/****************************************************************************
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** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
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**
** This file is part of the QtGui module of the Qt Toolkit.
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** 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
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****************************************************************************/

#ifndef QLOCK_P_H
#define QLOCK_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  This header file may
// change from version to version without notice, or even be
// removed.
//
// We mean it.
//

#include "QtCore/qstring.h"

QT_BEGIN_NAMESPACE

class QLockData;

class Q_GUI_EXPORT QLock
{
public:
    QLock(const QString &filename, char id, bool create = false);
    ~QLock();

    enum Type { Read, Write };

    bool isValid() const;
    void lock(Type type);
    void unlock();
    bool locked() const;

private:
    Type type;
    QLockData *data;
};


// Nice class for ensuring the lock is released.
// Just create one on the stack and the lock is automatically released
// when QLockHandle is destructed.
class Q_GUI_EXPORT QLockHandle
{
public:
    QLockHandle(QLock *l, QLock::Type type) : qlock(l) { qlock->lock(type); }
    ~QLockHandle() { if (locked()) qlock->unlock(); }

    void lock(QLock::Type type) { qlock->lock(type); }
    void unlock() { qlock->unlock(); }
    bool locked() const { return qlock->locked(); }

private:
    QLock *qlock;
};

QT_END_NAMESPACE

#endif // QLOCK_P_H
