exam_timer_teacher/qtlockedfile/qtlockedfile.h

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
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** Licensees holding valid commercial Qt licenses may use this file in
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** GNU General Public License Usage
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** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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#pragma once

#include <QFile>

#if defined(Q_OS_WIN)
#  if !defined(QT_QTLOCKEDFILE_EXPORT) && !defined(QT_QTLOCKEDFILE_IMPORT)
#    define QT_QTLOCKEDFILE_EXPORT
#  elif defined(QT_QTLOCKEDFILE_IMPORT)
#    if defined(QT_QTLOCKEDFILE_EXPORT)
#      undef QT_QTLOCKEDFILE_EXPORT
#    endif
#    define QT_QTLOCKEDFILE_EXPORT __declspec(dllimport)
#  elif defined(QT_QTLOCKEDFILE_EXPORT)
#    undef QT_QTLOCKEDFILE_EXPORT
#    define QT_QTLOCKEDFILE_EXPORT __declspec(dllexport)
#  endif
#else
#  define QT_QTLOCKEDFILE_EXPORT
#endif

namespace SharedTools {

class QT_QTLOCKEDFILE_EXPORT QtLockedFile : public QFile
{
public:
    enum LockMode { NoLock = 0, ReadLock, WriteLock };

    QtLockedFile();
    QtLockedFile(const QString &name);
    ~QtLockedFile();

    bool lock(LockMode mode, bool block = true);
    bool unlock();
    bool isLocked() const;
    LockMode lockMode() const;

private:
#ifdef Q_OS_WIN
    Qt::HANDLE m_semaphore_hnd;
    Qt::HANDLE m_mutex_hnd;
#endif
    LockMode m_lock_mode;
};

} // namespace SharedTools