static char sccsid[] = "@(#)random.c 8.2 (Berkeley) 5/19/95";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/stdlib/random.c,v 1.22 2003/02/04 11:24:08 ache Exp $");
+__FBSDID("$FreeBSD: src/lib/libc/stdlib/random.c,v 1.24 2004/01/20 03:02:18 das Exp $");
#include "namespace.h"
#include <sys/time.h> /* for srandomdev() */
#include <fcntl.h> /* for srandomdev() */
+#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h> /* for srandomdev() */
* congruential generator. If the amount of state information is less than
* 32 bytes, a simple linear congruential R.N.G. is used.
*
- * Internally, the state information is treated as an array of longs; the
+ * Internally, the state information is treated as an array of uint32_t's; the
* zeroeth element of the array is the type of R.N.G. being used (small
* integer); the remainder of the array is the state information for the
- * R.N.G. Thus, 32 bytes of state information will give 7 longs worth of
+ * R.N.G. Thus, 32 bytes of state information will give 7 ints worth of
* state information, which will allow a degree seven polynomial. (Note:
* the zeroeth word of state information also has some other information
* stored in it -- see setstate() for details).
*/
#define MAX_TYPES 5 /* max number of types above */
-#define NSHUFF 100 /* to drop part of seed -> 1st value correlation */
+#ifdef USE_WEAK_SEEDING
+#define NSHUFF 0
+#else /* !USE_WEAK_SEEDING */
+#define NSHUFF 50 /* to drop some "seed -> 1st value" linearity */
+#endif /* !USE_WEAK_SEEDING */
-static long degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 };
-static long seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 };
+static const int degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 };
+static const int seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 };
/*
* Initially, everything is set up as if from:
* MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3.
*/
-static long randtbl[DEG_3 + 1] = {
+static uint32_t randtbl[DEG_3 + 1] = {
TYPE_3,
#ifdef USE_WEAK_SEEDING
/* Historic implementation compatibility */
* in the initialization of randtbl) because the state table pointer is set
* to point to randtbl[1] (as explained below).
*/
-static long *fptr = &randtbl[SEP_3 + 1];
-static long *rptr = &randtbl[1];
+static uint32_t *fptr = &randtbl[SEP_3 + 1];
+static uint32_t *rptr = &randtbl[1];
/*
* The following things are the pointer to the state information table, the
* this is more efficient than indexing every time to find the address of
* the last element to see if the front and rear pointers have wrapped.
*/
-static long *state = &randtbl[1];
-static long rand_type = TYPE_3;
-static long rand_deg = DEG_3;
-static long rand_sep = SEP_3;
-static long *end_ptr = &randtbl[DEG_3 + 1];
+static uint32_t *state = &randtbl[1];
+static int rand_type = TYPE_3;
+static int rand_deg = DEG_3;
+static int rand_sep = SEP_3;
+static uint32_t *end_ptr = &randtbl[DEG_3 + 1];
-static inline long good_rand(long);
+static inline uint32_t good_rand(int32_t);
-static inline long good_rand (x)
- long x;
+static inline uint32_t good_rand (x)
+ int32_t x;
{
#ifdef USE_WEAK_SEEDING
/*
* Park and Miller, Communications of the ACM, vol. 31, no. 10,
* October 1988, p. 1195.
*/
- long hi, lo;
+ int32_t hi, lo;
/* Can't be initialized with 0, so use another value. */
if (x == 0)
srandom(x)
unsigned long x;
{
- long i, lim;
+ int i, lim;
- state[0] = x;
+ state[0] = (uint32_t)x;
if (rand_type == TYPE_0)
lim = NSHUFF;
else {
*
* Returns a pointer to the old state.
*
- * Note: The Sparc platform requires that arg_state begin on a long
+ * Note: The Sparc platform requires that arg_state begin on an int
* word boundary; otherwise a bus error will occur. Even so, lint will
* complain about mis-alignment, but you should disregard these messages.
*/
long n; /* # bytes of state info */
{
char *ostate = (char *)(&state[-1]);
- long *long_arg_state = (long *) arg_state;
+ uint32_t *int_arg_state = (uint32_t *)arg_state;
if (rand_type == TYPE_0)
state[-1] = rand_type;
rand_deg = DEG_4;
rand_sep = SEP_4;
}
- state = (long *) (long_arg_state + 1); /* first location */
+ state = int_arg_state + 1; /* first location */
end_ptr = &state[rand_deg]; /* must set end_ptr before srandom */
srandom(seed);
if (rand_type == TYPE_0)
- long_arg_state[0] = rand_type;
+ int_arg_state[0] = rand_type;
else
- long_arg_state[0] = MAX_TYPES * (rptr - state) + rand_type;
+ int_arg_state[0] = MAX_TYPES * (rptr - state) + rand_type;
return(ostate);
}
*
* Returns a pointer to the old state information.
*
- * Note: The Sparc platform requires that arg_state begin on a long
+ * Note: The Sparc platform requires that arg_state begin on an int
* word boundary; otherwise a bus error will occur. Even so, lint will
* complain about mis-alignment, but you should disregard these messages.
*/
setstate(arg_state)
char *arg_state; /* pointer to state array */
{
- long *new_state = (long *) arg_state;
- long type = new_state[0] % MAX_TYPES;
- long rear = new_state[0] / MAX_TYPES;
+ uint32_t *new_state = (uint32_t *)arg_state;
+ uint32_t type = new_state[0] % MAX_TYPES;
+ uint32_t rear = new_state[0] / MAX_TYPES;
char *ostate = (char *)(&state[-1]);
if (rand_type == TYPE_0)
(void)fprintf(stderr,
"random: state info corrupted; not changed.\n");
}
- state = (long *) (new_state + 1);
+ state = new_state + 1;
if (rand_type != TYPE_0) {
rptr = &state[rear];
fptr = &state[(rear + rand_sep) % rand_deg];
long
random()
{
- long i;
- long *f, *r;
+ uint32_t i;
+ uint32_t *f, *r;
if (rand_type == TYPE_0) {
i = state[0];
fptr = f; rptr = r;
}
- return(i);
+ return((long)i);
}
projects / apple / libc.git / blobdiff