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

pthread_cond_t cond;
pthread_mutex_t mutex;

#define NTHREAD 23

void *
worker(void *arg) {
	int *i = arg;
	*i = 0;
	pthread_mutex_lock(&mutex);
	for (;;) {
		pthread_cond_wait(&cond, &mutex);
		(*i)++;
	}
}

int
main(int argc, char *argv[])
{
	pthread_t t[NTHREAD];
	int v[NTHREAD];
	pthread_mutex_init(&mutex, NULL);
	pthread_cond_init(&cond, NULL);

	for (size_t i = 0; i < NTHREAD; i++)
		pthread_create(&t[i], NULL, worker, &v[i]);
	for (size_t i = 0;; i++) {
		pthread_cond_signal(&cond);
		if (i % 1000 == 0) {
			for (size_t k = 0; k < NTHREAD; k++)
				printf("%zu: %d\n", k, v[k]);
		}
	}
	for (size_t i = 0; i < NTHREAD; i++) {
		void *v;
		pthread_join(t[i], &v);
	}
	return 0;
}