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/*
* Copyright (C) 1999-2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: random.c,v 1.15 2001/01/09 21:56:22 bwelling Exp $ */
#include <config.h>
#include <stdlib.h>
#include <time.h> /* Required for time(). */
#include <isc/mutex.h>
#include <isc/once.h>
#include <isc/random.h>
#include <isc/string.h>
#include <isc/util.h>
static isc_once_t once = ISC_ONCE_INIT;
static void
initialize_rand(void)
{
srand(time(NULL));
}
static void
initialize(void)
{
RUNTIME_CHECK(isc_once_do(&once, initialize_rand) == ISC_R_SUCCESS);
}
void
isc_random_seed(isc_uint32_t seed)
{
initialize();
srand(seed);
}
void
isc_random_get(isc_uint32_t *val)
{
REQUIRE(val != NULL);
initialize();
*val = rand();
}
isc_uint32_t
isc_random_jitter(isc_uint32_t max, isc_uint32_t jitter) {
REQUIRE(jitter < max);
if (jitter == 0)
return (max);
else
return (max - rand() % jitter);
}
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