coll8.c

来自「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」· C语言 代码 · 共 40 行

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

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

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

    data = rank;

    MPI_Reduce ( &data, &result, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD );
    MPI_Bcast  ( &result, 1, MPI_INT, 0, MPI_COMM_WORLD );
    correct_result = 0;
    for(i=0;i<size;i++) 
      correct_result += i;
    if (result != correct_result) errors++;

    MPI_Reduce ( &data, &result, 1, MPI_INT, MPI_MIN, 0, MPI_COMM_WORLD );
    MPI_Bcast  ( &result, 1, MPI_INT, 0, MPI_COMM_WORLD );
    if (result != 0) errors++;

    MPI_Reduce ( &data, &result, 1, MPI_INT, MPI_MAX, 0, MPI_COMM_WORLD );
    MPI_Bcast  ( &result, 1, MPI_INT, 0, MPI_COMM_WORLD );
    if (result != (size-1)) errors++;

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