group_union.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 "group.h"

/* -- Begin Profiling Symbol Block for routine MPI_Group_union */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Group_union = PMPI_Group_union
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Group_union  MPI_Group_union
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Group_union as PMPI_Group_union
#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_Group_union PMPI_Group_union

#endif

#undef FUNCNAME
#define FUNCNAME MPI_Group_union

/*@
   MPI_Group_union - group union

   Arguments:
+  MPI_Group group1 - group1 
.  MPI_Group group2 - group2
-  MPI_Group *newgroup - new group

   Notes:

.N Fortran

.N Errors
.N MPI_SUCCESS
@*/
int MPI_Group_union(MPI_Group group1, MPI_Group group2, MPI_Group *newgroup)
{
    static const char FCNAME[] = "MPI_Group_union";
    int mpi_errno = MPI_SUCCESS;
    MPID_Group *group_ptr1 = NULL;
    MPID_Group *group_ptr2 = NULL;
    MPID_Group *new_group_ptr;
    int g1_idx, g2_idx, nnew, i, k, size1, size2, mylpid;
    MPID_MPI_STATE_DECL(MPID_STATE_MPI_GROUP_UNION);

    MPID_MPI_FUNC_ENTER(MPID_STATE_MPI_GROUP_UNION);
    /* Get handles to MPI objects. */
    MPID_Group_get_ptr( group1, group_ptr1 );
    MPID_Group_get_ptr( group2, group_ptr2 );
#   ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
	    MPIR_ERRTEST_INITIALIZED(mpi_errno);
            /* Validate group_ptr */
            MPID_Group_valid_ptr( group_ptr1, mpi_errno );
	    MPID_Group_valid_ptr( group_ptr2, mpi_errno );
	    /* If group_ptr is not valid, it will be reset to null */
            if (mpi_errno) {
                MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_GROUP_UNION);
                return MPIR_Err_return_comm( 0, FCNAME, mpi_errno );
            }
        }
        MPID_END_ERROR_CHECKS;
    }
#   endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */
    /* Determine the size of the new group.  The new group consists of all
       members of group1 plus the members of group2 that are not in group1.
    */
    g1_idx = group_ptr1->idx_of_first_lpid;
    g2_idx = group_ptr2->idx_of_first_lpid;

    /* If the lpid list hasn't been created, do it now */
    if (g1_idx < 0) { 
	MPIR_Group_setup_lpid_list( group_ptr1 ); 
	g1_idx = group_ptr1->idx_of_first_lpid;
    }
    if (g2_idx < 0) { 
	MPIR_Group_setup_lpid_list( group_ptr2 ); 
	g2_idx = group_ptr2->idx_of_first_lpid;
    }
    nnew = group_ptr1->size;

    /* Must lock against other threads because we need the flag elements 
       (which are part of the lpid_list of thie group) 
     */
    MPID_Common_thread_lock();
    {
	/* Clear the flag bits on the second group.  The flag is set if
	   a member of the second group belongs to the union */
	size2 = group_ptr2->size;
	for (i=0; i<size2; i++) {
	    group_ptr2->lrank_to_lpid[i].flag = 0;
	}
	/* Loop through the lists that are ordered by lpid (local process
	   id) to detect which processes in group 2 are not in group 1
	*/
	while (g1_idx >= 0 && g2_idx >= 0) {
	    int l1_pid, l2_pid;
	    l1_pid = group_ptr1->lrank_to_lpid[g1_idx].lpid;
	    l2_pid = group_ptr2->lrank_to_lpid[g2_idx].lpid;
	    if (l1_pid > l2_pid) {
		nnew++;
		group_ptr2->lrank_to_lpid[g2_idx].flag = 1;
		g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
	    }
	    else if (l1_pid == l2_pid) {
		g1_idx = group_ptr1->lrank_to_lpid[g1_idx].next_lpid;
		g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
	    }
	    else {
		/* l1 < l2 */
		g1_idx = group_ptr1->lrank_to_lpid[g1_idx].next_lpid;
	    }
	}
	/* If we hit the end of group1, add the remaining members of group 2 */
	while (g2_idx >= 0) {
	    nnew++;
	    group_ptr2->lrank_to_lpid[g2_idx].flag = 1;
	    g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
	}
	
	/* Allocate a new group and lrank_to_lpid array */
	mpi_errno = MPIR_Group_create( nnew, &new_group_ptr );
	if (mpi_errno) {
	    MPID_Common_thread_unlock();
	    MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_GROUP_UNION);
	    return MPIR_Err_return_comm( 0, FCNAME, mpi_errno );
	}
	/* If this process is in group1, then we can set the rank now. 
	   If we are not in this group, this assignment will set the
	   current rank to MPI_UNDEFINED */
	new_group_ptr->rank = group_ptr1->rank;
    
	/* Add group1 */
	size1 = group_ptr1->size;
	for (i=0; i<size1; i++) {
	    new_group_ptr->lrank_to_lpid[i].lrank = i;
	    new_group_ptr->lrank_to_lpid[i].lpid  = 
		group_ptr1->lrank_to_lpid[i].lpid;
	}

	/* Add members of group2 that are not in group 1 */
	
	if (group_ptr1->rank == MPI_UNDEFINED &&
	    group_ptr2->rank >= 0) {
	    mylpid = group_ptr2->lrank_to_lpid[group_ptr2->rank].lpid;
	}
	else {
	    mylpid = -2;
	}
	k = size1;
	for (i=0; i<size2; i++) {
	    if (group_ptr2->lrank_to_lpid[i].flag) {
		new_group_ptr->lrank_to_lpid[k].lrank = k;
		new_group_ptr->lrank_to_lpid[k].lpid = 
		    group_ptr2->lrank_to_lpid[i].lpid;
		if (new_group_ptr->rank == MPI_UNDEFINED &&
		    group_ptr2->lrank_to_lpid[i].lpid == mylpid)
		    new_group_ptr->rank = k;
		k++;
	    }
	}
	MPID_Common_thread_unlock();
    }
    *newgroup = new_group_ptr->handle;

    /* ... end of body of routine ... */
    MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_GROUP_UNION);
    return MPI_SUCCESS;
}