/*
 * Copyright (C) by Argonne National Laboratory
 *     See COPYRIGHT in top-level directory
 */

#include "adio.h"

/*
 * Scalable open:  for file systems capable of having one process
 * create/open a file and broadcast the result to everyone else.
 * - Does not need one process to create the file
 * - Does not need special handling for CREATE|EXCL
 */
void ADIOI_SCALEABLE_OpenColl(ADIO_File fd, int rank, int access_mode, int *error_code)
{
    int orig_amode_wronly;

    /* if we are doing deferred open, non-aggregators should return now */
    if (fd->hints->deferred_open && !(fd->is_agg)) {
        *error_code = MPI_SUCCESS;
        return;
    }

    /* For writing with data sieving, a read-modify-write is needed. If
     * the file is opened for write_only, the read will fail. Therefore,
     * if write_only, open the file as read_write, but record it as
     * write_only in fd, so that get_amode returns the right answer. */

    orig_amode_wronly = access_mode;
    if (access_mode & ADIO_WRONLY) {
        access_mode = access_mode ^ ADIO_WRONLY;
        access_mode = access_mode | ADIO_RDWR;
    }
    fd->access_mode = access_mode;

    (*(fd->fns->ADIOI_xxx_Open)) (fd, error_code);

    /* if error, may be it was due to the change in amode above.
     * therefore, reopen with access mode provided by the user. */
    fd->access_mode = orig_amode_wronly;
    if (*error_code != MPI_SUCCESS)
        (*(fd->fns->ADIOI_xxx_Open)) (fd, error_code);

    /* for deferred open: this process has opened the file (because if we are
     * not an aggregaor and we are doing deferred open, we returned earlier)*/
    fd->is_open = 1;

}
