static void unlock_mutex(pthread_mutex_t *l)
{
	int ret;

	if ((ret = pthread_mutex_unlock(l)) != 0) {
		fprintf(stderr, "pthread_mutex_unlock returned:%d %s\n", ret, strerror(ret));
		exit(1);
	}
}
static void unlock_mutex(pthread_mutex_t *l)
{
	int ret;

	if ((ret = pthread_mutex_unlock(l)) != 0) {
		fprintf(stderr, "pthread_mutex_unlock returned:%d %s\n", ret, strerror(ret));
		exit(1);
	}
}