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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_P_H
#define QSHAREDMEMORY_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include "qsharedmemory.h"
#include <QtCore/qstring.h>
#if QT_CONFIG(sharedmemory)
#include "qsystemsemaphore.h"
#include "qtipccommon_p.h"
#include "private/qobject_p.h"
#if QT_CONFIG(posix_shm)
# include <sys/mman.h>
#endif
#if QT_CONFIG(sysv_shm)
# include <sys/shm.h>
#endif
QT_BEGIN_NAMESPACE
class QSharedMemoryPrivate;
#if QT_CONFIG(systemsemaphore)
/*!
Helper class
*/
class QSharedMemoryLocker
{
public:
Q_NODISCARD_CTOR QSharedMemoryLocker(QSharedMemory *sharedMemory) : q_sm(sharedMemory)
{
Q_ASSERT(q_sm);
}
inline ~QSharedMemoryLocker()
{
if (q_sm)
q_sm->unlock();
}
inline bool lock()
{
if (q_sm && q_sm->lock())
return true;
q_sm = nullptr;
return false;
}
private:
QSharedMemory *q_sm;
};
#endif // QT_CONFIG(systemsemaphore)
class QSharedMemoryPosix
{
public:
static constexpr bool Enabled = QT_CONFIG(posix_shm);
static bool supports(QNativeIpcKey::Type type)
{ return type == QNativeIpcKey::Type::PosixRealtime; }
static bool runtimeSupportCheck();
bool handle(QSharedMemoryPrivate *self);
bool cleanHandle(QSharedMemoryPrivate *self);
bool create(QSharedMemoryPrivate *self, qsizetype size);
bool attach(QSharedMemoryPrivate *self, QSharedMemory::AccessMode mode);
bool detach(QSharedMemoryPrivate *self);
int hand = -1;
};
class QSharedMemorySystemV
{
public:
static constexpr bool Enabled = QT_CONFIG(sysv_shm);
static bool supports(QNativeIpcKey::Type type)
{ return quint16(type) <= 0xff; }
static bool runtimeSupportCheck();
#if QT_CONFIG(sysv_sem)
key_t handle(QSharedMemoryPrivate *self);
bool cleanHandle(QSharedMemoryPrivate *self);
bool create(QSharedMemoryPrivate *self, qsizetype size);
bool attach(QSharedMemoryPrivate *self, QSharedMemory::AccessMode mode);
bool detach(QSharedMemoryPrivate *self);
private:
void updateNativeKeyFile(const QNativeIpcKey &nativeKey);
QByteArray nativeKeyFile;
key_t unix_key = 0;
#endif
};
class QSharedMemoryWin32
{
public:
#ifdef Q_OS_WIN32
static constexpr bool Enabled = true;
#else
static constexpr bool Enabled = false;
#endif
static bool runtimeSupportCheck() { return Enabled; }
static bool supports(QNativeIpcKey::Type type)
{ return type == QNativeIpcKey::Type::Windows; }
Qt::HANDLE handle(QSharedMemoryPrivate *self);
bool cleanHandle(QSharedMemoryPrivate *self);
bool create(QSharedMemoryPrivate *self, qsizetype size);
bool attach(QSharedMemoryPrivate *self, QSharedMemory::AccessMode mode);
bool detach(QSharedMemoryPrivate *self);
Qt::HANDLE hand = nullptr;
};
class Q_AUTOTEST_EXPORT QSharedMemoryPrivate : public QObjectPrivate
{
Q_DECLARE_PUBLIC(QSharedMemory)
public:
QSharedMemoryPrivate(QNativeIpcKey::Type type) : nativeKey(type)
{ constructBackend(); }
~QSharedMemoryPrivate();
void *memory = nullptr;
qsizetype size = 0;
QNativeIpcKey nativeKey;
QString errorString;
#if QT_CONFIG(systemsemaphore)
using SemaphoreAccessMode = QSystemSemaphore::AccessMode;
QSystemSemaphore systemSemaphore{ QNativeIpcKey() };
bool lockedByMe = false;
#else
enum SemaphoreAccessMode {};
#endif
QSharedMemory::SharedMemoryError error = QSharedMemory::NoError;
union Backend {
Backend() {}
~Backend() {}
QSharedMemoryPosix posix;
QSharedMemorySystemV sysv;
QSharedMemoryWin32 win32;
};
QtIpcCommon::IpcStorageVariant<&Backend::posix, &Backend::sysv, &Backend::win32> backend;
void constructBackend();
void destructBackend();
bool initKey(SemaphoreAccessMode mode);
template <typename Lambda> auto visit(const Lambda &lambda)
{
return backend.visit(nativeKey.type(), lambda);
}
bool handle()
{
return visit([&](auto p) { return !!p->handle(this); });
}
bool cleanHandle()
{
return visit([&](auto p) { return p->cleanHandle(this); });
}
bool create(qsizetype size)
{
return visit([&](auto p) { return p->create(this, size); });
}
bool attach(QSharedMemory::AccessMode mode)
{
return visit([&](auto p) { return p->attach(this, mode); });
}
bool detach()
{
return visit([&](auto p) { return p->detach(this); });
}
inline void setError(QSharedMemory::SharedMemoryError e, const QString &message)
{ error = e; errorString = message; }
void setUnixErrorString(QLatin1StringView function);
void setWindowsErrorString(QLatin1StringView function);
#if QT_CONFIG(systemsemaphore)
bool tryLocker(QSharedMemoryLocker *locker, const QString &function) {
if (!locker->lock()) {
errorString = QSharedMemory::tr("%1: unable to lock").arg(function);
error = QSharedMemory::LockError;
return false;
}
return true;
}
QNativeIpcKey semaphoreNativeKey() const;
#endif // QT_CONFIG(systemsemaphore)
};
QT_END_NAMESPACE
#endif // QT_CONFIG(sharedmemory)
#endif // QSHAREDMEMORY_P_H
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