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/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** 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, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qsharedmemory.h"
#include "qsharedmemory_p.h"
#include "qsystemsemaphore.h"
#include <qdebug.h>
QT_BEGIN_NAMESPACE
#ifndef QT_NO_SHAREDMEMORY
QSharedMemoryPrivate::QSharedMemoryPrivate() : QObjectPrivate(),
memory(0), size(0), error(QSharedMemory::NoError),
systemSemaphore(QString()), lockedByMe(false), hand(0)
{
}
void QSharedMemoryPrivate::setErrorString(const QString &function)
{
BOOL 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;
#if defined QSHAREDMEMORY_DEBUG
qDebug() << errorString << "key" << key;
#endif
}
}
HANDLE QSharedMemoryPrivate::handle()
{
if (!hand) {
QString function = QLatin1String("QSharedMemory::handle");
QString safeKey = makePlatformSafeKey(key);
if (safeKey.isEmpty()) {
error = QSharedMemory::KeyError;
errorString = QSharedMemory::tr("%1: unable to make key").arg(function);
return false;
}
#ifndef Q_OS_WINCE
hand = OpenFileMapping(FILE_MAP_ALL_ACCESS, false, (wchar_t*)safeKey.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*)safeKey.utf16());
#endif
if (!hand) {
setErrorString(function);
return false;
}
}
return hand;
}
bool QSharedMemoryPrivate::cleanHandle()
{
if (hand != 0 && !CloseHandle(hand)) {
hand = 0;
return false;
setErrorString(QLatin1String("QSharedMemory::cleanHandle"));
}
hand = 0;
return true;
}
bool QSharedMemoryPrivate::create(int size)
{
// Get a windows acceptable key
QString safeKey = makePlatformSafeKey(key);
QString function = QLatin1String("QSharedMemory::create");
if (safeKey.isEmpty()) {
error = QSharedMemory::KeyError;
errorString = QSharedMemory::tr("%1: key error").arg(function);
return false;
}
// Create the file mapping.
hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size, (wchar_t*)safeKey.utf16());
setErrorString(function);
// hand is valid when it already exists unlike unix so explicitly check
if (error == QSharedMemory::AlreadyExists || !hand)
return false;
return true;
}
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;
// close handle
return cleanHandle();
}
#endif //QT_NO_SHAREDMEMORY
QT_END_NAMESPACE
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