unitclose.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/unitclose.c        92.2    06/18/99 18:38:26"

#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <liberrno.h>
#include <cray/nassert.h>
#include <sys/param.h>
#include <sys/stat.h>
#include "fio.h"

extern short    _f_abort;       /* Abort flag - set in _f_sig() */

/*
 *      _unit_close
 *
 *              Closes a Fortran unit.  On exit, the unit is closed and 
 *              optionally deallocated with the appropriate locks unlocked.
 *
 *              Upon entry, the unit pointer passed in must be locked, and
 *              the _openlock word must be locked.
 *
 *              This routine also posts CLOSE statistics for the unit if
 *              statistics gathering is active.
 *
 *      Arguments
 *
 *              cup     - Unit pointer
 *              cstat   - STATUS= specifier--CLST_UNSPEC, CLST_KEEP, or
 *                        CLST_DELETE.
 *
 *      Return value:
 *               0      normal return
 *              >0      system or library error status
 */

int
_unit_close(
        unit    *cup,   /* Unit table pointer */
        int     cstat,  /* STATUS= specifier value on CLOSE */
        FIOSPTR cssa)   /* non-NULL if called from _CLS() for explicit CLOSE */
{
        register short  delete; /* 1 if file should be deleted          */
        register int    ret;    /* Return status                        */
        register int    errn;   /* Status from low-level close operation*/
        plock_t         *lockp; /* Copy of auxiliary lock pointer       */
        struct ffsw     fst;    /* ffclose() status                     */
        struct fiostate state;  /* Local Fortran I/O state structure    */
        FIOSPTR         css; 

        if (cup == NULL)        /* If unit not connected */
                return(0);      

        assert ( cstat == CLST_UNSPEC ||
                 cstat ==   CLST_KEEP ||
                 cstat == CLST_DELETE );

        if (cssa != NULL)       /* If processing an explicit CLOSE */
                css     = cssa;
        else {                  /* If implicit/automatic close */
                (void) memset(&state, 0, sizeof(state)); /* be extra safe */
                css     = &state;
#ifdef  _UNICOS
                css->f_rtbgn    = _rtc();
#endif
        }

        cup->uend       = BEFORE_ENDFILE;
        errn            = 0;
        delete          = (cstat == CLST_DELETE || cup->uscrtch) ? 1 : 0;

        lockp   = cup->auxlockp; /* copy aux lock pointer for later */

        if (delete && !cup->utmpfil) {
                ret     = _unit_scratch(cup);
                errn    = errn ? errn : ret;
        }

/*
 *      Write out the current record if the last I/O was a nonadvancing WRITE.
 */
        if (cup->pnonadv) {             /* There is a current record */
                if (cup->uwrt) {
                        ret     = _nonadv_endrec(css, cup);
                        errn    = errn ? errn : ret;
                }
                cup->pnonadv    = 0;    /* Flag no current record */
        }

/*
 *      Truncate sequential files after last write if cup->utrunc.
 */
        if (cup->useq && cup->uwrt && cup->utrunc) {
                ret     = _unit_trunc(cup);
                errn    = errn ? errn : ret;
        }

/*
 *      Perform the close of the lower level file structure only if
 *      it is not a standard file.
 */
        if ( ! ((cup->ufs == STD || cup->ufs == FS_TEXT) &&
                (cup->ufp.std == stdin ||
                 cup->ufp.std == stdout ||
                 cup->ufp.std == stderr)) ) {

                switch (cup->ufs) {

                case FS_FDC:
                        if ( !_f_abort || !(cup->uflagword & FFC_NOCLOSE))
                                if (__ffclose(cup->ufp.fdc, &fst) < 0)
                                        errn    = errn ? errn : fst.sw_error;
                        break;

                case FS_TEXT:
                case STD:
                                
                        if (fclose(cup->ufp.std) != 0)
                                errn    = errn ? errn : errno;
                        break;

                case FS_AUX:
                        errn    = errn ? errn : FEMIXAUX;

                default:
                        errn    = errn ? errn : FEINTFST; /* Unknown file type */
                } /* switch */
        }

/*
 *      Unlock the lockp word.   This is a pointer to a lock word
 *      shared by another unit, usually cup->ufp.std->_lock.  
 */
        if (lockp != NULL)
                MEM_UNLOCK(lockp);

/*
 *      Post final statistics and deallocate the statistics packet.
 */
        FSTATS_POST(cup, T_CLOSE, css); /* Post CLOSE statistics */

        _ft_stclose(cup);               /* Send close packet to procstat
                                         * and then deallocate it.      */

/* 
 *      Deallocation of structures pointed to by the unit table follows
 */
        if (cup->ulinebuf != NULL)
                free(cup->ulinebuf);

        if (cup->upfcstk != NULL)
                free(cup->upfcstk);

        if (cup->urepdata != NULL)
                free(cup->urepdata);

/*
 *      Free ufnm and alfnm.  
 */
        if (cup->ufnm != NULL)
                free(cup->ufnm);

        if (cup->alfnm != NULL)
                free(cup->alfnm);
 
/*
 *      Mark the unit as unopen.
 */
        cup->ufs        = 0;

        return(errn);
}
  
/*
 *      _unit_scratch()
 *
 *              Unlink the file associated with a unit.  For some file types, 
 *              this operation affects subsequent close processing so as to
 *              suppress buffer flushing before the close.   
 *
 *      Return value
 *              0  on success
 *              >1 on error
 *
 *      Side effects
 *
 *              cup->uscrtch    is set to 1.
 *              cup->unlinked   is set to 1 if the file was unlinked.
 *              cup->usnglink   is set to 1 if the file is not a symbolic link 
 *                              and the file link count is 1.
 *
 *              The optimization in close processing to suppress buffer flushes
 *              may only occur if (cup->unlinked && cup->usnglink).
 */
int 
_unit_scratch(unit *cup)
{
        register int    ret;

        cup->uscrtch    = 1;

#ifdef  FC_SCRATCH
        if (cup->ufs == FS_FDC) {
                int             scrflags;
                struct ffsw     ffst;

                cup->unlinked   = 0;
                cup->usnglink   = 0;


                /*
                 * Use the FC_SCRATCH request to unlink the file, check if it 
                 * is a linked file and possibly setup close processing to 
                 * suppress buffer flushes.
                 */
                ret     = XRCALL(cup->ufp.fdc, fcntlrtn) cup->ufp.fdc,
                        FC_SCRATCH, &scrflags, &ffst);

                if (ret == 0) {
                        cup->unlinked   = (scrflags & SCR_UNLINKED)   ? 1 : 0;
                        cup->usnglink   = (scrflags & SCR_SINGLELINK) ? 1 : 0;
                        return(0);
                }

                /* Fall through on error;  FC_SCRATCH might not be supported */
        }
#endif

        cup->usnglink   = 0;    /* assume multiple links */

/*
 *      Perform the unlink only if connected to a real file.  Permit ENOENT
 *      errors in case a layer like mr.scr had closed the file at open time
 *      even though STATUS='SCRATCH' might not have been specified on the OPEN.
 *
 *      If the file has already been unlinked, or if the file has been renamed
 *      and a different file is now there with the same name, ignore the error.
 */
        if (cup->alfnm != NULL && cup->usysfd >= 0) {
                struct stat     sbuf;

                ret     = stat(cup->alfnm, &sbuf);

                if (ret != -1) {        /* If not already unlinked */

                        /*
                         * Ensure the device and inode number match before
                         * we pull the trigger.
                         */

                        if (sbuf.st_ino != cup->uinode ||
                            sbuf.st_dev != cup->udevice)
                                return(FENODELT);       /* Can't delete file */
                        else {

                                ret     = unlink(cup->alfnm);

                                if (ret == -1 && errno != ENOENT)
                                        return(errno);
                        }
                }

                cup->unlinked   = 1;
        }

        return(0);
}