cart_create.c

刚才是说明 现在是安装程序在 LINUX环境下进行编程的MPICH安装文件

/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *
 *  (C) 2001 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

#include "mpiimpl.h"
#include "topo.h"

/* -- Begin Profiling Symbol Block for routine MPI_Cart_create */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Cart_create = PMPI_Cart_create
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Cart_create  MPI_Cart_create
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Cart_create as PMPI_Cart_create
#endif
/* -- End Profiling Symbol Block */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
   the MPI routines */
#ifndef MPICH_MPI_FROM_PMPI
#define MPI_Cart_create PMPI_Cart_create

#endif

#undef FUNCNAME
#define FUNCNAME MPI_Cart_create

/*@
   MPI_Cart_create - cart_create

   Arguments:
+  MPI_Comm comm_old - communicator
.  int ndims - ndims
.  int *dims - dims
.  int *periods - periods
.  int reorder - reorder
-  MPI_Comm *comm_cart - communicator

   Notes:

.N Fortran

.N Errors
.N MPI_SUCCESS
@*/
int MPI_Cart_create(MPI_Comm comm_old, int ndims, int *dims, int *periods, 
		    int reorder, MPI_Comm *comm_cart)
{
    static const char FCNAME[] = "MPI_Cart_create";
    int mpi_errno = MPI_SUCCESS;
    int newsize, rank, nranks, i;
    MPID_Comm *comm_ptr = NULL, *newcomm_ptr;
    MPIR_Topology *cart_ptr;
    MPID_MPI_STATE_DECL(MPID_STATE_MPI_CART_CREATE);

    MPID_MPI_FUNC_ENTER(MPID_STATE_MPI_CART_CREATE);
    /* Get handles to MPI objects. */
    MPID_Comm_get_ptr( comm_old, comm_ptr );
#   ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            MPIR_ERRTEST_INITIALIZED(mpi_errno);

            /* Validate comm_ptr */
            MPID_Comm_valid_ptr( comm_ptr, mpi_errno );
	    /* If comm_ptr is not valid, it will be reset to null */
	    MPIR_ERRTEST_ARGNULL( dims, "dims", mpi_errno );
	    MPIR_ERRTEST_ARGNULL( periods, "periods", mpi_errno );
	    MPIR_ERRTEST_ARGNULL( comm_cart, "comm_cart", mpi_errno );
	    if (ndims <= 0) {
		/* Must have a positive number of dimensions */
		mpi_errno = MPIR_Err_create_code( MPI_ERR_DIMS, "**dims",
						  "**dims %d", 0 );
	    }
	    MPIR_ERRTEST_ARGNEG( ndims, "ndims", mpi_errno );
	    if (comm_ptr) {
		MPIR_ERRTEST_COMM_INTRA( comm_ptr, mpi_errno );
	    }
            if (mpi_errno) {
                MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE);
                return MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
            }
        }
        MPID_END_ERROR_CHECKS;
    }
#   endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */
    /* Check for invalid arguments */
    newsize = 1;
    for (i=0; i<ndims; i++) 
	newsize *= dims[i];

#   ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
	    if (newsize > comm_ptr->remote_size) {
		/* Use ERR_ARG instead of ERR_TOPOLOGY because there 
		   is no topology yet */
		mpi_errno = MPIR_Err_create_code( MPI_ERR_ARG, 
					  "**cartdim", "**cartdim %d %d", 
					  comm_ptr->remote_size, newsize );
	    }
	    if (mpi_errno) {
		MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE );
		return MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
	    }
        }
        MPID_END_ERROR_CHECKS;
    }
#   endif /* HAVE_ERROR_CHECKING */

    /* Create a new communicator as a duplicate of the input communicator
       (but do not duplicate the attributes) */

    mpi_errno = MPIR_Comm_copy( comm_ptr, newsize, &newcomm_ptr );
    if (mpi_errno) {
	MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE );
	return MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
    }

    /* If this process is not in the resulting communicator, return a 
       null communicator and exit */
    if (comm_ptr->rank >= newsize) {
	*comm_cart = MPI_COMM_NULL;
	MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE );
	return MPI_SUCCESS;
	
    }

    /* Create the topololgy structure */
    cart_ptr = (MPIR_Topology *)MPIU_Malloc( sizeof( MPIR_Topology ) );
    if (!cart_ptr) {
	mpi_errno = MPIR_Err_create_code( MPI_ERR_OTHER, "**nomem", 0 );
	MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE );
	return MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
    }

    cart_ptr->kind          = MPI_CART;
    cart_ptr->topo.cart.nnodes   = newsize;
    cart_ptr->topo.cart.ndims    = ndims;
    cart_ptr->topo.cart.dims     = (int *)MPIU_Malloc( ndims * sizeof(int) );
    cart_ptr->topo.cart.periodic = (int *)MPIU_Malloc( ndims * sizeof(int) );
    cart_ptr->topo.cart.position = (int *)MPIU_Malloc( ndims * sizeof(int) );
    if (!cart_ptr->topo.cart.dims || !cart_ptr->topo.cart.periodic ||
	!cart_ptr->topo.cart.position) {
	mpi_errno = MPIR_Err_create_code( MPI_ERR_OTHER, "**nomem", 0 );
	MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE );
	return MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
    }
    rank   = comm_ptr->rank;
    nranks = newsize;
    for (i=0; i<ndims; i++) {
	cart_ptr->topo.cart.dims[i]     = dims[i];
	cart_ptr->topo.cart.periodic[i] = periods[i];
	nranks = nranks / dims[i];
	/* FIXME: nranks could be zero (?) */
	cart_ptr->topo.cart.position[i] = rank / nranks;
	rank = rank % nranks;
    }

    /* Place this topology onto the communicator */
    mpi_errno = MPIR_Topology_put( newcomm_ptr, cart_ptr );

    *comm_cart = newcomm_ptr->handle;
    /* ... end of body of routine ... */

    MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_CART_CREATE);
    return MPI_SUCCESS;
}