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//==========================================================================
//
//      io/common/io_file.c
//
//      High-level file I/O support.
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####                                            
// -------------------------------------------                              
// This file is part of eCos, the Embedded Configurable Operating System.   
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under    
// the terms of the GNU General Public License as published by the Free     
// Software Foundation; either version 2 or (at your option) any later      
// version.                                                                 
//
// eCos 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 General Public License    
// for more details.                                                        
//
// You should have received a copy of the GNU General Public License        
// along with eCos; if not, write to the Free Software Foundation, Inc.,    
// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
//
// As a special exception, if other files instantiate templates or use      
// macros or inline functions from this file, or you compile this file      
// and link it with other works to produce a work based on this file,       
// this file does not by itself cause the resulting work to be covered by   
// the GNU General Public License. However the source code for this file    
// must still be made available in accordance with section (3) of the GNU   
// General Public License v2.                                               
//
// This exception does not invalidate any other reasons why a work based    
// on this file might be covered by the GNU General Public License.         
// -------------------------------------------                              
// ####ECOSGPLCOPYRIGHTEND####                                              
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    gthomas
// Contributors: gthomas
// Date:         2000-01-10
// Purpose:      
// Description:  
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================
 
 
// File I/O support
 
#include <pkgconf/io.h>
#include <cyg/io/file.h>
#include <cyg/error/codes.h>
 
struct file fds[CYGPKG_IO_NFILE];
 
//
// This function allcates a file "slot".
//
int
falloc(struct file **fp, int *fd)
{
    int i;
    struct file *f;
    f = &fds[0];
    for (i = 0;  i < CYGPKG_IO_NFILE;  i++, f++) {
        if (f->f_flag == 0) {
            f->f_flag = FALLOC;
            *fp = f;
            *fd = i;
            return 0;
        }
    }
    return EMFILE;  // No more files
}
 
//
// This function is used to return a file slot.
//
void
ffree(struct file *fp)
{
    fp->f_flag = 0;  // Mark free
}
 
//
// This function provides the mapping from a file descriptor (small
// integer used by application code) to the corresponding file slot.
cyg_bool
getfp(int fd, struct file **fp)
{
    struct file *f;
    if (fd >= CYGPKG_IO_NFILE)
        return -1;
    f =  &fds[fd];
    if (f->f_flag == 0)
        return -1;
    *fp = f;
    return 0;
}