249 lines
9.5 KiB
C++
249 lines
9.5 KiB
C++
/*************************************************************************
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*
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* $RCSfile: writeguard.cxx,v $
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*
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* $Revision: 1.3 $
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*
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* last change: $Author: as $ $Date: 2001-05-02 13:00:51 $
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*
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* The Contents of this file are made available subject to the terms of
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* either of the following licenses
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*
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* - GNU Lesser General Public License Version 2.1
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* - Sun Industry Standards Source License Version 1.1
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*
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* Sun Microsystems Inc., October, 2000
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*
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* GNU Lesser General Public License Version 2.1
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* =============================================
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* Copyright 2000 by Sun Microsystems, Inc.
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* 901 San Antonio Road, Palo Alto, CA 94303, USA
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License version 2.1, as published by the Free Software Foundation.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*
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*
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* Sun Industry Standards Source License Version 1.1
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* =================================================
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* The contents of this file are subject to the Sun Industry Standards
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* Source License Version 1.1 (the "License"); You may not use this file
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* except in compliance with the License. You may obtain a copy of the
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* License at http://www.openoffice.org/license.html.
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*
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* Software provided under this License is provided on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
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* WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
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* MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
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* See the License for the specific provisions governing your rights and
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* obligations concerning the Software.
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*
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* The Initial Developer of the Original Code is: Sun Microsystems, Inc.
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*
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* Copyright: 2000 by Sun Microsystems, Inc.
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*
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* All Rights Reserved.
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*
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* Contributor(s): _______________________________________
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*
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*
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************************************************************************/
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//_________________________________________________________________________________________________________________
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// my own includes
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//_________________________________________________________________________________________________________________
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#ifndef __FRAMEWORK_THREADHELP_WRITEGUARD_HXX_
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#include <threadhelp/writeguard.hxx>
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#endif
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#ifndef __FRAMEWORK_MACROS_DEBUG_HXX_
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#include <macros/debug.hxx>
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#endif
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//_________________________________________________________________________________________________________________
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// interface includes
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//_________________________________________________________________________________________________________________
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//_________________________________________________________________________________________________________________
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// other includes
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//_________________________________________________________________________________________________________________
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//_________________________________________________________________________________________________________________
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// const
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//_________________________________________________________________________________________________________________
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//_________________________________________________________________________________________________________________
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// namespace
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//_________________________________________________________________________________________________________________
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namespace framework{
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//_________________________________________________________________________________________________________________
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// non exported const
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//_________________________________________________________________________________________________________________
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//_________________________________________________________________________________________________________________
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// non exported declarations
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//_________________________________________________________________________________________________________________
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//_________________________________________________________________________________________________________________
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// definitions
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//_________________________________________________________________________________________________________________
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/*-****************************************************************************************************//**
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@short ctor
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@descr These ctors initialize the guard with a reference to used lock member of object to protect.
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Null isn't allowed as value!
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@seealso -
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@param "pLock" ,reference to used lock member of object to protect
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@param "rLock" ,reference to used lock member of object to protect
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@return -
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@onerror -
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*//*-*****************************************************************************************************/
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WriteGuard::WriteGuard( IRWLock* pLock )
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: m_pLock ( pLock )
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, m_eMode ( E_NOLOCK )
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{
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lock();
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}
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//*****************************************************************************************************************
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WriteGuard::WriteGuard( IRWLock& rLock )
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: m_pLock ( &rLock )
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, m_eMode ( E_NOLOCK )
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{
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lock();
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}
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/*-****************************************************************************************************//**
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@short dtor
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@descr We unlock the used lock member automaticly if user forget it.
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@seealso -
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@param -
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@return -
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@onerror -
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*//*-*****************************************************************************************************/
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WriteGuard::~WriteGuard()
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{
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unlock();
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}
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/*-****************************************************************************************************//**
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@short set write lock
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@descr Call this method to set the write lock. The call will block till all current threads are synchronized!
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@seealso method unlock()
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@param -
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@return -
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@onerror -
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*//*-*****************************************************************************************************/
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void WriteGuard::lock()
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{
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switch( m_eMode )
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{
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case E_NOLOCK : {
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// Acquire write access and set return state.
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// Mode is set later if it was successful!
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m_pLock->acquireWriteAccess();
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m_eMode = E_WRITELOCK;
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}
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break;
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case E_READLOCK : {
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// User has downgrade to read access before!
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// We must release it before we can set a new write access!
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m_pLock->releaseReadAccess ();
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m_pLock->acquireWriteAccess();
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m_eMode = E_WRITELOCK;
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}
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break;
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}
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}
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/*-****************************************************************************************************//**
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@short unset write lock
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@descr Call this method to unlock the rw-lock temp.!
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Normaly we do it at dtor automaticly for you ...
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@seealso method lock()
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@param -
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@return -
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@onerror -
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*//*-*****************************************************************************************************/
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void WriteGuard::unlock()
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{
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switch( m_eMode )
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{
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case E_READLOCK : {
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// Use has downgraded to a read lock!
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m_pLock->releaseReadAccess();
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m_eMode = E_NOLOCK;
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}
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break;
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case E_WRITELOCK : {
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m_pLock->releaseWriteAccess();
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m_eMode = E_NOLOCK;
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}
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break;
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}
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}
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/*-****************************************************************************************************//**
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@short downgrade write access to read access without new blocking!
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@descr If this write lock is set you can change it to a "read lock".
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An "upgrade" is the same like new calling "lock()"!
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@seealso -
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@param -
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@return -
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@onerror -
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*//*-*****************************************************************************************************/
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void WriteGuard::downgrade()
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{
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if( m_eMode == E_WRITELOCK )
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{
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m_pLock->downgradeWriteAccess();
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m_eMode = E_READLOCK;
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}
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}
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/*-****************************************************************************************************//**
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@short return internal lock state
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@descr For user they dont know what they are doing there ...
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@seealso -
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@param -
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@return Current set lock mode.
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@onerror No error should occure.
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*//*-*****************************************************************************************************/
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ELockMode WriteGuard::getMode() const
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{
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return m_eMode;
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}
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} // namespace framework
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