filelock.cpp

这是一个完整的图书馆供销存管理系统

/***************************************************************************
                          filelock.cpp  -  description
                             -------------------
    begin                : Fri Jul 20 2001
    copyright            : (C) 2001 by Mark
    email                : [e-mail]
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/


#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "filelock.h"


CFileLock::CFileLock(const char* sPath)
{
	if ((m_iFd = open(sPath, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR)) < 0)
		throw CFileLockException(strerror(errno), __FILE__, __LINE__);
}


CFileLock::~CFileLock()
{
	close(m_iFd);
}


bool CFileLock::Fcntl(int iCmd, int iType, int iOffset, int iLen, int iWhence)
{
	struct flock stLock;
	stLock.l_type = iType;
	stLock.l_start = iOffset;
	stLock.l_whence = iWhence;
	stLock.l_len = iLen;
	if (fcntl(m_iFd, iCmd, &stLock) < 0)
	{
		if (errno == EINTR)
			return false;
			
		throw CFileLockException(strerror(errno), __FILE__, __LINE__);
	}
	
	return true;
}