Linux下创建两个子进程，并在子进程异常退出时重新创建

墨蓝 2022-05-31 05:23 216阅读 0赞

**直接上代码，看注释即可：**

#include <iostream>
    #include <unistd.h>
    #include <errno.h>
    #include <string.h>
    #include <sys/wait.h>
    
    using namespace std;
    
    static int s_hmi_pid = -1;          // hmi进程id
    static int s_data_process_pid = -1; // DataProcess进程id
    static int s_recreate_count = 0;    // 子进程创建次数统计
    
    // 启动HMI
    void run_hmi()
    {
        char* argv[] = { "hmi", NULL };
    
        const char* path = "/home/hccloud/Desktop/printArgs";
        execv(path, argv);
    }
    
    // 启动DataProcess
    void run_data_process()
    {
        char* argv[] = { "data_process", NULL };
    
        const char* path = "/home/hccloud/Desktop/printArgs";
        execv(path, argv);
    }
    
    int main(/*int argc, char *argv[]*/)
    {
    start:
        printf("start !\n");
        if (s_hmi_pid == -1) // 防止重复创建
        {
            // fork 子进程
            s_hmi_pid = fork();
            if (s_hmi_pid == 0)
            {
                run_hmi();
                return 0; //子进程退出后返回
            }
            printf("hmi pid: %d\n", s_hmi_pid);
        }
    
        if (s_data_process_pid == -1) // 防止重复创建
        {
            // fork 子进程
            s_data_process_pid = fork();
            if (s_data_process_pid == 0)
            {
                run_data_process();
                return 0; //子进程退出后返回
            }
            printf("data_process pid: %d\n", s_data_process_pid);
        }
    
        int status = 0; // 子进程退出状态
        int pid = 0;
        while (s_recreate_count < 6) // 重新创建次数判断
        {
            pid = waitpid(-1, &status, WNOHANG); // 获取子进程状态
            printf("waitpid: %d !\n", pid);
            if (pid == s_hmi_pid && status != 0) // 如果子进程hmi异常退出，则重新创建
            {
                s_hmi_pid = -1; // 重设标志位，使其回到start处时可以重新创建
                s_recreate_count ++;
                goto start;
            }
    
            if (pid == s_data_process_pid && status != 0) // 如果子进程DataProcess异常退出，则重新创建
            {
                s_data_process_pid = -1; // 重设标志位，使其回到start处时可以重新创建
                s_recreate_count ++;
                goto start;
            }
            sleep(1); //
        }
    
        wait(NULL); // 等待子进程全部结束
    
        cout << "Hello World!" << endl;
        return 0;
    }