/*  "q1_master.txt" 
 *Question #1, Master/Slave to add up N numbers (integers only)
 *  (i think there's a bug if you enter a '1' for num items, hangs)
 *  master sends tids to all, and receives sum result from the 
 *  Nth slave (only one recv in the master process).
 *
 * tjn  3:54 PM 3/2/00
 *
 *     MASTER
 */
#include <stdio.h>
#include <pvm3.h>
#define  MAX 100

int main()
{
     int i,mytid,tids[MAX], n, ttl;
     ttl=n=0;

     printf("Enter number of items (<=20): ");
     scanf("%d", &n);
     
     mytid = pvm_mytid();
     if( pvm_spawn("slave", (char **)0, 0, "", n, tids) == n)
     {
          pvm_initsend(PvmDataDefault);
          pvm_pkint(&n, 1, 1);
          pvm_pkint(tids, n, 1);
          pvm_mcast(tids, n, 1);
          
          /* just to be careful we'll specify the N'th one */
          pvm_recv(tids[(n-1)], 1);		
          pvm_upkint(&ttl, 1, 1);

          printf("The sum of the numbers is: %d\n", ttl);
     }
     else
          fprintf(stderr, "ERROR: unable to spawn %d slaves\n", n);


     pvm_exit();
     return 0;
}