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-rw-r--r--src/test/test-rbtree.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/src/test/test-rbtree.c b/src/test/test-rbtree.c
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+/***
+ This file is part of systemd. See COPYING for details.
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/*
+ * Tests for RB-Tree
+ */
+
+#undef NDEBUG
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include "c-rbtree.h"
+
+/* verify that all API calls are exported */
+static void test_api(void) {
+ CRBTree t = {};
+ CRBNode n = C_RBNODE_INIT(n);
+
+ assert(!c_rbnode_is_linked(&n));
+
+ /* init, is_linked, add, remove, remove_init */
+
+ c_rbtree_add(&t, NULL, &t.root, &n);
+ assert(c_rbnode_is_linked(&n));
+
+ c_rbtree_remove_init(&t, &n);
+ assert(!c_rbnode_is_linked(&n));
+
+ c_rbtree_add(&t, NULL, &t.root, &n);
+ assert(c_rbnode_is_linked(&n));
+
+ c_rbtree_remove(&t, &n);
+ assert(c_rbnode_is_linked(&n)); /* @n wasn't touched */
+
+ c_rbnode_init(&n);
+ assert(!c_rbnode_is_linked(&n));
+
+ /* first, last, leftmost, rightmost, next, prev */
+
+ assert(!c_rbtree_first(&t));
+ assert(!c_rbtree_last(&t));
+ assert(&n == c_rbnode_leftmost(&n));
+ assert(&n == c_rbnode_rightmost(&n));
+ assert(!c_rbnode_next(&n));
+ assert(!c_rbnode_prev(&n));
+}
+
+/* copied from c-rbtree.c, relies on internal representation */
+static inline _Bool c_rbnode_is_red(CRBNode *n) {
+ return !((unsigned long)n->__parent_and_color & 1UL);
+}
+
+/* copied from c-rbtree.c, relies on internal representation */
+static inline _Bool c_rbnode_is_black(CRBNode *n) {
+ return !!((unsigned long)n->__parent_and_color & 1UL);
+}
+
+static size_t validate(CRBTree *t) {
+ unsigned int i_black, n_black;
+ CRBNode *n, *p, *o;
+ size_t count = 0;
+
+ assert(t);
+ assert(!t->root || c_rbnode_is_black(t->root));
+
+ /* traverse to left-most child, count black nodes */
+ i_black = 0;
+ n = t->root;
+ while (n && n->left) {
+ if (c_rbnode_is_black(n))
+ ++i_black;
+ n = n->left;
+ }
+ n_black = i_black;
+
+ /*
+ * Traverse tree and verify correctness:
+ * 1) A node is either red or black
+ * 2) The root is black
+ * 3) All leaves are black
+ * 4) Every red node must have two black child nodes
+ * 5) Every path to a leaf contains the same number of black nodes
+ *
+ * Note that NULL nodes are considered black, which is why we don't
+ * check for 3).
+ */
+ o = NULL;
+ while (n) {
+ ++count;
+
+ /* verify natural order */
+ assert(n > o);
+ o = n;
+
+ /* verify consistency */
+ assert(!n->right || c_rbnode_parent(n->right) == n);
+ assert(!n->left || c_rbnode_parent(n->left) == n);
+
+ /* verify 2) */
+ if (!c_rbnode_parent(n))
+ assert(c_rbnode_is_black(n));
+
+ if (c_rbnode_is_red(n)) {
+ /* verify 4) */
+ assert(!n->left || c_rbnode_is_black(n->left));
+ assert(!n->right || c_rbnode_is_black(n->right));
+ } else {
+ /* verify 1) */
+ assert(c_rbnode_is_black(n));
+ }
+
+ /* verify 5) */
+ if (!n->left && !n->right)
+ assert(i_black == n_black);
+
+ /* get next node */
+ if (n->right) {
+ n = n->right;
+ if (c_rbnode_is_black(n))
+ ++i_black;
+
+ while (n->left) {
+ n = n->left;
+ if (c_rbnode_is_black(n))
+ ++i_black;
+ }
+ } else {
+ while ((p = c_rbnode_parent(n)) && n == p->right) {
+ n = p;
+ if (c_rbnode_is_black(p->right))
+ --i_black;
+ }
+
+ n = p;
+ if (p && c_rbnode_is_black(p->left))
+ --i_black;
+ }
+ }
+
+ return count;
+}
+
+static void insert(CRBTree *t, CRBNode *n) {
+ CRBNode **i, *p;
+
+ assert(t);
+ assert(n);
+ assert(!c_rbnode_is_linked(n));
+
+ i = &t->root;
+ p = NULL;
+ while (*i) {
+ p = *i;
+ if (n < *i) {
+ i = &(*i)->left;
+ } else {
+ assert(n > *i);
+ i = &(*i)->right;
+ }
+ }
+
+ c_rbtree_add(t, p, i, n);
+}
+
+static void shuffle(void **nodes, size_t n_memb) {
+ unsigned int i, j;
+ void *t;
+
+ for (i = 0; i < n_memb; ++i) {
+ j = rand() % n_memb;
+ t = nodes[j];
+ nodes[j] = nodes[i];
+ nodes[i] = t;
+ }
+}
+
+/* run some pseudo-random tests on the tree */
+static void test_shuffle(void) {
+ CRBNode *nodes[256];
+ CRBTree t = {};
+ unsigned int i, j;
+ size_t n;
+
+ /* allocate and initialize all nodes */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ nodes[i] = malloc(sizeof(*nodes[i]));
+ assert(nodes[i]);
+ c_rbnode_init(nodes[i]);
+ }
+
+ /* shuffle nodes and validate *empty* tree */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+ n = validate(&t);
+ assert(n == 0);
+
+ /* add all nodes and validate after each insertion */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ insert(&t, nodes[i]);
+ n = validate(&t);
+ assert(n == i + 1);
+ }
+
+ /* shuffle nodes again */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+
+ /* remove all nodes (in different order) and validate on each round */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ c_rbtree_remove(&t, nodes[i]);
+ n = validate(&t);
+ assert(n == sizeof(nodes) / sizeof(*nodes) - i - 1);
+ c_rbnode_init(nodes[i]);
+ }
+
+ /* shuffle nodes and validate *empty* tree again */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+ n = validate(&t);
+ assert(n == 0);
+
+ /* add all nodes again */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ insert(&t, nodes[i]);
+ n = validate(&t);
+ assert(n == i + 1);
+ }
+
+ /* 4 times, remove half of the nodes and add them again */
+ for (j = 0; j < 4; ++j) {
+ /* shuffle nodes again */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+
+ /* remove half of the nodes */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes) / 2; ++i) {
+ c_rbtree_remove(&t, nodes[i]);
+ n = validate(&t);
+ assert(n == sizeof(nodes) / sizeof(*nodes) - i - 1);
+ c_rbnode_init(nodes[i]);
+ }
+
+ /* shuffle the removed half */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes) / 2);
+
+ /* add the removed half again */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes) / 2; ++i) {
+ insert(&t, nodes[i]);
+ n = validate(&t);
+ assert(n == sizeof(nodes) / sizeof(*nodes) / 2 + i + 1);
+ }
+ }
+
+ /* shuffle nodes again */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+
+ /* remove all */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ c_rbtree_remove(&t, nodes[i]);
+ n = validate(&t);
+ assert(n == sizeof(nodes) / sizeof(*nodes) - i - 1);
+ c_rbnode_init(nodes[i]);
+ }
+
+ /* free nodes again */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i)
+ free(nodes[i]);
+}
+
+typedef struct {
+ unsigned long key;
+ CRBNode rb;
+} Node;
+
+#define node_from_rb(_rb) ((Node *)((char *)(_rb) - offsetof(Node, rb)))
+
+static int compare(CRBTree *t, void *k, CRBNode *n) {
+ unsigned long key = (unsigned long)k;
+ Node *node = node_from_rb(n);
+
+ return (key < node->key) ? -1 : (key > node->key) ? 1 : 0;
+}
+
+/* run tests against the c_rbtree_find*() helpers */
+static void test_map(void) {
+ CRBNode **slot, *p;
+ CRBTree t = {};
+ Node *nodes[2048];
+ unsigned long i;
+
+ /* allocate and initialize all nodes */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ nodes[i] = malloc(sizeof(*nodes[i]));
+ assert(nodes[i]);
+ nodes[i]->key = i;
+ c_rbnode_init(&nodes[i]->rb);
+ }
+
+ /* shuffle nodes */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+
+ /* add all nodes, and verify that each node is linked */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ assert(!c_rbnode_is_linked(&nodes[i]->rb));
+ assert(!c_rbtree_find_entry(&t, compare, (void *)nodes[i]->key, Node, rb));
+
+ slot = c_rbtree_find_slot(&t, compare, (void *)nodes[i]->key, &p);
+ assert(slot);
+ c_rbtree_add(&t, p, slot, &nodes[i]->rb);
+
+ assert(c_rbnode_is_linked(&nodes[i]->rb));
+ assert(nodes[i] == c_rbtree_find_entry(&t, compare, (void *)nodes[i]->key, Node, rb));
+ }
+
+ /* shuffle nodes again */
+ shuffle((void **)nodes, sizeof(nodes) / sizeof(*nodes));
+
+ /* remove all nodes (in different order) */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i) {
+ assert(c_rbnode_is_linked(&nodes[i]->rb));
+ assert(nodes[i] == c_rbtree_find_entry(&t, compare, (void *)nodes[i]->key, Node, rb));
+
+ c_rbtree_remove_init(&t, &nodes[i]->rb);
+
+ assert(!c_rbnode_is_linked(&nodes[i]->rb));
+ assert(!c_rbtree_find_entry(&t, compare, (void *)nodes[i]->key, Node, rb));
+ }
+
+ /* free nodes again */
+ for (i = 0; i < sizeof(nodes) / sizeof(*nodes); ++i)
+ free(nodes[i]);
+}
+
+int main(int argc, char **argv) {
+ unsigned int i;
+
+ /* we want stable tests, so use fixed seed */
+ srand(0xdeadbeef);
+
+ test_api();
+
+ /*
+ * The tests are pseudo random; run them multiple times, each run will
+ * have different orders and thus different results.
+ */
+ for (i = 0; i < 4; ++i) {
+ test_shuffle();
+ test_map();
+ }
+
+ return 0;
+}
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