1/*
2 * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
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 APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef WTF_RandomNumberSeed_h
27#define WTF_RandomNumberSeed_h
28
29#include "RandomNumber.h"
30#include <stdlib.h>
31#include <time.h>
32
33#if HAVE(SYS_TIME_H)
34#include <sys/time.h>
35#endif
36
37#if OS(UNIX)
38#include <sys/types.h>
39#include <unistd.h>
40#endif
41
42namespace WTF {
43
44inline void initializeRandomNumberGenerator()
45{
46#if OS(DARWIN)
47    // On Darwin we use arc4random which initialises itself.
48#elif OS(WINCE)
49    // initialize rand()
50    srand(GetTickCount());
51#elif COMPILER(MSVC) && defined(_CRT_RAND_S)
52    // On Windows we use rand_s which initialises itself
53#elif OS(UNIX)
54    // srandomdev is not guaranteed to exist on linux so we use this poor seed, this should be improved
55    timeval time;
56    gettimeofday(&time, 0);
57    srandom(static_cast<unsigned>(time.tv_usec * getpid()));
58#else
59    srand(static_cast<unsigned>(time(0)));
60#endif
61
62}
63
64}
65
66#endif
67