replace singly linked-list Data structure with red-black tree for serverRequest
authorJaewook Jung <jw0213.jung@samsung.com>
Thu, 22 Sep 2016 01:53:17 +0000 (10:53 +0900)
committerAshok Babu Channa <ashok.channa@samsung.com>
Thu, 20 Oct 2016 07:02:12 +0000 (07:02 +0000)
Since every data structure used in stack is singly linked-list,
it would be quite inefficient for some data which can be stored massively
like received request info on server.
So I replaced it with red-black tree.
(tree.h from openBSD : http://openbsd.su/src/sys/sys/tree.h)

Change-Id: I68a9b7d00f7f1f9f6aecacee04e0627b72a4ff6b
Signed-off-by: Jaewook Jung <jw0213.jung@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/11443
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
resource/csdk/stack/include/internal/ocserverrequest.h
resource/csdk/stack/include/internal/tree.h [new file with mode: 0644]
resource/csdk/stack/src/ocserverrequest.c

index d7f7bae..ad07c96 100644 (file)
@@ -32,6 +32,8 @@
 #include "cacommon.h"
 #include "cainterface.h"
 
+#include "tree.h"
+
 /**
  * The signature of the internal call back functions to handle responses from entity handler
  */
@@ -94,8 +96,8 @@ typedef struct OCServerRequest
     /** Request to complete.*/
     uint8_t requestComplete;
 
-    /** Linked list; for multiple server request.*/
-    struct OCServerRequest * next;
+    /** Node entry in red-black tree.*/
+    RB_ENTRY(OCServerRequest) entry;
 
     /** Flag indicating slow response.*/
     uint8_t slowFlag;
@@ -118,10 +120,10 @@ typedef struct OCServerRequest
  * Following structure will be created in ocstack to aggregate responses
  * (in future: for block transfer).
  */
-typedef struct OCServerResponse {
-
-    /** Linked list; for multiple server response.*/
-    struct OCServerResponse * next;
+typedef struct OCServerResponse
+{
+    /** Node entry in red-black tree.*/
+    RB_ENTRY(OCServerResponse) entry;
 
     /** this is the pointer to server payload data to be transferred.*/
     OCPayload* payload;
diff --git a/resource/csdk/stack/include/internal/tree.h b/resource/csdk/stack/include/internal/tree.h
new file mode 100644 (file)
index 0000000..203ecfd
--- /dev/null
@@ -0,0 +1,970 @@
+/*     $OpenBSD: tree.h,v 1.16 2016/09/05 07:24:34 dlg Exp $   */
+/*
+ * Copyright 2002 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef        _SYS_TREE_H_
+#define        _SYS_TREE_H_
+
+/*
+ * This file defines data structures for different types of trees:
+ * splay trees and red-black trees.
+ *
+ * A splay tree is a self-organizing data structure.  Every operation
+ * on the tree causes a splay to happen.  The splay moves the requested
+ * node to the root of the tree and partly rebalances it.
+ *
+ * This has the benefit that request locality causes faster lookups as
+ * the requested nodes move to the top of the tree.  On the other hand,
+ * every lookup causes memory writes.
+ *
+ * The Balance Theorem bounds the total access time for m operations
+ * and n inserts on an initially empty tree as O((m + n)lg n).  The
+ * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
+ *
+ * A red-black tree is a binary search tree with the node color as an
+ * extra attribute.  It fulfills a set of conditions:
+ *     - every search path from the root to a leaf consists of the
+ *       same number of black nodes,
+ *     - each red node (except for the root) has a black parent,
+ *     - each leaf node is black.
+ *
+ * Every operation on a red-black tree is bounded as O(lg n).
+ * The maximum height of a red-black tree is 2lg (n+1).
+ */
+
+#define SPLAY_HEAD(name, type)                                         \
+struct name {                                                          \
+       struct type *sph_root; /* root of the tree */                   \
+}
+
+#define SPLAY_INITIALIZER(root)                                                \
+       { NULL }
+
+#define SPLAY_INIT(root) do {                                          \
+       (root)->sph_root = NULL;                                        \
+} while (0)
+
+#define SPLAY_ENTRY(type)                                              \
+struct {                                                               \
+       struct type *spe_left; /* left element */                       \
+       struct type *spe_right; /* right element */                     \
+}
+
+#define SPLAY_LEFT(elm, field)         (elm)->field.spe_left
+#define SPLAY_RIGHT(elm, field)                (elm)->field.spe_right
+#define SPLAY_ROOT(head)               (head)->sph_root
+#define SPLAY_EMPTY(head)              (SPLAY_ROOT(head) == NULL)
+
+/* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
+#define SPLAY_ROTATE_RIGHT(head, tmp, field) do {                      \
+       SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);  \
+       SPLAY_RIGHT(tmp, field) = (head)->sph_root;                     \
+       (head)->sph_root = tmp;                                         \
+} while (0)
+
+#define SPLAY_ROTATE_LEFT(head, tmp, field) do {                       \
+       SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);  \
+       SPLAY_LEFT(tmp, field) = (head)->sph_root;                      \
+       (head)->sph_root = tmp;                                         \
+} while (0)
+
+#define SPLAY_LINKLEFT(head, tmp, field) do {                          \
+       SPLAY_LEFT(tmp, field) = (head)->sph_root;                      \
+       tmp = (head)->sph_root;                                         \
+       (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);         \
+} while (0)
+
+#define SPLAY_LINKRIGHT(head, tmp, field) do {                         \
+       SPLAY_RIGHT(tmp, field) = (head)->sph_root;                     \
+       tmp = (head)->sph_root;                                         \
+       (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);        \
+} while (0)
+
+#define SPLAY_ASSEMBLE(head, node, left, right, field) do {            \
+       SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field); \
+       SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
+       SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field); \
+       SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field); \
+} while (0)
+
+/* Generates prototypes and inline functions */
+
+#define SPLAY_PROTOTYPE(name, type, field, cmp)                                \
+void name##_SPLAY(struct name *, struct type *);                       \
+void name##_SPLAY_MINMAX(struct name *, int);                          \
+struct type *name##_SPLAY_INSERT(struct name *, struct type *);                \
+struct type *name##_SPLAY_REMOVE(struct name *, struct type *);                \
+                                                                       \
+/* Finds the node with the same key as elm */                          \
+static __inline struct type *                                          \
+name##_SPLAY_FIND(struct name *head, struct type *elm)                 \
+{                                                                      \
+       if (SPLAY_EMPTY(head))                                          \
+               return(NULL);                                           \
+       name##_SPLAY(head, elm);                                        \
+       if ((cmp)(elm, (head)->sph_root) == 0)                          \
+               return (head->sph_root);                                \
+       return (NULL);                                                  \
+}                                                                      \
+                                                                       \
+static __inline struct type *                                          \
+name##_SPLAY_NEXT(struct name *head, struct type *elm)                 \
+{                                                                      \
+       name##_SPLAY(head, elm);                                        \
+       if (SPLAY_RIGHT(elm, field) != NULL) {                          \
+               elm = SPLAY_RIGHT(elm, field);                          \
+               while (SPLAY_LEFT(elm, field) != NULL) {                \
+                       elm = SPLAY_LEFT(elm, field);                   \
+               }                                                       \
+       } else                                                          \
+               elm = NULL;                                             \
+       return (elm);                                                   \
+}                                                                      \
+                                                                       \
+static __inline struct type *                                          \
+name##_SPLAY_MIN_MAX(struct name *head, int val)                       \
+{                                                                      \
+       name##_SPLAY_MINMAX(head, val);                                 \
+        return (SPLAY_ROOT(head));                                     \
+}
+
+/* Main splay operation.
+ * Moves node close to the key of elm to top
+ */
+#define SPLAY_GENERATE(name, type, field, cmp)                         \
+struct type *                                                          \
+name##_SPLAY_INSERT(struct name *head, struct type *elm)               \
+{                                                                      \
+    if (SPLAY_EMPTY(head)) {                                           \
+           SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;    \
+    } else {                                                           \
+           int __comp;                                                 \
+           name##_SPLAY(head, elm);                                    \
+           __comp = (cmp)(elm, (head)->sph_root);                      \
+           if(__comp < 0) {                                            \
+                   SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
+                   SPLAY_RIGHT(elm, field) = (head)->sph_root;         \
+                   SPLAY_LEFT((head)->sph_root, field) = NULL;         \
+           } else if (__comp > 0) {                                    \
+                   SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
+                   SPLAY_LEFT(elm, field) = (head)->sph_root;          \
+                   SPLAY_RIGHT((head)->sph_root, field) = NULL;        \
+           } else                                                      \
+                   return ((head)->sph_root);                          \
+    }                                                                  \
+    (head)->sph_root = (elm);                                          \
+    return (NULL);                                                     \
+}                                                                      \
+                                                                       \
+struct type *                                                          \
+name##_SPLAY_REMOVE(struct name *head, struct type *elm)               \
+{                                                                      \
+       struct type *__tmp;                                             \
+       if (SPLAY_EMPTY(head))                                          \
+               return (NULL);                                          \
+       name##_SPLAY(head, elm);                                        \
+       if ((cmp)(elm, (head)->sph_root) == 0) {                        \
+               if (SPLAY_LEFT((head)->sph_root, field) == NULL) {      \
+                       (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
+               } else {                                                \
+                       __tmp = SPLAY_RIGHT((head)->sph_root, field);   \
+                       (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
+                       name##_SPLAY(head, elm);                        \
+                       SPLAY_RIGHT((head)->sph_root, field) = __tmp;   \
+               }                                                       \
+               return (elm);                                           \
+       }                                                               \
+       return (NULL);                                                  \
+}                                                                      \
+                                                                       \
+void                                                                   \
+name##_SPLAY(struct name *head, struct type *elm)                      \
+{                                                                      \
+       struct type __node, *__left, *__right, *__tmp;                  \
+       int __comp;                                                     \
+\
+       SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
+       __left = __right = &__node;                                     \
+\
+       while ((__comp = (cmp)(elm, (head)->sph_root))) {               \
+               if (__comp < 0) {                                       \
+                       __tmp = SPLAY_LEFT((head)->sph_root, field);    \
+                       if (__tmp == NULL)                              \
+                               break;                                  \
+                       if ((cmp)(elm, __tmp) < 0){                     \
+                               SPLAY_ROTATE_RIGHT(head, __tmp, field); \
+                               if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
+                                       break;                          \
+                       }                                               \
+                       SPLAY_LINKLEFT(head, __right, field);           \
+               } else if (__comp > 0) {                                \
+                       __tmp = SPLAY_RIGHT((head)->sph_root, field);   \
+                       if (__tmp == NULL)                              \
+                               break;                                  \
+                       if ((cmp)(elm, __tmp) > 0){                     \
+                               SPLAY_ROTATE_LEFT(head, __tmp, field);  \
+                               if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
+                                       break;                          \
+                       }                                               \
+                       SPLAY_LINKRIGHT(head, __left, field);           \
+               }                                                       \
+       }                                                               \
+       SPLAY_ASSEMBLE(head, &__node, __left, __right, field);          \
+}                                                                      \
+                                                                       \
+/* Splay with either the minimum or the maximum element                        \
+ * Used to find minimum or maximum element in tree.                    \
+ */                                                                    \
+void name##_SPLAY_MINMAX(struct name *head, int __comp) \
+{                                                                      \
+       struct type __node, *__left, *__right, *__tmp;                  \
+\
+       SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
+       __left = __right = &__node;                                     \
+\
+       while (1) {                                                     \
+               if (__comp < 0) {                                       \
+                       __tmp = SPLAY_LEFT((head)->sph_root, field);    \
+                       if (__tmp == NULL)                              \
+                               break;                                  \
+                       if (__comp < 0){                                \
+                               SPLAY_ROTATE_RIGHT(head, __tmp, field); \
+                               if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
+                                       break;                          \
+                       }                                               \
+                       SPLAY_LINKLEFT(head, __right, field);           \
+               } else if (__comp > 0) {                                \
+                       __tmp = SPLAY_RIGHT((head)->sph_root, field);   \
+                       if (__tmp == NULL)                              \
+                               break;                                  \
+                       if (__comp > 0) {                               \
+                               SPLAY_ROTATE_LEFT(head, __tmp, field);  \
+                               if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
+                                       break;                          \
+                       }                                               \
+                       SPLAY_LINKRIGHT(head, __left, field);           \
+               }                                                       \
+       }                                                               \
+       SPLAY_ASSEMBLE(head, &__node, __left, __right, field);          \
+}
+
+#define SPLAY_NEGINF   -1
+#define SPLAY_INF      1
+
+#define SPLAY_INSERT(name, x, y)       name##_SPLAY_INSERT(x, y)
+#define SPLAY_REMOVE(name, x, y)       name##_SPLAY_REMOVE(x, y)
+#define SPLAY_FIND(name, x, y)         name##_SPLAY_FIND(x, y)
+#define SPLAY_NEXT(name, x, y)         name##_SPLAY_NEXT(x, y)
+#define SPLAY_MIN(name, x)             (SPLAY_EMPTY(x) ? NULL  \
+                                       : name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
+#define SPLAY_MAX(name, x)             (SPLAY_EMPTY(x) ? NULL  \
+                                       : name##_SPLAY_MIN_MAX(x, SPLAY_INF))
+
+#define SPLAY_FOREACH(x, name, head)                                   \
+       for ((x) = SPLAY_MIN(name, head);                               \
+            (x) != NULL;                                               \
+            (x) = SPLAY_NEXT(name, head, x))
+
+/* Macros that define a red-black tree */
+#define RB_HEAD(name, type)                                            \
+struct name {                                                          \
+       struct type *rbh_root; /* root of the tree */                   \
+}
+
+#define RB_INITIALIZER(root)                                           \
+       { NULL }
+
+#define RB_INIT(root) do {                                             \
+       (root)->rbh_root = NULL;                                        \
+} while (0)
+
+#define RB_BLACK       0
+#define RB_RED         1
+#define RB_ENTRY(type)                                                 \
+struct {                                                               \
+       struct type *rbe_left;          /* left element */              \
+       struct type *rbe_right;         /* right element */             \
+       struct type *rbe_parent;        /* parent element */            \
+       int rbe_color;                  /* node color */                \
+}
+
+#define RB_LEFT(elm, field)            (elm)->field.rbe_left
+#define RB_RIGHT(elm, field)           (elm)->field.rbe_right
+#define RB_PARENT(elm, field)          (elm)->field.rbe_parent
+#define RB_COLOR(elm, field)           (elm)->field.rbe_color
+#define RB_ROOT(head)                  (head)->rbh_root
+#define RB_EMPTY(head)                 (RB_ROOT(head) == NULL)
+
+#define RB_SET(elm, parent, field) do {                                        \
+       RB_PARENT(elm, field) = parent;                                 \
+       RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;              \
+       RB_COLOR(elm, field) = RB_RED;                                  \
+} while (0)
+
+#define RB_SET_BLACKRED(black, red, field) do {                                \
+       RB_COLOR(black, field) = RB_BLACK;                              \
+       RB_COLOR(red, field) = RB_RED;                                  \
+} while (0)
+
+#ifndef RB_AUGMENT
+#define RB_AUGMENT(x)  do {} while (0)
+#endif
+
+#define RB_ROTATE_LEFT(head, elm, tmp, field) do {                     \
+       (tmp) = RB_RIGHT(elm, field);                                   \
+       if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {             \
+               RB_PARENT(RB_LEFT(tmp, field), field) = (elm);          \
+       }                                                               \
+       RB_AUGMENT(elm);                                                \
+       if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {          \
+               if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))     \
+                       RB_LEFT(RB_PARENT(elm, field), field) = (tmp);  \
+               else                                                    \
+                       RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
+       } else                                                          \
+               (head)->rbh_root = (tmp);                               \
+       RB_LEFT(tmp, field) = (elm);                                    \
+       RB_PARENT(elm, field) = (tmp);                                  \
+       RB_AUGMENT(tmp);                                                \
+       if ((RB_PARENT(tmp, field)))                                    \
+               RB_AUGMENT(RB_PARENT(tmp, field));                      \
+} while (0)
+
+#define RB_ROTATE_RIGHT(head, elm, tmp, field) do {                    \
+       (tmp) = RB_LEFT(elm, field);                                    \
+       if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {             \
+               RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);         \
+       }                                                               \
+       RB_AUGMENT(elm);                                                \
+       if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {          \
+               if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))     \
+                       RB_LEFT(RB_PARENT(elm, field), field) = (tmp);  \
+               else                                                    \
+                       RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
+       } else                                                          \
+               (head)->rbh_root = (tmp);                               \
+       RB_RIGHT(tmp, field) = (elm);                                   \
+       RB_PARENT(elm, field) = (tmp);                                  \
+       RB_AUGMENT(tmp);                                                \
+       if ((RB_PARENT(tmp, field)))                                    \
+               RB_AUGMENT(RB_PARENT(tmp, field));                      \
+} while (0)
+
+/* Generates prototypes and inline functions */
+#define        RB_PROTOTYPE(name, type, field, cmp)                            \
+       RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
+#define        RB_PROTOTYPE_STATIC(name, type, field, cmp)                     \
+       RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
+#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)            \
+attr void name##_RB_INSERT_COLOR(struct name *, struct type *);                \
+attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
+attr struct type *name##_RB_REMOVE(struct name *, struct type *);      \
+attr struct type *name##_RB_INSERT(struct name *, struct type *);      \
+attr struct type *name##_RB_FIND(struct name *, struct type *);                \
+attr struct type *name##_RB_NFIND(struct name *, struct type *);       \
+attr struct type *name##_RB_NEXT(struct type *);                       \
+attr struct type *name##_RB_PREV(struct type *);                       \
+attr struct type *name##_RB_MINMAX(struct name *, int);                        \
+                                                                       \
+
+/* Main rb operation.
+ * Moves node close to the key of elm to top
+ */
+#define        RB_GENERATE(name, type, field, cmp)                             \
+       RB_GENERATE_INTERNAL(name, type, field, cmp,)
+#define        RB_GENERATE_STATIC(name, type, field, cmp)                      \
+       RB_GENERATE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
+#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)             \
+attr void                                                              \
+name##_RB_INSERT_COLOR(struct name *head, struct type *elm)            \
+{                                                                      \
+       struct type *parent, *gparent, *tmp;                            \
+       while ((parent = RB_PARENT(elm, field)) &&                      \
+           RB_COLOR(parent, field) == RB_RED) {                        \
+               gparent = RB_PARENT(parent, field);                     \
+               if (parent == RB_LEFT(gparent, field)) {                \
+                       tmp = RB_RIGHT(gparent, field);                 \
+                       if (tmp && RB_COLOR(tmp, field) == RB_RED) {    \
+                               RB_COLOR(tmp, field) = RB_BLACK;        \
+                               RB_SET_BLACKRED(parent, gparent, field);\
+                               elm = gparent;                          \
+                               continue;                               \
+                       }                                               \
+                       if (RB_RIGHT(parent, field) == elm) {           \
+                               RB_ROTATE_LEFT(head, parent, tmp, field);\
+                               tmp = parent;                           \
+                               parent = elm;                           \
+                               elm = tmp;                              \
+                       }                                               \
+                       RB_SET_BLACKRED(parent, gparent, field);        \
+                       RB_ROTATE_RIGHT(head, gparent, tmp, field);     \
+               } else {                                                \
+                       tmp = RB_LEFT(gparent, field);                  \
+                       if (tmp && RB_COLOR(tmp, field) == RB_RED) {    \
+                               RB_COLOR(tmp, field) = RB_BLACK;        \
+                               RB_SET_BLACKRED(parent, gparent, field);\
+                               elm = gparent;                          \
+                               continue;                               \
+                       }                                               \
+                       if (RB_LEFT(parent, field) == elm) {            \
+                               RB_ROTATE_RIGHT(head, parent, tmp, field);\
+                               tmp = parent;                           \
+                               parent = elm;                           \
+                               elm = tmp;                              \
+                       }                                               \
+                       RB_SET_BLACKRED(parent, gparent, field);        \
+                       RB_ROTATE_LEFT(head, gparent, tmp, field);      \
+               }                                                       \
+       }                                                               \
+       RB_COLOR(head->rbh_root, field) = RB_BLACK;                     \
+}                                                                      \
+                                                                       \
+attr void                                                              \
+name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
+{                                                                      \
+       struct type *tmp;                                               \
+       while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&     \
+           elm != RB_ROOT(head)) {                                     \
+               if (RB_LEFT(parent, field) == elm) {                    \
+                       tmp = RB_RIGHT(parent, field);                  \
+                       if (RB_COLOR(tmp, field) == RB_RED) {           \
+                               RB_SET_BLACKRED(tmp, parent, field);    \
+                               RB_ROTATE_LEFT(head, parent, tmp, field);\
+                               tmp = RB_RIGHT(parent, field);          \
+                       }                                               \
+                       if ((RB_LEFT(tmp, field) == NULL ||             \
+                           RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
+                           (RB_RIGHT(tmp, field) == NULL ||            \
+                           RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
+                               RB_COLOR(tmp, field) = RB_RED;          \
+                               elm = parent;                           \
+                               parent = RB_PARENT(elm, field);         \
+                       } else {                                        \
+                               if (RB_RIGHT(tmp, field) == NULL ||     \
+                                   RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
+                                       struct type *oleft;             \
+                                       if ((oleft = RB_LEFT(tmp, field)))\
+                                               RB_COLOR(oleft, field) = RB_BLACK;\
+                                       RB_COLOR(tmp, field) = RB_RED;  \
+                                       RB_ROTATE_RIGHT(head, tmp, oleft, field);\
+                                       tmp = RB_RIGHT(parent, field);  \
+                               }                                       \
+                               RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
+                               RB_COLOR(parent, field) = RB_BLACK;     \
+                               if (RB_RIGHT(tmp, field))               \
+                                       RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
+                               RB_ROTATE_LEFT(head, parent, tmp, field);\
+                               elm = RB_ROOT(head);                    \
+                               break;                                  \
+                       }                                               \
+               } else {                                                \
+                       tmp = RB_LEFT(parent, field);                   \
+                       if (RB_COLOR(tmp, field) == RB_RED) {           \
+                               RB_SET_BLACKRED(tmp, parent, field);    \
+                               RB_ROTATE_RIGHT(head, parent, tmp, field);\
+                               tmp = RB_LEFT(parent, field);           \
+                       }                                               \
+                       if ((RB_LEFT(tmp, field) == NULL ||             \
+                           RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
+                           (RB_RIGHT(tmp, field) == NULL ||            \
+                           RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
+                               RB_COLOR(tmp, field) = RB_RED;          \
+                               elm = parent;                           \
+                               parent = RB_PARENT(elm, field);         \
+                       } else {                                        \
+                               if (RB_LEFT(tmp, field) == NULL ||      \
+                                   RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
+                                       struct type *oright;            \
+                                       if ((oright = RB_RIGHT(tmp, field)))\
+                                               RB_COLOR(oright, field) = RB_BLACK;\
+                                       RB_COLOR(tmp, field) = RB_RED;  \
+                                       RB_ROTATE_LEFT(head, tmp, oright, field);\
+                                       tmp = RB_LEFT(parent, field);   \
+                               }                                       \
+                               RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
+                               RB_COLOR(parent, field) = RB_BLACK;     \
+                               if (RB_LEFT(tmp, field))                \
+                                       RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
+                               RB_ROTATE_RIGHT(head, parent, tmp, field);\
+                               elm = RB_ROOT(head);                    \
+                               break;                                  \
+                       }                                               \
+               }                                                       \
+       }                                                               \
+       if (elm)                                                        \
+               RB_COLOR(elm, field) = RB_BLACK;                        \
+}                                                                      \
+                                                                       \
+attr struct type *                                                     \
+name##_RB_REMOVE(struct name *head, struct type *elm)                  \
+{                                                                      \
+       struct type *child, *parent, *old = elm;                        \
+       int color;                                                      \
+       if (RB_LEFT(elm, field) == NULL)                                \
+               child = RB_RIGHT(elm, field);                           \
+       else if (RB_RIGHT(elm, field) == NULL)                          \
+               child = RB_LEFT(elm, field);                            \
+       else {                                                          \
+               struct type *left;                                      \
+               elm = RB_RIGHT(elm, field);                             \
+               while ((left = RB_LEFT(elm, field)))                    \
+                       elm = left;                                     \
+               child = RB_RIGHT(elm, field);                           \
+               parent = RB_PARENT(elm, field);                         \
+               color = RB_COLOR(elm, field);                           \
+               if (child)                                              \
+                       RB_PARENT(child, field) = parent;               \
+               if (parent) {                                           \
+                       if (RB_LEFT(parent, field) == elm)              \
+                               RB_LEFT(parent, field) = child;         \
+                       else                                            \
+                               RB_RIGHT(parent, field) = child;        \
+                       RB_AUGMENT(parent);                             \
+               } else                                                  \
+                       RB_ROOT(head) = child;                          \
+               if (RB_PARENT(elm, field) == old)                       \
+                       parent = elm;                                   \
+               (elm)->field = (old)->field;                            \
+               if (RB_PARENT(old, field)) {                            \
+                       if (RB_LEFT(RB_PARENT(old, field), field) == old)\
+                               RB_LEFT(RB_PARENT(old, field), field) = elm;\
+                       else                                            \
+                               RB_RIGHT(RB_PARENT(old, field), field) = elm;\
+                       RB_AUGMENT(RB_PARENT(old, field));              \
+               } else                                                  \
+                       RB_ROOT(head) = elm;                            \
+               RB_PARENT(RB_LEFT(old, field), field) = elm;            \
+               if (RB_RIGHT(old, field))                               \
+                       RB_PARENT(RB_RIGHT(old, field), field) = elm;   \
+               if (parent) {                                           \
+                       left = parent;                                  \
+                       do {                                            \
+                               RB_AUGMENT(left);                       \
+                       } while ((left = RB_PARENT(left, field)));      \
+               }                                                       \
+               goto color;                                             \
+       }                                                               \
+       parent = RB_PARENT(elm, field);                                 \
+       color = RB_COLOR(elm, field);                                   \
+       if (child)                                                      \
+               RB_PARENT(child, field) = parent;                       \
+       if (parent) {                                                   \
+               if (RB_LEFT(parent, field) == elm)                      \
+                       RB_LEFT(parent, field) = child;                 \
+               else                                                    \
+                       RB_RIGHT(parent, field) = child;                \
+               RB_AUGMENT(parent);                                     \
+       } else                                                          \
+               RB_ROOT(head) = child;                                  \
+color:                                                                 \
+       if (color == RB_BLACK)                                          \
+               name##_RB_REMOVE_COLOR(head, parent, child);            \
+       return (old);                                                   \
+}                                                                      \
+                                                                       \
+/* Inserts a node into the RB tree */                                  \
+attr struct type *                                                     \
+name##_RB_INSERT(struct name *head, struct type *elm)                  \
+{                                                                      \
+       struct type *tmp;                                               \
+       struct type *parent = NULL;                                     \
+       int comp = 0;                                                   \
+       tmp = RB_ROOT(head);                                            \
+       while (tmp) {                                                   \
+               parent = tmp;                                           \
+               comp = (cmp)(elm, parent);                              \
+               if (comp < 0)                                           \
+                       tmp = RB_LEFT(tmp, field);                      \
+               else if (comp > 0)                                      \
+                       tmp = RB_RIGHT(tmp, field);                     \
+               else                                                    \
+                       return (tmp);                                   \
+       }                                                               \
+       RB_SET(elm, parent, field);                                     \
+       if (parent != NULL) {                                           \
+               if (comp < 0)                                           \
+                       RB_LEFT(parent, field) = elm;                   \
+               else                                                    \
+                       RB_RIGHT(parent, field) = elm;                  \
+               RB_AUGMENT(parent);                                     \
+       } else                                                          \
+               RB_ROOT(head) = elm;                                    \
+       name##_RB_INSERT_COLOR(head, elm);                              \
+       return (NULL);                                                  \
+}                                                                      \
+                                                                       \
+/* Finds the node with the same key as elm */                          \
+attr struct type *                                                     \
+name##_RB_FIND(struct name *head, struct type *elm)                    \
+{                                                                      \
+       struct type *tmp = RB_ROOT(head);                               \
+       int comp;                                                       \
+       while (tmp) {                                                   \
+               comp = cmp(elm, tmp);                                   \
+               if (comp < 0)                                           \
+                       tmp = RB_LEFT(tmp, field);                      \
+               else if (comp > 0)                                      \
+                       tmp = RB_RIGHT(tmp, field);                     \
+               else                                                    \
+                       return (tmp);                                   \
+       }                                                               \
+       return (NULL);                                                  \
+}                                                                      \
+                                                                       \
+/* Finds the first node greater than or equal to the search key */     \
+attr struct type *                                                     \
+name##_RB_NFIND(struct name *head, struct type *elm)                   \
+{                                                                      \
+       struct type *tmp = RB_ROOT(head);                               \
+       struct type *res = NULL;                                        \
+       int comp;                                                       \
+       while (tmp) {                                                   \
+               comp = cmp(elm, tmp);                                   \
+               if (comp < 0) {                                         \
+                       res = tmp;                                      \
+                       tmp = RB_LEFT(tmp, field);                      \
+               }                                                       \
+               else if (comp > 0)                                      \
+                       tmp = RB_RIGHT(tmp, field);                     \
+               else                                                    \
+                       return (tmp);                                   \
+       }                                                               \
+       return (res);                                                   \
+}                                                                      \
+                                                                       \
+/* ARGSUSED */                                                         \
+attr struct type *                                                     \
+name##_RB_NEXT(struct type *elm)                                       \
+{                                                                      \
+       if (RB_RIGHT(elm, field)) {                                     \
+               elm = RB_RIGHT(elm, field);                             \
+               while (RB_LEFT(elm, field))                             \
+                       elm = RB_LEFT(elm, field);                      \
+       } else {                                                        \
+               if (RB_PARENT(elm, field) &&                            \
+                   (elm == RB_LEFT(RB_PARENT(elm, field), field)))     \
+                       elm = RB_PARENT(elm, field);                    \
+               else {                                                  \
+                       while (RB_PARENT(elm, field) &&                 \
+                           (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
+                               elm = RB_PARENT(elm, field);            \
+                       elm = RB_PARENT(elm, field);                    \
+               }                                                       \
+       }                                                               \
+       return (elm);                                                   \
+}                                                                      \
+                                                                       \
+/* ARGSUSED */                                                         \
+attr struct type *                                                     \
+name##_RB_PREV(struct type *elm)                                       \
+{                                                                      \
+       if (RB_LEFT(elm, field)) {                                      \
+               elm = RB_LEFT(elm, field);                              \
+               while (RB_RIGHT(elm, field))                            \
+                       elm = RB_RIGHT(elm, field);                     \
+       } else {                                                        \
+               if (RB_PARENT(elm, field) &&                            \
+                   (elm == RB_RIGHT(RB_PARENT(elm, field), field)))    \
+                       elm = RB_PARENT(elm, field);                    \
+               else {                                                  \
+                       while (RB_PARENT(elm, field) &&                 \
+                           (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
+                               elm = RB_PARENT(elm, field);            \
+                       elm = RB_PARENT(elm, field);                    \
+               }                                                       \
+       }                                                               \
+       return (elm);                                                   \
+}                                                                      \
+                                                                       \
+attr struct type *                                                     \
+name##_RB_MINMAX(struct name *head, int val)                           \
+{                                                                      \
+       struct type *tmp = RB_ROOT(head);                               \
+       struct type *parent = NULL;                                     \
+       while (tmp) {                                                   \
+               parent = tmp;                                           \
+               if (val < 0)                                            \
+                       tmp = RB_LEFT(tmp, field);                      \
+               else                                                    \
+                       tmp = RB_RIGHT(tmp, field);                     \
+       }                                                               \
+       return (parent);                                                \
+}
+
+#define RB_NEGINF      -1
+#define RB_INF 1
+
+#define RB_INSERT(name, x, y)  name##_RB_INSERT(x, y)
+#define RB_REMOVE(name, x, y)  name##_RB_REMOVE(x, y)
+#define RB_FIND(name, x, y)    name##_RB_FIND(x, y)
+#define RB_NFIND(name, x, y)   name##_RB_NFIND(x, y)
+#define RB_NEXT(name, x, y)    name##_RB_NEXT(y)
+#define RB_PREV(name, x, y)    name##_RB_PREV(y)
+#define RB_MIN(name, x)                name##_RB_MINMAX(x, RB_NEGINF)
+#define RB_MAX(name, x)                name##_RB_MINMAX(x, RB_INF)
+
+#define RB_FOREACH(x, name, head)                                      \
+       for ((x) = RB_MIN(name, head);                                  \
+            (x) != NULL;                                               \
+            (x) = name##_RB_NEXT(x))
+
+#define RB_FOREACH_SAFE(x, name, head, y)                              \
+       for ((x) = RB_MIN(name, head);                                  \
+           ((x) != NULL) && ((y) = name##_RB_NEXT(x), 1);              \
+            (x) = (y))
+
+#define RB_FOREACH_REVERSE(x, name, head)                              \
+       for ((x) = RB_MAX(name, head);                                  \
+            (x) != NULL;                                               \
+            (x) = name##_RB_PREV(x))
+
+#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)                      \
+       for ((x) = RB_MAX(name, head);                                  \
+           ((x) != NULL) && ((y) = name##_RB_PREV(x), 1);              \
+            (x) = (y))
+
+#ifdef _KERNEL
+
+/*
+ * Copyright (c) 2016 David Gwynne <dlg@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h> /* for NULL */
+
+struct rb_type {
+       int             (*t_compare)(const void *, const void *);
+       void            (*t_augment)(void *);
+       size_t            t_offset;     /* offset of rb_entry in type */
+};
+
+struct rb_entry {
+       struct rb_entry  *rbe_parent;
+       struct rb_entry  *rbe_left;
+       struct rb_entry  *rbe_right;
+       unsigned int      rbe_color;
+};
+
+struct rb_tree {
+       struct rb_entry *rbt_root;
+};
+
+static inline void
+_rb_init(struct rb_tree *rbt)
+{
+       rbt->rbt_root = NULL;
+}
+
+static inline int
+_rb_empty(struct rb_tree *rbt)
+{
+       return (rbt->rbt_root == NULL);
+}
+
+void   *_rb_insert(const struct rb_type *, struct rb_tree *, void *);
+void   *_rb_remove(const struct rb_type *, struct rb_tree *, void *);
+void   *_rb_find(const struct rb_type *, struct rb_tree *, const void *);
+void   *_rb_nfind(const struct rb_type *, struct rb_tree *, const void *);
+void   *_rb_root(const struct rb_type *, struct rb_tree *);
+void   *_rb_min(const struct rb_type *, struct rb_tree *);
+void   *_rb_max(const struct rb_type *, struct rb_tree *);
+void   *_rb_next(const struct rb_type *, void *);
+void   *_rb_prev(const struct rb_type *, void *);
+void   *_rb_left(const struct rb_type *, void *);
+void   *_rb_right(const struct rb_type *, void *);
+void   *_rb_parent(const struct rb_type *, void *);
+void   *_rb_color(const struct rb_type *, void *);
+
+#define RBT_HEAD(_name, _type)                                         \
+struct _name {                                                         \
+       struct rb_tree rbh_root;                                        \
+}
+
+#define RBT_INITIALIZER(_head) { { NULL } }
+
+#define RBT_ENTRY(_type)       struct rb_entry
+
+#define RBT_PROTOTYPE(_name, _type, _field, _cmp)                      \
+extern const struct rb_type *const _name##_RBT_TYPE;                   \
+                                                                       \
+static inline void                                                     \
+_name##_RBT_INIT(struct _name *head)                                   \
+{                                                                      \
+       _rb_init(&head->rbh_root);                                      \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_INSERT(struct _name *head, struct _type *elm)              \
+{                                                                      \
+       return _rb_insert(_name##_RBT_TYPE, &head->rbh_root, elm);      \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_REMOVE(struct _name *head, struct _type *elm)              \
+{                                                                      \
+       return _rb_remove(_name##_RBT_TYPE, &head->rbh_root, elm);      \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_FIND(struct _name *head, const struct _type *key)          \
+{                                                                      \
+       return _rb_find(_name##_RBT_TYPE, &head->rbh_root, key);        \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_NFIND(struct _name *head, const struct _type *key)         \
+{                                                                      \
+       return _rb_nfind(_name##_RBT_TYPE, &head->rbh_root, key);       \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_ROOT(struct _name *head)                                   \
+{                                                                      \
+       return _rb_root(_name##_RBT_TYPE, &head->rbh_root);             \
+}                                                                      \
+                                                                       \
+static inline int                                                      \
+_name##_RBT_EMPTY(struct _name *head)                                  \
+{                                                                      \
+       return _rb_empty(&head->rbh_root);                              \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_MIN(struct _name *head)                                    \
+{                                                                      \
+       return _rb_min(_name##_RBT_TYPE, &head->rbh_root);              \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_MAX(struct _name *head)                                    \
+{                                                                      \
+       return _rb_max(_name##_RBT_TYPE, &head->rbh_root);              \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_NEXT(struct _type *elm)                                    \
+{                                                                      \
+       return _rb_next(_name##_RBT_TYPE, elm);                         \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_PREV(struct _type *elm)                                    \
+{                                                                      \
+       return _rb_prev(_name##_RBT_TYPE, elm);                         \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_LEFT(struct _type *elm)                                    \
+{                                                                      \
+       return _rb_left(_name##_RBT_TYPE, elm);                         \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_RIGHT(struct _type *elm)                                   \
+{                                                                      \
+       return _rb_right(_name##_RBT_TYPE, elm);                        \
+}                                                                      \
+                                                                       \
+static inline struct _type *                                           \
+_name##_RBT_PARENT(struct _type *elm)                                  \
+{                                                                      \
+       return _rb_parent(_name##_RBT_TYPE, elm);                       \
+}
+
+#define RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, _aug)                \
+static int                                                             \
+_name##_RBT_COMPARE(const void *lptr, const void *rptr)                        \
+{                                                                      \
+       const struct _type *l = lptr, *r = rptr;                        \
+       return _cmp(l, r);                                              \
+}                                                                      \
+static const struct rb_type _name##_RBT_INFO = {                       \
+       _name##_RBT_COMPARE,                                            \
+       _aug,                                                           \
+       offsetof(struct _type, _field),                                 \
+};                                                                     \
+const struct rb_type *const _name##_RBT_TYPE = &_name##_RBT_INFO
+
+#define RBT_GENERATE_AUGMENT(_name, _type, _field, _cmp, _aug)         \
+static void                                                            \
+_name##_RBT_AUGMENT(void *ptr)                                         \
+{                                                                      \
+       struct _type *p = ptr;                                          \
+       return _aug(p);                                                 \
+}                                                                      \
+RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, _name##_RBT_AUGMENT)
+
+#define RBT_GENERATE(_name, _type, _field, _cmp)                       \
+    RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, NULL)
+
+#define RBT_INIT(_name, _head)         _name##_RBT_INIT(_head)
+#define RBT_INSERT(_name, _head, _elm) _name##_RBT_INSERT(_head, _elm)
+#define RBT_REMOVE(_name, _head, _elm) _name##_RBT_REMOVE(_head, _elm)
+#define RBT_FIND(_name, _head, _key)   _name##_RBT_FIND(_head, _key)
+#define RBT_NFIND(_name, _head, _key)  _name##_RBT_NFIND(_head, _key)
+#define RBT_ROOT(_name, _head)         _name##_RBT_ROOT(_head)
+#define RBT_EMPTY(_name, _head)                _name##_RBT_EMPTY(_head)
+#define RBT_MIN(_name, _head)          _name##_RBT_MIN(_head)
+#define RBT_MAX(_name, _head)          _name##_RBT_MAX(_head)
+#define RBT_NEXT(_name, _elm)          _name##_RBT_NEXT(_elm)
+#define RBT_PREV(_name, _elm)          _name##_RBT_PREV(_elm)
+#define RBT_LEFT(_name, _elm)          _name##_RBT_LEFT(_elm)
+#define RBT_RIGHT(_name, _elm)         _name##_RBT_RIGHT(_elm)
+#define RBT_PARENT(_name, _elm)                _name##_RBT_PARENT(_elm)
+
+#define RBT_FOREACH(_e, _name, _head)                                  \
+       for ((_e) = RBT_MIN(_name, (_head));                            \
+            (_e) != NULL;                                              \
+            (_e) = RBT_NEXT(_name, (_e)))
+
+#define RBT_FOREACH_SAFE(_e, _name, _head, _n)                         \
+       for ((_e) = RBT_MIN(_name, (_head));                            \
+            (_e) != NULL && ((_n) = RBT_NEXT(_name, (_e)), 1); \
+            (_e) = (_n))
+
+#define RBT_FOREACH_REVERSE(_e, _name, _head)                          \
+       for ((_e) = RBT_MAX(_name, (_head));                            \
+            (_e) != NULL;                                              \
+            (_e) = RBT_PREV(_name, (_e)))
+
+#define RBT_FOREACH_REVERSE_SAFE(_e, _name, _head, _n)                 \
+       for ((_e) = RBT_MAX(_name, (_head));                            \
+            (_e) != NULL && ((_n) = RBT_PREV(_name, (_e)), 1); \
+            (_e) = (_n))
+
+#endif /* _KERNEL */
+
+#endif /* _SYS_TREE_H_ */
index 041c75c..13c3142 100644 (file)
@@ -36,7 +36,6 @@
 #include "cacommon.h"
 #include "cainterface.h"
 
-#include <coap/utlist.h>
 #include <coap/pdu.h>
 
 // Module Name
 
 #define TAG  "OIC_RI_SERVERREQUEST"
 
-static struct OCServerRequest * serverRequestList = NULL;
-static struct OCServerResponse * serverResponseList = NULL;
+// for RB tree
+static int RBRequestTokenCmp(OCServerRequest *target, OCServerRequest *treeNode)
+{
+    return memcmp(target->requestToken, treeNode->requestToken, target->tokenLength);
+}
+
+static int RBResponseTokenCmp(OCServerResponse *target, OCServerResponse *treeNode)
+{
+    return memcmp(((OCServerRequest*)target->requestHandle)->requestToken,
+                  ((OCServerRequest*)treeNode->requestHandle)->requestToken,
+                  ((OCServerRequest*)target->requestHandle)->tokenLength);
+}
+
+RB_HEAD(ServerRequestTree, OCServerRequest) serverRequestTree = RB_INITIALIZER(&serverRequestTree);
+RB_GENERATE(ServerRequestTree, OCServerRequest, entry, RBRequestTokenCmp)
+RB_HEAD(ServerResponseTree, OCServerResponse) serverResponseTree =
+                                                            RB_INITIALIZER(&serverResponseTree);
+RB_GENERATE(ServerResponseTree, OCServerResponse, entry, RBResponseTokenCmp)
 
 //-------------------------------------------------------------------------------------------------
 // Local functions
@@ -73,12 +88,12 @@ static OCStackResult AddServerResponse (OCServerResponse ** response, OCRequestH
     VERIFY_NON_NULL(serverResponse);
 
     serverResponse->payload = NULL;
-
     serverResponse->requestHandle = requestHandle;
 
     *response = serverResponse;
+
+    RB_INSERT(ServerResponseTree, &serverResponseTree, serverResponse);
     OIC_LOG(INFO, TAG, "Server Response Added!!");
-    LL_APPEND (serverResponseList, serverResponse);
     return OC_STACK_OK;
 
 exit:
@@ -100,7 +115,7 @@ static void DeleteServerRequest(OCServerRequest * serverRequest)
 {
     if(serverRequest)
     {
-        LL_DELETE(serverRequestList, serverRequest);
+        RB_REMOVE(ServerRequestTree, &serverRequestTree, serverRequest);
         OICFree(serverRequest->requestToken);
         OICFree(serverRequest);
         serverRequest = NULL;
@@ -117,35 +132,15 @@ static void DeleteServerResponse(OCServerResponse * serverResponse)
 {
     if(serverResponse)
     {
-        LL_DELETE(serverResponseList, serverResponse);
+        RB_REMOVE(ServerResponseTree, &serverResponseTree, serverResponse);
         OCPayloadDestroy(serverResponse->payload);
         OICFree(serverResponse);
+        serverResponse = NULL;
         OIC_LOG(INFO, TAG, "Server Response Removed!!");
     }
 }
 
 /**
- * Find a server response and delete it from the server response list
- *
- * @param serverResponse - server response to find and delete
- */
-static void FindAndDeleteServerResponse(OCServerResponse * serverResponse)
-{
-    OCServerResponse* tmp;
-    if(serverResponse)
-    {
-        LL_FOREACH(serverResponseList, tmp)
-        {
-            if (serverResponse == tmp)
-            {
-                DeleteServerResponse(tmp);
-                return;
-            }
-        }
-    }
-}
-
-/**
  * Ensure no accept header option is included when sending responses and add routing info to
  * outgoing response.
  *
@@ -198,21 +193,23 @@ OCServerRequest * GetServerRequestUsingToken (const CAToken_t token, uint8_t tok
         return NULL;
     }
 
-    OCServerRequest * out = NULL;
     OIC_LOG(INFO, TAG,"Get server request with token");
     OIC_LOG_BUFFER(INFO, TAG, (const uint8_t *)token, tokenLength);
 
-    OIC_LOG(INFO, TAG,"Found token");
-    LL_FOREACH (serverRequestList, out)
+    OCServerRequest tmpFind, *out = NULL;
+
+    tmpFind.requestToken = token;
+    tmpFind.tokenLength = tokenLength;
+    out = RB_FIND(ServerRequestTree, &serverRequestTree, &tmpFind);
+
+    if (!out)
     {
-        OIC_LOG_BUFFER(INFO, TAG, (const uint8_t *)out->requestToken, tokenLength);
-        if(memcmp(out->requestToken, token, tokenLength) == 0)
-        {
-            return out;
-        }
+        OIC_LOG(INFO, TAG, "Server Request not found!!");
+        return NULL;
     }
-    OIC_LOG(ERROR, TAG, "Server Request not found!!");
-    return NULL;
+
+    OIC_LOG(INFO, TAG, "Found in server request list");
+    return out;
 }
 
 /**
@@ -224,16 +221,13 @@ OCServerRequest * GetServerRequestUsingToken (const CAToken_t token, uint8_t tok
  */
 OCServerRequest * GetServerRequestUsingHandle (const OCServerRequest * handle)
 {
-    OCServerRequest * out = NULL;
-    LL_FOREACH (serverRequestList, out)
+    if (!handle)
     {
-        if(out == handle)
-        {
-            return out;
-        }
+        OIC_LOG(ERROR, TAG, "Invalid Parameter handle");
+        return NULL;
     }
-    OIC_LOG(ERROR, TAG, "Server Request not found!!");
-    return NULL;
+
+    return GetServerRequestUsingToken(handle->requestToken, handle->tokenLength);
 }
 
 /**
@@ -246,16 +240,25 @@ OCServerRequest * GetServerRequestUsingHandle (const OCServerRequest * handle)
  */
 OCServerResponse * GetServerResponseUsingHandle (const OCServerRequest * handle)
 {
-    OCServerResponse * out = NULL;
-    LL_FOREACH (serverResponseList, out)
+    if (!handle)
     {
-        if(out->requestHandle == handle)
-        {
-            return out;
-        }
+        OIC_LOG(ERROR, TAG, "Invalid Parameter handle");
+        return NULL;
     }
-    OIC_LOG(ERROR, TAG, "Server Response not found!!");
-    return NULL;
+
+    OCServerResponse tmpFind, *out = NULL;
+
+    tmpFind.requestHandle = (OCRequestHandle)handle;
+    out = RB_FIND(ServerResponseTree, &serverResponseTree, &tmpFind);
+
+    if (!out)
+    {
+        OIC_LOG(INFO, TAG, "Server Response not found!!");
+        return NULL;
+    }
+
+    OIC_LOG(INFO, TAG, "Found in server response list");
+    return out;
 }
 
 OCStackResult AddServerRequest (OCServerRequest ** request, uint16_t coapID,
@@ -323,7 +326,6 @@ OCStackResult AddServerRequest (OCServerRequest ** request, uint16_t coapID,
             VERIFY_NON_NULL(serverRequest->requestToken);
             memcpy(serverRequest->requestToken, requestToken, tokenLength);
         }
-
     }
     serverRequest->tokenLength = tokenLength;
 
@@ -336,8 +338,9 @@ OCStackResult AddServerRequest (OCServerRequest ** request, uint16_t coapID,
     serverRequest->devAddr = *devAddr;
 
     *request = serverRequest;
+
+    RB_INSERT(ServerRequestTree, &serverRequestTree, serverRequest);
     OIC_LOG(INFO, TAG, "Server Request Added!!");
-    LL_APPEND (serverRequestList, serverRequest);
     return OC_STACK_OK;
 
 exit:
@@ -406,16 +409,14 @@ OCStackResult FormOCEntityHandlerRequest(
  */
 void FindAndDeleteServerRequest(OCServerRequest * serverRequest)
 {
-    OCServerRequest* tmp;
     if(serverRequest)
     {
-        LL_FOREACH(serverRequestList, tmp)
+        OCServerRequest* out = NULL;
+        out = RB_FIND(ServerRequestTree, &serverRequestTree, serverRequest);
+
+        if (out)
         {
-            if (serverRequest == tmp)
-            {
-                DeleteServerRequest(tmp);
-                return;
-            }
+            DeleteServerRequest(out);
         }
     }
 }
@@ -790,7 +791,7 @@ OCStackResult HandleAggregateResponse(OCEntityHandlerResponse * ehResponse)
             stackRet = HandleSingleResponse(ehResponse);
             //Delete the request and response
             FindAndDeleteServerRequest(serverRequest);
-            FindAndDeleteServerResponse(serverResponse);
+            DeleteServerResponse(serverResponse);
         }
         else
         {