8a16b7a18f
Mainly focus on files that use BSD 3-Clause license. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point.
142 lines
3.6 KiB
C
142 lines
3.6 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*
|
|
* Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the author nor the names of any co-contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* POSIX stdio FILE locking functions. These assume that the locking
|
|
* is only required at FILE structure level, not at file descriptor
|
|
* level too.
|
|
*
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "namespace.h"
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <pthread.h>
|
|
#include "un-namespace.h"
|
|
|
|
#include "local.h"
|
|
|
|
|
|
/*
|
|
* Weak symbols for externally visible functions in this file:
|
|
*/
|
|
__weak_reference(_flockfile, flockfile);
|
|
__weak_reference(_flockfile_debug_stub, _flockfile_debug);
|
|
__weak_reference(_ftrylockfile, ftrylockfile);
|
|
__weak_reference(_funlockfile, funlockfile);
|
|
|
|
void _flockfile_debug_stub(FILE *, char *, int);
|
|
int _ftrylockfile(FILE *);
|
|
|
|
void
|
|
_flockfile(FILE *fp)
|
|
{
|
|
pthread_t curthread = _pthread_self();
|
|
|
|
if (fp->_fl_owner == curthread)
|
|
fp->_fl_count++;
|
|
else {
|
|
/*
|
|
* Make sure this mutex is treated as a private
|
|
* internal mutex:
|
|
*/
|
|
_pthread_mutex_lock(&fp->_fl_mutex);
|
|
fp->_fl_owner = curthread;
|
|
fp->_fl_count = 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This can be overriden by the threads library if it is linked in.
|
|
*/
|
|
void
|
|
_flockfile_debug_stub(FILE *fp, char *fname, int lineno)
|
|
{
|
|
_flockfile(fp);
|
|
}
|
|
|
|
int
|
|
_ftrylockfile(FILE *fp)
|
|
{
|
|
pthread_t curthread = _pthread_self();
|
|
int ret = 0;
|
|
|
|
if (fp->_fl_owner == curthread)
|
|
fp->_fl_count++;
|
|
/*
|
|
* Make sure this mutex is treated as a private
|
|
* internal mutex:
|
|
*/
|
|
else if (_pthread_mutex_trylock(&fp->_fl_mutex) == 0) {
|
|
fp->_fl_owner = curthread;
|
|
fp->_fl_count = 1;
|
|
}
|
|
else
|
|
ret = -1;
|
|
return (ret);
|
|
}
|
|
|
|
void
|
|
_funlockfile(FILE *fp)
|
|
{
|
|
pthread_t curthread = _pthread_self();
|
|
|
|
/*
|
|
* Check if this file is owned by the current thread:
|
|
*/
|
|
if (fp->_fl_owner == curthread) {
|
|
/*
|
|
* Check if this thread has locked the FILE
|
|
* more than once:
|
|
*/
|
|
if (fp->_fl_count > 1)
|
|
/*
|
|
* Decrement the count of the number of
|
|
* times the running thread has locked this
|
|
* file:
|
|
*/
|
|
fp->_fl_count--;
|
|
else {
|
|
/*
|
|
* The running thread will release the
|
|
* lock now:
|
|
*/
|
|
fp->_fl_count = 0;
|
|
fp->_fl_owner = NULL;
|
|
_pthread_mutex_unlock(&fp->_fl_mutex);
|
|
}
|
|
}
|
|
}
|