qsystemsemaphore.h

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QSYSTEMSEMAPHORE_H
#define QSYSTEMSEMAPHORE_H
 
#include <QtCore/qcoreapplication.h>
#include <QtCore/qtipccommon.h>
#include <QtCore/qstring.h>
#include <QtCore/qscopedpointer.h>
 
QT_BEGIN_NAMESPACE
 
#if QT_CONFIG(systemsemaphore)
 
class QSystemSemaphorePrivate;
 
class Q_CORE_EXPORT QSystemSemaphore
{
    Q_GADGET
    Q_DECLARE_TR_FUNCTIONS(QSystemSemaphore)
public:
    enum AccessMode
    {
        Open,
        Create
    };
    Q_ENUM(AccessMode)
 
    enum SystemSemaphoreError
    {
        NoError,
        PermissionDenied,
        KeyError,
        AlreadyExists,
        NotFound,
        OutOfResources,
        UnknownError
    };
 
    QSystemSemaphore(const QNativeIpcKey &key, int initialValue = 0, AccessMode = Open);
    ~QSystemSemaphore();
 
    void setNativeKey(const QNativeIpcKey &key, int initialValue = 0, AccessMode = Open);
    void setNativeKey(const QString &key, int initialValue = 0, AccessMode mode = Open,
                      QNativeIpcKey::Type type = QNativeIpcKey::legacyDefaultTypeForOs())
    { setNativeKey({ key, type }, initialValue, mode); }
    QNativeIpcKey nativeIpcKey() const;
 
    QSystemSemaphore(const QString &key, int initialValue = 0, AccessMode mode = Open);
    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;
 
    static bool isKeyTypeSupported(QNativeIpcKey::Type type) Q_DECL_CONST_FUNCTION;
    static QNativeIpcKey platformSafeKey(const QString &key,
            QNativeIpcKey::Type type = QNativeIpcKey::DefaultTypeForOs);
    static QNativeIpcKey legacyNativeKey(const QString &key,
            QNativeIpcKey::Type type = QNativeIpcKey::legacyDefaultTypeForOs());
 
private:
    Q_DISABLE_COPY(QSystemSemaphore)
    QScopedPointer<QSystemSemaphorePrivate> d;
};
 
#endif // QT_CONFIG(systemsemaphore)
 
QT_END_NAMESPACE
 
#endif // QSYSTEMSEMAPHORE_H