{"id":423,"date":"2022-05-26T15:33:08","date_gmt":"2022-05-26T07:33:08","guid":{"rendered":"https:\/\/scutvk.cn\/?p=423"},"modified":"2022-05-26T15:33:08","modified_gmt":"2022-05-26T07:33:08","slug":"c-c-linux-%e4%b8%8d%e5%90%8c%e8%bf%9b%e7%a8%8b%e4%bf%a1%e5%8f%b7%e9%87%8f%e5%8f%8a%e6%95%b0%e6%8d%ae%e5%85%b1%e4%ba%ab-%e7%94%9f%e4%ba%a7%e8%80%85%e6%b6%88%e8%b4%b9%e8%80%85%e9%97%ae%e9%a2%98","status":"publish","type":"post","link":"https:\/\/scutvk.cn\/?p=423","title":{"rendered":"C\/C++ Linux \u4e0d\u540c\u8fdb\u7a0b\u4fe1\u53f7\u91cf\u53ca\u6570\u636e\u5171\u4eab-\u751f\u4ea7\u8005\u6d88\u8d39\u8005\u95ee\u9898"},"content":{"rendered":"\n

\u6b64\u4e3a\u534e\u5357\u7406\u5de5\u5927\u5b66\u64cd\u4f5c\u7cfb\u7edf\u5b9e\u9a8c\u4e09\uff0cby 2020 Network Engineering VK\uff0c\u8be6\u60c5\u5982\u4e0b\uff1a<\/p>\n\n\n\n

\u5b9e\u9a8c\u8981\u6c42\uff1a<\/strong><\/p>\n\n\n\n

1\uff0e\u751f\u4ea7\u8005\u6d88\u8d39\u8005\u95ee\u9898\uff08\u4fe1\u53f7\u91cf\uff09<\/p>\n\n\n\n

\u53c2\u8003\u6559\u6750\u4e2d\u7684\u751f\u4ea7\u8005\u6d88\u8d39\u8005\u7b97\u6cd5\uff0c\u521b\u5efa5\u4e2a\u8fdb\u7a0b\uff0c\u5176\u4e2d\u4e24\u4e2a\u8fdb\u7a0b\u4e3a\u751f\u4ea7\u8005\u8fdb\u7a0b\uff0c3\u4e2a\u8fdb\u7a0b\u4e3a\u6d88\u8d39\u8005\u8fdb\u7a0b\u3002\u4e00\u4e2a\u751f\u4ea7\u8005\u8fdb\u7a0b\u8bd5\u56fe\u4e0d\u65ad\u5730\u5728\u4e00\u4e2a\u7f13\u51b2\u4e2d\u5199\u5165\u5927\u5199\u5b57\u6bcd\uff0c\u53e6\u4e00\u4e2a\u751f\u4ea7\u8005\u8fdb\u7a0b\u8bd5\u56fe\u4e0d\u65ad\u5730\u5728\u7f13\u51b2\u4e2d\u5199\u5165\u5c0f\u5199\u5b57\u6bcd\u30023\u4e2a\u6d88\u8d39\u8005\u4e0d\u65ad\u5730\u4ece\u7f13\u51b2\u4e2d\u8bfb\u53d6\u4e00\u4e2a\u5b57\u7b26\u5e76\u8f93\u51fa\u3002\u4e3a\u4e86\u4f7f\u5f97\u7a0b\u5e8f\u7684\u8f93\u51fa\u6613\u4e8e\u770b\u5230\u7ed3\u679c\uff0c\u4eff\u7167\u7684\u5b9e\u4f8b\u7a0b\u5e8f\uff0c\u5206\u522b\u5728\u751f\u4ea7\u8005\u548c\u6d88\u8d39\u8005\u8fdb\u7a0b\u7684\u5408\u9002\u7684\u4f4d\u7f6e\u52a0\u5165\u4e00\u4e9b\u968f\u673a\u7761\u7720\u65f6\u95f4\u3002<\/p>\n\n\n\n

\u53ef\u9009\u7684\u5b9e\u9a8c\uff1a\u5728\u4e0a\u9762\u5b9e\u9a8c\u7684\u57fa\u7840\u4e0a\u5b9e\u73b0\u90e8\u5206\u6d88\u8d39\u8005\u6709\u9009\u62e9\u5730\u6d88\u8d39\u67d0\u4e9b\u4ea7\u54c1\u3002\u4f8b\u5982\u4e00\u4e2a\u6d88\u8d39\u8005\u53ea\u6d88\u8d39\u5c0f\u5199\u5b57\u7b26\uff0c\u4e00\u4e2a\u6d88\u8d39\u8005\u53ea\u6d88\u8d39\u5927\u5199\u5b57\u6bcd\uff0c\u800c\u53e6\u4e00\u4e2a\u6d88\u8d39\u8005\u5219\u65e0\u9009\u62e9\u5730\u6d88\u8d39\u4efb\u4f55\u4ea7\u54c1\u3002\u6d88\u8d39\u8005\u8981\u6d88\u8d39\u7684\u4ea7\u54c1\u6ca1\u6709\u65f6\uff0c\u6d88\u8d39\u8005\u8fdb\u7a0b\u88ab\u963b\u585e\u3002\u6ce8\u610f\u7f13\u51b2\u7684\u7ba1\u7406\u3002<\/p>\n\n\n\n

\n\n\n\n

\u5b9e\u73b0\u601d\u8def\uff1a<\/strong><\/p>\n\n\n\n

\u4fe1\u53f7\u91cf\uff1a<\/p>\n\n\n\n

\u91c7\u7528semaphore.h\uff0c\u5934\u6587\u4ef6\u5404\u51fd\u6570\u8be6\u7ec6\u8bf4\u660e\u53ef\u53c2\u8003\u6b64\u9875<semaphore.h> (opengroup.org)<\/a>\uff0c\u82f1\u6587\u96be\u770b\u770b\u4e0d\u61c2\u53ef\u770b\u8fd9\u4e2a\u535a\u5ba2semaphore – \u7b80\u4e66 (jianshu.com)<\/a>\uff0c\u6ce8\u610f\u70b9\uff1ainit\u65f6\u6ce8\u610f\u8981\u8bbe\u7f6e\u4e3a\u8fdb\u7a0b\u95f4\u4f5c\u7528\uff0c\u800c\u4e0d\u662f\u9650\u5236\u4e8e\u540c\u4e00\u8fdb\u7a0b\u5185\u3002<\/p>\n\n\n\n

\u6570\u636e\u5171\u4eab\uff1a<\/p>\n\n\n\n

\u6478\u7d22\u8bb8\u4e45\uff0c\u6ca1\u6709\u50cf\u591a\u7ebf\u7a0b\u7f16\u7a0b\u90a3\u6837\u7684\u76f4\u63a5\u53d8\u91cf\u5171\u4eab\u65b9\u6cd5\uff0c\u6700\u540e\u91c7\u7528\u4e86\u5171\u4eab\u5185\u5b58\uff0c\u4f7f\u7528\u65b9\u6cd5\u53c2\u8003\u535a\u5ba2\uff1aLinux\u8fdb\u7a0b\u95f4\u901a\u4fe1\uff08\u516d\uff09\uff1a\u5171\u4eab\u5185\u5b58 shmget()\u3001shmat()\u3001shmdt()\u3001shmctl() – 52php – \u535a\u5ba2\u56ed (cnblogs.com)<\/a>\uff0c\u5982\u679c\u4e0d\u662f\u6df1\u5165\u4e86\u89e3\u7684\u8bdd\uff0c\u6b64\u535a\u5ba2\u76f4\u63a5\u770b\u5171\u4eab\u5185\u5b58\u600e\u4e48\u7528\u5c31\u884c<\/p>\n\n\n\n

\u7a0b\u5e8f\u6267\u884c\uff1a<\/p>\n\n\n\n

\u5c06\u8981\u8bfb\u5199\u5171\u4eab\u5185\u5b58\u65f6\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n

\u5c1d\u8bd5\u83b7\u53d6\u4fe1\u53f7\u91cf—>\u8bfb\/\u5199\u5171\u4eab\u5185\u5b58—>\u5f52\u8fd8\u4fe1\u53f7\u91cf<\/p>\n\n\n\n

\n\n\n\n

\u6e90\u7801\uff1a<\/strong><\/p>\n\n\n\n

\u5e0c\u671b\u5927\u5bb6\u53ef\u4ee5\u4ece\u6211\u7684\u6e90\u7801\u4e2d\u83b7\u5f97\u6536\u83b7\/\u5b66\u4e60\uff0c\u800c\u4e0d\u662f\u76f4\u63a5\u590d\u5236\u7c98\u8d34\u5e94\u4ed8\u5b9e\u9a8c\u3002<\/p>\n\n\n\n

\u5934\u6587\u4ef6<\/p>\n\n\n\n

shmdata.h<\/p>\n\n\n\n

#ifndef _SHMDATA_H_HEADER\r\n#define _SHMDATA_H_HEADER\r\n \r\n \r\nstruct shared_use_st\r\n{\r\n    int Acounter; \/\/ \u5927\u5199\u8ba1\u6570\r\n    int acounter; \/\/ \u5c0f\u5199\u8ba1\u6570\r\n};\r\n<\/code><\/pre>\n\n\n\n
\u4e3b\u7a0b\u5e8f\uff1a<\/p>\n\n\n\n
#include <iostream>\r\n#include <unistd.h>  \r\n#include <stdio.h> \r\n#include <semaphore.h>\r\n#include <sys\/shm.h>\r\n#include \"shmdata.h\"\r\nusing namespace std;\r\nint main()\r\n{\r\n    pid_t fpid;\r\n    int fatherpid = getpid();\r\n    sem_t sm;\r\n    sem_init(&sm, 1, 1);\r\n\r\n    void *shm = NULL;\r\n    struct shared_use_st *shared; \/\/ \u6307\u5411shm\r\n\r\n    \/\/ \u521b\u5efa\u5171\u4eab\u5185\u5b58\r\n    int shmid = shmget((key_t)1234, sizeof(struct shared_use_st), 0666|IPC_CREAT);\r\n    if (shmid == -1)\r\n    {\r\n        fprintf(stderr, \"\u521b\u5efa\u5171\u4eab\u5185\u5b58\u5931\u8d25\\n\");\r\n        exit(EXIT_FAILURE);\r\n    }\r\n\r\n\r\n    \/\/ \u521b\u5efa\u5b50\u8fdb\u7a0b\r\n    for (int i = 0; i < 5; ++i)\r\n    {\r\n        fpid = fork();   \/\/\u8fd4\u56de\u5b50\u8fdb\u7a0b\u7684\u8fdb\u7a0bID\r\n        if (fpid == 0 || fpid < 0)\r\n        {\r\n            break;\r\n        }\r\n    }\r\n\r\n\r\n    \/\/ \u5c06\u5171\u4eab\u5185\u5b58\u8fde\u63a5\u5230\u5f53\u524d\u8fdb\u7a0b\u7684\u5730\u5740\u7a7a\u95f4\r\n    shm = shmat(shmid, 0, 0);\r\n    if (shm == (void *)-1)\r\n    {\r\n        fprintf(stderr, \"\u5171\u4eab\u5185\u5b58\u8fde\u63a5\u5931\u8d25\\n\");\r\n        exit(EXIT_FAILURE);\r\n    }\r\n    printf(\"\\n\u5171\u4eab\u5185\u5b58\u8fde\u63a5\u81f3 %X\\n\", (int*)shm);\r\n\r\n    \/\/ \u8bbe\u7f6e\u5171\u4eab\u5185\u5b58\r\n    shared = (struct shared_use_st*)shm; \/\/ \u6ce8\u610f\uff1ashm\u6709\u70b9\u7c7b\u4f3c\u901a\u8fc7 malloc() \u83b7\u53d6\u5230\u7684\u5185\u5b58\uff0c\u6240\u4ee5\u8fd9\u91cc\u9700\u8981\u505a\u4e2a \u7c7b\u578b\u5f3a\u5236\u8f6c\u6362\r\n\r\n    \/\/ \u6839\u636e\u5b50\u8fdb\u7a0b\u7684\u8eab\u4efd\u4e0d\u540c\uff0c\u5b89\u6392\u4efb\u52a1\r\n    if (fpid <= 0)\r\n    \/\/ \u5b50\u8fdb\u7a0b\u5904\u7406\r\n    {\r\n        int diff = getpid() - fatherpid;\r\n        if (diff % 2 == 0)\r\n        \/\/ \u751f\u4ea7\u8005\r\n        {\r\n            if (diff == 2)\r\n            \/\/ \u751f\u4ea7\u5927\u5199\u5b57\u6bcdA\r\n            {\r\n                while(1)\r\n                {\r\n                    sem_wait(&sm);     \/\/\u83b7\u53d6\u8d44\u6e90 \uff0c\u76f8\u5f53\u4e8eP\u64cd\u4f5c\r\n                    shared->Acounter = shared->Acounter + 1;\r\n                    cout << \"A\u751f\u4ea7\u8005 A:\\t\" << shared->Acounter << \"\\ta:\" << shared->acounter << endl;\r\n                    sem_post(&sm);    \/\/\u91ca\u653e\u8d44\u6e90\uff0c\u76f8\u5f53\u4e8eV\u64cd\u4f5c\r\n                    sleep(1);\r\n                }\r\n            }else\r\n            \/\/ \u751f\u4ea7\u5c0f\u5199\u5b57\u6bcda\r\n            {\r\n                while(1)\r\n                {\r\n                    sem_wait(&sm);     \/\/\u83b7\u53d6\u8d44\u6e90 \uff0c\u76f8\u5f53\u4e8eP\u64cd\u4f5c\r\n                    shared->acounter = shared->acounter + 1;\r\n                    cout << \"a\u751f\u4ea7\u8005 A:\\t\" << shared->Acounter << \"\\ta:\" << shared->acounter << endl;\r\n                    sem_post(&sm);    \/\/\u91ca\u653e\u8d44\u6e90\uff0c\u76f8\u5f53\u4e8eV\u64cd\u4f5c\r\n                    sleep(1);\r\n                }\r\n            }\r\n        }else\r\n        \/\/ \u6d88\u8d39\u8005\r\n        {\r\n            if (diff == 1)\r\n            \/\/ A\u6d88\u8d39\u8005\r\n            {\r\n                while(1)\r\n                {\r\n                    sem_wait(&sm);     \/\/\u83b7\u53d6\u8d44\u6e90 \uff0c\u76f8\u5f53\u4e8eP\u64cd\u4f5c\r\n                    if (shared->Acounter > 0)\r\n                    {\r\n                        shared->Acounter = shared->Acounter - 1;\r\n                        cout << \"A\u6d88\u8d39\u8005 A:\\t\" << shared->Acounter << \"\\ta:\" << shared->acounter << endl;                        \r\n                    }\r\n                    sem_post(&sm);    \/\/\u91ca\u653e\u8d44\u6e90\uff0c\u76f8\u5f53\u4e8eV\u64cd\u4f5c\r\n                    sleep(1);\r\n                }               \r\n            }\r\n            else if (diff == 3)\r\n            \/\/ a\u6d88\u8d39\u8005\r\n            {\r\n                while(1)\r\n                {\r\n                    sem_wait(&sm);     \/\/\u83b7\u53d6\u8d44\u6e90 \uff0c\u76f8\u5f53\u4e8eP\u64cd\u4f5c\r\n                    if (shared->acounter > 0)\r\n                    {\r\n                        shared->acounter = shared->acounter - 1;\r\n                        cout << \"a\u6d88\u8d39\u8005 A:\\t\" << shared->Acounter << \"\\ta:\" << shared->acounter << endl;\r\n                    }\r\n                    sem_post(&sm);    \/\/\u91ca\u653e\u8d44\u6e90\uff0c\u76f8\u5f53\u4e8eV\u64cd\u4f5c\r\n                    sleep(1);\r\n                }\r\n            }\r\n            else if (diff == 5)\r\n            \/\/ aA\u6d88\u8d39\u8005\r\n            {\r\n                while(1)\r\n                {\r\n                    sem_wait(&sm);     \/\/\u83b7\u53d6\u8d44\u6e90 \uff0c\u76f8\u5f53\u4e8eP\u64cd\u4f5c\r\n                    if (shared->Acounter > 0)\r\n                    {\r\n                        shared->Acounter = shared->Acounter - 1;\r\n                        cout << \"aA\u6d88\u8d39\u8005 A:\\t\" << shared->Acounter << \"\\ta:\" << shared->acounter << endl;\r\n                    }else if (shared->acounter > 0)\r\n                    {\r\n                        shared->acounter = shared->acounter - 1;\r\n                        cout << \"aA\u6d88\u8d39\u8005 A:\\t\" << shared->Acounter << \"\\ta:\" << shared->acounter << endl;\r\n                    }\r\n                    sem_post(&sm);    \/\/\u91ca\u653e\u8d44\u6e90\uff0c\u76f8\u5f53\u4e8eV\u64cd\u4f5c\r\n                    sleep(1);\r\n                }                \r\n            }\r\n        }\r\n    }else\r\n    \/\/ \u7236\u8fdb\u7a0b\u5904\u7406\r\n    {\r\n        cout << \"\u7236\u8fdb\u7a0b\" << getpid() << endl;\r\n    }\r\n    return 0;\r\n}\r\n<\/code><\/pre>\n\n\n\n
\u8fd0\u884c\u622a\u56fe\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6b64\u4e3a\u534e\u5357\u7406\u5de5\u5927\u5b66\u64cd\u4f5c\u7cfb\u7edf\u5b9e\u9a8c\u4e09\uff0cby 2020 N…<\/p>\n","protected":false},"author":1,"featured_media":424,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[5],"tags":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/scutvk.cn\/wp-content\/uploads\/2022\/05\/1.png","_links":{"self":[{"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/posts\/423"}],"collection":[{"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/scutvk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=423"}],"version-history":[{"count":1,"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/posts\/423\/revisions"}],"predecessor-version":[{"id":425,"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/posts\/423\/revisions\/425"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/scutvk.cn\/index.php?rest_route=\/wp\/v2\/media\/424"}],"wp:attachment":[{"href":"https:\/\/scutvk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=423"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scutvk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=423"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scutvk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=423"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}