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Files
amiga-clib2/library/stdio_ftell.c
Olaf Barthel c0c70bfd99 - Added stdio thread locking functions flockfile(), funlockfile(),
and ftrylockfile().

- Modified the internal FILE structure to allow for thread locking.
  Note that this again requires that the library is rebuilt!

- Added or modified macros for getc_unlocked(), getchar_unlocked(),
  putc_unlocked() and putchar_unlocked().

- Added rand_r().

- Added flockfile()/funlockfile() wrappers around all stdio
  functions.


git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@14841 87f5fb63-7c3d-0410-a384-fd976d0f7a62
2005-02-27 18:09:12 +00:00

132 lines
3.3 KiB
C

/*
* $Id: stdio_ftell.c,v 1.7 2005-02-27 18:09:10 obarthel Exp $
*
* :ts=4
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2005 by Olaf Barthel <olsen@sourcery.han.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of Olaf Barthel nor the names of contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */
/****************************************************************************/
#ifndef _STDIO_HEADERS_H
#include "stdio_headers.h"
#endif /* _STDIO_HEADERS_H */
/****************************************************************************/
long int
ftell(FILE *stream)
{
struct iob * file = (struct iob *)stream;
struct file_action_message fam;
long int result = -1;
int position;
assert( stream != NULL );
if(__check_abort_enabled)
__check_abort();
flockfile(stream);
#if defined(CHECK_FOR_NULL_POINTERS)
{
if(stream == NULL)
{
__set_errno(EFAULT);
goto out;
}
}
#endif /* CHECK_FOR_NULL_POINTERS */
assert( __is_valid_iob(file) );
assert( FLAG_IS_SET(file->iob_Flags,IOBF_IN_USE) );
assert( file->iob_BufferSize > 0 );
if(FLAG_IS_CLEAR(file->iob_Flags,IOBF_IN_USE))
{
SHOWMSG("this file is not even in use");
SET_FLAG(file->iob_Flags,IOBF_ERROR);
__set_errno(EBADF);
goto out;
}
SHOWMSG("calling the hook");
SHOWPOINTER(&fam);
fam.fam_Action = file_action_seek;
fam.fam_Offset = 0;
fam.fam_Mode = SEEK_CUR;
SHOWVALUE(fam.fam_Offset);
SHOWVALUE(fam.fam_Mode);
assert( file->iob_Action != NULL );
position = (*file->iob_Action)(file,&fam);
if(position < 0)
{
SET_FLAG(file->iob_Flags,IOBF_ERROR);
__set_errno(fam.fam_Error);
goto out;
}
if(__iob_read_buffer_is_valid(file))
{
/* Subtract the number of bytes still in the buffer which have
* not been read before.
*/
position -= __iob_num_unread_bytes(file);
}
else if (__iob_write_buffer_is_valid(file))
{
/* Add the number of bytes still stored in the buffer which have
* not been written to disk yet.
*/
position += __iob_num_unwritten_bytes(file);
}
result = position;
out:
funlockfile(stream);
return(result);
}