Basic fix for rbtree nil node

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/urcu-rbtree.c b/urcu-rbtree.c
index 4105bf43adc9d9a3129e530e7e6ebf8f10ccaf6d..31f609fbcf838ab7e5cdf6ee4ab822cfe988f207 100644 (file)
--- a/urcu-rbtree.c
+++ b/urcu-rbtree.c
@@ -45,7 +45,7 @@
  */
 
 /* Sentinel (bottom nodes). Don't care about p, left, right and key values */
-static struct rcu_rbtree_node nil = {
+struct rcu_rbtree_node rcu_rbtree_nil = {
        .color = COLOR_BLACK,
 };
 
@@ -175,7 +175,7 @@ static struct rcu_rbtree_node *left_rotate(struct rcu_rbtree_node **root,
        smp_wmb();
 
        /* Make parents point to the copies */
-       if (x->p == &nil)
+       if (x->p == &rcu_rbtree_nil)
                _STORE_SHARED(*root, yc);
        else if (x == x->p->left)
                _STORE_SHARED(x->p->left, yc);
@@ -202,10 +202,10 @@ static void left_rotate(struct rcu_rbtree_node **root,
 
        y = x->right;
        x->right = y->left;
-       if (y->left != &nil)
+       if (y->left != &rcu_rbtree_nil)
                y->left->p = x;
        y->p = x->p;
-       if (x->p == &nil)
+       if (x->p == &rcu_rbtree_nil)
                *root = y;
        else if (x == x->p->left)
                x->p->left = y;
@@ -246,7 +246,7 @@ static struct rcu_rbtree_node *right_rotate(struct rcu_rbtree_node **root,
        smp_wmb();
 
        /* Make parents point to the copies */
-       if (x->p == &nil)
+       if (x->p == &rcu_rbtree_nil)
                _STORE_SHARED(*root, yc);
        else if (x == x->p->right)
                _STORE_SHARED(x->p->right, yc);
@@ -273,10 +273,10 @@ static void right_rotate(struct rcu_rbtree_node **root,
 
        y = x->left;
        x->left = y->right;
-       if (y->right != &nil)
+       if (y->right != &rcu_rbtree_nil)
                y->right->p = x;
        y->p = x->p;
-       if (x->p == &nil)
+       if (x->p == &rcu_rbtree_nil)
                *root = y;
        else if (x == x->p->right)
                x->p->right = y;
@@ -349,10 +349,10 @@ int rcu_rbtree_insert(struct rcu_rbtree_node **root,
 {
        struct rcu_rbtree_node *x, *y;
 
-       y = &nil;
+       y = &rcu_rbtree_nil;
        x = *root;
 
-       while (x != &nil) {
+       while (x != &rcu_rbtree_nil) {
                y = x;
                if (comp(z->key, x->key) < 0)
                        x = x->left;
@@ -361,8 +361,8 @@ int rcu_rbtree_insert(struct rcu_rbtree_node **root,
        }
 
        z->p = y;
-       z->left = &nil;
-       z->right = &nil;
+       z->left = &rcu_rbtree_nil;
+       z->right = &rcu_rbtree_nil;
        z->color = COLOR_RED;
 
        /*
@@ -371,7 +371,7 @@ int rcu_rbtree_insert(struct rcu_rbtree_node **root,
         */
        smp_wmb();
 
-       if (y == &nil)
+       if (y == &rcu_rbtree_nil)
                _STORE_SHARED(*root, z);
        else if (comp(z->key, y->key) < 0)
                _STORE_SHARED(y->left, z);
@@ -412,7 +412,7 @@ rcu_rbtree_transplant(struct rcu_rbtree_node **root,
        smp_wmb();
 
        /* Assign upper-level pointer to vc, replacing u. */
-       if (u->p == &nil)
+       if (u->p == &rcu_rbtree_nil)
                _STORE_SHARED(*root, vc);
        else if (u == u->p->left)
                _STORE_SHARED(u->p->left, vc);
@@ -542,7 +542,7 @@ rcu_rbtree_remove_nonil(struct rcu_rbtree_node **root,
                /* Transplant y->right into y, external parent links */
 
                /* Assign upper-level pointer to xc, replacing y. */
-               if (y->p == &nil)
+               if (y->p == &rcu_rbtree_nil)
                        _STORE_SHARED(*root, xc);
                else if (y == y->p->left)
                        _STORE_SHARED(y->p->left, xc);
@@ -551,7 +551,7 @@ rcu_rbtree_remove_nonil(struct rcu_rbtree_node **root,
        }
 
        /* Transplant y into z, update external parent links */
-       if (z->p == &nil)
+       if (z->p == &rcu_rbtree_nil)
                _STORE_SHARED(*root, yc);
        else if (z == z->p->left)
                _STORE_SHARED(z->p->left, yc);
@@ -583,9 +583,9 @@ int rcu_rbtree_remove(struct rcu_rbtree_node **root,
        y = z;
        y_original_color = y->color;
 
-       if (z->left == &nil) {
+       if (z->left == &rcu_rbtree_nil) {
                x = rcu_rbtree_transplant(root, z, z->right, rballoc, rbfree);
-       } else if (z->right == &nil) {
+       } else if (z->right == &rcu_rbtree_nil) {
                x = rcu_rbtree_transplant(root, z, z->left, rballoc, rbfree);
        } else {
                y = rcu_rbtree_min(z->right, comp);

diff --git a/urcu-rbtree.h b/urcu-rbtree.h
index b12a0e343b4d83d689c8b3943259a2842e417554..8125170df9d31ce05a0a5748a9f9a8a07d3d6a76 100644 (file)
--- a/urcu-rbtree.h
+++ b/urcu-rbtree.h
@@ -60,6 +60,9 @@ struct rcu_rbtree_node {
        unsigned int color:1;
 };
 
+/* nil rbtree node. "root" must initially point to this node. */
+struct rcu_rbtree_node rcu_rbtree_nil;
+
 /*
  * Each of the search primitive and "prev"/"next" iteration must be called with
  * the RCU read-side lock held.