{"id":112,"date":"2014-11-06T16:16:19","date_gmt":"2014-11-06T16:16:19","guid":{"rendered":""},"modified":"2014-11-06T16:16:19","modified_gmt":"2014-11-06T16:16:19","slug":"","status":"publish","type":"post","link":"http:\/\/weizn.net\/?p=112","title":{"rendered":"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET"},"content":{"rendered":"

\n\t   
\nselect\u51fd\u6570\u7528\u4e8e\u5728\u975e\u963b\u585e\u4e2d\uff0c\u5f53\u4e00\u4e2a\u5957\u63a5\u5b57\u6216\u4e00\u7ec4\u5957\u63a5\u5b57\u6709\u4fe1\u53f7\u65f6\u901a\u77e5\u4f60\uff0c\u7cfb\u7edf\u63d0\u4f9bselect\u51fd\u6570\u6765\u5b9e\u73b0\u591a\u8def\u590d\u7528\u8f93\u5165\/\u8f93\u51fa\u6a21\u578b\uff0c\u539f\u578b\uff1a
\nint select(int maxfd,fd_set *rdset,fd_set
\n*wrset,fd_set *exset,struct timeval
\n*timeout);<\/span><\/span><\/span>\n<\/p>\n

\n\t  
\n\u6240\u5728\u7684\u5934\u6587\u4ef6\u4e3a\uff1a#include
\n<sys\/time.h> \u548c#include
\n<unistd.h><\/span><\/span><\/span>\n<\/p>\n

\n\t  
\n\u5148\u5bf9\u51fd\u6570\u4e2d\u7684\u53c2\u6570\u505a\u4e00\u4e2a\u7b80\u5355\u7684\u4ecb\u7ecd\u3002<\/span><\/span><\/span>\u53c2\u6570maxfd\u662f\u9700\u8981\u76d1\u89c6\u7684\u6700\u5927\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u503c+1\uff1brdset,wrset,exset\u5206\u522b\u5bf9\u5e94\u4e8e\u9700\u8981\u68c0\u6d4b\u7684\u53ef\u8bfb\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u96c6\u5408\uff0c\u53ef\u5199\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u96c6
\n\u5408\u53ca\u5f02\u5e38\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u96c6\u5408\u3002struct
\ntimeval\u7ed3\u6784\u7528\u4e8e\u63cf\u8ff0\u4e00\u6bb5\u65f6\u95f4\u957f\u5ea6\uff0c\u5982\u679c\u5728\u8fd9\u4e2a\u65f6\u95f4\u5185\uff0c\u9700\u8981\u76d1\u89c6\u7684\u63cf\u8ff0\u7b26\u6ca1\u6709\u4e8b\u4ef6\u53d1\u751f\u5219\u51fd\u6570\u8fd4\u56de\uff0c\u8fd4\u56de\u503c\u4e3a0\u3002 
\n    \u5728\u8fd9\u4e9b\u53c2\u6570\u4e2d\u6709\u4e00\u4e2a\u7c7b\u4f3c\u4e8e\u7ed3\u6784\u4f53\u7684\u4e1c\u897f\uff0c<\/span><\/span>fd_set\uff0c\u8fd9\u662f\u4ec0\u4e48\u7684\u540d\u5b57\uff0c\u6211\u4eec\u5148\u6765\u770b\u770b\u8fd9\u4e2a\u6240\u5177\u6709\u7684\u542b\u4e49\u5427\u3002\u8fd9<\/span><\/span>\u662f\u4e00\u7ec4\u6587\u4ef6\u63cf\u8ff0\u5b57(fd)\u7684\u96c6\u5408\uff0c\u5b83\u7528\u4e00\u4f4d\u6765\u8868\u793a\u4e00\u4e2afd\uff0c\u7b49\u7b49\uff0c\u6587\u4ef6\u63cf\u8ff0\u5b57\uff0c\u719f\u6089\u5427\uff0c\u4e4b\u524d\u90fd\u628a\u8fd9\u4e2a\u5f53\u505a\u4e00\u4e2a\u6587\u4ef6\u7684\u8def\u5f84\u4fdd\u5b58\u7684\u5730\u65b9\u4e86\uff0c\u4e5f\u5c31\u662f\u5f53\u505a\u662f\u4e00\u4e2a\u6587\u4ef6\u7684\u6807\u5fd7\u54e6\uff0c\u73b0\u4e0d\u5728\u505a\u731c\u60f3\u4e86\uff0c\u770b\u770b\u4e0b\u6587\u662f\u600e\u4e48\u4ecb\u7ecd\u7684\u5427\u3002<\/span><\/span>\n<\/p>\n

\n\t   
\n\u5bf9\u4e8efd_set\u7c7b\u578b\u901a\u8fc7\u4e0b\u9762\u56db\u4e2a\u5b8f\u6765\u64cd\u4f5c\uff1a
\n    FD_ZERO(fd_set *fdset)<\/span> \u5c06\u6307\u5b9a\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u6e05\u7a7a\uff0c\u5728\u5bf9\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u8fdb\u884c\u8bbe\u7f6e\u524d\uff0c\u5fc5\u987b\u5bf9\u5176\u8fdb\u884c\u521d\u59cb\u5316\uff0c\u5982\u679c\u4e0d\u6e05\u7a7a\uff0c\u7531\u4e8e\u5728\u7cfb\u7edf\u5206\u914d\u5185\u5b58\u7a7a\u95f4\u540e\uff0c\u901a\u5e38\u5e76\u4e0d\u4f5c\u6e05\u7a7a\u5904\u7406\uff0c\u6240\u4ee5\u7ed3\u679c\u662f\u4e0d\u53ef\u77e5\u7684\u3002
\n    FD_SET(fd_set *fdset)<\/span> \u7528\u4e8e\u5728\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u4e2d\u589e\u52a0\u4e00\u4e2a\u65b0\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002
\n    FD_CLR(fd_set *fdset)<\/span> \u7528\u4e8e\u5728\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u4e2d\u5220\u9664\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002
\n    FD_ISSET(int fd,fd_set *fdset)<\/span> \u7528\u4e8e\u6d4b\u8bd5\u6307\u5b9a\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u5426\u5728\u8be5\u96c6\u5408\u4e2d\u3002
\n<\/span><\/span>\n<\/p>\n

\n\t   
\n\u8fc7\u53bb\u3002\u3002\u3002\u3002\u3002\u3002\u597d\u957f\u4e00\u5927\u6bb5\u54e6\uff0c\u4e3a\u4e86\u4fdd\u8bc1\u5927\u5bb6\u7684\u6ce8\u610f\u529b\uff0c\u6211\u51b3\u5b9a\u5c06\u8fd9\u4e00\u5927\u6bb5\u957f\u957f\u7684\u5bf9\u8fc7\u53bb\u60c5\u51b5\u7684\u4ecb\u7ecd\u53bb\u6389\uff0c\u76f4\u63a5\u5bfb\u627e\u6b63\u9898\uff0c\u4fdd\u6301\u76ee\u6807\u7684\u5173\u6ce8\u5ea6\u554a\u3002\u73b0\u5728,UNIX
\n\u7cfb\u7edf\u901a\u5e38\u4f1a\u5728\u5934\u6587\u4ef6<sys\/select.h>\u4e2d\u5b9a\u4e49\u5e38\u91cfFD_SETSIZE\uff0c\u5b83\u662f\u6570\u636e\u7c7b\u578bfd_set\u7684\u63cf\u8ff0\u5b57\u6570\u91cf\uff0c\u5176\u503c\u901a\u5e38\u662f
\n1024\uff0c\u8fd9\u6837\u5c31\u80fd\u8868\u793a<1024\u7684fd\u3002<\/span><\/span>
\n<\/span><\/span>\n<\/p>\n

\n\t   
\n\u597d\u4e86\u5728\u7814\u7a76\u4e86\u4e00\u756a\u5173\u4e8efd_set\u7684\u4fe1\u606f\u4e4b\u540e\uff0c\u518d\u56de\u5230\u5bf9select\u51fd\u6570\u7684\u7406\u89e3\u4e0a\u6765\u5427\u3002<\/span><\/span>\n<\/p>\n

\n\t   
\n\u529f\u80fd\uff1a\u6d4b\u8bd5\u6307\u5b9a\u7684fd\u53ef\u8bfb\uff1f\u53ef\u5199\uff1f\u6709\u5f02\u5e38\u6761\u4ef6\u5f85\u5904\u7406\uff1f
\n   
\nreadset  \u7528\u6765\u68c0\u67e5\u53ef\u8bfb\u6027\u7684\u4e00\u7ec4\u6587\u4ef6\u63cf\u8ff0\u5b57\u3002
\n    writeset
\n\u7528\u6765\u68c0\u67e5\u53ef\u5199\u6027\u7684\u4e00\u7ec4\u6587\u4ef6\u63cf\u8ff0\u5b57\u3002
\n   
\nexceptset\u7528\u6765\u68c0\u67e5\u662f\u5426\u6709\u5f02\u5e38\u6761\u4ef6\u51fa\u73b0\u7684\u6587\u4ef6\u63cf\u8ff0\u5b57\u3002(\u6ce8\uff1a\u4e0d\u5305\u62ec\u9519\u8bef)
\n   
\ntimeout 
\n\u7528\u4e8e\u63cf\u8ff0\u4e00\u6bb5\u65f6\u95f4\u957f\u5ea6\uff0c\u5982\u679c\u5728\u8fd9\u4e2a\u65f6\u95f4\u5185\uff0c\u9700\u8981\u76d1\u89c6\u7684\u63cf\u8ff0\u7b26\u6ca1\u6709\u4e8b\u4ef6\u53d1\u751f\u5219\u51fd\u6570\u8fd4\u56de\uff0c\u8fd4\u56de\u503c\u4e3a0\u3002<\/span><\/span>\n<\/p>\n

\n\t   
\n\u5bf9\u4e8eselect\u51fd\u6570\u7684\u529f\u80fd\u7b80\u5355\u7684\u8bf4\u5c31\u662f\u5bf9\u6587\u4ef6fd\u505a\u4e00\u4e2a\u6d4b\u8bd5\u3002\u6d4b\u8bd5\u7ed3\u679c<\/span><\/span>\u6709\u4e09\u79cd\u53ef\u80fd\uff1a
\n   
\n1.timeout=NULL\uff08\u963b\u585e\uff1aselect\u5c06\u4e00\u76f4\u88ab\u963b\u585e\uff0c\u76f4\u5230\u67d0\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u53d1\u751f\u4e86\u4e8b\u4ef6\uff09
\n   
\n2.timeout\u6240\u6307\u5411\u7684\u7ed3\u6784\u8bbe\u4e3a\u975e\u96f6\u65f6\u95f4\uff08\u7b49\u5f85\u56fa\u5b9a\u65f6\u95f4\uff1a\u5982\u679c\u5728\u6307\u5b9a\u7684\u65f6\u95f4\u6bb5\u91cc\u6709\u4e8b\u4ef6\u53d1\u751f\u6216\u8005\u65f6\u95f4\u8017\u5c3d\uff0c\u51fd\u6570\u5747\u8fd4\u56de\uff09
\n   
\n3.timeout\u6240\u6307\u5411\u7684\u7ed3\u6784\uff0c\u65f6\u95f4\u8bbe\u4e3a0\uff08\u975e\u963b\u585e\uff1a\u4ec5\u68c0\u6d4b\u63cf\u8ff0\u7b26\u96c6\u5408\u7684\u72b6\u6001\uff0c\u7136\u540e\u7acb\u5373\u8fd4\u56de\uff0c\u5e76\u4e0d\u7b49\u5f85\u5916\u90e8\u4e8b\u4ef6\u7684\u53d1\u751f\uff09<\/span><\/span>\n<\/p>\n

\n\t \n<\/p>\n

\n\t   
\n\u8fd4\u56de\u503c\uff1a\u8fd4\u56de\u5bf9\u5e94\u4f4d\u4ecd\u7136\u4e3a1\u7684fd\u7684\u603b\u6570\u3002\u6ce8\u610f\u5566\uff1a<\/span>\u53ea\u6709\u90a3\u4e9b\u53ef\u8bfb\uff0c\u53ef\u5199\u4ee5\u53ca\u6709\u5f02\u5e38\u6761\u4ef6\u5f85\u5904\u7406\u7684fd\u4f4d\u4ecd\u7136\u4e3a1\u3002\u5426\u5219\u4e3a0\u54e6\u3002<\/span>\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u6bd4\u5982recv(),
\n\u5728\u6ca1\u6709\u6570\u636e\u5230\u6765\u8c03\u7528\u5b83\u7684\u65f6\u5019,\u4f60\u7684\u7ebf\u7a0b\u5c06\u88ab\u963b\u585e,\u5982\u679c\u6570\u636e\u4e00\u76f4\u4e0d\u6765,\u4f60\u7684\u7ebf\u7a0b\u5c31\u8981\u963b\u585e\u5f88\u4e45.\u8fd9\u6837\u663e\u7136\u4e0d\u597d\u3002\u6240\u4ee5\u91c7\u7528select\u6765\u67e5\u770b\u5957\u8282\u5b57\u662f\u5426\u53ef\u8bfb(\u4e5f\u5c31\u662f\u662f\u5426\u6709\u6570\u636e\u8bfb\u4e86)
\n\u3002
\n\u6b65\u9aa4\u5982\u4e0b\u2014\u2014
\n<\/span> socket s;
\n…..
\nfd_set set;
\nwhile(1)
\n{
\nFD_ZERO(&set);\/\/\u5c06\u4f60\u7684\u5957\u8282\u5b57\u96c6\u5408\u6e05\u7a7a
\nFD_SET(s, &set);\/\/\u52a0\u5165\u4f60\u611f\u5174\u8da3\u7684\u5957\u8282\u5b57\u5230\u96c6\u5408,\u8fd9\u91cc\u662f\u4e00\u4e2a\u8bfb\u6570\u636e\u7684\u5957\u8282\u5b57s
\nselect(0,&set,NULL,NULL,NULL);\/\/\u68c0\u67e5\u5957\u8282\u5b57\u662f\u5426\u53ef\u8bfb,
\n\/\/\u5f88\u591a\u60c5\u51b5\u4e0b\u5c31\u662f\u662f\u5426\u6709\u6570\u636e(\u6ce8\u610f,\u53ea\u662f\u8bf4\u5f88\u591a\u60c5\u51b5)
\n\/\/\u8fd9\u91ccselect\u662f\u5426\u51fa\u9519\u6ca1\u6709\u5199
\nif(FD_ISSET(s, &set) \/\/\u68c0\u67e5s\u662f\u5426\u5728\u8fd9\u4e2a\u96c6\u5408\u91cc\u9762,
\n{ \/\/select\u5c06\u66f4\u65b0\u8fd9\u4e2a\u96c6\u5408,\u628a\u5176\u4e2d\u4e0d\u53ef\u8bfb\u7684\u5957\u8282\u5b57\u53bb\u6389
\n\/\/\u53ea\u4fdd\u7559\u7b26\u5408\u6761\u4ef6\u7684\u5957\u8282\u5b57\u5728\u8fd9\u4e2a\u96c6\u5408\u91cc\u9762
\nrecv(s,…);
\n}
\n\/\/do something here
\n}<\/span>\n<\/p>\n

\n\t   
\n\u7406\u89e3select\u6a21\u578b\u7684\u5173\u952e\u5728\u4e8e\u7406\u89e3fd_set,\u4e3a\u8bf4\u660e\u65b9\u4fbf\uff0c\u53d6fd_set\u957f\u5ea6\u4e3a1\u5b57\u8282\uff0cfd_set\u4e2d\u7684\u6bcf\u4e00bit\u53ef\u4ee5\u5bf9\u5e94\u4e00\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26fd\u3002\u52191\u5b57\u8282\u957f\u7684fd_set\u6700\u5927\u53ef\u4ee5\u5bf9\u5e948\u4e2afd\u3002
\n   \uff081\uff09\u6267\u884cfd_set set;
\nFD_ZERO(&set);\u5219set\u7528\u4f4d\u8868\u793a\u662f0000,0000\u3002
\n  
\n\uff082\uff09\u82e5fd\uff1d5,\u6267\u884cFD_SET(fd,&set);\u540eset\u53d8\u4e3a0001,0000(\u7b2c5\u4f4d\u7f6e\u4e3a1)<\/span>\n<\/p>\n

\n\t  
\n\uff083\uff09\u82e5\u518d\u52a0\u5165fd\uff1d2\uff0cfd=1,\u5219set\u53d8\u4e3a0001,0011
\n  
\n\uff084\uff09\u6267\u884cselect(6,&set,0,0,0)\u963b\u585e\u7b49\u5f85
\n  
\n\uff085\uff09\u82e5fd=1,fd=2\u4e0a\u90fd\u53d1\u751f\u53ef\u8bfb\u4e8b\u4ef6\uff0c\u5219select\u8fd4\u56de\uff0c\u6b64\u65f6set\u53d8\u4e3a0000,0011\u3002\u6ce8\u610f\uff1a\u6ca1\u6709\u4e8b\u4ef6\u53d1\u751f\u7684fd=5\u88ab\u6e05\u7a7a\u3002<\/span>\n<\/p>\n

\n\t
\n\u57fa\u4e8e\u4e0a\u9762\u7684\u8ba8\u8bba\uff0c\u53ef\u4ee5\u8f7b\u677e\u5f97\u51faselect\u6a21\u578b\u7684\u7279\u70b9\uff1a<\/span>
\n  
\n\uff081)\u53ef\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e2a\u6570\u53d6\u51b3\u4e0esizeof(fd_set)\u7684\u503c\u3002<\/span><\/span>\n<\/p>\n

\n\t  
\n\uff082\uff09\u53ef\u4ee5\u6709\u6548\u7a81\u7834select\u53ef\u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u9650\u3002
\n  
\n\uff083\uff09\u5c06fd\u52a0\u5165select\u76d1\u63a7\u96c6\u7684\u540c\u65f6\uff0c\u8fd8\u8981\u518d\u4f7f\u7528\u4e00\u4e2a\u6570\u636e\u7ed3\u6784array\u4fdd\u5b58\u653e\u5230select\u76d1\u63a7\u96c6\u4e2d\u7684fd\uff0c\u4e00\u662f\u7528\u4e8e\u518dselect
\n\u8fd4\u56de\u540e\uff0carray\u4f5c\u4e3a\u6e90\u6570\u636e\u548cfd_set\u8fdb\u884cFD_ISSET\u5224\u65ad\u3002\u4e8c\u662fselect\u8fd4\u56de\u540e\u4f1a\u628a\u4ee5\u524d\u52a0\u5165\u7684\u4f46\u5e76\u65e0\u4e8b\u4ef6\u53d1\u751f\u7684fd\u6e05\u7a7a\uff0c\u5219\u6bcf\u6b21\u5f00\u59cb
\nselect\u524d\u90fd\u8981\u91cd\u65b0\u4ecearray\u53d6\u5f97fd\u9010\u4e00\u52a0\u5165\uff08FD_ZERO\u6700\u5148\uff09\uff0c\u626b\u63cfarray\u7684\u540c\u65f6\u53d6\u5f97fd\u6700\u5927\u503cmaxfd\uff0c\u7528\u4e8eselect\u7684\u7b2c\u4e00\u4e2a
\n\u53c2\u6570\u3002
\n  
\n\uff084\uff09\u53ef\u89c1select\u6a21\u578b\u5fc5\u987b\u5728select\u524d\u5faa\u73afarray\uff08\u52a0fd\uff0c\u53d6maxfd\uff09\uff0cselect\u8fd4\u56de\u540e\u5faa\u73afarray\uff08FD_ISSET\u5224\u65ad\u662f\u5426\u6709\u65f6\u95f4\u53d1\u751f\uff09\u3002<\/span>\n<\/p>\n

\n\t
\n\u4f7f\u7528select\u51fd\u6570\u7684\u8fc7\u7a0b\u4e00\u822c\u662f\uff1a
\n<\/span>   
\n\u5148\u8c03\u7528\u5b8fFD_ZERO\u5c06\u6307\u5b9a\u7684fd_set\u6e05\u96f6\uff0c\u7136\u540e\u8c03\u7528\u5b8fFD_SET\u5c06\u9700\u8981\u6d4b\u8bd5\u7684fd\u52a0\u5165fd_set\uff0c\u63a5\u7740\u8c03\u7528\u51fd\u6570select\u6d4b\u8bd5fd_set\u4e2d\u7684\u6240\u6709fd\uff0c\u6700\u540e\u7528\u5b8fFD_ISSET\u68c0\u67e5\u67d0\u4e2afd\u5728\u51fd\u6570select\u8c03\u7528\u540e\uff0c\u76f8\u5e94\u4f4d\u662f\u5426\u4ecd\u7136\u4e3a1\u3002<\/span><\/span>\n<\/p>\n

\u4ee5\u4e0b\u662f\u4e00\u4e2a\u6d4b\u8bd5\u5355\u4e2a\u6587\u4ef6\u63cf\u8ff0\u5b57\u53ef\u8bfb\u6027\u7684\u4f8b\u5b50\uff1a
\n<\/span>int isready(int
\nfd)
\n{
\nint rc;
\nfd_set fds;
\nstruct tim tv;
\nFD_ZERO(&fds);
\nFD_SET(fd,&fds);
\ntv.tv_sec = tv.tv_usec = 0;
\nrc = select(fd+1, &fds, NULL, NULL,
\n&tv);
\nif (rc < 0) \/\/error
\nreturn -1;
\nreturn FD_ISSET(fd,&fds) ? 1 : 0;
\n}<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

\n\t   
\nselect\u51fd\u6570\u7528\u4e8e\u5728\u975e\u963b\u585e\u4e2d\uff0c\u5f53\u4e00\u4e2a\u5957\u63a5\u5b57\u6216\u4e00\u7ec4\u5957\u63a5\u5b57\u6709\u4fe1\u53f7\u65f6\u901a\u77e5\u4f60\uff0c\u7cfb\u7edf\u63d0\u4f9bselect\u51fd\u6570\u6765\u5b9e\u73b0\u591a\u8def\u590d\u7528\u8f93\u5165\/\u8f93\u51fa\u6a21\u578b\uff0c\u539f\u578b\uff1a
\nint select(int maxfd,fd_set *rdset,fd_set
\n*wrset,fd_set *exset,struct timeval
\n*timeout);<\/span><\/span><\/span>\n<\/p>\n

\n\t  
\n\u6240\u5728\u7684\u5934\u6587\u4ef6\u4e3a\uff1a#i…<\/span><\/span><\/span>\n<\/p>\n

\n\t<\/span><\/span><\/span><\/span><\/span>\n<\/p>\n

\n\t<\/span><\/span>\n<\/p>\n

\n\t<\/span><\/span>\n<\/p>\n

\n\t<\/span><\/span>\n<\/p>\n

\n\t<\/span><\/span>\n<\/p>\n

\n\t<\/span><\/span><\/span><\/span>\n<\/p>\n

\n\t\n<\/p>\n

\n\t<\/span>\n<\/p>\n

\n\t<\/span>\n<\/p>\n

\n\t<\/span>\n<\/p>\n

\n\t<\/span><\/span>\n<\/p>\n

\n\t<\/span>\n<\/p>\n

\n\t<\/span><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[324],"tags":[],"class_list":["post-112","post","type-post","status-publish","format-standard","hentry"],"yoast_head":"\n[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET - Wayne's Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"http:\/\/weizn.net\/?p=112\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET - Wayne's Blog\" \/>\n<meta property=\"og:description\" content=\"    select\u51fd\u6570\u7528\u4e8e\u5728\u975e\u963b\u585e\u4e2d\uff0c\u5f53\u4e00\u4e2a\u5957\u63a5\u5b57\u6216\u4e00\u7ec4\u5957\u63a5\u5b57\u6709\u4fe1\u53f7\u65f6\u901a\u77e5\u4f60\uff0c\u7cfb\u7edf\u63d0\u4f9bselect\u51fd\u6570\u6765\u5b9e\u73b0\u591a\u8def\u590d\u7528\u8f93\u5165\/\u8f93\u51fa\u6a21\u578b\uff0c\u539f\u578b\uff1a int select(int maxfd,fd_set *rdset,fd_set *wrset,fd_set *exset,struct timeval *timeout);    \u6240\u5728\u7684\u5934\u6587\u4ef6\u4e3a\uff1a#i...\" \/>\n<meta property=\"og:url\" content=\"http:\/\/weizn.net\/?p=112\" \/>\n<meta property=\"og:site_name\" content=\"Wayne's Blog\" \/>\n<meta property=\"article:published_time\" content=\"2014-11-06T16:16:19+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"zinan\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebSite\",\"@id\":\"http:\/\/weizn.net\/#website\",\"url\":\"http:\/\/weizn.net\/\",\"name\":\"Wayne's Blog\",\"description\":\"\",\"publisher\":{\"@id\":\"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"http:\/\/weizn.net\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"zh-Hans\"},{\"@type\":\"WebPage\",\"@id\":\"http:\/\/weizn.net\/?p=112#webpage\",\"url\":\"http:\/\/weizn.net\/?p=112\",\"name\":\"[\\u8f6c]select()\\u51fd\\u6570\\u4ee5\\u53caFD_ZERO\\u3001FD_SET\\u3001FD_CLR\\u3001FD_ISSET - Wayne's Blog\",\"isPartOf\":{\"@id\":\"http:\/\/weizn.net\/#website\"},\"datePublished\":\"2014-11-06T16:16:19+00:00\",\"dateModified\":\"2014-11-06T16:16:19+00:00\",\"breadcrumb\":{\"@id\":\"http:\/\/weizn.net\/?p=112#breadcrumb\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"http:\/\/weizn.net\/?p=112\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"http:\/\/weizn.net\/?p=112#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\\u9996\\u9875\",\"item\":\"http:\/\/weizn.net\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"[\\u8f6c]select()\\u51fd\\u6570\\u4ee5\\u53caFD_ZERO\\u3001FD_SET\\u3001FD_CLR\\u3001FD_ISSET\"}]},{\"@type\":\"Article\",\"@id\":\"http:\/\/weizn.net\/?p=112#article\",\"isPartOf\":{\"@id\":\"http:\/\/weizn.net\/?p=112#webpage\"},\"author\":{\"@id\":\"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264\"},\"headline\":\"[\\u8f6c]select()\\u51fd\\u6570\\u4ee5\\u53caFD_ZERO\\u3001FD_SET\\u3001FD_CLR\\u3001FD_ISSET\",\"datePublished\":\"2014-11-06T16:16:19+00:00\",\"dateModified\":\"2014-11-06T16:16:19+00:00\",\"mainEntityOfPage\":{\"@id\":\"http:\/\/weizn.net\/?p=112#webpage\"},\"wordCount\":369,\"commentCount\":0,\"publisher\":{\"@id\":\"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264\"},\"articleSection\":[\"C\/C++\"],\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"http:\/\/weizn.net\/?p=112#respond\"]}]},{\"@type\":[\"Person\",\"Organization\"],\"@id\":\"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264\",\"name\":\"zinan\",\"logo\":{\"@id\":\"http:\/\/weizn.net\/#personlogo\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET - Wayne's Blog","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"http:\/\/weizn.net\/?p=112","og_locale":"zh_CN","og_type":"article","og_title":"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET - Wayne's Blog","og_description":"    select\u51fd\u6570\u7528\u4e8e\u5728\u975e\u963b\u585e\u4e2d\uff0c\u5f53\u4e00\u4e2a\u5957\u63a5\u5b57\u6216\u4e00\u7ec4\u5957\u63a5\u5b57\u6709\u4fe1\u53f7\u65f6\u901a\u77e5\u4f60\uff0c\u7cfb\u7edf\u63d0\u4f9bselect\u51fd\u6570\u6765\u5b9e\u73b0\u591a\u8def\u590d\u7528\u8f93\u5165\/\u8f93\u51fa\u6a21\u578b\uff0c\u539f\u578b\uff1a int select(int maxfd,fd_set *rdset,fd_set *wrset,fd_set *exset,struct timeval *timeout);    \u6240\u5728\u7684\u5934\u6587\u4ef6\u4e3a\uff1a#i...","og_url":"http:\/\/weizn.net\/?p=112","og_site_name":"Wayne's Blog","article_published_time":"2014-11-06T16:16:19+00:00","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"zinan","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"2 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebSite","@id":"http:\/\/weizn.net\/#website","url":"http:\/\/weizn.net\/","name":"Wayne's Blog","description":"","publisher":{"@id":"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"http:\/\/weizn.net\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"zh-Hans"},{"@type":"WebPage","@id":"http:\/\/weizn.net\/?p=112#webpage","url":"http:\/\/weizn.net\/?p=112","name":"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET - Wayne's Blog","isPartOf":{"@id":"http:\/\/weizn.net\/#website"},"datePublished":"2014-11-06T16:16:19+00:00","dateModified":"2014-11-06T16:16:19+00:00","breadcrumb":{"@id":"http:\/\/weizn.net\/?p=112#breadcrumb"},"inLanguage":"zh-Hans","potentialAction":[{"@type":"ReadAction","target":["http:\/\/weizn.net\/?p=112"]}]},{"@type":"BreadcrumbList","@id":"http:\/\/weizn.net\/?p=112#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"http:\/\/weizn.net\/"},{"@type":"ListItem","position":2,"name":"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET"}]},{"@type":"Article","@id":"http:\/\/weizn.net\/?p=112#article","isPartOf":{"@id":"http:\/\/weizn.net\/?p=112#webpage"},"author":{"@id":"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264"},"headline":"[\u8f6c]select()\u51fd\u6570\u4ee5\u53caFD_ZERO\u3001FD_SET\u3001FD_CLR\u3001FD_ISSET","datePublished":"2014-11-06T16:16:19+00:00","dateModified":"2014-11-06T16:16:19+00:00","mainEntityOfPage":{"@id":"http:\/\/weizn.net\/?p=112#webpage"},"wordCount":369,"commentCount":0,"publisher":{"@id":"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264"},"articleSection":["C\/C++"],"inLanguage":"zh-Hans","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["http:\/\/weizn.net\/?p=112#respond"]}]},{"@type":["Person","Organization"],"@id":"http:\/\/weizn.net\/#\/schema\/person\/e88bc12c590502d8b6249326f960b264","name":"zinan","logo":{"@id":"http:\/\/weizn.net\/#personlogo"}}]}},"_links":{"self":[{"href":"http:\/\/weizn.net\/index.php?rest_route=\/wp\/v2\/posts\/112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/weizn.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/weizn.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/weizn.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/weizn.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=112"}],"version-history":[{"count":0,"href":"http:\/\/weizn.net\/index.php?rest_route=\/wp\/v2\/posts\/112\/revisions"}],"wp:attachment":[{"href":"http:\/\/weizn.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/weizn.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=112"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/weizn.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}