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/*
PIM for Quagga
Copyright (C) 2008 Everton da Silva Marques
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING; if not, write to the
Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301 USA
$QuaggaId: $Format:%an, %ai, %h$ $
*/
#include "pim_rand.h"
#include "pim_time.h"
/* Quick and dirty random number generator from NUMERICAL RECIPES IN C:
THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5). */
/* BEWARE: '_qseed_' is assigned! */
#define QRANDOM(_qseed_) ((_qseed_) = (((_qseed_) * 1664525L) + 1013904223L))
static long qpim_rand_seed;
void pim_rand_init()
{
qpim_rand_seed = pim_time_monotonic_sec() ^ getpid();
}
long pim_rand()
{
return QRANDOM(qpim_rand_seed);
}
int pim_rand_next(int min, int max)
{
long rand;
assert(min <= max);
/* FIXME better random generator ? */
rand = QRANDOM(qpim_rand_seed);
if (rand < 0)
rand = -rand;
rand = rand % (1 + max - min) + min;
assert(rand >= min);
assert(rand <= max);
return rand;
}
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