1 /*
2 A C-program for MT19937, with initialization improved 2002/1/26.
3 Coded by Takuji Nishimura and Makoto Matsumoto.
4
5 Before using, initialize the state by using init_genrand(seed)
6 or init_by_array(init_key, key_length).
7
8 Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
9 All rights reserved.
10 Copyright (C) 2005, Mutsuo Saito,
11 All rights reserved.
12
13 Redistribution and use in source and binary forms, with or without
14 modification, are permitted provided that the following conditions
15 are met:
16
17 1. Redistributions of source code must retain the above copyright
18 notice, this list of conditions and the following disclaimer.
19
20 2. Redistributions in binary form must reproduce the above copyright
21 notice, this list of conditions and the following disclaimer in the
22 documentation and/or other materials provided with the distribution.
23
24 3. The names of its contributors may not be used to endorse or promote
25 products derived from this software without specific prior written
26 permission.
27
28 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
32 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
33 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
34 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
35 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
36 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
37 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
38 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39
40
41 Any feedback is very welcome.
42 http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
43 email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
44 */
45
46 #include "mt19937ar.h"
47 #include <stdlib.h>
48 #include <pthread.h>
49 #if defined(__APPLE__) || defined(__ANDROID__)
50 #include "pthread_spin_lock_shim.h"
51 #endif
52
53 /* Period parameters */
54 #define N 624
55 #define M 397
56 #define MATRIX_A 0x9908b0dfUL /* constant vector a */
57 #define UPPER_MASK 0x80000000UL /* most significant w-r bits */
58 #define LOWER_MASK 0x7fffffffUL /* least significant r bits */
59
60 static unsigned long mt[N]; /* the array for the state vector */
61 static int mti = N + 1; /* mti==N+1 means mt[N] is not initialized */
62 static pthread_spinlock_t lock;
63 static volatile int mt_initialized;
64
init_mt19937ar(void)65 void init_mt19937ar(void) {
66 if (!__sync_bool_compare_and_swap(&mt_initialized, 0, 1)) {
67 return; // initialized already
68 }
69 pthread_spin_init(&lock, 0);
70 }
71
72 __attribute__((constructor))
73
lock_constructor(void)74 void lock_constructor(void) {
75 init_mt19937ar();
76 }
77
78 __attribute__((destructor))
79
lock_destructor(void)80 void lock_destructor(void) {
81 if (!__sync_bool_compare_and_swap(&mt_initialized, 1, 0)) {
82 return; // initialized already
83 }
84 pthread_spin_destroy(&lock);
85 }
86
init_genrand_impl(unsigned long s)87 void init_genrand_impl(unsigned long s) {
88 mt[0] = s & 0xffffffffUL;
89 for (mti = 1; mti < N; mti++) {
90 mt[mti] = (1812433253UL * (mt[mti - 1] ^ (mt[mti - 1] >> 30)) + mti);
91 /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
92 /* In the previous versions, MSBs of the seed affect */
93 /* only MSBs of the array mt[]. */
94 /* 2002/01/09 modified by Makoto Matsumoto */
95 mt[mti] &= 0xffffffffUL;
96 /* for >32 bit machines */
97 }
98 }
99
100 /* initializes mt[N] with a seed */
init_genrand(unsigned long s)101 void init_genrand(unsigned long s) {
102 pthread_spin_lock(&lock);
103 init_genrand_impl(s);
104 pthread_spin_unlock(&lock);
105 }
106
107 /* initialize by an array with array-length */
108
109 /* init_key is the array for initializing keys */
110
111 /* key_length is its length */
112
113 /* slight change for C++, 2004/2/26 */
init_by_array(unsigned long init_key[],int key_length)114 void init_by_array(unsigned long init_key[], int key_length) {
115 pthread_spin_lock(&lock);
116 int i, j, k;
117 init_genrand_impl(19650218UL);
118 i = 1;
119 j = 0;
120 k = (N > key_length ? N : key_length);
121 for ( ; k; k--) {
122 mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1664525UL))
123 + init_key[j] + j; /* non linear */
124 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
125 i++;
126 j++;
127 if (i >= N) {
128 mt[0] = mt[N - 1];
129 i = 1;
130 }
131 if (j >= key_length) {
132 j = 0;
133 }
134 }
135 for (k = N - 1; k; k--) {
136 mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1566083941UL))
137 - i; /* non linear */
138 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
139 i++;
140 if (i >= N) {
141 mt[0] = mt[N - 1];
142 i = 1;
143 }
144 }
145 mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
146 pthread_spin_unlock(&lock);
147 }
148
149 /* generates a random number on [0,0xffffffff]-interval */
genrand_int32(void)150 unsigned long genrand_int32(void) {
151 pthread_spin_lock(&lock);
152 unsigned long y;
153 static unsigned long mag01[2] = { 0x0UL, MATRIX_A };
154 /* mag01[x] = x * MATRIX_A for x=0,1 */
155
156 if (mti >= N) { /* generate N words at one time */
157 int kk;
158
159 if (mti == N + 1) { /* if init_genrand() has not been called, */
160 init_genrand_impl(5489UL); /* a default initial seed is used */
161 }
162
163 for (kk = 0; kk < N - M; kk++) {
164 y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
165 mt[kk] = mt[kk + M] ^ (y >> 1) ^ mag01[y & 0x1UL];
166 }
167 for ( ; kk < N - 1; kk++) {
168 y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
169 mt[kk] = mt[kk + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
170 }
171 y = (mt[N - 1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
172 mt[N - 1] = mt[M - 1] ^ (y >> 1) ^ mag01[y & 0x1UL];
173
174 mti = 0;
175 }
176
177 y = mt[mti++];
178
179 /* Tempering */
180 y ^= (y >> 11);
181 y ^= (y << 7) & 0x9d2c5680UL;
182 y ^= (y << 15) & 0xefc60000UL;
183 y ^= (y >> 18);
184 pthread_spin_unlock(&lock);
185
186 return y;
187 }
188
189 /* generates a random number on [0,0x7fffffff]-interval */
genrand_int31(void)190 long genrand_int31(void) {
191 return (long) (genrand_int32() >> 1);
192 }
193
194 /* generates a random number on [0,1]-real-interval */
genrand_real1(void)195 double genrand_real1(void) {
196 return genrand_int32() * (1.0 / 4294967295.0);
197 /* divided by 2^32-1 */
198 }
199
200 /* generates a random number on [0,1)-real-interval */
genrand_real2(void)201 double genrand_real2(void) {
202 return genrand_int32() * (1.0 / 4294967296.0);
203 /* divided by 2^32 */
204 }
205
206 /* generates a random number on (0,1)-real-interval */
genrand_real3(void)207 double genrand_real3(void) {
208 return (((double) genrand_int32()) + 0.5) * (1.0 / 4294967296.0);
209 /* divided by 2^32 */
210 }
211
212 /* generates a random number on [0,1) with 53-bit resolution*/
genrand_res53(void)213 double genrand_res53(void) {
214 unsigned long a = genrand_int32() >> 5, b = genrand_int32() >> 6;
215 return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
216 }
217
218 /* These real versions are due to Isaku Wada, 2002/01/09 added */
219