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 OS(UNIX) 37 #include <sys/types.h> 38 #include <unistd.h> 39 #endif 40 41 #if USE(MERSENNE_TWISTER_19937) 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 OS(DARWIN) 53 // On Darwin we use arc4random which initialises itself. 54 #elif OS(WINCE) 55 // initialize rand() 56 srand(GetTickCount()); 57 #elif COMPILER(MSVC) && defined(_CRT_RAND_S) 58 // On Windows we use rand_s which initialises itself 59 #elif PLATFORM(BREWMP) 60 // On Brew MP we use AEECLSID_RANDOM which initialises itself 61 #elif OS(UNIX) 62 // srandomdev is not guaranteed to exist on linux so we use this poor seed, this should be improved 63 timeval time; 64 gettimeofday(&time, 0); 65 srandom(static_cast<unsigned>(time.tv_usec * getpid())); 66 #else 67 srand(static_cast<unsigned>(time(0))); 68 #endif 69 70 #if USE(MERSENNE_TWISTER_19937) 71 // use rand() to initialize the Mersenne Twister random number generator. 72 unsigned long initializationBuffer[4]; 73 initializationBuffer[0] = (rand() << 16) | rand(); 74 initializationBuffer[1] = (rand() << 16) | rand(); 75 initializationBuffer[2] = (rand() << 16) | rand(); 76 initializationBuffer[3] = (rand() << 16) | rand(); 77 init_by_array(initializationBuffer, 4); 78 #endif 79 } 80 81 } 82 83 #endif 84