{"id":2023,"date":"2016-12-25T23:36:45","date_gmt":"2016-12-25T15:36:45","guid":{"rendered":"http:\/\/www.51cos.com\/?p=2023"},"modified":"2016-12-26T00:04:56","modified_gmt":"2016-12-25T16:04:56","slug":"2023","status":"publish","type":"post","link":"http:\/\/www.51cos.com\/?p=2023","title":{"rendered":"\u4fee\u6539socket\u53d1\u9001\u7f13\u5b58\u533a\u548c\u63a5\u6536\u7f13\u5b58\u533a\u5927\u5c0f\uff0c\u4ee5\u53ca\u4f7f\u7528socket\u901a\u4fe1\u6ce8\u610f\u4e8b\u9879"},"content":{"rendered":"

1 .\u4fee\u6539Socket\u53d1\u9001\u7f13\u5b58\u533a\u548c\u63a5\u6536\u7f13\u5b58\u533a\u5927\u5c0f\u4ee3\u7801\uff1a<\/p>\n

\n#include \"stdio.h\"
\n#include \"stdlib.h\"
\n#include \"unistd.h\"
\n#include \"string.h\"
\n#include \"errno.h\"
\n#include \"sys\/types.h\"
\n#include \"sys\/socket.h\"
\n#include \"assert.h\"<\/p>\n
int main(int argc,char **argv)
\n{
\n    int err = -1; \/* \u8fd4\u56de\u503c *\/
\n    int s = -1; \/* socket\u63cf\u8ff0\u7b26 *\/
\n    int snd_size = 0; \/* \u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f *\/
\n    int rcv_size = 0; \/* \u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f *\/
\n    socklen_t optlen; \/* \u9009\u9879\u503c\u957f\u5ea6 *\/<\/p>\n
\/*
\n* \u5efa\u7acb\u4e00\u4e2aTCP\u5957\u63a5\u5b57
\n*\/
\n    s = socket(PF_INET,SOCK_STREAM,0);
\n    if( s == -1){
\n        printf(\"\u5efa\u7acb\u5957\u63a5\u5b57\u9519\u8bef\\n\");
\n        return -1;
\n    }<\/p>\n
\/*
\n* \u5148\u8bfb\u53d6\u7f13\u51b2\u533a\u8bbe\u7f6e\u7684\u60c5\u51b5
\n* \u83b7\u5f97\u539f\u59cb\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f
\n*\/
\n    optlen = sizeof(snd_size);
\n    err = getsockopt(s, SOL_SOCKET, SO_SNDBUF,&snd_size, &optlen);
\n    if(err<0){\n        printf(\"\u83b7\u53d6\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u9519\u8bef\\n\");\n    }\n\n\n\/*\n* \u83b7\u5f97\u539f\u59cb\u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\n*\/\n    optlen = sizeof(rcv_size);\n    err = getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcv_size, &optlen);\n    if(err<0){\n        printf(\"\u83b7\u53d6\u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\u9519\u8bef\\n\");\n    }\n\n    printf(\" \u53d1\u9001\u7f13\u51b2\u533a\u539f\u59cb\u5927\u5c0f\u4e3a: %d \u5b57\u8282\\n\",snd_size);\n    printf(\" \u63a5\u6536\u7f13\u51b2\u533a\u539f\u59cb\u5927\u5c0f\u4e3a: %d \u5b57\u8282\\n\",rcv_size);\n\n\/*\n* \u8bbe\u7f6e\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\n*\/\n    snd_size = 10*1024; \/* \u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u4e3a8K *\/\n    optlen = sizeof(snd_size);\n    err = setsockopt(s, SOL_SOCKET, SO_SNDBUF, &snd_size, optlen);\n    if(err<0){\n        printf(\"\u8bbe\u7f6e\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u9519\u8bef\\n\");\n    }\n\n\/*\n* \u8bbe\u7f6e\u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\n*\/\n    rcv_size = 10*1024; \/* \u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\u4e3a8K *\/\n    optlen = sizeof(rcv_size);\n    err = setsockopt(s,SOL_SOCKET,SO_RCVBUF, (char *)&rcv_size, optlen);\n    if(err<0){\n        printf(\"\u8bbe\u7f6e\u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\u9519\u8bef\\n\");\n    }\n\n\/*\n* \u68c0\u67e5\u4e0a\u8ff0\u7f13\u51b2\u533a\u8bbe\u7f6e\u7684\u60c5\u51b5\n* \u83b7\u5f97\u4fee\u6539\u540e\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\n*\/\n    optlen = sizeof(snd_size);\n    err = getsockopt(s, SOL_SOCKET, SO_SNDBUF,&snd_size, &optlen);\n    if(err<0){\n        printf(\"\u83b7\u53d6\u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u9519\u8bef\\n\");\n    }\n\n\/*\n* \u83b7\u5f97\u4fee\u6539\u540e\u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\n*\/\n    optlen = sizeof(rcv_size);\n    err = getsockopt(s, SOL_SOCKET, SO_RCVBUF,(char *)&rcv_size, &optlen);\n    if(err<0){\n        printf(\"\u83b7\u53d6\u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\u9519\u8bef\\n\");\n    }\n\n\/*\n* \u6253\u5370\u7ed3\u679c\n*\/\n    printf(\" \u53d1\u9001\u7f13\u51b2\u533a\u5927\u5c0f\u4e3a: %d \u5b57\u8282\\n\",snd_size);\n    printf(\" \u63a5\u6536\u7f13\u51b2\u533a\u5927\u5c0f\u4e3a: %d \u5b57\u8282\\n\",rcv_size);\n\n    close(s);\n    return 0;\n}\n \n\n2.socket\u7684\u6536\u53d1\u7f13\u51b2\u533a\u5e94\u8be5\u600e\u4e48\u8bbe\u7f6e?\n\u8bbe\u7f6e\u5927\u4e86\u589e\u5927\u7f51\u7edcI\/O\u7684\u6027\u80fd\uff0c\u5ef6\u8fdf\u4f1a\u6bd4\u8f83\u5927\uff0c\u8bbe\u7f6e\u5c0f\u4e86\u5b9e\u65f6\u6027\u6bd4\u8f83\u597d\u3002\nSocket\u7f16\u7a0b\u4e2d\uff0c\u4f7f\u7528send()\u4f20\u9001\u6570\u636e\u65f6\uff0c\u8fd4\u56de\u7ed3\u679c\u53d7\u5230\u4ee5\u4e0b\u51e0\u4e2a\u56e0\u7d20\u7684\u5f71\u54cd\uff1a \n\u2022 Blocking\u6a21\u5f0f\u6216non-blocking\u6a21\u5f0f \n\u2022 \u53d1\u9001\u7f13\u51b2\u533a\u7684\u5927\u5c0f \n\u2022 \u63a5\u6536\u7a97\u53e3\u5927\u5c0f \n\u6570\u636e\u53d1\u9001\u548c\u63a5\u6536\u7684\u8fc7\u7a0b\uff1a\n\u7a0b\u5e8f\u8c03\u7528send()\u53d1\u9001\u6570\u636e\u65f6\uff0c\u6570\u636e\u5c06\u9996\u5148\u8fdb\u5165\u53d1\u9001\u7f13\u51b2\u533a\uff0c\u7b49\u5f85\u53d1\u9001\u3002\u7cfb\u7edf\u5e95\u5c42socket\u8d1f\u8d23\u6570\u636e\u7684\u4f20\u9001\uff0c\u6570\u636e\u901a\u8fc7\u7f51\u7edc\u5230\u8fbe\u63a5\u6536\u65b9\u7684\u7f13\u51b2\u533a\u3002\u63a5\u6536\u65b9\u7f13\u51b2\u533a\u5185\u7684\u6570\u636e\uff0c\u7b49\u5f85\u5e94\u7528\u7a0b\u5e8f\u8c03\u7528recv()\u8bfb\u53d6\u3002\nhttp:\/\/www.tuicool.com\/articles\/QBrQze\n\n3.\n TCP\u5982\u679c\u7cfb\u7edf\u7f13\u51b2\u533a\u6ee1\uff0c\u5982\u679c\u6ca1\u6709\u53ca\u65f6recv\u63a5\u6536\u7684\u8bdd\uff0c\u5c31\u4e0d\u80fd\u518d\u53d1\u9001\u6570\u636e\u4e86\uff0csend\u5c31\u4f1a\u5931\u8d25\uff0cUDP\u7684\u8bdd\uff0c\u5982\u679c\u63a5\u6536\u7aef\u7684SOCKET\u7684\u7cfb\u7edfbuffer\u6ee1\u4e86\uff0c\u540e\u9762\u5230\u6765\u7684\u5305\u4f1a\u88ab\u4e22\u6389\u3002\n\n4.1. tcp \u63a5\u6536\u548c\u53d1\u9001\u7f13\u51b2\u533a\u9ed8\u8ba4\u503c\n[root@ www.linuxidc.com]# cat \/proc\/sys\/net\/ipv4\/tcp_rmem \n4096    87380   4161536\n87380  \uff1atcp\u63a5\u6536\u7f13\u51b2\u533a\u7684\u9ed8\u8ba4\u503c\n\n[root@ www.linuxidc.com]# cat \/proc\/sys\/net\/ipv4\/tcp_wmem\n4096    16384   4161536\n16384  \uff1a tcp \u53d1\u9001\u7f13\u51b2\u533a\u7684\u9ed8\u8ba4\u503c\n\n4.2. tcp \u6216udp\u6536\u53d1\u7f13\u51b2\u533a\u6700\u5927\u503c\n[root@ www.linuxidc.com]# cat \/proc\/sys\/net\/core\/rmem_max\n131071\n131071\uff1atcp \u6216 udp \u63a5\u6536\u7f13\u51b2\u533a\u6700\u5927\u53ef\u8bbe\u7f6e\u503c\u7684\u4e00\u534a\u3002\n\n[root@ www.linuxidc.com]# cat \/proc\/sys\/net\/core\/wmem_max \n131071\n131071\uff1atcp \u6216 udp \u53d1\u9001\u7f13\u51b2\u533a\u6700\u5927\u53ef\u8bbe\u7f6e\u503c\u5f97\u4e00\u534a\u3002\n\n\n4.3. udp\u6536\u53d1\u7f13\u51b2\u533a\u9ed8\u8ba4\u503c\n[root@ www.linuxidc.com]# cat \/proc\/sys\/net\/core\/rmem_default  \n111616\uff1audp\u63a5\u6536\u7f13\u51b2\u533a\u7684\u9ed8\u8ba4\u503c\n\n[root@ www.linuxidc.com]# cat \/proc\/sys\/net\/core\/wmem_default\n111616\n111616\uff1audp\u53d1\u9001\u7f13\u51b2\u533a\u7684\u9ed8\u8ba4\u503c\n\n4.4. tcp \u6216udp\u6536\u53d1\u7f13\u51b2\u533a\u6700\u5c0f\u503c\ntcp \u6216udp\u63a5\u6536\u7f13\u51b2\u533a\u7684\u6700\u5c0f\u503c\u4e3a 256 bytes\uff0c\u7531\u5185\u6838\u7684\u5b8f\u51b3\u5b9a\uff1b\ntcp \u6216udp\u53d1\u9001\u7f13\u51b2\u533a\u7684\u6700\u5c0f\u503c\u4e3a 2048 bytes\uff0c\u7531\u5185\u6838\u7684\u5b8f\u51b3\u5b9a\n\n\n\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
1 .\u4fee\u6539Socket\u53d1\u9001\u7f13\u5b58\u533a\u548c\u63a5\u6536\u7f13\u5b58\u533a\u5927\u5c0f\u4ee3\u7801\uff1a #include “stdio.h” #include […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-2023","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts\/2023","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2023"}],"version-history":[{"count":6,"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts\/2023\/revisions"}],"predecessor-version":[{"id":2029,"href":"http:\/\/www.51cos.com\/index.php?rest_route=\/wp\/v2\/posts\/2023\/revisions\/2029"}],"wp:attachment":[{"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2023"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.51cos.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}