1 files changed, 48 insertions, 0 deletions
diff --git a/list.h b/list.h
new file mode 100644
index 0000000..5cc1473
--- /dev/null
+++ b/list.h
@@ -0,0 +1,48 @@
+#ifndef paagllist
+#define paagllist
+
+#define AGL_DLIST_INIT(self)                                            \
+    do {                                                                \
+        (&(self))->prev = &(self);                                      \
+        (&(self))->next = &(self);                                      \
+    } while(0)
+
+#define AGL_OFFSET(structure, member)                                    \
+    ((int)((char *)((&((structure *)0)->member)) - (char *)0))
+
+#define AGL_LIST_RELOCATE(structure, member, ptr)                       \
+    ((structure *)(void *)((char *)ptr - AGL_OFFSET(structure, member)))
+
+#define AGL_DLIST_FOR_EACH(structure, member, pos, head)                \
+    for (pos = AGL_LIST_RELOCATE(structure, member, (head)->next);      \
+         &pos->member != (head);                                        \
+         pos = AGL_LIST_RELOCATE(structure, member, pos->member.next))
+
+#define AGL_DLIST_FOR_EACH_SAFE(structure, member, pos, n, head)        \
+    for (pos = AGL_LIST_RELOCATE(structure, member, (head)->next),      \
+           n = AGL_LIST_RELOCATE(structure, member, pos->member.next);  \
+         &pos->member != (head);                                        \
+         pos = n,                                                       \
+           n = AGL_LIST_RELOCATE(structure, member, pos->member.next))
+
+#define AGL_DLIST_FOR_EACH_BACKWARDS(structure, member, pos, head)       \
+    for (pos = AGL_LIST_RELOCATE(structure, member, (head)->prev);      \
+         &pos->member != (head);                                        \
+         pos = AGL_LIST_RELOCATE(structure, member, pos->member.prev))
+
+#define AGL_DLIST_UNLINK(structure, member, elem)                       \
+    do {                                                                \
+        agl_dlist *after  = (elem)->member.prev;                        \
+        agl_dlist *before = (elem)->member.next;                        \
+        after->next = before;                                           \
+        before->prev = after;                                           \
+        (elem)->member.prev = (elem)->member.next = &(elem)->member;    \
+    } while(0)
+
+
+typedef struct agl_dlist {
+	struct agl_dlist *prev;
+	struct agl_dlist *next;
+} agl_dlist;
+
+#endif