#include <err.h>
#include <pthread.h>
#include <stdio.h>

int
main()
{
	pthread_rwlock_t lck;
	int rv;

	pthread_rwlock_init(&lck, NULL);
	if ((rv = pthread_rwlock_tryrdlock(&lck)) != 0)
		errx(1, "lock 1: %d", rv);
	if ((rv = pthread_rwlock_tryrdlock(&lck)) != 0)
		errx(1, "lock 2: %d", rv);
	printf("success\n");
}