/*
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
FUNCTION
<<fclose>>---close a file

INDEX
	fclose
INDEX
	_fclose_r

SYNOPSIS
	#include <stdio.h>
	int fclose(FILE *<[fp]>);
	int _fclose_r(struct _reent *<[reent]>, FILE *<[fp]>);

DESCRIPTION
If the file or stream identified by <[fp]> is open, <<fclose>> closes
it, after first ensuring that any pending data is written (by calling
<<fflush(<[fp]>)>>).

The alternate function <<_fclose_r>> is a reentrant version.
The extra argument <[reent]> is a pointer to a reentrancy structure.

RETURNS
<<fclose>> returns <<0>> if successful (including when <[fp]> is
<<NULL>> or not an open file); otherwise, it returns <<EOF>>.

PORTABILITY
<<fclose>> is required by ANSI C.

Required OS subroutines: <<close>>, <<fstat>>, <<isatty>>, <<lseek>>,
<<read>>, <<sbrk>>, <<write>>.
*/

#include <_ansi.h>
#include <reent.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/lock.h>
#include "local.h"

int
_DEFUN(_fclose_r, (rptr, fp),
      struct _reent *rptr _AND
      register FILE * fp)
{
  int r;

  if (fp == NULL)
    return (0);			/* on NULL */

  CHECK_INIT (rptr, fp);

  /* We can't use the _newlib_flockfile_XXX macros here due to the
     interlocked locking with the sfp_lock. */
#ifdef _STDIO_WITH_THREAD_CANCELLATION_SUPPORT
  int __oldcancel;
  pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &__oldcancel);
#endif
  if (!(fp->_flags2 & __SNLK))
    _flockfile (fp);

  if (fp->_flags == 0)		/* not open! */
    {
      if (!(fp->_flags2 & __SNLK))
	_funlockfile (fp);
#ifdef _STDIO_WITH_THREAD_CANCELLATION_SUPPORT
      pthread_setcancelstate (__oldcancel, &__oldcancel);
#endif
      return (0);
    }
#ifdef _STDIO_BSD_SEMANTICS
  /* BSD and Glibc systems only flush streams which have been written to. */
  r = (fp->_flags & __SWR) ? __sflush_r (rptr, fp) : 0;
#else
  /* Follow POSIX semantics exactly.  Unconditionally flush to allow
     special handling for seekable read files to reposition file to last
     byte processed as opposed to last byte read ahead into the buffer. */
  r = __sflush_r (rptr, fp);
#endif
  if (fp->_close != NULL && fp->_close (rptr, fp->_cookie) < 0)
    r = EOF;
  if (fp->_flags & __SMBF)
    _free_r (rptr, (char *) fp->_bf._base);
  if (HASUB (fp))
    FREEUB (rptr, fp);
  if (HASLB (fp))
    FREELB (rptr, fp);
  __sfp_lock_acquire ();
  fp->_flags = 0;		/* release this FILE for reuse */
  if (!(fp->_flags2 & __SNLK))
    _funlockfile (fp);
#ifndef __SINGLE_THREAD__
  __lock_close_recursive (fp->_lock);
#endif

  __sfp_lock_release ();
#ifdef _STDIO_WITH_THREAD_CANCELLATION_SUPPORT
  pthread_setcancelstate (__oldcancel, &__oldcancel);
#endif

  return (r);
}

#ifndef _REENT_ONLY

int
_DEFUN(fclose, (fp),
       register FILE * fp)
{
  return _fclose_r(_REENT, fp);
}

#endif
