/*
 * Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2005 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2008 High Performance Computing Center Stuttgart, 
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * Copyright (c) 2007-2009 Cisco Systems, Inc.  All rights reserved.
 * $COPYRIGHT$
 * 
 * Additional copyrights may follow
 * 
 * $HEADER$
 */
#include "ompi_config.h"
#include <stdio.h>

#include "ompi/mpi/c/bindings.h"
#include "ompi/runtime/params.h"
#include "ompi/communicator/communicator.h"
#include "ompi/errhandler/errhandler.h"
#include "ompi/memchecker.h"

#if OPAL_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Comm_get_errhandler = PMPI_Comm_get_errhandler
#endif

#if OMPI_PROFILING_DEFINES
#include "ompi/mpi/c/profile/defines.h"
#endif


static const char FUNC_NAME[] = "MPI_Comm_get_errhandler";


int MPI_Comm_get_errhandler(MPI_Comm comm, MPI_Errhandler *errhandler)
{
    MPI_Errhandler tmp;

    /* Error checking */
    MEMCHECKER(
        memchecker_comm(comm);
    );

    OPAL_CR_NOOP_PROGRESS();

  /* Error checking */

  if (MPI_PARAM_CHECK) {
    OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
    if (ompi_comm_invalid(comm)) {
      return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM,
                                    FUNC_NAME);
    } else if (NULL == errhandler) {
      return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_ARG,
                                    FUNC_NAME);
    }
  }

  /* On 64 bits environments we have to make sure the reading of the
     error_handler became atomic. */
  do {
      tmp = comm->error_handler;
  } while (!OPAL_ATOMIC_CMPSET(&(comm->error_handler), tmp, tmp));

  /* Retain the errhandler, corresponding to object refcount decrease
     in errhandler_free.c. */
  *errhandler = tmp;
  OBJ_RETAIN(tmp);

  /* All done */

  return MPI_SUCCESS;
}