/* Copyright (C) 1993-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.

   As a special exception, if you link the code in this file with

   files compiled with a GNU compiler to produce an executable,

   that does not cause the resulting executable to be covered by

   the GNU Lesser General Public License.  This exception does not

   however invalidate any other reasons why the executable file

   might be covered by the GNU Lesser General Public License.

   This exception applies to code released by its copyright holders

   in files containing the exception.  */

/* Generic or default I/O operations. */

#include "libioP.h"

#include <stdlib.h>

#include <string.h>

#include <stdbool.h>

#include <sched.h>

#ifdef _IO_MTSAFE_IO

static _IO_lock_t list_all_lock = _IO_lock_initializer;

#endif

static FILE *run_fp;

#ifdef _IO_MTSAFE_IO

static void

flush_cleanup (void *not_used)

{

  if (run_fp != NULL)

    _IO_funlockfile (run_fp);

  _IO_lock_unlock (list_all_lock);

}

#endif

void

_IO_un_link (struct _IO_FILE_plus *fp)

{

  if (fp->file._flags & _IO_LINKED)

    {

      FILE **f;

#ifdef _IO_MTSAFE_IO

      _IO_cleanup_region_start_noarg (flush_cleanup);

      _IO_lock_lock (list_all_lock);

      run_fp = (FILE *) fp;

      _IO_flockfile ((FILE *) fp);

#endif

      if (_IO_list_all == NULL)

	;

      else if (fp == _IO_list_all)

	_IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;

      else

	for (f = &_IO_list_all->file._chain; *f; f = &(*f)->_chain)

	  if (*f == (FILE *) fp)

	    {

	      *f = fp->file._chain;

	      break;

	    }

      fp->file._flags &= ~_IO_LINKED;

#ifdef _IO_MTSAFE_IO

      _IO_funlockfile ((FILE *) fp);

      run_fp = NULL;

      _IO_lock_unlock (list_all_lock);

      _IO_cleanup_region_end (0);

#endif

    }

}

libc_hidden_def (_IO_un_link)

void

_IO_link_in (struct _IO_FILE_plus *fp)

{

  if ((fp->file._flags & _IO_LINKED) == 0)

    {

      fp->file._flags |= _IO_LINKED;

#ifdef _IO_MTSAFE_IO

      _IO_cleanup_region_start_noarg (flush_cleanup);

      _IO_lock_lock (list_all_lock);

      run_fp = (FILE *) fp;

      _IO_flockfile ((FILE *) fp);

#endif

      fp->file._chain = (FILE *) _IO_list_all;

      _IO_list_all = fp;

#ifdef _IO_MTSAFE_IO

      _IO_funlockfile ((FILE *) fp);

      run_fp = NULL;

      _IO_lock_unlock (list_all_lock);

      _IO_cleanup_region_end (0);

#endif

    }

}

libc_hidden_def (_IO_link_in)

/* Return minimum _pos markers

   Assumes the current get area is the main get area. */

ssize_t _IO_least_marker (FILE *fp, char *end_p);

ssize_t

_IO_least_marker (FILE *fp, char *end_p)

{

  ssize_t least_so_far = end_p - fp->_IO_read_base;

  struct _IO_marker *mark;

  for (mark = fp->_markers; mark != NULL; mark = mark->_next)

    if (mark->_pos < least_so_far)

      least_so_far = mark->_pos;

  return least_so_far;

}

/* Switch current get area from backup buffer to (start of) main get area. */

void

_IO_switch_to_main_get_area (FILE *fp)

{

  char *tmp;

  fp->_flags &= ~_IO_IN_BACKUP;

  /* Swap _IO_read_end and _IO_save_end. */

  tmp = fp->_IO_read_end;

  fp->_IO_read_end = fp->_IO_save_end;

  fp->_IO_save_end= tmp;

  /* Swap _IO_read_base and _IO_save_base. */

  tmp = fp->_IO_read_base;

  fp->_IO_read_base = fp->_IO_save_base;

  fp->_IO_save_base = tmp;

  /* Set _IO_read_ptr. */

  fp->_IO_read_ptr = fp->_IO_read_base;

}

/* Switch current get area from main get area to (end of) backup area. */

void

_IO_switch_to_backup_area (FILE *fp)

{

  char *tmp;

  fp->_flags |= _IO_IN_BACKUP;

  /* Swap _IO_read_end and _IO_save_end. */

  tmp = fp->_IO_read_end;

  fp->_IO_read_end = fp->_IO_save_end;

  fp->_IO_save_end = tmp;

  /* Swap _IO_read_base and _IO_save_base. */

  tmp = fp->_IO_read_base;

  fp->_IO_read_base = fp->_IO_save_base;

  fp->_IO_save_base = tmp;

  /* Set _IO_read_ptr.  */

  fp->_IO_read_ptr = fp->_IO_read_end;

}

int

_IO_switch_to_get_mode (FILE *fp)

{

  if (fp->_IO_write_ptr > fp->_IO_write_base)

    if (_IO_OVERFLOW (fp, EOF) == EOF)

      return EOF;

  if (_IO_in_backup (fp))

    fp->_IO_read_base = fp->_IO_backup_base;

  else

    {

      fp->_IO_read_base = fp->_IO_buf_base;

      if (fp->_IO_write_ptr > fp->_IO_read_end)

	fp->_IO_read_end = fp->_IO_write_ptr;

    }

  fp->_IO_read_ptr = fp->_IO_write_ptr;

  fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = fp->_IO_read_ptr;

  fp->_flags &= ~_IO_CURRENTLY_PUTTING;

  return 0;

}

libc_hidden_def (_IO_switch_to_get_mode)

void

_IO_free_backup_area (FILE *fp)

{

  if (_IO_in_backup (fp))

    _IO_switch_to_main_get_area (fp);  /* Just in case. */

  free (fp->_IO_save_base);

  fp->_IO_save_base = NULL;

  fp->_IO_save_end = NULL;

  fp->_IO_backup_base = NULL;

}

libc_hidden_def (_IO_free_backup_area)

int

__overflow (FILE *f, int ch)

{

  /* This is a single-byte stream.  */

  if (f->_mode == 0)

    _IO_fwide (f, -1);

  return _IO_OVERFLOW (f, ch);

}

libc_hidden_def (__overflow)

static int

save_for_backup (FILE *fp, char *end_p)

{

  /* Append [_IO_read_base..end_p] to backup area. */

  ssize_t least_mark = _IO_least_marker (fp, end_p);

  /* needed_size is how much space we need in the backup area. */

  size_t needed_size = (end_p - fp->_IO_read_base) - least_mark;

  /* FIXME: Dubious arithmetic if pointers are NULL */

  size_t current_Bsize = fp->_IO_save_end - fp->_IO_save_base;

  size_t avail; /* Extra space available for future expansion. */

  ssize_t delta;

  struct _IO_marker *mark;

  if (needed_size > current_Bsize)

    {

      char *new_buffer;

      avail = 100;

      new_buffer = (char *) malloc (avail + needed_size);

      if (new_buffer == NULL)

	return EOF;		/* FIXME */

      if (least_mark < 0)

	{

	  __mempcpy (__mempcpy (new_buffer + avail,

				fp->_IO_save_end + least_mark,

				-least_mark),

		     fp->_IO_read_base,

		     end_p - fp->_IO_read_base);

	}

      else

	memcpy (new_buffer + avail,

		fp->_IO_read_base + least_mark,

		needed_size);

      free (fp->_IO_save_base);

      fp->_IO_save_base = new_buffer;

      fp->_IO_save_end = new_buffer + avail + needed_size;

    }

  else

    {

      avail = current_Bsize - needed_size;

      if (least_mark < 0)

	{

	  memmove (fp->_IO_save_base + avail,

		   fp->_IO_save_end + least_mark,

		   -least_mark);

	  memcpy (fp->_IO_save_base + avail - least_mark,

		  fp->_IO_read_base,

		  end_p - fp->_IO_read_base);

	}

      else if (needed_size > 0)

	memcpy (fp->_IO_save_base + avail,

		fp->_IO_read_base + least_mark,

		needed_size);

    }

  fp->_IO_backup_base = fp->_IO_save_base + avail;

  /* Adjust all the streammarkers. */

  delta = end_p - fp->_IO_read_base;

  for (mark = fp->_markers; mark != NULL; mark = mark->_next)

    mark->_pos -= delta;

  return 0;

}

int

__underflow (FILE *fp)

{

  if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)

    return EOF;

  if (fp->_mode == 0)

    _IO_fwide (fp, -1);

  if (_IO_in_put_mode (fp))

    if (_IO_switch_to_get_mode (fp) == EOF)

      return EOF;

  if (fp->_IO_read_ptr < fp->_IO_read_end)

    return *(unsigned char *) fp->_IO_read_ptr;

  if (_IO_in_backup (fp))

    {

      _IO_switch_to_main_get_area (fp);

      if (fp->_IO_read_ptr < fp->_IO_read_end)

	return *(unsigned char *) fp->_IO_read_ptr;

    }

  if (_IO_have_markers (fp))

    {

      if (save_for_backup (fp, fp->_IO_read_end))

	return EOF;

    }

  else if (_IO_have_backup (fp))

    _IO_free_backup_area (fp);

  return _IO_UNDERFLOW (fp);

}

libc_hidden_def (__underflow)

int

__uflow (FILE *fp)

{

  if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)

    return EOF;

  if (fp->_mode == 0)

    _IO_fwide (fp, -1);

  if (_IO_in_put_mode (fp))

    if (_IO_switch_to_get_mode (fp) == EOF)

      return EOF;

  if (fp->_IO_read_ptr < fp->_IO_read_end)

    return *(unsigned char *) fp->_IO_read_ptr++;

  if (_IO_in_backup (fp))

    {

      _IO_switch_to_main_get_area (fp);

      if (fp->_IO_read_ptr < fp->_IO_read_end)

	return *(unsigned char *) fp->_IO_read_ptr++;

    }

  if (_IO_have_markers (fp))

    {

      if (save_for_backup (fp, fp->_IO_read_end))

	return EOF;

    }

  else if (_IO_have_backup (fp))

    _IO_free_backup_area (fp);

  return _IO_UFLOW (fp);

}

libc_hidden_def (__uflow)

void

_IO_setb (FILE *f, char *b, char *eb, int a)

{

  if (f->_IO_buf_base && !(f->_flags & _IO_USER_BUF))

    free (f->_IO_buf_base);

  f->_IO_buf_base = b;

  f->_IO_buf_end = eb;

  if (a)

    f->_flags &= ~_IO_USER_BUF;

  else

    f->_flags |= _IO_USER_BUF;

}

libc_hidden_def (_IO_setb)

void

_IO_doallocbuf (FILE *fp)

{

  if (fp->_IO_buf_base)

    return;

  if (!(fp->_flags & _IO_UNBUFFERED) || fp->_mode > 0)

    if (_IO_DOALLOCATE (fp) != EOF)

      return;

  _IO_setb (fp, fp->_shortbuf, fp->_shortbuf+1, 0);

}

libc_hidden_def (_IO_doallocbuf)

int

_IO_default_underflow (FILE *fp)

{

  return EOF;

}

int

_IO_default_uflow (FILE *fp)

{

  int ch = _IO_UNDERFLOW (fp);

  if (ch == EOF)

    return EOF;

  return *(unsigned char *) fp->_IO_read_ptr++;

}

libc_hidden_def (_IO_default_uflow)

size_t

_IO_default_xsputn (FILE *f, const void *data, size_t n)

{

  const char *s = (char *) data;

  size_t more = n;

  if (more <= 0)

    return 0;

  for (;;)

    {

      /* Space available. */

      if (f->_IO_write_ptr < f->_IO_write_end)

	{

	  size_t count = f->_IO_write_end - f->_IO_write_ptr;

	  if (count > more)

	    count = more;

	  if (count > 20)

	    {

	      f->_IO_write_ptr = __mempcpy (f->_IO_write_ptr, s, count);

	      s += count;

	    }

	  else if (count)

	    {

	      char *p = f->_IO_write_ptr;

	      ssize_t i;

	      for (i = count; --i >= 0; )

		*p++ = *s++;

	      f->_IO_write_ptr = p;

	    }

	  more -= count;

	}

      if (more == 0 || _IO_OVERFLOW (f, (unsigned char) *s++) == EOF)

	break;

      more--;

    }

  return n - more;

}

libc_hidden_def (_IO_default_xsputn)

size_t

_IO_sgetn (FILE *fp, void *data, size_t n)

{

  /* FIXME handle putback buffer here! */

  return _IO_XSGETN (fp, data, n);

}

libc_hidden_def (_IO_sgetn)

size_t

_IO_default_xsgetn (FILE *fp, void *data, size_t n)

{

  size_t more = n;

  char *s = (char*) data;

  for (;;)

    {

      /* Data available. */

      if (fp->_IO_read_ptr < fp->_IO_read_end)

	{

	  size_t count = fp->_IO_read_end - fp->_IO_read_ptr;

	  if (count > more)

	    count = more;

	  if (count > 20)

	    {

	      s = __mempcpy (s, fp->_IO_read_ptr, count);

	      fp->_IO_read_ptr += count;

	    }

	  else if (count)

	    {

	      char *p = fp->_IO_read_ptr;

	      int i = (int) count;

	      while (--i >= 0)

		*s++ = *p++;

	      fp->_IO_read_ptr = p;

	    }

	    more -= count;

	}

      if (more == 0 || __underflow (fp) == EOF)

	break;

    }

  return n - more;

}

libc_hidden_def (_IO_default_xsgetn)

FILE *

_IO_default_setbuf (FILE *fp, char *p, ssize_t len)

{

    if (_IO_SYNC (fp) == EOF)

	return NULL;

    if (p == NULL || len == 0)

      {

	fp->_flags |= _IO_UNBUFFERED;

	_IO_setb (fp, fp->_shortbuf, fp->_shortbuf+1, 0);

      }

    else

      {

	fp->_flags &= ~_IO_UNBUFFERED;

	_IO_setb (fp, p, p+len, 0);

      }

    fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = 0;

    fp->_IO_read_base = fp->_IO_read_ptr = fp->_IO_read_end = 0;

    return fp;

}

off64_t

_IO_default_seekpos (FILE *fp, off64_t pos, int mode)

{

  return _IO_SEEKOFF (fp, pos, 0, mode);

}

int

_IO_default_doallocate (FILE *fp)

{

  char *buf;

  buf = malloc(BUFSIZ);

  if (__glibc_unlikely (buf == NULL))

    return EOF;

  _IO_setb (fp, buf, buf+BUFSIZ, 1);

  return 1;

}

libc_hidden_def (_IO_default_doallocate)

void

_IO_init_internal (FILE *fp, int flags)

{

  _IO_no_init (fp, flags, -1, NULL, NULL);

}

void

_IO_init (FILE *fp, int flags)

{

  IO_set_accept_foreign_vtables (&_IO_vtable_check);

  _IO_init_internal (fp, flags);

}

static int stdio_needs_locking;

/* In a single-threaded process most stdio locks can be omitted.  After

   _IO_enable_locks is called, locks are not optimized away any more.

   It must be first called while the process is still single-threaded.

   This lock optimization can be disabled on a per-file basis by setting

   _IO_FLAGS2_NEED_LOCK, because a file can have user-defined callbacks

   or can be locked with flockfile and then a thread may be created

   between a lock and unlock, so omitting the lock is not valid.

   Here we have to make sure that the flag is set on all existing files

   and files created later.  */

void

_IO_enable_locks (void)

{

  _IO_ITER i;

  if (stdio_needs_locking)

    return;

  stdio_needs_locking = 1;

  for (i = _IO_iter_begin (); i != _IO_iter_end (); i = _IO_iter_next (i))

    _IO_iter_file (i)->_flags2 |= _IO_FLAGS2_NEED_LOCK;

}

libc_hidden_def (_IO_enable_locks)

void

_IO_old_init (FILE *fp, int flags)

{

  fp->_flags = _IO_MAGIC|flags;

  fp->_flags2 = 0;

  if (stdio_needs_locking)

    fp->_flags2 |= _IO_FLAGS2_NEED_LOCK;

  fp->_IO_buf_base = NULL;

  fp->_IO_buf_end = NULL;

  fp->_IO_read_base = NULL;

  fp->_IO_read_ptr = NULL;

  fp->_IO_read_end = NULL;

  fp->_IO_write_base = NULL;

  fp->_IO_write_ptr = NULL;

  fp->_IO_write_end = NULL;

  fp->_chain = NULL; /* Not necessary. */

  fp->_IO_save_base = NULL;

  fp->_IO_backup_base = NULL;

  fp->_IO_save_end = NULL;

  fp->_markers = NULL;

  fp->_cur_column = 0;

#if _IO_JUMPS_OFFSET

  fp->_vtable_offset = 0;

#endif

#ifdef _IO_MTSAFE_IO

  if (fp->_lock != NULL)

    _IO_lock_init (*fp->_lock);

#endif

}

void

_IO_no_init (FILE *fp, int flags, int orientation,

	     struct _IO_wide_data *wd, const struct _IO_jump_t *jmp)

{

  _IO_old_init (fp, flags);

  fp->_mode = orientation;

  if (orientation >= 0)

    {

      fp->_wide_data = wd;

      fp->_wide_data->_IO_buf_base = NULL;

      fp->_wide_data->_IO_buf_end = NULL;

      fp->_wide_data->_IO_read_base = NULL;

      fp->_wide_data->_IO_read_ptr = NULL;

      fp->_wide_data->_IO_read_end = NULL;

      fp->_wide_data->_IO_write_base = NULL;

      fp->_wide_data->_IO_write_ptr = NULL;

      fp->_wide_data->_IO_write_end = NULL;

      fp->_wide_data->_IO_save_base = NULL;

      fp->_wide_data->_IO_backup_base = NULL;

      fp->_wide_data->_IO_save_end = NULL;

      fp->_wide_data->_wide_vtable = jmp;

    }

  else

    /* Cause predictable crash when a wide function is called on a byte

       stream.  */

    fp->_wide_data = (struct _IO_wide_data *) -1L;

  fp->_freeres_list = NULL;

}

int

_IO_default_sync (FILE *fp)

{

  return 0;

}

/* The way the C++ classes are mapped into the C functions in the

   current implementation, this function can get called twice! */

void

_IO_default_finish (FILE *fp, int dummy)

{

  struct _IO_marker *mark;

  if (fp->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))

    {

      free (fp->_IO_buf_base);

      fp->_IO_buf_base = fp->_IO_buf_end = NULL;

    }

  for (mark = fp->_markers; mark != NULL; mark = mark->_next)

    mark->_sbuf = NULL;

  if (fp->_IO_save_base)

    {

      free (fp->_IO_save_base);

      fp->_IO_save_base = NULL;

    }

  _IO_un_link ((struct _IO_FILE_plus *) fp);

#ifdef _IO_MTSAFE_IO

  if (fp->_lock != NULL)

    _IO_lock_fini (*fp->_lock);

#endif

}

libc_hidden_def (_IO_default_finish)

off64_t

_IO_default_seekoff (FILE *fp, off64_t offset, int dir, int mode)

{

  return _IO_pos_BAD;

}

int

_IO_sputbackc (FILE *fp, int c)

{

  int result;

  if (fp->_IO_read_ptr > fp->_IO_read_base

      && (unsigned char)fp->_IO_read_ptr[-1] == (unsigned char)c)

    {

      fp->_IO_read_ptr--;

      result = (unsigned char) c;

    }

  else

    result = _IO_PBACKFAIL (fp, c);

  if (result != EOF)

    fp->_flags &= ~_IO_EOF_SEEN;

  return result;

}

libc_hidden_def (_IO_sputbackc)

int

_IO_sungetc (FILE *fp)

{

  int result;

  if (fp->_IO_read_ptr > fp->_IO_read_base)

    {

      fp->_IO_read_ptr--;

      result = (unsigned char) *fp->_IO_read_ptr;

    }

  else

    result = _IO_PBACKFAIL (fp, EOF);

  if (result != EOF)

    fp->_flags &= ~_IO_EOF_SEEN;

  return result;

}

unsigned

_IO_adjust_column (unsigned start, const char *line, int count)

{

  const char *ptr = line + count;

  while (ptr > line)

    if (*--ptr == '\n')

      return line + count - ptr - 1;

  return start + count;

}

libc_hidden_def (_IO_adjust_column)

int

_IO_flush_all_lockp (int do_lock)

{

  int result = 0;

  FILE *fp;

#ifdef _IO_MTSAFE_IO

  _IO_cleanup_region_start_noarg (flush_cleanup);

  _IO_lock_lock (list_all_lock);

#endif

  for (fp = (FILE *) _IO_list_all; fp != NULL; fp = fp->_chain)

    {

      run_fp = fp;

      if (do_lock)

	_IO_flockfile (fp);

      if (((fp->_mode <= 0 && fp->_IO_write_ptr > fp->_IO_write_base)

	   || (_IO_vtable_offset (fp) == 0

	       && fp->_mode > 0 && (fp->_wide_data->_IO_write_ptr

				    > fp->_wide_data->_IO_write_base))

	   )

	  && _IO_OVERFLOW (fp, EOF) == EOF)

	result = EOF;

      if (do_lock)

	_IO_funlockfile (fp);

      run_fp = NULL;

    }

#ifdef _IO_MTSAFE_IO

  _IO_lock_unlock (list_all_lock);

  _IO_cleanup_region_end (0);

#endif

  return result;

}

int

_IO_flush_all (void)

{

  /* We want locking.  */

  return _IO_flush_all_lockp (1);

}

libc_hidden_def (_IO_flush_all)

void

_IO_flush_all_linebuffered (void)

{

  FILE *fp;

#ifdef _IO_MTSAFE_IO

  _IO_cleanup_region_start_noarg (flush_cleanup);

  _IO_lock_lock (list_all_lock);

#endif

  for (fp = (FILE *) _IO_list_all; fp != NULL; fp = fp->_chain)

    {

      run_fp = fp;

      _IO_flockfile (fp);

      if ((fp->_flags & _IO_NO_WRITES) == 0 && fp->_flags & _IO_LINE_BUF)

	_IO_OVERFLOW (fp, EOF);

      _IO_funlockfile (fp);

      run_fp = NULL;

    }

#ifdef _IO_MTSAFE_IO

  _IO_lock_unlock (list_all_lock);

  _IO_cleanup_region_end (0);

#endif

}

libc_hidden_def (_IO_flush_all_linebuffered)

weak_alias (_IO_flush_all_linebuffered, _flushlbf)

/* The following is a bit tricky.  In general, we want to unbuffer the

   streams so that all output which follows is seen.  If we are not

   looking for memory leaks it does not make much sense to free the

   actual buffer because this will happen anyway once the program

   terminated.  If we do want to look for memory leaks we have to free

   the buffers.  Whether something is freed is determined by the

   function sin the libc_freeres section.  Those are called as part of

   the atexit routine, just like _IO_cleanup.  The problem is we do

   not know whether the freeres code is called first or _IO_cleanup.

   if the former is the case, we set the DEALLOC_BUFFER variable to

   true and _IO_unbuffer_all will take care of the rest.  If

   _IO_unbuffer_all is called first we add the streams to a list

   which the freeres function later can walk through.  */

static void _IO_unbuffer_all (void);

static bool dealloc_buffers;

static FILE *freeres_list;

static void

_IO_unbuffer_all (void)

{

  FILE *fp;

#ifdef _IO_MTSAFE_IO

  _IO_cleanup_region_start_noarg (flush_cleanup);

  _IO_lock_lock (list_all_lock);

#endif

  for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain)

    {

      if (! (fp->_flags & _IO_UNBUFFERED)

	  /* Iff stream is un-orientated, it wasn't used. */

	  && fp->_mode != 0)

	{

#ifdef _IO_MTSAFE_IO

	  int cnt;

#define MAXTRIES 2

	  for (cnt = 0; cnt < MAXTRIES; ++cnt)

	    if (fp->_lock == NULL || _IO_lock_trylock (*fp->_lock) == 0)

	      break;

	    else

	      /* Give the other thread time to finish up its use of the

		 stream.  */

	      __sched_yield ();

#endif

	  if (! dealloc_buffers && !(fp->_flags & _IO_USER_BUF))

	    {

	      fp->_flags |= _IO_USER_BUF;

	      fp->_freeres_list = freeres_list;

	      freeres_list = fp;

	      fp->_freeres_buf = fp->_IO_buf_base;

	    }

	  _IO_SETBUF (fp, NULL, 0);

	  if (fp->_mode > 0)

	    _IO_wsetb (fp, NULL, NULL, 0);

#ifdef _IO_MTSAFE_IO

	  if (cnt < MAXTRIES && fp->_lock != NULL)

	    _IO_lock_unlock (*fp->_lock);

#endif

	}

      /* Make sure that never again the wide char functions can be

	 used.  */

      fp->_mode = -1;

    }

#ifdef _IO_MTSAFE_IO

  _IO_lock_unlock (list_all_lock);

  _IO_cleanup_region_end (0);

#endif

}

libc_freeres_fn (buffer_free)

{

  dealloc_buffers = true;

  while (freeres_list != NULL)

    {

      free (freeres_list->_freeres_buf);

      freeres_list = freeres_list->_freeres_list;

    }

}

int

_IO_cleanup (void)

{

  /* We do *not* want locking.  Some threads might use streams but

     that is their problem, we flush them underneath them.  */

  int result = _IO_flush_all_lockp (0);

  /* We currently don't have a reliable mechanism for making sure that

     C++ static destructors are executed in the correct order.

     So it is possible that other static destructors might want to

     write to cout - and they're supposed to be able to do so.

     The following will make the standard streambufs be unbuffered,

     which forces any output from late destructors to be written out. */

  _IO_unbuffer_all ();

  return result;

}

void

_IO_init_marker (struct _IO_marker *marker, FILE *fp)

{

  marker->_sbuf = fp;

  if (_IO_in_put_mode (fp))

    _IO_switch_to_get_mode (fp);

  if (_IO_in_backup (fp))

    marker->_pos = fp->_IO_read_ptr - fp->_IO_read_end;