but i think if you just make a microwave-band, put it in a parabolic reflector, and point it at the sky, some significant portion of the noise will be cosmic background - celoyd
http://www.ecma-international.org/ecma-262/5.1/#sec-15.8.2.14
15.8.2.14 random ( ) Returns a Number value with positive sign, greater than or equal to 0 but less than 1, chosen randomly or pseudo randomly with approximately uniform distribution over that range, using an implementation-dependent algorithm or strategy. This function takes no arguments.
// Used by JavaScript APIs
uint32_t V8::Random(Context* context) {
ASSERT(context->IsNativeContext());
ByteArray* seed = context->random_seed();
uint32_t* state = reinterpret_cast<uint32_t*>(seed->GetDataStartAddress());
// When we get here, the RNG must have been initialized,
// see the Genesis constructor in file bootstrapper.cc.
ASSERT_NE(0, state[0]);
ASSERT_NE(0, state[1]);
// Mix the bits. Never replaces state[i] with 0 if it is nonzero.
state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16);
state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16);
return (state[0] << 14) + (state[1] & 0x3FFFF);
}Upstream
DEFINE_int(random_seed, 0,
"Default seed for initializing random generator "
"(0, the default, means to use system random).")EntropySource
#if V8_OS_CYGWIN || V8_OS_WIN
// Use rand_s() to gather entropy on Windows. See:
// https://code.google.com/p/v8/issues/detail?id=2905
unsigned first_half, second_half;
errno_t result = rand_s(&first_half);
ASSERT_EQ(0, result);
result = rand_s(&second_half);
ASSERT_EQ(0, result);
SetSeed((static_cast<int64_t>(first_half) << 32) + second_half);
#else
// Gather entropy from /dev/urandom if available.
FILE* fp = fopen("/dev/urandom", "rb");
if (fp != NULL) {
int64_t seed;
size_t n = fread(&seed, sizeof(seed), 1, fp);
fclose(fp);
if (n == 1) {
SetSeed(seed);
return;
}
}
// We cannot assume that random() or rand() were seeded
// properly, so instead of relying on random() or rand(),
// we just seed our PRNG using timing data as fallback.
// This is weak entropy, but it's sufficient, because
// it is the responsibility of the embedder to install
// an entropy source using v8::V8::SetEntropySource(),
// which provides reasonable entropy, see:
// https://code.google.com/p/v8/issues/detail?id=2905
int64_t seed = Time::NowFromSystemTime().ToInternalValue() << 24;
seed ^= TimeTicks::HighResolutionNow().ToInternalValue() << 16;
seed ^= TimeTicks::Now().ToInternalValue() << 8;
SetSeed(seed);
#endif // V8_OS_CYGWIN || V8_OS_WIN
}#if HAVE_OPENSSL
// V8 on Windows doesn't have a good source of entropy. Seed it from
// OpenSSL's pool.
V8::SetEntropySource(crypto::EntropySource);
#endif