1/*
2 *  Atomic read/write
3 *  Copyright (c) 2001 by Abramo Bagnara <abramo@alsa-project.org>
4 *
5 *   This library is free software; you can redistribute it and/or modify
6 *   it under the terms of the GNU Lesser General Public License as
7 *   published by the Free Software Foundation; either version 2.1 of
8 *   the License, or (at your option) any later version.
9 *
10 *   This program is distributed in the hope that it will be useful,
11 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 *   GNU Lesser General Public License for more details.
14 *
15 *   You should have received a copy of the GNU Lesser General Public
16 *   License along with this library; if not, write to the Free Software
17 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18 *
19 */
20
21#include <stdlib.h>
22#include <time.h>
23#include <sched.h>
24#include "iatomic.h"
25
26void snd_atomic_read_wait(snd_atomic_read_t *t)
27{
28	volatile const snd_atomic_write_t *w = t->write;
29	unsigned int loops = 0;
30	struct timespec ts;
31	while (w->begin != w->end) {
32		if (loops < MAX_SPIN_COUNT) {
33			sched_yield();
34			loops++;
35			continue;
36		}
37		loops = 0;
38		ts.tv_sec = 0;
39		ts.tv_nsec = SPIN_SLEEP_DURATION;
40		nanosleep(&ts, NULL);
41	}
42}
43
44