forked from qt-creator/qt-creator
		
	
		
			
				
	
	
		
			112 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/***************************************************************************
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**
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** This file is part of Qt Creator
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**
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** Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
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**
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** Contact:  Qt Software Information (qt-info@nokia.com)
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**
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**
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** Non-Open Source Usage
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**
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** Licensees may use this file in accordance with the Qt Beta Version
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** License Agreement, Agreement version 2.2 provided with the Software or,
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** alternatively, in accordance with the terms contained in a written
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** agreement between you and Nokia.
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**
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** GNU General Public License Usage
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**
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** Alternatively, this file may be used under the terms of the GNU General
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** Public License versions 2.0 or 3.0 as published by the Free Software
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** Foundation and appearing in the file LICENSE.GPL included in the packaging
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** of this file.  Please review the following information to ensure GNU
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** General Public Licensing requirements will be met:
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**
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** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
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** http://www.gnu.org/copyleft/gpl.html.
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**
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** In addition, as a special exception, Nokia gives you certain additional
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** rights. These rights are described in the Nokia Qt GPL Exception
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** version 1.3, included in the file GPL_EXCEPTION.txt in this package.
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**
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***************************************************************************/
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#include "qtlockedfile.h"
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <fcntl.h>
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namespace SharedTools {
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bool QtLockedFile::lock(LockMode mode, bool block)
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{
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    if (!isOpen()) {
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        qWarning("QtLockedFile::lock(): file is not opened");
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        return false;
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    }
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    if (mode == NoLock)
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        return unlock();
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    if (mode == m_lock_mode)
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        return true;
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    if (m_lock_mode != NoLock)
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        unlock();
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    struct flock fl;
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    fl.l_whence = SEEK_SET;
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    fl.l_start = 0;
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    fl.l_len = 0;
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    fl.l_type = (mode == ReadLock) ? F_RDLCK : F_WRLCK;
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    int cmd = block ? F_SETLKW : F_SETLK;
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    int ret = fcntl(handle(), cmd, &fl);
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    if (ret == -1) {
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        if (errno != EINTR && errno != EAGAIN)
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            qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
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        return false;
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    }
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    m_lock_mode = mode;
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    return true;
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}
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bool QtLockedFile::unlock()
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{
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    if (!isOpen()) {
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        qWarning("QtLockedFile::unlock(): file is not opened");
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        return false;
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    }
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    if (!isLocked())
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        return true;
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    struct flock fl;
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    fl.l_whence = SEEK_SET;
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    fl.l_start = 0;
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    fl.l_len = 0;
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    fl.l_type = F_UNLCK;
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    int ret = fcntl(handle(), F_SETLKW, &fl);
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    if (ret == -1) {
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        qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
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        return false;
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    }
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    m_lock_mode = NoLock;
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    return true;
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}
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QtLockedFile::~QtLockedFile()
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{
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    if (isOpen())
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        unlock();
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}
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} // namespace SharedTools
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