xref: /freebsd/lib/libc/stdio/fclose.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)fclose.c	8.1 (Berkeley) 6/4/93";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "namespace.h"
40 #include <errno.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include "un-namespace.h"
44 #include <spinlock.h>
45 #include "libc_private.h"
46 #include "local.h"
47 
48 int
49 fclose(FILE *fp)
50 {
51 	int r;
52 
53 	if (fp->_flags == 0) {	/* not open! */
54 		errno = EBADF;
55 		return (EOF);
56 	}
57 	FLOCKFILE(fp);
58 	r = fp->_flags & __SWR ? __sflush(fp) : 0;
59 	if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
60 		r = EOF;
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 	FUNLOCKFILE(fp);
84 	return (r);
85 }
86