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Diffstat (limited to 'lib/libc/stdlib/rand.c')
| -rw-r--r-- | lib/libc/stdlib/rand.c | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/lib/libc/stdlib/rand.c b/lib/libc/stdlib/rand.c deleted file mode 100644 index 077c1ba..0000000 --- a/lib/libc/stdlib/rand.c +++ /dev/null @@ -1,168 +0,0 @@ -/*- - * Copyright (c) 1990, 1993 - * The Regents of the University of California. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * 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. - * - * Posix rand_r function added May 1999 by Wes Peters <wes@softweyr.com>. - */ - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)rand.c 8.1 (Berkeley) 6/14/93"; -#endif /* LIBC_SCCS and not lint */ -#include <sys/cdefs.h> -__FBSDID("$FreeBSD$"); - -#include "namespace.h" -#include <sys/time.h> /* for sranddev() */ -#include <sys/types.h> -#include <fcntl.h> /* for sranddev() */ -#include <stdlib.h> -#include <unistd.h> /* for sranddev() */ -#include "un-namespace.h" - -#ifdef TEST -#include <stdio.h> -#endif /* TEST */ - -static int -do_rand(unsigned long *ctx) -{ -#ifdef USE_WEAK_SEEDING -/* - * Historic implementation compatibility. - * The random sequences do not vary much with the seed, - * even with overflowing. - */ - return ((*ctx = *ctx * 1103515245 + 12345) % ((u_long)RAND_MAX + 1)); -#else /* !USE_WEAK_SEEDING */ -/* - * Compute x = (7^5 * x) mod (2^31 - 1) - * without overflowing 31 bits: - * (2^31 - 1) = 127773 * (7^5) + 2836 - * From "Random number generators: good ones are hard to find", - * Park and Miller, Communications of the ACM, vol. 31, no. 10, - * October 1988, p. 1195. - */ - long hi, lo, x; - - /* Can't be initialized with 0, so use another value. */ - if (*ctx == 0) - *ctx = 123459876; - hi = *ctx / 127773; - lo = *ctx % 127773; - x = 16807 * lo - 2836 * hi; - if (x < 0) - x += 0x7fffffff; - return ((*ctx = x) % ((u_long)RAND_MAX + 1)); -#endif /* !USE_WEAK_SEEDING */ -} - - -int -rand_r(unsigned int *ctx) -{ - u_long val = (u_long) *ctx; - int r = do_rand(&val); - - *ctx = (unsigned int) val; - return (r); -} - - -static u_long next = 1; - -int -rand() -{ - return (do_rand(&next)); -} - -void -srand(seed) -u_int seed; -{ - next = seed; -} - - -/* - * sranddev: - * - * Many programs choose the seed value in a totally predictable manner. - * This often causes problems. We seed the generator using the much more - * secure random(4) interface. - */ -void -sranddev() -{ - int fd, done; - - done = 0; - fd = _open("/dev/random", O_RDONLY, 0); - if (fd >= 0) { - if (_read(fd, (void *) &next, sizeof(next)) == sizeof(next)) - done = 1; - _close(fd); - } - - if (!done) { - struct timeval tv; - unsigned long junk; - - gettimeofday(&tv, NULL); - srand((getpid() << 16) ^ tv.tv_sec ^ tv.tv_usec ^ junk); - } -} - - -#ifdef TEST - -main() -{ - int i; - unsigned myseed; - - printf("seeding rand with 0x19610910: \n"); - srand(0x19610910); - - printf("generating three pseudo-random numbers:\n"); - for (i = 0; i < 3; i++) - { - printf("next random number = %d\n", rand()); - } - - printf("generating the same sequence with rand_r:\n"); - myseed = 0x19610910; - for (i = 0; i < 3; i++) - { - printf("next random number = %d\n", rand_r(&myseed)); - } - - return 0; -} - -#endif /* TEST */ - |
