# hdf\_dlist.h ## **Overview** **Related Modules:** [DriverUtils](DriverUtils.md) **Description:** Declares doubly linked list structures and interfaces. This file provides interfaces such as inserting a node from the head or tail of a doubly linked list, checking whether a doubly linked list is empty, traversing a doubly linked list, and merging doubly linked lists. **Since:** 1.0 **Version:** 1.0 ## **Summary** ## Data Structures

Data Structure Name	Description
DListHead	Describes a doubly linked list.

## Macros

Macro Name and Value	Description
CONTAINER_OF(ptr, type, member) (type )((char )(ptr) - (char )&((type )0)->member)	Obtains the address of a structure variable from its member address.
DLIST_FIRST_ENTRY(ptr, type, member) CONTAINER_OF((ptr)->next, type, member)	Obtains the first node of a doubly linked list.
DLIST_LAST_ENTRY(ptr, type, member) CONTAINER_OF((ptr)->prev, type, member)	Obtains the last node of a doubly linked list.
DLIST_FOR_EACH_ENTRY(pos, head, type, member)	Traverses all nodes in a doubly linked list.
DLIST_FOR_EACH_ENTRY_SAFE(pos, tmp, head, type, member)	Traverses all nodes in a doubly linked list. This function is used to delete the nodes pointed to by pos during traversal.

## Functions

Function Name	Description
DListHeadInit (struct DListHead *head)	static void Initializes a doubly linked list.
DListIsEmpty (const struct DListHead *head)	static bool Checks whether a doubly linked list is empty.
DListRemove (struct DListHead *entry)	static void Removes a node from a doubly linked list.
DListInsertHead (struct DListHead entry, struct DListHead head)	static void Inserts a node from the head of a doubly linked list.
DListInsertTail (struct DListHead entry, struct DListHead head)	static void Inserts a node from the tail of a doubly linked list.
DListMerge (struct DListHead list, struct DListHead head)	static void Merges two linked lists by adding the list specified by list to the head of the list specified by head and initializes the merged list.