#include <stdio.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <stdlib.h>
#include "pvm3.h"
#define SELF "sspmd"
#define TIDTAG 17
#define TOKTAG 13

void pvm_bail(){ pvm_exit(); exit(EXIT_FAILURE); }

#define  PVM_ERROR_CHECK(X, Y) \
{ int _err_rtn_;\
  if((_err_rtn_ = X) < 0){\
    fprintf(stderr, "PVM error code %d: %s failed -- aborting\n", _err_rtn_, #X);\
    (Y);  } }

int main(void){
  int mytid, me, daddy, numt, i; 
  int  nproc =  100, nchild = nproc - 1, tids[nproc];      
  long start_time = time(NULL);
  PVM_ERROR_CHECK((mytid = pvm_mytid()), pvm_bail());
  daddy = pvm_parent();
  if(daddy  ==  PvmNoParent){
    /* parent code */
    me = 0;
    tids[0] = mytid;
    printf("i'm daddy with tid %d\n", tids[0]);
    printf("spawning at t = %ld\n", time(NULL) - start_time);
    numt = pvm_spawn(SELF, NULL, 0, "", nchild, &tids[1]);
    if(numt < nchild){
      printf("Aborting. Error codes are:\n");
      for(i = numt ; i < nchild ; i++) {
        printf("TID %d %d\n", i, tids[i]);
      }
      for(i = 1; i < numt; i++){
        pvm_kill(tids[i]);
      }
      pvm_exit();
      exit(EXIT_FAILURE);
    }
    PVM_ERROR_CHECK(pvm_initsend(PvmDataDefault), pvm_bail());
    PVM_ERROR_CHECK(pvm_pkint(&nproc, 1, 1), pvm_bail());
    PVM_ERROR_CHECK(pvm_pkint(tids, nproc, 1), pvm_bail());
    PVM_ERROR_CHECK(pvm_pklong(&start_time, 1, 1), pvm_bail());
    PVM_ERROR_CHECK(pvm_mcast(&tids[1], nchild, TIDTAG), pvm_bail());  }
  else {
    /* child code */
    PVM_ERROR_CHECK(pvm_recv(daddy, TIDTAG), pvm_bail());
    PVM_ERROR_CHECK(pvm_upkint(&nproc, 1, 1), pvm_bail());
    PVM_ERROR_CHECK(pvm_upkint(tids, nproc, 1), pvm_bail());
    PVM_ERROR_CHECK(pvm_upklong(&start_time, 1, 1), pvm_bail());
    /* Determine which slave I am (1 -- nproc-1) */
    for(i = 1; i < nproc ; i++)
      if(mytid == tids[i]){ me = i; break; }
    printf("i'm child %d with tid %d at time = %ld\n", 
           i, 
           tids[i],
           time(NULL) - start_time);
  }
  
  /* ring code */
  {
    int token = 58;
    int dst = (me == (nproc - 1)) ? 0 : me + 1;
    int src = (me == 0) ? (nproc - 1) : me - 1;
    
    if(me == 0){ 
      PVM_ERROR_CHECK(pvm_initsend(PvmDataDefault), pvm_bail());
      printf("sending token around the ring at time = %ld\n",  
             time(NULL) - start_time);
      PVM_ERROR_CHECK(pvm_pkint(&token, 1, 1), pvm_bail());
      PVM_ERROR_CHECK(pvm_send(tids[dst], TOKTAG), pvm_bail());
      PVM_ERROR_CHECK(pvm_recv(tids[src], TOKTAG), pvm_bail());
      printf("token arrived back safely at time = %ld\n",  
             time(NULL) - start_time); }
    else {
      PVM_ERROR_CHECK(pvm_recv(tids[src], TOKTAG), pvm_bail());
      PVM_ERROR_CHECK(pvm_upkint(&token, 1, 1), pvm_bail());
      printf("i'm child %d and i got token %d at time = %ld\n", 
             i, 
             token,
             time(NULL) - start_time);
      //      sleep(1);
      PVM_ERROR_CHECK(pvm_initsend(PvmDataDefault), pvm_bail());
      PVM_ERROR_CHECK(pvm_pkint(&token, 1, 1), pvm_bail());
      PVM_ERROR_CHECK(pvm_send(tids[dst],TOKTAG), pvm_bail()); 
    }
    pvm_exit();
    exit(EXIT_SUCCESS);
  }
}