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Subject: [OMPI users] Did you break MPI_Abort recently?
From: Mostyn Lewis (Mostyn.Lewis_at_[hidden])
Date: 2009-06-25 16:29:56


While using the BLACS test programs, I've seen that with recent SVN checkouts
(including todays) the MPI_Abort test left procs running. The last SVN I
have where it worked was 1.4a1r20936. By 1.4a1r21246 it fails.

Works O.K. in the standard 1.3.2 release.

A test program is below. GCC was used.

DM

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <math.h>
#include <mpi.h>

#define NUM_ITERS 100000

/* Prototype the function that we'll use below. */

static double f(double);

int
main(int argc, char *argv[])
{
   int iter, rank, size, i;
   int foo;
   double PI25DT = 3.141592653589793238462643;
   double mypi, pi, h, sum, x;
   double startwtime = 0.0, endwtime;
   int namelen;
   char processor_name[MPI_MAX_PROCESSOR_NAME];

   /* Normal MPI startup */

   MPI_Init(&argc, &argv);
   MPI_Comm_size(MPI_COMM_WORLD, &size);
   MPI_Comm_rank(MPI_COMM_WORLD, &rank);
   MPI_Get_processor_name(processor_name, &namelen);

   printf("Process %d of %d on %s\n", rank, size, processor_name);

   /* Do approximations for 1 to 100 points */

   /* sleep(5); */
   for (iter = 2; iter < NUM_ITERS; ++iter) {
     h = 1.0 / (double) iter;
     sum = 0.0;

     /* A slightly better approach starts from large i and works back */

     if (rank == 0)
       startwtime = MPI_Wtime();

     for (i = rank + 1; i <= iter; i += size) {
       x = h * ((double) i - 0.5);
       sum += f(x);
     }
     mypi = h * sum;

     if(iter == (NUM_ITERS - 1000)){
      MPI_Barrier(MPI_COMM_WORLD);
      if(rank == 2){
       MPI_Abort(MPI_COMM_WORLD, -1);
      } else {
       /* Just loop */
       foo = 1;
       while(foo == 1){
        foo = foo + 3;
        foo = foo - 2;
        foo = foo - 1;
       }
      }
     }
     MPI_Reduce(&mypi, &pi, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
   }

   /* All done */

   if (rank == 0) {
    printf("%d points: pi is approximately %.16f, error = %.16f\n",
            iter, pi, fabs(pi - PI25DT));
    endwtime = MPI_Wtime();
    printf("wall clock time = %f\n", endwtime - startwtime);
    fflush(stdout);
   }

   MPI_Finalize();
   return 0;
}

static double
f(double a)
{
   return (4.0 / (1.0 + a * a));
}