2 * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL 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
32 * $FreeBSD: src/lib/libc/stdio/_flock_stub.c,v 1.3 1999/08/28 00:00:55 peter Exp $
33 * $DragonFly: src/lib/libc/stdio/_flock_stub.c,v 1.9 2005/07/23 20:23:05 joerg Exp $
37 #include "namespace.h"
40 #include "un-namespace.h"
43 #include "priv_stdio.h"
45 void __flockfile(FILE *fp);
46 void __flockfile_debug(FILE *fp, char *fname, int lineno);
47 int __ftrylockfile(FILE *fp);
48 void __funlockfile(FILE *fp);
51 * Externally visible weak symbols.
53 __weak_reference(__flockfile, flockfile);
54 __weak_reference(__flockfile, _flockfile);
55 __weak_reference(__flockfile_debug, _flockfile_debug);
56 __weak_reference(__ftrylockfile, ftrylockfile);
57 __weak_reference(__ftrylockfile, _ftrylockfile);
58 __weak_reference(__funlockfile, funlockfile);
59 __weak_reference(__funlockfile, _funlockfile);
66 pthread_t curthread = _pthread_self();
68 if (fp->_lock->fl_owner == curthread)
69 fp->_lock->fl_count++;
72 * Make sure this mutex is treated as a private
75 _pthread_mutex_lock(&fp->_lock->fl_mutex);
76 fp->_lock->fl_owner = curthread;
77 fp->_lock->fl_count = 1;
82 __flockfile_debug(FILE *fp, char *fname __unused, int lineno __unused)
88 __ftrylockfile(FILE *fp)
90 pthread_t curthread = _pthread_self();
93 if (fp->_lock->fl_owner == curthread)
94 fp->_lock->fl_count++;
96 * Make sure this mutex is treated as a private
99 else if (_pthread_mutex_trylock(&fp->_lock->fl_mutex) == 0) {
100 fp->_lock->fl_owner = curthread;
101 fp->_lock->fl_count = 1;
109 __funlockfile(FILE *fp)
111 pthread_t curthread = _pthread_self();
114 * Check if this file is owned by the current thread:
116 if (fp->_lock->fl_owner == curthread) {
118 * Check if this thread has locked the FILE
121 if (fp->_lock->fl_count > 1)
123 * Decrement the count of the number of
124 * times the running thread has locked this
127 fp->_lock->fl_count--;
130 * The running thread will release the
133 fp->_lock->fl_count = 0;
134 fp->_lock->fl_owner = NULL;
135 _pthread_mutex_unlock(&fp->_lock->fl_mutex);