/*
 * CS170: 
 * print4.c -- forks off THREADS threads that print their ids
 */

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

#define THREADS 4

int Ego()
{
	int return_val;

	return_val = (int)pthread_self();

	return(return_val);
}

void *printme(void *arg)
{
	printf("Hi.  I'm thread %d\n", Ego());
	return NULL;
}

int
main()
{
	int i;
	int *vals;
	pthread_t *tid_array;
	void *retval;
	int err;

	vals = (int *)malloc(THREADS*sizeof(int));
	if(vals == NULL)
	{
		exit(1);
	}

	tid_array = (pthread_t *)malloc(THREADS*sizeof(pthread_t));
	if(tid_array == NULL)
	{
		exit(1);
	}

	for (i = 0; i < THREADS; i++) 
	{
		err = pthread_create(&(tid_array[i]),
				     NULL,
				     printme,
				     NULL);

		if(err != 0)
		{
			fprintf(stderr,"thread %d ",i);
			perror("on create");
			exit(1);
		}
			
    	}

	printf("main thread -- ");
  	printme(NULL);	/* main thread */


	for (i = 0; i < THREADS; i++) 
	{

		printf("I'm %d Trying to join with thread %d\n", 
			Ego(),(int)tid_array[i]);
    		pthread_join(tid_array[i], &retval);
    		printf("%d Joined with thread %d\n", 
			Ego(),(int)tid_array[i]);
  	}

	free(tid_array);

	return(0);
}