2 #define _POSIX_C_SOURCE 200112L
14 #include "sn_random.h"
16 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
17 static unsigned int seed;
18 static int have_init = 0;
20 static int read_dev_random (void *buffer, size_t buffer_size)
25 char *buffer_position;
28 fd = open ("/dev/random", O_RDONLY);
35 buffer_position = (char *) buffer;
36 yet_to_read = buffer_size;
38 while (yet_to_read > 0)
40 status = read (fd, (void *) buffer_position, yet_to_read);
46 fprintf (stderr, "read_dev_random: read failed.\n");
50 buffer_position += status;
51 yet_to_read -= (size_t) status;
59 } /* int read_dev_random */
61 static void do_init (void)
65 status = read_dev_random (&seed, sizeof (seed));
74 pthread_mutex_lock (&lock);
81 pthread_mutex_unlock (&lock);
86 int sn_true_random (void)
91 status = read_dev_random (&ret, sizeof (ret));
93 return (sn_random ());
96 } /* int sn_true_random */
98 int sn_bounded_random (int min, int max)
112 range = 1 + max - min;
113 rand = min + (int) (((double) range)
114 * (((double) sn_random ()) / (((double) RAND_MAX) + 1.0)));
116 assert (rand >= min);
117 assert (rand <= max);
120 } /* int sn_bounded_random */
122 /* vim: set shiftwidth=2 softtabstop=2 : */