diff options
Diffstat (limited to 'random.c')
| -rw-r--r-- | random.c | 155 |
1 files changed, 75 insertions, 80 deletions
@@ -29,45 +29,43 @@ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. - * - * $FreeBSD: src/lib/libc/stdlib/random.c,v 1.13 2000/01/27 23:06:49 jasone Exp $ - * */ #if defined(LIBC_SCCS) && !defined(lint) static const char sccsid[] = "@(#)random.c 8.2 (Berkeley) 5/19/95"; #endif /* LIBC_SCCS and not lint */ -#include "random.h" /* gawk addition */ - -/* - * srandomdev() isn't used by gawk, and it causes numerous - * compile headaches, so just blow it away. - */ -#if 0 -#if !defined (_MSC_VER) && !defined (__MINGW32__) && !defined (VMS) -#include <sys/time.h> /* for srandomdev() */ -#else -#include <time.h> /* for clock() */ -#define ssize_t size_t -#endif /* !defined (_MSC_VER) && !defined (__MINGW32__) && !defined (VMS) */ +#ifdef HAVE_CONFIG_H /* gawk addition */ +#include <config.h> #endif +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif #include <stdio.h> - -/* For gawk, don't this, use the decl of random() in random.h */ -#if 0 #include <stdlib.h> +#ifdef HAVE_UNISTD_H +#include <unistd.h> #endif -/* same thing here: */ -#if 0 -#ifdef HAVE_UNISTD_H -#include <unistd.h> /* for srandomdev() */ +#include "random.h" /* gawk addition */ + +#ifdef HAVE_SYS_TIME_H /* gawk addition */ +#include <sys/time.h> #endif -#ifdef HAVE_FCNTL_H + +#if 0 +#include <sys/cdefs.h> +__FBSDID("$FreeBSD: /repoman/r/ncvs/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() */ -#endif +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> /* for srandomdev() */ +#include "un-namespace.h" #endif /* @@ -86,10 +84,10 @@ static const char sccsid[] = "@(#)random.c 8.2 (Berkeley) 5/19/95"; * 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). @@ -105,7 +103,7 @@ static const char sccsid[] = "@(#)random.c 8.2 (Berkeley) 5/19/95"; * period of the generator is approximately deg*(2**deg - 1); thus doubling * the amount of state information has a vast influence on the period of the * generator. Note: the deg*(2**deg - 1) is an approximation only good for - * large deg, when the period of the shift register is the dominant factor. + * large deg, when the period of the shift is the dominant factor. * With deg equal to seven, the period is actually much longer than the * 7*(2**7 - 1) predicted by this formula. * @@ -167,8 +165,14 @@ static const char sccsid[] = "@(#)random.c 8.2 (Berkeley) 5/19/95"; */ #define MAX_TYPES 5 /* max number of types above */ -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 }; +#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 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: @@ -184,7 +188,7 @@ static long seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 }; * 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 */ @@ -219,8 +223,8 @@ static long randtbl[DEG_3 + 1] = { * 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 @@ -232,16 +236,16 @@ static long *rptr = &randtbl[1]; * 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 long good_rand __P((long)); +static inline uint32_t good_rand(int32_t); -static long good_rand (x) - register long x; +static inline uint32_t good_rand (x) + int32_t x; { #ifdef USE_WEAK_SEEDING /* @@ -259,12 +263,15 @@ static long good_rand (x) * Park and Miller, Communications of the ACM, vol. 31, no. 10, * October 1988, p. 1195. */ - register long hi, lo; + int32_t hi, lo; + /* Can't be initialized with 0, so use another value. */ + if (x == 0) + x = 123459876; hi = x / 127773; lo = x % 127773; x = 16807 * lo - 2836 * hi; - if (x <= 0) + if (x < 0) x += 0x7fffffff; return (x); #endif /* !USE_WEAK_SEEDING */ @@ -286,33 +293,34 @@ void srandom(x) unsigned long x; { - register long i; + int i, lim; + state[0] = (uint32_t)x; if (rand_type == TYPE_0) - state[0] = x; + lim = NSHUFF; else { - state[0] = x; for (i = 1; i < rand_deg; i++) state[i] = good_rand(state[i - 1]); fptr = &state[rand_sep]; rptr = &state[0]; - for (i = 0; i < 10 * rand_deg; i++) - (void)random(); + lim = 10 * rand_deg; } + for (i = 0; i < lim; i++) + (void)random(); } +#if 0 /* gawk doesn't use this */ /* * srandomdev: * * Many programs choose the seed value in a totally predictable manner. * This often causes problems. We seed the generator using the much more - * secure urandom(4) interface. Note that this particular seeding + * secure random(4) interface. Note that this particular seeding * procedure can generate states which are impossible to reproduce by * calling srandom() with any value, since the succeeding terms in the * state buffer are no longer derived from the LC algorithm applied to * a fixed seed. */ -#if 0 void srandomdev() { @@ -325,32 +333,19 @@ srandomdev() len = rand_deg * sizeof state[0]; done = 0; -#ifdef O_RDONLY - fd = open("/dev/urandom", O_RDONLY, 0); + fd = open("/dev/random", O_RDONLY, 0); if (fd >= 0) { if (read(fd, (void *) state, len) == (ssize_t) len) done = 1; close(fd); } -#endif /*O_RDONLY*/ if (!done) { - unsigned long junk; -#if !defined (_MSC_VER) && !defined (__MINGW32__) struct timeval tv; + unsigned long junk; gettimeofday(&tv, NULL); - srandom(getpid() ^ tv.tv_sec ^ tv.tv_usec ^ junk); -#else - clock_t ret_clock_t = clock(); - /* - * I don't like the idea of reading uninitialized memory - * even to generate a random number, but we do it anyway. - * SD. - */ - srandom(getpid() ^ ret_clock_t ^ junk); -#endif - + srandom((getpid() << 16) ^ tv.tv_sec ^ tv.tv_usec ^ junk); return; } @@ -380,7 +375,7 @@ srandomdev() * * 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. */ @@ -390,8 +385,8 @@ initstate(seed, arg_state, n) char *arg_state; /* pointer to state array */ long n; /* # bytes of state info */ { - register char *ostate = (char *)(&state[-1]); - register long *long_arg_state = (long *) arg_state; + char *ostate = (char *)(&state[-1]); + uint32_t *int_arg_state = (uint32_t *)arg_state; if (rand_type == TYPE_0) state[-1] = rand_type; @@ -423,13 +418,13 @@ initstate(seed, arg_state, n) 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); } @@ -448,7 +443,7 @@ initstate(seed, arg_state, n) * * 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. */ @@ -456,9 +451,9 @@ char * setstate(arg_state) char *arg_state; /* pointer to state array */ { - register long *new_state = (long *) arg_state; - register long type = new_state[0] % MAX_TYPES; - register 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) @@ -479,7 +474,7 @@ setstate(arg_state) (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]; @@ -508,8 +503,8 @@ setstate(arg_state) long random() { - register long i; - register long *f, *r; + uint32_t i; + uint32_t *f, *r; if (rand_type == TYPE_0) { i = state[0]; @@ -531,5 +526,5 @@ random() fptr = f; rptr = r; } - return(i); + return((long)i); } |