#include <pthread.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>



pthread_barrier_t bar;



void *f() {

    printf("Starting\n");

    pthread_barrier_wait(&bar);

    usleep(10);

    printf("Stopping\n");

    return NULL;

}



int main(){

    // create 100 threads

    int n = 100;

    pthread_t th[n];

    // the barrier opens after 50 threads and then resets

    // change this number and see what happens

    // if the count set for the barrier divides the number of threads, the program should terminate, otherwise, it will hang

    pthread_barrier_init(&bar, NULL, 50);

    for(int i = 0; i < n; i++) {

        pthread_create(&th[i], NULL, f, NULL);

    }



    for(int i = 0; i < n; i++) {

        pthread_join(th[i], NULL);

    }

    pthread_barrier_destroy(&bar);

    return 0;

}