#include <err.h>
#include <pthread.h>
#include <pthread_np.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static void *
setselfname(void *arg __unused)
{
        pthread_set_name_np(pthread_self(), __func__);
        pause();
        return NULL;
}

static void *
waitname(void *arg __unused)
{
        pause();
        return NULL;
}

static void *
resetname(void *arg __unused)
{
        pthread_set_name_np(pthread_self(), __func__);
        sleep(10);
        pthread_set_name_np(pthread_self(), NULL);
        pause();
        return NULL;
}

int
main(void)
{
        pthread_t tid1, tid2, tid3;
        char longname[256];
        int error;

        error = pthread_create(&tid1, NULL, setselfname, NULL);
        if (error)
                errc(1, error, "pthread_create(setselfname) failed");

        error = pthread_create(&tid2, NULL, waitname, NULL);
        if (error)
                errc(1, error, "pthread_create(waitname) failed");
        pthread_set_name_np(tid2, "waitname");

        error = pthread_create(&tid3, NULL, resetname, NULL);
        if (error)
                errc(1, error, "pthread_create(resetname) failed");

        memset(longname, 'x', sizeof(longname));
        longname[sizeof(longname) - 1] = '\0';
        pthread_set_name_np(pthread_self(), longname);

        pause();
        exit(0);
}