Merge lib into kern

There are no precise enough criteria to justify the separation of these
two directories.

1 files changed, 364 insertions, 0 deletions

diff --git a/kern/list.h b/kern/list.h
new file mode 100644
index 0000000..647e94c
--- /dev/null
+++ b/kern/list.h
@@ -0,0 +1,364 @@
+/*
+ * Copyright (c) 2009, 2010 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Simple doubly-linked list.
+ */
+
+#ifndef _KERN_LIST_H
+#define _KERN_LIST_H
+
+#include <kern/macros.h>
+#include <kern/stddef.h>
+
+/*
+ * Structure used as both head and node.
+ *
+ * This implementation relies on using the same type for both heads and nodes.
+ *
+ * It is recommended to encode the use of struct list variables in their names,
+ * e.g. struct list free_list or struct list free_objects is a good hint for a
+ * list of free objects. A declaration like struct list free_node clearly
+ * indicates it is used as part of a node in the free list.
+ */
+struct list {
+    struct list *prev;
+    struct list *next;
+};
+
+/*
+ * Static list initializer.
+ */
+#define LIST_INITIALIZER(list) { &(list), &(list) }
+
+/*
+ * Initialize a list.
+ */
+static inline void
+list_init(struct list *list)
+{
+    list->prev = list;
+    list->next = list;
+}
+
+/*
+ * Initialize a list node.
+ *
+ * An entry is in no list when its node members point to NULL.
+ */
+static inline void
+list_node_init(struct list *node)
+{
+    node->prev = NULL;
+    node->next = NULL;
+}
+
+/*
+ * Return true if node is in no list.
+ */
+static inline int
+list_node_unlinked(const struct list *node)
+{
+    return node->prev == NULL;
+}
+
+/*
+ * Macro that evaluates to the address of the structure containing the
+ * given node based on the given type and member.
+ */
+#define list_entry(node, type, member) structof(node, type, member)
+
+/*
+ * Return the first node of a list.
+ */
+static inline struct list *
+list_first(const struct list *list)
+{
+    return list->next;
+}
+
+/*
+ * Return the last node of a list.
+ */
+static inline struct list *
+list_last(const struct list *list)
+{
+    return list->prev;
+}
+
+/*
+ * Return the node next to the given node.
+ */
+static inline struct list *
+list_next(const struct list *node)
+{
+    return node->next;
+}
+
+/*
+ * Return the node previous to the given node.
+ */
+static inline struct list *
+list_prev(const struct list *node)
+{
+    return node->prev;
+}
+
+/*
+ * Get the first entry of a list.
+ */
+#define list_first_entry(list, type, member) \
+    list_entry(list_first(list), type, member)
+
+/*
+ * Get the last entry of a list.
+ */
+#define list_last_entry(list, type, member) \
+    list_entry(list_last(list), type, member)
+
+/*
+ * Return true if node is after the last or before the first node of the list.
+ */
+static inline int
+list_end(const struct list *list, const struct list *node)
+{
+    return list == node;
+}
+
+/*
+ * Return true if list is empty.
+ */
+static inline int
+list_empty(const struct list *list)
+{
+    return list == list->next;
+}
+
+/*
+ * Return true if list contains exactly one node.
+ */
+static inline int
+list_singular(const struct list *list)
+{
+    return (list != list->next) && (list->next == list->prev);
+}
+
+/*
+ * Split list2 by moving its nodes up to (but not including) the given
+ * node into list1 (which can be in a stale state).
+ *
+ * If list2 is empty, or node is list2 or list2->next, nothing is done.
+ */
+static inline void
+list_split(struct list *list1, struct list *list2, struct list *node)
+{
+    if (list_empty(list2) || (list2->next == node) || list_end(list2, node))
+        return;
+
+    list1->next = list2->next;
+    list1->next->prev = list1;
+
+    list1->prev = node->prev;
+    node->prev->next = list1;
+
+    list2->next = node;
+    node->prev = list2;
+}
+
+/*
+ * Append the nodes of list2 at the end of list1.
+ *
+ * After completion, list2 is stale.
+ */
+static inline void
+list_concat(struct list *list1, const struct list *list2)
+{
+    struct list *last1, *first2, *last2;
+
+    if (list_empty(list2))
+        return;
+
+    last1 = list1->prev;
+    first2 = list2->next;
+    last2 = list2->prev;
+
+    last1->next = first2;
+    first2->prev = last1;
+
+    last2->next = list1;
+    list1->prev = last2;
+}
+
+/*
+ * Set the new head of a list.
+ *
+ * This function is an optimized version of :
+ * list_init(&new_list);
+ * list_concat(&new_list, &old_list);
+ *
+ * After completion, old_head is stale.
+ */
+static inline void
+list_set_head(struct list *new_head, const struct list *old_head)
+{
+    if (list_empty(old_head)) {
+        list_init(new_head);
+        return;
+    }
+
+    *new_head = *old_head;
+    new_head->next->prev = new_head;
+    new_head->prev->next = new_head;
+}
+
+/*
+ * Add a node between two nodes.
+ */
+static inline void
+list_add(struct list *prev, struct list *next, struct list *node)
+{
+    next->prev = node;
+    node->next = next;
+
+    prev->next = node;
+    node->prev = prev;
+}
+
+/*
+ * Insert a node at the head of a list.
+ */
+static inline void
+list_insert(struct list *list, struct list *node)
+{
+    list_add(list, list->next, node);
+}
+
+/*
+ * Insert a node at the tail of a list.
+ */
+static inline void
+list_insert_tail(struct list *list, struct list *node)
+{
+    list_add(list->prev, list, node);
+}
+
+/*
+ * Insert a node before another node.
+ */
+static inline void
+list_insert_before(struct list *next, struct list *node)
+{
+    list_add(next->prev, next, node);
+}
+
+/*
+ * Insert a node after another node.
+ */
+static inline void
+list_insert_after(struct list *prev, struct list *node)
+{
+    list_add(prev, prev->next, node);
+}
+
+/*
+ * Remove a node from a list.
+ *
+ * After completion, the node is stale.
+ */
+static inline void
+list_remove(struct list *node)
+{
+    node->prev->next = node->next;
+    node->next->prev = node->prev;
+}
+
+/*
+ * Forge a loop to process all nodes of a list.
+ *
+ * The node must not be altered during the loop.
+ */
+#define list_for_each(list, node)   \
+for (node = list_first(list);       \
+     !list_end(list, node);         \
+     node = list_next(node))
+
+/*
+ * Forge a loop to process all nodes of a list.
+ */
+#define list_for_each_safe(list, node, tmp)             \
+for (node = list_first(list), tmp = list_next(node);    \
+     !list_end(list, node);                             \
+     node = tmp, tmp = list_next(node))
+
+/*
+ * Version of list_for_each() that processes nodes backward.
+ */
+#define list_for_each_reverse(list, node)   \
+for (node = list_last(list);                \
+     !list_end(list, node);                 \
+     node = list_prev(node))
+
+/*
+ * Version of list_for_each_safe() that processes nodes backward.
+ */
+#define list_for_each_reverse_safe(list, node, tmp) \
+for (node = list_last(list), tmp = list_prev(node); \
+     !list_end(list, node);                         \
+     node = tmp, tmp = list_prev(node))
+
+/*
+ * Forge a loop to process all entries of a list.
+ *
+ * The entry node must not be altered during the loop.
+ */
+#define list_for_each_entry(list, entry, member)                    \
+for (entry = list_entry(list_first(list), typeof(*entry), member);  \
+     !list_end(list, &entry->member);                               \
+     entry = list_entry(list_next(&entry->member), typeof(*entry),  \
+                        member))
+
+/*
+ * Forge a loop to process all entries of a list.
+ */
+#define list_for_each_entry_safe(list, entry, tmp, member)          \
+for (entry = list_entry(list_first(list), typeof(*entry), member),  \
+       tmp = list_entry(list_next(&entry->member), typeof(*entry),  \
+                        member);                                    \
+     !list_end(list, &entry->member);                               \
+     entry = tmp, tmp = list_entry(list_next(&entry->member),       \
+                                   typeof(*entry), member))
+
+/*
+ * Version of list_for_each_entry() that processes entries backward.
+ */
+#define list_for_each_entry_reverse(list, entry, member)            \
+for (entry = list_entry(list_last(list), typeof(*entry), member);   \
+     !list_end(list, &entry->member);                               \
+     entry = list_entry(list_prev(&entry->member), typeof(*entry),  \
+                        member))
+
+/*
+ * Version of list_for_each_entry_safe() that processes entries backward.
+ */
+#define list_for_each_entry_reverse_safe(list, entry, tmp, member)  \
+for (entry = list_entry(list_last(list), typeof(*entry), member),   \
+       tmp = list_entry(list_prev(&entry->member), typeof(*entry),  \
+                        member);                                    \
+     !list_end(list, &entry->member);                               \
+     entry = tmp, tmp = list_entry(list_prev(&entry->member),       \
+                                   typeof(*entry), member))
+
+#endif /* _KERN_LIST_H */