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//========================================================================

//

//      fflush.cxx

//

//      Implementation of C library file flush function as per ANSI 7.9.5.2

//

//========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

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//

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// or inline functions from this file, or you compile this file and link it

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//####ECOSGPLCOPYRIGHTEND####

//========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):     jlarmour

// Contributors:  

// Date:          2000-04-20

// Purpose:       Provides ISO C fflush() function

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

//========================================================================

// CONFIGURATION

#include <pkgconf/libc_stdio.h>   // Configuration header

// INCLUDES

#include <cyg/infra/cyg_type.h>     // Common project-wide type definitions

#include <stddef.h>                 // NULL and size_t from compiler

#include <errno.h>                  // Error codes

#include <stdio.h>                  // header for fflush()

#include <cyg/libc/stdio/stream.hxx>// C library streams

#include <cyg/libc/stdio/stdiofiles.hxx>  // C library files

#include <cyg/libc/stdio/stdiosupp.hxx>   // support for stdio

// FUNCTIONS

// flush all but one stream

externC Cyg_ErrNo

cyg_libc_stdio_flush_all_but( Cyg_StdioStream *not_this_stream )

{

    cyg_bool files_flushed[FOPEN_MAX] = { false }; // sets all to 0

    cyg_bool loop_again, looped = false;

    cyg_ucount32 i;

    Cyg_ErrNo err=ENOERR;

    Cyg_StdioStream *stream;

    do {

        loop_again = false;

        for (i=0; (i<FOPEN_MAX) && !err; i++) {

            if (files_flushed[i] == false) {

                stream = Cyg_libc_stdio_files::get_file_stream(i);

                if ((stream == NULL) || (stream == not_this_stream)) {

                    // if it isn't a valid stream, set its entry in the

                    // list of files flushed since we don't want to

                    // flush it

                    // Ditto if its the one we're meant to miss

                    files_flushed[i] = true;

                } // if

                else {

                    // valid stream

#ifdef CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO

                    // only buffers which we've written to need flushing

                    if ( !stream->flags.last_buffer_op_was_read)

#endif

                    {

                        // we try to flush the first time through so that

                        // everything is flushed that can be flushed.

                        // The second time through we should just wait

                        // in case some other lowerpri thread has locked the

                        // stream, otherwise we will spin needlessly and

                        // never let the lower pri thread run!

                        if ( (looped && stream->lock_me()) ||

                             stream->trylock_me() ) {

                            err = stream->flush_output_unlocked();

                            stream->unlock_me();

                            files_flushed[i] = true;

                        } // if

                        else {

                            loop_again = true;

                            looped = true;

                        }

                    }

                } // else

            } // if

        } // for

    } // do

    while(loop_again && !err);

    return err;

} // cyg_libc_stdio_flush_all_but()

externC int

fflush( FILE *stream )

{

    Cyg_StdioStream *real_stream = (Cyg_StdioStream *)stream;

    Cyg_ErrNo err;

    if (stream == NULL) {  // tells us to flush ALL streams

        err = cyg_libc_stdio_flush_all_but(NULL);

    } // if

    else {

        err = real_stream->flush_output();

    } // else

    if (err) {

        errno = err;

        return EOF;

    } // if

    return 0;

} // fflush()

// EOF fflush.cxx