16,22c16
< #define GLOBAL_RAND_SEED_KEY          "$mrb_g_rand_seed"
< #define GLOBAL_RAND_SEED_KEY_CSTR_LEN 16
<
< #define INSTANCE_RAND_SEED_KEY          "$mrb_i_rand_seed"
< #define INSTANCE_RAND_SEED_KEY_CSTR_LEN 16
<
< #define MT_STATE_KEY          "$mrb_i_mt_state"
---
> static char const MT_STATE_KEY[] = "$mrb_i_mt_state";
28,41c22,23
< static void mt_g_srand(unsigned long seed)
< {
<   init_genrand(seed);
< }
<
< static unsigned long mt_g_rand()
< {
<   return genrand_int32();
< }
<
< static double mt_g_rand_real()
< {
<   return genrand_real1();
< }
---
> static mrb_value mrb_random_rand(mrb_state *mrb, mrb_value self);
> static mrb_value mrb_random_srand(mrb_state *mrb, mrb_value self);
43,73c25
< static mrb_value
< mrb_random_mt_g_srand(mrb_state *mrb, mrb_value seed)
< {
<   if (mrb_nil_p(seed)) {
<     seed = mrb_fixnum_value(time(NULL) + mt_g_rand());
<     if (mrb_fixnum(seed) < 0) {
<       seed = mrb_fixnum_value( 0 - mrb_fixnum(seed));
<     }
<   }
<
<   mt_g_srand((unsigned) mrb_fixnum(seed));
<
<   return seed;
< }
<
< static mrb_value
< mrb_random_mt_g_rand(mrb_state *mrb, mrb_value max)
< {
<   mrb_value value;
<
<   if (mrb_fixnum(max) == 0) {
<     value = mrb_float_value(mrb, mt_g_rand_real());
<   }
<   else {
<     value = mrb_fixnum_value(mt_g_rand() % mrb_fixnum(max));
<   }
<
<   return value;
< }
<
< static void
---
> static void
77c29
< }
---
> }
79c31
< static unsigned long
---
> static unsigned long
83c35
< }
---
> }
85c37
< static double
---
> static double
89c41
< }
---
> }
91c43
< static mrb_value
---
> static mrb_value
93c45
< {
---
> {
95c47
<     seed = mrb_fixnum_value(time(NULL) + mt_rand(t));
---
>     seed = mrb_fixnum_value((mrb_int)(time(NULL) + mt_rand(t)));
97c49
<       seed = mrb_fixnum_value( 0 - mrb_fixnum(seed));
---
>       seed = mrb_fixnum_value(0 - mrb_fixnum(seed));
106c58
< static mrb_value
---
> static mrb_value
108c60
< {
---
> {
121c73
< static mrb_value
---
> static mrb_value
126c78
<   arg = mrb_fixnum_value(0);
---
>   arg = mrb_nil_value();
141,142c93,101
< static void
< mrb_random_g_rand_seed(mrb_state *mrb)
---
> static mrb_value
> get_random(mrb_state *mrb) {
>   return mrb_const_get(mrb,
>              mrb_obj_value(mrb_class_get(mrb, "Random")),
>              mrb_intern_lit(mrb, "DEFAULT"));
> }
>
> static mt_state *
> get_random_state(mrb_state *mrb)
144,149c103,104
<   mrb_value seed;
<
<   seed = mrb_gv_get(mrb, mrb_intern(mrb, GLOBAL_RAND_SEED_KEY, GLOBAL_RAND_SEED_KEY_CSTR_LEN));
<   if (mrb_nil_p(seed)) {
<     mrb_random_mt_g_srand(mrb, mrb_nil_value());
<   }
---
>   mrb_value random_val = get_random(mrb);
>   return DATA_GET_PTR(mrb, random_val, &mt_state_type, mt_state);
152c107
< static mrb_value
---
> static mrb_value
155,159c110,111
<   mrb_value max;
<
<   max = get_opt(mrb);
<   mrb_random_g_rand_seed(mrb);
<   return mrb_random_mt_g_rand(mrb, max);
---
>   mrb_value random = get_random(mrb);
>   return mrb_random_rand(mrb, random);
162c114
< static mrb_value
---
> static mrb_value
165,172c117,118
<   mrb_value seed;
<   mrb_value old_seed;
<
<   seed = get_opt(mrb);
<   seed = mrb_random_mt_g_srand(mrb, seed);
<   old_seed = mrb_gv_get(mrb, mrb_intern(mrb, GLOBAL_RAND_SEED_KEY, GLOBAL_RAND_SEED_KEY_CSTR_LEN));
<   mrb_gv_set(mrb, mrb_intern(mrb, GLOBAL_RAND_SEED_KEY, GLOBAL_RAND_SEED_KEY_CSTR_LEN), seed);
<   return old_seed;
---
>   mrb_value random = get_random(mrb);
>   return mrb_random_srand(mrb, random);
175c121
< static mrb_value
---
> static mrb_value
180,183c126
<
<   DATA_TYPE(self) = &mt_state_type;
<   DATA_PTR(self) = NULL;
<
---
>
188c131,132
<   }
---
>   }
>   mrb_data_init(self, NULL, &mt_state_type);
195,198c139,149
<   mrb_iv_set(mrb, self, mrb_intern(mrb, INSTANCE_RAND_SEED_KEY, INSTANCE_RAND_SEED_KEY_CSTR_LEN), seed);
<
<   DATA_PTR(self) = t;
<
---
>   if (mrb_nil_p(seed)) {
>     t->has_seed = FALSE;
>   }
>   else {
>     mrb_assert(mrb_fixnum_p(seed));
>     t->has_seed = TRUE;
>     t->seed = mrb_fixnum(seed);
>   }
>
>   mrb_data_init(self, t, &mt_state_type);
>
202,203c153,154
< static void
< mrb_random_rand_seed(mrb_state *mrb, mrb_value self)
---
> static void
> mrb_random_rand_seed(mrb_state *mrb, mt_state *t)
205,209c156
<   mrb_value seed;
<   mt_state *t = DATA_PTR(self);
<
<   seed = mrb_iv_get(mrb, self, mrb_intern(mrb, INSTANCE_RAND_SEED_KEY, INSTANCE_RAND_SEED_KEY_CSTR_LEN));
<   if (mrb_nil_p(seed)) {
---
>   if (!t->has_seed) {
214c161
< static mrb_value
---
> static mrb_value
218c165
<   mt_state *t = DATA_PTR(self);
---
>   mt_state *t = DATA_GET_PTR(mrb, self, &mt_state_type, mt_state);
221c168
<   mrb_random_rand_seed(mrb, self);
---
>   mrb_random_rand_seed(mrb, t);
225c172
< static mrb_value
---
> static mrb_value
230c177
<   mt_state *t = DATA_PTR(self);
---
>   mt_state *t = DATA_GET_PTR(mrb, self, &mt_state_type, mt_state);
234,235c181,189
<   old_seed = mrb_iv_get(mrb, self, mrb_intern(mrb, INSTANCE_RAND_SEED_KEY, INSTANCE_RAND_SEED_KEY_CSTR_LEN));
<   mrb_iv_set(mrb, self, mrb_intern(mrb, INSTANCE_RAND_SEED_KEY, INSTANCE_RAND_SEED_KEY_CSTR_LEN), seed);
---
>   old_seed = t->has_seed? mrb_fixnum_value(t->seed) : mrb_nil_value();
>   if (mrb_nil_p(seed)) {
>     t->has_seed = FALSE;
>   }
>   else {
>     mrb_assert(mrb_fixnum_p(seed));
>     t->has_seed = TRUE;
>     t->seed = mrb_fixnum(seed);
>   }
251,252c205,206
<   mrb_value random = mrb_nil_value();
<
---
>   mt_state *random = NULL;
>
254c208
<     mrb_get_args(mrb, "|o", &random);
---
>     mrb_get_args(mrb, "|d", &random, &mt_state_type);
256,261c210,211
<     if (mrb_nil_p(random)) {
<       mrb_random_g_rand_seed(mrb);
<     }
<     else {
<       mrb_data_check_type(mrb, random, &mt_state_type);
<       mrb_random_rand_seed(mrb, random);
---
>     if (random == NULL) {
>       random = get_random_state(mrb);
263c213,214
<
---
>     mrb_random_rand_seed(mrb, random);
>
265c216
<
---
>
269,276c220,222
<
<       if (mrb_nil_p(random)) {
<         j = mrb_fixnum(mrb_random_mt_g_rand(mrb, mrb_fixnum_value(RARRAY_LEN(ary))));
<       }
<       else {
<         j = mrb_fixnum(mrb_random_mt_rand(mrb, DATA_PTR(random), mrb_fixnum_value(RARRAY_LEN(ary))));
<       }
<
---
>
>       j = mrb_fixnum(mrb_random_mt_rand(mrb, random, mrb_fixnum_value(RARRAY_LEN(ary))));
>
278,280c224,226
<       RARRAY_PTR(ary)[i] = RARRAY_PTR(ary)[j];
<       RARRAY_PTR(ary)[j] = tmp;
<     }
---
>       mrb_ary_ptr(ary)->ptr[i] = RARRAY_PTR(ary)[j];
>       mrb_ary_ptr(ary)->ptr[j] = tmp;
>     }
282c228
<
---
>
298c244
<
---
>
301a248,317
> /*
>  *  call-seq:
>  *     ary.sample      ->   obj
>  *     ary.sample(n)   ->   new_ary
>  *
>  *  Choose a random element or +n+ random elements from the array.
>  *
>  *  The elements are chosen by using random and unique indices into the array
>  *  in order to ensure that an element doesn't repeat itself unless the array
>  *  already contained duplicate elements.
>  *
>  *  If the array is empty the first form returns +nil+ and the second form
>  *  returns an empty array.
>  */
>
> static mrb_value
> mrb_ary_sample(mrb_state *mrb, mrb_value ary)
> {
>   mrb_int n = 0;
>   mrb_bool given;
>   mt_state *random = NULL;
>   mrb_int len = RARRAY_LEN(ary);
>
>   mrb_get_args(mrb, "|i?d", &n, &given, &random, &mt_state_type);
>   if (random == NULL) {
>     random = get_random_state(mrb);
>   }
>   mrb_random_rand_seed(mrb, random);
>   mt_rand(random);
>   if (!given) {                 /* pick one element */
>     switch (len) {
>     case 0:
>       return mrb_nil_value();
>     case 1:
>       return RARRAY_PTR(ary)[0];
>     default:
>       return RARRAY_PTR(ary)[mt_rand(random) % len];
>     }
>   }
>   else {
>     mrb_value result;
>     mrb_int i, j;
>
>     if (n < 0) mrb_raise(mrb, E_ARGUMENT_ERROR, "negative sample number");
>     if (n > len) n = len;
>     result = mrb_ary_new_capa(mrb, n);
>     for (i=0; i<n; i++) {
>       mrb_int r;
>
>       for (;;) {
>       retry:
>         r = mt_rand(random) % len;
>
>         for (j=0; j<i; j++) {
>           if (mrb_fixnum(RARRAY_PTR(result)[j]) == r) {
>             goto retry;         /* retry if duplicate */
>           }
>         }
>         break;
>       }
>       mrb_ary_push(mrb, result, mrb_fixnum_value(r));
>     }
>     for (i=0; i<n; i++) {
>       mrb_ary_set(mrb, result, i, RARRAY_PTR(ary)[mrb_fixnum(RARRAY_PTR(result)[i])]);
>     }
>     return result;
>   }
> }
>
>
318c334
<
---
>
320a337,340
>   mrb_define_method(mrb, array, "sample", mrb_ary_sample, MRB_ARGS_OPT(2));
>
>   mrb_const_set(mrb, mrb_obj_value(random), mrb_intern_lit(mrb, "DEFAULT"),
>           mrb_obj_new(mrb, random, 0, NULL));