fclose.c revision 291602 
1/*-
2 * Copyright (c) 1990, 1993 The Regents of the University of California.
3 * Copyright (c) 2013 Mariusz Zaborski <oshogbo@FreeBSD.org>
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Chris Torek.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)fclose.c	8.1 (Berkeley) 6/4/93";
36#endif /* LIBC_SCCS and not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: stable/10/lib/libc/stdio/fclose.c 291602 2015-12-01 18:19:23Z ngie $");
39
40#include "namespace.h"
41#include <errno.h>
42#include <stdbool.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include "un-namespace.h"
46#include <spinlock.h>
47#include "libc_private.h"
48#include "local.h"
49
50static int
51cleanfile(FILE *fp, bool c)
52{
53	int r;
54
55	r = fp->_flags & __SWR ? __sflush(fp) : 0;
56	if (c) {
57		if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
58			r = EOF;
59	}
60
61	if (fp->_flags & __SMBF)
62		free((char *)fp->_bf._base);
63	if (HASUB(fp))
64		FREEUB(fp);
65	if (HASLB(fp))
66		FREELB(fp);
67	fp->_file = -1;
68	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
69
70	/*
71	 * Lock the spinlock used to protect __sglue list walk in
72	 * __sfp().  The __sfp() uses fp->_flags == 0 test as an
73	 * indication of the unused FILE.
74	 *
75	 * Taking the lock prevents possible compiler or processor
76	 * reordering of the writes performed before the final _flags
77	 * cleanup, making sure that we are done with the FILE before
78	 * it is considered available.
79	 */
80	STDIO_THREAD_LOCK();
81	fp->_flags = 0;		/* Release this FILE for reuse. */
82	STDIO_THREAD_UNLOCK();
83
84	return (r);
85}
86
87int
88fdclose(FILE *fp, int *fdp)
89{
90	int r, err;
91
92	if (fdp != NULL)
93		*fdp = -1;
94
95	if (fp->_flags == 0) {	/* not open! */
96		errno = EBADF;
97		return (EOF);
98	}
99
100	FLOCKFILE(fp);
101	r = 0;
102	if (fp->_close != __sclose) {
103		r = EOF;
104		errno = EOPNOTSUPP;
105	} else if (fp->_file < 0) {
106		r = EOF;
107		errno = EBADF;
108	}
109	if (r == EOF) {
110		err = errno;
111		(void)cleanfile(fp, true);
112		errno = err;
113	} else {
114		if (fdp != NULL)
115			*fdp = fp->_file;
116		r = cleanfile(fp, false);
117	}
118	FUNLOCKFILE(fp);
119
120	return (r);
121}
122
123int
124fclose(FILE *fp)
125{
126	int r;
127
128	if (fp->_flags == 0) {	/* not open! */
129		errno = EBADF;
130		return (EOF);
131	}
132
133	FLOCKFILE(fp);
134	r = cleanfile(fp, true);
135	FUNLOCKFILE(fp);
136
137	return (r);
138}
139