1 files changed, 281 insertions, 103 deletions
diff --git a/xorg-server/include/list.h b/xorg-server/include/list.h
index 9479d2d92..5933b973d 100644
--- a/xorg-server/include/list.h
+++ b/xorg-server/include/list.h
@@ -1,103 +1,281 @@
-/*
- * Copyright © 2010 Intel Corporation
- * Copyright © 2010 Francisco Jerez <currojerez@riseup.net>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- *
- */
-
-#ifndef _LIST_H_
-#define _LIST_H_
-
-/* classic doubly-link circular list */
-struct list {
-    struct list *next, *prev;
-};
-
-static void
-list_init(struct list *list)
-{
-    list->next = list->prev = list;
-}
-
-static inline void
-__list_add(struct list *entry,
-	    struct list *prev,
-	    struct list *next)
-{
-    next->prev = entry;
-    entry->next = next;
-    entry->prev = prev;
-    prev->next = entry;
-}
-
-static inline void
-list_add(struct list *entry, struct list *head)
-{
-    __list_add(entry, head, head->next);
-}
-
-static inline void
-__list_del(struct list *prev, struct list *next)
-{
-    next->prev = prev;
-    prev->next = next;
-}
-
-static inline void
-list_del(struct list *entry)
-{
-    __list_del(entry->prev, entry->next);
-    list_init(entry);
-}
-
-static inline Bool
-list_is_empty(struct list *head)
-{
-    return head->next == head;
-}
-
-#ifndef container_of
-#define container_of(ptr, type, member) \
-    (type *)((char *)(ptr) - (char *) &((type *)0)->member)
-#endif
-
-#define list_entry(ptr, type, member) \
-    container_of(ptr, type, member)
-
-#define list_first_entry(ptr, type, member) \
-    list_entry((ptr)->next, type, member)
-
-#define __container_of(ptr, sample, member)				\
-    (void *)((char *)(ptr)						\
-	     - ((char *)&(sample)->member - (char *)(sample)))
-
-#define list_for_each_entry(pos, head, member)				\
-    for (pos = __container_of((head)->next, pos, member);		\
-	 &pos->member != (head);					\
-	 pos = __container_of(pos->member.next, pos, member))
-
-#define list_for_each_entry_safe(pos, tmp, head, member)		\
-    for (pos = __container_of((head)->next, pos, member),		\
-	 tmp = __container_of(pos->member.next, pos, member);		\
-	 &pos->member != (head);					\
-	 pos = tmp, tmp = __container_of(pos->member.next, tmp, member))
-
-#endif
+/*
+ * Copyright © 2010 Intel Corporation
+ * Copyright © 2010 Francisco Jerez <currojerez@riseup.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef _LIST_H_
+#define _LIST_H_
+
+/**
+ * @file Classic doubly-link circular list implementation.
+ *
+ * Example:
+ * We need to keep a list of struct foo in the parent struct bar, i.e. what
+ * we want is something like this.
+ *
+ *     struct bar {
+ *          ...
+ *          struct foo *foos; -----> struct foo {}, struct foo {}, struct foo{}
+ *          ...
+ *     }
+ *
+ * We need one list head in bar and a list element in all foos (both are of
+ * data type 'struct list').
+ *
+ *     struct bar {
+ *          ...
+ *          struct list foos;
+ *          ...
+ *     }
+ *
+ *     struct foo {
+ *          ...
+ *          struct list entry;
+ *          ...
+ *     }
+ *
+ * Now we initialize the list head:
+ *
+ *     struct bar bar;
+ *     ...
+ *     list_init(&bar.foos);
+ *
+ * Then we create the first element and add it to this list:
+ *
+ *     struct foo *foo = malloc(...);
+ *     ....
+ *     list_add(&foo->entry, &bar.foos);
+ *
+ * Repeat the above for each element you want to add to the list. Deleting
+ * works with the element itself.
+ *      list_del(&foo->entry);
+ *      free(foo);
+ *
+ * Note: calling list_del(&bar.foos) will set bar.foos to an empty
+ * list again.
+ *
+ * Looping through the list requires a 'struct foo' as iterator and the
+ * name of the field the subnodes use.
+ *
+ * struct foo *iterator;
+ * list_for_each_entry(iterator, &bar.foos, entry) {
+ *      if (iterator->something == ...)
+ *             ...
+ * }
+ *
+ * Note: You must not call list_del() on the iterator if you continue the
+ * loop. You need to run the safe for-each loop instead:
+ *
+ * struct foo *iterator, *next;
+ * list_for_each_entry_safe(iterator, next, &bar.foos, entry) {
+ *      if (...)
+ *              list_del(&iterator->entry);
+ * }
+ *
+ */
+
+/**
+ * The linkage struct for list nodes. This struct must be part of your
+ * to-be-linked struct.
+ *
+ * Example:
+ * struct foo {
+ *      int a;
+ *      void *b;
+ *      struct list *mylist;
+ * }
+ *
+ * Position and name of the struct list field is irrelevant.
+ * There are no requirements that elements of a list are of the same type.
+ * There are no requirements for a list head, any struct list can be a list
+ * head.
+ */
+struct list {
+    struct list *next, *prev;
+};
+
+/**
+ * Initialize the list as an empty list.
+ *
+ * Example:
+ * list_init(&foo->mylist);
+ *
+ * @param The list to initialized.
+ */
+static void
+list_init(struct list *list)
+{
+    list->next = list->prev = list;
+}
+
+static inline void
+__list_add(struct list *entry,
+	    struct list *prev,
+	    struct list *next)
+{
+    next->prev = entry;
+    entry->next = next;
+    entry->prev = prev;
+    prev->next = entry;
+}
+
+/**
+ * Insert a new element after the given list head.
+ * The list changes from:
+ *      head → some element → ...
+ * to
+ *      head → new element → older element → ...
+ *
+ * Example:
+ * struct foo *newfoo = malloc(...);
+ * list_add(&newfoo->mylist, &foo->mylist);
+ *
+ * @param entry The new element to prepend to the list.
+ * @param head The existing list.
+ */
+static inline void
+list_add(struct list *entry, struct list *head)
+{
+    __list_add(entry, head, head->next);
+}
+
+static inline void
+__list_del(struct list *prev, struct list *next)
+{
+    next->prev = prev;
+    prev->next = next;
+}
+
+/**
+ * Remove the element from the list it is in. Using this function will reset
+ * the pointers to/from this element so it is removed from the list. It does
+ * NOT free the element itself or manipulate it otherwise.
+ *
+ * Using list_del on a pure list head (like in the example at the top of
+ * this file) will NOT remove the first element from
+ * the list but rather reset the list as empty list.
+ *
+ * Example:
+ * list_del(&newfoo->mylist);
+ *
+ * @param entry The element to remove.
+ */
+static inline void
+list_del(struct list *entry)
+{
+    __list_del(entry->prev, entry->next);
+    list_init(entry);
+}
+
+/**
+ * Check if the list is empty.
+ *
+ * Example:
+ * list_is_empty(&foo->mylist);
+ *
+ * @return True if the list contains one or more elements or False otherwise.
+ */
+static inline Bool
+list_is_empty(struct list *head)
+{
+    return head->next == head;
+}
+
+/**
+ * Returns a pointer to the container of this list element.
+ *
+ * Example:
+ * struct foo* f;
+ * f = container_of(&foo->mylist, struct foo, mylist);
+ * assert(f == foo);
+ *
+ * @param ptr Pointer to the struct list.
+ * @param type Data type of the list element.
+ * @param member Member name of the struct list field in the list element.
+ * @return A pointer to the data struct containing the list head.
+ */
+#ifndef container_of
+#define container_of(ptr, type, member) \
+    (type *)((char *)(ptr) - (char *) &((type *)0)->member)
+#endif
+
+/**
+ * Alias of container_of
+ */
+#define list_entry(ptr, type, member) \
+    container_of(ptr, type, member)
+
+/**
+ * Retrieve the first list entry for the given list pointer.
+ *
+ * Example:
+ * struct foo *first;
+ * first = list_first_entry(&foo->mylist, struct foo, mylist);
+ *
+ * @param ptr The list head
+ * @param type Data type of the list element to retrieve
+ * @param member Member name of the struct list field in the list element.
+ * @return A pointer to the first list element.
+ */
+#define list_first_entry(ptr, type, member) \
+    list_entry((ptr)->next, type, member)
+
+#define __container_of(ptr, sample, member)				\
+    (void *)((char *)(ptr)						\
+	     - ((char *)&(sample)->member - (char *)(sample)))
+/**
+ * Loop through the list given by head and set pos to struct in the list.
+ *
+ * Example:
+ * struct foo *iterator;
+ * list_for_each_entry(iterator, &foo->mylist, mylist) {
+ *      [modify iterator]
+ * }
+ *
+ * This macro is not safe for node deletion. Use list_for_each_entry_safe
+ * instead.
+ *
+ * @param pos Iterator variable of the type of the list elements.
+ * @param head List head
+ * @param member Member name of the struct list in the list elements.
+ *
+ */
+#define list_for_each_entry(pos, head, member)				\
+    for (pos = __container_of((head)->next, pos, member);		\
+	 &pos->member != (head);					\
+	 pos = __container_of(pos->member.next, pos, member))
+
+/**
+ * Loop through the list, keeping a backup pointer to the element. This
+ * macro allows for the deletion of a list element while looping through the
+ * list.
+ *
+ * See list_for_each_entry for more details.
+ */
+#define list_for_each_entry_safe(pos, tmp, head, member)		\
+    for (pos = __container_of((head)->next, pos, member),		\
+	 tmp = __container_of(pos->member.next, pos, member);		\
+	 &pos->member != (head);					\
+	 pos = tmp, tmp = __container_of(pos->member.next, tmp, member))
+
+#endif