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-rw-r--r--ccan/list/list.h190
1 files changed, 164 insertions, 26 deletions
diff --git a/ccan/list/list.h b/ccan/list/list.h
index 749db7849a..66ec94d2f6 100644
--- a/ccan/list/list.h
+++ b/ccan/list/list.h
@@ -104,6 +104,36 @@ static inline void list_node_init(struct list_node *n)
}
/**
+ * list_add_after - add an entry after an existing node in a linked list
+ * @h: the list_head to add the node to (for debugging)
+ * @p: the existing list_node to add the node after
+ * @n: the new list_node to add to the list.
+ *
+ * The existing list_node must already be a member of the list.
+ * The new list_node does not need to be initialized; it will be overwritten.
+ *
+ * Example:
+ * struct child c1, c2, c3;
+ * LIST_HEAD(h);
+ *
+ * list_add_tail(&h, &c1.list);
+ * list_add_tail(&h, &c3.list);
+ * list_add_after(&h, &c1.list, &c2.list);
+ */
+#define list_add_after(h, p, n) list_add_after_(h, p, n, LIST_LOC)
+static inline void list_add_after_(struct list_head *h,
+ struct list_node *p,
+ struct list_node *n,
+ const char *abortstr)
+{
+ n->next = p->next;
+ n->prev = p;
+ p->next->prev = n;
+ p->next = n;
+ (void)list_debug(h, abortstr);
+}
+
+/**
* list_add - add an entry at the start of a linked list.
* @h: the list_head to add the node to
* @n: the list_node to add to the list.
@@ -121,10 +151,34 @@ static inline void list_add_(struct list_head *h,
struct list_node *n,
const char *abortstr)
{
- n->next = h->n.next;
- n->prev = &h->n;
- h->n.next->prev = n;
- h->n.next = n;
+ list_add_after_(h, &h->n, n, abortstr);
+}
+
+/**
+ * list_add_before - add an entry before an existing node in a linked list
+ * @h: the list_head to add the node to (for debugging)
+ * @p: the existing list_node to add the node before
+ * @n: the new list_node to add to the list.
+ *
+ * The existing list_node must already be a member of the list.
+ * The new list_node does not need to be initialized; it will be overwritten.
+ *
+ * Example:
+ * list_head_init(&h);
+ * list_add_tail(&h, &c1.list);
+ * list_add_tail(&h, &c3.list);
+ * list_add_before(&h, &c3.list, &c2.list);
+ */
+#define list_add_before(h, p, n) list_add_before_(h, p, n, LIST_LOC)
+static inline void list_add_before_(struct list_head *h,
+ struct list_node *p,
+ struct list_node *n,
+ const char *abortstr)
+{
+ n->next = p;
+ n->prev = p->prev;
+ p->prev->next = n;
+ p->prev = n;
(void)list_debug(h, abortstr);
}
@@ -143,11 +197,7 @@ static inline void list_add_tail_(struct list_head *h,
struct list_node *n,
const char *abortstr)
{
- n->next = &h->n;
- n->prev = h->n.prev;
- h->n.prev->next = n;
- h->n.prev = n;
- (void)list_debug(h, abortstr);
+ list_add_before_(h, &h->n, n, abortstr);
}
/**
@@ -265,6 +315,39 @@ static inline void list_del_from(struct list_head *h, struct list_node *n)
}
/**
+ * list_swap - swap out an entry from an (unknown) linked list for a new one.
+ * @o: the list_node to replace from the list.
+ * @n: the list_node to insert in place of the old one.
+ *
+ * Note that this leaves @o in an undefined state; it can be added to
+ * another list, but not deleted/swapped again.
+ *
+ * See also:
+ * list_del()
+ *
+ * Example:
+ * struct child x1, x2;
+ * LIST_HEAD(xh);
+ *
+ * list_add(&xh, &x1.list);
+ * list_swap(&x1.list, &x2.list);
+ */
+#define list_swap(o, n) list_swap_(o, n, LIST_LOC)
+static inline void list_swap_(struct list_node *o,
+ struct list_node *n,
+ const char* abortstr)
+{
+ (void)list_debug_node(o, abortstr);
+ *n = *o;
+ n->next->prev = n;
+ n->prev->next = n;
+#ifdef CCAN_LIST_DEBUG
+ /* Catch use-after-del. */
+ o->next = o->prev = NULL;
+#endif
+}
+
+/**
* list_entry - convert a list_node back into the structure containing it.
* @n: the list_node
* @type: the type of the entry
@@ -385,9 +468,29 @@ static inline const void *list_tail_(const struct list_head *h, size_t off)
* printf("Name: %s\n", child->name);
*/
#define list_for_each_rev(h, i, member) \
- for (i = container_of_var(list_debug(h, LIST_LOC)->n.prev, i, member); \
- &i->member != &(h)->n; \
- i = container_of_var(i->member.prev, i, member))
+ list_for_each_rev_off(h, i, list_off_var_(i, member))
+
+/**
+ * list_for_each_rev_safe - iterate through a list backwards,
+ * maybe during deletion
+ * @h: the list_head
+ * @i: the structure containing the list_node
+ * @nxt: the structure containing the list_node
+ * @member: the list_node member of the structure
+ *
+ * This is a convenient wrapper to iterate @i over the entire list backwards.
+ * It's a for loop, so you can break and continue as normal. The extra
+ * variable * @nxt is used to hold the next element, so you can delete @i
+ * from the list.
+ *
+ * Example:
+ * struct child *next;
+ * list_for_each_rev_safe(&parent->children, child, next, list) {
+ * printf("Name: %s\n", child->name);
+ * }
+ */
+#define list_for_each_rev_safe(h, i, nxt, member) \
+ list_for_each_rev_safe_off(h, i, nxt, list_off_var_(i, member))
/**
* list_for_each_safe - iterate through a list, maybe during deletion
@@ -401,7 +504,6 @@ static inline const void *list_tail_(const struct list_head *h, size_t off)
* @nxt is used to hold the next element, so you can delete @i from the list.
*
* Example:
- * struct child *next;
* list_for_each_safe(&parent->children, child, next, list) {
* list_del(&child->list);
* parent->num_children--;
@@ -516,6 +618,24 @@ static inline void list_prepend_list_(struct list_head *to,
list_head_init(from);
}
+/* internal macros, do not use directly */
+#define list_for_each_off_dir_(h, i, off, dir) \
+ for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \
+ (off)); \
+ list_node_from_off_((void *)i, (off)) != &(h)->n; \
+ i = list_node_to_off_(list_node_from_off_((void *)i, (off))->dir, \
+ (off)))
+
+#define list_for_each_safe_off_dir_(h, i, nxt, off, dir) \
+ for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \
+ (off)), \
+ nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \
+ (off)); \
+ list_node_from_off_(i, (off)) != &(h)->n; \
+ i = nxt, \
+ nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \
+ (off)))
+
/**
* list_for_each_off - iterate through a list of memory regions.
* @h: the list_head
@@ -546,11 +666,18 @@ static inline void list_prepend_list_(struct list_head *to,
* printf("Name: %s\n", child->name);
*/
#define list_for_each_off(h, i, off) \
- for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.next, \
- (off)); \
- list_node_from_off_((void *)i, (off)) != &(h)->n; \
- i = list_node_to_off_(list_node_from_off_((void *)i, (off))->next, \
- (off)))
+ list_for_each_off_dir_((h),(i),(off),next)
+
+/**
+ * list_for_each_rev_off - iterate through a list of memory regions backwards
+ * @h: the list_head
+ * @i: the pointer to a memory region wich contains list node data.
+ * @off: offset(relative to @i) at which list node data resides.
+ *
+ * See list_for_each_off for details
+ */
+#define list_for_each_rev_off(h, i, off) \
+ list_for_each_off_dir_((h),(i),(off),prev)
/**
* list_for_each_safe_off - iterate through a list of memory regions, maybe
@@ -569,15 +696,26 @@ static inline void list_prepend_list_(struct list_head *to,
* printf("Name: %s\n", child->name);
*/
#define list_for_each_safe_off(h, i, nxt, off) \
- for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.next, \
- (off)), \
- nxt = list_node_to_off_(list_node_from_off_(i, (off))->next, \
- (off)); \
- list_node_from_off_(i, (off)) != &(h)->n; \
- i = nxt, \
- nxt = list_node_to_off_(list_node_from_off_(i, (off))->next, \
- (off)))
+ list_for_each_safe_off_dir_((h),(i),(nxt),(off),next)
+/**
+ * list_for_each_rev_safe_off - iterate backwards through a list of
+ * memory regions, maybe during deletion
+ * @h: the list_head
+ * @i: the pointer to a memory region wich contains list node data.
+ * @nxt: the structure containing the list_node
+ * @off: offset(relative to @i) at which list node data resides.
+ *
+ * For details see `list_for_each_rev_off' and `list_for_each_rev_safe'
+ * descriptions.
+ *
+ * Example:
+ * list_for_each_rev_safe_off(&parent->children, child,
+ * next, offsetof(struct child, list))
+ * printf("Name: %s\n", child->name);
+ */
+#define list_for_each_rev_safe_off(h, i, nxt, off) \
+ list_for_each_safe_off_dir_((h),(i),(nxt),(off),prev)
/* Other -off variants. */
#define list_entry_off(n, type, off) \
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 15:14:33 +0000