kolibrios/programs/develop/open watcom/trunk/clib/streamio/allocfp.c
Sergey Semyonov (Serge) 3be3768ce0 update CLib
git-svn-id: svn://kolibrios.org@614 a494cfbc-eb01-0410-851d-a64ba20cac60
2007-08-28 10:31:46 +00:00

93 lines
3.1 KiB
C

/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: Platform independent __allocfp() implementation.
*
****************************************************************************/
#include "variety.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "liballoc.h"
#include "fileacc.h"
#include "rtdata.h"
#include "seterrno.h"
#include "streamio.h"
#define KEEP_FLAGS (_READ | _WRITE | _DYNAMIC)
FILE *__allocfp( int handle )
{
FILE *end;
FILE *fp;
__stream_link *link;
unsigned flags;
handle = handle;
_AccessIOB();
/* Try and take one off the recently closed list */
link = _RWD_cstream;
if( link != NULL ) {
_RWD_cstream = link->next;
fp = link->stream;
flags = (fp->_flag & KEEP_FLAGS) | (_READ | _WRITE);
goto got_one;
}
/* See if there is a static FILE structure available. */
end = &_RWD_iob[_NFILES];
for( fp = _RWD_iob; fp < end; ++fp ) {
if( (fp->_flag & (_READ | _WRITE)) == 0 ) {
link = lib_malloc( sizeof( __stream_link ) );
if( link == NULL )
goto no_mem;
flags = _READ | _WRITE;
goto got_one;
}
}
/* Allocate a new dynamic structure */
flags = _DYNAMIC | _READ | _WRITE;
link = lib_malloc( sizeof( __stream_link ) + sizeof( FILE ) );
if( link == NULL )
goto no_mem;
fp = (FILE *)(link + 1);
got_one:
memset( fp, 0, sizeof( *fp ) );
fp->_flag = flags;
link->stream = fp;
link->stream->_link = link; /* point back to link structure */
link->next = _RWD_ostream;
_RWD_ostream = link;
_ReleaseIOB();
return( fp );
no_mem:
__set_errno( ENOMEM );
_ReleaseIOB();
return( NULL ); /* no free slots */
}