1 /** @file
2 Implementation of fflush as declared in <stdio.h>.
3
4 Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials are licensed and made available
6 under the terms and conditions of the BSD License that accompanies this
7 distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 Copyright (c) 1990, 1993
14 The Regents of the University of California. All rights reserved.
15
16 This code is derived from software contributed to Berkeley by
17 Chris Torek.
18
19 Redistribution and use in source and binary forms, with or without
20 modification, are permitted provided that the following conditions
21 are met:
22 - Redistributions of source code must retain the above copyright
23 notice, this list of conditions and the following disclaimer.
24 - Redistributions in binary form must reproduce the above copyright
25 notice, this list of conditions and the following disclaimer in the
26 documentation and/or other materials provided with the distribution.
27 - Neither the name of the University nor the names of its contributors
28 may be used to endorse or promote products derived from this software
29 without specific prior written permission.
30
31 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
32 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
35 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
36 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
37 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
38 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
39 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 POSSIBILITY OF SUCH DAMAGE.
42
43 NetBSD: fflush.c,v 1.15 2003/08/07 16:43:22 agc Exp
44 fflush.c 8.1 (Berkeley) 6/4/93
45 **/
46 #include <LibConfig.h>
47
48 #include <assert.h>
49 #include <errno.h>
50 #include <stdio.h>
51 #include "reentrant.h"
52 #include "local.h"
53
54 #ifdef _REENTRANT
55 extern rwlock_t __sfp_lock;
56 #endif
57
58 /* Flush a single file, or (if fp is NULL) all files. */
59 int
fflush(FILE * fp)60 fflush(FILE *fp)
61 {
62 int r;
63
64 if (fp == NULL) {
65 rwlock_rdlock(&__sfp_lock);
66 r = _fwalk(__sflush);
67 rwlock_unlock(&__sfp_lock);
68 return r;
69 }
70
71 FLOCKFILE(fp);
72 if ((fp->_flags & (__SWR | __SRW)) == 0) {
73 errno = EBADF;
74 r = EOF;
75 } else {
76 r = __sflush(fp);
77 }
78 FUNLOCKFILE(fp);
79 return r;
80 }
81
82 int
__sflush(FILE * fp)83 __sflush(FILE *fp)
84 {
85 unsigned char *p;
86 INT64 n;
87 int t;
88
89 _DIAGASSERT(fp != NULL);
90 if(fp == NULL) {
91 errno = EINVAL;
92 return (EOF);
93 }
94
95 t = fp->_flags;
96 if ((t & __SWR) == 0)
97 return (0);
98
99 if ((p = fp->_bf._base) == NULL)
100 return (0);
101
102 n = fp->_p - p; /* write this much */
103
104 /*
105 * Set these immediately to avoid problems with longjmp and to allow
106 * exchange buffering (via setvbuf) in user write function.
107 */
108 fp->_p = p;
109 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
110
111 for (; n > 0; n -= t, p += t) {
112 t = (*fp->_write)(fp->_cookie, (char *)p, (int)n);
113 if (t <= 0) {
114 fp->_flags |= __SERR;
115 return (EOF);
116 }
117 }
118 return (0);
119 }
120