FX::Maths::FRandomness Class Reference
#include <FXMaths.h>
Detailed Description
A fast quality source of pseudo entropy.Unlike FX::Secure::PRandomness, this class provides a much faster but not cryptographically secure pseudo random generator. In this it is much like FX::fxrandom(), except that instead of a 2^32 period this one has a mathematically proven 2^216091 period and is considered a much higher quality generator. Also, unlike FX::Secure::PRandomness, this class doesn't require the OpenSSL library to be compiled in.
Most use will by via FX::Maths::SysRandSrc which is a mutex protected static instance which can be used safely by multiple threads.
More specifically, this class is an implementation of the Mersenne Twister. Previous to v0.88 of TnFOX, this was a generic 64 bit implementation as detailed at http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html. Since v0.88, a SIMD-based improved version has been added (the old version is still used instead on big-endian machines or x86 with no SSE).
You should be aware that each instance consumes about 2.5Kb of internal state and thus shouldn't be copied around nor constructed & destructed repeatedly. The old pre-v0.88 version could generate around 1Gb/sec of randomness on a 3.0Ghz Core 2 processor. The new SIMD version can more than double that, even more so again when compiled with Intel's C++ compiler.
Public Member Functions | |
| FRandomness (FXulong seed) throw () | |
| FRandomness (FXuchar *seed, FXuval len) throw () | |
| FXulong | int64 () throw () |
| void | fill (FXuchar *d, FXuval len) throw () |
| double | real1 () throw () |
| double | real2 () throw () |
| double | real3 () throw () |
Static Public Attributes | |
| static const bool | usingSIMD |
Constructor & Destructor Documentation
| FX::Maths::FRandomness::FRandomness | ( | FXulong | seed | ) | throw () [inline] |
Constructs, using seed seed.
| FX::Maths::FRandomness::FRandomness | ( | FXuchar * | seed, | |
| FXuval | len | |||
| ) | throw () [inline] |
Constructs, using seed seed.
Member Function Documentation
| FXulong FX::Maths::FRandomness::int64 | ( | ) | throw () [inline] |
Generates a random number on [0, 2^64-1]-interval.
Reimplemented in FX::Maths::SysRandomness.
Referenced by FX::Maths::SysRandomness::int64().
| void FX::Maths::FRandomness::fill | ( | FXuchar * | d, | |
| FXuval | len | |||
| ) | throw () [inline] |
Generates lots of random data (make sure it's 16 byte aligned!).
| double FX::Maths::FRandomness::real1 | ( | ) | throw () [inline] |
generates a random number on [0,1]-real-interval by division of 2^53-1
Reimplemented in FX::Maths::SysRandomness.
Referenced by FX::Maths::SysRandomness::real1().
| double FX::Maths::FRandomness::real2 | ( | ) | throw () [inline] |
generates a random number on [0,1)-real-interval by division of 2^53
Reimplemented in FX::Maths::SysRandomness.
Referenced by FX::Maths::SysRandomness::real2().
| double FX::Maths::FRandomness::real3 | ( | ) | throw () [inline] |
generates a random number on (0,1)-real-interval by division of 2^52
Reimplemented in FX::Maths::SysRandomness.
Referenced by FX::Maths::SysRandomness::real3().
Member Data Documentation
const bool FX::Maths::FRandomness::usingSIMD [static] |
Indicates if implemented using SIMD.
The documentation for this class was generated from the following file:
