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()65 void init_mt19937ar() {
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))
lock_constructor()73 void lock_constructor() {
74 init_mt19937ar();
75 }
76
77 __attribute__((destructor))
lock_destructor()78 void lock_destructor() {
79 if (!__sync_bool_compare_and_swap(&mt_initialized, 1, 0)) {
80 return; // initialized already
81 }
82 pthread_spin_destroy(&lock);
83 }
84
init_genrand_impl(unsigned long s)85 void init_genrand_impl(unsigned long s) {
86 mt[0] = s & 0xffffffffUL;
87 for (mti = 1; mti < N; mti++) {
88 mt[mti] =
89 (1812433253UL * (mt[mti - 1] ^ (mt[mti - 1] >> 30)) + mti);
90 /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
91 /* In the previous versions, MSBs of the seed affect */
92 /* only MSBs of the array mt[]. */
93 /* 2002/01/09 modified by Makoto Matsumoto */
94 mt[mti] &= 0xffffffffUL;
95 /* for >32 bit machines */
96 }
97 }
98
99 /* initializes mt[N] with a seed */
init_genrand(unsigned long s)100 void init_genrand(unsigned long s) {
101 pthread_spin_lock(&lock);
102 init_genrand_impl(s);
103 pthread_spin_unlock(&lock);
104 }
105
106 /* initialize by an array with array-length */
107 /* init_key is the array for initializing keys */
108 /* key_length is its length */
109 /* slight change for C++, 2004/2/26 */
init_by_array(unsigned long init_key[],int key_length)110 void init_by_array(unsigned long init_key[], int key_length) {
111 pthread_spin_lock(&lock);
112 int i, j, k;
113 init_genrand_impl(19650218UL);
114 i = 1;
115 j = 0;
116 k = (N > key_length ? N : key_length);
117 for (; k; k--) {
118 mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1664525UL))
119 + init_key[j] + j; /* non linear */
120 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
121 i++;
122 j++;
123 if (i >= N) {
124 mt[0] = mt[N - 1];
125 i = 1;
126 }
127 if (j >= key_length) j = 0;
128 }
129 for (k = N - 1; k; k--) {
130 mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1566083941UL))
131 - i; /* non linear */
132 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
133 i++;
134 if (i >= N) {
135 mt[0] = mt[N - 1];
136 i = 1;
137 }
138 }
139 mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
140 pthread_spin_unlock(&lock);
141 }
142
143 /* generates a random number on [0,0xffffffff]-interval */
genrand_int32(void)144 unsigned long genrand_int32(void) {
145 pthread_spin_lock(&lock);
146 unsigned long y;
147 static unsigned long mag01[2] = {0x0UL, MATRIX_A};
148 /* mag01[x] = x * MATRIX_A for x=0,1 */
149
150 if (mti >= N) { /* generate N words at one time */
151 int kk;
152
153 if (mti == N + 1) { /* if init_genrand() has not been called, */
154 init_genrand_impl(5489UL); /* a default initial seed is used */
155 }
156
157 for (kk = 0; kk < N - M; kk++) {
158 y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
159 mt[kk] = mt[kk + M] ^ (y >> 1) ^ mag01[y & 0x1UL];
160 }
161 for (; kk < N - 1; kk++) {
162 y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
163 mt[kk] = mt[kk + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
164 }
165 y = (mt[N - 1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
166 mt[N - 1] = mt[M - 1] ^ (y >> 1) ^ mag01[y & 0x1UL];
167
168 mti = 0;
169 }
170
171 y = mt[mti++];
172
173 /* Tempering */
174 y ^= (y >> 11);
175 y ^= (y << 7) & 0x9d2c5680UL;
176 y ^= (y << 15) & 0xefc60000UL;
177 y ^= (y >> 18);
178 pthread_spin_unlock(&lock);
179
180 return y;
181 }
182
183 /* generates a random number on [0,0x7fffffff]-interval */
genrand_int31(void)184 long genrand_int31(void) {
185 return (long)(genrand_int32() >> 1);
186 }
187
188 /* generates a random number on [0,1]-real-interval */
genrand_real1(void)189 double genrand_real1(void) {
190 return genrand_int32() * (1.0 / 4294967295.0);
191 /* divided by 2^32-1 */
192 }
193
194 /* generates a random number on [0,1)-real-interval */
genrand_real2(void)195 double genrand_real2(void) {
196 return genrand_int32() * (1.0 / 4294967296.0);
197 /* divided by 2^32 */
198 }
199
200 /* generates a random number on (0,1)-real-interval */
genrand_real3(void)201 double genrand_real3(void) {
202 return (((double)genrand_int32()) + 0.5) * (1.0 / 4294967296.0);
203 /* divided by 2^32 */
204 }
205
206 /* generates a random number on [0,1) with 53-bit resolution*/
genrand_res53(void)207 double genrand_res53(void) {
208 unsigned long a = genrand_int32() >> 5, b = genrand_int32() >> 6;
209 return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
210 }
211 /* These real versions are due to Isaku Wada, 2002/01/09 added */
212