{"id":1438,"date":"2018-06-21T21:00:00","date_gmt":"2018-06-21T13:00:00","guid":{"rendered":"https:\/\/damogame.cn:15443\/wordpress\/?p=1438"},"modified":"2018-06-21T21:00:00","modified_gmt":"2018-06-21T13:00:00","slug":"linux-%e8%bf%9b%e7%a8%8b%e9%97%b4%e9%80%9a%e4%bf%a1-%e5%85%b1%e4%ba%ab%e5%86%85%e5%ad%98%ef%bc%88%e4%b8%8a%ef%bc%89","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/1438","title":{"rendered":"Linux \u8fdb\u7a0b\u95f4\u901a\u4fe1 : \u5171\u4eab\u5185\u5b58\uff08\u4e0a\uff09"},"content":{"rendered":"<h1 class=\"col-article-title\">Linux \u8fdb\u7a0b\u95f4\u901a\u4fe1 : \u5171\u4eab\u5185\u5b58\uff08\u4e0a\uff09<\/h1>\n<div class=\"col-markdown-nav absolute\">\n<h2 class=\"nav-title\">\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff1a<\/h2>\n<ul class=\"col-markdown-nav-list\">\n<li><a title=\"\u524d\u8a00\" data-key=\"2.1\">\u524d\u8a00<\/a><\/li>\n<li><a title=\"mmap\u5185\u5b58\u5171\u4eab\u6620\u5c04\" data-key=\"2.2\">mmap\u5185\u5b58\u5171\u4eab\u6620\u5c04<\/a><\/li>\n<li><a class=\"active\" title=\"XSI\u5171\u4eab\u5185\u5b58\" data-key=\"2.3\">XSI\u5171\u4eab\u5185\u5b58<\/a><\/li>\n<\/ul>\n<\/div>\n<div class=\"c-markdown J-articleContent\">\n<h2>\u524d\u8a00<\/h2>\n<p>\u672c\u6587\u4e3b\u8981\u8bf4\u660e\u5728Linux\u73af\u5883\u4e0a\u5982\u4f55\u4f7f\u7528\u5171\u4eab\u5185\u5b58\u3002\u9605\u8bfb\u672c\u6587\u53ef\u4ee5\u5e2e\u4f60\u89e3\u51b3\u4ee5\u4e0b\u95ee\u9898\uff1a<\/p>\n<ol class=\"ol-level-0\">\n<li>\u4ec0\u4e48\u662f\u5171\u4eab\u5185\u5b58\u548c\u4e3a\u4ec0\u4e48\u8981\u6709\u5171\u4eab\u5185\u5b58\uff1f<\/li>\n<li>\u5982\u4f55\u4f7f\u7528mmap\u8fdb\u884c\u5171\u4eab\u5185\u5b58\uff1f<\/li>\n<li>\u5982\u4f55\u4f7f\u7528XSI\u5171\u4eab\u5185\u5b58\uff1f<\/li>\n<li>\u5982\u4f55\u4f7f\u7528POSIX\u5171\u4eab\u5185\u5b58\uff1f<\/li>\n<li>\u5982\u4f55\u4f7f\u7528hugepage\u5171\u4eab\u5185\u5b58\u4ee5\u53ca\u5171\u4eab\u5185\u5b58\u7684\u76f8\u5173\u9650\u5236\u5982\u4f55\u914d\u7f6e\uff1f<\/li>\n<li>\u5171\u4eab\u5185\u5b58\u90fd\u662f\u5982\u4f55\u5b9e\u73b0\u7684\uff1f<\/li>\n<\/ol>\n<p>\u4f7f\u7528\u6587\u4ef6\u6216\u7ba1\u9053\u8fdb\u884c\u8fdb\u7a0b\u95f4\u901a\u4fe1\u4f1a\u6709\u5f88\u591a\u5c40\u9650\u6027\uff0c\u6bd4\u5982\u6548\u7387\u95ee\u9898\u4ee5\u53ca\u6570\u636e\u5904\u7406\u4f7f\u7528\u6587\u4ef6\u63cf\u8ff0\u7b26\u800c\u4e0d\u5982\u5185\u5b58\u5730\u5740\u8bbf\u95ee\u65b9\u4fbf\uff0c\u4e8e\u662f\u591a\u4e2a\u8fdb\u7a0b\u4ee5\u5171\u4eab\u5185\u5b58\u7684\u65b9\u5f0f\u8fdb\u884c\u901a\u4fe1\u5c31\u6210\u4e86\u5f88\u81ea\u7136\u8981\u5b9e\u73b0\u7684IPC\u65b9\u6848\u3002Linux\u7cfb\u7edf\u5728\u7f16\u7a0b\u4e0a\u4e3a\u6211\u4eec\u51c6\u5907\u4e86\u591a\u79cd\u624b\u6bb5\u7684\u5171\u4eab\u5185\u5b58\u65b9\u6848\u3002\u5305\u62ec\uff1a<\/p>\n<ol class=\"ol-level-0\">\n<li>mmap\u5185\u5b58\u5171\u4eab\u6620\u5c04\u3002<\/li>\n<li>XSI\u5171\u4eab\u5185\u5b58\u3002<\/li>\n<li>POSIX\u5171\u4eab\u5185\u5b58\u3002<\/li>\n<\/ol>\n<p>\u4e0b\u9762\u6211\u4eec\u5c31\u6765\u5206\u522b\u4ecb\u7ecd\u4e00\u4e0b\u8fd9\u4e09\u79cd\u5185\u5b58\u5171\u4eab\u65b9\u5f0f\u3002<\/p>\n<h2>mmap\u5185\u5b58\u5171\u4eab\u6620\u5c04<\/h2>\n<p>mmap\u672c\u6765\u7684\u662f\u5b58\u50a8\u6620\u5c04\u529f\u80fd\u3002\u5b83\u53ef\u4ee5\u5c06\u4e00\u4e2a\u6587\u4ef6\u6620\u5c04\u5230\u5185\u5b58\u4e2d\uff0c\u5728\u7a0b\u5e8f\u91cc\u5c31\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u5185\u5b58\u5730\u5740\u5bf9\u6587\u4ef6\u5185\u5bb9\u8fdb\u884c\u8bbf\u95ee\uff0c\u8fd9\u53ef\u4ee5\u8ba9\u7a0b\u5e8f\u5bf9\u6587\u4ef6\u8bbf\u95ee\u66f4\u65b9\u4fbf\u3002\u5176\u76f8\u5173\u8c03\u7528API\u539f\u578b\u5982\u4e0b\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\">#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>mman<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\n<span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token function\">mmap<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>addr<span class=\"token punctuation\">,<\/span> size_t length<span class=\"token punctuation\">,<\/span> int prot<span class=\"token punctuation\">,<\/span> int flags<span class=\"token punctuation\">,<\/span> int fd<span class=\"token punctuation\">,<\/span> off_t offset<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\nint <span class=\"token function\">munmap<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>addr<span class=\"token punctuation\">,<\/span> size_t length<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<\/pre>\n<p>\u7531\u4e8e\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u7684\u7279\u6027\u53ef\u4ee5\u7528\u5728\u5f88\u591a\u573a\u5408\uff0c\u6240\u4ee5Linux\u7cfb\u7edf\u7528\u5b83\u5b9e\u73b0\u4e86\u5f88\u591a\u529f\u80fd\uff0c\u5e76\u4e0d\u4ec5\u5c40\u9650\u4e8e\u5b58\u50a8\u6620\u5c04\u3002\u5728\u8fd9\u4e3b\u8981\u4ecb\u7ecd\u7684\u5c31\u662f\u7528mmap\u8fdb\u884c\u591a\u8fdb\u7a0b\u7684\u5185\u5b58\u5171\u4eab\u529f\u80fd\u3002Linux\u4ea7\u751f\u5b50\u8fdb\u7a0b\u7684\u7cfb\u7edf\u8c03\u7528\u662ffork\uff0c\u6839\u636efork\u7684\u8bed\u4e49\u4ee5\u53ca\u5176\u5b9e\u73b0\uff0c\u6211\u4eec\u77e5\u9053\u65b0\u4ea7\u751f\u7684\u8fdb\u7a0b\u5728\u5185\u5b58\u5730\u5740\u7a7a\u95f4\u4e0a\u8ddf\u7236\u8fdb\u7a0b\u662f\u5b8c\u5168\u4e00\u81f4\u7684\u3002\u6240\u4ee5Linux\u7684mmap\u5b9e\u73b0\u4e86\u4e00\u79cd\u53ef\u4ee5\u5728\u7236\u5b50\u8fdb\u7a0b\u4e4b\u95f4\u5171\u4eab\u5185\u5b58\u5730\u5740\u7684\u65b9\u5f0f\uff0c\u5176\u4f7f\u7528\u65b9\u6cd5\u662f\uff1a<\/p>\n<ol class=\"ol-level-0\">\n<li>\u7236\u8fdb\u7a0b\u5c06flags\u53c2\u6570\u8bbe\u7f6eMAP_SHARED\u65b9\u5f0f\u901a\u8fc7mmap\u7533\u8bf7\u4e00\u6bb5\u5185\u5b58\u3002\u5185\u5b58\u53ef\u4ee5\u6620\u5c04\u67d0\u4e2a\u5177\u4f53\u6587\u4ef6\uff0c\u4e5f\u53ef\u4ee5\u4e0d\u6620\u5c04\u5177\u4f53\u6587\u4ef6\uff08fd\u7f6e\u4e3a-1\uff0cflag\u8bbe\u7f6e\u4e3aMAP_ANONYMOUS\uff09\u3002<\/li>\n<li>\u7236\u8fdb\u7a0b\u8c03\u7528fork\u4ea7\u751f\u5b50\u8fdb\u7a0b\u3002\u4e4b\u540e\u5728\u7236\u5b50\u8fdb\u7a0b\u5185\u90fd\u53ef\u4ee5\u8bbf\u95ee\u5230mmap\u6240\u8fd4\u56de\u7684\u5730\u5740\uff0c\u5c31\u53ef\u4ee5\u5171\u4eab\u5185\u5b58\u4e86\u3002<\/li>\n<\/ol>\n<p>\u6211\u4eec\u5199\u4e00\u4e2a\u4f8b\u5b50\u8bd5\u4e00\u4e0b\uff0c\u8fd9\u6b21\u6211\u4eec\u5e76\u53d1100\u4e2a\u8fdb\u7a0b\u5199\u5171\u4eab\u5185\u5b58\u6765\u770b\u770b\u7ade\u4e89\u6761\u4ef6racing\u7684\u60c5\u51b5\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ cat racing_mmap<span class=\"token punctuation\">.<\/span>c \r\n#include <span class=\"token operator\">&lt;<\/span>unistd<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdlib<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdio<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>errno<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>fcntl<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>string<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>file<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>wait<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>mman<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\n#define COUNT <span class=\"token number\">100<\/span>\r\n\r\nint <span class=\"token function\">do_child<\/span><span class=\"token punctuation\">(<\/span>int <span class=\"token operator\">*<\/span>count<span class=\"token punctuation\">)<\/span>\r\n<span class=\"token punctuation\">{<\/span>\r\n    int interval<span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token comment\">\/* critical section *\/<\/span>\r\n    interval <span class=\"token operator\">=<\/span> <span class=\"token operator\">*<\/span>count<span class=\"token punctuation\">;<\/span>\r\n    interval<span class=\"token operator\">++<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token function\">usleep<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token operator\">*<\/span>count <span class=\"token operator\">=<\/span> interval<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token comment\">\/* critical section *\/<\/span>\r\n\r\n    <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token punctuation\">}<\/span>\r\n\r\nint <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span>\r\n<span class=\"token punctuation\">{<\/span>\r\n    pid_t pid<span class=\"token punctuation\">;<\/span>\r\n    int count<span class=\"token punctuation\">;<\/span>\r\n    int <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">;<\/span>\r\n\r\n    shm_p <span class=\"token operator\">=<\/span> <span class=\"token punctuation\">(<\/span>int <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token function\">mmap<\/span><span class=\"token punctuation\">(<\/span>NULL<span class=\"token punctuation\">,<\/span> <span class=\"token function\">sizeof<\/span><span class=\"token punctuation\">(<\/span>int<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> PROT_WRITE<span class=\"token operator\">|<\/span>PROT_READ<span class=\"token punctuation\">,<\/span> MAP_SHARED<span class=\"token operator\">|<\/span>MAP_ANONYMOUS<span class=\"token punctuation\">,<\/span> <span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>MAP_FAILED <span class=\"token operator\">==<\/span> shm_p<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"mmap()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token operator\">*<\/span>shm_p <span class=\"token operator\">=<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/span>count<span class=\"token operator\">=<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">&lt;<\/span>COUNT<span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">++<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        pid <span class=\"token operator\">=<\/span> <span class=\"token function\">fork<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n            <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"fork()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n            <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token punctuation\">}<\/span>\r\n\r\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">==<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n            <span class=\"token function\">do_child<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token punctuation\">}<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/span>count<span class=\"token operator\">=<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">&lt;<\/span>COUNT<span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">++<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">wait<\/span><span class=\"token punctuation\">(<\/span>NULL<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token function\">printf<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shm_p: %d\\n\"<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token function\">munmap<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">,<\/span> <span class=\"token function\">sizeof<\/span><span class=\"token punctuation\">(<\/span>int<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token punctuation\">}<\/span>\r\n<\/pre>\n<p>\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u5728\u5b50\u8fdb\u7a0b\u4e2d\u4e3a\u4e86\u5ef6\u957f\u4e34\u754c\u533a\uff08critical section\uff09\u5904\u7406\u7684\u65f6\u95f4\uff0c\u4f7f\u7528\u4e86\u4e00\u4e2a\u4e2d\u95f4\u53d8\u91cf\u8fdb\u884c\u6570\u503c\u4ea4\u6362\uff0c\u5e76\u4e14\u8fd8\u4f7f\u7528\u4e86usleep\u52a0\u5f3a\u4e86\u4e00\u4e0bracing\u7684\u6548\u679c\uff0c\u6700\u540e\u6267\u884c\u7ed3\u679c\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_mmap \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">20<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_mmap \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">17<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_mmap \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">14<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_mmap \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">15<\/span>\r\n<\/pre>\n<p>\u8fd9\u6bb5\u5171\u4eab\u5185\u5b58\u7684\u4f7f\u7528\u662f\u6709\u7ade\u4e89\u6761\u4ef6\u5b58\u5728\u7684\uff0c\u4ece\u6587\u4ef6\u9501\u7684\u4f8b\u5b50\u6211\u4eec\u77e5\u9053\uff0c\u8fdb\u7a0b\u95f4\u901a\u4fe1\u7edd\u4e0d\u4ec5\u4ec5\u662f\u901a\u4fe1\u8fd9\u4e48\u7b80\u5355\uff0c\u8fd8\u9700\u8981\u5904\u7406\u7c7b\u4f3c\u8fd9\u6837\u7684\u4e34\u754c\u533a\u4ee3\u7801\u3002\u5728\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u4f7f\u7528\u6587\u4ef6\u9501\u8fdb\u884c\u5904\u7406\uff0c\u4f46\u662f\u5171\u4eab\u5185\u5b58\u4f7f\u7528\u6587\u4ef6\u9501\u672a\u514d\u663e\u5f97\u592a\u4e0d\u534f\u8c03\u4e86\u3002\u9664\u4e86\u4e0d\u65b9\u4fbf\u4ee5\u53ca\u6548\u7387\u4f4e\u4e0b\u4ee5\u5916\uff0c\u6587\u4ef6\u9501\u8fd8\u4e0d\u80fd\u591f\u8fdb\u884c\u66f4\u9ad8\u7ea7\u7684\u8fdb\u7a0b\u63a7\u5236\u3002\u6240\u4ee5\uff0c\u6211\u4eec\u5728\u6b64\u9700\u8981\u5f15\u5165\u66f4\u9ad8\u7ea7\u7684\u8fdb\u7a0b\u540c\u6b65\u63a7\u5236\u539f\u8bed\u6765\u5b9e\u73b0\u76f8\u5173\u529f\u80fd\uff0c\u8fd9\u5c31\u662f\u4fe1\u53f7\u91cf\uff08semaphore\uff09\u7684\u4f5c\u7528\u3002\u6211\u4eec\u4f1a\u5728\u540e\u7eed\u7ae0\u8282\u4e2d\u96c6\u4e2d\u8bb2\u89e3\u4fe1\u53f7\u91cf\u7684\u4f7f\u7528\uff0c\u5728\u6b64\u53ea\u9700\u4e86\u89e3\u4f7f\u7528mmap\u5171\u4eab\u5185\u5b58\u7684\u65b9\u6cd5\u3002<\/p>\n<p>\u6211\u4eec\u6709\u5fc5\u8981\u4e86\u89e3\u4e00\u4e0bmmap\u7684\u5185\u5b58\u5360\u7528\u60c5\u51b5\uff0c\u4ee5\u4fbf\u77e5\u9053\u4f7f\u7528\u5b83\u7684\u6210\u672c\u3002\u6211\u4eec\u7533\u8bf7\u4e00\u6bb5\u6bd4\u8f83\u5927\u7684\u5171\u4eab\u5185\u5b58\u8fdb\u884c\u4f7f\u7528\uff0c\u5e76\u5bdf\u770b\u5185\u5b58\u5360\u7528\u60c5\u51b5\u3002\u6d4b\u8bd5\u4ee3\u7801\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ cat mmap_mem<span class=\"token punctuation\">.<\/span>c \r\n#include <span class=\"token operator\">&lt;<\/span>unistd<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdlib<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdio<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>errno<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>fcntl<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>string<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>file<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>wait<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>mman<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\n#define COUNT <span class=\"token number\">100<\/span>\r\n#define MEMSIZE <span class=\"token number\">1024<\/span><span class=\"token operator\">*<\/span><span class=\"token number\">1024<\/span><span class=\"token operator\">*<\/span><span class=\"token number\">1023<\/span><span class=\"token operator\">*<\/span><span class=\"token number\">2<\/span>\r\n\r\nint <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span>\r\n<span class=\"token punctuation\">{<\/span>\r\n    pid_t pid<span class=\"token punctuation\">;<\/span>\r\n    int count<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">;<\/span>\r\n\r\n    shm_p <span class=\"token operator\">=<\/span> <span class=\"token function\">mmap<\/span><span class=\"token punctuation\">(<\/span>NULL<span class=\"token punctuation\">,<\/span> MEMSIZE<span class=\"token punctuation\">,<\/span> PROT_WRITE<span class=\"token operator\">|<\/span>PROT_READ<span class=\"token punctuation\">,<\/span> MAP_SHARED<span class=\"token operator\">|<\/span>MAP_ANONYMOUS<span class=\"token punctuation\">,<\/span> <span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>MAP_FAILED <span class=\"token operator\">==<\/span> shm_p<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"mmap()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token function\">bzero<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">,<\/span> MEMSIZE<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token function\">sleep<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">3000<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token function\">munmap<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">,<\/span> MEMSIZE<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token punctuation\">}<\/span>\r\n<\/pre>\n<p>\u6211\u4eec\u7533\u8bf7\u4e00\u6bb5\u5927\u69822G\u7684\u5171\u4eab\u5185\u5b58\uff0c\u5e76\u7f6e0\u3002\u7136\u540e\u5728\u6267\u884c\u524d\u540e\u5206\u522b\u770b\u5185\u5b58\u7528\u91cf\uff0c\u770b\u4ec0\u4e48\u90e8\u5206\u6709\u53d8\u5316\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ free <span class=\"token operator\">-<\/span>g\r\n              total        used        free      shared  buff<span class=\"token operator\">\/<\/span>cache   available\r\nMem<span class=\"token punctuation\">:<\/span>             <span class=\"token number\">15<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">10<\/span>          <span class=\"token number\">11<\/span>\r\nSwap<span class=\"token punctuation\">:<\/span>            <span class=\"token number\">31<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">31<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>mmap_mem <span class=\"token operator\">&amp;<\/span>\r\n<span class=\"token punctuation\">[<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token number\">32036<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ free <span class=\"token operator\">-<\/span>g\r\n              total        used        free      shared  buff<span class=\"token operator\">\/<\/span>cache   available\r\nMem<span class=\"token punctuation\">:<\/span>             <span class=\"token number\">15<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">0<\/span>           <span class=\"token number\">2<\/span>          <span class=\"token number\">12<\/span>           <span class=\"token number\">9<\/span>\r\nSwap<span class=\"token punctuation\">:<\/span>            <span class=\"token number\">31<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">31<\/span>\r\n<\/pre>\n<p>\u53ef\u4ee5\u770b\u5230\uff0c\u8fd9\u90e8\u5206\u5185\u5b58\u7684\u4f7f\u7528\u88ab\u8bb0\u5f55\u5230\u4e86shared\u548cbuff\/cache\u4e2d\u3002\u5f53\u7136\u8fd9\u4e2a\u7ed3\u679c\u5728\u4e0d\u540c\u7248\u672c\u7684Linux\u4e0a\u53ef\u80fd\u662f\u4e0d\u4e00\u6837\u7684\uff0c\u6bd4\u5982\u5728Centos 6\u7684\u73af\u5883\u4e2dmmap\u7684\u5171\u4eab\u5185\u5b58\u53ea\u4f1a\u8bb0\u5f55\u5230buff\/cache\u4e2d\u3002\u9664\u4e86\u5360\u7528\u7a7a\u95f4\u7684\u95ee\u9898\uff0c\u8fd8\u5e94\u8be5\u6ce8\u610f\uff0cmmap\u65b9\u5f0f\u7684\u5171\u4eab\u5185\u5b58\u53ea\u80fd\u5728\u901a\u8fc7fork\u4ea7\u751f\u7684\u7236\u5b50\u8fdb\u7a0b\u95f4\u901a\u4fe1\uff0c\u56e0\u4e3a\u9664\u6b64\u4e4b\u5916\u7684\u5176\u5b83\u8fdb\u7a0b\u65e0\u6cd5\u5f97\u5230\u5171\u4eab\u5185\u5b58\u6bb5\u7684\u5730\u5740\u3002<\/p>\n<h2>XSI\u5171\u4eab\u5185\u5b58<\/h2>\n<p>\u4e3a\u4e86\u6ee1\u8db3\u591a\u4e2a\u65e0\u5173\u8fdb\u7a0b\u5171\u4eab\u5185\u5b58\u7684\u9700\u6c42\uff0cLinux\u63d0\u4f9b\u4e86\u66f4\u5177\u901a\u7528\u6027\u7684\u5171\u4eab\u5185\u5b58\u624b\u6bb5\uff0cXSI\u5171\u4eab\u5185\u5b58\u5c31\u662f\u8fd9\u6837\u4e00\u79cd\u5b9e\u73b0\u3002XSI\u662fX\/Open\u7ec4\u7ec7\u5bf9UNIX\u5b9a\u4e49\u7684\u4e00\u5957\u63a5\u53e3\u6807\u51c6(X\/Open System Interface)\u3002\u7531\u4e8eUNIX\u7cfb\u7edf\u7684\u5386\u53f2\u60a0\u4e45\uff0c\u5728\u4e0d\u540c\u65f6\u95f4\u70b9\u7684\u4e0d\u540c\u5382\u5546\u548c\u6807\u51c6\u5316\u7ec4\u7ec7\u5b9a\u4e49\u8fc7\u4e00\u4e9b\u5217\u6807\u51c6\uff0c\u800c\u76ee\u524d\u6bd4\u8f83\u901a\u7528\u7684\u6807\u51c6\u5b9e\u9645\u4e0a\u662fPOSIX\u3002\u6211\u4eec\u8fd8\u4f1a\u7ecf\u5e38\u9047\u5230\u7684\u6807\u51c6\u8fd8\u5305\u62ecSUS\uff08Single UNIX Specification\uff09\u6807\u51c6\uff0c\u5b83\u4eec\u5927\u6982\u7684\u5173\u7cfb\u662f\uff0cSUS\u662fPOSIX\u6807\u51c6\u7684\u8d85\u96c6\uff0c\u5b9a\u4e49\u4e86\u90e8\u5206\u989d\u5916\u9644\u52a0\u7684\u63a5\u53e3\uff0c\u8fd9\u4e9b\u63a5\u53e3\u6269\u5c55\u4e86\u57fa\u672c\u7684POSIX\u89c4\u8303\u3002\u76f8\u5e94\u7684\u7cfb\u7edf\u63a5\u53e3\u5168\u96c6\u88ab\u79f0\u4e3aXSI\u6807\u51c6\uff0c\u9664\u6b64\u4e4b\u5916XSI\u8fd8\u5b9a\u4e49\u4e86\u5b9e\u73b0\u5fc5\u987b\u652f\u6301\u7684POSIX\u7684\u54ea\u4e9b\u53ef\u9009\u90e8\u5206\u624d\u80fd\u8ba4\u4e3a\u662f\u9075\u5faaXSI\u7684\u3002\u5b83\u4eec\u5305\u62ec\u6587\u4ef6\u540c\u6b65\uff0c\u5b58\u50a8\u6620\u5c04\u6587\u4ef6\uff0c\u5b58\u50a8\u4fdd\u62a4\u53ca\u7ebf\u7a0b\u63a5\u53e3\u3002\u53ea\u6709\u9075\u5faaXSI\u6807\u51c6\u7684\u5b9e\u73b0\u624d\u80fd\u79f0\u4e3aUNIX\u64cd\u4f5c\u7cfb\u7edf\u3002<\/p>\n<p>XSI\u5171\u4eab\u5185\u5b58\u5728Linux\u5e95\u5c42\u7684\u5b9e\u73b0\u5b9e\u9645\u4e0a\u8ddfmmap\u6ca1\u6709\u4ec0\u4e48\u672c\u8d28\u4e0d\u540c\uff0c\u53ea\u662f\u5728\u4f7f\u7528\u65b9\u6cd5\u4e0a\u6709\u6240\u533a\u522b\u3002\u5176\u4f7f\u7528\u7684\u76f8\u5173\u65b9\u6cd5\u4e3a\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\">#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>ipc<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>shm<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\nint <span class=\"token function\">shmget<\/span><span class=\"token punctuation\">(<\/span>key_t key<span class=\"token punctuation\">,<\/span> size_t size<span class=\"token punctuation\">,<\/span> int shmflg<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\nint <span class=\"token function\">shmctl<\/span><span class=\"token punctuation\">(<\/span>int shmid<span class=\"token punctuation\">,<\/span> int cmd<span class=\"token punctuation\">,<\/span> struct shmid_ds <span class=\"token operator\">*<\/span>buf<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>types<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>shm<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\n<span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token function\">shmat<\/span><span class=\"token punctuation\">(<\/span>int shmid<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>shmaddr<span class=\"token punctuation\">,<\/span> int shmflg<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\nint <span class=\"token function\">shmdt<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>shmaddr<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<\/pre>\n<p>\u6211\u4eec\u9996\u5148\u8981\u6765\u7406\u89e3\u7684\u662fkey\u8fd9\u4e00\u4e2a\u53c2\u6570\u3002\u60f3\u8c61\u4e00\u4e0b\u6211\u4eec\u73b0\u5728\u9700\u8981\u89e3\u51b3\u7684\u95ee\u9898\uff1a\u201c\u5728\u4e00\u4e2a\u64cd\u4f5c\u7cfb\u7edf\u5185\uff0c\u5982\u4f55\u8ba9\u4e24\u4e2a\u4e0d\u76f8\u5173\uff08\u6ca1\u6709\u7236\u5b50\u5173\u7cfb\uff09\u7684\u8fdb\u7a0b\u53ef\u4ee5\u5171\u4eab\u4e00\u4e2a\u5185\u5b58\u6bb5\uff1f\u201d\u7cfb\u7edf\u4e2d\u662f\u5426\u6709\u73b0\u6210\u7684\u89e3\u51b3\u65b9\u6848\u5462\uff1f\u5f53\u7136\u6709\uff0c\u5c31\u662f\u6587\u4ef6\u3002\u6211\u4eec\u77e5\u9053\uff0c\u6587\u4ef6\u7684\u8bbe\u8ba1\u5c31\u53ef\u4ee5\u8ba9\u65e0\u5173\u7684\u8fdb\u7a0b\u53ef\u4ee5\u8fdb\u884c\u6570\u636e\u4ea4\u6362\u3002\u6587\u4ef6\u91c7\u7528\u8def\u5f84\u548c\u6587\u4ef6\u540d\u4f5c\u4e3a\u7cfb\u7edf\u5168\u5c40\u7684\u4e00\u4e2a\u6807\u8bc6\u7b26\uff0c\u4f46\u662f\u6bcf\u4e2a\u8fdb\u7a0b\u6253\u5f00\u8fd9\u4e2a\u6587\u4ef6\u4e4b\u540e\uff0c\u5728\u8fdb\u7a0b\u5185\u90e8\u90fd\u6709\u4e00\u4e2a\u201c\u6587\u4ef6\u63cf\u8ff0\u7b26\u201d\u53bb\u6307\u5411\u6587\u4ef6\u3002\u6b64\u65f6\u8fdb\u7a0b\u901a\u8fc7fork\u6253\u5f00\u7684\u5b50\u8fdb\u7a0b\u53ef\u4ee5\u7ee7\u627f\u7236\u8fdb\u7a0b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u4f46\u662f\u65e0\u5173\u8fdb\u7a0b\u4f9d\u7136\u53ef\u4ee5\u901a\u8fc7\u7cfb\u7edf\u5168\u5c40\u7684\u6587\u4ef6\u540d\u7528open\u7cfb\u7edf\u8c03\u7528\u518d\u6b21\u6253\u5f00\u540c\u4e00\u4e2a\u6587\u4ef6\uff0c\u4ee5\u4fbf\u8fdb\u884c\u8fdb\u7a0b\u95f4\u901a\u4fe1\u3002<\/p>\n<p>\u5b9e\u9645\u4e0a\u5bf9\u4e8eXSI\u7684\u5171\u4eab\u5185\u5b58\uff0c\u5176key\u7684\u4f5c\u7528\u5c31\u7c7b\u4f3c\u6587\u4ef6\u7684\u6587\u4ef6\u540d\uff0cshmget\u8fd4\u56de\u7684int\u7c7b\u578b\u7684shmid\u5c31\u7c7b\u4f3c\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u6ce8\u610f\u53ea\u662f\u201c\u7c7b\u4f3c\u201d\uff0c\u800c\u5e76\u975e\u662f\u540c\u6837\u7684\u5b9e\u73b0\u3002\u8fd9\u610f\u5473\u7740\uff0c\u6211\u4eec\u5728\u8fdb\u7a0b\u4e2d\u4e0d\u80fd\u7528select\u3001poll\u3001epoll\u8fd9\u6837\u7684\u65b9\u6cd5\u53bb\u63a7\u5236\u4e00\u4e2aXSI\u5171\u4eab\u5185\u5b58\uff0c\u56e0\u4e3a\u5b83\u5e76\u4e0d\u662f\u201c\u6587\u4ef6\u63cf\u8ff0\u7b26\u201d\u3002\u5bf9\u4e8e\u4e00\u4e2aXSI\u7684\u5171\u4eab\u5185\u5b58\uff0c\u5176key\u662f\u7cfb\u7edf\u5168\u5c40\u552f\u4e00\u7684\uff0c\u8fd9\u5c31\u65b9\u4fbf\u5176\u4ed6\u8fdb\u7a0b\u4f7f\u7528\u540c\u6837\u7684key\uff0c\u6253\u5f00\u540c\u6837\u4e00\u6bb5\u5171\u4eab\u5185\u5b58\uff0c\u4ee5\u4fbf\u8fdb\u884c\u8fdb\u7a0b\u95f4\u901a\u4fe1\u3002\u800c\u4f7f\u7528fork\u4ea7\u751f\u7684\u5b50\u8fdb\u7a0b\uff0c\u5219\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7shmid\u8bbf\u95ee\u5230\u76f8\u5173\u5171\u4eab\u5185\u5b58\u6bb5\u3002\u8fd9\u5c31\u662fkey\u7684\u672c\u8d28\uff1a\u7cfb\u7edf\u4e2d\u5bf9XSI\u5171\u4eab\u5185\u5b58\u7684\u5168\u5c40\u552f\u4e00\u8868\u793a\u7b26\u3002<\/p>\n<p>\u660e\u767d\u4e86\u8fd9\u4e2a\u672c\u8d28\u4e4b\u540e\uff0c\u6211\u4eec\u518d\u6765\u770b\u770b\u8fd9\u4e2akey\u5e94\u8be5\u5982\u4f55\u4ea7\u751f\u3002\u76f8\u5173\u65b9\u6cd5\u4e3a\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\">#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>types<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>ipc<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\nkey_t <span class=\"token function\">ftok<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> char <span class=\"token operator\">*<\/span>pathname<span class=\"token punctuation\">,<\/span> int proj_id<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<\/pre>\n<p>\u4e00\u4e2akey\u662f\u901a\u8fc7ftok\u51fd\u6570\uff0c\u4f7f\u7528\u4e00\u4e2apathname\u548c\u4e00\u4e2aproj_jd\u4ea7\u751f\u7684\u3002\u5c31\u662f\u8bf4\uff0c\u5728\u4e00\u4e2a\u53ef\u80fd\u4f1a\u4f7f\u7528\u5171\u4eab\u5185\u5b58\u7684\u9879\u76ee\u7ec4\u4e2d\uff0c\u5927\u5bb6\u53ef\u4ee5\u7ea6\u5b9a\u4e00\u4e2a\u6587\u4ef6\u540d\u548c\u4e00\u4e2a\u9879\u76ee\u7684proj_id\uff0c\u6765\u5728\u540c\u4e00\u4e2a\u7cfb\u7edf\u4e2d\u786e\u5b9a\u4e00\u6bb5\u5171\u4eab\u5185\u5b58\u7684key\u3002ftok\u5e76\u4e0d\u4f1a\u53bb\u521b\u5efa\u6587\u4ef6\uff0c\u6240\u4ee5\u5fc5\u987b\u6307\u5b9a\u4e00\u4e2a\u5b58\u5728\u5e76\u4e14\u8fdb\u7a0b\u53ef\u4ee5\u8bbf\u95ee\u7684pathname\u8def\u5f84\u3002\u8fd9\u91cc\u8fd8\u8981\u6307\u51fa\u7684\u4e00\u70b9\u662f\uff0cftok\u5b9e\u9645\u4e0a\u5e76\u4e0d\u662f\u6839\u636e\u6587\u4ef6\u7684\u6587\u4ef6\u8def\u5f84\u548c\u6587\u4ef6\u540d\uff08pathname\uff09\u4ea7\u751fkey\u7684\uff0c\u5728\u5b9e\u73b0\u4e0a\uff0c\u5b83\u4f7f\u7528\u7684\u662f\u6307\u5b9a\u6587\u4ef6\u7684inode\u7f16\u53f7\u548c\u6587\u4ef6\u6240\u5728\u8bbe\u5907\u7684\u8bbe\u5907\u7f16\u53f7\u3002\u6240\u4ee5\uff0c\u4e0d\u8981\u4ee5\u4e3a\u4f60\u662f\u7528\u4e86\u4e0d\u540c\u7684\u6587\u4ef6\u540d\u5c31\u4e00\u5b9a\u4f1a\u5f97\u5230\u4e0d\u540c\u7684key\uff0c\u56e0\u4e3a\u4e0d\u540c\u7684\u6587\u4ef6\u540d\u662f\u53ef\u4ee5\u6307\u5411\u76f8\u540cinode\u7f16\u53f7\u7684\u6587\u4ef6\u7684\uff08\u786c\u8fde\u63a5\uff09\u3002\u4e5f\u4e0d\u8981\u8ba4\u4e3a\u4f60\u662f\u7528\u4e86\u76f8\u540c\u7684\u6587\u4ef6\u540d\u5c31\u4e00\u5b9a\u53ef\u4ee5\u5f97\u5230\u76f8\u540c\u7684key\uff0c\u5728\u4e00\u4e2a\u7cfb\u7edf\u4e0a\uff0c\u540c\u4e00\u4e2a\u6587\u4ef6\u540d\u4f1a\u88ab\u5220\u9664\u91cd\u5efa\u7684\u51e0\u7387\u662f\u5f88\u5927\u7684\uff0c\u8fd9\u79cd\u884c\u4e3a\u5f88\u6709\u53ef\u80fd\u5bfc\u81f4\u6587\u4ef6\u7684inode\u53d8\u5316\u3002\u6240\u4ee5\u4e00\u4e2aftok\u7684\u6267\u884c\u4f1a\u9690\u542bstat\u7cfb\u7edf\u8c03\u7528\u4e5f\u5c31\u4e0d\u96be\u7406\u89e3\u4e86\u3002<\/p>\n<p>\u6700\u540e\u5927\u5bb6\u8fd8\u5e94\u8be5\u660e\u767d\uff0ckey\u4f5c\u4e3a\u5168\u5c40\u552f\u4e00\u6807\u8bc6\u4e0d\u4ec5\u4ec5\u4f53\u73b0\u5728XSI\u7684\u5171\u4eab\u5185\u5b58\u4e2d\uff0cXSI\u6807\u51c6\u7684\u5176\u4ed6\u8fdb\u7a0b\u95f4\u901a\u4fe1\u673a\u5236\uff08\u4fe1\u53f7\u91cf\u6570\u7ec4\u548c\u6d88\u606f\u961f\u5217\uff09\u4e5f\u4f7f\u7528\u8fd9\u4e00\u547d\u540d\u65b9\u5f0f\u3002\u8fd9\u90e8\u5206\u5185\u5bb9\u5728\u300aUNIX\u73af\u5883\u9ad8\u7ea7\u7f16\u7a0b\u300b\u4e00\u4e66\u4e2d\u5df2\u7ecf\u6709\u4e86\u5f88\u8be6\u5c3d\u7684\u8bb2\u89e3\uff0c\u672c\u6587\u4e0d\u5728\u8d58\u8ff0\u3002\u6211\u4eec\u8fd8\u662f\u53ea\u6765\u770b\u4e00\u4e0b\u5b83\u4f7f\u7528\u7684\u4f8b\u5b50\uff0c\u6211\u4eec\u7528XSI\u7684\u5171\u4eab\u5185\u5b58\u6765\u66ff\u6362\u521a\u624d\u7684mmap\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ cat racing_xsi_shm<span class=\"token punctuation\">.<\/span>c \r\n#include <span class=\"token operator\">&lt;<\/span>unistd<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdlib<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdio<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>errno<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>fcntl<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>string<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>file<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>wait<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>mman<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>ipc<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>shm<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>types<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\n#define COUNT <span class=\"token number\">100<\/span>\r\n#define PATHNAME <span class=\"token string\">\"\/etc\/passwd\"<\/span>\r\n\r\nint <span class=\"token function\">do_child<\/span><span class=\"token punctuation\">(<\/span>int proj_id<span class=\"token punctuation\">)<\/span>\r\n<span class=\"token punctuation\">{<\/span>\r\n    int interval<span class=\"token punctuation\">;<\/span>\r\n    int <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">,<\/span> shm_id<span class=\"token punctuation\">;<\/span>\r\n    key_t shm_key<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token comment\">\/* \u4f7f\u7528ftok\u4ea7\u751fshmkey *\/<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span>shm_key <span class=\"token operator\">=<\/span> <span class=\"token function\">ftok<\/span><span class=\"token punctuation\">(<\/span>PATHNAME<span class=\"token punctuation\">,<\/span> proj_id<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">==<\/span> <span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"ftok()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n    <span class=\"token comment\">\/* \u5728\u5b50\u8fdb\u7a0b\u4e2d\u4f7f\u7528shmget\u53d6\u5230\u5df2\u7ecf\u5728\u7236\u8fdb\u7a0b\u4e2d\u521b\u5efa\u597d\u7684\u5171\u4eab\u5185\u5b58id\uff0c\u6ce8\u610fshmget\u7684\u7b2c\u4e09\u4e2a\u53c2\u6570\u7684\u4f7f\u7528\u3002 *\/<\/span>\r\n    shm_id <span class=\"token operator\">=<\/span> <span class=\"token function\">shmget<\/span><span class=\"token punctuation\">(<\/span>shm_key<span class=\"token punctuation\">,<\/span> <span class=\"token function\">sizeof<\/span><span class=\"token punctuation\">(<\/span>int<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>shm_id <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmget()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u4f7f\u7528shmat\u5c06\u76f8\u5173\u5171\u4eab\u5185\u5b58\u6bb5\u6620\u5c04\u5230\u672c\u8fdb\u7a0b\u7684\u5185\u5b58\u5730\u5740\u3002 *\/<\/span>\r\n\r\n    shm_p <span class=\"token operator\">=<\/span> <span class=\"token punctuation\">(<\/span>int <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token function\">shmat<\/span><span class=\"token punctuation\">(<\/span>shm_id<span class=\"token punctuation\">,<\/span> NULL<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span>shm_p <span class=\"token operator\">==<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmat()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* critical section *\/<\/span>\r\n    interval <span class=\"token operator\">=<\/span> <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">;<\/span>\r\n    interval<span class=\"token operator\">++<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token function\">usleep<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token operator\">*<\/span>shm_p <span class=\"token operator\">=<\/span> interval<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token comment\">\/* critical section *\/<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u4f7f\u7528shmdt\u89e3\u9664\u672c\u8fdb\u7a0b\u5185\u5bf9\u5171\u4eab\u5185\u5b58\u7684\u5730\u5740\u6620\u5c04\uff0c\u672c\u64cd\u4f5c\u4e0d\u4f1a\u5220\u9664\u5171\u4eab\u5185\u5b58\u3002 *\/<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">shmdt<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmdt()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token punctuation\">}<\/span>\r\n\r\nint <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span>\r\n<span class=\"token punctuation\">{<\/span>\r\n    pid_t pid<span class=\"token punctuation\">;<\/span>\r\n    int count<span class=\"token punctuation\">;<\/span>\r\n    int <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">;<\/span>\r\n    int shm_id<span class=\"token punctuation\">,<\/span> proj_id<span class=\"token punctuation\">;<\/span>\r\n    key_t shm_key<span class=\"token punctuation\">;<\/span>\r\n\r\n    proj_id <span class=\"token operator\">=<\/span> <span class=\"token number\">1234<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u4f7f\u7528\u7ea6\u5b9a\u597d\u7684\u6587\u4ef6\u8def\u5f84\u548cproj_id\u4ea7\u751fshm_key\u3002 *\/<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span>shm_key <span class=\"token operator\">=<\/span> <span class=\"token function\">ftok<\/span><span class=\"token punctuation\">(<\/span>PATHNAME<span class=\"token punctuation\">,<\/span> proj_id<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">==<\/span> <span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"ftok()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u4f7f\u7528shm_key\u521b\u5efa\u4e00\u4e2a\u5171\u4eab\u5185\u5b58\uff0c\u5982\u679c\u7cfb\u7edf\u4e2d\u5df2\u7ecf\u5b58\u5728\u6b64\u5171\u4eab\u5185\u5b58\u5219\u62a5\u9519\u9000\u51fa\uff0c\u521b\u5efa\u51fa\u6765\u7684\u5171\u4eab\u5185\u5b58\u6743\u9650\u4e3a0600\u3002 *\/<\/span>\r\n    shm_id <span class=\"token operator\">=<\/span> <span class=\"token function\">shmget<\/span><span class=\"token punctuation\">(<\/span>shm_key<span class=\"token punctuation\">,<\/span> <span class=\"token function\">sizeof<\/span><span class=\"token punctuation\">(<\/span>int<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> IPC_CREAT<span class=\"token operator\">|<\/span>IPC_EXCL<span class=\"token operator\">|<\/span><span class=\"token number\">0600<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>shm_id <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmget()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u5c06\u521b\u5efa\u597d\u7684\u5171\u4eab\u5185\u5b58\u6620\u5c04\u8fdb\u7236\u8fdb\u7a0b\u7684\u5730\u5740\u4ee5\u4fbf\u8bbf\u95ee\u3002 *\/<\/span>\r\n    shm_p <span class=\"token operator\">=<\/span> <span class=\"token punctuation\">(<\/span>int <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token function\">shmat<\/span><span class=\"token punctuation\">(<\/span>shm_id<span class=\"token punctuation\">,<\/span> NULL<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span>shm_p <span class=\"token operator\">==<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmat()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u5171\u4eab\u5185\u5b58\u8d4b\u503c\u4e3a0\u3002 *\/<\/span>\r\n    <span class=\"token operator\">*<\/span>shm_p <span class=\"token operator\">=<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token comment\">\/*  \u6253\u5f00100\u4e2a\u5b50\u8fdb\u7a0b\u5e76\u53d1\u8bfb\u5199\u5171\u4eab\u5185\u5b58\u3002 *\/<\/span>\r\n    <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/span>count<span class=\"token operator\">=<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">&lt;<\/span>COUNT<span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">++<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        pid <span class=\"token operator\">=<\/span> <span class=\"token function\">fork<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n            <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"fork()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n            <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token punctuation\">}<\/span>\r\n\r\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">==<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n            <span class=\"token function\">do_child<\/span><span class=\"token punctuation\">(<\/span>proj_id<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token punctuation\">}<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u7b49\u5f85\u6240\u6709\u5b50\u8fdb\u7a0b\u6267\u884c\u5b8c\u6bd5\u3002 *\/<\/span>\r\n    <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/span>count<span class=\"token operator\">=<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">&lt;<\/span>COUNT<span class=\"token punctuation\">;<\/span>count<span class=\"token operator\">++<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">wait<\/span><span class=\"token punctuation\">(<\/span>NULL<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u663e\u793a\u5f53\u524d\u5171\u4eab\u5185\u5b58\u7684\u503c\u3002 *\/<\/span>\r\n    <span class=\"token function\">printf<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shm_p: %d\\n\"<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n\r\n    <span class=\"token comment\">\/* \u89e3\u9664\u5171\u4eab\u5185\u5b58\u5730\u8d28\u6620\u5c04\u3002 *\/<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">shmdt<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmdt()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token comment\">\/* \u5220\u9664\u5171\u4eab\u5185\u5b58\u3002 *\/<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">shmctl<\/span><span class=\"token punctuation\">(<\/span>shm_id<span class=\"token punctuation\">,<\/span> IPC_RMID<span class=\"token punctuation\">,<\/span> NULL<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmctl()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token punctuation\">}<\/span>\r\n<\/pre>\n<p>XSI\u5171\u4eab\u5185\u5b58\u8ddfmmap\u5728\u5b9e\u73b0\u4e0a\u5e76\u6ca1\u6709\u672c\u8d28\u533a\u522b\u3002\u800c\u4e4b\u6240\u4ee5\u5f15\u5165key\u548cshmid\u7684\u6982\u5ff5\uff0c\u4e5f\u4e3b\u8981\u662f\u4e3a\u4e86\u5728\u975e\u7236\u5b50\u5173\u7cfb\u7684\u8fdb\u7a0b\u4e4b\u95f4\u53ef\u4ee5\u5171\u4eab\u5185\u5b58\u3002\u6839\u636e\u4e0a\u9762\u7684\u4f8b\u5b50\u53ef\u4ee5\u770b\u5230\uff0c\u4f7f\u7528shmget\u53ef\u4ee5\u6839\u636ekey\u521b\u5efa\u5171\u4eab\u5185\u5b58\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2ashmid\u3002\u5b83\u7684\u7b2c\u4e8c\u4e2a\u53c2\u6570size\u7528\u6765\u6307\u5b9a\u5171\u4eab\u5185\u5b58\u6bb5\u7684\u957f\u5ea6\uff0c\u7b2c\u4e09\u4e2a\u53c2\u6570\u6307\u5b9a\u521b\u5efa\u7684\u6807\u5fd7\uff0c\u53ef\u4ee5\u652f\u6301\u7684\u6807\u5fd7\u4e3a\uff1aIPC_CREAT\u3001IPC_EXCL\u3002\u4eceLinux 2.6\u4e4b\u540e\uff0c\u8fd8\u5f15\u5165\u4e86\u652f\u6301\u5927\u9875\u7684\u5171\u4eab\u5185\u5b58\uff0c\u6807\u5fd7\u4e3a\uff1aSHM_HUGETLB\u3001SHM_HUGE_2MB\u7b49\u53c2\u6570\u3002shmget\u9664\u4e86\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5171\u4eab\u5185\u5b58\u4ee5\u5916\uff0c\u8fd8\u53ef\u4ee5\u8bbf\u95ee\u4e00\u4e2a\u5df2\u7ecf\u5b58\u5728\u7684\u5171\u4eab\u5185\u5b58\uff0c\u6b64\u65f6\u53ef\u4ee5\u5c06shmflg\u7f6e\u4e3a0\uff0c\u4e0d\u52a0\u4efb\u4f55\u6807\u8bc6\u6253\u5f00\u3002<\/p>\n<p>\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u4e0d\u7528\u901a\u8fc7\u4e00\u4e2akey\u6765\u751f\u6210\u5171\u4eab\u5185\u5b58\u3002\u6b64\u65f6\u53ef\u4ee5\u5728key\u7684\u53c2\u6570\u6240\u5728\u4f4d\u7f6e\u586b\uff1aIPC_PRIVATE\uff0c\u8fd9\u6837\u5185\u6838\u4f1a\u5728\u4fdd\u8bc1\u4e0d\u4ea7\u751f\u51b2\u7a81\u7684\u5171\u4eab\u5185\u5b58\u6bb5id\u7684\u60c5\u51b5\u4e0b\u65b0\u5efa\u4e00\u6bb5\u5171\u4eab\u5185\u5b58\u3002\u5f53\u7136\uff0c\u8fd9\u6837\u8c03\u7528\u5219\u5fc5\u7136\u610f\u5473\u7740\u662f\u65b0\u521b\u5efa\uff0c\u800c\u4e0d\u662f\u6253\u5f00\u5df2\u6709\u5f97\u5171\u4eab\u5185\u5b58\uff0c\u6240\u4ee5flag\u4f4d\u4e00\u5b9a\u662fIPC_CREAT\u3002\u6b64\u65f6\u4ea7\u751f\u7684\u5171\u4eab\u5185\u5b58\u53ea\u6709\u4e00\u4e2ashmid\uff0c\u800c\u6ca1\u6709key\uff0c\u6240\u4ee5\u53ef\u4ee5\u901a\u8fc7fork\u7684\u65b9\u5f0f\u5c06id\u4f20\u7ed9\u5b50\u8fdb\u7a0b\u3002<\/p>\n<p>\u5f53\u83b7\u5f97shmid\u4e4b\u540e\uff0c\u5c31\u53ef\u4ee5\u4f7f\u7528shmat\u6765\u8fdb\u884c\u5730\u5740\u6620\u5c04\u3002shmat\u4e4b\u540e\uff0c\u901a\u8fc7\u8bbf\u95ee\u8fd4\u56de\u7684\u5f53\u524d\u8fdb\u7a0b\u7684\u865a\u62df\u5730\u5740\u5c31\u53ef\u4ee5\u8bbf\u95ee\u5230\u5171\u4eab\u5185\u5b58\u6bb5\u4e86\u3002\u5f53\u7136\uff0c\u5728\u4f7f\u7528\u4e4b\u540e\u8981\u8bb0\u5f97\u4f7f\u7528shmdt\u89e3\u9664\u6620\u5c04\uff0c\u5426\u5219\u5bf9\u4e8e\u957f\u671f\u8fd0\u884c\u7684\u7a0b\u5e8f\u53ef\u80fd\u9020\u6210\u865a\u62df\u5185\u5b58\u5730\u5740\u6cc4\u6f0f\uff0c\u5bfc\u81f4\u6ca1\u6709\u53ef\u7528\u5730\u5740\u53ef\u7528\u3002shmdt\u5e76\u4e0d\u80fd\u5220\u9664\u5171\u4eab\u5185\u5b58\u6bb5\uff0c\u800c\u53ea\u662f\u89e3\u9664\u5171\u4eab\u5185\u5b58\u548c\u8fdb\u7a0b\u865a\u62df\u5730\u5740\u7684\u6620\u5c04\uff0c\u53ea\u8981shmid\u5bf9\u5e94\u7684\u5171\u4eab\u5185\u5b58\u8fd8\u5b58\u5728\uff0c\u5c31\u4ecd\u7136\u53ef\u4ee5\u7ee7\u7eed\u4f7f\u7528shmat\u6620\u5c04\u4f7f\u7528\u3002\u60f3\u8981\u5220\u9664\u4e00\u4e2a\u5171\u4eab\u5185\u5b58\u9700\u8981\u4f7f\u7528shmctl\u7684IPC_RMID\u6307\u4ee4\u5904\u7406\u3002\u4e5f\u53ef\u4ee5\u5728\u547d\u4ee4\u884c\u4e2d\u4f7f\u7528ipcrm\u5220\u9664\u6307\u5b9a\u7684\u5171\u4eab\u5185\u5b58id\u6216key\u3002<\/p>\n<blockquote><p>\u5171\u4eab\u5185\u5b58\u7531\u4e8e\u5176\u7279\u6027\uff0c\u4e0e\u8fdb\u7a0b\u4e2d\u7684\u5176\u4ed6\u5185\u5b58\u6bb5\u5728\u4f7f\u7528\u4e60\u60ef\u4e0a\u6709\u4e9b\u4e0d\u540c\u3002\u4e00\u822c\u8fdb\u7a0b\u5bf9\u6808\u7a7a\u95f4\u5206\u914d\u53ef\u4ee5\u81ea\u52a8\u56de\u6536\uff0c\u800c\u5806\u7a7a\u95f4\u901a\u8fc7malloc\u7533\u8bf7\uff0cfree\u56de\u6536\u3002\u8fd9\u4e9b\u5185\u5b58\u5728\u56de\u6536\u4e4b\u540e\u5c31\u53ef\u4ee5\u8ba4\u4e3a\u662f\u4e0d\u5b58\u5728\u4e86\u3002\u4f46\u662f\u5171\u4eab\u5185\u5b58\u4e0d\u540c\uff0c\u7528shmdt\u4e4b\u540e\uff0c\u5b9e\u9645\u4e0a\u5176\u5360\u7528\u7684\u5185\u5b58\u8fd8\u5728\uff0c\u5e76\u4ecd\u7136\u53ef\u4ee5\u4f7f\u7528shmat\u6620\u5c04\u4f7f\u7528\u3002\u5982\u679c\u4e0d\u662f\u7528shmctl\u6216ipcrm\u547d\u4ee4\u5220\u9664\u7684\u8bdd\uff0c\u90a3\u4e48\u5b83\u5c06\u4e00\u76f4\u4fdd\u7559\u76f4\u5230\u7cfb\u7edf\u88ab\u5173\u95ed\u3002\u5bf9\u4e8e\u521a\u63a5\u89e6\u5171\u4eab\u5185\u5b58\u7684\u7a0b\u5e8f\u5458\u6765\u8bf4\u8fd9\u53ef\u80fd\u9700\u8981\u9002\u5e94\u4e00\u4e0b\u3002\u5b9e\u9645\u4e0a\u5171\u4eab\u5185\u5b58\u7684\u751f\u5b58\u5468\u671f\u6839\u6587\u4ef6\u66f4\u50cf\uff1a\u8fdb\u7a0b\u5bf9\u6587\u4ef6\u63cf\u8ff0\u7b26\u6267\u884cclose\u5e76\u4e0d\u80fd\u5220\u9664\u6587\u4ef6\uff0c\u800c\u53ea\u662f\u5173\u95ed\u4e86\u672c\u8fdb\u7a0b\u5bf9\u6587\u4ef6\u7684\u64cd\u4f5c\u63a5\u53e3\uff0c\u8fd9\u5c31\u50cfshmdt\u7684\u4f5c\u7528\u3002\u800c\u771f\u6b63\u5220\u9664\u6587\u4ef6\u8981\u7528unlink\uff0c\u6d3b\u7740\u4f7f\u7528rm\u547d\u4ee4\uff0c\u8fd9\u5c31\u50cf\u662f\u5171\u4eab\u5185\u5b58\u7684shmctl\u7684IPC_RMID\u548cipcrm\u547d\u4ee4\u3002\u5f53\u7136\uff0c\u6587\u4ef6\u5982\u679c\u4e0d\u5220\u9664\uff0c\u4e0b\u6b21\u91cd\u542f\u4f9d\u65e7\u8fd8\u5728\uff0c\u56e0\u4e3a\u5b83\u653e\u5728\u786c\u76d8\u4e0a\uff0c\u800c\u5171\u4eab\u5185\u5b58\u4e0b\u6b21\u91cd\u542f\u5c31\u6ca1\u4e86\uff0c\u56e0\u4e3a\u5b83\u6bd5\u7adf\u8fd8\u662f\u5185\u5b58\u3002<\/p><\/blockquote>\n<p>\u5728\u8fd9\u91cc\uff0c\u8bf7\u5927\u5bb6\u7406\u89e3\u5173\u4e8e\u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528key\uff0c\u548c\u76f8\u5173\u5171\u4eab\u5185\u5b58id\u7684\u6982\u5ff5\u3002\u540e\u7eed\u6211\u4eec\u8fd8\u5c06\u770b\u5230\uff0c\u9664\u4e86\u5171\u4eab\u5185\u5b58\u5916\uff0cXSI\u7684\u4fe1\u53f7\u91cf\u3001\u6d88\u606f\u961f\u5217\u4e5f\u90fd\u662f\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\u8fdb\u884c\u76f8\u5173\u8d44\u6e90\u6807\u8bc6\u7684\u3002<\/p>\n<p>\u9664\u4e86\u53ef\u4ee5\u5220\u9664\u4e00\u4e2a\u5171\u4eab\u5185\u5b58\u4ee5\u5916\uff0cshmctl\u8fd8\u53ef\u4ee5\u67e5\u770b\u3001\u4fee\u6539\u5171\u4eab\u5185\u5b58\u7684\u76f8\u5173\u5c5e\u6027\u3002\u8fd9\u4e9b\u5c5e\u6027\u7684\u7ec6\u8282\u5927\u5bb6\u53ef\u4ee5man 2 shmctl\u67e5\u770b\u7ec6\u8282\u5e2e\u52a9\u3002\u5728\u7cfb\u7edf\u4e2d\u8fd8\u53ef\u4ee5\u4f7f\u7528ipcs -m\u547d\u4ee4\u67e5\u770b\u7cfb\u7edf\u4e2d\u6240\u6709\u5171\u4eab\u5185\u5b58\u7684\u7684\u4fe1\u606f\uff0c\u4ee5\u53caipcrm\u6307\u5b9a\u5220\u9664\u5171\u4eab\u5185\u5b58\u3002<\/p>\n<p>\u8fd9\u4e2a\u4f8b\u5b50\u6700\u540e\u6267\u884c\u5982\u4e0b\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_xsi_shm \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">27<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_xsi_shm \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">22<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_xsi_shm \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">21<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>racing_xsi_shm \r\nshm_p<span class=\"token punctuation\">:<\/span> <span class=\"token number\">20<\/span>\r\n<\/pre>\n<p>\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u6211\u4eec\u4ecd\u7136\u6ca1\u89e3\u51b3racing\u7684\u95ee\u9898\uff0c\u6240\u4ee5\u5f97\u5230\u7684\u7ed3\u679c\u4ecd\u7136\u662f\u4e0d\u786e\u5b9a\u7684\uff0c\u6211\u4eec\u4f1a\u5728\u8bb2\u89e3\u4fe1\u53f7\u91cf\u7684\u65f6\u5019\u5f15\u5165\u9501\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u5f53\u7136\u4e5f\u53ef\u4ee5\u7528\u6587\u4ef6\u9501\u3002\u6211\u4eec\u4e0b\u9762\u518d\u4fee\u6539\u521a\u624d\u7684mmap_mem.c\u7a0b\u5e8f\uff0c\u6362\u505ashm\u65b9\u5f0f\u518d\u6765\u770b\u770b\u5185\u5b58\u7684\u4f7f\u7528\u60c5\u51b5\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ cat xsi_shm_mem<span class=\"token punctuation\">.<\/span>c \r\n#include <span class=\"token operator\">&lt;<\/span>unistd<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdlib<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>stdio<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>errno<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>fcntl<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>string<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>file<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>wait<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>mman<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>ipc<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>shm<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n#include <span class=\"token operator\">&lt;<\/span>sys<span class=\"token operator\">\/<\/span>types<span class=\"token punctuation\">.<\/span>h<span class=\"token operator\">&gt;<\/span>\r\n\r\n#define COUNT <span class=\"token number\">100<\/span>\r\n#define MEMSIZE <span class=\"token number\">1024<\/span><span class=\"token operator\">*<\/span><span class=\"token number\">1024<\/span><span class=\"token operator\">*<\/span><span class=\"token number\">1023<\/span><span class=\"token operator\">*<\/span><span class=\"token number\">2<\/span>\r\n\r\nint <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span>\r\n<span class=\"token punctuation\">{<\/span>\r\n    pid_t pid<span class=\"token punctuation\">;<\/span>\r\n    int count<span class=\"token punctuation\">,<\/span> shm_id<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>shm_p<span class=\"token punctuation\">;<\/span>\r\n\r\n    shm_id <span class=\"token operator\">=<\/span> <span class=\"token function\">shmget<\/span><span class=\"token punctuation\">(<\/span>IPC_PRIVATE<span class=\"token punctuation\">,<\/span> MEMSIZE<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0600<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>shm_id <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmget()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n\r\n    shm_p <span class=\"token operator\">=<\/span> <span class=\"token function\">shmat<\/span><span class=\"token punctuation\">(<\/span>shm_id<span class=\"token punctuation\">,<\/span> NULL<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span>shm_p <span class=\"token operator\">==<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span><span class=\"token operator\">-<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmat()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token function\">bzero<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">,<\/span> MEMSIZE<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token function\">sleep<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">3000<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">shmdt<\/span><span class=\"token punctuation\">(<\/span>shm_p<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmdt()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">shmctl<\/span><span class=\"token punctuation\">(<\/span>shm_id<span class=\"token punctuation\">,<\/span> IPC_RMID<span class=\"token punctuation\">,<\/span> NULL<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>\r\n        <span class=\"token function\">perror<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">\"shmctl()\"<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n        <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token punctuation\">}<\/span>\r\n\r\n    <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token punctuation\">}<\/span>\r\n<\/pre>\n<p>\u6211\u4eec\u5728\u8fd9\u6bb5\u4ee3\u7801\u4e2d\u4f7f\u7528\u4e86IPC_PRIVATE\u65b9\u5f0f\u5171\u4eab\u5185\u5b58\uff0c\u8fd9\u662f\u4e0e\u524d\u9762\u7a0b\u5e8f\u4e0d\u4e00\u6837\u7684\u5730\u65b9\u3002\u6267\u884c\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ free <span class=\"token operator\">-<\/span>g\r\n              total        used        free      shared  buff<span class=\"token operator\">\/<\/span>cache   available\r\nMem<span class=\"token punctuation\">:<\/span>             <span class=\"token number\">15<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">10<\/span>          <span class=\"token number\">11<\/span>\r\nSwap<span class=\"token punctuation\">:<\/span>            <span class=\"token number\">31<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">31<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>xsi_shm_mem <span class=\"token operator\">&amp;<\/span>\r\n<span class=\"token punctuation\">[<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token number\">4539<\/span>\r\n<span class=\"token punctuation\">[<\/span>zorro@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span>$ free <span class=\"token operator\">-<\/span>g\r\n              total        used        free      shared  buff<span class=\"token operator\">\/<\/span>cache   available\r\nMem<span class=\"token punctuation\">:<\/span>             <span class=\"token number\">15<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">0<\/span>           <span class=\"token number\">2<\/span>          <span class=\"token number\">12<\/span>           <span class=\"token number\">9<\/span>\r\nSwap<span class=\"token punctuation\">:<\/span>            <span class=\"token number\">31<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">31<\/span>\r\n<\/pre>\n<p>\u8ddfmmap\u7684\u5171\u4eab\u5185\u5b58\u4e00\u6837\uff0cXSI\u7684\u5171\u4eab\u5185\u5b58\u5728free\u73b0\u5b9e\u4e2d\u4e5f\u4f1a\u5360\u7528shared\u548cbuff\/cache\u7684\u6d88\u8017\u3002\u5b9e\u9645\u4e0a\uff0c\u5728\u5185\u6838\u5e95\u5c42\u5b9e\u73b0\u4e0a\uff0c\u4e24\u79cd\u5185\u5b58\u5171\u4eab\u90fd\u662f\u4f7f\u7528\u7684tmpfs\u65b9\u5f0f\u5b9e\u73b0\u7684\uff0c\u6240\u4ee5\u5b83\u4eec\u5b9e\u9645\u4e0a\u7684\u5185\u5b58\u4f7f\u7528\u90fd\u662f\u4e00\u81f4\u7684\u3002<\/p>\n<p>\u5bf9\u4e8eLinux\u7cfb\u7edf\u6765\u8bf4\uff0c\u4f7f\u7528XSI\u5171\u4eab\u5185\u5b58\u7684\u65f6\u5019\u53ef\u4ee5\u901a\u8fc7shmget\u7cfb\u7edf\u8c03\u7528\u7684shmflg\u53c2\u6570\u6765\u7533\u8bf7\u5927\u9875\u5185\u5b58\uff08huge pages\uff09\uff0c\u5f53\u7136\u8fd9\u6837\u505a\u5c06\u4f7f\u8fdb\u7a0b\u7684\u5e73\u53f0\u79fb\u690d\u6027\u53d8\u5dee\u3002\u76f8\u5173\u7684\u53c2\u6570\u5305\u62ec\uff1a<\/p>\n<p>SHM_HUGETLB (since Linux 2.6)<\/p>\n<p>SHM_HUGE_2MB, SHM_HUGE_1GB (since Linux 3.8)<\/p>\n<p>\u4f7f\u7528\u5927\u9875\u5185\u5b58\u7684\u597d\u5904\u662f\u63d0\u9ad8\u5185\u6838\u5bf9\u5185\u5b58\u7ba1\u7406\u7684\u5904\u7406\u6548\u7387\uff0c\u8fd9\u4e3b\u8981\u662f\u56e0\u4e3a\u5728\u76f8\u540c\u5185\u5b58\u5927\u5c0f\u7684\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528\u5927\u9875\u5185\u5b58\uff082M\u4e00\u9875\uff09\u5c06\u6bd4\u4f7f\u7528\u4e00\u822c\u5185\u5b58\u9875\uff084k\u4e00\u9875\uff09\u7684\u5185\u5b58\u9875\u7ba1\u7406\u7684\u6570\u91cf\u5927\u5927\u51cf\u5c11\uff0c\u4ece\u800c\u51cf\u5c11\u4e86\u5185\u5b58\u9875\u8868\u9879\u7684\u7f13\u5b58\u538b\u529b\u548cCPU cache\u7f13\u5b58\u5185\u5b58\u5730\u8d28\u6620\u5c04\u7684\u538b\u529b\uff0c\u63d0\u9ad8\u4e86\u5bfb\u5740\u80fd\u529b\u548c\u5185\u5b58\u7ba1\u7406\u6548\u7387\u3002\u5927\u9875\u5185\u5b58\u8fd8\u6709\u5176\u4ed6\u4e00\u4e9b\u4f7f\u7528\u65f6\u9700\u8981\u6ce8\u610f\u7684\u5730\u65b9\uff1a<\/p>\n<ol class=\"ol-level-0\">\n<li>\u5927\u9875\u5185\u5b58\u4e0d\u80fd\u4ea4\u6362\uff08SWAP\uff09.<\/li>\n<li>\u4f7f\u7528\u4e0d\u5f53\u65f6\u53ef\u80fd\u9020\u6210\u66f4\u5927\u7684\u5185\u5b58\u6cc4\u6f0f\u3002<\/li>\n<\/ol>\n<p>\u6211\u4eec\u7ee7\u7eed\u4f7f\u7528\u4e0a\u9762\u7684\u7a0b\u5e8f\u4fee\u6539\u6539\u4e3a\u4f7f\u7528\u5927\u9875\u5185\u5b58\u6765\u505a\u4e00\u4e0b\u6d4b\u8bd5\uff0c\u5927\u9875\u5185\u5b58\u9700\u8981\u4f7f\u7528root\u6743\u9650\uff0c\u4ee3\u7801\u8ddf\u4e0a\u9762\u7a0b\u5e8f\u4e00\u6837\uff0c\u53ea\u9700\u8981\u4fee\u6539\u4e00\u4e0bshmget\u7684\u53c2\u6570\uff0c\u5982\u4e0b\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># cat xsi_shm_mem_huge<span class=\"token punctuation\">.<\/span>c \r\n<span class=\"token operator\">...<\/span><span class=\"token operator\">...<\/span>\r\n    shm_id <span class=\"token operator\">=<\/span> <span class=\"token function\">shmget<\/span><span class=\"token punctuation\">(<\/span>IPC_PRIVATE<span class=\"token punctuation\">,<\/span> MEMSIZE<span class=\"token punctuation\">,<\/span> SHM_HUGETLB<span class=\"token operator\">|<\/span><span class=\"token number\">0600<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token operator\">...<\/span><span class=\"token operator\">...<\/span>\r\n<\/pre>\n<p>\u5176\u4f59\u4ee3\u7801\u90fd\u4e0d\u53d8\u3002\u6211\u4eec\u7533\u8bf7\u7684\u5185\u5b58\u5927\u7ea6\u4e0d\u52302G\uff0c\u6240\u4ee5\u9700\u8981\u5728\u7cfb\u7edf\u5185\u5148\u7ed9\u6211\u4eec\u9884\u75592G\u4ee5\u4e0a\u7684\u5927\u9875\u5185\u5b58\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># echo <span class=\"token number\">2048<\/span> <span class=\"token operator\">&gt;<\/span> <span class=\"token operator\">\/<\/span>proc<span class=\"token operator\">\/<\/span>sys<span class=\"token operator\">\/<\/span>vm<span class=\"token operator\">\/<\/span>nr_hugepages\r\n<span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># cat <span class=\"token operator\">\/<\/span>proc<span class=\"token operator\">\/<\/span>meminfo <span class=\"token operator\">|<\/span>grep <span class=\"token operator\">-<\/span>i huge\r\nAnonHugePages<span class=\"token punctuation\">:<\/span>    <span class=\"token number\">841728<\/span> kB\r\nHugePages_Total<span class=\"token punctuation\">:<\/span>    <span class=\"token number\">2020<\/span>\r\nHugePages_Free<span class=\"token punctuation\">:<\/span>     <span class=\"token number\">2020<\/span>\r\nHugePages_Rsvd<span class=\"token punctuation\">:<\/span>        <span class=\"token number\">0<\/span>\r\nHugePages_Surp<span class=\"token punctuation\">:<\/span>        <span class=\"token number\">0<\/span>\r\nHugepagesize<span class=\"token punctuation\">:<\/span>       <span class=\"token number\">2048<\/span> kB\r\n<\/pre>\n<p>2048\u662f\u9875\u6570\uff0c\u6bcf\u98752M\uff0c\u6240\u4ee5\u8fd9\u91cc\u9884\u7559\u4e86\u51e0\u4e4e4G\u7684\u5185\u5b58\u7a7a\u95f4\u7ed9\u5927\u9875\u3002\u4e4b\u540e\u6211\u4e48\u597d\u8fd8\u9700\u8981\u786e\u4fdd\u5171\u4eab\u5185\u5b58\u7684\u9650\u5236\u4e0d\u4f1a\u4f7f\u6211\u4eec\u7533\u8bf7\u5931\u8d25\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># echo <span class=\"token number\">2147483648<\/span> <span class=\"token operator\">&gt;<\/span> <span class=\"token operator\">\/<\/span>proc<span class=\"token operator\">\/<\/span>sys<span class=\"token operator\">\/<\/span>kernel<span class=\"token operator\">\/<\/span>shmmax\r\n<span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># echo <span class=\"token number\">33554432<\/span> <span class=\"token operator\">&gt;<\/span> <span class=\"token operator\">\/<\/span>proc<span class=\"token operator\">\/<\/span>sys<span class=\"token operator\">\/<\/span>kernel<span class=\"token operator\">\/<\/span>shmall\r\n<\/pre>\n<p>\u4e4b\u540e\u7f16\u8bd1\u6267\u884c\u76f8\u5173\u547d\u4ee4\uff1a<\/p>\n<pre class=\"prism-token token  language-javascript\"><span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># echo <span class=\"token number\">1<\/span> <span class=\"token operator\">&gt;<\/span> <span class=\"token operator\">\/<\/span>proc<span class=\"token operator\">\/<\/span>sys<span class=\"token operator\">\/<\/span>vm<span class=\"token operator\">\/<\/span>drop_caches \r\n<span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># free <span class=\"token operator\">-<\/span>g\r\n              total        used        free      shared  buff<span class=\"token operator\">\/<\/span>cache   available\r\nMem<span class=\"token punctuation\">:<\/span>             <span class=\"token number\">15<\/span>           <span class=\"token number\">6<\/span>           <span class=\"token number\">6<\/span>           <span class=\"token number\">0<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">7<\/span>\r\nSwap<span class=\"token punctuation\">:<\/span>            <span class=\"token number\">31<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">31<\/span>\r\n<span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># <span class=\"token punctuation\">.<\/span><span class=\"token operator\">\/<\/span>xsi_shm_mem_huge <span class=\"token operator\">&amp;<\/span>\r\n<span class=\"token punctuation\">[<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token number\">5508<\/span>\r\n<span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># free <span class=\"token operator\">-<\/span>g\r\n              total        used        free      shared  buff<span class=\"token operator\">\/<\/span>cache   available\r\nMem<span class=\"token punctuation\">:<\/span>             <span class=\"token number\">15<\/span>           <span class=\"token number\">6<\/span>           <span class=\"token number\">6<\/span>           <span class=\"token number\">0<\/span>           <span class=\"token number\">2<\/span>           <span class=\"token number\">7<\/span>\r\nSwap<span class=\"token punctuation\">:<\/span>            <span class=\"token number\">31<\/span>           <span class=\"token number\">0<\/span>          <span class=\"token number\">31<\/span>\r\n<span class=\"token punctuation\">[<\/span>root@zorrozou<span class=\"token operator\">-<\/span>pc0 sharemem<span class=\"token punctuation\">]<\/span># cat <span class=\"token operator\">\/<\/span>proc<span class=\"token operator\">\/<\/span>meminfo <span class=\"token operator\">|<\/span>grep <span class=\"token operator\">-<\/span>i huge\r\nAnonHugePages<span class=\"token punctuation\">:<\/span>    <span class=\"token number\">841728<\/span> kB\r\nHugePages_Total<span class=\"token punctuation\">:<\/span>    <span class=\"token number\">2020<\/span>\r\nHugePages_Free<span class=\"token punctuation\">:<\/span>      <span class=\"token number\">997<\/span>\r\nHugePages_Rsvd<span class=\"token punctuation\">:<\/span>        <span class=\"token number\">0<\/span>\r\nHugePages_Surp<span class=\"token punctuation\">:<\/span>        <span class=\"token number\">0<\/span>\r\nHugepagesize<span class=\"token punctuation\">:<\/span>       <span class=\"token number\">2048<\/span> kB\r\n<\/pre>\n<p>\u5927\u5bb6\u53ef\u4ee5\u6839\u636e\u8fd9\u4e2a\u7a0b\u5e8f\u7684\u8f93\u51fa\u770b\u5230\uff0c\u5f53\u524d\u7cfb\u7edf\u73af\u5883\uff08archlinux kernel 4.5\uff09\u518d\u4f7f\u7528\u5927\u9875\u5185\u5b58\u4e4b\u540e\uff0cfree\u547d\u4ee4\u662f\u770b\u4e0d\u89c1\u5176\u5185\u5b58\u7edf\u8ba1\u7684\u3002\u540c\u6837\u7684\u8bbe\u7f6e\u5728Centos 7\u73af\u5883\u4e0b\u4e5f\u662f\u76f8\u540c\u7684\u663e\u793a\u3002\u8fd9\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u4f7f\u7528\u5927\u9875\u5185\u5b58\u4f5c\u4e3a\u5171\u4eab\u5185\u5b58\u4f7f\u7528\uff0c\u5c06\u5728free\u4e2d\u770b\u4e0d\u5230\u76f8\u5173\u5185\u5b58\u7edf\u8ba1\uff0c\u8fd9\u4f30\u8ba1\u662ffree\u547d\u4ee4\u76ee\u524d\u6682\u65f6\u6ca1\u5c06\u5927\u9875\u5185\u5b58\u7edf\u8ba1\u8fdb\u5185\u5b58\u4f7f\u7528\u6240\u5bfc\u81f4\uff0c\u6682\u65f6\u5927\u5bb6\u53ea\u80fd\u901a\u8fc7\/proc\/meminfo\u6587\u4ef6\u4e2d\u7684\u76f8\u5173\u7edf\u8ba1\u770b\u5230\u5927\u9875\u5185\u5b58\u7684\u4f7f\u7528\u4fe1\u606f\u3002<\/p>\n<p>XSI\u5171\u4eab\u5185\u5b58\u7684\u7cfb\u7edf\u76f8\u5173\u9650\u5236\u5982\u4e0b\uff1a<\/p>\n<p>\/proc\/sys\/kernel\/shmall\uff1a\u9650\u5236\u7cfb\u7edf\u7528\u5728\u5171\u4eab\u5185\u5b58\u4e0a\u7684\u5185\u5b58\u603b\u9875\u6570\u3002\u6ce8\u610f\u662f\u9875\u6570\uff0c\u5355\u4f4d\u4e3a4k\u3002<\/p>\n<p>\/proc\/sys\/kernel\/shmmax\uff1a\u9650\u5236\u4e00\u4e2a\u5171\u4eab\u5185\u5b58\u6bb5\u7684\u6700\u5927\u957f\u5ea6\uff0c\u5b57\u8282\u4e3a\u5355\u4f4d\u3002<\/p>\n<p>\/proc\/sys\/kernel\/shmmni\uff1a\u9650\u5236\u6574\u4e2a\u7cfb\u7edf\u53ef\u521b\u5efa\u7684\u6700\u5927\u7684\u5171\u4eab\u5185\u5b58\u6bb5\u4e2a\u6570\u3002<\/p>\n<p>XSI\u5171\u4eab\u5185\u5b58\u662f\u5386\u53f2\u6bd4\u8f83\u60a0\u4e45\uff0c\u4e5f\u6bd4\u8f83\u7ecf\u5178\u7684\u5171\u4eab\u5185\u5b58\u624b\u6bb5\u3002\u5b83\u51e0\u4e4e\u4ee3\u8868\u4e86\u5171\u4eab\u5185\u5b58\u7684\u9ed8\u8ba4\u5b9a\u4e49\uff0c\u5f53\u6211\u4eec\u8bf4\u6709\u5171\u4eab\u5185\u5b58\u7684\u65f6\u5019\uff0c\u4e00\u822c\u610f\u5473\u7740\u4f7f\u7528\u4e86XSI\u7684\u5171\u4eab\u5185\u5b58\u3002\u4f46\u662f\u8fd9\u79cd\u5171\u4eab\u5185\u5b58\u4e5f\u5b58\u5728\u4e00\u5207\u7f3a\u70b9\uff0c\u6700\u53d7\u75c5\u57a2\u7684\u5730\u65b9\u83ab\u8fc7\u4e8e\u4ed6\u63d0\u4f9b\u7684key\uff0bprojid\u7684\u547d\u540d\u65b9\u5f0f\u4e0d\u591fUNIX\uff0c\u6ca1\u6709\u9075\u5faa\u4e00\u5207\u7686\u6587\u4ef6\u7684\u8bbe\u8ba1\u7406\u5ff5\u3002\u5f53\u7136\u8fd9\u4e2a\u8bbe\u8ba1\u7406\u5ff5\u5728\u4e00\u822c\u7684\u5e94\u7528\u573a\u666f\u4e0b\u5e76\u4e0d\u662f\u4ec0\u4e48\u5fc5\u987b\u8981\u9075\u5b88\u7684\u7406\u5ff5\uff0c\u4f46\u662f\u5982\u679c\u5171\u4eab\u5185\u5b58\u53ef\u4ee5\u7528\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u65b9\u5f0f\u63d0\u4f9b\u7ed9\u7a0b\u5e8f\u8bbf\u95ee\uff0c\u6beb\u65e0\u7591\u95ee\u53ef\u4ee5\u5728Linux\u4e0a\u8ddfselect\u3001poll\u3001epoll\u8fd9\u6837\u7684IO\u5f02\u6b65\u4e8b\u4ef6\u9a71\u52a8\u673a\u5236\u914d\u5408\u4f7f\u7528\uff0c\u505a\u5230\u4e00\u4e9b\u66f4\u9ad8\u7ea7\u7684\u529f\u80fd\u3002\u4e8e\u662f\uff0c\u9075\u5faa\u4e00\u5207\u7686\u6587\u4ef6\u7406\u5ff5\u7684POSIX\u6807\u51c6\u7684\u8fdb\u7a0b\u95f4\u901a\u4fe1\u673a\u5236\u5e94\u8fd0\u800c\u751f\u3002<\/p>\n<p>\u63a5<a href=\"https:\/\/www.qcloud.com\/community\/article\/978203\" target=\"_blank\" rel=\"noopener\">Linux\u8fdb\u7a0b\u95f4\u901a\u4fe1:\u5171\u4eab\u5185\u5b58 \uff08\u4e0b\uff09<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Linux \u8fdb\u7a0b\u95f4\u901a\u4fe1 : \u5171\u4eab\u5185\u5b58\uff08\u4e0a<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[118],"class_list":["post-1438","post","type-post","status-publish","format-standard","hentry","tag-02-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/1438","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=1438"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/1438\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=1438"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=1438"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=1438"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}