/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2015 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <stdbool.h>
#include <stddef.h>
#include "util.h"
+#include "openvswitch/list.h"
-/* Doubly linked list head or element. */
-struct list {
- struct list *prev; /* Previous list element. */
- struct list *next; /* Next list element. */
-};
-
-#define LIST_INITIALIZER(LIST) { LIST, LIST }
+/* "struct ovs_list" with pointers that will (probably) cause segfaults if
+ * dereferenced and, better yet, show up clearly in a debugger. */
+#define OVS_LIST_POISON \
+(struct ovs_list) { (struct ovs_list *) (uintptr_t) 0xccccccccccccccccULL, \
+ (struct ovs_list *) (uintptr_t) 0xccccccccccccccccULL }
-static inline void list_init(struct list *);
-static inline void list_poison(struct list *);
+static inline void list_init(struct ovs_list *);
+static inline void list_poison(struct ovs_list *);
/* List insertion. */
-static inline void list_insert(struct list *, struct list *);
-static inline void list_splice(struct list *before, struct list *first,
- struct list *last);
-static inline void list_push_front(struct list *, struct list *);
-static inline void list_push_back(struct list *, struct list *);
-static inline void list_replace(struct list *, const struct list *);
-static inline void list_moved(struct list *);
-static inline void list_move(struct list *dst, struct list *src);
+static inline void list_insert(struct ovs_list *, struct ovs_list *);
+static inline void list_splice(struct ovs_list *before, struct ovs_list *first,
+ struct ovs_list *last);
+static inline void list_push_front(struct ovs_list *, struct ovs_list *);
+static inline void list_push_back(struct ovs_list *, struct ovs_list *);
+static inline void list_replace(struct ovs_list *, const struct ovs_list *);
+static inline void list_moved(struct ovs_list *, const struct ovs_list *orig);
+static inline void list_move(struct ovs_list *dst, struct ovs_list *src);
/* List removal. */
-static inline struct list *list_remove(struct list *);
-static inline struct list *list_pop_front(struct list *);
-static inline struct list *list_pop_back(struct list *);
+static inline struct ovs_list *list_remove(struct ovs_list *);
+static inline struct ovs_list *list_pop_front(struct ovs_list *);
+static inline struct ovs_list *list_pop_back(struct ovs_list *);
/* List elements. */
-static inline struct list *list_front(const struct list *);
-static inline struct list *list_back(const struct list *);
+static inline struct ovs_list *list_front(const struct ovs_list *);
+static inline struct ovs_list *list_back(const struct ovs_list *);
/* List properties. */
-static inline size_t list_size(const struct list *);
-static inline bool list_is_empty(const struct list *);
-static inline bool list_is_singleton(const struct list *);
-static inline bool list_is_short(const struct list *);
+static inline size_t list_size(const struct ovs_list *);
+static inline bool list_is_empty(const struct ovs_list *);
+static inline bool list_is_singleton(const struct ovs_list *);
+static inline bool list_is_short(const struct ovs_list *);
#define LIST_FOR_EACH(ITER, MEMBER, LIST) \
for (INIT_CONTAINER(ITER, (LIST)->next, MEMBER); \
&(ITER)->MEMBER != (LIST); \
ASSIGN_CONTAINER(ITER, (ITER)->MEMBER.next, MEMBER))
#define LIST_FOR_EACH_CONTINUE(ITER, MEMBER, LIST) \
- for (INIT_CONTAINER(ITER, (ITER)->MEMBER.next, MEMBER); \
+ for (ASSIGN_CONTAINER(ITER, (ITER)->MEMBER.next, MEMBER); \
&(ITER)->MEMBER != (LIST); \
ASSIGN_CONTAINER(ITER, (ITER)->MEMBER.next, MEMBER))
#define LIST_FOR_EACH_REVERSE(ITER, MEMBER, LIST) \
? INIT_CONTAINER(NEXT, (ITER)->MEMBER.next, MEMBER), 1 \
: 0); \
(ITER) = (NEXT))
+#define LIST_FOR_EACH_POP(ITER, MEMBER, LIST) \
+ while (!list_is_empty(LIST) \
+ && (INIT_CONTAINER(ITER, list_pop_front(LIST), MEMBER), 1))
\f
/* Inline implementations. */
/* Initializes 'list' as an empty list. */
static inline void
-list_init(struct list *list)
+list_init(struct ovs_list *list)
{
list->next = list->prev = list;
}
/* Initializes 'list' with pointers that will (probably) cause segfaults if
* dereferenced and, better yet, show up clearly in a debugger. */
static inline void
-list_poison(struct list *list)
+list_poison(struct ovs_list *list)
{
- memset(list, 0xcc, sizeof *list);
+ *list = OVS_LIST_POISON;
}
/* Inserts 'elem' just before 'before'. */
static inline void
-list_insert(struct list *before, struct list *elem)
+list_insert(struct ovs_list *before, struct ovs_list *elem)
{
elem->prev = before->prev;
elem->next = before;
/* Removes elements 'first' though 'last' (exclusive) from their current list,
then inserts them just before 'before'. */
static inline void
-list_splice(struct list *before, struct list *first, struct list *last)
+list_splice(struct ovs_list *before, struct ovs_list *first, struct ovs_list *last)
{
if (first == last) {
return;
/* Inserts 'elem' at the beginning of 'list', so that it becomes the front in
'list'. */
static inline void
-list_push_front(struct list *list, struct list *elem)
+list_push_front(struct ovs_list *list, struct ovs_list *elem)
{
list_insert(list->next, elem);
}
/* Inserts 'elem' at the end of 'list', so that it becomes the back in
* 'list'. */
static inline void
-list_push_back(struct list *list, struct list *elem)
+list_push_back(struct ovs_list *list, struct ovs_list *elem)
{
list_insert(list, elem);
}
/* Puts 'elem' in the position currently occupied by 'position'.
* Afterward, 'position' is not part of a list. */
static inline void
-list_replace(struct list *element, const struct list *position)
+list_replace(struct ovs_list *element, const struct ovs_list *position)
{
element->next = position->next;
element->next->prev = element;
}
/* Adjusts pointers around 'list' to compensate for 'list' having been moved
- * around in memory (e.g. as a consequence of realloc()).
+ * around in memory (e.g. as a consequence of realloc()), with original
+ * location 'orig'.
*
- * This always works if 'list' is a member of a list, or if 'list' is the head
- * of a non-empty list. It fails badly, however, if 'list' is the head of an
- * empty list; just use list_init() in that case. */
+ * ('orig' likely points to freed memory, but this function does not
+ * dereference 'orig', it only compares it to 'list'. In a very pedantic
+ * language lawyer sense, this still yields undefined behavior, but it works
+ * with actual compilers.) */
static inline void
-list_moved(struct list *list)
+list_moved(struct ovs_list *list, const struct ovs_list *orig)
{
- list->prev->next = list->next->prev = list;
+ if (list->next == orig) {
+ list_init(list);
+ } else {
+ list->prev->next = list->next->prev = list;
+ }
}
/* Initializes 'dst' with the contents of 'src', compensating for moving it
* around in memory. The effect is that, if 'src' was the head of a list, now
* 'dst' is the head of a list containing the same elements. */
static inline void
-list_move(struct list *dst, struct list *src)
+list_move(struct ovs_list *dst, struct ovs_list *src)
{
- if (!list_is_empty(src)) {
- *dst = *src;
- list_moved(dst);
- } else {
- list_init(dst);
- }
+ *dst = *src;
+ list_moved(dst, src);
}
/* Removes 'elem' from its list and returns the element that followed it.
Undefined behavior if 'elem' is not in a list. */
-static inline struct list *
-list_remove(struct list *elem)
+static inline struct ovs_list *
+list_remove(struct ovs_list *elem)
{
elem->prev->next = elem->next;
elem->next->prev = elem->prev;
/* Removes the front element from 'list' and returns it. Undefined behavior if
'list' is empty before removal. */
-static inline struct list *
-list_pop_front(struct list *list)
+static inline struct ovs_list *
+list_pop_front(struct ovs_list *list)
{
- struct list *front = list->next;
+ struct ovs_list *front = list->next;
list_remove(front);
return front;
/* Removes the back element from 'list' and returns it.
Undefined behavior if 'list' is empty before removal. */
-static inline struct list *
-list_pop_back(struct list *list)
+static inline struct ovs_list *
+list_pop_back(struct ovs_list *list)
{
- struct list *back = list->prev;
+ struct ovs_list *back = list->prev;
list_remove(back);
return back;
/* Returns the front element in 'list_'.
Undefined behavior if 'list_' is empty. */
-static inline struct list *
-list_front(const struct list *list_)
+static inline struct ovs_list *
+list_front(const struct ovs_list *list_)
{
- struct list *list = CONST_CAST(struct list *, list_);
+ struct ovs_list *list = CONST_CAST(struct ovs_list *, list_);
ovs_assert(!list_is_empty(list));
/* Returns the back element in 'list_'.
Undefined behavior if 'list_' is empty. */
-static inline struct list *
-list_back(const struct list *list_)
+static inline struct ovs_list *
+list_back(const struct ovs_list *list_)
{
- struct list *list = CONST_CAST(struct list *, list_);
+ struct ovs_list *list = CONST_CAST(struct ovs_list *, list_);
ovs_assert(!list_is_empty(list));
/* Returns the number of elements in 'list'.
Runs in O(n) in the number of elements. */
static inline size_t
-list_size(const struct list *list)
+list_size(const struct ovs_list *list)
{
- const struct list *e;
+ const struct ovs_list *e;
size_t cnt = 0;
for (e = list->next; e != list; e = e->next) {
/* Returns true if 'list' is empty, false otherwise. */
static inline bool
-list_is_empty(const struct list *list)
+list_is_empty(const struct ovs_list *list)
{
return list->next == list;
}
/* Returns true if 'list' has exactly 1 element, false otherwise. */
static inline bool
-list_is_singleton(const struct list *list)
+list_is_singleton(const struct ovs_list *list)
{
return list_is_short(list) && !list_is_empty(list);
}
/* Returns true if 'list' has 0 or 1 elements, false otherwise. */
static inline bool
-list_is_short(const struct list *list)
+list_is_short(const struct ovs_list *list)
{
return list->next == list->prev;
}