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. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * $FreeBSD: src/lib/libc/stdio/_flock_stub.c,v 1.16 2008/04/17 22:17:53 jhb Exp $
33 * POSIX stdio FILE locking functions. These assume that the locking
34 * is only required at FILE structure level, not at file descriptor
39 #include "namespace.h"
42 #include "un-namespace.h"
48 * Weak symbols for externally visible functions in this file:
50 __weak_reference(_flockfile, flockfile);
51 __weak_reference(_flockfile_debug_stub, _flockfile_debug);
52 __weak_reference(_ftrylockfile, ftrylockfile);
53 __weak_reference(_funlockfile, funlockfile);
58 pthread_t curthread = _pthread_self();
60 if (fp->_fl_owner == curthread)
64 * Make sure this mutex is treated as a private
67 _pthread_mutex_lock(&fp->_fl_mutex);
68 fp->_fl_owner = curthread;
74 * This can be overriden by the threads library if it is linked in.
77 _flockfile_debug_stub(FILE *fp, char *fname __unused, int lineno __unused)
83 _ftrylockfile(FILE *fp)
85 pthread_t curthread = _pthread_self();
88 if (fp->_fl_owner == curthread)
91 * Make sure this mutex is treated as a private
94 else if (_pthread_mutex_trylock(&fp->_fl_mutex) == 0) {
95 fp->_fl_owner = curthread;
104 _funlockfile(FILE *fp)
106 pthread_t curthread = _pthread_self();
109 * Check if this file is owned by the current thread:
111 if (fp->_fl_owner == curthread) {
113 * Check if this thread has locked the FILE
116 if (fp->_fl_count > 1) {
118 * Decrement the count of the number of
119 * times the running thread has locked this
125 * The running thread will release the
129 fp->_fl_owner = NULL;
130 _pthread_mutex_unlock(&fp->_fl_mutex);