fflush.c revision 92986 
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38static char sccsid[] = "@(#)fflush.c	8.1 (Berkeley) 6/4/93";
39#endif /* LIBC_SCCS and not lint */
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: head/lib/libc/stdio/fflush.c 92986 2002-03-22 21:53:29Z obrien $");
42
43#include "namespace.h"
44#include <errno.h>
45#include <stdio.h>
46#include "un-namespace.h"
47#include "libc_private.h"
48#include "local.h"
49
50static int	sflush_locked(FILE *);
51
52/*
53 * Flush a single file, or (if fp is NULL) all files.
54 * MT-safe version
55 */
56int
57fflush(FILE *fp)
58{
59	int retval;
60
61	if (fp == NULL)
62		return (_fwalk(sflush_locked));
63	FLOCKFILE(fp);
64	if ((fp->_flags & (__SWR | __SRW)) == 0) {
65		errno = EBADF;
66		retval = EOF;
67	} else
68		retval = __sflush(fp);
69	FUNLOCKFILE(fp);
70	return (retval);
71}
72
73/*
74 * Flush a single file, or (if fp is NULL) all files.
75 * Non-MT-safe version
76 */
77int
78__fflush(FILE *fp)
79{
80	int retval;
81
82	if (fp == NULL)
83		return (_fwalk(sflush_locked));
84	if ((fp->_flags & (__SWR | __SRW)) == 0) {
85		errno = EBADF;
86		retval = EOF;
87	} else
88		retval = __sflush(fp);
89	return (retval);
90}
91
92int
93__sflush(FILE *fp)
94{
95	unsigned char *p;
96	int n, t;
97
98	t = fp->_flags;
99	if ((t & __SWR) == 0)
100		return (0);
101
102	if ((p = fp->_bf._base) == NULL)
103		return (0);
104
105	n = fp->_p - p;		/* write this much */
106
107	/*
108	 * Set these immediately to avoid problems with longjmp and to allow
109	 * exchange buffering (via setvbuf) in user write function.
110	 */
111	fp->_p = p;
112	fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
113
114	for (; n > 0; n -= t, p += t) {
115		t = _swrite(fp, (char *)p, n);
116		if (t <= 0) {
117			fp->_flags |= __SERR;
118			return (EOF);
119		}
120	}
121	return (0);
122}
123
124static int
125sflush_locked(FILE *fp)
126{
127	int	ret;
128
129	FLOCKFILE(fp);
130	ret = __sflush(fp);
131	FUNLOCKFILE(fp);
132	return (ret);
133}
134