/* gcc -o mkthreads mkthreads.c -lpthread -lm */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <pthread.h>

int n;
int barrier=1;

#if 0
void *thread_fn(void *arg)
{
	int i = (int) arg;
	int j = 0;
	int k;

	printf("%d starting\n", i);


	for (k=0; k<100000000 ; k++) {
		usleep(1);
		for (j=0;j<1000000000;j++)
			i += j+j-2*j;
	}
	printf("%d ending %d\n", j);	
}
#endif

void *slow_exit(void *arg)
{
	int i = (int) arg;
//	printf("%d starting\n", i);
	usleep((n-i)*2);
//	while (barrier)
//		usleep(500);
//	printf("%d ending\n", i);	
}

int main(int argc, char *argv[])
{
	int i,rc, rep;
	pthread_t *ppthread;
	
	n = 5 ;
	if (argc > 1)
		n = atoi(argv[1]);

	rep = 10;
	if (argc > 2)
		rep = atoi(argv[2]);

	ppthread = malloc(n * sizeof(pthread_t));
	if (ppthread == NULL) {
		printf("Memory allocation failure\n");
		exit(-1);
	}

	while (rep) {
//		printf("%d Create threads\n", rep);
		for (i=0; i<n; i++) {
			rc = pthread_create(&ppthread[i], NULL, 
					    slow_exit, (void *)i);
			if (rc) {
				printf("Error creating thread %d\n", i);
				exit(-1);
			}
		}
//		printf("%d Join threads\n", rep);
		for (i=0; i<n; i++) {
			rc = pthread_join(ppthread[i], NULL);
			if (rc) {
				printf("Error joining thread %d\n", i);
				exit(-1);
			}
		}
		rep--;
	}
//	printf("Done.\n");
}