Remove rbt_nil
Since this is an intrusive tree, rbt_nil is the whole size of the node
and can be quite large. For example, miscelm is ~100 bytes.
diff --git a/include/jemalloc/internal/rb.h b/include/jemalloc/internal/rb.h
index 30ccab4..3770342 100644
--- a/include/jemalloc/internal/rb.h
+++ b/include/jemalloc/internal/rb.h
@@ -42,7 +42,6 @@
#define rb_tree(a_type) \
struct { \
a_type *rbt_root; \
- a_type rbt_nil; \
}
/* Left accessors. */
@@ -84,8 +83,8 @@
#define rbt_node_new(a_type, a_field, a_rbt, a_node) do { \
/* Bookkeeping bit cannot be used by node pointer. */ \
assert(((uintptr_t)(a_node) & 0x1) == 0); \
- rbtn_left_set(a_type, a_field, (a_node), &(a_rbt)->rbt_nil); \
- rbtn_right_set(a_type, a_field, (a_node), &(a_rbt)->rbt_nil); \
+ rbtn_left_set(a_type, a_field, (a_node), NULL); \
+ rbtn_right_set(a_type, a_field, (a_node), NULL); \
rbtn_red_set(a_type, a_field, (a_node)); \
} while (0)
#else
@@ -111,25 +110,23 @@
/* Node initializer. */
#define rbt_node_new(a_type, a_field, a_rbt, a_node) do { \
- rbtn_left_set(a_type, a_field, (a_node), &(a_rbt)->rbt_nil); \
- rbtn_right_set(a_type, a_field, (a_node), &(a_rbt)->rbt_nil); \
+ rbtn_left_set(a_type, a_field, (a_node), NULL); \
+ rbtn_right_set(a_type, a_field, (a_node), NULL); \
rbtn_red_set(a_type, a_field, (a_node)); \
} while (0)
#endif
/* Tree initializer. */
#define rb_new(a_type, a_field, a_rbt) do { \
- (a_rbt)->rbt_root = &(a_rbt)->rbt_nil; \
- rbt_node_new(a_type, a_field, a_rbt, &(a_rbt)->rbt_nil); \
- rbtn_black_set(a_type, a_field, &(a_rbt)->rbt_nil); \
+ (a_rbt)->rbt_root = NULL; \
} while (0)
/* Internal utility macros. */
#define rbtn_first(a_type, a_field, a_rbt, a_root, r_node) do { \
(r_node) = (a_root); \
- if ((r_node) != &(a_rbt)->rbt_nil) { \
+ if ((r_node) != NULL) { \
for (; \
- rbtn_left_get(a_type, a_field, (r_node)) != &(a_rbt)->rbt_nil;\
+ rbtn_left_get(a_type, a_field, (r_node)) != NULL; \
(r_node) = rbtn_left_get(a_type, a_field, (r_node))) { \
} \
} \
@@ -137,10 +134,9 @@
#define rbtn_last(a_type, a_field, a_rbt, a_root, r_node) do { \
(r_node) = (a_root); \
- if ((r_node) != &(a_rbt)->rbt_nil) { \
- for (; rbtn_right_get(a_type, a_field, (r_node)) != \
- &(a_rbt)->rbt_nil; (r_node) = rbtn_right_get(a_type, a_field, \
- (r_node))) { \
+ if ((r_node) != NULL) { \
+ for (; rbtn_right_get(a_type, a_field, (r_node)) != NULL; \
+ (r_node) = rbtn_right_get(a_type, a_field, (r_node))) { \
} \
} \
} while (0)
@@ -335,8 +331,8 @@
* Args:
* tree: Pointer to an initialized red-black tree object.
* cb : Callback function, which, if non-null, is called for each node
- * during iteration. There is no way to stop iteration once it has
- * begun.
+ * during iteration. There is no way to stop iteration once it
+ * has begun.
* arg : Opaque pointer passed to cb().
*/
#define rb_gen(a_attr, a_prefix, a_rbt_type, a_type, a_field, a_cmp) \
@@ -346,36 +342,30 @@
} \
a_attr bool \
a_prefix##empty(a_rbt_type *rbtree) { \
- return (rbtree->rbt_root == &rbtree->rbt_nil); \
+ return (rbtree->rbt_root == NULL); \
} \
a_attr a_type * \
a_prefix##first(a_rbt_type *rbtree) { \
a_type *ret; \
rbtn_first(a_type, a_field, rbtree, rbtree->rbt_root, ret); \
- if (ret == &rbtree->rbt_nil) { \
- ret = NULL; \
- } \
return (ret); \
} \
a_attr a_type * \
a_prefix##last(a_rbt_type *rbtree) { \
a_type *ret; \
rbtn_last(a_type, a_field, rbtree, rbtree->rbt_root, ret); \
- if (ret == &rbtree->rbt_nil) { \
- ret = NULL; \
- } \
return (ret); \
} \
a_attr a_type * \
a_prefix##next(a_rbt_type *rbtree, a_type *node) { \
a_type *ret; \
- if (rbtn_right_get(a_type, a_field, node) != &rbtree->rbt_nil) { \
+ if (rbtn_right_get(a_type, a_field, node) != NULL) { \
rbtn_first(a_type, a_field, rbtree, rbtn_right_get(a_type, \
a_field, node), ret); \
} else { \
a_type *tnode = rbtree->rbt_root; \
- assert(tnode != &rbtree->rbt_nil); \
- ret = &rbtree->rbt_nil; \
+ assert(tnode != NULL); \
+ ret = NULL; \
while (true) { \
int cmp = (a_cmp)(node, tnode); \
if (cmp < 0) { \
@@ -386,24 +376,21 @@
} else { \
break; \
} \
- assert(tnode != &rbtree->rbt_nil); \
+ assert(tnode != NULL); \
} \
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = (NULL); \
- } \
return (ret); \
} \
a_attr a_type * \
a_prefix##prev(a_rbt_type *rbtree, a_type *node) { \
a_type *ret; \
- if (rbtn_left_get(a_type, a_field, node) != &rbtree->rbt_nil) { \
+ if (rbtn_left_get(a_type, a_field, node) != NULL) { \
rbtn_last(a_type, a_field, rbtree, rbtn_left_get(a_type, \
a_field, node), ret); \
} else { \
a_type *tnode = rbtree->rbt_root; \
- assert(tnode != &rbtree->rbt_nil); \
- ret = &rbtree->rbt_nil; \
+ assert(tnode != NULL); \
+ ret = NULL; \
while (true) { \
int cmp = (a_cmp)(node, tnode); \
if (cmp < 0) { \
@@ -414,12 +401,9 @@
} else { \
break; \
} \
- assert(tnode != &rbtree->rbt_nil); \
+ assert(tnode != NULL); \
} \
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = (NULL); \
- } \
return (ret); \
} \
a_attr a_type * \
@@ -427,7 +411,7 @@
a_type *ret; \
int cmp; \
ret = rbtree->rbt_root; \
- while (ret != &rbtree->rbt_nil \
+ while (ret != NULL \
&& (cmp = (a_cmp)(key, ret)) != 0) { \
if (cmp < 0) { \
ret = rbtn_left_get(a_type, a_field, ret); \
@@ -435,17 +419,14 @@
ret = rbtn_right_get(a_type, a_field, ret); \
} \
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = (NULL); \
- } \
return (ret); \
} \
a_attr a_type * \
a_prefix##nsearch(a_rbt_type *rbtree, const a_type *key) { \
a_type *ret; \
a_type *tnode = rbtree->rbt_root; \
- ret = &rbtree->rbt_nil; \
- while (tnode != &rbtree->rbt_nil) { \
+ ret = NULL; \
+ while (tnode != NULL) { \
int cmp = (a_cmp)(key, tnode); \
if (cmp < 0) { \
ret = tnode; \
@@ -457,17 +438,14 @@
break; \
} \
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = (NULL); \
- } \
return (ret); \
} \
a_attr a_type * \
a_prefix##psearch(a_rbt_type *rbtree, const a_type *key) { \
a_type *ret; \
a_type *tnode = rbtree->rbt_root; \
- ret = &rbtree->rbt_nil; \
- while (tnode != &rbtree->rbt_nil) { \
+ ret = NULL; \
+ while (tnode != NULL) { \
int cmp = (a_cmp)(key, tnode); \
if (cmp < 0) { \
tnode = rbtn_left_get(a_type, a_field, tnode); \
@@ -479,9 +457,6 @@
break; \
} \
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = (NULL); \
- } \
return (ret); \
} \
a_attr void \
@@ -493,7 +468,7 @@
rbt_node_new(a_type, a_field, rbtree, node); \
/* Wind. */ \
path->node = rbtree->rbt_root; \
- for (pathp = path; pathp->node != &rbtree->rbt_nil; pathp++) { \
+ for (pathp = path; pathp->node != NULL; pathp++) { \
int cmp = pathp->cmp = a_cmp(node, pathp->node); \
assert(cmp != 0); \
if (cmp < 0) { \
@@ -513,7 +488,8 @@
rbtn_left_set(a_type, a_field, cnode, left); \
if (rbtn_red_get(a_type, a_field, left)) { \
a_type *leftleft = rbtn_left_get(a_type, a_field, left);\
- if (rbtn_red_get(a_type, a_field, leftleft)) { \
+ if (leftleft != NULL && rbtn_red_get(a_type, a_field, \
+ leftleft)) { \
/* Fix up 4-node. */ \
a_type *tnode; \
rbtn_black_set(a_type, a_field, leftleft); \
@@ -528,7 +504,8 @@
rbtn_right_set(a_type, a_field, cnode, right); \
if (rbtn_red_get(a_type, a_field, right)) { \
a_type *left = rbtn_left_get(a_type, a_field, cnode); \
- if (rbtn_red_get(a_type, a_field, left)) { \
+ if (left != NULL && rbtn_red_get(a_type, a_field, \
+ left)) { \
/* Split 4-node. */ \
rbtn_black_set(a_type, a_field, left); \
rbtn_black_set(a_type, a_field, right); \
@@ -561,7 +538,7 @@
/* Wind. */ \
nodep = NULL; /* Silence compiler warning. */ \
path->node = rbtree->rbt_root; \
- for (pathp = path; pathp->node != &rbtree->rbt_nil; pathp++) { \
+ for (pathp = path; pathp->node != NULL; pathp++) { \
int cmp = pathp->cmp = a_cmp(node, pathp->node); \
if (cmp < 0) { \
pathp[1].node = rbtn_left_get(a_type, a_field, \
@@ -573,7 +550,7 @@
/* Find node's successor, in preparation for swap. */ \
pathp->cmp = 1; \
nodep = pathp; \
- for (pathp++; pathp->node != &rbtree->rbt_nil; \
+ for (pathp++; pathp->node != NULL; \
pathp++) { \
pathp->cmp = -1; \
pathp[1].node = rbtn_left_get(a_type, a_field, \
@@ -616,7 +593,7 @@
} \
} else { \
a_type *left = rbtn_left_get(a_type, a_field, node); \
- if (left != &rbtree->rbt_nil) { \
+ if (left != NULL) { \
/* node has no successor, but it has a left child. */\
/* Splice node out, without losing the left child. */\
assert(!rbtn_red_get(a_type, a_field, node)); \
@@ -636,33 +613,32 @@
return; \
} else if (pathp == path) { \
/* The tree only contained one node. */ \
- rbtree->rbt_root = &rbtree->rbt_nil; \
+ rbtree->rbt_root = NULL; \
return; \
} \
} \
if (rbtn_red_get(a_type, a_field, pathp->node)) { \
/* Prune red node, which requires no fixup. */ \
assert(pathp[-1].cmp < 0); \
- rbtn_left_set(a_type, a_field, pathp[-1].node, \
- &rbtree->rbt_nil); \
+ rbtn_left_set(a_type, a_field, pathp[-1].node, NULL); \
return; \
} \
/* The node to be pruned is black, so unwind until balance is */\
/* restored. */\
- pathp->node = &rbtree->rbt_nil; \
+ pathp->node = NULL; \
for (pathp--; (uintptr_t)pathp >= (uintptr_t)path; pathp--) { \
assert(pathp->cmp != 0); \
if (pathp->cmp < 0) { \
rbtn_left_set(a_type, a_field, pathp->node, \
pathp[1].node); \
- assert(!rbtn_red_get(a_type, a_field, pathp[1].node)); \
if (rbtn_red_get(a_type, a_field, pathp->node)) { \
a_type *right = rbtn_right_get(a_type, a_field, \
pathp->node); \
a_type *rightleft = rbtn_left_get(a_type, a_field, \
right); \
a_type *tnode; \
- if (rbtn_red_get(a_type, a_field, rightleft)) { \
+ if (rightleft != NULL && rbtn_red_get(a_type, a_field, \
+ rightleft)) { \
/* In the following diagrams, ||, //, and \\ */\
/* indicate the path to the removed node. */\
/* */\
@@ -705,7 +681,8 @@
pathp->node); \
a_type *rightleft = rbtn_left_get(a_type, a_field, \
right); \
- if (rbtn_red_get(a_type, a_field, rightleft)) { \
+ if (rightleft != NULL && rbtn_red_get(a_type, a_field, \
+ rightleft)) { \
/* || */\
/* pathp(b) */\
/* // \ */\
@@ -759,7 +736,8 @@
left); \
a_type *leftrightleft = rbtn_left_get(a_type, a_field, \
leftright); \
- if (rbtn_red_get(a_type, a_field, leftrightleft)) { \
+ if (leftrightleft != NULL && rbtn_red_get(a_type, \
+ a_field, leftrightleft)) { \
/* || */\
/* pathp(b) */\
/* / \\ */\
@@ -785,7 +763,7 @@
/* (b) */\
/* / */\
/* (b) */\
- assert(leftright != &rbtree->rbt_nil); \
+ assert(leftright != NULL); \
rbtn_red_set(a_type, a_field, leftright); \
rbtn_rotate_right(a_type, a_field, pathp->node, \
tnode); \
@@ -808,7 +786,8 @@
return; \
} else if (rbtn_red_get(a_type, a_field, pathp->node)) { \
a_type *leftleft = rbtn_left_get(a_type, a_field, left);\
- if (rbtn_red_get(a_type, a_field, leftleft)) { \
+ if (leftleft != NULL && rbtn_red_get(a_type, a_field, \
+ leftleft)) { \
/* || */\
/* pathp(r) */\
/* / \\ */\
@@ -846,7 +825,8 @@
} \
} else { \
a_type *leftleft = rbtn_left_get(a_type, a_field, left);\
- if (rbtn_red_get(a_type, a_field, leftleft)) { \
+ if (leftleft != NULL && rbtn_red_get(a_type, a_field, \
+ leftleft)) { \
/* || */\
/* pathp(b) */\
/* / \\ */\
@@ -892,13 +872,13 @@
a_attr a_type * \
a_prefix##iter_recurse(a_rbt_type *rbtree, a_type *node, \
a_type *(*cb)(a_rbt_type *, a_type *, void *), void *arg) { \
- if (node == &rbtree->rbt_nil) { \
- return (&rbtree->rbt_nil); \
+ if (node == NULL) { \
+ return (NULL); \
} else { \
a_type *ret; \
if ((ret = a_prefix##iter_recurse(rbtree, rbtn_left_get(a_type, \
- a_field, node), cb, arg)) != &rbtree->rbt_nil \
- || (ret = cb(rbtree, node, arg)) != NULL) { \
+ a_field, node), cb, arg)) != NULL || (ret = cb(rbtree, node, \
+ arg)) != NULL) { \
return (ret); \
} \
return (a_prefix##iter_recurse(rbtree, rbtn_right_get(a_type, \
@@ -912,8 +892,8 @@
if (cmp < 0) { \
a_type *ret; \
if ((ret = a_prefix##iter_start(rbtree, start, \
- rbtn_left_get(a_type, a_field, node), cb, arg)) != \
- &rbtree->rbt_nil || (ret = cb(rbtree, node, arg)) != NULL) { \
+ rbtn_left_get(a_type, a_field, node), cb, arg)) != NULL || \
+ (ret = cb(rbtree, node, arg)) != NULL) { \
return (ret); \
} \
return (a_prefix##iter_recurse(rbtree, rbtn_right_get(a_type, \
@@ -940,21 +920,18 @@
} else { \
ret = a_prefix##iter_recurse(rbtree, rbtree->rbt_root, cb, arg);\
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = NULL; \
- } \
return (ret); \
} \
a_attr a_type * \
a_prefix##reverse_iter_recurse(a_rbt_type *rbtree, a_type *node, \
a_type *(*cb)(a_rbt_type *, a_type *, void *), void *arg) { \
- if (node == &rbtree->rbt_nil) { \
- return (&rbtree->rbt_nil); \
+ if (node == NULL) { \
+ return (NULL); \
} else { \
a_type *ret; \
if ((ret = a_prefix##reverse_iter_recurse(rbtree, \
- rbtn_right_get(a_type, a_field, node), cb, arg)) != \
- &rbtree->rbt_nil || (ret = cb(rbtree, node, arg)) != NULL) { \
+ rbtn_right_get(a_type, a_field, node), cb, arg)) != NULL || \
+ (ret = cb(rbtree, node, arg)) != NULL) { \
return (ret); \
} \
return (a_prefix##reverse_iter_recurse(rbtree, \
@@ -969,8 +946,8 @@
if (cmp > 0) { \
a_type *ret; \
if ((ret = a_prefix##reverse_iter_start(rbtree, start, \
- rbtn_right_get(a_type, a_field, node), cb, arg)) != \
- &rbtree->rbt_nil || (ret = cb(rbtree, node, arg)) != NULL) { \
+ rbtn_right_get(a_type, a_field, node), cb, arg)) != NULL || \
+ (ret = cb(rbtree, node, arg)) != NULL) { \
return (ret); \
} \
return (a_prefix##reverse_iter_recurse(rbtree, \
@@ -998,23 +975,20 @@
ret = a_prefix##reverse_iter_recurse(rbtree, rbtree->rbt_root, \
cb, arg); \
} \
- if (ret == &rbtree->rbt_nil) { \
- ret = NULL; \
- } \
return (ret); \
} \
a_attr void \
a_prefix##destroy_recurse(a_rbt_type *rbtree, a_type *node, void (*cb)( \
a_type *, void *), void *arg) { \
- if (node == &rbtree->rbt_nil) { \
+ if (node == NULL) { \
return; \
} \
a_prefix##destroy_recurse(rbtree, rbtn_left_get(a_type, a_field, \
node), cb, arg); \
- rbtn_left_set(a_type, a_field, (node), &rbtree->rbt_nil); \
+ rbtn_left_set(a_type, a_field, (node), NULL); \
a_prefix##destroy_recurse(rbtree, rbtn_right_get(a_type, a_field, \
node), cb, arg); \
- rbtn_right_set(a_type, a_field, (node), &rbtree->rbt_nil); \
+ rbtn_right_set(a_type, a_field, (node), NULL); \
if (cb) { \
cb(node, arg); \
} \
@@ -1023,7 +997,7 @@
a_prefix##destroy(a_rbt_type *rbtree, void (*cb)(a_type *, void *), \
void *arg) { \
a_prefix##destroy_recurse(rbtree, rbtree->rbt_root, cb, arg); \
- rbtree->rbt_root = &rbtree->rbt_nil; \
+ rbtree->rbt_root = NULL; \
}
#endif /* RB_H_ */
diff --git a/test/unit/rb.c b/test/unit/rb.c
index 14132c1..cf3d3a7 100644
--- a/test/unit/rb.c
+++ b/test/unit/rb.c
@@ -3,7 +3,7 @@
#define rbtn_black_height(a_type, a_field, a_rbt, r_height) do { \
a_type *rbp_bh_t; \
for (rbp_bh_t = (a_rbt)->rbt_root, (r_height) = 0; \
- rbp_bh_t != &(a_rbt)->rbt_nil; \
+ rbp_bh_t != NULL; \
rbp_bh_t = rbtn_left_get(a_type, a_field, rbp_bh_t)) { \
if (!rbtn_red_get(a_type, a_field, rbp_bh_t)) { \
(r_height)++; \
@@ -68,38 +68,43 @@
TEST_END
static unsigned
-tree_recurse(node_t *node, unsigned black_height, unsigned black_depth,
- node_t *nil)
+tree_recurse(node_t *node, unsigned black_height, unsigned black_depth)
{
unsigned ret = 0;
- node_t *left_node = rbtn_left_get(node_t, link, node);
- node_t *right_node = rbtn_right_get(node_t, link, node);
+ node_t *left_node;
+ node_t *right_node;
+
+ if (node == NULL)
+ return (ret);
+
+ left_node = rbtn_left_get(node_t, link, node);
+ right_node = rbtn_right_get(node_t, link, node);
if (!rbtn_red_get(node_t, link, node))
black_depth++;
/* Red nodes must be interleaved with black nodes. */
if (rbtn_red_get(node_t, link, node)) {
- assert_false(rbtn_red_get(node_t, link, left_node),
- "Node should be black");
- assert_false(rbtn_red_get(node_t, link, right_node),
- "Node should be black");
+ if (left_node != NULL)
+ assert_false(rbtn_red_get(node_t, link, left_node),
+ "Node should be black");
+ if (right_node != NULL)
+ assert_false(rbtn_red_get(node_t, link, right_node),
+ "Node should be black");
}
- if (node == nil)
- return (ret);
/* Self. */
assert_u32_eq(node->magic, NODE_MAGIC, "Bad magic");
/* Left subtree. */
- if (left_node != nil)
- ret += tree_recurse(left_node, black_height, black_depth, nil);
+ if (left_node != NULL)
+ ret += tree_recurse(left_node, black_height, black_depth);
else
ret += (black_depth != black_height);
/* Right subtree. */
- if (right_node != nil)
- ret += tree_recurse(right_node, black_height, black_depth, nil);
+ if (right_node != NULL)
+ ret += tree_recurse(right_node, black_height, black_depth);
else
ret += (black_depth != black_height);
@@ -181,8 +186,7 @@
node->magic = 0;
rbtn_black_height(node_t, link, tree, black_height);
- imbalances = tree_recurse(tree->rbt_root, black_height, 0,
- &(tree->rbt_nil));
+ imbalances = tree_recurse(tree->rbt_root, black_height, 0);
assert_u_eq(imbalances, 0, "Tree is unbalanced");
assert_u_eq(tree_iterate(tree), nnodes-1,
"Unexpected node iteration count");
@@ -253,7 +257,6 @@
for (j = 1; j <= NNODES; j++) {
/* Initialize tree and nodes. */
tree_new(&tree);
- tree.rbt_nil.magic = 0;
for (k = 0; k < j; k++) {
nodes[k].magic = NODE_MAGIC;
nodes[k].key = bag[k];
@@ -266,7 +269,7 @@
rbtn_black_height(node_t, link, &tree,
black_height);
imbalances = tree_recurse(tree.rbt_root,
- black_height, 0, &(tree.rbt_nil));
+ black_height, 0);
assert_u_eq(imbalances, 0,
"Tree is unbalanced");