/*
 * $Id: stdio_fflush.c,v 1.8 2005-04-24 08:46:37 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 */

/****************************************************************************/

int
fflush(FILE *stream)
{
	int result = EOF;

	ENTER();

	SHOWPOINTER(stream);

	if(__check_abort_enabled)
		__check_abort();

	/* Subtlety alert: the thread-safe library needs to obtain locks for
	   stdio, buffered files and file descriptors in a very particular
	   order in order to steer clear of deadlocks. The order is as given
	   above: stdio, buffered files, file descriptor table entries. Which
	   normally means that if code has any business locking stdio or the
	   file descriptor table entries, it should lock stdio first. This
	   function, at least in the UNIX_PATH_SEMANTICS variant, does not do
	   this. Here's why: if the 'stream' variable is NULL to start with,
	   no per-stream locking is performed anyway, and the stdio lock can
	   be obtained without running the risk of having obtain semaphores
	   in the wrong order. */
	flockfile(stream);

	#if defined(UNIX_PATH_SEMANTICS)
	{
		/* Flush a particular stream? */
		if(stream != NULL)
		{
			struct iob * file = (struct iob *)stream;

			assert( __is_valid_iob(file) );

			if(__iob_write_buffer_is_valid(file) && __flush_iob_write_buffer(file) < 0)
				goto out;
		}
		else
		{
			int failed_iob = -1;
			int i;

			__stdio_lock();

			/* Flush all streams which still have unwritten data in the buffer. */
			for(i = 0 ; i < __num_iob ; i++)
			{
				if(__iob[i] != NULL &&
				   FLAG_IS_SET(__iob[i]->iob_Flags,IOBF_IN_USE) &&
				   FLAG_IS_SET(__iob[i]->iob_Flags,IOBF_WRITE) &&
				   __iob_write_buffer_is_valid(__iob[i]))
				{
					if(__flush_iob_write_buffer(__iob[i]) < 0)
					{
						failed_iob = i;
						break;
					}
				}
			}

			__stdio_unlock();

			if(failed_iob >= 0)
				goto out;
		}
	}
	#else
	{
		struct iob * file = (struct iob *)stream;

		assert( stream != NULL );

		#if defined(CHECK_FOR_NULL_POINTERS)
		{
			if(stream == NULL)
			{
				SHOWMSG("invalid file handle");

				__set_errno(EFAULT);
				goto out;
			}
		}
		#endif /* CHECK_FOR_NULL_POINTERS */

		assert( __is_valid_iob(file) );

		if(__iob_write_buffer_is_valid(file) && __flush_iob_write_buffer(file) < 0)
			goto out;
	}
	#endif /* UNIX_PATH_SEMANTICS */

	result = OK;

 out:

	funlockfile(stream);

	RETURN(result);
	return(result);
}
