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/*
This file is part of the KDE games library
Copyright (C) 2003 Nicolas Hadacek <hadacek@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License version 2 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "kfilelock.h"
#include <unistd.h>
#include <sys/file.h>
#include <errno.h>
#include <kdebug.h>
KFileLock::KFileLock(int fd)
: _fd(fd), _locked(false)
{}
int KFileLock::lock()
{
kdDebug(11002) << "lock fd=" << _fd << endl;
#ifdef F_SETLK
# ifndef SEEK_SET
# define SEEK_SET 0
# endif
struct flock lock_data;
lock_data.l_type = F_WRLCK;
lock_data.l_whence = SEEK_SET;
lock_data.l_start = lock_data.l_len = 0;
if ( fcntl(_fd, F_SETLK, &lock_data)==-1 ) {
if ( errno==EAGAIN ) return -2;
return -1;
}
#else
# ifdef LOCK_EX
if ( flock (_fd, LOCK_EX|LOCK_NB)==-1 ) {
if ( errno==EWOULDBLOCK ) return -2;
return -1;
}
# else
if ( lockf(_fd, F_TLOCK, 0)==-1 ) {
if ( errno==EACCES ) return -2;
return -1;
}
# endif
#endif
_locked = true;
return 0;
}
KFileLock::~KFileLock()
{
unlock();
}
void KFileLock::unlock()
{
if ( !_locked ) return;
kdDebug(11002) << "unlock" << endl;
# ifdef F_SETLK
struct flock lock_data;
lock_data.l_type = F_UNLCK;
lock_data.l_whence = SEEK_SET;
lock_data.l_start = lock_data.l_len = 0;
(void)fcntl(_fd, F_SETLK, &lock_data);
# else
# ifdef F_ULOCK
lockf(_fd, F_ULOCK, 0);
# else
flock(_fd, LOCK_UN);
# endif
# endif
_locked = false;
}
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