Interpret EINTR as G_IO_ERROR_AGAIN.

[platform/upstream/glib.git] / grand.c

diff --git a/grand.c b/grand.c
index 2725d9f..47b9700 100644 (file)
--- a/grand.c
+++ b/grand.c
@@ -22,6 +22,7 @@
  * 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
+ * This code was adapted to glib by Sebastian Wilhelmi <wilhelmi@ira.uka.de>.
  */
 
 /*
@@ -31,6 +32,10 @@
  * GLib at ftp://ftp.gtk.org/pub/gtk/.  
  */
 
+/* 
+ * MT safe
+ */
+
 #include <glib.h>
 #include <math.h>
 #include <stdio.h>
@@ -57,8 +62,6 @@ struct _GRand
 {
   guint32 mt[N]; /* the array for the state vector  */
   guint mti; 
-  gboolean have_next_normal;
-  gdouble next_normal;
 };
 
 GRand*
@@ -70,25 +73,31 @@ g_rand_new_with_seed (guint32 seed)
 }
 
 GRand* 
-g_rand_new ()
+g_rand_new (void)
 {
-  guint32 seed = 0;
+  guint32 seed;
   GTimeVal now;
-  FILE* dev_random = fopen("/dev/random", "rb");
-
-  if (dev_random)
+  static gboolean dev_urandom_exists = TRUE;
+  
+  if (dev_urandom_exists)
     {
-      if (fread (&seed, sizeof (seed), 1, dev_random) != 1)
-       seed = 0;
-      fclose (dev_random);
+      FILE* dev_urandom = fopen("/dev/urandom", "rb");
+      if (dev_urandom)
+       {
+         if (fread (&seed, sizeof (seed), 1, dev_urandom) != 1)
+           seed = 0;
+         else
+           dev_urandom_exists = FALSE;
+         fclose (dev_urandom);
+       }       
+      else
+       dev_urandom_exists = FALSE;
+    }
+  if (!dev_urandom_exists)
+    {  
+      g_get_current_time (&now);
+      seed = now.tv_sec ^ now.tv_usec;
     }
-
-  /* Using /dev/random alone makes the seed computable for the
-     outside. This might pose security problems somewhere. This should
-     yield better values */
-
-  g_get_current_time (&now);
-  seed ^= now.tv_sec ^ now.tv_usec;
 
   return g_rand_new_with_seed (seed);
 }
@@ -96,7 +105,7 @@ g_rand_new ()
 void
 g_rand_free (GRand* rand)
 {
-  g_return_if_fail (rand);
+  g_return_if_fail (rand != NULL);
 
   g_free (rand);
 }
@@ -104,17 +113,19 @@ g_rand_free (GRand* rand)
 void
 g_rand_set_seed (GRand* rand, guint32 seed)
 {
-  g_return_if_fail (rand);
+  g_return_if_fail (rand != NULL);
 
   /* 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 & 0xffffffff;
   for (rand->mti=1; rand->mti<N; rand->mti++)
     rand->mt[rand->mti] = (69069 * rand->mt[rand->mti-1]) & 0xffffffff;
-
-  rand->have_next_normal = FALSE;
 }
 
 guint32
@@ -124,7 +135,7 @@ g_rand_int (GRand* rand)
   static const guint32 mag01[2]={0x0, MATRIX_A};
   /* mag01[x] = x * MATRIX_A  for x=0,1 */
 
-  g_return_val_if_fail (rand, 0);
+  g_return_val_if_fail (rand != NULL, 0);
 
   if (rand->mti >= N) { /* generate N words at one time */
     int kk;
@@ -158,7 +169,7 @@ g_rand_int_range (GRand* rand, gint32 min, gint32 max)
   guint32 dist = max - min;
   guint32 random;
 
-  g_return_val_if_fail (rand, min);
+  g_return_val_if_fail (rand != NULL, min);
   g_return_val_if_fail (max > min, min);
 
   if (dist <= 0x10000L) /* 2^16 */
@@ -218,42 +229,6 @@ g_rand_double_range (GRand* rand, gdouble min, gdouble max)
   return g_rand_int (rand) * ((max - min) * G_RAND_DOUBLE_TRANSFORM)  + min;
 }
 
-
-#if WE_REALLY_WANT_HAVE_MATH_LIB_LINKED
-gdouble
-g_rand_normal (GRand* rand, gdouble mean, gdouble standard_deviation)
-{
-  /* For a description of the used algorithm see Knuth: "The Art of
-     Computer Programming", Vol.2, Second Edition, Page 117: Polar
-     method for normal deviates due to Box, Muller, Marsaglia */
-  gdouble normal;
-  g_return_val_if_fail (rand, 0);
-
-  if (rand->have_next_normal) 
-    {
-      rand->have_next_normal = FALSE;
-      normal = rand->next_normal;
-    }
-  else
-    {
-      gdouble u1;
-      gdouble u2 = g_rand_double_range (rand, -1, 1); 
-      gdouble s, f;
-      do 
-       { 
-         u1 = u2;
-         u2 = g_rand_double_range (rand, -1, 1);
-         s = u1 * u1 + u2 * u2;
-       } while (s >= 1.0);
-      f = sqrt (-2 * log (s) / s);
-      normal = u1 * f;
-      rand->next_normal = u2 * f;
-      rand->have_next_normal = TRUE;
-    }
-  return mean + normal * standard_deviation;
-}
-#endif
-
 guint32
 g_random_int (void)
 {
@@ -306,21 +281,6 @@ g_random_double_range (gdouble min, gdouble max)
   return result;
 }
 
-#if WE_REALLY_WANT_HAVE_MATH_LIB_LINKED
-gdouble
-g_random_normal (gdouble mean, gdouble standard_deviation)
-{
-  double result;
-  G_LOCK (global_random);
-  if (!global_random)
-    global_random = g_rand_new ();
- 
-  result = g_rand_normal (global_random, mean, standard_deviation);
-  G_UNLOCK (global_random);
-  return result;
-}
-#endif
-
 void
 g_random_set_seed (guint32 seed)
 {