xref: /f-stack/freebsd/libkern/random.c (revision 22ce4aff)
1a9643ea8Slogwang /*-
2*22ce4affSfengbojiang  * SPDX-License-Identifier: BSD-3-Clause
3*22ce4affSfengbojiang  *
4a9643ea8Slogwang  * Copyright (c) 1992, 1993
5a9643ea8Slogwang  *	The Regents of the University of California.  All rights reserved.
6a9643ea8Slogwang  *
7a9643ea8Slogwang  * Redistribution and use in source and binary forms, with or without
8a9643ea8Slogwang  * modification, are permitted provided that the following conditions
9a9643ea8Slogwang  * are met:
10a9643ea8Slogwang  * 1. Redistributions of source code must retain the above copyright
11a9643ea8Slogwang  *    notice, this list of conditions and the following disclaimer.
12a9643ea8Slogwang  * 2. Redistributions in binary form must reproduce the above copyright
13a9643ea8Slogwang  *    notice, this list of conditions and the following disclaimer in the
14a9643ea8Slogwang  *    documentation and/or other materials provided with the distribution.
15*22ce4affSfengbojiang  * 3. Neither the name of the University nor the names of its contributors
16a9643ea8Slogwang  *    may be used to endorse or promote products derived from this software
17a9643ea8Slogwang  *    without specific prior written permission.
18a9643ea8Slogwang  *
19a9643ea8Slogwang  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20a9643ea8Slogwang  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21a9643ea8Slogwang  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22a9643ea8Slogwang  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23a9643ea8Slogwang  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24a9643ea8Slogwang  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25a9643ea8Slogwang  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26a9643ea8Slogwang  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27a9643ea8Slogwang  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28a9643ea8Slogwang  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29a9643ea8Slogwang  * SUCH DAMAGE.
30a9643ea8Slogwang  *
31a9643ea8Slogwang  *	@(#)random.c	8.1 (Berkeley) 6/10/93
32a9643ea8Slogwang  */
33a9643ea8Slogwang 
34a9643ea8Slogwang #include <sys/cdefs.h>
35a9643ea8Slogwang __FBSDID("$FreeBSD$");
36a9643ea8Slogwang 
37*22ce4affSfengbojiang #include <sys/types.h>
38a9643ea8Slogwang #include <sys/libkern.h>
39*22ce4affSfengbojiang #include <sys/prng.h>
40*22ce4affSfengbojiang #include <sys/systm.h>
41a9643ea8Slogwang 
42a9643ea8Slogwang /*
43*22ce4affSfengbojiang  * Pseudo-random number generator.  The result is uniform in [0, 2^31 - 1].
44a9643ea8Slogwang  */
45a9643ea8Slogwang u_long
random(void)46*22ce4affSfengbojiang random(void)
47a9643ea8Slogwang {
48*22ce4affSfengbojiang 	return (prng32() & 0x7fffffff);
49a9643ea8Slogwang }
50