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authorDavid Lamparter <equinox@diac24.net>2010-02-04 03:41:06 +0100
committerDavid Lamparter <equinox@diac24.net>2010-02-04 03:41:06 +0100
commit447a9a8dbde95fc6ce92691491ac193f0199e2cd (patch)
tree4bfce47ead136e60cc91df50c3e79e75ddd4c83d /pimd/pim_rand.c
parent08e2c2ee9044a14f2cd9d382eec8f96189520160 (diff)
parent168595ff42c4046167b0fbae2770c037c854abd0 (diff)
downloadquagga-447a9a8dbde95fc6ce92691491ac193f0199e2cd.tar.bz2
quagga-447a9a8dbde95fc6ce92691491ac193f0199e2cd.tar.xz
Merge branch 'merged/pimd' into dn42
Conflicts: lib/route_types.txt
Diffstat (limited to 'pimd/pim_rand.c')
-rw-r--r--pimd/pim_rand.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/pimd/pim_rand.c b/pimd/pim_rand.c
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+++ b/pimd/pim_rand.c
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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;
+}