/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpiimpl.h"

#include "mpicomm.h"

#include <stdint.h>

/* -- Begin Profiling Symbol Block for routine MPIX_Comm_agree */

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPIX_Comm_agree = PMPIX_Comm_agree

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPIX_Comm_agree  MPIX_Comm_agree

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPIX_Comm_agree as PMPIX_Comm_agree

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPIX_Comm_agree(MPI_Comm comm, int *flag) __attribute__ ((weak, alias("PMPIX_Comm_agree")));

#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

#undef MPIX_Comm_agree

#define MPIX_Comm_agree PMPIX_Comm_agree

#undef FUNCNAME

#define FUNCNAME MPIR_Comm_agree

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Comm_agree(MPIR_Comm * comm_ptr, int *flag)

{

    int mpi_errno = MPI_SUCCESS, mpi_errno_tmp = MPI_SUCCESS;

    MPIR_Group *comm_grp = NULL, *failed_grp = NULL, *new_group_ptr = NULL, *global_failed = NULL;

    int result, success = 1;

    MPIR_Errflag_t errflag = MPIR_ERR_NONE;

    int values[2];

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIR_COMM_AGREE);

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIR_COMM_AGREE);

    MPIR_Comm_group_impl(comm_ptr, &comm_grp);

    /* Get the locally known (not acknowledged) group of failed procs */

    mpi_errno = MPID_Comm_failure_get_acked(comm_ptr, &failed_grp);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    /* First decide on the group of failed procs. */

    mpi_errno = MPID_Comm_get_all_failed_procs(comm_ptr, &global_failed, MPIR_AGREE_TAG);

    if (mpi_errno)

        errflag = MPIR_ERR_PROC_FAILED;

    mpi_errno = MPIR_Group_compare_impl(failed_grp, global_failed, &result);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    /* Create a subgroup without the failed procs */

    mpi_errno = MPIR_Group_difference_impl(comm_grp, global_failed, &new_group_ptr);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    /* If that group isn't the same as what we think is failed locally, then

     * mark it as such. */

    if (result == MPI_UNEQUAL || errflag)

        success = 0;

    /* Do an allreduce to decide whether or not anyone thinks the group

     * has changed */

    mpi_errno_tmp = MPII_Allreduce_group(MPI_IN_PLACE, &success, 1, MPI_INT, MPI_MIN, comm_ptr,

                                         new_group_ptr, MPIR_AGREE_TAG, &errflag);

    if (!success || errflag || mpi_errno_tmp)

        success = 0;

    values[0] = success;

    values[1] = *flag;

    /* Determine both the result of this function (mpi_errno) and the result

     * of flag that will be returned to the user. */

    MPII_Allreduce_group(MPI_IN_PLACE, values, 2, MPI_INT, MPI_BAND, comm_ptr,

                         new_group_ptr, MPIR_AGREE_TAG, &errflag);

    /* Ignore the result of the operation this time. Everyone will either

     * return a failure because of !success earlier or they will return

     * something useful for flag because of this operation. If there was a new

     * failure in between the first allreduce and the second one, it's ignored

     * here. */

    if (failed_grp != MPIR_Group_empty)

        MPIR_Group_release(failed_grp);

    MPIR_Group_release(new_group_ptr);

    MPIR_Group_release(comm_grp);

    if (global_failed != MPIR_Group_empty)

        MPIR_Group_release(global_failed);

    success = values[0];

    *flag = values[1];

    if (!success) {

        MPIR_ERR_SET(mpi_errno_tmp, MPIX_ERR_PROC_FAILED, "**mpix_comm_agree");

        MPIR_ERR_ADD(mpi_errno, mpi_errno_tmp);

    }

  fn_exit:

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPIR_COMM_AGREE);

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}

#endif /* !defined(MPICH_MPI_FROM_PMPI) */

#undef FUNCNAME

#define FUNCNAME MPIX_Comm_agree

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

/*@

MPIX_Comm_agree - Performs agreement operation on comm

Input Parameters:

. comm - communicator (handle)

Output Parameters:

. newcomm - new communicator (handle)

.N ThreadSafe

.N Fortran

.N Errors

.N MPI_SUCCESS

.N MPI_ERR_COMM

@*/

int MPIX_Comm_agree(MPI_Comm comm, int *flag)

{

    int mpi_errno = MPI_SUCCESS;

    MPIR_Comm *comm_ptr = NULL;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIX_COMM_AGREE);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIX_COMM_AGREE);

    /* Validate parameters, and convert MPI object handles to object pointers */

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPIR_ERRTEST_COMM(comm, mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

        MPIR_Comm_get_ptr(comm, comm_ptr);

        MPID_BEGIN_ERROR_CHECKS;

        {

            /* Validate comm_ptr */

            MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, TRUE);

            if (mpi_errno)

                goto fn_fail;

        }

        MPID_END_ERROR_CHECKS;

    }

#else

    {

        MPIR_Comm_get_ptr(comm, comm_ptr);

    }

#endif

    /* ... body of routine ... */

    mpi_errno = MPIR_Comm_agree(comm_ptr, flag);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    /* ... end of body of routine ... */

  fn_exit:

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPIX_COMM_AGREE);

    MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    return mpi_errno;

  fn_fail:

    /* --BEGIN ERROR HANDLING-- */

#ifdef HAVE_ERROR_CHECKING

    {

        mpi_errno =

            MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__,

                                 MPI_ERR_OTHER, "**mpix_comm_agree", "**mpix_comm_agree %C", comm);

    }

#endif

    mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);

    goto fn_exit;

    /* --END ERROR HANDLING-- */

}