Linux Kernel: 　container_of　黑科技

 1 #include<stdio.h>
 2 
 3 #define offsetof(TYPE,MEMBER)  ((size_t)&((TYPE*)0)->MEMBER)
 4 
 5 #define container_of(ptr,type,member) ({       6     const typeof( ((type*)0)->member ) *__mptr = (ptr);   7     (type *)( (char *)__mptr - offsetof(type,member) );})
 8 
 9 
10 #define list_entry(ptr,type,member) 11     container_of(ptr,type,member)
12 
13 struct MyStruct {
14     int i_1;
15     int i_2;
16     int i_3;
17     int i_4;
18     int i_5;
19     int i_6;
20     int i_7;
21     int i_8;
22     int i_9;
23     int i_a;
24     int i_b;
25     int i_c;
26     int i_d;
27     int i_e;
28     int i_f;
29     int i_g;
30     int i_h;
31     int i_j;
32 };
33 
34 int main()
35 {
36     struct MyStruct Test = { 0,1,2,3,4,5,6,7,8,9,11,12,13,14,15,16,17,18};
37     printf("Just a test: Test->i_1: %d\n",Test.i_1);
38     int *ptr = &(Test.i_2);
39     printf("Now we got i_2: %d \n",*ptr);
40     struct MyStruct *struct_ptr = container_of(ptr,struct MyStruct,i_2);
41     printf("Now we got struct\n");
42     printf("Test.i_3 is: %d \n",struct_ptr->i_3);
43 
44     return 0;
45 }