Update list.h

Author: Barenboim

list.h

@@ -2,7 +2,7 @@
 #define _LINUX_LIST_H
 
 /*
- * Simple doubly linked list implementation.
+ * Circular doubly linked list implementation.
  *
  * Some of the internal functions ("__xxx") are useful when
  * manipulating whole lists rather than single entries, as
@@ -20,6 +20,13 @@ struct list_head {
 #define LIST_HEAD(name) \
 	struct list_head name = LIST_HEAD_INIT(name)
 
+/**
+ * INIT_LIST_HEAD - Initialize a list_head structure
+ * @list: list_head structure to be initialized.
+ *
+ * Initializes the list_head to point to itself.  If it is a list header,
+ * the result is an empty list.
+ */
 static inline void INIT_LIST_HEAD(struct list_head *list)
 {
 	list->next = list;
@@ -32,41 +39,41 @@ static inline void INIT_LIST_HEAD(struct list_head *list)
  * This is only for internal list manipulation where we know
  * the prev/next entries already!
  */
-static inline void __list_add(struct list_head *node,
-							  struct list_head *prev,
-							  struct list_head *next)
+static inline void __list_add(struct list_head *entry,
+			      struct list_head *prev,
+			      struct list_head *next)
 {
-	next->prev = node;
-	node->next = next;
-	node->prev = prev;
-	prev->next = node;
+	next->prev = entry;
+	entry->next = next;
+	entry->prev = prev;
+	prev->next = entry;
 }
 
 /**
  * list_add - add a new entry
- * @new: new entry to be added
+ * @entry: new entry to be added
  * @head: list head to add it after
  *
  * Insert a new entry after the specified head.
  * This is good for implementing stacks.
  */
-static inline void list_add(struct list_head *node, struct list_head *head)
+static inline void list_add(struct list_head *entry, struct list_head *head)
 {
-	__list_add(node, head, head->next);
+	__list_add(entry, head, head->next);
 }
 
 /**
  * list_add_tail - add a new entry
- * @new: new entry to be added
+ * @entry: new entry to be added
  * @head: list head to add it before
  *
  * Insert a new entry before the specified head.
  * This is useful for implementing queues.
  */
-static inline void list_add_tail(struct list_head *node,
-								 struct list_head *head)
+static inline void list_add_tail(struct list_head *entry,
+				 struct list_head *head)
 {
-	__list_add(node, head->prev, head);
+	__list_add(entry, head->prev, head);
 }
 
 /*
@@ -85,7 +92,8 @@ static inline void __list_del(struct list_head *prev, struct list_head *next)
 /**
  * list_del - deletes entry from list.
  * @entry: the element to delete from the list.
- * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
+ * Note: list_empty() on entry does not return true after this, the entry is
+ * in an undefined state.
  */
 static inline void list_del(struct list_head *entry)
 {
@@ -94,25 +102,25 @@ static inline void list_del(struct list_head *entry)
 
 /**
  * list_move - delete from one list and add as another's head
- * @list: the entry to move
+ * @entry: the entry to move
  * @head: the head that will precede our entry
  */
-static inline void list_move(struct list_head *list, struct list_head *head)
+static inline void list_move(struct list_head *entry, struct list_head *head)
 {
-	__list_del(list->prev, list->next);
-	list_add(list, head);
+	__list_del(entry->prev, entry->next);
+	list_add(entry, head);
 }
 
 /**
  * list_move_tail - delete from one list and add as another's tail
- * @list: the entry to move
+ * @entry: the entry to move
  * @head: the head that will follow our entry
  */
-static inline void list_move_tail(struct list_head *list,
-								  struct list_head *head)
+static inline void list_move_tail(struct list_head *entry,
+				  struct list_head *head)
 {
-	__list_del(list->prev, list->next);
-	list_add_tail(list, head);
+	__list_del(entry->prev, entry->next);
+	list_add_tail(entry, head);
 }
 
 /**
@@ -124,29 +132,30 @@ static inline int list_empty(const struct list_head *head)
 	return head->next == head;
 }
 
-static inline void __list_splice(struct list_head *list,
-								 struct list_head *head)
+static inline void __list_splice(const struct list_head *list,
+				 struct list_head *prev,
+				 struct list_head *next)
 {
 	struct list_head *first = list->next;
 	struct list_head *last = list->prev;
-	struct list_head *at = head->next;
 
-	first->prev = head;
-	head->next = first;
+	first->prev = prev;
+	prev->next = first;
 
-	last->next = at;
-	at->prev = last;
+	last->next = next;
+	next->prev = last;
 }
 
 /**
  * list_splice - join two lists
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  */
-static inline void list_splice(struct list_head *list, struct list_head *head)
+static inline void list_splice(const struct list_head *list,
+			       struct list_head *head)
 {
 	if (!list_empty(list))
-		__list_splice(list, head);
+		__list_splice(list, head, head->next);
 }
 
 /**
@@ -157,10 +166,10 @@ static inline void list_splice(struct list_head *list, struct list_head *head)
  * The list at @list is reinitialised
  */
 static inline void list_splice_init(struct list_head *list,
-									struct list_head *head)
+				    struct list_head *head)
 {
 	if (!list_empty(list)) {
-		__list_splice(list, head);
+		__list_splice(list, head, head->next);
 		INIT_LIST_HEAD(list);
 	}
 }
@@ -175,44 +184,44 @@ static inline void list_splice_init(struct list_head *list,
 	((type *)((char *)(ptr)-(size_t)(&((type *)0)->member)))
 
 /**
- * list_for_each	-	iterate over a list
+ * list_for_each - iterate over a list
  * @pos:	the &struct list_head to use as a loop counter.
  * @head:	the head for your list.
  */
 #define list_for_each(pos, head) \
 	for (pos = (head)->next; pos != (head); pos = pos->next)
 
 /**
- * list_for_each_prev	-	iterate over a list backwards
+ * list_for_each_prev - iterate over a list backwards
  * @pos:	the &struct list_head to use as a loop counter.
  * @head:	the head for your list.
  */
 #define list_for_each_prev(pos, head) \
 	for (pos = (head)->prev; pos != (head); pos = pos->prev)
 
 /**
- * list_for_each_safe	-	iterate over a list safe against removal of list entry
+ * list_for_each_safe - iterate over a list safe against removal of list entry
  * @pos:	the &struct list_head to use as a loop counter.
  * @n:		another &struct list_head to use as temporary storage
  * @head:	the head for your list.
  */
 #define list_for_each_safe(pos, n, head) \
 	for (pos = (head)->next, n = pos->next; pos != (head); \
-		 pos = n, n = pos->next)
+	     pos = n, n = pos->next)
 
 /**
- * list_for_each_entry	-	iterate over list of given type
+ * list_for_each_entry - iterate over list of given type
  * @pos:	the type * to use as a loop counter.
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  */
 #define list_for_each_entry(pos, head, member) \
 	for (pos = list_entry((head)->next, typeof (*pos), member); \
-		 &pos->member != (head); \
-		 pos = list_entry(pos->member.next, typeof (*pos), member))
+	     &pos->member != (head); \
+	     pos = list_entry(pos->member.next, typeof (*pos), member))
 
-/**
- * Single-linked list. Added by Xie Han <xiehan@sogou-inc.com>.
+/*
+ * Singly linked list implementation.
  */
 
 struct slist_node {
@@ -223,7 +232,7 @@ struct slist_head {
 	struct slist_node first, *last;
 };
 
-#define SLIST_HEAD_INIT(name)	{ { (struct slist_node *)0 }, &(name).first }
+#define SLIST_HEAD_INIT(name) { { (struct slist_node *)0 }, &(name).first }
 
 #define SLIST_HEAD(name) \
 	struct slist_head name = SLIST_HEAD_INIT(name)
@@ -234,32 +243,32 @@ static inline void INIT_SLIST_HEAD(struct slist_head *list)
 	list->last = &list->first;
 }
 
-static inline void slist_add_after(struct slist_node *node,
-								   struct slist_node *prev,
-								   struct slist_head *list)
+static inline void slist_add_after(struct slist_node *entry,
+				   struct slist_node *prev,
+				   struct slist_head *list)
 {
-	node->next = prev->next;
-	prev->next = node;
-	if (!node->next)
-		list->last = node;
+	entry->next = prev->next;
+	prev->next = entry;
+	if (!entry->next)
+		list->last = entry;
 }
 
-static inline void slist_add_head(struct slist_node *node,
-								  struct slist_head *list)
+static inline void slist_add_head(struct slist_node *entry,
+				  struct slist_head *list)
 {
-	slist_add_after(node, &list->first, list);
+	slist_add_after(entry, &list->first, list);
 }
 
-static inline void slist_add_tail(struct slist_node *node,
-								  struct slist_head *list)
+static inline void slist_add_tail(struct slist_node *entry,
+				  struct slist_head *list)
 {
-	node->next = (struct slist_node *)0;
-	list->last->next = node;
-	list->last = node;
+	entry->next = (struct slist_node *)0;
+	list->last->next = entry;
+	list->last = entry;
 }
 
 static inline void slist_del_after(struct slist_node *prev,
-								   struct slist_head *list)
+				   struct slist_head *list)
 {
 	prev->next = prev->next->next;
 	if (!prev->next)
@@ -271,35 +280,35 @@ static inline void slist_del_head(struct slist_head *list)
 	slist_del_after(&list->first, list);
 }
 
-static inline int slist_empty(struct slist_head *list)
+static inline int slist_empty(const struct slist_head *list)
 {
 	return !list->first.next;
 }
 
-static inline void __slist_splice(struct slist_head *list,
-								  struct slist_node *at,
-								  struct slist_head *head)
+static inline void __slist_splice(const struct slist_head *list,
+				  struct slist_node *prev,
+				  struct slist_head *head)
 {
-	list->last->next = at->next;
-	at->next = list->first.next;
+	list->last->next = prev->next;
+	prev->next = list->first.next;
 	if (!list->last->next)
 		head->last = list->last;
 }
 
-static inline void slist_splice(struct slist_head *list,
-								struct slist_node *at,
-								struct slist_head *head)
+static inline void slist_splice(const struct slist_head *list,
+				struct slist_node *prev,
+				struct slist_head *head)
 {
 	if (!slist_empty(list))
-		__slist_splice(list, at, head);
+		__slist_splice(list, prev, head);
 }
 
 static inline void slist_splice_init(struct slist_head *list,
-									 struct slist_node *at,
-									 struct slist_head *head)
+				     struct slist_node *prev,
+				     struct slist_head *head)
 {
 	if (!slist_empty(list)) {
-		__slist_splice(list, at, head);
+		__slist_splice(list, prev, head);
 		INIT_SLIST_HEAD(list);
 	}
 }
@@ -312,11 +321,11 @@ static inline void slist_splice_init(struct slist_head *list,
 
 #define slist_for_each_safe(pos, prev, head) \
 	for (prev = &(head)->first, pos = prev->next; pos; \
-		 prev = prev->next == pos ? pos : prev, pos = prev->next)
+	     prev = prev->next == pos ? pos : prev, pos = prev->next)
 
 #define slist_for_each_entry(pos, head, member) \
 	for (pos = slist_entry((head)->first.next, typeof (*pos), member); \
-		 &pos->member != (struct slist_node *)0; \
-		 pos = slist_entry(pos->member.next, typeof (*pos), member))
+	     &pos->member != (struct slist_node *)0; \
+	     pos = slist_entry(pos->member.next, typeof (*pos), member))
 
 #endif