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

pthread_barrier_t barrier;

int at_barrier = 0;
void *thread (int p) {
	while (1) {
		printf("Thread %d starting\n", p);
		usleep(1000000 * p);

		at_barrier++;
		printf("Thread %d at barrier (on barrier %d thread(s))\n", p, at_barrier);

		pthread_barrier_wait(&barrier);
		at_barrier--;

		if(!at_barrier)
			printf("---Barrier passed---\n");

		usleep(1000000 * p);
	}
}

int main () {
	pthread_t thr_id;
	pthread_attr_t attr;

	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

	pthread_barrier_init(&barrier, NULL, 5);
	
	pthread_create(&thr_id, &attr, thread, (void *) 1);
	pthread_create(&thr_id, &attr, thread, (void *) 2);
	pthread_create(&thr_id, &attr, thread, (void *) 3);
	pthread_create(&thr_id, &attr, thread, (void *) 4);
	pthread_create(&thr_id, &attr, thread, (void *) 5);
		
	usleep(50000000); //simulation time

	return 0;
}