Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tag: v1_6_4_preview1
Fetching contributors…

Cannot retrieve contributors at this time

file 181 lines (147 sloc) 3.248 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181
/**********************************************************************

random.c -

$Author$
$Date$
created at: Fri Dec 24 16:39:21 JST 1993

Copyright (C) 1993-2000 Yukihiro Matsumoto

**********************************************************************/

#include "ruby.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <time.h>
#ifndef NT
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#else
struct timeval {
        long tv_sec; /* seconds */
        long tv_usec; /* and microseconds */
};
#endif
#endif /* NT */

#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif

/*
* Prefer to use drand48, otherwise use random, or rand as a last resort.
*/
#ifdef HAVE_DRAND48

#ifndef HAVE_DRAND48_DECL
double drand48 _((void));
void srand48 _((long));
#endif

#define SRANDOM(s) srand48((long)(s))
#define RANDOM_NUMBER drand48()

#else /* not HAVE_DRAND48 */

/*
* The largest number returned by the random number generator is
* RANDOM_MAX. If we're using `rand' it's RAND_MAX, but if we're
* using `random' it's 2^31-1.
*/
#ifndef RANDOM_MAX
# ifndef HAVE_RANDOM
# define RANDOM_MAX RAND_MAX
# else
# define RANDOM_MAX 2147483647.0
# endif
#endif

#ifdef HAVE_RANDOM

#define RANDOM random
#define SRANDOM srandom

#else /* HAVE_RANDOM */

#define RANDOM rand
#define SRANDOM srand

#endif /* HAVE_RANDOM */

/* 0 <= RANDOM_NUMBER < 1 */
#define RANDOM_NUMBER (((double)RANDOM())/((double)RANDOM_MAX+1))

#endif /* not HAVE_DRAND48 */

static int first = 1;
#ifdef HAVE_RANDOM
static char state[256];
#endif

static int
rand_init(seed)
    long seed;
{
    int old;
    static unsigned int saved_seed;

#ifdef HAVE_RANDOM
    if (first == 1) {
initstate(1, state, sizeof state);
    }
    else {
setstate(state);
    }
#endif
    first = 0;

    SRANDOM(seed);
    old = saved_seed;
    saved_seed = seed;

    return old;
}

static VALUE
rb_f_srand(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    VALUE a;
    unsigned int seed, old;

    rb_secure(4);
    if (rb_scan_args(argc, argv, "01", &a) == 0) {
static int n = 0;
struct timeval tv;

gettimeofday(&tv, 0);
seed = tv.tv_sec ^ tv.tv_usec ^ getpid() ^ n++;
    }
    else {
seed = NUM2UINT(a);
    }
    old = rand_init(seed);

    return rb_uint2inum(old);
}

static VALUE
rb_f_rand(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    VALUE vmax;
    long val, max;

    rb_scan_args(argc, argv, "01", &vmax);
    if (first) {
struct timeval tv;

gettimeofday(&tv, 0);
rand_init(tv.tv_sec ^ tv.tv_usec ^ getpid());
    }
    switch (TYPE(vmax)) {
      case T_FLOAT:
if (RFLOAT(vmax)->value <= LONG_MAX && RFLOAT(vmax)->value >= LONG_MIN) {
max = (long)RFLOAT(vmax)->value;
break;
}
vmax = rb_dbl2big(RFLOAT(vmax)->value);
/* fall through */
      case T_BIGNUM:
return rb_big_rand(vmax, RANDOM_NUMBER);
      case T_NIL:
max = 0;
break;
      default:
max = NUM2LONG(vmax);
break;
    }

    if (max == 0) {
return rb_float_new(RANDOM_NUMBER);
    }
    val = max*RANDOM_NUMBER;

    if (val < 0) val = -val;
    return rb_int2inum(val);
}

void
Init_Random()
{
    rb_define_global_function("srand", rb_f_srand, -1);
    rb_define_global_function("rand", rb_f_rand, -1);
}
Something went wrong with that request. Please try again.