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/****************************************************************************
**
** Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of a Qt Solutions component.
**
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Solutions Commercial License Agreement provided
** with the Software or, alternatively, in accordance with the terms
** contained in a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** Please note Third Party Software included with Qt Solutions may impose
** additional restrictions and it is the user's responsibility to ensure
** that they have met the licensing requirements of the GPL, LGPL, or Qt
** Solutions Commercial license and the relevant license of the Third
** Party Software they are using.
**
** If you are unsure which license is appropriate for your use, please
** contact Nokia at qt-info@nokia.com.
**
****************************************************************************/
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include "qtlockedfile.h"
bool QtLockedFile::lock(LockMode mode, bool block)
{
if (!isOpen()) {
qWarning("QtLockedFile::lock(): file is not opened");
return false;
}
if (mode == NoLock)
return unlock();
if (mode == m_lock_mode)
return true;
if (m_lock_mode != NoLock)
unlock();
struct flock fl;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 0;
fl.l_type = (mode == ReadLock) ? F_RDLCK : F_WRLCK;
int cmd = block ? F_SETLKW : F_SETLK;
int ret = fcntl(handle(), cmd, &fl);
if (ret == -1) {
if (errno != EINTR && errno != EAGAIN)
qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
return false;
}
m_lock_mode = mode;
return true;
}
bool QtLockedFile::unlock()
{
if (!isOpen()) {
qWarning("QtLockedFile::unlock(): file is not opened");
return false;
}
if (!isLocked())
return true;
struct flock fl;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 0;
fl.l_type = F_UNLCK;
int ret = fcntl(handle(), F_SETLKW, &fl);
if (ret == -1) {
qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
return false;
}
m_lock_mode = NoLock;
return true;
}
QtLockedFile::~QtLockedFile()
{
if (isOpen())
unlock();
}
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