传入的结构体指针强制转为实例化结构体*v

struct val *v = (struct val *)arg;//传入的结构体指针强制转为实例化结构体*v

struct val{
   int num1;
      int num2;
  };

void *text3(void *arg)
{
    struct val *v = (struct val *)arg;
     int num3=v—>num1；
     int num4=v->num2；
     printf("arg is v.num1:%d,v.num2:%d\n",num3,num4);
    // printf("arg is v.num1:%d,v.num2:%d\n",v->num1,v->num2);
     pthread_exit(NULL);
}
例子：=======>>>>【C】——如何用线程进行参数的传递;