RCU RBTree: Populate range information (augmented rbtree)
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 30 May 2011 17:16:01 +0000 (13:16 -0400)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 30 May 2011 17:16:01 +0000 (13:16 -0400)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
urcu-rbtree.c
urcu/rcurbtree.h

index f4fc6984c029da0d03b24b135f708e773244249c..824883df25e91976f68ed0c3b94958ee509563a1 100644 (file)
@@ -39,6 +39,7 @@
 #include <urcu/rcurbtree.h>
 #include <urcu-pointer.h>
 #include <urcu-call-rcu.h>
+#include <urcu/compiler.h>
 
 #ifdef DEBUG
 #define dbg_printf(args...)    printf(args)
@@ -152,6 +153,192 @@ struct rcu_rbtree_node *dup_decay_node(struct rcu_rbtree *rbtree,
        return xc;
 }
 
+/*
+ * Info for range lookups:
+ * Range lookup information is only valid when used when searching for
+ * ranges. It should never be used in next/prev traversal because the
+ * pointers to parents are not in sync with the parent vision of the
+ * children range.
+ */
+static
+void _set_left_dup_decay(struct rcu_rbtree *rbtree,
+                       struct rcu_rbtree_node *node,
+                       struct rcu_rbtree_node *left,
+                       struct rcu_rbtree_node **top,
+                       struct rcu_rbtree_node **top_child,
+                       unsigned int *top_child_pos, int copy)
+{
+       struct rcu_rbtree_node *first_node = node;      /* already a copy */
+
+       node->_left = left;
+       do {
+               void *min_child_key;
+
+               if (rcu_rbtree_is_nil(left)) {
+                       min_child_key = node->key;
+               } else {
+                       min_child_key = left->min_child_key;
+                       assert(rbtree->comp(left->key, left->min_child_key) >= 0);
+                       assert(rbtree->comp(node->key, left->min_child_key) >= 0);
+               }
+               if (min_child_key != node->min_child_key) {
+                       if (node != first_node) {
+                               if (copy) {
+                                       node = dup_decay_node(rbtree, node);
+                                       node->_left = left;
+                                       set_parent(left, node, IS_LEFT);
+                               }
+                       }
+                       node->min_child_key = min_child_key;
+               } else {
+                       if (node != first_node) {
+                               if (top)
+                                       *top = node;
+                               if (top_child)
+                                       *top_child = left;
+                               if (top_child_pos)
+                                       *top_child_pos = get_pos(left);
+                       } else {
+                               if (top)
+                                       *top = get_parent(node);
+                               if (top_child)
+                                       *top_child = node;
+                               if (top_child_pos)
+                                       *top_child_pos = get_pos(node);
+                       }
+                       return;
+               }
+               left = node;
+       } while (get_pos(node) == IS_LEFT
+                && !rcu_rbtree_is_nil(node = get_parent(node)));
+
+       if (rcu_rbtree_is_nil(node)) {
+               if (top)
+                       *top = node;
+               if (top_child)
+                       *top_child = left;
+               if (top_child_pos)
+                       *top_child_pos = IS_LEFT;       /* arbitrary */
+       } else {
+               assert(get_pos(node) == IS_RIGHT);
+               if (top)
+                       *top = get_parent(node);
+               if (top_child)
+                       *top_child = node;
+               if (top_child_pos)
+                       *top_child_pos = IS_RIGHT;
+       }
+}
+
+static
+void set_left_dup_decay(struct rcu_rbtree *rbtree,
+                       struct rcu_rbtree_node *node,
+                       struct rcu_rbtree_node *left,
+                       struct rcu_rbtree_node **top,
+                       struct rcu_rbtree_node **top_child,
+                       unsigned int *top_child_pos)
+{
+       _set_left_dup_decay(rbtree, node, left, top, top_child,
+                           top_child_pos, 1);
+}
+
+static
+void set_left_update_decay(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node,
+             struct rcu_rbtree_node *left)
+{
+       struct rcu_rbtree_node *first_node = node;      /* already a copy */
+
+       do {
+               if (node != first_node) {
+                       set_parent(node->_right,
+                               get_decay(get_parent(node->_right)), IS_RIGHT);
+               }
+       } while (get_pos(node) == IS_LEFT
+                && !rcu_rbtree_is_nil(node = get_parent(node)));
+}
+
+static
+void set_right_dup_decay(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node,
+                       struct rcu_rbtree_node *right,
+                       struct rcu_rbtree_node **top,
+                       struct rcu_rbtree_node **top_child,
+                       unsigned int *top_child_pos)
+{
+       struct rcu_rbtree_node *first_node = node;      /* already a copy */
+
+       node->_right = right;
+       do {
+               void *max_child_key;
+
+               if (rcu_rbtree_is_nil(right)) {
+                       max_child_key = node->key;
+               } else {
+                       max_child_key = right->max_child_key;
+                       assert(rbtree->comp(right->key, right->max_child_key) <= 0);
+                       assert(rbtree->comp(node->key, right->max_child_key) <= 0);
+               }
+               if (max_child_key != node->max_child_key) {
+                       if (node != first_node) {
+                               node = dup_decay_node(rbtree, node);
+                               node->_right = right;
+                               set_parent(right, node, IS_RIGHT);
+                       }
+                       node->max_child_key = max_child_key;
+               } else {
+                       if (node != first_node) {
+                               if (top)
+                                       *top = node;
+                               if (top_child)
+                                       *top_child = right;
+                               if (top_child_pos)
+                                       *top_child_pos = get_pos(right);
+                       } else {
+                               if (top)
+                                       *top = get_parent(node);
+                               if (top_child)
+                                       *top_child = node;
+                               if (top_child_pos)
+                                       *top_child_pos = get_pos(node);
+                       }
+                       return;
+               }
+               right = node;
+       } while (get_pos(node) == IS_RIGHT
+                && !rcu_rbtree_is_nil(node = get_parent(node)));
+
+       if (rcu_rbtree_is_nil(node)) {
+               if (top)
+                       *top = node;
+               if (top_child)
+                       *top_child = right;
+               if (top_child_pos)
+                       *top_child_pos = IS_RIGHT;      /* arbitrary */
+       } else {
+               assert(get_pos(node) == IS_LEFT);
+               if (top)
+                       *top = get_parent(node);
+               if (top_child)
+                       *top_child = node;
+               if (top_child_pos)
+                       *top_child_pos = IS_LEFT;
+       }
+}
+
+static
+void set_right_update_decay(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node,
+             struct rcu_rbtree_node *right)
+{
+       struct rcu_rbtree_node *first_node = node;      /* already a copy */
+
+       do {
+               if (node != first_node) {
+                       set_parent(node->_left,
+                               get_decay(get_parent(node->_left)), IS_LEFT);
+               }
+       } while (get_pos(node) == IS_RIGHT
+                && !rcu_rbtree_is_nil(node = get_parent(node)));
+}
+
 /*
  * TODO
  * Deal with memory allocation errors.
@@ -172,8 +359,8 @@ void show_tree(struct rcu_rbtree *rbtree)
                printf("{ 0x%lX p:%lX r:%lX l:%lX %s %s %s} ",
                        (unsigned long)node->key,
                        (unsigned long) get_parent(node)->key,
-                       (unsigned long) node->right->key,
-                       (unsigned long) node->left->key,
+                       (unsigned long) node->_right->key,
+                       (unsigned long) node->_left->key,
                        node->color ? "red" : "black",
                        get_pos(node) ? "right" : "left",
                        node->nil ? "nil" : "");
@@ -206,9 +393,9 @@ struct rcu_rbtree_node* rcu_rbtree_search(struct rcu_rbtree *rbtree,
        while (!rcu_rbtree_is_nil(x) && k != x->key) {
                usleep(10);
                if (rbtree->comp(k, x->key) < 0)
-                       x = rcu_dereference(x->left);
+                       x = rcu_dereference(x->_left);
                else
-                       x = rcu_dereference(x->right);
+                       x = rcu_dereference(x->_right);
        }
        return x;
 }
@@ -228,10 +415,10 @@ struct rcu_rbtree_node *rcu_rbtree_min_dup_decay(struct rcu_rbtree *rbtree,
        } else
                *zr = x = dup_decay_node(rbtree, x);
 
-       while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->left))) {
+       while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->_left))) {
                x = dup_decay_node(rbtree, xl);
                set_parent(x, get_decay(get_parent(x)), get_pos(x));
-               get_parent(x)->left = get_decay(get_parent(x)->left);
+               get_parent(x)->_left = get_decay(get_parent(x)->_left);
        }
        return x;
 }
@@ -247,18 +434,18 @@ struct rcu_rbtree_node *rcu_rbtree_min_update_decay(struct rcu_rbtree *rbtree,
        if (rcu_rbtree_is_nil(x))
                return x;
        else {
-               set_parent(x->right, get_decay(get_parent(x->right)),
-                          get_pos(x->right));
-               set_parent(x->left, get_decay(get_parent(x->left)),
-                          get_pos(x->left));
+               set_parent(x->_right, get_decay(get_parent(x->_right)),
+                          get_pos(x->_right));
+               set_parent(x->_left, get_decay(get_parent(x->_left)),
+                          get_pos(x->_left));
        }
 
-       while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->left))) {
+       while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->_left))) {
                x = xl;
-               set_parent(x->right, get_decay(get_parent(x->right)),
-                          get_pos(x->right));
-               set_parent(x->left, get_decay(get_parent(x->left)),
-                          get_pos(x->left));
+               set_parent(x->_right, get_decay(get_parent(x->_right)),
+                          get_pos(x->_right));
+               set_parent(x->_left, get_decay(get_parent(x->_left)),
+                          get_pos(x->_left));
        }
        return x;
 }
@@ -273,7 +460,7 @@ struct rcu_rbtree_node *rcu_rbtree_min(struct rcu_rbtree *rbtree,
        if (rcu_rbtree_is_nil(x))
                return x;
 
-       while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->left)))
+       while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->_left)))
                x = xl;
        return x;
 }
@@ -288,7 +475,7 @@ struct rcu_rbtree_node *rcu_rbtree_max(struct rcu_rbtree *rbtree,
        if (rcu_rbtree_is_nil(x))
                return x;
 
-       while (!rcu_rbtree_is_nil(xr = rcu_dereference(x->right)))
+       while (!rcu_rbtree_is_nil(xr = rcu_dereference(x->_right)))
                x = xr;
        return x;
 }
@@ -312,7 +499,7 @@ struct rcu_rbtree_node *rcu_rbtree_next(struct rcu_rbtree *rbtree,
 
        x = rcu_dereference(x);
 
-       if (!rcu_rbtree_is_nil(xr = rcu_dereference(x->right)))
+       if (!rcu_rbtree_is_nil(xr = rcu_dereference(x->_right)))
                return rcu_rbtree_min(rbtree, xr);
        y = get_parent_and_pos(x, &x_pos);
        while (!rcu_rbtree_is_nil(y) && x_pos == IS_RIGHT) {
@@ -330,7 +517,7 @@ struct rcu_rbtree_node *rcu_rbtree_prev(struct rcu_rbtree *rbtree,
 
        x = rcu_dereference(x);
 
-       if (!rcu_rbtree_is_nil(xl = rcu_dereference(x->left)))
+       if (!rcu_rbtree_is_nil(xl = rcu_dereference(x->_left)))
                return rcu_rbtree_max(rbtree, xl);
        y = get_parent_and_pos(x, &x_pos);
        while (!rcu_rbtree_is_nil(y) && x_pos == IS_LEFT) {
@@ -345,9 +532,9 @@ struct rcu_rbtree_node *rcu_rbtree_prev(struct rcu_rbtree *rbtree,
  * traversal:
  *
  * with x being a right child, the assumption that:
- *   get_parent(x)->right == x
+ *   get_parent(x)->_right == x
  * or if x is a left child, the assumption that:
- *   get_parent(x)->left == x
+ *   get_parent(x)->_left == x
  *
  * This explains why we have to allocate a vc copy of the node for left_rotate,
  * right_rotate and transplant operations.
@@ -366,64 +553,69 @@ static
 void left_rotate(struct rcu_rbtree *rbtree,
                 struct rcu_rbtree_node *x)
 {
-       struct rcu_rbtree_node *y, *y_left, *x_p;
-       unsigned int x_pos;
+       struct rcu_rbtree_node *y, *y_left, *top, *top_child;
+       unsigned int top_child_pos;
 
-       y = x->right;
-       y_left = y->left;
+       y = x->_right;
+       y_left = y->_left;
 
        /* Now operate on new copy, decay old versions */
        x = dup_decay_node(rbtree, x);
        y = dup_decay_node(rbtree, y);
        y_left = dup_decay_node(rbtree, y_left);
 
-       x_pos = get_pos(x);
-       x_p = get_parent(x);
-
        /* Internal node modifications */
-       x->right = y_left;
        set_parent(y, get_parent(x), get_pos(x));
        set_parent(x, y, IS_LEFT);
-       y->left = x;
+       set_left_dup_decay(rbtree, y, x, &top, &top_child, &top_child_pos);
+       set_right_dup_decay(rbtree, x, y_left, NULL, NULL, NULL);
+       assert(!is_decay(top));
+       assert(!is_decay(top_child));
+
        if (!rcu_rbtree_is_nil(y_left))
                set_parent(y_left, x, IS_RIGHT);
 
        cmm_smp_wmb();  /* write into node before publish */
 
        /* External references update (visible by readers) */
-       if (rcu_rbtree_is_nil(x_p))
-               _CMM_STORE_SHARED(rbtree->root, y);
-       else if (x_pos == IS_LEFT)
-               _CMM_STORE_SHARED(x_p->left, y);
+       if (rcu_rbtree_is_nil(top))
+               _CMM_STORE_SHARED(rbtree->root, top_child);
+       else if (top_child_pos == IS_LEFT)
+               _CMM_STORE_SHARED(top->_left, top_child);
        else
-               _CMM_STORE_SHARED(x_p->right, y);
+               _CMM_STORE_SHARED(top->_right, top_child);
 
        /* Point children to new copy (parent only used by updates/next/prev) */
-       set_parent(x->left, get_decay(get_parent(x->left)),
-               get_pos(x->left));
-       set_parent(y->right, get_decay(get_parent(y->right)),
-               get_pos(y->right));
+       set_parent(x->_left, get_decay(get_parent(x->_left)),
+               get_pos(x->_left));
+       set_parent(y->_right, get_decay(get_parent(y->_right)),
+               get_pos(y->_right));
        if (!rcu_rbtree_is_nil(y_left)) {
-               set_parent(y_left->right, get_decay(get_parent(y_left->right)),
-                       get_pos(y_left->right));
-               set_parent(y_left->left, get_decay(get_parent(y_left->left)),
-                       get_pos(y_left->left));
+               set_parent(y_left->_right,
+                       get_decay(get_parent(y_left->_right)),
+                       get_pos(y_left->_right));
+               set_parent(y_left->_left,
+                       get_decay(get_parent(y_left->_left)),
+                       get_pos(y_left->_left));
        }
+       set_left_update_decay(rbtree, y, x);
 
        /* Sanity checks */
-       assert(y == rbtree->root || get_parent(y)->left == y || get_parent(y)->right == y);
-       assert(x == rbtree->root || get_parent(x)->left == x || get_parent(x)->right == x);
-       assert(rcu_rbtree_is_nil(x->right) || get_parent(x->right) == x);
-       assert(rcu_rbtree_is_nil(x->left) || get_parent(x->left) == x);
-       assert(rcu_rbtree_is_nil(y->right) || get_parent(y->right) == y);
-       assert(rcu_rbtree_is_nil(y->left) || get_parent(y->left) == y);
+       assert(y == rbtree->root || get_parent(y)->_left == y
+               || get_parent(y)->_right == y);
+       assert(x == rbtree->root || get_parent(x)->_left == x
+               || get_parent(x)->_right == x);
+       assert(rcu_rbtree_is_nil(x->_right) || get_parent(x->_right) == x);
+       assert(rcu_rbtree_is_nil(x->_left) || get_parent(x->_left) == x);
+       assert(rcu_rbtree_is_nil(y->_right) || get_parent(y->_right) == y);
+       assert(rcu_rbtree_is_nil(y->_left) || get_parent(y->_left) == y);
        assert(!is_decay(rbtree->root));
        assert(!is_decay(x));
        assert(!is_decay(y));
-       assert(!is_decay(x->right));
-       assert(!is_decay(x->left));
-       assert(!is_decay(y->right));
-       assert(!is_decay(y->left));
+       assert(!is_decay(x->_right));
+       assert(!is_decay(x->_left));
+       assert(!is_decay(y->_right));
+       assert(!is_decay(y->_left));
 }
 
 #else
@@ -436,19 +628,19 @@ void left_rotate(struct rcu_rbtree *rbtree,
        struct rcu_rbtree_node *y;
 
        lock_test_mutex();
-       y = x->right;
-       x->right = y->left;
-       if (!rcu_rbtree_is_nil(y->left))
-               set_parent(y->left, x, IS_RIGHT);
+       y = x->_right;
+       x->_right = y->_left;
+       if (!rcu_rbtree_is_nil(y->_left))
+               set_parent(y->_left, x, IS_RIGHT);
        set_parent(y, get_parent(x), get_pos(x));
        if (rcu_rbtree_is_nil(get_parent(x)))
                rbtree->root = y;
-       else if (x == get_parent(x)->left) {
-               get_parent(x)->left = y;
+       else if (x == get_parent(x)->_left) {
+               get_parent(x)->_left = y;
        } else {
-               get_parent(x)->right = y;
+               get_parent(x)->_right = y;
        }
-       y->left = x;
+       y->_left = x;
        set_parent(x, y, IS_LEFT);
        unlock_test_mutex();
 }
@@ -460,64 +652,70 @@ static
 void right_rotate(struct rcu_rbtree *rbtree,
                  struct rcu_rbtree_node *x)
 {
-       struct rcu_rbtree_node *y, *y_right, *x_p;
-       unsigned int x_pos;
+       struct rcu_rbtree_node *y, *y_right, *top, *top_child;
+       unsigned int top_child_pos;
 
-       y = x->left;
-       y_right = y->right;
+       y = x->_left;
+       y_right = y->_right;
 
        /* Now operate on new copy, decay old versions */
        x = dup_decay_node(rbtree, x);
        y = dup_decay_node(rbtree, y);
        y_right = dup_decay_node(rbtree, y_right);
 
-       x_pos = get_pos(x);
-       x_p = get_parent(x);
-
        /* Internal node modifications */
-       x->left = y_right;
        set_parent(y, get_parent(x), get_pos(x));
        set_parent(x, y, IS_RIGHT);
-       y->right = x;
+       set_right_dup_decay(rbtree, y, x, &top, &top_child, &top_child_pos);
+       set_left_dup_decay(rbtree, x, y_right, NULL, NULL, NULL);
+       assert(!is_decay(top));
+       assert(!is_decay(top_child));
+
        if (!rcu_rbtree_is_nil(y_right))
                set_parent(y_right, x, IS_LEFT);
 
        cmm_smp_wmb();  /* write into node before publish */
 
        /* External references update (visible by readers) */
-       if (rcu_rbtree_is_nil(x_p))
-               _CMM_STORE_SHARED(rbtree->root, y);
-       else if (x_pos == IS_RIGHT)
-               _CMM_STORE_SHARED(x_p->right, y);
+       if (rcu_rbtree_is_nil(top))
+               _CMM_STORE_SHARED(rbtree->root, top_child);
+       else if (top_child_pos == IS_RIGHT)
+               _CMM_STORE_SHARED(top->_right, top_child);
        else
-               _CMM_STORE_SHARED(x_p->left, y);
+               _CMM_STORE_SHARED(top->_left, top_child);
 
        /* Point children to new copy (parent only used by updates/next/prev) */
-       set_parent(x->right, get_decay(get_parent(x->right)),
-               get_pos(x->right));
-       set_parent(y->left, get_decay(get_parent(y->left)),
-               get_pos(y->left));
+       set_parent(x->_right, get_decay(get_parent(x->_right)),
+               get_pos(x->_right));
+       set_parent(y->_left, get_decay(get_parent(y->_left)),
+               get_pos(y->_left));
        if (!rcu_rbtree_is_nil(y_right)) {
-               set_parent(y_right->left, get_decay(get_parent(y_right->left)),
-                       get_pos(y_right->left));
-               set_parent(y_right->right, get_decay(get_parent(y_right->right)),
-                       get_pos(y_right->right));
+               set_parent(y_right->_left,
+                       get_decay(get_parent(y_right->_left)),
+                       get_pos(y_right->_left));
+               set_parent(y_right->_right,
+                       get_decay(get_parent(y_right->_right)),
+                       get_pos(y_right->_right));
        }
+       set_right_update_decay(rbtree, y, x);
+       
 
        /* Sanity checks */
-       assert(y == rbtree->root || get_parent(y)->right == y || get_parent(y)->left == y);
-       assert(x == rbtree->root || get_parent(x)->right == x || get_parent(x)->left == x);
-       assert(rcu_rbtree_is_nil(x->left) || get_parent(x->left) == x);
-       assert(rcu_rbtree_is_nil(x->right) || get_parent(x->right) == x);
-       assert(rcu_rbtree_is_nil(y->left) || get_parent(y->left) == y);
-       assert(rcu_rbtree_is_nil(y->right) || get_parent(y->right) == y);
+       assert(y == rbtree->root || get_parent(y)->_right == y
+               || get_parent(y)->_left == y);
+       assert(x == rbtree->root || get_parent(x)->_right == x
+               || get_parent(x)->_left == x);
+       assert(rcu_rbtree_is_nil(x->_left) || get_parent(x->_left) == x);
+       assert(rcu_rbtree_is_nil(x->_right) || get_parent(x->_right) == x);
+       assert(rcu_rbtree_is_nil(y->_left) || get_parent(y->_left) == y);
+       assert(rcu_rbtree_is_nil(y->_right) || get_parent(y->_right) == y);
        assert(!is_decay(rbtree->root));
        assert(!is_decay(x));
        assert(!is_decay(y));
-       assert(!is_decay(x->left));
-       assert(!is_decay(x->right));
-       assert(!is_decay(y->left));
-       assert(!is_decay(y->right));
+       assert(!is_decay(x->_left));
+       assert(!is_decay(x->_right));
+       assert(!is_decay(y->_left));
+       assert(!is_decay(y->_right));
 }
 
 #else
@@ -530,19 +728,19 @@ void right_rotate(struct rcu_rbtree *rbtree,
        struct rcu_rbtree_node *y;
 
        lock_test_mutex();
-       y = x->left;
-       x->left = y->right;
-       if (!rcu_rbtree_is_nil(y->right))
-               set_parent(y->right, x, IS_LEFT);
+       y = x->_left;
+       x->_left = y->_right;
+       if (!rcu_rbtree_is_nil(y->_right))
+               set_parent(y->_right, x, IS_LEFT);
        set_parent(y, get_parent(x), get_pos(x));
        if (rcu_rbtree_is_nil(get_parent(x)))
                rbtree->root = y;
-       else if (x == get_parent(x)->right) {
-               get_parent(x)->right = y;
+       else if (x == get_parent(x)->_right) {
+               get_parent(x)->_right = y;
        } else {
-               get_parent(x)->left = y;
+               get_parent(x)->_left = y;
        }
-       y->right = x;
+       y->_right = x;
        set_parent(x, y, IS_RIGHT);
        unlock_test_mutex();
 }
@@ -558,15 +756,15 @@ static void rcu_rbtree_insert_fixup(struct rcu_rbtree *rbtree,
        assert(!is_decay(rbtree->root));
 
        while (get_parent(z)->color == COLOR_RED) {
-               if (get_parent(z) == get_parent(get_parent(z))->left) {
-                       y = get_parent(get_parent(z))->right;
+               if (get_parent(z) == get_parent(get_parent(z))->_left) {
+                       y = get_parent(get_parent(z))->_right;
                        if (y->color == COLOR_RED) {
                                get_parent(z)->color = COLOR_BLACK;
                                y->color = COLOR_BLACK;
                                get_parent(get_parent(z))->color = COLOR_RED;
                                z = get_parent(get_parent(z));
                        } else {
-                               if (z == get_parent(z)->right) {
+                               if (z == get_parent(z)->_right) {
                                        z = get_parent(z);
                                        left_rotate(rbtree, z);
                                        z = get_decay(z);
@@ -582,14 +780,14 @@ static void rcu_rbtree_insert_fixup(struct rcu_rbtree *rbtree,
                                assert(!is_decay(rbtree->root));
                        }
                } else {
-                       y = get_parent(get_parent(z))->left;
+                       y = get_parent(get_parent(z))->_left;
                        if (y->color == COLOR_RED) {
                                get_parent(z)->color = COLOR_BLACK;
                                y->color = COLOR_BLACK;
                                get_parent(get_parent(z))->color = COLOR_RED;
                                z = get_parent(get_parent(z));
                        } else {
-                               if (z == get_parent(z)->left) {
+                               if (z == get_parent(z)->_left) {
                                        z = get_parent(z);
                                        right_rotate(rbtree, z);
                                        z = get_decay(z);
@@ -614,25 +812,26 @@ static void rcu_rbtree_insert_fixup(struct rcu_rbtree *rbtree,
 int rcu_rbtree_insert(struct rcu_rbtree *rbtree,
                      struct rcu_rbtree_node *z)
 {
-       struct rcu_rbtree_node *x, *y;
+       struct rcu_rbtree_node *x, *y, *top, *top_child;
+       unsigned int top_child_pos;
 
        dbg_printf("insert %p\n", z->key);
        assert(!is_decay(rbtree->root));
 
        y = make_nil(rbtree);
-       if (!rbtree->root)
-               rbtree->root = make_nil(rbtree);
        x = rbtree->root;
        while (!rcu_rbtree_is_nil(x)) {
                y = x;
                if (rbtree->comp(z->key, x->key) < 0)
-                       x = x->left;
+                       x = x->_left;
                else
-                       x = x->right;
+                       x = x->_right;
        }
 
-       z->left = make_nil(rbtree);
-       z->right = make_nil(rbtree);
+       z->_left = make_nil(rbtree);
+       z->_right = make_nil(rbtree);
+       z->min_child_key = z->key;
+       z->max_child_key = z->key;
        z->color = COLOR_RED;
        z->nil = 0;
        z->decay_next = NULL;
@@ -650,12 +849,29 @@ int rcu_rbtree_insert(struct rcu_rbtree *rbtree,
         */
        cmm_smp_wmb();
 
-       if (rcu_rbtree_is_nil(y))
+       if (rcu_rbtree_is_nil(y)) {
                _CMM_STORE_SHARED(rbtree->root, z);
-       else if (rbtree->comp(z->key, y->key) < 0)
-               _CMM_STORE_SHARED(y->left, z);
-       else
-               _CMM_STORE_SHARED(y->right, z);
+       } else if (rbtree->comp(z->key, y->key) < 0) {
+               set_left_dup_decay(rbtree, y, z, &top, &top_child,
+                               &top_child_pos);
+               if (rcu_rbtree_is_nil(top))
+                       _CMM_STORE_SHARED(rbtree->root, top_child);
+               else if (top_child_pos == IS_LEFT)
+                       _CMM_STORE_SHARED(top->_left, top_child);
+               else
+                       _CMM_STORE_SHARED(top->_right, top_child);
+               set_left_update_decay(rbtree, y, z);
+       } else {
+               set_right_dup_decay(rbtree, y, z, &top, &top_child,
+                               &top_child_pos);
+               if (rcu_rbtree_is_nil(top))
+                       _CMM_STORE_SHARED(rbtree->root, top_child);
+               else if (top_child_pos == IS_LEFT)
+                       _CMM_STORE_SHARED(top->_left, top_child);
+               else
+                       _CMM_STORE_SHARED(top->_right, top_child);
+               set_right_update_decay(rbtree, y, z);
+       }
        rcu_rbtree_insert_fixup(rbtree, z);
        /*
         * Make sure to commit all _CMM_STORE_SHARED() for non-coherent caches.
@@ -675,8 +891,12 @@ int rcu_rbtree_insert(struct rcu_rbtree *rbtree,
 static
 void rcu_rbtree_transplant(struct rcu_rbtree *rbtree,
                        struct rcu_rbtree_node *u,
-                       struct rcu_rbtree_node *v)
+                       struct rcu_rbtree_node *v,
+                       unsigned int copy_parents)
 {
+       struct rcu_rbtree_node *top, *top_child;
+       unsigned int top_child_pos;
+
        dbg_printf("transplant %p\n", v->key);
 
        if (!rcu_rbtree_is_nil(v))
@@ -690,18 +910,40 @@ void rcu_rbtree_transplant(struct rcu_rbtree *rbtree,
        } else {
                set_parent(v, get_parent(u), get_pos(u));
                cmm_smp_wmb();  /* write into node before publish */
-               if (get_pos(u) == IS_LEFT)
-                       _CMM_STORE_SHARED(get_parent(u)->left, v);
+
+               if (get_pos(u) == IS_LEFT) {
+                       _set_left_dup_decay(rbtree, get_parent(u), v,
+                                       &top, &top_child, &top_child_pos,
+                                       copy_parents);
+               } else {
+                       assert(copy_parents);
+                       set_right_dup_decay(rbtree, get_parent(u), v,
+                                       &top, &top_child, &top_child_pos);
+               }
+
+               if (rcu_rbtree_is_nil(top))
+                       _CMM_STORE_SHARED(rbtree->root, top_child);
+               else if (top_child_pos == IS_LEFT)
+                       _CMM_STORE_SHARED(top->_left, top_child);
                else
-                       _CMM_STORE_SHARED(get_parent(u)->right, v);
+                       _CMM_STORE_SHARED(top->_right, top_child);
+
+               /* Point children to new copy (parent only used by updates/next/prev) */
+               if (get_pos(u) == IS_LEFT) {
+                       if (copy_parents)
+                               set_left_update_decay(rbtree, get_parent(u), v);
+               } else {
+                       assert(copy_parents);
+                       set_right_update_decay(rbtree, get_parent(u), v);
+               }
        }
 
        /* Point children to new copy (parent only used by updates/next/prev) */
        if (!rcu_rbtree_is_nil(v)) {
-               set_parent(v->right, get_decay(get_parent(v->right)),
-                       get_pos(v->right));
-               set_parent(v->left, get_decay(get_parent(v->left)),
-                       get_pos(v->left));
+               set_parent(v->_right, get_decay(get_parent(v->_right)),
+                       get_pos(v->_right));
+               set_parent(v->_left, get_decay(get_parent(v->_left)),
+                       get_pos(v->_left));
        }
        assert(!is_decay(rbtree->root));
 }
@@ -712,17 +954,18 @@ void rcu_rbtree_transplant(struct rcu_rbtree *rbtree,
 static
 void rcu_rbtree_transplant(struct rcu_rbtree *rbtree,
                           struct rcu_rbtree_node *u,
-                          struct rcu_rbtree_node *v)
+                          struct rcu_rbtree_node *v,
+                          unsigned int copy_parents)
 {
        dbg_printf("transplant %p\n", v->key);
 
        lock_test_mutex();
        if (rcu_rbtree_is_nil(get_parent(u)))
                rbtree->root = v;
-       else if (u == get_parent(u)->left)
-               get_parent(u)->left = v;
+       else if (u == get_parent(u)->_left)
+               get_parent(u)->_left = v;
        else
-               get_parent(u)->right = v;
+               get_parent(u)->_right = v;
        set_parent(v, get_parent(u), get_pos(u));
        unlock_test_mutex();
 }
@@ -736,11 +979,11 @@ static void rcu_rbtree_remove_fixup(struct rcu_rbtree *rbtree,
 
        while (x != rbtree->root && x->color == COLOR_BLACK) {
                assert(!is_decay(get_parent(x)));
-               assert(!is_decay(get_parent(x)->left));
-               if (x == get_parent(x)->left) {
+               assert(!is_decay(get_parent(x)->_left));
+               if (x == get_parent(x)->_left) {
                        struct rcu_rbtree_node *w;
 
-                       w = get_parent(x)->right;
+                       w = get_parent(x)->_right;
 
                        if (w->color == COLOR_RED) {
                                w->color = COLOR_BLACK;
@@ -748,26 +991,26 @@ static void rcu_rbtree_remove_fixup(struct rcu_rbtree *rbtree,
                                left_rotate(rbtree, get_parent(x));
                                x = get_decay(x);
                                assert(!is_decay(rbtree->root));
-                               w = get_parent(x)->right;
+                               w = get_parent(x)->_right;
                        }
-                       if (w->left->color == COLOR_BLACK
-                           && w->right->color == COLOR_BLACK) {
+                       if (w->_left->color == COLOR_BLACK
+                           && w->_right->color == COLOR_BLACK) {
                                w->color = COLOR_RED;
                                x = get_parent(x);
                                assert(!is_decay(rbtree->root));
                                assert(!is_decay(x));
                        } else {
-                               if (w->right->color == COLOR_BLACK) {
-                                       w->left->color = COLOR_BLACK;
+                               if (w->_right->color == COLOR_BLACK) {
+                                       w->_left->color = COLOR_BLACK;
                                        w->color = COLOR_RED;
                                        right_rotate(rbtree, w);
                                        assert(!is_decay(rbtree->root));
                                        x = get_decay(x);
-                                       w = get_parent(x)->right;
+                                       w = get_parent(x)->_right;
                                }
                                w->color = get_parent(x)->color;
                                get_parent(x)->color = COLOR_BLACK;
-                               w->right->color = COLOR_BLACK;
+                               w->_right->color = COLOR_BLACK;
                                left_rotate(rbtree, get_parent(x));
                                assert(!is_decay(rbtree->root));
                                x = rbtree->root;
@@ -775,7 +1018,7 @@ static void rcu_rbtree_remove_fixup(struct rcu_rbtree *rbtree,
                } else {
                        struct rcu_rbtree_node *w;
 
-                       w = get_parent(x)->left;
+                       w = get_parent(x)->_left;
 
                        if (w->color == COLOR_RED) {
                                w->color = COLOR_BLACK;
@@ -783,26 +1026,26 @@ static void rcu_rbtree_remove_fixup(struct rcu_rbtree *rbtree,
                                right_rotate(rbtree, get_parent(x));
                                assert(!is_decay(rbtree->root));
                                x = get_decay(x);
-                               w = get_parent(x)->left;
+                               w = get_parent(x)->_left;
                        }
-                       if (w->right->color == COLOR_BLACK
-                           && w->left->color == COLOR_BLACK) {
+                       if (w->_right->color == COLOR_BLACK
+                           && w->_left->color == COLOR_BLACK) {
                                w->color = COLOR_RED;
                                x = get_parent(x);
                                assert(!is_decay(rbtree->root));
                                assert(!is_decay(x));
                        } else {
-                               if (w->left->color == COLOR_BLACK) {
-                                       w->right->color = COLOR_BLACK;
+                               if (w->_left->color == COLOR_BLACK) {
+                                       w->_right->color = COLOR_BLACK;
                                        w->color = COLOR_RED;
                                        left_rotate(rbtree, w);
                                        assert(!is_decay(rbtree->root));
                                        x = get_decay(x);
-                                       w = get_parent(x)->left;
+                                       w = get_parent(x)->_left;
                                }
                                w->color = get_parent(x)->color;
                                get_parent(x)->color = COLOR_BLACK;
-                               w->left->color = COLOR_BLACK;
+                               w->_left->color = COLOR_BLACK;
                                right_rotate(rbtree, get_parent(x));
                                assert(!is_decay(rbtree->root));
                                x = rbtree->root;
@@ -820,50 +1063,77 @@ void rcu_rbtree_remove_nonil(struct rcu_rbtree *rbtree,
                             struct rcu_rbtree_node *z,
                             struct rcu_rbtree_node *y)
 {
-       struct rcu_rbtree_node *x;
+       struct rcu_rbtree_node *x, *top, *top_child;
+       unsigned int top_child_pos;
 
        dbg_printf("remove nonil %p\n", z->key);
        show_tree(rbtree);
 
        assert(!is_decay(z));
        assert(!is_decay(y));
-       assert(!is_decay(y->right));
+       assert(!is_decay(y->_right));
        assert(!is_decay(get_parent(y)));
-       x = y->right;
+       x = y->_right;
        assert(!is_decay(x));
        if (get_parent(y) == z) {
                y = dup_decay_node(rbtree, y);
                set_parent(x, y, get_pos(x));   /* parent for nil */
-               y->left = z->left;
-               rcu_rbtree_transplant(rbtree, z, y);
+               /* y is z's right node: set left will just update y */
+               set_left_dup_decay(rbtree, y, z->_left,
+                               &top, &top_child, &top_child_pos);
+               assert(top_child == y);
+               rcu_rbtree_transplant(rbtree, z, y, 1);
        } else {
                struct rcu_rbtree_node *oy_right, *z_right;
 
                /*
                 * Need to make sure y is always visible by readers.
                 */
-               y = rcu_rbtree_min_dup_decay(rbtree, z->right, &z_right);
+               y = rcu_rbtree_min_dup_decay(rbtree, z->_right, &z_right);
                assert(!is_decay(y));
                assert(!is_decay(z));
-               oy_right = y->right;
-               y->right = z_right;
-               set_parent(y->right, y, IS_RIGHT);
-               assert(!is_decay(z->left));
-               y->left = z->left;
+               oy_right = y->_right;
+
+               /*
+                * The max child key of z_right does not change, because
+                * we're only changing its left children.
+                */
+               y->_right = z_right;
+               set_parent(y->_right, y, IS_RIGHT);
+               if (rcu_rbtree_is_nil(y->_right))
+                       y->max_child_key = y->key;
+               else
+                       y->max_child_key = y->_right->max_child_key;
+
+               assert(!is_decay(z->_left));
+               y->_left = z->_left;
+               if (rcu_rbtree_is_nil(y->_left))
+                       y->min_child_key = y->key;
+               else
+                       y->min_child_key = y->_left->min_child_key;
+
                assert(!is_decay(oy_right));
-               rcu_rbtree_transplant(rbtree, y, oy_right);
-               rcu_rbtree_transplant(rbtree, z, y);
+               /*
+                * Transplant of oy_right to old y's location will only
+                * trigger a min/max update of the already copied branch
+                * (which is not visible yet). We are transplanting
+                * oy_right as a left child of old y's parent, so the
+                * min values update propagated upward necessarily stops
+                * at z_right.
+                */
+               rcu_rbtree_transplant(rbtree, y, oy_right, 0);
+               rcu_rbtree_transplant(rbtree, z, y, 1);
                /* Update children */
-               (void) rcu_rbtree_min_update_decay(rbtree, y->right);
+               (void) rcu_rbtree_min_update_decay(rbtree, y->_right);
        }
        y = get_decay(y);
        assert(!is_decay(z));
-       assert(!is_decay(z->left));
+       assert(!is_decay(z->_left));
        y->color = z->color;
-       set_parent(y->left, y, IS_LEFT);
-       set_parent(y->right, get_decay(get_parent(y->right)), IS_RIGHT);
-       assert(!is_decay(y->left));
-       assert(!is_decay(y->right));
+       set_parent(y->_left, y, IS_LEFT);
+       set_parent(y->_right, get_decay(get_parent(y->_right)), IS_RIGHT);
+       assert(!is_decay(y->_left));
+       assert(!is_decay(y->_right));
 }
 
 int rcu_rbtree_remove(struct rcu_rbtree *rbtree,
@@ -880,21 +1150,21 @@ int rcu_rbtree_remove(struct rcu_rbtree *rbtree,
        y = z;
        y_original_color = y->color;
 
-       if (rcu_rbtree_is_nil(z->left)) {
-               rcu_rbtree_transplant(rbtree, z, z->right);
+       if (rcu_rbtree_is_nil(z->_left)) {
+               rcu_rbtree_transplant(rbtree, z, z->_right, 1);
                assert(!is_decay(z));
-               x = get_decay(z->right);
+               x = get_decay(z->_right);
                show_tree(rbtree);
-       } else if (rcu_rbtree_is_nil(z->right)) {
-               rcu_rbtree_transplant(rbtree, z, z->left);
+       } else if (rcu_rbtree_is_nil(z->_right)) {
+               rcu_rbtree_transplant(rbtree, z, z->_left, 1);
                assert(!is_decay(z));
-               x = get_decay(z->left);
+               x = get_decay(z->_left);
                show_tree(rbtree);
        } else {
-               y = rcu_rbtree_min(rbtree, z->right);
+               y = rcu_rbtree_min(rbtree, z->_right);
                assert(!is_decay(y));
                y_original_color = y->color;
-               x = y->right;
+               x = y->_right;
                rcu_rbtree_remove_nonil(rbtree, z, y);
                x = get_decay(x);
                show_tree(rbtree);
index 3825f07170c44e78df2d0fe84675fb164cb77e68..3efbbfad8350cb338a9336f2bbb4a3f9dac1ed77 100644 (file)
@@ -60,11 +60,14 @@ typedef void (*rcu_rbtree_free)(struct rcu_head *head);
 struct rcu_rbtree_node {
        /* must be set upon insertion */
        void *key;
+       /* augmented tree */
+       void *min_child_key, *max_child_key;
 
        /* internally reserved */
        /* parent uses low bit for "0 -> is left, 1 -> is right" */
        unsigned long parent;
-       struct rcu_rbtree_node *left, *right;
+       /* _left and _right must be updated with set_left(), set_right() */
+       struct rcu_rbtree_node *_left, *_right;
        struct rcu_rbtree_node *decay_next;
        struct rcu_head head;           /* For delayed free */
        unsigned int color:1;
@@ -89,7 +92,7 @@ struct rcu_rbtree {
                                .color = COLOR_BLACK,   \
                                .nil = 1,               \
                        },                              \
-                       .root = &x.nil_node,            \
+                       .root = &(x).nil_node,          \
                };
 
 /*
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