{"id":405,"date":"2024-08-19T20:02:56","date_gmt":"2024-08-19T12:02:56","guid":{"rendered":"http:\/\/114.55.108.251\/?p=405"},"modified":"2025-03-04T09:46:20","modified_gmt":"2025-03-04T01:46:20","slug":"1","status":"publish","type":"post","link":"https:\/\/guapicoding.com\/?p=405","title":{"rendered":"Linux\u7cfb\u7edf\u7f16\u7a0b Part6\uff08IPC\u3001\u7ba1\u9053\u3001\u5171\u4eab\u5b58\u50a8\u6620\u5c04\uff09"},"content":{"rendered":"\n

IPC\u65b9\u6cd5\uff08Inter-Process Communication\uff09<\/h2>\n\n\n\n

Linux \u73af\u5883\u4e0b\uff0c\u8fdb\u7a0b\u5730\u5740\u7a7a\u95f4\u76f8\u4e92\u72ec\u7acb\uff0c\u6bcf\u4e2a\u8fdb\u7a0b\u5404\u81ea\u6709\u4e0d\u540c\u7684\u7528\u6237\u5730\u5740\u7a7a\u95f4\u3002\u4efb\u4f55\u4e00\u4e2a\u8fdb\u7a0b\u7684\u5168\u5c40\u53d8\u91cf\u5728\u53e6\u4e00\u4e2a\u8fdb\u7a0b\u4e2d\u90fd\u770b\u4e0d\u5230\uff0c\u6240\u4ee5\u8fdb\u7a0b\u548c\u8fdb\u7a0b\u4e4b\u95f4\u4e0d\u80fd\u76f8\u4e92\u8bbf\u95ee\uff0c\u8981\u4ea4\u6362\u6570\u636e\u5fc5\u987b\u901a\u8fc7\u5185\u6838\u3002\u5728\u5185\u6838\u4e2d\u5f00\u8f9f\u4e00\u5757\u7f13\u51b2\u533a\uff0c\u8fdb\u7a0b1\u628a\u6570\u636e\u4ece\u7528\u6237\u7a7a\u95f4\u62f7\u8d1d\u5230\u5185\u6838\u7f13\u51b2\u533a\uff0c\u8fdb\u7a0b2\u518d\u4ece\u5185\u6838\u7f13\u51b2\u533a\u628a\u6570\u636e\u8bfb\u8d70\uff0c\u5185\u6838\u63d0\u4f9b\u7684\u8fd9\u79cd\u673a\u5236\u79f0\u4e3a\u8fdb\u7a0b\u95f4\u901a\u4fe1(IPC\uff0cInter-Process Communication) <\/p>\n\n\n

\n
\"\"<\/div><\/figure>\n<\/div>\n\n\n

\u5e38\u7528\u7684\u8fdb\u7a0b\u95f4\u901a\u4fe1\u65b9\u5f0f\uff1a<\/p>\n\n\n\n

    \n
  • \u7ba1\u9053<\/strong>\uff08\u6700\u7b80\u5355\uff0c\u4f46\u9700\u8981\u8840\u7f18\u5173\u7cfb\uff0c\u4e5f\u53eb\u533f\u540d\u7ba1\u9053\uff09<\/li>\n\n\n\n
  • FIFO\uff08\u7ba1\u9053\u7684\u4e00\u79cd\uff0c\u65e0\u9700\u8840\u7f18\u5173\u7cfb\uff0c\u4e5f\u53eb\u547d\u540d\u7ba1\u9053\uff09<\/li>\n\n\n\n
  • \u4fe1\u53f7<\/strong>\uff08\u5f00\u9500\u6700\u5c0f\uff09<\/li>\n\n\n\n
  • \u5171\u4eab\u6620\u5c04\u533ammap<\/strong>\uff08\u65e0\u8840\u7f18\u5173\u7cfb\uff09<\/li>\n\n\n\n
  • \u672c\u5730\u5957\u63a5\u5b57socket\uff08\u6700\u7a33\u5b9a\uff09<\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n

    \u7ba1\u9053<\/h2>\n\n\n\n

    \u7ba1\u9053\u662f\u4e00\u79cd\u6700\u57fa\u672c\u7684IPC\u673a\u5236\uff0c\u4f5c\u7528\u4e8e\u6709\u8840\u7f18\u5173\u7cfb\u7684\u8fdb\u7a0b\u4e4b\u95f4\uff0c\u5b8c\u6210\u6570\u636e\u4f20\u9012\u3002<\/p>\n\n\n\n

      \n
    • \u539f\u7406\uff1a\u7ba1\u9053\u5b9e\u4e3a\u5185\u6838\u4f7f\u7528\u73af\u5f62\u961f\u5217\u673a\u5236\uff0c\u501f\u52a9\u5185\u6838\u7f13\u51b2\u533a\uff084k\uff09\u5b9e\u73b0<\/li>\n\n\n\n
    • \u7279\u6027\uff1a\n
        \n
      • \u5c5e\u4e8e\u4f2a\u6587\u4ef6\uff0c\u672c\u8d28\u662f\u5185\u6838\u7f13\u51b2\u533a<\/li>\n\n\n\n
      • \u7531\u4e24\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26\u5f15\u7528\uff0c\u4e00\u4e2a\u8868\u793a\u8bfb\u7aef\uff0c\u4e00\u4e2a\u8868\u793a\u5199\u7aef<\/li>\n\n\n\n
      • \u6570\u636e\u4ece\u7ba1\u9053\u7684\u5199\u7aef\u6d41\u5165\u7ba1\u9053\uff0c\u4ece\u8bfb\u7aef\u6d41\u51fa<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • \u5c40\u9650\u6027\uff1a\n
          \n
        • \u8fdb\u7a0b\u4e0d\u80fd\u81ea\u5df1\u5199\u6570\u636e\uff0c\u518d\u81ea\u5df1\u8bfb<\/li>\n\n\n\n
        • \u7ba1\u9053\u4e2d\u6570\u636e\u4e0d\u80fd\u53cd\u590d\u8bfb\u53d6\uff0c\u4e00\u65e6\u8bfb\u8d70\uff0c\u6570\u636e\u5c31\u6ca1\u6709\u4e86<\/li>\n\n\n\n
        • \u534a\u53cc\u5de5\u901a\u4fe1\u65b9\u5f0f\uff0c\u5728\u540c\u4e00\u65f6\u95f4\u6570\u636e\u53ea\u80fd\u5355\u65b9\u5411\u6d41\u52a8<\/li>\n\n\n\n
        • \u53ea\u80fd\u5728\u6709\u8840\u7f18\u5173\u7cfb\u7684\u8fdb\u7a0b\u95f4\u53ef\u7528\uff08\u7236\u5b50\u3001\u5144\u5f1f\uff09<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n

          ps\uff1a\u4f7f\u7528\u547d\u4ee4ulimit -a<\/code>\u53ef\u4ee5\u83b7\u53d6\u7ba1\u9053\u7f13\u51b2\u533a\u5927\u5c0f\uff0c\u9ed8\u8ba4\u4e3a4KB<\/p>\n\n\n\n

          \"\"<\/div><\/figure>\n\n\n\n

          pipe\u51fd\u6570<\/h4>\n\n\n\n

          int pipe(int fd[2]);<\/code> \u521b\u5efa\u5e76\u6253\u5f00\u7ba1\u9053<\/p>\n\n\n\n

            \n
          • \u4f20\u51fa\u53c2\u6570\uff1a\n
              \n
            • fd[0]\uff1a\u8bfb\u7aef<\/li>\n\n\n\n
            • fd[1]\uff1a\u5199\u7aef<\/li>\n<\/ul>\n<\/li>\n\n\n\n
            • \u8fd4\u56de\u503c\uff1a\n
                \n
              • \u6210\u529f\uff1a0<\/li>\n\n\n\n
              • \u5931\u8d25\uff1a-1\uff0cerrno<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n
                \n
                \"\"<\/div><\/figure>\n<\/div>\n\n\n

                \u7ba1\u9053\u7684\u8bfb\u5199\u884c\u4e3a<\/h4>\n\n\n\n

                \u8bfb\u7ba1\u9053\uff1a<\/p>\n\n\n\n

                  \n
                • \u7ba1\u9053\u6709\u6570\u636e\uff1aread\u8fd4\u56de\u5b9e\u9645\u8bfb\u5230\u7684\u5b57\u8282\u6570<\/li>\n\n\n\n
                • \u7ba1\u9053\u65e0\u6570\u636e\uff1a\n
                    \n
                  • \u65e0\u5199\u7aef\uff1aread\u8fd4\u56de0\uff08\u7c7b\u4f3c\u4e8e\u8bfb\u5230\u6587\u4ef6\u5c3e\uff09<\/li>\n\n\n\n
                  • \u6709\u5199\u7aef\uff1aread\u963b\u585e\u7b49\u5f85\uff08\u7b49\u7740\u5199\u7aef\u7684\u6570\u636e\u6d41\u8fc7\u6765\uff09<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n

                    \u5199\u7ba1\u9053\uff1a<\/p>\n\n\n\n

                      \n
                    • \u65e0\u8bfb\u7aef\uff1a\u5f02\u5e38\u7ec8\u6b62\uff08SIGPIPE\u4fe1\u53f7\u5bfc\u81f4\uff09<\/li>\n\n\n\n
                    • \u6709\u8bfb\u7aef\uff1a\n
                        \n
                      • \u7ba1\u9053\u5df2\u6ee1\uff1a\u963b\u585e\u7b49\u5f85<\/li>\n\n\n\n
                      • \u7ba1\u9053\u672a\u6ee1\uff1a\u8fd4\u56de\u5199\u51fa\u7684\u5b57\u8282\u4e2a\u6570<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n

                        \u7f16\u7a0b\u7ec3\u4e60\uff1a<\/h4>\n\n\n\n

                        \u4f7f\u7528\u7ba1\u9053\u5b9e\u73b0\u7236\u5b50\u8fdb\u7a0b\u95f4\u901a\u4fe1<\/strong>\uff0c\u5b8c\u6210\uff1als | wc -l<\/code>\uff0c\u5047\u5b9a\u7236\u8fdb\u7a0b\u5b9e\u73b0ls<\/code>\uff0c\u5b50\u8fdb\u7a0b\u5b9e\u73b0wc<\/code><\/p>\n\n\n\n

                        \u63d0\u793a\uff1als<\/code>\u547d\u4ee4\u6b63\u5e38\u4f1a\u5c06\u7ed3\u679c\u5199\u5230stdout\uff0c\u4f46\u73b0\u5728\u8981\u5199\u5165\u7ba1\u9053\u7684\u5199\u7aef\uff1bwc -l<\/code>\u6b63\u5e38\u5e94\u8be5\u4ecestdin\u8bfb\u53d6\u6570\u636e\uff0c\u4f46\u73b0\u5728\u8981\u4ece\u7ba1\u9053\u7684\u8bfb\u7aef\u8bfb<\/p>\n\n\n\n

                        \u5b8c\u6574\u4ee3\u7801\uff1a<\/p>\n\n\n\n

                        #include<stdio.h>\n#include<stdlib.h>\n#include<string.h>\n#include<errno.h>\n#include<unistd.h>\n#include<pthread.h>\n\n\/\/\u4f7f\u7528\u7ba1\u9053\u5b9e\u73b0\u7236\u5b50\u8fdb\u7a0b\u95f4\u901a\u4fe1\uff0c\u5b8c\u6210\uff1als | wc -l\n\/\/\u5047\u5b9a\u7236\u8fdb\u7a0b\u5b9e\u73b0ls\uff0c\u5b50\u8fdb\u7a0b\u5b9e\u73b0wc\nint main(int argc, char *argv[]) {\n    int ret;\n    int fd[2];\n    ret = pipe(fd); \/\/\u5148\u521b\u5efa\u7ba1\u9053\uff0c\u518dfork\u8fdb\u7a0b\uff0c\u8fd9\u6837\u7236\u5b50\u8fdb\u7a0b\u90fd\u62e5\u6709\u4e86\u8fd9\u4e2a\u7ba1\u9053\n    if(ret == -1) {\n        perror(\"pipe error:\");\n        exit(1);\n    }\n\n    pid_t pid;\n    pid = fork(); \/\/\u73b0\u5728\u7236\u5b50\u8fdb\u7a0b\u90fd\u638c\u7ba1\u7740\u540c\u4e00\u4e2a\u7ba1\u9053\n                   \/\/\u56e0\u6b64\u7236\u8fdb\u7a0b\u8981\u5173\u95ed\u8bfb\u7aef\uff0c\u5b50\u8fdb\u7a0b\u5173\u95ed\u5199\u7aef\n    if(pid > 0) {\n        close(fd[0]);\n        dup2(fd[1], STDOUT_FILENO);  \/\/\u91cd\u5b9a\u5411\n        execlp(\"ls\", \"ls\", NULL);\n    } else if(pid == 0) {\n        close(fd[1]);\n        dup2(fd[0], STDIN_FILENO);\n        execlp(\"wc\", \"wc\", \"-l\", NULL);\n    } else {\n        perror(\"fork error:\");\n    }\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
                        FIFO<\/h4>\n\n\n\n
                        FIFO\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u7ba1\u9053\uff0c\u5e38\u88ab\u79f0\u4e3a\u547d\u540d\u7ba1\u9053\uff0c\u53ef\u4ee5\u7528\u4e8e\u65e0\u8840\u7f18\u5173\u7cfb\u7684\u8fdb\u7a0b\u95f4\u901a\u4fe1<\/p>\n\n\n\n
                        \u521b\u5efa\u547d\u540d\u7ba1\u9053\uff1amkfifo<\/code>\uff08\u547d\u4ee4\u6216\u51fd\u6570\u90fd\u53ef\u4ee5\uff09<\/p>\n\n\n\n
                        \u5b9e\u73b0\u975e\u8840\u7f18\u5173\u7cfb\u8fdb\u7a0b\u95f4\u901a\u4fe1\uff1a\u628afifo\u5f53\u6210\u6587\u4ef6\u64cd\u4f5c\u5373\u53ef<\/p>\n\n\n\n
                          \n
                        • \u8bfb\u7aef\uff1aopen fifo O_RDONLY<\/code><\/li>\n\n\n\n
                        • \u5199\u7aef\uff1aopen fifo O_WRONLY<\/code><\/li>\n<\/ul>\n\n\n\n
                          \n\n\n\n
                          \u5171\u4eab\u5b58\u50a8\u6620\u5c04\uff08mmap\uff09<\/h2>\n\n\n\n
                          \u6587\u4ef6\u5b9e\u73b0\u8fdb\u7a0b\u95f4\u901a\u4fe1<\/h4>\n\n\n\n
                          \u6253\u5f00\u7684\u6587\u4ef6\u662f\u5185\u6838\u4e2d\u7684\u4e00\u5757\u7f13\u51b2\u533a\uff0c\u591a\u4e2a\u65e0\u8840\u7f18\u5173\u7cfb\u7684\u8fdb\u7a0b\u53ef\u4ee5\u540c\u65f6\u8bbf\u95ee\u8be5\u6587\u4ef6<\/p>\n\n\n\n
                          \u5b58\u50a8\u6620\u5c04I\/O<\/h4>\n\n\n\n
                          \u5b58\u50a8\u6620\u5c04I\/O\u4f7f\u4e00\u4e2a\u78c1\u76d8\u6587\u4ef6\u4e0e\u5b58\u50a8\u7a7a\u95f4\u7684\u4e00\u4e2a\u7f13\u51b2\u533a\u76f8\u6620\u5c04\uff08\u76ee\u7684\uff1a\u5f53\u6587\u4ef6\u5728\u78c1\u76d8\u4e0a\u65f6\uff0c\u53ea\u80fd\u4f7f\u7528write<\/code>\u3001read<\/code>\u7b49\u7cfb\u7edf\u8c03\u7528\u51fd\u6570\uff0c\u800c\u6620\u5c04\u5230\u5b58\u50a8\u7a7a\u95f4\u4e0a\uff0c\u64cd\u4f5c\u6587\u4ef6\uff08\u6307\u9488\uff09\u53ef\u7528\u7684\u51fd\u6570\u5c31\u5f88\u591a\u4e86\uff0c\u6bd4\u5982strcpy<\/code>\u3001memcmp<\/code>\u51fd\u6570\u7b49\u7b49\uff09<\/p>\n\n\n\n
                          \u521b\u5efa\/\u91ca\u653e\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a<\/h4>\n\n\n\n
                          void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset);<\/code> \u521b\u5efa\u5171\u4eab\u5185\u5b58\u6620\u5c04 <\/p>\n\n\n\n
                            \n
                          • \u53c2\u6570\uff1a\n
                              \n
                            • addr\uff1a\u6307\u5b9a\u6620\u5c04\u533a\u7684\u9996\u5730\u5740\uff08\u901a\u5e38\u4f20NULL\uff0c\u8868\u793a\u8ba9\u7cfb\u7edf\u81ea\u52a8\u5206\u914d\uff09<\/li>\n\n\n\n
                            • length\uff1a\u8868\u793a\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a\u7684\u5927\u5c0f\uff08<= \u6587\u4ef6\u7684\u5b9e\u9645\u5927\u5c0f\uff09<\/li>\n\n\n\n
                            • prot\uff1a\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a\u7684\u8bfb\u5199\u5c5e\u6027 \n
                                \n
                              • PROT_READ<\/li>\n\n\n\n
                              • PROT_WRITE<\/li>\n\n\n\n
                              • PROT_READ|PROT_WRITE<\/li>\n<\/ul>\n<\/li>\n\n\n\n
                              • flags\uff1a\u6807\u6ce8\u5171\u4eab\u5185\u5b58\u7684\u5171\u4eab\u5c5e\u6027\n
                                  \n
                                • MAP_SHARED<\/li>\n\n\n\n
                                • MAP_PRIVATE<\/li>\n\n\n\n
                                • MAP_ANONYMOUS<\/li>\n<\/ul>\n<\/li>\n\n\n\n
                                • fd\uff1a\u7528\u4e8e\u521b\u5efa\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a\u7684\u90a3\u4e2a\u6587\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26<\/li>\n\n\n\n
                                • offset\uff1a\u504f\u79fb\u4f4d\u7f6e\uff0c\u5fc5\u987b\u662f 4k \u7684\u6574\u6570\u500d\uff08\u9ed8\u8ba4\u4e3a0\uff0c\u8868\u793a\u6620\u5c04\u6587\u4ef6\u5168\u90e8\uff09<\/li>\n<\/ul>\n<\/li>\n\n\n\n
                                • \u8fd4\u56de\u503c\uff1a\n
                                    \n
                                  • \u6210\u529f\uff1a\u6620\u5c04\u533a\u7684\u9996\u5730\u5740<\/li>\n\n\n\n
                                  • \u5931\u8d25\uff1aMAP_FAILED (void*(-1))\uff0c errno<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
                                    int munmap(void *addr, size_t length);<\/code> \u91ca\u653e\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a <\/p>\n\n\n\n
                                      \n
                                    • \u53c2\u6570\uff1a\n
                                        \n
                                      • addr\uff1ammap<\/code>\u51fd\u6570\u7684\u8fd4\u56de\u503c<\/li>\n\n\n\n
                                      • length\uff1a\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a\u7684\u5927\u5c0f<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
                                        \u6ce8\u610f\u4e8b\u9879\uff1a<\/p>\n\n\n\n
                                          \n
                                        1. \u7528\u4e8e\u521b\u5efa\u6620\u5c04\u533a\u7684\u6587\u4ef6\u5927\u5c0f\u4e3a0\uff0c\u5b9e\u9645\u521b\u5efa\u975e0\u5927\u5c0f\u7684\u6620\u5c04\u533a\uff0c\u62a5\u9519\u201c\u603b\u7ebf\u9519\u8bef\u201d<\/li>\n\n\n\n
                                        2. \u7528\u4e8e\u521b\u5efa\u6620\u5c04\u533a\u7684\u6587\u4ef6\u5927\u5c0f\u4e3a0\uff0c\u5b9e\u9645\u521b\u5efa0\u5927\u5c0f\u7684\u6620\u5c04\u533a\uff0c\u62a5\u9519\u201c\u65e0\u6548\u53c2\u6570\u201d<\/li>\n\n\n\n
                                        3. \u7528\u4e8e\u521b\u5efa\u6620\u5c04\u533a\u7684\u6587\u4ef6\u8bfb\u5199\u5c5e\u6027\u4e3a\u53ea\u8bfb\uff0c\u6620\u5c04\u533a\u5c5e\u6027\u4e3a\u8bfb\u3001\u5199\uff0c\u62a5\u9519\u201c\u65e0\u6548\u53c2\u6570\u201d<\/li>\n\n\n\n
                                        4. \u521b\u5efa\u6620\u5c04\u533a\u9700\u8981\u90a3\u4e2a\u6587\u4ef6\u6709\u8bfb\u6743\u9650\uff0c\u53ea\u6709\u5199\u6743\u9650\u662f\u4e0d\u884c\u7684\u3002\u5f53\u8bbf\u95ee\u6743\u9650\u6307\u5b9a\u4e3aMAP_SHARED\u65f6\uff0c mmap\u7684\u8bfb\u5199\u6743\u9650\u5e94\u8be5 <=\u6587\u4ef6\u7684open\u6743\u9650<\/strong><\/li>\n\n\n\n
                                        5. \u6587\u4ef6\u63cf\u8ff0\u7b26fd\u5728mmap\u521b\u5efa\u6620\u5c04\u533a\u5b8c\u6210\u540e\u5373\u53ef\u5173\u95ed\uff0c\u540e\u7eed\u8bbf\u95ee\u6587\u4ef6\u662f\u7528\u5730\u5740\u8bbf\u95ee\u7684<\/li>\n\n\n\n
                                        6. offset\u504f\u79fb\u91cf\u5fc5\u987b\u662f 4096\u7684\u6574\u6570\u500d\uff08\u56e0\u4e3aMMU\u6620\u5c04\u7684\u6700\u5c0f\u5355\u4f4d\u662f4k\uff09<\/li>\n\n\n\n
                                        7. \u5bf9\u7533\u8bf7\u7684\u6620\u5c04\u533a\u5185\u5b58\uff0c\u4e0d\u80fd\u8d8a\u754c\u8bbf\u95ee <\/li>\n\n\n\n
                                        8. munmap\u7528\u4e8e\u91ca\u653e\u7684\u5730\u5740\uff0c\u5fc5\u987b\u662fmmap\u7533\u8bf7\u8fd4\u56de\u7684\u5730\u5740<\/li>\n\n\n\n
                                        9. \u6620\u5c04\u533a\u8bbf\u95ee\u6743\u9650\u4e3aMAP_PRIVATE\uff0c\u5bf9\u5185\u5b58\u6240\u505a\u7684\u6240\u6709\u4fee\u6539\u53ea\u5728\u5185\u5b58\u4e0a\u751f\u6548\uff0c\u4e0d\u4f1a\u6620\u5c04\u5230\u78c1\u76d8\u4e0a <\/li>\n\n\n\n
                                        10. \u6620\u5c04\u533a\u8bbf\u95ee\u6743\u9650\u4e3aMAP_PRIVATE\uff0c\u53ea\u9700\u8981open\u6587\u4ef6\u65f6\u6709\u8bfb\u6743\u9650\u5373\u53ef\uff0c\u7528\u4e8e\u521b\u5efa\u6620\u5c04\u533a <\/li>\n\n\n\n
                                        11. mmap\u521b\u5efa\u6620\u5c04\u533a\u51fa\u9519\u7387\u5f88\u9ad8\uff0c\u56e0\u6b64\u4e00\u5b9a\u8981\u68c0\u67e5\u51fd\u6570\u8fd4\u56de\u503c\uff0c\u786e\u4fdd\u6620\u5c04\u533a\u5efa\u7acb\u6210\u529f\u518d\u8fdb\u884c\u540e\u7eed\u64cd\u4f5c<\/li>\n<\/ol>\n\n\n\n
                                          mmap\u51fd\u6570\u7684\u4fdd\u9669\u8c03\u7528\u65b9\u5f0f<\/strong>\uff1a<\/p>\n\n\n\n
                                            \n
                                          1. fd = open(\"\u6587\u4ef6\u540d\"\uff0c O_RDWR);<\/code><\/li>\n\n\n\n
                                          2. mmap(NULL, \u6709\u6548\u6587\u4ef6\u5927\u5c0f\uff0c PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);<\/code><\/li>\n<\/ol>\n\n\n\n
                                            \u7f16\u7a0b\u7ec3\u4e60\uff1a\u521b\u5efa\u5171\u4eab\u5185\u5b58\u6620\u5c04\u533a\u8fdb\u884c\u6587\u4ef6\u8bfb\u5199<\/h4>\n\n\n\n
                                            #include <stdio.h>\n#include <stdlib.h>\n#include <string.h>\n#include <fcntl.h>\n#include <unistd.h>\n#include <pthread.h>\n#include <sys\/stat.h>\n#include <dirent.h>\n#include <errno.h>\n#include <sys\/mman.h>\n\nvoid sys_err(const char *str) {\n    perror(str);\n    exit(1);\n}\n\nint main(int argc, char *argv[]) {\n    char *p = NULL;\n    int fd;\n    \n    fd = open(\"testmap\", O_RDWR | O_CREAT | O_TRUNC, 0644);\n    if(fd == -1) {\n        sys_err(\"open error\");\n    }\n    \n    ftruncate(fd, 20); \/\/\u5c06\u6587\u4ef6\u5927\u5c0f\u622a\u65ad\u4e3a20\u5b57\u8282\uff0c\u9700\u8981\u5199\u6743\u9650\n    int len = lseek(fd, 0, SEEK_END); \/\/\u83b7\u53d6\u6587\u4ef6\u5f53\u524d\u5927\u5c0f\n\n    p = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);\n    if(p == MAP_FAILED) {\n        sys_err(\"mmap error\");\n    }\n    \n    close(fd);  \n\n    \/\/\u8fd9\u6837\u5c31\u53ef\u4ee5\u4f7f\u7528p\u5bf9\u6587\u4ef6\u8fdb\u884c\u8bfb\u5199\u64cd\u4f5c\n    strcpy(p, \"hello mmap\"); \/\/\u5199\n    printf(\"---%s\\n\", p); \/\/\u8bfb\n\n    int ret = munmap(p, len);\n    if(ret == -1) {\n        sys_err(\"munmap error\");\n    }\n\n    return 0;\n}\n<\/code><\/pre>\n\n\n\n
                                            mmap\u7236\u5b50\u8fdb\u7a0b\u901a\u4fe1<\/h4>\n\n\n\n
                                            \u7236\u8fdb\u7a0b\u5148\u521b\u5efa\u6620\u5c04\u533a\uff1aopen(\u2026, O_RDWR); mmap(\u2026, MAP_SHARED, \u2026); <\/code><\/p>\n\n\n\n
                                            fork()\u518d\u521b\u5efa\u5b50\u8fdb\u7a0b <\/p>\n\n\n\n
                                            \u4e00\u4e2a\u8fdb\u7a0b\u8bfb\uff0c \u53e6\u5916\u4e00\u4e2a\u8fdb\u7a0b\u5199 <\/p>\n\n\n\n
                                            \u203bmmap\u65e0\u8840\u7f18\u5173\u7cfb\u8fdb\u7a0b\u95f4\u901a\u4fe1\u3010\u5fc5\u987b\u4f1a\u5199\u3011<\/h4>\n\n\n\n
                                            \u4e24\u4e2a\u8fdb\u7a0b\u6253\u5f00\u540c\u4e00\u4e2a\u6587\u4ef6\uff0c\u521b\u5efa\u6620\u5c04\u533a\uff0c\u6307\u5b9a\u53c2\u6570flags\u4e3aMAP_SHARED<\/p>\n\n\n\n
                                            \u4e00\u4e2a\u8fdb\u7a0b\u5199\u5165\uff0c\u53e6\u5916\u4e00\u4e2a\u8fdb\u7a0b\u8bfb\u51fa <\/p>\n\n\n\n
                                            mmap_w.c\uff1a<\/p>\n\n\n\n
                                            #include <stdio.h>\n#include <stdlib.h>\n#include <string.h>\n#include <fcntl.h>\n#include <unistd.h>\n#include <sys\/mman.h>\n#include <dirent.h>\n#include <errno.h>\n\nstruct student {\n    int id;\n    char name[256];\n    int age;\n};\n\nvoid sys_err(const char *str) {\n    perror(str);\n    exit(1);\n}\n\nint main(int argc, char *argv[]) {\n    struct student stu = {1, \"guapi\", 18};\n    struct student *p;\n    int fd = 0;\n\n    fd = open(\"test_brommp\", O_RDWR | O_CREAT | O_TRUNC, 0664);\n    if (fd == -1) {\n        sys_err(\"open error\");\n    }\n\n    ftruncate(fd, sizeof(stu));\n\n    p = mmap(NULL, sizeof(stu), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);\n    if (p == MAP_FAILED) {\n        sys_err(\"mmap error\");\n    }\n\n    close(fd);\n\n    while (1) {\n        memcpy(p, &stu, sizeof(stu));\n        stu.id++;\n        sleep(1);\n    }\n\n    munmap(p, sizeof(stu));\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
                                            mmap_r.c\uff1a<\/p>\n\n\n\n
                                            #include <stdio.h>\n#include <stdlib.h>\n#include <string.h>\n#include <fcntl.h>\n#include <unistd.h>\n#include <sys\/mman.h>\n#include <dirent.h>\n#include <errno.h>\n\nstruct student {\n    int id;\n    char name[256];\n    int age;\n};\n\nvoid sys_err(const char *str) {\n    perror(str);\n    exit(1);\n}\n\nint main(int argc, char *argv[]) {\n    struct student stu;\n    struct student *p; \n    int fd = 0;\n    \n    fd = open(\"test_brommp\", O_RDONLY);\n    if(fd == -1) {\n        sys_err(\"open error\");\n    }\n    \n    p = mmap(NULL, sizeof(stu), PROT_READ, MAP_SHARED, fd, 0);\n    if(p == MAP_FAILED) {\n        sys_err(\"mmap error\");\n    }\n\n    close(fd);\n\n    while(1) {\n        printf(\"%d %s %d\\n\", p->id, p->name, p->age);\n        sleep(1);\n    }\n\n    munmap(p, sizeof(stu));\n\n    return 0;\n}\n\n<\/code><\/pre>\n\n\n\n
                                            ps\uff1a\u65e0\u8840\u7f18\u5173\u7cfb\u8fdb\u7a0b\u95f4\u901a\u4fe1\uff0c\u7528mmap\u65b9\u6cd5\u6570\u636e\u53ef\u4ee5\u91cd\u590d\u8bfb\u53d6\uff0c\u800c\u7528fifo\u7684\u8bdd\u6570\u636e\u53ea\u80fd\u8bfb\u53d6\u4e00\u6b21 <\/p>\n\n\n\n
                                            \u533f\u540d\u6620\u5c04<\/h4>\n\n\n\n
                                            \u4e0d\u518d\u4f9d\u9644\u4e8e\u6587\u4ef6\u5efa\u7acb\u5171\u4eab\u6620\u5c04\u533a\uff0c\u4f46\u53ea\u80fd\u7528\u4e8e\u6709\u8840\u7f18\u5173\u7cfb\u8fdb\u7a0b\u95f4\u901a\u4fe1 <\/p>\n\n\n\n
                                            p = (int *)mmap(NULL, 40, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);<\/code><\/p>\n\n\n\n
                                            <\/p>\n","protected":false},"excerpt":{"rendered":"
                                            IPC\u65b9\u6cd5\uff08Inter-Process Communication\uff09 Linux \u73af\u5883\u4e0b\uff0c\u8fdb\u7a0b\u5730\u5740\u7a7a\u95f4\u76f8\u4e92\u72ec\u7acb […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,10],"tags":[22,21,24,23],"class_list":{"0":"post-405","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"hentry","6":"category-linux","8":"tag-ipc","9":"tag-linux","10":"tag-mmap","11":"tag-23"},"_links":{"self":[{"href":"https:\/\/guapicoding.com\/index.php?rest_route=\/wp\/v2\/posts\/405","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/guapicoding.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/guapicoding.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/guapicoding.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/guapicoding.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=405"}],"version-history":[{"count":100,"href":"https:\/\/guapicoding.com\/index.php?rest_route=\/wp\/v2\/posts\/405\/revisions"}],"predecessor-version":[{"id":645,"href":"https:\/\/guapicoding.com\/index.php?rest_route=\/wp\/v2\/posts\/405\/revisions\/645"}],"wp:attachment":[{"href":"https:\/\/guapicoding.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=405"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/guapicoding.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=405"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/guapicoding.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}