xref: /freebsd/tools/test/stress2/lib/random_int.c (revision 9768746ba83efa02837c5b9c66348db6e900208f)
1 /*-
2  * Copyright (c) 2008 Peter Holm <pho@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/types.h>
29 #include <stdlib.h>
30 #include "stress.h"
31 
32 int
33 random_int(int mi, int ma)
34 {
35 	return (arc4random()  % (ma - mi + 1) + mi);
36 }
37 
38 #ifdef TEST
39 #include <stdio.h>
40 int
41 main()
42 {
43 	int i, j, min, max, r;
44 	min = 100;
45 	max = 1;
46 	for (i = 0; i < 10000; i++) {
47 		j += (r = random_int(1,100));
48 		if (max < r)
49 			max = r;
50 		if (min > r)
51 			min = r;
52 	}
53 	printf("Average is %d, min = %d, max = %d\n", j / 10000, min, max);
54 	return (0);
55 }
56 #endif
57