Fix race condition allowing to run several instances of qBittorrent at the same time

2026-01-10 01:22:31 -06:00 · 2010-06-09 09:48:14 +00:00
parent 7ab206ebac
commit b9394f2ba2
24 changed files with 1713 additions and 156 deletions
--- a/src/qtsingleapp/qtlockedfile_unix.cpp
+++ b/src/qtsingleapp/qtlockedfile_unix.cpp
@@ -0,0 +1,121 @@
+/****************************************************************************
+** 
+** Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+** 
+** This file is part of a Qt Solutions component.
+**
+** Commercial Usage  
+** Licensees holding valid Qt Commercial licenses may use this file in
+** accordance with the Qt Solutions Commercial License Agreement provided
+** with the Software or, alternatively, in accordance with the terms
+** contained in a written agreement between you and Nokia.
+** 
+** 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.
+** 
+** 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.
+** 
+** Please note Third Party Software included with Qt Solutions may impose
+** additional restrictions and it is the user's responsibility to ensure
+** that they have met the licensing requirements of the GPL, LGPL, or Qt
+** Solutions Commercial license and the relevant license of the Third
+** Party Software they are using.
+** 
+** If you are unsure which license is appropriate for your use, please
+** contact Nokia at qt-info@nokia.com.
+** 
+****************************************************************************/
+
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "qtlockedfile.h"
+
+bool QtLockedFile::lock(LockMode mode, bool block)
+{
+    if (!isOpen()) {
+        qWarning("QtLockedFile::lock(): file is not opened");
+        return false;
+    }
+ 
+    if (mode == NoLock)
+        return unlock();
+           
+    if (mode == m_lock_mode)
+        return true;
+
+    if (m_lock_mode != NoLock)
+        unlock();
+
+    struct flock fl;
+    fl.l_whence = SEEK_SET;
+    fl.l_start = 0;
+    fl.l_len = 0;
+    fl.l_type = (mode == ReadLock) ? F_RDLCK : F_WRLCK;
+    int cmd = block ? F_SETLKW : F_SETLK;
+    int ret = fcntl(handle(), cmd, &fl);
+    
+    if (ret == -1) {
+        if (errno != EINTR && errno != EAGAIN)
+            qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
+        return false;
+    }
+
+    
+    m_lock_mode = mode;
+    return true;
+}
+
+
+bool QtLockedFile::unlock()
+{
+    if (!isOpen()) {
+        qWarning("QtLockedFile::unlock(): file is not opened");
+        return false;
+    }
+
+    if (!isLocked())
+        return true;
+
+    struct flock fl;
+    fl.l_whence = SEEK_SET;
+    fl.l_start = 0;
+    fl.l_len = 0;
+    fl.l_type = F_UNLCK;
+    int ret = fcntl(handle(), F_SETLKW, &fl);
+    
+    if (ret == -1) {
+        qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
+        return false;
+    }
+    
+    m_lock_mode = NoLock;
+    return true;
+}
+
+QtLockedFile::~QtLockedFile()
+{
+    if (isOpen())
+        unlock();
+}
+