/*
  * These are list macros/functions derived from the Linux kernel.
  * All original copyright (GPLv2) applies here.
  *        -- nenolod
  */
 
 #ifndef __LIST_H
 #define __LIST_H
 
 #include "common.h"
 
 #ifndef _WIN32
 #define SINLINE static inline
 #else
 #define SINLINE static
 #endif
 
 #ifdef _WIN32
 #define typeof(x)   Client 
 /* ^ FIXME if/when Microsoft supports this.
  * All functions use Client at the moment, with the exception of CAP, which has
  * to use list_for_each_entry2 because of it
  * Yeah this looks ugly and hacky.. thanks nenolod for making all code use this
  * non-portable gcc-specific stuff and violating all our code rules. Once again.
  */
 #endif
 
 /**
  * container_of - cast a member of a structure out to the containing structure
  * @ptr:        the pointer to the member.
  * @type:       the type of the container struct this is embedded in.
  * @member:     the name of the member within the struct.
  *
  */
 #define container_of(ptr, type, member) \
 	((type *)( (char *)ptr - offsetof(type, member) ))
 
 struct list_head {
 	struct list_head *next, *prev;
 };
 
 /*
  * Simple doubly linked list implementation.
  *
  * Some of the internal functions ("__xxx") are useful when
  * manipulating whole lists rather than single entries, as
  * sometimes we already know the next/prev entries and we can
  * generate better code by using them directly rather than
  * using the generic single-entry routines.
  */
 
 #define LIST_HEAD_INIT(name) { &(name), &(name) }
 
 #define LIST_HEAD(name) \
 	struct list_head name = LIST_HEAD_INIT(name)
 
 SINLINE void INIT_LIST_HEAD(struct list_head *list)
 {
 	list->next = list;
 	list->prev = list;
 }
 
 /*
  * Insert a new entry between two known consecutive entries.
  *
  * This is only for internal list manipulation where we know
  * the prev/next entries already!
  */
 SINLINE void __list_add(struct list_head *new,
 			      struct list_head *prev,
 			      struct list_head *next)
 {
 	next->prev = new;
 	new->next = next;
 	new->prev = prev;
 	prev->next = new;
 }
 
 /**
  * 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.
  * This is good for implementing stacks.
  */
 SINLINE void list_add(struct list_head *new, struct list_head *head)
 {
 	__list_add(new, head, head->next);
 }
 
 
 /**
  * list_add_tail - add a new entry
  * @new: 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.
  */
 SINLINE void list_add_tail(struct list_head *new, struct list_head *head)
 {
 	__list_add(new, head->prev, head);
 }
 
 /*
  * Delete a list entry by making the prev/next entries
  * point to each other.
  *
  * This is only for internal list manipulation where we know
  * the prev/next entries already!
  */
 SINLINE void __list_del(struct list_head * prev, struct list_head * next)
 {
 	next->prev = prev;
 	prev->next = 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.
  */
 SINLINE void __list_del_entry(struct list_head *entry)
 {
 	__list_del(entry->prev, entry->next);
 }
 
 SINLINE void list_del(struct list_head *entry)
 {
 	__list_del_entry(entry);
 	INIT_LIST_HEAD(entry);
 }
 
 /**
  * list_replace - replace old entry by new one
  * @old : the element to be replaced
  * @new : the new element to insert
  *
  * If @old was empty, it will be overwritten.
  */
 SINLINE void list_replace(struct list_head *old,
 				struct list_head *new)
 {
 	new->next = old->next;
 	new->next->prev = new;
 	new->prev = old->prev;
 	new->prev->next = new;
 }
 
 SINLINE void list_replace_init(struct list_head *old,
 					struct list_head *new)
 {
 	list_replace(old, new);
 	INIT_LIST_HEAD(old);
 }
 
 /**
  * list_del_init - deletes entry from list and reinitialize it.
  * @entry: the element to delete from the list.
  */
 SINLINE void list_del_init(struct list_head *entry)
 {
 	__list_del_entry(entry);
 	INIT_LIST_HEAD(entry);
 }
 
 /**
  * list_move - delete from one list and add as another's head
  * @list: the entry to move
  * @head: the head that will precede our entry
  */
 SINLINE void list_move(struct list_head *list, struct list_head *head)
 {
 	__list_del_entry(list);
 	list_add(list, head);
 }
 
 /**
  * list_move_tail - delete from one list and add as another's tail
  * @list: the entry to move
  * @head: the head that will follow our entry
  */
 SINLINE void list_move_tail(struct list_head *list,
 				  struct list_head *head)
 {
 	__list_del_entry(list);
 	list_add_tail(list, head);
 }
 
 /**
  * list_is_last - tests whether @list is the last entry in list @head
  * @list: the entry to test
  * @head: the head of the list
  */
 SINLINE int list_is_last(const struct list_head *list,
 				const struct list_head *head)
 {
 	return list->next == head;
 }
 
 /**
  * list_empty - tests whether a list is empty
  * @head: the list to test.
  */
 SINLINE int list_empty(const struct list_head *head)
 {
 	return head->next == head;
 }
 
 /**
  * list_empty_careful - tests whether a list is empty and not being modified
  * @head: the list to test
  *
  * Description:
  * tests whether a list is empty _and_ checks that no other CPU might be
  * in the process of modifying either member (next or prev)
  *
  * NOTE: using list_empty_careful() without synchronization
  * can only be safe if the only activity that can happen
  * to the list entry is list_del_init(). Eg. it cannot be used
  * if another CPU could re-list_add() it.
  */
 SINLINE int list_empty_careful(const struct list_head *head)
 {
 	struct list_head *next = head->next;
 	return (next == head) && (next == head->prev);
 }
 
 /**
  * list_rotate_left - rotate the list to the left
  * @head: the head of the list
  */
 SINLINE void list_rotate_left(struct list_head *head)
 {
 	struct list_head *first;
 
 	if (!list_empty(head)) {
 		first = head->next;
 		list_move_tail(first, head);
 	}
 }
 
 /**
  * list_is_singular - tests whether a list has just one entry.
  * @head: the list to test.
  */
 SINLINE int list_is_singular(const struct list_head *head)
 {
 	return !list_empty(head) && (head->next == head->prev);
 }
 
 SINLINE void __list_cut_position(struct list_head *list,
 		struct list_head *head, struct list_head *entry)
 {
 	struct list_head *new_first = entry->next;
 	list->next = head->next;
 	list->next->prev = list;
 	list->prev = entry;
 	entry->next = list;
 	head->next = new_first;
 	new_first->prev = head;
 }
 
 /**
  * list_cut_position - cut a list into two
  * @list: a new list to add all removed entries
  * @head: a list with entries
  * @entry: an entry within head, could be the head itself
  *	and if so we won't cut the list
  *
  * This helper moves the initial part of @head, up to and
  * including @entry, from @head to @list. You should
  * pass on @entry an element you know is on @head. @list
  * should be an empty list or a list you do not care about
  * losing its data.
  *
  */
 SINLINE void list_cut_position(struct list_head *list,
 		struct list_head *head, struct list_head *entry)
 {
 	if (list_empty(head))
 		return;
 	if (list_is_singular(head) &&
 		(head->next != entry && head != entry))
 		return;
 	if (entry == head)
 		INIT_LIST_HEAD(list);
 	else
 		__list_cut_position(list, head, entry);
 }
 
 SINLINE 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;
 
 	first->prev = prev;
 	prev->next = first;
 
 	last->next = next;
 	next->prev = last;
 }
 
 /**
  * list_splice - join two lists, this is designed for stacks
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  */
 SINLINE void list_splice(const struct list_head *list,
 				struct list_head *head)
 {
 	if (!list_empty(list))
 		__list_splice(list, head, head->next);
 }
 
 /**
  * list_splice_tail - join two lists, each list being a queue
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  */
 SINLINE void list_splice_tail(struct list_head *list,
 				struct list_head *head)
 {
 	if (!list_empty(list))
 		__list_splice(list, head->prev, head);
 }
 
 /**
  * list_splice_init - join two lists and reinitialise the emptied list.
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  *
  * The list at @list is reinitialised
  */
 SINLINE void list_splice_init(struct list_head *list,
 				    struct list_head *head)
 {
 	if (!list_empty(list)) {
 		__list_splice(list, head, head->next);
 		INIT_LIST_HEAD(list);
 	}
 }
 
 /**
  * list_splice_tail_init - join two lists and reinitialise the emptied list
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  *
  * Each of the lists is a queue.
  * The list at @list is reinitialised
  */
 SINLINE void list_splice_tail_init(struct list_head *list,
 					 struct list_head *head)
 {
 	if (!list_empty(list)) {
 		__list_splice(list, head->prev, head);
 		INIT_LIST_HEAD(list);
 	}
 }
 
 /**
  * list_entry - get the struct for this entry
  * @ptr:	the &struct list_head pointer.
  * @type:	the type of the struct this is embedded in.
  * @member:	the name of the list_struct within the struct.
  */
 #define list_entry(ptr, type, member) \
 	container_of(ptr, type, member)
 
 /**
  * list_first_entry - get the first element from a list
  * @ptr:	the list head to take the element from.
  * @type:	the type of the struct this is embedded in.
  * @member:	the name of the list_struct within the struct.
  *
  * Note, that list is expected to be not empty.
  */
 #define list_first_entry(ptr, type, member) \
 	list_entry((ptr)->next, type, member)
 
 /**
  * list_for_each	-	iterate over a list
  * @pos:	the &struct list_head to use as a loop cursor.
  * @head:	the head for your list.
  */
 #define list_for_each(pos, head) \
 	for (pos = (head)->next; pos != (head); pos = pos->next)
 
 /**
  * __list_for_each	-	iterate over a list
  * @pos:	the &struct list_head to use as a loop cursor.
  * @head:	the head for your list.
  *
  * This variant doesn't differ from list_for_each() any more.
  * We don't do prefetching in either case.
  */
 #define __list_for_each(pos, head) \
 	for (pos = (head)->next; pos != (head); pos = pos->next)
 
 /**
  * list_for_each_prev	-	iterate over a list backwards
  * @pos:	the &struct list_head to use as a loop cursor.
  * @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
  * @pos:	the &struct list_head to use as a loop cursor.
  * @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)
 
 /**
  * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
  * @pos:	the &struct list_head to use as a loop cursor.
  * @n:		another &struct list_head to use as temporary storage
  * @head:	the head for your list.
  */
 #define list_for_each_prev_safe(pos, n, head) \
 	for (pos = (head)->prev, n = pos->prev; \
 	     pos != (head); \
 	     pos = n, n = pos->prev)
 
 /** Walk through client lists (with examples).
  * @param	pos	The variable to use as a loop cursor
  * @param	head	The head of your list
  * @param	member	The name of the list_struct within the struct.
  * @ingroup ListFunctions
  * @section Examples
  * @subsection client_list List all clients
  * @code
  * CMD_FUNC(cmd_listallclients)
  * {
  *     Client *acptr;
  *     sendnotice(client, "List of all clients:");
  *     list_for_each_entry(acptr, &client_list, client_node)
  *         sendnotice(client, "Client %s", acptr->name);
  * }
  * @endcode
  * @subsection lclient_list List all LOCAL clients
  * @code
  * CMD_FUNC(cmd_listalllocalclients)
  * {
  *     Client *acptr;
  *     sendnotice(client, "List of all local clients:");
  *     list_for_each_entry(acptr, &lclient_list, lclient_node)
  *         sendnotice(client, "Client %s", acptr->name);
  * }
  * @endcode
  * @subsection global_server_list List all servers
  * @code
  * CMD_FUNC(cmd_listallservers)
  * {
  *     Client *acptr;
  *     sendnotice(client, "List of all servers:");
  *     list_for_each_entry(acptr, &global_server_list, client_node)
  *         sendnotice(client, "Server %s", acptr->name);
  * }
  * @endcode
  * @subsection server_list List all LOCALLY connected servers
  * @code
  * CMD_FUNC(cmd_listallservers)
  * {
  *     Client *acptr;
  *     sendnotice(client, "List of all LOCAL servers:");
  *     list_for_each_entry(acptr, &server_list, special_node)
  *         sendnotice(client, "Server %s", acptr->name);
  * }
  * @endcode
  * @subsection oper_list List all LOCALLY connected IRCOps
  * @code
  * CMD_FUNC(cmd_listlocalircops)
  * {
  *     Client *acptr;
  *     sendnotice(client, "List of all LOCAL IRCOps:");
  *     list_for_each_entry(acptr, &oper_list, special_node)
  *         sendnotice(client, "User %s", acptr->name);
  * }
  * @endcode
  */
 #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))
 
 /**
  * list_for_each_entry	-	iterate over list of given type
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  */
 #define list_for_each_entry2(pos, tpe, head, member)				\
 	for (pos = list_entry((head)->next, tpe, member);	\
 	     &pos->member != (head); 	\
 	     pos = list_entry(pos->member.next, tpe, member))
 
 /**
  * list_for_each_entry_reverse - iterate backwards over list of given type.
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  */
 #define list_for_each_entry_reverse(pos, head, member)			\
 	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
 	     &pos->member != (head); 	\
 	     pos = list_entry(pos->member.prev, typeof(*pos), member))
 
 /**
  * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
  * @pos:	the type * to use as a start point
  * @head:	the head of the list
  * @member:	the name of the list_struct within the struct.
  *
  * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
  */
 #define list_prepare_entry(pos, head, member) \
 	((pos) ? : list_entry(head, typeof(*pos), member))
 
 /**
  * list_for_each_entry_continue - continue iteration over list of given type
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  *
  * Continue to iterate over list of given type, continuing after
  * the current position.
  */
 #define list_for_each_entry_continue(pos, head, member) 		\
 	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
 	     &pos->member != (head);	\
 	     pos = list_entry(pos->member.next, typeof(*pos), member))
 
 /**
  * list_for_each_entry_continue_reverse - iterate backwards from the given point
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  *
  * Start to iterate over list of given type backwards, continuing after
  * the current position.
  */
 #define list_for_each_entry_continue_reverse(pos, head, member)		\
 	for (pos = list_entry(pos->member.prev, typeof(*pos), member);	\
 	     &pos->member != (head);	\
 	     pos = list_entry(pos->member.prev, typeof(*pos), member))
 
 /**
  * list_for_each_entry_from - iterate over list of given type from the current point
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  *
  * Iterate over list of given type, continuing from current position.
  */
 #define list_for_each_entry_from(pos, head, member) 			\
 	for (; &pos->member != (head);	\
 	     pos = list_entry(pos->member.next, typeof(*pos), member))
 
 /** Walk through client lists - special 'safe' version.
  * This is a special version, in case clients are removed from the list
  * while the list is iterated. It is unlikely that you need to use this
  * from modules, so use list_for_each_entry() instead.
  * Examples are also in list_for_each_entry().
  * @param	pos	The variable to use as a loop cursor
  * @param	n	Variable to be used for temporary storage
  * @param	head	The head of your list
  * @param	member	The name of the list_struct within the struct.
  * @ingroup ListFunctions
  */
 #define list_for_each_entry_safe(pos, n, head, member)			\
 	for (pos = list_entry((head)->next, typeof(*pos), member),	\
 		n = list_entry(pos->member.next, typeof(*pos), member);	\
 	     &pos->member != (head); 					\
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
  * list_for_each_entry_safe_continue - continue list iteration safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  *
  * Iterate over list of given type, continuing after current point,
  * safe against removal of list entry.
  */
 #define list_for_each_entry_safe_continue(pos, n, head, member) 		\
 	for (pos = list_entry(pos->member.next, typeof(*pos), member), 		\
 		n = list_entry(pos->member.next, typeof(*pos), member);		\
 	     &pos->member != (head);						\
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
  * list_for_each_entry_safe_from - iterate over list from current point safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  *
  * Iterate over list of given type from current point, safe against
  * removal of list entry.
  */
 #define list_for_each_entry_safe_from(pos, n, head, member) 			\
 	for (n = list_entry(pos->member.next, typeof(*pos), member);		\
 	     &pos->member != (head);						\
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
  * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
  * @member:	the name of the list_struct within the struct.
  *
  * Iterate backwards over list of given type, safe against removal
  * of list entry.
  */
 #define list_for_each_entry_safe_reverse(pos, n, head, member)		\
 	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
 		n = list_entry(pos->member.prev, typeof(*pos), member);	\
 	     &pos->member != (head); 					\
 	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
 
 /**
  * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
  * @pos:	the loop cursor used in the list_for_each_entry_safe loop
  * @n:		temporary storage used in list_for_each_entry_safe
  * @member:	the name of the list_struct within the struct.
  *
  * list_safe_reset_next is not safe to use in general if the list may be
  * modified concurrently (eg. the lock is dropped in the loop body). An
  * exception to this is if the cursor element (pos) is pinned in the list,
  * and list_safe_reset_next is called after re-taking the lock and before
  * completing the current iteration of the loop body.
  */
 #define list_safe_reset_next(pos, n, member)				\
 	n = list_entry(pos->member.next, typeof(*pos), member)
 
 #endif

© 2023 acidvegas, inc • generated with stagit