1 /* 2 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved. 3 * (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/) 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 APPLE COMPUTER, INC. ``AS IS'' AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "config.h" 28 #include "RandomNumber.h" 29 30 #include "RandomNumberSeed.h" 31 32 #include <limits> 33 #include <limits.h> 34 #include <stdint.h> 35 #include <stdlib.h> 36 37 #if OS(WINCE) 38 extern "C" { 39 #include "wince/mt19937ar.c" 40 } 41 #endif 42 43 #if PLATFORM(BREWMP) 44 #include <AEEAppGen.h> 45 #include <AEESource.h> 46 #include <AEEStdLib.h> 47 #endif 48 49 namespace WTF { 50 51 double weakRandomNumber() 52 { 53 #if COMPILER(MSVC) && defined(_CRT_RAND_S) 54 // rand_s is incredibly slow on windows so we fall back on rand for Math.random 55 return (rand() + (rand() / (RAND_MAX + 1.0))) / (RAND_MAX + 1.0); 56 #elif PLATFORM(BREWMP) 57 uint32_t bits; 58 GETRAND(reinterpret_cast<byte*>(&bits), sizeof(uint32_t)); 59 return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0); 60 #else 61 return randomNumber(); 62 #endif 63 } 64 65 double randomNumber() 66 { 67 #if !ENABLE(JSC_MULTIPLE_THREADS) 68 static bool s_initialized = false; 69 if (!s_initialized) { 70 initializeRandomNumberGenerator(); 71 s_initialized = true; 72 } 73 #endif 74 75 #if COMPILER(MSVC) && defined(_CRT_RAND_S) 76 uint32_t bits; 77 rand_s(&bits); 78 return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0); 79 #elif OS(DARWIN) 80 uint32_t bits = arc4random(); 81 return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0); 82 #elif OS(UNIX) 83 uint32_t part1 = random() & (RAND_MAX - 1); 84 uint32_t part2 = random() & (RAND_MAX - 1); 85 // random only provides 31 bits 86 uint64_t fullRandom = part1; 87 fullRandom <<= 31; 88 fullRandom |= part2; 89 90 // Mask off the low 53bits 91 fullRandom &= (1LL << 53) - 1; 92 return static_cast<double>(fullRandom)/static_cast<double>(1LL << 53); 93 #elif OS(WINCE) 94 return genrand_res53(); 95 #elif OS(WINDOWS) 96 uint32_t part1 = rand() & (RAND_MAX - 1); 97 uint32_t part2 = rand() & (RAND_MAX - 1); 98 uint32_t part3 = rand() & (RAND_MAX - 1); 99 uint32_t part4 = rand() & (RAND_MAX - 1); 100 // rand only provides 15 bits on Win32 101 uint64_t fullRandom = part1; 102 fullRandom <<= 15; 103 fullRandom |= part2; 104 fullRandom <<= 15; 105 fullRandom |= part3; 106 fullRandom <<= 15; 107 fullRandom |= part4; 108 109 // Mask off the low 53bits 110 fullRandom &= (1LL << 53) - 1; 111 return static_cast<double>(fullRandom)/static_cast<double>(1LL << 53); 112 #elif PLATFORM(BREWMP) 113 uint32_t bits; 114 ISource* randomSource; 115 116 IShell* shell = reinterpret_cast<AEEApplet*>(GETAPPINSTANCE())->m_pIShell; 117 ISHELL_CreateInstance(shell, AEECLSID_RANDOM, reinterpret_cast<void**>(&randomSource)); 118 ISOURCE_Read(randomSource, reinterpret_cast<char*>(&bits), 4); 119 ISOURCE_Release(randomSource); 120 121 return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0); 122 #else 123 uint32_t part1 = rand() & (RAND_MAX - 1); 124 uint32_t part2 = rand() & (RAND_MAX - 1); 125 // rand only provides 31 bits, and the low order bits of that aren't very random 126 // so we take the high 26 bits of part 1, and the high 27 bits of part2. 127 part1 >>= 5; // drop the low 5 bits 128 part2 >>= 4; // drop the low 4 bits 129 uint64_t fullRandom = part1; 130 fullRandom <<= 27; 131 fullRandom |= part2; 132 133 // Mask off the low 53bits 134 fullRandom &= (1LL << 53) - 1; 135 return static_cast<double>(fullRandom)/static_cast<double>(1LL << 53); 136 #endif 137 } 138 139 } 140