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/****************************************************************************
**
** Copyright (C) 2012 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
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** 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
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qsharedmemory.h"
#include "qsharedmemory_p.h"
#include <qdebug.h>
#ifndef QT_NO_SHAREDMEMORY
//#define QSHAREDMEMORY_DEBUG
QT_BEGIN_NAMESPACE
QSharedMemoryPrivate::QSharedMemoryPrivate()
: QObjectPrivate(), memory(0), size(0), error(QSharedMemory::NoError),
#ifndef QT_NO_SYSTEMSEMAPHORE
systemSemaphore(QString()), lockedByMe(false),
#endif
hand(0)
{
}
void QSharedMemoryPrivate::setErrorString(const QString &function)
{
DWORD windowsError = GetLastError();
if (windowsError == 0)
return;
switch (windowsError) {
case ERROR_ALREADY_EXISTS:
error = QSharedMemory::AlreadyExists;
errorString = QSharedMemory::tr("%1: already exists").arg(function);
break;
case ERROR_FILE_NOT_FOUND:
#ifdef Q_OS_WINCE
// This happens on CE only if no file is present as CreateFileMappingW
// bails out with this error code
case ERROR_INVALID_PARAMETER:
#endif
error = QSharedMemory::NotFound;
errorString = QSharedMemory::tr("%1: doesn't exist").arg(function);
break;
case ERROR_COMMITMENT_LIMIT:
error = QSharedMemory::InvalidSize;
errorString = QSharedMemory::tr("%1: invalid size").arg(function);
break;
case ERROR_NO_SYSTEM_RESOURCES:
case ERROR_NOT_ENOUGH_MEMORY:
error = QSharedMemory::OutOfResources;
errorString = QSharedMemory::tr("%1: out of resources").arg(function);
break;
case ERROR_ACCESS_DENIED:
error = QSharedMemory::PermissionDenied;
errorString = QSharedMemory::tr("%1: permission denied").arg(function);
break;
default:
errorString = QSharedMemory::tr("%1: unknown error %2").arg(function).arg(windowsError);
error = QSharedMemory::UnknownError;
#ifdef QSHAREDMEMORY_DEBUG
qDebug() << errorString << "key" << key;
#endif
break;
}
}
HANDLE QSharedMemoryPrivate::handle()
{
if (!hand) {
// don't allow making handles on empty keys
if (nativeKey.isEmpty()) {
error = QSharedMemory::KeyError;
errorString = QSharedMemory::tr("%1: key is empty").arg(QLatin1String("QSharedMemory::handle"));
return false;
}
#ifndef Q_OS_WINCE
hand = OpenFileMapping(FILE_MAP_ALL_ACCESS, false, (wchar_t*)nativeKey.utf16());
#else
// This works for opening a mapping too, but always opens it with read/write access in
// attach as it seems.
hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, 0, (wchar_t*)nativeKey.utf16());
#endif
if (!hand)
setErrorString(QLatin1String("QSharedMemory::handle"));
}
return hand;
}
void QSharedMemoryPrivate::cleanHandle()
{
if (hand != 0 && !CloseHandle(hand))
setErrorString(QLatin1String("QSharedMemory::cleanHandle"));
hand = 0;
}
bool QSharedMemoryPrivate::create(int size)
{
if (nativeKey.isEmpty()) {
error = QSharedMemory::KeyError;
errorString = QSharedMemory::tr("%1: key is empty").arg(QLatin1String("QSharedMemory::create"));
return false;
}
// Create the file mapping.
hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size, (wchar_t*)nativeKey.utf16());
setErrorString(QLatin1String("QSharedMemory::create"));
// hand is valid when it already exists unlike unix so explicitly check
return !(error == QSharedMemory::AlreadyExists || !hand);
}
bool QSharedMemoryPrivate::attach(QSharedMemory::AccessMode mode)
{
// Grab a pointer to the memory block
int permissions = (mode == QSharedMemory::ReadOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS);
memory = (void *)MapViewOfFile(handle(), permissions, 0, 0, 0);
if (0 == memory) {
setErrorString(QLatin1String("QSharedMemory::attach"));
cleanHandle();
return false;
}
// Grab the size of the memory we have been given (a multiple of 4K on windows)
MEMORY_BASIC_INFORMATION info;
if (!VirtualQuery(memory, &info, sizeof(info))) {
// Windows doesn't set an error code on this one,
// it should only be a kernel memory error.
error = QSharedMemory::UnknownError;
errorString = QSharedMemory::tr("%1: size query failed").arg(QLatin1String("QSharedMemory::attach"));
return false;
}
size = info.RegionSize;
return true;
}
bool QSharedMemoryPrivate::detach()
{
// umap memory
if (!UnmapViewOfFile(memory)) {
setErrorString(QLatin1String("QSharedMemory::detach"));
return false;
}
memory = 0;
size = 0;
// close handle
cleanHandle();
return true;
}
QT_END_NAMESPACE
#endif // QT_NO_SHAREDMEMORY
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