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/* $NetBSD: flockfile.c,v 1.8 2003/07/22 00:56:25 nathanw Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <LibConfig.h>
#include <sys/EfiCdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: flockfile.c,v 1.8 2003/07/22 00:56:25 nathanw Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include "reentrant.h"
#include "local.h"
#ifdef __weak_alias
__weak_alias(flockfile,_flockfile)
__weak_alias(ftrylockfile,_ftrylockfile)
__weak_alias(funlockfile,_funlockfile)
#endif
#ifdef _REENTRANT
/*
* XXX This code makes the assumption that a thr_t (pthread_t) is a
* XXX pointer.
*/
extern int __isthreaded;
void
flockfile(FILE *fp)
{
__flockfile_internal(fp, 0);
}
int
ftrylockfile(FILE *fp)
{
int retval;
if (__isthreaded == 0)
return 0;
retval = 0;
mutex_lock(&_LOCK(fp));
if (_LOCKOWNER(fp) == thr_self()) {
_LOCKCOUNT(fp)++;
} else if (_LOCKOWNER(fp) == NULL) {
_LOCKOWNER(fp) = thr_self();
_LOCKCOUNT(fp) = 1;
} else
retval = -1;
mutex_unlock(&_LOCK(fp));
return retval;
}
void
funlockfile(FILE *fp)
{
__funlockfile_internal(fp, 0);
}
void
__flockfile_internal(FILE *fp, int internal)
{
if (__isthreaded == 0)
return;
mutex_lock(&_LOCK(fp));
if (_LOCKOWNER(fp) == thr_self()) {
_LOCKCOUNT(fp)++;
if (internal)
_LOCKINTERNAL(fp)++;
} else {
/* danger! cond_wait() is a cancellation point. */
int oldstate;
thr_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate);
while (_LOCKOWNER(fp) != NULL)
cond_wait(&_LOCKCOND(fp), &_LOCK(fp));
thr_setcancelstate(oldstate, NULL);
_LOCKOWNER(fp) = thr_self();
_LOCKCOUNT(fp) = 1;
if (internal)
_LOCKINTERNAL(fp) = 1;
}
if (_LOCKINTERNAL(fp) == 1)
/* stash cancellation state and disable */
thr_setcancelstate(PTHREAD_CANCEL_DISABLE,
&_LOCKCANCELSTATE(fp));
mutex_unlock(&_LOCK(fp));
}
void
__funlockfile_internal(FILE *fp, int internal)
{
if (__isthreaded == 0)
return;
mutex_lock(&_LOCK(fp));
if (internal) {
_LOCKINTERNAL(fp)--;
if (_LOCKINTERNAL(fp) == 0)
thr_setcancelstate(_LOCKCANCELSTATE(fp), NULL);
}
_LOCKCOUNT(fp)--;
if (_LOCKCOUNT(fp) == 0) {
_LOCKOWNER(fp) = NULL;
cond_signal(&_LOCKCOND(fp));
}
mutex_unlock(&_LOCK(fp));
}
#else /* _REENTRANT */
void
flockfile(FILE *fp)
{
/* LINTED deliberate lack of effect */
(void)fp;
return;
}
int
ftrylockfile(FILE *fp)
{
/* LINTED deliberate lack of effect */
(void)fp;
return (0);
}
void
funlockfile(FILE *fp)
{
/* LINTED deliberate lack of effect */
(void)fp;
return;
}
#endif /* _REENTRANT */
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