coll9.c

MPICH是MPI的重要研究,提供了一系列的接口函数,为并行计算的实现提供了编程环境.

#include "mpi.h"
#include <stdio.h>
#include "test.h"

void addem ( int *, int *, int *, MPI_Datatype * );

void addem(invec, inoutvec, len, dtype)
int *invec, *inoutvec, *len;
MPI_Datatype *dtype;
{
  int i;
  for ( i=0; i<*len; i++ ) 
    inoutvec[i] += invec[i];
}

int main( int argc, char **argv )
{
    int              rank, size, i;
    int              data;
    int              errors=0;
    int              result = -100;
    int              correct_result;
    MPI_Op           op;

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

    data = rank;
    MPI_Op_create( (MPI_User_function *)addem, 1, &op );
    MPI_Reduce ( &data, &result, 1, MPI_INT, op, 0, MPI_COMM_WORLD );
    MPI_Bcast  ( &result, 1, MPI_INT, 0, MPI_COMM_WORLD );
    MPI_Op_free( &op );
    correct_result = 0;
    for(i=0;i<size;i++) 
      correct_result += i;
    if (result != correct_result) errors++;

    Test_Waitforall( );
    MPI_Finalize();
    if (errors)
      printf( "[%d] done with ERRORS(%d)!\n", rank, errors );
    return errors;
}