+++ /dev/null
-/* Copyright (c) 2007-2014. The SimGrid Team.
- * All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#include "surf/random_mgr.h"
-#include "xbt/sysdep.h"
-#include "src/internal_config.h" /*_XBT_WIN32*/
-#include <math.h>
-#include <stdlib.h>
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(random, surf, "Random part of surf");
-
-#ifdef _XBT_WIN32
-
-static unsigned int _seed = 2147483647;
-
-#ifdef __VISUALC__
-typedef unsigned __int64 uint64_t;
-typedef unsigned int uint32_t;
-#endif
-
-struct drand48_data {
- unsigned short int __x[3]; /* Current state. */
- unsigned short int __old_x[3]; /* Old state. */
- unsigned short int __c; /* Additive const. in congruential formula. */
- unsigned short int __init; /* Flag for initializing. */
- unsigned long long int __a; /* Factor in congruential formula. */
-};
-
-static struct drand48_data __libc_drand48_data = { 0 };
-
-union ieee754_double {
- double d;
-
- /* This is the IEEE 754 double-precision format. */
- struct {
- /* Together these comprise the mantissa. */
- unsigned int mantissa1:32;
- unsigned int mantissa0:20;
- unsigned int exponent:11;
- unsigned int negative:1;
- /* Little endian. */
- } ieee;
-
- /* This format makes it easier to see if a NaN is a signalling NaN. */
- struct {
- /* Together these comprise the mantissa. */
- unsigned int mantissa1:32;
- unsigned int mantissa0:19;
- unsigned int quiet_nan:1;
- unsigned int exponent:11;
- unsigned int negative:1;
-
- } ieee_nan;
-};
-
-#define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */
-
-double drand48(void);
-
-int
-_drand48_iterate(unsigned short int xsubi[3], struct drand48_data *buffer);
-
-int
-_erand48_r(unsigned short int xsubi[3], struct drand48_data *buffer,
- double *result);
-
-
-int
-_erand48_r(unsigned short int xsubi[3], struct drand48_data *buffer,
- double *result)
-{
- union ieee754_double temp;
-
- /* Compute next state. */
- if (_drand48_iterate(xsubi, buffer) < 0)
- return -1;
-
- /* Construct a positive double with the 48 random bits distributed over
- its fractional part so the resulting FP number is [0.0,1.0). */
-
- temp.ieee.negative = 0;
- temp.ieee.exponent = IEEE754_DOUBLE_BIAS;
- temp.ieee.mantissa0 = (xsubi[2] << 4) | (xsubi[1] >> 12);
- temp.ieee.mantissa1 = ((xsubi[1] & 0xfff) << 20) | (xsubi[0] << 4);
-
- /* Please note the lower 4 bits of mantissa1 are always 0. */
- *result = temp.d - 1.0;
-
- return 0;
-}
-
-int _drand48_iterate(unsigned short int xsubi[3],
- struct drand48_data *buffer)
-{
- uint64_t X;
- uint64_t result;
-
- /* Initialize buffer, if not yet done. */
-
- if (buffer->__init == 0) {
- buffer->__a = 0x5deece66dull;
- buffer->__c = 0xb;
- buffer->__init = 1;
- }
-
- /* Do the real work. We choose a data type which contains at least
- 48 bits. Because we compute the modulus it does not care how
- many bits really are computed. */
-
- X = (uint64_t) xsubi[2] << 32 | (uint32_t) xsubi[1] << 16 | xsubi[0];
-
- result = X * buffer->__a + buffer->__c;
-
-
- xsubi[0] = result & 0xffff;
- xsubi[1] = (result >> 16) & 0xffff;
- xsubi[2] = (result >> 32) & 0xffff;
-
- return 0;
-}
-
-double _drand48(void);
-void _srand(unsigned int seed);
-int _rand(void);
-int _rand_r(unsigned int *pseed);
-
-double _drand48(void)
-{
- double result;
-
- (void) _erand48_r(__libc_drand48_data.__x, &__libc_drand48_data,
- &result);
-
- return result;
-}
-
-void _srand(unsigned int seed)
-{
- _seed = seed;
-}
-
-int _rand(void)
-{
- const long a = 16807;
- const long m = 2147483647;
- const long q = 127773; /* (m/a) */
- const long r = 2836; /* (m%a) */
-
- long lo, k, s;
-
- s = (long) _seed;
-
- k = (long) (s / q);
-
- lo = (s - q * k);
-
- s = a * lo - r * k;
-
- if (s <= 0)
- s += m;
-
- _seed = (int) (s & RAND_MAX);
-
- return _seed;
-}
-
-int _rand_r(unsigned int *pseed)
-{
- const long a = 16807;
- const long m = 2147483647;
- const long q = 127773; /* (m/a) */
- const long r = 2836; /* (m%a) */
-
- long lo, k, s;
-
- s = (long) *pseed;
-
- k = (long) (s / q);
-
- lo = (s - q * k);
-
- s = a * lo - r * k;
-
- if (s <= 0)
- s += m;
-
- return (int) (s & RAND_MAX);
-
-}
-
-
-#define rand_r _rand_r
-#define drand48 _drand48
-
-#endif
-
-static double custom_random(e_random_generator_t generator, long int *seed)
-{
- switch (generator) {
-
- case DRAND48:
- return drand48();
- case RAND:
- return (double) rand_r((unsigned int *) seed) / RAND_MAX;
- case RNGSTREAM :
- XBT_INFO("Seen RNGSTREAM");
- return 0.0;
- default:
- return drand48();
- }
-}
-
-/* Generate numbers between min and max with a given mean and standard deviation */
-double random_generate(random_data_t random)
-{
- double a, b;
- double alpha, beta, gamma;
- double U1, U2, V, W, X;
-
- if (random == NULL)
- return 0.0f;
-
- if (random->std == 0)
- return random->mean * (random->max - random->min) + random->min;
-
- a = random->mean * (random->mean * (1 - random->mean) /
- (random->std * random->std) - 1);
- b = (1 -
- random->mean) * (random->mean * (1 -
- random->mean) / (random->std *
- random->std) - 1);
-
- alpha = a + b;
- if (a <= 1. || b <= 1.)
- beta = ((1. / a) > (1. / b)) ? (1. / a) : (1. / b);
- else
- beta = sqrt((alpha - 2.) / (2. * a * b - alpha));
- gamma = a + 1. / beta;
-
- do {
- /* Random generation for the Beta distribution based on
- * R. C. H. Cheng (1978). Generating beta variates with nonintegral shape parameters. _Communications of the ACM_, *21*, 317-322.
- * It is good for speed because it does not call math functions many times and respect the 4 given constraints
- */
- U1 = custom_random(random->generator, &(random->seed));
- U2 = custom_random(random->generator, &(random->seed));
-
- V = beta * log(U1 / (1 - U1));
- W = a * exp(V);
- } while (alpha * log(alpha / (b + W)) + gamma * V - log(4) <
- log(U1 * U1 * U2));
-
- X = W / (b + W);
-
- return X * (random->max - random->min) + random->min;
-}
-
-random_data_t random_new(e_random_generator_t generator, long int seed,
- double min, double max, double mean, double std)
-{
- random_data_t random = xbt_new0(s_random_data_t, 1);
-
- random->generator = generator;
- random->seed = seed;
- random->min = min;
- random->max = max;
-
- /* Check user stupidities */
- if (max < min)
- THROWF(arg_error, 0, "random->max < random->min (%f < %f)", max, min);
- if (mean < min)
- THROWF(arg_error, 0, "random->mean < random->min (%f < %f)", mean,
- min);
- if (mean > max)
- THROWF(arg_error, 0, "random->mean > random->max (%f > %f)", mean,
- max);
-
- /* normalize the mean and standard deviation before storing */
- random->mean = (mean - min) / (max - min);
- random->std = std / (max - min);
-
- if (random->mean * (1 - random->mean) < random->std * random->std)
- THROWF(arg_error, 0, "Invalid mean and standard deviation (%f and %f)",
- random->mean, random->std);
-
- return random;
-}
