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

#ifndef NUM_THREADS
#define NUM_THREADS 20
#endif

static pthread_mutex_t	barrier_mutex;
static pthread_t	tids[NUM_THREADS];
static int		done = 0;

static void *
malloc_thread(void *unused)
{
	void *m;
	int i = 0;

	pthread_mutex_lock(&barrier_mutex);
	pthread_mutex_unlock(&barrier_mutex);
	while (done == 0) {
		m = malloc(16);
		free(m);
		i++;
	}
	return ((void *)i);
}

int
main(int argc, char *argv[])
{

	int i;
	int ret;
	void *count;

	pthread_mutex_init(&barrier_mutex, NULL);
	pthread_mutex_lock(&barrier_mutex);
	for (i = 0; i < NUM_THREADS; i++) {
		ret = pthread_create(&tids[i], NULL, malloc_thread, NULL);
		if (ret != 0) {
			printf("pthread_create returned %d\n", ret);
			exit(1);
		}
	}
	pthread_mutex_unlock(&barrier_mutex);

	sleep (10);

	done = 1;
	for (i = 0; i < NUM_THREADS; i++) {
		ret = pthread_join(tids[i], &count);
		printf("pthread_join thread %d returned %d, count %d\n",
		    i, ret, (int)count);
	}
	return (0);
}