glib/libglib/src/grand.c
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/glib/libglib/src/grand.c	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,782 @@
+/* GLIB - Library of useful routines for C programming
+ * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
+ * Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * 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.
+ */
+
+/* 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.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/.  
+ */
+
+/* 
+ * MT safe
+ */
+
+#include "config.h"
+
+#include <math.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "glib.h"
+#include "gthreadinit.h"
+#include "galias.h"
+
+#ifdef __SYMBIAN32__
+#include <glib_wsd.h>
+#endif
+
+#if EMULATOR
+#define g_thread_functions_for_glib_use (*_g_thread_functions_for_glib_use())
+#define g_thread_use_default_impl (*_g_thread_use_default_impl())
+#endif /* EMULATOR */
+
+#ifdef G_OS_WIN32
+#include <process.h>		/* For getpid() */
+#endif
+
+#if EMULATOR
+
+PLS_MACRO(global_random,grand,GStaticMutex)
+PLS(global_random,grand,GRand *)
+
+#define g__global_random_lock (*FUNCTION_NAME_MACRO(global_random,grand)())
+#define global_random (*FUNCTION_NAME(global_random,grand)())
+
+#else
+
+G_LOCK_DEFINE_STATIC (global_random);
+static GRand* global_random = NULL;
+
+#endif /* EMULATOR */
+
+/* Period parameters */  
+#define N 624
+#define M 397
+#define MATRIX_A 0x9908b0df   /* constant vector a */
+#define UPPER_MASK 0x80000000 /* most significant w-r bits */
+#define LOWER_MASK 0x7fffffff /* least significant r bits */
+
+/* Tempering parameters */   
+#define TEMPERING_MASK_B 0x9d2c5680
+#define TEMPERING_MASK_C 0xefc60000
+#define TEMPERING_SHIFT_U(y)  (y >> 11)
+#define TEMPERING_SHIFT_S(y)  (y << 7)
+#define TEMPERING_SHIFT_T(y)  (y << 15)
+#define TEMPERING_SHIFT_L(y)  (y >> 18)
+
+#if EMULATOR
+
+PLS(initialized ,get_random_version,gboolean)
+PLS(random_version ,get_random_version,guint)
+
+#define initialized (*FUNCTION_NAME(initialized,get_random_version)())
+#define random_version (*FUNCTION_NAME(random_version,get_random_version)())
+
+#endif /* EMULATOR */
+
+static guint
+get_random_version (void)
+{
+  #if !(EMULATOR)
+  static gboolean initialized = FALSE;
+  static guint random_version;
+  #endif /* EMULATOR */
+  
+  if (!initialized)
+    {
+      const gchar *version_string = g_getenv ("G_RANDOM_VERSION");
+      if (!version_string || version_string[0] == '\000' || 
+	  strcmp (version_string, "2.2") == 0)
+	random_version = 22;
+      else if (strcmp (version_string, "2.0") == 0)
+	random_version = 20;
+      else
+	{
+	  g_warning ("Unknown G_RANDOM_VERSION \"%s\". Using version 2.2.",
+		     version_string);
+	  random_version = 22;
+	}
+      initialized = TRUE;
+    }
+  
+  return random_version;
+}
+
+#if EMULATOR
+#undef initialized
+#undef random_version
+#endif /* EMULATOR */
+
+/* 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  */
+  guint mti; 
+};
+
+/**
+ * g_rand_new_with_seed:
+ * @seed: a value to initialize the random number generator.
+ * 
+ * Creates a new random number generator initialized with @seed.
+ * 
+ * Return value: the new #GRand.
+ **/
+EXPORT_C GRand*
+g_rand_new_with_seed (guint32 seed)
+{
+  GRand *rand = g_new0 (GRand, 1);
+  g_rand_set_seed (rand, seed);
+  return rand;
+}
+
+/**
+ * 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.
+ * 
+ * Creates a new random number generator initialized with @seed.
+ * 
+ * Return value: the new #GRand.
+ *
+ * Since: 2.4
+ **/
+EXPORT_C GRand*
+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);
+  return rand;
+}
+
+/**
+ * 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).
+ * 
+ * Return value: the new #GRand.
+ **/
+
+#if EMULATOR
+
+PLS(dev_urandom_exists,g_rand_new ,gboolean)
+#define dev_urandom_exists (*FUNCTION_NAME(dev_urandom_exists,g_rand_new )())
+
+#endif /* EMULATOR */
+
+EXPORT_C GRand* 
+g_rand_new (void)
+{
+  guint32 seed[4];
+  GTimeVal now;
+#if defined(G_OS_UNIX) && !defined(__SYMBIAN32__)
+  #if !(EMULATOR)
+  static gboolean dev_urandom_exists = TRUE;
+  #endif /* EMULATOR */
+
+  if (dev_urandom_exists)
+    {
+      FILE* dev_urandom;
+
+      do
+        {
+	  errno = 0;
+	  dev_urandom = fopen("/dev/urandom", "rb");
+	}
+      while G_UNLIKELY (errno == EINTR);
+
+      if (dev_urandom)
+	{
+	  int r;
+
+	  do
+	    {
+	      errno = 0;
+	      r = fread (seed, sizeof (seed), 1, dev_urandom);
+	    }
+	  while G_UNLIKELY (errno == EINTR);
+
+	  if (r != 1)
+	    dev_urandom_exists = FALSE;
+
+	  fclose (dev_urandom);
+	}	
+      else
+	dev_urandom_exists = FALSE;
+    }
+#else
+  #if !(EMULATOR)
+  static gboolean dev_urandom_exists = FALSE;
+  #endif /* EMULATOR */
+#endif
+
+  if (!dev_urandom_exists)
+    {  
+      g_get_current_time (&now);
+      seed[0] = now.tv_sec;
+      seed[1] = now.tv_usec;
+      seed[2] = getpid ();
+#if defined G_OS_UNIX && !defined __SYMBIAN32__
+      seed[3] = getppid ();
+#else
+      seed[3] = 0;
+#endif
+    }
+
+  return g_rand_new_with_seed_array (seed, 4);
+}
+
+#if EMULATOR
+#undef dev_urandom_exists 
+#endif /* EMULATOR */
+
+/**
+ * g_rand_free:
+ * @rand_: a #GRand.
+ *
+ * Frees the memory allocated for the #GRand.
+ **/
+EXPORT_C void
+g_rand_free (GRand* rand)
+{
+  g_return_if_fail (rand != NULL);
+
+  g_free (rand);
+}
+
+/**
+ * g_rand_copy:
+ * @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.
+ *
+ * Since: 2.4
+ **/
+EXPORT_C GRand *
+g_rand_copy (GRand* rand)
+{
+  GRand* new_rand;
+
+  g_return_val_if_fail (rand != NULL, NULL);
+  new_rand = g_new0 (GRand, 1);
+  memcpy (new_rand, rand, sizeof (GRand));
+
+  return new_rand;
+}
+
+/**
+ * g_rand_set_seed:
+ * @rand_: a #GRand.
+ * @seed: a value to reinitialize the random number generator.
+ *
+ * Sets the seed for the random number generator #GRand to @seed.
+ **/
+EXPORT_C void
+g_rand_set_seed (GRand* rand, guint32 seed)
+{
+  g_return_if_fail (rand != NULL);
+
+  switch (get_random_version ())
+    {
+    case 20:
+      /* setting initial seeds to mt[N] using         */
+      /* the generator Line 25 of Table 1 in          */
+      /* [KNUTH 1981, The Art of Computer Programming */
+      /*    Vol. 2 (2nd Ed.), pp102]                  */
+      
+      if (seed == 0) /* This would make the PRNG procude only zeros */
+	seed = 0x6b842128; /* Just set it to another number */
+      
+      rand->mt[0]= seed;
+      for (rand->mti=1; rand->mti<N; rand->mti++)
+	rand->mt[rand->mti] = (69069 * rand->mt[rand->mti-1]);
+      
+      break;
+    case 22:
+      /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
+      /* In the previous version (see above), MSBs of the    */
+      /* seed affect only MSBs of the array mt[].            */
+      
+      rand->mt[0]= seed;
+      for (rand->mti=1; rand->mti<N; rand->mti++)
+	rand->mt[rand->mti] = 1812433253UL * 
+	  (rand->mt[rand->mti-1] ^ (rand->mt[rand->mti-1] >> 30)) + rand->mti; 
+      break;
+    default:
+      g_assert_not_reached ();
+    }
+}
+
+/**
+ * g_rand_set_seed_array:
+ * @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.
+ *
+ * Since: 2.4
+ **/
+EXPORT_C void
+g_rand_set_seed_array (GRand* rand, const guint32 *seed, guint seed_length)
+{
+  int i, j, k;
+
+  g_return_if_fail (rand != NULL);
+  g_return_if_fail (seed_length >= 1);
+
+  g_rand_set_seed (rand, 19650218UL);
+
+  i=1; j=0;
+  k = (N>seed_length ? N : seed_length);
+  for (; k; k--)
+    {
+      rand->mt[i] = (rand->mt[i] ^
+		     ((rand->mt[i-1] ^ (rand->mt[i-1] >> 30)) * 1664525UL))
+	      + seed[j] + j; /* non linear */
+      rand->mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
+      i++; j++;
+      if (i>=N)
+        {
+	  rand->mt[0] = rand->mt[N-1];
+	  i=1;
+	}
+      if (j>=seed_length)
+	j=0;
+    }
+  for (k=N-1; k; k--)
+    {
+      rand->mt[i] = (rand->mt[i] ^
+		     ((rand->mt[i-1] ^ (rand->mt[i-1] >> 30)) * 1566083941UL))
+	      - i; /* non linear */
+      rand->mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
+      i++;
+      if (i>=N)
+        {
+	  rand->mt[0] = rand->mt[N-1];
+	  i=1;
+	}
+    }
+
+  rand->mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ 
+}
+
+/**
+ * g_rand_int:
+ * @rand_: a #GRand.
+ *
+ * Returns the next random #guint32 from @rand_ equally distributed over
+ * the range [0..2^32-1].
+ *
+ * Return value: A random number.
+ **/
+EXPORT_C guint32
+g_rand_int (GRand* rand)
+{
+  guint32 y;
+  static const guint32 mag01[2]={0x0, MATRIX_A};
+  /* mag01[x] = x * MATRIX_A  for x=0,1 */
+
+  g_return_val_if_fail (rand != NULL, 0);
+
+  if (rand->mti >= N) { /* generate N words at one time */
+    int 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++) {
+      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];
+    }
+    y = (rand->mt[N-1]&UPPER_MASK)|(rand->mt[0]&LOWER_MASK);
+    rand->mt[N-1] = rand->mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];
+    
+    rand->mti = 0;
+  }
+  
+  y = rand->mt[rand->mti++];
+  y ^= TEMPERING_SHIFT_U(y);
+  y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
+  y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
+  y ^= TEMPERING_SHIFT_L(y);
+  
+  return y; 
+}
+
+/* transform [0..2^32] -> [0..1] */
+#define G_RAND_DOUBLE_TRANSFORM 2.3283064365386962890625e-10
+
+/**
+ * g_rand_int_range:
+ * @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.
+ **/
+EXPORT_C gint32 
+g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
+{
+  guint32 dist = end - begin;
+  guint32 random;
+
+  g_return_val_if_fail (rand != NULL, begin);
+  g_return_val_if_fail (end > begin, begin);
+
+  switch (get_random_version ())
+    {
+    case 20:
+      if (dist <= 0x10000L) /* 2^16 */
+	{
+	  /* 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
+	   * 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. 
+	   */
+	  
+	  gdouble double_rand = g_rand_int (rand) * 
+	    (G_RAND_DOUBLE_TRANSFORM +
+	     G_RAND_DOUBLE_TRANSFORM * G_RAND_DOUBLE_TRANSFORM);
+	  
+	  random = (gint32) (double_rand * dist);
+	}
+      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 */
+	  random = (gint32) g_rand_double_range (rand, 0, dist);
+	}
+      break;
+    case 22:
+      if (dist == 0)
+	random = 0;
+      else 
+	{
+	  /* maxvalue is set to the predecessor of the greatest
+	   * multiple of dist less or equal 2^32. */
+	  guint32 maxvalue;
+	  if (dist <= 0x80000000u) /* 2^31 */
+	    {
+	      /* maxvalue = 2^32 - 1 - (2^32 % dist) */
+	      guint32 leftover = (0x80000000u % dist) * 2;
+	      if (leftover >= dist) leftover -= dist;
+	      maxvalue = 0xffffffffu - leftover;
+	    }
+	  else
+	    maxvalue = dist - 1;
+	  
+	  do
+	    random = g_rand_int (rand);
+	  while (random > maxvalue);
+	  
+	  random %= dist;
+	}
+      break;
+    default:
+      random = 0;		/* Quiet GCC */
+      g_assert_not_reached ();
+    }      
+ 
+  return begin + random;
+}
+
+/**
+ * g_rand_double:
+ * @rand_: a #GRand.
+ *
+ * Returns the next random #gdouble from @rand_ equally distributed over
+ * the range [0..1).
+ *
+ * Return value: A random number.
+ **/
+EXPORT_C gdouble 
+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 */
+  gdouble retval = g_rand_int (rand) * G_RAND_DOUBLE_TRANSFORM;
+  retval = (retval + g_rand_int (rand)) * G_RAND_DOUBLE_TRANSFORM;
+
+  /* The following might happen due to very bad rounding luck, but
+   * actually this should be more than rare, we just try again then */
+  if (retval >= 1.0) 
+    return g_rand_double (rand);
+
+  return retval;
+}
+
+/**
+ * g_rand_double_range:
+ * @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.
+ **/
+EXPORT_C gdouble 
+g_rand_double_range (GRand* rand, gdouble begin, gdouble end)
+{
+  return g_rand_double (rand) * (end - begin) + begin;
+}
+
+/**
+ * g_random_int:
+ *
+ * Return a random #guint32 equally distributed over the range
+ * [0..2^32-1].
+ *
+ * Return value: A random number.
+ **/
+EXPORT_C guint32
+g_random_int (void)
+{
+  guint32 result;
+
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_LOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  if (!global_random)
+    global_random = g_rand_new ();
+  
+  result = g_rand_int (global_random);
+
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_UNLOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  return result;
+}
+
+/**
+ * g_random_int_range:
+ * @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.
+ **/
+EXPORT_C gint32 
+g_random_int_range (gint32 begin, gint32 end)
+{
+  gint32 result;
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_LOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  if (!global_random)
+    global_random = g_rand_new ();
+  
+  result = g_rand_int_range (global_random, begin, end);
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_UNLOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  return result;
+}
+
+/**
+ * g_random_double:
+ *
+ * Returns a random #gdouble equally distributed over the range [0..1).
+ *
+ * Return value: A random number.
+ **/
+EXPORT_C gdouble 
+g_random_double (void)
+{
+  double result;
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_LOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  if (!global_random)
+    global_random = g_rand_new ();
+  
+  result = g_rand_double (global_random);
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_UNLOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  return result;
+}
+
+/**
+ * g_random_double_range:
+ * @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).
+ *
+ * Return value: A random number.
+ **/
+EXPORT_C gdouble 
+g_random_double_range (gdouble begin, gdouble end)
+{
+  double result;
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_LOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  if (!global_random)
+    global_random = g_rand_new ();
+ 
+  result = g_rand_double_range (global_random, begin, end);
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_UNLOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  return result;
+}
+
+/**
+ * g_random_set_seed:
+ * @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.
+ **/
+EXPORT_C void
+g_random_set_seed (guint32 seed)
+{
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_LOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+  if (!global_random)
+    global_random = g_rand_new_with_seed (seed);
+  else
+    g_rand_set_seed (global_random, seed);
+
+  #if EMULATOR
+  #undef global_random
+  #endif /* EMULATOR */
+
+  G_UNLOCK (global_random);
+
+  #if EMULATOR
+  #define global_random (*FUNCTION_NAME(global_random,grand)())
+  #endif /* EMULATOR */
+
+}
+
+
+#define __G_RAND_C__
+#include "galiasdef.c"