* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/* Originally developed and coded by Makoto Matsumoto and Takuji
* Nishimura. Please mail <matumoto@math.keio.ac.jp>, if you're using
* code from this file in your own programs or libraries.
* Further information on the Mersenne Twister can be found at
- * http://www.math.keio.ac.jp/~matumoto/emt.html
+ * http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
* This code was adapted to glib by Sebastian Wilhelmi.
*/
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
- * GLib at ftp://ftp.gtk.org/pub/gtk/.
+ * GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
-/*
+/*
* MT safe
*/
#include "config.h"
+#define _CRT_RAND_S
#include <math.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
-#ifdef HAVE_UNISTD_H
+#include "grand.h"
+
+#include "genviron.h"
+#include "gmain.h"
+#include "gmem.h"
+#include "gtestutils.h"
+#include "gthread.h"
+
+#ifdef G_OS_UNIX
#include <unistd.h>
#endif
-#include "glib.h"
-#include "gthreadinit.h"
-
#ifdef G_OS_WIN32
-#include <process.h> /* For getpid() */
+#include <stdlib.h>
+#include <process.h> /* For getpid() */
#endif
+/**
+ * SECTION:random_numbers
+ * @title: Random Numbers
+ * @short_description: pseudo-random number generator
+ *
+ * The following functions allow you to use a portable, fast and good
+ * pseudo-random number generator (PRNG).
+ *
+ * Do not use this API for cryptographic purposes such as key
+ * generation, nonces, salts or one-time pads.
+ *
+ * This PRNG is suitable for non-cryptographic use such as in games
+ * (shuffling a card deck, generating levels), generating data for
+ * a test suite, etc. If you need random data for cryptographic
+ * purposes, it is recommended to use platform-specific APIs such
+ * as `/dev/random` on UNIX, or CryptGenRandom() on Windows.
+ *
+ * GRand uses the Mersenne Twister PRNG, which was originally
+ * developed by Makoto Matsumoto and Takuji Nishimura. Further
+ * information can be found at
+ * [this page](http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html).
+ *
+ * If you just need a random number, you simply call the g_random_*
+ * functions, which will create a globally used #GRand and use the
+ * according g_rand_* functions internally. Whenever you need a
+ * stream of reproducible random numbers, you better create a
+ * #GRand yourself and use the g_rand_* functions directly, which
+ * will also be slightly faster. Initializing a #GRand with a
+ * certain seed will produce exactly the same series of random
+ * numbers on all platforms. This can thus be used as a seed for
+ * e.g. games.
+ *
+ * The g_rand*_range functions will return high quality equally
+ * distributed random numbers, whereas for example the
+ * `(g_random_int()%max)` approach often
+ * doesn't yield equally distributed numbers.
+ *
+ * GLib changed the seeding algorithm for the pseudo-random number
+ * generator Mersenne Twister, as used by #GRand. This was necessary,
+ * because some seeds would yield very bad pseudo-random streams.
+ * Also the pseudo-random integers generated by g_rand*_int_range()
+ * will have a slightly better equal distribution with the new
+ * version of GLib.
+ *
+ * The original seeding and generation algorithms, as found in
+ * GLib 2.0.x, can be used instead of the new ones by setting the
+ * environment variable `G_RANDOM_VERSION` to the value of '2.0'.
+ * Use the GLib-2.0 algorithms only if you have sequences of numbers
+ * generated with Glib-2.0 that you need to reproduce exactly.
+ */
+
+/**
+ * GRand:
+ *
+ * The GRand struct is an opaque data structure. It should only be
+ * accessed through the g_rand_* functions.
+ **/
+
G_LOCK_DEFINE_STATIC (global_random);
-static GRand* global_random = NULL;
/* Period parameters */
#define N 624
static guint
get_random_version (void)
{
- static gboolean initialized = FALSE;
+ static gsize initialized = FALSE;
static guint random_version;
-
- if (!initialized)
+
+ if (g_once_init_enter (&initialized))
{
const gchar *version_string = g_getenv ("G_RANDOM_VERSION");
if (!version_string || version_string[0] == '\000' ||
version_string);
random_version = 22;
}
- initialized = TRUE;
+ g_once_init_leave (&initialized, TRUE);
}
return random_version;
}
-/* This is called from g_thread_init(). It's used to
- * initialize some static data in a threadsafe way.
- */
-void
-_g_rand_thread_init (void)
-{
- (void)get_random_version ();
-}
-
struct _GRand
{
guint32 mt[N]; /* the array for the state vector */
/**
* g_rand_new_with_seed:
- * @seed: a value to initialize the random number generator.
+ * @seed: a value to initialize the random number generator
*
* Creates a new random number generator initialized with @seed.
*
- * Return value: the new #GRand.
+ * Returns: the new #GRand
**/
GRand*
g_rand_new_with_seed (guint32 seed)
/**
* g_rand_new_with_seed_array:
- * @seed: an array of seeds to initialize the random number generator.
- * @seed_length: an array of seeds to initialize the random number generator.
+ * @seed: an array of seeds to initialize the random number generator
+ * @seed_length: an array of seeds to initialize the random number
+ * generator
*
* Creates a new random number generator initialized with @seed.
*
- * Return value: the new #GRand.
- **/
+ * Returns: the new #GRand
+ *
+ * Since: 2.4
+ */
GRand*
-g_rand_new_with_seed_array (const guint32 *seed, guint seed_length)
+g_rand_new_with_seed_array (const guint32 *seed,
+ guint seed_length)
{
GRand *rand = g_new0 (GRand, 1);
g_rand_set_seed_array (rand, seed, seed_length);
* g_rand_new:
*
* Creates a new random number generator initialized with a seed taken
- * either from <filename>/dev/urandom</filename> (if existing) or from
- * the current time (as a fallback).
+ * either from `/dev/urandom` (if existing) or from the current time
+ * (as a fallback).
+ *
+ * On Windows, the seed is taken from rand_s().
*
- * Return value: the new #GRand.
- **/
+ * Returns: the new #GRand
+ */
GRand*
g_rand_new (void)
{
guint32 seed[4];
- GTimeVal now;
#ifdef G_OS_UNIX
static gboolean dev_urandom_exists = TRUE;
+ GTimeVal now;
if (dev_urandom_exists)
{
FILE* dev_urandom;
do
- {
- errno = 0;
+ {
dev_urandom = fopen("/dev/urandom", "rb");
}
- while G_UNLIKELY (errno == EINTR);
+ while G_UNLIKELY (dev_urandom == NULL && errno == EINTR);
if (dev_urandom)
{
int r;
+ setvbuf (dev_urandom, NULL, _IONBF, 0);
do
{
errno = 0;
if (r != 1)
dev_urandom_exists = FALSE;
- do
- {
- errno = 0;
- fclose (dev_urandom);
- }
- while G_UNLIKELY (errno == EINTR);
+ fclose (dev_urandom);
}
else
dev_urandom_exists = FALSE;
}
-#else
- static gboolean dev_urandom_exists = FALSE;
-#endif
if (!dev_urandom_exists)
{
seed[0] = now.tv_sec;
seed[1] = now.tv_usec;
seed[2] = getpid ();
-#ifdef G_OS_UNIX
seed[3] = getppid ();
+ }
+#else /* G_OS_WIN32 */
+ /* rand_s() is only available since Visual Studio 2005 */
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+ gint i;
+
+ for (i = 0; i < G_N_ELEMENTS (seed); i++)
+ rand_s (&seed[i]);
#else
- seed[3] = 0;
+#warning Using insecure seed for random number generation because of missing rand_s() in Windows XP
+ GTimeVal now;
+
+ g_get_current_time (&now);
+ seed[0] = now.tv_sec;
+ seed[1] = now.tv_usec;
+ seed[2] = getpid ();
+ seed[3] = 0;
+#endif
+
#endif
- }
return g_rand_new_with_seed_array (seed, 4);
}
/**
* g_rand_free:
- * @rand_: a #GRand.
+ * @rand_: a #GRand
*
* Frees the memory allocated for the #GRand.
- **/
+ */
void
-g_rand_free (GRand* rand)
+g_rand_free (GRand *rand)
{
g_return_if_fail (rand != NULL);
/**
* g_rand_copy:
- * @rand_: a #GRand.
+ * @rand_: a #GRand
*
* Copies a #GRand into a new one with the same exact state as before.
* This way you can take a snapshot of the random number generator for
* replaying later.
*
- * Return value: the new #GRand.
- **/
-GRand *
-g_rand_copy (GRand* rand)
+ * Returns: the new #GRand
+ *
+ * Since: 2.4
+ */
+GRand*
+g_rand_copy (GRand *rand)
{
GRand* new_rand;
/**
* g_rand_set_seed:
- * @rand_: a #GRand.
- * @seed: a value to reinitialize the random number generator.
+ * @rand_: a #GRand
+ * @seed: a value to reinitialize the random number generator
*
* Sets the seed for the random number generator #GRand to @seed.
- **/
+ */
void
-g_rand_set_seed (GRand* rand, guint32 seed)
+g_rand_set_seed (GRand *rand,
+ guint32 seed)
{
g_return_if_fail (rand != NULL);
/* [KNUTH 1981, The Art of Computer Programming */
/* Vol. 2 (2nd Ed.), pp102] */
- if (seed == 0) /* This would make the PRNG procude only zeros */
+ if (seed == 0) /* This would make the PRNG produce only zeros */
seed = 0x6b842128; /* Just set it to another number */
rand->mt[0]= seed;
/**
* g_rand_set_seed_array:
- * @rand_: a #GRand.
+ * @rand_: a #GRand
* @seed: array to initialize with
* @seed_length: length of array
*
- * Initializes the random number generator by an array of
- * longs. Array can be of arbitrary size, though only the
- * first 624 values are taken. This function is useful
- * if you have many low entropy seeds, or if you require more then
- * 32bits of actual entropy for your application.
- **/
+ * Initializes the random number generator by an array of longs.
+ * Array can be of arbitrary size, though only the first 624 values
+ * are taken. This function is useful if you have many low entropy
+ * seeds, or if you require more then 32 bits of actual entropy for
+ * your application.
+ *
+ * Since: 2.4
+ */
void
-g_rand_set_seed_array (GRand* rand, const guint32 *seed, guint seed_length)
+g_rand_set_seed_array (GRand *rand,
+ const guint32 *seed,
+ guint seed_length)
{
int i, j, k;
}
/**
+ * g_rand_boolean:
+ * @rand_: a #GRand
+ *
+ * Returns a random #gboolean from @rand_.
+ * This corresponds to a unbiased coin toss.
+ *
+ * Returns: a random #gboolean
+ */
+/**
* g_rand_int:
- * @rand_: a #GRand.
+ * @rand_: a #GRand
*
* Returns the next random #guint32 from @rand_ equally distributed over
* the range [0..2^32-1].
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
guint32
-g_rand_int (GRand* rand)
+g_rand_int (GRand *rand)
{
guint32 y;
static const guint32 mag01[2]={0x0, MATRIX_A};
if (rand->mti >= N) { /* generate N words at one time */
int kk;
- for (kk=0;kk<N-M;kk++) {
+ for (kk = 0; kk < N - M; kk++) {
y = (rand->mt[kk]&UPPER_MASK)|(rand->mt[kk+1]&LOWER_MASK);
rand->mt[kk] = rand->mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
}
- for (;kk<N-1;kk++) {
+ for (; kk < N - 1; kk++) {
y = (rand->mt[kk]&UPPER_MASK)|(rand->mt[kk+1]&LOWER_MASK);
rand->mt[kk] = rand->mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
}
/**
* g_rand_int_range:
- * @rand_: a #GRand.
- * @begin: lower closed bound of the interval.
- * @end: upper open bound of the interval.
+ * @rand_: a #GRand
+ * @begin: lower closed bound of the interval
+ * @end: upper open bound of the interval
*
* Returns the next random #gint32 from @rand_ equally distributed over
* the range [@begin..@end-1].
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
gint32
-g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
+g_rand_int_range (GRand *rand,
+ gint32 begin,
+ gint32 end)
{
guint32 dist = end - begin;
guint32 random;
{
/* This method, which only calls g_rand_int once is only good
* for (end - begin) <= 2^16, because we only have 32 bits set
- * from the one call to g_rand_int (). */
-
- /* we are using (trans + trans * trans), because g_rand_int only
+ * from the one call to g_rand_int ().
+ *
+ * We are using (trans + trans * trans), because g_rand_int only
* covers [0..2^32-1] and thus g_rand_int * trans only covers
* [0..1-2^-32], but the biggest double < 1 is 1-2^-52.
*/
}
else
{
- /* Now we use g_rand_double_range (), which will set 52 bits for
- us, so that it is safe to round and still get a decent
- distribution */
+ /* Now we use g_rand_double_range (), which will set 52 bits
+ * for us, so that it is safe to round and still get a decent
+ * distribution
+ */
random = (gint32) g_rand_double_range (rand, 0, dist);
}
break;
else
{
/* maxvalue is set to the predecessor of the greatest
- * multiple of dist less or equal 2^32. */
+ * multiple of dist less or equal 2^32.
+ */
guint32 maxvalue;
if (dist <= 0x80000000u) /* 2^31 */
{
/**
* g_rand_double:
- * @rand_: a #GRand.
+ * @rand_: a #GRand
*
* Returns the next random #gdouble from @rand_ equally distributed over
* the range [0..1).
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
gdouble
-g_rand_double (GRand* rand)
+g_rand_double (GRand *rand)
{
/* We set all 52 bits after the point for this, not only the first
32. Thats why we need two calls to g_rand_int */
/**
* g_rand_double_range:
- * @rand_: a #GRand.
- * @begin: lower closed bound of the interval.
- * @end: upper open bound of the interval.
+ * @rand_: a #GRand
+ * @begin: lower closed bound of the interval
+ * @end: upper open bound of the interval
*
* Returns the next random #gdouble from @rand_ equally distributed over
* the range [@begin..@end).
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
gdouble
-g_rand_double_range (GRand* rand, gdouble begin, gdouble end)
+g_rand_double_range (GRand *rand,
+ gdouble begin,
+ gdouble end)
+{
+ gdouble r;
+
+ r = g_rand_double (rand);
+
+ return r * end - (r - 1) * begin;
+}
+
+static GRand *
+get_global_random (void)
{
- return g_rand_double (rand) * (end - begin) + begin;
+ static GRand *global_random;
+
+ /* called while locked */
+ if (!global_random)
+ global_random = g_rand_new ();
+
+ return global_random;
}
/**
+ * g_random_boolean:
+ *
+ * Returns a random #gboolean.
+ * This corresponds to a unbiased coin toss.
+ *
+ * Returns: a random #gboolean
+ */
+/**
* g_random_int:
*
* Return a random #guint32 equally distributed over the range
* [0..2^32-1].
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
guint32
g_random_int (void)
{
guint32 result;
G_LOCK (global_random);
- if (!global_random)
- global_random = g_rand_new ();
-
- result = g_rand_int (global_random);
+ result = g_rand_int (get_global_random ());
G_UNLOCK (global_random);
return result;
}
/**
* g_random_int_range:
- * @begin: lower closed bound of the interval.
- * @end: upper open bound of the interval.
+ * @begin: lower closed bound of the interval
+ * @end: upper open bound of the interval
*
* Returns a random #gint32 equally distributed over the range
* [@begin..@end-1].
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
gint32
-g_random_int_range (gint32 begin, gint32 end)
+g_random_int_range (gint32 begin,
+ gint32 end)
{
gint32 result;
G_LOCK (global_random);
- if (!global_random)
- global_random = g_rand_new ();
-
- result = g_rand_int_range (global_random, begin, end);
+ result = g_rand_int_range (get_global_random (), begin, end);
G_UNLOCK (global_random);
return result;
}
*
* Returns a random #gdouble equally distributed over the range [0..1).
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
gdouble
g_random_double (void)
{
double result;
G_LOCK (global_random);
- if (!global_random)
- global_random = g_rand_new ();
-
- result = g_rand_double (global_random);
+ result = g_rand_double (get_global_random ());
G_UNLOCK (global_random);
return result;
}
/**
* g_random_double_range:
- * @begin: lower closed bound of the interval.
- * @end: upper open bound of the interval.
+ * @begin: lower closed bound of the interval
+ * @end: upper open bound of the interval
*
- * Returns a random #gdouble equally distributed over the range [@begin..@end).
+ * Returns a random #gdouble equally distributed over the range
+ * [@begin..@end).
*
- * Return value: A random number.
- **/
+ * Returns: a random number
+ */
gdouble
-g_random_double_range (gdouble begin, gdouble end)
+g_random_double_range (gdouble begin,
+ gdouble end)
{
double result;
G_LOCK (global_random);
- if (!global_random)
- global_random = g_rand_new ();
-
- result = g_rand_double_range (global_random, begin, end);
+ result = g_rand_double_range (get_global_random (), begin, end);
G_UNLOCK (global_random);
return result;
}
/**
* g_random_set_seed:
- * @seed: a value to reinitialize the global random number generator.
+ * @seed: a value to reinitialize the global random number generator
*
* Sets the seed for the global random number generator, which is used
- * by the <function>g_random_*</function> functions, to @seed.
- **/
+ * by the g_random_* functions, to @seed.
+ */
void
g_random_set_seed (guint32 seed)
{
G_LOCK (global_random);
- if (!global_random)
- global_random = g_rand_new_with_seed (seed);
- else
- g_rand_set_seed (global_random, seed);
+ g_rand_set_seed (get_global_random (), seed);
G_UNLOCK (global_random);
}
-
projects / platform / upstream / glib.git / blobdiff