Rename the TtyLocker class to QTtyLocker as it gets to Qt scope

Change-Id: I74b90ec2a6cb08a9bc75225e04995a3b05f2c6e9
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>

1 files changed, 184 insertions, 0 deletions

diff --git a/src/serialport/qttylocker_unix.cpp b/src/serialport/qttylocker_unix.cpp
new file mode 100644
index 00000000..15aee0c6
--- /dev/null
+++ b/src/serialport/qttylocker_unix.cpp
@@ -0,0 +1,184 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Denis Shienkov <denis.shienkov@gmail.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtSerialPort module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 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, 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.
+**
+** 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qttylocker_unix_p.h"
+
+#ifdef HAVE_BAUDBOY_H
+#  include <baudboy.h>
+#  include <cstdlib>
+#elif defined (HAVE_LOCKDEV_H)
+#  include <lockdev.h>
+#  include <unistd.h>
+#else
+#  include <signal.h>
+#  include <errno.h>
+#  include <fcntl.h>
+#  include <sys/stat.h>
+#  include <unistd.h>
+#  include <QtCore/qfile.h>
+#  include <QtCore/qdir.h>
+#  include <QtCore/qstringlist.h>
+#endif // defined (HAVE_BAUDBOY_H)
+
+QT_BEGIN_NAMESPACE
+
+QT_BEGIN_NAMESPACE_SERIALPORT
+
+#if !(defined (HAVE_BAUDBOY_H) || defined (HAVE_LOCKDEV_H))
+
+static
+const char * const entryLockDirectoryList[] = {
+    "/var/lock",
+    "/etc/locks",
+    "/var/spool/locks",
+    "/var/spool/uucp",
+    "/tmp",
+    0
+};
+
+// Returns the full path first found in the directory where you can create a lock file
+// (ie a directory with access to the read/write).
+// Verification of directories is of the order in accordance with the order
+// of records in the variable lockDirList.
+static
+QString lookupFirstSharedLockDir()
+{
+    for (int i = 0; entryLockDirectoryList[i] != 0; ++i) {
+        if (::access(entryLockDirectoryList[i], R_OK | W_OK) == 0)
+            return QLatin1String(entryLockDirectoryList[i]);
+    }
+    return QString();
+}
+
+// Returns the name of the lock file which is tied to the
+// device name, eg "LCK..ttyS0", etc.
+static
+QString generateLockFileNameAsNamedForm(const char *portName)
+{
+    QString result(lookupFirstSharedLockDir());
+    if (!result.isEmpty()) {
+        result.append(QLatin1String("/LCK.."));
+        result.append(QString::fromLatin1(portName).replace(QLatin1Char('/'), QLatin1Char('_')));
+    }
+    return result;
+}
+
+#endif //!(defined (HAVE_BAUDBOY_H) || defined (HAVE_LOCKDEV_H))
+
+// Try lock serial device. However, other processes can not access it.
+bool QTtyLocker::lock(const char *portName)
+{
+#ifdef HAVE_BAUDBOY_H
+    if (::ttylock(portName)
+        ::ttywait(portName);
+    return ::ttylock(portName) != -1;
+#elif defined (HAVE_LOCKDEV_H)
+    return ::dev_lock(portName) != -1;
+#else
+    QFile f(generateLockFileNameAsNamedForm(portName));
+    if (f.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        QString content(QLatin1String("     %1 %2\x0A"));
+        content = content.arg(::getpid()).arg(::getuid());
+        if (f.write(content.toLocal8Bit()) > 0) {
+            f.close();
+            return true;
+        }
+        f.close();
+    }
+    return false;
+#endif
+}
+
+// Try unlock serial device. However, other processes can access it.
+bool QTtyLocker::unlock(const char *portName)
+{
+#ifdef HAVE_BAUDBOY_H
+    return ::ttyunlock(portName != -1;
+#elif defined (HAVE_LOCKDEV_H)
+    return ::dev_unlock(portName, ::getpid()) != -1;
+#else
+    QFile f(generateLockFileNameAsNamedForm(portName));
+    return f.remove();
+#endif
+}
+
+// Verifies the device is locked or not.
+// If returned currentPid = true - this means that the device is locked the current process.
+bool QTtyLocker::isLocked(const char *portName, bool *currentPid)
+{
+    if (!currentPid)
+        return true;
+
+    *currentPid = false;
+
+#ifdef HAVE_BAUDBOY_H
+    return ::ttylocked(portName) != -1;
+#elif defined (HAVE_LOCKDEV_H)
+    return ::dev_testlock(portName) != -1;
+#else
+
+    QFile f(generateLockFileNameAsNamedForm(portName));
+    if (!f.exists())
+        return false;
+    if (!f.open(QIODevice::ReadOnly))
+        return true;
+
+    QString content(QLatin1String(f.readAll()));
+    f.close();
+
+    const pid_t pid = content.section(' ', 0, 0, QString::SectionSkipEmpty).toInt();
+
+    if (::kill(pid, 0) == -1) {
+        if (errno == ESRCH) // Process does not exists
+            return false;
+    } else {
+        if (::getpid() == pid) // Process exists and it is "their", i.e current
+            *currentPid = true;
+    }
+
+    return true;
+
+#endif
+}
+
+QT_END_NAMESPACE_SERIALPORT
+
+QT_END_NAMESPACE