1*43a90889SApple OSS Distributions /*
2*43a90889SApple OSS Distributions * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3*43a90889SApple OSS Distributions *
4*43a90889SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*43a90889SApple OSS Distributions *
6*43a90889SApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*43a90889SApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*43a90889SApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*43a90889SApple OSS Distributions * compliance with the License. The rights granted to you under the License
10*43a90889SApple OSS Distributions * may not be used to create, or enable the creation or redistribution of,
11*43a90889SApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to
12*43a90889SApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any
13*43a90889SApple OSS Distributions * terms of an Apple operating system software license agreement.
14*43a90889SApple OSS Distributions *
15*43a90889SApple OSS Distributions * Please obtain a copy of the License at
16*43a90889SApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*43a90889SApple OSS Distributions *
18*43a90889SApple OSS Distributions * The Original Code and all software distributed under the License are
19*43a90889SApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*43a90889SApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*43a90889SApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*43a90889SApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*43a90889SApple OSS Distributions * Please see the License for the specific language governing rights and
24*43a90889SApple OSS Distributions * limitations under the License.
25*43a90889SApple OSS Distributions *
26*43a90889SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*43a90889SApple OSS Distributions */
28*43a90889SApple OSS Distributions /*-
29*43a90889SApple OSS Distributions * Copyright (c) 1992, 1993
30*43a90889SApple OSS Distributions * The Regents of the University of California. All rights reserved.
31*43a90889SApple OSS Distributions *
32*43a90889SApple OSS Distributions * Redistribution and use in source and binary forms, with or without
33*43a90889SApple OSS Distributions * modification, are permitted provided that the following conditions
34*43a90889SApple OSS Distributions * are met:
35*43a90889SApple OSS Distributions * 1. Redistributions of source code must retain the above copyright
36*43a90889SApple OSS Distributions * notice, this list of conditions and the following disclaimer.
37*43a90889SApple OSS Distributions * 2. Redistributions in binary form must reproduce the above copyright
38*43a90889SApple OSS Distributions * notice, this list of conditions and the following disclaimer in the
39*43a90889SApple OSS Distributions * documentation and/or other materials provided with the distribution.
40*43a90889SApple OSS Distributions * 3. All advertising materials mentioning features or use of this software
41*43a90889SApple OSS Distributions * must display the following acknowledgement:
42*43a90889SApple OSS Distributions * This product includes software developed by the University of
43*43a90889SApple OSS Distributions * California, Berkeley and its contributors.
44*43a90889SApple OSS Distributions * 4. Neither the name of the University nor the names of its contributors
45*43a90889SApple OSS Distributions * may be used to endorse or promote products derived from this software
46*43a90889SApple OSS Distributions * without specific prior written permission.
47*43a90889SApple OSS Distributions *
48*43a90889SApple OSS Distributions * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49*43a90889SApple OSS Distributions * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50*43a90889SApple OSS Distributions * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51*43a90889SApple OSS Distributions * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52*43a90889SApple OSS Distributions * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53*43a90889SApple OSS Distributions * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54*43a90889SApple OSS Distributions * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55*43a90889SApple OSS Distributions * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56*43a90889SApple OSS Distributions * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57*43a90889SApple OSS Distributions * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58*43a90889SApple OSS Distributions * SUCH DAMAGE.
59*43a90889SApple OSS Distributions *
60*43a90889SApple OSS Distributions * @(#)random.c 8.1 (Berkeley) 6/10/93
61*43a90889SApple OSS Distributions */
62*43a90889SApple OSS Distributions
63*43a90889SApple OSS Distributions #include <sys/types.h>
64*43a90889SApple OSS Distributions #include <sys/random.h>
65*43a90889SApple OSS Distributions #include <libkern/libkern.h>
66*43a90889SApple OSS Distributions #include <dev/random/randomdev.h>
67*43a90889SApple OSS Distributions
68*43a90889SApple OSS Distributions /*
69*43a90889SApple OSS Distributions * Pseudo-random number generator for randomizing the profiling clock,
70*43a90889SApple OSS Distributions * and whatever else we might use it for. The result is uniform on
71*43a90889SApple OSS Distributions * [0, 2^31 - 1].
72*43a90889SApple OSS Distributions */
73*43a90889SApple OSS Distributions u_int32_t
random(void)74*43a90889SApple OSS Distributions random(void)
75*43a90889SApple OSS Distributions {
76*43a90889SApple OSS Distributions /* Zero all but bottom 31 bits, also works for 64-bit longs */
77*43a90889SApple OSS Distributions u_int32_t mask = (u_int32_t)-1 >> ((sizeof(u_int32_t) * 8) - 31);
78*43a90889SApple OSS Distributions return mask & RandomULong();
79*43a90889SApple OSS Distributions }
80