/*

 * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#ifndef WTF_RandomNumberSeed_h

#define WTF_RandomNumberSeed_h

#include <stdlib.h>

#include <time.h>

#if HAVE(SYS_TIME_H)

#include <sys/time.h>

#endif

#if OS(UNIX)

#include <sys/types.h>

#include <unistd.h>

#endif

#if OS(WINCE)

extern "C" {

void init_by_array(unsigned long init_key[],int key_length);

}

#endif

// Internal JavaScriptCore usage only

namespace WTF {

inline void initializeRandomNumberGenerator()

{

#if OS(DARWIN)

    // On Darwin we use arc4random which initialises itself.

#elif OS(WINCE)

    // initialize rand()

    srand(static_cast<unsigned>(time(0)));

    // use rand() to initialize the real RNG

    unsigned long initializationBuffer[4];

    initializationBuffer[0] = (rand() << 16) | rand();

    initializationBuffer[1] = (rand() << 16) | rand();

    initializationBuffer[2] = (rand() << 16) | rand();

    initializationBuffer[3] = (rand() << 16) | rand();

    init_by_array(initializationBuffer, 4);

#elif COMPILER(MSVC) && defined(_CRT_RAND_S)

    // On Windows we use rand_s which initialises itself

#elif OS(UNIX)

    // srandomdev is not guaranteed to exist on linux so we use this poor seed, this should be improved

    timeval time;

    gettimeofday(&time, 0);

    srandom(static_cast<unsigned>(time.tv_usec * getpid()));

#else

    srand(static_cast<unsigned>(time(0)));

#endif

}

inline void initializeWeakRandomNumberGenerator()

{

#if COMPILER(MSVC) && defined(_CRT_RAND_S)

    // We need to initialise windows rand() explicitly for Math.random

    unsigned seed = 0;

    rand_s(&seed);

    srand(seed);

#endif

}

}

#endif