Messages in this thread Patch in this message | | | Subject | [PATCH 01/02] Add back plist docs | From | Daniel Walker <> | Date | Tue, 03 Jan 2006 09:53:30 -0800 |
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Add back copyrights, documentation, and function descriptions. Updated with Oleg's comments .
Signed-Off-By: Daniel Walker <dwalker@mvista.com>
Index: linux-2.6.15/include/linux/plist.h =================================================================== --- linux-2.6.15.orig/include/linux/plist.h +++ linux-2.6.15/include/linux/plist.h @@ -1,3 +1,77 @@ +/* + * Descending-priority-sorted double-linked list + * + * (C) 2002-2003 Intel Corp + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>. + * + * 2001-2005 (c) MontaVista Software, Inc. + * Daniel Walker <dwalker@mvista.com> + * + * (C) 2005 Thomas Gleixner <tglx@linutronix.de> + * Tested and made it functional. + * + * Licensed under the FSF's GNU Public License v2 or later. + * + * Based on simple lists (include/linux/list.h). + * + * + * This is a priority-sorted list of nodes; each node has a + * priority from INT_MIN (highest) to INT_MAX (lowest). + * + * Addition is O(K), removal is O(1), change of priority of a node is + * O(K) and K is the number of RT priority levels used in the system. + * (1 <= K <= 99) + * + * This list is really a list of lists: + * + * - The tier 1 list is the prio_list, different priority nodes. + * + * - The tier 2 list is the node_list, serialized nodes. + * + * Simple ASCII art explanation: + * + * |HEAD | + * | | + * |prio_list.prev|<------------------------------------| + * |prio_list.next|<->|pl|<->|pl|<--------------->|pl|<-| + * |10 | |10| |21| |21| |21| |40| (prio) + * | | | | | | | | | | | | + * | | | | | | | | | | | | + * |node_list.next|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-| + * |node_list.prev|<------------------------------------| + * + * The nodes on the prio_list list are sorted by priority to simplify + * the insertion of new nodes. There are no nodes with duplicate + * priorites on the list. + * + * The nodes on the node_list is ordered by priority and can contain + * entries which have the same priority. Those entries are ordered + * FIFO + * + * Addition means: look for the prio_list node in the prio_list + * for the priority of the node and insert it before the node_list + * entry of the next prio_list node. If it is the first node of + * that priority, add it to the prio_list in the right position and + * insert it into the serialized node_list list + * + * Removal means remove it from the node_list and remove it from + * the prio_list if the node_list list_head is non empty. In case + * of removal from the prio_list it must be checked whether other + * entries of the same priority are on the list or not. If there + * is another entry of the same priority then this entry has to + * replace the removed entry on the prio_list. If the entry which + * is removed is the only entry of this priority then a simple + * remove from both list is sufficient. + * + * INT_MIN is the highest priority, 0 is the medium highest, INT_MAX + * is lowest priority. + * + * No locking is done, up to the caller. + * + * NOTE: This implementation does not offer as many interfaces as + * linux/list.h does -- it is lazily minimal. You are welcome to + * add them. + */ #ifndef _LINUX_PLIST_H_ #define _LINUX_PLIST_H_ @@ -13,24 +87,46 @@ struct pl_node { struct pl_head plist; }; +/** + * #PL_HEAD_INIT - static struct pl_head initializer + * + * @head: struct pl_head variable name + */ #define PL_HEAD_INIT(head) \ { \ .prio_list = LIST_HEAD_INIT((head).prio_list), \ .node_list = LIST_HEAD_INIT((head).node_list), \ } +/** + * #PL_NODE_INIT - static struct pl_node initializer + * + * @node: struct pl_node variable name + * @__prio: initial node priority + */ #define PL_NODE_INIT(node, __prio) \ { \ .prio = (__prio), \ .plist = PL_HEAD_INIT((node).plist), \ } +/** + * pl_head_init - dynamic struct pl_head initializer + * + * @head: &struct pl_head pointer + */ static inline void pl_head_init(struct pl_head *head) { INIT_LIST_HEAD(&head->prio_list); INIT_LIST_HEAD(&head->node_list); } +/** + * pl_node_init - Dynamic struct pl_node initializer + * + * @node: &struct pl_node pointer + * @prio: initial node priority + */ static inline void pl_node_init(struct pl_node *node, int prio) { node->prio = prio; @@ -40,23 +136,63 @@ static inline void pl_node_init(struct p extern void plist_add(struct pl_node *node, struct pl_head *head); extern void plist_del(struct pl_node *node); +/** + * plist_for_each - iterate over the plist + * + * @pos1: the type * to use as a loop counter. + * @head: the head for your list. + */ #define plist_for_each(pos, head) \ list_for_each_entry(pos, &(head)->node_list, plist.node_list) +/** + * plist_for_each_entry_safe - iterate over a plist of given type safe + * against removal of list entry + * + * @pos1: the type * to use as a loop counter. + * @n1: another type * to use as temporary storage + * @head: the head for your list. + */ #define plist_for_each_safe(pos, n, head) \ list_for_each_entry_safe(pos, n, &(head)->node_list, plist.node_list) +/** + * plist_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 plist_for_each_entry(pos, head, mem) \ list_for_each_entry(pos, &(head)->node_list, mem.plist.node_list) +/** + * plist_for_each_entry_safe - iterate over list of given type safe against + * removal of list entry + * + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ #define plist_for_each_entry_safe(pos, n, head, mem) \ list_for_each_entry_safe(pos, n, &(head)->node_list, mem.plist.node_list) +/** + * plist_empty - return !0 if a plist_head is empty + * + * @head: &struct pl_head pointer + */ static inline int plist_empty(const struct pl_head *head) { return list_empty(&head->node_list); } +/** + * plist_unhashed - return !0 if plist_node is not on a list + * + * @node: &struct pl_node pointer + */ static inline int plist_unhashed(const struct pl_node *node) { return list_empty(&node->plist.node_list); @@ -64,9 +200,23 @@ static inline int plist_unhashed(const s /* All functions below assume the pl_head is not empty. */ +/** + * plist_first_entry - get the struct for the first entry + * + * @ptr: the &struct pl_head pointer. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + */ #define plist_first_entry(head, type, member) \ container_of(plist_first(head), type, member) +/** + * plist_first - return the first node (and thus, highest priority) + * + * @head: the &struct pl_head pointer + * + * Assumes the plist is _not_ empty. + */ static inline struct pl_node* plist_first(const struct pl_head *head) { return list_entry(head->node_list.next, struct pl_node, plist.node_list); Index: linux-2.6.15/lib/plist.c =================================================================== --- linux-2.6.15.orig/lib/plist.c +++ linux-2.6.15/lib/plist.c @@ -1,9 +1,32 @@ + /* - * lib/plist.c - Priority List implementation. + * lib/plist.c + * + * Descending-priority-sorted double-linked list + * + * (C) 2002-2003 Intel Corp + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>. + * + * 2001-2005 (c) MontaVista Software, Inc. + * Daniel Walker <dwalker@mvista.com> + * + * (C) 2005 Thomas Gleixner <tglx@linutronix.de> + * Tested and made it functional. + * + * Licensed under the FSF's GNU Public License v2 or later. + * + * Based on simple lists (include/linux/list.h). */ #include <linux/plist.h> +/** + * plist_add - add @node to @head returns !0 if the plist prio changed, 0 + * otherwise. XXX: Fix return code. + * + * @node: &struct pl_node pointer + * @head: &struct pl_head pointer + */ void plist_add(struct pl_node *node, struct pl_head *head) { struct pl_node *iter; @@ -25,6 +48,12 @@ eq_prio: list_add_tail(&node->plist.node_list, &iter->plist.node_list); } +/** + * plist_del - Remove a @node from plist. returns !0 if the plist prio + * changed, 0 otherwise. XXX: Fix return code. + * + * @node: &struct pl_node pointer + */ void plist_del(struct pl_node *node) { if (!list_empty(&node->plist.prio_list)) {
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