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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 302 insertions, 0 deletions

diff --git a/src/corelib/kernel/qsharedmemory_unix.cpp b/src/corelib/kernel/qsharedmemory_unix.cpp
new file mode 100644
index 0000000000..b30117f6c1
--- /dev/null
+++ b/src/corelib/kernel/qsharedmemory_unix.cpp
@@ -0,0 +1,302 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 "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 (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 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(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, 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(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 ? 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(nativeKey))
+            return false;
+    }
+    return true;
+}
+
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_SHAREDMEMORY