{"id":779,"date":"2024-11-07T08:37:25","date_gmt":"2024-11-07T00:37:25","guid":{"rendered":"https:\/\/fwq.ai\/blog\/779\/"},"modified":"2024-11-07T08:37:25","modified_gmt":"2024-11-07T00:37:25","slug":"c%e8%af%ad%e8%a8%80%e7%bd%91%e7%bb%9c%e7%bc%96%e7%a8%8b%e6%9c%80%e4%bd%b3%e5%ae%9e%e8%b7%b5%e6%8c%87%e5%8d%97","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/779\/","title":{"rendered":"C\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u6307\u5357"},"content":{"rendered":"<p>c\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u5305\u62ec\uff1a\u4f7f\u7528\u9002\u5f53\u7684\u5957\u63a5\u5b57\u7c7b\u578b\u3001\u91c7\u7528\u975e\u963b\u585ei\/o\u3001\u8fdb\u884c\u9519\u8bef\u5904\u7406\u3001\u9632\u6b62\u7f13\u51b2\u533a\u6ea2\u51fa\u3001\u4f7f\u7528\u8fde\u63a5\u590d\u7528\u3001\u786e\u4fdd\u7ebf\u7a0b\u5b89\u5168\u3001\u5904\u7406\u4fe1\u53f7\u4ee5\u53ca\u6839\u636e\u9700\u8981\u8bbe\u7f6e\u5957\u63a5\u5b57\u9009\u9879\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528\u975e\u963b\u585ei\/o\u51fd\u6570\u548cselect()\u51fd\u6570\u6765\u5b9e\u73b0\u975e\u963b\u585e\u5957\u63a5\u5b57\u670d\u52a1\u5668\uff0c\u4ece\u800c\u63d0\u9ad8\u54cd\u5e94\u6027\u548c\u541e\u5410\u91cf\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1127\" src=\"https:\/\/fwq.ai\/blog\/wp-content\/uploads\/2024\/11\/172862082167900.jpg\" width=\"720\" height=\"288\" srcset=\"https:\/\/fwq.ai\/blog\/wp-content\/uploads\/2024\/11\/172862082167900.jpg 720w, https:\/\/fwq.ai\/blog\/wp-content\/uploads\/2024\/11\/172862082167900-300x120.jpg 300w, https:\/\/fwq.ai\/blog\/wp-content\/uploads\/2024\/11\/172862082167900-670x268.jpg 670w\" sizes=\"auto, (max-width: 720px) 100vw, 720px\" title=\"C\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u6307\u5357\u63d2\u56fe\" alt=\"C\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u6307\u5357\u63d2\u56fe\" \/><\/p>\n<h2>C \u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u6307\u5357<\/h2>\n<h3>\u524d\u8a00<\/h3>\n<p>\u5728 C \u8bed\u8a00\u4e2d\u7f16\u5199\u53ef\u9760\u4e14\u9ad8\u6548\u7684\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f\u9700\u8981\u9075\u5b88\u6700\u4f73\u5b9e\u8df5\u3002\u672c\u6587\u5c06\u63a2\u8ba8\u4e00\u4e9b\u91cd\u8981\u7684\u6700\u4f73\u5b9e\u8df5\uff0c\u4ee5\u5e2e\u52a9\u60a8\u63d0\u9ad8\u4ee3\u7801\u7684\u7a33\u5065\u6027\u3001\u6027\u80fd\u548c\u5b89\u5168\u6027\u3002<\/p>\n<h3>1. \u4f7f\u7528\u6b63\u786e\u7684\u5957\u63a5\u5b57\u7c7b\u578b<\/h3>\n<ul>\n<li>\u4f7f\u7528 TCP \u5957\u63a5\u5b57\u8fdb\u884c\u53ef\u9760\u4e14\u6309\u5e8f\u4f20\u8f93\u3002<\/li>\n<li>\u4f7f\u7528 UDP \u5957\u63a5\u5b57\u8fdb\u884c\u4e0d\u53ef\u9760\u7684\u3001\u9762\u5411\u6570\u636e\u62a5\u7684\u4f20\u8f93\u3002<\/li>\n<li>\u4e86\u89e3\u4e0d\u540c\u7684\u5957\u63a5\u5b57\u7c7b\u578b\u53ca\u5176\u7528\u9014\u3002<\/li>\n<\/ul>\n<h3>2. \u975e\u963b\u585e I\/O<\/h3>\n<ul>\n<li>\u4f7f\u7528\u975e\u963b\u585e I\/O \u51fd\u6570\uff0c\u4f8b\u5982 fcntl(2) \u548c poll(2)\u3002<\/li>\n<li>\u8fd9\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u5728\u7b49\u5f85 I\/O \u8bf7\u6c42\u5b8c\u6210\u65f6\u7ee7\u7eed\u6267\u884c\u5176\u4ed6\u4efb\u52a1\uff0c\u63d0\u9ad8\u54cd\u5e94\u6027\u548c\u541e\u5410\u91cf\u3002<\/li>\n<\/ul>\n<h3>3. \u9519\u8bef\u5904\u7406<\/h3>\n<ul>\n<li>\u4f7f\u7528 errno \u53d8\u91cf\u83b7\u53d6\u9519\u8bef\u4ee3\u7801\u3002<\/li>\n<li>\u6839\u636e\u9519\u8bef\u4ee3\u7801\u6267\u884c\u9002\u5f53\u7684\u5f02\u5e38\u5904\u7406\uff0c\u63d0\u4f9b\u7528\u6237\u53cb\u597d\u7684\u9519\u8bef\u6d88\u606f\u3002<\/li>\n<li>\u4e0d\u8981\u5ffd\u7565\u9519\u8bef\uff0c\u56e0\u4e3a\u5b83\u53ef\u80fd\u5bfc\u81f4\u4e0d\u7a33\u5b9a\u548c\u4e0d\u5b89\u5168\u7684\u5e94\u7528\u7a0b\u5e8f\u3002<\/li>\n<\/ul>\n<h3>4. \u7f13\u51b2\u533a\u6ea2\u51fa\u9632\u62a4<\/h3>\n<ul>\n<li>\u4f7f\u7528\u5b89\u5168\u51fd\u6570\uff0c\u4f8b\u5982 strncat(3)\u3001strlcpy(3) \u548c snprintf(3)\uff0c\u6765\u9632\u6b62\u7f13\u51b2\u533a\u6ea2\u51fa\u3002<\/li>\n<li>\u8bbe\u7f6e\u7f13\u51b2\u533a\u5927\u5c0f\u5e76\u4ed4\u7ec6\u68c0\u67e5\u8f93\u5165\u6570\u636e\u3002<\/li>\n<li>\u4f7f\u7528\u6808\u6ea2\u51fa\u68c0\u6d4b\u5de5\u5177\uff0c\u4f8b\u5982 AddressSanitizer\u3002<\/li>\n<\/ul>\n<h3>5. \u8fde\u63a5\u590d\u7528<\/h3>\n<ul>\n<li>\u4f7f\u7528 select(2)\u3001poll(2) \u6216 epoll(7) \u51fd\u6570\u8fdb\u884c\u8fde\u63a5\u590d\u7528\u3002<\/li>\n<li>\u8fd9\u5141\u8bb8\u4e00\u4e2a\u5e94\u7528\u7a0b\u5e8f\u540c\u65f6\u76d1\u63a7\u591a\u4e2a\u5957\u63a5\u5b57\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u4ee5\u63d0\u9ad8\u53ef\u4f38\u7f29\u6027\u548c\u6027\u80fd\u3002<\/li>\n<\/ul>\n<h3>6. \u7ebf\u7a0b\u5b89\u5168<\/h3>\n<ul>\n<li>\u5728\u591a\u7ebf\u7a0b\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u4f7f\u7528\u4e92\u65a5\u9501\u6216\u539f\u5b50\u53d8\u91cf\u6765\u4fdd\u62a4\u5171\u4eab\u6570\u636e\u7ed3\u6784\u3002<\/li>\n<li>\u907f\u514d\u7ade\u6001\u6761\u4ef6\u548c\u6570\u636e\u635f\u574f\u3002<\/li>\n<\/ul>\n<h3>7. \u4fe1\u53f7\u5904\u7406<\/h3>\n<ul>\n<li>\u5728\u4fe1\u53f7\u5904\u7406\u7a0b\u5e8f\u4e2d\u5c0f\u5fc3\u5730\u5904\u7406\u7f51\u7edc\u76f8\u5173\u64cd\u4f5c\u3002<\/li>\n<li>\u6b63\u786e\u6e05\u7406\u5957\u63a5\u5b57\u5e76\u91ca\u653e\u76f8\u5173\u8d44\u6e90\u3002<\/li>\n<\/ul>\n<h3>8. \u5957\u63a5\u5b57\u9009\u9879<\/h3>\n<ul>\n<li>\u6839\u636e\u9700\u8981\u8bbe\u7f6e\u5957\u63a5\u5b57\u9009\u9879\uff0c\u4f8b\u5982 SO_REUSEADDR\u3001SO_LINGER \u548c SO_SNDBUF\u3002<\/li>\n<li>\u4f18\u5316\u5e94\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u548c\u884c\u4e3a\u3002<\/li>\n<\/ul>\n<h3>\u5b9e\u6218\u6848\u4f8b<\/h3>\n<p><strong>\u975e\u963b\u585e\u5957\u63a5\u5b57\u670d\u52a1\u7aef<\/strong><\/p>\n<pre>#include &lt;stdio.h&gt;\n#include &lt;stdlib.h&gt;\n#include &lt;unistd.h&gt;\n#include &lt;netdb.h&gt;\n#include &lt;arpa&gt;\n\nint main() {\n    \/\/ 1. \u521b\u5efa\u4e00\u4e2a\u76d1\u542c\u5957\u63a5\u5b57\n    int sockfd = socket(AF_INET, SOCK_STREAM, 0);\n    if (sockfd == -1) {\n        perror(\"socket\");\n        exit(1);\n    }\n\n    \/\/ 2. \u8bbe\u7f6e\u5957\u63a5\u5b57\u4e3a\u975e\u963b\u585e\n    int flags = fcntl(sockfd, F_GETFL, 0);\n    if (flags == -1) {\n        perror(\"fcntl\");\n        exit(1);\n    }\n    flags |= O_NONBLOCK;\n    if (fcntl(sockfd, F_SETFL, flags) == -1) {\n        perror(\"fcntl\");\n        exit(1);\n    }\n\n    \/\/ 3. \u7ed1\u5b9a\u5957\u63a5\u5b57\n    struct sockaddr_in addr;\n    memset(&amp;amp;addr, 0, sizeof(addr));\n    addr.sin_family = AF_INET;\n    addr.sin_port = htons(8080);\n    if (bind(sockfd, (struct sockaddr *) &amp;amp;addr, sizeof(addr)) == -1) {\n        perror(\"bind\");\n        exit(1);\n    }\n\n    \/\/ 4. \u76d1\u542c\u5957\u63a5\u5b57\n    if (listen(sockfd, 5) == -1) {\n        perror(\"listen\");\n        exit(1);\n    }\n\n    \/\/ 5. \u8fdb\u5165\u4e8b\u4ef6\u5faa\u73af\n    while (1) {\n        \/\/ \u76d1\u6d4b\u5957\u63a5\u5b57\u662f\u5426\u53ef\u8bfb\n        struct timeval timeout;\n        timeout.tv_sec = 1;\n        timeout.tv_usec = 0;\n        fd_set fds;\n        FD_ZERO(&amp;amp;fds);\n        FD_SET(sockfd, &amp;amp;fds);\n        int nready = select(sockfd + 1, &amp;amp;fds, NULL, NULL, &amp;amp;timeout);\n        if (nready == -1) {\n            perror(\"select\");\n            exit(1);\n        }\n\n        \/\/ \u5982\u679c\u5957\u63a5\u5b57\u53ef\u8bfb\uff0c\u63a5\u53d7\u8fde\u63a5\n        if (FD_ISSET(sockfd, &amp;amp;fds)) {\n            struct sockaddr_in client_addr;\n            socklen_t len = sizeof(client_addr);\n            int newsockfd = accept(sockfd, (struct sockaddr *) &amp;amp;client_addr, &amp;amp;len);\n            if (newsockfd == -1) {\n                perror(\"accept\");\n            } else {\n                \/\/ \u5904\u7406\u8fde\u63a5...\n            }\n        }\n    }\n\n    \/\/ 6. \u5173\u95ed\u5957\u63a5\u5b57\n    close(sockfd);\n    return 0;\n}&lt;\/arpa&gt;&lt;\/netdb.h&gt;&lt;\/unistd.h&gt;&lt;\/stdlib.h&gt;&lt;\/stdio.h&gt;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fC\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u6307\u5357\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>c\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u5305\u62ec\uff1a\u4f7f\u7528\u9002\u5f53\u7684\u5957\u63a5\u5b57\u7c7b\u578b\u3001\u91c7\u7528\u975e\u963b\u585ei\/o\u3001\u8fdb\u884c\u9519\u8bef\u5904\u7406\u3001\u9632\u6b62\u7f13\u51b2\u533a\u6ea2\u51fa\u3001\u4f7f\u7528\u8fde\u63a5\u590d\u7528\u3001\u786e\u4fdd\u7ebf\u7a0b\u5b89\u5168\u3001\u5904\u7406\u4fe1\u53f7\u4ee5\u53ca\u6839\u636e\u9700\u8981\u8bbe\u7f6e\u5957\u63a5\u5b57\u9009\u9879\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528\u975e\u963b\u585ei\/o\u51fd\u6570\u548cselect()\u51fd\u6570\u6765\u5b9e\u73b0\u975e\u963b\u585e\u5957\u63a5\u5b57\u670d\u52a1\u5668\uff0c\u4ece\u800c\u63d0\u9ad8\u54cd\u5e94\u6027\u548c\u541e\u5410\u91cf\u3002 C \u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u6307\u5357 \u524d\u8a00 \u5728 C \u8bed\u8a00\u4e2d\u7f16\u5199\u53ef\u9760\u4e14\u9ad8\u6548\u7684\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f\u9700\u8981\u9075\u5b88\u6700\u4f73\u5b9e\u8df5\u3002\u672c\u6587\u5c06\u63a2\u8ba8\u4e00\u4e9b\u91cd\u8981\u7684\u6700\u4f73\u5b9e\u8df5\uff0c\u4ee5\u5e2e\u52a9\u60a8\u63d0\u9ad8\u4ee3\u7801\u7684\u7a33\u5065\u6027\u3001\u6027\u80fd\u548c\u5b89\u5168\u6027\u3002 1. \u4f7f\u7528\u6b63\u786e\u7684\u5957\u63a5\u5b57\u7c7b\u578b \u4f7f\u7528 TCP \u5957\u63a5\u5b57\u8fdb\u884c\u53ef\u9760\u4e14\u6309\u5e8f\u4f20\u8f93\u3002 \u4f7f\u7528 UDP \u5957\u63a5\u5b57\u8fdb\u884c\u4e0d\u53ef\u9760\u7684\u3001\u9762\u5411\u6570\u636e\u62a5\u7684\u4f20\u8f93\u3002 \u4e86\u89e3\u4e0d\u540c\u7684\u5957\u63a5\u5b57\u7c7b\u578b\u53ca\u5176\u7528\u9014\u3002 2. \u975e\u963b\u585e I\/O \u4f7f\u7528\u975e\u963b\u585e I\/O \u51fd\u6570\uff0c\u4f8b\u5982 fcntl(2) \u548c poll(2)\u3002 \u8fd9\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u5728\u7b49\u5f85 I\/O \u8bf7\u6c42\u5b8c\u6210\u65f6\u7ee7\u7eed\u6267\u884c\u5176\u4ed6\u4efb\u52a1\uff0c\u63d0\u9ad8\u54cd\u5e94\u6027\u548c\u541e\u5410\u91cf\u3002 3. \u9519\u8bef\u5904\u7406 \u4f7f\u7528 errno \u53d8\u91cf\u83b7\u53d6\u9519\u8bef\u4ee3\u7801\u3002 \u6839\u636e\u9519\u8bef\u4ee3\u7801\u6267\u884c\u9002\u5f53\u7684\u5f02\u5e38\u5904\u7406\uff0c\u63d0\u4f9b\u7528\u6237\u53cb\u597d\u7684\u9519\u8bef\u6d88\u606f\u3002 \u4e0d\u8981\u5ffd\u7565\u9519\u8bef\uff0c\u56e0\u4e3a\u5b83\u53ef\u80fd\u5bfc\u81f4\u4e0d\u7a33\u5b9a\u548c\u4e0d\u5b89\u5168\u7684\u5e94\u7528\u7a0b\u5e8f\u3002 4. \u7f13\u51b2\u533a\u6ea2\u51fa\u9632\u62a4 \u4f7f\u7528\u5b89\u5168\u51fd\u6570\uff0c\u4f8b\u5982 strncat(3)\u3001strlcpy(3) \u548c snprintf(3)\uff0c\u6765\u9632\u6b62\u7f13\u51b2\u533a\u6ea2\u51fa\u3002 \u8bbe\u7f6e\u7f13\u51b2\u533a\u5927\u5c0f\u5e76\u4ed4\u7ec6\u68c0\u67e5\u8f93\u5165\u6570\u636e\u3002 \u4f7f\u7528\u6808\u6ea2\u51fa\u68c0\u6d4b\u5de5\u5177\uff0c\u4f8b\u5982 AddressSanitizer\u3002 5. \u8fde\u63a5\u590d\u7528 \u4f7f\u7528 select(2)\u3001poll(2) \u6216 epoll(7) \u51fd\u6570\u8fdb\u884c\u8fde\u63a5\u590d\u7528\u3002 \u8fd9\u5141\u8bb8\u4e00\u4e2a\u5e94\u7528\u7a0b\u5e8f\u540c\u65f6\u76d1\u63a7\u591a\u4e2a\u5957\u63a5\u5b57\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u4ee5\u63d0\u9ad8\u53ef\u4f38\u7f29\u6027\u548c\u6027\u80fd\u3002 6. \u7ebf\u7a0b\u5b89\u5168 \u5728\u591a\u7ebf\u7a0b\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u4f7f\u7528\u4e92\u65a5\u9501\u6216\u539f\u5b50\u53d8\u91cf\u6765\u4fdd\u62a4\u5171\u4eab\u6570\u636e\u7ed3\u6784\u3002 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-779","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/779","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=779"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/779\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}