/*
 * Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2020 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 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) 2015      Research Organization for Information Science
 *                         and Technology (RIST). All rights reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#include "ompi_config.h"

#include "ompi/mpi/c/bindings.h"
#include "ompi/runtime/params.h"
#include "ompi/communicator/communicator.h"
#include "ompi/errhandler/errhandler.h"
#include "ompi/runtime/mpiruntime.h"
#include "opal/mca/threads/threads.h"

#if OMPI_BUILD_MPI_PROFILING
#if OPAL_HAVE_WEAK_SYMBOLS
#pragma weak MPI_Is_thread_main = PMPI_Is_thread_main
#endif
#define MPI_Is_thread_main PMPI_Is_thread_main
#endif

static const char FUNC_NAME[] = "MPI_Is_thread_main";


int MPI_Is_thread_main(int *flag)
{
    if (MPI_PARAM_CHECK) {
        OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
        if (NULL == flag) {
            return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_COMM, FUNC_NAME);
        }
    }

    /* Compare this thread ID to the main thread ID */

    *flag = (int) opal_thread_self_compare(ompi_mpi_main_thread);

    return MPI_SUCCESS;
}