xref: /freebsd/lib/libc/tests/stdlib/tsearch_test.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
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 <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <atf-c.h>
30 #define _SEARCH_PRIVATE
31 #include <search.h>
32 #include <stdbool.h>
33 #include <stdlib.h>
34 #include <stdio.h>
35 
36 static int n_nodes = 0;
37 static int n_seen = 0;
38 
39 /* Validates the integrity of an AVL tree. */
40 static inline unsigned int
41 tnode_assert(const posix_tnode *n)
42 {
43 	unsigned int height_left, height_right;
44 	int balance;
45 
46 	if (n == NULL)
47 		return 0;
48 	height_left = tnode_assert(n->llink);
49 	height_right = tnode_assert(n->rlink);
50 	balance = (int)height_left - (int)height_right;
51 	ATF_CHECK(balance >= -1);
52 	ATF_CHECK(balance <= 1);
53 	ATF_CHECK_EQ(balance, n->balance);
54 	return (height_left > height_right ? height_left : height_right) + 1;
55 }
56 
57 static int
58 compar(const void *a, const void *b)
59 {
60 
61 	return *(int *)a - *(int *)b;
62 }
63 
64 static void
65 treewalk(const posix_tnode *node, VISIT v, int level)
66 {
67 
68 	if (v == postorder || v == leaf)
69 		n_seen++;
70 }
71 
72 ATF_TC_WITHOUT_HEAD(tsearch_test);
73 ATF_TC_BODY(tsearch_test, tc)
74 {
75 	/*
76 	 * Run the test below in a deterministic fashion to prevent this
77 	 * test from potentially flapping. We assume that this provides
78 	 * enough coverage.
79 	 */
80 #if 0
81 	unsigned short random_state[3];
82 	arc4random_buf(random_state, sizeof(random_state));
83 #else
84 	unsigned short random_state[3] = { 26554, 13330, 3246 };
85 #endif
86 
87 #define NKEYS 1000
88 	/* Create 1000 possible keys. */
89 	int keys[NKEYS];
90 	for (int i = 0; i < NKEYS; ++i)
91 		keys[i] = i;
92 
93 	/* Apply random operations on a binary tree and check the results. */
94 	posix_tnode *root = NULL;
95 	bool present[NKEYS] = {};
96 	for (int i = 0; i < NKEYS * 10; ++i) {
97 		int key = nrand48(random_state) % NKEYS;
98 		int sample = i;
99 
100 		/*
101 		 * Ensure each case is tested at least 10 times, plus a
102 		 * random sampling.
103 		 */
104 		if ((sample % NKEYS) > 3)
105 			sample = nrand48(random_state) % 3;
106 
107 		switch (sample) {
108 		case 0:  /* tdelete(). */
109 			if (present[key]) {
110 				ATF_CHECK(tdelete(&key, &root, compar) != NULL);
111 				present[key] = false;
112 				ATF_CHECK(n_nodes > 0);
113 				n_nodes--;
114 			} else {
115 				ATF_CHECK_EQ(NULL,
116 				    tdelete(&key, &root, compar));
117 			}
118 			break;
119 		case 1:  /* tfind(). */
120 			if (present[key]) {
121 				ATF_CHECK_EQ(&keys[key],
122 				    *(int **)tfind(&key, &root, compar));
123 			} else {
124 				ATF_CHECK_EQ(NULL, tfind(&key, &root, compar));
125 			}
126 			break;
127 		case 2:  /* tsearch(). */
128 			if (present[key]) {
129 				ATF_CHECK_EQ(&keys[key],
130 				    *(int **)tsearch(&key, &root, compar));
131 			} else {
132 				ATF_CHECK_EQ(&keys[key], *(int **)tsearch(
133 				    &keys[key], &root, compar));
134 				present[key] = true;
135 				n_nodes++;
136 			}
137 			break;
138 		}
139 		tnode_assert(root);
140 	}
141 
142 	/* Walk the tree. */
143 	twalk(root, treewalk);
144 	ATF_CHECK_EQ(n_nodes, n_seen);
145 
146 	/* Remove all entries from the tree. */
147 	for (int key = 0; key < NKEYS; ++key)
148 		if (present[key])
149 			ATF_CHECK(tdelete(&key, &root, compar) != NULL);
150 	ATF_CHECK_EQ(NULL, root);
151 }
152 
153 ATF_TP_ADD_TCS(tp)
154 {
155 
156 	ATF_TP_ADD_TC(tp, tsearch_test);
157 
158 	return (atf_no_error());
159 }
160