net: fix race condition in several drivers when reading stats
[linux-2.6/btrfs-unstable.git] / net / batman-adv / ring_buffer.c
blobc8f61e395b74864de3ef5c7944074358eda1706c
1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
3 * Marek Lindner
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA
20 #include "main.h"
21 #include "ring_buffer.h"
23 void batadv_ring_buffer_set(uint8_t lq_recv[], uint8_t *lq_index,
24 uint8_t value)
26 lq_recv[*lq_index] = value;
27 *lq_index = (*lq_index + 1) % BATADV_TQ_GLOBAL_WINDOW_SIZE;
30 uint8_t batadv_ring_buffer_avg(const uint8_t lq_recv[])
32 const uint8_t *ptr;
33 uint16_t count = 0, i = 0, sum = 0;
35 ptr = lq_recv;
37 while (i < BATADV_TQ_GLOBAL_WINDOW_SIZE) {
38 if (*ptr != 0) {
39 count++;
40 sum += *ptr;
43 i++;
44 ptr++;
47 if (count == 0)
48 return 0;
50 return (uint8_t)(sum / count);