你是否真的懂 [程序的运行顺序] 多进程 / 进程池

class demo
{
public:
        demo(int age,char *name):m_age(age),m_name(name){}
        void run();
        void child();
        void parent();
public:
        int m_age;
        char *m_name;
        pid_t pid;
        int num[3];
};

void demo::child()
{
        printf("child run %d==%d=%dn",getpid(),pid,m_age);
        while(1){
                sleep(1);
                printf("child run %d=%d=%dn",m_age);
                printf("我要访问demo类成员的数据n");
                printf("demo::m_name=%sn",m_name);
                printf("demo::m_age=%dn",m_age);
                printf("demo::pid=%dn",pid);
                for(int i=0;i<3;i++){
                        printf("demo::num[%d]=%dn",i,num[i]);
                }
        }

}

void demo::parent()
{
        printf("parent run %d=%d=%dn",m_age);
        while(1){
                sleep(1);
                printf("parent run %d=%d=%dn",this->m_name);
                printf("demo::m_age=%dn",this->m_age);
                printf("demo::pid=%dn",this->pid);
                for(int i=0;i<3;i++){
                        printf("demo::num[%d]=%dn",this->num[i]);
                }
        }
}
void demo::run()
{
        cout<<"main process "<<getpid()<<" start"<<endl;
        m_age=0;
        for(int i=0;i<3;i++){
                num[i] = i;//父进程可访问全部的值  123
                pid = fork();//复制之时，子进程是得不到pid的内容的，而父亲运行时是返回它自己  所以一直不变
                if(pid>0){
                        continue;
                }
                else if(pid==0){
                        m_age=i+1;
                        break;
                }
        }


}
int main()
{
        demo *obj = new demo(100,(char*)"jack");
        obj->run();
        if(obj->m_age){
                obj->child();
        }else{
                obj->parent();
        }
        return 0;
}