/* * This program performs some simple tests of the MPI_Bcast broadcast * functionality. * * It checks the handling of different datatypes by different participants * (with matching type signatures, of course), as well as different * roots and communicators. */#include "test.h"#include "mpi.h"#include <stdlib.h>int main( int argc, char **argv ){    int rank, size, ret, passed, i, *test_array;    int stride, count, root;    MPI_Datatype newtype;    MPI_Comm     comm = MPI_COMM_WORLD;    /* Set up MPI */    MPI_Init(&argc, &argv);    MPI_Comm_rank(comm, &rank);    /* Setup the tests */    Test_Init("bcastvec", rank);    /* Allow for additional communicators */    MPI_Comm_size(comm, &size);    /* MPI_Comm_rank(comm, &rank); */    stride = (rank + 1);    test_array = (int *)malloc(size*stride*sizeof(int));    /* Create the vector datatype EXCEPT for process 0 (vector of       stride 1 is contiguous) */    if (rank > 0) {	count = 1;        MPI_Type_vector( size, 1, stride, MPI_INT, &newtype);        MPI_Type_commit( &newtype );    }    else {	count = size;	newtype = MPI_INT;    }    /* Perform the test.  Each process in turn becomes the root.       After each operation, check that nothing has gone wrong */    passed = 1;    for (root = 0; root < size; root++) {	/* Fill the array with -1 for unset, rank + i * size for set */	for (i=0; i<size*stride; i++) test_array[i] = -1;	if (rank == root) 	    for (i=0; i<size; i++) test_array[i*stride] = rank + i * size;	MPI_Bcast( test_array, count, newtype, root, comm );	for (i=0; i<size; i++) {	    if (test_array[i*stride] != root + i * size) {		passed = 0;	    }	}    }    free(test_array);    if (rank != 0) MPI_Type_free( &newtype );    if (!passed)	Test_Failed("Simple Broadcast test with datatypes");    else {	if (rank == 0)	    Test_Passed("Simple Broadcast test with datatypes");	}    /* Close down the tests */    if (rank == 0)	ret = Summarize_Test_Results();    else {	ret = 0;    }    Test_Finalize();    /* Close down MPI */    Test_Waitforall( );    MPI_Finalize();    return ret;}