Use Linux kernel list in user programs

Use Linux kernel list-general Linux technology-Linux programming and kernel information in your program. The following is a detailed description. In our daily programs, we often encounter writing linked lists. For c ++ programs, stl provides two templates: list and vector, which are easy to use. If you restrict the compiler to use only c, many people encapsulate related interfaces by themselves, which takes unnecessary time. The linux Kernel provides the object-oriented linked list: include/linux/list. h.

Reprinted Please retain original (msn and email: jinglexy at yahoo dot com dot cn), Suzhou Koda Technology Research Institute.

Here is the linked list program obtained from kernel 2.6.10 of montavista. There are some differences between kernel 2.6 and kernel 2.4. Only the usage is described here.

First, modify the source program and add the following program after # ifdef _ KERNEL _ and 3 include statements:

(Blue is added)

# Ifdef _ KERNEL __


# Include

# Include

# Include

# Elif 1


# Define prefetch (x) 1

# Define smp_wmb (x) 1


# Define offsetof (TYPE, MEMBER) (size_t) & (TYPE *) 0)-> MEMBER)

# Define container_of (ptr, type, member )({\

Const typeof (type *) 0)-> member) * _ mptr = (ptr );\

(Type *) (char *) _ mptr-offsetof (type, member ));})



The following is a test procedure:

# Include

# Include

# Include

# Include "list. h"



# Define DEBUG do {\

Printf ("************************** \ n ");\

Printf ("list 1: \ n ");\

List_for_each (I, & list1 ){\

Mylist_t * ops = \

List_entry (I ,\

Mylist_t, list );\

Printf ("pf is % d \ n", ops-> pf );\

}\

\

Printf ("list 2: \ n ");\

List_for_each (I, & list2 ){\

Mylist_t * ops = \

List_entry (I ,\

Mylist_t, list );\

Printf ("pf is % d \ n", ops-> pf );\

}\

} While (0 );



# If 1

Typedef struct _ mylist {

Int pf;

Char name [FILENAME_MAX];



Struct list_head list;

} Mylist_t;

# Else

Typedef struct _ mylist {

Struct list_head list;



Int pf;

Char name [FILENAME_MAX];

} Mylist_t;

# Endif



Static LIST_HEAD (list1);/* define 2 list */

Static LIST_HEAD (list2 );



Int main (int argc, char * argv [])

{

Struct list_head * I;

Mylist_t elem1;

Mylist_t elem2;



INIT_LIST_HEAD (& list1 );

INIT_LIST_HEAD (& list2 );

Elem1.pf = 2008;

Elem2.pf = 8002;

List_add (& elem1.list, & list1 );

List_del (& elem1.list );



List_add (& elem1.list, & list1 );

List_add_tail (& elem2.list, & list1 );

DEBUG;



/* Move element to another list */

List_move_tail (& elem2.list, & list2 );

List_splice_init (& list1, & list2);/* merge */

DEBUG;



Return 0;

}

Compile with gcc, run the gcc test. c program, and the result is exactly what we want.