/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** 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
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** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** 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
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** $QT_END_LICENSE$
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****************************************************************************/

#ifndef QSYSTEMSEMAPHORE_H
#define QSYSTEMSEMAPHORE_H

#include <QtCore/qstring.h>
#include <QtCore/qscopedpointer.h>

QT_BEGIN_NAMESPACE


#ifndef QT_NO_SYSTEMSEMAPHORE

class QSystemSemaphorePrivate;

class Q_CORE_EXPORT QSystemSemaphore
{

public:
    enum AccessMode
    {
        Open,
        Create
    };

    enum SystemSemaphoreError
    {
        NoError,
        PermissionDenied,
        KeyError,
        AlreadyExists,
        NotFound,
        OutOfResources,
        UnknownError
    };

    QSystemSemaphore(const QString &key, int initialValue = 0, AccessMode mode = Open);
    ~QSystemSemaphore();

    void setKey(const QString &key, int initialValue = 0, AccessMode mode = Open);
    QString key() const;

    bool acquire();
    bool release(int n = 1);

    SystemSemaphoreError error() const;
    QString errorString() const;

private:
    Q_DISABLE_COPY(QSystemSemaphore)
    QScopedPointer<QSystemSemaphorePrivate> d;
};

#endif // QT_NO_SYSTEMSEMAPHORE

QT_END_NAMESPACE

#endif // QSYSTEMSEMAPHORE_H

