Files
vxWorks/libc/stdio/fflush.c
2025-08-20 18:25:46 +08:00

166 lines
4.5 KiB
C

/* fflush.c - flush file stdio.h */
/* Copyright 1992-1995 Wind River Systems, Inc. */
/*
modification history
--------------------
01g,05feb99,dgp document errno values
01f,10mar95,ism removed SPR#2548 changes.
01e,20jan95,ism changed FIOFLUSH to FIOSYNC
01d,03oct94,ism added FIOFLUSH ioctl to __sflush() as per SPR#2548
01c,05mar93,jdi documentation cleanup for 5.1.
01b,20sep92,smb documentation additions
01a,29jul92,jcf Added OBJ_VERIFY
smb taken from UCB stdio
*/
/*
DESCRIPTION
*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
INCLUDE FILE: stdio.h, error.h
SEE ALSO: American National Standard X3.159-1989
NOMANUAL
*/
#include "vxWorks.h"
#include "stdio.h"
#include "errno.h"
#include "objLib.h"
#include "private/stdioP.h"
#include "sys/ioctl.h"
#include "ioLib.h"
/******************************************************************************
*
* fflush - flush a stream (ANSI)
*
* This routine writes to the file any unwritten data for a specified output
* or update stream for which the most recent operation was not input; for an
* input stream the behavior is undefined.
*
* CAVEAT
* ANSI specifies that if <fp> is a null pointer, fflush() performs the
* flushing action on all streams for which the behavior is defined; however,
* this is not implemented in VxWorks.
*
* INCLUDE FILES: stdio.h
*
* RETURNS: Zero, or EOF if a write error occurs.
*
* ERRNO: EBADF
*
* SEE ALSO: fclose()
*/
int fflush
(
FAST FILE * fp /* stream to flush */
)
{
if (OBJ_VERIFY (fp, fpClassId) != OK)
return (EOF);
/* ANSI specifies that fflush (NULL) will flush all task's file pointers.
* The problem is that we don't keep such a list today so we return EOF
* for now.
*/
if ((fp == NULL) ||
((fp->_flags & __SWR) == 0))
{
errno = EBADF;
return (EOF);
}
return (__sflush(fp));
}
/******************************************************************************
*
* __sflush - flush stream pointed to by fp.
*
* INCLUDE: stdio.h
*
* RETURNS: ZERO or EOF
* NOMANUAL
*/
int __sflush
(
FAST FILE *fp
)
{
FAST unsigned char *p;
FAST int n;
FAST int t;
if (OBJ_VERIFY (fp, fpClassId) != OK)
return (EOF);
t = fp->_flags;
if ((t & __SWR) == 0)
return (0);
if ((p = fp->_bf._base) == NULL)
return (0);
n = fp->_p - p; /* write this much */
/* Set these immediately to avoid problems with longjmp and to allow
* exchange buffering (via setvbuf) in user write function.
*/
fp->_p = p;
fp->_w = (t & (__SLBF|__SNBF)) ? (0) : (fp->_bf._size);
for (; n > 0; n -= t, p += t)
{
t = __swrite (fp, (char *)p, n);
if (t <= 0)
{
fp->_flags |= __SERR;
return (EOF);
}
}
return (0);
}