\u5ba2\u6237\u7aef\u8bf7\u6c42\n    &gt;&gt;&gt;\u5ba2\u6237\u7aef\u53d1\u9001\u4fe1\u606f:hello<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">epoll\u51fd\u6570\u96c6\u5408<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>epoll<\/code>\u662fLinux\u5185\u6838\u63d0\u4f9b\u7684\u4e00\u79cd\u9ad8\u6548\u7684I\/O\u591a\u8def\u590d\u7528\u673a\u5236\uff0c\u76f8\u6bd4\u4e8e<code>select<\/code>\u548c<code>poll<\/code>\uff0c<code>epoll<\/code>\u5728\u5904\u7406\u5927\u91cf\u6587\u4ef6\u63cf\u8ff0\u7b26\u65f6\u6027\u80fd\u66f4\u597d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0e<code>select<\/code>\u548c<code>poll<\/code>\u7cfb\u7edf\u8c03\u7528\u4e0d\u540c\uff0c<code>epoll<\/code>\u662f\u4e8b\u4ef6\u9a71\u52a8\u578b\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b83\u662f\u7ee7<code>poll<\/code>\u51fd\u6570\u4e4b\u540e\u8fed\u4ee3\u51fa\u7684\u4e00\u4e2a\u9ad8\u6027\u80fd\u51fd\u6570\u96c6\u5408\uff0c\u5b83\u5e76\u4e0d\u662f\u4e00\u4e2a\u51fd\u6570\u3002\u63a5\u4e0b\u6765\u5148\u770b\u770b\u51fd\u6570\u96c6\u5408\u4e2d\u7684\u5177\u4f53\u8fd8\u51fd\u6570\uff0c\u8fd9\u4e2a\u51fd\u6570\u96c6\u5408\u7684\u89e3\u6790\u8bf7\u6309\u8fd9\u4e2a\uff08<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\"><a href=\"#epoll_analyze\" data-type=\"internal\" data-id=\"#epoll_analyze\">&#8211;&gt; \u8df3\u8f6c<\/a><\/mark>\uff09\uff0c<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong><code>epoll_create<\/code><\/strong>\u51fd\u6570<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8be5\u51fd\u6570\u7684\u4f5c\u7528\u662f\u521b\u5efa\u4e00\u4e2aepoll\u5b9e\u4f8b\uff0c\u5e76\u8fd4\u56de\u8fd9\u4e2a\u5b9e\u4f8b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/epoll.h&gt;\n\nint epoll_create(int size);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>int size<\/strong>\uff1a\u8fd9\u4e2a\u53c2\u6570\u7528\u4e8e\u6307\u5b9a<code>epoll<\/code>\u5b9e\u4f8b<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u5efa\u8bae<\/mark>\u53ef\u4ee5\u76d1\u89c6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u6570\u91cf\u4e0a\u9650\u3002\u8fd9\u4ec5\u4ec5\u662f\u4e00\u4e2a\u5efa\u8bae\uff0c\u56e0\u4e3a\u540e\u7eed\u64cd\u4f5c\u7cfb\u7edf\u4f1a\u66f4\u5177\u9700\u8981\u52a8\u6001\u8c03\u6574\u3002<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u6ce8\u610f\uff1a\u8fd9\u4ec5\u4ec5\u662fLinux\u65e9\u671f\u7248\u672csize\u53c2\u6570\u5177\u6709\u8be5\u529f\u80fd\uff0c\u4eceLinux 2.6.8\u8fd9\u4e2a\u53c2\u6570\u5e76\u4e0d\u8d77\u4f5c\u7528,\u64cd\u4f5c\u7cfb\u7edf\u5b8c\u5168\u5ffd\u7565\u4e86\u8be5\u53c2\u6570\uff0c\u8be5\u53c2\u6570\u6210\u4e3a\u4e86\u4f4e\u7248\u672c\u5185\u6838\u517c\u5bb9\u7684\u4ea7\u7269\uff0c\u5c5e\u4e8e\u5386\u53f2\u9057\u7559\u3002\u4f46\u662f\u5b83\u7684\u503c\u5fc5\u987b\u8981\u5927\u4e8e0<\/mark>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u8fc7\u5728\u73b0\u4ee3\u7f16\u7a0b\u7f16\u7a0b\u4e2d\uff0c\u5b58\u5728\u4e00\u4e2a\u6539\u8fdb\u7248\u672c\u7684\u5b9e\u4f8b\u521b\u5efa\u51fd\u6570\uff1a<code>epoll_create1(int flags)<\/code>\u51fd\u6570\u3002<strong>\u540c\u65f6\u4e5f\u662f\u66f4\u4e3a\u63a8\u8350\u4f7f\u7528\u7684\u51fd\u6570<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\u8be5\u51fd\u6570\u7684\u53c2\u6570\u5982\u4e0b\uff1a<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>0<\/code>\uff1a\u4e0d\u8bbe\u7f6e\u4efb\u4f55\u6807\u5fd7\uff0c\u5c31\u548c\u4e0a\u8ff0\u7684<code>epoll_create(int size)<\/code>\u4f5c\u7528\u4e00\u6837\u3002<\/li>\n\n\n\n<li><code>EPOLL_CLOEXEC<\/code>\uff1a<mark style=\"background-color:#f78da7\" class=\"has-inline-color\">\u5728\u5b50\u8fdb\u7a0b\u4e2d\u81ea\u52a8\u5173\u95ed epoll \u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\u8fd9\u5bf9\u4e8e\u907f\u514d\u6587\u4ef6\u63cf\u8ff0\u7b26\u6cc4\u6f0f\u975e\u5e38\u6709\u7528<\/mark>\u3002\u8fd9\u6bb5\u8bdd\u6bd4\u8f83\u96be\u4ee5\u7406\u89e3\uff0c\u901a\u4fd7\u70b9\u8bb2\uff0c\u5f53\u4e00\u4e2a\u8fdb\u7a0b\u521b\u5efa\u5b50\u8fdb\u7a0b\u7684\u60c5\u51b5\u4e0b\uff0c\u5b50\u8fdb\u7a0b\u5c31\u590d\u5236\u4e86\u4e4b\u524d\u7236\u8fdb\u7a0b\u6267\u884c\u8fc7\u7684\u4ee3\u7801\uff0c\u4ee5\u53ca\u53d8\u91cf\u4e2d\u7684\u503c\u3002\u4e5f\u5c31\u8bf4\uff0c\u5b50\u8fdb\u7a0b\u53ef\u4ee5\u76f4\u63a5\u8bbf\u95ee\u7236\u8fdb\u7a0b\u521b\u5efa\u7684epoll\u5b9e\u4f8b\uff0c\u4f46\u662f\u4e24\u4e2a\u8fdb\u7a0b\u8bbf\u95ee\u540c\u4e00\u4e2a\u5b9e\u4f8b\u4f1a\u53d1\u751f\u4ec0\u4e48\u5462\uff1f\u4e3e\u51e0\u4e2a\u4f8b\u5b50\uff1a<mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">\uff081\uff09\u5b50\u8fdb\u7a0b\u5173\u95ed\u4e86\u67d0\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u800c\u540e\u7236\u8fdb\u7a0b\u8bbf\u95ee\u8fd9\u4e2a\u88ab\u5173\u95ed\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\uff082\uff09\u5b50\u8fdb\u7a0b\u548c\u7236\u8fdb\u7a0b\u540c\u65f6\u8bbf\u95ee\u540c\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\uff083\uff09\u4e5f\u8bb8\u5b50\u8fdb\u7a0b\u4e0d\u9700\u8981\u8fd9\u4e9b\u5b9e\u4f8b\uff0c\u90a3\u4e48\u4fdd\u5b58\u5728\u5b9e\u4f8b\u4e2d\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u80fd\u56e0\u4e3a\u6ca1\u6709\u88ab\u5b50\u8fdb\u7a0bclose\u800c\u5bfc\u81f4\u63cf\u8ff0\u7b26\u6cc4\u9732<\/mark>\u3002\u663e\u7136\u8fd9\u4e9b\u60c5\u51b5\u7ad9\u5728\u7236\u8fdb\u7a0b\u7684\u89d2\u5ea6\u770b\uff0c\u5bfc\u81f4\u7a0b\u5e8f\u51fa\u73b0\u5f02\u5e38\u751a\u81f3\u5d29\u6e83\u3002\u6b64\u65f6<code>EPOLL_CLOEXEC<\/code>\u53c2\u6570\u53ef\u4ee5\u8ba9\u5b50\u8fdb\u7a0b\u5728\u521b\u5efa\u7684\u65f6\u5019\uff0c\u9762\u5411\u5b50\u8fdb\u7a0b\u5173\u95edepoll\u5b9e\u4f8b\uff0c\u90a3\u4e48\u5b50\u8fdb\u7a0b\u65e0\u6cd5\u8bbf\u95ee\u5230\u7236\u8fdb\u7a0b\u7684epoll\uff0c\u4ece\u800c\u5b9e\u73b0\u66f4\u4e3a\u5b89\u5168\u7684\u63a7\u5236\u3002\uff08<mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\"><a href=\"#EPOLL_CLOEXEC_Demonstration\" data-type=\"internal\" data-id=\"#EPOLL_CLOEXEC_Demonstration\">&#8211;&gt;\u793a\u4f8b\u8df3\u8f6c<\/a><\/mark>\uff09<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b83\u7684\u8fd4\u56de\u503c\u4e0eepoll_create(int size)\u4e00\u81f4\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de\u4e00\u4e2a\u6307\u5411\u65b0\u521b\u5efa\u7684<code>epoll<\/code>\u5b9e\u4f8b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6e<code>errno<\/code>\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"EPOLL_CLOEXEC_Demonstration\">epoll_create1(int flags)\u7684<code>EPOLL_CLOEXEC<\/code>\u53c2\u6570\u6548\u679c\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/epoll.h&gt;\n#include &lt;unistd.h&gt;\n#include &lt;stdio.h&gt;\n#include &lt;stdlib.h&gt;\n#include &lt;sys\/wait.h&gt;\n#include &lt;sys\/types.h&gt;\n\nint main() {\n    \/\/ \u521b\u5efa epoll \u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u5e76\u8bbe\u7f6e EPOLL_CLOEXEC \u53c2\u6570\n    int epoll_fd = epoll_create1(EPOLL_CLOEXEC);\n    if (epoll_fd == -1) {\n        perror(\"epoll\u5b9e\u4f8b\u751f\u6210\u5931\u8d25\");\n        return 1;\n    }\n\n    pid_t pid = fork();\n    if (pid == -1) {\n        perror(\"\u5b50\u8fdb\u7a0b\u521b\u5efa\u5931\u8d25\");\n        close(epoll_fd);\n        return 1;\n    }\n\n    if (pid == 0) { \/\/ \u5b50\u8fdb\u7a0b\n        \/\/ \u5c1d\u8bd5\u8bbf\u95ee\u7236\u8fdb\u7a0b\u7684 epoll \u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u76d1\u63a7\u6807\u51c6\u8f93\u5165\n        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, STDIN_FILENO, NULL) == -1) {\n            perror(\"\u5728\u5b50\u8fdb\u7a0b\u4f7f\u7528\u4e86epoll_ctl\u51fa\u73b0\u9519\u8bef\");\n        } else {\n            printf(\"\u5b50\u8fdb\u7a0b\u6210\u529f\u8bbf\u95eeepoll\u5b9e\u4f8b\\n\");\n        }\n        exit(0);\n    } else { \/\/ \u7236\u8fdb\u7a0b\n        \/\/ \u7b49\u5f85\u5b50\u8fdb\u7a0b\u7ed3\u675f\n        wait(NULL);\n        printf(\"\u5b50\u8fdb\u7a0b\u7ed3\u675f\\n\");\n    }\n\n    \/\/ \u5173\u95ed epoll \u6587\u4ef6\u63cf\u8ff0\u7b26\n    close(epoll_fd);\n    return 0;\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u6267\u884c\u7ed3\u679c<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u5728\u5b50\u8fdb\u7a0b\u4f7f\u7528\u4e86epoll_ctl\u51fa\u73b0\u9519\u8bef: Bad address\n\u5b50\u8fdb\u7a0b\u7ed3\u675f<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><strong><code>epoll_ctl<\/code><\/strong>\u51fd\u6570<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8be5\u51fd\u6570\u7684\u4f5c\u7528\u662f\u64cd\u4f5cepoll\u5b9e\u4f8b\uff0c\u4e0d\u8fc7\u672c\u8d28\u4e0a\u662f\u5bf9epoll\u5b9e\u4f8b\u4e2d\u7684\u5957\u63a5\u5b57\u8fdb\u884c\u7ba1\u7406\u3002\u51fd\u6570\u63d0\u4f9b\u4e86\u4e09\u79cd\u64cd\u4f5c\u65b9\u5f0f\uff1a\u589e\u3001\u5220\u3001\u6539\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/epoll.h&gt;\n\nint epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>epfd<\/strong>\uff1a\u7531<code>epoll_create<\/code>\u8fd4\u56de\u7684<code>epoll<\/code>\u5b9e\u4f8b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li><strong>op<\/strong>\uff1a\u64cd\u4f5c\u7c7b\u578b\uff0c\u53ef\u4ee5\u662f\u4ee5\u4e0b\u4e09\u4e2a\u5b8f\u4e4b\u4e00\uff1a\n<ul class=\"wp-block-list\">\n<li><code>EPOLL_CTL_ADD<\/code>\uff1a\u5c06\u65b0\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6dfb\u52a0\u5230<code>epoll<\/code>\u5b9e\u4f8b\u4e2d\u3002\u5982\u679c\u53cd\u590d\u6dfb\u52a0\u540c\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u4f1a\u5bfc\u81f4\u51fd\u6570\u62a5\u9519<\/li>\n\n\n\n<li><code>EPOLL_CTL_MOD<\/code>\uff1a\u4fee\u6539\u5df2\u7ecf\u6ce8\u518c\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u4e8b\u4ef6\u3002<\/li>\n\n\n\n<li><code>EPOLL_CTL_DEL<\/code>\uff1a\u4ece<code>epoll<\/code>\u5b9e\u4f8b\u4e2d\u5220\u9664\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>fd<\/strong>\uff1a\u8981\u64cd\u4f5c\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li><strong>event<\/strong>\uff1a\u6307\u5411<code>epoll_event<\/code>\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u7528\u4e8e\u63cf\u8ff0\u8981\u76d1\u89c6\u7684\u4e8b\u4ef6\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><code>epoll_event<\/code>\u7ed3\u6784\u4f53\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct epoll_event {\n    uint32_t events;    \/\/ \u4e8b\u4ef6\u7c7b\u578b\n    epoll_data_t data;  \/\/ \u7528\u6237\u6570\u636e\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u4e2d events\u5e38\u7528\u4e8b\u4ef6\u7c7b\u578b\u6709\u4ee5\u4e0b\u9009\u9879\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>EPOLLIN<\/strong>\uff1a\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u8bfb\uff08\u5305\u62ec\u5bf9\u7aefSOCKET\u6b63\u5e38\u5173\u95ed\uff09\u3002<\/li>\n\n\n\n<li><strong>EPOLLOUT<\/strong>\uff1a\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u53ef\u4ee5\u5199\u3002\uff08\u6ce8\u610f\u662f\u68c0\u67e5\u662f\u5426\u53ef\u5199\uff0c\u5c31\u662f\u5199\u7f13\u51b2\u533a\u662f\u5426\u6ee1\u4e86\uff0c\u800c\u4e0d\u662f\u662f\u5426\u5199\u5165\uff09<\/li>\n\n\n\n<li><strong>EPOLLPRI<\/strong>\uff1a\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6709\u7d27\u6025\u7684\u6570\u636e\u53ef\u8bfb\uff08\u5e26\u5916\u6570\u636e\uff09\u3002<\/li>\n\n\n\n<li><strong>EPOLLERR<\/strong>\uff1a\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u53d1\u751f\u9519\u8bef\u3002<\/li>\n\n\n\n<li><strong>EPOLLHUP<\/strong>\uff1a\u8868\u793a\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u88ab\u6302\u65ad\u3002<\/li>\n\n\n\n<li><strong>EPOLLET<\/strong>\uff1a\u5c06<code>epoll<\/code>\u8bbe\u4e3a\u8fb9\u7f18\u89e6\u53d1\uff08Edge Triggered\uff09\u6a21\u5f0f\u3002<\/li>\n\n\n\n<li><strong>EPOLLONESHOT<\/strong>\uff1a\u53ea\u76d1\u542c\u4e00\u6b21\u4e8b\u4ef6\uff0c\u5f53\u76d1\u542c\u5b8c\u8fd9\u6b21\u4e8b\u4ef6\u540e\uff0c\u5982\u679c\u8fd8\u9700\u8981\u7ee7\u7eed\u76d1\u542c\u8fd9\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u9700\u8981\u518d\u6b21\u5c06\u5176\u6dfb\u52a0\u5230<code>epoll<\/code>\u5b9e\u4f8b\u4e2d\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u4e2d\u6700\u5e38\u7528\u7684\u662f<code>EPOLLIN<\/code>\u548c<code>EPOLLOUT<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u800cdata\u53c2\u6570\u662f\u4e00\u4e2a\u8054\u5408\u4f53\uff0c\u4f46\u662f\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5185\u6838\u4e0d\u4f1a\u5bf9data\u53c2\u6570\u4e5f\u5c31\u662f\u7528\u6237\u6570\u636e\u8fdb\u884c\u4efb\u4f55\u64cd\u4f5c\uff0c\u5b83\u4f1a\u539f\u5c01\u4e0d\u52a8\u8fd4\u56de\u7ed9\u5f00\u53d1\u8005\uff0c\u5f00\u53d1\u8005\u5fc5\u987b\u81ea\u5df1\u8d1f\u8d23\u4f20\u5165\u7684\u6570\u636e\u7684\u662f\u5426\u88ab\u81ea\u5df1\u89e3\u6790\uff0c\u8be5\u53c2\u6570\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>typedef union epoll_data {\n    void *ptr; \/\/\u53ef\u4ee5\u5b58\u50a8\u4e00\u4e2a\u6307\u5411\u7528\u6237\u81ea\u5b9a\u4e49\u6570\u636e\u7ed3\u6784\u7684\u6307\u9488\u3002\n    int fd;\/\/\u53ef\u4ee5\u5b58\u50a8\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002\n    uint32_t u32;\/\/\u53ef\u4ee5\u5b58\u50a8\u4e00\u4e2a 32 \u4f4d\u7684\u6574\u6570\u3002\n    uint64_t u64;\/\/\u53ef\u4ee5\u5b58\u50a8\u4e00\u4e2a 64 \u4f4d\u7684\u6574\u6570\u3002\n} epoll_data_t;\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\u8fd4\u56de0\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6e<code>errno<\/code>\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b1-1<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u589e\u52a0\u64cd\u4f5c<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u521b\u5efa epoll \u5b9e\u4f8b&nbsp; &nbsp; \nint epfd = epoll_create(10); \/\/\u5efa\u8bae\u5b9e\u4f8b\u63cf\u8ff0\u7b26\u4e0a\u9650\u4e3a10\uff0c\u5b9e\u9645\u4e0a\u8fd9\u4e2a\u503c\u4f1a\u88ab\u5ffd\u7565&nbsp; &nbsp; \nif (epfd == -1) {\n&nbsp; &nbsp; &nbsp; &nbsp; return EXIT_FAILURE;&nbsp; &nbsp; \n}&nbsp; &nbsp; \nstruct epoll_event ev = {\n&nbsp; &nbsp; &nbsp; &nbsp; .events = EPOLLIN, &nbsp;\/\/ \u76d1\u542c\u8bfb\u4e8b\u4ef6\n&nbsp; &nbsp; &nbsp; &nbsp; .data.fd = sock_fd &nbsp;\/\/ \u5c06\u5957\u63a5\u5b57\u6587\u4ef6\u63cf\u8ff0\u7b26\u5b58\u50a8\u5728 data \u4e2d&nbsp; &nbsp; \n};&nbsp; &nbsp; \n\/\/ \u64cd\u4f5c\u51fd\u6570\u8d4b\u503c&nbsp; &nbsp; \nif (epoll_ctl(epfd, EPOLL_CTL_ADD, sock_fd, &amp;ev) == -1) {\n&nbsp; &nbsp; &nbsp; &nbsp; perror(\"epoll_ctl: EPOLL_CTL_ADD\");\n&nbsp; &nbsp; &nbsp; &nbsp; close(epfd);\n&nbsp; &nbsp; &nbsp; &nbsp; return EXIT_FAILURE;&nbsp; &nbsp; \n}&nbsp; &nbsp; \n\/\/ \u5176\u4ed6\u4ee3\u7801...&nbsp; &nbsp; \nclose(epfd);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u4fee\u6539\u64cd\u4f5c<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct epoll_event ev;\nev.events = EPOLLOUT; \/\/ \u4fee\u6539\u4e3a\u76d1\u542c\u5199\u4e8b\u4ef6\nev.data.fd = sockfd;  \/\/ \u4ecd\u7136\u662f\u540c\u4e00\u4e2a\u5957\u63a5\u5b57\n\nif (epoll_ctl(epfd, EPOLL_CTL_MOD, sockfd, &amp;ev) == -1) {\n    perror(\"epoll_ctl: EPOLL_CTL_MOD\");\n    exit(EXIT_FAILURE);\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u5220\u9664\u64cd\u4f5c<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>if (epoll_ctl(epfd, EPOLL_CTL_DEL, sockfd, NULL) == -1) {\n    perror(\"epoll_ctl: EPOLL_CTL_DEL\");\n    exit(EXIT_FAILURE);\n}\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><strong><code>epoll_wait<\/code><\/strong>\u51fd\u6570<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9ad8\u6548\u6027<\/strong>\uff1a<code>epoll_wait<\/code>&nbsp;\u53ef\u4ee5\u540c\u65f6\u76d1\u89c6\u5927\u91cf\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u9002\u7528\u4e8e\u9ad8\u5e76\u53d1\u573a\u666f\u3002<\/li>\n\n\n\n<li><strong>\u7075\u6d3b\u6027<\/strong>\uff1a\u652f\u6301\u591a\u79cd\u4e8b\u4ef6\u7c7b\u578b\uff0c\u5982\u53ef\u8bfb\u3001\u53ef\u5199\u3001\u9519\u8bef\u7b49\u3002<\/li>\n\n\n\n<li><strong>\u53ef\u6269\u5c55\u6027<\/strong>\uff1a\u53ef\u4ee5\u52a8\u6001\u6dfb\u52a0\u6216\u5220\u9664\u76d1\u89c6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;sys\/epoll.h&gt;\n\nint epoll_wait(int epfd, struct epoll_event *events,int maxevents, int timeout);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>epfd<\/code>\uff1a\u7531&nbsp;<code>epoll_create<\/code>&nbsp;\u6216&nbsp;<code>epoll_create1<\/code>&nbsp;\u521b\u5efa\u7684 epoll \u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n\n\n\n<li><code>events<\/code>\uff1a\u6307\u5411&nbsp;<code>epoll_event<\/code>&nbsp;\u7ed3\u6784\u4f53\u6570\u7ec4\u7684\u6307\u9488\uff0c\u7528\u4e8e\u8fd4\u56de\u53d1\u751f\u7684\u4e8b\u4ef6\u3002<\/li>\n\n\n\n<li><code>maxevents<\/code>\uff1a\u671f\u671b\u6355\u83b7\u7684\u4e8b\u4ef6\u7684\u6700\u5927\u6570\u91cf\uff0c\u5fc5\u987b\u5927\u4e8e 0\u3002<\/li>\n\n\n\n<li><code>timeout<\/code>\uff1a\u7b49\u5f85\u4e8b\u4ef6\u53d1\u751f\u7684\u8d85\u65f6\u65f6\u95f4\uff0c\u5355\u4f4d\u4e3a\u6beb\u79d2\u3002\u53d6\u503c\u4e3a\uff1a\n<ul class=\"wp-block-list\">\n<li><code>-1<\/code>\uff1a\u65e0\u9650\u7b49\u5f85\uff0c\u76f4\u5230\u6709\u4e8b\u4ef6\u53d1\u751f\u3002<\/li>\n\n\n\n<li><code>0<\/code>\uff1a\u7acb\u5373\u8fd4\u56de\uff0c\u4e0d\u7b49\u5f85\u3002<\/li>\n\n\n\n<li>\u5927\u4e8e&nbsp;<code>0<\/code>\uff1a\u7b49\u5f85\u6307\u5b9a\u7684\u6beb\u79d2\u6570\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6210\u529f\u65f6\uff0c\u8fd4\u56de\u53d1\u751f\u7684\u4e8b\u4ef6\u6570\u91cf\u3002<\/li>\n\n\n\n<li>\u8d85\u65f6\u65f6\uff0c\u8fd4\u56de&nbsp;<code>0<\/code>\u3002<\/li>\n\n\n\n<li>\u5931\u8d25\u65f6\uff0c\u8fd4\u56de&nbsp;<code>-1<\/code>&nbsp;\u5e76\u8bbe\u7f6e&nbsp;<code>errno<\/code>&nbsp;\u4ee5\u6307\u793a\u9519\u8bef\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u7efc\u5408\u793a\u4f8b1.1<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h&gt;\n#include &lt;sys\/types.h&gt;          \n#include &lt;sys\/socket.h&gt;\n#include &lt;string.h&gt;\n#include &lt;netinet\/in.h&gt;\n#include &lt;arpa\/inet.h&gt;\n #include &lt;unistd.h&gt;\n#include &lt;sys\/epoll.h&gt;\n\nint main(){\n    int sock_id = socket(AF_INET, SOCK_STREAM, 0);\n    if(sock_id == -1){\n        perror(\"\u5957\u63a5\u5b57\u751f\u6210\u51fa\u9519\");\n        return 0;\n    }\n    struct sockaddr_in addr;\n    memset(&amp;addr,0,sizeof(struct sockaddr_in));\n    addr.sin_family = AF_INET;\n    addr.sin_port = htons(8888);\n    addr.sin_addr.s_addr = inet_addr(\"127.0.0.1\");\n    \n    if(bind(sock_id,(struct sockaddr*)&amp;addr,sizeof(addr))){\n        perror(\"\u5957\u63a5\u5b57\u7ed1\u5b9a\u51fa\u9519\");\n        return 0;\n    }\n\n    if(listen(sock_id,5)){\n        perror(\"\u8f6c\u5316\u4e3a\u76d1\u542c\u5957\u63a5\u5b57\u5931\u8d25\");\n        return 0;\n    }\n\n    \/\/\u5b9a\u4e49\u4e00\u4e2a\u7f13\u51b2\u533a\n    char text&#91;50];\n\n    \/\/\u521d\u59cb\u5316\u4e00\u4e2aepoll\u5b9e\u4f8b\n    int epfd = epoll_create(10);\/\/\u8be5\u53c2\u6570\u88ab\u5ffd\u7565\uff0c\u53ea\u9700\u5927\u4e8e0\u5373\u53ef\n    if(epfd == -1){\n        perror(\"epoll\u5b9e\u4f8b\u521b\u5efa\u5931\u8d25\");\n        close(sock_id);\n        return 0;\n    }\n    \/\/\u8bbe\u7f6e\u4e8b\u4ef6\uff0c\u5c06\u5c06\u76d1\u542c\u5957\u63a5\u5b57\u52a0\u5165epoll\u5b9e\u4f8b\u4e2d\u3002\n    struct epoll_event epevent = {\n        .events = EPOLLIN,  \/\/\u76d1\u542c\u53ef\u8bfb\u4e8b\u4ef6\n        .data.fd = sock_id  \/\/\u7528\u6237\u6570\u636e\n    };\n    if(epoll_ctl(epfd,EPOLL_CTL_ADD,epevent.data.fd,&amp;epevent)){\n        perror(\"\u76d1\u542c\u5957\u63a5\u5b57\u6dfb\u52a0\u5931\u8d25\uff0cepool_ctl\u51fd\u6570\u6267\u884c\u51fa\u9519\");\n        close(sock_id);\n        close(epfd);\n        return 0;\n    }\n    \/\/\u521b\u5efa\u4e00\u4e2a\u4e8b\u4ef6\u6570\u7ec4\u7528\u4e8e\u5b58\u50a8\u8fd4\u56de\u7684\u7ed3\u679c\n    struct epoll_event reepevent&#91;1024];\n    \/\/\u5b9a\u4e49\u6570\u91cf\u65f6\u95f4\u6570\u7ec4\u7684\u603b\u6570\u91cf\n    int num = sizeof(reepevent)\/sizeof(reepevent&#91;0]);\n    while(1){\n        printf(\"\u7b49\u5f85\u5ba2\u6237\u7aef\u4fe1\u53f7\\n\");\n        \/\/\u963b\u585e\uff0c\u7b49\u5f85\u4fe1\u53f7\uff0c\u83b7\u53d6\u89e6\u53d1\u4fe1\u53f7\u7684\u603b\u6570\n        int event_count = epoll_wait(epfd,reepevent,num,-1);\n        \/\/\u904d\u5386\u89e6\u53d1\u4fe1\u53f7\u7684\u603b\u6570\n        for(int i = 0;i&lt;event_count;++i){\n            \/\/\u68c0\u67e5\u662f\u5426\u662f\u76d1\u542c\u5957\u63a5\u5b57\u51fa\u73b0\u4fe1\u53f7\n            if(reepevent&#91;i].data.fd == sock_id){\n                printf(\"\u5ba2\u6237\u7aef\u53d1\u51fa\u8fde\u63a5\u8bf7\u6c42\\n\");\n                \/\/\u5982\u679c\u662f\u76d1\u542c\u5957\u63a5\u5b57\u51fa\u73b0\u4fe1\u53f7\uff0c\u90a3\u4e48\u5c31\u5efa\u7acb\u65b0\u7684\u8fde\u63a5\u5957\u63a5\u5b57\n                int fd = accept(sock_id,NULL,NULL);\n                if(fd == -1){\n                    \/\/\u51fd\u6570\u6267\u884c\u51fa\u9519\n                    perror(\"\u8fde\u63a5\u5957\u63a5\u5b57\u5efa\u7acb\u51fa\u9519\");\n                    close(sock_id);\n                    continue;\n                }\n                \/\/\u5efa\u7acb\u5b8c\u6210\uff0c\u52a0\u5165epoll\u5b9e\u4f8b\u4e2d\uff0c\u4e8b\u5b9e\u4e0a\uff0c\u867d\u7136epoll_ctl\u9700\u8981\u7684\u662f\u4e00\u4e2a\u6307\u9488\uff0c\u4f46\u662f\u5b83\u4f1a\u5c06\u5176\u4e2d\u7684\u503c\u4ece\u7528\u6237\u6001\u590d\u5236\u5230\u5185\u6838\u6001\uff0c\u6240\u4ee5\u5373\u4f7f\u4ee3\u7801\u4e2d\u7684temp\u88ab\u9500\u6bc1\u4e5f\u4e0d\u662f\u5f71\u54cd\u5230\u7cfb\u7edf\u4e2d\u4fdd\u5b58\u7684\u503c\u3002\n                struct epoll_event temp = {\n                    .events = EPOLLIN,\n                    .data.fd = fd\n                };\n                if(epoll_ctl(epfd,EPOLL_CTL_ADD,temp.data.fd,&amp;temp) == -1){\n                    perror(\"epoll\u5b9e\u4f8b\u6dfb\u52a0\u5931\u8d25\");\n                    close(fd);\n                    continue;\n                }\n            }\n            \/\/\u5426\u5219\u5c31\u662f\u8fde\u63a5\u5957\u63a5\u5b57\u51fa\u73b0\u4e86\u4fe1\u53f7\n            else{\n                printf(\"\u5ba2\u6237\u7aef\u53d1\u6765\u6d88\u606f\\n\");\n                int r_recv = recv(reepevent&#91;i].data.fd,text,sizeof(text),MSG_NOSIGNAL);\n                \/\/\u68c0\u67e5\u51fd\u6570\u6267\u884c\u662f\u5426\u51fa\u9519\n                if(r_recv == -1){\n                    perror(\"recv\u51fd\u6570\u6267\u884c\u51fa\u9519\");\n                    continue;\n                }\n                \/\/\u68c0\u67e5\u5bf9\u65b9\u662f\u5426\u65ad\u5f00\u8fde\u63a5\n                else if(r_recv == 0){\n                    \/\/\u4eceepoll\u4e2d\u5220\u9664\u5b9e\u4f8b\n                    if(epoll_ctl(epfd,EPOLL_CTL_DEL,reepevent&#91;i].data.fd,NULL) == -1){\n                        return 0;\n                    }\n                    close(reepevent&#91;i].data.fd);\n                }\n                \/\/\u5904\u7406\u5ba2\u6237\u7aef\u8bf7\u6c42\n                else{\n                    printf(\"    &gt;&gt;&gt;\u5ba2\u6237\u7aef\u4f20\u6765\u6d88\u606f\uff1a&#91;%s]\\n\",text);\n                }\n            }\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u6267\u884c\u7ed3\u679c1.1<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u7b49\u5f85\u5ba2\u6237\u7aef\u4fe1\u53f7\n\u5ba2\u6237\u7aef\u53d1\u51fa\u8fde\u63a5\u8bf7\u6c42\n\u7b49\u5f85\u5ba2\u6237\u7aef\u4fe1\u53f7\n\u5ba2\u6237\u7aef\u53d1\u6765\u6d88\u606f\n    &gt;&gt;&gt;\u5ba2\u6237\u7aef\u4f20\u6765\u6d88\u606f\uff1a&#91;hello]\n\u7b49\u5f85\u5ba2\u6237\u7aef\u4fe1\u53f7\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"epoll_analyze\">epoll\u51fd\u6570\u96c6\u5408\u7684\u89e3\u6790<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\">\u8fed\u4ee3\u5347\u7ea7<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">\u9996\u5148\u8fd9\u4e2a\u51fd\u6570\u89e3\u51b3\u4e86<code>select<\/code>\u51fd\u6570\u548c<code>poll<\/code>\u51fd\u6570\u5e94\u5bf9\u9ad8\u5e76\u53d1\u6548\u7387\u7684\u4e3b\u8981\u95ee\u9898\uff0c\u524d\u9762\u5206\u6790\u8fc7\uff0c<code>select<\/code>\u548c<code>epoll<\/code>\u5728\u8fd4\u56de\u7ed3\u679c\u540e\uff0c\u7531\u4e8e\u7ebf\u6027\u8868\u7684\u7279\u6027\u4e0d\u5f97\u4e0d\u904d\u5386\u6574\u4e2a\u7ed3\u679c\u96c6\u5408\u5bfb\u627e\u4ea7\u751f\u4fe1\u53f7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u8f6e\u8be2\u673a\u5236\uff0c\u800c<code>epoll<\/code>\u91c7\u7528\u4e86\u7ea2\u9ed1\u6811\u7684\u7ed3\u6784\uff0c\u5728\u9762\u5bf9\u9ad8\u5e76\u53d1\u7684\u573a\u666f\u8fce\u5203\u6709\u4f59\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5e76\u4e14\u5b83\u4ece\u5185\u6838\u6001\u8fd4\u56de\u7528\u6237\u6001\u7684\u65f6\u5019\uff0c\u4e0d\u518d\u9700\u8981\u590d\u5236\u6574\u4e2a\u8868\uff0c\u800c\u662f\u5c06\u4ea7\u751f\u6d88\u606f\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u751f\u6210\u4e00\u4e2a\u961f\u5217\u8fd4\u56de\uff0c\u8282\u7701\u4e86\u6574\u4f53\u590d\u5236\u6d88\u8017\u7684\u65f6\u95f4\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u76f4\u63a5\u904d\u5386\u8fd9\u4e2a\u961f\u5217\uff0c\u800c\u961f\u5217\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u90fd\u662f\u9700\u8981\u5904\u7406\u7684\uff0c\u6ca1\u6709\u4efb\u4f55\u5197\u4f59\u7684\u5904\u7406\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u540c\u65f6\u8003\u8651\u5230\u4e86\u5e76\u53d1\u573a\u666f\uff0c\u8fd9\u4e2a\u51fd\u6570\u96c6\u65b0\u52a0\u4e86\u4e00\u4e2a\u65b0\u7684\u7279\u6027\uff0c<mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">epoll\u51fd\u6570\u96c6\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u6bd4\u5982\u4f60\u53ef\u4ee5\u5728\u8c03\u7528epoll_ctl\u7684\u540c\u65f6\u8c03\u7528epoll_wait\u3002<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>epoll<\/code>&nbsp;\u63d0\u4f9b\u4e86\u4e24\u79cd\u89e6\u53d1\u6a21\u5f0f\uff1a<strong>\u8fb9\u6cbf\u89e6\u53d1\uff08Edge-Triggered, ET\uff09<\/strong>&nbsp;\u548c&nbsp;<strong>\u6c34\u5e73\u89e6\u53d1\uff08Level-Triggered, LT\uff09<\/strong>\u3002\u8fd9\u4e24\u79cd\u6a21\u5f0f\u5728\u5904\u7406\u4e8b\u4ef6\u65f6\u6709\u4e0d\u540c\u7684\u884c\u4e3a\uff1a<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">\u6c34\u5e73\u89e6\u53d1\u6a21\u5f0f\uff08Level-Triggered, LT\uff09<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u6c34\u5e73\u89e6\u53d1\u6a21\u5f0f\u662f\u9ed8\u8ba4\u6a21\u5f0f<\/mark>\uff0c\u7b80\u5355\u6765\u8bb2\uff0c\u5c31\u662f\u5f53\u4e8b\u4ef6\u89e6\u53d1\u540e\u6bd4\u5982\u8bfb\u4fe1\u53f7\uff0c\u5982\u679c\u4f20\u5165\u6709100\u4e2a\u5b57\u8282\u53ef\u8bfb\uff0c\u4f46\u662f\u4f60\u672c\u8f6e\u5faa\u73af\u53ea\u8bfb\u4e8650\u4e2a\u5b57\u8282\uff0c\u90a3\u4e48\u5728\u4e0b\u4e00\u8f6e\u5faa\u73af\u540e\uff0c\u7531\u4e8e\u7f13\u51b2\u533a\u8fd8\u5269\u4f59\u90e8\u5206\u5b57\u8282\uff0c\u8bfb\u4fe1\u53f7\u4f1a\u88ab\u518d\u6b21\u89e6\u53d1\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u79cd\u6a21\u5f0f\u7684\u597d\u5904\u5c31\u50cf\u662f\u4e00\u4e2a\u975e\u5e38\u8d34\u5fc3\u7684\u52a9\u7406\uff0c\u5b83\u4f1a\u65f6\u523b\u63d0\u9192\u4f60\u6ca1\u6709\u5b8c\u6210\u7684\u4efb\u52a1\u3002\u8fd9\u5c06\u4f7f\u4f60\u7684\u5f00\u53d1\u53d8\u5f97\u7b80\u5355\uff0c\u4e0d\u9700\u8981\u62c5\u5fc3\u51fa\u73b0\u9057\u6f0f\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f46\u662f\u7f3a\u70b9\u5c31\u662f\uff1a\u91cd\u590d\u7684\u89e6\u53d1\u8bfb\u4fe1\u53f7\u4e8b\u4ef6\uff0c\u4f1a\u6d88\u8017\u7cfb\u7edf\u8d44\u6e90\uff0c\u76f8\u5bf9\u6765\u8bf4\u6548\u7387\u6bd4\u8f83\u4f4e\uff0c\u8fd9\u79cd\u7b56\u7565\u4e5f\u5c31\u662f\u7528\u6548\u7387\u6362\u904d\u5386\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f\uff08Edge-Triggered, ET\uff09<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#8ed1fc\" class=\"has-inline-color\">\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f\u9700\u8981\u663e\u793a\u58f0\u660e<\/mark>\uff0c\u7b80\u5355\u6765\u8bb2\uff0c\u4f9d\u65e7\u7528\u8bfb\u4fe1\u53f7\u4e3e\u4f8b\uff0c\u5982\u679c\u4e8b\u4ef6\u89e6\u53d1\u540e\uff0c\u6709100\u4e2a\u5b57\u8282\u9700\u8981\u8bfb\u53d6\uff0c\u4f46\u662f\u4ec5\u4ec5\u8bfb\u53d6\u4e8650\u4e2a\u5b57\u8282\uff0c\u90a3\u4e48\u5728\u4e0b\u4e00\u8f6e\u5faa\u73af\u4e2d\uff0c\u5373\u4f7f\u7f13\u51b2\u533a\u5b58\u5728\u5269\u4f59\u768450\u4e2a\u5b57\u8282\uff0c\u4e5f\u4e0d\u4f1a\u518d\u89e6\u53d1\u4fe1\u53f7\uff0c\u9664\u975e\u6709\u65b0\u7684\u5b57\u8282\u4f20\u5165\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e5f\u5c31\u610f\u5473\u7740\u5b83\u53ea\u4f1a\u8ba9\u4f20\u5165\u7684\u4fe1\u53f7\u89e6\u53d1\u4e00\u6b21\u3002\u5f00\u53d1\u8005\u5fc5\u987b\u8981\u5728\u672c\u6b21\u5faa\u73af\u4e2d\u5b8c\u6210\u7f13\u51b2\u533a\u6570\u636e\u7684\u8bfb\u53d6\u3002\u5f53\u7136\u5373\u4f7f\u4fe1\u53f7\u53ea\u4f1a\u89e6\u53d1\u4e00\u6b21\uff0c\u4f46\u662f\u7f13\u51b2\u533a\u7684\u6570\u636e\u5e76\u4e0d\u4f1a\u4e22\u5931\uff0c\u8fd9\u4e5f\u5c31\u53ef\u80fd\u8ba9\u5f00\u53d1\u8005\u89e3\u6790\u6570\u636e\u7684\u65f6\u5019\uff0c\u9020\u6210\u6570\u636e\u5e72\u6270\u7684\u60c5\u51b5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u8fc7\u6709\u4ee3\u4ef7\u81ea\u7136\u6709\u76f8\u5e94\u7684\u8865\u507f\uff0c\u6ca1\u6709\u4e86\u76f8\u540c\u4e8b\u4ef6\u53cd\u590d\u89e6\u53d1\uff0c\u5927\u5927\u63d0\u9ad8\u4e86\u8fd0\u884c\u6548\u7387\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">\u7247\u6bb5\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct epoll_event event;\nevent.events = EPOLLIN | EPOLLET;  \/\/ \u8bbe\u7f6e\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f\nevent.data.fd = sock_id;\nif (epoll_ctl(epfd, EPOLL_CTL_ADD, sock_id, &amp;event) == -1) {\n    perror(\"epoll_ctl: sock_id\");\n    exit(EXIT_FAILURE);\n}\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u8fb9\u6cbf\u89e6\u53d1\u60f3\u91cd\u65b0\u8bbe\u7f6e\u6c34\u5e73\u89e6\u53d1\uff0c\u9700\u8981\u5c06<code>event.events = EPOLLIN | EPOLLET; <\/code> \u5199\u6210<code>event.events = EPOLLIN; <\/code>\u7136\u540e\u7528\u4fee\u6539\u64cd\u4f5c\u5199\u5165\u5373\u53ef\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u8fc7\u8fd8\u8981\u8865\u5145\u7684\u4e00\u70b9\u662f\uff0c\u8fd9\u79cd\u6a21\u5f0f\u901a\u5e38\u548c\u975e\u963b\u585eIO\u8fdb\u884c\u642d\u914d\u4f7f\u7528\uff0c\u56e0\u4e3a\u963b\u585e\u578bIO\u4f1a\u5bfc\u81f4\u6570\u636e\u4e3a\u7a7a\u65f6\u963b\u585e\uff0c\u8fd9\u663e\u7136\u4e0e\u63d0\u9ad8\u6548\u7387\u7684\u521d\u8877\u76f8\u53cd\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u5b9e\u4ece\u6548\u7387\u7684\u89d2\u5ea6\u8bf4\uff0c\u4e5f\u4e0d\u5355\u5355\u53ea\u6709epoll\u7684\u8fb9\u6cbf\u89e6\u53d1\u4f7f\u7528\u975e\u963b\u585eIO\uff0c\u6240\u6709\u7684IO\u590d\u7528\u51fd\u6570\u90fd\u548c\u975e\u963b\u585eIO\u642d\u914d\u6bd4\u8f83\u5408\u9002\uff0c\u56e0\u4e3a\u7528\u6237\u7684\u6570\u636e\u957f\u5ea6\u4e0d\u53ef\u80fd\u603b\u662f\u76f8\u540c\uff0c\u800c\u670d\u52a1\u5668\u7f13\u51b2\u533a\u4e5f\u4e0d\u53ef\u80fd\u65e0\u9650\u5927\uff0c\u6240\u4ee5\u5f80\u5f80\u4f1a\u8fdb\u884c\u591a\u6b21\u8bfb\u53d6\uff0c\u90a3\u4e48\u8fd9\u79cd\u60c5\u51b5\u4e0b\u5c31\u5f88\u96be\u907f\u514d\u4ea7\u751f\u963b\u585e\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#f78da7\" class=\"has-inline-color\">\u8bbe\u7f6e\u4e3a\u975e\u963b\u585e\u51fd\u6570<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;fcntl.h&gt;\n\/\/\u5c06\u4e00\u4e2a\u5957\u63a5\u5b57\u8f6c\u6362\u4e3a\u975e\u963b\u585e\u578b\nint set_nonblocking(int fd) {\n    \/\/\u83b7\u53d6\u5f53\u524d\u4f20\u5165\u5957\u63a5\u5b57\u7684\u7c7b\u578b\n    int flags = fcntl(fd, F_GETFL, 0);\n    if (flags == -1) {\n        perror(\"\u5957\u63a5\u5b57\u4fe1\u606f\u83b7\u53d6\u5931\u8d25\");\n        return -1;\n    }\n    \/\/\u7ed9\u5957\u63a5\u5b57\u6dfb\u52a0\u975e\u963b\u585e\u5c5e\u6027\n    flags |= O_NONBLOCK;\n    \/\/\u5c06\u65b0\u7684\u5957\u63a5\u5b57\u4fe1\u606f\u5199\u5165\u5957\u63a5\u5b57\u4e2d\n    if (fcntl(fd, F_SETFL, flags) == -1) {\n        perror(\"\u5957\u63a5\u5b57\u8bbe\u7f6e\u5931\u8d25\");\n        return -1;\n    }\n    return 0;\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u800c\u975e\u963b\u585e\u7684\u51fd\u6570\u901a\u5e38\u53ef\u4ee5\u4f7f\u7528\u9519\u8bef\u503c\u6bd4\u5982<code> if (errno == EAGAIN) <\/code>\u5224\u65ad\u662f\u5426\u7f13\u51b2\u533a\u4e3a\u7a7a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#9b51e0\" class=\"has-inline-color\">\u6574\u4f53\u603b\u7ed3epoll\u51fd\u6570\u7684\u6267\u884c\u8fc7\u7a0b<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7528\u6237\u521b\u610f\u4e00\u4e2aepoll\u5b9e\u4f8b<\/li>\n\n\n\n<li>\u7528\u6237\u5728\u5408\u9002\u7684\u65f6\u5019\u5b9a\u4e49\u4e00\u4e2a\u4e8b\u4ef6\u7ed3\u6784\u4f53\uff0c\u5e76\u4ea4\u7531\u5185\u6838\u4ece\u7528\u6237\u6001\u62f7\u8d1d\u5230\u5185\u6838\u6001\uff0c\u540c\u65f6\u5185\u6838\u4f1a\u4e3a\u6bcf\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u6307\u5b9a\u4e00\u4e2a\u56de\u8c03\u51fd\u6570\uff0c\u7528\u4e8e\u4e4b\u540e\u7684\u5c06\u5c31\u7eea\u4e8b\u4ef6\u653e\u5165\u5c31\u7eea\u94fe\u8868\u4e2d\u3002<\/li>\n\n\n\n<li>\u5185\u6838\u8ba9epoll_wait\u4e2d\u963b\u585e\uff0c\u5185\u90e8\u7ef4\u62a4\u4e00\u4e2a\u53cc\u5411\u94fe\u8868\u7ed3\u6784\u4f53\u7684\u5c31\u7eea\u8868\uff0c\u4e00\u68f5\u7ea2\u9ed1\u6811\u7528\u6765\u5b58\u653e\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u4e00\u4e2a\u7b49\u5f85\u961f\u5217\u5b58\u653e\u963b\u585e\u8fdb\u7a0b\u3002<\/li>\n\n\n\n<li>\u5f53\u6709\u4fe1\u53f7\u51fa\u73b0\u65f6\uff0c\u5bf9\u5e94\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4f1a\u901a\u8fc7\u56de\u8c03\u51fd\u6570\u88ab\u653e\u5165\u5c31\u7eea\u94fe\u8868\u4e2d\uff0c\u907f\u514d\u4e86\u4e0d\u5fc5\u8981\u7684\u8f6e\u8be2\uff0c\u7136\u540e\u5185\u6838\u68c0\u67e5\u963b\u585e\u961f\u5217\u4e2d\u7684\u8fdb\u7a0b\uff0c\u5c31\u7eea\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u5c5e\u4e8e\u8be5\u8fdb\u7a0b\uff0c\u90a3\u4e48\u8be5\u8fdb\u7a0b\u4f1a\u88ab\u5524\u9192\u3002<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u4fe1\u53f7\u9a71\u52a8IO<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4fe1\u53f7\u9a71\u52a8I\/O\u662f\u4e00\u79cd\u57fa\u4e8e\u4fe1\u53f7\u7684I\/O\u6a21\u578b\uff0c\u4e3b\u8981\u7528\u4e8e\u5728\u6570\u636e\u51c6\u5907\u597d\u65f6\u901a\u77e5\u8fdb\u7a0b\u8fdb\u884cI\/O\u64cd\u4f5c\u3002\u4ee5\u4e0b\u662f\u4fe1\u53f7\u9a71\u52a8I\/O\u7684\u5de5\u4f5c\u539f\u7406\u548c\u7279\u70b9\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6ce8\u518c\u4fe1\u53f7\u5904\u7406\u51fd\u6570<\/strong>\uff1a\u8fdb\u7a0b\u9996\u5148\u9700\u8981\u901a\u8fc7\u7cfb\u7edf\u8c03\u7528<code>sigaction<\/code>\u5411\u5185\u6838\u6ce8\u518c\u4e00\u4e2a\u4fe1\u53f7\u5904\u7406\u51fd\u6570\uff0c\u5e76\u8bbe\u7f6e\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e3a\u975e\u963b\u585e\u6a21\u5f0f\u3002<\/li>\n\n\n\n<li><strong>\u7b49\u5f85\u4fe1\u53f7<\/strong>\uff1a\u5f53\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u6709\u6570\u636e\u53ef\u8bfb\u65f6\uff0c\u5185\u6838\u4f1a\u53d1\u9001\u4e00\u4e2a\u4fe1\u53f7\uff08\u901a\u5e38\u662fSIGIO\uff09\u901a\u77e5\u8fdb\u7a0b\u3002<\/li>\n\n\n\n<li><strong>\u5904\u7406\u4fe1\u53f7<\/strong>\uff1a\u8fdb\u7a0b\u5728\u4fe1\u53f7\u5904\u7406\u51fd\u6570\u4e2d\u6267\u884c\u76f8\u5e94\u7684I\/O\u64cd\u4f5c\uff0c\u5982\u8bfb\u53d6\u6570\u636e\u3002<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\">\u4f18\u70b9<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u975e\u963b\u585e<\/strong>\uff1a\u8fdb\u7a0b\u5728\u7b49\u5f85I\/O\u4e8b\u4ef6\u65f6\u4e0d\u4f1a\u88ab\u963b\u585e\uff0c\u53ef\u4ee5\u6267\u884c\u5176\u4ed6\u4efb\u52a1\uff0c\u63d0\u9ad8\u4e86CPU\u5229\u7528\u7387\u3002<\/li>\n\n\n\n<li><strong>\u5b9e\u65f6\u54cd\u5e94<\/strong>\uff1a\u4fe1\u53f7\u5230\u6765\u540e\u7acb\u5373\u5904\u7406I\/O\u4e8b\u4ef6\uff0c\u54cd\u5e94\u901f\u5ea6\u5feb\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">\u7f3a\u70b9<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u590d\u6742\u6027<\/strong>\uff1a\u7f16\u7a0b\u76f8\u5bf9\u590d\u6742\uff0c\u9700\u8981\u5904\u7406\u4fe1\u53f7\u76f8\u5173\u7684\u95ee\u9898\u3002<\/li>\n\n\n\n<li>\u9891\u7e41\u4fe1\u53f7\uff1a\u5f53\u6570\u636e\u91cf\u8f83\u5927\u65f6\uff0c\u4fe1\u53f7\u9891\u7e41\u4ea7\u751f\uff0c\u53ef\u80fd\u4f1a\u5f71\u54cd\u6027\u80fd<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4fe1\u53f7\u9a71\u52a8I\/O\u4e3b\u8981\u7528\u4e8eUDP\u5957\u63a5\u5b57\u3002\u5728UDP\u534f\u8bae\u4e2d\uff0c\u4fe1\u53f7\u9a71\u52a8I\/O\u53ef\u4ee5\u901a\u8fc7\u4fe1\u53f7\u673a\u5236\u6765\u5904\u7406I\/O\u4e8b\u4ef6\u3002\u5f53\u6570\u636e\u5230\u8fbe\u65f6\uff0c\u5185\u6838\u4f1a\u53d1\u9001\u4e00\u4e2a\u4fe1\u53f7\uff08\u901a\u5e38\u662fSIGIO\uff09\u901a\u77e5\u8fdb\u7a0b\u8fdb\u884cI\/O\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u76f8\u6bd4\u4e4b\u4e0b\uff0c\u4fe1\u53f7\u9a71\u52a8I\/O\u5728TCP\u5957\u63a5\u5b57\u4e0a\u51e0\u4e4e\u6ca1\u6709\u4f7f\u7528\uff0c\u56e0\u4e3aTCP\u9700\u8981\u5904\u7406\u66f4\u591a\u7684\u4e8b\u4ef6\uff0c\u5982\u8fde\u63a5\u5efa\u7acb\u3001\u8fde\u63a5\u786e\u8ba4\u3001\u6570\u636e\u786e\u8ba4\u548c\u65ad\u5f00\u8fde\u63a5\u7b49\uff0c\u8fd9\u4e9b\u4e8b\u4ef6\u90fd\u4f1a\u89e6\u53d1\u4fe1\u53f7\uff0c\u589e\u52a0\u4e86\u5904\u7406\u7684\u590d\u6742\u6027\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">sigaction\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;signal.h>\n\nint sigaction(int signum, const struct sigaction *act,struct sigaction *oldact);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>signum<\/code>\uff1a\u6307\u5b9a\u4fe1\u53f7\uff0c\u53ef\u4ee5\u662f\u4efb\u4f55\u6709\u6548\u7684\u4fe1\u53f7\uff0c\u9664\u4e86\u00a0<code>SIGKILL<\/code>\u00a0\u548c\u00a0<code>SIGSTOP<\/code>\u3002<\/li>\n\n\n\n<li><code>act<\/code>\uff1a\u5982\u679c\u975e NULL\uff0c\u5219\u4e3a\u00a0<code>signum<\/code>\u00a0\u5b89\u88c5\u65b0\u7684\u52a8\u4f5c\u3002<\/li>\n\n\n\n<li><code>oldact<\/code>\uff1a\u5982\u679c\u975e NULL\uff0c\u5219\u4fdd\u5b58\u4e4b\u524d\u7684\u52a8\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><code>struct sigaction<\/code>\u00a0\u7ed3\u6784<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct sigaction {\n    void (*sa_handler)(int);\/\/\u6307\u5b9a\u4fe1\u53f7\u5904\u7406\u51fd\u6570,\u8fd9\u662f\u6700\u5e38\u7528\u7684\u4fe1\u53f7\u5904\u7406\u51fd\u6570\u6307\u9488\u3002\u5b83\u6307\u5411\u4e00\u4e2a\u63a5\u53d7\u4fe1\u53f7\u7f16\u53f7\u4f5c\u4e3a\u53c2\u6570\u7684\u51fd\u6570\n    void (*sa_sigaction)(int, siginfo_t *, void *);\/\/\u6307\u5b9a\u4fe1\u53f7\u5904\u7406\u51fd\u6570\uff0c\u4f46\u63d0\u4f9b\u66f4\u591a\u4fe1\u606f,\u5f53 sa_flags \u4e2d\u8bbe\u7f6e\u4e86 SA_SIGINFO \u6807\u5fd7\u65f6\uff0c\u4f7f\u7528 sa_sigaction \u800c\u4e0d\u662f sa_handler\u3002\u5b83\u53ef\u4ee5\u63a5\u6536\u66f4\u591a\u7684\u53c2\u6570\uff0c\u5305\u62ec\u4fe1\u53f7\u4fe1\u606f\u548c\u4e0a\u4e0b\u6587\u3002\n    sigset_t sa_mask;\n    int sa_flags;\n    void (*sa_restorer)(void);\/\/\u7528\u4e8e\u6062\u590d\u4fe1\u53f7\u5904\u7406\u7a0b\u5e8f\u7684\u5185\u90e8\u4f7f\u7528,\u8fd9\u4e2a\u5b57\u6bb5\u901a\u5e38\u7531\u5185\u6838\u4f7f\u7528\uff0c\u7528\u6237\u4ee3\u7801\u4e00\u822c\u4e0d\u9700\u8981\u8bbe\u7f6e\u6216\u4f7f\u7528\u5b83\n};<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>sa_handler<\/code>\uff1a\u6307\u5b9a\u4fe1\u53f7\u5904\u7406\u51fd\u6570\uff0c\u53ef\u4ee5\u662f\u00a0<code>SIG_DFL<\/code>\uff08\u9ed8\u8ba4\u52a8\u4f5c\uff09\u3001<code>SIG_IGN<\/code>\uff08\u5ffd\u7565\u4fe1\u53f7\uff09\u6216\u6307\u5411\u4fe1\u53f7\u5904\u7406\u51fd\u6570\u7684\u6307\u9488\u3002<\/li>\n\n\n\n<li><code>sa_sigaction<\/code>\uff1a\u5982\u679c\u00a0<code>sa_flags<\/code>\u00a0\u4e2d\u6307\u5b9a\u4e86\u00a0<code>SA_SIGINFO<\/code>\uff0c\u5219\u4f7f\u7528\u6b64\u5b57\u6bb5\u4ee3\u66ff\u00a0<code>sa_handler<\/code>\u3002<\/li>\n\n\n\n<li><code>sa_mask<\/code>\uff1a\u6307\u5b9a\u5728\u4fe1\u53f7\u5904\u7406\u7a0b\u5e8f\u6267\u884c\u671f\u95f4\u5e94\u88ab\u963b\u585e\u7684\u4fe1\u53f7\u3002<\/li>\n\n\n\n<li><code>sa_flags<\/code>\uff1a\u4fee\u6539\u4fe1\u53f7\u884c\u4e3a\u7684\u6807\u5fd7\uff0c\u53ef\u4ee5\u662f\u4ee5\u4e0b\u503c\u7684\u6309\u4f4d\u6216\uff1a\n<ul class=\"wp-block-list\">\n<li><code>SA_NOCLDSTOP<\/code>\uff1a\u5982\u679c\u00a0<code>signum<\/code>\u00a0\u662f\u00a0<code>SIGCHLD<\/code>\uff0c\u5219\u5b50\u8fdb\u7a0b\u505c\u6b62\u65f6\u4e0d\u63a5\u6536\u901a\u77e5\u3002<\/li>\n\n\n\n<li><code>SA_NOCLDWAIT<\/code>\uff1a\u5982\u679c\u00a0<code>signum<\/code>\u00a0\u662f\u00a0<code>SIGCHLD<\/code>\uff0c\u5219\u5b50\u8fdb\u7a0b\u7ec8\u6b62\u65f6\u4e0d\u53d8\u6210\u50f5\u5c38\u8fdb\u7a0b\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728<code>void (*sa_sigaction)(int, siginfo_t *, void *);<\/code>\u5b57\u6bb5\u4e2d\uff0c\u7b2c\u4e00\u4e2a\u53c2\u6570\u4ee3\u8868\u6536\u5230\u7684\u4fe1\u53f7\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662f\u4e00\u4e2a\u7ed3\u6784\u4f53\uff0c\u8be5\u7ed3\u6784\u4f53\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>typedef struct {\n    int      si_signo;  \/* \u4fe1\u53f7\u7f16\u53f7 *\/\n    int      si_errno;  \/* \u4e0e\u4fe1\u53f7\u76f8\u5173\u7684\u9519\u8bef\u7801 *\/\n    int      si_code;   \/* \u4fe1\u53f7\u7684\u6765\u6e90\u6216\u539f\u56e0 *\/\n    pid_t    si_pid;    \/* \u53d1\u9001\u4fe1\u53f7\u7684\u8fdb\u7a0b ID *\/\n    uid_t    si_uid;    \/* \u53d1\u9001\u4fe1\u53f7\u7684\u7528\u6237 ID *\/\n    void    *si_addr;   \/* \u5f15\u53d1\u6545\u969c\u7684\u5185\u5b58\u5730\u5740 *\/\n    int      si_status; \/* \u9000\u51fa\u72b6\u6001\u6216\u4fe1\u53f7 *\/\n    union sigval si_value;  \/* \u4fe1\u53f7\u643a\u5e26\u7684\u503c *\/\n} siginfo_t;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7b2c\u4e09\u4e2a\u53c2\u6570<strong><code>void *<\/code><\/strong>\u6307\u5411\u7684\u662f\u4e00\u4e2aucontext_t\u7ed3\u6784\u4f53\uff0c\u8fd9\u4e2a\u7ed3\u6784\u4f53\u4fdd\u5b58\u7684\u662f\u4fe1\u53f7\u53d1\u751f\u65f6\u7684\u4e0a\u4e0b\u6587\u4fe1\u606f\uff08\u5982\u5bc4\u5b58\u5668\u72b6\u6001\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6210\u529f\u65f6<\/strong>\uff1a\u8fd4\u56de\u00a0<code>0<\/code>\u3002<\/li>\n\n\n\n<li><strong>\u5931\u8d25\u65f6<\/strong>\uff1a\u8fd4\u56de\u00a0<code>-1<\/code>\uff0c\u5e76\u8bbe\u7f6e\u00a0<code>errno<\/code>\u00a0\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u793a\u4f8b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h>\n#include &lt;sys\/types.h>\n#include &lt;sys\/socket.h>\n#include &lt;netinet\/in.h>\n#include &lt;string.h>\n#include &lt;unistd.h>\n#include &lt;signal.h>\n#include &lt;fcntl.h>\n\nint listenfd;\nvolatile int read_flag = 0;\nstatic char buf&#91;256] = {0};\n\nvoid do_sigio(int sig) {\n    struct sockaddr_in cli_addr;\n    int clifd, clilen;\n    read_flag = 1;\n    memset(buf, 0, sizeof(buf));\n    recvfrom(listenfd, buf, sizeof(buf), 0, (struct sockaddr *)&amp;cli_addr, &amp;clilen);\n    printf(\"Received message: %s\\n\", buf);\n    sendto(listenfd, \"Reply\", sizeof(\"Reply\"), 0, (struct sockaddr *)&amp;cli_addr, sizeof(cli_addr));\n    read_flag = 0;\n}\n\nint main(int argc, char *argv&#91;]) {\n    struct sockaddr_in serv_addr;\n    listenfd = socket(AF_INET, SOCK_DGRAM, 0);\n    bzero((char *)&amp;serv_addr, sizeof(serv_addr));\n    serv_addr.sin_family = AF_INET;\n    serv_addr.sin_port = htons(7779);\n    serv_addr.sin_addr.s_addr = INADDR_ANY;\n\n    struct sigaction sigio_action;\n    memset(&amp;sigio_action, 0, sizeof(sigio_action));\n    sigio_action.sa_handler = do_sigio;\n    sigaction(SIGIO, &amp;sigio_action, NULL);\n\n    fcntl(listenfd, F_SETOWN, getpid());\n    int flags = fcntl(listenfd, F_GETFL, 0);\n    flags |= O_ASYNC;\n    fcntl(listenfd, F_SETFL, flags);\n\n    bind(listenfd, (struct sockaddr *)&amp;serv_addr, sizeof(serv_addr));\n    while (1) {\n        sleep(2);\n    }\n    close(listenfd);\n    return 0;\n}\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u5f02\u6b65IO<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728Linux\u7f51\u7edc\u7f16\u7a0b\u4e2d\uff0c\u5f02\u6b65I\/O\uff08Asynchronous I\/O\uff09\u662f\u4e00\u79cd\u9ad8\u6548\u7684I\/O\u6a21\u578b\u3002\u4e0e\u540c\u6b65I\/O\u4e0d\u540c\uff0c\u5f02\u6b65I\/O\u5141\u8bb8\u7528\u6237\u7ebf\u7a0b\u5728\u53d1\u8d77I\/O\u64cd\u4f5c\u540e\u7acb\u5373\u8fd4\u56de\u5e76\u7ee7\u7eed\u6267\u884c\u5176\u4ed6\u4efb\u52a1\uff0c\u800c\u4e0d\u9700\u8981\u7b49\u5f85I\/O\u64cd\u4f5c\u5b8c\u6210\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5f02\u6b65I\/O\u7684\u5de5\u4f5c\u539f\u7406<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u53d1\u8d77\u8bf7\u6c42<\/strong>\uff1a\u7528\u6237\u7ebf\u7a0b\u8c03\u7528\u5f02\u6b65I\/O\u51fd\u6570\uff08\u5982<code>aio_read<\/code>\u6216<code>aio_write<\/code>\uff09\u53d1\u8d77I\/O\u64cd\u4f5c\u3002<\/li>\n\n\n\n<li><strong>\u7acb\u5373\u8fd4\u56de<\/strong>\uff1a\u5185\u6838\u7acb\u5373\u8fd4\u56de\uff0c\u8868\u793aI\/O\u8bf7\u6c42\u5df2\u6210\u529f\u53d1\u8d77\uff0c\u7528\u6237\u7ebf\u7a0b\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u5176\u4ed6\u4efb\u52a1\u3002<\/li>\n\n\n\n<li><strong>\u5185\u6838\u5904\u7406<\/strong>\uff1a\u5185\u6838\u5728\u540e\u53f0\u5904\u7406I\/O\u64cd\u4f5c\uff0c\u5305\u62ec\u6570\u636e\u51c6\u5907\u548c\u6570\u636e\u62f7\u8d1d\u3002<\/li>\n\n\n\n<li><strong>\u901a\u77e5\u5b8c\u6210<\/strong>\uff1a\u5f53I\/O\u64cd\u4f5c\u5b8c\u6210\u540e\uff0c\u5185\u6838\u901a\u8fc7\u4fe1\u53f7\uff08\u5982SIGIO\uff09\u901a\u77e5\u7528\u6237\u7ebf\u7a0b\uff0c\u7528\u6237\u7ebf\u7a0b\u53ef\u4ee5\u5904\u7406\u5b8c\u6210\u7684I\/O\u64cd\u4f5c<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5f02\u6b65I\/O\u7684\u4f18\u70b9<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9ad8\u6027\u80fd<\/strong>\uff1a\u7531\u4e8e\u7528\u6237\u7ebf\u7a0b\u5728\u7b49\u5f85I\/O\u64cd\u4f5c\u65f6\u53ef\u4ee5\u6267\u884c\u5176\u4ed6\u4efb\u52a1\uff0c\u5f02\u6b65I\/O\u63d0\u9ad8\u4e86\u7cfb\u7edf\u7684\u5e76\u53d1\u6027\u548c\u54cd\u5e94\u6027\u3002<\/li>\n\n\n\n<li><strong>\u975e\u963b\u585e<\/strong>\uff1aI\/O\u64cd\u4f5c\u7684\u4e24\u4e2a\u9636\u6bb5\uff08\u53d1\u8d77\u8bf7\u6c42\u548c\u6570\u636e\u62f7\u8d1d\uff09\u90fd\u4e0d\u4f1a\u963b\u585e\u7528\u6237\u7ebf\u7a0b\uff0c\u5185\u6838\u81ea\u52a8\u5b8c\u6210\u8fd9\u4e9b\u64cd\u4f5c<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f02\u6b65I\/O\u5728UDP\u548cTCP\u4e24\u8005\u4e2d\u90fd\u6709\u5e7f\u6cdb\u7684\u5e94\u7528\uff0c\u4e3b\u8981\u56e0\u4e3a\u5b83\u80fd\u591f\u63d0\u9ad8\u7cfb\u7edf\u7684\u5e76\u53d1\u6027\u548c\u54cd\u5e94\u901f\u5ea6\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5f02\u6b65I\/O\u6a21\u578b\u4e2d\uff0cI\/O\u64cd\u4f5c\u901a\u5e38\u662f\u975e\u963b\u585e\u7684\u3002\u8fd9\u610f\u5473\u7740\u5f53\u8fdb\u7a0b\u53d1\u8d77I\/O\u8bf7\u6c42\u65f6\uff0c\u5b83\u4e0d\u4f1a\u88ab\u6302\u8d77\u7b49\u5f85I\/O\u64cd\u4f5c\u5b8c\u6210\uff0c\u800c\u662f\u7acb\u5373\u8fd4\u56de\uff0c\u8fdb\u7a0b\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u5176\u4ed6\u4efb\u52a1\u3002\u5f02\u6b65I\/O\u6a21\u578b\u7684\u7279\u70b9\u662f\u5185\u6838\u4f1a\u5728I\/O\u64cd\u4f5c\u5b8c\u6210\u540e\u901a\u77e5\u8fdb\u7a0b\uff0c\u8fd9\u6837\u8fdb\u7a0b\u53ef\u4ee5\u5728I\/O\u64cd\u4f5c\u5b8c\u6210\u65f6\u5904\u7406\u7ed3\u679c<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>aio_read<\/strong>\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;aio.h>\n\nint aio_read(struct aiocb *aiocbp);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>aiocbp<\/strong>\uff1a\u6307\u5411<code>aiocb<\/code>\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u8be5\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u5f02\u6b65I\/O\u64cd\u4f5c\u7684\u76f8\u5173\u4fe1\u606f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u6784\u4f53\u5b9a\u4e49:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct aiocb {\n    int aio_fildes;                \/\/ \u6587\u4ef6\u63cf\u8ff0\u7b26\n    off_t aio_offset;              \/\/ \u6587\u4ef6\u504f\u79fb\u91cf\n    volatile void *aio_buf;        \/\/ \u6570\u636e\u7f13\u51b2\u533a\n    size_t aio_nbytes;             \/\/ \u8981\u4f20\u8f93\u7684\u5b57\u8282\u6570\n    int aio_reqprio;               \/\/ \u8bf7\u6c42\u4f18\u5148\u7ea7\n    struct sigevent aio_sigevent;  \/\/ \u4fe1\u53f7\u4e8b\u4ef6\n    int aio_lio_opcode;            \/\/ \u5217\u8868I\/O\u64cd\u4f5c\u7801\n};\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6210\u5458\u8bf4\u660e<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>aio_fildes<\/strong>\uff1a\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u8868\u793a\u8981\u8fdb\u884c\u5f02\u6b65I\/O\u64cd\u4f5c\u7684\u6587\u4ef6\u6216\u8bbe\u5907\u3002<\/li>\n\n\n\n<li><strong>aio_offset<\/strong>\uff1a\u6587\u4ef6\u504f\u79fb\u91cf\uff0c\u8868\u793a\u4ece\u6587\u4ef6\u7684\u54ea\u4e2a\u4f4d\u7f6e\u5f00\u59cb\u8bfb\u6216\u5199\u3002<\/li>\n\n\n\n<li><strong>aio_buf<\/strong>\uff1a\u6307\u5411\u6570\u636e\u7f13\u51b2\u533a\u7684\u6307\u9488\uff0c\u7528\u4e8e\u5b58\u50a8\u8bfb\u5165\u7684\u6570\u636e\u6216\u8981\u5199\u5165\u7684\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>aio_nbytes<\/strong>\uff1a\u8981\u4f20\u8f93\u7684\u5b57\u8282\u6570\uff0c\u8868\u793a\u8bfb\u6216\u5199\u64cd\u4f5c\u7684\u5b57\u8282\u6570\u3002<\/li>\n\n\n\n<li><strong>aio_reqprio<\/strong>\uff1a\u8bf7\u6c42\u4f18\u5148\u7ea7\uff0c\u901a\u5e38\u8bbe\u7f6e\u4e3a0\u3002<\/li>\n\n\n\n<li><strong>aio_sigevent<\/strong>\uff1a\u5f02\u6b65\u64cd\u4f5c\u5b8c\u6210\u65f6\u7684\u901a\u77e5\u673a\u5236\uff0c\u53ef\u4ee5\u8bbe\u7f6e\u4e3a\u4fe1\u53f7\u901a\u77e5\u6216\u7ebf\u7a0b\u56de\u8c03\u3002<\/li>\n\n\n\n<li><strong>aio_lio_opcode<\/strong>\uff1a\u5217\u8868I\/O\u64cd\u4f5c\u7801\uff0c\u7528\u4e8e\u6279\u91cfI\/O\u64cd\u4f5c\u65f6\u6307\u5b9a\u64cd\u4f5c\u7c7b\u578b\uff08\u5982\u8bfb\u6216\u5199\uff09<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u4e2d<code>struct sigevent<\/code>\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct sigevent {\n    int sigev_notify;                  \/\/ \u901a\u77e5\u7c7b\u578b\n    int sigev_signo;                   \/\/ \u4fe1\u53f7\u7f16\u53f7\n    union sigval sigev_value;          \/\/ \u4fe1\u53f7\u503c\n    void (*sigev_notify_function)(union sigval); \/\/ \u901a\u77e5\u51fd\u6570 (SIGEV_THREAD)\n    pthread_attr_t *sigev_notify_attributes;     \/\/ \u901a\u77e5\u5c5e\u6027\n    pid_t sigev_notify_thread_id;      \/\/ \u7ebf\u7a0bID (Linux\u7279\u6709)\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6210\u5458\u8bf4\u660e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>sigev_notify<\/strong>\uff1a\u6307\u5b9a\u901a\u77e5\u7c7b\u578b\uff0c\u53ef\u4ee5\u662f\u4ee5\u4e0b\u503c\u4e4b\u4e00\uff1a\n<ul class=\"wp-block-list\">\n<li><code>SIGEV_NONE<\/code>\uff1a\u4e0d\u8fdb\u884c\u4efb\u4f55\u901a\u77e5\u3002<\/li>\n\n\n\n<li><code>SIGEV_SIGNAL<\/code>\uff1a\u901a\u8fc7\u53d1\u9001\u6307\u5b9a\u7684\u4fe1\u53f7\uff08<code>sigev_signo<\/code>\uff09\u901a\u77e5\u8fdb\u7a0b\u3002<\/li>\n\n\n\n<li><code>SIGEV_THREAD<\/code>\uff1a\u901a\u8fc7\u8c03\u7528\u6307\u5b9a\u7684\u901a\u77e5\u51fd\u6570\uff08<code>sigev_notify_function<\/code>\uff09\u901a\u77e5\u8fdb\u7a0b\uff0c\u7c7b\u4f3c\u4e8e\u542f\u52a8\u4e00\u4e2a\u65b0\u7ebf\u7a0b\u3002<\/li>\n\n\n\n<li>SIGEV_THREAD_ID\uff1a\u901a\u77e5\u7279\u5b9a\u7ebf\u7a0b\uff08Linux\u7279\u6709\uff09<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>sigev_signo<\/strong>\uff1a\u4fe1\u53f7\u7f16\u53f7\uff0c\u5f53<code>SIGEV_NOTIFY<\/code>\u4e3a<code>SIGEV_SIGNAL<\/code>\u65f6\u4f7f\u7528\u3002<\/li>\n\n\n\n<li><strong>sigev_value<\/strong>\uff1a\u4fe1\u53f7\u503c\uff0c\u53ef\u4ee5\u662f\u6574\u6570\u6216\u6307\u9488\uff0c\u7528\u4e8e\u4f20\u9012\u9644\u52a0\u4fe1\u606f\u3002<\/li>\n\n\n\n<li><strong>sigev_notify_function<\/strong>\uff1a\u901a\u77e5\u51fd\u6570\uff0c\u5f53<code>SIGEV_NOTIFY<\/code>\u4e3a<code>SIGEV_THREAD<\/code>\u65f6\u4f7f\u7528\u3002<\/li>\n\n\n\n<li><strong>sigev_notify_attributes<\/strong>\uff1a\u901a\u77e5\u5c5e\u6027\uff0c\u7528\u4e8e\u8bbe\u7f6e\u65b0\u7ebf\u7a0b\u7684\u5c5e\u6027\u3002<\/li>\n\n\n\n<li><strong>sigev_notify_thread_id<\/strong>\uff1a\u7ebf\u7a0bID\uff0c\u5f53SIGEV_NOTIFY\u4e3aSIGEV_THREAD_ID\u65f6\u4f7f\u7528\uff08Linux\u7279\u6709\uff09<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u4e2a\u7b80\u5355\u7684\u793a\u4f8b\u662f<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct aiocb cb;\nchar buffer&#91;1024];\n\nmemset(&amp;cb, 0, sizeof(struct aiocb));\ncb.aio_fildes = fd;                \/\/ \u6587\u4ef6\u63cf\u8ff0\u7b26\ncb.aio_buf = buffer;               \/\/ \u6570\u636e\u7f13\u51b2\u533a\ncb.aio_nbytes = sizeof(buffer);    \/\/ \u8981\u8bfb\u53d6\u7684\u5b57\u8282\u6570\ncb.aio_offset = 0;                 \/\/ \u6587\u4ef6\u504f\u79fb\u91cf\ncb.aio_sigevent.sigev_notify = SIGEV_NONE;  \/\/ \u4e0d\u4f7f\u7528\u4fe1\u53f7\u901a\u77e5\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6210\u529f\u65f6\u8fd4\u56de0\uff0c\u5e76\u5c06\u8bf7\u6c42\u6392\u961f\u3002<br>\u5931\u8d25\u65f6\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6eerrno\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>aio_write<\/strong>\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;aio.h>\n\nint aio_write(struct aiocb *aiocbp);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>aiocbp<\/strong>\uff1a\u6307\u5411<code>aiocb<\/code>\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u8be5\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u5f02\u6b65I\/O\u64cd\u4f5c\u7684\u76f8\u5173\u4fe1\u606f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u6784\u4f53\u5b9a\u4e49:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct aiocb {<br>    int aio_fildes;                \/\/ \u6587\u4ef6\u63cf\u8ff0\u7b26<br>    off_t aio_offset;              \/\/ \u6587\u4ef6\u504f\u79fb\u91cf<br>    volatile void *aio_buf;        \/\/ \u6570\u636e\u7f13\u51b2\u533a<br>    size_t aio_nbytes;             \/\/ \u8981\u4f20\u8f93\u7684\u5b57\u8282\u6570<br>    int aio_reqprio;               \/\/ \u8bf7\u6c42\u4f18\u5148\u7ea7<br>    struct sigevent aio_sigevent;  \/\/ \u4fe1\u53f7\u4e8b\u4ef6<br>    int aio_lio_opcode;            \/\/ \u5217\u8868I\/O\u64cd\u4f5c\u7801<br>};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6210\u529f\u65f6\u8fd4\u56de0\uff0c\u5e76\u5c06\u8bf7\u6c42\u6392\u961f\u3002<br>\u5931\u8d25\u65f6\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6eerrno\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>aio_error<\/strong>\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;aio.h>\n\nint aio_error(const struct aiocb *aiocbp);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>aiocbp<\/strong>\uff1a\u6307\u5411<code>aiocb<\/code>\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u8be5\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u5f02\u6b65I\/O\u64cd\u4f5c\u7684\u76f8\u5173\u4fe1\u606f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u6784\u4f53\u5b9a\u4e49:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct aiocb {<br>    int aio_fildes;                \/\/ \u6587\u4ef6\u63cf\u8ff0\u7b26<br>    off_t aio_offset;              \/\/ \u6587\u4ef6\u504f\u79fb\u91cf<br>    volatile void *aio_buf;        \/\/ \u6570\u636e\u7f13\u51b2\u533a<br>    size_t aio_nbytes;             \/\/ \u8981\u4f20\u8f93\u7684\u5b57\u8282\u6570<br>    int aio_reqprio;               \/\/ \u8bf7\u6c42\u4f18\u5148\u7ea7<br>    struct sigevent aio_sigevent;  \/\/ \u4fe1\u53f7\u4e8b\u4ef6<br>    int aio_lio_opcode;            \/\/ \u5217\u8868I\/O\u64cd\u4f5c\u7801<br>};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6210\u529f<\/strong>\uff1a\u8fd4\u56de0\uff0c\u8868\u793a\u5f02\u6b65I\/O\u64cd\u4f5c\u5df2\u6210\u529f\u5b8c\u6210\u3002<\/li>\n\n\n\n<li><strong>\u5931\u8d25<\/strong>\uff1a\u8fd4\u56de\u4e0e\u540c\u6b65I\/O\u64cd\u4f5c\u76f8\u540c\u7684\u9519\u8bef\u72b6\u6001\uff08\u5982<code>read<\/code>\u3001<code>write<\/code>\u548c<code>fsync<\/code>\u5b50\u4f8b\u7a0b\u4e2d\u63cf\u8ff0\u7684\u9519\u8bef\u72b6\u6001\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>aio_return<\/strong>\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u539f\u578b<\/mark><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;aio.h>\n\nssize_t aio_return(struct aiocb *aiocbp);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u53c2\u6570<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>aiocbp<\/strong>\uff1a\u6307\u5411<code>aiocb<\/code>\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u8be5\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u5f02\u6b65I\/O\u64cd\u4f5c\u7684\u76f8\u5173\u4fe1\u606f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u6784\u4f53\u5b9a\u4e49:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct aiocb {<br>    int aio_fildes;                \/\/ \u6587\u4ef6\u63cf\u8ff0\u7b26<br>    off_t aio_offset;              \/\/ \u6587\u4ef6\u504f\u79fb\u91cf<br>    volatile void *aio_buf;        \/\/ \u6570\u636e\u7f13\u51b2\u533a<br>    size_t aio_nbytes;             \/\/ \u8981\u4f20\u8f93\u7684\u5b57\u8282\u6570<br>    int aio_reqprio;               \/\/ \u8bf7\u6c42\u4f18\u5148\u7ea7<br>    struct sigevent aio_sigevent;  \/\/ \u4fe1\u53f7\u4e8b\u4ef6<br>    int aio_lio_opcode;            \/\/ \u5217\u8868I\/O\u64cd\u4f5c\u7801<br>};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">\u51fd\u6570\u8fd4\u56de\u503c<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6210\u529f<\/strong>\uff1a\u8fd4\u56de\u4e0e\u540c\u6b65<code>read<\/code>\u3001<code>write<\/code>\u3001<code>fsync<\/code>\u6216<code>fdatasync<\/code>\u8c03\u7528\u76f8\u540c\u7684\u503c\u3002<\/li>\n\n\n\n<li><strong>\u5931\u8d25<\/strong>\uff1a\u8fd4\u56de-1\uff0c\u5e76\u8bbe\u7f6e<code>errno<\/code>\u4ee5\u6307\u793a\u9519\u8bef\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u7efc\u5408\u793a\u4f8b<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;aio.h>\n#include &lt;arpa\/inet.h>\n#include &lt;fcntl.h>\n#include &lt;netinet\/in.h>\n#include &lt;stdio.h>\n#include &lt;stdlib.h>\n#include &lt;string.h>\n#include &lt;sys\/socket.h>\n#include &lt;unistd.h>\n\n#define PORT 8080\n#define BUFFER_SIZE 1024\n\nvoid aio_completion_handler(sigval_t sigval) {\n    struct aiocb *req = (struct aiocb *)sigval.sival_ptr;\n    if (aio_error(req) == 0) {\n        ssize_t bytes_transferred = aio_return(req);\n        printf(\"Transferred %zd bytes\\n\", bytes_transferred);\n    } else {\n        perror(\"aio_error\");\n    }\n}\n\nint main() {\n    int server_fd, new_socket;\n    struct sockaddr_in address;\n    int opt = 1;\n    int addrlen = sizeof(address);\n    char buffer&#91;BUFFER_SIZE] = {0};\n\n    \/\/ \u521b\u5efa\u5957\u63a5\u5b57\n    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {\n        perror(\"socket failed\");\n        exit(EXIT_FAILURE);\n    }\n\n    \/\/ \u7ed1\u5b9a\u7aef\u53e3\n    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &amp;opt, sizeof(opt))) {\n        perror(\"setsockopt\");\n        exit(EXIT_FAILURE);\n    }\n    address.sin_family = AF_INET;\n    address.sin_addr.s_addr = INADDR_ANY;\n    address.sin_port = htons(PORT);\n\n    if (bind(server_fd, (struct sockaddr *)&amp;address, sizeof(address)) &lt; 0) {\n        perror(\"bind failed\");\n        exit(EXIT_FAILURE);\n    }\n\n    if (listen(server_fd, 3) &lt; 0) {\n        perror(\"listen\");\n        exit(EXIT_FAILURE);\n    }\n\n    if ((new_socket = accept(server_fd, (struct sockaddr *)&amp;address, (socklen_t *)&amp;addrlen)) &lt; 0) {\n        perror(\"accept\");\n        exit(EXIT_FAILURE);\n    }\n\n    \/\/ \u521d\u59cb\u5316aiocb\u7ed3\u6784\u4f53\n    struct aiocb cb;\n    memset(&amp;cb, 0, sizeof(struct aiocb));\n    cb.aio_fildes = new_socket;\n    cb.aio_buf = buffer;\n    cb.aio_nbytes = BUFFER_SIZE;\n    cb.aio_offset = 0;\n    cb.aio_sigevent.sigev_notify = SIGEV_THREAD;\n    cb.aio_sigevent.sigev_notify_function = aio_completion_handler;\n    cb.aio_sigevent.sigev_notify_attributes = NULL;\n    cb.aio_sigevent.sigev_value.sival_ptr = &amp;cb;\n\n    \/\/ \u53d1\u8d77\u5f02\u6b65\u8bfb\u64cd\u4f5c\n    if (aio_read(&amp;cb) == -1) {\n        perror(\"aio_read\");\n        close(new_socket);\n        close(server_fd);\n        return 1;\n    }\n\n    \/\/ \u7b49\u5f85\u5f02\u6b65\u8bfb\u64cd\u4f5c\u5b8c\u6210\n    while (aio_error(&amp;cb) == EINPROGRESS) {\n        \/\/ \u53ef\u4ee5\u5728\u8fd9\u91cc\u6267\u884c\u5176\u4ed6\u4efb\u52a1\n    }\n\n    ssize_t bytes_read = aio_return(&amp;cb);\n    if (bytes_read == -1) {\n        perror(\"aio_return\");\n    } else {\n        printf(\"Read %zd bytes: %s\\n\", bytes_read, buffer);\n    }\n\n    \/\/ \u53d1\u8d77\u5f02\u6b65\u5199\u64cd\u4f5c\n    const char *response = \"Hello from server\";\n    memset(&amp;cb, 0, sizeof(struct aiocb));\n    cb.aio_fildes = new_socket;\n    cb.aio_buf = (void *)response;\n    cb.aio_nbytes = strlen(response);\n    cb.aio_offset = 0;\n    cb.aio_sigevent.sigev_notify = SIGEV_THREAD;\n    cb.aio_sigevent.sigev_notify_function = aio_completion_handler;\n    cb.aio_sigevent.sigev_notify_attributes = NULL;\n    cb.aio_sigevent.sigev_value.sival_ptr = &amp;cb;\n\n    if (aio_write(&amp;cb) == -1) {\n        perror(\"aio_write\");\n        close(new_socket);\n        close(server_fd);\n        return 1;\n    }\n\n    \/\/ \u7b49\u5f85\u5f02\u6b65\u5199\u64cd\u4f5c\u5b8c\u6210\n    while (aio_error(&amp;cb) == EINPROGRESS) {\n        \/\/ \u53ef\u4ee5\u5728\u8fd9\u91cc\u6267\u884c\u5176\u4ed6\u4efb\u52a1\n    }\n\n    ssize_t bytes_written = aio_return(&amp;cb);\n    if (bytes_written == -1) {\n        perror(\"aio_return\");\n    } else {\n        printf(\"Written %zd bytes\\n\", bytes_written);\n    }\n\n    close(new_socket);\n    close(server_fd);\n    return 0;\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u6e29\u99a8\u63d0\u793a\uff0c\u5728\u5b66\u4e60\u672c\u7bc7\u4e4b\u524d\uff0c\u60a8\u9700\u8981\u5bf9\u7f51\u7edc\u6a21\u578b\u3001TCP\\UDP\u6709\u521d\u6b65\u4e86\u89e3 \u7f51\u7edc\u57fa\u7840\u77e5\u8bc6 \u7f51\u7edc\u5b57\u8282\u5e8f\u548c\u4e3b\u673a\u5b57\u8282\u5e8f \u4e3b [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,1,4],"tags":[18,33,41],"class_list":["post-1111","post","type-post","status-publish","format-standard","hentry","category-c-c","category-learning","category-os","tag-c","tag-linux","tag-41"],"_links":{"self":[{"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/posts\/1111","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/comments?post=1111"}],"version-history":[{"count":20,"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/posts\/1111\/revisions"}],"predecessor-version":[{"id":1132,"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/posts\/1111\/revisions\/1132"}],"wp:attachment":[{"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/media?parent=1111"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/categories?post=1111"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.chxzking.cn\/index.php\/wp-json\/wp\/v2\/tags?post=1111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}