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Diffstat (limited to 'src/corelib/kernel/qsharedmemory_systemv.cpp')
-rw-r--r-- | src/corelib/kernel/qsharedmemory_systemv.cpp | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/src/corelib/kernel/qsharedmemory_systemv.cpp b/src/corelib/kernel/qsharedmemory_systemv.cpp new file mode 100644 index 0000000000..b3fe300a43 --- /dev/null +++ b/src/corelib/kernel/qsharedmemory_systemv.cpp @@ -0,0 +1,254 @@ +/**************************************************************************** +** +** Copyright (C) 2014 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. +** +** $QT_BEGIN_LICENSE:LGPL21$ +** 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 or version 3 as published by the Free +** Software Foundation and appearing in the file LICENSE.LGPLv21 and +** LICENSE.LGPLv3 included in the packaging of this file. Please review the +** following information to ensure the GNU Lesser General Public License +** requirements will be met: https://www.gnu.org/licenses/lgpl.html and +** 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. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qplatformdefs.h" + +#include "qsharedmemory.h" +#include "qsharedmemory_p.h" +#include "qsystemsemaphore.h" +#include <qdir.h> +#include <qdebug.h> + +#include <errno.h> + +#ifndef QT_POSIX_IPC + +#ifndef QT_NO_SHAREDMEMORY +#include <sys/types.h> +#include <sys/ipc.h> +#include <sys/shm.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#endif //QT_NO_SHAREDMEMORY + +#include "private/qcore_unix_p.h" + +#ifndef QT_NO_SHAREDMEMORY +QT_BEGIN_NAMESPACE + +/*! + \internal + + If not already made create the handle used for accessing the shared memory. +*/ +key_t QSharedMemoryPrivate::handle() +{ + // already made + if (unix_key) + return unix_key; + + // don't allow making handles on empty keys + if (nativeKey.isEmpty()) { + errorString = QSharedMemory::tr("%1: key is empty").arg(QLatin1String("QSharedMemory::handle:")); + error = QSharedMemory::KeyError; + return 0; + } + + // ftok requires that an actual file exists somewhere + if (!QFile::exists(nativeKey)) { + errorString = QSharedMemory::tr("%1: UNIX key file doesn't exist").arg(QLatin1String("QSharedMemory::handle:")); + error = QSharedMemory::NotFound; + return 0; + } + + unix_key = ftok(QFile::encodeName(nativeKey).constData(), 'Q'); + if (-1 == unix_key) { + errorString = QSharedMemory::tr("%1: ftok failed").arg(QLatin1String("QSharedMemory::handle:")); + error = QSharedMemory::KeyError; + unix_key = 0; + } + return unix_key; +} + +#endif // QT_NO_SHAREDMEMORY + +#if !(defined(QT_NO_SHAREDMEMORY) && defined(QT_NO_SYSTEMSEMAPHORE)) +/*! + \internal + Creates the unix file if needed. + returns \c true if the unix file was created. + + -1 error + 0 already existed + 1 created + */ +int QSharedMemoryPrivate::createUnixKeyFile(const QString &fileName) +{ + int fd = qt_safe_open(QFile::encodeName(fileName).constData(), + O_EXCL | O_CREAT | O_RDWR, 0640); + if (-1 == fd) { + if (errno == EEXIST) + return 0; + return -1; + } else { + close(fd); + } + return 1; +} +#endif // QT_NO_SHAREDMEMORY && QT_NO_SYSTEMSEMAPHORE + +#ifndef QT_NO_SHAREDMEMORY + +bool QSharedMemoryPrivate::cleanHandle() +{ + unix_key = 0; + return true; +} + +bool QSharedMemoryPrivate::create(int size) +{ + // build file if needed + bool createdFile = false; + int built = createUnixKeyFile(nativeKey); + if (built == -1) { + errorString = QSharedMemory::tr("%1: unable to make key").arg(QLatin1String("QSharedMemory::handle:")); + error = QSharedMemory::KeyError; + return false; + } + if (built == 1) { + createdFile = true; + } + + // get handle + if (!handle()) { + if (createdFile) + QFile::remove(nativeKey); + return false; + } + + // create + if (-1 == shmget(unix_key, size, 0600 | IPC_CREAT | IPC_EXCL)) { + QString function = QLatin1String("QSharedMemory::create"); + switch (errno) { + case EINVAL: + errorString = QSharedMemory::tr("%1: system-imposed size restrictions").arg(QLatin1String("QSharedMemory::handle")); + error = QSharedMemory::InvalidSize; + break; + default: + setErrorString(function); + } + if (createdFile && error != QSharedMemory::AlreadyExists) + QFile::remove(nativeKey); + return false; + } + + return true; +} + +bool QSharedMemoryPrivate::attach(QSharedMemory::AccessMode mode) +{ + // grab the shared memory segment id + int id = shmget(unix_key, 0, (mode == QSharedMemory::ReadOnly ? 0400 : 0600)); + if (-1 == id) { + setErrorString(QLatin1String("QSharedMemory::attach (shmget)")); + return false; + } + + // grab the memory + memory = shmat(id, 0, (mode == QSharedMemory::ReadOnly ? SHM_RDONLY : 0)); + if ((void*) - 1 == memory) { + memory = 0; + setErrorString(QLatin1String("QSharedMemory::attach (shmat)")); + return false; + } + + // grab the size + shmid_ds shmid_ds; + if (!shmctl(id, IPC_STAT, &shmid_ds)) { + size = (int)shmid_ds.shm_segsz; + } else { + setErrorString(QLatin1String("QSharedMemory::attach (shmctl)")); + return false; + } + + return true; +} + +bool QSharedMemoryPrivate::detach() +{ + // detach from the memory segment + if (-1 == shmdt(memory)) { + QString function = QLatin1String("QSharedMemory::detach"); + switch (errno) { + case EINVAL: + errorString = QSharedMemory::tr("%1: not attached").arg(function); + error = QSharedMemory::NotFound; + break; + default: + setErrorString(function); + } + return false; + } + memory = 0; + size = 0; + + // Get the number of current attachments + int id = shmget(unix_key, 0, 0400); + cleanHandle(); + + struct shmid_ds shmid_ds; + if (0 != shmctl(id, IPC_STAT, &shmid_ds)) { + switch (errno) { + case EINVAL: + return true; + default: + return false; + } + } + // If there are no attachments then remove it. + if (shmid_ds.shm_nattch == 0) { + // mark for removal + if (-1 == shmctl(id, IPC_RMID, &shmid_ds)) { + setErrorString(QLatin1String("QSharedMemory::remove")); + switch (errno) { + case EINVAL: + return true; + default: + return false; + } + } + + // remove file + if (!QFile::remove(nativeKey)) + return false; + } + return true; +} + + +QT_END_NAMESPACE + +#endif // QT_NO_SHAREDMEMORY + +#endif // QT_POSIX_IPC |