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 COMPUTER, 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 COMPUTER, 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 <stdlib.h>
30 #include <time.h>
31
32 #if HAVE(SYS_TIME_H)
33 #include <sys/time.h>
34 #endif
35
36 #if PLATFORM(UNIX)
37 #include <sys/types.h>
38 #include <unistd.h>
39 #endif
40
41 #if PLATFORM(WINCE)
42 extern "C" {
43 void init_by_array(unsigned long init_key[],int key_length);
44 }
45 #endif
46
47 // Internal JavaScriptCore usage only
48 namespace WTF {
49
initializeRandomNumberGenerator()50 inline void initializeRandomNumberGenerator()
51 {
52 #if PLATFORM(DARWIN)
53 // On Darwin we use arc4random which initialises itself.
54 #elif PLATFORM(WINCE)
55 // initialize rand()
56 srand(static_cast<unsigned>(time(0)));
57
58 // use rand() to initialize the real RNG
59 unsigned long initializationBuffer[4];
60 initializationBuffer[0] = (rand() << 16) | rand();
61 initializationBuffer[1] = (rand() << 16) | rand();
62 initializationBuffer[2] = (rand() << 16) | rand();
63 initializationBuffer[3] = (rand() << 16) | rand();
64 init_by_array(initializationBuffer, 4);
65 #elif COMPILER(MSVC) && defined(_CRT_RAND_S)
66 // On Windows we use rand_s which initialises itself
67 #elif PLATFORM(UNIX)
68 // srandomdev is not guaranteed to exist on linux so we use this poor seed, this should be improved
69 timeval time;
70 gettimeofday(&time, 0);
71 srandom(static_cast<unsigned>(time.tv_usec * getpid()));
72 #else
73 srand(static_cast<unsigned>(time(0)));
74 #endif
75 }
76
initializeWeakRandomNumberGenerator()77 inline void initializeWeakRandomNumberGenerator()
78 {
79 #if COMPILER(MSVC) && defined(_CRT_RAND_S)
80 // We need to initialise windows rand() explicitly for Math.random
81 unsigned seed = 0;
82 rand_s(&seed);
83 srand(seed);
84 #endif
85 }
86 }
87
88 #endif
89