X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/bb6ac9c6781e2639da8957ccf08957974d6ce697..a7430c3a3c007a1746ac3d8ff320058a66e70b64:/src/surf/random_mgr.c diff --git a/src/surf/random_mgr.c b/src/surf/random_mgr.c index 90d0b93ef3..8bad98fa8a 100644 --- a/src/surf/random_mgr.c +++ b/src/surf/random_mgr.c @@ -1,184 +1,188 @@ +/* Copyright (c) 2007, 2008, 2009, 2010. 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 "gras_config.h" /*_XBT_WIN32*/ + +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(random, surf, "Random part of surf"); -#ifdef WIN32 +#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. */ +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; +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. */ +#define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */ -double -drand48 (void); +double drand48(void); int -_drand48_iterate (unsigned short int xsubi[3], struct drand48_data *buffer); +_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); +_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) +_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; + 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) +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; + 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) +double _drand48(void) { - double result; - - (void) _erand48_r (__libc_drand48_data.__x, &__libc_drand48_data, &result); - - return result; - } - -void -_srand(unsigned int seed) + double result; + + (void) _erand48_r(__libc_drand48_data.__x, &__libc_drand48_data, + &result); + + return result; +} + +void _srand(unsigned int seed) { - _seed = seed; + _seed = seed; } -int -_rand(void) +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; + 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) +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); - + 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); + } @@ -187,77 +191,94 @@ _rand_r(unsigned int* pseed) #endif -static double custom_random(Generator generator, long int *seed){ - switch(generator) { - - case DRAND48: - return drand48(); - case RAND: - return (double)rand_r((unsigned int*)seed)/RAND_MAX; - default: - return drand48(); - } +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 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 == 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 ); + 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); + beta = ((1. / a) > (1. / b)) ? (1. / a) : (1. / b); else - beta = sqrt ((alpha-2.) / (2.*a*b - alpha)); - gamma = a + 1./beta; + 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)); + U1 = custom_random(random->generator, &(random->seed)); + U2 = custom_random(random->generator, &(random->seed)); - V = beta * log(U1/(1-U1)); + V = beta * log(U1 / (1 - U1)); W = a * exp(V); - } while (alpha * log(alpha/(b + W)) + gamma*V - log(4) < log(U1*U1*U2)); + } 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(Generator generator, long int seed, - double min, double max, - double mean, double std){ +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->seed = seed; random->min = min; random->max = max; /* Check user stupidities */ if (max < min) - THROW2(arg_error,0,"random->max < random->min (%f < %f)",max, min); + THROWF(arg_error, 0, "random->max < random->min (%f < %f)", max, min); if (mean < min) - THROW2(arg_error,0,"random->mean < random->min (%f < %f)",mean, min); + THROWF(arg_error, 0, "random->mean < random->min (%f < %f)", mean, + min); if (mean > max) - THROW2(arg_error,0,"random->mean > random->max (%f > %f)",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) - THROW2(arg_error,0,"Invalid mean and standard deviation (%f and %f)",random->mean, random->std); - + 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; }