qsharedmemory.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 QSHAREDMEMORY_H
#define QSHAREDMEMORY_H
 
#include <QtCore/qtipccommon.h>
#ifndef QT_NO_QOBJECT
# include <QtCore/qobject.h>
#else
# include <QtCore/qobjectdefs.h>
# include <QtCore/qscopedpointer.h>
# include <QtCore/qstring.h>
#endif
 
QT_BEGIN_NAMESPACE
 
#if QT_CONFIG(sharedmemory)
 
class QSharedMemoryPrivate;
 
class Q_CORE_EXPORT QSharedMemory : public QObject
{
    Q_OBJECT
    Q_DECLARE_PRIVATE(QSharedMemory)
 
public:
    enum AccessMode
    {
        ReadOnly,
        ReadWrite
    };
    Q_ENUM(AccessMode)
 
    enum SharedMemoryError
    {
        NoError,
        PermissionDenied,
        InvalidSize,
        KeyError,
        AlreadyExists,
        NotFound,
        LockError,
        OutOfResources,
        UnknownError
    };
    Q_ENUM(SharedMemoryError)
 
    QSharedMemory(QObject *parent = nullptr);
    QSharedMemory(const QNativeIpcKey &key, QObject *parent = nullptr);
    ~QSharedMemory();
 
    QSharedMemory(const QString &key, QObject *parent = nullptr);
    void setKey(const QString &key);
    QString key() const;
 
    void setNativeKey(const QNativeIpcKey &key);
    void setNativeKey(const QString &key, QNativeIpcKey::Type type = QNativeIpcKey::legacyDefaultTypeForOs())
    { setNativeKey({ key, type }); }
    QString nativeKey() const;
    QNativeIpcKey nativeIpcKey() const;
#if QT_CORE_REMOVED_SINCE(6, 5)
    void setNativeKey(const QString &key);
#endif
 
    bool create(qsizetype size, AccessMode mode = ReadWrite);
    qsizetype size() const;
 
    bool attach(AccessMode mode = ReadWrite);
    bool isAttached() const;
    bool detach();
 
    void *data();
    const void* constData() const;
    const void *data() const;
 
#if QT_CONFIG(systemsemaphore)
    bool lock();
    bool unlock();
#endif
 
    SharedMemoryError 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(QSharedMemory)
};
 
#endif // QT_CONFIG(sharedmemory)
 
QT_END_NAMESPACE
 
#endif // QSHAREDMEMORY_H