Linux kernel-linked list

definition of the Linux kernel list (defines a doubly linked list, without data fields)

defined in the/linux-source-3.13.0/include/linux/types.h header file.

1 struct List_head {2         struct list_head *next, *prev; 3 };

We can use this data structure to define linked lists that contain data fields, such as:

 1  struct   My_list  2  3    void  * mydata; // void * can point to any type of data   4  struct  list_head list; //  hide the list pointer  5 }      

Declaration and initialization macros for linked lists (list.h)

defined in the/linux-source-3.13.0/include/linux/list.h.

1 #define List_head_init (name) {& (name), & (name)}

Initializes the head node of a doubly linked list named name. (Name.pre = &name, Name.next = &name)

1 #define 2         struct list_head name = List_head_init (name)

By calling List_head, you declare and initialize one of your own linked headers, generating an empty list. such as: List_head (Mylist_head)

Adding a node to a linked list

Defined in the/linux-source-3.13.0/include/linux/list.h

Specific implementation:

1 /*2 * Insert A new entry between, known consecutive entries.3  *4 * This was only for internal list manipulation where we know5 * The Prev/next entries already!6  */7 #ifndef config_debug_list8 StaticInlinevoid__list_add (structList_head *New,9                               structList_head *Prev,Ten                               structList_head *next) One { ANext->prev =New; -         New->next =Next; -         New->prev =prev; thePrev->next =New; - } - #else - extern void__list_add (structList_head *New, +                               structList_head *Prev, -                               structList_head *next); + #endif A  at /** - * List_add-add a new entry - * @new: New entry to be added - * @head: List head to add it after -  * - * Insert A new entry after the specified head. in * This is good for implementing stacks. -  */ to StaticInlinevoidList_add (structList_head *New,structList_head *head) //Insert new node after head node, loop list does not end, head can be any node  + { -__list_add (New, head, head->next); the } *  $ /**Panax Notoginseng * List_add_tail-add a new entry - * @new: New entry to be added the * @head: List head to add it before +  * A * Insert A new entry before the specified head. the * This was useful for implementing queues. +  */ - StaticInlinevoidList_add_tail (structList_head *New,structList_head *head) //Insert new node before head node  $ { $__list_add (New, head->prev, head); -}

traversing a linked list

Defined in the/linux-source-3.13.0/include/linux/list.h

1 /* * 2 * List_for_each        -       iterate over a list3  * @pos: The &struct list_head to use as        a lo OP cursor. 4 * @head: The       head for your list. 5  */ 6 #define 7          for (pos = (head)->next; pos! = (head); pos = pos->next)

It is actually a for loop that uses the incoming POS as the loop variable to move the POS from top to back (next direction) from the table header until it returns to head.

1 /* * 2 * List_entry-get The struct for this entry 3 * @ptr: The        &struct list_head pointer. 4 * @type: The       type of the struct this was embedded in. 5 * @member: The name of the     list_struct within the struct. 6  */ 7 #define 8         Container_of (PTR, type, member)

LIST_ENTRY macro: A member variable (menber) pointer (PRT) from the struct body (type) to find the first pointer to the struct (type).

Linux kernel-linked list