xref: /freebsd/lib/libc/tests/stdlib/tsearch_test.c (revision 4b9d6057)
1 /*-
2  * Copyright (c) 2015 Nuxi, https://nuxi.nl/
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <atf-c.h>
27 #define _SEARCH_PRIVATE
28 #include <search.h>
29 #include <stdbool.h>
30 #include <stdlib.h>
31 #include <stdio.h>
32 
33 static int n_nodes = 0;
34 static int n_seen = 0;
35 
36 /* Validates the integrity of an AVL tree. */
37 static inline unsigned int
38 tnode_assert(const posix_tnode *n)
39 {
40 	unsigned int height_left, height_right;
41 	int balance;
42 
43 	if (n == NULL)
44 		return 0;
45 	height_left = tnode_assert(n->llink);
46 	height_right = tnode_assert(n->rlink);
47 	balance = (int)height_left - (int)height_right;
48 	ATF_CHECK(balance >= -1);
49 	ATF_CHECK(balance <= 1);
50 	ATF_CHECK_EQ(balance, n->balance);
51 	return (height_left > height_right ? height_left : height_right) + 1;
52 }
53 
54 static int
55 compar(const void *a, const void *b)
56 {
57 
58 	return *(int *)a - *(int *)b;
59 }
60 
61 static void
62 treewalk(const posix_tnode *node, VISIT v, int level)
63 {
64 
65 	if (v == postorder || v == leaf)
66 		n_seen++;
67 }
68 
69 ATF_TC_WITHOUT_HEAD(tsearch_test);
70 ATF_TC_BODY(tsearch_test, tc)
71 {
72 	/*
73 	 * Run the test below in a deterministic fashion to prevent this
74 	 * test from potentially flapping. We assume that this provides
75 	 * enough coverage.
76 	 */
77 #if 0
78 	unsigned short random_state[3];
79 	arc4random_buf(random_state, sizeof(random_state));
80 #else
81 	unsigned short random_state[3] = { 26554, 13330, 3246 };
82 #endif
83 
84 #define NKEYS 1000
85 	/* Create 1000 possible keys. */
86 	int keys[NKEYS];
87 	for (int i = 0; i < NKEYS; ++i)
88 		keys[i] = i;
89 
90 	/* Apply random operations on a binary tree and check the results. */
91 	posix_tnode *root = NULL;
92 	bool present[NKEYS] = {};
93 	for (int i = 0; i < NKEYS * 10; ++i) {
94 		int key = nrand48(random_state) % NKEYS;
95 		int sample = i;
96 
97 		/*
98 		 * Ensure each case is tested at least 10 times, plus a
99 		 * random sampling.
100 		 */
101 		if ((sample % NKEYS) > 3)
102 			sample = nrand48(random_state) % 3;
103 
104 		switch (sample) {
105 		case 0:  /* tdelete(). */
106 			if (present[key]) {
107 				ATF_CHECK(tdelete(&key, &root, compar) != NULL);
108 				present[key] = false;
109 				ATF_CHECK(n_nodes > 0);
110 				n_nodes--;
111 			} else {
112 				ATF_CHECK_EQ(NULL,
113 				    tdelete(&key, &root, compar));
114 			}
115 			break;
116 		case 1:  /* tfind(). */
117 			if (present[key]) {
118 				ATF_CHECK_EQ(&keys[key],
119 				    *(int **)tfind(&key, &root, compar));
120 			} else {
121 				ATF_CHECK_EQ(NULL, tfind(&key, &root, compar));
122 			}
123 			break;
124 		case 2:  /* tsearch(). */
125 			if (present[key]) {
126 				ATF_CHECK_EQ(&keys[key],
127 				    *(int **)tsearch(&key, &root, compar));
128 			} else {
129 				ATF_CHECK_EQ(&keys[key], *(int **)tsearch(
130 				    &keys[key], &root, compar));
131 				present[key] = true;
132 				n_nodes++;
133 			}
134 			break;
135 		}
136 		tnode_assert(root);
137 	}
138 
139 	/* Walk the tree. */
140 	twalk(root, treewalk);
141 	ATF_CHECK_EQ(n_nodes, n_seen);
142 
143 	/* Remove all entries from the tree. */
144 	for (int key = 0; key < NKEYS; ++key)
145 		if (present[key])
146 			ATF_CHECK(tdelete(&key, &root, compar) != NULL);
147 	ATF_CHECK_EQ(NULL, root);
148 }
149 
150 ATF_TP_ADD_TCS(tp)
151 {
152 
153 	ATF_TP_ADD_TC(tp, tsearch_test);
154 
155 	return (atf_no_error());
156 }
157