| /**************************************************************************** |
| ** |
| ** Copyright (C) 2011 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. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
| ** GNU Lesser General Public License Usage |
| ** 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. |
| ** |
| ** 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. |
| ** |
| ** Other Usage |
| ** Alternatively, this file may be used in accordance with the terms and |
| ** conditions contained in a signed written agreement between you and Nokia. |
| ** |
| ** |
| ** |
| ** |
| ** |
| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| #include "qplatformdefs.h" |
| |
| #include "qsharedmemory.h" |
| #include "qsharedmemory_p.h" |
| #include "qsystemsemaphore.h" |
| #include <qdir.h> |
| #include <qdebug.h> |
| |
| #include <errno.h> |
| |
| #ifndef QT_NO_SHAREDMEMORY |
| #include <sys/types.h> |
| #include <sys/ipc.h> |
| #include <sys/shm.h> |
| #include <sys/types.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 |
| |
| QSharedMemoryPrivate::QSharedMemoryPrivate() |
| : QObjectPrivate(), memory(0), size(0), error(QSharedMemory::NoError), |
| #ifndef QT_NO_SYSTEMSEMAPHORE |
| systemSemaphore(QString()), lockedByMe(false), |
| #endif |
| unix_key(0) |
| { |
| } |
| |
| void QSharedMemoryPrivate::setErrorString(const QString &function) |
| { |
| // EINVAL is handled in functions so they can give better error strings |
| switch (errno) { |
| case EACCES: |
| errorString = QSharedMemory::tr("%1: permission denied").arg(function); |
| error = QSharedMemory::PermissionDenied; |
| break; |
| case EEXIST: |
| errorString = QSharedMemory::tr("%1: already exists").arg(function); |
| error = QSharedMemory::AlreadyExists; |
| break; |
| case ENOENT: |
| errorString = QSharedMemory::tr("%1: doesn't exist").arg(function); |
| error = QSharedMemory::NotFound; |
| break; |
| case EMFILE: |
| case ENOMEM: |
| case ENOSPC: |
| errorString = QSharedMemory::tr("%1: out of resources").arg(function); |
| error = QSharedMemory::OutOfResources; |
| break; |
| default: |
| errorString = QSharedMemory::tr("%1: unknown error %2").arg(function).arg(errno); |
| error = QSharedMemory::UnknownError; |
| #if defined QSHAREDMEMORY_DEBUG |
| qDebug() << errorString << "key" << key << "errno" << errno << EINVAL; |
| #endif |
| } |
| } |
| |
| /*! |
| \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 (key.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 |
| QString fileName = makePlatformSafeKey(key); |
| if (!QFile::exists(fileName)) { |
| errorString = QSharedMemory::tr("%1: UNIX key file doesn't exist").arg(QLatin1String("QSharedMemory::handle:")); |
| error = QSharedMemory::NotFound; |
| return 0; |
| } |
| |
| unix_key = ftok(QFile::encodeName(fileName).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 true if the unix file was created. |
| |
| -1 error |
| 0 already existed |
| 1 created |
| */ |
| int QSharedMemoryPrivate::createUnixKeyFile(const QString &fileName) |
| { |
| if (QFile::exists(fileName)) |
| return 0; |
| |
| 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(makePlatformSafeKey(key)); |
| 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(makePlatformSafeKey(key)); |
| return false; |
| } |
| |
| // create |
| if (-1 == shmget(unix_key, size, 0666 | 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(makePlatformSafeKey(key)); |
| 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 ? 0444 : 0660)); |
| 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, 0444); |
| 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(makePlatformSafeKey(key))) |
| return false; |
| } |
| return true; |
| } |
| |
| |
| QT_END_NAMESPACE |
| |
| #endif // QT_NO_SHAREDMEMORY |