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-rw-r--r--src/gui/embedded/qwssharedmemory.cpp185
1 files changed, 185 insertions, 0 deletions
diff --git a/src/gui/embedded/qwssharedmemory.cpp b/src/gui/embedded/qwssharedmemory.cpp
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+++ b/src/gui/embedded/qwssharedmemory.cpp
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+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 "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