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

/*

 *   Copyright (C) 1997 University of Chicago.

 *   See COPYRIGHT notice in top-level directory.

 */

#include "mpioimpl.h"

#ifdef HAVE_WEAK_SYMBOLS

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_File_seek_shared = PMPI_File_seek_shared

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_File_seek_shared MPI_File_seek_shared

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_File_seek_shared as PMPI_File_seek_shared

/* end of weak pragmas */

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_File_seek_shared(MPI_File fh, MPI_Offset offset, int whence)

    __attribute__ ((weak, alias("PMPI_File_seek_shared")));

#endif

/* Include mapping from MPI->PMPI */

#define MPIO_BUILD_PROFILING

#include "mpioprof.h"

#endif

/*@

    MPI_File_seek_shared - Updates the shared file pointer

Input Parameters:

. fh - file handle (handle)

. offset - file offset (integer)

. whence - update mode (state)

.N fortran

@*/

int MPI_File_seek_shared(MPI_File fh, MPI_Offset offset, int whence)

{

    int error_code = MPI_SUCCESS, tmp_whence, myrank;

    static char myname[] = "MPI_FILE_SEEK_SHARED";

    MPI_Offset curr_offset, eof_offset, tmp_offset;

    ADIO_File adio_fh;

    ROMIO_THREAD_CS_ENTER();

    adio_fh = MPIO_File_resolve(fh);

    /* --BEGIN ERROR HANDLING-- */

    MPIO_CHECK_FILE_HANDLE(adio_fh, myname, error_code);

    MPIO_CHECK_NOT_SEQUENTIAL_MODE(adio_fh, myname, error_code);

    MPIO_CHECK_FS_SUPPORTS_SHARED(adio_fh, myname, error_code);

    /* --END ERROR HANDLING-- */

    tmp_offset = offset;

    MPI_Bcast(&tmp_offset, 1, ADIO_OFFSET, 0, adio_fh->comm);

    /* --BEGIN ERROR HANDLING-- */

    if (tmp_offset != offset) {

        error_code = MPIO_Err_create_code(MPI_SUCCESS, MPIR_ERR_RECOVERABLE,

                                          myname, __LINE__, MPI_ERR_ARG, "**notsame", 0);

        error_code = MPIO_Err_return_file(adio_fh, error_code);

        goto fn_exit;

    }

    /* --END ERROR HANDLING-- */

    tmp_whence = whence;

    MPI_Bcast(&tmp_whence, 1, MPI_INT, 0, adio_fh->comm);

    /* --BEGIN ERROR HANDLING-- */

    if (tmp_whence != whence) {

        error_code = MPIO_Err_create_code(MPI_SUCCESS, MPIR_ERR_RECOVERABLE,

                                          myname, __LINE__, MPI_ERR_ARG, "**iobadwhence", 0);

        error_code = MPIO_Err_return_file(adio_fh, error_code);

        goto fn_exit;

    }

    /* --END ERROR HANDLING-- */

    ADIOI_TEST_DEFERRED(adio_fh, "MPI_File_seek_shared", &error_code);

    MPI_Comm_rank(adio_fh->comm, &myrank);

    if (!myrank) {

        switch (whence) {

            case MPI_SEEK_SET:

                /* --BEGIN ERROR HANDLING-- */

                if (offset < 0) {

                    error_code = MPIO_Err_create_code(MPI_SUCCESS,

                                                      MPIR_ERR_RECOVERABLE,

                                                      myname, __LINE__,

                                                      MPI_ERR_ARG, "**iobadoffset", 0);

                    error_code = MPIO_Err_return_file(adio_fh, error_code);

                    goto fn_exit;

                }

                /* --END ERROR HANDLING-- */

                break;

            case MPI_SEEK_CUR:

                /* get current location of shared file pointer */

                ADIO_Get_shared_fp(adio_fh, 0, &curr_offset, &error_code);

                /* --BEGIN ERROR HANDLING-- */

                if (error_code != MPI_SUCCESS) {

                    error_code = MPIO_Err_create_code(MPI_SUCCESS,

                                                      MPIR_ERR_FATAL,

                                                      myname, __LINE__,

                                                      MPI_ERR_INTERN, "**iosharedfailed", 0);

                    error_code = MPIO_Err_return_file(adio_fh, error_code);

                    goto fn_exit;

                }

                /* --END ERROR HANDLING-- */

                offset += curr_offset;

                /* --BEGIN ERROR HANDLING-- */

                if (offset < 0) {

                    error_code = MPIO_Err_create_code(MPI_SUCCESS,

                                                      MPIR_ERR_RECOVERABLE,

                                                      myname, __LINE__,

                                                      MPI_ERR_ARG, "**ionegoffset", 0);

                    error_code = MPIO_Err_return_file(adio_fh, error_code);

                    goto fn_exit;

                }

                /* --END ERROR HANDLING-- */

                break;

            case MPI_SEEK_END:

                /* find offset corr. to end of file */

                ADIOI_Get_eof_offset(adio_fh, &eof_offset);

                offset += eof_offset;

                /* --BEGIN ERROR HANDLING-- */

                if (offset < 0) {

                    error_code = MPIO_Err_create_code(MPI_SUCCESS,

                                                      MPIR_ERR_RECOVERABLE,

                                                      myname, __LINE__,

                                                      MPI_ERR_ARG, "**ionegoffset", 0);

                    error_code = MPIO_Err_return_file(adio_fh, error_code);

                    goto fn_exit;

                }

                /* --END ERROR HANDLING-- */

                break;

            default:

                /* --BEGIN ERROR HANDLING-- */

                error_code = MPIO_Err_create_code(MPI_SUCCESS,

                                                  MPIR_ERR_RECOVERABLE,

                                                  myname, __LINE__, MPI_ERR_ARG,

                                                  "**iobadwhence", 0);

                error_code = MPIO_Err_return_file(adio_fh, error_code);

                goto fn_exit;

                /* --END ERROR HANDLING-- */

        }

        ADIO_Set_shared_fp(adio_fh, offset, &error_code);

        /* --BEGIN ERROR HANDLING-- */

        if (error_code != MPI_SUCCESS) {

            error_code = MPIO_Err_create_code(MPI_SUCCESS,

                                              MPIR_ERR_FATAL,

                                              myname, __LINE__,

                                              MPI_ERR_INTERN, "**iosharedfailed", 0);

            error_code = MPIO_Err_return_file(adio_fh, error_code);

            goto fn_exit;

        }

        /* --END ERROR HANDLING-- */

    }

    /* FIXME: explain why the barrier is necessary */

    MPI_Barrier(adio_fh->comm);

    error_code = MPI_SUCCESS;

  fn_exit:

    ROMIO_THREAD_CS_EXIT();

    return error_code;

}