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/***************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Qt Software Information (qt-info@nokia.com)
**
**
** Non-Open Source Usage
**
** Licensees may use this file in accordance with the Qt Beta Version
** License Agreement, Agreement version 2.2 provided with the Software or,
** alternatively, in accordance with the terms contained in a written
** agreement between you and Nokia.
**
** GNU General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU General
** Public License versions 2.0 or 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 GNU
** General Public Licensing requirements will be met:
**
** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
** http://www.gnu.org/copyleft/gpl.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt GPL Exception version
** 1.2, included in the file GPL_EXCEPTION.txt in this package.
**
***************************************************************************/
#include "qtlockedfile.h"
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
namespace SharedTools {
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();
}
} // namespace SharedTools
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