unit.c

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/*

  Copyright (C) 2000, 2001, Silicon Graphics, Inc.  All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2.1 of the GNU Lesser General Public License 
  as published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement 
  or the like.  Any license provided herein, whether implied or 
  otherwise, applies only to this software file.  Patent licenses, if
  any, provided herein do not apply to combinations of this program with 
  other software, or any other product whatsoever.  

  You should have received a copy of the GNU Lesser General Public 
  License along with this program; if not, write the Free Software 
  Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
  USA.

  Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/



#pragma ident "@(#) libf/fio/unit.c     92.1    06/18/99 18:38:26"
#include <errno.h>
#include <foreign.h>
#include <fortran.h>
#include <liberrno.h>
#include "fio.h"

/*
 *      UNIT function status values
 */
#define UNIT_PDONE      (-2.0)  /* Partial record read complete, data remains */
#define UNIT_DONE       (-1.0)  /* Operation completed */
#define UNIT_EOF        (0.0)   /* EOF on BUFFER IN */
#define UNIT_PERROR     (1.0)   /* Partially recovered error */
#define UNIT_ERROR      (2.0)   /* Unrecovered Error */

/*
 *      _UNIT_
 *
 *              Wait for completion of BUFFER IN/OUT and return a status.
 *
 *      Return value:
 *
 *              -2.0    Partial record read complete, data remains
 *              -1.0    Operation complete
 *               0.0    End of file
 *               1.0    Partially recovered error
 *               2.0    Unrecovered error
 *
 *              Undocumented feature: S2 is assigned on exit the specific error
 *              code for the previous BUFFER IN or BUFFER OUT statement for
 *              FFIO files when value 2.0 is returned by the function.
 *
 *      Define duplicate entry points
 *
 *              UNIT    - if user declares it EXTERNAL
 *              @UNIT   - if user declares it INTRINSIC on CRAY-2 systems
 *              $UNIT   - if user declares it INTRINSIC on CX/CEA systems
 *              _UNIT   - if user declares it INTRINSIC with CF77 6.0.0.3 or
 *                         previous on the T3D (obsolete)
 */
#ifdef  _UNICOS
#pragma _CRI duplicate _UNIT_ as UNIT
#pragma _CRI duplicate _UNIT_ as $UNIT
#ifdef _CRAYMPP
#pragma _CRI duplicate _UNIT_ as _UNIT
#endif
#endif  /* _UNICOS */

_f_real
_UNIT_(_f_int *unump)
{
        register unum_t unum;
        long            s2ret;          /* value to be returned in S2 */
        _f_real         status;
        unit            *cup;
        struct fiostate cfs;

        s2ret   = 0;
        unum    = *unump;

        STMT_BEGIN(unum, 0, T_UNIT, NULL, &cfs, cup);   /* lock the unit */
/*
 *      If not connected, do an implicit open.  Abort if the open fails.
 */
        if (cup == NULL)
                cup     = _imp_open(&cfs, SEQ, UNF, unum, 0, NULL);

        if (cup->ufs == FS_AUX)
                _ferr(&cfs, FEMIXAUX);

/*
 *      According to the file structure make the appropriate call
 *      to check file status.  File status routines are file
 *      structure dependent.
 */
        cup->unitchk    = 1;    /* indicate that UNIT has now been called */

        WAITIO(cup, {});

        if (cup->uerr) {
                status  = UNIT_ERROR;
                /*
                 * This undocumented behavior of returning the error number
                 * in S2 is preserved for now.
                 */
                s2ret   = cup->uffsw.sw_error;
                goto done;
        }
        else if (!cup->uwrt && cup->uend) {
                status  = UNIT_EOF;
                goto done;
        }
        else if (cup->ufs == FS_FDC         &&  FFSTAT(cup->uffsw) ==  FFCNT &&
                 (cup->uflagword & FFC_REC) && !cup->uwrt                    &&
                 cup->urecmode == PARTIAL) {

                status  = UNIT_PDONE;
                goto done;
        }
        status  = UNIT_DONE;

done:
        STMT_END(cup, T_UNIT, NULL, &cfs);      /* unlock the unit */

#ifdef  _CRAY1
        (void) _sets2(s2ret);
#endif

        return( (_f_real) status);
}