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

#define NUM_THREADS 3

pthread_barrier_t barrier;

void *thread_func(void *arg) {
    int thread_id = *(int*) arg;

    printf("Thread %d is waiting at the barrier\n", thread_id);
    pthread_barrier_wait(&barrier);
    printf("Thread %d has passed the barrier\n", thread_id);

    return NULL;
}

int main() {
    pthread_t threads[NUM_THREADS];
    int thread_ids[NUM_THREADS];

    pthread_barrier_init(&barrier, NULL, NUM_THREADS);

    for (int i = 0; i < NUM_THREADS; i++) {
        thread_ids[i] = i;
        pthread_create(threads + i, NULL, thread_func, &thread_ids[i]);
    }
    for (int i = 0; i < NUM_THREADS; i++) {
        pthread_join(threads[i], NULL);
    }

    pthread_barrier_destroy(&barrier);

    return 0;
}