aboutsummaryrefslogtreecommitdiffstats
path: root/tools/lib/lockdep/tests/ABBA_2threads.c
blob: 39325ef8a2ac176f9ebbbc7aaa6e799de171f8c1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <pthread.h>

pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t b = PTHREAD_MUTEX_INITIALIZER;
pthread_barrier_t bar;

void *ba_lock(void *arg)
{
	int ret, i;

	pthread_mutex_lock(&b);

	if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
		pthread_barrier_destroy(&bar);

	pthread_mutex_lock(&a);

	pthread_mutex_unlock(&a);
	pthread_mutex_unlock(&b);
}

int main(void)
{
	pthread_t t;

	pthread_barrier_init(&bar, NULL, 2);

	if (pthread_create(&t, NULL, ba_lock, NULL)) {
		fprintf(stderr, "pthread_create() failed\n");
		return 1;
	}
	pthread_mutex_lock(&a);

	if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
		pthread_barrier_destroy(&bar);

	pthread_mutex_lock(&b);

	pthread_mutex_unlock(&b);
	pthread_mutex_unlock(&a);

	pthread_join(t, NULL);

	return 0;
}