share.c

/*  DSM Assignment: Shared memory test
 *
 *  Author : Manuel M T Chakravarty
 *  Created: 25 March 2000
 *
 *  Version $Revision: 1.4 $ from $Date: 2003/03/30 14:31:21 $
 *
 *  Copyright (c) 2000 MMT Chakravarty & University of New South Wales
 *
 *  DESCRIPTION ---------------------------------------------------------------
 *
 *  Test shared use of memory
 *
 *  DOCU ----------------------------------------------------------------------
 *
 *  language: ANSI C
 *
 *  TODO ----------------------------------------------------------------------
 *
 */

#include <stdio.h>
#include "sm.h"


void fatal (int nid, char *msg)
{
  printf ("node %d: Fatal internal error:\n%s\n", nid, msg);
  exit (1);
}

int main (int argc, char *argv[])
{
  int   nodes, nid;
  char *sharedChar, *sharedChar2;

  if (sm_node_init (&argc, &argv, &nodes, &nid))
    fatal (nid, "share: Cannot initialise!");

  /* first, node #0 allocates a shared variable and uses it to communicate
   * the letter `A' to node #1
   */
  if (0 == nid) {
    sharedChar = (char *) sm_malloc (sizeof (char));
    *sharedChar = 'A';
  }
  sm_bcast ((void **) &sharedChar, 0);
  /* Checkpoint A */
  printf ("node %d: 1st shared variable is at %p.\n", nid, sharedChar);
  if (0 != nid)
    printf ("node %d: Value in 1st shared variable is %d\n", 
      nid, *sharedChar);
  /* Checkpoint B */
  sm_barrier ();

  /* next, node #1 allocates a shared variable and uses it to allow node #0
   * to communicate the letter `B' to it
   */
  if (1 == nid)
    sharedChar2 = (char *) sm_malloc (sizeof (char));
  sm_bcast ((void **) &sharedChar2, 1);
  /* Checkpoint C */
  if (0 == nid)
    *sharedChar2 = 'B';
  /* Checkpoint D */
  sm_barrier ();  /* make sure node #0 wrote the character */
  if (0 != nid)
    printf ("node %d: Value in 2nd shared variable is %d\n", 
      nid, *sharedChar2);
  /* Checkpoint E */

  sm_barrier ();

  sm_node_exit ();
  return 0;
}