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) 1993-2002 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_INITSTATE
static char state[256];
#endif
static int
rand_init(seed)
long seed;
{
int old;
static unsigned int saved_seed;
#ifdef HAVE_INITSTATE
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 sd;
unsigned int seed, old;
rb_secure(4);
if (rb_scan_args(argc, argv, "01", &sd) == 0) {
static int n = 0;
struct timeval tv;
gettimeofday(&tv, 0);
seed = tv.tv_sec ^ tv.tv_usec ^ getpid() ^ n++;
}
else {
seed = NUM2UINT(sd);
}
old = rand_init(seed);
return UINT2NUM(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 LONG2NUM(val);
}
void
Init_Random()
{
rb_define_global_function("srand", rb_f_srand, -1);
rb_define_global_function("rand", rb_f_rand, -1);
}
|
