| /**************************************************************************** |
| ** |
| ** 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 QtGui 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 "qwssharedmemory_p.h" |
| |
| #if !defined(QT_NO_QWS_MULTIPROCESS) |
| |
| #include <sys/shm.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| QWSSharedMemory::QWSSharedMemory() |
| : shmBase(0), shmSize(0), character(0), shmId(-1), key(-1) |
| { |
| } |
| |
| |
| QWSSharedMemory::~QWSSharedMemory() |
| { |
| detach(); |
| } |
| |
| /* |
| man page says: |
| On Linux, it is possible to attach a shared memory segment even if it |
| is already marked to be deleted. However, POSIX.1-2001 does not spec- |
| ify this behaviour and many other implementations do not support it. |
| */ |
| |
| bool QWSSharedMemory::create(int size) |
| { |
| if (shmId != -1) |
| detach(); |
| shmId = shmget(IPC_PRIVATE, size, IPC_CREAT|0600); |
| |
| if (shmId == -1) { |
| #ifdef QT_SHM_DEBUG |
| perror("QWSSharedMemory::create allocating shared memory"); |
| qWarning("Error allocating shared memory of size %d", size); |
| #endif |
| return false; |
| } |
| shmBase = shmat(shmId,0,0); |
| shmctl(shmId, IPC_RMID, 0); |
| if (shmBase == (void*)-1) { |
| #ifdef QT_SHM_DEBUG |
| perror("QWSSharedMemory::create attaching to shared memory"); |
| qWarning("Error attaching to shared memory id %d", shmId); |
| #endif |
| shmBase = 0; |
| return false; |
| } |
| return true; |
| } |
| |
| bool QWSSharedMemory::attach(int id) |
| { |
| if (shmId == id) |
| return id != -1; |
| if (shmId != -1) |
| detach(); |
| |
| shmBase = shmat(id,0,0); |
| if (shmBase == (void*)-1) { |
| #ifdef QT_SHM_DEBUG |
| perror("QWSSharedMemory::attach attaching to shared memory"); |
| qWarning("Error attaching to shared memory 0x%x of size %d", |
| id, size()); |
| #endif |
| shmBase = 0; |
| return false; |
| } |
| shmId = id; |
| return true; |
| } |
| |
| |
| void QWSSharedMemory::detach () |
| { |
| if (!shmBase) |
| return; |
| shmdt (shmBase); |
| shmBase = 0; |
| shmSize = 0; |
| shmId = -1; |
| } |
| |
| void QWSSharedMemory::setPermissions (mode_t mode) |
| { |
| struct shmid_ds shm; |
| shmctl (shmId, IPC_STAT, &shm); |
| shm.shm_perm.mode = mode; |
| shmctl (shmId, IPC_SET, &shm); |
| } |
| |
| int QWSSharedMemory::size () const |
| { |
| struct shmid_ds shm; |
| shmctl (shmId, IPC_STAT, &shm); |
| return shm.shm_segsz; |
| } |
| |
| |
| // old API |
| |
| |
| |
| QWSSharedMemory::QWSSharedMemory (int size, const QString &filename, char c) |
| { |
| shmSize = size; |
| shmFile = filename; |
| shmBase = 0; |
| shmId = -1; |
| character = c; |
| key = ftok (shmFile.toLatin1().constData(), c); |
| } |
| |
| |
| |
| bool QWSSharedMemory::create () |
| { |
| shmId = shmget (key, shmSize, IPC_CREAT | 0666); |
| return (shmId != -1); |
| } |
| |
| void QWSSharedMemory::destroy () |
| { |
| if (shmId != -1) |
| shmctl(shmId, IPC_RMID, 0); |
| } |
| |
| bool QWSSharedMemory::attach () |
| { |
| if (shmId == -1) |
| shmId = shmget (key, shmSize, 0); |
| |
| shmBase = shmat (shmId, 0, 0); |
| if ((long)shmBase == -1) |
| shmBase = 0; |
| |
| return (long)shmBase != 0; |
| } |
| |
| |
| QT_END_NAMESPACE |
| |
| #endif // QT_NO_QWS_MULTIPROCESS |